Elastic vibration-reduction ballast bed system

The invention discloses an elastic vibration-reduction ballast bed system, which comprises a concrete ballast bed and a low-frequency vibration isolator installed in the concrete ballast bed. An elastic mechanism in the low-frequency vibration isolator consists of a positive stiffness elastic element made of metal rubber or the positive stiffness elastic element and a negative stiffness elastic element which are connected in parallel. The positive stiffness elastic element is a disc spring, a spiral spring, the metal rubber, a metal rubber-spring armour, a metal rubber-lead core composite spring or any series-parallel combination of the disc spring, the spiral spring, the metal rubber, the metal rubber-spring armour and the metal rubber-lead core composite spring. The negative stiffness elastic element is a disc spring or a diaphragm spring. The elastic vibration-reduction ballast bed system can meet requirements of middle-high-grade vibration reduction and has a simple structure. The site ...

Behavior guidance method and device

The embodiment of the invention provides a behavior guidance method which comprises the following steps of: acquiring a current network state in response to a first behavior of a user; when the acquired current network state meets an execution condition of a second behavior, executing related operation aiming at the second behavior. A user can successfully use functions supplied by application software running on client equipment after being guided to the next behavior according to the behavior of the user and a network environment, and thus the user can have better experience. In addition, the embodiment of the invention also provides a behavior guidance device..

Additive for fiber strengthening

Compositions that include a polymer and an aldaric acid, such as glucaric acid, are disclosed. The compositions may include polyvinyl alcohol and glucaric acid. The compositions may also include polyacrylonitrile and glucaric acid. In addition, the compositions may further include lignin. Also disclosed are fibers including the compositions, methods of making the fibers, and uses of the fibers.

COAGULATION MAP FOR FIBER SPINNING

Disclosed are methods for preparing a lignin/poly(vinyl alcohol) (PVA) fiber and for preparing a lignin/polyacrylonitrile (PAN) fiber. The methods can comprise adding a dope of lignin and PVA or a dope of lignin and PAN to a coagulation bath containing a solvent comprising one or more components, wherein the one or more components are present in the solvent in concentrations based on the hydrogen bonding character (f) of the solvent, the polar character (f) of the solvent, and the dispersive character (f) of the solvent; and gel-spinning a lignin/PVA fiber or a lignin/PAN fiber from the coagulation bath. 1. A method for preparing a lignin/poly(vinyl alcohol) (PVA) fiber , the method comprising:{'sub': H', 'p', 'D, '(a) adding a dope of lignin and PVA to a coagulation bath containing a solvent comprising one or more components, wherein the one or more components are present in the solvent in concentrations such that the hydrogen bonding character (f) of the solvent is between 20% and 30%, the polar character (f) of the solvent is between 25% and 35%, and the dispersive character (f) of the solvent is between 40% and 50%; and'}(b) gel-spinning a lignin/PVA fiber from the coagulation bath,wherein a lignin/PVA fiber is produced.2. The method of claim 1 , wherein the dope is prepared at about 80° C. to about 85° C.3. The method of claim 1 , wherein the dope comprises a weight ratio of 5-90% (w/w) lignin to PVA.4. The method of claim 1 , wherein the dope comprises PVA at a molecular weight of about 100-500 kg/mol claim 1 , and further wherein the PVA is characterized by at least about 85% hydrolysis.5. The method of claim 1 , wherein the dope is provided in a solution of about 80% DMSO to about 100% DMSO (v/v) in distilled water at about 60° C. to about 85° C.6. The method of claim 1 , further comprising conditioning the dope at room temperature for at least two hours prior to the adding step.7. The method of claim 1 , wherein the coagulation bath is maintained at a pre- ...

SYSTEM FOR CONNECTING AND SEALING FLEXIBLE AND RIGID PIPES UNDER HIGH PRESSURE

A system for connecting and sealing flexible and rigid pipes under high pressure comprises a flexible pipe, rigid pipes, and transition connectors, wherein two ends of each transition connector are respectively connected with the flexible pipe and one rigid pipe, external sides of the flexible pipe and the transition connectors are coated with a rubber layer, and buckling sleeves are buckled on the rubber layer outside the transition connectors. Compared with the prior, the system can greatly improve the sealing performance of the flexible pipe and the rigid pipes, and thus can be used under high-low temperature and high-pressure atmospheres and be applied to air-conditioning pipes of new-energy vehicles. 1. A system for connecting and sealing flexible and rigid pipes under high pressure , comprising a flexible pipe and rigid pipes , wherein:the system further comprises transition connectors having a wall thickness 5-20 times that of the flexible pipe;two ends of each said transition connector are respectively connected with the flexible pipe and one said rigid pipe, and external sides of the flexible pipe and the transition connectors are coated with a rubber layer; andbuckling sleeves are buckled on the rubber layer outside the transition connectors.2. The system for connecting and sealing flexible and rigid pipes under high pressure according to claim 1 , wherein the flexible pipe is a metal corrugated pipe.3. The system for connecting and sealing flexible and rigid pipes under high pressure according to claim 2 , wherein the metal corrugated pipe serving as the flexible pipe is made from stainless steel.4. The system for connecting and sealing flexible and rigid pipes under high pressure according to claims 1 , wherein the flexible pipe is cut to a specified length and is then connected with the transition connectors.5. The system for connecting and sealing flexible and rigid pipes under high pressure according to claim 1 , wherein the rubber layer includes:an ...

Composição compreendendo polímero, ácido aldárico e aditivo, método para produção da mesma e aditivo de concreto e artigo fibroso compreendendo a composição

a presente invenção refere-se a composições que incluem um polímero e um ácido aldárico, como ácido sacárico. as composições podem incluir álcool polivinílico e ácido sacárico. as composições podem também incluir poliacrilonitrila e ácido sacárico. além disso, as composições podem incluir ainda lignina. são também descritas fibras incluindo as composições, métodos para produzir as fibras e usos das fibras.

Additive for fiber strengthening

Compositions that include a polymer and an aldaric acid, such as glucaric acid, are disclosed. The compositions may include polyvinyl alcohol and glucaric acid. The compositions may also include polyacrylonitrile and glucaric acid. In addition, the compositions may further include lignin. Also disclosed are fibers including the compositions, methods of making the fibers, and uses of the fibers.

Motor driving apparatus, motor system, and electric vehicle

A motor driving apparatus, a motor system, and an electric vehicle are described that improve running efficiency of a motor and avoid damaging an inverter. The motor driving apparatus includes a three-level inverter, a motor parameter obtaining circuit, and a control circuit. The three-level inverter is configured to invert a direct current provided by the first power supply into an alternating current, and provide the alternating current for the motor; the motor parameter obtaining circuit is configured to be separately coupled to the motor and the control circuit, and is configured to: obtain a motor working condition signal of the motor, and provide the motor working condition signal for the control circuit; and the control circuit is configured to control the three-level inverter in the target working mode so that a midpoint voltage of the three-level inverter is less than a first voltage threshold.

Electric motor driving apparatus, electric motor system, and electric vehicle

This application provides a motor driving apparatus, a motor system, and an electric vehicle, to improve running efficiency of a motor and avoid damaging an inverter. The motor driving apparatus includes a three-level inverter, a motor parameter obtaining circuit, and a control circuit. The three-level inverter is configured to be separately connected to a first power supply and a motor, to invert a direct current provided by the first power supply into an alternating current, and provide the alternating current for the motor; the motor parameter obtaining circuit is configured to be separately coupled to the motor and the control circuit, and is configured to: obtain a motor working condition signal of the motor, and provide the motor working condition signal for the control circuit; and the control circuit is configured to: select a target working mode from a plurality of working modes based on the motor working condition signal, and control the three-level inverter in the target working mode, so that a midpoint voltage of the three-level inverter is less than a first voltage threshold.

Motor controller, control method, and power assembly

A motor control unit, a control method, and a power assembly relate to the field of inverter circuits, and are used to reduce costs of an inverter circuit and improve system efficiency of the inverter circuit. The motor control unit includes a three-phase full-bridge three-level inverter circuit (111) and a control apparatus (112). The three-phase full-bridge three-level inverter circuit (111) includes a vertical bridge circuit and a horizontal bridge circuit. A current capacity of a switching transistor in the vertical bridge circuit is greater than or equal to a maximum current of a motor. A current capacity of a switching transistor in the horizontal bridge circuit is less than the current capacity of the switching transistor in the vertical bridge circuit. The control apparatus (112) is configured to control the switching transistor in the horizontal bridge circuit based on torque of the motor, a current output by an output terminal of the vertical bridge circuit, a temperature of the switching transistor in the horizontal bridge circuit, and a terminal voltage of the switching transistor in the horizontal bridge circuit.

Motor controller, control method, and power assembly

Motor control unit, control method, and power assembly

A motor control unit includes a three-phase full-bridge three-level inverter circuit and a control apparatus. The three-phase full-bridge three-level inverter circuit includes a vertical bridge circuit and a horizontal bridge circuit. A current capacity of a switching transistor in the vertical bridge circuit is greater than or equal to a maximum current of a motor. A current capacity of a switching transistor in the horizontal bridge circuit is less than the current capacity of the switching transistor in the vertical bridge circuit. The control apparatus is configured to control the switching transistor in the horizontal bridge circuit based on torque of the motor, a current output by an output terminal of the vertical bridge circuit, a temperature of the switching transistor in the horizontal bridge circuit, and a terminal voltage of the switching transistor in the horizontal bridge circuit.

Electric motor driving apparatus, electric motor system, and electric vehicle