火电厂无线数据采集系统的抗干扰设计

在火电厂中,电磁环境复杂,为避免汽轮机无线热力特性数据采集系统因受到干扰而影响系统的安全、可靠运行,本文分别从硬件和软件两方面提出了抗干扰措施,并进行了相关的设计。通过测试,本无线采集系统能够在电厂实际环境中正常、稳定的运行。     

关于冷却塔的热力性能研究

研究冷却塔热力性能与机组经济性的关系,论述自然通风、冷却塔填料特性、散热面积和循环水量对出塔水温的影响,分析导致冷却塔热力性能缺陷的主要原因,为火电厂的节能降耗提供有价值的研究方向。     

分析热力站供热系统的自控策略

随着科学技术的不断发展,很多先进技术也应用与热力站供热系统控制中去,使得热力站供热系统控制呈现出自动化、科学化的特性。虽然热力站供热系统自动化控制经过科研人员长时间的研究已经取得了非常可观的发展成就,但是其中还存在着一些不足之处,科研人员还需要进一步加强研究力度,找寻更多有效的自动控制策略应用与热力站供热系统中去,从而保证热力站供热系统可以进一步发展。     

汽车管芯式散热器的特性仿真

文章以管芯式散热器为研究对像,采用微元法建立数学模型,并且用Matlab/simulink软件对其进行热力特性仿真模拟.仿真结果与试验结果比较后表明,其吻合程度良好,可以在一定条件下,直接应用于管芯式散热器的传热与运动性能检测.     

天津滨海新区软土工程性质研究手段的探讨

探讨了室内土工试验、原位测试、地球物理勘探等针对于软土工程特性研究手段的特点及优缺点,得到了在室内土工试验的基础上,结合原位测试等手段,可以较好的探究滨海新区软土的工程性质的结论.     

汽轮机五六段抽汽串接问题的分析

根据修前热力试验分析提出5#、6#低加工作不正常,经过提前分析及检修解决了5段、6段抽汽的串接问题,即5#、6#低加工作已经正常;提高了凝结水温度,改善了回热系统经济性,并通过修后热力试验数据得到了证实。     

单跨拱桥荷载试验研究

对某拱桥进行静力荷载试验和动力荷载试验,测试并分析静载工况下的拱肋和系梁挠度、吊杆拉力、拱肋与系梁的截面应力。试验结果表明该桥受力合理,具有良好的刚度与强度。在动载试验中,测试其自振特性,并进行了跳车试验,分析了在行车下的冲击作用。     

暖通工程中热力管道直埋技术的应用研究

热力管道工程是暖通工程的重要组成部分,良好的热力管道铺设技术也是城市供暖的基础。所以,本文以较为常见的热力管道直埋技术作为研究对象,探讨不同直埋技术形式的特性,从而以理论研究挖掘更为理想的直埋技术类型,以期能够对相关领域提供些许理论借鉴。     

螺旋桨飞机振动实时测试系统设计

螺旋桨飞机飞行过程中,存在多种振源扰动。根据某螺旋桨飞机振动测试分析的需要,设计了一种机载振动实时测试系统,采用飞行试验进行机体动态响应测试,以评估飞机的颤振、振动特性。系统测试检查结果表明,测试过程中、系统工作正常,测试结果符合实际情况,且测试系统对机上系统无不利影响。对于螺旋桨飞机,机载振动实时测试系统对飞机的颤振、振动评估有重要意义。     

330MW热电联产机组热耗偏高原因分析及改进措施

某330MW级热电联产#1机自投产以来,机组热耗一直偏高于设计值,#1机进行了热力性能试验,试验结果表明,机组实际热力系统工质泄漏量、高压缸效率、中压缸效率及高压缸前轴封至中压缸漏汽量均超过设计值。根据试验结果情况,分析#1机组热耗偏高的原因,提出了降低该机组热耗的优化改进措施。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.