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161.
Kłonkowski Andrzej M. Widernik Teresa Grobelna Beata Jóźwiak Wojciech K. Proga Henryk Szubiakiewicz Ewa 《Journal of Sol-Gel Science and Technology》2001,20(2):161-180
The sol-gel process is a useful method for preparing two series of organically and co-ordinately modified xerogels of the types [CuN
n
]·N
5–n
·5xSiO4/2 (n < 4) and [Cu(N–N)n]·(N–N)2–n
·2x SiO4/2(n 2), where N = NH2(CH2)3 SiO3/2, N–N = NH2(CH2)2NH·(CH2)3SiO3/2 and x = [SiO4/2]/[N] or [SiO4/2]/[N–N]. The amino groups in the materials are coordinately active and participate partly in the coordination sphere of Cu(II) ions. The composition of the coordination sphere can be varied with the SiO4/2 content and also as a result of the thermal decomposition of the organic residues at higher temperatures.Because the xerogel materials are considered to be catalyst precursors, this study is focused on their coordination and thermal properties. The prepared xerogels, such as silica, aminated silicates with N and N–N, as well as those entities complexed with Cu(II), were characterised by FT-IR spectroscopy. During gelation and thermal decomposition the materials were analysed by electron paramagnetic resonance (EPR) spectroscopy. The xerogels were additionally studied by UV-Vis absorption spectroscopy. The gaseous products of the thermal decomposition of these materials in an Ar atmosphere were investigated by the use of FT-IR spectroscopy coupled with TG and DTG thermal analysis. These data were complemented by temperature-programmed decomposition (TPDec) in a 2% O2 + 98% Ar stream coupled with quadrupole mass spectroscopy. 相似文献
162.
New complexes:Zn(Hsalox)(ox), Zn(Hsalox)(NHPh), Zn(Hsalox)(Hsal) and Zn(Hsalox)2(1,2-diMeim) have been synthesised as a result of a reaction of Zn(salox) and Zn(Hsalox)2 (where: salox
2–=OC6H4CHNO2–, Hsalox
–=OC6H4CHNOH–) with 8-hydroxyquinoline (Hox), o-aminophenol (NH2Ph), o-hydroxybenzoic acid (H2Sal) and 1,2-dimethylimidazole (1,2-diMeim). Chemical, X-ray and thermal analyses of the complexes and their sinters have
been carried out. Thermal decomposition pathways have been postulated for the complexes. The mixtures about not definite composition
have been obtained as a result of a reaction of zinc(o-hydroxybenzaldoximates) with imidazole(Him) and 4-methylimidazole (4-MeHim).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
163.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(10):1128-1132
Imidazole‐4,5‐dicarboxylic acid (H3IDC) and its derivatives are widely used in the preparation of new coordination polymers owing to their versatile bridging coordination modes and potential hydrogen‐bonding donors and acceptors. A new one‐dimensional coordination polymer, namely catena‐poly[[diaquacadmium(II)]‐μ3‐2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylato)], [Cd(C16H6N4O8)0.5(H2O)2]n or [Cd(H2Phbidc)1/2(H2O)2]n, has been synthesized by the reaction of Cd(OAc)2·2H2O (OAc is acetate) with 2,2′‐(1,2‐phenylene)bis(1H‐imidazole‐4,5‐dicarboxylic acid) (H6Phbidc) under solvothermal conditions. In the polymer, one type of Cd ion (Cd1) is six‐coordinated by two N atoms and two O atoms from one H2Phbidc4− ligand and by two O atoms from two water molecules, forming a significantly distorted octahedral CdN2O4 coordination geometry. In contrast, the other type of Cd ion (Cd2) is six‐coordinated by two N atoms and two O atoms from two symmetry‐related H2Phbidc4− ligands and by two O atoms from two symmetry‐related water molecules, leading to a more regular octahedral coordination geometry. The Cd1 and Cd2 ions are linked by H2Phbidc4− ligands into a one‐dimensional chain which runs parallel to the b axis. In the crystal, the one‐dimensional chains are connected through hydrogen bonds, generating a two‐dimensional layered structure parallel to the ab plane. Adjacent layers are further linked by hydrogen bonds, forming a three‐dimensional structure in the solid state. 相似文献
164.
Manganese(II) complexes having the general composition Mn(L)2X2 (where L = 3‐bromoacetophenone semicarbazone, 3‐bromoacetophenone thiosemicarbazone, 1‐tetralone semicarbazone, 1‐tetralone thiosemicarbazone, flavanone semicarbazone or flavanone thiosemicarbazone and X = Cl? or ½SO42?) were synthesized. All the complexes were characterized using elemental analyses, molar conductance and magnetic moment measurements, and mass, 1H NMR, infrared, electron paramagnetic resonance and electronic spectral studies. The molar conductance of the complexes in dimethylsulfoxide lies in the range 10–20 Ω?1 cm2 mol?1 indicating their non‐electrolytic nature. All the complexes show magnetic moments corresponding to five unpaired electrons. The possible geometries of the complexes were assigned on the basis of electron paramagnetic resonance, electronic and infrared spectral studies. Some of the synthesized ligands and their complexes were screened for their antifungal activities against fungi Macrophomina phaseolina, Botrytis cinerea and Phoma glomerata using the food poison technique and their antibacterial activities against Xanthomonas campestris pv. campestris and Ralstonia solanacearum using the paper disc diffusion method. They showed appreciable activities. 相似文献
165.
Four Zn(II) complexes, [Zn L 2(SO4)]n ( 1 ), [Zn L 4(H2O)2]?2(NO3)?4EtOH ( 2 ), [Zn L 2Cl2]? L ( 3 ), and [Zn L 2Br2]? L ( 4 ) ( L = uniconazole), were synthesized using a hydrothermal method and characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal XRD. Complex 1 formed a one‐dimensional polymer chain. However, complexes 2 ‐ 4 were obtained as zero‐dimensional mononuclear coordination compounds. The antifungal activities of these complexes were then evaluated against four selected fungi using the mycelial growth rate method. The resulting data indicate that all complexes show better antifungal activities than their ligands and mixtures. In addition, the interactions between the metal salts of complexes 1 ‐ 4 and uniconazole seem to be synergistic. Furthermore, the polymer chain structure of complex 1 significantly enhanced the bioactivity, especially against Botryosphaeria ribis ( I ). Density functional theory (DFT) calculations were carried out to help explain the enhanced bioactivity after the formation of Zn(II) complexes. The resulting data show that the HOMO–LUMO energy gaps of complexes 1 ‐ 4 (0.0578, 0.0946, 0.1053, and 0.1245 eV) are smaller than that of the free ligand (0.1247 eV) and correlate with the antifungal activity of the zinc complexes. 相似文献
166.
Mohamed Shaker S. Adam 《应用有机金属化学》2018,32(4)
Three novel paramagnetic metal complexes (MH2ID) of Ni2+, Cu2+ and VO2+ ions with 3‐hydroxy‐3,3’‐biindoline‐2,2’‐dione (dihydroindolone, H4ID) were synthesized and characterized by different spectroscopic methods. The ligand (H4ID) was synthesized via homocoupling reaction of isatin in presence of phenylalanine in methanol. Complexation of low valent Ni2+, Cu2+ ions and high valent VO2+ ions with H4ID carried out in 1: 2 molar ratios. A comparison in the catalytic potential of paramagnetic complexes of low and high valent metal ion was explored in the oxidation processes of cis‐cyclooctene, benzyl alcohol and thiophene by an aqueous H2O2, as a green terminal oxidant, in the presence and absence of acetonitrile, as an organic solvent, at 85 °C. NiH2ID, CuH2ID and VOH2ID show good catalytic activity, i.e. good chemo‐ and regioselectivity. VOH2ID has the highest catalytic potential compared to both Ni2+‐ and Cu2+‐species in the same homogenous aerobic atmosphere. Catalytic oxidation of other alkenes and alcohols was also studied using NiH2ID, CuH2ID or VOH2ID as a pre‐catalyst by an aqueous H2O2. A mechanistic pathway for those oxidation processes was proposed. 相似文献
167.
K. Manjunatha Tuhin S. Koley Vishal Kandathil Ramesh B. Dateer Geetha Balakrishna B. S. Sasidhar Shivaputra A. Patil Siddappa A. Patil 《应用有机金属化学》2018,32(4)
As a continuation of our efforts to develop new heterogeneous nanomagnetic catalysts for greener reactions, we identified a Schiff base–palladium(II) complex anchored on magnetic nanoparticles (SB‐Pd@MNPs) as a highly active nanomagnetic catalyst for Suzuki–Miyaura cross‐coupling reactions between phenylboronic acid and aryl halides and for the reduction of nitroarenes using sodium borohydride in an aqueous medium at room temperature. The SB‐Pd@MNPs nanomagnetic catalyst shows notable advantages such as simplicity of operation, excellent yields, short reaction times, heterogeneous nature, easy magnetic work up and recyclability. Characterization of the synthesized SB‐Pd@MNPs nanomagnetic catalyst was performed with various physicochemical methods such as attenuated total reflectance infrared spectroscopy, UV–visible spectroscopy, inductively coupled plasma atomic emission spectroscopy, energy‐dispersive X‐ray spectroscopy, field‐emission scanning electron microscopy, transmission electron microscopy, powder X‐ray powder diffraction, thermogravimetric analysis and Brunauer–Emmett–Teller surface area analysis. 相似文献
168.
An environmentally friendly copper‐based catalyst supported on 2‐Methoxy‐1‐phenylethanone functionalized MCM‐41 was prepared and characterized by FT‐IR, FE‐SEM, TEM, XRD, EDX, BET and ICP techniques. The catalyst was applied for the C?S cross‐coupling reaction of aryl halides with thiourea. Corresponding products were produced in good yields in aerobic conditions. The catalyst could be recovered and recycled for several times. 相似文献
169.
Three new dinuclear Cu(II) complexes with the formulas [Cu2(pxdmbtacn)Cl4] ( 1 ), [Cu2(pxdmbtacn)Cl0.7(NO3)1.3(OH)2(H2O)1.3]?6H2O ( 2 ) and [Cu2(pxdiprbtacn)Cl4] ( 3 ) together with one previously reported complex, [Cu2(pxbtacn)Cl4] ( 4 ), were obtained from Cu(II) salts with three p‐xylylene‐bridged bis‐tacn ligands bearing pendant alkyl substituents or without pendant group. Complex 2 was structurally characterized as a centrosymmetric dinuclear molecule with each metal center being coordinated to some labile ligands in addition to one tacn ring. Based on the results of mass spectrometry and UV–visible spectroscopy, complexes 1 and 3 are capable of existing in aqueous solution as dinuclear species but 4 can partially form a dimer of the original dinuclear motif. Complexes 1 , 3 and 4 can all effectively cleave supercoiled DNA oxidatively in the presence of hydrogen peroxide. The superoxide dismutase (SOD) activities of 1 and 3 measured under physiological conditions are comparable to that of the native CuZnSOD enzyme but the enzymatic activity of 4 is about three‐ to fourfold lower. Furthermore, complexes 1 , 3 and 4 demonstrate moderate scavenging effect on hydrogen peroxide and their catalase activities are in the decreasing order of 3 > 1 > 4 . 相似文献
170.
A new heterocyclic Schiff bases, 6‐methyl/8methyl‐2‐oxo‐1,2‐dihydroquinoline‐3‐carboxaldehyde semicarbazones (H2‐6MOQsc‐H) ( H 2 L 1 ) and (H2‐8MOQsc‐H) ( H 2 L 2 ) and their corresponding copper(II) complexes [CuCl2(H2‐6MOQsc‐H)].3H2O ( 1 ), [CuCl2(H2‐8MOQsc‐H)].3H2O ( 2 ), [CuNO3(H2‐6MOQsc‐H)(H2O)].NO3 ( 3 ) and [CuNO3(H2‐8MOQsc‐H)(H2O)].NO3 ( 4 ) have been synthesized and characterized by various physicochemical techniques. The single crystal X‐ray diffraction and spectral data revealed that all of the complexes ( 1‐4 ), the ligands coordinated to the Cu(II) ion in a neutral manner via ONO donor atoms and all the complexes exhibited distorted squarepyramidal geometry. The consequence of electronegativity and ring size of nitrogen heterocyclic moiety of ONO donor type of copper(II) chelates on nucleic acid interaction and albumin binding was investigated by in vitro experiments. The interaction of compounds with calf‐thymus DNA (CT‐DNA) has been explored by absorption and emission titration, which exposed those ligands/complexes, could bind with CT‐DNA through electrostatic interaction. The results of gel electrophoresis proved the ability of complexes ( 1‐4 ) to cleave the pBR322 plasmid DNA. The interaction of serum albumin (BSA) was investigated by UV‐Vis, fluorescence, synchronous and three dimensional fluorescence spectra. In addition, radical scavenging activity, antifungal activity and cytotoxicity of the newly synthesized compounds were also evaluated. From the results of in vitro studies, it is seen that complex 3 has more potential as compared with other complexes and ligands. 相似文献