全文获取类型
收费全文 | 564篇 |
免费 | 15篇 |
国内免费 | 29篇 |
专业分类
管理学 | 73篇 |
民族学 | 9篇 |
人口学 | 29篇 |
丛书文集 | 23篇 |
理论方法论 | 47篇 |
综合类 | 227篇 |
社会学 | 102篇 |
统计学 | 98篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 11篇 |
2019年 | 22篇 |
2018年 | 13篇 |
2017年 | 22篇 |
2016年 | 16篇 |
2015年 | 20篇 |
2014年 | 52篇 |
2013年 | 106篇 |
2012年 | 23篇 |
2011年 | 27篇 |
2010年 | 23篇 |
2009年 | 31篇 |
2008年 | 33篇 |
2007年 | 25篇 |
2006年 | 23篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 20篇 |
2002年 | 12篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有608条查询结果,搜索用时 296 毫秒
61.
目的:系统评价中国围产儿先天性心脏病发生的主要危险因素,为其防治工作提供参考?方法:对国内26篇关于先天性心脏病发病危险因素的研究文献进行Meta分析?累计病例7 964例,对照12 929例?根据齐性检验结果计算各危险因素合并比值比(OR)及其95%可信区间(95%CI)模型?结果:先天性心脏病各危险因素的OR值及95%CI分别为:流产史1.69(1.24~2.31)?环境噪音1.28(0.39~4.19)?孕期检查胎儿异常2.31(1.25~4.27)?孕期服用药物1.88(1.57~2.23)?接触有害物质3.46(2.11~5.66)?近亲婚配史2.88(1.88~4.40)?被动吸烟1.16(0.69~1.95)?孕早期精神因素2.58(1.36~4.91)?父亲饮酒1.88(1.44~2.45)?孕早期感冒3.06(2.17~4.32)?结论:流产史?孕期检查胎儿异常?孕期服用药?早期精神因素?父亲饮酒?近亲婚配和孕早期感冒是先天性心脏病的危险因素? 相似文献
62.
骆新泉 《河北科技大学学报(社会科学版)》2014,(4):66-70
清代女词人赵我佩存词173首,收于《碧桃仙馆词》中。赵氏体至孱弱,工愁善病,其词多言"病、瘦",直抒胸臆,清丽婉约。赵氏"病、瘦"词是一种自我表达的方式,不但记录了赵氏受苦受难的身体感受,也记录了赵氏受苦受难的心灵感受。她通过疾病所导致的苦难和情感上的残缺,唤醒自己及同时代的女性长期以来对疾病苦痛煎熬及夫妻离居造成的情感缺失的麻木,找寻迷失的自己,并关注自己的生存环境和生存状态。可以说赵氏词以独特的"病、瘦"言说参与到中国文学现代化的进程中来,为后世读者竖起了一座"病、瘦"词的丰碑。 相似文献
63.
考察了神木县石炮谷、黄沙谷、黑九枝等18个谷子品种的展示田,每个品种都感染了不同程度的白发病;其发生原因有气候诱因、品种抗病性差、留种问题等;防治措施为轮作倒茬,及时清理田间病株,选择抗病品种防治谷子病害等。 相似文献
64.
Sebastian Kurtek Wei Wu Gary E. Christensen Anuj Srivastava 《Journal of applied statistics》2013,40(6):1270-1288
We present a novel methodology for a comprehensive statistical analysis of approximately periodic biosignal data. There are two main challenges in such analysis: (1) the automatic extraction (segmentation) of cycles from long, cyclostationary biosignals and (2) the subsequent statistical analysis, which in many cases involves the separation of temporal and amplitude variabilities. The proposed framework provides a principled approach for statistical analysis of such signals, which in turn allows for an efficient cycle segmentation algorithm. This is achieved using a convenient representation of functions called the square-root velocity function (SRVF). The segmented cycles, represented by SRVFs, are temporally aligned using the notion of the Karcher mean, which in turn allows for more efficient statistical summaries of signals. We show the strengths of this method through various disease classification experiments. In the case of myocardial infarction detection and localization, we show that our method compares favorably to methods described in the current literature. 相似文献
65.
Jixian Wang 《Pharmaceutical statistics》2021,20(3):645-656
In a clinical trial, sometimes it is desirable to allocate as many patients as possible to the best treatment, in particular, when a trial for a rare disease may contain a considerable portion of the whole target population. The Gittins index rule is a powerful tool for sequentially allocating patients to the best treatment based on the responses of patients already treated. However, its application in clinical trials is limited due to technical complexity and lack of randomness. Thompson sampling is an appealing approach, since it makes a compromise between optimal treatment allocation and randomness with some desirable optimal properties in the machine learning context. However, in clinical trial settings, multiple simulation studies have shown disappointing results with Thompson samplers. We consider how to improve short-run performance of Thompson sampling and propose a novel acceleration approach. This approach can also be applied to situations when patients can only be allocated by batch and is very easy to implement without using complex algorithms. A simulation study showed that this approach could improve the performance of Thompson sampling in terms of average total response rate. An application to a redesign of a preference trial to maximize patient's satisfaction is also presented. 相似文献
66.
本文研究发现,中华鳖聚缩虫病病原为聚缩虫(Zoothamniumsp),其分类地位隶属于原生动物门,纤毛纲,绿毛目,钟形上科,聚缩虫属。聚缩虫(Z.sp)呈树枝状群居于中华鳖体表面引起聚缩虫病。动物应激试验证明,聚缩虫对次氨酸钠、石灰水、氨水等碱性溶液敏感,易导致虫体萎缩,甚至解体。 相似文献
67.
68.
Longitudinal studies suffer from patient dropout. The dropout process may be informative if there exists an association between dropout patterns and the rate of change in the response over time. Multiple patterns are plausible in that different causes of dropout might contribute to different patterns. These multiple patterns can be dichotomized into two groups: quantitative and qualitative interaction. Quantitative interaction indicates that each of the multiple sources is biasing the estimate of the rate of change in the same direction, although with differing magnitudes. Alternatively, qualitative interaction results in the multiple sources biasing the estimate of the rate of change in opposing directions. Qualitative interaction is of special concern, since it is less likely to be detected by conventional methods and can lead to highly misleading slope estimates. We explore a test for qualitative interaction based on simultaneous confidence intervals. The test accommodates the realistic situation where reasons for dropout are not fully understood, or even entirely unknown. It allows for an additional level of clustering among participating subjects. We apply these methods to a study exploring tumor growth rates in mice as well as a longitudinal study exploring rates of change in cognitive functioning for Alzheimer's patients. 相似文献
69.
TOM BRITTON THEODORE KYPRAIOS PHILIP D. O'NEILL 《Scandinavian Journal of Statistics》2011,38(3):578-599
Abstract. A stochastic epidemic model is defined in which each individual belongs to a household, a secondary grouping (typically school or workplace) and also the community as a whole. Moreover, infectious contacts take place in these three settings according to potentially different rates. For this model, we consider how different kinds of data can be used to estimate the infection rate parameters with a view to understanding what can and cannot be inferred. Among other things we find that temporal data can be of considerable inferential benefit compared with final size data, that the degree of heterogeneity in the data can have a considerable effect on inference for non‐household transmission, and that inferences can be materially different from those obtained from a model with only two levels of mixing. We illustrate our findings by analysing a highly detailed dataset concerning a measles outbreak in Hagelloch, Germany. 相似文献
70.
王建国 《北京科技大学学报(社会科学版)》2011,27(1):104-110,119
居民健康对劳动参与的影响至关重要。国内相关研究只使用了自我评价的一般健康状况来衡量健康水平,然而健康是多维的,该指标可能未能全面度量我国居民真实健康水平对劳动参与的影响。为了克服这个问题,本文还同时使用短期疾病冲击、疾病史、身体质量指数、营养摄入等多个健康指标。结果表明,自我评价的一般健康状况没能完全揭示我国居民真实健康水平对劳动参与的影响,包括其在内的各个健康指标均为此可以提供相对独立的信息。 相似文献