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141.
142.
143.
Marin Coldea Natalia Dihoiu Iuliu Pop 《Journal of Physics and Chemistry of Solids》1981,42(7):563-565
27Al Knight shifts vs temperature and magnetic susceptibility for the intermetallic compounds Gd2Ni17?xAlx (x = 17; 16.2; 16; 15) are presented. The results are discussed in terms of the uniform polarization model fo the conduction electrons by the 4f and 3d spins localized on the Gd and Ni ions. The phenomenological exchange constants Jsf and Jsd range between ?1.80×10?3 and 1.19×10?3 eV and ?0.63×10?3 and ?0.52×10?3 eV, respectively. 相似文献
144.
Pabla?Aguirre Natalia?Mena Victoria?Tapia Miguel?Arredondo Marco?T?Nú?ezEmail author 《BMC neuroscience》2005,6(1):3
Background
Iron is necessary for neuronal function but in excess generates neurodegeneration. Although most of the components of the iron homeostasis machinery have been described in neurons, little is known about the particulars of their iron homeostasis. In this work we characterized the response of SH-SY5Y neuroblastoma cells and hippocampal neurons to a model of progressive iron accumulation. 相似文献145.
Rostislav?E.?MaiborodaEmail author Natalia?M.?Markovich 《Computational Statistics》2004,19(4):569-592
Summary Common non-parametric estimators of a probability density function (PDF) show bad performance for heavy-tailed PDFs. Using
a parametric approximation of the true cumulative distribution function (CDF), the transformation-retransformation of the
data is explored here as a useful tool for the reliable PDF prediction. The PDF estimators are compared by their capacity
to solve a classification problem. Simulation results and an application to Web data analysis are presented, too. 相似文献
146.
Gutsul EI Belkova NV Sverdlov MS Epstein LM Shubina ES Bakhmutov VI Gribanova TN Minyaev RM Bianchini C Peruzzini M Zanobini F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(10):2219-2228
The reactions of the octahedral dihydrido complexes [MH(2)(PP(3))] [M=Fe, Ru, Os; PP(3)=P(CH(2)CH(2)PPh(2))(3)] with a variety of weak ROH acids have been studied by IR and NMR methods in either CH(2)Cl(2) or THF in the temperature range from 190 to 290 K. This study has allowed the determination of the spectral and thermodynamic properties associated with the formation of dihydrogen bonds (DHB) between the terminal hydrides and the OH group. Both the DHB enthalpy values and the hydride basicity factors (E(j)) have been found to increase in the order Fe < Ru < Os. The proton transfer process, leading to the DHB complexes, and eventually to eta(2)-H(2) products, has been found to depend on the acidic strength of the alcohol as well as the nature of the solvent. Low temperature IR and NMR techniques have been used to trace the complete energy profile of the proton transfer process involving the osmium complex [OsH(2)(PP(3))] with trifluoroethanol. 相似文献
147.
The paper presents a bicriterion approach to solve the single-machine scheduling problem in which the job release dates can be compressed while incurring additional costs. The two criteria are the makespan and the compression cost. For the case of equal job processing times, an O(n4) algorithm is developed to construct integer Pareto optimal points. We discuss how the algorithm developed can be modified to construct an -approximation of noninteger Pareto optimal points. The complexity status of the problem with total weighted completion time criterion is also established. 相似文献
148.
Kseniya V. Zherikova Ludmila N. Zelenina Natalia B. Morozova Tamara P. Chusova 《Journal of Thermal Analysis and Calorimetry》2012,108(3):1325-1329
Complexes of ruthenium(III) with the following beta-diketone derivatives: 2,4-pentanedione (Ru(acac)3), 1,1,1,6,6,6-hexafluoro-2,4-pentanedione (Ru(hfac)3), and 2-methoxy-2,6-dimethyl-3,5-heptanedione (Ru(mdhd)3) were synthesized, purified, and identified by chemical analysis and melting points. By difference-scanning calorimetry (DSC) in vacuum the thermodynamic characteristics of melting processes were defined. Using the static method with quartz membrane zero-manometer, the temperature dependencies of saturated and unsaturated vapor pressure were obtained for Ru(hfac)3. The standard thermodynamic characteristics of vaporization processes enthalpy ?H T* and entropy ?S° T* were determined. 相似文献
149.
Natalia Sh. Lebedeva Anatoly I. Vyugin Natalia A. Pavlycheva Elena V. Parfenyuk Olga I. Davidova 《Thermochimica Acta》2002,390(1-2):179-186
The heats of interactions of zinc(II)tetraphenylporphyrine with 30 types of neutral molecules in benzene and carbon tetrachloride were measured using the calorimetric titration method. The thermodynamic characteristics of complex formation were calculated. The satisfactory multiparameter correlation of thermodynamic stability of the molecular complexes formed with physicochemical properties of the neutral molecules (electron pair donor ability, volume, electronic and orientational polarization) was obtained. 相似文献
150.
Natalia A. Nikonorova Nikolai N. Smirnov Ricardo Diaz‐Calleja Alexander V. Yakimansky 《Journal of Polymer Science.Polymer Physics》2008,46(14):1488-1496
Local forms of molecular mobility of comb‐like random copolymethacrylates, containing side‐chain nonlinear optical chromophores and amyl‐ or octafluoroamyl‐groups, are studied. In the glassy state, two relaxation processes are found, which are due to reorientation of terminal polar groups (γ2‐process) and rotation of chromophore groups about their long axes (β‐process). For octafluoroamyl‐containing copolymers, the γ2‐process is superposition of the two molecular motions due to reorientation of terminal chromophore groups and ? CF2H groups. The intensity and relaxation times in the range of the γ2‐process depend on the chemical structure and concentration of chromophores in a copolymer. For the β‐process, the molecular mobility weakly depends on the chromophore structure, being mainly determined by the relative lengths of the rigid chromophore and flexible side chains. On the global spectrum of depolarization current it was observed the γ1‐process due to reorientation of (CH2)n spacers between chromophore groups and copolymer backbone. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1488–1496, 2008 相似文献