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361.
对土壤中总汞的两种不同测定方法进行了对比分析.通过方法检出限、精密度、准确度和加标回收率的对比,结果表明,水浴消解-原子荧光光谱法检出限为2.1 ng/g,精密度为2.52~4.63%,加标回收率介于94%~ 104%;汞分析仪直接测定法检出限为0.08 ng/g,精密度为2.89~ 5.61%,加标回收率介于90%~102%.相比水浴消解-原子荧光法,直接测定法操作更加简单、便捷,而且无繁琐的前处理环节,适于大批量土壤中总汞的分析测定,是一个比较理想的分析方法. 相似文献
362.
利用海水水质单因子判别法、富营养化指数法和浮游藻类生物多样性指数法从不同角度对近3年北黄海丹东近岸海域的水质状况、富营养化状况和生境质量状况进行对比评价和分析.结果表明:以理化指标为评价因子的水质状况与富营养化状况评价结果在四类和二类功能区水体中一致性均较好;以生物指标为评价因子的生物多样性指数评价同水质状况和富营养化评价结果在四类功能区水体中的一致性较好,而在二类功能区水体中一致性较差. 相似文献
363.
环境空气PM2.5连续监测系统手工采样比对测试 总被引:2,自引:1,他引:1
借鉴美国EPA关于PM2.5连续监测仪器手工采样比对测试的性能指标和检测方法,结合我国现行的相关技术规范,选取两种不同原理4种型号典型的进口和国产环境空气PM2.5连续自动监测系统,分别在春、夏、秋、冬这4个季节开展了PM2.5连续自动监测与手工采样测量(重量法)之间的比对测试.研究确定了符合我国环境质量现状和环境监测管理需求的PM2.5连续监测系统与手工采样比对测试(调试)的质控措施要求(手工采样测量结果平行性≤5μg·m-3或5%)和技术指标要求(线性回归方程斜率1±0.15;截距0±10;相关系数≥0.95)以及相应的操作方法,为我国环境空气PM2.5连续自动监测系统的现场有效使用和数据质量保证提供了必要的技术手段和质控方法. 相似文献
364.
海南岛生态环境质量分析评价 总被引:1,自引:0,他引:1
运用遥感和地理信息系统等技术 ,按照景观生态学的原理 ,对海南生态环境现状进行了评价 ,并对近十年来的变化进行了对比分析。结果表明 ,海南生态环境质量由中部向外依次降低 ,天然林从数量上看面积在减少 ,从空间上看沿着边缘线向中部山区退缩。另外 ,土地沙化 /土地退化在向着恢复逆转的方向发展。 相似文献
365.
Jia-Ren Liu Hong-Wei Dong Xuan-Le Tang Xiao-Hui Han Chang-Hao Sun Bao-Feng Yang 《Environmental pollution (Barking, Essex : 1987)》2009,157(2):357-364
A previous study showed that the cancer mortalities are higher for residents who lived nearby the Songhua River heavily polluted by organic contamination. It is important to determine its risk of carcinogenic potential. Short-term genotoxic bio-assays using Salmonella, Sister Chromatid Exchange (SCE), and Micronuclei (MN) assays were employed to examine the genotoxic activity of ether extracts of water samples taken from the Songhua River. The results of the Salmonella bioassay indicated that there were indirect frame-shift mutagens in the water samples. A dose-response relationship for the SCE and MN assays was obtained. These results showed that organic extracts of water samples have genotoxic activity and the risk of carcinogenic potential to human health. The mutagenesis of water samples had changed compared to the results in 1994-1995. An increasing trend of risk of carcinogenic potential in the Songhua River after ten years should be noted and needs to be studied further. 相似文献
366.
我国城市人居环境改善与能源消费关系研究 总被引:5,自引:0,他引:5
陆歆弘 《中国人口.资源与环境》2010,20(4)
随着我国经济建设水平和综合国力的提高,近20年来人居环境的改善有目共睹。但与此同时能源消耗和温室气体排放增加是个不容回避的问题。本文选择城市人均住宅建筑面积、人均拥有道路面积、人均公园绿地面积三个指标反映我国城市人居环境质量,研究了我国城市人居环境改善和能源消费之间的变化关系。通过与发达国家的对比,发现我国人居环境建设并没有像发达国家那样带来人均生活能源消费的同幅增长,而是出现了"喇叭口"现象,两个指标之间最大相差2.4倍,但也存在一个适度的节能居住条件,中国目前已经偏离了这个最优点并处于耗能的上升期。德国与我国类似,在户均住房面积和人均能源消费量之间也存在一种类似U型曲线关系,但上升阶段明显比我国更陡。虽然与德国、日本、美国相比我国在人均能源消费上最少,但从总量和长期趋势来看,中国仍面临着重重挑战,必须通过使用节能技术和新能源来降低能耗、减少二氧化碳排放,营造节能又宜居的城市人居环境。 相似文献
367.
分析了石灰石—石膏湿法脱硫系统中碳酸盐含量的两种测定方法,并对各测定方法的优、缺点和适用范围进行了比较。 相似文献
368.
369.
Philopatry, male presence and grooming reciprocation among female primates: a comparative perspective 总被引:3,自引:0,他引:3
Competition for food and a safe location in a group are considered to be the main determinants of variation in social relationships
among female primates. The effect of the presence of males is usually overlooked, however. Here we put forward two hypotheses
connecting the (relative) number of males in a group, a statistic measuring the strength of positive relationships among females
(the degree of reciprocity of grooming) and female residence. Under the first hypothesis, we assumed that philopatric females
suffer especially from competition for males. Because females of these species are restrained to their native group and thus
do not move to groups where better conditions (i.e. more males) prevail, a higher socionomic sex ratio would imply reduced
competition and this should be reflected in better relationships among females (i.e. in a higher degree of reciprocation).
The second hypothesis is based on the contention of Wrangham (1987) that groups with more males are better able to defend
large food sources: in these groups female relationships would suffer less from within-group competition for food. We therefore
also expected a positive correlation between the absolute number of males and grooming reciprocation. To test the hypotheses,
matrices of grooming interactions were collected by going through the primatological literature. For ten female-resident and
four female-transfer primate species, the degree of grooming reciprocation was quantified using a specially adapted matrix
statistic. The results favoured the first (competition for males) hypothesis. The degree of grooming reciprocation among females
was positively correlated with socionomic sex ratio, but neither with group size nor with the absolute number of males. Correlations
between the degree of reciprocity and sex ratio were confirmed at three levels: within the same group at different points
in time, between groups of the same species, and between species. In addition, the degree of reciprocation increased with
sex ratio more strongly in typical single/variable male than in multi-male species. This we interpreted as a direct consequence
of the lower social availability of males for females in multi-male groups than single-male groups. In turn, this effect may
be due to males competing for females in multi-male groups.
Received: 28 May 1997 / Accepted after revision: 9 November 1997 相似文献
370.