This paper observed Qian Xuesen's contribution to system science, system engineering, control theory and systematology in China, and showed his position as the tutor of Chinese system science.
This paper, from the angle of view of modern engineeing science and with lively examples, expounds the outstanding contributions of Academician Qian Xuesen in the initiation and macroscopic design of Chinas space undertakings,the direction and decision of key space technical problems,as well as the organizing and leading work for the development of guided missiles,launch vehicles and spacecrafts.
Traditional forest resources inventory is a hard mission, which needs much time, work and money. At the end of 1970s, remote sensing technology was introduced into China and has been used since then in the activities of forest resource inventory, especially in estimating forest stock volume, they include： Estimating volume stock of forest using quantitative value and qualitative factors of satellite data; Application of above — mentioned techniquess in different climate zones in China (The method has been spreaded over 7 million hectares in China); Estimating forestland, including area of fragments woodland and index of forest network etc. Through careful analysis of precision against costs, it is indicated that remote sensing method can save 1/3 to 1/2 budget in comparison with the traditional method.
In recent years, based on the previous study and by using modern statistic measure, new exploration and deeper study were done. These studies have solved some key problems in application of remote sensing in forestry resource inventory, such as calibrating remote sensing image against sampling plots on the ground, decreasing field work, increasing accuracy of stock volume on compartment, fast selecting optimal function, and avoiding factors that are hard to be determined by remote sensing data (such as age group, crown canopy, etc.). Both theor etical and practical applications have confirmed that remote sensing information play a leading role in estimating forest stock volume.
These discussed studies have made a good basis for the application of remote sensing in forest inventory, and given strong support for establishing a new system of forest inventory, which use remote sensing technology as primary measure.
At the end of this paper, a frame of new system of forest resource inventory is put forward, and suggestion on key problem in the new system is discussed.
Geophysical prospecting technique is now the main approach to explore oil and gas fields. In China, oil fields sueh as Karamai, Daqing, Shengli and Liaohe were all found by geophysical method. Especially 3 - D seismic survey played a great role in oil exploration.
Recently, scientists and engineers are interested in coefficients of static friction on micro and nano scale. On macro scale, the friction force is proportional to load, the apparent coefficients of static friction are always constant and not related with the load and the contact area between the load and the substrate, which have been described as Amontons' laws. However, a lot of experiments carried out with scanning microscope, atomic force microscope and friction force microscope on micro or nano scale showed that Amontons' laws can not used successfully. On micro or nano scale, there is no general expression published in literatures to describe the relationship between the coefficients of static friction and the load. Also the published data do not compare with and discuss each other. In this paper, from the definition of differential coefficients of static friction, the expressions for differential and apparent coefficients of static friction, 〓 and 〓 for several models are deduced. Only 〓 can be measured in experiments, which can be the coefficients on micro or macro scale depending on the load on the substract, but 〓 can not be measured because the differential variables are too small to measure. In Amontons' model, 〓 equals to 〓 and both are constant. In single asperity model with load on micro or nano scale, 〓 and 〓 are not constant but propotional to P-1. In the model based on absoption layers as third bodies between two contact bodies, 〓 is a constant, 〓 is not a constant but proportional to P-1. 〓 is a constant only in high normal pressure. In the model based on constant P, 〓 and 〓 are related with F and A . Finally, the experimental data published in literatures have been discussed based on the novelly deduced expressions.
An invented patent about the method for separating image of Atom Force/Photon Scanning Tunneling Microscope (AF/PSTM) and its numerical simulation results are introduced. In AF/PSTM π-symmetry lighting beams were used for eliminating false image. The AF/PSTM bi-functional tip is made of bent optical fiber and works on constant amplitude resonance. △ICD and △ICI are AC information of photon tunnel of AF/PSTM under constant average distance (〓→A )scanning mode (constant amplitude mode) and constant average intensity scanning mode respectively. Both (△ICD/〓CD)2 and (△ICI)2 are approximately linear with refractive index (n1) of the sample. Results of the numerical simulation illustrate that the method for separating image of AF/PSTM is efficient. AF/PSTM constant average distance (〓→A ) scanning mode (constant amplitude mode) has more advantages than that of constant average intensity one, such as the better response sensitivity of refractive index of the sample, and ability of getting three images of transmisitivity, refractive index and morphology of sample simultaneously. Some excellencies of this method are listed at last.
After reviewing the basic idea, methods of optimization and scale up for fermentation process adopted by many researchers for quite a long time, the author believes that the static optimizing method based on the kinetic conception with conventional optimum operating condition, in fact, is only an extension of kinetic conception of chemical engineering to the fermentation process. Such being the case, the existence of cellular metabolic flux is often neglected. Thus, the viewpoint to emphasize the metabolic flux analysis and control in bioreactor is put forward in this paper. Through several further experiments, the optimization technology of fermentation process at multi-levels based on the parameter correlation methodology and scaling-up strategy with multi parameters modulation have been realized. With the development of process sensing and computer technology, the new concept bioreactor (FUS-50L(A)) is used for fermentation processes optimization and scale up. This new bioreactor aimed at the measurement of material flux has been successfully applied to the fermentation of penicillin, erythromycin, aureomycin, inosine, guanosine, as well as the cultivation of recombinant human serum albumin, malaria vaccine, etc. As a result, thirty percent to several folds increase in titers were achieved. The process can be directly used for the scale up of Permentor from 50 liters to several hundred liters, even to 100 m3.
Based on the fact that risk assessment of environmental pollution accidents among factories is a multi-criteria and multi-stage process, and is of relativity and fuzziness, the fuzzy rank theory is developed and applied to solve such ranking problems by means of the fuzzy weighted distance, membership degree and the extensive Minimum Square Criterion. Furthermore, the methodology is applied to assess the risk of potential pollution accidents among four important chemical factories in Dalian, and the results are more reasonable than those obtained by the Index Method.
This paper discussed the intelligence control of the complex large scale systems , especially of the economy system. The entity participated in competition is regarded as a point in the fuzzy extension economy space, and all kinds of restriction conditions as a N-dimensions' jieke. Then the definition of the jieke's restriction degree is given. When the entity participates in competition, it must get the information first, and wipe off the information yawp. In order to find the best jieke and jie-gate, the extension force can be used.
For a hydropower project, river diversion planning directly decides the dam construction and has a bearing on the diversion standard. The relations between selection of diversion standard and investment, construction duration, risk and its losses of diversion structures should be coordinated. This paper systematically analyzes the controlling factors of choosing diversion standard during initial construction, and puts forward a quantitative analytic method of the factors. By means of multi-objective decision-making theory, a risk model of river duversuib standard during initial stage construction is established. A case study shows that the quantitative analysis and decision model ave effective, and are of great aid to the handling of the relations between the duration, investment and the risk for diversion construction.
According to the principle of positioning a new car navigation system of triple accuracy which consists of GPS navigation,adaptive navigation and mpa matching is presented in this paper. At present, the most wide civilian application of the GPS is the car navigation system. It is a high technique method to solve traffic jam. It is a communication and transportation management mode in the 21st century. It is the intelligent transporation system (ITS).
Focused on the features of stealth, super-maneuverability and supersonic cruise of the future fighter, the authors identified the main difficulties and gave some practical solutions to lift-drag characteristics at sub-/tran-sonic speed, high A. O. A. aerodynamic performances at low speed and supersonic drag characteristics. The authors believed that design goals could only be achieved by studying flow principles deeply, digging up the potentials of present aerodynamic improving measures, developing new aerodynamic concepts, adopting interrelated integration and flight control measures and compromising on the multiple design points.
Based on the study of the present theories and application in prototype back analysis of dam, the hot problems which need to be solved urgently in back analysis are pointed out and studied. Some new back analysis theories and methods are introduced.
A typical cavitation erosion resisting sample,the weld deposited coationg of boronic stainless steel, and a typical erosion and abrasion resisting sample,the weld deposited coating of WC ceramic are micro-analyzed and studied by means of light microscope, scanning electron microscope(SEM) ,electon probe and X-rays diffraction. The obtained results indicate that the weld deposited coating of boronic stainless steel has better resistance to cavitation eroion, while weld deposited coating of WC ceramics is a better barrier to erosion and abrasion. Forthermore,the material failure from erosion and abrasion is resulted from the combining actions of the minus pressure because of bubble crumbling and the tangential componental force caused by the dashing of silt granular.
This paper summarizes the characteristics of bauxite resources and alumina production in China The research contents, key techniques and results of performance of diaspore tube digestion are introduced. The develpment direction and significance of Diaspore bauxite digestion technology are described.