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本文主要介绍了无线收发芯片nRF401,模数转换芯片TLC0820的相关技术和它的工作原理,及以nRF401为核心的PTR2000无线收发模块的相关特性和接口设计及软件编程的要求。 相似文献
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无线数传芯片性能比较与应用研究 总被引：1，自引：0，他引：1
分析了nRF401、CC1020、nRF903三种典型无线数传芯片的功能、应用领域及工作特性,给出了典型应用电路,提出了一种无线数传芯片性能的横向比较方法,通过该方法可以直观地看出不同芯片的性能差异,为系统设计时快速有效的完成无线数传芯片的选型提供有力的数据参考,为整个系统性能的保障车口系统设计的顺利完成奠定良好的基础。该方法对其它芯片选型具有良好的借鉴作用。 相似文献
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无线通信技术满足了用户对在不同移动状态下获取网络信息的强烈需求,也符合当今社会人员流动性大、工作生活节奏紧张的发展趋势;另一方面,无线通信技术具有网络部署迅速便捷的特点,对于缺乏线缆资源的新兴运营商来说,无线通信技术是成功部署通信网络,迅速为用户提供语音和数据服务的最佳手段。为此,介绍了单片无线收发一体芯片nRF401在无线传输中的应用。 相似文献
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本设计提出了一种基于单片机控制的无线数据传输问题的解决方案。该方案以nRF401为无线传输芯片来设计无线烟雾检测报警系统,采用低功耗、性价比高的AT89S51单片机作为控制核心,采用MC14468离子型烟雾检测报警芯片作为检测火灾及烟雾的传感器,再结合其他外围电路组成烟雾检测报警系统,并最终进行显示和发出声光报警。该系统使用方便,扩展性强,可广泛应用于商场、酒店、居民住宅等高层建筑等场合。 相似文献
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本文介绍了一个以AT89C系列单片机为嵌入式MCU,直接从用电设备上采集数据,通过nRF401无线收发芯片为数据传输工具,有效地把分布于工厂内部的生产设备的用电数据实时地传输到企业的ERP系统的无线嵌入式电量采集系统的设计与实现。该系统对企业的生产成本的控制起到了积极的作用,为企业下一步将要实施的RTE打下了坚实的基础。 相似文献
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该文介绍了以MCU、内嵌8051的RF收发芯片nRF9E5为核心,通过远程指定电话控制,由DTMF集成电路MT8880、语音录放芯片ISD4001和RF收发芯片nRF905等芯片组成的智能家居系统,并给出了该系统主机和分机的基本原理以及设计方案。 相似文献
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文章从工程实际需要出发,在介绍无线收发一体芯片nRF2401的基础上,采用微处理器芯片PICl8F6621、交流采样技术和带有串行接口的功率/电能芯片CS5460,给出了基于nRF2401的高压交流信号无线数据采集系统的整体设计,开通过整个系统的仿真则试,其结果完全符合设计要求, 相似文献
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基于nRF2401的高压交流信号数据采集系统的设计 总被引：1，自引：0，他引：1
文章从工程实际需要出发,在介绍无线收发一体芯片nRF2401的基础上,采用微处理器芯片PIC18F6621、交流采样技术和带有串行接口的功率/电能芯片CS5460,给出了基于nRF2401的高压交流信号无线数据采集系统的整体设计,并通过整个系统的仿真测试,其结果完全符合设计要求。 相似文献
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本文采用无线收发芯片nRF2401和AT89S52单片机设计了一种汽车防撞预警器,描述了nRF2401芯片的特点和工作方式,以及预警系统的设计方案,提出利用m序列控制系统的工作时序来提高系统报警的精确度。此系统主要应用于经常行驶在山路或路面环境较差的车辆上,避免汽车碰撞事故的发生。 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
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. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US 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 the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
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. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
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. 相似文献
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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. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
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. 相似文献
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Milton Mueller 《The Information Society》2001,17(3):151-163
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. 相似文献
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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.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
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. 相似文献
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Prof. SUN Changpu from the CAS Institute of Theoretical Physics coworkers from University of Basel in Switzerland have worked out a way - at least in theory - to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams is similar to the famous Stern-Gerlach effect whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states 《中国科学院院刊(英文版)》2008,22(1):23-23
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）. 相似文献