首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   93篇
  免费   0篇
安全科学   2篇
环保管理   4篇
综合类   52篇
基础理论   20篇
污染及防治   14篇
社会与环境   1篇
  2017年   1篇
  2015年   1篇
  2013年   2篇
  2012年   3篇
  2010年   2篇
  2009年   2篇
  2008年   4篇
  2007年   4篇
  2006年   2篇
  2005年   2篇
  2004年   1篇
  2003年   4篇
  2002年   3篇
  2001年   1篇
  2000年   3篇
  1999年   2篇
  1998年   4篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   3篇
  1988年   2篇
  1986年   2篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1966年   4篇
  1965年   2篇
  1964年   1篇
  1963年   3篇
  1962年   2篇
  1961年   2篇
  1960年   2篇
  1959年   3篇
  1958年   4篇
  1957年   3篇
  1955年   1篇
  1954年   4篇
  1940年   1篇
  1937年   1篇
排序方式: 共有93条查询结果,搜索用时 15 毫秒
71.
An exploratory field study conducted in Europe and the U.S. examines the challenges of managing environmental quality at the enterprise level. The results show that effective environmental quality management depend to a considerable degree on the ability to deal with the multidisciplinary organizational, technical, social, and cultural issues involved in the integration of environmental cost accounting at the enterprise level. The study suggests that the tools and techniques of modern project management can provide an important framework for developing and implementing environmental quality control systems. The recommendations put considerable emphasis on the human side, focusing on the criteria under which environmental quality is best achievable. Strong senior management leadership, people skills, organizational linkages, and alliances, all are critical for dealing with the complexities of managing responsibly toward sustained developments in today’s organizations.  相似文献   
72.
Wir danken M. Chlupka-Spohr, R. Handel, Chr. Trautmann und J. Vetter für wertvolle Anregungen zu diesem Bericht.  相似文献   
73.
We report on a live-born male with 46,XY/47,XY+4/47,XY,+6 mosaicism. Trisomy 4 mosaicism was detected by karyotyping chorionic villus samples (CVS) and was confirmed by the analysis of 16 metaphases obtained from cultured amniotic fluid cells. Eight metaphases were normal (46,XY), two had trisomy 4 (47,XY,+4), and two had trisomy 6 (47,XY,+6). Two postnatal chromosomal analyses of blood lymphocytes at birth and at the age of one week were normal. Chromosomal analysis of cultured skin fibroblasts from the right inguinal region at the age of 12 months revealed trisomy 4 (47,XY,+4) in 49 metaphases, trisomy 6 (47,XY,+6) in 2 metaphases, and a normal karyotype (46,XY) in 49 cells of the 100 analyzed metaphases, respectively. The main clinical findings consist of prenatal growth retardation, hypoplasia of the right side of the face, a dysplastic and posteriorly rotated right ear, a high vaulted palate, retrognathia, aplasia of the right thumb, hypoplasia of the fingernails, a deep sacral dimple, and patchy skin hypopigmentation of the right leg. When last seen at the age of 14 months, his development was nearly normal. Five patients with trisomy 4 mosaicism have been reported previously, but none with an additional trisomy 6 mosaicism. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
74.
Influences on dust emissions from livestock operations are number, weight, and kind of animals and characteristics of the housing system. Differences between facilities cannot be explained solely by mechanistic input variables. The objective of this study was to characterize the main input variables for modeling emissions of particulate matter with a mass median diameter < or = 10 microm (PM10) from swine facilities using a data-based model. Investigations were performed in mechanically ventilated facilities for weaning, growing-finishing, and sows in Italy and Germany. The measurements included inside and outside concentration of airborne PM10 particles (scatter light photometry), ventilation rate (calibrated measuring fans), indoor air climate at a measuring frequency of 60 s, feeding times, and animal-related data such as weight and animal activity. Dust concentration and emission were simulated using a dynamic transfer function. The results indicated that the average PM10 emission rate was influenced considerably by housing system. The simulation of the PM10 emission rate resulted in a mean percentage error per data set of 21 to 39%, whereas the average simulated and measured emission rate per data set differed by about 4 to 19%. High prediction errors occurred especially during situations in which the absolute level and spatial location of the measured activity peaks did not correspond with the measured dust peaks. Further recommendations of the study were to improve continuous and accurate measurements of input variables, such as the activity level in animal houses, and to optimize the amount of measuring days in relation to the model accuracy.  相似文献   
75.
A computer aided tool was created for the calculation of emission values in Saxony. It is based on the Geographic Information System ArcInfo and enables the emission values for past, present and future periods to be assessed. At present, the anthropogenic air pollutants SO2, NOx, CO, NH3, NMVOC, TSP, CO2, CH4 and N2O can be calculated by means of emission factors and statistical values. The tool is open to future expansions. The moduls represent the following emission groups: Power stations, large agricultural farms and large industrial plants as point sources, as well as transport, households, small consumer and the total emission of agriculture as area sources. The local resolution of emission values, the relationship of emission values to geographic or political territories, the inclusion of a high resolved digital street network, and the use of actual data concerning land use, density of population and density of build up areas are realized by GIS ArcInfo. The dynamic emission inventory can be used, alone or in conjunction with an atmospheric dispersion model, to assess trends in air quality.  相似文献   
76.
77.
78.
79.
80.
The scepticism prevailing with regard to the promotion of an elite in science--not, however, in the arts or in sports--originates from increasing mistrust vis-à-vis a new power based on knowledge held by certain social classes only. It has to be removed by opening the education system, by establishing new patterns of confidence between scientists and policy-makers, and by linking knowledge and responsibility. The confusion between elite and talent is another cause of this sceptical attitude. The task of education is not, however, to promote an elite, but to promote gifted pupils. Whether gifted young people will eventually become part of an élite is another question.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号