全文获取类型
| 收费全文 | 1089篇 |
| 免费 | 267篇 |
| 国内免费 | 98篇 |
专业分类
| 安全科学 | 39篇 |
| 废物处理 | 48篇 |
| 环保管理 | 114篇 |
| 综合类 | 602篇 |
| 基础理论 | 174篇 |
| 污染及防治 | 352篇 |
| 评价与监测 | 100篇 |
| 社会与环境 | 24篇 |
| 灾害及防治 | 1篇 |
出版年
| 2025年 | 7篇 |
| 2024年 | 22篇 |
| 2023年 | 41篇 |
| 2022年 | 34篇 |
| 2021年 | 45篇 |
| 2020年 | 42篇 |
| 2019年 | 45篇 |
| 2018年 | 38篇 |
| 2017年 | 43篇 |
| 2016年 | 50篇 |
| 2015年 | 53篇 |
| 2014年 | 65篇 |
| 2013年 | 112篇 |
| 2012年 | 72篇 |
| 2011年 | 103篇 |
| 2010年 | 60篇 |
| 2009年 | 68篇 |
| 2008年 | 64篇 |
| 2007年 | 57篇 |
| 2006年 | 55篇 |
| 2005年 | 44篇 |
| 2004年 | 39篇 |
| 2003年 | 49篇 |
| 2002年 | 31篇 |
| 2001年 | 27篇 |
| 2000年 | 35篇 |
| 1999年 | 25篇 |
| 1998年 | 24篇 |
| 1997年 | 24篇 |
| 1996年 | 12篇 |
| 1995年 | 12篇 |
| 1994年 | 17篇 |
| 1993年 | 19篇 |
| 1992年 | 14篇 |
| 1991年 | 2篇 |
| 1990年 | 1篇 |
| 1987年 | 1篇 |
| 1985年 | 1篇 |
| 1982年 | 1篇 |
排序方式： 共有1454条查询结果，搜索用时 0 毫秒
131.
Klaassien J. Ganzeveld Annechien van Hagen Martin H. van Agteren Wim de Koning Anton J. M. Schoot Uiterkamp 《Journal of Cleaner Production》1999,7(6):690
Two types of fermented organic waste (trade and industry waste and fruit and vegetable waste) were successfully used as a sole carbon source to produce poly-3-hydroxybutyrate-co-valerate (PHBV) by Ralstonia eutrophus (formerly Alcaligenes eutrophus) via oxygen limitation.The production of PHBV could be optimized by optimizing the oxygen transfer through the fermentor. Thereby, a peak concentration of 1.1 g PHBV per liter cell suspension, 40 w% of cell dry weight, was obtained at an aeration rate of 0.24 mol O2/h·kg biomass. The yield of PHBV on the fatty acid concentration in the organic waste was 0.16 g polymer/g volatile organic matter. The process obtained, compares well with the commercial production process of PHBV based on glucose. 相似文献
132.
长江流域是我国重要的畜禽养殖区,也是最重要的生态带和经济带,提高该区域畜禽粪污处理利用水平,对保护长江流域生态环境,推动区域经济可持续发展具有重要意义。以该区域平原地429个畜禽规模养殖场为研究对象,围绕畜禽粪污收集、处理、粪肥还田利用等畜禽粪污资源化利用全链条技术深入剖析,分析该区畜禽粪污资源化利用关键工艺技术与设施装备。结果表明:畜禽规模养殖场粪污收集方式以干清粪为主,固体粪便普遍采用堆沤处理,72.3%以上的养殖场堆(沤)肥设施面积符合规范要求;畜禽粪水处理主要采用贮存和厌氧发酵技术,仅17.89%的养殖场粪水贮存池容积和67.5%的养殖场沼气发酵容积达到建设规范要求;粪肥还田是粪污资源化利用主要方向,以水果蔬菜等经济作物为主,但存在养殖场配套粪肥消纳土地面积不足等问题,近25.56%的养殖场未达到要求。建议根据该区域养殖和区位条件,进一步规范提升粪污资源化利用技术,提高粪污资源化利用技术和装备水平,引导规模养殖场按照种养平衡的要求配套消纳土地,同时加强对施用粪肥的农田土壤进行跟踪评估,提高粪肥还田利用水平。 相似文献
133.
134.
Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47 × 10^5±0.11× 10^5 U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to S.0 （optimum pH 3.5）. The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil （used in planting trees） and rice soil （originating as red soil）. The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil. 相似文献
135.
白洋淀的纤毛虫及与水质污染的关系 总被引：5，自引：0，他引：5
对白洋淀纤毛虫的种类组成、优势种进行了初步调查，同时对水质进行理化监测，共鉴定出纤毛虫４８种。根据Ｍａｒｓｓｏｎ引出的污水生物体系法分析，白洋淀纤毛虫主要由耐有机污染的种群组成。说明白洋淀主要受有机污染。纤毛虫的种类数与水体中ＴＮ、ＴＰ、ＢＯＤ５有着密切关系。 相似文献
136.
《环境科学学报(英文版)》2023,35(4):387-395
This study examined the effectiveness for degradation of hydrophobic (HPO), transphilic (TPI) and hydrophilic (HPI) fractions of natural organic matter (NOM) during UV/H2O2, UV/TiO2 and UV/K2S2O8 (UV/PS) advanced oxidation processes (AOPs). The changing characteristics of NOM were evaluated by dissolved organic carbon (DOC), the specific UV absorbance (SUVA), trihalomethanes formation potential (THMFP), organic halogen adsorbable on activated carbon formation potential (AOXFP) and parallel factor analysis of excitation–emission matrices (PARAFAC-EEMs). In the three UV-based AOPs, HPI fraction with low molecular weight and aromaticity was more likely to degradate than HPO and TPI, and the removal efficiency of SUVA for HPO was much higher than TPI and HPI fraction. In terms of the specific THMFP of HPO, TPI and HPI, a reduction was achieved in the UV/H2O2 process, and the higest removal rate even reached to 83%. UV/TiO2 and UV/PS processes can only decrease the specific THMFP of HPI. The specific AOXFP of HPO, TPI and HPI fractions were all able to be degraded by the three UV-based AOPs, and HPO content is more susceptible to decompose than TPI and HPI content. UV/H2O2 was found to be the most effective treatment for the removal of THMFP and AOXFP under given conditions. C1 (microbial or marine derived humic-like substances), C2 (terrestrially derived humic-like substances) and C3 (tryptophan-like proteins) fluorescent components of HPO fraction were fairly labile across the UV-based AOPs treatment. C3 of each fraction of NOM was the most resistant to degrade upon the UV-based AOPs. Results from this study may provide the prediction about the consequence of UV-based AOPs for the degradation of different fractions of NOM with varied characteristics. 相似文献
137.
138.
《环境科学学报(英文版)》2024,36(3):732-740
Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m3)and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution conditions.In this study,we present an optimized method for an-alyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fluorescence de-tector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analy-sis in ambient aerosol samples were investigated especially for those collected in pollution episodes.The results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH4+.To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample extract.After pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by HPLC-FLD.The recoveries are in the range of 67％-106％.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enan-tiomers determination.We suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the influence of biomass burning. 相似文献
139.
高温嗜粪菌的选育和猪粪发酵研究 总被引：14，自引：0，他引：14
筛选得到了８株嗜高温（５５℃）嗜粪细菌，均具有较强的发酵猪粪能力。加入所选育菌株进行的猪粪高温（５５℃）固体好氧发酵实验发明，２４ｈ内可将猪粪发酵成无臭味、深褐色的稳定和无害化产物，常温下长时间放置也不会产生腐败和臭味。此发酵产物的氮试验法结果显示，猪粪已发酵至表观成熟和稳定化，可作为进一步制取优质有机复合肥料的良好前体物。 相似文献
140.