Relationship Among Reserve Ratio, Government Spending and Economic Growth

The relationship among reserve ration, government spending and economic growth was analyzed. A monetary endogenous growth model is well developed by taking into account the growth-enhancing effects of reserve-augmenting seigniorage. If the government spends all the seigniorage revenue on the provision of a public input which has positive externality on the private sector‘s production, some results to be utterly different from Bronx‘s have been obtained: the economy has a unique saddle-balanced growth path, but it has nothing to do with reserve ratio. However, the higher reserve ratio, the faster speed of economic convergence.     

氮化硅晶须的研究现状

介绍了晶须的生长机理、氮化硅晶须的制备方法以及影响其生长的因素。阐述了氮化硅晶须增强复合材料的现状,指出加强晶须的基础研究,改进制备技术和降低成本是今后的发展方向。     

Model of Precipitation Kinetics Induced by Strain for Microalloyed Steels

In microalloyed steels, static recrystallisation is temporarily inhibited by precipitation which is occurring at the same time. A high number of microalloyed steels containing various combinations of carbon, nitrogen and precipitate forming elements like V, Nb and Ti were recrystallised at different temperatures and strain rates. From these results recrystallisation‐precipitation–time‐temperature (RPTT) diagrams were established. The influence of grain size and strain rate on the RPTT diagrams was studied. The precipitation kinetics were mathematically described for isothermal conditions and converted to cooling conditions, which enables an application to hot rolling. Under cooling conditions, completion of recrystallisation is prevented, especially for Nb alloyed steels.     

Multivariate Modeling of Age and Retest in Longitudinal Studies of Cognitive Abilities.

Longitudinal multivariate mixed models were used to examine the correlates of change between memory and processing speed and the contribution of age and retest to such change correlates. Various age- and occasion-mixed models were fitted to 2 longitudinal data sets of adult individuals (N > 1,200). For both data sets, the results indicated that the correlation between the age slopes of memory and processing speed decreased when retest effects were included in the model. If retest effects existed in the data but were not modeled, the correlation between the age slopes was positively biased. The authors suggest that although the changes in memory and processing speed may be correlated over time, age alone does not capture such a covariation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

燃烧合成TiB2-Cu-Ni金属陶瓷二次热压行为研究

采用燃烧合成技术制备了相对密度为90％左右的TiB2—40Cu-8Ni金属陶瓷复合材料。为进一步提高复合材料的力学性能，首先研究了TiB2—40Cu金属一陶瓷高温压缩弹塑性变形行为，证明了高陶瓷体积分数下金属陶瓷在高温环境中具有一定的塑性行为；然后分别在1200℃、1250℃、1300℃温度下对复合材料进行二次热压，详细研究了TiB2—40Cu-8Ni复合材料液一固两相区间的变形行为、组织特征及力学性能的变化。结果表明：经过二次热压后，材料的相对密度和抗弯强度有了较大幅度的提高，在1300℃时，材料的相对密度提高了5％，抗弯强度达到608MPa。复合材料中TiB2颗粒的形貌也发生了改变，大部分由原来的等轴状转变为长棒状，同时根据TiB2晶体结构特征，分析了复合材料中TiB2的生长机制。     

Time derivative equations for mode I fatigue crack growth in metals

Predicting fatigue crack growth in metals remains a difficult task since the available models based on the Paris law are cycle-derivative equations (da/dN), while service loads are often far from being cyclic. This imposes a cycle-reconstruction of the load sequence, which significantly modifies the load history in the signal. The main objective of this paper is therefore to propose a set of time-derivative equations for fatigue crack growth in order to avoid any cycle reconstruction. The model is based on the thermodynamics of dissipative processes. Its main originality lies in the introduction of a supplementary state variable for the crack, which allows describing continuously the state of the crack throughout any complex load sequence. The state of the crack is considered to be fully characterized at the global scale by its length a, its plastic blunting ρ, and its elastic opening. In the equations, special attention is paid to the elastic energy stored inside the crack tip plastic zone, since, in practice, residual stresses at the crack tip are known to considerably influence fatigue crack growth. The model consists finally in two laws: a crack propagation law, which is a relationship between dρ/dt and da/dt and which observes the inequality stemming from the inequality of Clausius Duhem, and an elastic–plastic constitutive behaviour for the cracked structure, which provides dρ/dt versus load and which stems from the energy balance equation. The model was implemented and tested. It successfully reproduces the main features of fatigue crack growth as reported in the literature, such as the Paris law, the stress ratio effect, and the overload retardation effect.     

镧热还原氧化钐过程动力学控速环节的探索

讨论了镧热还原氧化钐过程的一般动力学过程，探讨了在制备金属钐温度下的动力学控速环节，分析了影响控速环节的因素，通过镧渣分析和配料优化实验，找出了提高反应速度的方法。     

压电式传感器测定蛋白质吸附动力学参数

利用液隔电极型压电式传感器实时监测牛血清白蛋白(BSA)在石英表面吸附过程。基于所提出的吸附动力学模型,估算出BSA在石英表面的吸附速率常数为ka=1.27×103mol-1·L·s-1,脱附速率常数为kd=1.31×10-3s-1,由可逆吸附态向不可逆吸附态的转化速率常数为kf=3.46×10-4s-1。     

我国经济增长对外商直接投资影响的实证分析

我国自2002年加入WTO以来，很快就成为了全球利用外资最多的国家，面对这种情况，开展对外商直接投资(FDI)问题的研究已成为当前经济研究领域的重要课题。这里运用实证分析的方法，对我国经济增长的各相关指标进行分析，进而研究探讨外商的投资行为，以从中了解、把握国民经济持续、快速增长对影响外商直接投资的基本规律，为合理预测FDI的发展趋势和规模提供有效的指导意义。     

Managing empowerment and control in an intranet environment

Abstract. An intranet increases in sophistication and complexity as it evolves. This evolution leads to an increasing need for control over the intranet. However, this is a contentious issue, as an intranet is deemed to be an empowering technology. Consequently, intranet control systems must balance empowerment and control so as not to negate each other. This paper investigates intranet control activities and their effect on users' perceptions of empowerment throughout the evolution of an intranet in Hewlett Packard (Ireland). The growth of the intranet is charted as a six-stage model that illustrates an evolution of purpose, control and empowerment. The control strategies for managing the intranet implemented at each stage are investigated, and their resultant effects on empowerment are evaluated. The study reveals the importance of balancing control strategies with empowerment initiatives in managing intranet environments. Based on the evidence available, the study recommends the implementation of specific controls at particular stages in the evolution of an intranet in order to achieve control systems that balance empowerment and control.