全文获取类型
收费全文 | 7204篇 |
免费 | 479篇 |
国内免费 | 2694篇 |
专业分类
安全科学 | 653篇 |
废物处理 | 402篇 |
环保管理 | 554篇 |
综合类 | 4355篇 |
基础理论 | 1210篇 |
环境理论 | 1篇 |
污染及防治 | 2216篇 |
评价与监测 | 322篇 |
社会与环境 | 305篇 |
灾害及防治 | 359篇 |
出版年
2024年 | 24篇 |
2023年 | 144篇 |
2022年 | 445篇 |
2021年 | 348篇 |
2020年 | 313篇 |
2019年 | 285篇 |
2018年 | 290篇 |
2017年 | 376篇 |
2016年 | 381篇 |
2015年 | 418篇 |
2014年 | 512篇 |
2013年 | 746篇 |
2012年 | 622篇 |
2011年 | 721篇 |
2010年 | 485篇 |
2009年 | 462篇 |
2008年 | 570篇 |
2007年 | 434篇 |
2006年 | 415篇 |
2005年 | 293篇 |
2004年 | 204篇 |
2003年 | 251篇 |
2002年 | 206篇 |
2001年 | 157篇 |
2000年 | 189篇 |
1999年 | 160篇 |
1998年 | 154篇 |
1997年 | 149篇 |
1996年 | 126篇 |
1995年 | 117篇 |
1994年 | 75篇 |
1993年 | 75篇 |
1992年 | 78篇 |
1991年 | 60篇 |
1990年 | 33篇 |
1989年 | 15篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1975年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
961.
962.
963.
本文描述了六安地震台TJ-Ⅱ体应变仪钻孔的地质构造特点与钻孔岩芯物理特性,介绍了TJ-Ⅱ体应变仪在六安台运行情况。通过六安台TJ-Ⅱ一年观测资料的同震效应与区域前兆异常分析,初步探讨了地下形变对大别山区未来中强震预测研究的实际意义。 相似文献
964.
Lijing Meng Licheng Liu Xuehong Zi Hongxing Dai Zhen Zhao Xinping Wang Hong He 《Frontiers of Environmental Science & Engineering in China》2010,4(2):164-171
A new method called ultrasonic-assisted membrane reaction (UAMR) was reported for the fabrication of ceria-zirconia solid
solution. A series of ceria-zirconia solid solutions with different Ce/Zr molar ratios were prepared by the UAMR method and
characterized by X-ray diffraction (XRD), N2 adsorption, hydrogen temperature-programmed reduction (H2-TPR), scanning electron microscope (SEM), and transmission electron microscopy (TEM) techniques. The UAMR method proved to
be superior, especially when the Ce/Zr molar ratio was lower than 1, in fabricating ceria-zirconia solid solutions with large
BET surface area, high oxygen storage capacity (OSC), and low reduction temperature. 相似文献
965.
ZHANG Peng SONG Jinming FANG Jie LIU Zhigang LI Xuegang YUAN Huamao 《环境科学学报(英文版)》2009,21(8):1080-1088
Sixteen polycyclic aromatic hydrocarbons (PAHs) and 28 polychlorinated biphenyls (PCBs) were measured at a 2-cm interval in a core sample from the middle of the southern Yellow Sea for elucidating their historical variations in inflow and sources. The chronology was obtained using the 210Pb method. PAHs concentrations decreased generally with depth and two climax values occurred in 14–16 cm and 20–22 cm layers, demonstrating that the production and usage of PAHs might reach peaks in the periods of 1956–1962... 相似文献
966.
长三角重点行业大气污染物排放及控制对策 总被引:3,自引:0,他引:3
研究重点分析了长江三角洲地区电力和水泥行业的大气污染物排放特征,并结合相关行业统计数据和污染物排放因子,对2004年这两个重点行业的大气污染物排放量进行了估算。结论如下:长三角地区火电行业2004年SO2、烟尘、NOX和燃煤大气汞排放量分别为149.2×104t、21.1×104t、87.6×104t和13.7t。2004年江、浙、沪三地水泥行业共排放工艺粉尘76.2×104t,其中PM10为70.1×104t、PM2.5为45.9×104t,气态污染物SO2、NOX、CO和氟化物排放量分别为12.4×104t、49.5×104t、247.9×104t和7.4×104t。并对长三角地区电力和水泥行业的污染控制问题提出一些相关举措。 相似文献
967.
968.
969.
Hongxun Hou Shuying Wang Yongzhen Peng Zhiguo Yuan Fangfang Yin Wang Gan 《Frontiers of Environmental Science & Engineering in China》2009,3(1):106-111
The anaerobic-anoxic oxidation ditch (A2/O OD) process is popularly used to eliminate nutrients from domestic wastewater. In order to identify the existence of denitrifying
phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal, and enhance the denitrifying
phosphorus removal in the A2/O OD process, a pilot-scale A2/O OD plant (375 L) was conducted. At the same time batch tests using sequence batch reactors (12 L and 4 L) were operated
to reveal the significance of anoxic phosphorus removal. The results indicated that: The average removal efficiency of COD,
NH4+, PO43−, and TN were 88.2%, 92.6%, 87.8%, and 73.1%, respectively, when the steady state of the pilotscale A2/O OD plant was reached during 31–73 d, demonstrating a good denitrifying phosphorus removal performance. Phosphorus uptake
took place in the anoxic zone by poly-phosphorus accumulating organisms NO2− could be used as electron receptors in denitrifying phosphorus removal, and the phosphorus uptake rate with NO2− as the electron receptor was higher than that with NO3− when the initial concentration of either NO2− or NO3− was 40 mg/L. 相似文献
970.
Xiaoxin Cao Xia Huang Xiaoyuan Zhang Peng Liang Mingzhi Fan 《Frontiers of Environmental Science & Engineering in China》2009,3(3):307-312
Current methods for testing the electricity generation capacity of isolates are time- and labor-consuming. This paper presents
a rapid voltage testing system of exoelectrogenic bacteria called Quickscreen, which is based on a microliter microbial fuel
cell (MFC). Geobacter sulfurreducens and Shewanella baltica were used as the model exoelectrogenic bacteria; Escherichia coli that cannot generate electricity was used as a negative control. It was found that the electricity generation capacity of
the isolates could be determined within about five hours by using Quickscreen, and that its time was relatively rapid compared
with the time needed by using larger MFCs. A parallel, stable, and low background voltage was achieved using titanium as a
current collector in the blank run. The external resistance had little impact on the blank run during the initial period.
The cathode with a five-hole configuration, used to hydrate the carbon cathode, gave higher cathode potential than that with
a one-hole configuration. Steady discharge and current interrupt methods showed that the anode mostly contributed to the large
internal resistance of the Quickscreen system. However, the addition of graphite felt decreased the resistance from 18 to
5 kΩ. This device was proved to be useful to rapidly evaluate the electricity generation capacity of different bacteria. 相似文献