全文获取类型
收费全文 | 2641篇 |
免费 | 334篇 |
国内免费 | 469篇 |
专业分类
安全科学 | 732篇 |
废物处理 | 65篇 |
环保管理 | 507篇 |
综合类 | 1155篇 |
基础理论 | 216篇 |
污染及防治 | 283篇 |
评价与监测 | 91篇 |
社会与环境 | 94篇 |
灾害及防治 | 301篇 |
出版年
2024年 | 7篇 |
2023年 | 29篇 |
2022年 | 94篇 |
2021年 | 123篇 |
2020年 | 120篇 |
2019年 | 74篇 |
2018年 | 69篇 |
2017年 | 114篇 |
2016年 | 124篇 |
2015年 | 133篇 |
2014年 | 145篇 |
2013年 | 169篇 |
2012年 | 198篇 |
2011年 | 209篇 |
2010年 | 171篇 |
2009年 | 170篇 |
2008年 | 127篇 |
2007年 | 183篇 |
2006年 | 165篇 |
2005年 | 168篇 |
2004年 | 109篇 |
2003年 | 94篇 |
2002年 | 83篇 |
2001年 | 78篇 |
2000年 | 87篇 |
1999年 | 54篇 |
1998年 | 32篇 |
1997年 | 36篇 |
1996年 | 21篇 |
1995年 | 38篇 |
1994年 | 22篇 |
1993年 | 26篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 14篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1973年 | 3篇 |
1972年 | 7篇 |
1971年 | 9篇 |
1970年 | 3篇 |
排序方式: 共有3444条查询结果,搜索用时 125 毫秒
31.
32.
本文阐述了一种新型二级立式族进型颗粒层除尘器,它的关键技术采用独创的床外清灰及气流输送、滤料循环系统。该除尘器适用范围广、除尘效率高、成为新一代的除尘器专利产品。 相似文献
33.
Ossie Geifman-Holtzman Eliezer J. Holtzman Theresa J. Vadnais Vincent E. Phillips Eleanor L. Capeless Diana W. Bianchi MD 《黑龙江环境通报》1995,15(3):261-268
The objective of this study was to detect fetal HLA-DQα gene sequences in maternal blood. HLA-DQα genotypes of 70 pregnant women and their partners were determined for type A1. We specifically sought couples where the father, but not the mother, had genotype A1. In 12 women, maternal blood samples were flow-sorted. Candidate fetal cells were isolated and amplified by using PCR primers specific for a paternal HLA-DQα A1 allele. Fetal HLA-DQα A1 genotype was predicted from sorted cells; amniocytes or cheek swabs were used for confirmation. Six of twelve sorted samples had amplification products indicating the presence of the HLA-DQα A1 allele; 6/12 did not. Prediction of the fetal genotype was 100 per cent correct, as determined by subsequent amplification of amniocytes or cheek swabs. We conclude that paternally inherited uniquely fetal HLA-DQα gene sequences can be identified in maternal blood. This system permits the identification of fetal cells independent of fetal gender, and has the potential for non-invasive prenatal diagnosis of paternally inherited conditions. 相似文献
34.
A stopped-flow reversed flow injection method for the determination of free cyanide is proposed. Pyridine-barbituric acid mixture is injected in the flow system as reagent to form the colour species with cyanide. The flow is stopped when the reagent zone comes in the flow cell, where absorbance-time data are collected at 580nm wavelength. The linear range of the determination is 0.1 -10μg/ml CN-. The sampling rate is 60h-1 and the relative standard deviation is 1.6% (n=16) at 5.0 μg/ml CN-1 level. With satisfactory results, the proposed method was applied to the determination of free cyanide in wastewater without sample pretreatment. 相似文献
35.
Zhang Qide Wang Yuxi Yu Shuqing Song Liming Liu Xianwan Li Changzhi Lin Hejie 《环境科学学报(英文版)》1989,1(1):73-84
The authors seek, through tests on simulated sand samples in a wind tunnel and analysis of minerals combination and trace elements, to discover the environmental implications of flying-up, falling-down and concentration variation as a function of natural wind speed and direction, distance of movement, range and extent of influence on the atmospheric environment, of micro-granular components on the ground surface in the Keerqin desert area in northwest Liaoning Province of China. 相似文献
36.
37.
38.
Soil and water loss in the Lancang River-Mekong River watershed (in Yunnan section, China) and its control measures 总被引:1,自引:0,他引:1
MekongRiverisoriginatedinthenorthernrangeofTibetQinghaiPlateauofChina,flowingthroughsixcountries,theyareChina(YunnanProvince),M?.. 相似文献
39.
40.