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191.
Wenhe Du Jingxuan Yang Zhongmin Yao Junguo Lu Daosen Liu Quanling Cui 《Journal of Russian Laser Research》2014,35(4):416-423
Both increasing experimental evidence and some results of theoretical investigation have shown that there exist two kinds of turbulence in the aerosphere, Kolmogorov and non-Kolmogorov turbulence. Thus, it is necessary to improve the theory of optical wave propagation through atmospheric turbulence, namely, study the laser-beam propagation in non-Kolmogorov turbulence, before analyzing the joint influence of the Kolmogorov turbulence and non-Kolmogorov one on satellite laser communication. The beam wander will lead to the performance degradation of satellite laser communication systems and exert an influence on the achievement and stability of its links. In this paper, we consider a theoretical power spectrum of refractive-index fluctuations with a generalized power law in order to derive the variance of Gaussian-beam wave wander in weak turbulence for a horizonal path and analyze the influence of spectral power-law variations on the beam wander. We show that the expression for the beam-wander variance is of concise closed form and independent of the optical wavelength. 相似文献
192.
This paper proposes a novel method to obtain frequency modulation (FM) signals from a single fringe pattern for phase retrieval. First, a 1D discrete Meyer wavelet is employed to decompose the pattern image signal row by row and the soft-thresholding approach is applied to remove noise. The low frequency coefficients of the wavelet decomposition are then set to 0, and the signal is reconstructed. Moreover, the optimal wavelet decomposition level is adaptively determined using a cost function-based method. The reconstructed signal, which no longer contains a background component, is normalized using a nonlinear and piecewise normalization method. The proposed method is faster and more accurate than some other phase retrieval approaches, which is illustrated with two test cases. 相似文献
193.
Lisa M. Jones Hao Zhang Weidong Cui Sandeep Kumar Justin B. Sperry James A. Carroll Michael L. Gross 《Journal of the American Society for Mass Spectrometry》2013,24(6):835-845
As therapeutic monoclonal antibodies (mAbs) become a major focus in biotechnology and a source of the next-generation drugs, new analytical methods or combination methods are needed for monitoring changes in higher order structure and effects of post-translational modifications. The complexity of these molecules and their vulnerability to structural change provide a serious challenge. We describe here the use of complementary mass spectrometry methods that not only characterize mutant mAbs but also may provide a general framework for characterizing higher order structure of other protein therapeutics and biosimilars. To frame the challenge, we selected members of the IgG2 subclass that have distinct disulfide isomeric structures as a model to evaluate an overall approach that uses ion mobility, top-down MS sequencing, and protein footprinting in the form of fast photochemical oxidation of proteins (FPOP). These three methods are rapid, sensitive, respond to subtle changes in conformation of Cys?→?Ser mutants of an IgG2, each representing a single disulfide isoform, and may be used in series to probe higher order structure. The outcome suggests that this approach of using various methods in combination can assist the development and quality control of protein therapeutics. 相似文献
194.
W. Chen X. L. Xu P. Zhou Y. M. Cui Y. G. Li 《Russian Journal of Coordination Chemistry》2013,39(3):301-304
Two silver(I) compounds, [Ag(R,R-hxn)](C7H4BrO2) · 2H2O (I) (Chxn = 1,2-diaminocyclohexane) and [Ag(C5H6N2)2]2(C8H4O4) · 10H2O (II), were synthesized and complex I was structurally characterized by X-ray crystallography. Compound I contains a catena-(trans-1,2-diaminocyclohexane) silver polycation ([Ag(Chxn)]∞) in a roughly linear fashion, while II possesses a linear-type silver monocation. Compounds I and II were evaluated for their inhibitory activities against Helicobacter pylori urease in vitro. Both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid. 相似文献
195.
Anatoli Tchigvintsev Dmitri Tchigvintsev Robert Flick Ana Popovic Aiping Dong Xiaohui Xu Greg Brown Wenyun Lu Hong Wu Hong Cui Ludmila Dombrowski Jeong Chan Joo Natalia Beloglazova Jinrong Min Alexei Savchenko Amy A. Caudy Joshua D. Rabinowitz Alexey G. Murzin Alexander F. Yakunin 《Chemistry & biology》2013,20(11):1386-1398
196.
197.
Hierarchical ZSM-11 with intergrowth structures:Synthesis,characterization and catalytic properties 总被引:1,自引:0,他引:1
Qingjun Yu Chaoyue Cui Qiang Zhang Jing Chen Yang Li Jinpeng Sun Chunyi Li Qiukai Cui Chaohe Yang Honghong Shan 《天然气化学杂志》2013,(5):761-768
Hierarchical ZSM-11 microspheres with intercrystalline mesoporous properties and rod-like crystals intergrowth morphology have been synthesized using a spot of tetrabutylammonium as a single template.XRD,FTIR,SEM,TEM and N2 adsorption analysis revealed that each individual particle was composed of nanosized rod crystals inserting each other and the intercrystalline voids existing among rods gave a significant mesopore size distribution.Steam treatment result demonstrated the excellent hydrothermal stability of samples.Various crystallization modes including constant temperature crystallization (one-stage crystallization) and two-stage temperature-varying crystallization with different 1st stage durations were investigated.The results suggested that the crystallization modes were mainly responsible for the adjustable particle size and textural properties of samples while the small amount of tetrabutylammonium bromide was mainly used to direct the formation of both ZSM-11 framework and its intergrowth morphology.Furthermore,the performance of optimal ZSM-11 as an active component for the catalytic pyrolysis of heavy oil was also investigated.Compared with the commercial pyrolysis catalyst,the hierarchical ZSM-11 catalyst exhibited a high selectivity to desired products(LPG+gasoline+diesel),as well as a much lower dry gas and coke yield,plus a high selectivity and yield of light olefins(C=3 C=4)and very poor selectivity to benzene.Therefore,fully open micropore-mesopore connectivity would make such hierarchically porous ZSM-11 zeolites very attractive for applications in clean petrochemical catalysis field. 相似文献
198.
Chunlei Wang Shuhong Xu Yujie Shao Zhuyuan Wang Yiping Cui 《Journal of Cluster Science》2013,24(2):439-447
In this paper, conformations of the ternary structures ZnSe(Te), ZnS(Te), ZnS(Se), CdSe(Te), CdS(Te) and CdS(Se) were optimized, and their orbital, spectra have been investigated at the B3LYP/LANL2DZ level. First, we have found some rules which agreed with experimental results. HOMO–LUMO gaps, WBI values and the wavelengths of the absorption peaks of ternary structures changed gradually with the ratio of Te, Se and S atoms in ternary structures. Second, analysis of Raman spectra revealed that doped structures had the spectra of two relevant binary clusters. Namely, Raman spectra of ternary ZnSe(Te) clusters had the Raman peaks of ZnSe and ZnTe. In this way, with the help of the Raman spectra, the formations of the ternary structures can be determined in experiment. This was important to estimate during synthesis progress. Finally, calculated results have proved that ZnS and CdS structures had the shorter wavelengths of the absorption peaks, the higher excited energies of singlets, and good stability. 相似文献
199.
The B3LYP/6-31G** method was used to investigate IR and Raman spectra, heat of formation, and thermodynamic properties of a new designed polynitro cage compound 1,3,5,7,9,11-hexanitrotetradecahydro-1H-1,3,4,5,7,7b,9,11,12a,12b1,12b2,13-dodecaaza-4,8,12-(epimethanetriyl)cyclohepta[l]cyclopenta[def]phenanthrene. The detonation and pressure were evaluated using the Kamlet–Jacobs equations based on the theoretical density and HOFs. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that N8–NO2 bond is predicted to be the trigger bond during pyrolysis. There exists an essentially linear relationship between the WBIs of N–NO2 bonds and the charges – $ Q_{{{\text{NO}}_{ 2} }} $ on the nitro groups. The crystal structure obtained by molecular mechanics belongs to the P21 space group, with lattice parameters Z = 2, a = 11.4658 Å, b = 15.2442 Å, c = 10.2451 Å, ρ = 2.07 g cm?3. The designed compound has high thermal stability and good detonation properties and is a promising high-energy density compound. 相似文献
200.