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1.
姜美霞 《内蒙古科技与经济》1999,(Z2)
在讲解由与非门组成的基本ＲＳ ,同步ＲＳ ,和主从ＲＳ触发器及ＪＫ触发器的过程中 ,由于涉及的触发器各类较多 ,因此 ,对这些触发器逻辑功能的理解和记忆比较困难。为了使学生便于学习与记忆 ,可将这些触发器联系起来 ,使教与学都变得较为简单。首先 ,将基本ＲＳ触发器与同步ＲＳ触发器联系。基本ＲＳ触发器的逻辑功能可由逻辑电路直接分析出 ,如真值表 ( 1)所示。为便于记忆 ,可强调低电平有效 ,- Ｒ端为置Ｏ端 ,- Ｓ为置 1端。在基本ＲＳ触发器的基础上 ,构成了同步ＲＳ触发器 ,教学时 ,强调同步ＲＳ触发器在ＣＰ =1期间接收信号 ,其逻辑… 相似文献
2.
观察了力平脂对高脂血症者的治疗作用和安全性．确诊高脂血症者６８例，力平脂，０．１，Ｔｉｄ，服一个月为一疗程后，血清总胆固醇（ＴＣ）平均降低２０．９８％，甘油三酯平均降低５１．８８％，ＨＤＬ－Ｃ平均升高１０．２６％，ＬＤＬ－Ｃ平均降低１２．５７％，ＡｐｏＡ１平均升高２．２４％，ＡｐｏＢ平均降低２１．１０％，从调血脂的个体疗效分析，力平脂降低ＴＣ的总有效率８４．６１％，降低ＴＧ的总有效率９５．２４％，升高ＨＤＬ－Ｃ的总有效率６１．７７％，降低ＬＤＬ－Ｃ的总有效率为５５．８８％，升高ＡｐｏＡ１的总有效率３８．２４％，降低ＡｐｏＢ的总有效率７７．９４％．提示：力平脂治疗高脂血症者，对降低ＴＣ，ＴＧ，ＬＤＬ－Ｃ，ＡｐｏＢ和升高ＨＤＬ－Ｃ，ＡｐｏＡ１均有明显效果，其中降低ＴＧ的疗效尤为突出，副作用轻微．临床实践表明：力平脂是一个疗效高、安全、服用方便的调血脂新药 相似文献
3.
总结基本RS触发器、同步RS触发器、主从RS触发器和主从JK触发器等不同电路结构触发器的动作特点,特别对不定态、空翻．一次翻转等进行讨论．以便学生理解和记忆。 相似文献
4.
XML（eXtensible Markup Language）作为一种Internet上主要的数据表示和交换标准之一，应用范围非常广泛．因此XML文档的设计十分重要。一个设计良好的XML模式是XML应用的基础。通过借鉴面向对象中设计模式理论，提出了两种实用的XML设计模式：扇形陷阱设计模式和深坑陷阱设计模式，并且给出了相应的应用实例。在XML设计中使用这两种设计模式，可以保证文档的质量，提高设计效率。 相似文献
5.
应用在单相和三相电度表中的ＸＴ３型整体式磁推轴承是应用温度系数小、磁感应矫顽力ＨＣＢ≥２７０ＫＡ／ｍ的稀土制成．它具有设计合理新颖、结构紧凑、防尘防震、安装使用方便和具有自滑润耐磨损长寿命的特点．在工作气隙不小于０．６ｍｍ之下，最大承重可达７５ｇ．ＸＴ３型整体式磁推轴承是一种高科技产品，克服了分体式磁推轴承存在的诸多问题，在我国生产的电度表中能与宝石轴承完全互换 相似文献
6.
介绍了目前比较流行的ＩＮＴＲＡＮＥＴ技术以及ＤＬＡＬＯＧ公司开发的基于ＩＮＴＲＡＮＥＴ的最新光盘检索软件ＤＬＡＬＯＧ＠ＳＩＴＥ,主要谈论了该软件的安装和检索方法。 相似文献
7.
研究了深层培养红栓菌的富锗转化。在ＰＤＡ天然培养基中添加ＧｅＯ＿２，红栓菌ＮＪ８７０１可高效富集锗，最高达４８２ｐｐｍ．１５０ｐｐｍ的锗可较好地促进红栓菌ＮＪ８７０１的生长代谢；酶活测定分析表明，富锗菌体内的抗衰老相关酶：超氧化物歧化酶（ＳＯＤ），过氧化物酶（ＰＥＲ），过氧化氢酶（ＣＡＴ）酶活均显著提高；进一步的多糖分析显示，菌丝体内的锗能与多糖成分以Ｇｅ─Ｏ键结合． 相似文献
8.
高脂血症是指血液中的总胆固醇（ＴＣ）及低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）增高，或甘油三酯 （ＴＧ）增高，或二者兼有。高脂血症是动脉粥样硬化及冠心病的主要诱因之一，其发生与遗传，内分泌紊乱有关，但多数与饮食密切相关。以下介绍一些降脂食品供您选食，以求达到膳食平衡、促进健康的目的。 １．每日膳食应选择中等量的碳水化合物（米饭、面食等）及低脂肪（油、肥肉、油炸食品等）的食品，这比低碳水化合物（吃饭很少）、高脂肪的膳食效果要好。 ２．控制食用油的摄入量，每天２５克左右。为了减少油脂的摄入量，可多吃些凉拌、蒸… 相似文献
9.
差动电流开关的控阈技术及施密特电路 总被引：2，自引：0，他引：2
在输入信号的变化过程中，施密特电路实现阈值突变的核心部件为阈值可控开关．本文从分析差动电流开关着手，对现有ＴＴＬ施密特集成电路进行了剖析，并设计了几种ＥＣＬ施密特电路 相似文献
10.
大鼠梗阻性黄疸对急性胃粘膜病变的影响及洛赛克对它的预防研究 总被引：1，自引：0，他引：1
通过制作大鼠 Ｏ Ｊ和 Ａ Ｇ Ｍ Ｌ 模型,研究了 Ｏ Ｊ对 Ａ Ｇ Ｍ Ｌ 的影响及洛赛克对 Ａ Ｇ Ｍ Ｌ 的预防作用．结果表明： Ｏ Ｊ能明显加强大鼠应激下 Ａ Ｇ Ｍ Ｌ 的形成,且其 Ａ Ｇ Ｍ Ｌ 的严重性与胆道梗阻时间相关,洛赛克对 Ｏ Ｊ大鼠应激下 Ａ Ｇ Ｍ Ｌ 的形成有预防作用 相似文献
11.
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
12.
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
13.
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
14.
《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
15.
《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
16.
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
17.
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
18.
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
19.
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
20.
Leah A. Lievrouw 《The Information Society》1998,14(2):83-96
The main premise of this article is that in information societies generally, and in virtual social contexts particularly, a distinctive style of interaction to facilitate the communication of difference, heterotopic communication , has emerged. It rests on two cultural foundations: an ideological belief in the positive, socially integrating power of communication, and a prevailing ethic of instrumental rationality, subjective individualism, and strategically practiced self-interest. The former is demonstrated by the use of simulation and spectacle as sources of information; exhibitionism/voyeurism as a communicative style; and the awareness of surveillance. The latter is seen in the competitive use of knowledge as a commodity; a surface globalism masking deep parochialism; lateral as well as vertical information inequity; and the use of public versus private as strategies for engagement rather than as spaces. Those who engage in heterotopic communication resort to their 'own devices' both in the sense of personal agendas, strategies, interests, and interpretations, and in the form of the telecommunication tools that help realize them. These personal and technological devices allow individuals with the right educational and technical resources to avoid exposure to disagreement, difference, or other information that does not serve their direct purposes or reflect their particular views of the world; yet they also help convey the appearance of openness, availability, and cooperation. This style of interaction is used strategically in combination with information and communication technologies to gain social or economic advantages, but it may encourage social separatism and parochialism, inhibit the negotiation of disputes, and emphasize competing interests. 相似文献