Die gegenw aartige Situation des Leseverhaltensvon Kindern und Jugendlichen in China

Als ein wichtiger Aspekt des Soziallebens haben sich die Lesekultur und die Lesegewohnheiten von Kindem und Ju- gendlichen in China mit der rasenden Entwicldung der Gesellschaft und dem zunehmenden Kulturaustausch mit Auslaandern geaadert.In dieser Arbeit handelt es sich um die Lesemotive und-verhalten der chinesischen Kinder und Jugendlichen.Auf der Basis vieler sozialer Umfragen unter jungen Lesem werden die gegenw? rtigen Situationen und Einflussfaktoren des Leseverhaltens der Jugendlichen in China dargesteUt und erforscht.     

Interpretation der Erzhlung "Der groβe Wildenberg"

Siegfried Lenz gehort jener Generation an, die den zweiten Weltkrieg miterlebt hat, dessen Erfolg vor allem in der Gegenwartsbezogenheit seiner Werke begrandet ist. Seine Erzahlung ＂Der groβe Wildenberg＂ ist eine Satire auf den modernen Bu rokratismus.     

Spatial patterns of ephemeral plants in Gurbantünggüt Desert

In the present research,the authors measured parameters of richness,cover and importance value of ephemeral and ephemeroid plants on south-north and east-west transects in the Gurbantünggüt Desert in early spring,and investigated and analyzed the microhabitats,such as terrain,geomorphology,soil physical-chemical properties and crusts. By comparison,the regional differences in the ephemeral distribution in the desert were revealed. The species of ephemeral plants in the south and center are the richest and those in the west are the poorest in the desert. The cover of ephemeral plants in the mid-south is higher than that in the north,and that in the mid-east is higher than that in the west. The response of ephemeral plants to the spatial variation of the desert habitat forms the population-habitat gradient of ephemeral plants. The characteristics are:(1) In the habitat with higher terrain,coarser textured soil with poorer sorting and correspondingly higher organic matter and lower alkali-saline contents,Carex physoides and Eremopyrum orientale are the dominant ephemeral plants;(2) In the dry habitat with lower terrain,looser textured soil,some organic matter,alkali-saline soil,and developed crust,the ephemeral plants Alyssum linifolium and Erodium oxyrrhynchum are of characteristic of drought and alkali-saline tolerance;(3) In the habitat with lower terrain,some water and more alkali-saline soil,the ephemeral plants Neotorularia torulosa and Hypecoum parviflorum being of alkali-saline tolerance are mainly developed. However,most ephemerals are distributed in a habitat order of higher terrain,some organic,and less alkali-saline soil on the above-mentioned ephemeral population-habitat gradient. The spatial gradient of variation in desert microhabitats is small,and as a whole,the physio-logical character of mesophytism is represented by the desert ephemerals.     

Measurement of the Mie-Grüneisen equation of state for polyimide

An equation of state(EOS) is a thermodynamic equation describing the state of matter under a given set of physical conditions,and the Mie-Grüneisen EOS is a widely used EOS for solid materials.Polyimide is a typical complex high-molecular polymer of imide monomers which is widely used in the manufacture of parts for aerospace technology and for fabricating the inertial fusion energy shells(IFE).When a spacecraft collides with a meteoroids(or orbital debris) or the IFE shells are radiated by high power laser,the polyimide used in the equipment is in high pressure state.In order to study the safety of the spacecraft and IFE shells,the EOS of polyimide should be determined.In our research,the three key parameters of the Mie-Grüneisen EOS based on the shock adiabat for polyimide have been determined with two-stage light-gas gun experiments,i.e.the bulk speed of sound of polyimide is determined as 2.62±0.22 km/s,the linear Hugoniot slope coefficient is determined as 1.25±0.063,and the Grüneisen parameter at initial state is determined as 1.53±0.135.The Mie-Grüneisen EOS for polyimide is finally obtained,and the parameter values are proved reliable via the comparison of Grüneisen parameter value calculated from two different theoretical models using the experimental data.     

Efficient Translation of LTL to Büchi Automata

The construction of Büchi automata from linear temporal logic is a significant step in model check-ing. This paper presents a depth-first construction algorithm to obtain simple Büchi automata from linear-time temporal logic which significantly reduces the sizes of the state spaces. A form-filling algorithm was used to reduce the size of the generated automata and the algorithms were applied directly to state-based Büchi automata, without transformation into transition-based automata. A form-filling algorit...     

Crum定理的一个新证明

导出了新的Plücker关系式,利用Wronskian技巧和Plücker关系式证明著名的Crum定理.给出了Crum定理一个新的简洁证明.在附录中证明了三个plücker关系式.     

Mechanical analysis of superplastic bulge in a cylindrical die

Previous mechanical analytical theories of superplastic bulge into a shaped die are all based on uniform thinning assumption, but in fact, the thinning process is obviously non-uniform. In this paper, the non-uniform thinning mechanical analytical equations of superplastic bulge in a cylindrical die based on superplastic bulge constitutive equation with variable m are established and verified by experiments performed on typical superplastic material ZnAl4Cu alloy sheet. Experimental results show that the non-uniform thinning mechanical analytical model can reflect the deformation process of bulging in a cylindrical die.     

Teichmüller空间的拓扑结构

研究了有限维Teichmüller空间上的拓扑结构,证明了有限维Teichmüller空间中一些拓扑结构的相互拓扑等价性.证明了可以利用黎曼曲面的长度谱定义无穷维Teichmüller空间上的一个度量.     

不确定的Lü系统的自适应Backstepping控制

混沌反控制模型Lü系统连接了著名的Lorenz系统和Chen系统,并代表了它们之间的连续演变.针对混沌系统的控制问题,已有很多控制方法.本文是针对Lü系统参数未知情形,研究了混沌控制在Lü系统中的问题,并将Lü系统转换成一种非线性的一般严格反馈形式,利用自适应Backstepping设计方法,针对Lü系统的三个未知参数,结合Lü系统的特性设计出一种新的自适应控制器,保证闭环系统全局稳定,仿真结果表明了该方法的可行性和有效性.     

Selection of the Optimal Cooling Parameters to the Multi-Cavity Die

This study is subject to the finite element and abd uc tive network method application in the multi-cavity die. In order to select the optimal cooling system parameters to minimize the warp of a die-casting die, t he Taguchi‘s method and the abductive network are used. These methods are appli ed to create an efficient model with functional nodes for the considered problem . Once the cooling system parameters are developed, this network can be used to predict the warp for the die-casting die accurately. A ...     

Grüneisen参数体积相关性的理论研究

根据常用势模型运用关于Grüneisen参数体积相关性的Slater公式、Dugdale-McDonald公式和Vasehenko-Zubarev公式,计算了NaCl在0-30GPa压强范围内的Grüneisen参数,通过计算结果与实验数据的比较与分析,提出了对Grüneisen参数经验值一种新的修正方法,修正后的数据在整个压强范围内与实验值吻合得较好.     

几乎Prüfer整环的反向极限

Prüfer整环是交换环理论中一种重要的环类,它在代数数论、同调代数和乘法理想理论等的研究中起着重要的作用.主要研究了Prüfer整环的一种推广―几乎Prüfer整环的性质,给出了如下2个结果:几乎赋值整环的反向极限是几乎赋值整环;几乎Prüfer整环的反向极限在riding假设的条件下是几乎Prüfer整环.但在一般条件下,给出例子说明几乎Prüfer整环的反向极限未必是几乎Prüfer整环.     

Application and Development of LTCC for RFIC

Introduction In order to realize further progressin highfre-quency wireless communicationtechnology,systemsolution in hardware technology plays the i mpor-tant role of bringing greater higher integration,small form factors and more sophisticated func-tions.To miniaturize the RF module,three tech-nologies are needed:direct conversion one chipRFIC(System-on-Chip,SOC),bare die packagingtechnology and passive embedded substrate[1].Direct conversion one chip ICis needed to re-duce die area and…     

Lubrication effectiveness of composite lubricants during P/M electrostatic die wall lubrication and warm compaction

The lubrication effectiveness of the composite lubricants, 50wt% ethylene bis-stearamide (EBS) wax + 50wt% graphite and 50wt% EBS wax + 50wt% BN, during the powder metallurgy (P/M) electrostatic die wall lubrication and warm compaction was studied. The results show that the combination of 50wt% EBS wax and 50wt% graphite has excellent lubrication performance, resulting in fairly high green densities, but the mixture of 50wt% EBS wax and 50wt% BN has less beneficial effect. In addition, corresponding die temperatures should be applied when different die wall lubricants are used to achieve the highest green densities.     

Application of Rapid Prototyping Technology in Die Making of Diesel Engine

This paper studies engineering applications of rapid prototyping (RP) technology in die making of diesel engine. On demand of product development and die making of, an integrated system of reverse engineering and rapid prototyping (RE/RP) for engineering application is constructed, and effective application of RP technology in die making is thus realized. Taking the casting die for clutch house of diesel engine as an example, this paper studied the engineering application of laminated object manufacturing (LOM) technology in rapid die making and discussed related technologies as parameter setting of temperature and pressure in heat pressing, the matching of laser power and cutting speed of laser, and layout and post treatment of the prototype in RP technology. The casting die manufactured with LOM technology has satisfactory lifetime and is successfully used in 100 rough castings of clutch house for diesel engine. The manufacturing cost for the die is decreased and the production period is shortened.     

Application of mesoscale modeling optimization to development of advanced materials

The rapid development of computer modeling in recent years offers opportunities for materials preparation in a more economic and efficient way. In the present paper, a practicable route for research and development of advanced materials by applying the visual and quantitative modeling technique on the mesoscale is introduced. A 3D simulation model is developed to describe the microstructure evolution during the whole process of deformation, recrystallization and grain growth in a material containing particles. In the light of simulation optimization, the long-term stabilized fine grain structures ideal for high-temperature applications are designed and produced. In addition, the feasibility, reliability and prospects of material development based on mesoscale modeling are discussed.     

Kneser-Süss不等式与等周不等式的关系

证明了Kneser-Süss不等式的一种特殊形式、等周不等式与Minkowski不等式的一种特殊形式3者是等价的.进一步地,还将Kneser-Süss不等式推广为Lp-Kneser-Süss不等式.     

A Framework to Support Agility Strategy Formulation

In the last decade, turbulent times and uncertainti es in the business environment have made ground for a new business era, and “chang e“ has become a major characteristic of the new era. This has resulted in tirele ss evolution of business systems and the creation of new manufacturing and manag ement philosophies. Agile Manufacturing (AM) is a step forward in generation of new means for better performance and success of business, and in practice is a s trategic approach to manufacturing by considering ...     

Damage prediction of 7025 aluminum alloy during equal-channel angular pressing

Equal-channel angular pressing (ECAP) is a prominent technique that imposes severe plastic deformation into materials to enhance their mechanical properties. In this research, experimental and numerical approaches were utilized to investigate the mechanical properties, strain behavior, and damage prediction of ECAPed 7025 aluminum alloy in various conditions, such as die channel angle, outer corner angle, and friction coefficient. Experimental results indicate that, after the first pass, the yield strength, ultimate tensile strength, and hardness magnitude are improved by approximately 95%, 28%, and 48.5%, respectively, compared with the annealed state, mainly due to grain refinement during the deformation. Finite element analysis shows that the influence of die channel angle is more important than that of outer corner angle or friction coefficient on both the strain behavior and the damage prediction. Also, surface cracks are the main cause of damage during the ECAP process for every die channel angle except for 90°; however, the cracks initiated from the neighborhood of the central regions are the possible cause of damage in the ECAPed sample with the die channel angle of 90°.     

超混沌 Lü系统的反同步研究

针对超混沌 Lü系统,解析地设计了非线性控制器,基于线性系统稳定性定理,实现了超混沌 Lü系统的反同步和异结构反同步,给出了理论分析和数值模拟结果.结果表明所设计的非线性控制器能够有效地使两系统达到反同步.