全文获取类型
| 收费全文 | 455篇 |
| 免费 | 77篇 |
| 国内免费 | 11篇 |
专业分类
| 543篇 |
出版年
| 2025年 | 5篇 |
| 2024年 | 5篇 |
| 2023年 | 8篇 |
| 2022年 | 7篇 |
| 2021年 | 9篇 |
| 2020年 | 11篇 |
| 2019年 | 7篇 |
| 2018年 | 11篇 |
| 2017年 | 12篇 |
| 2016年 | 13篇 |
| 2015年 | 10篇 |
| 2014年 | 17篇 |
| 2013年 | 56篇 |
| 2012年 | 14篇 |
| 2011年 | 17篇 |
| 2010年 | 13篇 |
| 2009年 | 24篇 |
| 2008年 | 26篇 |
| 2007年 | 26篇 |
| 2006年 | 18篇 |
| 2005年 | 21篇 |
| 2004年 | 22篇 |
| 2003年 | 17篇 |
| 2002年 | 16篇 |
| 2001年 | 16篇 |
| 2000年 | 21篇 |
| 1999年 | 10篇 |
| 1998年 | 9篇 |
| 1997年 | 9篇 |
| 1996年 | 8篇 |
| 1995年 | 13篇 |
| 1994年 | 9篇 |
| 1993年 | 5篇 |
| 1992年 | 12篇 |
| 1991年 | 7篇 |
| 1990年 | 1篇 |
| 1989年 | 3篇 |
| 1988年 | 4篇 |
| 1987年 | 2篇 |
| 1986年 | 2篇 |
| 1985年 | 5篇 |
| 1984年 | 3篇 |
| 1983年 | 2篇 |
| 1982年 | 2篇 |
| 1981年 | 3篇 |
| 1980年 | 3篇 |
| 1979年 | 1篇 |
| 1977年 | 3篇 |
| 1976年 | 4篇 |
| 1975年 | 1篇 |
排序方式： 共有543条查询结果，搜索用时 15 毫秒
161.
According to classical utility theory the valuation of any lottery should depend only on its outcomes and their respective probabilities, and should not be affected by the nature, complexity and structure of the chance mechanism. Previous research has documented systematic violations of this principle. For example, most subjects prefer lotteries in which the payoffs are contingent on the joint occurrence of multiple (high probability) events to simple lotteries, and lotteries in which the earlier stages offer higher probabilities than the later stages. We review the various violations of this principle and suggest a classification into two major types associated with misunderstanding of chance mechanisms and attitude towards the chance mechanism and process. In the present study 40 subjects were presented with 30 pairs of binary gambles. In any given pair the lotteries had identical outcomes and equal ‘reduced’ probabilities (and thus equal expected values). However, the chance mechanisms varied along a variety of factors such as the size of the sample space, the number of stages, temporal ordering, order of probabilities, their transparency and time constraints. Half the subjects saw lotteries involving gains and the other half considered only losses. After choosing one lottery in each pair, the subjects were asked to explain and justify their choices. The findings revealed systematic violations of the reducibility principle: subjects displayed a preference for lotteries with larger sample spaces, and for lotteries that allow quicker resolutions in the earlier stages. A clear distinction between some patterns of preferences in the gains and loss domains was revealed. In gambles involving gains subjects preferred to have the highest probability on the first stage (and the lowest probability on the last stage), but displayed the opposite preferences for losses. A content analysis of the subjects' stated reasons for their choices identified eight major categories. The most frequently invoked were hope, fun, simplicity, stress and time. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
162.
Tony Rosqvist 《Journal of Multi-Criteria Decision Analysis》2001,10(4):205-218
Investments on capital goods are assessed with respect to the life cycle profit as well as the economic lifetime of the investment. The outcome of an investment with respect to these economic criteria is generally non‐deterministic. An assessment of different investment options thus requires probabilistic modelling to explicitly account for the uncertainties. A process for the assessment of life cycle profit and the evaluation of the adequacy of the assessment is developed. The primary goal of the assessment process is to aid the decision‐maker in structuring and quantifying investment decision problems characterized by multiple criteria and uncertainty. The adequacy of the assessment process can be evaluated by probabilistic criteria indicating the degree of uncertainty in the assessment. Bayesian inference is used to re‐evaluate the initial assessment, as evidence of the system performance becomes available. Thus authentication of contracts of guarantee is supported. Numerical examples are given to demonstrate features of the described life cycle profit assessment process. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
163.
MAGNE ARVE FLATEN ROLF W. GRÅWE CARL B. DAHL TROND HAUG 《Scandinavian journal of psychology》1991,32(1):70-78
The purpose of the first experiment was to investigate whether diazepam could acquire anxiogenic properties by signalling an aversive event. Rats were trained in an operant chamber in the pentylenetetrazol (PTZ) model of anxiety. Thereafter the animals were divided into groups that received classical diazepam conditioning (Group 1), and conditioning of diazepam + tone (Group 2). In the test phase diazepam was injected prior to placement in the operant chamber. Group 2 selected the PTZ-appropriate lever more often than the other groups, indicating that the tone induced anxiety, and diazepam did not. Tones and shock may therefore be more easily associated than diazepam and shock. The second experiment investigated this. Rats were trained the same way as in the first experiment. Thereafter the experimental group received injections of a small dose of diazepam prior to a second injection of a large dose of diazepam. The hypothesis was that a compensatory anxiogenic conditional response to diazepam's anxiolytic effect should be elicited by the small dose. There were no differences between the groups in lever selection, indicating that a compensatory anxiogenic response was not elicited. 相似文献
164.
吸毒者回归社会的过程:归属与认同的剥夺 总被引：1，自引：0，他引：1
该研究通过回顾性研究与问卷测量的方法,对吸毒者的认同感、归属感与复吸风险进行了分析和探讨,并对他们的生存状况进行了初步调查,结果表明:不利的社会处境是高复吸风险的诱发因素,戒毒人员回归社会后的生存状况不容乐观;吸毒者的自我认同和社会认同程度都显著低于健康人群,社会缺乏对戒毒人员有效的社会支持;归属剥夺是导致复吸的危险性因素,戒毒人员回归社会之后缺乏亲密的人际交往和情感交流。 相似文献
165.
Galuska CM Winger G Hursh SR Woods JH 《Journal of the experimental analysis of behavior》2006,86(2):181-195
Given a commodity available at different prices, a unit-price account of choice predicts preference for the cheaper alternative. This experiment determined if rhesus monkeys preferred remifentanil (an ultra-short-acting micro-opioid agonist) delivered at a lower unit price over a higher-priced remifentanil alternative (Phases 1 and 3). Choice between equal-priced alternatives also was assessed (Phase 2). A discrete-trials procedure was arranged in which three monkeys chose between two remifentanil alternatives by responding on one of two levers. Different prices were arranged by manipulating drug dose (0.3 and 0.1 microg/kg/injection) and/or the ratio requirement. Monkeys usually chose the larger-dose alternative even when it was more expensive. Only when unit prices were relatively high (e.g., large response requirements) did monkeys choose the cheaper (or equally priced) smaller-dose alternative. Employing larger doses (0.9 and 0.3 microg/kg/injection) attenuated the larger-dose preference. The results demonstrate that choice was not determined simply by unit price. An alternative model that employs demand-function analysis to generate choice predictions is proposed. 相似文献
166.
Ziegler D Keith JR Pitts RC Galizio M 《Journal of the experimental analysis of behavior》2002,78(2):215-223
A morphine versus saline discrimination was demonstrated using the Morris swim task as the behavioral baseline. The apparatus was a large circular pool filled with water made opaque by floating polypropylene pellets. Rats were placed in the tank in randomly selected locations (12 trials per session) and could escape by swimming to a platform submerged 2 cm below the surface. Morphine (5.6 mg/kg) or saline was injected prior to training sessions. The position of the platform in a given session depended on the drug condition, thus forming the basis for discriminative responding. Three of the 4 rats acquired the discrimination, as evidenced by direct swims to the condition-appropriate platform. Generalization probe sessions were conducted following acquisition. Probe sessions were preceded by injections of morphine (0, 1.0, 3.0, 5.6, or 10.0 mg/kg) and involved placing the rat in the pool for 1 min without a platform. Swim patterns revealed a gradient, with probe swimming more concentrated in the area of the morphine platform position after higher morphine doses. In addition, dose-dependent increases in the likelihood of swimming first to the morphine-associated platform location were obtained. These results illustrate the generality of drug discrimination across different behavioral procedures, and of particular interest with respect to spatial learning, demonstrate interoceptive stimulus control of navigation. 相似文献
167.
R J DeGrandpre W K Bickel S A Rizvi J R Hughes 《Journal of the experimental analysis of behavior》1993,59(3):483-500
The effects of income (money available to spend during the experimental session) on human choice were examined in a concurrent-schedule arrangement. Subjects were 7 nicotine-dependent smokers, and reinforcers were puffs on the subject's usual brand of cigarette (\"own\") and puffs on a less preferred brand of cigarette with equal nicotine content (\"other\"). Across sessions, income varied and the price of the two reinforcers was held constant, with the other puffs one fifth the price of the own puffs. As income increased, consumption of own puffs increased while consumption of the less expensive other puffs decreased. These effects of income on choice were highly consistent across subjects. For some subjects, however, income had little effect on total puff consumption. Finally, an additional condition examined whether price and income manipulations would have functionally equivalent effects on choice by repeating an income condition in which the price of the other brand was increased. Although the increased price of the other puffs decreased their consumption in 4 subjects, 2 subjects showed increased consumption of the other puffs at the higher price. The results, when defined in economic terms, indicate that the own puffs were a normal good (consumption and income are directly related), the other puffs were an inferior good (consumption and income are inversely related), and the direct relationship between consumption of the other puffs and their price is defined as a Giffengood effect. The latter result also suggests that for these 2 subjects, price and income manipulations had equivalent effects on choice. These results extend findings from previous studies that have examined the effects of income on choice responding to human subjects and drug reinforcers, and provide a framework for further experimental tests of the effects of income on human choice behavior. Methodological and theoretical implications for the study of choice and for behavioral pharmacology are discussed. 相似文献
168.
Response-contingent deliveries of oral pentobarbital maintained responding of 3 rhesus monkeys during daily 3-hr sessions. Deliveries of pentobarbital were arranged under nonindependent concurrent variable-ratio variable-ratio schedules. Responses to either schedule counted toward completion of both variable-ratio schedule requirements. This schedule is similar in some respects to conventional concurrent variable-interval variable-interval schedules, in which passage of time counts toward completion of the interval value on both schedules. Restricted nonindependent concurrent variable-ratio variable-ratio schedules were also studied. On that schedule, when a drug delivery was assigned to one spout, it had to be collected before responses on the opposite spout again counted toward completion of the schedule requirements. Relative reinforcer magnitude was varied by changing the drug concentration on one schedule while keeping the drug concentration constant on the other variable-ratio schedule. Under both types of concurrent variable-ratio schedules, the relative rate of responding corresponded to the relative drug intake. Unlike earlier studies of concurrent variable-interval variable-interval intravenous cocaine reinforcement, preference was proportionate to concentration, and exclusive preferences did not develop. The relationship between relative rate of responding and relative drug intake was well described by the generalized matching law. 相似文献
169.
Mark K. Greenwald 《Journal of applied behavior analysis》2008,41(4):603-607
A positive reinforcement contingency increased opioid abstinence during outpatient dose tapering (4, 2, then 0 mg/day during Weeks 1 through 3) in non‐treatment‐seeking heroin‐dependent volunteers who had been maintained on buprenorphine (8 mg/day) during an inpatient research protocol. The control group (n = 12) received $4.00 for completing assessments at each thrice‐weekly visit during dose tapering; 10 of 12 lapsed to heroin use 1 day after discharge. The abstinence reinforcement group (n = 10) received $30.00 for each consecutive opioid‐free urine sample; this significantly delayed heroin lapse (median, 15 days). 相似文献
170.
《Theoria》2018,84(2):120-139
A phenomenon called perspectival disagreement is laid out and modelled on the basis of modifications to known consensus measures for qualitative representations of preferences and transitive values by binary relations. Cases of perspectival disagreement are of general philosophical interest, because they allow for the possibility that two or more agents judge the value positions of other agents differently even when their assessments are based on the same evidence. Various examples of perspectival disagreement are given, generalizations are discussed, and it is argued that any representation by cardinal utilities also gives rise to some form of perspectivity. Although the examples strongly suggest that this phenomenon occurs in real life, it is concluded in the end that it does not pose any fundamental threat to representations of preferences and values as binary relations. Instead, position‐sensitive measures of disagreement ought to be taken as a modelling option for cases in which the relative importance of preference changes matters to an agent. 相似文献