免费师范生教育的理性思考与新制度设计

师范生免费教育政策的实施具有现实迫切性,且经历了一个历史过程,通过对我国现阶段实施免费师范生教育的情况进行论证发现,从招生制度、培养制度、就业制度以及该制度的推广等四个方面可以得出有利于师范生免费教育的新制度设计的启示。     

基于自由树的中心的MAODV改进算法

MAODV路由协议是应用于移动Ad Hoc网络的一个组播路由协议,协议中的组长选取具有较大的随机性。本文分析了协议中组长的位置选取的相关特征,并在此基础上提出了基于自由树的中心的MAODV改进,改进算法避免了MAODV路由协议中组长处于组播共享树叶子结点的位置,减少了数据分组的传输次数,降低了网络传输的延迟。     

负载型TiO2降解活性艳红X-3B溶液的研究

以钛酸四丁酯、正硅酸乙酯为前驱体,冰醋酸为水解抑制剂,用溶胶-凝胶法制备了纳米TiO2／SiO2复合粒子。考查了SiO2负载量、复合粒子焙烧温度、催化剂用量对活性艳红X-3B光催化降解率的影响。结果表明,当n（Ti）／n（Si）=3,焙烧温度为700℃、粒子添加量w（TiO2）／w（SiO2）=2％时对活性艳红X-3B降解性能最好。     

关于推进公共图书馆免费开放一些问题的思考

本文对公共图书馆实行免费开放的作用和意义作了阐述,并对免费开放后出现的一些问题作了分析,并提出相应的措施。     

不同药物对力竭游泳小鼠肾自由基代谢的影响

目的:旨在探讨人参茎叶、北冬虫夏草和辽东(楤)木对一次力竭游泳小鼠肾脏自由基代谢的影响及其机制.方法:昆明种雄性小鼠80只,随机分为五组:正常组(NC,n=16)、运动组(EC,n=16)、人参组(PG,n=16)、虫草组(CM,n=16)、(楤)木组(AE,n=16),经过6周灌胃后,进行一次性力竭游泳.采用分光光度法测定运动后即刻小鼠肾脏SOD、GSH-PX和MDA.结果:1)与NC组相比:EC组SOD、GSH-PX水平显著下降,MDA水平显著升高,P＜0.01.2)与EC组相比:PG组小鼠游泳至力竭的时间明显增加,MDA水平明显下降,P＜0.05;SOD、GSH-PX水平显著升高,P＜0.01.CM组小鼠游泳至力竭的时间明显增加,P＜0.05;SOD、GSH-PX水平显著升高,MDA水平显著下降,P＜0.01.AE组小鼠游泳至力竭的时间明显增加,GSH-PX明显升高,P＜0.05;SOD水平显著升高,MDA水平显著下降,P＜0.01.结论:1)一次性力竭游泳运动可引起小鼠肾脏抗氧化酶活性下降,脂质过氧化作用增强.2)人参茎叶提取物、北虫草发酵液和辽东(楤)木根皮提取物可改善小鼠肾脏抗氧化能力,在一定程度上预防了肾脏的脂质过氧化损伤.且这三种药物在预防肾运动源性自由基损伤方面的作用效果相似.     

中国新诗自由形式的必然性及其走向

中国诗歌自格律化以来，已有千余年的发展史。在其漫长的演进过程中，格律体式已成为其继续提升的桎梏。到新化运动，这种体式被彻底打破，而在新诗格律化建设中，无数次试验均收效甚微。从新诗史的角度考察，中国新诗的自由形式更合于新诗本身的品性，不定型就是其已有或应有形式。当然，这种形式上的自由并非“绝端的自由”，而是有着审美控制力的自由。对形式美的自觉追求，应是中国新诗发展的题中之义。     

股权分置改革改善现金股利掠夺效应的有效性

利用2003～2007年样本数据,研究了股权分置改革对现金股利掠夺效应的影响,结果发现股权分置改革改善了现金股利的利益输送行为,加强了自由现金流假说。     

免费能成为垄断平台的长期均衡策略吗？

在平台经济的发展中,“免费”已成为诸多平台企业常见的定价策略。本文将用户异质性偏好和产品质量差异引入到双边市场理论,探讨了平台长期对部分用户免费的可能性。研究发现：对于单边的垄断平台而言,用户间异质性的边际网络效应是平台实施长期免费策略的必要条件;在引入广告商或者平台竞争后,即使用户间获得的边际网络效应无差异,免费依然可能成为平台的均衡策略;随着边际网络效应的增强或产品间的质量差异扩大,对部分用户免费也更有可能成为平台的长期均衡策略。本文为平台定价策略和平台反垄断政策的制定提供有益借鉴。     

The use and abuse of metatags

The web creates manyopportunities for encroachment on intellectualproperty including trademarks. Our principaltask in this paper is an investigation into anunusual form of such encroachment: theimproper use of metatags. A metatag is a pieceof HTML code that provides summary informationabout a web page. If used in an appropriatemanner, these metatags can play a legitimaterole in helping consumers locate information. But the ``keyword'' metatag is particularlysusceptible to manipulation. These tags can beeasily abused by web site creators anxious tobait search engines and bring scores ofvisitors to their sites. The law aboutmetatags is far from settled and many legalscholars are uncomfortable with the conclusionthat the unauthorized use of a trademark in ametatag represents infringement. How should weassess this practice known as ``spamdexing'' froma normative perspective? Is it commercial fairplay or something more sinister? We make thecase here that there are salient moral problemswith spamdexing since it exploits thereputational goodwill of trademark owners andconfuses consumers. It violates basic moralduties and it flouts the golden rule principle. Hence unauthorized use of a competitor'strademark in a metatag is not morallyacceptable.     

Effects of Conceptual Change and Traditional Confirmatory Simulations on Pre-Service Teachers’ Understanding of Direct Current Circuits

The objective of this research is to investigate the effects of simulations based on conceptual change conditions (CCS) and traditional confirmatory simulations (TCS) on pre-service elementary school teachers’ understanding of direct current electric circuits. The data was collected from a sample consisting of 89 students; 48 students in the experimental group who were taught simulations based on CCS, and 41 students in control group who followed the TCS. Subjects in both groups used open source software (Qucs) to simulate electric circuits. All students were administered Electric Circuits Concepts Test (DIRECT), Science Process Skills Test, Physics Attitude Scale, and Computer Attitude Scale before the treatment. Pre-test analyses revealed that there is no significant difference between experimental and control groups in terms of understanding of direct current electricity. After completing 3 weeks treatment, all students received the DIRECT again as a post-test. Analysis of covariance was used. Science process skills and attitudes toward computers were taken as covariates. The results showed that the conceptual change based simulations caused significantly better acquisition of conceptual change of direct current electricity concepts than the confirmatory simulation. While science process skills and attitudes towards computer made significant contributions to the variations in achievement, gender differences and interactions between gender and treatment did not. Eleven weeks later, the DIRECT was reapplied to the students in both groups. Eleven weeks delayed post-test results showed that the experimental group outperformed the control group in understanding of direct current electric concepts.