中国股票市场风险的实证分析研究

本文从实证角度说明了上证指数和深证成份指数存在着GARCH现象 ,并建立了沪、深两市股指波动率的IGARCH(1,1) M模型与EGARCH(1,1) M模型。将估计的IGARCH(1,1) M模型与EGARCH(1,1) M模型比较得出 ,对上证指数的波动率 ,IGARCH(1,1) M模型与EGARCH(1,1) M模型的模拟效果基本相同 ,而对深证成份指数的波动率 ,IGARCH M模型要略优于EGARCH M模型。同时还对两市的股指收益的波动率进行了预测分析     

Characterization of charge trapping in submicrometer NMOSFET's bygate capacitance measurements

Trapping of net positive charge at low gate stress voltage, and of net negative charge at high gate stress voltage, is observed through changes in the gate-to-drain capacitance of the stressed junction. These observations can be explained in terms of electron trapping, hole trapping, and generation of acceptor-like interface states located in the upper half of the bandgap. Channel shortening is also observed and found to exhibit a logarithmic time dependence     

Discovery of a new long-lived isomeric state in 125Ce

A new long-lived isomeric state in the near proton dripline nucleus ¹²⁵Ce has been identified with Schottky mass spectrometry at GSI. The excitation energy E ^* = 103(12)keV and the decay time of 193(1)s have been obtained from a single stored fully ionized ^125m Ce⁵⁸⁺ ion. The data implies an E3 transition and a 1/2⁺ assignment for the spin of the isomer.     

微机传真系统

本文介绍了集传真技术、通信技术、微型计算机技术于一体的微机传真系统，提出了微机传真系统在硬件接口及报表识别上的实现方法。     

T_C≥400°C高温PTC陶瓷的研制

利用国产原料，采用传统的陶瓷材料制备工艺，研制了居里温度ＴＣ≥４００°Ｃ的高温ＰＴＣ陶瓷，制成了居里温度ＴＣ＝４１２°Ｃ，电阻Ｒ≤１０３Ω，ｌｇ（Ｒｍａｘ／Ｒｍｉｎ）＝４的高性能ＰＴＣ热敏陶瓷材料     

Urban radiowave propagation: a 3-D path-integral wave analysis

A discussion concerning the need for three-dimensional (3-D) urban radiowave propagation models is presented and followed by a review of previously published work on this topic using the asymptotic path-integral technique. The limitations and advantages of this technique are explained and it is applied to study diffraction by a small number of canonical geometries. The validity of this technique is verified by comparison with controlled laboratory measurements taken at millimetric wave frequencies. Finally, its ability to classify field components according to their distribution in space is employed in order to analyze the observed field strength distributions in the model environments     

Interfacial effects on stress distribution in model composites

Raman mechanical spectroscopy was used to examine interfacial effects on the stress distribution in model polydiacetylene fiber/epoxy composites. Epoxy release agents were coated on fiber surfaces to modify the interfacial adhesion properties. The modified fiber surfaces were then characterized by scanning electron microscopy and x-ray photoelectron spectroscopy as well as optical microscopy. No difference in the maximum stress value or stress distribution was observed for the two types of fibers, coated or uncoated, used in composites. This suggests that adhesion properties at the composite interface do not affect tensile stress transfer efficiency nor, therefore, the composite tensile modulus along the fiber axis direction in uniaxial composites. Experimental data were also compared with theoretical calculations assuming perfect bonding between fiber and matrix, and idealized frictional force transfer mechanism at the fiber–matrix interface.     

关于生物系统超微弱发光的实验研究

生物系统存在超微弱光子辐射现象。通过一系列实验研究,我们认为,这种光子辐射既有低水平化学发光的性质,又有受激辐射的性质,是受激的低水平化学发光。     

砷化镓声电荷转移延迟线的设计与工艺研究

由于声电荷转移(ACT)这一新颖的高速缓冲抽样技术的发明,使得新一代高速高频信号处理器件的实现成为可能。本文研究了第二代平面结构的ACT器件转移沟道的电位分布特性,给出了平面结构ACT延迟线的设计,并研究了ACT器件的工艺实现。