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131.
提出并实现了一个基于.NET架构的J2EE标准,以WebService为基础的web服务器构建多媒体远程教学系统平台,以此教学平台框架开发的多媒体远程教学系统具有更高的跨平台性和互动性。利用基于.NET架构的J2EE标准,提出了远程教学系统平台的系统设计与实现方法。  相似文献   
132.
This study examines the organizational characteristics of 51 higher education institutions in relationship to student performance and growth. The study first finds that organizational measures of mission, size, wealth, complexity, and selectivity are statistically represented by the 2-year versus 4-year college mission. Findings indicate that 2-year and 4-year campuses indeed do exert significantly different influences on undergraduate GPA and self-reported intellectual growth. Next, the study uses both OLS regression and HLM to examine these influences. High school percentile rank and college classroom experiences are better predictors of Cum GPA at 4-year institutions, while student effort is a better predictor of GPA at 2-year institutions. Whereas the most important predictors of Cum GPA include precollege measures such as high school percentile rank and SAT score, the most influential predictors of student intellectual growth are campus experiences including classroom vitality, peer support, student effort, commitment, and involvement. Controlling for all other variables, students at 2-year institutions receive higher grades, and students at 4-year campuses experience more growth.  相似文献   
133.
用Cu2O制备CuO气敏元件,对乙醇、汽油、丁烷和氢气等气氛进行气敏试验,并进行机理分析,结果表明,由Cu2O制备的CuO气敏元件,对所测气体的灵敏度优于由CuO制备的气敏元件。  相似文献   
134.
催化动力学光度法测定痕量钒(V)   总被引:1,自引:0,他引:1  
研究了在酸性介质中痕量钒催化 H2 O2氧化抗坏学酸体系的反应和动力学条件 ,建立了催化动力学光度法测定痕量钒的新方法。该方法的检出限为 0 .0 5 ng/ m L ,线性范围为 0~ 0 .5μg/ 2 5 m L ,该方法用于水样及人发中痕量钒的测定 ,结果令人满意  相似文献   
135.
通过对创建J2EE Web技术的研究,提出了对控制器、业务层模型和数据库访问的改进方法.这些方法能优化Web性能,提高访问速度,对创建高效的Web应用具有一定的借鉴作用.  相似文献   
136.
综述了无机盐、无机酸、杂多酸(盐)、固体超强酸等催化剂催化合成草莓酯的实验情况.结果表明,硫酸铝、CuCl2 ·2H2 O、固体超强酸SO2 -4 -TiO2 /Al2 O3、活性炭固载硅钨酸等催化剂催化合成草莓酯的收率较高,具有一定的工业应用价值.  相似文献   
137.
S. Negassi 《Research Policy》2004,33(3):365-384
The scope of this paper is to report new empirical evidence on the determinants of R&D co-operation. Indeed, the literature on the capabilities of firms emphasises the role of knowledge in the performance and evolution of firms who use knowledge developed in others to build their own knowledge capital. R&D co-operation between firms is one of the many strategies by which this knowledge may be transmitted. Several theoretical models have stressed that R&D co-operation is more likely when the level of spillovers is high. While this supposition is used in many theoretical models, it has rarely been tested before. Our results do not lend strong support to this intuition. Indeed, our spillover variables (national pure spillovers, national rent spillovers and imports of machine tools), which were supposed to match the theoretical notion of spillovers used in these theoretical models have a positive but not a significant role when explaining R&D co-operation. The R&D co-operation increases with size and with R&D intensity, but not with market share. It also increases with the budget spent on paying license fees and on acquiring patents and labour from foreign firms. In this study, we also analyse the determinants of innovation. In more precise terms, we compare the effects of R&D co-operation to those played by traditional internal factors and those exerted by external, pure and rent spillovers on the innovation capacity of the firms. Our results show that the commercial success of innovations of French firms depends mainly on size, market share, R&D intensity and human capital. Inward FDI from industrialised countries exerts a positive and significant effect. The finding highlights the important role of the absorptive capacity of firms. Spillover measurements, such as the acquisition of machine tools, foreign patents, licenses, and technological opportunities have a positive impact on innovation.  相似文献   
138.
徐昱东 《科研管理》2016,37(8):76-84
基于向量误差修正模型(VECM),利用山东省1995-2012年时间序列数据,实证分析了外商直接投资(FDI)和对外贸易开放水平对碳排放强度的影响,研究发现:FDI对碳排放强度具有抑制效应,对外贸易开放度对碳排放强度具有助长效应,且后者的弹性系数为前者的1.5倍。论文给出的政策建议:升级外商投资的能耗准入标准;创造良好外部条件利用外商直接投资技术溢出效应以加快山东省低碳技术发展步伐;及时淘汰内资企业中的落后产能,避免内资企业成为"污染天堂"的替罪羊;发挥山东省的示范和借鉴价值、挖掘区域经济的发展潜力,须建立和落实生态补偿制度等。  相似文献   
139.
本文探讨了设计网上银行支付系统所需要的安全技术,对支付系统的安全性进行了研究,设计了支付系统应具备的功能,设计了系统模型和流程,给出了一种网上银行B2C电子支付系统的安全、可靠,便捷的解决方案.  相似文献   
140.
BackgroundCecropin P1, acting as an antimicrobial, has a broad-spectrum antibacterial activity with some antiviral and antifungal properties. It is a promising natural alternative to antibiotics which is originally isolated from the pig intestinal parasitic nematode Ascaris suum. Many studies have shown that Cecropin P1 is helpful for the prevention or treatment of clinical diseases. Therefore, it is very necessary to establish a safe, nontoxic, and efficient expression method of Cecropin P1.ResultsThe results indicated that the recombinant protein was about 5.5 kDa showed by Tricine–SDS–PAGE and Western blot. And Cecropin P1 was efficiently secreted and expressed after 12 h of induction, with an increasing yield over the course of the induction. Its maximum concentration was 7.83 mg/L after concentration and purification. In addition, in vitro experiments demonstrated that Cecropin P1 not only exerted a strong inhibitory effect on Escherichia coli, Salmonella sp., Shigella sp., and Pasteurella sp., but also displayed an antiviral activity against PRRSV NADC30-Like strain.ConclusionsCollectively, the strategy of expressing Cecropin P1 in Saccharomyces cerevisiae is harmless, efficient, and safe for cells. In addition, the expressed Cecropin P1 has antiviral and antibacterial properties concurrently.How to cite: Jiang R, Zhang P, Wu X, et al., Expression of antimicrobial peptide Cecropin P1 in Saccharomyces cerevisiae and its antibacterial and antiviral activity in vitro. Electron J Biotechnol 2021;50. https://doi.org/10.1016/j.ejbt.2020.12.006  相似文献   
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