Electrical characteristics of new three-phase traction power supply system for rail transit

A novel three-phase traction power supply system is proposed to eliminate the adverse effects caused by electric phase separation in catenary and accomplish a unifying manner of traction power supply for rail transit.With the application of two-stage three-phase continuous power supply structure,the electrical characteristics exhibit new features differing from the existing traction system.In this work,the principle for voltage levels determining two-stage network is dissected in accordance with the requirements of traction network and electric locomotive.The equivalent model of three-phase traction system is built for deducing the formula of current distribution and voltage losses.Based on the chain network model of the traction network,a simulation model is established to analyze the electrical characteristics such as traction current distribution,voltage losses,system equivalent impedance,voltage distribution,voltage unbalance and regenerative energy utilization.In a few words,quite a lot traction current of about 99%is undertaken by long-section cable network.The proportion of system voltage losses is small attributed to the two-stage three-phase power supply structure,and the voltage unbal-ance caused by impedance asymmetry of traction network is less than 1‰.In addition,the utilization rate of regenerative energy for locomotive achieves a significant promotion of over 97%.

Evolution of Middle East's Power Structure

Wang: The U. S. stated purposes of military actions against Iraq are to "overthrow Saddam" and "transform Iraq. " I am afraid such actions would cause a big stir. Tang: I think so. American military actions against Iraq will not only promote the birth of a new Iraq but also change the international relations and military balance in the Middle East. Washington’s revealed intention shows that it hopes to create a democratic and pro-

Current Situation of Power Development in the World and Its Enlightenment to China's Power Industry

Based on a detailed analysis of China's current power installed capacity,power generation,power structure,as well as the world's power installed capacity,power generation,power structure,and power regional distribution,some policy suggestions have been put forward through objective analysis and comparison.Firstly,power sectors in China should develop from high-speed growth to high-quality development,digest power excessive production capacity,control newly-added production capacity absolutely,and control the construction of power points orderly according to power planning.Secondly,non-fossil energy power generation needs to develop energetically,and should attach great importance to biomass power generation,in addition to gas power generation,wind power,and solar power.Lastly,on the basis of building a moderately prosperous society in all respects,electricity consumption per capita should be improved in the high-quality development stage in China,and the development of energy conservation and emission reduction,renewable energy,and distributed energy and so on should be considered collaboratively.

Analysis on the Irregular and Asymmetrical Power/Ground Structure by PEEC Modeling

In order to provide some reference for the design of the power/ground system, a complicated power/ground system in time and frequency domains was analyzed, which is based on PEEC (Partial Element Equivalent Circuit). According to the actual requirements, characteristics of some common power/ground structures in time and frequency domains, such as SSN (Simultaneous Switching Noise), are obtained for the future research. The results show the first resonance point is changed with the structure of the power/ground networks.

A Novel Interface-Gate Structure for SOI Power MOSFET to Reduce Specific On-Resistance

A novel silicon-on-insulator （SOI） power metM-oxide-semiconductor field effect transistor with an interface-gate （IG SOI） structure is proposed, in which the trench polysificon gate extends into the buried oxide layer （BOX） at the source side and an IG is formed. Firstly, the IG offers an extra accumulation channel for the carriers. Secondly, the subsidiary depletion effect of the IG results in a higher impurity doping for the drift region. A low specific on-resistance is therefore obtained under the condition of a slightly enhanced breakdown voltage for the IG SOI. The influences of structure parameters on the device performances are investigated. Compared with the conventional trench gate SOI and lateral planar gate SOI, the specific on-resistances of the IG SOI are reduced by 36.66% and 25.32% with the breakdown voltages enhanced by 2.28% and 10.83% at the same SOI layer of 3 μm, BOX of 1 μm, and half-cell pitch of 5.5 μm, respectively.

MECHANICAL VIBRATIONAL POWER FLOW IN BEAM-PLATE ASSEMBLIES

The vibrational power flow in the beam-plate assemblies and then with the isolators is investigated using analytical ' power flow' approach based on the some concepts of mechanical mo- bility and structural dynamics. Theoretical expressions of the power flow in the structures are given and examined. The numerical results of the expressions are good agreements with the measuring re- sults obtained by the technique of vibration intensity. On the basis of these results, possible ways of reducing the vibrational power flow in the structures are suggested .

Global Power Structure Shifted and Transitional Multi-polarity Emerged

The world is facing the third important global power shift.The United States,EU, Japan,Russia,China,and the newly emerging power group are becoming the six big forces in the international center stage,while the former three forces and the latter three belong to two groups,waning and waxing respectively.The major shift in the global balance of power is bound to give rise to the transitional multi-polar configuration,which implies a shifting of leadership over the configuration,China and U.S.outweighing other forces,global issues looming large,homogeneity blending with heterogeneity,and a shifting center of world powers.The transitional multi-polar configuration is all about change,upon which China is one of the decisive forces.

The Separation of Powers from Functions and the Establishment of a New Structure of Management and Operation of State-owned Assets

The development of the socialist market economy demands the furtherintensification of the reform of the management operating system (MOS)of the state-owned assets, the strengthening of the efficiency in the man-agement of state-owned assets,and the improvement of the operating bene-

The New Knowledge System Regarding the Idea of Community and Power-Structures of Society:The Bengali Narrative Ballads of Maimansingha Gitika

Circulation and reception of various national literatures,particularly significant texts and literary traditions in minority languages such as Bengali,are often neglected by the scholarly community and literary institutions.This creates an incomplete view of world literature,which should encompass the wholeness or totality of literature from different geographical locations.In an effort to minimize this gap,this research article explores the popular collection of Bengali narrative ballads,Maimansingha Gitika,compiled by Dineshchandra Sen.Most of the collected narrative ballads were composed between the 16th and early 18th century,yet this prime text is largely unavailable to readers and unobtainable to experts in politico-cultural and historical contexts.Using the concept of community and new historicism,this article analyzes two narrative ballads from Maimansingha Gitika,offering critical insights into the power structures of society and the new knowledge systems surrounding the concept of community.Through this analysis,the article highlights the importance of including prime texts in different national languages to inform the scholarly community about the rich literary traditions and relationality of knowledge extracted from minority languages to contemporary Euro-American knowledge structures.

Pathway Planning of Nuclear Power Development Incorporating Assessment of Nuclear Event Risk

The nuclear event risk(NER)is an important and disputed factor that should be reasonably considered when planning the pathway of nuclear power development(NPD)to assess the benefits and risks of developing nuclear power more objectively.This paper aims to explore the impact of nuclear events on NPD pathway planning.The influence of nuclear events is quantified as a monetary risk component,and an optimization model that incorporates the NER in the objective function is proposed.To optimize the pathway of NPD in the lowcarbon transition course of power supply structure evolution,a simulation model is built to deduce alternative NPD pathways and corresponding power supply evolution scenarios under the constraint of an exogenously assigned carbon emission pathway(CEP);moreover,a method is proposed to describe the CEP by superimposing the maximum carbon emission space and each carbon emission reduction(CER)component,and various CER components are clustered considering the emission reduction characteristics and resource endowments of different power generation technologies.A case study is conducted to explore the impact of NER and its risk valuation uncertainty on NPD pathway planning.The method presented in this paper allows the impact of nuclear events on NPD pathway planning to be quantified and improves the level of coordinated optimization of benefits and risks.

“Technology Alliance”:A Strategic Path for New Technological Hegemony

Science and technology(sci-tech)is becoming the primary battlefield of strategic competition among major countries as the new round of technological revolution and industrial transformation gain momentum worldwide.The competitions on the rules,criteria,and system of sci-tech development and applications will directly impact the reshaping of the power structure of international strategy and the international system.On the basis of the techno-multilateralism strategy,the United States,along with its partners,sets up a“technology alliance”in the high technological field.It aims to hold the power of new technology by jointly formulating new rules and criteria for global technological development and governance.The framework of“technology alliance”taking shape influences profoundly global power structure,international pattern,and the international system.

Structural Design and Analysis of a Booster Arm Made of a Carbon Fiber Reinforced Epoxy Composite Material

An analysis of a booster arm made of a carbon fiber reinforced epoxy composite material is conducted by means of a finite element analysis method.The mechanical properties are also determined through stretching and compression performance tests.It is found that the surface treatment of the fibers causes the silane coupling agent to undergo a chemical reaction on the surface of the glass fiber.The used material succeeds in producing significant vibrations damping(vibration attenuation effect is superior to that obtained with conventional alloy materials).

Gaze and Oppositional Gaze: On Sethe's Subjectivity Construction in Beloved

Beloved is generally considered as one of the most accomplished and renowned works by Toni Morrison.In Beloved,Sethe is constantly under the gaze of whites and is reduced to the Other situated at the bottom of the power structure of society.Under the school teacher's disdainful gaze,she becomes the Other between animal and human and loses her subjectivity.Under Amy's sympathetic gaze,Sethes feels ashamed of her status as a black woman and falls into identity crisis.However,Sethe struggles to resist whites' oppression and reconstruct her subjectivity through the oppositional gaze.The reversal of the subject and object of the gaze exposes the cruelty and inhumanity of slavery and deconstructs the binary opposition between blacks and whites.

Study on Sustainable Development Mechanism of rural electricity under the new urbanization

The construction of a new socialist countryside is a strategic focus of future economic and social development of our country, including the construction of rural power grids under the new urbanization and development, it has played a crucial role in supporting and promoting. Due to historical reasons, China has not yet formed a sound and sustainable development of rural power system and management system. In order to meet the requirements under the new urbanization of rural construction, we provide a solid foundation for the development of new rural construction, and long-term development of rural electricity has become an urgent need to study the issue. At present, the reform in the field of rural electrification, rural power enterprise management, rural power system and other existing research we have conducted a preliminary study, but overall, the research in this area is still in the exploratory stage, we need a more systematic and in-depth research and discussion.

Research on Multichannel Supply Chain Pricing Under Different Dominance

In a multichannel supply chain comprising of dual-channel retailers with both physical and online channels as well as single-channel e-tailers with online channels,a multichannel demand model for e-commerce is constructed based on customer channel preferences,and a Stackerberg game model with price competition dominated by dual-channel retailers and single-channel e-tailers as well as a Bertrand game model with equal rights are established to analyze the impact of different channel rights structures on the price,demand,and profit of the two retailers.The results show that the single-channel e-tailer under the dual-channel retailer-dominated game has the highest profit,and the dual-channel retailer xmder the single-channel e-tailer-dominated game has the highest profit;thus,both retailers should accept the other's dominant channel rights for profit maximization.

Technology Transforms Politics:Internet + Government Services and the Transformation of the Grassroots Power Structure

Since the rise of the Internet in China,China’s local governments have actively used Internet technology to facilitate public administration and public services.What impact,then,have different types of social media had on local governance?This paper,based on years of investigation of J Town and L Sub-district in Shanghai(2012-2018),finds that Internet technology has profoundly transformed the grassroots power structure.Before the rise of the Internet,the grassroots power structure included local government,activists and the masses;in the age of Weibo and home owners forums,grassroots opinion leaders rose,becoming an impressive social force that local government could not afford to ignore;in the age of WeChat,however,the influence of grassroots opinion leaders declined,as local government can interact directly with the masses through WeChat public accounts and WeChat group chats,with the network technology becoming a tool for micromanagement.These three stages correspond to three types of government characterized by limited mobilization,consultation,and user-friendliness,respectively.

THE TRACE IDENTITY, A POWERFUL TOOL FOR CONSTRUCTING THE HAMILTONIAN STRUCTURE OF INTEGRABLE SYSTEMS (Ⅱ)

An isospectral problem with four potentials is discussed. The corresponding hierarchy of nonlinearevolution equations is derived. It is shown that the AKNS, Levi, D-AKNS hierarchies and a new oneare reductions of the above hierarchy. In each case the relevant Hamiltonian form is established bymaking use of the trase identity.

MOCVD growth of AlGaInP/GaInP quantum well laser diode with asymmetric cladding structure for high power applications

In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode （LD）, we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by metal organic chemical vapor deposition （MOCVD）. For the devices with 100-ttm-wide stripe and 1000-/zm-long cavity under continuous-wave （CW） operation condition, the typical threshold current is 190 mA, the slope efficiency is 1.31 W/A, the wall-plug efficiency reaches 63%, and the maximum output power reaches higher than 7 W. And the internal absorption value decreases to 1.5 cm^-1.