首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18962篇
  免费   200篇
  国内免费   1篇
管理学   2812篇
民族学   134篇
人口学   3188篇
丛书文集   35篇
理论方法论   1113篇
综合类   440篇
社会学   8078篇
统计学   3363篇
  2023年   54篇
  2020年   144篇
  2019年   186篇
  2018年   1863篇
  2017年   1920篇
  2016年   1297篇
  2015年   201篇
  2014年   263篇
  2013年   1494篇
  2012年   618篇
  2011年   1364篇
  2010年   1211篇
  2009年   957篇
  2008年   979篇
  2007年   1175篇
  2006年   206篇
  2005年   421篇
  2004年   422篇
  2003年   368篇
  2002年   263篇
  2001年   230篇
  2000年   218篇
  1999年   184篇
  1998年   133篇
  1997年   131篇
  1996年   159篇
  1995年   110篇
  1994年   110篇
  1993年   98篇
  1992年   144篇
  1991年   124篇
  1990年   118篇
  1989年   114篇
  1988年   105篇
  1987年   91篇
  1986年   97篇
  1985年   111篇
  1984年   115篇
  1983年   127篇
  1982年   99篇
  1981年   89篇
  1980年   86篇
  1979年   95篇
  1978年   92篇
  1977年   81篇
  1976年   70篇
  1975年   70篇
  1974年   59篇
  1973年   63篇
  1971年   53篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
371.
Objective: This study aims to investigate the effect of smoking on sexual functions in AS patients.

Patients and methods: A total of 67 male AS patients with a median age of 34 years (range: 18–57) reporting sexual activity at least for the past 4 weeks period were included. Patients were divided into smokers (Group 1, n?=?47) and non-smokers (Group 2, n?=?20). Fagerström test for nicotine dependence, smoking history, exhaled carbon monoxide test were recorded for smoking AS patients. Visual analogue scale (VAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Quality of Life (ASQoL), International Index of Erectile Function (IIEF), Beck Depression Inventory (BDI) were filled for both groups.

Results: There was no significant difference between smokers and non-smokers in all evaluation parameters. BASMI scores were significantly lower in the mild dependency subgroup as compared to those with moderate or severe dependency (p?=?.005 and p?=?.007, respectively). Total IIEF score and IIEF categories correlated significantly with BASDAI, BASFI, BASMI, ASQoL, pain, fatigue, and cumulative smoking. BDI showed an inverse correlation with the IIEF score and IIEF category (p?r?=?–0.520, p?r?=?–0.508, respectively).

Conclusions: Sexual function in AS patients is associated with the pain, fatigue, disease activity, functional status, quality of life, depression as well as the cumulative exposure to smoking, and that sexual functions tend to decline with increasing degree of cigarette dependency.  相似文献   
372.
Competing risks occur in a time-to-event analysis in which a patient can experience one of several types of events. Traditional methods for handling competing risks data presuppose one censoring process, which is assumed to be independent. In a controlled clinical trial, censoring can occur for several reasons: some independent, others dependent. We propose an estimator of the cumulative incidence function in the presence of both independent and dependent censoring mechanisms. We rely on semi-parametric theory to derive an augmented inverse probability of censoring weighted (AIPCW) estimator. We demonstrate the efficiency gained when using the AIPCW estimator compared to a non-augmented estimator via simulations. We then apply our method to evaluate the safety and efficacy of three anti-HIV regimens in a randomized trial conducted by the AIDS Clinical Trial Group, ACTG A5095.  相似文献   
373.
The use of Bayesian nonparametrics models has increased rapidly over the last few decades driven by increasing computational power and the development of efficient Markov chain Monte Carlo algorithms. We review some applications of these models in economic applications including: volatility modelling (using both stochastic volatility models and GARCH-type models) with Dirichlet process mixture models, uses in portfolio allocation problems, long memory models with flexible forms of time-dependence, flexible extension of the dynamic Nelson-Siegel model for interest rate yields and multivariate time series models used in macroeconometrics.  相似文献   
374.
In this paper, we study space–time generalized additive models. We apply the penalyzed likelihood method to fit generalized additive models (GAMs) for nonseparable spatio-temporal correlated data in order to improve the estimation of the response and smooth terms of GAMs. The results show that our space–time generalized additive models estimated response and smooth terms reasonable well, and in addition, the mean squared error, mean absolute deviation and coverage intervals improved considerably compared to the classic GAM. An application on particulate matter concentration in the North-Italian region of Piemonte is also presented.  相似文献   
375.
The chances that children have to participate in child protection services are largely contingent upon the attitudes and skills of case managers. They have a crucial role in ensuring that a child's voice is being listened to and acknowledged in often sensitive dialogues. Therefore, the aim of this study is to investigate what case managers need to facilitate child participation. By handing case managers a participation toolbox developed by children and through the use of reflexive monitoring in action, we elaborated on the barriers faced in practice. The results show that the intention to facilitate child participation is quickly overruled by often subconscious thoughts and beliefs, stemming from the complex interplay of child image, protection, and participation. Case managers need to be aware of this interplay and how this unknowingly steers their actions. Therefore, iterative reflection should be facilitated within organizations for an actual change in their daily practice and to amplify the role of children in the decision‐making processes within child protection services.  相似文献   
376.
Control often weakens autonomy in organizational theories. While many scholars focus on the paradox of control and autonomy, few pay attention to how an organization obtains both control and autonomy. By exploring Zhangjiakou Internal Immigrant Organization, this study finds two mechanisms can contribute to the balanced combination of control and autonomy. First, managers play ambidextrous official-merchant roles, which means superiors take both bureaucratic and autonomous management styles. Second, members have dual organizational goals for both political status and network support. In conclusion, the successful combination is shaped by the subjective interaction between the government, superior managers and subordinate members.  相似文献   
377.
Larregue argued that while there is an ideological imbalance among academics that this imbalance has not unfairly impacted our findings. He also implies that it is the activism of conservatives, rather than progressives, which has created real problems in academia. As such he disputes claims that activism among progressive academics has create a backlash from political conservatives. However, Larregue does not address the previous empirical work on the subject of academic bias. Furthermore, his argument of methodological rigor does not address the tendency of scholars to overlook alternate theories. His argument that progressive scholars are no more biased than conservative scholars fails to account for the sheer number of progressive scholars relative to conservative scholars as it concerns the possibly of institutional bias. I also find his focus on fraud to be misplaced since scholars do not have to engage in fraud to be in ideological silos that do not take alternative theories into account. As to his second major argument, I am unsure whether liberal academic activism leads to conservative mistrust and await further future research on this topic. I do commend Larregue in bringing the question of sources of conservative mistust to our attention.  相似文献   
378.
The pursuit of operational excellence in the manufacturing industry is at rise but its measurement still lacks of appropriate indicators to determine its financial benefits. The ambiguity is due to the impact arisen from manufacturing fluctuations such as price and cost, production mix and direct and indirect parameters variations. Manufacturing fluctuations distort the cost benefit of operational excellence. This paper, therefore, proposes the OEP (Operational Excellence Profitability) indicators to isolate the impact of manufacturing fluctuation and distinctly identify the payback of operational excellence strategies and initiatives through cost benefits of achieving higher efficiency and yield. The paper presents the conceptual and mathematical development of the proposed OEP indicators and the formulas used for their calculation. Hypothetical and industrial-based investigations and applications of the OEP indicators are conducted for their validation. The results obtained from the hypothetical exercise and industrial case suggest that OEP indicators can provide an effective cost-benefit analysis of operational excellence. This would contribute in providing manufacturing organizations with more complete information regarding the performance of their processes, which will allow their directors and managers to take better decisions related to the management and improvement of their processes.  相似文献   
379.
Interoception, often defined as the perception of internal physiological changes, is implicated in many adult social affective processes, but its effects remain understudied in the context of parental socialization of children's emotions. We hypothesized that what parents know about the interoceptive concomitants of emotions, or interoceptive knowledge (e.g., “my heart races when excited”), may be especially relevant in emotion socialization and in supporting children's working models of emotions and the social world. We developed a measure of mothers' interoceptive knowledge about their own emotions and examined its relation to children's social affective outcomes relative to other socialization factors, including self‐reported parental behaviors, emotion beliefs, and knowledge of emotion‐relevant situations and non‐verbal expressions. To assess these, mothers (N = 201) completed structured interviews and questionnaires. A few months later, third‐grade teachers rated children's social skills and emotion regulation observed in the classroom. Results indicated that mothers' interoceptive knowledge about their own emotions was associated with children's social affective skills (emotion regulation, social initiative, cooperation, self‐control), even after controlling for child gender and ethnicity, family income, maternal stress, and the above maternal socialization factors. Overall, findings suggest that mothers' interoceptive knowledge may provide an additional, unique pathway by which children acquire social affective competence.  相似文献   
380.
Many optimisation problems arise in managing the Blood Donation (BD) supply chain. Most of them have been addressed in the literature, while other problems, e.g. donation scheduling, have not been sufficiently addressed so far. However, blood collection from donors may have a disruptive impact on the entire BD supply chain if not properly managed. For example, scheduling donation appointments based on some system metrics may improve the flow of blood units through the BD supply chain and increase the quality of service perceived by donors. In this short communication, we present the donation scheduling problem and highlight the lack of work in the literature that deals with this problem. Then, we analyse the impact of an unbalanced flow of blood units on the BD system and the benefits that may derive from a suitable appointment scheduling. Finally, we propose suggestions for future research in BD collection scheduling that may improve the BD process.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号