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971.
Le‐Qing Fan Ji‐Huai Wu 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):m548-m549
The title compound, [ZnI2(bipy)]n (bipy is 4,4′‐bipyridine, C10H8N2), has been prepared by the hydrothermal reaction of ZnI2 and bipy at 433 K. Each Zn atom is coordinated by two N atoms from two different bipy ligands and by two I atoms in a distorted tetrahedral geometry, with Zn—N distances ranging from 2.068 (7) to 2.101 (8) Å and Zn—I distances ranging from 2.5471 (13) to 2.5673 (13) Å. The molecular structure features a zigzag polymeric chain. Face‐to‐face π–π stacking interactions between adjacent bipy ligands stabilize the structure. 相似文献
972.
973.
An N. Le Ruiqi Liang Xiaoyu Ji Xiaowei Fu Mingjiang Zhong 《Journal of polymer science. Part A, Polymer chemistry》2021,59(21):2571-2580
The random copolymerization of norbornene-functionalized macromonomers was explored as a method of synthesizing mixed-graft block copolymers (mGBCPs). The copolymerization kinetics of a model system of polystyrene (PS) and poly(lactic acid) (PLA) macromonomers was first analyzed, revealing a gradient composition of side chains along the mGBCP backbone. The phase separation behavior of mGBCPs with PS and PLA side chains of various backbone lengths and side chain molar ratios was investigated, and increasing the backbone length was found to stabilize the phase-separated nanostructures. The graft architecture was also demonstrated to improve the processability of the mGBCP, compared to a linear counterpart. Investigations of mGBCPs comprised of polydimethylsiloxane and poly(ethylene oxide) side chains exemplified the diverse self-assembled morphologies, including a Frank-Kasper A15 phase, that can be obtained with mGBCPs synthesized by random copolymerization of macromonomers. Lastly, a ternary mGBCP was synthesized by the copolymerization of three macromonomers. 相似文献
974.
(Copper signals from seawater matrices in electrothermal atomic absorption spectrometry. Part 1: study of the effects of principal inorganic ions.)The effects of the main inorganic ions of seawater (Na+, Mg2+, Ca2+, Cl?, SO2?4), and of nitrate as modifier, on the electrothermal atomic absorption spectrometric signal of copper are studied. Sodium chloride, sulfate or nitrate, magnesium chloride or nitrate, and calcium chloride can cause serious interferences. Thermal treatment at about 700°C prevents the interference of MgCl2 by its hydrolysis. Ashing can be done without loss of copper at higher temperatures in the presence of sulfate salts (1300°C) and nitrate salts (1200°C) than in the presence of chloride salts (1100°C). This is ascribed to the stabilising effect of oxides and sulfides. A study of the influence of two-component matrices, MCl-MNO3 or MCl-MSO4, on the atomization signal of copper confirms this stabilizing effect which adds to the decrease in interference connected with removal of chloride in acidic medium. 相似文献
975.
976.
Dr. Sheng‐Liang Zhong Dr. Yang Lu Dr. Min‐Rui Gao Dr. Shu‐Juan Liu Jun Peng Le‐Cheng Zhang Prof. Dr. Shu‐Hong Yu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(17):5222-5231
A family of monodisperse YF3, YF3:Ce3+ and YF3:Ce3+/Ln3+ (Ln=Tb, Eu) mesocrystals with a morphology of a hollow spindle can be synthesized by a solvothermal process using yttrium nitrate and NH4F as precursors. The effects of reaction time, fluorine source, solvents, and reaction temperature on the synthesis of these mesocrystals have been studied in detail. The results demonstrate that the formation of a hollow spindle‐like YF3 can be ascribed to a nonclassical crystallization process by means of a particle‐based reaction route in ethanol. It has been shown that the fluorine sources selected have a remarkable effect on the morphologies and crystalline phases of the final products. Moreover, the luminescent properties of Ln3+‐doped and Ce3+/Ln3+‐co‐doped spindle‐like YF3 mesocrystals were also investigated. It turns out that Ce3+ is an efficient sensitizer for Ln3+ in the spindle‐like YF3 mesocrystals. Remarkable fluorescence enhancement was observed in Ce3+/Ln3+‐co‐doped YF3 mesocrystals. The mechanism of the energy transfer and electronic transition between Ce3+ and Ln3+ in the host material of YF3 mesocrystals was also explored. The cytotoxicity study revealed that these YF3‐based nanocrystals are biocompatible for applications, such as cellular imaging. 相似文献
977.
Manuel Tzouros Laurent Bigler Stefan Bienz Manfred Hesse Akira Inada Hiroko Murata Yuka Inatomi Tsutomu Nakanishi Dedy Darnaedi 《Helvetica chimica acta》2004,87(6):1411-1425
The investigation of the MeOH extract of the leaves of Chisocheton weinlandii Harms (Meliaceae) revealed two new open‐chain spermidine alkaloids, chisitine 1 ( 1 ) and chisitine 2 ( 2 ). Their structures were elucidated by NMR spectroscopy, tandem‐mass spectrometry, and independant syntheses (Scheme 3). Detailed MS/MS fragmentation pathways are discussed for both compounds based on H/D exchange and 18O‐labeling experiments (Schemes 1 and 2). 相似文献
978.
Prof. Dr. Skye Fortier José Veleta Dr. Amélie Pialat Jennifer Le Roy Kamran B. Ghiassi Prof. Dr. Marilyn M. Olmstead Dr. Alejandro Metta‐Magaña Prof. Dr. Muralee Murugesu Prof. Dr. Dino Villagrán 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(6):1931-1936
After more than 50 years, the synthesis and electronic structure of the first and only reported “U0 complex” [U(bipy)4] ( 1 ) has been reinvestigated. Additionally, its one‐electron reduced product [Na(THF)6][U(bipy)4] ( 2 ) has been newly discovered. High resolution crystallographic analyses combined with magnetic and computational data show that 1 and its derivative 2 are best described as highly reduced species containing mid‐to‐high‐valent uranium ligated by redox non‐innocent ligands. 相似文献
979.
Danny Schuhknecht Dr. Valeri Leich Dr. Thomas P. Spaniol Iskander Douair Prof. Dr. Laurent Maron Prof. Dr. Jun Okuda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(13):2821-2825
Potassium silanide [KSiH3]∞ contains 4.2 wt % of hydrogen and has been intensely studied as hydrogen storage material. The macrocyclic ligand Me4TACD (1,4,7,10-tetramethyl-1,4,7,10-tetraaminocyclododecane, L ) stabilizes the full range of triphenylsilyl complexes [( L )MSiPh3]n (M=Li–Cs), which react with H2 or PhSiH3 to form molecular [( L )MSiH3]n that can be isolated in soluble form and fully characterized. 相似文献
980.
The energy transfer of homogeneous scalar turbulence is studied numerically by triad interaction in spectral space. The different transfer properties between turbulent kinetic energy and turbulent scalar energy reveal that non-local energy transfer exists as important as the local energy transfer in scalar turbulence. The non-local energy transfer of scalar turbulence results from non-local triad interaction. As a result there will be longer inertiaconvective range in scalar turbulence than the inertial subrange in turbulent kinetic transfer at Reλ = Peλ. The non-local transfer of turbulent scalar energy generates more energy transfer into dissipation range. The discovery of non-local transfer of turbulent scalar energy indicates that this phenomenon should be concerned carefully in numerical scheme and subgrid modelling of direct numerical simulation or large eddy simulation scalar turbulence. 相似文献