全文获取类型
收费全文 | 130篇 |
免费 | 7篇 |
国内免费 | 55篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 20篇 |
环保管理 | 13篇 |
综合类 | 90篇 |
基础理论 | 28篇 |
污染及防治 | 28篇 |
评价与监测 | 4篇 |
社会与环境 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 16篇 |
2013年 | 16篇 |
2012年 | 8篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 3篇 |
排序方式: 共有192条查询结果,搜索用时 31 毫秒
91.
农田土壤自养微生物碳同化潜力及其功能基因数量、关键酶活性分析 总被引:8,自引:6,他引:2
研究农田土壤自养微生物碳同化潜力,对全面认识农田生态系统碳吸收和碳储存有着重要意义.选取6种典型农田土壤,通过14C连续标记示踪技术结合密闭系统模拟培养,量化了土壤自养微生物碳同化潜力及其向土壤活性碳库组分转化,同时结合分子生物学技术及酶学分析方法,探讨了不同土壤自养微生物细菌固碳功能基因(cbbL)丰度及关键酶(RubisCO)活性.结果表明,土壤自养微生物具有可观的CO2同化潜力,在本实验条件下,全球每年表层(0~20 cm)土壤通过自养微生物的同化作用可固定的碳为0.57~7.3 Pg.供试土壤的14C土壤有机碳(14C-SOC)含量范围为10.63~133.81 mg·kg-1,而14C可溶性有机碳(14C-DOC)、14C微生物生物量碳(14C-MBC)含量范围分别为0.96~8.10 mg·kg-1、1.70~49.16 mg·kg-1.土壤可溶解性有机碳(DOC)、微生物量碳(MBC)和SOC的更新率分别为5.07%~14.3%、2.51%~13.12%和0.09%~0.64%.土壤细菌cbbL丰度范围为2.40×107~1.9×108copies·g-1,且RubisCO酶活性(CO2/soil)范围为34.06~71.86 nmol·(g·min)-1.相关分析表明,土壤14C-SOC与14C-MBC及RubisCO酶活性均呈极显著正相关关系(P<0.01).说明土壤对大气CO2的同化作用主要是由自养微生物参与的同化过程,且较高的RubisCO酶活性意味着较高的自养微生物CO2同化潜力. 相似文献
92.
电辅助微生物反应器降解苯并噻唑效能的研究 总被引:1,自引:0,他引:1
本研究采用单室电辅助微生物反应器(EAMR)氧化苯并噻唑(BTH),考察了外加电压和COD/BTH对BTH降解效能的影响.结果发现,BTH在阳极氧化降解为2-羟基苯并噻唑(OHBT)后,噻唑环断裂,最终转化为2-甲磺酰基苯胺;BTH的降解过程符合表观一级动力学规律,并且提高外加电压和引入共基质代谢作用均能提高BTH的降解反应速率常数;在外加电压0.7 V和COD/BTH值为30∶1时,48 h后BTH的降解率可以达到96%,实现了BTH类废水的高效脱毒,为后续生物处理创造了有利的条件. 相似文献
93.
94.
Yiqun Chen Fang Yu Shengwen Liang Zongping Wang Zizheng Liu Ya Xiong 《Waste management (New York, N.Y.)》2014,34(11):2014-2021
Three reactors, ordinary, greenhouse, and solar, were constructed and tested to compare their impacts on the composting of municipal sewage sludge. Greenhouse and solar reactors were designed to evaluate the use of solar energy in sludge composting, including their effects on temperature and compost quality. After 40 days of composting, it was found that the solar reactor could provide more stable heat for the composting process. The average temperature of the solar reactor was higher than that of the other two systems, and only the solar reactor could maintain the temperature above 55 °C for more than 3 days. Composting with the solar reactor resulted in 31.3% decrease in the total organic carbon, increased the germination index to 91%, decreased the total nitrogen loss, and produced a good effect on pot experiments. 相似文献
95.
长期连作及秸秆还田对棉田土壤微生物量及种群结构的影响 总被引:1,自引:0,他引:1
通过采用常规微生物培养技术分析长期不同连作年限及秸秆还田棉田土壤微生物量及种群结构变化,揭示棉花连作及秸秆还田与土壤微生物多样性关系。研究表明,随着连作年限增加,秸秆还田连作模式下真菌数量持续增加,细菌和微生物总量在连作5-20 a逐渐下降,25 a后又上升;非秸秆还田连作模式随着连作年限增加其微生物种群变化与秸秆还田连作模式变化一致,但非秸秆还田连作模式土壤细菌和微生物总量分别比秸秆还田连作模式在连作5、10和15 a降低42.9%、57.9%、70.6%和41.9%、54.7%和65.7%,而真菌数量增加28.4%、80.8%和116.7%。说明棉花秸秆还田能够增加微生物数量,改善棉田土壤微生物种群结构。连作棉田土壤Simpson指数和Shannon指数呈随连作年限增加呈增加的趋势,连作棉田土壤微生物细菌/真菌(B/F)和放线菌/真菌(A/F)比值在秸秆还田模式下先逐渐减小至连作25 a有升高,而非秸秆还田模式下持续下降。 相似文献
96.
为了考察CANON工艺的快速启动策略及功能微生物的种群特征,在常温MBR反应器内接种普通活性污泥后间歇运行.启动策略为以调控曝气时间和曝气量作为主要方法,首先在限氧条件下启动亚硝化,之后进一步降低DO启动CANON工艺.在CANON工艺启动成功后,通过调整曝气时间和无机碳源浓度提高了总氮去除负荷,并采用PCR-DGGE技术分析了稳定运行的CANON工艺内功能微生物的种群特征.结果表明,CANON工艺经36d成功启动,NH4+-N去除率和总氮去除率最终稳定在99%和84%左右,氮去除负荷达到0.41kg/(m3·d).DGGE测序结果表明,Nitrosomonas和Candidatus Kuenenia stuttgartiensis是反应器内的优势菌种,两种微生物协同作用,共同在MBR内完成了高效的自养脱氮. 相似文献
97.
98.
Solid Waste Treatment as a High-Priority and Low- Cost Alternative for Greenhouse Gas Mitigation 总被引:5,自引:0,他引:5
The increased concern about environmental problems caused by inadequate waste management, as well as the concern about global
warming, promotes actions toward a sustainable management of the organic fraction of the waste. Landfills, the most common
means to dispose of municipal solid waste (MSW), lead to the conversion of the organic waste to biogas, containing about 50%
methane, a very active greenhouse gas (GHG). One unit of methane has a global warming potential of 21 computed for a 100-year
horizon or 56 computed for 20 years. The waste sector in Israel contributes 13% of total greenhouse gases (GHG) emissions
for a time horizon of 100 years (for a time horizon of 20 years, the waste sector contribution equals to more than 25% of
total GHG emissions). The ultimate goal is to minimize the amount of methane (CH4) by converting it to CO2. This can be achieved by physicochemical means (e.g., landfill gas flare, incineration) or by biological processes (e.g.,
composting, anaerobic digestion). Since the waste in Israel has a high organic material content, it was found that the most
cost-effective means to treat the degradable organic components is by aerobic composting (investment of less than US$ 10 to
reduce emission of one ton CO2 equivalent per year). Another benefit of this technology is the ability to implement it within a short period. The suggested
approach, which should be implemented especially in developing countries, could reduce a significant amount of GHG at relatively
low cost and short time. The development of a national policy for proper waste treatment can be a significant means to abate
GHG emissions in the short term, enabling a gain in time to develop other means for the long run. In addition, the use of
CO2 quotas will credit the waste sector and will promote profitable proper waste management. 相似文献
99.
Seven mixtures from four organic residues—an aerobic sewage sludge, a city refuse, a peat residue, and a grape debris—were
composted, and the changes undergone by their different carbon fractions during their composting and maturation were studied.
In most cases a decrease in carbon fractions during the composting and maturation processes was observed. The extractable
carbon, however, increased during maturation. Organic matter mineralization was greater in the composts with city refuse than
in those with sewage sludge. The samples with peat residue showed the lowest decreases in carbon fractions. During maturation,
an increase of humiclike fraction was observed, which was reflected by a decrease in the soluble carbon-precipitated carbon
ratio at pH 2. Water-soluble carbon was the carbon fraction most easily degradable by microorganisms, and its amount correlated
significantly with composting time in all the samples. 相似文献
100.
Karen K. Leonas Michael A. Cole Xiang-Yang Xiao 《Journal of Polymers and the Environment》1994,2(4):253-261
The degradation of four formulations of yard waste-filled collection bags was evaluated in a field-scale test of 15.5- or 31-m-long windrows at a community yard waste composting site. Variables of bag contents, bag chemical composition, and length of exposure were evaluated. Chemical compositions of the bags included (1) low-density polyethylene (LDPE) + 6% cornstarch + 2 levels of prooxidant, (2) LDPE + 9% cornstarch + prooxidants, and (3) LDPE without cornstarch but with photooxidation enhancers. Results showed that all products weakened and/or disintegrated to some extent. However, the bags with 6% starch disintegrated too slowly to allow timely processing of the compost. The bags with 9% starch and other additives to promote multiple degradation mechanisms degraded at the fastest rate of those evaluated here. The photodegradable bags with solar exposure during composting disintegrated rapidly, but when turned to expose new surfaces to light, further strength losses occurred slowly.Paper presented at the Biodegradable Materials and Packaging Conference, September 22–23, 1993, Natick, Massachusetts. 相似文献