Flotation column used in bauxite reverse flotation desilicon

A floatation column for backfloatation of bauxite to remove Si is composed of a column body, an ore feeder, a foam tank on the top of the column body, a contactor at lower end of the column body and communicated with the ore slurry circulating pipe in the column body, an ore discharging port, a washing water feeder installed in the upper enriching area of the column, flow stabilizing plates and dispersers. Its advantages are reduced loss, high Si/Al ratio of ore concentrate and high recovery rate of Al2O3.

Hydrological forecasting method based on Cartesian product genetic programming

The invention discloses a hydrological forecasting method based on Cartesian product genetic programming, and the method comprises the steps: collecting hydrological data, and constructing a watershed hydrological data set; generating an initial population, namely a plurality of individuals capable of being decoded into a neural network; initializing the number of iterations of the population, and starting iteration; the fitness of each individual in the population is calculated and evaluated, and parent individuals of the next-generation population are selected by adopting a tournament method; carrying out genetic manipulation on parent individuals by randomly selecting operators to generate a next-generation population; adding one to the number of iterations of the population, judging whether the number of iterations of the population is equal to the maximum number of iterations, if so, ending iteration, and outputting an individual with the highest fitness in the final population as ...

HPLC (High Performance Liquid Chromatography) analysis method suitable for continuously measuring hyperoside and quercetin system

The invention relates to an HPLC (High Performance Liquid Chromatography) analysis method suitable for continuously measuring a hyperoside and quercetin system. The HPLC analysis method is characterized by comprising the following steps: 1, setting liquid chromatography conditions; 2, preparing a mobile phase for analysis, the mobile phase A is ultrapure water; the mobile phase B is methanol; 3, an analysis program is set to be isocratic elution, the elution concentration is as follows: the mobile phase A is 20-40%, the mobile phase B is 60-80%, and the flow velocity is 0.5-2 mL/min; 4, preparing a plurality of to-be-detected solutions containing hyperoside and quercetin samples; and the like. The HPLC analysis method suitable for continuously measuring the hyperoside and quercetin system is easy to operate, when hyperoside and quercetin are continuously measured, a large amount of time cost and economic cost are saved, the operation complexity is greatly simplified, and meanwhile the good ...

Intein Wir Gp071 variant, coding gene and application of intein Wir Gp071 variant in preparation of nonapeptide-1

The invention discloses intein Wir Gp071. The amino acid sequence of the intein Wir Gp071 is as shown in SEQ ID No. 1. The invention also discloses an intein Wir Gp071 variant of which the amino acid sequence is shown as SEQ ID No.3. The invention also discloses a coding gene of the intein Wir Gp071 and application of the intein Wir Gp071 variant in preparation of nonapeptide-1. The invention provides a novel intein Wir Gp071 sequence and a novel intein Wir Gp071 variant sequence, the intein Wir Gp071 sequence and nonapeptide-1 can form a fusion protein, and high-purity non-modified nonapeptide-1 is obtained through expression. The nonapeptide-1 can be obtained on the basis of an intein Wir Gp071-nonapeptide-1 recombinant expression vector, the preparation method is simple, the high-purity nonapeptide-1 can be efficiently obtained only through simple steps such as cell disruption and intein cutting, continuous production can be achieved after successful construction, the output is large ...

Unmeasured watershed runoff prediction method based on spatial modeling and improved LSTM

The invention discloses an unmeasured drainage basin runoff prediction method based on spatial modeling and improved LSTM. The method comprises the steps of analyzing static feature data of a target drainage basin and introducing prior knowledge; spatialization modeling is carried out on an unmeasured drainage basin, and data of an original measuring station is divided into a plurality of sub-drainage basins according to watersheds in data processing; inputting the gridded meteorological forced data as independent variables into a network model of the prediction method; building an LSTM network model with a static input gate for runoff prediction of a target drainage basin; optimizing network model training by using a Nash efficiency function and an Adam strategy; and performing runoff prediction on a target drainage basin by applying the trained network model, and calibrating a prediction result by using an SAC-SMA model. The method is high in precision and high in physical interpretability ...

Phage-assisted self-cyclization circular RNA evolution system

The invention discloses a self-cyclization gIII gene for assisting a self-cyclization circular RNA (Ribonucleic Acid) evolutionary phage. The self-cyclization gIII gene is characterized in that the sequence of the self-cyclization gIII gene is shown as SEQ ID No.6. The invention further discloses a phage assisting in self-cyclization circular RNA evolution and a phage assisting in self-cyclization circular RNA evolution system. According to the phage-assisted self-cyclization RNA evolutionary system, a mutagenic plasmid MP6 is converted into a host strain, the host strain is infected with the M13 phage, and the mutagenic plasmid continuously mutates a phage genome. The high-activity self-cyclization sequence variant is subjected to RNA cyclization, so that the N end and the C end of pIII protein are recombined into complete pIII protein; the self-cyclization sequence variant with low activity cannot be subjected to RNA cyclization, and active pIII protein cannot be expressed. The new generation ...

Cellular pathology image anomaly detection method based on improved YOLOv5 and OfficientNet

The invention discloses a cell pathology image anomaly detection method based on improved YOLOv5 and OfficientNet. The cell pathology image anomaly detection method comprises the following steps: acquiring a digital scanning image of a cell smear as an original input image; cutting the original input image with overlap as a cut image; detecting all abnormal cells and abnormal cell clusters in the cut image by using an improved YOLOv5 model and obtaining position and size information of the abnormal cells and the abnormal cell clusters; using the position and size information to cut out an abnormal cell and abnormal cell cluster target image from the cut image, and cutting and filling the target image; classifying the target image by using an improved OfficientNet model to obtain a classification result of the target image; and summarizing a target image classification result and position and size information thereof as a final anomaly detection result to be displayed on the original input ...

Proline hydroxylase L593m with high expression and high activity, coding gene and application of proline hydroxylase L593m in catalyzing hydroxylation of collagen

The invention discloses a proline hydroxylase L593m with high expression and high activity. The proline hydroxylase L593m is characterized in that the amino acid sequence of the proline hydroxylase L593m is as shown in SEQ ID No.3. The invention also discloses a coding gene, an expression vector and an expression host bacterium of the gene, and application of the gene in catalyzing hydroxylation of collagen. The invention provides a proline 4-hydroxylase variant L593m with high expression and activity, the amino acid sequence of the proline 4-hydroxylase variant L593m is shown as SEQ: NO.3, and the nucleotide sequence of the proline 4-hydroxylase variant L593m is shown as SEQ: NO.4. Compared with L593, the proline 4-hydroxylase variant L593m has the characteristics of simple expression, better activity, easier purification, higher yield and the like, can be used for in-vivo hydroxylation of collagen, and is suitable for industrial production and application.

Ssp DnaB intein and application thereof in expression and separation of transdermal peptide

The invention relates to a novel Ssp DnaB intein, and the sequence of the novel Ssp DnaB intein is as shown in SEQ ID No.5. The invention further discloses a DnaB-cTAT fusion protein, and the sequence of the DnaB-cTAT fusion protein is as shown in SEQ ID No. 1. The invention also discloses a coding gene, an expression plasmid, a prokaryotic vector and an expression separation method of the protein. The intein used in the invention is an Ssp DnaB system, and through codon optimization and point mutation, the intein has very high intein self-cleavage activity, which is about 85%. The first amino acid is mutated into alanine from cysteine Cys so as to inactivate the self-cleavage activity of the N end of intein.

HPLC (High Performance Liquid Chromatography) analysis method suitable for L-carnosine

The invention relates to an HPLC (High Performance Liquid Chromatography) analysis method suitable for L-carnosine. The HPLC analysis method is characterized by comprising the following steps: 1, preparing a solution of an L-carnosine sample to be detected; 2, setting liquid chromatography conditions according to the prepared L-carnosine sample to be detected; 3, preparing a mobile phase for analysis; 4, determining the L-carnosine sample to be detected by adopting an analysis program; 5, cleaning the chromatographic column for 1-5 minutes by adopting a mobile phase B; the HPLC analysis method suitable for the L-carnosine is easy to operate, when the L-carnosine is continuously measured, a large amount of time cost and economic cost are saved, the operation complexity is greatly simplified, and meanwhile the good analysis effect is achieved.

Separation and purification method for whole-cell catalytic production of alpha-arbutin

The invention relates to a separation and purification method for whole-cell catalytic production of alpha-arbutin, which is characterized in that high-purity alpha-arbutin is extracted from a catalytic solution for whole-cell catalytic production of alpha-arbutin by adopting a resin adsorption and resin and activated carbon decoloration method. The alpha-arbutin product obtained through the method is high in recovery rate and purity, especially toxic hydroquinone cannot be completely detected, the method is low in raw material cost, equipment can be repeatedly utilized, and large-batch production of alpha-arbutin can be achieved.

FDH-GDH fusion protein, coding gene, FDH-GDH co-evolution system and FDH-GDH co-evolution method

The invention discloses an FDH-GDH fusion protein, the fusion protein comprises a first amino acid sequence with CO2 reductase activity and a second amino acid sequence with glycerol dehydrogenase activity, and the first amino acid sequence and the second amino acid sequence are connected through a connecting peptide. The invention also discloses a coding gene, an expression vector and a surface display engineering bacterium. The invention further discloses an FDH-GDH co-evolution system and method. According to the method disclosed by the invention, glycerol dehydrogenase and CO2 reductase are combined for use, and glycerol is converted into dihydroxyacetone while CO2 is fixed to produce formic acid. CO2 fixation is realized, and products with high added value, such as dihydroxy acetone and the like, are produced. The invention further provides a co-evolution method of CO2 reductase and glycerol dehydrogenase, high-activity CO2 reductase and glycerol dehydrogenase fusion protein is obtained ...

HPLC-ELSD (High Performance Liquid Chromatography-Evaporative Light Scattering Detector) analysis method suitable for continuously analyzing glassine and carbohydrates

The invention relates to an HPLC-ELSD (High Performance Liquid Chromatography-Evaporative Light Scattering Detector) analysis method suitable for continuously analyzing a glassine and carbohydrates, which is characterized by comprising the following steps of: 1, preparing a plurality of to-be-detected sample solutions which comprise one or more of glassine and carbohydrates; 2, setting liquid chromatography conditions; 3, preparing a mobile phase for analysis; 4, cleaning the chromatographic column; 5, determining one of the to-be-detected samples by adopting an analysis program, and recording a chromatogram map; 6, randomly calculating the corresponding content according to the standard curve of each substance; and the like. The HPLC-ELSD analysis method suitable for continuously analyzing the glassine and the carbohydrates is simple to operate, and when a plurality of samples are continuously analyzed and measured, a large amount of time cost and economic cost are saved, and the complexity ...

Method for identifying and alarming violent behavior based on spatio-temporal information

The invention discloses a violent behavior identification and alarm method based on spatio-temporal information. The method comprises the following steps: constructing a physical layer; acquiring an action video and performing data transmission; constructing a data processing layer: performing division processing on the data obtained in the physical layer and generating an action feature map; calculating spatio-temporal feature information in human motion according to the motion feature map obtained by the data processing layer; constructing a behavior recognition layer: firstly, constructing a recognition model by using a composite neural network; then training the identification model; and finally, inputting to-be-identified data into the trained identification model to obtain an output result. And constructing a control layer: establishing a matching relationship between the action behavior and the alarm association library to obtain an automatic identification instruction, and triggering ...

Face emotion recognition method based on improved residual convolutional network inception block structure

The invention discloses a face emotion recognition method based on an improved residual convolutional network inception block structure, and the method comprises the steps: collecting an FER2013 data set, carrying out the data preprocessing of the FER2013 data set, dividing the FER2013 data set into an 80% training set and a 20% test set, and obtaining an image set for model training and testing; training is carried out by using the preprocessed training set, the network training effect is enhanced by using identical mapping, and the network width and the convolution depth are expanded; selecting a Softmax feature classifier as a model feature classifier; and performing face emotion recognition by using the lightweight residual convolutional network with the improved inception block structure, and outputting a face emotion recognition result. According to the method, the problems of network degradation, large network parameter quantity, network over-fitting and the like can be solved, and ...

Intein evolution system and method, corresponding mutant plasmid and reporter plasmid

The invention discloses an intein evolutionary system, which comprises an expression gene containing nickase and low-fidelity DNA polymerase, and a mutant plasmid of an expression gene of a dimerization oligopeptide system consisting of two oligopeptides, the reporter plasmid comprises a fusion protein expression gene of antibiotic resistance protein-N and intein-N genes and a fusion protein expression gene of intein-C and antibiotic resistance protein-C genes; and expression vectors of the mutant plasmid and the reporter plasmid. The invention also discloses the mutant plasmid, the reporter plasmid and a corresponding intein evolution method. According to the invention, nicking enzyme and DNA polymerase are adopted to continuously mutate the intein gene, and the activity-enhanced intein gene generates more complete antibiotic resistance proteins through the splicing effect of intein, so that the strain obtains high antibiotic resistance. Through high-resistance culture and screening, a ...

Support column used for article box and article box assembly

The invention discloses a support column used for an article box and an article box assembly. The support column used for the article box comprises a column body, the two ends of the column body are separably arranged at two article boxes which are spaced up and down, and one side of the column body is provided with a locating part used for combining with the locating part of another adjacent support column. When the support column is arranged in the article box to form the article box assembly, the support column can conveniently cause the left side and the right side of the article box to be connected, and the connected structural strength is better.

Method for decolorizing and deodorizing bio-based nicotinamide

The invention discloses a method for decolorizing and deodorizing bio-based nicotinamide, which comprises the following steps: dissolving to-be-treated nicotinamide in absolute ethyl alcohol, then adding activated carbon to carry out adsorption reaction, filtering to remove activated carbon and residual impurities in the solution, and re-crystallizing: heating and concentrating, cooling to room temperature, separating out crystals, filtering and collecting the crystals, thereby obtaining the bio-based nicotinamide. The mixed color and odor in the nicotinamide can be removed. The method for decolorizing and deodorizing nicotinamide synthesized by escherichia coli, provided by the invention, is simple and convenient to operate, low in cost, high in substance purity and high in recovery rate, and is suitable for decolorizing and deodorizing nicotinamide produced by large-scale industrial biological fermentation.

Intein variant and application of intein variant in preparation of blue copper peptide by biological method

The invention discloses an intein variant and application of the intein variant in biological preparation of blue copper peptide, the amino acid sequence of the intein variant is shown as SEQ ID NO: 1, and the nucleotide sequence of the intein variant is shown as SEQ ID NO: 2. A fusion protein is formed by the fusion protein and GHK, an efficient and stable recombinant expression vector of the blue copper peptide is prepared after a vector plasmid is introduced, and the high-purity blue copper peptide can be obtained through induced expression. Moreover, the preparation difficulty of the blue copper peptide based on the method is low, pollution and generation of toxic and harmful byproducts can be effectively reduced, the yield is large, and the method is suitable for large-scale industrial mass production of the blue copper peptide and has relatively high market value.

Phage biosensor

The invention discloses a bacteriophage biosensor. The bacteriophage biosensor comprises host bacteria; the reporter plasmid expresses the fluorescent protein, and a phage inducible promoter is inserted into the upstream of an expression gene of the fluorescent protein. The invention discloses a bacteriophage biosensor. The bacteriophage biosensor is composed of host bacteria and reporter plasmids. After host bacteria are impregnated with the phage, expression of non-coding RNA containing MCP binding sites and PCP binding sites which are arranged repeatedly is started through a phage induction promoter on a reporter plasmid, the non-coding RNA collects MCP-GFP-N and PCP-GFP-C, and GFP fluorescence is activated. And the titer of the phage can be quantified through fluorescence intensity detection. The bacteriophage biosensor disclosed by the invention has the advantages of simplicity in operation, short time consumption, high accuracy and the like, and is very suitable for bacteriophage ...

Method for acquiring type I fracture energy of heterogeneous rock

The invention discloses a method for acquiring type I fracture energy of heterogeneous rocks, and belongs to the technical field of rock mechanics analysis. The method comprises the following steps: loading a heterogeneous rock sample by using loading equipment to obtain a stress-strain curve; in the loading process, a pulse laser imaging system is used for shooting a crack propagation image of the heterogeneous rock sample so as to obtain the crack propagation position at each determined moment, the crack propagation length in a determined time interval and a new fracture surface created by the crack propagation, and the time precision of shooting is picosecond magnitude; a three-dimensional laser scanning system is used for scanning a new section created by crack propagation, and the area of the new section in each time interval is obtained; and calculating the fracture energy of the heterogeneous rock by using the obtained parameters. According to the method, the multi-point I-type fracture ...

Intein Ssp tau, coding gene and application of intein Ssp tau in preparation of tetrapeptide-5

The invention discloses intein Ssp tau. The intein Ssp tau is characterized in that the amino acid sequence of the intein Ssp tau is as shown in SEQ ID No.2. The invention also discloses a coding gene of the gene and application of the gene in preparation of tetrapeptide-5. The invention also discloses an intein Ssp tau-tetrapeptide-5 recombinant protein, a corresponding coding gene, an expression vector and an expression host bacterium. The invention discloses a brand new intein Ssp tau and an intein Ssp tau mediated tetrapeptide-5 expression, separation and purification technology. A fusion protein is formed by Ssp tau and tetrapeptide-5, and a fusion protein gene sequence is constructed on PET-28a (+), so that a recombinant expression vector of tetrapeptide-5 is obtained. And performing simple steps of induced expression, cell disruption, ultrafiltration, intein self-cutting, secondary ultrafiltration, rotary evaporation freeze-drying and the like to efficiently obtain the high-purity ...

Escherichia coli and application thereof in catalytic synthesis of psicose

The invention discloses Escherichia coli for biosynthesis of psicose, which is characterized in that a FruA gene of the Escherichia coli is knocked out, and cfu, ibpA and ibpB genes and a DPEase recombinant gene are inserted into a genome of the Escherichia coli, so that a DPEase protein product is anchored on the cell surface of the Escherichia coli. The invention also discloses a preparation method, CRISPR plasmids A and B and a corresponding transposase system. According to the invention, the FruA gene of Escherichia coli is knocked out, so that the non-purposiveness consumption of fructose is reduced. The FruA-deleted escherichia coli strain is subjected to high-temperature-resistant and high-fructose-resistant domestication, cfu, pA and ibpB genes are inserted, and then the FruA-deleted escherichia coli strain is subjected to high-temperature-resistant and high-fructose-resistant domestication, so that the stability of an escherichia coli host in a catalytic environment (55 DEG C) ...

FLOTATION MACHINE SUITABLE FOR FLOTATING ROUGH AND HEAVY GRANULATED ORES

The present invention is a special equipment for mineral separation. The said flotation machine features its impeller, which has spiral vanes and is mounted onto conical underpan. During rotation, the impeller produces strong stirring effect and thus the slurry-gas mixture sprays obliquely downwards. Therefore, mineral with great specific weight and great size does not settle in the flotation tank. The said machine has a single impeller and a middle-mineral self-sucking returning unit, and is an inflated stirring flotation machine with slurry sucking capacity.

Cth TerA intein variant and application of Cth TerA intein variant in biological preparation of tetrapeptide-7

The invention discloses intein and application of the intein in preparation of tetrapeptide-7 by a biological method. The amino acid sequence of a Cth TerA intein variant is as shown in SEQ ID NO: 3. In the invention, the Cth TerA intein variant and the tetrapeptide-7 form the fusion protein, the efficient and stable recombinant expression vector of the tetrapeptide-7 is prepared after the vector plasmid is introduced, and the high-purity non-modified tetrapeptide-7 can be obtained through induced expression after the recombinant expression vector is transferred into bacteria to obtain engineering bacteria, so that the method has the advantages of simplicity, convenience, rapidness, no toxic by-products, large output, low cost, high efficiency and the like. And the method is suitable for large-scale industrial mass production of the tetrapeptide-7, so that the high-quality tetrapeptide-7 is obtained, and the method has a relatively high market value.

Method for rapidly and sensitively determining activity of 4-prolyl hydroxylase

The invention discloses a method for rapidly and sensitively determining the activity of 4-prolyl hydroxylase. The method comprises the following steps: adding a 4-prolyl hydroxylase sample to be detected into a reaction buffer solution containing an L-proline substrate for reaction, detecting the color development condition of supernate by using a hydroxyproline detection kit, and calculating the content of trans-4-hydroxy-L-proline to obtain the enzymatic activity of the 4-prolyl hydroxylase. By optimizing and improving the detection method, the sensitivity of enzyme activity detection can be remarkably improved, the reaction time can be shortened and only needs 5-20 minutes, radioactive isotopes and complex instruments and equipment do not need to be used, a substrate for enzyme activity detection is low in price and easy to obtain, the detection cost is remarkably reduced, and the method is suitable for industrial production. More excellent 4-prolyl hydroxylases can be explored from ...

Synthesis method for extracting chassis image of vehicle based on monitoring video content

The invention provides a synthesis method for extracting chassis image of vehicle based on monitoring video content, mainly comprising the following steps of: converting frames into grayscale pictures and pre-processing; forming irregular polygons of moving regions; removing partial irregular polygons through the area; forming a rectangular bounding box; matching the w-SIFT algorithm; computing an average offset distance in the Y direction; performing stretching transformation in the X direction; and splicing the pictures and transiting smoothly. The invention has the beneficial effect of automatically converting a chassis monitoring video of the vehicle into a single static image comprising the full description of the vehicle through inputting the chassis monitoring video of the vehicle,wherein the image can be used for further image recognition. The method can save plenty of time cost for manually splicing the pictures and markedly improve the spliced effect; and the obtained result can ...

Abnormal cell detection method based on improved YOLOv7 and Swinin-Unet

The invention discloses an abnormal cell detection method based on improved YOLOv7 and Swinin-Unet, and the method comprises the steps: collecting pathological cell smear images, and making an abnormal cell detection data set and a segmentation data set; an improved YOLOv7 model is built, and training is carried out; establishing a detection result screening module, and classifying cells in an output image of the detection network; the method comprises the following steps of: constructing a Swindow-Unet model and training the model for segmenting overlapped cell cluster images: on the basis of the Unet model, aiming at a local relationship and a global relationship of cell images under multiple scales, introducing a Swindow-Transform module for sampling; and carrying out abnormal cell detection by using the improved YOLOv7 and Swinin-Unet models. According to the method, context information during cell detection is fully utilized, cell clusters difficult to detect are effectively processed ...

Method for extracting squalene

The invention discloses a method for extracting squalene, which comprises the following steps: selecting saccharomyces cerevisiae as an extraction raw material of squalene, and obtaining high-yield and high-purity saccharomyces cerevisiae intracellular squalene by adopting a specific thallus drying mode, an extracting agent, a solid-liquid ratio, extraction temperature and extraction time. The raw materials are easy to obtain, the cost is low, the problems that a traditional method is complex in technology, lack of raw materials and the like are solved, squalene extraction steps are simple and easy to implement, time consumption is low, the operation process is easy to control, practicability is high, large-scale production is facilitated, and the problem that the current market demand of squalene is continuously increased can be effectively solved. The obtained squalene is wide in application and can be used for preparing food, medicines and cosmetics.

Method for purifying bio-based nicotinamide

The invention discloses a purification method of bio-based nicotinamide, which takes a nicotinamide reaction solution after whole-cell catalysis as a raw material, and comprises the following specific steps: centrifuging: removing cells and cell tissue fragments in the reaction solution; dehydrating: carrying out rotary evaporation to dryness on the reaction liquid at 40-80 DEG C to obtain solid powder; re-dissolving: adding absolute ethyl alcohol with the mass 10-20 times that of the absolute ethyl alcohol to dissolve the light solid powder; impurity removal: filtering to remove disodium hydrogen phosphate and sodium dihydrogen phosphate in the solution; crystallizing: rotating and concentrating to 30-50% of the original volume at 40-80 DEG C, cooling to room temperature, crystallizing, filtering, repeating the step, and collecting nicotinamide crystals; and drying: carrying out rotary drying on the residual ethanol to obtain a nicotinamide product. According to the method, nicotinamide ...

Lactose negative sensing plasmid and negative feedback lactose biosensor

The invention discloses a lactose negative sensing plasmid which is provided with an mf-Lon protease gene with lactose induced expression and a fluorescent protein-pdt # 3 gene with constitutive expression, and further discloses a negative feedback lactose biosensor which is an escherichia coli strain with the lactose negative sensing plasmid. When a sample contains lactose, the lactose can induce expression of mf-Lon protease, and the fluorescent protein is rapidly degraded in a targeted manner by recognizing a pdt # 3 label of the fluorescent protein-pdt # 3. When the culture environment does not contain lactose, the mf-Lon protease cannot be expressed, and the fluorescent protein stably exists in cells. The negative feedback lactose biosensor can be used for quickly identifying whether a sample contains lactose or not, and has the advantages of high sensitivity, high efficiency and the like. Meanwhile, the invention discloses application of the negative feedback lactose biosensor in ...

Intein variant and application thereof in preparation of snake venom-like peptide precursor by biological method

The invention discloses an intein variant and application thereof in biological preparation of a snake venom-like peptide precursor, the amino acid sequence of the intein variant is as shown in SEQ ID NO: 5, and the nucleotide sequence of the intein variant is as shown in SEQ ID NO: 6. A fusion protein is formed by the fusion protein and AP dipeptide, an efficient and stable recombinant expression vector of the AP dipeptide is prepared after a vector plasmid is introduced, and high-purity unmodified AP dipeptide can be obtained through induced expression. Moreover, the AP dipeptide based on the method is low in preparation difficulty, pollution and generation of toxic and harmful byproducts can be effectively reduced, the yield is large, and the method is suitable for large-scale industrial mass production of the AP dipeptide and has high market value.

Flotation machine suitable for flotating rough and heavy granulated ores

适用于铝土矿反浮选脱硅的浮选柱

... 本发明属于选矿用的浮选设备，它由柱体、给矿器1、泡沫槽2、排矿口3、清洗水给水器4等组成，其特征在于：柱体的上端设置泡沫槽2，下端设置接触器7与柱体内的矿浆循环管8相通；柱体内上部富集区安装清洗水给水器4；柱体内的分选区安装给矿器1，其下方设置稳流板9；栏式分散器10、11分别设置在清洗给水器4与给矿器1之下；本发明在实际应用中减少了水硬铝石因受泡沫夹杂的损失，提高了铝土矿精矿的铝硅比，提高了三氧化二铝回收率。 ...

Application of efficient mutagenesis method to improvement of phage assisted evolution efficiency

The invention discloses application of an efficient mutagenesis method to improvement of phage assisted evolution efficiency. The efficient mutagenesis method is a physical mutagenesis method or a chemical mutagenesis method. The invention also discloses a method for improving the auxiliary evolution efficiency of the bacteriophage, which comprises the following steps: infecting a host strain by using the M13 bacteriophage, treating the host strain infected with the bacteriophage by using efficient physical mutagenesis modes such as plasma, microwave, ionizing radiation, ultraviolet and the like and efficient chemical mutagenesis modes such as diethyl sulfate, nitrosoguanidine and the like, and then releasing the offspring bacteriophage to complete a round of evolution, thereby obtaining the improved auxiliary evolution efficiency of the bacteriophage. And repeating the evolution process until the evolved target gene is obtained. Compared with a traditional mode that mutation evolution ...

Extraction method of transparent low-acyl gellan gum

The invention relates to an extraction method of transparent low-acyl gellan gum, which comprises the following steps: pretreatment of fermentation liquor: diluting gellan gum fermentation liquor by 3-8 times according to a volume ratio by using water, and obtaining gellan gum diluent at room temperature or after heating and boiling; deacylating: adding alkali liquor into the gellan gum diluent at a high temperature of 60-80 DEG C, and adjusting the pH to strong alkalinity to obtain low-acyl gellan gum liquid; adding an alkaline earth metal flocculant and a filter aid for flocculation and impurity removal; flocculating, extracting and collecting a filter cake; washing the filter cake with alcohol, dissolving the filter cake into a flocculation state, adding alkali liquor to adjust the pH value to 7-8, and filtering to obtain a gellan gum filter cake again; and performing post-treatment to obtain a powdery product. The whole process is simplified, the cost is low, only a small amount of ...

Synthesis method for extracting chassis image of vehicle based on monitoring video content

The invention provides a synthesis method for extracting chassis image of vehicle based on monitoring video content, mainly comprising the following steps of: converting frames into grayscale pictures and pre-processing; forming irregular polygons of moving regions; removing partial irregular polygons through the area; forming a rectangular bounding box; matching the w-SIFT algorithm; computing an average offset distance in the Y direction; performing stretching transformation in the X direction; and splicing the pictures and transiting smoothly. The invention has the beneficial effect of automatically converting a chassis monitoring video of the vehicle into a single static image comprising the full description of the vehicle through inputting the chassis monitoring video of the vehicle, wherein the image can be used for further image recognition. The method can save plenty of time cost for manually splicing the pictures and markedly improve the spliced effect; and the obtained result ...

Phage-assisted intein evolution system and evolution method

The invention discloses a phage-assisted intein evolution system which comprises host bacteria containing F plasmids, a phage-assisted intein evolution system and a phage-assisted intein evolution system, the gIII gene is replaced by a recombinant M13 bacteriophage of an N-terminal fusion protein gene, and the N-terminal fusion protein gene is a pIII protein N-terminal-intein N-terminal fusion protein; the mutant plasmid is used for mutating an M13 phage genome; the gIII helper plasmid is used for expressing C-terminal fusion protein, and the C-terminal fusion protein is intein C-terminal-pIII protein C-terminal fusion protein; the intein is a fracture type intein. And a corresponding evolutionary method. By utilizing the evolution method, the bacteriophage in the evolution pool is gradually replaced by the progeny bacteriophage containing the high-activity intein variant DNA sequence in the genome, and the progeny bacteriophage is obtained through separation, so that the intein with high ...

Mutant plasmid with controllable copy number and application thereof in phage assisted evolution

The invention discloses a plasmid with a controllable copy number, which comprises a ColE1 replicon, and an operon is inserted in the downstream of a promoter of the ColE1 replicon. The invention also discloses a mutant plasmid with a controllable copy number, the mutant plasmid expresses an enzyme causing DNA damage and low-fidelity repair, the mutant plasmid comprises a ColE1 replicon, and a cumate operon is inserted into the downstream of a promoter of the replicon. The invention also discloses application of the mutant plasmid in phage assisted evolution and a phage assisted evolution system. According to the invention, the copy number of the mutant plasmid is controlled by utilizing the phage-induced promoter, and the expression of the mutant gene is induced by utilizing the phage-induced promoter, so that the copy number of the mutant plasmid in host bacteria which is not infected by the phage is relatively low, the expression of the mutant gene is inhibited, and meaningless background ...

Method for generating sculpture three-dimensional model driven by human body movements

The invention discloses a method for generating sculpture three-dimensional model driven by human body movements. In the method, in terms of any given virtual sculpture, the improved Kinect movement recognition technology is adopted to recognize user joint point information and capture movement parameters of joint points, the posture of the virtual sculpture is guided to be adjusted according to the relevance between the joint points and control points selected by a user to achieve innovative sculpture three-dimensional model design and is changed through a virtual sculpture editing algorithm, and real-time operation can be carried out on the virtual sculpture. In the method, different restraints of the virtual sculpture relative to a general three-dimensional model are taken into full consideration, and styles and features of a sculpture can be well kept.

Intein Crv Rpb2 variant, coding gene and application of intein Crv Rpb2 variant in preparation of hexapeptide-9

The invention discloses an intein Crv Rpb2 variant. The intein Crv Rpb2 variant is characterized in that the amino acid sequence of the intein Crv Rpb2 variant is shown as SEQ ID No.3. The invention also discloses a coding gene of the protein, an application of the protein in preparation of hexapeptide-9, a Crv Rpb2 variant-(GPQ) 2 fusion protein, a corresponding coding gene, an expression vector and expression host bacteria. The invention provides a novel intein Crv Rpb2 variant, the intein Crv Rpb2 variant and hexapeptide-9 can form a fusion protein, and high-purity non-modified hexapeptide-9 is obtained through expression. The hexapeptide-9 can be obtained based on an intein Crv Rpb2 variant-(GPQ) 2 recombinant expression vector, the preparation method is simple, the high-purity hexapeptide-9 can be efficiently obtained only through simple steps of cell disruption, intein cutting and the like, continuous production can be achieved after successful construction, the output is large, and ...

Pathological cell image segmentation method and system based on adaptive fusion module and cross-stage AU-Net network

The invention discloses a pathological cell image segmentation method and system based on an adaptive fusion module and a cross-stage AU-Net network. The AU-Net network comprises a cross-stage module, an adaptive fusion module and a dense cavity convolution block. The method comprises the steps that a basic U-Net network structure is built, and coding and decoding paths of the basic U-Net network structure comprise convolution operation and sampling operation; the cross-stage modules are respectively applied to a coding path and a decoding path of the U-Net model, so that the expression capability of information is enhanced; a self-adaptive fusion module is introduced into the coding path of the U-Net after the cross-stage module is added, so that the weight of the key region is increased, and the segmentation precision of the pathological cell image is improved; and a dense hole convolution block is used for replacing a convolution block used for connecting a coding path and a decoding ...

Escherichia coli Rosetta strain and application thereof in catalytic synthesis of alpha-arbutin

The invention discloses an Escherichia coli Rosetta strain for biosynthesis of alpha-arbutin, which is characterized in that recombinant genes of FruA, CscK, Pgi and sucrose phosphorylase SmsP are inserted into a genome of the Escherichia coli Rosetta strain, so that a sucrose phosphorylase SmsP protein product is anchored on the surface of an Escherichia coli cell. The invention also discloses application of the corresponding transposase plasmid, the CRISPR plasmid and the strain in catalytic synthesis of alpha-arbutin. According to the invention, escherichia coli Rosetta (DE3) is used as a chassis cell, and a CRISPR (clustered regularly interspaced short palindromic repeats) transposition technology is used for enhancing FruA, CscK and Pgi genes in a fructose metabolic pathway, so that the metabolic pathway of a reaction accompanying product fructose is enhanced. The sucrose phosphorylase is anchored on the surface of escherichia coli by using an enzyme anchoring technology, so that the ...

Semi-supervised cervical cancer image classification method based on virtual adversarial training network

The invention discloses a semi-supervised cervical cancer image classification method based on a virtual adversarial training network, and the method comprises the steps: collecting a cervical cancer image data set, and obtaining a training data set and a test data set for a semi-supervised network; carrying out data enhancement on the labeled and unlabeled cervical cancer images in the training data set, wherein translation transformation, rotation transformation and scaling transformation are carried out on the cervical cancer images; building a backbone network, wherein the backbone network comprises AlexNet and a mixed attention mechanism; a virtual adversarial training network is built, given input is adopted, disturbance is increased, and the model gives different outputs; the model punishes the sensitivity due to disturbance; related features of the cervical cancer image are obtained through the virtual adversarial training network and sent to the classifier for classification, and ...

Overexpression genes galK and galT and engineering bacteria thereof

Aiming at the limitation of a wild type strain WK on utilization of galactose, two key genes, namely a galactokinase gene galK and a UDP-glucose-hexose-1-phosphate uridyl transferase gene galT, for regulating galactose metabolism in the wild type strain WK are found, and the wild type strain WK is modified by utilizing the two key genes; and the engineering bacteria WK-Gal-2, WK-Gal-3 and WK-Gal-4 are obtained by using the engineering bacteria. The utilization efficiency of the seaweed biomass is greatly improved. The utilization efficiency of galactose and the yield of butanol are improved to different extents by the engineering bacteria, wherein the improvement effect of the strain WK-Gal-4 is optimal. Therefore, the utilization efficiency of galactose in the seaweed biomass by the solventogenic clostridium is improved to a certain extent, the process of converting the solventogenic clostridium into biobutanol is promoted, and a new method is provided for expanding the substrate range ...