A Random Multi-Access Method for Data Services in CDMA Cellular System

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小学数学研究性学习初探

一、问题的提出 我们认为,学生的创新意识是在主动探索知识的过程中得到培养的,学生的实践能力是在应用知识,解决问题的实践活动中得到发展的.基于小学数学教学适应培养创新型人才的需要,笔者提出了"小学数学研究性学习的探索"的课题.     

价值链理论在地矿物资公司经营中的应用研究

本文应用价值链理论分析了销售企业的价值链构成及其特点,并为某地矿物资公司建立了价值链模型,从竞争力优势分析出发,明确了能给公司带来最大价值的重点业务活动。应用中,公司创造了可观的经济效益,更好地保障了地矿系统的物资供应。     

Performance of PAHs emission from bituminous coal combustion

Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.     

吸引基金论文提高学报的学术质量

鉴于地方高校学报在办刊过程中出现的困惑，分析了地方高校学报在全国学术期刊环境中所处的地位及其生存价值，从六个方面探讨了地方高校学报的发展策略。     

基于上证30及深圳成指的我国股票市场“羊群行为”的实证研究

本文采用CSAD（横截面收益绝对差）方法，对我国股票市场是否存在“羊群行为”进行了实证检验。结果发现：在上涨行情中，我国深圳证券市场与上海证券市场均不存在“羊群行为”；但在下跌行情中，深圳证券市场与上海证券市场均存在“羊群行为”，且深圳证券市场比上海证券市场具有更多的“羊群行为”。对产生“羊群行为”的原因，作者进行了简要分析。     

英国政府对促进科学园区发展的政策分析

本文通过设置调查问卷和查阅资料,重点研究英国政府是如何通过制定公共政策促进科学园区发展的,其中主要有政府倡议建立科学园、财政投入政策、设立风险投资资金、鼓励企业入驻等.这些对我国发展高新技术园区具有启发作用和借鉴意义.     

中外医学期刊《读者来信》栏目现状的分析与思考

通过比较部分国内外生物医学期刊《读者来信》栏目的现状,分析国内期刊读者来信较少的原因.强调国内医学期刊应重视《读者来信》栏目,并针对当前问题提出了改进建议.     

一矩阵方程组的反射解

We derive necessary and sufficient conditions for the existence and an expression of the （anti）reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D. The explicit solutions of the approximation problem min x∈Ф ｜｜X - E｜｜F was given, where E is a given complex matrix and Ф is the set of all reflexive （or antireflexive） solutions of the system mentioned above, and ｜｜·｜｜ is the Frobenius norm. Furthermore, it was pointed that some results in a recent paper are special cases of this paper.     

物理化学实验教学的探索与实践

针对目前物理化学实验教学中普遍存在的问题,提出了一些改进实验教学的方案,并付诸实践。