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   17067篇
  免费   275篇
管理学   2191篇
民族学   68篇
人才学   6篇
人口学   1439篇
丛书文集   78篇
教育普及   3篇
理论方法论   1522篇
综合类   177篇
社会学   8694篇
统计学   3164篇
  2023年   86篇
  2021年   96篇
  2020年   212篇
  2019年   322篇
  2018年   362篇
  2017年   525篇
  2016年   364篇
  2015年   270篇
  2014年   356篇
  2013年   3275篇
  2012年   490篇
  2011年   455篇
  2010年   332篇
  2009年   308篇
  2008年   341篇
  2007年   361篇
  2006年   371篇
  2005年   343篇
  2004年   312篇
  2003年   249篇
  2002年   311篇
  2001年   403篇
  2000年   360篇
  1999年   397篇
  1998年   284篇
  1997年   253篇
  1996年   287篇
  1995年   289篇
  1994年   307篇
  1993年   301篇
  1992年   312篇
  1991年   297篇
  1990年   319篇
  1989年   285篇
  1988年   292篇
  1987年   254篇
  1986年   237篇
  1985年   257篇
  1984年   244篇
  1983年   196篇
  1982年   192篇
  1981年   166篇
  1980年   170篇
  1979年   180篇
  1978年   159篇
  1977年   134篇
  1976年   138篇
  1975年   144篇
  1974年   92篇
  1973年   93篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Violence against psychiatric staff seems to be on the increase. Such abuse can lead to mental health consequences for the staff and a reluctance to be closely involved with patients. Few Swedish investigations have examined violence against mental nurses and psychiatrists, or undertaken comparative studies between them. In this study we examined the extent, nature and determinants (i.e. risk factors) of violence against psychiatric nurses (n = 731) and psychiatrists (n = 320) working in the eight health care districts of Stockholm. These caregivers were assessed cross-sectionally by means of a questionnaire covering various areas (e.g. violence and work environment). The majority of the participants (85%) reported having been exposed to violence during their careers, with 57% being victimized in the past 12 months. Physical violence was common, and factors such as negative attitudes to work and diminished sense of autonomy were associated with an increased vulnerability to violence. Nurses and psychiatrists did not differ in violence variables. In spite of the weaknesses of the design (cross-sectional self-selecting sample), this study corroborates previous findings and identifies personal factors associated with violence that have received little attention in the literature (e.g. lack of respect for the organization of care).  相似文献   
992.
A risk assessment was conducted to determine the likelihood of certain health risks resulting from exposure to soils and food crops contaminated with polychlorinated biphenyl (PCBs). PCBs have contaminated soils, river sediments, and air in the past as a result of industrial activities at a capacitor plant located in the City of Serpukhov, Russian Federation. This risk assessment and suggestions for remediation are designed to aid in decision-making efforts by a joint Russian-American research team developing a community, national, and international response to industrial contamination. Bobovnikova et al. (The Science of the Total Environment 139/140, 357-364, [1993]) have reported that PCBs are elevated in soils and sediments, breast milk, and locally grown foods in the Serpukhov area. Data from these and other investigators have been used in this risk assessment to calculate a potential cancer risk resulting from exposure to PCBs. Our assessment indicates that members of the local population may be at increased risk of cancer, and possibly other adverse health effects, as a result of PCB contamination of their environment. Because previously unassessed environmental contamination is a common problem in the former Soviet Republics, as well as many other areas of the world, we believe this type of evaluation, using known methods, can serve as a model for assessment efforts in other parts of the globe and result in remediative efforts in regions constrained by faltering economies.  相似文献   
993.
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   
994.
Those who don't "interview well" are not likely to receive the job offer, despite their qualifications. A job interview is actually a fierce competitive activity that offers only two grades: an A or F. By nature, physicians are competitive; they like to win. Infrequent interviewees are prone to making easily corrected mistakes, such as showing no enthusiasm or having poor eye contact. The key for interviewing success is preparation--doing research, developing a personal statement, and role-playing practice interviews. View the interview as a sales call whose bottom-line goal is to achieve an offer, or at least to let you leave with the option to return for future discussions.  相似文献   
995.
Previous theoretical and empirical research provides substantial support for a contingency approach toward international entry-mode selection. Similarly, additional empirical research supports the notion that different international ownership-based entry modes tend to be associated with varying performance levels. In this study we provide an initial attempt to use Werner, Brouthers and Brouthers' (1996) multiple measures of Perceived Environmental Uncertainty (PEU) to determine the entry mode choices of firms and link these risk-adjusted mode choices to managerial satisfaction with firm performance. We hypothesize and find that firms which make PEU risk-adjusted entry mode choices are significantly more satisfied with their firm's performance than firms whose entry mode choices cannot be predicted using multiple PEU risk measures.  相似文献   
996.
This research examines a model centered on organizational learning in purchasing. Two different studies are conducted to test the hypotheses among purchasing users (Study 1) and buyers (Study 2). The user sample consists of users representing 355 strategic business units of a Fortune 500 multinational corporation. The buyer sample consists of corporate buyers of 200 multinational corporations drawn from the membership directory of the National Association of Purchasing Management (NAPM). In each study, the focus is on the learning relationships between corporate buyers and internal users in the purchasing organization. Based on the two studies, the results suggest that organizational learning in the purchasing process is influenced by the organizational culture factors of localness, transformational leadership, and openness. Organizational learning has a positive effect on information processing in the purchasing system, which, in turn, has a positive influence on the cycle time of the purchasing process.  相似文献   
997.
How people leave a devastated area after a disaster is critical to understanding their ability to cope with risks they face while evacuating. Knowledge of their needs for communications about these risks is particularly crucial in planning for emergency responses. A convenience sample of 1,444 persons who survived the World Trade Center (WTC) attacks on September 11, 2001 were surveyed to ascertain their initial and ultimate destinations once they had left the buildings, how they arrived there, the role of types of obstacles they encountered, and the need for information and the seeking of other people as potential factors in influencing the process of leaving immediately. This survey was part of a larger, original survey. Results showed differences in how people traveled by mode to initial and ultimate destinations, how immediately they left the area, and factors associated with when they left. How they traveled and when they left were associated with where people lived, their tendency in times of stress to seek out other people including who they knew in the immediate area (e.g., co‐workers or friends), the physical conditions surrounding them, and the importance to some of waiting for more information. Many people indicated they did not leave immediately because they had no information about where to go or what services would be available to them. Perceptions and communications about risks they were facing were reflected in the choices they considered in how and when to leave the area. These findings have numerous ramifications for understanding and guiding personal behavior in catastrophic situations.  相似文献   
998.
999.
This paper considers a joint preventive maintenance (PM) and production/inventory control policy of an unreliable single machine, mono-product manufacturing cell with stochastic non-negligible corrective and preventive delays. The production/inventory control policy, which is based on the hedging point policy (HPP), consists in building and maintaining a safety stock of finished products in order to respond to demand and to avoid shortages during maintenance actions. Without considering the impact of preventive and corrective actions on the overall performance of the production system, most authors working in the reliability and maintainability domains confirm that the age-based preventive maintenance policy (ARP) outperforms the classical block-replacement policy (BRP). In order to reduce wastage incurred by the classical BRP, we consider a modified block replacement policy (MBRP), which consists in canceling a preventive maintenance action if the time elapsed since the last maintenance action exceeds a specified time threshold. The main objective of this paper is to determine the joint optimal policy that minimizes the overall cost, which is composed of corrective and preventive maintenance costs as well as inventory holding and backlog costs. A simulation model mimicking the dynamic and stochastic behavior of the manufacturing cell, based on more realistic considerations of the real behavior of industrial manufacturing cells, is proposed. Based on simulation results, the joint optimal MBRP/HPP parameters are obtained through a numerical approach that combines design of experiment, analysis of variance and response surface methodologies. The joint optimal MBRP/HPP policy is compared to classical joint ARP/HPP and BRP/HPP optimal policies, and the results show that the proposed MBRP/HPP outperforms the latter. Sensitivity analyses are also carried out in order to confirm the superiority of the proposed MBRP/HPP, and it is observed that for practitioners, the proposed joint MBRP/HPP offers not only cost savings, but is also easy to manage, as compared to the ARP/HPP policy.  相似文献   
1000.
In 1999, two articles in The Physician Executive -- "Part I: Global Theory and the Nature of Risk (July-August)." and "Part II: Towards a Choice-Based Model of Managed Care (October-November)" -- outlined the flaws of orthodox managed care theory and highlighted the unique advantages of moving to a genuinely market-based model, which included the concept of direct contracting for integrated episodes of care. This follow-up focuses on comparing an episode contracting system to a traditional capitated program and outlines the features that make this approach much more attractive to physicians, payers, and most importantly patients.  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