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371.
This paper describes a Decision Support System for Disaster Management (DSS-DM) to aid operational and strategic planning and policy-making for disaster mitigation and preparedness in a less-developed infrastructural context. Such contexts require a more flexible and robust system for fast prediction of damage and losses. The proposed system is specifically designed for earthquake scenarios, estimating the extent of human losses and injuries, as well as the need for temporary shelters. The DSS-DM uses a scenario approach to calculate the aforementioned parameters at the district and sub-district level at different earthquake intensities. The following system modules have been created: clusters (buildings) with respect to use; buildings with respect to construction typology; and estimations of damage to clusters, human losses and injuries, and the need for shelters. The paper not only examines the components of the DSS-DM, but also looks at its application in Besiktas municipality in the city of Istanbul, Turkey. 相似文献
372.
大型地下方厅多导洞施工力学效应分析 总被引:2,自引:2,他引:0
杜彬 《中国安全科学学报》2005,15(2):51-54
针对北京城铁 13号线东直门站地下方厅开挖跨度大、覆盖层薄、地质条件极差的施工难题 ,笔者采用三维有限元数值模型 ,模拟开挖支护施工流程 ,考虑到围岩介质的复杂特性 ,施工作业方式 ,包括分布开挖工序 ,支护结构形式和施作时机 ,以及开挖面推进过程中的空间效应 ;按形变压力理论 ,选用“连续体”计算模型 ,采用增量变弹性法和增量叠代的混合法进行计算分析 ,对多导洞开挖支护施工方案进行了计算分析 ;基本掌握了在覆土厚度小的情况下开挖大跨平顶直墙方厅时 ,周围土体的应力分布特征和变形特性 ,对于优化施工方案、修改支护参数、采取局部加固措施起到了重要作用。实践表明采用多导洞施工方案是科学合理的 ,有利地保证了周边环境和施工安全。 相似文献
373.
《组织行为杂志》2017,38(3):391-414
Building on the premises of the conservation of resources theory, the aim of this study was to investigate long‐term effects of job resources on vigor among native and immigrant employees in Israel. More specifically, we investigated the effects of baseline and change in job control and supervisor support on change in vigor levels, as well as the degree to which these effects differ among educated native and immigrant employees in Israel. We surveyed 235 white‐collar Eastern European and Russian immigrants and 235 white‐collar native Israelis matched on occupational and demographic characteristics at two points of measurement with a 30‐month time lag. Latent change score modeling revealed that among both immigrants and natives, change in job control was related to change in vigor. Multiple group analyses further revealed that among immigrant employees only, baseline levels of supervisor support were associated with change in vigor. In conclusion, these findings suggest that the utilization of resources as a means of acquiring new resources may be influenced by immigrant background. Managerial implications are discussed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
374.
强膨胀软岩巷道的支护问题是西部地区矿井建设中普遍遇到的难题。为解决强膨胀软岩遇水泥化、崩解等给巷道掘进、支护等工程带来的困难,以强膨胀软岩巷道支护工程为研究对象,通过理论分析和现场调研,研究强膨胀软岩巷道变形机理;利用有限元分析软件MIDAS/GTS建立强膨胀软岩巷道数值仿真模型,分析了锚网喷架联合支护时巷道塑性区范围、表面位移和钢支架的受力特征。进行现场测试,获得了巷道围岩变形和锚杆受力变化规律。结果表明,采用钢支架与锚网喷构成联合支护体系可有效提高支护结构整体刚度,提升围岩的自稳能力和自承能力。 相似文献
375.
Roman M. Wittig Catherine Crockford Robert M. Seyfarth Dorothy L. Cheney 《Behavioral ecology and sociobiology》2007,61(6):899-909
Theory predicts that females in species with matrilineal dominance hierarchies should use nepotistic support systems to maintain
their family’s rank. Female Old World monkeys, however, form alliances against other females at surprisingly low rates. Nonetheless,
in many species, females utter threat vocalizations when observing others’ disputes, suggesting that these vocalizations may
function as ‘vocal alliances’. We describe a playback experiment testing the efficacy of vocal alliances in free-ranging female
baboons. Subjects were played the same female’s threat-grunts under three separate conditions: after being threatened by the
signaller’s close relative to mimic kin support, after being threatened by a female maternally unrelated to the signaller
to mimic non-kin support, and after a friendly interaction with the signaller’s close relative as a control. Subjects responded
more strongly to the playback and avoided the signaller and her matrilineal relatives for a longer period of time in kin support
trials than in either non-kin support or no aggression trials. In contrast, there was no difference in subjects’ behaviour
between non-kin support and no aggression trials. These results corroborate observational data showing that vocal support
occurs at a higher rate than physical support in female baboons, and that kin are more likely to provide vocal support than
non-kin. We conclude that vocal support plays a similar role as physical support in the alliances of female baboons. 相似文献
376.
Learning,retention and coding of nest-associated visual cues by the Australian desert ant, <Emphasis Type="Italic">Melophorus bagoti</Emphasis> 总被引:3,自引:0,他引:3
Ajay Narendra Aung Si Danielle Sulikowski Ken Cheng 《Behavioral ecology and sociobiology》2007,61(10):1543-1553
A variety of social insects use visual cues for homing. In this study, we examine the possible factors affecting the learning
and retention of nest-associated visual cues by the Australian desert ant Melophorus bagoti and the manner in which such cues are encoded by foraging ants. We placed four prominent cylindrical landmarks around a nest
and trained foragers from that nest to a food source. Ants were tested with the landmark array in a distant testing field
after (1) a known number of exposures to the landmarks (1, 3, 7 or 15 trials, spread over a period of 1 day, 2 days or ≥3 days)
and (2) after a known period of delay (0, 24, 48, 96 or 192 h). The results show that a combination of an increase in training
trials and an increase in number of training days affected the acquisition of landmark memory. Moreover, once the landmarks
were learnt, they became a part of long-term memory and lasted throughout the ants’ foraging lifetime. To examine visual cue
encoding behaviour, ants trained under similar conditions for 4 days were tested with (1) an identical landmark array, (2)
landmarks of the same size used in training, but placed at twice the distance from each other, and (3) landmarks whose dimensions
were doubled and placed at twice the distance from each other. In conditions (1) and (3), the ants searched extensively at
the centre of the four landmarks, suggesting that, similar to the Saharan ant (genus Cataglyphis) and the honeybee, M. bagoti too uses a snapshot to match the view of the landmarks around the nest. But contrary to the snapshot model, in condition
(2), the ants did not search extensively at the centre of the landmarks, but searched primarily 0.5 m from the landmark, the
distance from each landmark to the nest during training. We discuss how various search models fare in accounting for these
findings. 相似文献
377.
378.
烟草花叶病毒siRNA设计及其植物表达载体构建 总被引:1,自引:1,他引:1
RNA干扰技术已广泛应用于沉默基因表达的研究.本文分析烟草花叶病毒(TMV)基因序列,选择设计编码小分子发卡结构RNA(hpRNA)的cDNA;并根据农杆菌双元载体质粒p2355多克隆位点区限制性酶切位点,两端分别加入XbaI和BamHI酶切位点;分别合成单链DNA复性后插入到p2355上,经PCR、测序验证,表明已成功构建了具有潜在表达烟草花叶病毒siRNA的植物表达载体.图3表1参26 相似文献
379.
Martin T. Schultz Mitchell J. Small Paul S. Fischbeck R. Scott Farrow 《Environmental Modeling and Assessment》2006,11(4):345-359
Environmental models are often too large and cumbersome for effective use in regulatory decision making or in the characterization of uncertainty. This paper describes and compares four response surfaces that could complement a large-scale water quality model, the U.S. National Water Pollution Control Assessment Model (NWPCAM), in simulation and regulatory decision support applications. Results show that a physically based reduced-form model that exploits the mathematical structure of the underlying water quality model is a better predictor of policy-relevant outputs than the polynomial expansions that are frequently used in response surface studies. 相似文献
380.
Erin M.K. Haacker Vaishali Sharda Amanda M. Cano R. Aaron Hrozencik Agustín Núez Zachary Zambreski Soheil Nozari Garvey Engulu B. Smith Lacey Moore Sumit Sharma Prasanna Gowda Chittaranjan Ray Meagan Schipanski Reagan Waskom 《Journal of the American Water Resources Association》2019,55(1):6-23
Agricultural water management (AWM) is an interdisciplinary concern, cutting across traditional domains such as agronomy, climatology, geology, economics, and sociology. Each of these disciplines has developed numerous process‐based and empirical models for AWM. However, models that simulate all major hydrologic, water quality, and crop growth processes in agricultural systems are still lacking. As computers become more powerful, more researchers are choosing to integrate existing models to account for these major processes rather than building new cross‐disciplinary models. Model integration carries the hope that, as in a real system, the sum of the model will be greater than the parts. However, models based upon simplified and unrealistic assumptions of physical or empirical processes can generate misleading results which are not useful for informing policy. In this article, we use literature and case studies from the High Plains Aquifer and Southeastern United States regions to elucidate the challenges and opportunities associated with integrated modeling for AWM and recommend conditions in which to use integrated models. Additionally, we examine the potential contributions of integrated modeling to AWM — the actual practice of conserving water while maximizing productivity. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series. 相似文献