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   208篇
  免费   12篇
管理学   30篇
民族学   2篇
人口学   30篇
丛书文集   5篇
理论方法论   14篇
综合类   3篇
社会学   105篇
统计学   31篇
  2022年   4篇
  2021年   3篇
  2020年   2篇
  2019年   10篇
  2018年   9篇
  2017年   11篇
  2016年   12篇
  2015年   10篇
  2014年   10篇
  2013年   33篇
  2012年   15篇
  2011年   7篇
  2010年   7篇
  2009年   8篇
  2008年   3篇
  2007年   6篇
  2006年   9篇
  2005年   6篇
  2004年   2篇
  2003年   2篇
  2002年   5篇
  2001年   2篇
  2000年   4篇
  1999年   6篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1992年   2篇
  1989年   3篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   3篇
  1983年   3篇
  1982年   1篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1974年   2篇
  1973年   1篇
排序方式: 共有220条查询结果,搜索用时 15 毫秒
211.
Recent resource recovery facility stack tests have increased the available pool of data on emissions from these facilities. This has led to more accurate predictions of emissions from proposed facilities. The source, type, and rate of emissions presented are based upon a review of the literature, theoretical approaches, stack test data from existing facilities, permit levels of other facilities, and discussions with equipment manufacturers. The pollutants selected for study are those regulated by United States Environmental Protection Agency (USEPA) Prevention of Significant Deterioration (PSD) regulations and other pollutants of concern. The pollutants studied are particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide, nonmethane hydrocarbons, hydrogen sulfide, reduced sulfide, reduced sulfur compounds, total reduced sulfur, lead, mercury, beryllium, arsenic, cadmium, chromium, chromium +6, copper, manganese, nickel, vanadium, zinc, hydrogen chloride, fluorides, sulfuric acid mist, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, vinyl chloride, dioxins, furans, formaldehyde, and asbestos.  相似文献   
212.
213.
Floyd Bennett Field (FBF), 579 ha in extent, is a division of Gateway National Recreation Area. It is the site of a former airfield, constructed by filling salt marshes with dredged materials. Except for the portion known locally as the North Forty, all sections of FBF have been cut over to maintain low vegetation. A grassland management plan (GRAMP) for 165 ha was initiated in 1986, to maintain habitats for open-country birds. Over the next few years, encroaching woody vegetation was removed manually and mechanically from the management area. Since then, it has been maintained as a grassland and receives annual mowing, as well as continued manual removal of the larger woody sprouts.A portion of the GRAMP management area (III) was selected for intensive study of vegetation composition. A grid system was created and vegetation cover was estimated in 127, 1 m × 1 m quadrats. The quadrats were subjected to cluster analysis (CA). Eleven clusters were recognized. These clusters were treated as plant associations. The following types were distinguished: (native) little bluestem–dewberry grassland, six-weeks fescue annual grassland, a grass marsh, a rush marsh, a switchgrass dry grassland, and a deer-tongue panicgrass grassland; (exotic) mugwort herbland, oriental bittersweet-Japanese honeysuckle vineland, Kentucky bluegrass-mixed grassland, Japanese knotweed tall herbland, and spotted knapweed-common St. Johnswort herbland. The little bluestem–dewberry association accounted for nearly half of all quadrats; six subclusters were recognized. The plant associations determined by CA were compared with plant lists compiled during traverses of all of the map categories in the six GRAMP Areas (I, II, III, IV, V, VI). A table was created to relate the quantitative data of the plant associations to the appropriate map categories. A nonmetric multidimensional scaling ordination (NMDS) was performed on the quadrat data. Finally, the plant associations were compared with those described in the literature of local vegetation studies. The mowing program has been effective in decreasing woody plant cover and has permitted the invasion of a few taxa into monospecific communities, but attendant disturbance of the substrate is likely to cause an increase in exotic plant taxa. As earlier studies noted, mowing has caused the increase in cover of sod-forming grass, and bare ground has virtually disappeared in the managed area. This has negative implications for the maintenance of those grassland bird species that require open ground for nesting.  相似文献   
214.
This study utilized Kenny's social relations model (SRM) to explore the interpersonal correlates of narcissism in an adolescent sample from a voluntary residential program. Participants were forty‐seven 16–18‐year‐olds (24 males, 23 females) attending a 22‐week residential program. Participants completed a self‐report measure of narcissism and rated one another on narcissism‐related traits and social status variables. Individuals with high levels of self‐reported narcissism were perceived by peers as antagonistic and likely to engage in future delinquency. Self‐reported narcissism was also associated with peer perceptions of narcissism‐related traits. Therefore, adolescent narcissism seems to be detected by peers and is associated with peer perceptions of some negative qualities. Potential implications of these findings are discussed.  相似文献   
215.
婚姻形式与生育水平:对中国农村三个县的考察   总被引:2,自引:0,他引:2  
应用在招赘婚姻高度流行区、中度流行区和低度流行区的调查数据 ,研究了婚姻形式以及个人、家庭和社会因素对生育水平的影响及其区域差异。研究结果有助于理解农村人口在社会转型中婚姻与生育的变化过程和后果 ,为在农村稳定低生育率提供新的思路和途径。  相似文献   
216.
The Tobii Pro TX300 is a popular eye tracker in developmental eye-tracking research, yet it is no longer manufactured. If a TX300 breaks down, it may have to be replaced. The data quality of the replacement eye tracker may differ from that of the TX300, which may affect the experimental outcome measures. This is problematic for longitudinal and multi-site studies, and for researchers replacing eye trackers between studies. We, therefore, ask how the TX300 and its successor, the Tobii Pro Spectrum, compare in terms of eye-tracking data quality. Data quality—operationalized through precision, accuracy, and data loss—was compared between eye trackers for three age groups (around 5-months, 10-months, and 3-years). Precision was better for all gaze position signals obtained with the Spectrum in comparison to the TX300. Accuracy of the Spectrum was higher for the 5-month-old and 10-month-old children. For the three-year-old children, accuracy was similar across both eye trackers. Gaze position signals from the Spectrum exhibited lower proportions of data loss, and the duration of the data loss periods tended to be shorter. In conclusion, the Spectrum produces gaze position signals with higher data quality, especially for the younger infants. Implications for data analysis are discussed.  相似文献   
217.
We present a novel real-time univariate monitoring scheme for detecting a sustained departure of a process mean from some given standard assuming a constant variance. Our proposed stopping rule is based on the total variation of a nonparametric taut string estimator of the process mean and is designed to provide a desired average run length for an in-control situation. Compared to the more prominent CUSUM fast initial response (FIR) methodology and allowing for a restart following a false alarm, the proposed two-sided taut string (TS) scheme produces a significant reduction in average run length for a wide range of changes in the mean that occur at or immediately after process monitoring begins. A decision rule for when to choose our proposed TS chart compared to the CUSUM FIR chart that takes into account both false alarm rate and average run length to detect a shift in the mean is proposed and implemented. Supplementary materials are available online.  相似文献   
218.
219.
The efficient development of software has become a critical factor to the success of many organizations. Significant competitive advantage can be realized by reducing the time to complete software development, while maintaining or improving quality levels. Project management activities, including the measurement of performance at the level of the project, can help the organization to both control projects and learn from experience. Traditionally, the productivity of a software development project has been measured as the complexity of code produced per unit of labor involved. An increasing number of organizations, however, are adopting the practice of software reuse, and under such conditions, such a traditional measure of productivity does not fully capture all the relevant elements of the reuse-driven development environment. This research develops a new performance measure that considers four major components of performance: productivity associated with development of new code, productivity associated with the reuse of previously written code, quality of the reuse decision, and relative value of reuse to the company. To illustrate the feasibility of the measure, a real-world productivity assessment is presented for an example company, and related implementation issues are discussed.  相似文献   
220.
In this article, we outline a unique conceptual framework connecting legitimacy types (Suchman, 1995 ), theories of corporate responsibility (Brummer, 1991 ), and levels of organizational moral development based on Kohlberg's ( 1971 ) moral development stages. In addition, based on Global Reporting Initiative (GRI) categories, we found empirical support for our framework, by content analyzing Fortune 500 corporate citizenship reports from four different industries (i.e., chemicals, motor vehicle/auto parts, pharmaceutical, and utilities), at three data points (i.e., 2002, 2007, and 2012). Our analysis indicates that motor vehicle/auto parts and chemicals industries are at a higher developmental level, and portray moral legitimacy along with social demandingness corporate responsibility in recent years; while the pharmaceutical and utilities sectors are at a lower developmental level, showing signs of pragmatic legitimacy, alongside classical and stakeholder corporate responsibility strategies. This article contributes to the current organizational moral development literature by developing and finding empirical support of a conceptual framework of organizational moral development, legitimacy, and corporate responsibility. In particular, our findings provide a deeper understanding of the differences in moral development levels across four focal industries over a 10‐year timespan.  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