The Difference of the Pulmonary-Artery Pressure of the Migrants from Difference Elevation at the 4636 - 4907 m Altitude

Study Objective： To compare and analyze the changes of the pulmonary-artery pressure of the migrants coming from different elevation in the hypoxic environment of 4636 - 4907 m extreme altitude. To explore the susceptibility to hypoxic pulmonary-artery hypertension （PH） in the subjects from different altitude and profession. Methods： By using Color Doppler Ultmsonography （CDU）, measuring the pulmonary-artery pressure of 207 healthy men, who had continuously being lived and worked at the extreme altitude for more than six months, and then were divided into three groups according to their profession and the altitude of original living place. Results： There was a significant difference in the outcomes of pulmonary-artery pressure from the 3 groups. Conclusions： Altitude of original living place, labor intensity are some of factors that impact the pulmonary-artery pressure of the people who exposure to a hypoxic environment. The pulmonary- artery pressure of person without strenuously physical work experience was more sensitive to hypoxic surroundings than that of labor workers. It was not always the fact at an extreme altitude that the moderate altitude mountaineers were superior to other migrants from a lower altitude or plain. The higher PH was found in the groups of the moderate altitude mountaineers and labor workers. It is unlikely certain that one with PH would surfer from HAPE.     

快速成型技术的典型方法比较

本文介绍了一种当今国内外最新制造技术—快速成型技术。对该技术的四种典型方法进行了较详细的分析和比较，并对快速成型技术的未来发展提出了自己的看法。     

爆破地震峰值的神经网络预报模型

对爆破地震值进行预报,方法,采用神经网络模型,对秦山核电站某爆破工程监测得到的２０组震动峰值数据进行学习,然后对另１０组数据进行预报。结果,实测值与预报所在分类区域完全一致。     

磁性纳米催化剂SO2-4/TiO2-Fe3O4的制备及表征

用溶胶一凝胶法、沉淀法将磁性材料与固体酸进行组装，制备了磁性纳米固体酸催化剂SO4^2-／TiO2-Fe3O4．该类催化剂能通过外加磁场进行分离、回收．扫描电镜、透射电镜观察及磁性能、比表面积测试结果表明，用溶胶-凝胶法制备的催化剂比用沉淀法制备的催化剂具有更小的粒径、更高的磁强度和更优异的催化性能．X射线衍射、傅里叶红外光谱分析表明，影响催化剂磁性能和催化活性的主要因素是Ti与Fe的摩尔比、焙烧温度和浸渍液浓度。     

电力铁路高压直流牵引电网光纤隔离监控及计算机继电保护系统

本文介绍一应用光纤和计算机技术测控电气化铁路直流电网高压、大电流的继电保护系统．光纤作为监控信号的传输信道，实现了高压电量的安全测控．以单片计算机为核心的数据采集控制系统，实现了继电保护的高速性和准确性．     

在生物圈保护区中开展生态旅游的探讨

介绍了生物圈保护区和生态旅游产生的背景和发展，论述了在生物圈保护区中开展生态旅游的可行性以及对其产生的正负影响，提取了应采取的对策。     

The glass transition temperature and microstructure of polyurethane/epoxy resin interpenetrating polymer networks nanocomposites

GLASS TRANSITION TEMPERATURE (TG) HAS BEEN EXTEN- SIVELY STUDIED FOR MANY POLYMERS SINCE IT IS ONE OF THE MOST FUNDAMENTAL FEATURES RELATIVE DIRECTLY TO POLYMER PROPERTIES. IN GENERAL, INORGANIC NANOFILLERS DO NOT DI- RECTLY CONTRIBUTE TO THE TG OF THE MA…     

北京大气中痕量烷烃的浓度分析与研究

采用二步深冷浓缩与气相色谱质谱联用（ACIS-GC／MS）对北京大气中痕量烷烃进行长期连续观测，观测数据表明：日变化有双峰和三峰变化，冬、春呈现与交通高峰吻合的双峰变化，即：上午08：00点至10：00和下午17：00前后各出现一个高值；四季日变化中夜间22：00出现第三峰值；夏季变化呈三峰型，最大值在正午前后．季变化峰值出现在夏季，低值出现在冬季．     

"一带一路"中国地方性政策的文本量化研究

"一带一路"对世界经济及我国民生的发展和改善发挥了积极作用,自"一带一路"实施以来,中国多个相关省、自治区、直辖市围绕自身特点积极布局,发布了一系列地方性"一带一路"相关政策.文章基于关键词词频—逆文件频率(TF-IDF),对中国"一带一路"沿线各省、自治区、直辖市在2014—2020年颁布的"一带一路"相关的政策文本进行量化分析和研究,通过可视化关键词的地理分布和构建的关键词网络发现,社团内部地区间的政策相似性主要并不取决于权重较大的关键词,而是由更多较小权重关键词共同决定的.文章还利用显性比较优势(RCA)进一步量化了各地的政策关键词的显性差异,得出各省、自治区、直辖市在政策关注上具有不同侧重的结论.