太阳能灭蚊灯（HJ-7S）

Steel for brake drum and manufacturing method thereof

The invention provides steel for a brake drum and a manufacturing method thereof.The steel comprises 0.08%-0.10% of C, smaller than or equal to 0.08% of Si, 0.50%-0.80% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.005% of S, 0.02%-0.05% of Als, 0.005%-0.01% of Nb, 0.002%-0.004% of La + Ce, smaller than or equal to 25 ppm of O, smaller than or equal to 40 ppm of N and the balance Fe and other inevitable impurities, the content of Mn is low, only trace Nb alloy strengthening elements and rare earth elements are added, and the manufacturing cost is low; the manufacturing method is good in stability, and the finally obtained finished product is uniform and fine in structure and small in mechanical property fluctuation; the product is low in yield ratio, high in elongation, good in thinning spinning performance, high in surface quality, suitable for producing brake drums of various models and beneficial to large-scale application and popularization of brake drum production ...

Construction site personnel dynamic information detection method based on digital twinning

The invention discloses a construction site personnel dynamic information detection method based on digital twinning, and the method comprises the following steps: obtaining the identity information data of construction site personnel, the identity information data comprising facial information data and footstep vocal print feature data; positioning a sound source position of a construction site worker according to the obtained footstep vocal print feature data to obtain working area positioning data; converting the obtained footstep voiceprint feature data into digital voiceprint tags, and inputting the digital voiceprint tags into a database for storage; extracting and comparing the obtained footstep vocal print features to obtain identification result data; and projecting the identity information data of the construction site personnel and the working area positioning data into the three-dimensional model, and determining the distribution data of the construction site personnel and the ...