U型管换热器管束固有频率研究

本文充分考虑了各种影响因素，采用理论分析和实验研究相结合的方法，得到了Ｕ型管管束固有频率的计算公式。实验结果表明，该公式的误差，一般在±８％以内，满足工程设计要求。另外，本文提供了相应图表，使工程设计简单方便。     

氨合成反应的BOC—MP法研究

用键级守恒莫尔势函数法（ＢＯＣ－ＭＰ）研究了铁催化剂表面氨合成反应的缔合式和解离式两种机理，计算表明缔合式机理速控步骤的活化能垒Ｎ２，ａｄ＋Ｈａｄ→ＮＨａｄ＋Ｎ（９２ｋＪｍｏｌ－１）低于解离式机理速控步骤Ｎａｄ＋Ｈａｄ→ＮＨａｄ（１６３ｋＪｍｏｌ－１）的活化能垒，但反应Ｎ２，ａｄ→Ｎａｄ＋Ｎａｄ（５０ｋＪｍｏｌ－１）的活化能垒又明显低于缔合式途径速控步骤的活化能垒．由此可推断，在铁催化剂表面存在着两种氨合成竞争反应途径，但缔合式机理在反应能量学上较为有利．     

冰醋酸对于测定植物材料中超氧阴离子含量的灵敏度的影响

利用羟胺氧化法测定超氧阴离子 ,在偶氮反应试剂中加入冰醋酸能够提高检测灵敏度 5 0 % .在植物材料的O2 - · 的提取过程中同时加入EDTA和羟胺 ,抑制SOD活性并及时“固定”O2 - · ,这样所测得的O2 - · 含量更能反映体内的实际情况 .同时发现提取上清液照光不产生O2 - · ,间接验证了O2 - · 来源于光合膜系统 .     

龙口市城区土地基准地价更新研究

时效性是基准地价的重要特征．龙口市城区土地定级估价工作始于1995年，至今城区环境、基础设施、城市用地布局等已发生了很大变化，为保持基准地价的现势性，对龙口市城区基准地价进行了更新．并与第一次结果相对比。做了补充和完善．     

Analysis of simple sequence repeats markers derived from Phytophthora sojae expressed sequence tags

Five thousand and eight hundred publicly available expressed sequence tags (ESTs) of Phytophthora sojae were electronically searched and 415 simple sequence repeats (SSRs) were identified in 369 ESTs. The average density of SSRs was one SSR per 8.9 kb of EST sequence screened. The most frequent repeats were trinucleotide repeats (50.1%) and the least frequent were tetranucleotide repeats (8.2%). Forty primer pairs were designed and tested on 5 strains of P. sojae. Thirty-three primer pairs had successful PCR amplifications. Of the 33 functional primer pairs, 28 primer pairs produced characteristic SSR bands of the expected size, and 15 primer pairs (45.5%) detected polymorphism among 5 tested strains of P. sojae. Based on the polymorphisms detected with 20 EST-SSR markers, the 5 tested strains of P. sojae were clustered into 3 groups. In this study, the SSR markers of P. sojae were developed for the first time. These markers could be useful for identification, genetic variation study, and molecular mapping of P. sojae and its relative species.     

Recent Progress of Somatic Cell Nuclear Transfer in Pigs

Research in the field of somatic cell nuclear transfer (SCNT) and transgenic cloning in pigs has become a global hotspot，because porcine organs probably can be the first source of donor organs for human xenotransplantation. In recent years, though great progress has been made in porcine SCNT, the efficiency of nuclear transfer remains very low (<1%). Thus, it is necessary to improve the procedure of nuclear transfer and to investigate some basic problems further. Recent progress and the related problems of SCNT in pigs are reviewed and analyzed so as to offer some beneficial illumination to researchers.     

论奥运经济对中国经济的积极影响

本文运用文献资料，比较分析法对奥运会影响下的中国经济进行分析研究，阐述了奥运经济对中国体育产业、房地产、证券、就业、旅游等方面的积极影响，以抓住奥运契机，充分发挥奥运经济带动效应，推动中国经济的发展。     

Effect of cold rolling process on microstructure and mechanical properties of high strength β titanium alloy thin sheets

The microstructure and mechanical properties of Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe high strength titanium alloy sheets prepared by unidirectional cold rolling and two-step cross cold rolling were investigated. Results showed that the β phase grains were refined significantly by cold rolling followed by solution treatment for a short time.Compared to unidirectional cold rolling, the short time solution treatment after two-step cross rolling could significantly reduce the non-uniformity of the microstructure of the alloy sheets. After aging treatment at 550 ℃,the anisotropy of the mechanical properties still existed in the unidirectional rolled sheets, and the tensile strength was highest along the rolling direction. After solution and aging treatment, the anisotropy of the mechanical properties of the two-step cross rolling process sheet was not obvious than unidirectional cold rolling,and alloy had good strength and plasticity matching.     

虚拟仿真实验平台的慕课设计

从课前准备、教学实施和评价总结等环节讨论了虚拟仿真实验慕课设计,结合数字电子技术给出了具体的虚拟仿真实验慕课设计结果,从而达到理论与实践相结合、推进基于慕课学习进程和提高学生学习效果的目的。     

“中华老字号”本体档案资源库的构建研究

为了更好发挥老字号档案的价值,本文分析了当前"中华老字号"数字化档案展览现状,提出创建老字号本体资源库,构建老字号档案间的语义互联关系。通过对老字号档案数字化展品的语义组织,深入挖掘潜在信息资源,为用户提供智能化、个性化、便捷化的用户体验。