全文获取类型
收费全文 | 20313篇 |
免费 | 386篇 |
国内免费 | 1篇 |
专业分类
管理学 | 2899篇 |
民族学 | 76篇 |
人才学 | 1篇 |
人口学 | 1957篇 |
丛书文集 | 82篇 |
教育普及 | 2篇 |
理论方法论 | 1843篇 |
现状及发展 | 1篇 |
综合类 | 263篇 |
社会学 | 9938篇 |
统计学 | 3638篇 |
出版年
2021年 | 121篇 |
2020年 | 299篇 |
2019年 | 390篇 |
2018年 | 470篇 |
2017年 | 652篇 |
2016年 | 511篇 |
2015年 | 368篇 |
2014年 | 490篇 |
2013年 | 3173篇 |
2012年 | 670篇 |
2011年 | 657篇 |
2010年 | 481篇 |
2009年 | 403篇 |
2008年 | 492篇 |
2007年 | 498篇 |
2006年 | 501篇 |
2005年 | 472篇 |
2004年 | 440篇 |
2003年 | 405篇 |
2002年 | 448篇 |
2001年 | 535篇 |
2000年 | 544篇 |
1999年 | 478篇 |
1998年 | 353篇 |
1997年 | 326篇 |
1996年 | 336篇 |
1995年 | 312篇 |
1994年 | 292篇 |
1993年 | 297篇 |
1992年 | 348篇 |
1991年 | 330篇 |
1990年 | 289篇 |
1989年 | 299篇 |
1988年 | 298篇 |
1987年 | 260篇 |
1986年 | 250篇 |
1985年 | 283篇 |
1984年 | 273篇 |
1983年 | 258篇 |
1982年 | 221篇 |
1981年 | 183篇 |
1980年 | 169篇 |
1979年 | 200篇 |
1978年 | 177篇 |
1977年 | 163篇 |
1976年 | 137篇 |
1975年 | 161篇 |
1974年 | 121篇 |
1973年 | 116篇 |
1972年 | 95篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Assessment of Airborne Exposure to Trihalomethanes from Tap Water in Residential Showers and Baths 总被引:4,自引:0,他引:4
This study evaluates airborne concentrations of common trihalomethane (THM) compounds in bathrooms during showering and bathing in homes supplied with chlorinated tap water. Three homes in an urban area were selected, each having three bedrooms, a full bath, and approximately 1,000 square feet of living area. THMs were concurrently measured in tap water and air in the shower/bath enclosure and the bathroom vanity area using Summa canisters. Chloroform (TCM), bromodichloromethane (BDCM), and chlorodibromomethane (CDBM) were quantified using U.S. Environmental Protection Agency (EPA) Method TO-14. Air samples were collected prior to, during, and after the water-use event for 16 shower and 7 bath events. Flow rate and temperature were measured, but not controlled. The increase in average airborne concentration (+/- standard error) during showers (expressed as microg/m3 in shower enclosure or bathroom air per microg/L in water) was 3.3+/-0.4 for TCM, 1.8+/-0.3 for BDCM, and 0.5+/-0.1 for CDBM (n = 12), and during baths was 1.2+/-0.4 for TCM, 0.59+/-0.21 for BDCM, and 0.15+/-0.05 for CDBM (n = 4). The relative contribution of each chemical to the airborne concentrations was consistent for all shower and bath events, with apparent release of TCM > BDCM > CDBM. The results are therefore consistent with their relative concentration in tap water and their vapor pressures. When the shower findings for TCM are normalized for water concentration, flow rate, shower volume, and duration, the average exposure concentrations in these urban residences are about 30% lower than those reported by other investigators using EPA analytical methods. This difference is likely attributable primarily to greater air exchange rates in residential shower/bath stalls compared to more "airtight" laboratory shower chambers. This appears to be the first field study to thoroughly evaluate THM exposures from residential showers and baths, and can be used to validate previously published models of tap water volatile chemical transfer to indoor air. 相似文献
982.
Hudson RJ 《Physician executive》2000,26(4):26-33
Richard L. Reece, MD, interviewed Robert J. Hudson, MD, on April 24, 2000 to discuss his experiences as a physician executive who has made the career transition from practicing physician to managed care executive to biotech entrepreneur. Along the way, he's hired and fired others, and been fired himself. Painful as it is, many physician executives' career realities include being fired. Organizations, after all, are living organizations--they grow, wither, and molt. And as they molt, organizations shed and regrow new skin. What do physician executives do when they've been fired? They go through their own cycle and retreat, reflect, and re-emerge, often reinventing themselves as they go. An essential part of this process is looking within to plumb likes and dislikes, strengths and weaknesses, nightmares and dreams, and positive and negative experiences. For most executives, out of these experiences has come a circle of friends and a Rolodex. Start by reaching out to the circle, by going through your Rolodex, and you can broadcast the news of your rebirth. 相似文献
983.
Next to doing nothing, fixing a problem is often the worst thing you could do with it. Fix a problem but miss the context, and you still have the problem--only it's bigger, it's weirder, it costs more, and everybody's grumpy. When something comes at you with a "problem" label, use it as an opportunity to connect things up, to explore, to ask the bigger questions, to find the new possibilities. When we react to a problem, we put ourselves into a dilemma. To find fruitful and creative solutions, we need to be in a place of choice, with many possibilities. Real participation--giving people real choice--is the only way you can bring people's intelligence and life experiences to bear on the situation at hand. 相似文献
984.
Application of Executive Order 12898 to risk assessment of highway or rail transport of hazardous materials has proven difficult; in general, the location and conditions affecting the propagation of a plume of hazardous material released in a potential accident are unknown. Therefore, analyses have only been possible in a geographically broad or approximate manner. The advent of geographic information systems and development of software enhancements at Sandia National Laboratories have made kilometer-by-kilometer analysis of populations tallied by U.S. Census blocks along entire routes practicable. Tabulations of total or racially/ethnically distinct populations close to a route, its alternatives, or the broader surrounding area, can then be compared and differences evaluated statistically. This article presents methods of comparing populations and their racial/ethnic compositions using simple tabulations, histograms, and chi-square tests for statistical significance of differences found. Two examples of these methods are presented: comparison of two routes and comparison of a route with its surroundings. 相似文献
985.
The simplified Conjoint Expected Risk (CER) model by Holtgrave and Weber posits that perceived risk is a linear combination of the subjective judgments of the probabilities of harm, benefit, and status quo, and the expected harm and benefit of an activity. It modifies Luce and Weber's original CER model—that uses objective information to evaluate financial gambles—to accommodate activities such as health/technology activities where values of the model variables are subjective. If the simplified model is a valid modification of the original model, its performance should not be sensitive to the use of subjective information. However, because people may evaluate information differently when objective information is provided to them than when they generate information on their own, the performance of the simplified CER model may not be robust to the source of model-variable information. We compared the use of objective and subjective information, and results indicate that the estimates of the simplified CER model parameters and the proportion of variance in risk judgments accounted for by the model are similar under these two conditions. Thus, the simplified CER model is viable with activities for which harm and benefit information is subjective. 相似文献
986.
V. V. Chari Patrick J. Kehoe Ellen R. Mcgrattan 《Econometrica : journal of the Econometric Society》2000,68(5):1151-1179
We construct a quantitative equilibrium model with firms setting prices in a staggered fashion and use it to ask whether monetary shocks can generate business cycle fluctuations. These fluctuations include persistent movements in output along with the other defining features of business cycles, like volatile investment and smooth consumption. We assume that prices are exogenously sticky for a short time. Persistent output fluctuations require endogenous price stickiness in the sense that firms choose not to change prices much when they can do so. We find that for a wide range of parameter values, the amount of endogenous stickiness is small. Thus, we find that in a standard quantitative model, staggered price‐setting, alone, does not generate business cycle fluctuations. 相似文献
987.
Nicole Gravina Jamie Villacorta Kristin Albert Ronald Clark Scott Curry David Wilder 《Journal of Organizational Behavior Management》2018,38(2-3):191-224
We reviewed the Journal of Applied Behavior Analysis (JABA), Journal of Organizational Behavior Management (JOBM), and Behavior Analysis in Practice (BAP) from 1990 to 2016, to identify articles that evaluated organizational behavior management interventions in a human service setting. Of those articles, 75 articles met the inclusion criteria for the review, 44 from JABA (1990 to 2016), 22 from JOBM (1990 to 2016), and 7 from BAP (2008 to 2016). We categorized each selected article by setting, employee population, client population, assessment, dependent variable, independent variable, and outcome measures. Results from the review are discussed for all three journals. Recommendations are made to broaden the scope of population and dependent variable targets, include more assessments, and include outcome data when applicable. 相似文献
988.
From a motivational perspective of feedback-seeking behavior, we examined the mediating role of leaders' negative feedback-seeking from subordinates in the relationship between the quality of leader-member exchange (LMX) and subordinates' evaluation of leader effectiveness, along with the moderating role of subordinate expertise in the mediated relationship. Using 151 unique matched sets of leader and subordinate reports obtained from 5 large Korean companies, we found that the positive relationship between LMX and leader effectiveness was mediated by leaders' negative feedback-seeking. Additionally, the positive relationship between LMX and leader negative feedback-seeking was stronger when perceived subordinate expertise was lower. Lastly, the indirect effect of LMX on leader effectiveness through leader negative feedback-seeking was stronger when perceived subordinate expertise was lower. These findings were obtained after controlling for leaders' power distance and goal orientations that might influence their motives to seek or avoid feedback. Theoretical and practical implications are discussed. 相似文献
989.
Marcelo Cano-Kollmann T.J. Hannigan Ram Mudambi 《Journal of International Management》2018,24(2):87-92
Innovation is increasingly the outcome of global networks that connect geographically dispersed knowledge centers. The international business (IB) literature has developed a sophisticated understanding of the multinational enterprise (MNE) as an organization generates value by integrating knowledge across national borders. We advance this literature by making three key arguments. First we highlight the three megatrends that shape the strategy of the modern MNE: the disaggregation of the value chain into ever narrower activities, the migration of value to knowledge-intensive intangibles and the rise of huge emerging markets like China and India, whose domestic firms can grow to enormous size before venturing abroad. Second, we trace these three megatrends to falling spatial transaction costs, enabled in the main, by digitalization. Third, we draw on earlier research on the generic forms of global linkages, arguing that the IB literature has limited itself to organizational pipelines, while paying relatively little attention to personal relationships. The latter are particularly important in the genesis of both entrepreneurship and radical innovation, but are particularly sensitive to the anti-globalization policies. An environment where technology continues to reduce spatial transaction costs, while policy raises them, strengthens large MNEs at the expense of innovative international new ventures. 相似文献
990.
Henry J. Liu Peter E. D. Love Jim Smith Zahir Irani Nick Hajli Michael C. P. Sing 《生产规划与管理》2018,29(1):68-83
Public–Private Partnerships (PPPs) have become a critical vehicle for delivering infrastructure worldwide. Yet, the use of such a procurement strategy has received considerable criticism, as they have been prone to experiencing time/cost overruns and during their operation poorly managed. A key issue contributing to the poor performance of PPPs is the paucity of an effective and comprehensive performance measurement system. There has been a tendency for the performance of PPPs to be measured based on their ex-post criteria of time, cost and quality. Such criteria do not accommodate the complexities and lifecycle of an asset. In addressing this problem, the methodology of sequential triangulation is used to develop and examine the effectiveness of a ‘Process Management Life Cycle Performance Measurement System’. The research provides public authorities and private-sector entities embarking on PPPs with a robust mechanism to effectively measure, control and manage their projects’ life cycle performances, ensuring the assets are ‘future proofed’. 相似文献