Polypyrrole Shell@3D‐Ni Metal Core Structured Electrodes for High‐Performance Supercapacitors

Three‐dimensional (3D) nanometal films serving as current collectors have attracted much interest recently owing to their promising application in high‐performance supercapacitors. In the process of the electrochemical reaction, the 3D structure can provide a short diffusion path for fast ion transport, and the highly conductive nanometal may serve as a backbone for facile electron transfer. In this work, a novel polypyrrole (PPy) shell@3D‐Ni‐core composite is developed to enhance the electrochemical performance of conventional PPy. With the introduction of a Ni metal core, the as‐prepared material exhibits a high specific capacitance (726 F g^?1 at a charge/discharge rate of 1 A g^?1), good rate capability (a decay of 33 % in C_sp with charge/discharge rates increasing from 1 to 20 A g^?1), and high cycle stability (only a small decrease of 4.2 % in C_sp after 1000 cycles at a scan rate of 100 mV s^?1). Furthermore, an aqueous symmetric supercapacitor device is fabricated by using the as‐prepared composite as electrodes; the device demonstrates a high energy density (≈21.2 Wh kg^?1) and superior long‐term cycle ability (only 4.4 % and 18.6 % loss in C_sp after 2000 and 5000 cycles, respectively).     

锂离子电池用聚合物电解质的最新进展II.含液聚合物电解质

由于干态聚合物电解质目前还不能满足聚合物锂离子电池的应用要求,人们致力于开发含液体增塑剂的聚合物电解质,包括凝胶型和微孔型两类体系。本文综述了含液聚合物电解质的最新进展,重点论述了各种新体系和新方法。     

CPLD在雷达伺服轴角编码电路中的应用

介绍一种针对正、余弦旋转变压器—数字转换器(RDC)模块，用复杂可编程逻辑器件(CPLD)技术实现伺服轴角编码电路设计的方案。分析了轴角编码器系统中14XSZ系列旋转变压器—数字转换器的原理、轴角粗精组合原理及轴角纠错原理。详细介绍了CPLD的内部功能电路、CPLD轴角粗精组合和纠错实现电路，以及CPLD的工作时序图。提出了利用CPLD实现轴角粗精组合处理的方案，并通过了实际系统运行的考验，证明该方案可行。     

X波段及DBS接收用PHEMT单片低噪声放大器

报道了X波段及DBS接收用单片低噪声放大器的研制结果。利用CAD软件对单片电路进行优化设计，设计工作包括MBE材料、PHEMT器件和单片电路三部分。在研制过程中，开展了关键工艺的专题研究。研究结果为：单级单片放大器在10：5－11．6GHz范围内，NF≤1．82dB，G≥7.72dB；在11．7－12．2GHz范围内，NF≤1．80dB，G≥6．8dB；双级放大器在10．4－11．1GHz范围内，NF≤1．96dB，G≥15．3dB，最低噪声系数为1．63dB，最高增益为16．07dB。     

NOESY技术在地胆草倍半萜内酯化合物结构鉴定中的应用（I）

明确从地胆草中分离得到的两对牦牛儿内酯型的立体异构体即地胆草种内酯（scabertopin）、异地胆草种内酯（isoscabertopin）、异去氧地胆草内酯（isodeoxyelephantopin）和去氧地胆草内酯（deoxyelephantopin）的C-2相对构型；方法 NOESY技术，并结合这4个化合物的¹H NMR，¹³C NMR，HMQC谱；结果 两对立体异构体的NOESY谱有明显差异；结论 通过分析NOESY谱，找寻H-1相关信息，若发现H-1与H-8，H-9β和14-CH₃有NOE相关，可以判断化合物的C-2为α构型，若H-1与H-5，H-7，H-3α及H-9α之间有NOE相关，则化合物的C-2为β构型.     

Detection of low caloric power of coal by pulse fast-thermal neutron analysis

This paper introduces the analysis method and principle of pulse fast-thermal neutron analysis (PFTNA). A system for the measurement of low caloric power of coal by PFTNA is also presented. The 14 MeV pulse neutron generator and BGO detector and 4096 MCA were applied in this system. A multiple linear regression method applied to the data solved the interferential problem of multiple elements. The error of low caloric power between chemical analysis and experiment was less than 0.4 MJ/kg. This revised version was published online in July 2006 with corrections to the Cover Date.     

大焦深成像系统仿真实验研究

如何增大非相干光学成像系统的焦深是应用光学研究领域的热点问题.本文对采用高次非球面光学掩模板与图像处理相结合增大成像光学系统焦深的新方法进行了深入分析,建立了大焦深成像系统仿真实验模型,并进行了大焦深成像系统仿真实验.实验结果证明了该方法在维持原相对孔径的同时使光学系统在较大的离焦范围内有好的成像质量.实际应用中还要综合考虑模板参量、信噪比等关键因素.     

Novel algorithms for shared segment protection

The major challenges in designing survivable schemes are how to allocate a minimal amount of spare resources (e.g., bandwidth) using fast (e.g., polynomial-time) algorithms, and, in case a failure occurs, to be able to recover quickly from it. All existing approaches invariably make tradeoffs. We propose novel shared segment protection algorithms which make little or no compromise . We develop an elegant integer linear programming (ILP) model to determine an optimal set of segments to protect a given active path. Although the ILP approach is useful for a medium-size network, it is too time consuming for large networks. Accordingly, we also design a fast heuristic algorithm based on dynamic programming to obtain a near-optimal set of segments. Although the heuristic algorithm has a polynomial time complexity, it can achieve a bandwidth efficiency as high as some best-performing shared path protection schemes and, at the same time, much faster recovery than these shared path protection schemes. The proposed scheme is also applicable to a wide range of networking technologies, including Internet Protocol and wavelength-division multiplexing networks under the generalized multiprotocol label switched framework.     

Achieving fast and bandwidth-efficient shared-path protection

Dynamic provisioning of restorable bandwidth guaranteed paths is a challenge in the design of broad-band transport networks, especially next-generation optical networks. A common approach is called (failure-independent) path protection, whereby for every mission-critical active path to be established, a link (or node) disjoint backup path (BP) is also established. To optimize network resource utilization, shared path protection should be adopted, which often allows a new BP to share the bandwidth allocated to some existing BPs. However, it usually leads the backup paths to use too many links, with zero cost in term of additional backup bandwidth, along its route. It will violate the restoration time guarantee. In this paper, we propose novel integer linear programming (ILP) formulations by introducing two parameters (/spl epsi/ and /spl mu/) in both the sharing with complete information (SCI) scheme and the distributed partial information management (DPIM) scheme. Our results show that the proposed ILP formulations can not only improve the network resource utilization effectively, but also keep the BPs as short as possible.     

荧光光谱法研究蛋白质构象的电磁-温度协同效应

长期以来电磁生物效应受到人们普遍关注，近年来从各个角度进行了相关研究。电磁－温度协同效应是当前的热点。本研究通过电磁场及温度协同对蛋白质影响的研究，发现蛋白质在电磁场作用下的不可逆变性，而且这种变性也遵循Arrhenius规律，并进一步得出电磁－温度协同作用的蛋白质变性模型。本文从分子反应动力学的角度解释了电磁－温度协同效应，并对非热效应作了一定的探讨。