电视精密跟踪控制系统的设计和应用

本文介绍了一个用于实际的电视精密跟踪控制系统,该控制系统在外场跟踪飞行体时稳定可靠,跟踪精度为数角秒.文中论述了人参与的复合捕获控制系统,找到了该系统参数的设计准则,即在切换时要满足相对变化量Δ≤15%.其次,重点论述了三阶无静差电视精密跟踪控制系统的设计方法,即利用 Z 变换直接求解,使得系统满足最佳条件旬(?)_(max)/(?)K_i=0和(?)_(max)/(?)K_f~2>0,从而,使得该控制系统满足了高稳定度和高精度的技术指标,并在实际中获得了应用.

空间电流体系地磁反演及理论研究

The space currents definitely take effects on electromagnetic environment and also are scientific highlight in the space research. Space currents as a momentum and energy provider to Geospace Storm, disturb the varied part of geomagnetic field, distort magnetospheric configuration and furthermore take control of the coupling between magnetosphere and ionosphere. Due to both academic and commercial objectives above, we carry on geomagnetic inverse and theoretical studies about the space currents by using geomagnetic data from INTERMAGNET. At first, we apply a method of Natural Orthogonal Components (NOC) to decomposition the solar daily variation, especially for (solar quiet variation). NOC is just one of eign mode analysis, the most advantage of this method is that the basic functions (BFs) were not previously designated, but naturally came from the original data so that there are several BFs usually corresponding to the process really happened and have more physical meaning than the traditional spectrum analysis with the fixed BFs like Fourier trigonometric functions. The first two eign modes are corresponding to the and daily variation and their amplitudes both have the seasonal and day-to-day trend, that will be useful for evaluating geomagnetic activity indices. Because of the too strict constraints of orthogonality, we try to extend orthogonal contraints to the non-orthogonal ones in order to give more suitable and appropriate decomposition of the real processes when the most components did not satisfy orthogonality. We introduce a mapping matrix which can transform the real physical space to a new mathematical space, after that process, the modified components which associated with the physical processes have satisfied the orthogonality in the new mathematical space, furthermore, we can continue to use the NOC decomposition in the new mathematical space, and then all the components inversely transform back to original physical space, so that we would have finished the non-orthogonal decomposition which more generally in the real world. Secondly, geomagnetic inverse of the ring current’s topology is conducted. Configurational changes of the ring current in the magnetosphere lead to different patterns of disturbed ground field, so that the global configuration of ring current can be inferred from its geomagnetic perturbations. We took advantages of worldwide geomagnetic observatories network to investigate the disturbed geomagnetic field which produced by ring current. It was found that the ring current was not always centered at geomagnetic equator, and significantly deviated off the equator during several intense magnetic storms. The deviation owing to the tilting and latitudinal shifting of the ring current with respect to the earth’s dipole can be estimated from global geomagnetic survey. Furthermore those two configurational factors which gave a quantitative description of the ring current configuration, will be helpful to improve the Dst calibration and understand the dependence of ring current’s configuration on the plasma sheet location relative to the equator when magnetotail field warped. Thirdly, the energization and physical acceleration process of ring current during magnetic storm has been proposed. When IMF Bz component increase, the enhanced convection electric field drive the plasma injection into the inner magnetosphere. During the transport process, a dynamic heating is happened which make the particles more ‘hot’ when the injection is more deeply inward. The energy gradient along the injection path is equivalent to a kind of force, which resist the plasma more earthward injection, as a diamagnetic effect of the magnetosphere anti and repellent action to the exotically injected plasma. The acceleration efficiency has a power law form. We use analytical way to quantitatively describe the dynamical process by introducing a physical parameter: energization index, which will be useful to understand how the particle is heated. At the end, we give a scheme of how to get the from storm time geomagnetic data. During intense magnetic storms, the lognormal trend of geomagnetic Dst decreases depend on the heating dynamic of magnetosphere controlling ring current. The descending pattern of main phase is governed by the magnetospheric configuration, which can be describled by the energization index. The amplitude of Dst correlated with convection electric field or south component of the solar wind. Finally, the Dst index is predicted by upstream solar wind parameter. As we known space weather have posed many chanllenges and impacts on techinal system, the geomagnetic index for evaluating the activity space weather. We review the most popular Dst prediction method and repeat the Dst forecasting model works. A concise and convnient Key Points model of the polar region is also introduced to space weather. In summary, this paper contains some new quantitative and physical description of the space currents with special focus on the ring current. Whatever we do is just to gain a better understanding of the natural world, particularly the space environment around Earth through analytical deduction, algorithm designing and physical analysis, to quantitative interpretation. Applications of theoretical physics in conjunction with data analysis help us to understand the basic physical process govering the universe.

单程波算子空间-波数域可分近似方法研究

In the petroleum exploration industry, it is very important to simulate the evolvement of wave field beneath our earth in the aspects of time and space quickly and effectively. Because of the huge data size in petroleum exploration and also the strict requirement of time limit in the actual process of production, simplification of models and approximation of algorithm are necessary. At the same time, every fine improvement to algorithm has its great practical significance and use value. Based on the reasons above, this dissertation researches the separable approximation methods of space-wave number domain for One-way Wave Operator and gets the conclusions as follow: 1. It is insufficient to value One-way Wave Operator purely from the mathematical modulus and phase error, while, holding some specific structural character of operator should be more important. Because, the evaluation criterion of One-way Wave Operator’s imaging ability is quite complicate and obscured, which is similar to the evaluation of an artwork. 2. We can not search for a best or most effective One-way Wave Operator approximation solution for all. However, to different speed model and precision requirement the best approximation solution does exist which is maybe also a compromise, because it is very beneficial to One-way Wave Operator to take full advantage of speed model’s pre-tested information.

锦屏电站地下厂房卸荷岩体参数研究

It is a basic work to ascertain the parameters of rock mass for evaluation about stability of the engineering. Anisotropism、inhomogeneity and discontinuity characters of the rock mass arise from the existing of the structural plane. Subjected to water、weathering effect、off-loading, mechanical characters of the rock mass are greatly different from rock itself, Determining mechanical parameters of the rock mass becomes so difficult because of structure effect、dimension effect、rheological character, ‘Can’t give a proper parameter’ becomes one of big problems for theoretic analysis and numerical simulation. With the increment of project scale, appraising the project rock mass and ascertaining the parameters of rock mass becomes more and more important and strict. Consequently, researching the parameters of rock mass has important theoretical significance and actual meaning. The Jin-ping hydroelectric station is the first highest hyperbolic arch dam in the world under construction, the height of the dam is about 305m, it is the biggest hydroelectric station at lower reaches of Yalong river. The length of underground factory building is 204.52m, the total height of it is 68.83m, the maximum of span clearance is 28.90m. Large-scale excavation in the underground factory of Jin-ping hydroelectric station has brought many kinds of destructive phenomenon, such as relaxation、spilling, providing a precious chance for study of unloading parameter about rock mass. As we all know, Southwest is the most important hydroelectric power base in China, the construction of the hydroelectric station mostly concentrate at high mountain and gorge area, basically and importantly, we must be familiar with the physical and mechanical character of the rock mass to guarantee to exploit safely、efficiently、quickly, in other words, we must understand the strength and deformation character of the rock mass. Based on enough fieldwork of geological investigation, we study the parameter of unloading rock mass on condition that we obtain abundant information, which is not only important for the construction of Jin-ping hydroelectric station, but also for the construction of other big hydroelectric station similar with Jin-ping. This paper adopt geological analysis、test data analysis、experience analysis、theory research and Artificial Neural Networks （ANN） brainpower analysis to evaluate the mechanical parameter, the major production is as follows: (1)Through the excavation of upper 5-layer of the underground powerhouse and the statistical classification of the main joints fractures exposed, We believe that there are three sets of joints, the first group is lay fracture, the second group and the fourth group are steep fracture. These provide a strong foundation for the following calculation of and analysis; (2)According to the in-situ measurement about sound wave velocity、displacement and anchor stress, we analyses the effects of rock unloading effect，the results show a obvious time-related character and localization features of rock deformation. We determine the depth of excavation unloading of underground factory wall based on this. Determining the rock mass parameters according to the measurement about sound wave velocity with characters of low- disturbing、dynamic on the spot, the result can really reflect the original state, this chapter approximately the mechanical parameters about rock mass at each unloading area; (3)Based on Hoek-Brown experienced formula with geological strength index GSI and RMR method to evaluate the mechanical parameters of different degree weathering and unloading rock mass about underground factory, Both of evaluation result are more satisfied; (4)From the perspective of far-field stress, based on the stress field distribution ideas of two-crack at any load conditions proposed by Fazil Erdogan (1962)，using the strain energy density factor criterion (S criterion) proposed by Xue changming(1972)，we establish the corresponding relationship between far-field stress and crack tip stress field, derive the integrated intensity criterion formula under the conditions of pure tensile stress among two line coplanar intermittent jointed rock，and establish the corresponding intensity criterion for the exploratory attempt; (5)With artificial neural network, the paper focuses on the mechanical parameters of rock mass that we concerned about and the whole process of prediction of deformation parameters, discusses the prospect of applying in assessment about the parameters of rock mass，and rely on the catalog information of underground powerhouse of Jinping I Hydropower Station, identifying the rock mechanics parameters intellectually，discusses the sample selection, network design, values of basic parameters and error analysis comprehensively. There is a certain significance for us to set up a set of parameters evaluation system，which is in construction of large-scale hydropower among a group of marble mass.

中小学生欺负行为及其主要影响因素研究

The present paper studied the school bullying and the primary impact factors, for understanding the nature of bullying, and providing measures and references to the elimination and controlling of school bullying. Primarily with methods of questionnaires and psychometrics, combined with case study and interviews, the following findings were found: in Chinese culture, bullying is a behavior intentionally causing harm to the weaker or weakers. There were 5 types of bullying-physical, social exclusion, threat, breakage and verbal. In Chinese schools the occurrence of bullying had regular patterns. The factor that impact children's bullying behavior was personality traits, interpersonal techniques, family atmosphere, education and upbringing styles. In personality traits, bullies tended to be more extroversive, impulsive, obstinate, obdurate and lack of sympathy. Victims tended to be more introversive, self-restrained, lack of confidence, lonely, anxious and depressive. Both of them expressed more mental problem tendencies than normal children did. When confronted with interpersonal conflicts, they used little problem solving strategies. Bullies had more extroverted emotional responses, and victims had more social support strategies. In the light of family influence, bullies were relatively superior in family's social economic conditions. But their parents had little time and energy spent on them. They tended to be punitive, and had indulgent, reject or despotic upbringing styles. The role of victim might be related to the disadvantage of family's social economic status. Their parents had the tendency of spoiling and overindulgence. The research concluded that in different cultures the connotation of bullying was not homogenous. The occurrence of school bullying had regular patterns. Bullying behavior was primarily influenced by the personality traits of both bullies and victims, the coping strategies of interpersonal conflicts, family's social economic status, parents' basic emotional attitudes, ways of educating, punitive tendencies and school atmosphere. The occurrence of bullying behavior was the result of the combined process of past experience, behavior habits, personality traits, cognitive evaluation, certain evocative clues and the environment conditions. It reminded that quality education and mental health education in schools was essential. Strengthening basic social skill training in school, creating positive family atmosphere, having more communications between schools and families and implementing strict regulations against bullying was essential to interfere and eliminate the school bullying.