全文获取类型
收费全文 | 285篇 |
免费 | 52篇 |
国内免费 | 10篇 |
专业分类
347篇 |
出版年
2025年 | 2篇 |
2024年 | 12篇 |
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 11篇 |
2020年 | 18篇 |
2019年 | 12篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 18篇 |
2015年 | 12篇 |
2014年 | 7篇 |
2013年 | 27篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 17篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 19篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 2篇 |
排序方式: 共有347条查询结果,搜索用时 0 毫秒
21.
借鉴国内外相关成功经验,结合我国实际情况,对“人体器官移植工作体系”的构成以及各系统职能进行初步探讨。研究了该体系在阻止人体器官商业化、提高人体移植器官分配的公平高效性等方面发挥的作用。 相似文献
22.
肾脏移植是救治终末期肾功能衰竭的最佳手段。亲属活体捐献肾脏是扩大供肾来源的有效手段。当前国内开展亲属肾移植存在伦理、法律和健康风险,主要来自供体和医疗两方面。为防范风险,医务人员应严格审查供受者的血缘关系,签署完整规范的法律文书,进行全面细致的术前评估,制定完善的手术方案。 相似文献
23.
24.
科学的统筹规划、紧凑有序的接台管理,能够更好地服务患者,提高医院工作效率。探索大型综合性医院手术室合理有效地安排手术、加快手术周转的措施。讨论如何有效利用手术室的物资和人力资源,进行全盘科学的筹划,抓住关键环节,合理安排工序。进而成功破除制约手术科室的瓶颈,大大提高了手术科室的效率。 相似文献
25.
Relative allocation on concurrent schedules can depend on schedule parameters when behavioral parameters are constant
下载免费PDF全文

Houston AI McNamara JM Sumida BH 《Journal of the experimental analysis of behavior》1987,47(1):127-131
We develop a simple model of switching between the initial links of a concurrent-chain procedure. Behavior is determined by four parameters μ1, μ2, q1, and q2. The first two are the basic rates of switching from Schedule 1 and Schedule 2, respectively. The second two are the probabilities of leaving Schedule 1 and Schedule 2 after the corresponding terminal link has been completed. We show that for fixed values of these four parameters, the relative allocation on the initial links may change as a result of changes in initial-link schedules. The effect can be quite large if the switching rates are low. An implication is that relative allocation is not necessarily a good measure of behavior. 相似文献
26.
Effects of differences between stimuli, responses, and reinforcer rates on conditional discrimination performance
下载免费PDF全文

In a discrete-trial conditional discrimination procedure, 4 pigeons obtained food reinforcers by pecking a key with a short latency on trials signaled by one stimulus and by pecking the same key with a long latency on trials signaled by a second stimulus. The physical difference between the two stimuli and the temporal separation between the latency values required for reinforcement were varied factorially over four sets of conditions, and the ratio of reinforcer rates for short and long latencies was varied within each set of conditions. Stimulus discrimination varied directly with both stimulus and response differences and was unaffected by the reinforcer ratio. Sensitivity to reinforcement, estimated by generalized-matching-law fits to the data within each set of conditions, varied directly with the response difference but inversely with the stimulus difference arranged between sets of conditions. Because variations in stimulus differences, response differences, and reinforcer differences did not have equivalent effects, these findings question the functional equivalence of the three terms of the discriminated operant: antecedent stimuli, behavior, and consequences. 相似文献
27.
中学生厌学心理及其干预与学习效率的相关研究 总被引:16,自引:1,他引:16
本研究旨在考察两个问题:1.心理咨询是否是改变中学生厌学心理的有效途径,如果是,它能够在多大程度上改变厌学心理;2.厌学心理的改善能否有效提高中学生学习效率。本实验用问卷调查法从183名中学生中筛选出有厌学心理的学生24名。运用个体心理咨询、团体心理咨询等手段对这24名学生进行为期4个月干预、结果表明:心理咨询能够有效且明显地改善厌学心理。但要完全消除厌学心理则还需要辅以其他干预手段;随着学生厌学心理的改善,其学习效率也相应有了明显的提高。 相似文献
28.
29.
该文受Berkson将检验方法用于估计未知参数的启发,根据三个拟合优度统计量导出三种新的求取等值系数的方法,即:平方根等值方法(Square Root criterion,SQRTcrit)、对称相对熵等值方法(Symmetric Relative Entropy criterion,SREcrit)、加权等值方法(Weighted criterion,Wcrit),即Haebara准则的加权式。虽然在被检验的两个分布列很接近时,这三个多项拟合优度检验方法是渐近等价的,然而用它们求取等值系数时,Monte-Carlo模拟结果表明这三种新等值方法的行为表现存在差异。它们之间的差异和随机误差的大小有密切关系,即与项目参数估计的精度有关;还与等值系数A的范围有关。 相似文献
30.
The study investigated interactions between learner expertise and task complexity evaluated from both cognitive and affective perspectives. One hundred and seventy-three students, both novices and advanced learners, were asked to learn Japanese writing in a pen-tablet-based digital learning environment with varying task complexity levels. Cognitive load and learning-centred emotions were measured at intervals during learning, while writing performance was monitored by runtime tracking. Results indicated that while advanced learners performed better than novices across the range of task complexity, the moderate task complexity was shown to be superior in enhancing performance for both levels of expertise. Results for learning-centred emotions showed that advanced learners reported lower enjoyment and higher frustration when completing the low complexity task, whereas the moderately complex task was reported to be the most enjoyable and less frustrating for these learners. No significant difference in emotions was found across levels of task complexity for novices. Finally, a constructed composite indicator of cognitive-affective efficiency of instructional conditions showed a significant interaction between levels of learner expertise and task complexity primarily caused by affective factors. 相似文献