一种新型四轴搜救飞行器设计

为了解决重大自然灾害的灾后现场搜救问题,本文设计了一种新型的四轴搜救飞行器。该飞行器主要以MSP430单片机为控制核心,包括旋翼电机、姿态检测模块、无线视频传输模块、无线遥控模块等,其中姿态检测由陀螺仪传感器、加速度传感器以及大气压传感器。实验结果验证了该飞行器的有效性,能实现无线遥控以及远程视频传输。     

基于DSP的嵌入式无线数据传输系统研究

随着人们对信息数据传输系统的要求越来越高,无线数据传输系统逐渐得到广泛地研究和应用。对基于DSP的嵌入式无线视频图像数据传输系统进行了研究设计,给出了系统的总体结构设计和功能设计方案,并在此基础上重点完成了数据采集模块和无线数据传输通信网络模块的硬件设计,对于进一步提高利用DSP嵌入式技术开发实时无线数据传输通信系统及其应用水平具有一定借鉴意义。     

基于GPRS无线传输技术的水资源远程监控系统的设计

针对目前用水单位地理位置分布分散,难以实现对其用水量实时监测的特点,设计了采用GPRS无线传输技术的水资源远程监控系统。该系统使用NET技术实现,系统结构为B／S三层结构,由数据采集模块、无线传输模块和信息处理模块组成。实践证明,该系统具有可靠性高、网络覆盖范围广、传输速度快的特点。     

基于互联网的智能家居安防系统设计

针对传统的家居安防现状,文章设计了一种能够智能化、实时监测室内环境情况的安防系统,适用于各大厂房和住宅区的安全保障工作,系统主要包括门禁、报警和监控三大部分,实现对环境的实时监测,并且通过短信收发器将环境的异常信息及时地发送给控制室的工作人员,有效地防止了火灾、有害气体泄漏和外来人员入侵,以及通过无线传输模块远程控制电灯和窗帘的开关。     

基于无线通信技术的汽车多点温控系统

随着无线通信技术的发展,在越来越多的领域,无线模式正在逐步替代有线模式,无线技术与温度传感器的结合,也成了温度检测系统新的发展趋势,它能够有效解决由有线模式带来的诸多不变,适应更多温度测量的场合。本文主要研究汽车内部多点温度的检测系统,阐述了无线多点温度传感系统的设计思想和实现方法,无线部分采用NRF905无线收发模块,实现了高效的数据传输,温度检测后的数据由无线发射模块传给显示终端,由终端分辨出是由哪个点传来的温度数据,使用无线通信技术进行数据采集、比较传统意义上的传输显得更加实用、高效、快捷。     

ARM与nRF24L01的无线温湿度采集系统

针对传统有线的温湿度采集系统布线麻烦、成本高、布局固定、灵活性欠佳的特点,将短距离无线通信技术应用到各节点的温湿度采集传输,设计基于ARM处理器和n RF24L01无线传输模块的远程温湿度采集与传输系统。该系统以Cortex-A8为内核的S5PV210处理器和ARM9内核S3C2440处理器为主控器件,无线收发模块选用n RF24L01,使用VC++6.0来设计上位机程序。本文详细的阐述了该系统各个硬件模块的设计方案,给出了各部分的软件设计。经过实验验证,该系统工作稳定,传输效率高,可以实现对远程各个节点的温湿度的采集和无线传输。     

基于MSP430的一氧化碳报警系统设计

对基于MSP430G2553单片机的一氧化碳检测报警系统进行了研究,该系统主要由主控制模块,CO电化学传感器,液晶显示以及无线传输模块构成。利用了MSP430单片机和CC1100无线传输的超低功耗与高集成度以及电化学传感器高灵敏度与准确度的特点。该系统非常适用于矿井等需要电池供电和空间有限的场合。     

基于单片机的气压温度感知系统研究

如今5G技术愈发成熟,万物互联的时代即将到来,而实现智能控制的前提便是智能感知。文章以8051单片机为处理芯片,设计了一款气压温度感知系统。该系统由供能模块、数据采集模块、无线通信模块、显示及语音模块等构成,最终实现了对气压、温度的检测、显示以及异常情况下的语音报警功能。硬件上构建了稳压电路、气压检测电路、液晶显示电路、无线传输接收电路、ISD1820语音报警电路,软件上设计了系统的整体程序控制流程。     

基于单片机控制的短距离无线传输

阐述了采用AT89C52单片机实现数据采集和无线传输的原理和结构组成。该系统以单片机作为控制核心,PTR2000作为无线传输模块,实现单片机跟PC机之间的无线传输。单片机实时进行数据采集,将采集的数据通过无线传输模块传送到PC机;PC机通过无线传输模块向单片机发送指令。此方案与蓝牙技术相比成本低、功耗低而且协议简单。     

基于RFID测温系统的设计——对于医学药品生产车间的温度监控

设计了一套用于控制医学药品生产车间温度的测温系统。此系统采用核心STC89C52电路、无线射频模块电路、测温模块电路等组件实现了超温警报、温度信息储存和无线传输,同时通过无线射频技术传输实时温度,并显示在接收端。本设计适用于在险恶环境下对产品的温度监控,有效的提高了药品在生产过程中的效率以及减少药品储存和运输过程中的损耗。     

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.     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

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.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

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