Iron and steel industry in China will continue to evolve with increasing demand of domestic market. Steel remains to be the an irreplaceable material used in almost all objects in the professional and private life, due to its excellent and wide performance and reclaimable property. In the past 20 years Chinese iron and steel industry has changed significantly. The annual production of crude steel in China has exceeded one hundred million tons. New processes were developed and a large variety of new products were also invented to satisfy the needs of economic development in China. The application of new technologies such as thin slab continuous casting ,casting ~ rolling with liquid core and low temperature rolling will have a wide applying demand in Chinese iron and steel industry, which will be more competitive and attractive for investment. A good deal attention has been paid to the development of new environment - friendly and energy - saving processes for the next generation of iron and steelmaking. Introduction of physical field, for example electric field, magnetic field, microwave field and ultrasonic field, to a chemical reaction or solidification system will give an unexpected result. Its industrial application will bring a revolutionary change in iron and steel manufacturing.
This paper discusses the strategy significance and urgency of the development of civil helicopter on the basis of the present development of helicopter in the world, and especially in connection with China´s actual condition. Owing to its high tech content and unique flight ability, helicopter is playing a more and more important role in the construction of national economy, and becoming a new economic increase point. This paper analyzes the relationship of supplementing each other between the military helicopter industry and the civil heli-copter industry, and looks back the development road of tens of years of helicopter in China, also forecasts the development tendency of helicopter, and presents the development plan of the civil helicopter industry on the existing foundation. The policy suggestion is also put forward on the development of the civil helicopter for the future.
Rural energy forecast belongs to the category of regional energy forecast. To forecast the demand of energy consumption in rural area of China will be useful for drawing out the rural energy strategy with rural sustainable development. Based on analysis and calculation this paper brings forward the conventional scheme and the strengthening renewable energy utilization scheme.The energy consumption in rural region is mainly divided into two components, i.e. used for economic development and for farmer households living. Following the progress in implementation of the state key project “Small Rural City - township Construction” most of rural population will be urbanized locally. It is expected by the year of 2020 and 2050, there will be about 670 and 480 millions of pepole living in rural area, and in the case of the “strengthening” scheme, the total commodity energy demand is about 1290 and 1632 Mt coal equivalent ,respectively.If the energy consumption in village and town enterprises is not included in two schemes, the total energy demand in rural area will be 970 〜1080 Mt coal equivalent in 2050. The coal consumption will account for 31.7% of the total.
Ever since 1994, the evaluations made by expert have proved that the wheel/rail approach for the Beijing-Shanghai High Speed Railway is feasible. However there were three academicians who proposed in 1999 that China was not suitable to develop wheel/rail type high speed trains and great efforts should be paid to development of maglev trains. Then what are the reasons for almost 10 countries and regions in the world that have constructed or are constructing or are planning to construct this type of high speed railways and none of them have constructed a maglev line in real revenue service so far. And in particular why there still exits a big debate on the development of maglev even in Japan and Germany that have long-term test and research experience. For the latter question, the three academicians have the following explanations： The superiority of maglev system can not be brought into full play due to the fact that the distance from the capitals to major cities is relatively short, the high speed highway network and the wheel/rail type high speed railway network are already available, and they do not feel any urgent needs. The author holds that the crucial point, which is a decisive factor, is that maglev system is rather poor in economic benefits and it is by no means perfect technically. The paper also points out that the maglev system has no superiority over civil aviation and high speed railways in terms of technology and economy except that its speed is higher than wheel/rail type railways. Therefore, the so-called “technical leap-forward”，is hard to find ground. The author proposes that it is better to carry out feasibility study of follow-up nature with regard to the application of maglev system no high speed railways. It is not appropriate to spend several hundred million yuan to build a test section. It is essential to approve the wheel/rail type Beijing - Shanghai High Speed Railway at an early date.
This paper introduces the Maglev technology and High Speed Wheel-rail technology systematically with respect to the establishment of Beijing - Shanghai High Speed Railway, compares the advantages and disadvantages of this two technologies and proposes some viewpoints about this problem. The purpose of this paper is to present some valuable references to the construction of Beijing - Shanghai High Speed Railway.
This article explains that modern biotechnology not only has a powerful spreading, driving force and economic value, but it also reserves a great potential to relax the global pressures from population, food, natural resources and environment. None of ohter technologies have such a power, or can replace biotechnology. The article also discusses the main contents of biotechnology and its new trends of industrialization. The author holds GMO food must be put in order by both science and relevant regulations, after reviewed the background and new trends of present GMO debate. The current debate has focused on the public acceptability, trade benefit and relevant policy on GMO food. GMO food will only be interrupted for the time being, and will have another development tide under the supervision of relevant laws and regulation. Finally, the paper proposes suggestions for the countermeasure and attitude that China should hold during the development and industrialization of modern biotechnology.
The Characteristics of water and the issue of water resources in China are mainly discussed in the paper. The viewpoint that the situation of water resources in China cann´t be judged simplily by the amount of average yearly precipitation, and the exploitation and utilization of water resources depend on the humen´s control and management are expounded. In general the water resources in China is enough for using, its unbalnced distribution in space-time is the most problem. Lots of experiences about bringing water under control and using water were accumulated by the Chinese farmers in thousand-years-histroy´s practice. Saving water in agriculture is very important,the key measure is to advocate “decentralized storage and decentralized utilization of water” so that the loss and pollutiion of runoff can be controled. In order to raise the efficiency of water use,a series of research and practical work needs to be carried out.
The application of integrated membrane separation processes in water purification, wastewater treatment, cleaning manufacture, etc. , was reviewed in this paper. Processes such as preparation of ultrapure water, drinking water purification, sewage treatment and reuse, organic wastewater treatment, multipurpose use of whey, sea water desalination were discussed in detail. The advantages and prospect of integrated membrane separation process were also analyzed in the review.
Secondary regulation is novel hydraulic transmission technology which possesses many outstanding advantages, such as convenient controlling, easily composing network components just like that in an electric system, and even simpler energy recovering and regeneration than in an electric system. Researches in secondary regulation technology will have no hesitation to enlarge the application scope and enhance the product competitive power of the hydaulic system. Torque servo loading system is a typical equipment in secondary regulation research with; briniant application future. In the paper, by modeling a secondary regulated torque loading system in detail, some nature dynamic characteristics of secondary regulation technology is analyzed. Finally, a computer control system of the secondary regulated loading equipment is established and several experimental curves prove the theoretical analyzing results.
This paper describes the development of the ground-to-air jammer. Initially this equipment can only jam the bomb-aiming radar, but now it has evolved into a ground-to-air jamming system or series, which can jam a variety of radars , including airborne radar on combat aircraft, missile guidance radar, precise guid-ance radar, AW ACS radar and sat ellite-borne radar, etc. The paper analyzes the jamming conception, methods and jamming station configuration against these types of radars.
The paper provides the conceptual analysis of the jamming suppression factors taken for jamming new types of radars, derives their mathematical expressions, and gives both the computer-simulated result and real-test result to further prove the confidence of the theoretical analysis.
The paper notes that in 2 current conflicts in 1990s, the intruders won the wars with very low loss rate (only several parts of ten thousands), because the other side had not equipped with the ground-to-air jamming systems. If they had got the ground-to-air jamming equipment deployed in their air defense system, they would have supported their air defense system to function well, reduced their own loss rate, increased the enemy´s loss, and made intruders not to win so easily.
The paper concludes that the ground-to-air jamming system plays a very important role in the national defense. It has both defensive and offensive functions with its 3D jamming capabilities. Also it is very, cost effective and quite suitable for the developing countries. The ground-to-air jamming system will have a bright future.
Through arranging the physical properties of the eight precious metals in accordance with their positions in the Periodic Table, three laws can be obtained： their atomic radii are close to each other and the density and specific heat nearly obey the relation of multiple proportions; melting point, boiling point, hardness and other mechanic properties vary linearly; electrical conductivity and heat conductivity vary irregularly. The cause of these three laws is analyzed by aid of the valence bond theory on the basis of atomic structure characteristics.
Studies are presented on five radio propagation models in ITU - R recommendations. The mcxlels include statistical prediction method for tropospheric scatter transmission loss, prediction method for sea reflection fading in maritime mobile satellite telecommunications, conversion method for ionosphereic scintillation fading, simplified prediction method for attenuation by atmospheric gases and modified prediction method for field strength in land mobile services.
By the aid of the spectrum detecting device of welding arc, the droplet transfer spectral information of pulsed MIG welding has been researched experimentally. Results show that the arc spectral information can reflect well droplet transfer process in pulsed MIG welding. Many kinds of spectral information modes of droplet transfer have been found, which can reflect various droplet transfer types, such as one-peak-zero-base, one-peak-one-base, one-peak-two-base, two-peak-zero-base, two-peak-one-base, two-peak-two-base, three-peak-zero-base and so on. Especially, they can sharply and clearly reflect multiple drops spray transfer in the period of pulse peak. These spectral information have excellent character and therefore the spectral real-time and precise control of droplet transfer in pulsed MIG welding will be realized.
Weather modification (rain enhancement, hail suppression, fog clearing, etc.) is introduced in this paper, including the basic scientific principle, history of development, present status, scientific-technical progress, scope of activities, increasing demand, organization, etc. , in China and abroad. A typical operational system of weather modification in China is described, which consists of monitoring and forecasting of weather and cloud, seeding technology (conception model, seeding criteria, effective agent, delivery system) ,numerical modeling, communication-commanding and evaluating systems. The importance of scientific-technical research system is emphasized. The main aspects of research on the concerned applied sciences and technical development are proposed. The important role of long-term stable scientific demonstrative experiments is explained. The direction of further development in this field is also suggested.