外界条件对冬虫夏草胞外多糖构象的影响

以人工培养冬虫夏草菌丝发酵液中分离纯化的胞外多糖EPS-1A为原料,利用紫外光谱和圆二色谱研究不同外界条件如处理温度、金属离子(Ca2+)、变性剂(尿素)及化学修饰剂(刚果红)对胞外多糖EPS-1A构象的影响。结果表明：刚果红反应揭示胞外多糖EPS-1A为无规线团链构象;外界条件均不能改变胞外多糖EPS-1A在溶液中的无规线团链构象,只是在不同程度上影响多糖分子的分子内和分子间氢键相互作用,使多糖变得松散、无序。     

开关功率变换器中的间歇现象 ——仿真与实验

 文章从电路耦合滤波的角度考虑,分析了一类间歇分谐波与间歇混沌现象产生的原理,确定耦合电路传导和辐射干扰是产生该现象的根源,并构造了一个开关变换器模型作为研究对象,仿真与实验均得到了相似的非线性现象,同时对不同的电路参数集,讨论并分析了其对间歇现象产生所起的不同影响,为变换器的稳定设计提供信息.该研究方法也可推广到其他非线性电路系统的类似研究中.     

A generalized counter scheme

The transposition heuristic is a common method used to improve the performance of accessing records in a linked list. After the list has reached a steady state for the transposition heuristic, we begin to keep a frequency count for each record. A method of re-arranging the records, called the generalized counter scheme, is introduced and is shown to be optimal among all possible methods of re-arrangement based on the counts. The scheme is applicable even when the count is small.The usual counter scheme is also shown to be optimal for any finite count.     

F-P半导体激光器中的串扰现象

研究应用F-P半导体激光器的两个模式时,在不同输入功率和失谐波长下的各种串扰现象.发现对已实现注入锁定的模式,注入功率越大,串扰现象越小;失谐波长越大,串扰现象越小.     

心理授权与情绪智力对科研人员创新绩效的影响

目的探讨情绪智力与心理授权对科研人员创新绩效的影响机制。方法采用情绪智力、心理授权以及科研人员创新问卷,在科研团队中收集了128个团队中的333对上下级配对调查问卷数据。结果多层线性分析的结果表明心理授权对情绪智力与科研人员创新之间的关系具有中介作用。结论情绪智力对心理授权没有显著地正向预测作用;情绪智力可通过心理授权影响科研人员的创新绩效。     

方管内表面等离子体离子注入动力学GPU-PIC仿真

内表面改性近年日益受到人们重视。本文采用基于Graphic Processing Unit(GPU)的Particle-in-cell(PIC)模型对方形管内表面的离子注入动力学过程进行数值仿真研究。结果表明在注入过程中,辅助地电极周围形成离子空穴,随时间延长,离子空穴发生交联并不断扩展,直至所有离子注入到方管内壁。离子空穴的形成和扩展使得在管内部形成离子密度波,密度波的传播速度随时间增加。由于等离子体鞘层的不均匀重叠使得管内的初始鞘层厚度分布不均,其中位于拐角附近的鞘层较厚,从而又导致了方管内壁周向上的注入剂量和能量分布存在不均匀性,内壁平面附近位置的注入剂量和注入能量均相对较大,而拐角附近的离子注入剂量和能量最小。本文采用GPU加速PIC的算法取得了高达90的加速比,极大缩短了等离子体粒子模拟的计算时间。     

PDA-SVM Hybrid: A Unified Model for Kernel-Based Supervised Classification

For most practical supervised learning applications, the training datasets are often linearly nonseparable based on the traditional Euclidean metric. To strive for more effective classification capability, a new and flexible distance metric has to be adopted. There exist a great variety of kernel-based classifiers, each with their own favorable domain of applications. They are all based on a new distance metric induced from a kernel-based inner-product. It is also known that classifier’s effectiveness depends strongly on the distribution of training and testing data. The problem lies in that we just do not know in advance the right models for the observation data and measurement noise. As a result, it is impossible to pinpoint an appropriate model for the best tradeoff between the classifier’s training accuracy and error resilience. The objective of this paper is to develop a versatile classifier endowed with a broad array of parameters to cope with various kinds of real-world data. More specifically, a so-called PDA-SVM Hybrid is proposed as a unified model for kernel-based supervised classification. This paper looks into the interesting relationship between existing classifiers (such as KDA, PDA, and SVM) and explains why they are special cases of the unified model. It further explores the effects of key parameters on various aspects of error analysis. Finally, simulations were conducted on UCI and biological data and their performance compared.     

计算圆环天线的麦克斯韦电路理论

本文以麦克斯韦电路理论为基础对圆环天线加以分析,得到圆环天线的表面电流分布.经比对发现本文计算结果与矩量法计算结果一致,证明了本文方法的有效性和正确性.通过对圆环天线二阶MC方程的深入研究,得到了圆环天线表面电流的解析表达式,该式适于计算任意大小圆环天线的表面电流分布.本文成果对求解复杂电磁结构问题具有一定参考意义.     

混合动力车用VRLA蓄电池负极的失效机理及碳添加剂的作用（1）

综述了常规阀控式铅酸蓄电池在混合动力车应用中,硫酸铅不断积累的特点及产生的机理。结合失效机理,论述了各类碳材料加入负极后,对蓄电池性能改善作用方面的新研发进展。不同种类的碳添加剂对抑制硫酸盐积累具有各自不同的作用,其复合添加剂的协同效应更能有效抑制负极硫酸铅的不断积累和延长蓄电池循环寿命,是更有前途的添加剂。