X射线脉冲星导航探测器的微通道板甄选

根据应用于X射线脉冲星导航系统的大面阵X射线探测器对微通道板(MCP)性能的要求,研究了甄选微通道板的方法。确定了甄选微通道板的4个关键参量,分别是增益的均匀性、阻抗匹配、暗计数率、增益系数。针对这4个参量设计了相应的测试实验,制定了甄选MCP的流程,并对采用该流程甄选出的MCP进行了幅值和计数率的测试。测试结果显示:采用单通道阳极接收信号时,每一个探测单元的幅值存在的相对误差各不相同,第i个探测单元输出的信号幅值的最大相对误差Δ1i和最小相对误差Δ2i的波动分别为7%~13.5%,3%~6.7%;而采用四通道共享阳极时输出信号的Δ1i为7.8%、Δ2i为3.1%;单通道阳极计数率之和(n=n1+n2+n3+n4)与四通道共享阳极计数率N的相对误差为4.38%,小于预估值10%。上述实验结果表明该甄选方法能够甄选出满足探测器要求的MCP。     

Au线键合中"塌线"问题的研究

目前,在半导体闪存多芯片的金线键合工艺中,为满足堆叠芯片不断增加等结构需要,键合线弧要求更低、更长,制造工艺变得相对更加复杂。针对生产过程中常遇到的塌线问题,通过对金线键合工艺中线弧形成动作的过程分析,以金线弹动现象为线索,探究了生产过程中塌线问题产生的原因,并给出了相应解决方案。经过此研究,长线键合的生产工艺能力得到加强,其成果对新封装产品的研发及基板设计具有有益的参考价值。     

数字电位器MCP41010在止鼾器中的应用

在设计的止鼾器恒流源电路中采用MCP41010数字电位器来改变恒流源对人体的刺激电流,从而可以根据人体对止鼾器刺激电流的适应程度适时改变电流的大小。在此介绍Microchip公司生产的MCP41010数字电位器的工作原理和主要特点,描述MCP41010的指令字格式。采用MCP41010作为恒流源电路的射极电阻,AVR单片机AT90S8535的I／O口与MCP41010相连接,单片机程序模拟MCP41010的SPI总线时序,从而达到改变阻值的目的。实验结果表明,使用MCP41010达到了很好的效果。     

MAMA紫外探测器系统与高增益MCP（三）

介绍了多阳极微道板阵列（ＭＡＭＡ）紫外探测器系统的最新结构与性能，以及高增益ＭＣＰ工作的基本特性，并给出了对各类高增益ＭＣＰ测试的结果。     

一种CAN总线智能节点的设计

介绍基于MCP2510的CAN总线智能节点的硬件和软件设计.     

Chemotaxis of Beneficial Rhizobacteria to Root Exudates: The First Step towards Root–Microbe Rhizosphere Interactions

Chemotaxis, the ability of motile bacteria to direct their movement in gradients of attractants and repellents, plays an important role during the rhizosphere colonization by rhizobacteria. The rhizosphere is a unique niche for plant–microbe interactions. Root exudates are highly complex mixtures of chemoeffectors composed of hundreds of different compounds. Chemotaxis towards root exudates initiates rhizobacteria recruitment and the establishment of bacteria–root interactions. Over the last years, important progress has been made in the identification of root exudate components that play key roles in the colonization process, as well as in the identification of the cognate chemoreceptors. In the first part of this review, we summarized the roles of representative chemoeffectors that induce chemotaxis in typical rhizobacteria and discussed the structure and function of rhizobacterial chemoreceptors. In the second part we reviewed findings on how rhizobacterial chemotaxis and other root–microbe interactions promote the establishment of beneficial rhizobacteria-plant interactions leading to plant growth promotion and protection of plant health. In the last part we identified the existing gaps in the knowledge and discussed future research efforts that are necessary to close them.     

Comparison of the performance of four measure-correlate-predict algorithms

Measure-correlate-predict (MCP) algorithms are used to predict the wind resource at target sites for wind power development. This paper describes some of the MCP approaches found in the literature and then compares the performance of four of them, using a common set of data from a variety of sites (complex terrain, coastal, offshore). The algorithms that are compared include a linear regression model, a model using distributions of ratios of the wind speeds at the two sites, a vector regression method, and a method based on the ratio of the standard deviations of the two data sets. The MCP algorithms are compared using a set of performance metrics that are consistent with the ultimate goals of the MCP process. The six different metrics characterize the estimation of (1) the correct mean wind speed, (2) the correct wind speed distribution, (3) the correct annual energy production at the target site, assuming a sample wind turbine power curve, and (4) the correct wind direction distribution. The results indicate that the method using the ratio of the standard deviations of the two data sets and the model that uses the distribution of ratios of the wind speeds at the two sites work the best. The linear regression model and the vector regression model give biased estimates of a number of the metrics, due to the characteristics of linear regression.     

基于微通道板的电子探测器的性能研究

设计了一个基于微通道板的电子探测器，从实验上详细研究了在一种新的高压分配方式下各个分压对探测效率的影响，其中包括两片微通道板之间所加电压对探测效率的影响。     

The revisit of QoS routing based on non‐linear Lagrange relaxation

The development of efficient quality of service (QoS) routing algorithms in a high‐speed networking or the next generation IP networking environment is a very important and at the same time very difficult task due to the need to provide divergent services with multiple QoS requirements. Recently, a heuristic algorithm H_MCOP, which is based on a non‐linear Lagrange relaxation (NLR) technique, has been proposed to resolve the contradiction between the time complexity and the quality of solution. Even though H_MCOP has demonstrated outstanding capability of finding feasible solutions to the multi‐path constrained (MCP) problem, it has not exploited the full capability that an NLR‐based technique could offer. In this paper, we propose a new NLR‐based heuristic called NLR_MCP, in which the search process is interpreted from a probability's perspective. Simulation results indicate that NLR_MCP can achieve a higher probability of finding feasible solutions than H_MCOP. We also verify that the performance improvement of a MCP heuristic has a tremendous impact on the performance of a higher level heuristic that uses a MCP heuristic as the basic step. Copyright © 2006 John Wiley & Sons, Ltd.     

Enhanced benzene formation on Pt/H-mordenite and Pd/H-mordenite

The distribution of methylcyclopentane (MCP) ring enlargement (RE) products between benzene (Bz) and cyclohexane (CH) provides information on the reaction mechanism. The Bz/CH ratio is in excess of the calculated and experimentally determined equilibrium ratio. This implies that benzene is a primary product; it eliminates the possibility of direct hydride ion transfer to carbenium ions as the prevailing mechanism. The results are consistent with the concept that metal-proton adducts are instrumental in bifunctional catalysis.