全文获取类型
收费全文 | 379篇 |
免费 | 10篇 |
专业分类
化学 | 288篇 |
晶体学 | 4篇 |
力学 | 3篇 |
数学 | 9篇 |
物理学 | 85篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 14篇 |
2012年 | 9篇 |
2011年 | 24篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 22篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 16篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1974年 | 2篇 |
1970年 | 3篇 |
1968年 | 3篇 |
1961年 | 1篇 |
排序方式: 共有389条查询结果,搜索用时 15 毫秒
121.
122.
Arumugam S Môri N Takeshita N Takashima H Noda T Eisaki H Uchida S 《Physical review letters》2002,88(24):247001
We have investigated the pressure effect on T(c) and the Hall coefficient in the static stripe-ordered phase of La(1.48)Nd(0.4)Sr(0.12)CuO(4) crystal under hydrostatic pressure. We found a dramatic change of the Hall coefficient and an abrupt increase of T(c) at low pressure of about 0.1 GPa. The results are indicative of a transition from one- to two-dimensional charge transport, associated with the suppression of low-temperature-tetragonal (LTT) phase. From the uniaxial pressure measurements it turns out that the observed critical change is induced primarily due to the in-plane compression of the CuO(2) planes which would make the pinning potential of the LTT lattice distortions weaker. 相似文献
123.
Human body is charged during walking. Continuous monitoring of the body potential has been made using an induction electrode set on ceiling of a room. The body voltage estimated from the induced voltage was a few hundred volts and dependent on material of shoes, as expected. The induced voltage varied periodically while walking and the waveform was different depending on examinees or manner of walking, even the same footwear was used. In this study, spectrum analysis was made on the acquired voltage, and frequency component was compared. The voltage spectrum of 4 different persons, and 3 different walking patterns of one person were obtained, and their correlation was compared. The results indicate that the spectrum was different depending on the examinees. Among the tested 4 examinees, personal identification was possible using the correlation of the induced voltage while walking. This novel contactless body potential monitoring method can be applied to many new fields such as medical practice and food factory. 相似文献
124.
Masanao Ozawa 《Foundations of Physics》2011,41(3):592-607
The recently established universal uncertainty principle revealed that two nowhere commuting observables can be measured simultaneously
in some state, whereas they have no joint probability distribution in any state. Thus, one measuring apparatus can simultaneously
measure two observables that have no simultaneous reality. In order to reconcile this discrepancy, an approach based on quantum
logic is proposed to establish the relation between quantum reality and measurement. We provide a language speaking of values
of observables independent of measurement based on quantum logic and we construct in this language the state-dependent notions
of joint determinateness, value identity, and simultaneous measurability. This naturally provides a contextual interpretation,
in which we can safely claim such a statement that one measuring apparatus measures one observable in one context and simultaneously
it measures another nowhere commuting observable in another incompatible context. 相似文献
125.
126.
The chain length dependence involving a chiral memory effect of 2,6-pyridylene ethynylene oligomers ‘meta-ethynylpyridines’ was investigated. The meta-ethynylpyridine oligomers associated with octyl β-d-glucopyranoside form a helical complex giving induced CD; the induced chirality could be memorized with the help of Cu(OTf)2 as an additive. Contrary to our expectations, the study of the length dependence revealed that the 12-meric oligomer showed a more sustainable chiral memory effect than those observed in both of the shorter 6-meric and longer 18-meric oligomers. 相似文献
127.
Masaki Takashima 《Fluid Dynamics Research》1996,17(6):293-310
The stability against small disturbances of the pressure-driven plane laminar motion of an electrically conducting fluid under a transverse magnetic field is investigated. Assuming that the outer regions adjacent to the fluid layer are electrically non-conducting and not ferromagnetic, the appropriate boundary conditions on the magnetic field perturbations are presented. The Chebyshev collocation method is adopted to obtain the eigenvalue equation, which is then solved numerically. The critical Reynolds number Rc, the critical wave number αc, and the critical wave speed cc are obtained for wide ranges of the magnetic Prandtl number Pm and the Hartmann number M. It is found that except for the case when Pm is sufficiently small, the magnetic field has both stabilizing and destabilizing effects on the fluid flow, and that for a fixed value of M the fluid flow becomes more unstable as Pm increases. 相似文献
128.
T. Shimoda K. Tajiri K. Kura A. Odahara M. Suga Y. Hirayama N. Imai H. Miyatake M. Pearson C. D. P. Levy K. P. Jackson R. Legillon C. Petrache T. Fukuchi N. Hamatani T. Hori M. Kazato Y. Kenmoku T. Masue H. Nishibata T. Suzuki A. Takashima R. Yokoyama 《Hyperfine Interactions》2014,225(1-3):183-191
Spin-polarized radioactive nuclear beams at TRIUMF enable a new spectroscopic method which efficiently assigns spins and parities of the daughter levels by taking advantage of the asymmetric β-decay of the polarized parent nucleus. This method was successfully applied to structure studies of 29Mg and 30Mg in connection with the physics of the “island of inversion”. In 29Mg, two low-lying levels with intruder configuration were assigned. In 30Mg, coexistence of spherical shape, prolate shape and γ-collectivity was strongly suggested. 相似文献
129.
Shuichi Shimma Yuki Takashima Jun Hashimoto Kan Yonemori Kenji Tamura Akinobu Hamada 《Journal of mass spectrometry : JMS》2013,48(12):1285-1290
Mass spectrometry (MS) was used to measure the concentrations of drug and biological compounds in plasma and tissues. Matrix‐assisted laser desorption/ionization (MALDI) imaging MS (IMS) has recently been applied to the analysis of localized drugs on biological tissue surfaces. In MALDI‐IMS, matrix application process is crucial for successful results. However, it is difficult to obtain homogeneous matrix crystals on the tissue surface due to endogenous salts and tissue surface heterogeneity. Consequently, the non‐uniform crystals degrade the quality of the spectrum and likely cause surface imaging artifacts. Furthermore, the direct application of matrix solution can cause tissue shrinkage due to the organic solvents. Here, we report an alternative two‐step matrix application protocol which combines the vacuum deposition of matrix crystals and the spraying of matrix solution to produce a homogeneous matrix layer on the tissue surface. Our proposed technique can also prevent cracking or shrinking of the tissue samples and improve the ionization efficiency of the distributed exogenous material. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
130.
Herein macromolecular recognition by cyclodextrins (CDs) is summarized. Recognition of macromolecules by CDs is classified as main‐chain recognition or side‐chain recognition. We found that CDs form inclusion complexes with various polymers with high selectivity. Polyrotaxanes in which many CDs are entrapped in a polymer chain were prepared. Tubular polymers were prepared from the polyrotaxanes. CDs were found to recognize side‐chains of polymers selectively. CD host polymers were found to form gels with guest polymers in water. These gels showed self‐healing properties. When azobenzene was used as a guest, the gel showed sol‐gel transition by photoirradiation. When ferrocene was used, redox‐responsive gels were obtained. Macroscopic self‐assembly through molecular recognition has been discovered. Photoswitchable gel association and dissociation have been observed. 相似文献