全文获取类型
收费全文 | 2593篇 |
免费 | 296篇 |
国内免费 | 451篇 |
出版年
2023年 | 40篇 |
2022年 | 55篇 |
2021年 | 97篇 |
2020年 | 116篇 |
2019年 | 96篇 |
2018年 | 113篇 |
2017年 | 124篇 |
2016年 | 118篇 |
2015年 | 77篇 |
2014年 | 96篇 |
2013年 | 219篇 |
2012年 | 153篇 |
2011年 | 212篇 |
2010年 | 172篇 |
2009年 | 185篇 |
2008年 | 210篇 |
2007年 | 245篇 |
2006年 | 224篇 |
2005年 | 190篇 |
2004年 | 109篇 |
2003年 | 90篇 |
2002年 | 57篇 |
2001年 | 37篇 |
2000年 | 37篇 |
1999年 | 33篇 |
1998年 | 30篇 |
1997年 | 21篇 |
1996年 | 24篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 16篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1971年 | 6篇 |
1968年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有3340条查询结果,搜索用时 31 毫秒
241.
The present study aims to explore the influence of emotional context on word evaluation. Participants were asked to read an “adjective + noun” phrase, where the adjective could be a positive or negative word, and the noun could be a positive, neutral or negative word, and then to make an emotional evaluation on the emotional tone of the target noun based on a 9-point Likert scale. In a control condition, an isolated noun was presented with no context. Results showed that positive context made the evaluation of target words bias toward positive tone, while negative context shaped the evaluation of target words toward negative tone. The modulatory effect of negative context was greater than that of positive context in shaping evaluation of emotional words with opposite valence. Moreover, the modulatory effect of emotional context was constrained by the inherent meaning of target word. The present study demonstrated the flexibility as well as the relative stability of emotional meaning of word. 相似文献
242.
Sandra S. Liu Lucette B. Comer Alan J. Dubinsky 《Journal of Personal Selling & Sales Management》2013,33(4):303-311
The present study promulgates a research stream in the area of understanding women's position in the management of the Chinese sales force. The study investigates attitudes toward women as sales managers held by Chinese salespeople. Male salespeople consistently rated the female sales managers lower than did female salespeople on three sets of attitude items. This finding indicates the presence of male resistance to women in sales management positions. 相似文献
243.
244.
Gail A. Wasserman Pam Factor-Litvak Xinhua Liu Andrew C. Todd Jennie K. Kline Vesna Slavkovich 《Child neuropsychology》2013,19(1):22-34
We report associations between serial measures of blood lead and intelligence in children age 10–12 years, half heavily exposed to lead from the prenatal period onward, and half relatively unexposed. For a subsample, we examine bone lead-IQ associations, comparing them with blood lead associations. Both blood and bone lead levels were associated with intelligence decrements, small relative to the contribution of social factors. For each doubling of Tib-Pb, Full Scale, Performance, and Verbal IQ decreased by an estimated 5.5, 6.2, and 4.1 points, respectively. Bone lead-IQ associations were stronger than those for blood lead, which nonetheless provide robust analogues. Current BPb, easy to obtain, provides a useful means for assessing Pb exposure/IQ associations. 相似文献
245.
HaiYing Wu YaHong Chen XinFang Su ChengRong Deng Zi-Jiang Liu 《Philosophical Magazine Letters》2013,93(4):198-204
A phase transition of MgS under high pressure is investigated using a first-principles method. It is found from energy-volume calculations that the rock-salt (B1) phase of MgS transforms into a FeSi-type (B28) phase at 143?GPa. The calculated ground-state parameters in the B1 phase are in excellent agreement with available experimental and theoretical data. Ab initio phonon calculations are also performed to investigate the structural behaviour of MgS under high pressure. An unstable transverse acoustic mode and a phase transition from B1 to B28 phase at ~143.7?GPa driven by this soft mode are predicted. The B28 structure of MgS is stable up to 350?GPa according to lattice dynamics calculations. 相似文献
246.
In this study, (Gd1? x Nd x )2(Zr1? x Ce x )2O7 (0 ≤ x ≤ 0.5) ceramics have been prepared by pressureless sintering at 1973 K to investigate the influence of Nd and Ce co-doping on their electrical conductivity. The electrical conductivity of the ceramics was investigated by impedance spectroscopy measurements from 723 to 1173 K over the frequency range of 20 Hz to 2 MHz in air. The measured values obey the Arrhenius relation. For each composition, the grain conductivity gradually increases with increasing temperature from 723 to 1173 K. At a given temperature, it gradually decreases with increasing neodymium and cerium contents from x = 0 to 0.3; thereafter, the grain conductivity exhibits a slight increase with further increasing neodymium and cerium contents up to x = 0.5. 相似文献
247.
The effect of chemical stresses upon the relation between extended dislocations and high-temperature creep in a thin plate has been investigated. The critical stress needed for the contraction of extended jogs and its effect on the creep rate are obtained. The results indicate that the critical stress needed for the contraction increases with decreasing stacking fault energy (SFE). However, creep occurs more easily with increasing SFE and increasing angle of the Burgers vector to the dislocation line, as well as with the concentration of any diffusing atoms. 相似文献
248.
C. P. Chang 《Philosophical Magazine Letters》2013,93(5):249-250
Abstract Chaki (1988) has recently proposed a model for diffusion-induced grain boundary migration (DIGM). In his Letter he concluded that the interface energy of a grain boundary and the free energy of mixing are responsible for DIGM and, from the equations he derived, it was claimed that they can explain many DIGM experimental results. However, on examining his model closely there appear to be some fundamental difficulties. The following are comments on his Letter: (1) In Chaki's calculation of ΔGs he assumed that, after interface 1 had moved a distance δx, the radius of curvature of this interface increased from R to R + δx, which gives a surface energy drop of 2γVm δx/R2. However from many DIGM observations (for example Balluffi and Cahn (1981)) the curvature of a migrating boundary is increased rather then decreased, that is, the surface free- energy term actually prevents a grain boundary from migrating rather than helping it! (2) Chaki considered ΔGcryst during the migration of interface 2. It is also necessary to consider AGcrys, during the migration of interface 1, since within the migration distance δx the structure is changed from a crystalline structure to a grain boundary core structure. ΔGm should also be considered during the migration of interface 2 since the concentration of the area swept by interface 2 will not be the same as that of a grain boundary core. 相似文献
249.
Y. Wang S.L. Shang H. Zhang L.-Q. Chen Z.-K. Liu 《Philosophical Magazine Letters》2013,93(12):851-859
To understand the Invar anomalies, such as negative thermal expansion and spontaneous magnetization, we have applied our recently developed thermodynamic framework for a system with itinerant-electron magnetism to the ordered Fe3Pt. The framework has coherently predicted the finite temperature intermixing between the fully ferromagnetic (FM) configuration and the spin-flipping configurations (SFCs). We have also discovered a tri-critical point at which a high-temperature second-order phase transition, between the fully ordered FM phase and the paramagnetic phase which is disordered due to SFCs, becomes first order at low temperatures. 相似文献
250.