The article briefly reviews the development and progress in China ´s Shipbuilding Industry over the past 18 years, and the main reasons that the international competitive edge in China ,s shipyards declined in recent years has been pointed out： a. The traditional management mode does not fit the large extent incremental production situation, b. No enough strength on production pre-research and developing, c. Computer integrated technology has not been effectively used in shipyards, d. Be lack of experienced scientific and technical and managerial personals.
In order to narrow the gap with the world advanced shipyards and enhances the international competitive edge the article has put forward 4 proposals which can be referred to by the officials of large and medium shipyards： a. Transform shipbuilding production mode. b. Complete technical innovative system to strengthen the pre-research and developing of the shipbuilding products, c. Combine the transformation of production mode, steadily setup computer integration systems, d. Cultivate production management and designing per-sonel in line with the new shipbuilding production mode.
Based on the summing up the past experience and looking for the future, the author advances some new thought on water-related human activities in the new century, and cites enormous cases and data to testify them and holds that in the water-related human activities in the 21st century, the relationships among human activities, water-body dynamic states, ecological environment, economic development and social progress should be properly dealt with. Their relationships can be called as： human-water-environment-development-society relationship for short. Furthermore the author considers that it is important to master the long-term effect of human water-related activities and other productive activities upon water-body dynamics as well as the inverse actions. Water-saving and water quality protection should be put in the first and important position of water-related human activities. Research, exploration and utilization of waters in atmosphere and sea should be intensified. Afforestation and protection of existing forest, — the “green reservoir” should be regarded as decisive measures to protect and restore water sources, which should be put into the implementation. The relationship among farmland, forest and water-cover area should be properly dealt with, in which the area of water-cover should be protected and enlarged properly. Also, marsh must be properly protected, and great concerns must be shown for small streams and small waterbodies. In the future water-related human activities, the human beings should adapt to and take advantage of the nature rather than against it, make full use of information technologies of various kinds to establish “informative water resources” Through understanding and mastering of hydrome-terological phenomena, set up adjustable agriculture 一 “strainable agriculture”，thereby find proper strategic to save water in the sectors with high water-consuming while obtaining enough agriculture produces.
The super-resolution near-field optical imaging is an advanced project in the front of high engi-neering science and is an industry that should be developed early in the 21th century in China. In this paper, the historical events and PSTM developments in China are introduced. The imaging expressions of all kinds of the super-resolution near-field optical imaging systems are derived and compared with each others. In general, only with the mode of constant separation of tip-sample may obtain the pure optical image of sample, such as the image of refractive index, reflectivity or transmisivity of sample. The evanescent wave emitted from sample surface and the probe tip smaller than the diffraction limit are the two basic conditions of super-resolution in optical imaging. The other key to obtain the super-resolution is the modulated tip with vertical vibration in the mixture field of evanescent wave and propagating wave in near-field. For the transparent sample PSTM is the best to separate the pure optical image and topography of sampe. The author has applied for two invented patents on PSTM, which will be benificial to the development of PSTM industry in China.
A disturbance vortex method for simulating rotor/stator interaction in turbomachinery was developed[1,2]. This method has some obvious advantages in simulating unsteady flow in turbomachinery, such as understandable physical picture and good convergency. However, there is an important simplification in reference 1, which ignores the disturbance expansion. As a result, the computational process is greatly simplified. The main purpose of the present paper is to take the disturbance expansion into consideration with the aim to lay down a solid mathematical and physical foundation for the disturbance vortex method. Since the disturbance expansion has been taken into account, one has to solve the mass, vorticity transport and energy transport equations for disturbance motion in a coupled way. These are the main differences between the present paperand reference 1.
To validate the computational method, the unsteady flows caused by rotor/stator interaction in the first stage of NASA - 67 compressor were simulated in reference 1. And unsteady velocity correlation parameters at several locations inside the passage were compared with the experimental data. In order to find out the influence of ignoring the disturbance expansion on computational results, the same example was studied in the present paper. From the simulation results it can seen that the disturbance vortex method still converges fast even the disturbance expansion is taken into consideration.
It is noted that the additional velocity component which is needed to meet the nonpenetrate condition on the body surface is expressed by an elliptic-type Laplace equation rather than a hyperbolic-type equation even the flow is unsteady and compressible. It is also noted that setting the disturbance expansion to be zero is not equivalent to an incompressible disturbance motion.
Through the study on structure, this paper systematically analysed various factors affecting stability of emulsion explosives, and drew a conclusion that zero osmosis pressure might be a good criterion of its stability. The experimental results show that the osmosis pressures of several kinds of stable emulsion explosive are near zero.
In this paper, the social and academic background of introducing the bay scallop Argopecten ir-radians and the processes of the introduction, industrialization and restoration of germplasm are reviewed, its economic and social benefits and effects on the resource of native species, ecology and´ environment of farming areas are discussed, and prospects of the introduction engineering are forecasted. In the late 1970s, to relieve the decline in Bohai Sea and Huanghai Sea mariculture industry, the U.S. bay scallop was introduced as a restorative measure. On the basis of the development of a series of successful artificial breeding and grow-out technology, the world s first scallop culture industry had its footing in China´s shallow sea regions. The bay scallop transplants in the South China Sea and East China Sea also showed satisfactory results. The restoration of germplasm to cultured stock of bay scallop brought about the sustainable development of the scallop culture industry.
The natural bay scallop populations have not been found in the farming areas of China, so there is no hazard of adverse effects of bioinvasion. The ecological and environmental effects of introduction engineering are the large-scale biodeposition where it is farmed, resulting in self-pollution. However this has no direct relationship with the incidence of mass mortality of Chlamys farreri reported in recent years. Above all, the introduction engineering of the bay scallop, targeted to meet the national socio-economic needs, has brought about immense socio-economic benefits, and uplifted the international status of China´s shellfish research. It is expected that the introduction engineering of the bay scallop has bright prospects of its sustainable development as an industry and will bring about profound and lasting benefits to the country ´s marine economic development.
In this paper, a newly developed accelerometer based on the principle of area changeable capacitance is presented at the first time. The movable mass is designed as many bars connected together and suspended by elastic beams. Two comb-shaped fixed electrodes with their fingers side by side are alternately placed under the mass. The mass moves in the direction parallel with the substrate plane under the effect of acceleration. The movable mass and fixed electrodes compose a differential capacitor unit. It is concluded by theoretical analysis that the signal of the acceleration is only proportionally related to the area between movable mass and fixed electrodes but not related to the gap between them. The parasitic capacitance Cp between the mass and fixed electrodes and CB induced by boundary effect both lower the sensitivity of the accelerometer by about 20 % , and lead to a vertical effect on accelerometer that could be ignored if compared with the sensitivity. The quasi-LIGA technology with Ni as structure layer and Cu as sacrificial layer is used to fabricate the sensor chips. The fixed electrodes are fabricated on a glass substrate. A Cu sacrificial layer used to determine the gap between the mass and fixed electrodes is then electroplated with the fixed electrodes layer. Finally, the movable Ni mass is also electroplated with the Cu layer and is released after selective etch of the Cu layer. After packaging in IC ceramic die under atmosphere, the accelerometer is put on avibrator to be tested under a frequency of 25 Hz. The output signal is connected to the interface circuit with electric wires. The experimental results show that the accelerometer has typical sensitivity of 58.1 mV/ (m·s-2) and non-linearity of 4% FS in operating range of 20 m/s2. The obtained non-linearity is not ideal and the reason is discussed based on experimental conditions
The conception of the generating lock P <G ,X, X´> and the central encrypting system composed of P<G ,X, X´>with data generating technology are proposed in this paper[3〜6]. These systems include the generating lock P<G ,X, X´> and single-tooth central encrypting system, and the generating lock P <G ,X, X´> and multi-tooth central encrypting system. The single-tooth encrypting-decrypting algorithm multi-tooth encrypting-decrypting algorithm, multi-tooth static encrypting-decrypting algorithm, multi-tooth dynamic encrypting-decrypting algorithm as well as the structure character of central encrypting system are provided. The paper points out that arbitrary two persons A and B can choose irregular distributed positive integer sets, XA={x1, x2, …，xn}, XB ={x1,x2,…xm}, m≥4, n≥4, XA≠XB , respectively and complete their secret communication with P < G, X, X´>. The experiment result shows that the method proposed has good application character and security character.
Analyzing the status of floodcontrol operation in china, this paper sumarized decision making problems of floodcontrol and proposed multiobjective decision making theory, model and methods. These include some new achievements such as multiobjective fuzzy optimum seeking theory and model for multilayer system ,definition of objective weight etc. some of the theory and model were applied to reservoirs floodcontrol operations and satisfactory results were achieved.
The design and implementation of the first ATM Switching system of China (Named BTC -9500) was started in 1993. The prototype was completed in 1995. Much field trial has been done since then, with the development of China´s broadband network. The prototype has been improved as well.
BTC - 9500 was then transferred to Shanghai Bell for manufacturing and marketing. It has been used in China´s nation wide broadband backbones. It was named China´s Important New Product, and won prizes from both the Nation and the Ministry of Information Industry.
The research on the BTC - 9500 networking unveiled the disadvantage of ATM switch/IP router combination. The scheme of switching both ATM cells and IP datagram within a single switching fabric was proposed and implemented in BTC - 9500.The cost is reduced. The network is simplified. A model of new generation platform that supports multi-service switching is given.
Based on the experience, some viewpoints on the development of the new generation network are proposed in this paper.
The development of a multilanguage, multiedit direction Windows '95 Platform is introduced, which can process Uigur, Kazak, Arabic, Chinese, as well as English. The technique difficulties and the solution in processing different width letter of multilanguage information under Windows system are described in detail. Some renovation methods of the multilanguage processing and display technique are proposed in this paper.
The expansion of Ammonium Nitrate (AN) is a novel technology. The guideline of this innovation is the self-sensitization of AN. It is a breakthrough form classic method. The approach to self-sensitization is the expansion of AN. Its essence is a surface active technology applied to powder industrial explosive, and it is a physical chemistry process under coercive crystallization.
In this paper, the mechanism and technical characteristics of expansion are discussed and its unique advantage is shown. The expanding technology of AN is mainly applied to rock expanded AN explosive and its comparison with other industry explosives is given. The expanding technology is also used in manufacturing of permitted explosive for coal mine.
For the design optimization of erosion and abrasion resisting metallic materials basic study and productively applied research were conducted. Basic study indicates that W, Co and Cr have better erosion and abrasion resisting property than other ones among ten useful constructive metals. Productively applied researche indicates that thermal sprayed WC- M hard faced ceramics in the tungsten parental materials, rare earth plating chromium in the chromium parental materials, and CoCrWC hard faced ceramic in the cobalt parental materials are better erosion and abrasion resisting materials with high performance and low cost.
At present, the breeding area of kelp in China is about 15000 hectares, and annual yield of dry product is 270 000 tonnes accounting for 50% of the total yield of seaweed in the world. TA emulsive powder can remarkably increase the yield and improve the quality of kelp. After the kelp seedling soaked in 2 mg/L TA solution for 2 hours and then put into breeding, the growth of rhizoid can be promoted and the seedling preservation rate can be raised, the content of chlorophyll and fucoxanthin increased, photosynthesis rate raised, accumulation of dry substance increased, activity of PEP carboxylase raised, metabolism of carbon promoted, activity of nitric-reductase raised, metabolism of nitrogen promoted, absorption of nitrogen, phosporous, potassium increased, growth and development promoted, contents of nucleic acid and protein raised, physiological adjusmtent strengthened, anti-disease property strengthened, rate of incidence of disease reduced. The yield of dry substance increased by 6.5 t per hectar in average compated with the treatment on the blank, that is increased by 35% . At the sametime, 24.24 kg iodine, 1.665t brown alg gum, and 1.278 t mannitol in kelp are increased per hectar. TA emulsive powder is a pioneer product at home and abroad. It has the advantages of non-toxic, high efficiency, low cost, no deterioration and convenience in storage and transport, etc. It has been popularized in 15 000 hectares in the whole country and the economic benefit is more than 300 million yuan.
The substitution of a large-scale clean energy for burning coal is needed in China because of serious pollution in cities and CO2 emission. Nuclear energy is an option of the clean energy, it can not only be used for generating electricity but also for urban district heating in stead of coal. A non-pressurized heating reactor has been designed based on experience of pool type research reactors of China. It can supply heat for urban district heating system and has a high level of safety and reliability. This is a realizable and economical solution for clean energy supply. Since the district heating systems are plentifully developed in cities of China, the heating sources which can be used in the systems will be able to improve air-environment and decrease greenhouse gas emission in a large-scale.
In recent years, the GNP (General Gross National Production) of the major countries in the world shows apparent relation with their consumption of steel and the steel is reconfirmed as the backbone of the engineering materials. This is due to the fact that the steel making industry has been reformed perfectly by the high technique — Advanced Process Control System and brought out new steels with superior property as “high tech” steels. Micro-alloyed steel is one of the major high tech steels with largest market demand. Micro-alloyed steels are produced by the Advanced Metallurgical Manufacturing Process with addition of strong carbide and nitride alloying elements, i. e. , Nb, Ti, and V to refine their grain size in re-heating and to harden and toughen their matrix after rolling. There were developed the micro-alloyed steel of HW60R for the manufacture of large dumping trucks in open-mining, the line pipe steels of X52 ～ X65 for the construction of high pressure pipeline, and the micro-alloyed weathersteel for transportation container manufacture with great economic successes in China. In view of the micro-alloyed steels being environment conscious materials and the further development of high tough line-pipe steels, high strength ship steels and high tough SUF steel plate, the micro-alloyed steels are prospective in China in the 21 century.
Electrical drive is an interface among information, power and motion. People have contacted it for a long time, but are still in doubt whether it belongs to high tech. The author tries to introduce personal view on this field in this paper and hopes to promote one´s understanding on it. Following problems are discussed: what is electrical drive; its effects on national economy; relations with other fields; the state-of-the-are of electric drive R & D in China and is developing trends.
A brief review of the advance of copper smelting technology and the price fluctuations of copper products indicate that the competition of copper market depends upon the production cost relying on metallurgy technology. In order to ensure the smooth development of the copper industry in China and win competition in the world, we must persist in domestic r & D and incorporation with foreign technology for copper smelting. This paper commentes on the deficiencies of intensified oxidizing-PS convetring-pyrorefining-electrolysis processes and analyzes the feasibility and basises of combined pyrometallurgical and hydrometallurgical method. The new combined process route will be more advantageous in future competition.
This Issue
Feb 2000, Volume 2 Issue 2