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901.
Phenotypic variation in natural populations is the outcome of the joint effects of environmentally induced adaptations and neutral processes on the genetic architecture of quantitative traits. In this study, we examined the role of adaptation in shaping wild barley phenotypic variation along different environmental gradients. Detailed phenotyping of 164 wild barley (Hordeum spontaneum) accessions from Israel (of the Barley1K collection) and 18 cultivated barley (H. vulgare) varieties was conducted in common garden field trials. Cluster analysis based on phenotypic data indicated that wild barley in this region can be differentiated into three ecotypes in accordance with their ecogeographical distribution: north, coast and desert. Population differentiation (QST) for each trait was estimated using a hierarchical Bayesian model and compared to neutral differentiation (FST) based on 42 microsatellite markers. This analysis indicated that the three clusters diverged in morphological but not in reproductive characteristics. To address the issue of phenotypic variation along environmental gradients, climatic and soil gradients were compared with each of the measured traits given the geographical distance between sampling sites using a partial Mantel test. Flowering time and plant growth were found to be differentially correlated with climatic and soil characteristic gradients, respectively. The H. vulgare varieties were superior to the H. spontaneum accessions in yield components, yet resembled the Mediterranean types in vegetative characteristics and flowering time, which may indicate the geographical origin of domesticated barley.  相似文献   
902.
The main goal of this collaborative study was to evaluate the experimental panel of cryopreserved mycoplasma reference strains recently prepared by the American Type Culture Collection (ATCC®) in order to assess the viability and dispersion of cells in the mycoplasma stocks by measuring the ratio between the number of genomic copies (GC) and the number of colony forming units (CFU) in the reference preparations. The employment of microbial reference cultures with low GC/CFU ratios is critical for unbiased and reliable comparison of mycoplasma testing methods based on different methodological approaches, i.e., Nucleic Acid Testing (NAT) and compendial culture-based techniques. The experimental panel included ten different mycoplasma species known to represent potential human and animal pathogens as well as common contaminants of mammalian and avian cell substrates used in research, development, and manufacture of biological products. Fifteen laboratories with expertise in field of mycoplasma titration and quantification of mycoplasmal genomic DNA participated in the study conducted from February to October of 2012. The results of this study demonstrated the feasibility of preparing highly viable and dispersed (possessing low GC/CFU ratios) frozen stocks of mycoplasma reference materials, required for reliable comparison of NAT-based and conventional mycoplasma detection methods.  相似文献   
903.
In most industrialized countries, policy debates around stem cell science manifest in public discourse. Assuming that a functioning public sphere exists where matters of science policy can be discussed, examination of these discourses can help provide an understanding of how science policies evolve. The aim of this paper is to provide a preliminary analysis of how the public discourses around stem cell science have developed in Singapore. Using a theoretical model of “focused discourse,” our analysis indicates that there have been five distinct phases, marked by discernible shifts that reflect important changes in how biomedical science is funded in Singapore. While our results are preliminary, we argue that public discourses around science policies do exist in Singapore but are limited by a lack of diversity that would be expected in a more heterogeneous public sphere.  相似文献   
904.
This paper explores the “pre-embryo” debate in America to analyze the relationship between scientific uncertainty and moral decision-making. This paper explores how an ethical debate among bioethicists around the term “pre-embryo” has been transformed into a scientific “fact” debate between developmental biology and embryology. This transformation is driven by the scientism of ethical reasoning that stresses scientific claims to increase the credibility of ethical claims. This paper concludes that the “pre-embryo” debate is not an ethical controversy over a unified science but rather credibility struggles between two heterogeneous assemblages of science and bioethics.  相似文献   
905.
王超  方舟 《动物学杂志》2021,56(5):756-769
几何形态测量学是头足类角质颚形态分析的重要研究方法,其中包括地标点法和轮廓线法。虽然地标点类型被划分为三种,但基于地标点法的角质颚形态研究对于地标点的选取与建立并没有一个统一的标准,因此探究可以更好地展示角质颚形态变异程度所需要的地标点以及样本数是十分必要的。为探究不同地标点和样本数对角质颚形态分析的影响,本研究利用2018和2019年捕捞的剑尖枪乌贼(Uroteuthis edulis)角质颚样本,使用R语言LaMBDA包LaSEC函数,对300对角质颚样本分别使用10、20、28个地标点和50、80、100、200、300对样本组合,以探讨不同地标点和样本数方案时表示形态变异的平稳度。研究结果表明,地标点数量会使质心大小结果产生误差;为了更好地展示角质颚的形态变异程度,最终确定研究样本在50对以内时,上颚和下颚采用26个地标点;研究样本为50~300对时采用27个地标点。研究分析认为,基于LaSEC的头足类角质颚地标点和样本定量分析可以拟定表示角质颚形态变异的最佳地标点数量,并通过角质颚形态变异箭头图来明确表示角质颚形态变异的最佳地标点方案,为后续基于地标点法的头足类角质颚形态研究提供科学依据。  相似文献   
906.
An entirely online upper‐division university marine invertebrates course modeled after a field experience‐intensive course that also provided interaction with live animals and research experience was offered at Rosario Beach Marine Laboratory in the summer of 2020. We describe online methods we used for providing field experiences to students participating online, as well as a workstation and interactive method for identification and detailed anatomical examination of live macroinvertebrates with students. Students were also involved as active participants in a field research project. Nearly all of the equipment involved is inexpensive or readily available in most university biology laboratories or classrooms.  相似文献   
907.
908.
王科  蔡磊  姚一建 《生物多样性》2021,29(8):1064-80
菌物是全球生物多样性最丰富的生物类群之一, 每年有大量新物种被描述和发现, 统计和分析菌物新名称发表数据, 可实时展示菌物分类学的研究热点, 并为学科的未来发展提供参考数据。根据世界菌物名称信息库Fungal Names、Index Fungorum和MycoBank所收录的数据, 2020年全球共发表了4,996个菌物新名称, 包括652个新高阶分类单元、2,905个新种及种下单元、1,342个新组合和97个其他名称, 是历史上发表菌物新名称数量最多的一年。这些新名称隶属于12门44纲173目469科1,386属, 盘菌、小型子囊菌、地衣和伞菌是本年度最受关注的类群。来自全球的1,978位学者将上述菌物新名称发表在133个期刊的885篇论文和9部专著中, 其中669位作者是首次参与新名称发表, 是历年来新作者最多的一年。本年度发表的菌物新物种的模式标本来自世界103个国家和地区, 东亚和东南亚是新物种发现的最热点地区, 而中国是发现新物种最多的国家, 共发现663种, 占全球的23%, 是排名第二位的泰国的2.28倍。西南地区是我国新物种发现的热点地区, 云南、贵州、西藏三省区本年度发现的新物种数量占全国的44.80%。除了新物种来源, 中国学者在本年度的菌物分类学研究中取得了令人瞩目的成果, 333位中国学者参与发表了1,271个菌物新名称, 占全球新名称总数的1/4。这些菌物新名称隶属于8门24纲87目209科440属, 发表在45个期刊的258篇研究论文和1部专著中。通过上述研究发现, 全球菌物新物种发现的速度仍在加快, 命名作者和新名称发表数量在逐步增加, 研究类群规模在逐渐扩大。但菌物物种描述率仍处于较低水平, 持续、高效地发现菌物新物种将是菌物学者的重点研究方向之一。  相似文献   
909.
生物技术基地平台是开展生物技术研究、生产和服务的重要基础保障,生物技术基地平台相关政策在指导和推动我国生物技术基地平台建设发展中发挥着重要作用。以近十年来中共中央、国务院以及科技部等政府部门制定的生物技术基地平台政策为研究对象,梳理归纳我国生物技术基地平台政策的价值内涵,探讨建设规律,以期为基地平台的创新发展提供借鉴指导。  相似文献   
910.
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