国家图书馆社会责任再思考

论述了我国国家图书馆应承担的社会责任及履行社会责任的具体措施,并对国家图书馆社会责任的拓展进行了探讨。     

机构知识库在国内的实践及不足分析

目前,我国机构知识库数量少,规模小,文献类型单一,标准化程度不够,资源共享能力差,功能开发不够完善,运行效果欠佳,建设程度差别较大;而开放存取意识不强,资源瓶颈问题突出,建设机制不完善,技术力量薄弱是导致这些问题的主要原因。因此,我国机构知识库建设要加强宣传推广,寻求相关支持,科学规划,建立政策体系,完善功能,积极寻求合作,构建IR联盟。表2。参考文献18。     

高等农业院校毕业生就业状况分析——以湖北、湖南、广东四所高等农业院校为例

本文在对湖北、湖南、广东三省四所高等农科院校毕业生就业数据处理的基础之上．从就业率、毕业生流向和社会评价三个方面对农科毕业生的就业状况进行了系统分析．对于了解我国农科毕业生的就业状况具有重大意义。     

网页设计与制作职业岗位的教学探索与实践

互联网上信息的快速传递与数量庞大、内容丰富多彩的网站有密切的关系。如何让学生掌握网站的设计与制作这一职业所需要的技能,并为社会服务呢？本文针对高等职业技术学院图形图像制作专业网页设计与制作职业岗位,对教学的针对性、内容的选取、教学方法的构建、职业能力的综合提高等方面进行了初步的探索与实践,让我们的教学更接近、符合、满足市场对应用型人才的需求。     

Microfluidic wet spinning of chitosan-alginate microfibers and encapsulation of HepG2 cells in fibers

The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fibers, including a 1:5 ratio of 2% (w∕w) water-soluble chitosan (WSC) solution to 2% (w∕w) alginate solution. Ratio including higher than 2% (w∕w) WSC solution increased aggregation throughout the mixture. By suspending cells in the WSC-alginate solution, we successfully fabricated HepG2 cell-laden fibers. The encapsulated HepG2 cells in the chitosan-alginate fibers were more viable than cells encapsulated in pure alginate fibers, suggesting that cross-linked chitosan provides a better environment for HepG2 cells than alginate alone. In addition, we found that the adhesion of HepG2 cells on the chitosan-alginate fiber is much better than that on the alginate fibers.     

Bromo-oxidation reaction in enzyme-entrapped alginate hollow microfibers

In this article, the authors present the fabrication of an enzyme-entrapped alginate hollow fiber using a microfluidic device. Further use of enzyme-entrapped alginate hollow fibers as a biocatalytic microchemical reactor for chemical synthesis is also deliberated in this article. To ensure that there is no enzyme leaching from the fiber, fiber surfaces were coated with chitosan. To confine the mobility of reactants and products within the porous hollow fibers the entire fibers were embedded into a transparent polydimethylsiloxane (PDMS) matrix which also works as a support matrix. A vanadium-containing bromoperoxidase enzyme isolated from Corallina confusa was used as a model enzyme to demonstrate the use of these alginate hollow-fiber reactors in bromo-oxidation of phenol red to bromophenol blue at different dye flow rates. Stability of the entrapped enzyme at different temperatures and the effect of the chitosan coating on the reaction conversion were also studied. It was observed that molecules as big as 27 kDa can be retained in the matrix after coating with chitosan while molecules with molecular-weight of around 378 Da can still diffuse in and out of the matrix. The kinetic conversion rate in this microfluidic bioreactor was more than 41-fold faster when compared with the standard test-tube procedure.     

基于BP神经网络的纤维混凝土力学性能预测模型

基于BP神经网络预测模型对不同材料掺量的纤维混凝土进行混凝土力学性能预测,找到适宜的隐藏层单元数和误差目标值.通过将预测数据和实测数据进行对比,研究该预测模型对于混杂纤维混凝土强度预测的可行性.经检验当隐藏层单元数为9个,目标误差值为1e-7时,预测值的准确性最高.     

科技论文学术影响力评价探究

基于国内主流数据库资源的对比分析,提出科技论文学术影响力评价要素及途径.以知网为主、其他数据库为辅设计评价指标,构建定量指标和定性指标相结合的评价体系,以期对科技论文学术影响力进行评价.     

对通俗舞蹈与艺术舞蹈的融通发展的若干思考

舞蹈是人们在日常生活中为了表达情感应运而生的,经过人们不断地升华,它所表达的内容又是高于生活的。舞蹈主要分为通俗舞蹈和艺术舞蹈,由于两者的风格不同,被人们接受的程度也不尽相同,二者的发展出现了不平衡的状况。本文分析了通俗舞蹈与艺术舞蹈融通发展的关系。     

Time-frequency analysis of EEG signals evoked by voluntary,stimulated and imaginary motions

In order to investigate the characteristics of sensorimotor cortex during motor execution(ME), voluntary, stimulated and imaginary finger flexions were performed by ten volunteer subjects. Electroencephalogram(EEG) data were recorded according to the modified 10-20 International EEG System. The patterns were compared by the analysis of the motion-evoked EEG signals focusing on the contralateral(C3) and ipsilateral(C4) channels for hemispheric differences. The EEG energy distributions at alpha(8—13 Hz), beta(14—30 Hz) and gamma(30—50 Hz) bands were computed by wavelet transform(WT) and compared by the analysis of variance(ANOVA). The timefrequency(TF) analysis indicated that there existed a contralateral dominance of alpha post-movement event-related synchronization(ERS) pattern during the voluntary task, and that the energy of alpha band increased in the ipsilateral area during the stimulated(median nerve of wrist) task. Besides, the contralateral alpha and beta event-related desynchronization(ERD) patterns were observed in both stimulated and imaginary tasks. Another significant difference was found in the mean power values of gamma band(p0.01)between the imaginary and other tasks. The results show that significant hemispheric differences such as alpha and beta band EEG energy distributions and TF changing phenomena(ERS/ERD) were found between C3 and C4 areas during all of the three patterns. The largest energy distribution was always at the alpha band for each task.