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51.
The specification of anterior neuroectoderm is controlled by a highly conserved molecular mechanism in bilaterians. A forkhead family gene, foxQ2, is known to be one of the pivotal regulators, which is zygotically expressed in this region during embryogenesis of a broad range of bilaterians. However, what controls the expression of this essential factor has remained unclear to date. To reveal the regulatory mechanism of foxQ2, we performed cis‐regulatory analysis of two foxQ2 genes, foxQ2a and foxQ2b, in a sea urchin Hemicentrotus pulcherrimus. In sea urchin embryos, foxQ2 is initially expressed in the entire animal hemisphere and subsequently shows narrower expression restricted to the anterior pole region. In this study, as a first step to understand the foxQ2 regulation, we focused on the later restricted expression and analyzed the upstream cis‐regulatory sequences of foxQ2a and foxQ2b by using the constructs fused to short half‐life green fluorescent protein. Based on deletion and mutation analyses of both foxQ2, we identified each of the five regulatory sequences, which were 4–9 bp long. Neither of the regulatory sequences contains any motifs for ectopic activation or spatial repression, suggesting that later mRNA localization is regulated in situ. We also suggest that the three amino acid loop extension‐class homeobox gene Meis is involved in the maintenance of foxQ2b, the expression of which is dominant during embryogenesis.  相似文献   
52.
A number of studies have shown that primates monitor and select plant species in their diet as a function of their secondary compound composition. The possibility also exists that secondary compounds, when used in appropriate concentrations, may have a beneficial, medicinal aspect. In this regard, synthesis of a variety of data suggested a connection between selection of Balanites by Ethiopian baboons, and the distribution of schistosomiasis. To test the hypothesis that the secondary compounds in Balanites might be selected for ‘medicinal purposes’, we conducted an experiment on the effect of adding the active principle, diosgenin, to the food of schistosome-infected mice. The hypothesis was that this steroidal saponin might alter the host's hormonal milieu, making a less hospitable environment for the adult schistosomes. Sacrifice of the mice showed diosgenin-fed animals to have an augmented rather than decreased response to the disease. However, the data support the developing literature that shows that the host's hormonal environment has a major effect on the parasitic diseases they are subject to, and that the hormonal environment can be dramatically influenced by the secondary compounds in the diet.  相似文献   
53.
对成都市温江区不同栽植年限园林植物土壤动物群落特征进行调查分析,4次取样共捕获土壤动物10258只,隶属26目78科。不同园林植物土壤动物类群数存在显著差异,基本以红花檵木、银杏样地最高,结缕草样地最低,各栽植年限土壤动物类群数均低于周边农田和撂荒地;桂花样地土壤动物类群数、个体数受季节变化影响较小,其余样地土壤动物个体数具有明显的季节动态,而类群数随季节变化不显著;土壤动物多样性指数受园林植物种类及栽植年限影响,银杏样地土壤动物密度-类群指数(DG)及Margalef丰富度指数(D)和结缕草样地土壤动物Shannon多样性指数(H)D指数均随栽植年限增加而显著降低,桂花样地土壤动物DG指数、D指数则随栽植年限增加显著升高,红花檵木样地土壤动物多样性各指数随栽植年限增加未表现规律性变化,其中土壤动物DG、DH指数各栽植年限基本以桂花样地最低;聚类及典型关联分析(CCA)表明,园林植物种类对样地生境的影响大于栽植年限,土壤动物对不同生境因子响应不同,其中速效P、土壤pH对土壤动物影响较大。土壤动物群落特征受园林植物种类、栽植年限及栽培管理方式的影响,而过度人为干扰、单一植物连栽会对土壤动物产生不利影响,并可能导致土壤地力衰退。  相似文献   
54.
55.
衡阳盆地土壤动物多样性研究   总被引:4,自引:2,他引:4  
对衡阳盆地紫色页岩土壤 9种生境中的土壤动物进行了调查研究 ,共获得土壤动物35 85只 ,隶属于 4门 8纲 39目 ,其中线虫类、蜱螨类为优势类群 ,占总捕量的 5 0 2 4 % ;常见类群 1 2类 ,占总捕量的 4 4 0 1 %。从土壤动物水平分布上看 ,9种生境相似程度较大 ,其中尤以芦竹林和桃树林、阔叶林和桉树林、芦竹林和桉树林之间相似程度更突出。从土壤动物垂直分布上看 ,9种生境中只有桃树林、柑桔林垂直分布较为明显 ,而各种生境中土壤动物具有明显的表聚性。芦竹林、柑桔林、桉树林、菜地、阔叶林和桃树林 6种生境土壤动物群落的多样性及均匀度呈基本一致的趋势 ,且各生境间差别不大  相似文献   
56.
ABSTRACT

In 2016, the Gerontological Society of America (GSA) developed a research focus on the benefits and potential risks associated with pets among older adults. With the goal of developing a roadmap for human–animal interaction (HAI) research in older people residing in both the community and institutions, GSA convened a workshop of international experts and policy-makers in the fields of aging and HAI. The status of current knowledge was shared on the success factors for healthy aging and the potential challenges (GSA, 2016). Participants considered what roles pets might play in the lives of older adults and their potential to mitigate loneliness, social isolation, and depression, and to enhance mobility and cognitive function. Existing research was shared to provide insights into the ways in which pets can impact older adults and their caregivers and to identify where further research is needed. This paper introduces a series of papers from that meeting, with some additional papers from meeting attendees to expand on the topics covered and provide key perspectives and gaps in information needed, as a foundation for those considering research into this topic. Although HAI/Animal-Assistant Intervention (AAI) research is in its infancy, there is some evidence that pet ownership or animal interaction can have major benefits for many older adults. At the same time, there are some risks to both the pet and the older adult that need to be addressed. Innovative approaches to both AAIs and the ways to overcome challenges are presented in this themed issue of Anthrozoös. Our hope is that the findings from these reviews and reports will stimulate additional work in this area.  相似文献   
57.
[目的]糖尿病是由于多种因素和遗传因素导致体内胰岛素相对或绝对分泌不足,而引起的代谢性内分泌疾病,它以血糖、尿糖升高为特点,起病隐蔽,通过并发症使人致残致死,是继心血管、癌症之后的第三大致死性疾病,很可能成为21世纪人类的“第一杀手”(1,2)。本文采用人工诱导的方法,建立恒河猴糖尿病动物模型,研究糖尿病疾病的发展和及其并发症的发生、发展规律和防治措施,同时对于治疗糖尿病新药的安全性评价和药物疗效的观察具有广阔的运用前景。[方法]选用成熟的、健康的、雄性恒河猴9只,随机分成三个组,其中高剂量组(60mg/kg)1只,中剂量组(45m…  相似文献   
58.
目的构建地方医科大学实验动物管理工作水平评价指标体系,为高校实验动物管理工作的评价提供参考。方法根据研究主题确定咨询专家人选37人,采用Delphi法进行问卷调查和统计分析。结果两轮咨询问卷回收率分别为70.27%和76.92%。权威系数为0.855;第二轮指标体系的协调系数为0.486。结论本次研究构成的地方医科大学实验动物管理工作水平评价指标体系是可靠的。  相似文献   
59.
Introduced exotic species cause environmental changes and threat public health in target sites. Illegal trade has enhanced this problem. To first report these risks in Brazil, exotic snakes found in São Paulo City (SPC) (23°32 S, 46°38 W), southeastern Brazil, and sent to Instituto Butantan between 1995 and 2000, were listed and characterized by their biological attributes. Seventy-six individuals of sixteen alien species were collected. Euriecians snakes, mainly booids, were predominant. Using multivariate techniques, their ecological niches were compared to those of 26 native species, as a way to point out the resource's availability. To evaluate the potential of successful implantation, two species absent in SPC and considered as problem snakes are included in these analyses: the brown treesnake Boiga irregularis and the habu Trimeresurus flavoviridis. There were niche similarities between these pest snakes, exotic booids and native viperids largely due to the similarities in the chosen prey (mammals), diel activity (nocturnal), color pattern (variegated) and body size (medium to large). To avoid predictable undesirable effects of implanted pest snakes, traffic control and punishment should be improved, as well as parallel environmental education programs.  相似文献   
60.
Investigating sexual dimorphism is important for our understanding of its influence on reproductive strategies including male-male competition, mate choice, and sexual conflict. Measuring physical traits in wild animals can be logistically challenging and disruptive for the animals. Therefore body size and ornament variation in wild primates have rarely been quantified. Gorillas are amongst the most sexually dimorphic and dichromatic primates. Adult males (silverbacks) possess a prominent sagittal crest, a pad of fibrous and fatty tissue on top of the head, have red crest coloration, their saddle appears silver, and they possess a silverline along their stomach. Here we measure levels of sexual dimorphism and within-male variation of body length, head size, and sexual dichromatism in a population of wild western gorillas using photogrammetry. Digital photogrammetry is a useful and precise method to measure sexual dimorphism in physical traits yielding sexual dimorphism indices (ISD), similar to those derived from traditional measurements of skeletal remains. Silverbacks were on an average 1.23 times longer in body length than adult females. Sexual dimorphism of head size was highest in measures of crest size (max ISD: 60.4) compared with measures of facial height (max ISD: 24.7). The most sexually dimorphic head size measures also showed the highest within-sex variation. We found no clear sex differences in crest coloration but there was large sexual dichromatism with high within-male variation in saddle coloration and silverline size. Further studies should examine if these sexually dimorphic traits are honest signals of competitive ability and confer an advantage in reproductive success.  相似文献   
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