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71.
In 2009, a group of local foundations, the school district, arts organizations, and the Mayor's Office launched the Boston Public Schools Arts Education Initiative (BPS-AE)—a multiyear, citywide, public–private initiative aimed at increasing BPS students' access to in-school arts education. Managed by a strong local intermediary with deep experience in education, this initiative used several complementary, overlaid strategies: direct service, system building, and community engagement—all of which were supported by a philanthropic collaborative of local and national funders. Today, 17,000 more BPS students receive arts education; nearly 130 additional full-time certified arts teachers have been hired; and district spending on arts has risen to $26 million annually, compared to $15 million in 2009. There is also growing demand from the larger community for more and better arts education. In 2015, BPS-AE produced a case study that provides a more detailed explication of the multitiered strategy it used to achieve these results. The study offers recommendations as to how other cities can involve diverse key constituencies to advance this kind of initiative, create leadership structures that support effective citywide collaboration, engage community stakeholders in participatory planning processes, leverage private philanthropy to boost public funding, and develop a centralized support system for school principals and arts teachers.  相似文献   
72.
以科尔沁沙地沙丘-草甸过渡带区域主要土地覆被类型为研究对象,以1987-2017年多时相Landsat TM/OLI遥感影像解译分类为基础,参考生态学植被演替研究方法,系统分析研究区30年来的土地利用/覆被动态演变规律,研究结果表明:(1)决策树法在复杂下垫面不同覆被类型的同步识别效果较好,所有影像分类精度均达到88%以上,分类效果较好,其中2017年分类精度最高为95.24%,达到了分类研究的要求;(2)研究区存在着"半灌丛-草甸地-灌丛"的植被结构特征,且整体表现为"南进北退"的变化趋势。结合土地利用动态度分析结果表明人类活动干涉下,研究区整体上遵循了半干旱区植被条件改善的一般规律,侧面反映该研究区域生态环境的持续不稳定性和脆弱性;(3)研究区覆被类型发生变化的总面积达到2623.59 hm2,总变化强度为63.76%。其中正向演替的比例为52.61%,以半灌丛面积的持续减小与沙地草甸面积的持续扩张为主要变化特征。但同时,半灌丛转为沙地的面积为184.95 hm2,表明以放牧为主的研究区同时发生着局部的逆行演变;(4)质心迁移结果反映了1987-2017年间,除人为影响较大的林地、草地以及耕地向北迁移外,其他植被类型的质心都有很明显的南迁,主要植被类型重心迁移距离依次由大到小为耕地 > 半灌丛 > 灌丛 > 沙地草甸 > 湿地草甸 > 林地。研究通过记录科尔沁沙地连续扩展的时空模式,展示了遥感-生态和时间序列影像在30 m分辨率下跟踪土地利用/覆被变化的潜力,为提高干旱半干旱区土地利用情况的动态监测效率,开展土地利用/覆被动态演变研究提供参考。  相似文献   
73.
Predation risk and feeding patterns of crucian carp   总被引:1,自引:0,他引:1  
As part of an experimental study of the direct and indirect effects of piscivory on prey fish, the diets of crucian carp Carassius carassius were compared across sections of a divided pond; two sections were stocked with crucian carp alone and two with crucian carp plus perch Perca fluviatilis . Analysis of crucian gut contents indicated that the composition of invertebrate prey did not differ in the presence v . absence of perch. However, crucians, particularly small individuals (<10cm) that were most vulnerable to predation, displayed a lower intake of invertebrate prey in sections with perch. Although diet composition differed between crucians caught in inshore v. offshore habitats (with habitat use being related to crucian size and the presence or absence of perch), no clear pattern existed between habitat and total food intake. Overall, the major effects of predators on the diet of crucian carp appeared to be caused by increased ecological density (resulting from confinement of small crucians inshore) and reduced activity levels, rather than simple shifts to safer habitats.  相似文献   
74.
Thirteen captive species of the genusMacaca were presented with certain non-edible objects and the subsequent manipulation was observed. The following results were obtained: (1) Thefascicularis group species displayed a great variety in rolling the manipulandum, which has been reported to be one of the actions characterizing cercopithecine species; (2) manipulating the object with one finger was typical of thesilenus-sylvanus andsinica groups, whereas use of the fingers moving opposably was common to all species ofMacaca; (3) secondary manipulations in relation to the wire-mesh were observed only inM. silenus, M. sinica, andM. nemestrina, whereas those in relation to water were common to allMacaca species; and (4) within-subgroup differences were great in thesilenus-sylvanus andsinica groups as compared to thefascicularis group.  相似文献   
75.
There was a pronounced decline in activity of young pool-dwelling Atlantic salmon, Salmo salar, and brown trout, Salmo trutta, as the water temperatures dropped in the autumn and early winter, and the fish switched from a predominantly diurnal towards a nocturnal activity pattern. Such a switch in activity pattern has previously been observed in young brown trout, but the present study is the first documentation for juvenile Atlantic salmon under natural conditions. Juvenile fish fed actively even when water temperatures were below 0°C, although foraging behaviour at near-freezing temperatures was recorded exclusively during night surveys. This indicates that other proximate factors, in addition to water temperature, affect the activity of young salmon and trout in rivers. Trout kept feeding positions significantly higher above bottom than salmon in August and September, but both species reduced the height above bottom at the onset of winter, possibly due to reduced swimming performance and lowered food availability in the upper part of the water column.  相似文献   
76.
ObjectivesTo describe quitting experiences of cancer patients in a Cancer Center in Jordan; to study patients’ perceptions regarding the process of smoking cessation; and to provide insights about patients in this difficult setting in order to inform oncology practitioners with regards to how improve perceptions and skills related to quitting.MethodsAn Arabic cross-sectional questionnaire was developed to evaluate smoking and quitting behaviors in the context of cancer. The tool used as its framework the Theoretical Domains Framework to capture quitting perceptions of cancer patients who smoke, as well as social, environmental, and system-level factors that influence quitting. Eligible patients who were treated at the Center (both in-patient and out-patient settings) and who were current smokers or who smoked up to the time of cancer diagnosis were eligible. Patients were interviewed between July, 2018 and January 2020 using two versions of the questionnaire: an ‘ex-smokers’ version, and a ‘current smokers’ version.ResultsOnly a third of subjects (104/350) had been smoke-free for at least 30 days. Both smokers and ex-smokers generally felt that quitting was important, but mean importance and confidence scores (out of 10) were significantly lower in current smokers (8.2 versus 9.1, p-value=0.002; 6.4 versus 8.7, p-value=0.000). Roughly 31% of subjects believed smoking harms were exaggerated and that smoking was not an addiction. About 62% of subjects agreed quitting required skills, and 78.5% felt the steps to quit were clear, but across several listed strategies for quitting, use of these was limited (even in ex-smokers). Among current smokers, roughly a third exhibited forms of cessation fatigue.ConclusionJordanian cancer patients who smoke present with limited knowledge about the quitting process. Even when some success is observed, low rates of utilization of specific quitting strategies were observed, highlighting the need for better counseling about quitting.  相似文献   
77.
A placebo is a substance or intervention believed to be inactive, but is administered by the healthcare professional as if it was an active medication. Unlike standard treatments, clinical use of placebo usually involves deception and is therefore ethically problematic. Our attitudes toward the clinical use of placebo, which inevitably includes deception or withholding information, have a tremendous effect on our practice regarding truth‐telling and informed consent. A casual attitude towards it weakens the current practice based on shared decision‐making and mutual trust between patients and healthcare professionals. Issues concerning the clinical use of placebo are thus intimately related to patient‐provider relationships, the public's trust in medicine, and medical education. A review of recent survey studies suggests that the clinical use of placebo appears to be fairly well accepted among healthcare professionals and is common in clinical settings in various countries. However, we think that an ethical discussion is urgently needed because of its controversial nature. If judged to be ethically wrong, the practice should end. In the present paper, we discuss the ethicality of the clinical use of placebo with deception and argue against it, concluding that it is unethical and should be banned. We will show that most arguments in favor of the clinical use of placebo can be refuted and are therefore incorrect or weak. These arguments will be presented and examined individually. Finally, we will briefly consider issues relevant to the clinical use of placebo without deception.  相似文献   
78.
ABSTRACT Investigators generally pool observations of males and females in studies of the foraging behavior of sexually monochromatic songbirds. However, such pooling can obscure possible intersexual differences. We compared the foraging behavior of male and female Western Wood‐Pewees (Contopus sordidulus), a sexually monochromatic species, in the Sierra Nevada Mountains of California during the breeding seasons of 2007 and 2008. We recorded 143 foraging observations (male N= 74, female N= 69). Overall, mean foraging rates of females (2.8 attacks/min) were higher (P < 0.001) than those of males (1.1 attacks/min). In addition, female foraging rates were significantly higher during incubation than during the nest building, nestling, and fledgling periods. When foraging, males perched higher above ground than females (means = 17.1 and 6.7 m, respectively). Differences between male and female Western Wood‐Pewees in foraging rates and perch heights suggest that males may spend more time on vigilance while females focus on foraging quickly during incubation and when feeding nestlings. Because metrics such as foraging attack rates are sometimes used as indicators of habitat quality and we found that rates can differ between the sexes and among nesting stages, investigators should consider the possibility of such differences when assessing habitat quality, especially for sexually monochromatic species of birds.  相似文献   
79.
城市公园是城市生态系统的重要组成部分和城市生物多样性热点地区,具有丰富的声景观资源。由于声景观及声学方法具有信息量大,成本低,低侵入的特点,因此其研究和应用对生态系统健康及监测具有较高价值。声景观研究通过总结生物声的活动或多样性来衡量生物多样性。记录了北京20个城市公园的春季声景观,使用定量方法描述了声景观特征与变化;测试三种了已被证明与生物多样性相关并被广泛使用的声学指数(BIO、ADI、NDSI)与植被群落关系,完成了城市环境中声景观与环境关系的初步探究。研究结果表明:(1)声学指数能够有效表征城市公园声景观信息,具有显著的时间动态特性,能准确反映鸟类黎明合唱等重要生物生态活动;(2)声学强度指数也具有显著的时间动态变化和沿频率梯度的变化,不同的频率区间反映了不同声学群落的活动信息;(3)植被结构尤其是垂直结构对声景观起着重要作用,垂直异质性越大,声学多样性越高。发现支持声景观作为公园植被状况的度量,强调了其作为生物多样性和生态系统健康状况监测方法,用于城市管理和可持续发展的巨大潜力。  相似文献   
80.
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