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901.
The fate of 100 marked recruits of the rhizophytic alga Halimeda incrassata was followed in Puerto Morelos reef lagoon, Mexican Caribbean (20°52′N, 86°51′W), until death of the last individual from
April 2005–2007. Juvenile mortality was relatively high (19%), the half-life of adult thalli was 13 months and maximal lifespan
was 2 years. First age of sexual reproduction was 10 months, but only 6% of the marked thalli reproduced sexually. A subsequent
static life-table approach (February–April 2008) at two sites indicated low spatial variation in transition probabilities
between the life stages. Recruits were found throughout the year (density 2–11 thalli m−2) and were mostly of clonal origin. In a disturbed area, the density of sexual recruits was ~0.01 thalli m2. Temporal fluctuations in population size depended on mortality rates, which increased slightly after hurricanes Emily (July
2005) and Wilma (October 2005), but might otherwise be regulated by density-dependent processes. 相似文献
902.
Several ecologically and commercially important fish species spend the winter in a state of minimum feeding activity and at
lower risk of predation. To enable this overwintering behaviour, energetic reserves are generated prior to winter to support
winter metabolism. Maintenance metabolism in fish scales with body size and increases with temperature, and the two factors
together determine a critical threshold size for passive overwintering below which the organism is unlikely to survive without
feeding. This is because the energetic cost of metabolism exceeds maximum energy reserves. In the present study, we estimated
the energetic cost of overwintering from a bioenergetic model. The model was parameterised using respirometry-based measurements
of standard metabolic rate in buried A. tobianus (a close relative to A. marinus) at temperatures from 5.3 to 18.3°C and validated with two independent long-term overwintering experiments. Maximum attainable
energy reserves were estimated from published data on A. marinus in the North Sea. The critical threshold size in terms of length (L
th) for A. marinus in the North Sea was estimated to be 9.5 cm. We then investigated two general predictions: (1) Fish smaller than L
th display winter feeding activity, and (2) size at maturation of iteroparous species is larger than L
th to ensure sufficient energy reserves to accommodate both the metabolic cost of passive overwintering and reproductive investments.
Both predictions were found to be consistent with data on size at maturation and total body energy in December and February. 相似文献
903.
Emile van Lieshout 《Behavioral ecology and sociobiology》2011,65(2):149-156
Phenotypic variation in male genitalia may affect copulation behaviour, which can have important fitness consequences for
males. Male genitalia commonly possess traits that increase male control over copulation, but in species where females control
mating, a poor functional understanding often prevents insight into the processes responsible for such effects. Here, I investigate
the effect of male genital length on copulation behaviour in the earwig Euborellia brunneri, where both sexes exhibit extremely elongated genitalia that correspond in shape. This model system is particularly suitable
because pairs mate repeatedly and females can limit both the number and duration of copulations. I used both virgin and mated
males and females in a double-mating design because longer male genitalia confer benefits in sperm competition. Consistent
with a greater predicted male mating effort in mated females, the duration of individual copulations increased, but this traded
off against mating frequency as cumulative mating duration remained unchanged. In contrast, male genital length increased
both individual and cumulative mating duration, regardless of mating status. This difference suggests that, while males may
modify copulation duration in response to mating status, females facultatively adjust mating frequency to prevent mating excessively
or express preferences for increased male genital length. Notably, this study demonstrates that male genital phenotypes that
are successful in sperm competition also enjoy female-mediated mating benefits. 相似文献
904.
Matthew A. Etterson Susan N. Ellis-FelegeDavid Evers Gilles GauthierJoseph A. Grzybowski Brady J. MattssonLaura R. Nagy Brian J. OlsenCraig M. Pease Max Post van der BurgAaron Potvien 《Ecological modelling》2011,222(14):2178-2190
Fecundity is fundamental to the fitness, population dynamics, conservation, and management of birds. For all the efforts made to measure fecundity or its surrogates over the past century of avian research, it is still mismeasured, misrepresented, and misunderstood. Fundamentally, these problems arise because of partial observability of underlying processes such as renesting, multiple brooding, and temporary emigration. Over the last several decades, various analytical approaches have been developed to estimate fecundity from incomplete and biased data. These, include scalar arithmetic formulae, partial differential equations, individual-based simulations, and Markov chain methodology. In this paper, we: (1) identify component processes of avian reproduction; (2) review existing methods for modeling fecundity; (3) place these diverse models under a common conceptual framework; (4) describe the parameterization, validation, and limitations of such models; and (5) point out future considerations and challenges in the application of fecundity models. We hope this synthesis of existing literature will help direct researchers toward the most appropriate methods to assess avian reproductive success for answering questions in evolutionary ecology, natural history, population dynamics, reproductive toxicology, and management. 相似文献
905.
Recently it has come to our attention that a paper was published in this journal entitled “recycling greenhouse gas fossil
fuel emissions into low radiocarbon food products to reduce human genetic damage” (Williams in Environ Chem Lett 5:197–202,
2007). In this article, it is argued that food grown in a greenhouse is healthier for people, when the greenhouse is fertilised
with CO2 prepared from fossil fuels. In this comment, however, we argue that the effect on human health is completely negligible. 相似文献
906.
Sánchez Jiménez A van Tongeren M Galea KS Steinsvåg K MacCalman L Cherrie JW 《Journal of environmental monitoring : JEM》2011,13(6):1841-1846
The aim of this study was to compare the performance of the TSI Aerodynamic Particle Sizer (APS) and the TSI portable photometer SidePak to measure airborne oil mist particulate matter (PM) with aerodynamic diameters below 10 μm, 2.5 μm and 1 μm (PM(10), PM(2.5) and PM(1)). Three SidePaks each fitted with either a PM(10), PM(2.5) or a PM(1) impactor and an APS were run side by side in a controlled chamber. Oil mist from two different mineral oils and two different drilling fluid systems commonly used in offshore drilling technologies were generated using a nebulizer. Compared to the APS, the SidePaks overestimated the concentration of PM(10) and PM(2.5) by one order of magnitude and PM(1) concentrations by two orders of magnitude after exposure to oil mist for 3.3-6.5 min at concentrations ranging from 0.003 to 18.1 mg m(-3) for PM(10), 0.002 to 3.96 mg m(-3) for PM(2.5) and 0.001 to 0.418 mg m(-3) for PM(1) (as measured by the APS). In a second experiment a SidePak monitor previously exposed to oil mist overestimated PM(10) concentrations by 27% compared to measurements from another SidePak never exposed to oil mist. This could be a result of condensation of oil mist droplets in the optical system of the SidePak. The SidePak is a very useful instrument for personal monitoring in occupational hygiene due to its light weight and quiet pump. However, it may not be suitable for the measurement of particle concentrations from oil mist. 相似文献
907.
Furlan Lorenzo Pozzebon Alberto Duso Carlo Simon-Delso Noa Sánchez-Bayo Francisco Marchand Patrice A. Codato Filippo Bijleveld van Lexmond Maarten Bonmatin Jean-Marc 《Environmental science and pollution research international》2021,28(10):11798-11820
Environmental Science and Pollution Research - Over-reliance on pesticides for pest control is inflicting serious damage to the environmental services that underpin agricultural productivity. The... 相似文献
908.
Bonmatin Jean-Marc Giorio Chiara Sánchez-Bayo Francisco Bijleveld van Lexmond Maarten 《Environmental science and pollution research international》2021,28(10):11709-11715
Environmental Science and Pollution Research - 相似文献
909.
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