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21.
1991MRSubjectionClassification81R05,20C351IntroductionIiiapreviouspaper['].wit11avediscussedhowtoconstructthewavefllucti()llsofL-S(\011piing,single-lferlllionsystelll.Alldthecoefficientsoffi.actiollalparentage(CFP)withfixs(1seniorityharebeedcalclllatedbyarecurrentformula.Practically,withthe11alpoftileoperatorsofferrxlionpairsthegeneralwavefunctionsofmanyfermionswithsixlgle-lcouldbeobtainedfi.omthewavefullctionswithoutfermionpairs.Asaresult,therecurrentforlllulaofdeterrxliningCFPissimplif…  相似文献   
22.
Molecular mutagens and carcinogens are structures which carry chemical and electronic properties that disturb and interact with the genomic machinery. Principally, a rule of thumb for carcinogens is that carcinogens are expected to introduce covalent irreversible bonding to one or several types of DNA bases, causing errors in the reading frame for the polymerases. 8‐methoxy‐6‐nitrophenanthro[3,4‐d][1,3]dioxole‐5‐carboxylic acid, better known as Aristolochic acid (AA1) is a recognized carcinogen which causes urotherial cancer and is found in certain plants. Its structure is particularly interesting given that it is closely related to phenanthrene in its polycyclic arrangement, and has four functional groups, a carboxyl‐, a nitro‐, a methoxy‐ and a dioxolane group. In this work, the structure of AA1 has been resolved at the MPWPW91 density functional theory method in combination with Aug‐cc‐pVDZ basis sets. A geometry analysis shows that in AA1 the carboxyl group's torsion is caused by steric strain from the nitro group, which elevates the molecular plane of the first phenanthrene ring with 0.1Å. The wavefunction analysis of AA1 shows that the ring deformation enhances a double π‐bond localization in the first ring, adjacent to the dioxalane group, and results in a decrease of ring aromaticity and induces a potentially frozen resonance. Intermolecular and intramolecular interactions were characterized by atoms in molecules and reduced density gradient analysis. This study brings novel information on the geometry and electronic structure of AA1, which are important for the further knowledge of its transformation in vivo and in situ. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
23.
贾多杰 《中国物理 C》2008,32(7):509-514
It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-II superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].  相似文献   
24.
通过把坡密子与观察到的量子数为 IGJPC=0+2++的同位旋张量介子联系起来的思想, 研究了坡密子的胶子内涵。 有4个由胶子组成的这样的介子都满足坡密子自旋与质量的关系。 这些坡密子的候选者可能是混杂态。 它们其中之一 f2(2 220)介子可能包含着最大的胶子球成分。 阐明了实验上还不清楚的关于这个介子宽度的问题, 并给出了它的理论下限。 也说明为什么这个介子没有在p实验中发现的原因。 We study the gluonic content of the Pomeron through relating the Pomeron trajectory to the observed IGJPC=0+2++ isoscalar tensor mesons. Four of these mesons satisfy the spin mass relation of the Pomeron. These Pomeronian candidates may be hybrid states. One of them, the f2(2 220) meson, can have a predominant glueball component. We address the unsettled experimental situation about the width of this meson and give a theoretical lower bound for it. We also show why this meson has not been seen in p experiments.  相似文献   
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26.
The concept of resonance-assisted hydrogen bonds(RAHBs)highlights the synergistic interplay between theπ-resonance and hydrogen bonding interactions.This concept has been well-accepted in academia and is widely used in practice.However,it has been argued that the seemingly enhanced intramolecular hydrogen bonding(IMHB)in unsaturated compounds may simply be a result of the constraints imposed by theσ-skeleton framework.Thus,it is crucial to estimate the strength of IMHBs.In this work,we used two approaches to probe the resonance effect and estimate the strength of the IMHBs in the two exemplary cases of the enol forms of acetylacetone and o-hydroxyacetophenone.One approach is the block-localized wavefunction(BLW)method,which is a variant of the ab initio valence bond(VB)theory.Using this approach,it is possible to derive the geometries and energetics with resonance shut down.The other approach is Edmiston’s truncated localized molecular orbital(TLMO)technique,which monitors the energy changes by removing the delocalization tails from localized molecular orbitals.The integrated BLW and TLMO studies confirmed that the hydrogen bonding in these two molecules is indeed enhanced byπ-resonance,and that this enhancement is not a result ofσconstraints.  相似文献   
27.
Within the framework of the complex basis function method, the photoionization cross sections of H(2)(+) and H(2) were calculated based on the variational principle for the frequency-dependent polarizabilities. In these calculations, complex orbital exponents of Gaussian-type basis functions for the final state continuum wavefunctions were fully optimized for each photon energy with the numerical Newton-Raphson method. In most cases, the use of only one or two complex Gaussian-type basis functions was enough to obtain excellent agreement with previous high precision calculations and available experimental results. However, there were a few cases, in which the use of complex basis functions having various angular momentum quantum numbers was crucial to obtain the accurate results. The behavior of the complex orbital exponents as a function of photon energy was discussed in relation to the scaling relation and the effective charge for photoelectron. The success of this method implies the effectiveness of the optimization of orbital exponents to reduce the number of basis functions and shows the possibility to calculate photoionization cross sections of general molecules using only Gaussian-type basis functions.  相似文献   
28.
讨论了高能强子 -强子散射过程中的坡密子以及坡密子的 QCD内容 .认为坡密子有可能就是具有量子数 IG=0 + ,JPC=2 + +的张量胶子球 ξ( 2 2 30 ) .用雷其化胶子球模型计算了高能质子 -质子散射截面和坡密子 -核子的耦合参数 β.理论结果与实验的要求一致. The pomeron in high energy hadron hadron scattering as well as the QCD nature of the pomeron are discussed. We claimed that the pomeron may be the tenser glueball ξ(2 230) with quantum number I G =0 +, J PC =2 ++ . Under this reggeized glueball model the cross section of high energy proton proton scattering and the coupling parameter of the pomeron nucleon, β , are calculated. The theoretical results of the present model are in good agreement with experimental data.  相似文献   
29.
We try to develop a possibly more efficient way for extracting the wavefunction and spectroscopy of pure QCD from discretized Hamiltonian field theory. By further exploring the eigenvalue equation method for solving the Schrödinger equation, we find that within thb approach a more suitable choice of the glueball operators can lead to significantly much better results, therefore more rapid convergence to the continuum limit. This is nicely demonstrated in the three-dimensional example.  相似文献   
30.
By successively taking into account various interactions for d2 ions in trigonally distorted cubic crystal fields, detailed analyses, derivations and calculations of the zero-field splitting (ZFS) and g factors of the ground state have been carried out; and their physical essentials and origins have been clearly revealed. The mistakes and shortcomings in some references have been corrected and improved. The calculated results are in excellent agreement with experimental data and much better than those of previous work. It is found that both the combined action of the trigonal field and spin-orbit interaction and the interaction between the ground state and excited states are quite necessary for causing ZFS of the ground state, and both the spin-orbit interaction and the admixture between the ground state and excited states are necessary for causing the deviation of g factors of the ground state from spin-only values.  相似文献   
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