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991.
The reaction of 2,6‐pyridinedicarboxylic acid ( 1 , LH2) with CeCl3·7H2O and Sm(NO3)3·6H2O in the presence of triethylamine led to the coordination polymer complexes [M(L)(LH)(H2O)2]·4H2O [M = Ce ( 2 ) and Sm ( 3 )]. Both complexes were characterized by elemental analyses, IR spectroscopy and the crystal structures of 2 and 3 . Crystal data for 2 at ?80 °C: monoclinic, space group P21/c, a = 1404.6(1), b = 1122.1(1), c = 1296.1(1) pm, β = 102.09(1)°, Z = 4, R1 = 0.0217 and for 3 at ?80 °C: monoclinic, space group P21/c, a = 1395.1(1), b = 1120.1(1), c = 1282.8(1) pm, β = 102.71(1)°, Z = 4, R1 = 0.019. 相似文献
992.
1 INTRODUCTION The 10-benzylidene anthrones which are important intermediate for organic syntheses[1~3] usually possess thermochromism[4] and photo- chromism[5], and have been found recently to have evident anti-cancer activity[6]. We found that the substituents in the phenyl ring will affect the bioactivity of those compounds. For more deeply investigating the structure-activity relationships (SAR) and understanding interactions between the three dimensional structure of the compound … 相似文献
993.
Evert J. Ditzel Xavier L. R. Fontaine Norman N. Greenwood John D. Kennedy Mark Thornton-Pett 《无机化学与普通化学杂志》1992,616(10):79-85
The action of SMe2 on the ten-vertex nido-ruthenaborane [6-(η6-C6Me6)RuB9Hl3] ( 1 ) provides a high-yield route to the unsubstituted isocloso-ruthenaborane [1-(η6-C6Me6)RuB9H9] (2). The benzene analogue [1-(η6-C6Me6)RuB9H9] is prepared similarly. By contrast, reaction of (1) with PhNH2 gives a variety of B-phenylamino isocloso derivatives, including orange crystals of [1-(η6-C6Me6)-2-(PhNH)-isocloso-1-RuB 9 H8] ( 3 ), red-orange [1-(η6-C6Me6)-2,3-(PhNH)2-isocloso-1-RuB9H7] ( 4 ) and dark-red [1-(η6-C6Me6)-5,6,7-(PhNH)3-isocloso-1-RuB9H6] ( 5 ). Detailed 1H and 11B nmr properties of these various compounds are described. The structure of ( 3 ) has been established by a single-crystal X-ray diffraction study of the solvate [1-(η6-C6Me6)-2-(PhNH)-isocloso-1-RuB9H8] · 1/2 CH2Cl2; the crystals were monoclinic, space group C2/c, with a = 1895.1(3), b = 1556.6(3), c = 1716.4(3) pm, β = 104.37(1)° and z = 8. 相似文献
994.
Reaction of COC12.6H20 with equimolar bis(3,5-dimethylpyrazolyl)methane (dmpzm) produced a mononuclear adduct [Co(dmpzm)Cl2] (1). Treatment of 1 with sodium dicyanamide (dca) afforded a polymeric complex [Co(dmpzm)(μ-dca)2]∞ (2). 1 and 2 were characterized by elemental analysis, IR spectra, thermogravimetric analysis and single-crystal X-ray diffraction. The cobalt atom in 1 adopts a distorted tetrahedral coordination geometry, bound to two N atoms of one dmpzm and two Cl atoms. Complex 2 has a 2D brick-wall network (extended along the bc plane) in which the { [Co(dmpzm)(μ-dca)]2} n^2n+ chains are interconnected by pairs of μ-dca anions along the c axis. The magnetic properties of 1 and 2 were also investigated. 相似文献
995.
CrystalandMolecularStructureofaNewMono-substitutedTitanoceneComplex,{(η~5-Cp)[η~5-(1-(4-OCH_3)C_6H_4)C_6H_(10)Cp](TiCl_2)}·0.3(n-... 相似文献
996.
Summary The provitamin A content of some food samples was determined by methods involving MgO: Hyflosupercel gravityflow column chromatography (GFCC) and reversed phase high performance liquid chromatography (HPLC), the quantitation being done by external standardization (HPLC-ES) or internal standardization (HPLC-IS) with Sudan. The results obtained with - and -carotene in carrots, -carotene and -cryptoxanthin in papaya and -carotene in tomato and kale agreed well, showing that any of the these techniques can be used, provided the analysis is done under optimum conditions. Good separation of the different provitamins using GFCC depends on the analyst's skill and visual acuity. HPLC-ES required a constant supply of provitamin standards, thus the varying purity of commercially available standards and the high instability of these compounds could pose grave problems. Due to the stability of Sudan, HPLC-IS appeared to be the method of choice although passage of the extract through a MgO: Hyflosupercel minicolumn was required prior to injection to separate chlorophylls, dihydroxy- and polyoxycarotenoids which would otherwise elute with Sudan. Nonconformity of the Sudan structure to those of the provitamins did not effect the quantitative results. The chromatographic separation, identity and quantification of the provitamins could be more easily established by using HPLC-IS, complemented with GFCC. 相似文献
997.
X-Ray Crystal Structure Determination of 1,3-Bis(diethylamino)-1,3-dibenzyl-2,4-diphenyl-1λ5, 3λ5-diphosphete Benzylidene-diethylamino-benzylfuorophosphorane, 1 , reacts with lithium bis(trimethylsilyl)amide to give the title compounds 2 and 1-diethylamino-2,3-diphenylphosphirane, 3 . Only one of the stereoisomers of 2 is formed in which the two benzyl groups are located on the same side of the planar four-membered ring. 2 crystallizes in the monoclinic space group P21/n. 相似文献
998.
Pyrrolidine dithio carbamate (pdtc) cobalt(III) chelate has been used as a coprecipitation matrix for obtaining preconcentration factors of 100 or more for
analytical estimation of trace metals in natural waters. This chelate, suitable for bivalent and trivalent ions, crystallizes
as dark green crystals in monoclinic space group C2/c with unit cell parametersa = 28.89 ?,b = 14.39 ?,c = 16.17 ? andΒ = 104.2‡. X-ray crystallographic analysis of these crystals reveals that threepdtc are coordinated to a Co
0
3 +
atom through their sulphur atoms, the six sulphur atoms forming a distorted octahedra around the metal atom at an average
distance of 2.26 ?. The thiocarbamate part of the ligands is nearly planar but the pyrrolidine rings are puckered. 相似文献
999.
Synthesis and Structure of the First Ternary Lead(II) Copper(I) Oxide: PbCu2O2 PbCu2O2 can be prepared by solid state reaction or by precipitation from a basic aqueous solution. Single crystals of the new compound were prepared by recrystallisation from a molten mixture (PbO? Cu2O) and investigated by X-ray diffractometer technique. PbCu2O2 crystallizes isotypically with the homologue silver compound PbAg2O2 (monoclinic with a = 8.223 Å, b = 8.289 Å, c = 6.015 Å, β = 132.62°, Z = 4, space group C? C 1 2/c 1). The crystallographic data from the X-ray investigation are reported. The structure is built by endless [PbO4/4]- and [CuO2/4]-chains. Pb2+ has a one-sided asymmetric coordination with four next oxygen neighbours and Cu+ forms a stretched dumbbell with two oxygen atoms. 相似文献
1000.
Ba3N2 reacts at 950°C under pure N2 with Zr to yield dark red, air-sensitive Ba[ZrN2]. This new compound crystallizes in the tetragonal space group P4/nmm with a = 416.10(2), c = 839.2(1) pm and Z = 2. The crystal structure was solved and refined using X-ray and neutron powder diffraction data. In the nitrido zirconate [ZrN2]2? the Zr atoms exhibit a square-pyramidal coordination by five N atoms at distances of 201(3) and 220.2(2) pm. The pyramids share all the edges in the basal plane to form layers parallel to (001) with their apices alternately pointing up and down. The Ba2+ cations are integrated into these layers at the levels of the pyramidal apices. The structure can be interpreted as a stuffed PbFCl type. Ba2[NbN3] is formed by the reaction of Ba3N2 and NbN or of Ba and Nb at 1 000°C under N2. Isostructural to Ba2[TaN3] it crystallizes in the monoclinic space group C2/c with a = 613.2(3), b = 1 176.8(3), c = 1 322.9(4) pm, β = 91.65(2)°, Z = 8. The nitrido niobate anions form chains of corner sharing NbN4 tetrahedra with distances Nb? N between 188(1) and 199.9(9) pm. 相似文献