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221.
R 指数、AR 指数:h 指数功能扩展的补充指标 总被引:32,自引:0,他引:32
分析了h 指数功能扩展后在科学家个人科研绩效评价中的三个缺陷,即缺乏灵敏度,缺乏区
分度,缺乏波动性。针对这些缺陷,提出了R 指数和AR 指数。R 指数用于解决h 指数的灵敏度和区分
度的问题;AR 指数用于解决h 指数只升不降的问题。利用17 位普赖斯奖得主的论文数量和被引频次数
量进行了h 指数、R 指数和AR 指数的测算。针对h 指数与R 指数或AR 指数配伍使用后的双因素问题,
设计了标准化(h,R)指数和等效(h,R)指数。实测数据证明R 指数和AR 指数是h 指数功能扩展的补
充指标。 相似文献
分度,缺乏波动性。针对这些缺陷,提出了R 指数和AR 指数。R 指数用于解决h 指数的灵敏度和区分
度的问题;AR 指数用于解决h 指数只升不降的问题。利用17 位普赖斯奖得主的论文数量和被引频次数
量进行了h 指数、R 指数和AR 指数的测算。针对h 指数与R 指数或AR 指数配伍使用后的双因素问题,
设计了标准化(h,R)指数和等效(h,R)指数。实测数据证明R 指数和AR 指数是h 指数功能扩展的补
充指标。 相似文献
222.
This study evaluates trends in quality of nanotechnology and nanoscience papers produced by authors from the People's Republic of China (PRC). The metric used to gauge quality is ratio of highly cited nanotechnology papers to total nanotechnology papers produced in sequential time frames. The USA is both the most prolific nanotechnology publishing country and most represented country on highly cited nanotechnology papers (both in absolute numbers of highly cited papers and highly cited papers relative to total publications) over the 1998-2003 time frame, based on the SCl/SSCl databases. Some of the smaller hi-tech countries have relatively high ratios (-2) of highly cited papers to total publications (e.g. Denmark, Netherlands, Switzerland). Countries that have exhibited rapid growth in SCl/SSCl nanotechnology paper production in recent years (e.g. PRC, South Korea) had ratios an order of magnitude less than that of the USA for 1998, but by 2003 had increased to about 20% that of the USA (-2.5). PRC and South Korea have climbed in the publications rankings from 6th and 9th in 1998, respectively, to 2nd and 6th in 2005, respectively. PRC's ratio monotonically increased from 0.16 to 0.45 over the 1998-2003 period, and South Korea's ratio increased from 0.11 to about 0.6 over that same period, indicating their papers are getting more and more citations proportionately. Thus, under rapid growth conditions, PRC and South Korea have been able to increase their share of participation in highly cited papers. As of 2003, PRC and South Korea have ratios comparable to nations like Japan, France, Italy, and Australia but not yet approaching those of the highly cited countries. None of the top ten publications producing institutions are from the USA, while all of the top ten highly cited publications producers are from the USA. Over the 1998-2003 time period, the top six total publications producing institutions (globally) remained the same, with Chinese Academy of Sciences (which consists 相似文献
223.
Although, Feyerabend himself seems never to have used the term ‘perspectivism’ to designate a philosophical position, I think his views about science are very well characterized as perspectival. In fact, his later writings contain much that contributes to current thinking about perspectivism. I would like, therefore, to distinguish my own perspectivism from Feyerabend's. In the end, I will argue, his perspectivism is lacking enough of the critical bite that the younger Feyerabend found so attractive in Popper's philosophy. 相似文献
224.
Ronald N. Giere 《Studies in history and philosophy of science》2009,40(2):221-223
Adopting the stage metaphor suggested in Brown’s review, and treating Scientific perspectivism as a play in five acts, I respond to his review as a playwright might respond to a generally favorable review. Taking the reader behind the stage door, I discuss the playwright’s intentions for each act, paying special attention to the expected audience for the play as a whole. The result, therefore, supplements the review from the standpoint of the playwright. It also provides answers to some of the reviewer’s questions. 相似文献
225.
Ronald J. Kass 《西北部美国博物学家》2011,48(1)
A checklist of the vascular plants of the House Range, Juab and Millard counties, Utah, is presented. A flora of 373 species and infraspecific taxa in 231 genera and 60 families are reported. The geology, physiography, climate, and plant communities are briefly discussed. Several endemics occur in the study area and a new taxon has been described. 相似文献
226.
Previous work suggested that Gambel oak seedlings are rare in the northern parts of its range in Utah where summer rainfall is relatively low but should be abundant in southern parts of the range where summer rainfall is usually high. Gambel oak grades from a relatively minor component of a ponderosa pine/mixed conifer assemblage in the south to a virtually monotypic formation in the north, where it exists as long-lived clones. Quadrat analysis in Arizona and New Mexico, within the oak zone, revealed a seedling density ranging from 120 to 1320 per hectare. We found a significant tendency of seedlings to be located on the NE (cool, shady) side of sheltering objects in the environment. Mature ponderosa pine ranged in density from ca 40 to 500 stems per hectare, whereas mature Gambel oak ranged from ca 10 to 20 genets per hectare with ca 1 to 7 ramets per clone. These results support our previous conclusion that Gambel oak in northern Utah probably became established as a minor component of a mixed pine/oak woodland at a time in mid-Holocene when summer rainfall was much higher than today. 相似文献
227.
Ronald M. Lanner 《西北部美国博物学家》2011,45(2)
Limber pine ( Pinus flexilis James) seeds are usually wingless but occasionally have short, stubby wings. To determine the effectiveness of these wings in slowing seed descent, rates of fall were determined before and after wing removal. A similar experiment was conducted with seeds of Himalayan blue pine ( P. griffithii McClelland), a white pine with typically long seed wings. The short wings of limber pine seeds were found to influence rate of seed fall far less than the wings of Himalayan blue pine. This is consistent with evidence suggesting that limber pine seeds are not effectively dispersed by wind but are dependent for dispersal on Clark's Nutcracker ( Nucifraga columbiana ). 相似文献
228.
Named as a new species from the House Range of Millard County, Utah, as Primula domensis Kass & Welsh. 相似文献
229.