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   4316篇
  免费   47篇
  国内免费   7篇
教育   3341篇
科学研究   219篇
各国文化   82篇
体育   299篇
综合类   1篇
文化理论   61篇
信息传播   367篇
  2021年   24篇
  2020年   49篇
  2019年   81篇
  2018年   95篇
  2017年   122篇
  2016年   94篇
  2015年   83篇
  2014年   94篇
  2013年   1090篇
  2012年   69篇
  2011年   93篇
  2010年   72篇
  2009年   97篇
  2008年   107篇
  2007年   99篇
  2006年   99篇
  2005年   91篇
  2004年   82篇
  2003年   97篇
  2002年   79篇
  2001年   68篇
  2000年   69篇
  1999年   64篇
  1998年   57篇
  1997年   63篇
  1996年   62篇
  1995年   62篇
  1994年   50篇
  1993年   54篇
  1992年   50篇
  1991年   60篇
  1990年   53篇
  1989年   55篇
  1988年   44篇
  1987年   39篇
  1986年   46篇
  1985年   58篇
  1984年   32篇
  1983年   42篇
  1982年   44篇
  1981年   43篇
  1980年   32篇
  1979年   63篇
  1978年   31篇
  1977年   47篇
  1976年   34篇
  1975年   31篇
  1974年   39篇
  1973年   25篇
  1972年   23篇
排序方式: 共有4370条查询结果,搜索用时 0 毫秒
191.
192.
A rejoinder to Gudykunst and Hammer's critique of a recent paper is presented. We argue that their position is based on two mutually exclusive propositions and cannot therefore be credible. We continue to maintain that the evidence on intercultural effectiveness shows both culture-general and culture-specific components.  相似文献   
193.
194.
195.
In this holistic review of cycling science, the objectives are: (1) to identify the various human and environmental factors that influence cycling power output and velocity; (2) to discuss, with the aid of a schematic model, the often complex interrelationships between these factors; and (3) to suggest future directions for research to help clarify how cycling performance can be optimized, given different race disciplines, environments and riders. Most successful cyclists, irrespective of the race discipline, have a high maximal aerobic power output measured from an incremental test, and an ability to work at relatively high power outputs for long periods. The relationship between these characteristics and inherent physiological factors such as muscle capilliarization and muscle fibre type is complicated by inter-individual differences in selecting cadence for different race conditions. More research is needed on high-class professional riders, since they probably represent the pinnacle of natural selection for, and physiological adaptation to, endurance exercise. Recent advances in mathematical modelling and bicycle-mounted strain gauges, which can measure power directly in races, are starting to help unravel the interrelationships between the various resistive forces on the bicycle (e.g. air and rolling resistance, gravity). Interventions on rider position to optimize aerodynamics should also consider the impact on power output of the rider. All-terrain bicycle (ATB) racing is a neglected discipline in terms of the characterization of power outputs in race conditions and the modelling of the effects of the different design of bicycle frame and components on the magnitude of resistive forces. A direct application of mathematical models of cycling velocity has been in identifying optimal pacing strategies for different race conditions. Such data should, nevertheless, be considered alongside physiological optimization of power output in a race. An even distribution of power output is both physiologically and biophysically optimal for longer ( > 4 km) time-trials held in conditions of unvarying wind and gradient. For shorter races (e.g. a 1 km time-trial), an 'all out' effort from the start is advised to 'save' time during the initial phase that contributes most to total race time and to optimize the contribution of kinetic energy to race velocity. From a biophysical standpoint, the optimum pacing strategy for road time-trials may involve increasing power in headwinds and uphill sections and decreasing power in tailwinds and when travelling downhill. More research, using models and direct power measurement, is needed to elucidate fully how much such a pacing strategy might save time in a real race and how much a variable power output can be tolerated by a rider. The cyclist's diet is a multifactorial issue in itself and many researchers have tried to examine aspects of cycling nutrition (e.g. timing, amount, composition) in isolation. Only recently have researchers attempted to analyse interrelationships between dietary factors (e.g. the link between pre-race and in-race dietary effects on performance). The thermal environment is a mediating factor in choice of diet, since there may be competing interests of replacing lost fluid and depleted glycogen during and after a race. Given the prevalence of stage racing in professional cycling, more research into the influence of nutrition on repeated bouts of exercise performance and training is required.  相似文献   
196.
197.
G.W.A. Dummer's Electronic Inventions: 1745-1976 (Oxford, England: Pergamon Press, 1976—£5.50 or $10.00)

Carl Dreher's Sarnoff: An American Success (New York: Quadrangle/ New York Times Book Co., 1977—$12.50)

George W. Bartlett, ed. NAB Engineering Handbook (Washington: National Association of Broadcasters, 1975—$45.00; $30.00 to NAB and BEA members)

Richard Veith's Talk-Back TV: Two-Way Cable Television (Blue Ridge Summit. Pa.: TAB Books, 1976—$9.95/5.95)

Dan Rather with Mickey Herskowitz' The Camera Never Blinks: Adventures of a TV Journalist (New York: Morros, 1977—$10.00)

F. Gifford's Tape: A Radio News Handbook (New York: Hastings House, 1977—$12.95/6.95)

F. Earle Barcus' Children's Television: An Analysis of Programming and Advertising (New York: Praeger Special Studies, 1977—price not given, but likely around $18.00)

Douglas Davis and Allison Simmons' The New Television: A Public/Private Art (Cambridge, Mass.: MIT Press, 1977—$14.95)

The Videophile's Newsletter (Jim Lowe, 2014 South Magnolia Drive, Tallahassee, Fla. 32301—$7.50 for five issues)

Separations Procedures in the Telephone Industry: The Historical Origins of a Public Policy, by James W. Sichter (January 1977, Publication P-77-2, 146 pp. $23.40, paper)

The Communications Act Policy Toward Competition: The Sound of One Hand Clapping by Hamilton Loeb (March 1977, Working Paper W-77-1, 68 pp., $ 10.90)

Broadcasting: The Next Ten Years (New York: National Broadcasting Co., Department of Corporate Planning, 1977—apparently free on request, paper)

NFLCP Newsletter (P.O. Box 119, Cambridge, Mass. 02142—$7.50 annually, bimonthly; $15.00 to organizations)

Gary Gerani and Paul H. Schulman's Fantastic Television (New York: Harmony Books/Crown Publishers, 1977—$12.95/5.95)  相似文献   
198.
Pupils with Severe Learning Difficulties as Personal Target Setters   总被引:1,自引:0,他引:1  
Richard Rose, Senior Lecturer at University College, Northampton, and Will Fletcher and Gaynor Goodwin, Watling View School, St Albans, argue that although many schools have attempted to enable pupils with special educational needs to play an active part in their own planning procedures and assessment, few have identified and analysed the skills required by both pupils and teachers. Theydescribe a one-year small-scale action-research project, in a school for children with severe learning difficulties, which resulted in the development of procedures for the assessment of 'pupil readiness' for full involvement in the target-setting process.  相似文献   
199.
Susan Krieger Hip Capitalism (Beverly Hills, Calif.: Sage Publications, 1979—$15.00/ 7 .95)

Richard P. Adler, ed. All in the Family: A Critical Appraisal (New York: Praeger Publishers (for the coth edition)/Cambria Press, 360 Bryant St., Palo Alto, Calif. 94302 (for paperback orders), 1979—$22.00/6.95)

Lauren R. Sass, ed. Television: The American Medium in Crisis (Facts on File, 119 West 57th St., New York 10019—price not given)

Encyclomedia: 1979 Television Edition (Encyclomedia, 342 Madison Ave. New York, N.Y. 10017—$57.00, paper)  相似文献   
200.
This article examines the effect that postsecondary education has on earnings and the duration of time spent in the Social Security disability programs for young persons who are deaf or hard of hearing. Our hypothesis is that investments in postsecondary training increase the likelihood of employment for persons who are deaf or hard of hearing and thus reduce dependency on disability-related income support programs. A longitudinal data set based upon records from the National Technical Institute for the Deaf and Social Security administrative records is used for this analysis. We find that those who graduate, even those who graduate with vocational degrees, experience significant earnings benefits and reductions in the duration of time spent on federal disability programs when compared with those who do not graduate with a degree. This finding suggests that reductions in the duration of time spent on Social Security programs are not limited to those with the highest level of scholastic aptitude and that investments in post-secondary education can benefit a broad group of deaf and hard-of-hearing persons. In addition, the data show that individuals who attend college, but withdraw before graduation, fair no better economically than individuals who never attended college.  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