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411.
Luděk Bartoš Jitka Bartošová Jan Pluháček Jana Šindelářová 《Behavioral ecology and sociobiology》2011,65(8):1567-1572
Based on questionnaires from horse breeders, we found that bringing a pregnant mare which had been mated away from home into
a vicinity of a familiar male who was not the father of her foetus increased probability of pregnancy disruption. These mares
aborted in 31% of cases, while none of those mated within the home stable aborted. Repeated sexual activity either by a stallion
or dominant gelding from the normal home group was observed shortly after the mare came from away-mating. Pregnant mares isolated
from home males by a fence were even seen soliciting them over the fence. We speculate that, once returned to the home “herd”,
and introduced to familiar males, mares were more likely to terminate their pregnancy to save energy and avoid likely future
infanticidal loss of their progeny by dominant male(s) of the home social group. This is a newly discovered phenomenon where
a mare manipulates the male’s paternity assessment by promiscuous mating. It may explain a common increased incidence of foetal
loss in domestic horses occurring in nearly 40% of pregnancies. We conclude that the common practice of transporting the mare
for mating and then bringing her back to an environment with males, stallions or geldings, which did not sire the foetus,
is the main cause of high percentages of pregnancy disruption in domestic horses. 相似文献
412.
Davina L. Hill Jan Lindström Ruedi G. Nager 《Behavioral ecology and sociobiology》2011,65(11):2049-2059
Whether parental effort can be negotiated between partners over ecological time and adjusted across different contexts is
not well understood. We manipulated male extra-pair copulation (EPC) opportunity in captive zebra finches, Taeniopygia guttata, to test whether males adjust incubation effort to the mating context and to examine how females respond to their partner’s
effort. Birds without previous breeding experience were paired randomly and bred with the same partner twice. In the first
breeding attempt, half the males received EPC opportunities with ‘extra-pair females’ during incubation, while the other half
did not. Males that received EPC opportunities in the first breeding attempt did not in the second breeding attempt and vice
versa. We recorded incubation effort on days when EPC opportunities were not presented. In their first breeding attempt, males
with EPC opportunities incubated less than those without. Females compensated fully for the deficit in male care so that a
pair’s combined incubation effort was unchanged. In the second attempt, when a male’s opportunity for EPCs was switched, individuals
showed the same level of incubation effort that they had previously, irrespective of the current availability of extra-pair
females. This suggests that division of effort was negotiated in the first breeding attempt and maintained without significant
adjustments in the second attempt. The effects of male EPC opportunity in the first breeding attempt on subsequent incubation
effort suggests that individual parental decisions can be shaped by previous experience and this may partly explain conflicting
results in studies where individuals’ histories were not known. 相似文献
413.
Rapid incorporation and short-term distribution of a nonylphenol isomer and the herbicide MCPA in soil-derived organo-clay complexes 总被引:1,自引:0,他引:1
Patrick Riefer Timm Klausmeyer Jan Schwarzbauer Andreas Sch?ffer Burkhard Schmidt Phillipe F. X. Corvini 《Environmental Chemistry Letters》2011,9(3):411-415
Organo-clay complexes in soil are a major sink for xenobiotics and, thus, often enhance their persistence dramatically. However,
the knowledge on environmental processes of non-extractable residue formation on a short time scale is very restricted. Therefore,
this study examined the distribution of 4-(3,5-dimethylhept-3-yl)phenol (NP) and 4-chloro-2-methylphenoxyacetic acid (MCPA)
in soil over a short time period of 48 h and in different soil sub-fractions. The overall proportion of organo-clay-associated
bound residues was not only abundant but also in the same range for both substances (MCPA: 8%; NP: 11% of applied 14C-radioactivity). However, a more detailed view revealed two different distribution patterns: a higher proportion of clay-associated
NP was accompanied by a lower content of bound residues, whereas a smaller fraction of clay-associated MCPA was characterized
by a higher proportion of non-extractable residues. Further on, a selective accumulation of bound residues among clay-associated
humic fractions was observed. NP residues were linked predominantly to humic acids, whereas MCPA residues tended to be incorporated
more into fulvic acids. It was evident that the overall distribution was influenced primarily by the physico-chemical properties
of the contaminants. This study demonstrates in detail a rapid initial incorporation accompanied by a specific distribution
into soil sub-fractions for selected xenobiotics in soil and points to a complex interaction of clay-associated organic matter
with low molecular weight compounds. 相似文献
414.
Tom Hennebel Henri Simoen Pieter Verhagen Wim De Windt Jan Dick Christian Weise Frank Pietschner Nico Boon Willy Verstraete 《Environmental Chemistry Letters》2011,9(3):417-422
Lindane (??-hexachlorocyclohexane, ??-HCH) is a recalcitrant and toxic organochlorine insecticide. Due to its non-selective production process and widespread use, HCH isomers and their degradation products have been detected frequently in soils and groundwater. An innovative technology using microbial produced Pd(0) nanoparticles, i.e. bio-Pd, was developed to treat groundwater containing a mixture of HCHs and chlorobenzenes. In a first step, the groundwater was de-ironized and most of the chlorobenzenes were removed in a biological trickling filter. The ??g?L?1 levels of HCHs and chlorobenzenes were removed in a second step by the bio-Pd-based technology. Therefore, a 200-L pilot scale reactor was developed with 100?mg?L?1 bio-Pd encapsulated in alginate beads. Hydrogen gas was bubbled at the bottom of the reactor and served to charge the bio-Pd catalyst. The reactor influent contained 5.2???g?L?1 HCHs and 51.1???g?L?1 chlorobenzenes. During a test period of 10?days, 29% of the HCH isomers and 63% of the chlorobenzenes were removed applying a nominal hydraulic residence time of 4?h. These removal percentages could be increased to 75 and 68% by doubling the nominal hydraulic residence time to 8?h. This study demonstrated that biologically produced nanoparticles of Pd can be applied for the large-scale remediation of groundwater contaminated with HCHs. 相似文献
415.
Ji?�� Barek Dana Cabalkov�� Jan Fischer Tom��? Navr��til Karolina Peckov�� Bogdan Yosypchuk 《Environmental Chemistry Letters》2011,9(1):83-86
A new method for the determination of submicromolar and nanomolar concentrations of herbicide Bifenox using differential pulse voltammetry at a mercury meniscus modified silver solid amalgam electrode is described. This new type of working electrode is non-toxic, environmentally friendly, and compatible with principles of green analytical chemistry, and its surface can be easily electrochemically renewed in the case of passivation. The newly developed direct differential pulse voltammetric determination of Bifenox gives limit of determination 6.7·10?7 and 6.9·10?7?M in drinking and river water, respectively. Both the selectivity and the sensitivity can be further increased by preliminary separation and preconcentration using solid phase extraction. This combination enables to reach limit of determination 0.9?×?10?9 and 1.5?×?10?9?M for drinking and river water, respectively. Because of lower running and investment costs, this electroanalytical method can be used for large scale monitoring of possible water contamination with tested herbicide. 相似文献
416.
Jasmin Shah M. Rasul Jan Behisht Ara Farhat-un-Nisa Shehzad 《Environmental monitoring and assessment》2011,178(1-4):111-119
A method for the determination of herbicides residues, triazine (atrazine, metribuzin, ametryn, and terbutryn), in soil samples with high-performance liquid chromatography (HPLC)?CUV detection is described. The proposed method is based on microwave-assisted extraction (MAE) of soil samples for 4 min at 80% of 850-W magnetron outputs in the presence of mixture of solvents (methanol/acetonitrile/ethylacetate). Related important factors influencing the MAE efficiency, such as the solvent type and volume, irradiation energy, and time, were optimized in detail. Calibration curve ranges established using HPLC for metribuzin, atrazine, ametryn, and terbutryn are 1.0?C19.0, 0.9?C18.0, 0.6?C11.0, and 0.7?C11.0 µg mL???1, respectively. The limits of detection of metribuzin, atrazine, ametryn, and terbutryn are 0.30, 0.24, 0.16, and 0.20 µg mL???1 while limits of quantification are 1.0, 0.80, 0.50, and 0.60 µg mL???1, respectively. A Plackett?CBurman factorial design was used as a screening method in order to select the variables that influence MAE extraction. The recoveries of the method at three different spiked levels were assessed by analyzing real soil samples and were found to be in the range of 83.33 ± 0.12?C96.33 ± 0.23 with good precision (<8%). 相似文献
417.
Claudia P. Kruizinga Jan M.H. Schellekens 《International journal of occupational safety and ergonomics》2013,19(3):271-286
A pilot study was conducted regarding the effects of working posture, handling frequency, and task duration on musculoskeletal discomfort. Participants rated their discomfort perceived while performing a repetitive task at 8 different combinations of manipulations. Pauses between the work periods lasted 15 min. Discomfort was rated according to Borg’s category-ratio scale CR-10 and postures were recorded by an optoelectronic movement registration system. From linear multiple regression analysis equations for predicting discomfort at various body regions were obtained. Coefficients of determination especially point to trunk inclination and handling frequency as major determinants of musculoskeletal discomfort. 相似文献
418.
Jan Rzepecki 《International journal of occupational safety and ergonomics》2013,19(2):181-193
AbstractThis article presents a method of assessing the economic outcome of implementing an occupational safety and health management system (OSH MS). Developed at the Central Institute for Labour Protection – National Research Institute (Poland), this method focuses on identifying the economic expenses comprising bookkeeping and alternative cost incurred to implement and improve an OSH MS. The method was next used in a study in 20 enterprises. While varying greatly among those enterprises, the alternative cost of implementing and maintaining an OSH MS was much higher than the bookkeeping cost, which was also much lower than the cost of statutory prevention measures. The implementation of an OSH MS resulted in both tangible and intangible benefits, including reduced premiums for work accident insurance. 相似文献
419.
The adverse impacts of climate change are widely recognized as well as the importance of the mitigation of carbon dioxide (CO2). Battery driven vehicles are expected to have a bright future, since GHG emissions can be reduced. Lithium-ion (Li-ion) batteries appear to be the most promising, due to their high energy density. Recently, the discussion concerning adequate lithium carbonate (Li2CO3) resources is resolved. The current challenge is the needed increase in flow rate of Li2CO3 into society to foresee in forecasted demand. This research determines ten factors which influence the availability of Li-ion batteries for the EU27 in the coming decades. They are used in a system dynamics analysis. The results of this research show that undersupply can be expected in the EU27 until 2045 somewhere between 0.5 Mt and 2.8 Mt. Substitution of Li2CO3 in other end-use markets and recycling can relieve the strain on Li2CO3 supply to some extent. In 2050, 20% of the vehicle fleet in the EU27 can be battery electric vehicles (BEVs). The lack of resources in the EU27 and the geographical distribution of lithium in politically sensitive areas suggest that the shares of lithium available for the EU27 will be less than assumed in this research. The increase in flow rate shows to be the bottle-neck for a transition to (partly) battery driven vehicles in the EU27, at least when Li-ion batteries are used. Focusing on large-scale application of BEVs with Li-ion batteries in order to substantially mitigate CO2 emissions in transport is a futile campaign. 相似文献
420.
Jan Ahlers 《Umweltwissenschaften und Schadstoff-Forschung》2004,16(2):75-76
Ohne Zusammenfassung 相似文献