运动饮料配方设计概论

运动中，人体生理发生一系列的变化，包括水分损失、血糖／糖原消耗、电解质损失等，导致运动中／后的疲劳和运动能力下降。以运动中人体生理特点为基础，通过讨论运动前／中／后补充水、碳水化合物及电解质的问题，论证了运动饮料配方设计的原理依据。     

草酸钙在硫酸软骨素自组装膜上周期沉淀的研究

利用硫酸软骨素(chondroitin sulfate，CS)在云母基底上通过浇铸法制备的自组装膜为基底，诱导草酸钙在其上的凝集生长。发现当硫酸软骨素的浓度为1．Omg／ml时在该膜体系中可形成规整的周期性草酸钙环状沉淀。这种有序的环状结构可能是耗散结构的一种具体表现形式。利用原子力显微镜(atomic forcemicroscope，AFM)和傅立叶红外光谱仪对这种结构进行了表征，实验结果显示合适浓度下形成的CS膜在一定程度上可以抑制草酸钙的凝集结晶，表明高分子基质与无机离子间强烈的相互作用对无机盐的成核结晶有显著影响，为探讨结石的形成与抑制提供了一定的实验依据。     

Σ-ΔA/D转换技术及仿真

Σ－ΔＡ／Ｄ转换技术近年来颇受重视，因为基于该技术的Ａ／Ｄ转换器能达到很高的分辨率（１６ｂｉｔ以上），并另具一系列优点。本文对Σ－ΔＡ／Ｄ转换器的基本原理，包括过采样（Ｏｖｅｒｓａｍｐｌｉｎｇ），噪声成形（ＮｏｉｓｅＳｈａｐｉｎｇ），以及数字抽取滤波（ＤｉｇｉｔａｌＤｅｃｉｍａｔｉｏｎＦｉｌｔｅｒｉｎｇ）等内容，均作了叙述。作者还对一个２０ｂｉｔΣ－Δ转换器的算法进行了计算机仿真。该转换器采用了高阶ＭＡＳＨ噪声成形技术，而其数字抽取滤波部分则由梳状滤波器与级联的半带滤波器构成。文章中给出了仿真结果。     

甲醇燃料的研发现状及发展前景

介绍了甲醇燃料的理化性质、作为车用替代燃料的性能及研发现状，分析了甲醇汽油存在的问题及发展前景。     

Stem cells in prostatic epithelia

The normal prostate is, structurally and functionally, a highly complex glandular tissue in which populations of epithelial and stromal cells interact, one with the other, and are under a constant state of proliferation, differentiation, elimination and selective secondary replenishment so that functional integrity of the tissue is maintained. The ability of normal prostatic tissue to maintain its structure and function is dependent upon retention of cells, generally regarded as 'stem cells', which are able to respond by proliferation and selective differentiation within a wide range of phenotypic alternatives. With respect to cells in the epithelial compartment, replenishment is possible at several levels from within distinct pathways of normal cellular differentiation. It is now appreciated that fully differentiated prostatic epithelial cells retain a far greater degree of phenotypic 'plasticity' than was earlier apparent from morphological examination of the intact tissue. This inherent plasticity, coupled with the ability of the intact tissue to respond to diverse environmental (particularly humoral) stimuli by regenerating a wide and divergent spectrum of functional prostatic epithelial phenotypes is its strength--but also its weakness. Disturbance and distortion of the homeostatic regulatory mechanisms, whether physical or humoral, which control the normal sequence of epithelial proliferation, differentiation and elimination exposes these cells, particularly multipotent 'stem cells', to an increased probability of genetic change, thus resulting in either transient, or permanent, neoplastic transformation.     

Towards a generalized TLM algorithm for solving arbitraryreciprocal and nonreciprocal planar structures

A generalized transmission line matrix (TLM) algorithm is developed in the frequency domain to tackle arbitrary both reciprocal and nonreciprocal anisotropic waveguiding problems. In particular, the modeling issue for arbitrary planar structures is stressed in this work. A new three-dimensional (3-D) condensed node is used to consider the effect of both electric and magnetic constitutive tensors. Various results indicate how the modal dispersive behavior can be manipulated by changing not only the anisotropic characteristics of the substrate, but also the strip/slot geometry as well as the magnitude and orientation of the applied static magnetic field. The present algorithm is useful for CAD and simulation of a large class of gyrotropic waveguide-based microwave and millimeter-wave circuits     

直流电动机参数测定

根据直流电机的可逆原理并利用常规的实验仪表，可以简便、准确地测出直流电动机的主要参数－电磁转矩、输出转矩和效率．