复变量双曲余弦平方-高斯光束的双焦开关

推导了复变量双曲余弦平方-高斯光束(EchSGB)通过无光阑透镜系统后的轴上光强分布公式,在此基础上通过大量的数值分析发现,在菲涅耳数较小的情形下,当光束参数a<0.91且b>1时,轴上焦点出现两次位置不同的跃变一双焦开关(DFS)现象,讨论了光束入射距离及光束参数对其产生和变化的影响.最后对该光束的特例-余弦平方高斯光束的DFS现象作了一些分析讨论.     

张开关切的眼,涵养悲悯的心:高考作文高分策略(十)

高考原题再现2007年上海高考作文题(70分)以"必须跨过这道坎"为题目,写一篇文章。要求:(1)不少于800字。(2)不要写成诗歌。(3)不得透露个人相关信息。阅卷老师精点牛玉凯(07高考阅卷老师)阅卷中我们发现许多考生习惯堆积材料,刻意修饰语言,看得出来,他们平常单纯注重     

In-package P/G planes analysis and optimization based on transmission matrix method

Power integrity （PI） has become a limiting factor for the chip＇s overall performance, and how to place in-package decoupling capacitors to improve a chip＇s PI performance has become a hot issue. In this paper, we propose an improved transmission matrix method （TMM） for fast decoupling capacitance allocation. An irregular grid partition mechanism is proposed, which helps speed up the impedance computation and complies better with the irregular power/ground （P/G） plane or planes with many vias and decoupling capacitors. Furthermore, we also ameliorate the computation procedure of the impedance matrix whenever decoupling capacitors are inserted or removed at specific ports. With the fast computation of impedance change, in-package decoupling capacitor allocation is done with an efficient change based method in the frequency domain. Experimental results show that our approach can gain about 5× speedup compared with a general TMM, and is efficient in restraining the noise on the P/G plane.     

Zero-voltage switching converter absorbing parasitic parameters for super high frequency induction heating

This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.     

浅谈建筑施工供电的安全技术措施

建筑施工中,供电安全是各项安全控制因素中的重点.从接地保护系统、配电箱开关箱、配电线路和用电设备等几个方面分析讨论了的建筑施工供电的安全技术措施.强调安全措施的落实,可以有效避免施工用电安全事故的发生,节约成本,提高效益.     

基于稀疏约束的离焦图像多尺度去模糊方法

由于传统方法没有充分考虑加性噪声对图像处理效果的影响,导致去模糊处理后图像易丢失细节信息,峰值信噪比较小以及图像清晰度较差的问题.为此提出基于稀疏约束的离焦图像多尺度去模糊方法.通过建立观测模型,判断图像斑点位置,消除离焦图像中因噪声引起的序列斑点,降低加性噪声的影响程度.进而分离离焦图像中的前景聚焦和离焦背景区域,提取出离焦图像的深度图.最后通过稀疏约束获取模糊核,并运用该模糊核实现对离焦图像的去模糊处理.实验结果表明,所提方法在图像细节保留、清晰度提升和峰值信噪比方面均具有优越性,有效提升了图像的感官效果.     

GG-1A柜开关一体化改造

在10kV开关无油化改造工作中应用的ZN28-10型开关由于没有采用相应的操作机构,引起较多故障,故进行了改造。根据对GG-1A柜开关的结构和原理进行分析,萧山供电局采用厦门ABB开关有限公司生产的固定安装式VD4型真空开关对重要变电所的大电流开关及电容器开关进行改造。VD4型开关为开关本体与开关操作机构一体化的真空开关,其结构与功能均适合GG-1A柜的改造,且在萧山供电局改造后使用情况良好。     

浅谈开关板式有功功率表、无功功率表的在线检验

文章分析了开关板式有功功率表及无功功率表的在线检验情况.     

对一个装置的探究

我在进行电化学教学时,有同学提出了图1所示装置是属于原电池还是电解池的问题。从电解池的构成要件看属于电解池,那到底是不是电解池呢?我们将同一规格的灯泡 A_1和 A_2,电池、开关和导线,按图2和图3连接好,合上开关,     

基于优化设计的新型锁相环及其虚拟实现

提出一种基于LabVIEW虚拟实现的新型正交锁相环设计.与传统锁相环相比,新型锁相环不仅能够更准确地检测和跟踪输入信号频率及其变化,而且对于失真输入信号,能够精确检测出其基波信号.该系统的性能对波形畸变不敏感,特别适合于外部干扰如开关型暂态信号的情况.实验结果表明检测方法具有很好的实时性和较高的检测精度以及抑制谐波和噪声的能力.