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31.
Studies on Oxide Catalysts. XVII. On the Relations between Electric and Catalytic Properties of Doped Zinc Oxide Catalysts The electric conductivity and thermo EMF of zinc oxide catalysts doped with Li2O, Ga2O3 and Fe2O3, and, on the other hand, their activity of dehydrogenation in the catalytic decomposition of isopropanol have been studied. The electric measurements were carried out preferably in an atmosphere of isopropanol. In washed single-phase catalysts doped with Li2O (n-type semiconductors) the relation between the catalytic activity of dehydrogenation and the FERMI level position postulated by VOL'KEN?TEJN was verified quantitatively. The absorption of the isopropanol is considered to be the rate-determining acceptor step. In unwashed zinc oxide catalysts doped with Li2O, however, the inversion from n- to p-type (between 0.3 and 0.5 mole-% Li2O) causes a change in the character of the rate-determining step from an acceptor to a donor step. For the two-phase and three-phase solid systems of ZnO? Ga2O3 and ZnO? Fe2O3, respectively, it was not possible to find quantitative relations according to the electron theory of catalysis. 相似文献
32.
The thermal decomposition of ammonium l2-molybdophosphate, prepared under various conditions was studied on the thermobalance. For the HNO3 washed precipitate, a drying temperature of 160° to 415° was recommended; for the NH4NO3 washed compound, a drying temperature of 260° to 430° should be employed. 相似文献
33.
W.W. Wendlandt 《Thermochimica Acta》1974,9(2):101-107
Sealed and open tube DTA curves are reported for nickel sulfate, nitrate, ammonium sulfate, chloride, acetate, formate and perchlorate hydrates. The endothermic peaks for the sealed tube reactions were smaller than those found for the open tubes, due to the lack of water vaporization in the former. With the exception of NiSO4-(NH4)2SO4-6H2O, the peaks for the sealed and open tube reactions appeared at about the same initial peak temperature. The sealed tube reaction intervals (Tf-Ti) were shorter than those found for the open tube. 相似文献
34.
A high pressure electrical conductivity (EC) apparatus. capable of operation at pressures from 1 to 170 atm in the temperature range from 25 to 500°C, is described. The effects of the sample holder geometry, pressure, and sample packing on the resulting EC curves are given. Operation of the apparatus is illustrated by the deaquation reactions of BaCI2·2H20. 相似文献
35.
XRD, isothermal and temperature-programmed reduction (TPR) experiments were carried out with SiO2, SiO2–Al2O3 and -Al2O3 supported catalysts. Molybdena is in a more disperse state on supports containing more alumina and it is more reducible on SiO2–Al2O3 than on SiO2 or -Al2O3. TPR curves were shown to reflect connections between reduction kinetics and dispersity.
-, , SiO2, SiO2–Al2O3 -Al2O3. , , SiO2–Al2O3 SiO2 -Al2O3. .相似文献
36.
W. W. Wendlandt 《Journal of Thermal Analysis and Calorimetry》1969,1(4):469-472
The octahedral-tetrahedral structural transition of Co(py)2Cl2 was studied by high temperature reflectance spectroscopy and dynamic reflectance spectroscopy. The reversibility of the transition by standing at room temperature for 24 hrs was established.
The financial support of this work by the Robert A. Welch Foundation of Houston, Texas, is gratefully acknowledged. The assistance of Mr. Sherman Bradley is also acknowledged. 相似文献
Zusammenfassung Es wurde durch Hochtemperatur-Reflexions-Spektroskopie und dynamische Reflexions-Spektroskopie bewiesen, daß die strukturelle Umwandlung des oktaedrischen Co(py)2Cl2 in die tetraedrische Form nach 24 stündigem Stehen bei Zimmertemperatur reversibel ist.
Résumé On a pruvé par spectroscopie de reflexion de haute température et spectroscopie de reflexion dynamique la réversibilité de la transition structurale octaédrique-tetraédrique de Co(py)2Cl2 après 24 heures.
— ë Co[Py]2Cl2 . 24 .
The financial support of this work by the Robert A. Welch Foundation of Houston, Texas, is gratefully acknowledged. The assistance of Mr. Sherman Bradley is also acknowledged. 相似文献
37.
H. Bremer W. Reschetilowski K.-P. Wendlandt V. Kanazirev Kh. Minchev V. Penchev 《无机化学与普通化学杂志》1985,531(12):67-72
Studies on Oxide Catalysts. XLIII. Thermoanalytic and Catalytic Investigations of Platinum-Containing Zeolites H-ZSM-5 By impregnation with H2PtCl6 from ethanolic solution, after reduction a higher metal dispersion in zeolites Pt/H-ZSM-5 is achieved than by impregnation from aqueous solution. Over such samples, bifunctional catalyzed reactions are more favoured than over zeolites Pt/H-ZSM-5 obtained by impregnation with H2PtCl6 from aqueous solution. 相似文献
38.
W. Schwieger K. -H. Bergk B. Unger K. -P. Wendlandt H. Toufar E. Brunner 《Reaction Kinetics and Catalysis Letters》1992,46(2):271-278
Template-free synthetic, boron-containing pentasil type zeolites exhibit structural and catalytic properties similar to those of SABO zeolites made in the presence of n-propylamine.
, , , SABO, -.相似文献
39.
The thermal properties of the Cu(II), Ni(II) and Co(II) complexes of iminodiacetic acid (H2IMDA) were determined using TG, DTG and DSC techniques. The complexes, of general formula, MIMDA-2H2O evolved water of hydration from 50 to 150°C which was followed by the decomposition of the anhydrous complex in the 250 to 400°C temperature range. The thermal stability, as determined by procedural decomposition temperatures, was: Ni(II) >Co(II) >Cu(II). The thermal stability is discussed in terms of IR spectra, ΔH, and ΔS, as well as thermal data. 相似文献
40.
W.W. Wendlandt 《Thermochimica Acta》1980,37(1):89-96
The thermal dissociation of the [Co(NH3)6]X3 (X = Cl?, Br?, I?, and NO?3), [Co(en)3]X3 (X = Cl?, Br?, I?, NO?3, HSO?4 and C2O2?4), cis- [Co(en)2Cl2]Cl, and trans-[Co(en)2ClBr]NO3 complexes was investigated by an electrical conductivity (EC) technique. During the thermal dissociation reactions, liquid or semi-liquid phases are formed which cause large increases in the EC of the compound. The effect of concentration of the complex in a matrix medium as well as the composition of the matrix material on the EC curves were also determined. 相似文献