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101.
Polymer characterization has largely helped in the development of thermal analyzers and calorimeters, based mainly on the thermocouple technology, or more recently the semiconductor technology. With the use of an integrated silicon thermopile as a detector, a new thermal technique is appearing, to give more possibilities of investigations in the field of polymeric materials. Combining high sensitivity and use of small amount of sample, the originality of the new design comes from its low power consumption, giving rise to a portable version of the instrument. With such a concept, the thermal analysis technique is carried on the industrial site, to perform online measurements.Melting and crystallization, glass transition, control of reticulation are a promising field of applications for the characterization of polymeric materials on industrial sites.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
102.
103.
Shan‐Ci Chen Qingdong Zheng Qikai Zhang Dongdong Cai Jinyun Wang Zhigang Yin Changquan Tang 《Journal of polymer science. Part A, Polymer chemistry》2013,51(9):1999-2005
An angular‐shaped naphthalene tetracarboxylic diimide (NDI) was designed and synthesized as a new building block for n‐type conjugated polymers to tune their energy levels. Three n‐type copolymers incorporating this angular‐shaped NDI as the acceptor moiety were obtained by Stille coupling reactions and had number average molecular weights of 18.7–73.0 kDa. All‐polymer bulk‐heterojunction solar cells made from blends of these polymers with poly(3‐hexylthiophene) gave a power conversion efficiency up to 0.32% and exhibited an open‐circuit voltage (Voc) up to 0.94 V due to their relative high‐lying lowest unoccupied molecular orbital energy levels. The high Voc of 0.94 V is higher than that of solar cells based on linear‐shaped NDI‐containing polymers (<0.6 V). The results indicate that the angular‐shaped NDI is a promising building block for constructing nonfullerene polymer acceptors for solar cells with high open‐circuit voltages. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
104.
Constant phase elements (CPEs) with impedance ZCPE=1/(Qsαf) are widely used to explain electrochemical impedance spectroscopy (EIS) data. It has long been known that different circuits can explain EIS data in an equivalent manner because they exhibit identical impedance for all frequencies (two-terminal non-distinguishable (TTND) circuit). Equivalent circuits containing two CPEs are considered here. TTND circuits containing two CPEs become distinguishable, at least theoretically, if the CPE exponents are different. The experimental distinguishability of these circuits is discussed. The 12 transformation formulae between the four circuits containing two CPEs and two resistors are given for CPEs with equal exponents. 相似文献
105.
Dylan F. Williams S. E. Schwarz 《International Journal of Infrared and Millimeter Waves》1986,7(2):183-195
A planar, subharmonically-pumped, hybrid millimeter-wave receiver with integral antenna is described. Coplanar waveguide filters are used to isolate the ports and provide image enhancement. The integral planar antenna has 12 dB gain and is suited for use as a feed. The main lobe is normal to the substrate surface. The receiver is designed for an instantaneous bandwidth of 10 GHz. Experiments at 71 GHz indicate single-sideband mixer conversion loss of 6.5 dB. We believe that this represents the highest level of integration yet demonstrated in this frequency range. 相似文献
106.
光纤CAN总线接口设计 总被引:3,自引:0,他引:3
基于CAN控制器SJAl000提出了光纤CAN(Fiber—CAN)总线网络的设计方案。采用光纤作为传输介质提高电动汽车CAN通信网抗干扰能力。详细分析了双绞线CAN(Wire—CAN)总线的接口协议,设计了基于此协议的Fiber—CAN总线接口电路和相应的接口驱动,以及光纤CAN总线和双绞线CAN总线间转换接口。通过3个节点的Fiber-CAN总线组网,验证了接口协议和接口电路设计的正确性。 相似文献
107.
108.
In this paper we study multivalued martingales in continuous time. First we show that every multivalued martingale in continuous time can be represented as the closure of a sequence of martingale selections. Then we prove two results concerning the cadlag modifications of continuous time multivalued martingales, in Kuratowski-Mosco convergence and in convergence in the Hausdorff metric respectively.
109.
对于一类同时存在扩散耦合和梯度耦合的非线性振子系统, 通过空间傅里叶变换,得到具有不同波矢的各运动模式的相互独立的运动方程. 计算各横截模的Lyapunov指数, 可在耦合参数平面上确定同步混沌的稳定区域. 在稳定区域边界, 一对共轭横截模式失稳,导致同步混沌的Hopf分岔. 对耦合Lorenz振子系统进行了数值模拟,并设计了耦合Lorenz振子系统的电路, 进行耦合振子系统同步混沌Hopf分岔的电路仿真实验. 计算和仿真的结果表明,Hopf分岔的特征频率等于失稳横截模式的振荡频率.
关键词:
耦合非线性振子
同步混沌
横截模式
电路仿真 相似文献
110.
Michal Fećkan 《Applications of Mathematics》1997,42(5):369-393
Ordinary differential inclusions depending on small parameters are considered such that the unperturbed inclusions are ordinary differential equations possessing manifolds of periodic solutions. Sufficient conditions are determined for the persistence of some of these periodic solutions after multivalued perturbations. Applications are given to dry friction problems. 相似文献