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991.
Essam S. Zakaria Ismail M. Ali Ibrahim M. El-Naggar 《Journal of Radioanalytical and Nuclear Chemistry》2004,261(3):689-696
The ion-exchange isotherms of Ni2+/H+ and Co2+/H+ have been determined with a solution of 0.1 ionic strength for both forward and backward reactions at 25°C by a batch technique. The thermodynamic equilibrium constants for
the exchange process have been calculated using the Gains and Thomas equation. The preference Ni2+>Co2+ has been shown. The ion exchange selectivity for exchange of Ni2+ and Co2+ ions with hydrogen ions on zirconium titanate has been investigated as a function of [HCl] from aqueous and 25% of methanol
and/or ethanol solutions. The values of the thermodynamic functions for the studied systems have been reported.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
992.
Y. A. Ibrahim M. M. Eid M. A. Badawy S. A. L. Abdel-Hady 《Journal of heterocyclic chemistry》1981,18(5):953-956
The action of hydrazine on 3,5-dioxo-4-aryl-2,3,4,5-tetrahydro-1,2,4-triazines gave 4-amino-3,5-dixo-2,3,4,5-tetrahydro-1,2,4-triazines. The intermediates of this reaction were isolated and shown to be α-ketoacidhydra-zide 4-arylsemicarbazones and not the α-ketoanilidecarbohydrazones. The realtive rates of cyclization of the latter isomeric derivatives provide a support for a proposed intermediates which were not isolated in the reaction of 3-mercapto and 3-methylmercapto-4-aryl-5-oxo-4,5-dihydro-1,2,4-triazines with hydrazine. 相似文献
993.
Photolytic substitutions of iron selenocarboxylate complexes CpFe(CO)2SeCOR with triphenylphosphine, triphenylarsine or triphenylantimony (EPh3) gave exclusively the monosubstituted complexes CpFe(CO)(EPh3)SeCOR [R = 3,5-C6H3(NO2)2
(1), 4-C6H4NO2
(2), Ph (3), 2-C6H4Me (4), and E = P (a), As (b), Sb (c)] in high yields. 相似文献
994.
Electron-beam (EB) irradiation technique has been used to improve the properties of 60/40 blends of NR/LLDPE in the presence of compatibilisers such as LNR-6 and LNR-16. Improvement in the physical properties of the blend correspond with the increase in the interactions created by EB irradiation as measured by gel content. For this blend ratio, the radiation dose of 200 kGy is found to be optimum. While LNR-6 shows some complimentary effects when it is used together with EB irradiation technique; LNR-16, however, causes an imperfection effect in the blend. The crosslinking process that takes place as a result of EB irradiation occurs at the expense of crystalline arrangement of the semi-crystalline LLDPE. For the morphological fixation purposes EB irradiation technique is found to be very effective. 相似文献
995.
Two synthetic routes to compounds of the type π-Cp2TiIIIR (R=CH3, CH2Si(CH3)3, C6F5) have been investigated: (a) chemical reduction of π-Cp2TiIV(R)Cl by zinc or aluminum metal in tetrahydrofuran, and (b) conventional organometallic syntheses using organo-lithium or -magnesium reagents and [π-Cp2TiIIICl]2. The preferred route is via an organolithium reagent, since chemical reduction gives a mixture of products. Green, monomeric complexes (R = CH2Si(CH3)3, C6F5) were isolated and characterised. From the reaction of π-Cp2TiIVCl2 and trimethylsilylmethyllithium in a 1/1 ratio, π-CpTiIV [CH2Si(CH3)3]3 was obtained. Unlike π-Cp2TiIIIC6F5, π-Cp2TiIIICH2Si(CH3)3 does not form a blue complex with molecular nitrogen. 相似文献
996.
SOLIMAN Ahmed Youssef ATTIA Ibrahim Abd El-Mogoud SALEM Moneer Abdu Ibrahim SOLIMAN El-SayedAhmed GABER Adel Mohy El-Deen 《中国化学》1996,14(5):437-446
Science Department, Faculty of Teachers, P.O.Box 2313, Al Hasa, 31982, Saudi Arabia Faculty of Engineering, Ain Shames University, EgyptChemistry Department, Faculty of Science, Ain Shames University, Egypt 相似文献
997.
Summary Complexes of CuII, CoII, NiII, CdII, ZnII and HgII with salicylidinebenzenesulphonylhydrazone (HSBS) have been prepared and characterized by elemental analyses, molar conductivities, magnetic moments, spectral (visible, i.r., n.m.r.) and thermal (d.t.a., t.g., d.t.g.) measurements. The magnetic and spectral studies confirm that the NiII complex is square, whereas the CoII complex is tetrahedral. The molar conductivities for the complexes lie in the non-electrolyte range. The corrosion inhibition of aluminium using HSBS was studied by chemical and electrochemical methods. Also, the antimicrobial activities of HSBS and its complexes have been investigated. 相似文献
998.
A rapid and sensitive spectrophotometrc method has been developed for the microdetermination of some phenothiazine derivatives as the pure substances and in different dosage forms. The method depends on the formation of stable donor-acceptor complexes between phenothiazines and chloranilic acid in an acetonitrile-2-propanol solvent mixture. The resulting intensely purple chloranilic acid radical anion possesses a characteristic absorption maximum at 515 nm. Beer's law is obeyed over the concentration ranges 1-6, 1-10 and 5-30 mug ml for prochlorperazine dimaleate, trifluoperazine dihydrochloride and thiethylperazine dihydrochloride, with apparent molar absorptivities of 7.76 x 10(4), 1.95 x 10(4) and 6.64 x 10(3) 1. mole(-1).cm(-1), respectively. Statistical comparison of the results with those of an official method shows excellent agreement and indicates no significant difference in precision. 相似文献
999.
Hoong‐Kun Fun S. Kannan Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):m368-m370
In the title compound, [UO2(C15H11O2)2(C14H14OS)], the UVI atom is coordinated by seven O atoms in a distorted pentagonal–bipyramidal geometry. Both diphenylpropane‐1,3‐dionate systems are nearly planar. The sulfoxide moiety is in a distorted tetrahedral geometry, while its two aromatic rings are nearly orthogonal to one another. The crystal packing is stabilized by two bifurcated hydrogen‐bonding interactions involving both uranyl O atoms. 相似文献
1000.
Anders Hallberg Ibrahim Al-Showaier Arnold R. Martin 《Journal of heterocyclic chemistry》1984,21(3):841-844
Electron impact induced fragmentation patterns of simple phenothiazines have been reinvestigated using metastable ion studies, exact mass measurements and deuterated derivatives. Secondary fragmentation processes involving ions m/e 198, 171, 167, 166, 154, 140 and 139 have been clarified. Mechanisms for the release of sulfur (SH· and CSH·) nitrogen (HCN and H2CN·) containing fragments from phenothiazine molecular ion are proposed based on the deuterium content of the daughter ions obtained from 1,9-dideutenophenothiazine. A revised mechanism for the expulsion of ketene from 10-acetylphenothiazine is suggested based on the fragmentation pattern of the 1,9-dideuterioderivative. The composition of m/e 140 was determined by high resolution measurement to be C10H6N and not C11H7 as previously reported. 相似文献