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91.
92.
V. S. Kaganovich Z. A. Kerzina M. I. Rybinskaya E. Kolehmainen 《Russian Chemical Bulletin》1995,44(6):1131-1132
The reaction of cluster Ru6C(CO)17 (1) with nickelocene is studied. Five CO ligands rather than a metal-ligand crown are substituted for two cyclopentadienyl groups to give a new complex Ru6C(5-Cp)2(CO)12 (2). The reaction of cluster1 with entamethylcyclopentadiene leads to new complex Ru6C(-15-CH2C5Me4)(CO)14 (3) containing the cr-bond CH2-Ru, along with an 5-coordinated cyclopentadienyl ring.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1171–1172, June, 1995. 相似文献
93.
94.
Esna Killian Kevin Blann Annette Bollmann John T. Dixon Sven Kuhlmann Munaka C. Maumela Hulisani Maumela David H. Morgan Palesa Nongodlwana Matthew J. Overett Mari Pretorius Karola Hfener Peter Wasserscheid 《Journal of molecular catalysis. A, Chemical》2007,270(1-2):214-218
A systematic study was conducted on the Cr catalysed tri- and tetramerisation of ethylene using bis(diphenylphosphino)amine ligands with N-aryl functionality. This study revealed that the oligomerisation reaction product selectivity is primarily dependent on the structure and size of the N-aryl groups.
Addition of sufficient steric bulk to the N-phenyl group via ortho-alkyl substitution increased the combined 1-hexene and 1-octene selectivity (overall alpha selectivity) to above 82% at an overall 1-octene selectivity of 56%. The introduction of a single carbon spacer between the N-atom and the aryl-moiety, as well as the addition of branching on this carbon, resulted in further selectivity improvements, achieving an overall 1-octene selectivity of 64% and an overall alpha selectivity of 84%. This was obtained at catalyst productivities in excess of 1,000,000 g/g Cr/h. 相似文献
95.
Victor Barba Julián Vázquez Rosa Santillan 《Journal of organometallic chemistry》2005,690(9):2351-2357
The syntheses of eight [4.3.0] heterobicyclic boronates containing a N → B coordinative bond are described. The monomeric compounds were prepared by reaction of arylboronic acids with a tridentate ligand having the ONO donor set of atoms. It was shown that substituents at the para-position of the B-phenyl moiety transmit electronic effects to the CN bond which in turn is polarized by formation of the N → B coordination bond. At the same time, related tridentate ligands were also reacted with 1,4-benzenediboronic acid in order to prepare benzene diboron complexes. The structure of this type of compounds was confirmed by X-ray analysis for one of the derivatives. 相似文献
96.
Oana Bumbu Cristian Silvestru Michael B Hursthouse 《Journal of organometallic chemistry》2003,687(1):118-124
The reactions between PhHgCl or PhHgAc and M[(XPR2)(YPR′2)N] (M=Na, K; X, Y=O, S; R, R′=Me, Ph, OEt), in 1:1 molar ratio, have been investigated. PhHg[(XPR2)(YPR′2)N] derivatives were isolated as microcrystalline powders and were characterised using IR and NMR (1H, 13C and 31P) spectroscopy and mass spectrometry. The molecular structure of PhHg[(OPR2)(SPPh2)N] [R=Me (1), Ph (2)] was investigated by X-ray diffraction. In the monomeric unit, PhHg[(OPR2)(SPPh2)N], the mercury atom forms the primary bonds with the carbon of the phenyl group and the sulfur atom of the phosphorus ligand [Hg(1)-S(1) 2.405(1) Å for 1, 2.398(2) Å for 2]. These primary bonds are significantly deviated from the expected linear arrangement [C(1)-Hg(1)-S(1) 166.4(2)° for 1, 165.0(2)° for 2]. Both compounds exhibit dimeric associations in the crystal through S,O-bridging organophosphorus ligands [Hg(1)-O(1) 2.556(4) Å for 1, 2.588(4) Å for 2], thus resulting in a distorted T-shaped arrangement of the CHgSO coordination core.. The formation of a 12-membered Hg2O2S2P4N2 ring with different conformation in 1 and 2, respectively, results in different additional chalcogen atoms being in the proximity of the metal atom. Weak transannular Hg?O [2.753(4) Å] are also established in 1, leading to a tricyclic ladder structure with a planar central Hg2O2 ring. 相似文献
97.
The chelate oxides of bis(trimethylantimony) (Me3SbL1)2O (i = 1 or 2, L1-acetylacetonate, L2 - trifluoroacetylacetonate) and bis(triethylantimony) (Et3SbL1)2O have been obtained in 79–85% yields by a one-step oxidation of trialkylantimony withtertbutylhydroperoxide in the presence of -diketones in benzene at 20 °C.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 154–155, January, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 94-03-08846). 相似文献
98.
Veiros LF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(8):2505-2518
The mechanisms of three closely related reactions were studied in detail by means of DFT/B3 LYP calculations with a VDZP basis set. Those reactions correspond to 1) the reductive elimination of methane from [Zr(eta5-Ind)2(CH3)(H)] (Ind=C9H7-, indenyl), 2) the formation of the THF adduct, [Zr(eta5-Ind)(eta6-Ind)(thf)] and 3) the interconversion between the two indenyl ligands in the Zr sandwich complex, [Zr(eta5-Ind)(eta9-Ind)], which forms the link between the two former reactions. An analysis of the electronic structure of this species indicates a saturated 18-electron complex. A full understanding of the indenyl interchange process required the characterisation of several isomers of the Zr-bis(indenyl) species, corresponding to different spin states (S=0 and S=1), different coordination modes of the two indenyl ligands (eta5/eta9, eta5/eta5 and eta6/eta9), and three conformations for each isomer (syn, anti, and gauche). The fluxionality observed was found to occur in a mechanism involving bis(eta5-Ind) intermediates, and the calculated activation energy (11-14 kcal mol(-1)) compares very well with the experimental values. Two alternative mechanisms were explored for the reductive elimination of methane from the methyl/hydride complex. In the more favourable one, the initial complex, [Zr(eta5-Ind)2(CH3)(H)], yields [Zr(eta5-Ind)2] and methane in one crucial step, followed by a smooth transition of the Zr intermediate to the more stable eta5/eta9-species. The overall activation energy calculated (Ea=29 kcal mol(-1)) compares well with experimental values for related species. The formation of the THF adduct follows a one step mechanism from the appropriate conformer of the [Zr(eta5-Ind)(eta9-Ind)] complex, producing easily (Ea=6.5 kcal mol(-1)) the known product, [Zr(eta5-Ind)(eta6-Ind)(thf)], a species previously characterised by X-ray crystallography. This complex was found to be trapped in a potential well that prevents it from evolving to the 3.4 kcal mol(-1) more stable isomer, [Zr(eta5-Ind)2(thf)], with both indenyl ligands in a eta5-coordination mode and a spin-triplet state (S=1). 相似文献
99.
Summary The electrochemical reduction of the Fe(III) complexes with a series of substituted N,N-Ethylenebisacetonimines was investigated by cyclic voltammetry in acetonitrile solution at a platinum electrode. The substituent does not significantly influence the redox properties of the studied complexes. The symmetry of the redox orbital is responsible for the observed behaviour of the complexes.
Elektrochemisches Verhalten einer Reihe von Fe(III)-Komplexen mit vierzähnigen Schiffschen Basen als Liganden
Zusammenfassung Die elektrochemische Reduktion der Fe(III)-Komplexe einer Reihe von substituierten N,N-Ethylenbisacetoniminen wurde mittels cyclischer Voltammetrie in Acetonitril an einer Platinelektrode untersucht. Der Substituent beeinflußt die Redoxeigenschaften der untersuchten Komplexe nicht signifikant. Das beobachtete Verhalten der Komplexe wird von der Symmetrie des Redoxorbitals bestimmt.相似文献
100.
合成了双[水杨醛(对硝基苯)亚胺]合镍催化剂A和双[水杨醛(对甲氧基苯)亚胺]合镍催化剂B.该两种双[N,O]配体合镍配合物/MAO催化体系能有效地催化极性单体甲基丙烯酸甲酯(MMA)聚合,催化活性可高达105gPMMA/(molNi.h).其中配体对位含有硝基吸电子(共轭)效应的催化剂A/MAO体系有相对较高的聚合反应热稳定性,温度达50℃时仍具有高催化活性.配体对位含有甲氧基推电子(共轭)效应的催化剂B/MAO则在30℃和Al/Ni摩尔比为600时表现出最高的催化活性.催化剂B/MAO体系催化得到PMMA的链序列结构以间规为主(含高达73.2%rr三元组),具有较高的玻璃化转变温度(Tg=106.4℃). 相似文献