Seed Technologies Corp., Ltd.

National University of Defense Technology

Hunan Terry New Materials Company Ltd.

Central South University

Zhuzhou Crrc Times Electric Co., Ltd

Crrc Zhuzhou Institute Co., Ltd.

Crrc Zhuzhou Locomotive Co., Ltd

Bin Liu

Yuehua Xu

Wei Li

Hang Zhang

Jinsong Huang

Cheng Zhu

Zhaoyun Ding

Xianqiang Zhu

Yi Liu

Weike Liu

Xiong Liu

Yuan Yuan

Wenqing Mei

Zhihua Cao

Yong Liu

Ande Zhou

Xin Jin

ChengShang Zhou

Aijun Chen

Liangjie Liu

Yun Zhou

Songping Huang

Yu Qi

Zechun Dou

Ji Wu

Yuecheng Xie

Zhiyong Chen

Zhiming Tang

Tao Peng

Deqi Cao

Ziyang Gan

Libing Fan

Ying Yang

Yunlong Li

Fei Wang

Pei Sun

Zhongling Zhang

Shun Li

There is provided an electric traction system, comprising: a step-down transformer comprising a primary winding for operatively coupling to an AC power supply and a secondary winding which is inductively coupled to the primary winding; a traction converter module comprising a first input terminal and a second input terminal which are operatively coupled to the secondary winding, and a plurality of AC-to-AC power converters, each of which comprises first and second input nodes, configured to receive AC power and output nodes configured to supply AC power, wherein the first and second input nodes, of the plurality of AC-to-AC power converters are electrically connected in series between the first input terminal and the second input terminal; and at least one electric motor configured to be driven by the traction converter module.

Electric traction system

The disclosure relates to a method and device for identifying unknown traffic data based on a dynamic network environment. The method includes following steps. The known traffic in the network data is classified by using the known network traffic classification model, then the preliminary determination is performed according to a classification prediction result, network data preliminarily determined as the unknown traffic data is classified by using the adaptive clustering method, and then respective classes are identified by using a similarity coefficient estimation method so as to identify the classes of the malicious traffic and the normal traffic, that is, to further identify and learn the unknown traffic data, and transform it into known traffic data, and then the known network traffic classification model is trained and updated again with the new known traffic data.

Method and device for identifying unknown traffic data based dynamic network environment

Disclosed are a network traffic analysis method and a device based on multi-source network traffic data. The method includes: deploying a pre-training classifier pool in a network stream data source; receiving multi-source network stream data at a current moment for each data source, classifying the multi-source network stream data through an online classifier, performing feature processing and transformation on data collected by each network stream data source at each preset time interval, and transmitting processed traffic data features and a feature transformation matrix to a traffic drift detection module. The traffic drift detection module contains historical concept data to detect a concept drift according to the traffic data features, the feature transformation matrix and the historical concept data; if the concept drift is detected, the online classifier deployed by multiple sources is reset. This method is used for continuous real-time and accurate analysis of the multi-source network traffic data.

Network traffic analysis method and device based on multi-source network traffic data

Provided is a method for promoting densification of a metal body by utilizing metal expansion induced by hydrogen absorption. The hydrogen absorption expansion refers to a volume expansion effect produced by absorbing hydrogen on some metal blocks or metal powder in a hydrogen atmosphere under certain temperature conditions. Hydrogen is introduced into a rigid closed mold filled with a hydrogen absorption expansion material or filled with the hydrogen absorption expansion material and a material to be densified, and the mold and/or the material to be densified are/is densified by using the volume expansion effect of the hydrogen absorption expansion material. The present method may be used for eliminating residual pores from a metal material so as to improve the properties of the material.

Method for promoting densification of metal body by utilizing metal expansion induced by hydrogen absorption

There are provided a power supply system for a diesel multiple-unit train, a diesel multiple-unit train including the power supply system, and a traction control method for a diesel multiple-unit train. The power supply system includes: a diesel power pack, a traction inverter connected to a traction motor, and an auxiliary inverter connected to a train load. The power supply system further includes a direct current chopper and a supercapacitor. A high-voltage side of the direct current chopper is connected to the diesel power pack, and a low-voltage side of the direct current chopper is connected to the supercapacitor. The supercapacitor is connected to the traction inverter and the train load.

Diesel multiple unit, and electricity supply system and traction control method therefor

A matrix body PDC drill bit includes a drill crown and a bit body, and further includes a combined limiting sleeve. A connecting block and a connecting sleeve are provided at a junction of the drill crown and the bit body; multiple engaging teeth and engaging grooves for defining circumferential rotation and mutual engagement are provided between the connecting sleeve and the connecting block; the combined limiting sleeve includes several sub-limiting sleeves which are combined and spliced along an outer peripheral surface of the connecting sleeve and are configured to fixedly connected into a whole; an inner side of each sub-limiting sleeve is provided with upper limiting bumps and lower limiting bumps; the connecting block is inserted into the connecting sleeve to allow the upper limiting bumps and the lower limiting bumps to abut against fixed end surfaces of the connecting block and the connecting sleeve, respectively.

Matrix body PDC drill bit

An additive manufacturing method for making a metal matrix composite component includes melting a powdered mixture with an electron beam. The powdered mixture comprises powdered tungsten carbide in an amount of 45 wt % to 72 wt % of the powdered mixture and a powdered binder in an amount of 28 wt % to 55 wt % of the powdered mixture. The powdered binder comprises boron, silicon, and nickel.

Metal matrix compositions and methods for manufacturing same

Oxide dispersion-strengthened alloy (ODS), lead-free and free-cutting brass and producing method thereof. The mass percent of components in the brass are: 52.0%-90.0% of copper, 0.001%-0.99% of phosphorus, 0.15%-0.70% of tin, 0.25%-3.0% of manganese, 0.15%-0.90% of aluminum, 0.10%-1.5% of nickel, 0.191%-0.90% of oxygen, and 0.06%-0.80% of carbon, the ratio of aluminum to oxygen not exceeding 27:24, with the balance being zinc and inevitable impurities, wherein lead is not more than 0.08%. The brass is produced by a powder metallurgy method: brass powder, copper oxide powder, and graphite micro powder are mixed evenly; 0.001%-1.5% of a forming agent is added and mixed evenly with the mixture; and then molded by compression, and sintering are performed before post-treatment.

Oxide dispersion-strengthened alloy (ODS), lead-free and free-cutting brass and producing method thereof

Disclosed is an alloy drill. Components of the alloy drill are: 14-30 wt % of a binder phase being one or more of Co, Ni, Fe, and Cu; 0.32-9.7 wt % of an additive being one or more of TaC, MoC, Cr3C2, and MnC; and the remainder as a hard phase being WC. In the alloy drill, WC is used as the hard phase to improve its hardness and wear resistance, Cu, Ni, Fe, or Co as the binder phase can improve its anti-corrosion performance and anti-fatigue performance, and TaC, MoC, Cr3C2, or MnC as the additive can further improve its thermal stability and wear resistance. Thus, the alloy drill has superior wear resistance and impact toughness, and also possesses excellent anti-corrosion performance and anti-fatigue performance.

Alloy drill and manufacturing method thereof

Disclosed are a lead-free, high-sulphur and easy-cutting copper-manganese alloy and preparation method thereof. The alloy comprises the following components in percentage by weight: 52.0-95.0 wt. % of copper, 0.01-0.20 wt. % of phosphorus, 0.01-20 wt. % of tin, 0.55-7.0 wt. % of manganese, 0.191-1.0 wt. % of sulphur, one or more metals other than zinc that have an affinity to sulphur less than the affinity of manganese to sulphur, with the sum of the contents thereof no more than 2.0 wt. %, and the balance being zinc and inevitable impurities, wherein the metals other than zinc that have an affinity to sulphur less than the affinity of manganese to sulphur are nickel, iron, tungsten, cobalt, molybdenum, antimony, bismuth and niobium. The copper alloy is manufactured by a powder metallurgy method, in which after uniformly mixing the alloy powder, sulphide powder and nickel powder, pressing and shaping, sintering, re-pressing, and re-sintering are carried out to obtain the copper alloy, and the resulting copper alloy is thermally treated.

Lead-free, high-sulphur and easy-cutting copper-manganese alloy and preparation method thereof

Growing community of inventors

Hunan, China

Bin Liu