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   174696篇
  免费   7837篇
  国内免费   157篇
  182690篇
  2021年   1496篇
  2020年   2775篇
  2019年   3434篇
  2018年   3547篇
  2017年   3975篇
  2016年   4615篇
  2015年   3917篇
  2014年   4810篇
  2013年   23462篇
  2012年   4602篇
  2011年   3809篇
  2010年   3916篇
  2009年   4781篇
  2008年   3911篇
  2007年   3517篇
  2006年   4114篇
  2005年   4081篇
  2004年   3589篇
  2003年   3198篇
  2002年   3064篇
  2001年   3272篇
  2000年   3083篇
  1999年   3105篇
  1998年   2841篇
  1997年   2674篇
  1996年   2586篇
  1995年   2412篇
  1994年   2393篇
  1993年   2342篇
  1992年   2565篇
  1991年   2402篇
  1990年   2268篇
  1989年   2216篇
  1988年   2182篇
  1987年   2221篇
  1986年   2177篇
  1985年   2434篇
  1984年   2533篇
  1983年   2340篇
  1982年   2396篇
  1981年   2364篇
  1980年   2209篇
  1979年   2223篇
  1978年   2212篇
  1977年   2157篇
  1976年   1970篇
  1975年   2020篇
  1974年   2062篇
  1973年   1976篇
  1972年   1538篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
Emerson (1988) provided a simple C-language timing routine for use with PC AT class machines. Unfortunately, this version of the timing routine makes use of nonstandard functions that are not available in all C-language packages. A modified version of this timing routine that does not make use of one of these nonstandard functions is provided. This version of TIMEX runs under the widely available Microsoft C 5.1. The need and availability of the remaining four nonstandard C functions is discussed. Constants needed to convert the timing routine units into seconds and milliseconds are also provided.  相似文献   
943.
944.
A microcomputer running a spreadsheet program makes an excellent visual aid for demonstrating statistical concepts and procedures. Some advantages of this setup over traditional visual aids are described. Several statistical demonstrations that I have found to work well are presented.  相似文献   
945.
The purpose of the present paper is to describe and compare some inexpensive software packages that calculate a variety of statistics on microcomputers running MS-DOS. For each package, hardware requirements, program capabilities, limitations, accuracy, error handling, and other features are considered.  相似文献   
946.
Studies that compare objective data on communication activity to data provided in verbal reports have indicated that verbal report data are not as accurate as one might hope. Researchers of communication have used verbal reports as their primary source of data because it presents a cheap and easy way to collect the data. This paper presents an easy alternative involving the study ofelectronic communication: a method that allows the collection of objective information on electronic communication, thus avoiding the problems associated with self-reports. The paper reviews the available literature on the accuracy of self-reports of communication, presents the instrument used to collect the objective electronic communication data, and discusses some of the difficulties and limitations encountered in implementing a study using the instrument.  相似文献   
947.
In this study, we describe the process of transforming neuron polarization values that meet the assumptions of ratio data into ordinal data. This is a crisp-to-fuzzy set transformation. A computerized simulation of the application of this process is discussed and nonparametric methods of analyzing fuzzy-set data are presented.  相似文献   
948.
Researchers interested in studying discrimination learning in primates have typically utilized variations in the Wisconsin General Test Apparatus (WGTA). In the present experiment, a new testing apparatus for the study of primate learning is proposed. In the video-task paradigm, rhesus monkeys (Macaca mulatta) respond to computer-generated stimuli by manipulating a joystick. Using this apparatus, discrimination learning-set data for 2 monkeys were obtained. Performance on Trial 2 exceeded 80% within 200 discrimination learning problems. These data illustrate the utility of the video-task paradigm in comparative research. Additionally, the efficient learning and rich data that were characteristic of this study suggest several advantages of the present testing paradigm over traditional WGTA testing.  相似文献   
949.
In this paper, we discuss the potential of HyperCard for research and instruction in psychology. First we give a general overview of the HyperCard program; after that, we present two HyperCard stacks as sample solutions for two specific research applications. Surveyor, a self-contained survey tool, is a HyperCard-based vehicle for developing, administering, and processing tests and surveys. Queston demonstrates how HyperCard can be used as a data-management and data-analysis tool during the stages of questionnaire development. Both stacks illustrate how flexible HyperCard is and how easy it is to use it to manage, analyze, and process data, to transfer data to other programs, and to print reports. HyperCard, unlike traditional applications, gives the user a great degree of control over the way information is stored, mainipulated, and presented. Although both stacks are custom-made for specific purposes, the concepts underlying the design can be generally applied and adapted for other purposes.  相似文献   
950.
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