全文获取类型
收费全文 | 664篇 |
免费 | 32篇 |
国内免费 | 14篇 |
专业分类
安全科学 | 41篇 |
废物处理 | 24篇 |
环保管理 | 154篇 |
综合类 | 73篇 |
基础理论 | 213篇 |
环境理论 | 2篇 |
污染及防治 | 119篇 |
评价与监测 | 41篇 |
社会与环境 | 32篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 10篇 |
2022年 | 8篇 |
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 10篇 |
2018年 | 29篇 |
2017年 | 26篇 |
2016年 | 34篇 |
2015年 | 32篇 |
2014年 | 27篇 |
2013年 | 53篇 |
2012年 | 37篇 |
2011年 | 52篇 |
2010年 | 40篇 |
2009年 | 33篇 |
2008年 | 43篇 |
2007年 | 48篇 |
2006年 | 37篇 |
2005年 | 12篇 |
2004年 | 23篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有710条查询结果,搜索用时 328 毫秒
61.
Service has received increasing attention in the management literature, yet sustainability of service is often overlooked. In this Incubator we examine the potential for client involvement through shared and self‐leadership to foster empathy enhanced service and reduced costs, both of which may support a more sustainable service delivery process. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
62.
Haiting Zhang Huiyu Dong Craig Adams Zhimin Qiang Gang Luan Lei Wang 《环境科学学报(英文版)》2015,27(7):116-124
The chemistry associated with the disinfection of aquarium seawater is more complicated than that of freshwater, therefore limited information is available on the formation and speciation of disinfection byproducts(DBPs) in marine aquaria. In this study, the effects of organic precursors, bromide(Br-) and pre-ozonation on the formation and speciation of several typical classes of DBPs, including trihalomethanes(THM4), haloacetic acids(HAAs),iodinated trihalomethanes(I-THMs), and haloacetamides(HAc Ams), were investigated during the chlorination/chloramination of aquarium seawater. Results indicate that with an increase in dissolved organic carbon concentration from 4.5 to 9.4 mg/L, the concentrations of THM4 and HAAs increased by 3.2–7.8 times under chlorination and by 1.1–2.3 times under chloramination. An increase in Br-concentration from 3 to 68 mg/L generally enhanced the formation of THM4, I-THMs and HAc Ams and increased the bromine substitution factors of all studied DBPs as well, whereas it impacted insignificantly on the yield of HAAs. Pre-ozonation with 1 mg/L O3 dose substantially reduced the formation of all studied DBPs in the subsequent chlorination and I-THMs in the subsequent chloramination. Because chloramination produces much lower amounts of DBPs than chlorination, it tends to be more suitable for disinfection of aquarium seawater. 相似文献
63.
64.
65.
Gebbink WA Letcher RJ Burgess NM Champoux L Elliott JE Hebert CE Martin P Wayland M Weseloh DV Wilson L 《Environment international》2011,37(7):1175-1182
In the present study, we identified and examined the spatial trends, sources and dietary relationships of bioaccumulative perfluorinated sulfonate (PFSA; C(6), C(8), and C(10) chain lengths) and carboxylate (PFCA; C(6) to C(15) chain lengths) contaminants, as well as precursor compounds including several perfluorinated sulfonamides, and fluorotelomer acids and alcohols, in individual eggs (collected in 2008) from four gull species [glaucous-winged (Larus glaucescens), California (Larus californicus), ring-billed (Larus delawarensis) and herring (Larus argentatus) gulls] from 15 marine and freshwater colony sites in provinces across Canada. The pattern of PFSAs was dominated by perfluorooctane sulfonate (PFOS; >89% of ΣPFSA concentration) regardless of egg collection location. The highest ΣPFSA concentrations were found in the eggs collected in the urbanized areas in the Great Lakes and the St. Lawrence River area [Big Chicken Island 308 ng/g ww, Toronto Harbour 486 ng/g ww, and Ile Deslauriers (HG) 299 ng/g ww]. Also, eggs from all freshwater colony sites had higher ΣPFSA concentrations, which were significant (p<0.05) in many cases, compared to the marine sites with the exception of the Sable Island colony in Atlantic Canada off the coast of Nova Scotia. C(6) to C(15) chain length PFCAs were detected in the eggs, although the pattern was variable among the 15 sites, where PFUnA and PFTrA dominated the pattern for most colonies. Like the ΣPFSA, the highest concentrations of ΣPFCA were found in the eggs from Big Chicken Island, Toronto Harbour, Ile Deslauriers (HG), and Sable Island, although not all freshwater sites had higher concentrations compared to marine sites. Dietary tracers [δ(15)N and δ(13)C stable isotopes (SIs)] revealed that PFSA and PFCA exposure is colony dependent. SI signatures suggested that gulls from most marine colony sites were exposed to PFCs via marine prey. The exception was the Mandarte Island colony in Pacific British Columbia, where PFSA and PFCA exposure appeared to be via terrestrial and/or freshwater prey consumption. The same was true for the freshwater sites where egg SIs suggested both aquatic and terrestrial prey consumption as the source for PFC exposure depending on the colony. Both aquatic (marine and freshwater) and terrestrial prey are likely sources of PFC exposure to gulls but exposure scenarios are colony-specific. 相似文献
66.
Lisa G. Shaffer Justine Coppinger S. Annie Morton Sarah Alliman Jessica Burleson Ryan Traylor Cathryn Walker Steve Byerly Allen N. Lamb Roger Schultz J. Britt Ravnan Catherine D. Kashork Beth S. Torchia Scott Sulpizio Kyle Sundin Mack Schermer Karl Adler Stephanie Dallaire Blake C. Ballif 《黑龙江环境通报》2011,31(8):778-787
67.
68.
More knowledge of the proximate factors that influence parasite loads would help us understand the selective pressures faced by hosts and host-parasite evolution. Testosterone has been associated with increased parasite loads in vertebrates. Here we asked whether experimentally elevated testosterone affected ectoparasite loads in free-ranging northern fence lizards (Sceloporus undulatus hyacinthinus). Males were captured, given testosterone or sham implants, and released. In 2 consecutive years, testosterone-implanted males had significantly more ectoparasites at recapture than did controls. Additionally, ectoparasite loads were positively correlated with testosterone concentrations in unmanipulated males, and males had significantly more ectoparasites than did females. The results are consistent with an effect of testosterone on parasite loads. However, rather than elevated testosterone increasing mite loads in experimental males, it appeared that high testosterone inhibited a natural seasonal decline in mite loads. Testosterone-implanted males also lost body mass whereas controls gained mass. Among controls, those retaining the most ectoparasites over the course of the experiment experienced the smallest gains in body mass, suggesting that the mites are costly. 相似文献
69.
70.