This article has provided an introduction to the generating process, definition, main types and critical technical and economic advantages of high speed railway, as well as the current situation and development trend of high speed railway in the world, and expounded that the high speed railway embodys high and latest techniques, e. g. the track of high speed railway is the foundation of high speed operation, high speed train is the heart of high speed operation, train performance control system is the main center of high speed operation ,safety monitoring system is the guarantee of high speed operation.
The development, main features and advantages of the high-speed magnetically levitated train are shortly described. It is particularly suitable for the development of the future high-speed passenger transportation network in China. Some suggestions to develop high-speed magnetically levitated train technology in China are presented.
From the viewpoint of the characteristics of passenger flow in China and that increasing the speed of transportation is essential to the social development, this article described that China needs high speed railway. The construction of Beijing—Shanghai high speed railway is a correct strategy choice in several aspects, such as the demand of socio-economic development of the related regions zones of optimal alternative of capacity enhancement of railways, and so on. The paper has also made a brief of the technical reservation and technical line of the construction of Beijing—Shanghai high speed railway, and given an account of forecasted demand, possible main technical alternatives and socio-economic benefits. Specific proposals have been raised for the construction of Beijing—Shanghai high speed railway, as well.
This article treats about the status on the new scientific problems of physics and electronics in the 21st century, involving vacuum energy, negative mass of electron, quantum potential, virtual particles, superstring theory and tachyons; as well as the EPR thinking experiment, quantum entanglement , quantum teleportation, quantum information theory and quantum computers.
Novel microelectronic devices, such as HEMT and PHEMT, etc. , which are based on molecular beam epitaxial (MBE) GaAs-based microstructures, have found widespread applications in modern day information technology. These devices have already been commercialized in some foreign countries. In China, continuous endeavor since mid-80, s in making GaAs-based microstructural materials by MBE has led to successful realizations of many such novel devices. Notably, the HEMT and PHEMT devices made from microstructural materials grown by MBE in Institute of Semiconductors, Chinese Academy of Sciences have demonstrated very good performances approaching the world-best. This paper aims at exploring the ways by which such research results can be transferred from laboratory to market.
This paper reviews the developing course of artificial diamond after the discovery of natural diamond. The yearly production of artificial diamond of China has been broke 5 × 108cts at 1999. At the end of 20th century, CVD Carbon and the first partical of higher than centimeter class C60 monocrystal in the world were developed in China.
The Three Gorges Project (TGP) is the greatest water conservancy engineering being built in the world. Each of the technical design and the engineering constuction in the project can be a worldwide key technical difficult and a representative case of water conservancy engineering.
Based on the overall examination of the Three Gorges Project navigation construction technical design, which started in 1994, the following 6 topics are described and discussed： 1) the general layout of the TGP navigation construction; 2) lock´s filling and emptying system and the lock´s hydraulics; 3) the design of the high slope of the permanent ship lock; 4) the hydro-structure of the permanent ship lock; 5) shiplift; 6) scientific research and its achievement during the technical design stage.
New framework of knowledge representation of fuzzy language field and fuzzy language value structure is shown in this paper. Then the generalized cell automation that can synthetically process fuzzy indeterminacy and random indeterminacy and the generalized inductive logic causal model are brought forward. On this basis, the new logic indeterminate causal inductive automatic reasoning mechanism which is based on fuzzy state describing is brought forward. At the end of this paper its application in the development of intelligent controller is discussed.
Based on theoretical analysis, computation and physical model tests, the breaking criteria for irregular waves, wave spectrum transformation, wave breaking phenomena and the method of analysis and computation, as well as the non-breaking critical slope condition are discussed in this paper. The computation results are compared with both physical model test data and data by field wave spectral measurement, which coincide with each other quite well.
Mathematic model of agricultural eco-engineering is to provide the knowledge of system's present situation, function and structure. The model is also used in the forecast system for something that is about to happen and taking an additional measure to control the system for achieving the system optimization. Based on theoetic study and practice, a mathematic model of small sized agricultural eco-engineering has been established.
Taking a farmer's family in Liuminying Village of Daxing County,Beijing,as an example,the paper introduces the mathematic model of small sized agricultural eco-engineering and its application in practice.
This thesis took the three essential factors of forest fire (fire source, environment, and litter) as the point of departure,and has approached the forecast method of forest fire in tropical area of southwest China in a macroscopic scale.
This study supported by mathematical method was from a new angle. For example,in the aspect of forest fire forecast, the main cause of forest fire was artificial fire, which had lots of randomness. So Markov random processes could be employed in the study. In the aspect of the analysis of environment that contributes to forest fire,correlation would reveal the relation among cosmos earth and life,for instance,the relation between the El Nino (or La Nina) and the forest fire. Especially in the aspect of estimating the amount of litter,a new estimate method based on space remote sensing data was raised. It provided an effective and quantitative way with higher reliability for forest fire forecast on region scale.
A brief account of the meaning of atmospheric science and its importance to human*s existence and development are given, including taking precautions against natural calamities and reducing natural disasters, development and use of climate resource, protection of ecological environment, sustainable utilization of water resource, etc. Atmospheric science brings benefit to mankind through the development and use of atmospheric information, which is necessary to be engineered inaccordance with the characteristic of information engineering. The basic conditions and effects of main meteorological engineering constructions are briefly reviewed. Basic thinking for the next three decades about atmospheric science engineering construction and some key projects to be constructed and some main measures are initially envisaged .Key projects include automatic atmospheric monitoring system enginnering, short-range climate forecast system engineering, satellite synthetic application system extending engineering, mesoscale (local) numerical weather forecast system engineering, weather modification system engineering and meteorological service system engineering.
Flue gas desulfurization, a well-established clean coal technology, is imperative to the coal-combusted power plants. The lime-gypsum method, commonly used in the developed countries, of high investment and cost, little usage of product gypsum, is impossible to be widely adopted in China. The authors have proposed a proprietary and novel ammonia desulfurization process (NADS), which is able to recover SO2 from flue gases, producing ammonium sulfate, or phosphate, or nitrate, and simultaneously concentrated sulfuric acid, commericialized on a 25MW unit. Compared with the conventional FGD processes, NADS can result in an investment reduction of more than 70% , and an operating cost reduction of more than 70%. In this papaer, economic feasibility studies have been done based upon a 200MW and a 300MW unit, with the results that the investments are 60 and 80 million RMB，respectively, and the capital payback periods are eight and five years respecfively. It can be speculated that the NADS can find great applications in China.
The applications of information technology in petrochemical companies, especially main functions and technical features of advanced process control technology and optimization technology are reviewed. Then, based on the gaps between domestic and foreign petrochemical companies, the strategy of improving process control is proposed.
This Issue
May 2000, Volume 2 Issue 5