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91.
根据Thomas-Fermi近似,在基于最小动量态上玻色-爱因斯坦凝聚的前提下,研究了囚禁弱相互作用玻色气体势场的最优化问题.导出了指数吸引势阱中有效势场和粒子数极限判据,粒子数给定时,可由此判据求出所需势场强度;势场强度给定时,可由此判据求出粒子数极限.根据吸引相互作用系统的稳定性以及求出的排斥相互作用的最大粒子数极限,结合有效势场判据,分别给出了囚禁吸引和排斥相互作用玻色气体时,势场强度的最佳取值范围.
关键词:
玻色-爱因斯坦凝聚
弱相互作用
粒子数极限
势场强度 相似文献
92.
Dipl.‐Chem. Alexander Rupp Dr. Nataliya Roznyatovskaya Dr. Harald Scherer Dr. Witali Beichel Petra Klose Carola Sturm Dr. Anke Hoffmann Dr. Jens Tübke Prof. Dr. Thorsten Koslowski Prof. Dr. Ingo Krossing 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9794-9804
Several, partly new, ionic liquids (ILs) containing imidazolium and ammonium cations as well as the medium‐sized [NTf2]? (0.230 nm3; Tf=CF3SO3?) and the large [Al(hfip)4]? (0.581 nm3; hfip=OC(H)(CF3)2) anions were synthesized and characterized. Their temperature‐dependent viscosities and conductivities between 25 and 80 °C showed typical Vogel–Fulcher–Tammann (VFT) behavior. Ion‐specific self‐diffusion constants were measured at room temperature by pulsed‐gradient stimulated‐echo (PGSTE) NMR experiments. In general, self‐diffusion constants of both cations and anions in [Al(hfip)4]?‐based ILs were higher than in [NTf2]?‐based ILs. Ionicities were calculated from self‐diffusion constants and measured bulk conductivities, and showed that [Al(hfip)4]?‐based ILs yield higher ionicities than their [NTf2]? analogues, the former of which reach values of virtually 100 % in some cases.From these observations it was concluded that [Al(hfip)4]?‐based ILs come close to systems without any interactions, and this hypothesis is underlined with a Hirshfeld analysis. Additionally, a robust, modified Marcus theory quantitatively accounted for the differences between the two anions and yielded a minimum of the activation energy for ion movement at an anion diameter of slightly greater than 1 nm, which fits almost perfectly the size of [Al(hfip)4]?. Shallow Coulomb potential wells are responsible for the high mobility of ILs with such anions. 相似文献
93.
Hong‐Jian Wang Paul v. R. Schleyer Judy I. Wu Yan Wang Hai‐Jun Wang 《International journal of quantum chemistry》2011,111(5):1031-1038
The resonance energies (REs) of neutral three membered ring analogs of the cyclopropenyl cation, computed using block localized wave function (BLW) methods, reveal considerable variations. The RE's of cyclopropenes substituted with exocyclic double bonded groups C?X, (X = O, NH, CH2, S, PH, SiH2) increase with the electronegativity of X in the same row (SiH2 < PH < S and CH2 < NH < O). The extra cyclic resonance energies (ECREs) (an energetic measure of aromaticity based on comparisons with the RE's of acyclic models) of these derivatives range from +10.5 kcal/mol for cyclopropenone (X = O) (somewhat aromatic; the benzene ECRE is 29.3 kcal/mol) to ?2.4 kcal/mol (slightly antiaromatic) for X = SiH2. Additional disubstitution of the C?C double bond by X′ groups (X′ = CH3, NH2, OH, SiH3, PH2, SH) increases the REs considerably, but has only small effects on the ECREs. Even the ECRE of deltic acid (X = O, X′ = OH) is only increased to +13.3 kcal/mol. The conclusion based on ECRE's, that all 12 of the three membered rings are only marginally aromatic/antiaromatic, is supported by the satisfactorily plot (R2 = 0.92) of ECRE against values of NICS(0)πzz (a superior nucleus chemical independent shift magnetic index of aromaticity), which range only from ?6.1 ppm (diatropic) for deltic acid (cf., ?35.5 ppm for benzene and ?14.2 ppm for the parent cyclopropenium ion) to +8.9 ppm (paratropic) for the silicon derivative, X = SiH2, X′ = SiH3. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
94.
Weakly R-KKM mappings——intersection theorems and minimax inequalities in topological spaces 总被引:1,自引:0,他引:1
In this paper, we introduce the concepts of weakly R-KKM mappings, R-convex and ,R-β-quasiconvex in general topological spaces without any convex structure. Relating to these, we obtain an extension to general topological spaces of Fan's matching theorem, namely that Lemma 1.2 in this paper. On this basis, two intersection theorems are proved in topological spaces. By using intersection theorems, some minimax inequalities of Ky Fan type are also proved in topological spaces. Our results generalize and improve the corresponding results in the literature. 相似文献
95.
The collision frequencies of electron-neutral-particle in weakly ionized complex plasmas with the non-Maxwellian velocity distributions are studied. The average collision frequencies of electron-neutral-particle in plasmas are accurately derived. We find that these collision frequencies are significantly dependent on the power-law spectral indices of non-Maxwellian distribution functions and so they are generally different from the collision frequencies in plasmas with a Maxwellian velocity distribution, which will affect the transport properties of the charged particles in plasmas. Numerically analyses are made to show the roles of the spectral indices in the average collision frequencies respectively. 相似文献
96.
WU Shuyin 《偏微分方程(英文版)》2011,(2):165-179
In this paper we prove the existence and uniqueness of global weak solutions to the weakly dissipative Camassa-Holm equation. 相似文献
97.
O.A. Shegai V.I. Mashanov H.-H. Cheng O.P. Pchelyakov 《Physica E: Low-dimensional Systems and Nanostructures》2009,42(1):22-24
At low temperatures a lateral photoconductivity (PC) of Ge/Si (1 0 0) self-organized quantum rings (QRs) structures as a function of interband light intensity has been investigated for different values of lateral voltage and temperature. In contrast to self-organized Ge/Si quantum dots (QDs) structures (grown at the same conditions) where the stepped PC was registered, for QRs structures essential smoothing of PC steps was observed. Such behavior is determined by decreasing of strain potential around QRs in conductive Si matrix due to a transfer of Ge atoms from the center of QDs to its periphery accompanied by Ge/Si intermixing. 相似文献
98.
An imaginary potential with universal normalization for dissipative processes in heavy-ion reactions
D. Pereira J. Lubian J.R.B. Oliveira D.P. de Sousa L.C. Chamon 《Physics letters. [Part B]》2009,670(4-5):330-335
In this work we present new coupled channel calculations with the São Paulo potential (SPP) as the bare interaction, and an imaginary potential with system and energy independent normalization that has been developed to take into account dissipative processes in heavy-ion reactions. This imaginary potential is based on high-energy nucleon interaction in nuclear medium. Our theoretical predictions for energies up to ≈100 MeV/nucleon agree very well with the experimental data for the p,n+nucleus, 16O + 27Al, 16O + 60Ni, 58Ni + 124Sn, and weakly bound projectile 7Li + 120Sn systems. 相似文献
99.
S. V. Dmitriev A. A. Nazarov A. I. Potekaev A. I. Pshenichnyuk L. Z. Khadeeva 《Russian Physics Journal》2009,52(2):132-137
Using a biatomic chain of atoms as an example, whose interaction was represented by the Morse potential, we revealed a possibility
for a long-lived, dynamic, long-period, nanosized state to persist in the lattice structure. This nanosized structure (in
the case in question, the length of the spatial period of energy localization was found to be 16–20 nm) is generated under
excitation of a vibrational short-wave mode, with the atoms of the light component only participating. The resulting dynamic
nanostructures are principally different in their nature and characteristics from those described earlier and developed via
a mechanism of modulation instability of short-wave vibrational modes.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 21–26, February, 2009. 相似文献
100.
Hisatoyo Morinaga Hiroshi Morikawa Atsushi Sudo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2010,48(20):4529-4536
A new water‐soluble poly(ethylene imine)‐derivative having imidazolidine moieties was developed. With using branched poly(ethylene imine) (BPEI) as a precursor, it was modified by Michael addition reaction of its primary amino group to an acrylate having poly(ethylene glycol) (PEG) chain. The modified BPEI was reacted with octanal to give the corresponding BPEI derivative having octanal‐derived imidazolidine moieties. The obtained polymer inherited the high hydrophilicity of the attached PEG chains to allow hydrolysis of the imidazolidine moieties under homogeneous conditions in aqueous media, leading to long‐lasting release of octanal. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献