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991.
This study presents a novel separation, preconcentration and determination of basic fuchsin (BF) in an aqueous solution by sodium dodecyl sulfate (SDS)-bounded iron oxide nanoparticles (S-IONPs). It is shown that the novel magnetic nano-adsorbent is quite efficient for the adsorption and desorption of BF at 25 °C. Different parameters such as pH, temperature, ionic strength and composition of desorbent solvent were optimized. The effect of some co-existing ions on the determination was investigated. The nanoparticles were analyzed by transmission electron microscopy (TEM) and the sizes of S-IONPs were in the range of 20-100 nm. The method showed good linearity for the determination of BF in the range of 10-300 ng mL−1 with a regression coefficient of 0.9989. The limit of detection (LOD) (signal-to-noise ratio of 3:1) was 0.0073 μg L−1 and the relative standard deviation (RSD) for 0.03 μg mL−1 and 0.2 μg mL−1 of BF were 4.53% and 4.73%, respectively. The BF was determined successfully in spiked samples of Karoon River water. 相似文献
992.
Thermal decomposition of transition metal malonates, MCH2C2O4?xH2O and transition metal succinates, M(CH2)2C2O4?xH2O (M=Mn, Fe, Co, Ni, Cu, Zn) has been studied employing TG, DTG, DTA, XRD, SEM, IR and Mössbauer spectroscopic techniques. After dehydration, the anhydrous metal malonates and succinates decompose directly to their respective metal oxides in the temperature ranges 310–400 and 400–525°C, respectively. The oxides obtained have been found to be nanosized. The thermal stability of succinates have been found to be higher than that of the respective malonates. 相似文献
993.
V. I. Ovcharenko S. V. Fokin G. V. Romanenko V. N. Ikorskii R. Z. Sagdeev D. S. Yachevskii D. L. Chizhov V. N. Charushin 《Russian Chemical Bulletin》2006,55(11):1904-1908
Heterospin complexes of bis(μ2-1,1,2,2,8,8,9,9-octafluorononane-3,5,7-trionato)dicopper(II) ([Cu2L2]) with nitronyl nitroxides 2-(1-methyl-1H-pyrazol-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide (2) and 4,4,5,5-tetramethyl-2-(3-pyridinyl)-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide (1) were synthesized and structurally characterized. Crystals of the complexes are formed by the discrete bis[1-methyl-4-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)-1H-pyrazole]-bis (μ2-1,1,2,2,8,8,9,9-octafluorononane-3,5,7-trionato)dicopper(II) etherate (3) and bis[3-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)pyridine]-bis (μ2-1,1,2,2,8,8,9,9-octafluorononane-3,5,7-trionato)dicopper(II) (4) molecules. Each Cu atom of the dinuclear chelate fragment coordinates one paramagnetic ligand through the N atom of the
pyrazole or pyridine fragment, respectively. In complex 3, the paramagnetic ligands are located on one side of the plane of the chelate fragment, whereas the ligands in complex 4 are located above and below the plane of the chelate fragment. The magnetic properties of complexes 3 and 4 are determined by dominant antiferromagnetic exchange interactions between the unpaired electrons of the CuII atoms in the dinuclear Cu2L2 moiety.
Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1836–1840, November, 2006. 相似文献
994.
O. M. Shabanov F. O. Ismailova D. G. Maksumova S. M. Gadzhiev A. O. Magomedova 《Russian Journal of Electrochemistry》2006,42(9):986-989
Effects of high-voltage pulses on electrochemical properties of a molten magnesium electrolyte is studied experimentally. It is established that the electroconductivity of the melt subjected to the pulses and the electrolysis current at a constant voltage increase by up to 25%. The relaxation time of nonequilibrium melt reaches a few tens of minutes and under certain conditions its dynamics is oscillatory. 相似文献
995.
L. V. Morozova I. V. Tatarinova N. P. Kuznetsova M. V. Markova O. A. Tarasova L. M. Sinegovskaya T. I. Vakul’skaya A. I. Mikhaleva B. A. Trofimov 《Russian Chemical Bulletin》2006,55(6):1010-1014
Polyfunctionalized linear copolymers of N-allenylimidazole and di(ethylene glycol) divinyl ether with polyconjugated (polyvinylene) blocks in the main chain and exomethylene
bonds and vinyloxyethoxyethyl groups in the side chain were prepared. Using the reaction of the copolymers with CuCl2, a possibility of synthesis of polymeric metal complexes for catalysis of organic reactions was shown. The IR and ESR spectra
of the complexes were studied.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 973–977, June, 2006. 相似文献
996.
Bijal Kottukkal Bahuleyan Dae-Won Park Chang-Sik Ha Il Kim 《Catalysis Surveys from Asia》2006,10(2):65-73
In this review article, we have consolidated our recent studies on late transition metal catalysts (mainly Fe, Co) for olefin polymerization/oligomerization. A series of bisiminopyridyl Co(II) and Fe(II) complexes were synthesized. These catalysts when activated with MAO in aromatic or aliphatic hydrocarbon solvents, oligomerize or polymerize ethylene to α-olefins or high molecular weight polymers with exceptionally high activities and selectivities. The electronic and steric effects of allyloxy and benzyloxy substituted bisiminopyridyl Fe(II) and Co(II) complexes were also investigated. The influence of catalyst structure and temperature on the polymerization activity, thermal properties and molecular weight were discussed. The effects of heterogenization of these catalysts on silica and modified SBA-15 were analyzed. The polymerization of polar monomers such as vinyl ethers and methyl methacrylate was tested and no specific trends in activity and polymer molecular weight with changes in steric bulkiness around the metal center were observed with the same catalyst system. 相似文献
997.
对废轮胎回转窑中试热解炭的重金属离子Pb2+、Cr3+和Cr6+吸附特性进行了研究,分析了溶液pH值、接触时间、吸附剂用量以及溶液初始浓度对重金属去除率的影响。结果表明,溶液pH值对热解炭的重金属去除率有显著影响,阳离子Pb2+、Cr3+的去除率随pH的增加而增大,在弱酸和中性环境中去除率接近100%;Cr6+在强酸性溶液中被还原成为Cr3+,经二次吸附,总Cr去除率可达99%以上;Pb2+和Cr3+的去除率随热解炭用量和吸附时间的增大而增加,热解炭用量和吸附时间有一个最佳值。Pb2+和Cr3+的吸附为单分子层吸附,可用Langnuir和两段Freundlich等温吸附式描述,Freundlich拟合指数表明,热解炭具有较好的吸附性能。经酸洗后的热解炭对Pb2+的去除率变低。 相似文献
998.
999.
平面四方金属苯配合物的二阶超极化率的量子化学计算 总被引:4,自引:1,他引:4
反位平面四方型过渡金属有机配合物[XM(PEt3)2-C6H4-A] (M=Pd, Pt; X=Br, I; A=NO2, CHO), 具有较高的二阶超极化率. 采用从头算方法对该配合物的二阶超极化率进行了研究. 构型在MP2/Lanl2DZ水平优化. 基组采用赝势价分裂基Lanl2DZ添加弥散函数和极化函数. HF水平计算(个别情况用MP2计算验证)表明, 苯的对位取代基A的吸电子能力越强, 金属对位配体X的供电子能力越强, 则配合物的二阶超极化率越大. 相似文献
1000.
Filippi A Speranza M Paladini A De Carolis R Guidoni AG Laganà A Satta M 《Journal of mass spectrometry : JMS》2006,41(1):98-102
Diastereomeric clusters of general formula [MAB(2)](+) and [MA(2)B](+) (M = Li(I), Na(I), Ag(I), Ni(II)-H, or Cu(II)-H; A = (R)-(-)- and (S)-(+)-(1-aminopropyl)phosphonic acid; B = (1R)-(-)- and (1S)-(+)-(1-aminohexyl)phosphonic acid) have been readily generated in the electrospray ionization (ESI) source of a triple-quadrupole mass spectrometer and their collision-induced dissociation (CID) investigated. CID of diastereomeric complexes, e.g. [MA(S)(B(S))(2)](+) and [MA(R)(B(S))(2)](+), leads to fragmentation patterns characterized by R(homo) = [MA(S)B(S)](+)/[M(B(S))(2)](+) and R(hetero) = [MA(R)B(S)](+)/[M(B(S))(2)](+) abundance ratios, which depend upon the relative stability of the diastereomeric [MA(S)B(S)](+) and [MA(R)B(S)](+) complexes in the gas phase. The chiral resolution factor R(chiral) = R(homo)/R(hetero) is found to depend not only on the nature of the M ion but also on that of the fragmenting species, whether [MAB(2)](+) or [MA(2)B](+). The origin of this behavior is discussed. 相似文献