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   476篇
  免费   11篇
  国内免费   1篇
管理学   60篇
民族学   5篇
人口学   49篇
丛书文集   3篇
理论方法论   60篇
综合类   11篇
社会学   280篇
统计学   20篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2020年   8篇
  2019年   8篇
  2018年   12篇
  2017年   23篇
  2016年   18篇
  2015年   15篇
  2014年   8篇
  2013年   86篇
  2012年   18篇
  2011年   21篇
  2010年   18篇
  2009年   10篇
  2008年   15篇
  2007年   21篇
  2006年   19篇
  2005年   18篇
  2004年   13篇
  2003年   11篇
  2002年   17篇
  2001年   16篇
  2000年   10篇
  1999年   10篇
  1998年   12篇
  1997年   10篇
  1996年   6篇
  1995年   3篇
  1994年   6篇
  1993年   4篇
  1992年   5篇
  1991年   6篇
  1990年   1篇
  1988年   5篇
  1987年   5篇
  1986年   5篇
  1985年   6篇
  1984年   5篇
  1983年   4篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1971年   1篇
排序方式: 共有488条查询结果,搜索用时 15 毫秒
91.
Make‐to‐order (MTO) manufacturers must ensure concurrent availability of all parts required for production, as any unavailability may cause a delay in completion time. A major challenge for MTO manufacturers operating under high demand variability is to produce customized parts in time to meet internal production schedules. We present a case study of a producer of MTO offshore oil rigs that highlights the key aspects of the problem. The producer was faced with an increase in both demand and demand variability. Consequently, it had to rely heavily on subcontracting to handle production requirements that were in excess of its capacity. We focused on the manufacture of customized steel panels, which represent the main sub‐assemblies for building an oil rig. We considered two key tactical parameters: the planning window of the master production schedule and the planned lead time of each workstation. Under the constraint of a fixed internal delivery lead time, we determined the optimal planning parameters. This improvement effort reduced the subcontracting cost by implementing several actions: the creation of a master schedule for each sub‐assembly family of the steel panels, the smoothing of the master schedule over its planning window, and the controlling of production at each workstation by its planned lead time. We report our experience in applying the analytical model, the managerial insights gained, and how the application benefits the oil‐rig producer.  相似文献   
92.
We study the pricing problem of a “platform” intermediary to jointly determine the selling price of the platforms (hardware) sold to consumers and the royalty charged to content developers for content (software), when the demands for content and for platforms are interdependent. Our model elucidates the impact of supply chain replenishment costs and demand uncertainty on the strategic issues of platform pricing in a two‐sided market.  相似文献   
93.
94.
After a long development period, the national Recovery Audit Contractor (RAC) program is now fully operational Read about how one large hospital system structured its RAC team and management process.  相似文献   
95.
Research has established that exposure to a combination of diagnostic (i.e., relevant) and nondiagnostic (i.e., irrelevant) information results in predictions that are more regressive than predictions based on diagnostic information (Hackenbrack, 1992; Hoffman and Patton, 1997). This phenomenon has been labeled the dilution effect (e.g., Tetlock and Boettger, 1989) and has been documented when individuals make predictions. This study tests for the dilution effect when small groups make predictions, and examines the effect of using a procedure designed to reduce the dilution effect. Results indicate that group predictions are influenced by nondiagnostic information in the same manner as are individual predictions, and allowing participants to rate the diagnosticity of information prior to making predictions does not reduce the dilution effect.  相似文献   
96.
Investigations of peer collaboration often vary task or social aspects of collaborative contexts and assume that these aspects of the context are experienced similarly by individuals. The present study examined how social aspects (group friendship and gender) of a peer collaborative context related to differences in adolescents' interpretations of task and social problems that occurred while collaborating with peers in a naturalistic classroom setting. Eighth-grade adolescents ( N = 82, 44 females) worked with peers on a six-week Spanish project at school. Adolescents chose to work primarily with same-gender peers and friends. Task and social interpretations of problems were assessed twice. The salience of task problems decreased over time; social problems became somewhat more salient. Social problems were less salient to females than to males. Greater group friendship was associated with the lesser salience of task problems early in the project. The salience of social problems, gender, and friendship were important for understanding performance on the project. The value of considering the context of peer collaborative problem solving from individuals' perspectives is discussed.  相似文献   
97.
The T25 single-point estimate method of evaluating the carcinogenic potency of a chemical, which is currently used by the European Union (EU) and is denoted the EU approach, is based on the selection of a single dose in a chronic bioassay with an incidence rate that is significantly higher than the background rate. The T25 is determined from that single point by a linear extrapolation or interpolation to the chronic dose (in mg/kg/day), at which a 25% increase in the incidence of the specified tumor type is expected, corrected for the background rate. Another method used to obtain a carcinogenic potency value based on a 25% increase in incidence above the background rate is the estimation of a T25 derived from a benchmark dose (BMD) response model fit to the chronic bioassay data for the specified tumor type. A comparison was made between these two methods using 276 chronic bioassays conducted by the National Toxicology Program. In each of the 2-year bioassays, a tumor type was selected based on statistical and biological significance, and both EU T25 and BMD T25 estimates were determined for that end point. In addition, simulations were done using underlying cumulative probability distributions to examine the effect of dose spacing, the number of animals per dose group, the possibility of a dose threshold, and variation in the background incidence rates on the EU T25 and BMD estimates. The simulations showed that in the majority of cases the EU T25 method underestimated the true T25 dose and overestimated the carcinogenic potency. The BMD estimate is generally less biased and has less variation about the true T25 value than the EU estimate.  相似文献   
98.
Determining the difference in perception of risk between experts, or more educated professionals, and laypeople is important so that a potential hazard can be effectively communicated to the public. Many surveys have been conducted to better understand the difference between expert and public opinions, and often laypeople exhibit higher perceptions of risk to hazards in comparison to experts. This is especially true when health risk is due to radiation, nuclear power, and nuclear waste. This article focuses on one section of a risk perception survey given to two groups of individuals with a more specialized education (scientists and physicians) and laypeople (villagers) in the Semipalatinsk region of Kazakhstan. All of these groups live near the former Soviet nuclear test site. Originally, it was expected that the scientists and physicians would have similar perceptions of radiation risk, while the public perceptions would be higher, but this was not always the case. For example, when perceptions of risk pertain to the health impacts of nuclear testing or the dose-response nature of radiation exposure, the physicians tend to agree with the laypeople, not the scientists. The villagers are always the most risk-averse group, followed by the physicians and then the scientists. These differences are likely due to different frames of reference for each of the populations.  相似文献   
99.
The purposes of this study were to learn whether children's beliefs about the legitimacy of aggression can be reliably assessed and whether these beliefs relate to children's everyday social behavior with peers, as well as their responses to hypothetical ambiguous provocation situations. Fourth- and fifth-grade students ( n = 781) responded to a 16-item questionnaire designed to measure children's beliefs about the legitimacy of aggression. Children's behavioral orientation was assessed using two methods: (1) children's responses to ten hypothetical situations involving ambiguous provocation, and (2) peer evaluations of children's aggressive, withdrawn, and prosocial behavior. Results indicated that children's beliefs about the legitimacy of aggression were reliably measured. Furthermore, results from both measures of behavioral style showed that children who believed strongly in the legitimacy of aggression were more aggressive, less withdrawn, and less prosocial. The findings suggest that one focus of efforts to decrease children's aggression should be the modification of their beliefs about the legitimacy of aggressive actions.  相似文献   
100.
This longitudinal study highlights the role of specific parenting behaviors in specific contexts when predicting moral development in children of varying temperament types. A sample of mother–child dyads took part in a competing demands task involving differing ‘do’ and ‘don't’ contextual demands when the child was 2 years of age. Child temperament was also assessed at this time, yielding inhibited, exuberant, and low‐reactive temperament groups. Children's moral behavior was assessed at 5.5 years of age. Models examining the interaction of temperament and mother behaviors in each context indicated that mother's reasoning/explanation and ignoring in the ‘do’ context predicted later moral behavior in inhibited children whereas redirection and commands in the ‘don't’ context predicted moral behavior in exuberant children.  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