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61.
以某陆上原油长输管道为例,设定了陆上原油长输管道泄漏爆炸事故情景背景信息及演化过程,从预防、准备、预警、响应、恢复等阶段,梳理分析了事故情景应对全过程的任务及职责主体;针对各项任务从计划预案、人员队伍、装备物资、培训演练、运行机制等方面开展了情景应对能力评估;并针对存在的差距和不足,从企业和政府2个层面提出了针对此类情景的应急能力提升对策建议。该研究可为相关政府及企业加强油气长输管道事故应急准备能力建设提供参考。 相似文献
62.
生态旅游区不同距离带上植物群落的结构对比 总被引:6,自引:0,他引:6
通过对芦芽山自然保护区植物群落的结构分析 ,揭示旅游活动和群落演替的内在机理 ,为景区植被保护和旅游管理提供依据 .结果表明 :不同地段上各植被层由于各种因素的影响而有所不同 ,大部分景区的植被生长良好 .不同距离带上各植被层大致表现出近距离 <中距离 <远距离的格局规律 ,但其明显度不尽一致 ,说明各植被层反映旅游活动对群落结构作用程度的能力大小依次为乔木层 <灌木层 <苔藓层 <草本层 .5个旅游影响因子的变化趋势 ,反映了旅游活动对群落生态环境的结构作用的规律 .距游径的水平距离愈远 ,垃圾量愈少 ,林下死枝下高愈高 ,枯层愈厚 ,树桩量愈多 ,幼苗量也愈多 .不同距离带上的变化规律客观地描绘了旅游活动的规律性变化 ,近距离处旅游活动强度最大 ,中距离处次之 ,远距离处则最小 .图 1表 1参 8 相似文献
63.
A molecular genetic analysis of social structure, dispersal, and interpack relationships of the African wild dog (Lycaon pictus ) 总被引:7,自引:0,他引:7
Derek J. Girman M. G. L. Mills Eli Geffen Robert K. Wayne 《Behavioral ecology and sociobiology》1997,40(3):187-198
The African wild dog is a highly social, pack-living predator of the African woodland and savannah. The archetypal wild dog
pack consists of a single dominant breeding pair, their offspring, and non-breeding adults who are either offspring or siblings
of one of the breeding pair. Non-breeding adults cooperate in hunting, provisioning and the protection of young. From these
observations follows the prediction that the genetic structure of wild dogs packs should resemble that of a multigenerational
family, with all same-sexed adults and offspring within a pack related as sibs or half-sibs. Additionally, a higher kinship
between females from neighboring packs should be evident if females tend to have small dispersal distances relative to males.
We test these predictions through analysis of mitochondrial DNA control region sequences and 14 microsatellite loci in nine
wild dog packs from Kruger National Park, Republic of South Africa. We show that as predicted, African wild dog packs generally
consist of an unrelated alpha male and female, subdominant close relatives, and offspring of the breeding pair. Sub-dominant
wild dogs occasionally reproduce but their offspring rarely survive to 1 year of age. Relatedness influences the timing and
location of dispersal events as dispersal events frequently coincide with a change in pack dominance hierarchy and dispersers
often move to areas with a high proportion of close relatives.
Received: 22 February 1996 / Accepted after revision: 16 November 1996 相似文献
64.
Jessica L. Adams Kari W. Camelio Matthew J. Orique Daniel T. Blumstein 《Behavioral ecology and sociobiology》2006,60(5):742-747
Antipredator behavior includes several qualitatively distinct activities, but few studies have determined the degree to which these activities are independent. If behaviors are not independent, then the nature of the relationship would illustrate potential performance constraints. We studied crimson rosellas (Platycercus elegans) and first focused on acoustic predator discrimination. We measured time allocation before and after playback of one of three experimental treatments (peregrine falcons—Falco peregrinus, wedge-tailed eagles—Aquila audax, and crimson rosellas) to determine whether or not rosellas discriminated predators from non-predators, and specifically whether or not they discriminated large from small predators. We then focused on the decision to flee. We experimentally approached subjects and measured the distance at which they oriented to us (alert distance) and the distance at which they fled (flight initiation distance; FID). We found that rosellas could distinguish among predators; however, there was no effect on general wariness as measured by FID. These two processes of antipredator behavior may, thus, be independent. 相似文献
65.
Katriina Tiira Anssi Laurila Katja Enberg Jorma Piironen Sami Aikio Esa Ranta Craig R. R. Primmer 《Behavioral ecology and sociobiology》2006,59(5):657-665
A key question of evolutionary importance is what factors influence who becomes dominant. Individual genetic variation has been found to be associated with several fitness traits, including behaviour. Could it also be a factor influencing social dominance? We investigated the association between social status and the amount of intra-individual genetic variation in juvenile brown trout (Salmo trutta). Genetic variation was estimated using 12 microsatellite loci. Dominant individuals had higher mean heterozygosity than subordinates in populations with the longest hatchery background. Heterozygosity–heterozygosity correlations did not find any evidence of inbreeding; however, single-locus analysis revealed four loci that each individually differed significantly between dominant and subordinate fish, thus giving more support to local than general effect as the mechanism behind the observed association between genetic diversity and a fitness-associated trait. We did not find any significant relation between mean d 2 and social status, or internal relatedness and social status. Our results suggest that individual genetic variation can influence dominance relations, but manifestation of this phenomenon may depend on the genetic background of the population. 相似文献
66.
67.
Conventional mathematical programming methods, such as linear programming, non linear programming, dynamic programming and
integer programming have been used to solve the cost optimization problem for regional wastewater treatment systems. In this
study, a river water quality management model was developed through the integration of a genetic algorithm (GA). This model
was applied to a river system contaminated by three determined discharge sources to achieve the water quality goals and wastewater
treatment cost optimization in the river basin. The genetic algorithm solution, described the treatment plant efficiency,
such that the cost of wastewater treatment for the entire river basin is minimized while the water quality constraints in
each reach are satisfied. This study showed that genetic algorithm can be applied for river water quality modeling studies
as an alternative to the present methods. 相似文献
68.
Recent theory and empirical work suggests that there may be variation among females in mate preferences that is adaptive.
One of the possible mechanisms maintaining variability in preferences and preferred traits is that the benefits of mate choice
may depend on compatibility with potential mating partners. We examined fitness consequences of mate choice in a species of
fish, the sand goby, Pomatoschistus minutus with a special focus on mate compatibility. Females were given the opportunity to establish their mate preferences in a dichotomous
mate choice experiment. This information was then applied by mating the focal or control female with either the preferred
or the non-preferred male. The parental performance of the males of these four mating combinations was then measured. In a
separate experiment, we assessed the female differential allocation by determining the residual gonad weight of spawned females
as a measure of the proportion of eggs spawned. We also estimated the amount of filial cannibalism separately for both sexes.
Our results show that preferred males provided benefits in the form of an increased number of hatching eggs. This benefit
was the same when the male was mated with a focal or a control female. Hence, we found no support for benefits that depend
on mate compatibility. Neither did we find support for the hypothesis that females would lay a different number of eggs depending
on the male status. The results also indicate that male filial cannibalism has a strong role in determining hatching success
in this species. 相似文献
69.
Assuming that a male’s genetic characteristics affect those of his offspring, extra-pair copulation has been hypothesized
to increase heterozygosity of the progeny—the “genetic compatibility” hypothesis—and the genetic diversity within litters—the
“genetic diversity” hypothesis. We tested these two hypotheses in the alpine marmot (Marmota marmota), a socially monogamous mammal showing a high rate of extra-pair paternity (EPP). In a first step, we tested the assumption
that a male’s genetic characteristics (heterozygosity and genetic similarity to the female) affect those of his offspring.
Genetic similarity between parents influenced offspring heterozygosity, offspring genetic similarity to their mother, and
litter genetic diversity. The father’s heterozygosity also influenced litter genetic diversity but did not affect offspring
heterozygosity. Hence, heterozygosity seems not to be heritable in the alpine marmot. In a second step, we compared genetic
characteristics of extra-pair young (EPY) and within-pair young (WPY). EPY were less genetically similar to their mother but
not more heterozygous than WPY. EPY siblings were also less genetically similar than their WPY half siblings. Finally, the
presence of EPY promoted genetic diversity within the litter. Thus, our data support both the “genetic compatibility” and
the “genetic diversity” hypotheses. We discuss further investigations needed to determine the primary causes of EPP in this
species. 相似文献
70.