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981.
Information technology in the form of the Internet and its commercial offspring (referred to in this article collectively as the Net) has received much attention as a vehicle to increase political participation. In this article, we explore the potential of the Net, a vast, loosely coupled system of electronic forums, for facilitating and hindering democratic participation. In so doing, we identify five assumptions that undergird the claim that the Net will enhance democratic participation and suggest that increased democratic participation rests on three fundamental characteristics: access, voice, and dialogue. In order for this network of electronic forums to facilitate democratic participation, educational, economic, and cultural barriers to access, voice, and dialogue must be overcome. The final part of this article raises additional challenges to realizing democracy via the Net.  相似文献   
982.
Of all the senses, that of taste is perhaps the hardest to define and quantify and elucidation of the underlying mechanisms is unrespondingly difficult. This article describes a conceptual model — at the molecular level — for the four basic taste modalities, using apparent specific volume as a fundamental parameter. It also considers possible practical applications.  相似文献   
983.
The need for collaborative ventures in Europe has long been stressed in the editorial pages of this journal, and more than ten years ago (Endeavour, 28, 54, 1969) we gave strong support for a proposal to establish a European Laboratory of Molecular Biology. For this we then incurred some criticism, on the ground that such a laboratory would weaken national academic institutes striving to establish themselves in this rapidly developing field. Nevertheless, we continued to maintain (30, 2, '71) ‘the great political and scientific importance of this [concept]—and of other such collaborative enterprises—if Europe is to maintain the initiative in fields where the great institutions of the United States have established a dominant position.’ In the event, the Laboratory was established at Heidelberg in 1974, though not formally opened until 1978. The Director-General, Sir John Kendrew, here surveys the policy and achievements of this important new institute.  相似文献   
984.
Throughout 1982 Britain has been celebrating the Festival of India. Its purpose has been to focus attention on India's contribution to many aspects of human achievement—in art and literature, in dancing and drama, and in science and technology. In London, a special Science in India exhibition was staged at the Science Museum. This article reviews the scientific achievements of ancient and mediaeval India.  相似文献   
985.
A method has been presented in recent papers for deriving precisely stabilized waveform generators by relating them to second-order conservative oscillators. The present paper suggests a method for considerably generalizing the previous class ofgenerator models. This should enable the development of a larger variety of waveform generators with ease and flexibility. The new method is analyzed and is shown to possess implications to theoretical biology and other fields.  相似文献   
986.
外国直接投资对于中国技术创新作用的影响分析   总被引:11,自引:0,他引:11  
本文运用我国29个省、市、自治区从1995到2003年的面板数据定量地评估了外国直接投资对我国技术创新(用专利申请量来表征)作用的影响.结论认为:FDI对于中国的技术创新会发挥积极的影响,但前提是要跨越一定的人力资本门槛;FDI对我国外观设计的专利申请量影响程度最大,而对发明专利申请量影响最小,对实用新型的专利申请量影响次之;另外FDI对中国技术创新的影响也存在着明显的区域性特征,FDI对东部地区专利申请量的影响要强于对中部地区的影响,而FDI对于西部地区的专利申请量几乎没有影响.  相似文献   
987.
In 1982, the Small Business Innovation Development Act established the small business innovation research (SBIR) program. This program reserves a percentage of federal agencies’ extramural R&D budgets for research projects conducted by small businesses. When this Act was reauthorized in 1992, the selection criteria for funding dramatically increased the likelihood of funding for projects that promised to lead to commercial success. Using data from a survey of the SBIR program award recipients at NASA Langley Research Center, we address three questions about this change: (i) was there a shift to projects with more commercial potential? (ii) did these projects experience higher rates of commercial success? and (iii) was there a reduction in basic research accompanying the increased commercial success? Our analysis suggests, the answer to all three of these questions is ‘yes’.  相似文献   
988.
Thomas S. Kuhn (18 July 1922-17 June 1996)   总被引:1,自引:0,他引:1  
  相似文献   
989.
Lymphatic filariasis caused mainly by infection fromW. bancrofti andB. malayi remains a major cause of clinical morbidity in tropical and subtropical countries. Analysis ofB. malayi mf, infective larval and adult worm lysates for the activity of enzymes led to the demonstration of activities of three key enzymes of carbohydrate metabolism viz., Malate dehydrogenase (MDH), Malic enzyme (ME) and Glucose-6-phosphate dehydrogenase (G6PDH) in all the three stages of the parasite. The specific activity of all the three dehydrogenases was significantly high in mf lysate compared to their activity in lysates of the other two stages (P<0.001). Analysis by native polyacrylamide gel to their activity inlysates of the other two stages (P<0.001). Analysis by native polyacrylamide gel electrophoresis (PAGE) using 7.5% non-gradient gel showed the presence of two isoforms of each of the three enzymes (MDH, ME & G6PDH) in mf lysate, while only one form of each enzyme was present in L3 larval and adult worm lysates. Further proteolytic enzyme activity was demonstrated both in microfilarial and infective larval lysates ofB. malayi. While both mf and L3 larval lysates showed optimal protease activity at alkaline pH of 9.0, the mf lysate showed increased activity also at pH 3.0. The infective larval lysate was markedly inhibited by Tosylamide-L-Phenylalanine chloromethyl ketone (TPCK), a thiol protease inhibitor, while the protease activity in mf lysate was significantly inhibited by both TPCK and a serine protease inhibitor Phenyl Methyl Sulphonyl Flouride (PMSF). In sodium do-decyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), using gelatin copolymerized gel, the microfilarial lysate showed 3 protease molecules of 40 kDa, 180 kDa and 200 kDa and the L3 larval lysate had 6 protease molecules of 18, 25, 37, 49, 70 and 200 kDa size.  相似文献   
990.
Heat transfer in laminar tube flow with convective boundary conditions and axial heat conduction in the fluid is solved exactly. The effects of the external Biot numbers and the axial conduction in fluid on the temperature distribution and the local Nusselt number are determined for both the upstream and the downstream regions. In order to illustrate the effects of velocity profile, the results for the slug flow and the parabolic velocity profiles are plotted simultaneously. The heat transfer characteristics of the flow are found to be rather sensitive to the Péclét number, the external Biot numbers and the velocity profile in the thermal entrance region.  相似文献   
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