溶胶-凝胶法制备TiO_2/MCM-41负载型光催化剂及其性能表征

以钛酸丁酯为钛源、MCM-41分子筛为载体,采用溶胶-凝胶法制备TiO2/MCM-41负载型光催化剂,并通过XRD、BET、TEM、XPS对最佳条件下制备的光催化剂进行表征。结果表明,所制光催化剂是一种具有均匀规则孔道结构的介孔材料,其粉体比表面积高达358.8m2/g;经700℃煅烧,催化剂主要晶相为锐钛矿相。光催化剂中的Ti以+4价存在,TiO2表面羟基氧所占比率为38.0%。以水中甲基橙为模拟污染物,TiO2/MCM-41光催化剂对浓度为25mg/L的甲基橙溶液降解0.5h后,其脱色率为93.7%。     

关于人体模型处理技术的探究

选择VRML和Java3D技术处理三维人体模型,该方法不仅可以高效地支持人体模型的可视化,还支持基于三维人体模型的研究与应用.采用Java3D技术对三维人体模型进行处理,可成功地解决前人利用VRML技术开发系统所碰到的若干问题.     

太原市游泳培训市场状况的调研报告

采用文献资料法、访谈法为主要研究方法,以太原市的迎泽区、万柏林区、小店区、杏花岭区的13家游泳馆、太原市的游泳培训机构及游泳消费者作为研究对象,全面了解分析了太原市游泳培训市场的现状.结果表明:游泳场馆、培训机构和游泳消费者三个要素的结合初步形成了太原市游泳培训市场.太原市游泳培训市场近几年发展良好,但仍存在一些问题:1.管理手段、经营方式和经营理念的落后限制了游泳培训俱乐部的发展;2.在经营方式上只注重儿童培训,忽视成人消费群体的培训;3.在经营理念上大都只注重短期效应,在教学质量上没有严格的标准要求.建议提升经营理念,注重市场的长远发展.     

The resettlement planning and practice of Three Gorges Project

Migrant resettlement is essential to the success of the Three Gorges Project (TGP),and the smooth implementation of resettlement is ensured by the resettlement planning and effective organization management.In the process of resettlement planning and implementation,systematic legislation and document support system is established;environmental capacity analysis and assets appraisal methods are introduced;resettlement sites are selected through in-depth analysis and comparison;the relationship between resettlement compensation and local development is correctly understood and considered,and reasonable resettlement schedules are well prepared.Through the establishment of efficient management system and capital management mode of "static control and dynamic management",as well as the timely adjustment of plan according to actual situations,the resettlement is accomplished smoothly.Thus,the social stability of the reservoir area is ensured;the economic development of reservoir area is promoted,and it has promoted successfully the improvement of legislation,regulations and techniques for land requisition and resettlement.The paper also discusses the theory and prospective work of resettlement.     

一类Turing模型的Hopf分歧分析

讨论Turing模型的三阶泰勒展开式的常微形式:u′=αu(1-r1v2)+v(1-r2u),t0,v′=v(β+αr1uv)+u(γ+r2v),t0,u(0)=u0,v(0)=v0,其中-1β0,0α1,r10,r1、r2分别是三次项、二次项的系数.通过考虑平衡解的稳定性,判断Hopf分歧发生的条件和分歧方向.     

ARP攻击原理与防范

ARP攻击是一种阻碍用户正常使用网络服务的攻击,就此对ARP协议的工作原理、ARP攻击的原理进行了深入的分析和探讨,并指出了相应的防御解决方法。     

Hwasun County countryside winter heating Exploration and Research

近年来,和顺县委、县政府秉持“和民心、顺民意”的发展理念,急群众所急,想群众所想,把解决乡村冬季取暖工作放在新农村建设的首位,经广大干部群众和科技人员的共同努力,截至目前,取得了非常满意的成绩.已经推广的吊炕和正在推广的农户地暖,很好地解决了乡村冬季取暖的问题,为全省乃至全国有效利用农村可再生能源、促进节能减排、改善生态环境开辟出了一条新路子.     

Analysis of Ultra - wideband Wireless Communications Technology Development

超宽带无线通信技术是一种具有高速、低成本和低能耗特点的无线通信技术,该技术的发展对于解决短距离内数据高速度无线传输具有重要的意义.文章拟从概念、特点、发展等方面对之进行论述.     

云南松优良家系超级苗选择研究

 为探讨云南松苗期选择的依据和标准,加速现有优良遗传资源的早期、短期开发利用,对20个家系1 a苗木的生长性状差异进行了分析.结果表明:家系之间以及同一家系不同个体之间的苗高、地径生长量存在极显著差异,且苗高生长量差异明显大于地径生长量.因此,以各家系平均高生长量加1倍标准差为最低标准进行超级苗选择,在11 331株育种群体中共选超级苗1 629株,入选率为14.3%.其中,超级苗平均高度为8.92 cm,比育种群体平均高度增加35.9%;超级苗平均地径为3.50 mm,比育种群体平均地径增加3.6%.     

Exact inference for two exponential populations with competing risks data

In a reliability comparative test, the joint censoring model is usually adopted to evaluate the performances of units with the same facility. However, most researchers ignore the pos- sibility that there is more than one factor for the failure when a test unit fails. To solve this problem, we consider a joint Type-II hybrid censoring model for the analysis of exponential competing failure data. Based on the maximum likelihood theory, we compute the maximum likelihood estimators （MLEs） of parameters and then obtain the condition ensuring MLEs existence for every unknown parameter. Then we derive the conditional exact distributions and corresponding moment properties for parameters by the moment generating function （MGF）. A Monte-Carlo simulation is conducted to compare the performances of different ways. And finally, we conduct a numerical example to illustrate the proposed method.