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991.
The component in the heavy-ion optical potential due to the Coulomb coupling to inelastic channels has been calculated using the on-energy-shell approximation for the intermediate-channel Green's functions. Closed expressions were derived for the Coulomb polarization potential representing coupling to all orders in the K = 0 rotational band. As a test of this general aproach for coupling to higher states, elastic-scattering calculations were performed with a truncated expression which included reorientation in the 2+ state and coupling to the 4+ state to all orders. Comparison with coupled-channels calculations indicate the increasing importance of off-shell effects with increasing coupling strength. An analytical estimate of offshell effects is presented. Limits on the range of validity of the optical-potential approach are determined. 相似文献
992.
993.
N. S. Prostakov Mikhalis Makuli N. M. Mikhailova Hussein Abubakr N. D. Sergeeva A. A. Obynochnyi 《Chemistry of Heterocyclic Compounds》1985,21(4):449-452
3-Methyl-9-phenylethynyl-2-azafluoren-9-ol, 3-methyl-9-phenacylidene-2-azafluorene, and spiro compounds with 2-azafluorene, indan, pyrazoline, and cyclopropane fragments were obtained starting from 3-methyl-2-azafluorenone by successive transformations. Information regarding the spatial structures of the synthesized compounds was obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 539–541, April, 1985. 相似文献
994.
995.
Mohamed M. El-Kerdawy Ali A. El-Emam Hussein I. El-Subbagh Elie Abushanab 《Monatshefte für Chemie / Chemical Monthly》1989,120(11):991-995
Summary Interaction of ethyl 2-acetamido-5-bromothiazole-4-carboxylate (2) with 2-methyl-5-chlorothiophenol (3) afforded the thioether4, which was hydrolysed to the corresponding carboxylic acid5. Attempted cyclization of5 to6 yielded the decarboxylated product7. On the other hand, interaction of 2-acetamido-5-bromothiazole (9) with thiosalicylic acid (10) yielded the thioether11, which was cyclized to compound12. Acid hydrolysis of12 yielded the amino derivative13, which was reacted with certain selected alkyl halides using sodium hydride to afford compounds14–18.
Synthese von substituierten 4H-Thiazolo[4,5-b][1]benzothiopyran-4-onen als mögliche schistosomicide Wirkstoffe
Zusammenfassung Die Reaktion von Ethyl 2-Acetamido-5-bromthiazol-4-carboxylat (2) mit 2-Methyl-5-chlorthiophenol (3) ergab den Thioether4, der zur entsprechenden Carbonsäure5 hydrolysiert wurde. Die versuchte Cyclisierung von5 zu6 ergab das Decarboxylierungsprodukt7. Andererseits ergab die Reaktion von 2-Acetamido-5-bromthiazol (9) mit Thiosalizylsäure (10) den Thioether11, der zu Verbindung12 cyclisiert werden konnte. Saure Hydrolyse von12 ergab das Aminoderivat13, das mit geeigneten Alkylhalogeniden unter Verwendung von Natriumhydrid zu den Verbindungen14–18 führte.相似文献
996.
Ahmad Q. Hussein Mustafa M. El-Abadelah Wail S. Sabri 《Journal of heterocyclic chemistry》1984,21(2):455-459
Condensation of arylnitrile oxides with α-amino acid esters, other than those of glycine and analine, has been found to constitute a synthetic route to the hitherto unknown 1,2,4-oxadiazin-6-ones 7. α-Amino alcohols yield with nitrile oxides the corresponding acyclic N-(arylhydroxamoyl)amino alcohols, which are also accessible by borohydride reduction of compounds 7 . In contrast, the adducts formed from nitrile oxides and α-amino acids are unstable; they decompose readily into the aldehyde, derived from the amino acid, together with the aldoxime, derived from the nitrile oxide. Both decomposition products are also formed when compounds 7 are subjected to mild hydrolysis. 相似文献
997.
N. S. Prostakov A. V. Varlamov A. A. Fomichev A. é. Aliev V. M. Polosin V. A. Rezakov Hussein Annan 《Chemistry of Heterocyclic Compounds》1989,25(1):108-112
9-Imino derivatives of dihydrosilaazaanthracenes were obtained from 10,10-diorganosila-2-azaanthrones. It was shown by PMR spectroscopy that they exist in the form of Z and E isomers. The azomethines were reduced to secondary amines, from which the N-acyl derivatives were obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 126–129, January, 1989. 相似文献
998.
The factors affecting the ultramicrodetermination of tryptophan and kynurenine were investigated by paper electrophoresis, paper chromatography and spectrophotometry. The electrolyte used in electrophoresis influences the mobility, the separation and the ultraviolet spectra of tryptophan and kynurenine. The pre-treatment of filter paper for chromatography did not influence the RF of tryptophan and kynurenine, but interfered with their quantitative determination. The effect of ultraviolet irradiation of d-, l-, and dl-tryptophan as well as d-, l-, and dl-kynurenine was studied. 相似文献
999.
S. S. Tahir Rauf Naseem Anwar ul Haq Khalid Saeed 《Accreditation and quality assurance》2005,10(7):362-368
This inter-laboratory comparison study was arranged for 28 laboratories from different public and private sector organizations
in Pakistan having wastewater testing capabilities aimed at improving the quality and comparability of test results. This
national inter-laboratory study was started in December 2003 and completed in July 2004. Laboratories were invited to analyze
the wastewater collected from printed circuit board (PCB) industry for lead and copper contamination. The samples fulfill
the criteria for homogeneity and stability as done by the reference laboratory. The results obtained from participating laboratories
were analyzed in terms of Hampel Test for outliers, while the performance evaluation of the participating laboratories was
done on the basis of Z-score. An assigned value derived from the participant's results was compared with a reference value provided by a reference
laboratory. Overall >50% of the participating laboratories have shown good performance in this PT-program 相似文献
1000.
Syed Raza Shah Zarbad Shah Najeeb Ullah Javid Hussain Rashid Al-Harrasi Ajmal Khan Jeremy M. Rawson Ahmed Al-Harrasi Muhammad U. Anwar 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(3):294-303
Reactions of 1,10‐phenanthroline (phen) and 2‐(3,4‐dichlorophenyl)acetic acid (dcaH) with Mn(CO3) (M = LiI, NaI and MgII; n = 1 and 2) in MeOH yield the mononuclear lithium complex aqua[2‐(3,4‐dichlorophenyl)acetato‐κO](1,10‐phenanthroline‐κ2N,N′)lithium(I), [Li(C8H5Cl2O2)(C12H8N2)(H2O)] or [Li(dca)(phen)(H2O)] ( 1 ), the dinuclear sodium complex di‐μ‐aqua‐bis{[2‐(3,4‐dichlorophenyl)acetato‐κO](1,10‐phenanthroline‐κ2N,N′)sodium(I)}, [Na2(C8H5Cl2O2)2(C12H8N2)2(H2O)2] or [Na2(dca)2(phen)2(H2O)2] ( 2 ), and the one‐dimensional chain magnesium complex catena‐poly[[[diaqua(1,10‐phenanthroline‐κ2N,N′)magnesium]‐μ‐2‐(3,4‐dichlorophenyl)acetato‐κ2O:O′] 2‐(3,4‐dichlorophenyl)acetate monohydrate], {[Mg(C8H5Cl2O2)(C12H8N2)(H2O)2](C8H5Cl2O2)·H2O}n or {[Mg(dca)(phen)(H2O)2](dca)·H2O}n ( 3 ). In these complexes, phen binds via an N,N′‐chelate pocket, while the deprotonated dca? ligands coordinate either in a monodentate (in 1 and 2 ) or bidentate (in 3 ) fashion. The remaining coordination sites around the metal ions are occupied by water molecules in all three complexes. Complex 1 crystallizes in the triclinic space group P with one molecule in the asymmetric unit. The Li+ ion adopts a four‐coordinated distorted seesaw geometry comprising an [N2O2] donor set. Complex 2 crystallizes in the triclinic space group P with half a molecule in the asymmetric unit, in which the Na+ ion adopts a five‐coordinated distorted spherical square‐pyramidal geometry, with an [N2O3] donor set. Complex 3 crystallizes in the orthorhombic space group P212121, with one Mg2+ ion, one phen ligand, two dca? ligands and three water molecules in the asymmetric unit. Both dcaH ligands are deprotonated, however, one dca? anion is not coordinated, whereas the second dca? anion coordinates in a bidentate fashion bridging two Mg2+ ions, resulting in a one‐dimensional chain structure for 3 . The Mg2+ ion adopts a distorted octahedral geometry, with an [N2O4] donor set. Complexes 1 – 3 were evaluated against urease and α‐glucosidase enzymes for their inhibition potential and were found to be inactive. 相似文献