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941.
低空域无人机遥感技术具有高时效性、高分辨率、低成本、易操控等优势,作为地面与高空遥感(航天与航空遥感)间测量尺度空缺的有益补充,低空无人机遥感扩展了样地样方空间尺度,提高了中、小尺度遥感观测信息的精细化程度,实现了草原生境信息的快速采集、处理与分析应用,是草原"星-空-地"一体化监测的重要组成。针对草原监测评价,总结了国内外低空无人机遥感在草原基况调查(草原草层高度监测、草原植被覆盖度监测与草原地上生物量估算)、草原动态监测(草原植被长势监测、草原产草量估测与草畜平衡监测)和草原应急管理(草原火灾、雪灾与生物灾害监测)中的应用。结合大数据、人工智能、云计算与物联网等新型技术,分析了低空无人机遥感在草原生态监测领域存在的不足和未来的发展方向,以期为低空无人机遥感关于草原监测评价与智慧草原的后续研究提供参考。 相似文献
942.
【目的】利用原核表达系统对牛分枝杆菌Mb0950c蛋白进行表达和纯化,通过小鼠模型评价其免疫原性,建立血清学间接ELISA方法用于牛结核病的临床检测。【方法】构建pET32a-Mb0950c原核表达质粒,并转化至BL21(DE3)中诱导蛋白的表达,对蛋白进行纯化。使用流式细胞术(flow cytometry,FCM)、ELISA等对该蛋白在小鼠中的免疫原性进行分析。建立基于Mb0950c的间接ELISA方法,评价该方法的临床检测潜力。【结果】SDS-PAGE和Western blotting结果显示,成功获得了可溶性Mb0950c蛋白,且具有良好免疫反应性;FCM结果显示,Mb0950c蛋白上调了T细胞表面CD69分子的表达。细胞因子和抗体结果表明,该蛋白能够诱导特异性的IFN-γ和IL-4的分泌,同时能诱导机体分泌特异性的抗体,且以IgG1型为主。建立了ELISA检测方法应用于牛结核临床检测,结果显示,该方法与牛结核外周血IFN-γ外释放试验和皮试试验结果的阳性符合率、阴性符合率和总符合率分别为65.7%、97.9%和72.4%。【结论】在原核表达系统中可溶性表达Mb0950c蛋白,... 相似文献
943.
蔚县盆地地处泥河湾盆地(广义)的东南端,是更新世人类活动的重要区域。2017-2018年,中国科学院古脊椎动物与古人类研究所等在盆地内开展系统的旧石器考古调查,新发现并确认了27处旧石器地点。相关地貌、地层对比显示,新地点年代可大致分为中更新世和晚更新世晚期两个阶段,文化遗物分别埋藏于泥河湾河湖相堆积和黄土堆积中。中更新世石制品类型包括石核、石片、石器和断块等,原料以火山岩为主,均采用锤击法进行剥片和修理石器;晚更新世晚期遗址包括石核、石片和细石叶等,原料以白云岩和燧石居多,火山岩次之,以硬锤锤击法为主要剥片技术,软锤技术少量发现。对石制品初步分析表明,蔚县盆地中更新世地点表现出了一套与阳原盆地早-中更新世不同的原料及石制品组合,且在蔚县盆地晚更新世晚期存在小型石片石器和细石器两种工业。本次调查扩大了泥河湾盆地古人类活动的地理范围与文化内涵,为揭示泥河湾盆地(广义)早期人类的迁徙与适应行为提供了有价值的线索。 相似文献
944.
山西省平陆县处于黄河中下游之交处,位于运城盆地南部,是古人类生存的重要地带。2018年3月-10月在平陆县开展的考古调查,复查确认和新发现旧石器时代地点共10处,采集石制品共45件。采集的大多石制品个体较小;原料以石英为主;打片方法以锤击法和砸击法为主;石制品类型包括石核、石片、断块和石器等,其中石器类型只见刮削器。据地层和石制品特征推测,这些地点主要属于中更新世晚期和晚更新世。平陆石工业体现了"石核—石片"技术从中更新世至晚更新世的继承和发展,为更深入探讨平陆及周边地区人群的扩散和演化提供了地层依据和实物资料。 相似文献
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947.
We introduce a photosynthetic pigment‐encoding phycoerythrin gene, consisting of alpha (cpeA) and beta (cpeB) units that can be used for biodiversity surveys of callithamnioid red algae. A set of polymerase chain reaction (PCR) primers were designed to amplify an approximately 1‐kb fragment of the gene from 14 taxa. These have been proven useful in isolating the gene from samples mixed with diatoms. Pairwise distance and synonymous and nonsynonymous nucleotide substitution rates of the cpeA and cpeB regions are described. This is the first study to examine the phycoerythrin sequences for use in red alga biodiversity surveys. 相似文献
948.
While the process of habituation is essential for researchers to observe primates in their natural habitats, ethical dilemmas may arise from its consequences. We collected data from 286 participants via an online survey to investigate: (a) how primatologists perceive their ethical duties toward their subjects; (b) the extent to which primatologists are concerned about the potential ethical consequences of habituation; and (c) the methods primatologists use to reduce potential harms caused by habituation. Overall, primatologists felt an extremely strong duty to mitigate harms that they may cause (e.g., to not stress individuals during observation, treat injuries, and reunite separated individuals) and expressed very high concern for habituation's potential to increase the vulnerability of their subjects to poaching and disease transfer. Ratings for those items were so high that they could not be included in subsequent exploratory factor analyses that were designed to reveal constructs underlying respondents’ ratings of their ethical duties and concerns. Factor analysis of ratings of ethical duties revealed that primatologists reported a strong duty to mitigate harms caused by other humans and a lower perceived duty to mitigate naturally occurring harmful events. Factor analysis on ethical concern ratings revealed that respondents were concerned about harms during the habituation process, the presence of unhabituated behavior after habituation had been established, and indirect harms of habituation. Concerns for unhabituated behavior and indirect harms were rated slightly higher than concern for harms during the habituation process. To mitigate potential harms, primatologists primarily reported engaging in strategies to reduce stress in their subjects. Our findings reveal a disconnect between primatologists' ratings of their ethical concerns and their reported mitigation practices that may, in part, stem from gaps in knowledge about the true impacts of habituation. We suggest areas of discussion and research in the field necessary to address those gaps. 相似文献
949.
Julia D. Monk Eunbi Kwon Audrey Derose-Wilson Samantha G. Robinson Henrietta A. Bellman Sarah M. Karpanty Daniel H. Catlin James D. Fraser 《The Journal of wildlife management》2020,84(7):1338-1347
Conservation of shorebirds throughout their breeding and migratory ranges has become a priority as shorebird populations decline globally. Along the North Atlantic Coast, management efforts have particularly focused on preserving nesting habitat for piping plovers (Charadrius melodus), which are protected under the Endangered Species Act. It is unclear whether these conservation measures suffice to protect foraging habitat for piping plovers and other shorebirds on stopover during migration along the Atlantic Flyway. To evaluate the extent to which conservation of piping plover nesting areas extends to all habitats used by plovers, and to determine whether these protections also benefited non-breeding migratory shorebirds in the region, we conducted weekly shorebird surveys, recording the number and locations of piping plovers and other species, during northward and southward migration on Fire Island and Westhampton Island, New York, USA, from 2014–2016. We used canonical correspondence analysis (CCA) to assess the degree of spatiotemporal overlap between breeding plovers, foraging plovers, and other migratory shorebirds that temporarily stage at the site. The spatiotemporal distribution of migratory shorebirds matched more closely with piping plovers seen during foraging than piping plovers observed tending nests and engaging in other breeding activities. Migratory shorebirds and foraging piping plovers were more abundant and frequent in wet intertidal zones outside of fenced-off nesting areas, which were not protected under current management regimes. Therefore, additional protection of piping plover foraging habitat could benefit plovers and migratory shorebirds that use similar feeding grounds during stopover on northward and southward migration. © 2020 The Wildlife Society. 相似文献
950.
Brendan A. Wintle Terry V. Walshe Kirsten M. Parris Michael A. McCarthy 《Diversity & distributions》2012,18(4):417-424
Aim Conservation practitioners use biological surveys to ascertain whether or not a site is occupied by a particular species. Widely used statistical methods estimate the probability that a species will be detected in a survey of an occupied site. However, these estimates of detection probability are alone not sufficient to calculate the probability that a species is present given that it was not detected. The aim of this paper is to demonstrate methods for correctly calculating (1) the probability a species occupies a site given one or more non‐detections, and (2) the number of sequential non‐detections necessary to assert, with a pre‐specified confidence, that a species is absent from a site. Location Occupancy data for a tree frog in eastern Australia serve to illustrate methods that may be applied anywhere species’ occupancy data are used and detection probabilities are < 1. Methods Building on Bayesian expressions for the probability that a site is occupied by a species when it is not detected, and the number of non‐detections necessary to assert absence with a pre‐specified confidence, we estimate occupancy probabilities across tree frog survey locations, drawing on information about where and when the species was detected during surveys. Results We show that the number of sequential non‐detections necessary to assert that a species is absent increases nonlinearly with the prior probability of occupancy, the probability of detection if present, and the desired level of confidence about absence. Main conclusions If used more widely, the Bayesian analytical approaches illustrated here would improve collection and interpretation of biological survey data, providing a coherent way to incorporate detection probability estimates in the design of minimum survey requirements for monitoring, impact assessment and distribution modelling. 相似文献