秀珍菇原生质体的分离与再生的研究

通过对秀珍菇原生质体的分离与再生的影响因素的试验研究,表明以0.6M甘露醇为渗稳剂用1%纤维素酶 1%蜗牛酶,30℃酶解3～4小时原生质体产生最高,原生质体再生则以0.6M甘露醇或0.6M蔗糖为渗稳剂较好。     

云计算环境下应用层DDOS攻击特点及防范研究

本文研究云计算环境下应用层DDOS攻击特点及其对应的防御方法,文章先对应用层DDOS攻击的分类和特点做了相关分析．对正常用户访问和应用层DDOS攻击的行为特征进行比较分析。对应用层DDOS攻击依据特点进行分类并设计相应的检测算法．分多种类多阶段对其进行检测．设计相关实验,实验表明算法可以较好的发现和防御应用层DDOS攻击的发生．     

混凝土结构的劣化分析与控制

结构混凝土的劣化常常导致结构过早地进行维修或拆除,甚至发生严重事故.有些基层结构设计工程师在设计中往往仅考虑结构的受力状态及变形程度,而对混凝土随时间和环境变化产生性能劣化的认识不清,重视不够.从混凝土自身形成过程、混凝土状态特点与环境因素间相互作用方面,定性分析了其内部损伤发展的各个阶段及影响机理,并结合多年在污水处理工程上的设计经验及有关规范要求,在工程设计、施工管理及使用维护方面提出一些控制措施,以利于建筑物、构筑物使用寿命的提高.     

“But I just want a book!” Is your discovery layer meeting your users’ needs?

Abstract

In January 2016, the University of Toledo Libraries implemented EBSCO Discovery Services (EDS) as its discovery layer. Administrators questioned whether users were able to find consortial material in the EDS, so they assembled a task force to conduct a pilot usability test. The task force gathered demographic data and recorded the screens of 25 students answering six task questions. Results showed participants could easily find most items except books, and for tasks that were open-ended, many students continued searching even though they found relevant material. To determine why participants could not find books, the task force consulted with EBSCO and discovered a configuration problem that was easily resolved by editing a mapping table and adding a custom limiter for print books. The searching issue was more difficult to determine, and the task force suggests a lack of library instruction may be at least partly to blame. Libraries invest significant resources in discovery layers. If users have difficulty using them or finding relevant material for their assignments, libraries need to address that issue and instruction is one solution. This pilot study reports on what the University Libraries did to make the EDS more usable for its users.     

数字图书馆系统结构及相关问题探讨

从哈工大学图书馆的实际情况出发，对一类分布式数字图书馆系统结构进行研究，运用中间构件技术和智能主体技术构造一种三层客户／服务器模式的数字图书馆系统结构模型，该模型可扩展性和安全性好，对分布异构的数字资源具有很强的集成能力。另外，还对相关的问题进行探讨，给出一种信息模型，使信息组织灵活方便；提出一种优化的资源调度方法，能使系统运行成本降低；同时，还对数字图书馆的互操作性问题进行讨论，提出相应的互操作性规范。     

A study of the interrelationship between the behaviour and social status of a class of Year 2 pupils

The influence of social status on child development has been the subject of research for several decades, with children who are not accepted by their peers being shown to be at risk of a range of difficulties both at the time and in later life. Strong links have also been established between behaviour and social status. A small‐scale action research project considered the social structure of a Year 2 class and used data gathered through sociometric interviews and observations to identify some factors which may have influenced the social status of individuals within that group. From this data, three children considered at risk of peer rejection or isolation were identified and an intervention programme was implemented. At the end of the year sociometric interviews and observations were repeated and it was found that one child's social behaviours and status among his peers had increased significantly over the course of the project.     

试论当代中国的社会分层与大众体育的关系

中国二十余年来的变化使国家的社会结构发生了巨大的变迁,其中一个突出的特点就是逐渐形成了社会阶层的差异。本文通过对当代中国社会分层的了解,力求以社会学的观点来分析和探讨当代中国社会分层演进中的大众体育,提出了从社会分层的视角来研究大众体育的关系。     

电镀液和镀层中钐的分光光度法测定

本文探讨了钐离子在弱酸性介质中与偶氮胂Ⅲ反应生成稳定络合物的最佳条件，提出了直接在水相中测定钐的分光光度法．本方法简便、快速、准确，适用于镀液和镀层中钐含量的快速测定．     

自由来流中展向速度对流动稳定性的影响

采用线性稳定性理论研究了三维平板边界层中展向来流速度对流动稳定性的影响。在基本流中给出了展向速度的大小,从特征值、特征函数和扰动波的增长幅值上显示不同展向来流速度的计算结果,并和无展向来流速度的二维边界层进行比较,结果表明,展向速度对边界层内的扰动起着不稳定的作用,且展向速度越大稳定性越差。     

J2EE和.NET在电子商务应用中的比较

摘概述了电子商务的多层体系结构以及J2EE和．NET技术，最后对J2EE和．NET在构建电子商务系统中的应用做了详细的比较．