全文获取类型
收费全文 | 427篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 18篇 |
废物处理 | 11篇 |
环保管理 | 95篇 |
综合类 | 102篇 |
基础理论 | 82篇 |
污染及防治 | 81篇 |
评价与监测 | 22篇 |
社会与环境 | 15篇 |
灾害及防治 | 7篇 |
出版年
2022年 | 4篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 36篇 |
2012年 | 17篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 10篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 15篇 |
2005年 | 12篇 |
2004年 | 7篇 |
2003年 | 12篇 |
2002年 | 18篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 10篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1988年 | 3篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1979年 | 3篇 |
1968年 | 3篇 |
1964年 | 3篇 |
1962年 | 3篇 |
1961年 | 4篇 |
1960年 | 6篇 |
1959年 | 3篇 |
1958年 | 5篇 |
1957年 | 7篇 |
1955年 | 3篇 |
1941年 | 5篇 |
1939年 | 6篇 |
1935年 | 3篇 |
1922年 | 3篇 |
排序方式: 共有433条查询结果,搜索用时 46 毫秒
371.
Crossley A Sheppard LJ Cape JN Smith RI Harvey FJ 《Environmental pollution (Barking, Essex : 1987)》1997,96(2):185-193
An eighteen-year-old clone of Sitka spruce (Picea sitchensis (Bong.) Carr) growing in the field was used to evaluate the whole tree response of 'mature' Sitka spruce to acid mist treatment. The mist, an equimolar mixture of H(2)SO(4) and NH(4)NO(3) at pH 2.5 with or without particles (soda glass ballotini < 20 microm diameter), was applied twice weekly (equivalent to 4 mm precipitation week(-1)) throughout the growing season, May-November 1990-1992. The annual dose of S, N, H applied as mist (at 51, 48 and 3.3 kg ha(-1), respectively) was 2.5 times that measured in the Scottish uplands. Throughout the experiment there was no evidence of visible injury symptoms, yet there was a highly significant reduction (p < 0.02) in the stem-area increment relative to the stem area at the start, measured using vernier dendrometer bands. There was no significant difference between the (acid mist + particle) and the acid mist only treatments. The mean relative stem-area increment over two complete growing seasons (1991-1992) was 65% for control trees, but only 53% for acid-misted trees. 相似文献
372.
The addition of N2O5 to 1-hexene in synthetic air results in 1,2-hexanedioldinitrate and 2-hexanon-1-ol-nitrate as the main products and some -hydroxy-1-ol-nitrate. In the reaction with cyclohexene, cis/trans-1,2-cyclohexanediol-dinitrate and cyclohexene-1-on-2-ol-nitrate have been detected. The addition of NO3 to isoprene produces 4-nitrato-3-methylbutenal-2. The reaction of NO3 with methylenecyclohexane and sabinene in air results in 1-(methylnitrate) cyclohexane-1-ol and both epimers of 1-(methylnitrate)-4-(isopropyl) cyclo-hexene-4-ol, respectively. The main products of the addition of NO3 to - and β-pinene were probably rearranged compounds of the limonene type: -pinene produces 1-(methyl)-2-(nitrato)-4-(2-propane-2-ol)-cyclohex-1-ene and β-pinene produces 1-(methylnitrate)-4-(2-propane-2-ol)cyclohex-1-ene. Other rearrangements give rise to a variety of nitrates and ketonitrates of structures as yet unknown in the - and β-pinene systems.
The probably particle-borne addition of NO2 to -pinene, β-pinene and camphene in air produces 2-nitrolimonene, 7-nitrolimonene and nitrocamphene as the main reaction products. 相似文献
373.
Although the taxonomy of deep-sea protobranch bivalves is becoming better known, relatively little information is available on their reproductive biology and whether or not populations show reproductive periodicities. We have examined the reproductive biology of three common sympatric species as part of a long-term time-series of samples taken from 2900 m in the Rockall Trough from 1973 to 1983. Malletia cuneata Jeffreys, 1876 produces a maximum of 30 oocytes at any one time and these grow to a maximum size of 240 m. Maximum fecundity of Ledella pustulosa (Jeffreys, 1876) and Yoldiella jeffreysi (Hidalgo, 1877) is 174 and 360, respectively, and both species produce an egg of 120 m in diameter. These data indicate lecithotrophic early development in L. pustulosa and Y. jeffreysi, but direct development in M. cuneata; however, evidence from the prodissoconch length of M. cuneata suggests lecithotrophic development. L. pustulosa and Y. jeffreysi also differ from M. cuneata in having a distinct reproductive cycle with spawnout in the winter months. Both the continuously breeding M. cuneata and the seasonally breeding L. pustulosa ingest diatoms, coccoliths and foraminiferans, but whereas the diet of M. cuneata appears to be constant throughout the year there is an apparent reduction in the feeding activity of L. pustulosa concomitant with the deposition of phytodetritus on the deep-sea bed. 相似文献
374.
375.
Becker MW Collins SA Metge DW Harvey RW Shapiro AM 《Journal of contaminant hydrology》2004,69(3-4):195-213
The influence of physicochemical characteristics and motility on bacterial transport in groundwater were examined in flow-through columns. Four strains of bacteria isolated from a crystalline rock groundwater system were investigated, with carboxylate-modified and amidine-modified latex microspheres and bromide as reference tracers. The bacterial isolates included a gram-positive rod (ML1), a gram-negative motile rod (ML2), a nonmotile mutant of ML2 (ML2m), and a gram-positive coccoid (ML3). Experiments were repeated at two flow velocities, in a glass column packed with glass beads, and in another packed with iron-oxyhydroxide coated glass beads. Bacteria breakthrough curves were interpreted using a transport equation that incorporates a sorption model from microscopic observation of bacterial deposition in flow-cell experiments. The model predicts that bacterial desorption rate will decrease exponentially with the amount of time the cell is attached to the solid surface. Desorption kinetics appeared to influence transport at the lower flow rate, but were not discernable at the higher flow rate. Iron-oxyhydroxide coatings had a lower-than-expected effect on bacterial breakthrough and no effect on the microsphere recovery in the column experiments. Cell wall type and shape also had minor effects on breakthrough. Motility tended to increase the adsorption rate, and decrease the desorption rate. The transport model predicts that at field scale, desorption rate kinetics may be important to the prediction of bacteria transport rates. 相似文献
376.
Jürgen Burhenne Marc Ludwig Paskalis Nikoloudis Michael Spiteller 《Environmental science and pollution research international》1997,4(1):10-15
The photolytically induced decomposition of fluoroquinolone carboxylic acids (enrofloxacin, danofloxacin, ciprofloxacin and norfloxacin) at concentrations of 10 mg/l in pure water and an irradiation intensity of 200 W/m2 (xenon lamp) led to half-lives from 20.6 min (danofloxacin) to 105.9 min (norfloxacin). The environmental half-life of enrofloxacin was calculated by the GCSOLAR program and resulted in 1.8 to 55.4 hours, depending on the season and degree of latitude. During the irradiation procedure, products were built up which primarily demonstrated alterations involving the piperazine ring as compared with the parent compounds. The amount of14CO2 evolved by the photomineralization of14C-labeled enrofloxacin reached 26.4 % of the applied radioactivity. The main photoproducts were isolated by HPLC and their structural elucidation was carried out by different spectroscopic methods (MS, GC/MS and1H-NMR). 相似文献
377.
Harvey F. Ludwig 《The Environmentalist》2006,26(3):147-155
Based on some 60 years of consulting practice in the field of environmental/sanitary engineering, about half in the USA and
other affluent industrialized countries (ICs) and half with non-affluent developing countries (DCs), the Consultant summarizes
the lessons leaned on why the technology transfer (TT) operation of the Multilateral Development Banks (MDBs) and other International
Assistance Agencies (IAAs) have failed to achieve effective transfer of appropriate technology to DC practicioners in the
environmental/sanitary engineering field, and presents the Consultant’s recommendations on feasible measures by which MDBs
can significantly improve their TT operations. Eleven specific measures are recommended, all believed to be feasible for use
by MDBs, as follows: (i) post-construction monitoring of project performance, (ii) develop appropriate design criteria for
key infrastructure sectors, (iii) be realistic on O&M expectations, (iv) increase infrastructure project budgets to support
TT, (v) prepare appropriate technology textbooks, (vi) sponsor graduate university programs in appropriate TT, (vii) sponsor
appropriate TT professional journal, (viii) furnish copies of selected 1C references to DC-ers, (ix) sponsor work-type training
assignments in ICs, (x) plan TT projects as series of steps, (xi) utilize ratired IC-ers for peripatetic training in DCs. 相似文献
378.
Jose de Anda Harvey Shear Ulrich Maniak Pedro F. Zdrate‐del Valle 《Journal of the American Water Resources Association》2004,40(1):97-109
ABSTRACT: Lake Chapala is the largest natural water body in Mexico and also one of the most important shallow lakes in Latin America. For the past several years it has suffered various environmental problems such as the upstream overuse of water, contamination, and sedimentation. For the past 10 years the lake has had less than 50 percent of its historical water level over the past century. No criteria are reported in the literature that establish a water storage volume that will guarantee water quality conditions necessary for the survival of the lake. After determining the behavior of total solids concentrations in relation to the variations in the lake's depth, we proposed a minimum water column height of 5.0 m, representing a storage volume of about 5,000 Mm3. This volume would result in the recommended water quality standards for total dissolved solids. Calculated distribution maps show that the total solids concentration in the lake has increased since the end of the 1970s. The solids are primarily concentrated in the eastern part of the lake, as a consequence of the high solids discharged from the Lerma River, its main tributary. 相似文献
379.
John H. Rodgers R. S. Harvey 《Journal of the American Water Resources Association》1976,12(6):1109-1118
ABSTRACT: Productivity measurements of organisms attached to artificial substrates ranged from 6.5–7.6 mg C/m2/hr and were 17-65% greater in stirred bottles (simulated flow) than under static conditions. Carbon-14 was used to determine the effect of current on the primary productivity of these organisms in six artificial streams at the Flowing Streams Laboratory on the Savannah River Plant (U.S. Energy Research and Development Administration, Aiken, South Carolina, U.SA.). Seasonal changes in dominant organisms were monitored from June 1973 to March 1974. Estimates of productivity, accumulated biomass, and levels of chlorophyll a were compared for possible correlation. Production of chlorophyll a ranged from 50 to 381 mg/m2, and accumulated biomass ranged from 45 to 181 g/m2 on the artificial substrates (glass microscope slides) during the period of study. Productivity of attached organisms was generally an order of magnitude greater than productivity of phytoplankton or tychoplankton. The consistently higher productivity in simulated flowing systems than in static systems tends to cast some doubt on values obtained when lotic communities have been enclosed or isolated in chambers or bottles without inducing a current or stirring action. 相似文献
380.