首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   226篇
  免费   0篇
  国内免费   1篇
化学   132篇
晶体学   1篇
力学   1篇
数学   11篇
物理学   82篇
  2023年   4篇
  2022年   2篇
  2021年   4篇
  2020年   7篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2015年   5篇
  2014年   6篇
  2013年   10篇
  2012年   11篇
  2011年   16篇
  2010年   7篇
  2009年   13篇
  2008年   15篇
  2007年   19篇
  2006年   18篇
  2005年   20篇
  2004年   20篇
  2003年   11篇
  2002年   9篇
  2001年   9篇
  2000年   11篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1988年   1篇
排序方式: 共有227条查询结果,搜索用时 31 毫秒
61.
Taiki Takahashi 《Physica A》2007,385(2):637-644
Impulsivity and inconsistency in intertemporal choice (discounting) have drawn attention in econophysics and neuroeconomics. Although it is well established that most people often show irrational discounting (e.g., hyperbolic discounting), little is known regarding whether the irrationality is mitigated or not, when the choice was performed by someone else instead of subject herself. This point is important for economic policy-making. In order to compare consistency and impulsivity in choices for oneself versus someone else, we experimentally estimated the consistency parameter q in Tsallis’ statistics-based discount function for oneself and someone else, by assessing the points of subjective equality (indifference points) at 7 delays (1 week to 25 years) in humans. We observed that (i) most people are more inconsistent when the outcomes of intertemporal choice are only relevant to someone else (q=−8.89) than when relevant to oneself (q=−2.63), and (ii) impulsivity, distinguished from inconsistency by utilizing the Tsallis statistics-based q-exponential discount function, is also larger in the choice for someone else than for oneself. Our results indicate that (i) leaving decision-making processes with some others may neither reduce impulsivity nor correct inconsistency and (ii) when q-exponential discounting is utilized, the definition range of q-parameter should be extended to q<0, and smaller (q<1) and larger (q>1) values indicate more inconsistent discounting. Together, the usefulness of the q-exponential discounting for analyzing the dynamic consistency of economic policy was demonstrated in the present study.  相似文献   
62.
Superradiant light scattering from noncondensed, thermal atomic vapors was experimentally studied. We found that superradiant gain is independent of quantum degeneracy and determined only by the shape of the atomic cloud and a contained number of atoms. Superradiant pump-probe spectroscopy was also developed to measure the atomic correlation function, revealing the Doppler-width-limited coherence time of the thermal gas and sudden buildup of long-lived coherence below the transition temperature.  相似文献   
63.
Energy-storable dye-sensitized solar cell with a polypyrrole electrode   总被引:2,自引:0,他引:2  
A three-electrode-type solar-rechargeable battery, energy-storable dye-sensitized solar cell (ES-DSSC), has been constructed by the hybridization of a typical Gratzel cell and a conducting polymer charge-storage electrode; efficient photo-charging can be accomplished by visible-light irradiation.  相似文献   
64.
A local probing technique of cyclotron emission is applied to image nonequilibrium electrons generated along edge channels in quantum Hall conductors. In a lower-magnetic field region of a quantum Hall state plateau (filling factor 2相似文献   
65.
57Fe Mössbauer spectra were measured of reaction products formed during an incubation experiment with sulfate-reducing bacteria, which were isolated from estuarine sediments of the Tama River in Tokyo. The spectrum of the product incubated for several days showed some overlapping sextets. This product had a different chemical form from amorphous iron monosulfide produced by inorganic reaction between ferrous and sulfide ions. It was estimated that the structure of nearest neighbor of iron in this product was similar to that of pyrrhotite (Fe1?x S). After several months of incubation, other singlet and doublet appeared successively on the spectrum, corresponding to mackinawite (FeS1?x ) and new sulfide, respectively. Both values of isomer shift and quadrupole splitting of new sulfide increased with increasing incubation time and approached those of pyrite (FeS2). Extended X-ray absorption fine structure (EXAFS) showed that iron atoms were coordinated by sulfur in the incubation product.  相似文献   
66.
The nonadiabatic entropy production is a useful tool for the thermodynamic analysis of continuously dissipating, nonequilibrium steady states. For open quantum systems, two seemingly distinct definitions for the nonadiabatic entropy production have appeared in the literature, one based on the quantum relative entropy and the other based on quantum trajectories. We show that these two formulations are equivalent. Furthermore, this equivalence leads us to a proof of the monotonicity of the quantum relative entropy under a special class of completely-positive, trace-preserving quantum maps, which circumvents difficulties associated with the noncommuntative structure of operators.  相似文献   
67.
A chiral charge-transfer (CT) complex was formed using achiral 9,10-bis(3,5-dihydroxyphenyl)anthracene (BDHA) as an electron donor and achiral 1,1′-dimethyl-4,4′-bipyridinium dichloride (MVCl2) as an electron acceptor. This chiral CT complex can include n-alkyl alcohol molecules as guests. On the other hand, when 1,1′-diphenyl-4,4′-bipyridinium dichloride and 1,1′-dibenzyl-4,4′-bipyridinium dichloride were used as electron acceptors, achiral CT complexes without guests were formed. It was found that the chiral crystallisation of the BDHA/MVCl2–CT host system was caused by steric and electric intermolecular interactions between host component molecules BDHA and MVCl2 during crystallisation.  相似文献   
68.
A tunable supramolecular phenylacetylene host system with a chiral channel-like cavity is developed by using (1R,2S)-2-amino-1,2-diphenylethanol. This host system possesses a chiral 21-helical columnar structure; chiral cavities are constructed by the self-assembly of the 21-helical column, and guest molecules are included by varying the packing of this column.  相似文献   
69.
Although most fulgides show their photochromism in the solid state, crystal structure changes accompanying the photochromism have not been previously observed. The photochromic reactions have been so far considered to take place on surfaces or at defects of the crystals or to proceed with destruction of the crystals. In this study we have succeeded in observing crystal structure changes accompanying the photochromism of fulgides using X-ray diffraction analysis. Detection of the photoproducts in the crystal structures was not possible when the single crystals of the fulgides were irradiated with steady UV light. Two-photon excitation by pulsed laser light was essential to produce a sufficient amount of the photoproducts without significant deterioration in the quality of the crystals.  相似文献   
70.
Rotational spectra of an open-shell complex, Ar-NO, in the electronic ground state have been analyzed by employing an analysis using a free-rotor model, where previously observed data by Mills et al. [J. Phys. Chem. 90, 3331 (1986); 90, 4961 (1986)] and additional transitions observed by Fourier-transform microwave spectroscopy in the present study are simultaneously analyzed with a standard deviation of the least-squares fit to be 27.5 kHz. A two-dimensional intermolecular potential energy surface for Ar-NO has been determined from the analysis. The determined potential energy surface is compared with those of Ar-OH and Ar-SH, which are also complexes containing an open-shell species with the 2Pi ground electronic state.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号