基于独立分量分析的失匹配负波快速提取

失匹配负波(MM N)是一种由刺激变化所诱发的听觉诱发电位成分,其过低的信噪比造成检测和提取比较困难。提出利用独立分量分析(ICA)方法对多导听觉诱发电位信号进行多次分解,根据MM N产生的生理机制及其信号特征,设计合理的独立分量选取原则,提取MM N。该方法通过仿真实验验证,能有效提高信噪比。在真实数据的处理中,仅用传统方法20%左右的实验时间,实现MM N成分波的提取。这将促进MM N在认知神经科学及临床上的应用。     

DMSO对马铃薯块茎圆片的透性、蛋白谱及多核糖体状况的影响

二甲亚砜(DMSO)应用于植物研究,报道较少。有人报道可作为冷冻保护剂;可以使黑麦根尖细胞的有丝分裂指数下降;DMSO与EDTA(二乙胺四乙酸)配合处理玉米植株,可以提高玉米的杂交重组率.本文研究DMSO对马铃薯块茎圆片的细胞透性、可溶性蛋白及多核糖体状况的影响,为DMSO作为一个外源因素和预处理手段,应用于植物组织培养提供实验依据.     

A Fuzzy Stopping Problem with the Concept

Stimulated by Zadeh's paper (Journal of Statistical Planning and Inference,2002, 105, 233--264), we will try to consider a perceptive analysis of the optimal stopping problem. In this paper, the fuzzy perception value of the expectation of the optimal stopped reward is characterized and calculated by a new recursive equation. Also, a numerical example described by triangular fuzzy numbers is given.     

Representability and local representability of algebraic theories

A finitary monosorted algebraic theory is called locally representable (or representable) in a category with finite products if every its initial segment is the domain of a full faithful finite-products-preserving functor into (or if itself is the domain of such a functor). The question of when local representability implies representability is discussed, and theories for which local representability always implies representability are fully characterized. Received December 20, 1996; accepted in final form March 19, 1998.     

Calculation of the Band Intensities of the IR Spectra of Oriented Polymers

An attempt has been made to extend the theory of IR spectra of polymers to oriented polymers. Formulas for the absorption-band intensities in polarization IR spectra of oriented polymers reflecting the dependence of the polarized absorption-band intensity on the structural and orientation characteristics of polymers have been obtained. These formulas permit calculating the intensity of polarized absorption bands at different degrees of orientation of the polymer.     

A Three‐Dimensional Capsule‐like Carbon Nanocage as a Segment Model of Capped Zigzag [12,0] Carbon Nanotubes: Synthesis,Characterization, and Complexation with C70

Herein we report the synthesis and photophysical and supramolecular properties of a novel three‐dimensional capsule‐like hexa‐peri‐hexabenzocoronene (HBC)‐containing carbon nanocage, tripodal‐[2]HBC, which is the first synthetic model of capped zigzag [12,0] carbon nanotubes (CNTs). Tripodal‐[2]HBC was synthesized by the palladium‐catalyzed coupling of triboryl hexabenzocoronene and L‐shaped cyclohexane units, followed by nickel‐mediated C?Br/C?Br coupling and subsequent aromatization of the cyclohexane moieties. The physical properties of tripodal‐[2]HBC and its supramolecular host–guest interaction with C₇₀ were further studied by UV/Vis and fluorescence spectroscopy. Theoretical calculations revealed that the strain energy of tripodal‐[2]HBC was as high as 55.2 kcal mol^?1.     

Detecting the Rouse and Sub-Rouse Modes in Poly(Butyl Acrylate) and Poly(Ethyl Acrylate) Through Two-Dimensional Dynamic Mechanical Spectra

The difficulties of observing sub-Rouse modes (SRM) and Rouse modes (RM) in acrylate polymers has resulted in many arguments and disputes concerning the nature of their glass-rubber transition. Because different modes have different sensitivity to external perturbations, the two-dimensional dynamic analysis mechanical spectra (2D-DMS) was introduced to detect the local segments motion (LSM), SRM, and RM in poly(butyl acrylate) (PBA) and poly(ethyl acrylate) (PEA). The results of the asynchronous spectra showed the LSM, SRM, and RM of PBA and PEA are located, respectively, at about (?46 ～ ?29°C), (?28 ～ ?10°C), (?4 ～ 27°C), and about (?12 ～ ?5°C), (?3 ～ 6°C), and (10 ～ 44°C). Furthermore, the LSM and SRM of PBA and PEA have an overlap in the synchronous spectra. This is suggested to be caused by the higher coupling effect in PBA and PEA when compared with strong glass formation polymers, like polyisobutylene (PIB).     

把握认知特点 提高习题教学质量

解答物理问题的过程，实质上是新的问题情境与原有物理认知结构－－学生头脑中的知识结构相互作用的过程。研究习题教学的认知特点，根据认知规律开展教学，优化习题结构，重视思维能力的培养，对提高习题教学质量具有重要的作用。     

川芎嗪联合血液光量子疗法治疗突发性耳聋18例临床观察

将３６例突发性耳聋患者随机分为２组，Ａ组用川芎嗪联合血液光量子疗法治疗；Ｂ组为对照组，采用传统药物低分子右旋糖酐治疗．结果表明，Ａ组显效率达６６．７％，治疗后１周听力损失值平均恢复２７．８ｄＢ．对眩晕伴随症状改善率达７７．８％，疗效优于Ｂ组．对血流变指标改善Ａ组也好于Ｂ组．ＢＡＥＰ的恢复２组无差异．