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91.
Armand Gautier 《Fresenius' Journal of Analytical Chemistry》1901,40(6):420-422
Ohne Zusammenfassung 相似文献
92.
The fragmentation modes of 3-benzoyloxy-cyclopentene and of 4-benzoyloxy-cyclopentene have been studied on deuterium-labelled analogues. A mathematical model is proposed for the study of the rearrangement reactions which occur during the expulsion of H2O and of \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CO}_2 {\rm H}^. $\end{document} from the molecular ion of 3-benzoyloxy-cyclopentene. 相似文献
93.
Armand Blaschette Peter G. Jones Thomas Hammann Martina Nveke Dietmar Schomburg Heiko K. Cammenga Matthias Epple Ingeborg Steppuhn 《无机化学与普通化学杂志》1993,619(5):912-922
Polysulfonyl Amines. XL. Preparation of Silver(I) Disulfonylamide Acetonitrile Complexes. Characterization of Tetraacetonitrilesilver(I) bis(dimesylamido)argentate(I) and (1,1,3,3-Tetraoxo-1,3,2-benzodithiazolido)acetonitrilesilver(I) by X-Ray Diffractometry and Thermal Analysis The following silver(I) disulfonylamides were prepared for the first time or by improved procedures: AgN(SO2CH3)2 ( 2a ); AgN(SO2C6H4-4-X)2 with X = F ( 2b ), Cl ( 2c ), Br ( 2d ), CH3 ( 2e ); silver(I) 1,2-benzenedisulfonimide AgN(SO2)2C6H4 ( 2f ). With acetonitrile, the salts 2a to 2e form (1/2) complexes AgN(SO2R)· 2 CH3CN ( 4a to 4e ), whereas 2f gives the (1/1) complex AgN(SO2)2C6H · CH3CN ( 4f ). The crystallographic data (at - 95°C) for the title compounds 4a and 4f are: 4a , space group C2/c, a = 1 967.6(4), b = 562.2(1), c = 2 353.0(5) pm, β = 102.21(2)°, V = 2.5440 nm3, Z = 4, Dx = 1.891 Mg m?3; 4f , space group P21/m, a = 741.5(3), b = 980.4(4), c = 756.6(3) pm, β = 99.28(2)°, V = 0.5428 nm3, Z = 2, Dx = 2.246 Mg m?3. 4a forms an ionic crystal [Ag(NCCH3)4]⊕[Ag{N(SO2CH3)2}2]? with a tetrahedrally coordinated silver atom (lying on a twofold axis) in the cation (225.3/225.7 pm for the two independent Ag? N distances, N? Ag? N 106.2—114.5°) and a linear-dicoordinated silver atom in the centrosymmetric anion (Ag? N 213.9 pm, two intraionic secondary Ag…O contacts 303.4 pm). 4f consists of uncharged molecules [C6H4(SO2)2N1AgN2CCH3] with crystallographic mirror symmetry (Ag? N1 218.8, Ag? N2 216.1 pm, N1? Ag? N2 174.3°), associated into strands by intermolecular secondary silver-oxygen contacts (Ag…O 273.8 pm, O…Ag…O 175.6, N? Ag…O 91.9/88.2°). The thermochemical behaviour of 4f was investigated using thermogravimetry, differential scanning calorimetry (DSC), time- and temperature-resolved X-ray diffractometry (TXRD), and solution calorimetry. The desolvation process occurs in the temperature range from 60 to 200°C and appears to be complex, although no crystalline intermediate could be detected. The desolvation enthalpy at 298 K was found to be + 26.8(4) kJ mol?1. 4a is desolvated in two steps at - 15 to 60°C and 60 to 95°C (DSC), suggesting the formation of AgN(SO2CH3) · CH3CN as an intermediate. 相似文献
94.
Polysulfonylamines. CLXVI. Crystal Structures of Metal Di(methanesulfonyl)amides. 15. The Isotypic Crystal Structures of Ammonium and Cesium Dimesylamide: Crystallographic Congruency of Hydrogen Bonds N—H···O/N and Metal‐Ligand Interactions Cs—O/N The ammonium salt NH4[N(SO2CH3)2] and its previously reported cesium analogue Cs[N(SO2CH3)2] are isostructural (monoclinic, space group P21/n, Z = 4, V at —140 °C: 0.761 and 0.832 nm3 respectively). The cesium ion adopts an irregular (O6N)‐heptacoordination by forming close contacts to one (O, N)‐chelating, one (O, O)‐chelating and three κ1O‐bonding anions, whereas in the ammonium‐based structure each of the seven Cs—O/N interactions is perfectly mimicked by an N—H···O/N hydrogen‐bond component. To this effect, three N—H donors are engaged in asymmetric three‐centre bonds, the fourth in a moderately strong and approximately linear two‐centre bond. The crystal packings consist of anion monolayers that intercalate planar zigzag rows of cations propagating around symmetry centres (Cs···Cs alternatingly 422.5 and 487.5 pm, Cs···Cs···Cs 135.7°; N···N alternatingly 397.4 and 474.1 pm, N···N···N 136.1°). Each cation row is surrounded by and bonded to four translation‐generated anion stacks, and each anion stack connects two cation rows. The net effect is that the packings display congruent three‐dimensional networks of metal‐ligand bonds or hydrogen bonds, respectively. Moreover, close C—H···O/N interanion contacts consistent with weak hydrogen bonding are observed in both structures. 相似文献
95.
Jrg Dalluhn Hans‐Heinrich Prhl Axel K. Fischer Peter G. Jones Armand Blaschette 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1109-1111
The prominent features in the molecular structure of the title compound (alternative name: 2‐diethylcarbamoyl‐1,1,3,3‐tetraoxo‐1,3,2‐benzodithiazole), C11H14N2O5S2, arise in the urea moiety S2N—C(O)—N′C2: the sum of the angles at N is 332.3 (1)°, the N—C(O)—N′C2 unit is planar, and distances N—C(O) = 1.494 (3) Å, N′—C(O) = 1.325 (2) Å and C—O = 1.215 (2) Å. The molecules are associated via five C—H?O hydrogen bonds to form layers parallel to the yz plane. This compound and its dimethyl homologue, which were synthesized by treating the silver salt of o‐benzenedisulfonimide with carbamoyl chlorides, are prone to rapid hydrolysis at the weak N—C(O) bond. For both molecules, the rotational barrier about the partial N′—C(O) double bond is ca 50 kJ mol?1 at 250 K (from dynamic 1H NMR experiments). 相似文献
96.
Kaszuba Natalia Kasprzyk-Kucewicz Teresa Bałamut Karolina Morawiec Tadeusz Stanek Agata Wziątek-Kuczmik Daria Cholewka Armand 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6745-6753
Journal of Thermal Analysis and Calorimetry - The main goal of this study was to find out if thermal imaging may be useful in the evaluation of two types of anaesthetic injections—with and... 相似文献
97.
Tepper AW Bubacco L Canters GW 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(29):7668-7675
The (1)H NMR relaxation characteristics of the histidines in the oxidised type-3 copper site of tyrosinase (Ty(met)) from the bacterium Streptomyces antibioticus in the halide-bound forms (Ty(met)X with X = F(-), Cl(-), Br(-)) have been determined and analysed. The (1)H NMR spectra of the Ty(met)X species display remarkably sharp, well-resolved, paramagnetically shifted (1)H signals, which originate from the protons of the six His residues coordinated to the two Cu(II) ions in the type-3 centre. From the temperature-dependence of the (1)H paramagnetic shifts the following values for the exchange-coupling parameter -2J were determined: 260 (Ty(met)F), 200 (Ty(met)Cl) and 162 cm(-1) (Ty(met)Br). The (1)H T(1) relaxation is dipolar in origin and correlates with the Cu--H distances. Electronic relaxation times tau(S) derived from the (1)H T(1) data amount to about 10(-11) s and follow the order Ty(met)F>Ty(met)Cl>Ty(met)Br. They are two orders of magnitude shorter than the tau(S) values reported for mononuclear copper systems, in accordance with the sharpness of the (1)H signals. The results corroborate the Cu(2) bridging mode of the halide ions. On the basis of the measured hyperfine interaction constants for the ligand histidine nuclei, it is concluded that 70-80 % of the spin density in the excited triplet state resides on the two copper ions and the bridging atoms. 相似文献
98.
Binet C Bourrier D Dilhan M Estève D Ferrère S Garrigue JC Granier H Lattes A Gué AM Mauzac M Mingotaud AF 《Talanta》2006,69(3):757-762
Liquid crystalline thin films elastomers that are able to bind pesticides have been developed. The synthesis involves grafting mesogen and crosslinkable groups on a polysiloxane chain in the presence of a template molecule. The molecular imprinted material is obtained after thin film deposition, UV crosslinking and washing. Experiments of readsorption of pesticide are presented. Development of a multisensor platform based on thermal and capacitive sensors is described and tests of deposition of the polymer film are presented. 相似文献
99.
We experimentally demonstrate that continuous-wave supercontinuum generation in optical fibers can be significantly enhanced by using both multiwavelength pumping and dispersion management. We show by detailed spectral analysis that continuum enhancement is achieved mainly through a combination of Raman-assisted modulation instabilities, soliton compression, and dispersive wave generation. With this technique, an 800 nm wide (from 1.2 to 2.0 microm) 2 W supercontinuum source is reported that uses a three-wavelength pump and a dispersion-tailored four-optical fibers arrangement. 相似文献
100.