C194铜合金的强化机制研究

为了研究C194铜合金的强化机制，对比分析了两种成分略有不同的C194铜合金带材的力学性能及其微观组织。研究发现C194合金组织中的析出相包括α—Fe和Fe3P两种，其中α—Fe是C194铜合金的主要强化相，而不是Fe3P。如果合金中P含量较高，则多余的P与合金元素Fe结合形成金属间化合物Fe3P，并以粗大颗粒形式析出，这将导致起主要强化作用的α-Fe相数量减少，从而使材料强度降低，同时由于P对合金的导电、导热性能均有显著影响，对材料综合性能不利，因此在生产中应严格控制P的含量，且尽量取下限，抑制Fe3P的形成和析出，促进α-Fe在时效过程的弥散析出，从而达到理想的强化效果。     

基于自适应收缩因子的SAR图像去噪

针对合成孔径雷达 (SAR)图像固有的斑点噪声 ,提出了基于自适应收缩因子的去噪方法 .该方法首先将图像分解至平稳小波域 ,利用与信号相关小波系数的空间及尺度相关性 ,自适应地得到收缩因子 ,修正小波系数 .与基于Mallat分解的阈值去噪及Wiener滤波相比 ,该方法在有效抑制SAR图像噪声的同时 ,较好地保持了图像边缘细节 ,达到了理想的去噪效果     

Total Travel Cost in Stochastic Assignment Models

Deterministic assignment models are sometimes used to approximate properties of more complex stochastic models. One property that is of particular interest from a system optimization viewpoint is total travel cost. This paper looks at the approximation of mean total travel cost. It is shown that deterministic models will underestimate this quantity in many common situations. Furthermore, discrepancies between total travel cost under the different modelling frameworks can lead to situations in which network modifications which are detrimental according to a stochastic model appear beneficial when using the natural deterministic approximation. We conclude that estimation of mean travel cost in stochastic assignment is often best done using simulation. Some suggestions are made regarding the implementation of traffic assignment simulation.     

Enantioselective extraction of terbutaline enantiomers by lipophilic tartaric acid

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电力系统振荡过程中序分量选相元件动作行为分析

对超高压输电线路微机保护所用序分量选相原理和防止振荡时误选相所用的不对称故障开放判据进行了较详细的介绍，对于振荡中心和单相接地故障在同一条长输电线路且两者之间有较远距离的情况，从不对称故障开放判据和阻抗排作法两个方面分析了造成误选相的原因，理论分析和动模试验都证实了这种误选相现象的存在，为以后序分量选相原理的改进提供参考。     

一种有限时段Markov决策过程的强化学习算法

研究有限时段非平稳的Markov决策过程的强化学习算法。通过引入一个人工吸收状态，把有限时段问题变为无限时段问题，从而可利用通常的强化学习方法来求解。在文献[3]提出的算法思想基础上，提出了一种新的有限时段非平稳的Markov决策过程的强化学习算法，并用无完全模型的库存控制问题进行了实验。     

三相单开关零电流Cuk型功率因数校正器的研究

提出了一种新颖的三相Cuk型高功率因数校正电路。在电路拓扑中采用三相全桥整流桥和单管功率开关实现高功率因数和低谐波电流输入；同时在中间储能电容(过渡电容)上串联一电感以及在续流二极管上并联一小电容，使得电路工作在复合谐振状态，从而获得零电流开关。文章分析了电路的工作原理，仿真验证了理论分析结果，同时一个2kW的试验电路验证了结论的正确性。该电路具有输出电压调节范围宽、功率因数和效率高等特点，具有很好的实用化前景。     

高效液相色谱手性固定相研究进展

对近年来高效液相色谱手性固定相的研究进行了综述。重点介绍了手性固定相的分类、拆分机理和应用的新进展。讨论了各类手性固定相优缺点，提出了目前存在的问题、今后的研究方向和重点。     

A new instrument for passive remote sensing: 2. Measurement of leaf and canopy reflectance changes at 531 nm and their relationship with photosynthesis and chlorophyll fluorescence

A previously described passive remote sensing fluorimeter (see companion paper) was modified to detect changes in the reflectance of vegetation. The utility of this remote sensing technique to measure the Physiological Reflectance Index (PRI) is shown at both leaf level under laboratory conditions and at the canopy level in the field. PRI, defined as the relative changes in reflectance at 531 nm with respect to those at 570 nm (PRI=R531−R570/R531+R570), is related to xanthophyll-related, dynamic changes of non-photochemical quenching of chlorophyll fluorescence. The robustness of this relationship by simultaneous remote sensing of PRI and chlorophyll fluorescence is strengthened. At the leaf level, the existence of two kinetically distinct components of PRI is shown. A fast (within seconds) component that is partly attributed to ΔpH induced chloroplast shrinkage, and a slow (within minutes), main component that is related to xanthophyll de-epoxidation, as demonstrated by its disappearance in the presence of DTT. Overall, PRI correlated better with non-photochemical quenching of chlorophyll fluorescence (NPQ) than with any other measured parameter, including the photochemical efficiency of PSII. Finally, at the canopy level and under field conditions, it is shown that PRI can be a useful tool for remote sensing of water stress in grapevines.     

A Statistical Control Chart for Stationary Process Data

In the statistical process control environment, a primary method to deal with autocorrelated data is the use of a residual chart. Although this methodology has the advantage that it can be applied to any autocorrelated data, it needs some modeling effort in practice. In addition, the detection capability of the residual chart is not always great. This article proposes a statistical control chart for stationary process data. It is simple to implement, and no modeling effort is required. Comparisons are made among the proposed chart, the residual chart, and other charts. When the process autocorrelation is not very strong and the mean changes are not large, the new chart performs better than the residual chart and the other charts.