基于叠加原理大功率可编程谐波电压源的研制

针对大容量电力电子装置对测试电压谐波源的要求，本文对大功率可编程电压谐波电压源的拓扑结构和控制方法进行了研究，提出一种采用谐波与基波分离控制的实现方法，给出了系统的拓扑结构，分析了系统的控制原理。仿真和实验结果证明，该方法能有效提高系统容量，实现用小的开关器件得到大功率的电压谐波源输出的设想。该电压谐波源可以模拟各种电压质量问题，以该拓扑结构搭建的实验平台能满足大功率的电力设备对测试用电压谐波源的要求。     

基于DDS的8通道同步宽带信号源设计

介绍了一种利用单片机控制技术的8通道同步宽带信号源设计方法,该信号源可用于产生三维空间平面内旋转磁场,以满足多相位复杂生物系统试验和新型生物芯片及传感器的开发.8通道可调相位的高精度频率信号源由DDS芯片AD9959发生.多片DDS芯片同步后,在标准50Ω负载下,经过三级放大实现100Hz~100MHz带宽输出,并通过引入幅值检测和相位同步控制负反馈,实现变负载后信号源稳频、稳幅和恒相位差输出.     

充分考虑河流生态系统保护因素完善水库调度方式

长江流域现行水库调度方式主要分为防洪调度与兴利调度．现行的水库管理制度和调度运行模式，主要是处理、协调防洪和兴利的矛盾以及兴利任务之间的利益。从河流生态系统保护的角度看，现行调度方式主要存在两方面的问题．一是大多数的水库调度方案没有考虑坝下游生态保护和库区水环境保护的要求．二是缺乏对水资源的统一调度与管理。从三峡水库调度运行面临的问题和沱、岷江流域梯级开发及水库调度存在的问题看，完善水库调度方式非常必要，拳文提出基本思路和对策．     

纳米SiC和微米SiC填充聚醚醚酮的磨损机理研究

利用热压法分别以纳米ＳｉＣ和微米ＳｉＣ作为填产制取了两类不同ＳｉＣ填充的聚醚醚酮复合材料，并对它们在干摩擦条件下的摩擦磨损性能进行了研究，同时还用扫描电子显微镜对摩擦表面形貌进行了观察，进而对材料的磨损机理作了分析与讨论。研究结果表明，１０％（ｗｔ）纳米ＳｉＣ作为填料能有效的改善其填充聚醚醚酮的摩擦磨损性能，而相同含量的微米ＳｉＣ作为填为只能使其填充聚醚醚酮的耐磨性能有所改善，但没有减摩效果。微米     

信号侦察中的跳频信号识别方法

为了解决跳频设备已经大量装备而对跳频信号的侦察识别仍然困难的问题,作者提出了两种跳频信号识别方法,包括最大相关处理法和时间相关统计法.在对跳带内的信号进行数字信道化处理后,再经过最大相关处理,时-频图上的跳频信号的分布情况将会变得非常清晰;时间相关统计法是充分利用跳频信号在时间上的断续性和每跳间的连续性来识别跳频信号.经过实验验证,上述两种识别方法的使用,在跳频信号的侦察识别上效果非常明显.     

Chiral mesoporous organosilicas with R-(+)-Binol integrated in the framework

Bifunctionalized chiral mesoporous organosilicas with both R-(+)-Binol and ethylene moieties integrated in the framework was synthesized by co-condensation of 1,2-bis(trimethoxysilyl)ethane (BTME) and (R)-2,2′-dimethoxy-6,6′-di-[(2-trimethoxysilyl)-ethenyl]-1,1′-binaphthyl (R-MMB) in acidic medium using P123 as template for the first time. With the molar fraction of R-MMB increasing from10 to 20% in the initial mixture, the mesostructure of the material changes from a well-ordered 2D hexagonal mesostructure to a worm-like structure. The materials have a pore diameter in the range of 4.8–5.2 nm with BET surface areas varying from 356 to 894 m² g^?1. The results of FT-IR, ¹³C and ²⁹Si solid-state NMR shows the integration of the organic groups in the material though some Si–C bond cleavage was observed during the synthesis. The circular dichroism spectrum of the material dissolved in NaOH confirms that the chirality of R-(+)-Binol in the material remains unchanged compared with the molecular precursor. The hydroxyl groups of the R-(+)-Binol units were liberated by treatment of the material with BBr₃. The resultant materials were used in Ti-promoted asymmetric addition of diethylzinc to benzaldehyde. High catalytic activity (99%) with moderate enantioselectivity (39.7%) was achieved, which also confirms that R-Binol was incorporated in the PMOs successfully.     

采用LED光纤传感器的绝缘子串泄漏电流测量方法

测量绝缘子串的泄漏电流是目前监测输电线路绝缘子串表面污秽状态的主要手段之一,然而由于输电线路环境的复杂性,常常会伴生出大量的电磁干扰,会在泄漏电流的采集源头产生噪声从而导致采集失真。为提高传感器测量绝缘子泄漏电流的抗干扰能力和准确度,采用廉价稳定的光学器件—发光二极管(light emitting diode,LED)设计并制作了1套光纤传感器装置,利用光电转换和光信号的稳定性,以3片XP-160绝缘子串为试验对象,取盐密为0.05～0.2mg/cm2,在同一相对湿度(85%)下,采用逐渐加压法监测绝缘子串的泄漏电流。经试验验证,该光纤电流传感器可以实现选择性测量泄漏电流的正半周波或者负半周波,经过改进使用差分电路后可以实现测量全波泄漏电流,其零休时间<1ms,波形响应时间<0.1ms,测量电流的灵敏度达到40V/A,线性拟合度均>99.94%,频率响应在1～10kHz范围内,可以满足对泄漏电流测量的基本要求。     

微动图和能量的方法在微动研究中的应用

介绍了微动的两种研究方法：微动图和能量的方法。归纳了微动图的组成、分类、作法及其在减轻微动损伤方面的作用。讨论了能量的方法在微动摩擦学研究中的应用，包括微动磨损体积与摩擦过程中释放的总能量的关系及能量分布在解释微动实验现象中的成功运用。最后指出微动摩擦学的研究仍然面临巨大挑战。     

Red AIE Luminogens with Tunable Organelle Specific Anchoring for Live Cell Dynamic Super Resolution Imaging

Lysosomes and mitochondria play an important role in maintaining cell homeostasis. Visualizing the long-term activities of lysosomes and mitochondria on the nanometer scale in live cells is essential for further understanding their functions but remains challenging due to the limitations of existing fluorescent probes, such as aggregation-caused quenching (ACQ) effect, limited signal-to-noise ratio from fluorescence “always on” in the process of targeting organelle and poor photobleaching resistance. Herein, two efficient red-emitting aggregation-induced emission (AIE) luminogens are reported, which showed “off-on” fluorescence characteristic and specific lysosomes as well as mitochondria targeting capability. Owing to their AIE characteristics, a Stokes’ shift larger than 100 nm, good biocompatibility, and excellent photostability, the AIE luminogens have been successfully utilized for high fidelity imaging of lysosomes and mitochondria. By virtue of these two probes, stimulated emission depletion (STED) images of dynamic lysosomal fusion and mitochondrial fission with a high resolution of 65.6 nm are obtained. Furthermore, the interactions between lysosomes and mitochondria in the process of mitophagy are recorded. This study also provides practical guidance for designing specific organelle targeting probes to support live cell dynamic super-resolution imaging.     

锂锰氧化物离子筛及其研究进展

详细介绍了国内外锂锰氧化物离子筛的研究现状和发展前景，重点介绍了目前较为热点的结构理论、作用机理和造粒等问题，对离子筛应用可能存在的溶损问题也提出了自己的见解。