合成草莓酯的新型催化剂

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.     

B/S模式程序中的分布式计算应用一例

B／S模式的应用程序主要是集中式计算和处理，本简要的以实例无纸化考试系统设计，说明了在B／S模式中采用分布式计算处理的一种思路。     

R&D co-operation and innovation a microeconometric study on French firms

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.     

Expression of antimicrobial peptide Cecropin P1 in Saccharomyces cerevisiae and its antibacterial and antiviral activity in vitro

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     

试论情报人员的创造性思维

运用创造性思维的基本原理,阐述了情报人员创造性思维的基本含义,重点论述了情报人员创造性思维的基本特点和培养创造性思维的基本方法。旨在于拓宽情报学理论研究的领域,改变情报人员传统思维方式,探索情报人员创造性思维的规律。     

中国水生植物新记录属——钻叶荠属(十字花科)

 报道中国十字花科一新记录属¾钻叶荠属Subularia L. 及一新记录种¾钻叶荠S. aquatica L.。     

中国西部柳属新植物

 Two new species and one new variety of Salix L. from western China, namcl. S. ludingensis T. Y. Ding et C. F. Fang, S. neoamnematchinensis T. Y. Ding et C. F. Fang, and S. taoensis Gorz var. leiocarpa T. Y. Ding et C. F.Fang, are reported in this paper.     

美国西部发展对中国西部大开发的启示

19世纪中期,为发展经济、壮大国防,新生的美国政府制定了一系列政策法令鼓励向西部移民,兴修水利,发展农业,修建铁路,开发森林、矿产及土地资源,大大促进了西部地区的发展.至20世纪初,美国一跃成为世界工业经济与军事强国.然而,对西部资源掠夺式的开发行为对生态环境造成了巨大危害,不平等的民族政策严重地损害了土著文化传统,土地投机和完全的市场导向引起了严重的两极分化.本文简要回顾了美国西部开发的过程,比较了中美两国西部开发的异同点,借鉴美国西部开发的经验与教训,提出了对中国西部大开发的几点启示:①重视环境教育,调整思想认识;②加强资源保护,改善生态环境;③制订优惠政策,规范开发行为;④发挥市场导向,重视政府调控;⑤增加资金投入,搞好基础设施;⑥发展教育事业,推进科技创新;⑦坚持民族平等,实现共同富裕.     

关于科研单位参与市场竞争的几点认识

本文就科研单位适应市场经济，实现战略转变，总结了实践经验，讨论了几点认识。提出科研单位不能仅以科技成果转让为目标，应加速发展科技产业；不应仅满足于出成果，而应重视并着力于科技成果的转化，才能在社会主义市场经济条件下实现其价值和形成自我积累、自我发展的能力。     

“大学域” 图书馆资源共享研究

随着高等教育规模的扩大，大学城在我国得到了迅速的发展。文章分析了大学城在我国产生的必然性，大学城资源共享的主要领域，提出了大学城图书馆之间可以在政策制定、协调采购、目录编制、馆际互借、对外交流和利用现代信息技术方面实现资源共享，分析了在资源共享方面存在的问题。