几种异质小麦染色体G-带带型的分析比较

本文采用改良的去壁低渗火焰干燥法和改良的 ASG 法,对中国春小麦及其异质系(卵圆山羊草)中国春、(节节麦)中国春的染色体进行了 G-带带型的比较研究,结果表明:二种异质小麦的染色体 G-带带型与对照相比均无显著差异,从而证明异源细胞质对普通小麦 G-带带型无明显影响.     

四杆同源机构的构成特性和传动角特性

四杆曲线同源机构与原始机构的对应杆长具有比例和对调关系,且同源机构要由反装构形得到,从而揭示出同源机构与原始机构在尺寸型上的内在联系;在大多数的使用情况下,四杆曲线同源机构与原始机构具有相同的传动角.     

浮纹织机针综的智能控制系统

在普通1515A型多梭箱织机上附加浮纹装置（针综开口、暂停、横动、变换机构等）织造浮纹织物,依靠织机中凸轮齿轮花型控制其在地布中运动距离是传统的方法。本文用PLC和交流伺服系统组成绝对位置控制系统来控制针综横向运动的精确距离,智能化控制系统具有手动、自动控制、花样数据设置和修改、掉电保护等人机对话功能。     

继电保护装置自取能电源供电异常分析及改进建议

采用自供电即电流互感器自取能的微机保护装置,在供电系统设计以及装置可靠性上,存在着一定的安全隐患。结合具体事故案例,分析了高压开关柜微机保护装置供电系统存在的问题,根据现场运行情况,通过对比多种供电方案,提出一种外部双电源交流不同源带铅酸蓄电池储能装置的供电方案,并对外部双电源交流不同源带储能电源装置的参数进行了计算,该供电解决方案经在实际装置中应用表明,其运行工况满足设备运行要求。     

异源细胞质对普通小麦花粉育性的影响

本文以中国春小麦细胞核置换到小麦属和山羊草属不同细胞质的同核异质稳定核质杂种为材料,研究了异源细胞质对普通小麦花粉育性及小孢子发育的影响,结果表明;普通小麦中国春的花粉育性不同程度地受到多种异源细胞质的明显影响,其小孢子败育主要发生在四分体时期.     

基于并联负载发夹型谐振器的四阶带通滤波器

针对现代无线通信系统中平坦带通滤波器的需求,提出了一种并联负载的发夹型谐振器,并利用提出的谐振器构建了四阶平坦带通滤波器。首先,通过在发夹型谐振器磁场最强的位置（中心位置）设置电阻,设计了一种新的并联型谐振器,从而可以通过改变电阻值来灵活地调整固有品质因数;其次,采用具有高、低固有品质因数的耦合拓扑来构建四阶平坦带通滤波器。最后,在印刷电路板上制备了一个具有传输零点和平坦带通的四阶带通滤波器。实验结果表明,该四阶带通滤波器的实测结果与仿真结果吻合较好,与其他多阶带通滤波器相比,该四阶带通滤波器具有可灵活控制的固有品质因数和小于0.2dB通带平坦度。     

阻力型水平轴水轮机水动力及尾流特性分析

水轮机是水能利用与水力发电的核心技术装备。传统的升力型水平轴水轮机需满足一定流速条件才可获得既定的效率,因此该型水轮机并不适用于流速较低的区域。为了拓展水平轴水轮机的适用范围,依据阿基米德螺旋线原理,设计了两种具有不同旋叶倾角的新型阻力型水平轴水轮机,并采用计算流体力学方法对二者的水动力及尾流特性进行了三维数值模拟研究。结果表明,变角水轮机在尖速比为0.5～2.0的范围内具有更高的功率系数,且其峰值功率系数相比定角水轮机提升了16%。此外,与一些文献中所报道的升力型水轮机在尖速比为0.5～2.0的范围内相比,变角水轮机也具有较高的功率系数。以尖速比为1.5为例,其功率系数相比至少提升了60%以上。与此同时,变角水轮机在全尖速比范围内具有更低的推力系数,但其性能波动比定角水轮机要明显。流场分析显示,两种阻力型水平轴水轮机的后方均出现了呈环状螺旋形的叶尖涡带和呈条状的毂涡带,而变角水轮机的叶尖涡带和毂涡带的连续性更强,向下游发展的轨迹也更长。此外,变角水轮机的尾流恢复比定角水轮机更快。研究结果揭示了阻力型水平轴水轮机的水动力及尾流特性,为其优化设计和推广应用提供了一定的参考依据。     

先进沸水堆(ABWR)的特性与可用性

本文介绍了先进沸水堆ABWR的结构、安全性、经济性,与常规沸水堆相比和与压水堆相比所具有的优点。ABWR是世界上20世纪末和21世纪的先进核电厂堆型,与世界上我国现行核电厂相比具有明显优点。本文也介绍了ABWR的现状和在中国采用的可行性,可作为我国选择核电厂堆型的参考。     

眼动技术在连弧纹铭带镜设计因子提取中的应用

通过使用眼动仪对连弧纹铭带镜中的设计因子进行提取,达到优化新文创时代下文创产品设计开发的目的 .运用眼动实验分析20名被试观看连弧纹铭带镜的视觉热区,依据实验数据对被试在连弧纹铭带镜中的兴趣区域进行划分.结合层次分析法确定被试主要兴趣区域,采用归纳与演绎对其中的显性设计因子和隐形设计因子进行提取.将提取的设计因子应用于...     

带阻三极管及其应用

带阻三极管是三极管的一种派生型,其结构是将三极管芯和限流电阻做在一起,同封在一个外壳内。应用带阻三极管不仅可减少电路上的元件和焊点,给电路设计、制造及检修带来方便,而且由于具有较大的输入阻抗和低噪音性能,还可以提高产品质量。带阻三极管在录像机和高品质彩电中应用较多,     

Optimal allocation for electric vehicle charging stations using Trip Success Ratio

This paper proposes a new model for optimally allocating Plug–in Electric Vehicle (PEV) Charging Stations (CSs) in the network. The model considers Trip Success Ratio (TSR) in order to enhance CS accessibility for PEV drivers. Diversity of usage and different driving habits are considered in the presented model, as well as different trip types (In-city, Highway). The allocation model has two stages: modeling TSR to estimate Charging Station Service Range (CSSR), and the CS allocation stage. In the first stage, the service range of charging stations has been estimated using TSR with consideration of the uncertainty of trip distances (In-city, Highway) and the uncertainty in the Remaining Electric Range (RER) of PEVs. The estimated CSSR is utilized in the CS allocation stage in order to optimize the CS location set that covers the network with a certain guaranteed TSR level. The allocation problem has been formulated as the Maximum Covering Location Problem (MCLP) in order to make the optimal decision for allocating CSs in the network.     

Optimal Power System Stabilizers design via Cuckoo Search algorithm

Cuckoo Search (CS) algorithm is introduced in this paper for optimal Power System Stabilizers (PSSs) design in a multimachine power system. The PSSs parameter tuning problem is formulated as an optimization problem which is solved by CS Algorithm. An eigenvalues based objective function involving the damping ratio, and the damping factor of the lightly damped electromechanical modes is considered for the PSSs design problem. The performance of the proposed CS based PSSs (CSPSS) has been compared with Genetic Algorithm (GA) based PSSs (GAPSS) and the Conventional PSSs (CPSS) under different operating conditions and disturbances. The results of the developed CSPSS are verified through time domain analysis, eigenvalues and performance indices. Also, the effectiveness of the proposed algorithm in providing good damping characteristics is confirmed.     

DC/DC模块有源均流技术研究

在电力电子系统集成研究中，利用标准模块集成电力电子应用系统的过程中，必然设计到标准模块的级联和并联运行。该文主要研究标准模块的并联运行技术。如何平均分配负载电流是并联技术的一个重要方面。在中等功率场合，有源均流法被广泛采用。该文从均流的内在原理出发，对各种均流方法进行了系统的总结和分类，总结了18种可能的有源均流方法。并对18种有源均流方法进行了系统的仿真研究。通过仿真分析，得到8种实用的均流方法，并对这8种方法的优缺点进行了讨论。从中功率系统集成的角度出发，对方案进行了优选，在通用场合，外环调节的均流控制方法是较好的选择。     

A novel approach based on cuckoo search for DG allocation in distribution network

This paper presents a novel approach based on cuckoo search (CS) which is applied for optimal distributed generation (DG) allocation to improve voltage profile and reduce power loss of the distribution network. The voltage profile which is the main criterion for power quality improvement is indicated by two indices: voltage deviations from the target value which must be minimized and voltage variations from the initial network without DG which must be maximized. The CS was inspired by the obligate brood parasitism of some cuckoo species by putting their eggs in the nests of other species. Some host birds can engage direct contest with the infringing cuckoos. For example, if a host bird detects the eggs are not their own, it will either throw these alien eggs away. The CS has been compared with other evolutionary algorithms such as genetic algorithm (GA) and particle swarm optimization (PSO) and different cases have been investigated for indicating the applicability of the proposed algorithm. The results indicate the better performance of CS compared with other methods due to the fewer parameters which must be well-tuned in this method. In addition, in this method the convergence rate is not sensitive to the parameters used, so the fine adjustment is not needed for any given problems.     

Deterrents to women taking computer science courses

The United States faces a shortage of computer scientists. Despite the current economic downturn, the most recent estimate indicates a labor force shortage of IT professionals. The shortage of IT professionals, and especially of computer scientists, provides impetus for increasing the representation of women in computer science (CS). We examine why so few students, and particularly few women, choose to enter the beginning phase of the CS pipeline by choosing to try out CS courses. Women are seriously under-represented at this early juncture of the CS pipeline. If we are serious about making CS a more inclusive field, we need to make an impact at this early juncture. This is not to belittle the laudable efforts to reduce attrition among women CS majors. However, for maximum effect, interventions to increase the flow of women into the CS pipeline also need to occur before women declare their major.     

山西阳光发电有限责任公司1号、2号机组CS275总线系统剖析

分析了西门子 TELEPERM- ME系统 CS2 75总线系统的结构和工作原理 ,并就该系统在山西阳光发电有限责任公司 1号、2号机组的应用情况进行分析评论。针对目前系统存在的问题或不足提出了部分解决方案     

采用 sEMG 的手势识别用 APSO/ CS-SVM 方法

针对基于参数寻优的支持向量机(SVM)方法存在早熟收敛、全局寻优能力差、局部寻优精度低等问题,提出一种自适应粒子群/布谷鸟(APSO/CS)参数寻优方法,旨在实现SVM模型中核函数参数、惩罚因子的优化。测试函数分别对APSO/CS、APSO、CS的参数寻优性能进行了对比分析,表明APSO/CS寻优能够加快局部和全局寻优的收敛速度。采用表面肌电信号(sEMG)对APSO/CS、APSO、CS寻优的SVM方法进行了手势识别对比测试,实验测试结果表明,采用APSO/CS寻优的SVM方法进行手势识别时正确率最高,最高正确率可达94.50%,该方法可为识别分类算法提供一种新思路。     

Compressive image acquisition in modern CMOS IC design

Compressive sampling (CS) offers bandwidth, power, and memory size reduction compared to conventional (Nyquist) sampling. These are very attractive features for the design of modern complementary metal‐oxide semiconductor (CMOS) image sensors, cameras, and camera systems. However, very few integrated circuit (IC) designs based on CS exist because of the missing link between the well‐established CS theory on one side, and the practical aspects/effects related to physical IC design on the other side. This paper focuses on the application of compressed image acquisition in CMOS image sensor integrated circuit design. A new CS scheme is proposed, which is suited for hardware implementation in CMOS IC design. All the main physical non‐idealities are explained and carefully modeled. Their influences on the acquired image quality are analyzed in the general case and quantified for the case of the proposed CS scheme. The presented methodology can also be used for different CS schemes and as a general guideline in future CS based CMOS image sensor designs. Copyright © 2013 John Wiley & Sons, Ltd.     

300 Mvar大型同步调相机的启动及继电保护

随着直流输电、新能源、大电网、特高压等技术的发展,同步调相机重新得到关注,300 Mvar大型同步调相机即将使用。综述了我国调相机的以往应用状况及大型同步调相机的需求背景,介绍大型调相机的静止变频SFC启动方式。重点分析几种特殊的调相机保护功能及原理。首次提出了300 Mvar调相机的继电保护功能配置方案、原理及实现等。