全文获取类型
收费全文 | 13530篇 |
免费 | 645篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 451篇 |
妇产科学 | 104篇 |
基础医学 | 2606篇 |
口腔科学 | 91篇 |
临床医学 | 1650篇 |
内科学 | 714篇 |
皮肤病学 | 44篇 |
神经病学 | 2555篇 |
特种医学 | 385篇 |
外科学 | 287篇 |
综合类 | 1668篇 |
预防医学 | 2825篇 |
眼科学 | 13篇 |
药学 | 575篇 |
2篇 | |
中国医学 | 150篇 |
肿瘤学 | 74篇 |
出版年
2024年 | 22篇 |
2023年 | 229篇 |
2022年 | 439篇 |
2021年 | 514篇 |
2020年 | 500篇 |
2019年 | 478篇 |
2018年 | 391篇 |
2017年 | 420篇 |
2016年 | 414篇 |
2015年 | 354篇 |
2014年 | 904篇 |
2013年 | 1058篇 |
2012年 | 887篇 |
2011年 | 1060篇 |
2010年 | 770篇 |
2009年 | 792篇 |
2008年 | 900篇 |
2007年 | 839篇 |
2006年 | 646篇 |
2005年 | 420篇 |
2004年 | 346篇 |
2003年 | 268篇 |
2002年 | 191篇 |
2001年 | 180篇 |
2000年 | 137篇 |
1999年 | 104篇 |
1998年 | 95篇 |
1997年 | 63篇 |
1996年 | 51篇 |
1995年 | 60篇 |
1994年 | 54篇 |
1993年 | 45篇 |
1992年 | 44篇 |
1991年 | 38篇 |
1990年 | 37篇 |
1989年 | 26篇 |
1988年 | 24篇 |
1987年 | 31篇 |
1986年 | 20篇 |
1985年 | 47篇 |
1984年 | 36篇 |
1983年 | 23篇 |
1982年 | 34篇 |
1981年 | 31篇 |
1980年 | 34篇 |
1979年 | 34篇 |
1978年 | 27篇 |
1977年 | 39篇 |
1976年 | 20篇 |
1974年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
大学生寻求专业性心理帮助态度的预测因素研究 总被引:2,自引:0,他引:2
目的:探讨大学生寻求专业性心理帮助态度的预测因素。方法:选取700名不同年级、不同专业的大学生作样本,进行问卷调查。结果:以寻求专业性心理帮助态度为因变量,进行性别(2)×专业(2)的方差分析。结果发现,性别的主效应显著,F(1,615)=3.294,P=0.050。专业的主效应显著,F(1,615)=20.896,P=0.001。性别和专业的交互效应没达到显著性水平,F(1,615)=1.890,P=0.170。以寻求专业性心理帮助态度为因变量,回归分析结果得出R=0.636,R2=0.405,F=29.641,P=0.001,说明建立的回归方程是有意义的。结论:①对寻求专业性心理帮助态度有显著预测作用的变量按预测作用大小排序依次是:是否求助过、依赖的自我结构、自我隐藏度、专业、内控性和性别。②女生的寻求专业性心理帮助的态度比男生积极。③文体艺术类学生的寻求专业性心理帮助的态度比非文体艺术类学生积极。④自我结构是相互依赖的人寻求专业性心理帮助的态度积极。⑤自我隐藏度高的人寻求专业性心理帮助的态度消极。⑥内控者寻求专业性心理帮助的态度消极。 相似文献
82.
The Topography of Non-Linear Cortical Dynamics at Rest, in Mental Calculation and Moving Shape Perception 总被引:3,自引:0,他引:3
Andreas Meyer-Lindenberg Ulrike Bauer Stefan Krieger Stefanie Lis Kinga Vehmeyer Georg Schüler Bernd Gallhofer 《Brain topography》1998,10(4):291-299
Differential cortical activation by cognitive processing was studied using dimensional complexity, a measure derived from nonlinear dynamics that indicates the degrees of freedom (complexity) of a dynamic system. We examined the EEG of 32 healthy subjects at rest, during a visually presented calculation task, and during a moving shape perception task. As a nonlinear measure of connectivity, the mutual dimension of selected electrode pairs was used. The first Lyapunov coefficient was also calculated. Data were tested for non-linearity using a surrogate data method and compared to spectral EEG measures (power, coherence). Surrogate data testing confirmed the presence of nonlinear structure in the data. Cognitive activation led to a highly significant rise in dimensional complexity. While both tasks activated central, parietal and temporal areas, mental arithmetic showed frontal activation and an activity maximum at T3, while the moving shape task led to occipital activation and a right parietal activity maximum. Analysis of mutual dimension showed activation of a bilateral temporal-right frontal network in calculation. The Lyapunov coefficent showed clear topographic variation, but was not significantly changed by mental tasks (p<.09). While dimensional complexity was almost unrelated to power values, nonlinear (mutual dimension) and linear (coherence) measures of connectivity shared up to 37% of variance. Data are interpreted in terms of increased cortical complexity as a result of recruitment of asynchronously active, distributed neuronal assemblies in cognition. The topography of nonlinear dynamics are related to neuropsychological and neuroimaging findings on mental calculation and moving shape perception. 相似文献
83.
高中学生自我价值感与应对方式、心理健康的相关研究 总被引:27,自引:4,他引:27
卢秀琼 《中国临床心理学杂志》2002,10(3):195-196,194
关于自我价值感的研究已经从概念、结构的探讨进入更为深入的自我价值感水平、发展特点以及与其他心理成分的关系的研究。国内关于自我价值感的相关研究 ,多数是借助国外的自尊量表作为测查工具 ,且仅仅从总体上考察了其他心理因素与自我价值感的相互关系[1-4] 。自我价值感作为应对的资源[5] ,不同自我价值感的人 ,在面对同一压力源时 ,可能有不同的应对反应 ,由此引起不同的情绪感受 ,因此 ,心理健康可能也存在差异。本研究将应用国内专家编制的有关量表 ,并将自我价值感视为一个较稳定的人格变量 ,考察自我价值感与应对方式、心理健康的… 相似文献
84.
Secretory immunoglobulin A and cardiovascular reactions to mental arithmetic, cold pressor, and exercise: effects of alpha-adrenergic blockade 总被引:6,自引:0,他引:6
The mechanism underlying acute changes in secretory immunoglobulin A (sIgA) remains to be determined. In this experiment, sIgA and cardiovascular activity were monitored at rest and while participants performed a mental arithmetic task, cold pressor, and submaximal cycle exercise following placebo or 1 mg of the alpha-adrenergic blocker, doxazosin. Under placebo, the tasks produced patterns of cardiovascular activity indicative of combined alpha- and beta-adrenergic, alpha-adrenergic, and beta-adrenergic activation, respectively. Doxazosin was associated with reduced blood pressure during cold pressor, but not during arithmetic or exercise. Mental arithmetic elicited increases in sIgA concentration and exercise produced increases in both sIgA concentration and secretion rate; these changes were unaffected by alpha blockade. In contrast, the cold pressor was associated with decreases in both sIgA concentration and secretion rate, which were blocked by doxazosin. These data suggest that acute decreases, but not increases, in sIgA are mediated by alpha-adrenergic mechanisms. 相似文献
85.
丁新胜 《中国健康心理学杂志》2005,13(5):359-361
目的 从微观层面探讨归因、自我效能感、教育观念、人格因素对教师心理健康的影响。方法 使用《教师心理健康问卷》和CPSQ人格问卷》进行问卷调查。结果 能力和努力归因对教师心理健康有正向的预测作用;任务难度和运气归因对教师心理健康有负向的预测作用。工作效能和创造效能对教师心理健康都有正向的预测作用。成功教育、挫折教育和主动探索的教育观念对教师的心理健康都是正向的预测作用。神经质分数低的教师出现心理问题的几率不大;趋向于外向、开放、随和以及尽职尽责的教师,心理健康水平较高。结论 归因、自我效能感、教育观念、人格因素对教师心理健康都有程度不同的影响。 相似文献
86.
Dieter Böning Ulrich Tibes Ursula Schweigart 《European journal of applied physiology》1976,35(4):243-249
Summary Red cell concentrations of hemoglobin (MCHC), H+, Na+, K+, Mg++, Cl– were measured in femoral venous blood of six untrained (UT), six endurance trained (TR) and three semitrained (ST) subjects during graded increasing work (4, 8, 12, 18 and 24 mkp/s, 10–15 min on each step) on a bicycle ergometer. Before exercise no significant differences were detected for the measured variables when comparing UT and TR. During exercise MCHC, [Na+], [K+] and [Mg++] remained constant indicating lack of water shift into the erythrocytes in spite of a marked acidosis (lowest pHBlood value 7.225). This lack resulted from an elevated extracellular osmolality. [H+]Ery and [Cl–]Ery maximally increased by 2.0×10–8 eq/kg H2O and 10 meq/l, respectively. The change was markedly greater in UT than in TR at equal load. However, if [H+]Ery and [Cl–]Ery were related to pH of whole blood, differences between groups almost disappeared and the ions were distributed as predictable from in vitro experiments (Fitzsimmons and Sendroy, 1961). Behaviour of H+ and Cl– may be of importance for oxygen dissociation under in vivo conditions.Supported by Bundesinstitut für Sportwissenschaften, Köln 相似文献
87.
目的探讨抑郁障碍患者与家属的家庭亲密度适应性和情绪状况,为抑郁障碍患者的健康教育及家庭干预提供科学有效的理论依据。方法选择2006年6~9月在北京大学第六医院就诊的抑郁障碍患者95例及共同陪伴的直系家属95例为调查对象。采用家庭亲密度和适应性量表中文版(FACES-CV)、Zung氏焦虑自评量表和Zung氏抑郁自评量表。结果1患者的家庭亲密度得分与国内常模一致(P>0.05),但适应性得分低于国内常模(P<0.01);焦虑、抑郁得分高于国内常模(P<0.01)。家属的家庭亲密度得分高于国内常模(P<0.01),适应性得分低于国内常模(P<0.01)。家属的焦虑得分与国内常模一致(P>0.05),但抑郁得分高于国内常模(P<0.05)。2家庭模式分型构成比:中间型47.9%,平衡性26.3%,极端型25.8%。患者的家庭"拱极模式"以"僵硬—松散型"居多,家属则以"自由—缠结型"居多。3家庭亲密度与患者的家属的文程化度有关,相关系数范围(r=0.21~0.26,P<0.05)、与家庭人数呈负相关(r=-0.21,P<0.01);与患者及家属的焦虑、抑郁情绪呈显著负相关,相关系数范围(r=-0.30~0.37,P<0.01);家庭适应性与患者的年龄(r=0.28,P<0.01)、文化程度(r=0.34,P<0.01)有关。与家属的年龄(r=0.26,P<0.05)文化程度(r=0.22,P<0.05)有关。与患者和家属的焦虑、抑郁情绪呈显著负相关,相关系数范围(r=-0.30~-0.42,P<0.01)。结论家庭亲密度适应性与患者和家属的文化程度、焦虑、抑郁情绪有关,家庭亲密度与患者的家庭人数有关,家庭适应性与患者和家属的年龄有关。 相似文献
88.
The effect of physical training on the cutaneous vascular response during transient exercise load is unclear. We determined the phase response and amplitude response of cutaneous vascular conductance (CVC) in the hand during sinusoidal exercise in endurance exercise-trained and untrained subjects. Subjects exercised on a cycle ergometer with a sinusoidal load for 32 min. The load variation ranged from 10% [23 (1) W in the trained group, 19 (1) W in the untrained group] to 60% [137 (4) W, 114 (6) W] of peak O2 uptake, and five different time periods (1, 2, 4, 8, and 16 min) were selected. Skin blood flow in the dorsal hand and palm were monitored by laser-Doppler flowmetry. CVC was evaluated from the ratio of blood flow to mean arterial pressure. During sinusoidal exercise, the amplitude of CVC was smaller in the dorsal hand than palm for shorter periods (1, 2, and 4 min) (P<0.05). The phase lag of CVC was smaller in the dorsal hand than palm for longer periods (8 and 16 min) (P<0.05). The amplitude response did not differ significantly between the two groups. The phase lag of CVC in the dorsal hand (P<0.05) and palm (P=0.06) was larger in the trained group than untrained group. These findings suggest that glabrous and nonglabrous skin vascular responses in the hand differ during transient exercise load, and physically trained subjects show a slower vascular response in the two skin areas to exercise stimulation than do untrained subjects. 相似文献
89.
Older and younger aerobically trained and sedentary adults participated in an S1-S2-S3 paradigm designed to elicit event-related potential (ERP) and behavioral responses to determine the influence of cardiovascular fitness on cognitive and motor processes. The paradigm provided warning (S1) as to the difficulty level of an upcoming decision task (S2). Participants had to decide the taller of two bars on presentation of S2 but hold their response until S3, to which they indicated their choice motorically. Results revealed age-related differences for ERP measures as older participants showed increased amplitude of the stimulus preceding negativity (SPN) prior to S2, and longer latencies and equipotentiality of P3 in response to S2. Fitness effects were also observed for the contingent negative variation (CNV) with decreased amplitude for fit relative to sedentary individuals. Age interacted with fitness for P3 latency to S2 as older sedentary individuals showed the longest latency followed by older fit and both younger groups. No significant group differences were observed for reaction time (RT) to S3. Therefore, physical fitness is associated with attenuation of cognitive decline in older individuals and greater economy of motor preparation for both young and older participants. 相似文献
90.