Optimization of some factors affecting the performance of query expansion

This paper examines the factors affecting the performance of global query expansion based on term co-occurrence data and suggests a way to maximize the retrieval effectiveness. Major parameters to be optimized through experiments are term similarity measure and the weighting scheme of additional terms. The evaluation of four similarity measures tested in query expansion reveal that mutual information and Yule's Y, which emphasize low frequency terms, achieve better performance than cosine and Jaccard coefficients that have the reverse tendency. In the evaluation of three weighting schemes, similarity weight performs well only with short queries, whereas fixed weights of approximately 0.5 and similarity rank weights were effective with queries of any length. Furthermore, the optimal similarity rank weight achieving the best overall performance seems to be the least affected by test collections and the number of additional terms. For the efficiency of retrieval, the number of additional terms needs not exceed 70 in our test collections, but the optimal number may vary according to the characteristics of the similarity measure employed.     

企业技术创新中的风险及其控制

论述了企业技术创新是既具有潜在高效益，又具有潜在高风险的科学技术研究活动。分析企业技术创新中的风险，是为了让技术创新成果的持有者、接受者认识到技术创新的风险性及产生的原因，便于双方及时采取有效的措施，把风险控制在最小范围。从企业技术创新过程出发，分析了企业技术创新存在的风险，并根据这些风险产生的原因，探讨了其防范措施。     

基于用户利用数据的高校图书馆资源共享服务趋势与优化策略探究

在多元便捷的信息环境下,图书馆资源共享服务当前面临着激烈的竞争,需转变服务思路。通过采集样本图书馆在CALIS平台上5年的用户数据,从业务趋势、用户结构分布、平台使用习惯、对比分析、定位分析多个维度,解析了用户群体特征。并提出了多项服务质量优化举措以及分层式宣传策略,进而为资源共享服务的发展提供参考。     

过渡语语用学视阈下高中学生语用能力的培养

在过渡语语用能力发展的认知理论框架下,对高中生目的语的语用意识和语用能力进行了调查,分析了高中生语用能力滞后的原因,并结合高中生英语学习实际情况,提出了语用能力培养途径。     

电磁场课程“部分电容”实验装置研发

针对目前"部分电容"实验存在的问题,采用电力工程中真实的电缆,研制开发了多导体系统的"部分电容"实验装置,该装置为平行多导体结构。介绍了电缆的选取原则和实验装置设计的关键。对已开发的装置,进行了实验测量。与传统的实验装置相比,该装置是一种基于实际工程的、结构紧凑,同时适合学生进行开发性实验的装置。     

研究型实验常用的研究方法

研究型实验的目的是培养学生应用知识、调配知识的能力,通过介绍常用于研究型实验的几种研究方法--观察法、模仿方法、对偶方法、组合方法和移植方法,可以加强学生在完成研究型实验中的自主性,使他们能应用这些方法去设计更多的创新实验.     

法律论证的概念——系统—结构主义的进路

法律论证问题已经受到广泛的理论关注,其中值得注意的是,目前几乎所有界定都有将法律论证与作为一个系统的法律方法等同之倾向。这种界定倾向当然不合理,因为法律论证仅仅是诸多法律方法之一种。以系统论视角来对法律论证进行界定也许可以很好地避免这种倾向。从系统论的角度讲,欲恰切地界定系统中的某种成分,就必须将它还原到系统中,从它与作为整体的系统本身以及系统的其他成分之互动关系的角度来进行。     

Decolorization Kinetics of Sludge Protein Solution by ~（60）Coγ-Ray Irradiation/H_2O_2 Oxidation

In order to carry out decolorization, sludge protein solution, a dark brown close to black solution from activated sludge, was subjected to ⁶⁰Co γ-ray irradiation in the presence of hydrogen peroxide. UV/Vis spectrophotometric method was used to investigate the effect of H2O2 on the coloration apparent kinetics and rate constants of sludge protein solution under γ-ray irradiation. In addition, the effects of irradiation dose, initial sludge protein solution concentration, and pH value on the decolorization efficiency of sludge protein solution were studied. Results showed that the decolorization apparent kinetics of sludge protein solution was a first-order reaction. The solution decolorization percentage increased with the increase of irradiation dose or the decrease of initial sludge protein solution concentration. The examination results of pH value showed that the sludge protein solution could be more efficiently decolorized in alkaline media than in acid media. Moreover, sensory evaluation and foamability analysis indicated that irradiated samples under H2O2 oxidation showed better sensory score and foamability.     

基于校企合作的工程实践教学改革创新探索

在工程训练中除了要让学生多动手外,还要加强工程训练中各个环节的关联性,创造实际生产的氛围,这样才能达到工程训练的目的,培养学生的工程意识和工程素养。由于工程训练所需的各种资源有限,实际上很难达到应有的训练要求。本文就如何充分使用现有工程训练资源,利用学校与企业互补的特点,通过有针对性的校企合作,来丰富工程训练的教学内容,改革工程训练模式,完善实践教学手段,同时提高工程实践教学师资队伍的实际工作能力,从而达到解决工程训练中存在的这些问题的目的,进行了探索。     

苏轼的文学成就与贬谪

迭遭贬谪使苏轼溶入了现实生活,根植于社会实践中。体察民情,关心民瘼,是他文学创作的源泉;政治受挫,思想成熟,是他文学创作的灵感。贬谪是＂根＂,文学成就是＂果＂,贬谪促成了苏轼辉煌的文学成就。