玉米淀粉与丙烯酸胺接枝共聚物的制备

本文研究玉米淀粉与丙烯酰胺接枝共聚物的合成工艺及其在造纸工艺中用作干强剂、助留/助滤剂的效果。研究表明玉米淀粉与丙烯酰胺的质量比为5:3.5,引发剂硝酸铈铵用量为0.2g,反应时间为3h,反应温度为62℃,聚合物质量较好。     

Bi含量对SrBi4Ti4O15铁电材料性能的影响

~~Bi含量对SrBi_4Ti_4O_(15)铁电材料性能的影响@朱骏$扬州大学物理科学与技术学院!江苏扬州,225002 @毛翔宇$扬州大学物理科学与技术学院!江苏扬州,225002 @卢网平$扬州大学物理科学与技术学院!江苏扬州,225002 @惠荣$扬州大学物理科学与技术学院!江苏扬州,225002 @陆文峰$扬州大学物理科学与技术学院!江苏扬州,225002 @陈小兵$扬州大学物理科学与技术学院!江苏扬州,225002~~~~~~~~     

舟桥丙丁接头接触分析的计算机模拟

深入考察接触行为的特点，并以舟桥纵向连接件丙丁接头为例，建立了两种接触计算模型。采用大型通用有限元程序进行分析，模拟丙丁接头受力时的应力应变。与经验合成计算结果和常规有限元分析的结果进行对比，证明接触分析方法对连接件塑性变形、疲劳分析和优化设计有重要的指导意义。     

解乘数法用于工程保障组织的优化分析

工程保障组织优化分析属于多目标决策问题，定性分析与判断是其原则上的指导。通过对兵力与工程任务分配问题进行数学建模，经量化分析与计算生成合理组织方案，实现最大的工程保障效能。“解乘数法”用于求解工程保障组织数学模型，计算简便，结果直观。     

数字化天气雷达强度标定方法

数字化天气雷达的组网观测是天气雷达发展的必然趋势，现有数字化天气雷达提供的强度场必须经过强度标定后再用于组网，因此迫切要求制定数字化天气雷达标定方法。指出了使用标定方程时应注意的量纲问题，针对有关文献中存在的问题提出了解决方法。     

Effect of Carboxymethyl Starch as Stabilizer for Increasing the Stability of Warp Sizing Pastes

The influences of carboxymethyl starch used as stabilizer upon the stability of native cornstarch-polyvinyl alcohol blend pastes for warp sizing have been investigated. The effect of the modified starch on the paste stability was evaluated in terms of the initial demixing time and the volume percentage of separated starch. The carboxymethyl starch with a series of different degrees of substitution was prepared in ethanol dispersion by varying the amount of monochloroacetic acid reacted with refined native cornstarch. The paste stability strongly depends on the modification extent and amount of carboxymethyl starch used, and on native starch content in the paste. Increase in the modification extent and/or the amount of the modified starch effectively retards the phase separation and reduces the separation extent of native cornstarch-polyvinyl alcohol blend pastes. Moreover, the mechanism and favorable modification extent of carboxymethyl starch for enhancing paste stability are also investigated and disc     

Ratio K: a New Way of Metering and Evaluating the Risk and Return of Stock Investment

Although widely used, both the Markowitz model and VAR (Value at Risk) model have some limitations in evaluating the risk and return of stock investment. By the analysis of the conceptions of risk and return, together with the three hypotheses of technological analysis, a novelty model of metering and evaluating the risk and return of stock investment is established. The major indicator of this model , risk-return ratio K, combines the characteristic indicators of risk and return. Regardless of the form of the risk-return probability density functions, this indicator K can always reflect the risk-return performances of the invested stocks clearly and accurately. How to use the model to make optimum investment and how to make portfolio combined with clustering analysis is also explained.     

企业技术创新的关键在于企业与科技人员互动

企业技术创新要求企业与科技人员合作 ,合作的基础是利益诱导。在分析了企业与科技人员的利益目标差异的基础上 ,用一个抽象的组合激励理论模型 ,说明了两者“双赢”的行为选择 ,为推动企业技术创新提供了一种思路。     

Evolution of the South China Sea and monsoon history revealed in deep-sea records

As the third summary report of ODP Leg 184 to the South China Sea (SCS), this paper discusses the evolution of the East Asian monsoon and the SCS basin. A multi-proxy approach, involving geochemistry, micropale-ontology, pollen and other analyses, was adopted for reconstructing the evolutionary history of the East Asian monsoon, which was characterized by a series of paleo-climate events especially at 8, 3.2, 2.2 and 0.4 Ma. The new record indicates similar stages in the development of the East and South Asian monsoons, with an enhanced winter monsoon over East Asia being the major difference. The rich spectrums of monsoon variability from the southern SCS also reveal other characteristic features of the low latitude ocean. Evidence for the evolution of the SCS includes the hemipelagic Oligocene sediments, implying the existence of deep water environments during the early seafloor spreading stage of the SCS basin. The four major unconformities and some remarkabl ediagenetic features in upper Oligocene deposits indicate the strongest tectonic events in the region. From a careful comparison of lithologies and sedimentation rates, we conclude that the prominent differences in sedimentary environments between the southern and northern SCS were established only by ～3 Ma.     

无剪切闭锁的厚薄板矩形单元的构造

在板弯曲的有限元计算中 ,因为剪切闭锁现象导致厚板元无法自动退化为薄板元 ,工程中很难构造既适用于厚板又适用于薄板的计算单元 ,因此采用由龙驭球教授提出的广义协调元法 ,构造了矩形厚薄板弯曲通用计算单元 .通过铁木辛柯梁理论 ,建立了板单元边界和板单元内部的位移插值场函数 .计算结果表明该单元可顺利解决剪切闭锁现象 ,可在实际工程中推广应用