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911.
Hui Xue Xiaoyi Ren Shiyu Li Xu Wu Hao Cheng Bin Xu Baojing Gu Guofu Yang Changhui Peng Ying Ge Jie Chang 《Environmental monitoring and assessment》2013,185(10):8501-8516
Tea plantations are rapidly expanding in China and other countries in the tropical and subtropical zones, driven by relatively high private economic benefit. However, the impact of tea plantations on the regional environment, including ecosystem services and disservices are unclear. In this study, we developed an assessment framework for determining the private economic benefits and environmental externalities (the algebraic sum of the regulating services and disservices) of tea plantations in China. Our results showed that tea plantations provided private economic benefits of 5,652 yuan ha?1 year?1 (7.6 yuan?=?1 USD in 2007) for tea farmers, plus positive environmental externalities of 6,054 yuan ha?1 year?1 for the society. The environmental externalities were calculated as the sum of the value of four regulating services, including carbon sequestration (392 yuan ha?1 year?1); soil retention (72 yuan ha?1 year?1); soil fertility protection (3,189 yuan ha?1 year?1) and water conservation (2,685 yuan ha?1 year?1), and three disservices, including CO2 emission (?39 yuan ha?1 year?1), N2O emission (?137 yuan ha?1 year?1) and nonpoint source pollution (?108 yuan ha?1 year?1). Before the private optimal level, the positive environmental externalities can be maintained by private economic benefits; if a social optimal level is required, subsidies from government are necessary. 相似文献
912.
Yandong Yang Liang Zhang Hedong Shao Shujun Zhang Pengchao Gu Yongzhen Peng 《Frontiers of Environmental Science & Engineering》2017,11(2):8
Conventional biological removal of nitrogen and phosphorus is usually limited due to the lack of biodegradable carbon source, therefore, new methods are needed. In this study, a new alternative consisting of enhanced biological phosphorus removal (EBPR) followed by partial nitritationanammox (PN/A), is proposed to enhance nutrients removal from municipal wastewater. Research was carried out in a laboratory-scale system of combined two sequencing batch reactors (SBRs). In SBR1, phosphorus removal was achieved under an alternating anaerobic-aerobic condition and ammonium concentration stayed the same since nitrifiers were washed out from the reactor under short sludge retention time of 2–3 d. The remaining ammonium was further treated in SBR2 where PN/A was established by inoculation. A maximum of nitrogen removal rate of 0.12 kg N?m–3?d–1 was finally achieved. During the stable period, effluent concentrations of total phosphorus and total nitrogen were 0.25 and 10.8 mg?L–1, respectively. This study suggests EBPR-PN/A process is feasible to enhance nutrients removal from municipal wastewater of low influent carbon source.
相似文献
913.
Jing Gu Hongtao Yu Xie Quan Shuo Chen 《Frontiers of Environmental Science & Engineering》2017,11(6):13
The spontaneous oxidation process of pristine silicon (Si) limits its application as photocatalyst or electrode in aqueous solution or moist air. Covering a protection layer on Si surface is an effective approach to overcome this disadvantage. In this paper, α-Fe2O3 is demonstrated to be an excellent alternative as a protection material. α-Fe2O3 layer was deposited around each p-type Si micropillar (SiMP) in well-ordered array by chemical bath deposition method. The diameter of SiMP was 5 mm and the thickness of α-Fe2O3 layer was about 20 nm. The photoeletrochemical stability of SiMP/α-Fe2O3 was proved by 10 circles cyclic voltammetry testing. Compared with SiMP, its optical absorption and photocurrent density improved 2 times and 4 times, respectively, and its onset potential for hydrogen evolution moved positively about 0.4 V. These improved performances could be ascribed to the enhanced photogenerated-charge-separation efficiency deriving from built-in electric field at the interface between Si and α-Fe2O3. The above results show an effective strategy to utilize Si material as photocatalyst or electrode in aqueous solution or moist air. 相似文献
914.
废水处理中湿式氧化技术研究进展 总被引:22,自引:1,他引:22
综述了湿式氧化技术的特点,影响因素、反应机理和动力学,并就其在废水处理中的研究和应用现状,指出湿式氧化是在处理高浓度难降解有机有害废水中较有发展前任的技术。 相似文献
915.
采用物化-生化-物化工艺处理染料化工废水。在生化工段成功地运用了生物活性炭技术,克服了染料化工废水因可供微生物生长的养料少,含盐浓度高而影响生化处理效果的弊端,使处理后出水水质达到国家规律的排放标准。 相似文献
916.
金矿开采具有其独特的环境效应 ,特别是贵州等地的卡林型金矿 ,因为这种金矿富含As、Tl、Hg、Sb、Pb等有毒元素 ,而且矿区发育喀斯特地形 ,使这类金矿的开采具有“毒上加毒”的污染特征和“明暗相间”的污染扩散迁移特征。本文通过对紫木凼金矿从1 989年到 1 995年开采六年间土壤、地表水、地下水的监测项目的变化对比 ,证明了黄金生产造成了矿区土壤、地表水、地下水中CN- 、As、Hg、Pb、Zn等的增高 ,其中以对地表水的影响最大 ;确定了主要的污染源有采矿废石、矿渣及废液 ,主要污染物有CN- 、As、Hg、Pb和Zn ,由于矿区Tl的区域背景值较低 ,未造成Tl的二次污染。 相似文献
917.
市场经济条件下矿区复垦土地经营管理模式探讨 总被引:1,自引:0,他引:1
调查和研究了目前我国矿区复垦土地的经营管理方式。分析了农村传统的个体经营管理方式对复垦效益的不利影响,提出了适合我国国情的复垦经营管理多元化模式,论述了其适用条件、运行机制、保障措施等。文章认为集约化经营、适度规模经营是复垦土地经营管理的发展方向。 相似文献
918.
919.
ZIC—ⅡA型离子色谱法同时测定地面水中阴离子 总被引:1,自引:0,他引:1
单柱离子色谱法同时测定地面水中F^-、cl^-,NO^-3-N、PO^3-4、SO^-24阴离子。以0.3M碳酸氢钾、0.24M碳酸钠缓冲液为淋洗液,在PH=4.0。流速为2ml/min的条件下,测得各阴离子检出限,线性回归方程及相关系,方法的精密度和准确度。 相似文献
920.
燃煤电厂氟污染规律研究 总被引:10,自引:0,他引:10
长期饮用高氟水或摄取高氟食物会引起氟中毒症,本文以燃用高氟煤物的淮北电厂为例,通过对电厂氟污染源及其周围大气,地表水,地下水,灰场土壤和灰场农作物的监测,分析了电厂的氟迁移转化规律,研究了电厂的氟污染源对周围环境的影响,并提出了综合治理电厂氟污染的对策。 相似文献