全文获取类型
收费全文 | 3318篇 |
免费 | 59篇 |
国内免费 | 115篇 |
专业分类
安全科学 | 157篇 |
废物处理 | 273篇 |
环保管理 | 575篇 |
综合类 | 390篇 |
基础理论 | 684篇 |
环境理论 | 5篇 |
污染及防治 | 1000篇 |
评价与监测 | 265篇 |
社会与环境 | 121篇 |
灾害及防治 | 22篇 |
出版年
2023年 | 25篇 |
2022年 | 47篇 |
2021年 | 53篇 |
2020年 | 36篇 |
2019年 | 56篇 |
2018年 | 113篇 |
2017年 | 102篇 |
2016年 | 139篇 |
2015年 | 98篇 |
2014年 | 111篇 |
2013年 | 260篇 |
2012年 | 185篇 |
2011年 | 231篇 |
2010年 | 147篇 |
2009年 | 185篇 |
2008年 | 192篇 |
2007年 | 206篇 |
2006年 | 177篇 |
2005年 | 145篇 |
2004年 | 149篇 |
2003年 | 131篇 |
2002年 | 118篇 |
2001年 | 76篇 |
2000年 | 53篇 |
1999年 | 41篇 |
1998年 | 37篇 |
1997年 | 40篇 |
1996年 | 28篇 |
1995年 | 26篇 |
1994年 | 21篇 |
1993年 | 31篇 |
1992年 | 19篇 |
1991年 | 26篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1978年 | 8篇 |
1976年 | 6篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 5篇 |
排序方式: 共有3492条查询结果,搜索用时 31 毫秒
1.
Poudel Jeeban Lee You Min Kim Hyeok Jin Oh Sea Cheon 《Journal of Material Cycles and Waste Management》2021,23(1):214-221
Journal of Material Cycles and Waste Management - Owing to various advantages of artificial marble compared to natural marble, its application has been rising exponentially, which has resulted in... 相似文献
2.
Christopher E. Rushton James E. Tate Simon P. Shepherd David C. Carslaw 《Journal of the Air & Waste Management Association (1995)》2018,68(2):111-122
Emissions of nitrogen oxides (NOx) by vehicles in real driving environments are only partially understood. This has been brought to the attention of the world with recent revelations of the cheating of the type of approval tests exposed in the dieselgate scandal. Remote-sensing devices offer investigators an opportunity to directly measure in situ real driving emissions of tens of thousands of vehicles. Remote-sensing NO2 measurements are not as widely available as would be desirable. The aim of this study is to improve the ability of investigators to estimate the NO2 emissions and to improve the confidence of the total NOx results calculated from standard remote-sensing device (RSD) measurements. The accuracy of the RSD speed and acceleration module was also validated using state-of-the-art onboard global positioning system (GPS) tracking. Two RSDs used in roadside vehicle emissions surveys were tested side by side under off-carriageway conditions away from transient pollution sources to ascertain the consistency of their measurements. The speed correlation was consistent across the range of measurements at 95% confidence and the acceleration correlation was consistent at 95% confidence intervals for all but the most extreme acceleration cases. VSP was consistent at 95% confidence across all measurements except for those at VSP ≥ 15 kW t?1, which show a small underestimate. The controlled distribution gas nitric oxide measurements follow a normal distribution with 2σ equal to 18.9% of the mean, compared to 15% observed during factory calibration indicative of additional error introduced into the system. Systematic errors of +84 ppm were observed but within the tolerance of the control gas. Interinstrument correlation was performed, with the relationship between the FEAT and the RSD4600 being linear with a gradient of 0.93 and an R2 of 0.85, indicating good correlation. A new method to calculate NOx emissions using fractional NO2 combined with NO measurements made by the RSD4600 was constructed, validated, and shown to be more accurate than previous methods.Implications: Synchronized remote-sensing measurements of NO were taken using two different remote-sensing devices in an off-road study. It was found that the measurements taken by both instruments were well correlated. Fractional NO2 measurements from a prior study, measurable on only one device, were used to create new NOx emission factors for the device that could not be measured by the second device. These estimates were validated against direct measurement of total NOx emission factors and shown to be an improvement on previous methodologies. Validation of vehicle-specific power was performed with good correlation observed. 相似文献
3.
4.
5.
6.
7.
8.
Chih-Ping Chen Schu-Rern Chern Wayseen Wang Chen-Chi Lee Wen-Lin Chen Li-Feng Chen Tung-Yao Chang Chin-Yuan Tzen 《黑龙江环境通报》2001,21(5):346-350
A prenatal diagnosis of partial monosomy 18p(18p11.2→pter) and trisomy 21q(21q22.3→qter) in a fetus with alobar holoprosencephaly (HPE) and premaxillary agenesis (PMA) but without the classical Down syndrome phenotype is reported. A 27-year-old primigravida woman was referred for genetic counselling at 21 weeks' gestation due to sonographic findings of craniofacial abnormalities. Level II ultrasonograms manifested alobar HPE and median orofacial cleft. Cytogenetic analysis and fluorescence in situ hybridization (FISH) on cells obtained from amniocentesis revealed partial monosomy 18p and a cryptic duplication of 21q,46,XY,der(18)t(18;21)(p11.2;q22.3), resulting from a maternal t(18;21) reciprocal translocation. The breakpoints were ascertained by molecular genetic analysis. The pregnancy was terminated. Autopsy showed alobar HPE with PMA, pituitary dysplasia, clinodactyly and classical 18p deletion phenotype but without the presence of major typical phenotypic features of Down syndrome. The phenotype of this antenatally diagnosed case is compared with those observed in six previously reported cases with monosomy 18p due to 18;21 translocation. The present study is the first report of concomitant deletion of HPE critical region of chromosome 18p11.3 and cryptic duplication of a small segment of distal chromosome 21q22.3 outside Down syndrome critical region. The present study shows that cytogenetic analyses are important in detecting chromosomal aberrations in pregnancies with prenatally detected craniofacial abnormalities, and adjunctive molecular investigations are useful in elucidating the genetic pathogenesis of dysmorphism. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
9.
10.