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31.
为精准识别地下矿山声发射事件,采用基于改进的完全集合经验模态分解模型(ICEEMDAN)和多通道卷积神经网络(MC-CNN)模型对声发射信号进行处理后得到分量图,根据各通道输入分量峭度值赋予不同权重,并利用卷积神经网络对输入数据进行训练,最终采用五折交叉实验方法验证该分类识别方法的可行性及有效性.结果表明:基于ICEE... 相似文献
32.
在升船机施工过程中,由于建筑物多为高坝垂直型,致使上下施工、内外施工和不同性质的施工同时进行,增加了作业条件的危险性,这给升船机施工中的安全管理带来很大困难.以升船机施工为出发点,分析升船机施工中的作业单元流程.按照事故分类的标准,将升船机施工的危险源按照高处坠落、物体打击、垮塌三类事故进行风险辨识.运用LEC-M法确定升船机施工各类危险源的安全风险等级评价,依据危险源评价所涉及到的具体条款,提出降低危险源风险的有效措施.该方法在三峡升船机筒体工程上得到具体应用,并取得良好效果. 相似文献
33.
When two closely related species are sympatric the process of species recognition (identifying conspecifics) and mate-quality recognition (increased fitness benefits) can yield a conflict when heterospecifics resemble high-quality conspecifics. Conflict in species versus mate-quality recognition may serve as a possible mechanism for the persistence of unisexual, gynogenetic Amazon mollies (Poecilia formosa). Amazon mollies require sperm from closely related species (e.g., sailfin mollies, P. latipinna) to start embryogenesis but inheritance is strictly maternal. When choosing mates, male sailfin mollies from populations sympatric with Amazon mollies may rely on traits indicating species identity rather than those indicating mate quality. Conversely, males from allopatric populations may rely more on traits indicating mate quality. Previous work has found that male sailfin mollies in sympatry exhibit a significantly greater mating preference for female sailfin mollies over Amazon mollies compared to males in allopatry. In addition, male sailfin mollies prefer to associate with and produce more sperm in the presence of larger conspecific females, which are more fecund. We hypothesized that male sailfin mollies experience a conflict in species recognition and mate-quality recognition in the presence of Amazon mollies that are relatively larger than female sailfin mollies. To test this hypothesis, we paired males from sympatric and allopatric populations with a larger Amazon molly and a smaller female sailfin molly. We scored the number of mating attempts that males directed to conspecific and heterospecific females. Males in most sympatric and allopatric populations demonstrate no clear preference for conspecifics. In addition, we found some evidence for a difference in mating preference between allopatric and sympatric populations with males from allopatry showing a greater heterospecific mate preference. These results indicate a conflict between species and mate-quality recognition. In sympatry this conflict may contribute to the persistence of gynogenetic Amazon mollies. 相似文献
34.
土壤遥感分类识别专家系统的结构设计 总被引:3,自引:0,他引:3
介绍了土壤遥感分类识别专家系统的设计原理与实现方法,阐述了土壤遥感分类识别专家系统的土壤分类决策判断树的构造原理,讨论了土壤遥感分类识别专家知识表示的基本原则和系统知识库中专家知识的组织方式,以及专家系统推理机的设计原理和推理规则的构建方法。系统采用压缩编码方式存储地学专题图形和遥感图像数据,具有数据与图像的存储更新、查询检索、分析处理、特征提取和信息输出等功能。该系统可以对遥感图像进行土壤类型的分类识别,并对分类精度进行监测与评价。用该系统对新疆天山北麓阜康试验区的土壤分类识别进行了试验研究,并对试验结果进行了讨论与评价。 相似文献
35.
Social animals often use vocal communication signals that contain individual signatures. As bats emit echolocation calls several
times per second to orient in space, these might seem ideal candidates for conveying the caller's individual identity as a
free by-product. From a proximate perspective, however, coding of caller identity is hampered by the simple acoustic structure
of echolocation signals, by their task-specific design and by propagation loss. We investigated the occurrence of individual
signatures in echolocation calls in individually marked, free-living Bechstein's bats (Myotis bechsteinii) in a situation with defined social context in the field. The bats belonged to two different colonies, for both of which
genetic data on relatedness structure was available. While our data clearly demonstrate situation specificity of call structure,
the evidence for individual-specific signatures was relatively weak. We could not identify a robust and simple parameter that
would convey the caller's identity despite the situation-specific call variability. Discriminant function analysis assigned
calls to call sequences with good performance, but worsened drastically when tested with other sequences from the same bats.
Therefore, we caution against concluding from a satisfactory discrimination performance with identical training and test sequences
that individual bats can reliably be told apart by echolocation calls. At least the information contained in a single call
sequence seems not to be sufficient for that purpose. Starting frequencies did give the best discrimination between individuals,
and it was also this parameter that was correlated with genetic relatedness in one of our two study colonies. Echolocation
calls could serve as an additional source of information for individual recognition in Bechstein's bats societies, while it
is unlikely that a large number of individuals could be reliably identified in different situations based on echolocation
alone. 相似文献
36.
Grzegorz Owczarek Grzegorz Gralewicz Natalia Skuza Piotr Jurowski 《International journal of occupational safety and ergonomics》2016,22(1):66-70
In this research the factors used to evaluate the light transmission through two types of acrylic hydrophobic intraocular lenses, one that contained yellow chromophore that blocks blue light transmission and the other which did not contain that filter, were defined according to various light condition, e.g., daylight and at night. The potential influence of light transmission trough intraocular lenses with or without yellow chromophore on functional vision in everyday environmental conditions was analysed. 相似文献
37.
Daniel T. Blumstein Louise Cooley Jamie Winternitz Janice C. Daniel 《Behavioral ecology and sociobiology》2008,62(3):457-468
We conducted four experiments to determine whether yellow-bellied marmots, Marmota flaviventris, discriminate among predator vocalizations, and if so, whether the recognition mechanism is learned or experience-independent.
First, we broadcast to marmots the social sounds of coyotes, Canis latrans, wolves, Canis lupus, and golden eagles, Aquila chrysaetos, as well as conspecific alarm calls. Coyotes and eagles are extant predators at our study site, while wolves have been absent
since the mid-1930s. In three follow-up experiments, we reversed the eagle call and presented marmots with forward and reverse
calls to control for response to general properties of call structure rather than those specifically associated with eagles,
we tested for novelty by comparing responses to familiar and unfamiliar birds, and we tested for the duration of predator
sounds by comparing a wolf howl (that was much longer than the coyote in the first experiment) with a long coyote howl of
equal duration to the original wolf. Marmots suppressed foraging and increased looking most after presentation of the conspecific
alarm call and least after that of the coyote in the first experiment, with moderate responses to wolf and eagle calls. Marmots
responded more to the forward eagle call than the reverse call, a finding consistent with a recognition template. Marmots
did not differentiate vocalizations from the novel and familiar birds, suggesting that novelty itself did not explain our
results. Furthermore, marmots did not differentiate between a wolf howl and a coyote howl of equal duration, suggesting that
the duration of the vocalizations played a role in the marmots’ response. Our results show that marmots may respond to predators
based solely on acoustic stimuli. The response to currently novel wolf calls suggests that they have an experience-independent
ability to identify certain predators acoustically. Marmots’ response to predator vocalizations is not unexpected because
25 of 30 species in which acoustic predator discrimination has been studied have a demonstrated ability to respond selectively
to cues from their predators. 相似文献
38.
The concept of degraded images applied to hazard recognition training in mining for reduction of lost-time injuries 总被引:1,自引:0,他引:1
Introduction: This paper discusses the application of a training intervention that uses degraded images for improving the hazard recognition skills of miners. Method: NIOSH researchers, in an extensive literature review, identified fundamental psychological principles on perception that may be employed to enhance the ability of miners to recognize and respond to hazards in their dangerous work environment. Three studies were conducted to evaluate the effectiveness of the degraded image training intervention. A model of hazard recognition was developed to guide the study. Results: In the first study, miners from Pennsylvania, West Virginia and Alabama, who were taught with the aid of degraded images, scored significantly better on follow-up hazard recognition performance measures than those trained using traditional instructional methodologies. The second and third studies investigated the effectiveness of the training intervention at two mining companies. Data collected over a 3-year period showed that lost-time injuries at mines in Alabama and Illinois declined soon after the training intervention was instituted. Impact on Industry: Further exploration of the hazard recognition model and the development of other interventions based on the model could support the validity of the steps in the hazard recognition model. 相似文献
40.
基于模糊模式识别的模糊综合评价在高层建筑火灾危险评价中的应用 总被引:2,自引:3,他引:2
针对高层建筑火灾危险的特点,建立了高层建筑火灾危险评价的指标体系,并应用层次分析法确定了其权重。根据高层建筑火灾危险评价系统具有多因素、多层次的特点,采用模糊综合评价方法;针对模糊综合评价的不足之处,提出把权广义距离之和最小模糊模式识别运用到模糊综合评价当中,建立了基于模糊模式识别的模糊综合评价模型;该评价模型避免了单因素矩阵的确定和模糊算子的选择问题,用安全状态特征值来表征最终的评价结果,能使评价结果更加准确,可操作性强。通过对陕西某高层建筑火灾危险评价实例证明,该模型具有较好的应用价值,为日常的安全管理和性能化防火设计提供了有用依据。 相似文献