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921.
《Journal of Coordination Chemistry》2012,65(14):1217-1223
In this study, 5-bromosalicyliden-p-aminoacetophenoneoxime (LH) was synthesized starting from p-aminoacetophenoneoxime and 5-bromosalicylaldehyde. Complexes of this ligand with Co+?2, Ni+?2, Cu+?2 and Zn+?2 were prepared with a metal?:?ligand ratio of 1?:?2. Their structures have been elucidated on the basis of elemental analyses, IR, 1H and 13C NMR spectra, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses (TGA). 相似文献
922.
《Journal of Coordination Chemistry》2012,65(2):281-292
In this study, the formation constants of 1?:?1 binary complexes of Cu(II) with L-glutamic acid, L-aspartic acid, glycine, L-alanine, L-valine, and L-leucine and 1?:?2 binary complexes of L-glutamic acid, glycine and the protonation macro- and microconstants of all these amino acids were determined potentiometrically in aqueous solutions at 5.0, 20.0, and 35.0°C at a constant ionic strength of I?=?0.10?mol?L?1 (NaClO4). The thermodynamic parameters ΔG f°, ΔH f°, and ΔS f° were determined for the protonation of all amino acids used in this study and for the complex formation reactions of them with Cu(II). The results were analysed by means of Principle of hard and soft [Lewis] acids and bases. Additionally, in order to confirm the complex formation and determine the stability constants of complexes, UV-Vis spectroscopic studies were carried out. The stability constants obtained by spectrophotometrically are confirmed by those determined potentiometrically. 相似文献
923.
《Journal of Coordination Chemistry》2012,65(6):1094-1106
Pyrazolone derivatives (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one [PMP-EA] (1), (Z)-1-(3-chlorophenyl)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1H-pyrazol-5(4H)-one [MCPMP-EA] (2), and (Z)-4-((2-hydroxyethylimino)(p-tolyl)methyl)-3-methyl-1-p-tolyl-1H-pyrazol-5(4H)-one [PTPMP-EA] (3) have been synthesized and characterized. The molecular geometry of 2 has been determined by single-crystal X-ray study. These ligands exist in amine-one tautomeric form in the solid state. Three copper(II) complexes, [Cu(PMP-EA)(H2O)2] (4), [Cu(MCPMP-EA)(H2O)2] (5), and [Cu(PTPMP-EA)(H2O)2] (6), respectively, have been synthesized using these ligands and characterized by microanalytical data, molar conductivity, IR, UV–Visible, FAB-Mass, magnetic measurement, TG-DTA studies, and ESR spectral studies; Cu(II) is five-coordinated with [ML(H2O)2] composition. The interaction of the complexes with CT-DNA (calfthymus) was investigated using different methods. The results suggest that the copper complexes bind to DNA via intercalation and can quench the fluorescence intensity of EB bound to DNA. 相似文献
924.
《Journal of Coordination Chemistry》2012,65(9):1597-1610
Six mononuclear Mo(V) Schiff-base complexes were prepared by the reaction of MoCl5 with Schiff bases, namely HL1–HL3 and HL4–HL6, such as 5-hydroxy-3-methyl-1(2-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (I), 5-hydroxy-3-methyl-1(3-chloro)phenyl-1H-pyrazolone-4-carbaldehyde (II), and 5-hydroxy-3-methyl-1(3-sulfoamido)phenyl-1H-pyrazolone-4-carbaldehyde (III) with ethanolamine and propanolamine, respectively, in aqueous ethanolic medium. The resulting complexes have been characterized by elemental analyses, molar conductance, FT-IR, 1H-NMR, electronic, electron spin resonance (ESR) spectra, magnetic susceptibility, and thermal study. The molar conductivity data show them to be non-electrolytes. IR and 1H-NMR spectral data suggest that the ligand is a dibasic bidentate with ON donor toward metal ion. Electronic, magnetic, and ESR spectral data suggest that the oxomolybdenum(V) complexes have distorted octahedral geometry. One chloride coordinated to molybdenum is confirmed by thermal study. 相似文献
925.
《Journal of Coordination Chemistry》2012,65(8):1351-1359
Sn(II)-complexes of seven 2-amino-5-substituted-aryl-1,3,4-oxadiazole Schiff bases have been synthesized and characterized by various physico-chemical studies. Their structures have been confirmed by elemental analyses, infrared, 1H NMR, UV-Vis, and mass spectral studies as well as thermal decomposition. Conductance measurements in methanol show these complexes to be non-electrolytes, and the molecular weight determinations support the proposed molecular formulae. The molecular structures of the complexes have been optimized by CS Chem 3-D Ultra Molecular Modeling and Analysis Program showing tetrahedral geometry. The bio-efficacy of the complexes has been examined against the growth of bacteria (Escherichia coli and Staphylococcus aureus) and fungi (Aspergillus flavus and Candida albicans) in vitro to evaluate their anti-microbial potential. 相似文献
926.
《Journal of Coordination Chemistry》2012,65(9):1533-1543
Indium(III) chloride tetrahydrate and Schiff-base ligands derived from adamantaneamine and 3-/4-methoxysalicylaldehyde gave two complexes, C22H32Cl3InN2O3 (1) and C36H44Cl3InN2O4 (2), respectively. The complexes were characterized by IR, 1H NMR, elemental analysis, molar conductance, thermal analysis, and single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic system, P21/n space group with the asymmetric unit consisting of one indium(III), one N-(3-methoxysalicylidene)-aminoadamantane (L1), three chlorides and one N,N-dimethylformamide molecule. The indium is six-coordinate with reversed triangular-prism geometry via three oxygens and three chlorides. Complex 2 crystallizes in the triclinic system, P 1 space group; the asymmetric unit consists of one indium(III), two N-(4methoxysalicylidene)-aminoadamantane (L2), and three chlorides. The indium is five-coordinate with distorted trigonal-bipyramidal geometry via two oxygens and three chlorides. Antibacterial activities of the complexes have been investigated against Escherichia coli and Staphylococcus aureus. 相似文献
927.
《Journal of Coordination Chemistry》2012,65(9):1608-1616
Condensation of X-benzaldehyde with (R)-2-amino-2-phenylethanol gives the enantiopure Schiff bases (R)-2-(X-benzaldimine)-2-phenylethanol (X?=?H, HL1; 2,4-dimethoxy, HL2). The Schiff bases coordinate with dinuclear [Rh(η4-cod)(µ-O2CCH3)]2 to afford the cationic complexes [Rh(η4-cod){(R)-2-(benzaldimine)-2-phenylethanol-κ 2 N,O}](acetate), [Rh(η4-cod)(HL1)](ac) (1) and [Rh(η4-cod){(R)-2-(2,4-dimethoxy-benzaldimine)-2-phenylethanol-κ 2 N,O}](acetate), [Rh(η4-cod)(HL2)](ac) (2), respectively. The Schiff bases and complexes are isolated as solids in good yields and characterized by elemental analysis, IR, UV-Vis, 1H/13C-NMR, mass spectroscopy, and polarimetry. 相似文献
928.
Shuming Zhang 《Journal of computational chemistry》2012,33(31):2469-2482
The ionization (dissociation) constant (pKa) is one of the most important properties of a drug molecule. It is reported that almost 68% of ionized drugs are weak bases. To be able to predict accurately the pKa value(s) for a drug candidate is very important, especially in the early stages of drug discovery, as calculations are much cheaper than determining pKa values experimentally. In this study, we derive two linear fitting equations (pKa = a × ΔE + b; where a and b are constants and ΔE is the energy difference between the cationic and neutral forms, i.e., ΔE = Eneutral?Ecationic) for predicting pKas for organic bases in aqueous solution based on a training/test set of almost 500 compounds using our previously developed protocol (OLYP/6‐311+G**//3‐21G(d) with the the conductor‐like screening model solvation model, water as solvent; see Zhang, Baker, Pulay, J. Phys. Chem. A 2010 , 114, 432). One equation is for saturated bases such as aliphatic and cyclic amines, anilines, guanidines, imines, and amidines; the other is for unsaturated bases such as heterocyclic aromatic bases and their derivatives. The mean absolute deviations for saturated and unsaturated bases were 0.45 and 0.52 pKa units, respectively. Over 60% and 86% of the computed pKa values lie within ±0.5 and ±1.0 pKa units, respectively, of the corresponding experimental values. The results further demonstrate that our protocol is reliable and can accurately predict pKa values for organic bases. © 2012 Wiley Periodicals, Inc. 相似文献
929.
Eros G Nagy K Mehdi H Pápai I Nagy P Király P Tárkányi G Soós T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(2):574-585
Catalytic hydrogenation that utilizes frustrated Lewis pair (FLP) catalysts is a subject of growing interest because such catalysts offer a unique opportunity for the development of transition-metal-free hydrogenations. The aim of our recent efforts is to further increase the functional-group tolerance and chemoselectivity of FLP catalysts by means of size-exclusion catalyst design. Given that hydrogen molecule is the smallest molecule, our modified Lewis acids feature a highly shielded boron center that still allows the cleavage of the hydrogen but avoids undesirable FLP reactivity by simple physical constraint. As a result, greater latitude in substrate scope can be achieved, as exemplified by the chemoselective reduction of α,β-unsaturated imines, ketones, and quinolines. In addition to synthetic aspects, detailed NMR spectroscopic, DFT, and (2)H isotopic labeling studies were performed to gain further mechanistic insight into FLP hydrogenation. 相似文献
930.
本文提出了一个新颖的基于四粒子cluster态和Bell态制备任意三粒子远程制备方案.在发送者(Alice)对自己手中的粒子做正交完备测量,接受者(Bob)对自己手中的粒子做适当的幺正变换后,任意三粒子远程制备成功.对于Alice的两种不同的正交完备基测量的情况,分别计算了远程制备成功的概率.另外,本方案成功制备的概率在一般情况和一些特殊情况下是可以计算的.分析结果表明:在一般情况下,远程态制备可以以1/8的概率实现;但在一些特殊情况下,成功的概率可以提高到1/4、1/2,甚至1. 相似文献