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1.
Nelly A. Kachurovskaya Georgii M. Zhidomirov Rutger A. van Santen 《Research on Chemical Intermediates》2004,30(1):99-103
Periodical calculations of Zn(II) metal cation stabilization in cationic positions with distantly placed aluminium ions has been performed for high-silica ferrierite. It was found that decrease of the stabilization energy at large distances between Al ions (more than 10 Å) is about of 2 eV in comparison with nearest possible position of two Al ions in the zeolite lattice and weekly depended on following increase of the Al-Al distance. Main changes in stabilization energy occured within a 3-Å interval of these distances. Only for the localizations of both Al ions in one zeolite ring zinc cationic form is more stable than hydrogen form. 相似文献
2.
Tsibakhashvili NY Asatiani NV Abuladze MK Birkaya BG Sapojnikova NA Mosulishvili LM Holman HY 《Biomedical chromatography : BMC》2002,16(5):327-331
Rapid and effective separation of bacteria Arthrobacter oxydans was performed using capillary electrophoresis. For optimal separation of bacteria the influence of buffer concentration, pH and applied voltage were studied. It was found that the most appropriate conditions for electrophoretic mobility measurements are as follows: applied voltage 6-14 kV; buffer concentration 5-10 mM pH 6-8. At the stationary phase of growth there are always two main heterogeneous peaks. They are connected with the morphology of bacteria as well as with cell aggregation. The heterogeneity of samples may be explained by surface modifications of bacterial cells. 相似文献
3.
4.
Pierre Thuéry Nelly Keller Monique Lance Julien-Daniel Vigner Martine Nierlich 《Journal of inclusion phenomena and macrocyclic chemistry》1994,20(1):89-96
The doubly deprotonated form of calix[6]arene, with two protonated triethylamines as counter-ions, crystallizes in the monoclinic system: space groupP21/n,a=8.465(4),b=17.822(8),c=15.182(6) Å,=90.18(4)°,V=2291(2) Å3,Z=2. Refinement led to a final conventionalR value of 0.063 for 1046 reflections. The macrocycle conformation is not apinched cone, usual for freeR-calix[6]arene, but a distorted 1,2,3-alternate cone, since the molecule lies on a symmetry center. Furthermore, one of the torsion angles defined by the methylene bridges is near to zero, which is unusual in calixarene structures.
Supplementary Data relating to this article (atomic coordinates for hydrogen atoms, anisotropic displacement parameters for oxygen and nitrogen atoms, and observed and calculated structure factors) are deposited with the British Library as Supplementary Publication No. SUP 82182 (7 pages). 相似文献
5.
Nelly Konopik 《Monatshefte für Chemie / Chemical Monthly》1961,92(1):8-21
Zusammenfassung Analog der Brenzcatechingermaniumsäure geben die komplexen Germaniumsäuren von Pyrogallol und 2,3-Dihydroxynaphthalin-6-sulfonsäure in saurer Lösung (pH<4,0) an der Hg-Tropfelektrode relativ positiv liegende Reduktionsstufen, die in Abhängigkeit vom pH, von der Ionenstärke, von der o-Diphenol-sowie von der Ge-Konzentration untersucht wurden. Ferner wurde festgestellt, daß der Grenzstrom durch Diffusion kontrolliert wird und daß bei der Reduktion je Ge-Atom 4 Elektronen aufgenommen werden. Mit Hilfe derJ obschen Methode der kontinuierlichen Variation wurde potentiometrisch und spektrophotometrisch die Zusammensetzung der in Lösung befindlichen Komplexe zu 1 Ge: 3 Phenol bestimmt.Mit 13 AbbildungenHerrn Prof. Dr.J. Heyrovský zum. 70. Geburtstag gewidmet.Der elektrochemische Teil der Arbeit wurde beim 2. Seminar für Elektrochemie Ende Dezember 1960 in Karaikudi vorgetragen. 相似文献
6.
Nelly Konopik 《Fresenius' Journal of Analytical Chemistry》1966,224(1):107-116
Zusammenfassung Germaniumsäure reagiert mit den Formen H4Y und H3Y- der Äthylendiamintetraessigsäure unter Bildung von 11-Komplexverbindungen mit den folgenden Stabilitätskonstanten: K
H4Y=6.27·104 bzw. K
H4Y=5.99·104 und K
H3Y=3,78·104 bzw. K
H3Y=2,35·104 (25°C; Ionenstarke 0,1 m), je nachdem, mit welchen Werten für die Dissoziationskonstanten der ÄDTE gerechnet wird.
Herrn Prof. Dr. M. von Stackelberg zum 70. Geburtstag gewidmet.
Herrn Prof. Dr. H. Nowotny danke ich für wertvolle Diskussionen. Bei der Ausführung der Experimente haben mich in dankenswerter Weise vor allem Herr A. Grumer, ferner Frl. L. Docekal, Frl. E. Hofmeister und Herr P. Angelbeger unterstützt. 相似文献
Summary Germanic acid reacts with the species H4Y and H3Y- of EDTA forming 11 complex compounds. The following stability constants have been obtained: K H4Y=6.27x104 resp. K H4Y=5.99x104 and K HaY=3.78x104 resp. K H2Y=2.35x104 (25°C; ionic strength 0.1 m), depending on the values inserted for the dissociation constants of the EDTA.
Herrn Prof. Dr. M. von Stackelberg zum 70. Geburtstag gewidmet.
Herrn Prof. Dr. H. Nowotny danke ich für wertvolle Diskussionen. Bei der Ausführung der Experimente haben mich in dankenswerter Weise vor allem Herr A. Grumer, ferner Frl. L. Docekal, Frl. E. Hofmeister und Herr P. Angelbeger unterstützt. 相似文献
7.
Viktoriya V. Skripacheva Ella Kh. Kazakova Nelly A. Markarova Vladimir E. Kataev Ludmila V. Ermolaeva Wolf D. Habicher 《Journal of inclusion phenomena and macrocyclic chemistry》2002,42(1-2):77-81
The binding of different sized and shaped metal complexes [Co(His)2]ClO4(1), [Co(en)2C2O4]Cl (2) and [K18-crown-6]SCN (3)(en-ethylendiamine, His-L-histidynate-anion) with a new tetrasulfonatomethylcalix[4]resorcinarene([H8X]Na4) was investigated in neutral and alkaline aqueous media by NMR and pH-metrictitration methods and compared with those of recently studied NMe4Br (4). The resultsobtained indicate that the outer-sphere coordination of complexes 1–3 by[H8X]4- proceeds via the interaction of hydrophobic fragments of the guestswith both the negatively charged rim and the hydrophobic cavity as a -base. Thenature of binding does not change for cations 1, 2 and 4 on going from[H8X]4- in neutral to [H4X]8- in alkaline media, while the inclusionof 3 decreases on going from [H8X]4- to [H4X]8-. 相似文献
8.
Justes DR Mitrić R Moore NA Bonacić-Koutecký V Castleman AW 《Journal of the American Chemical Society》2003,125(20):6289-6299
We present joint theoretical and experimental results which provide evidence for the selectivity of V(x)O(y)(+) clusters in reactions toward ethylene due to the charge and different oxidation states of vanadium for different cluster sizes. Density functional calculations were performed on the reactions between V(x)O(y)(+) and ethylene, allowing us to identify the structure-reactivity relationship and to corroborate the experimental results obtained by Castleman and co-workers (Zemski, K. A.; Justes, D. R.; Castleman, A. W., Jr. J. Phys. Chem. A 2001, 105, 10237). The lowest-energy structures for the V(2)O(2)(-)(6)(+) and V(4)O(8)(-)(10)(+) clusters and the V(2)O(3)(-)(6)(+)-C(2)H(4) and V(4)O(10)(+)-C(2)H(4) complexes, as well as the energetics for reactions between ethylene and V(2)O(4)(-)(6)(+) and V(4)O(10)(+) are presented here. The oxygen transfer reaction pathway was determined to be the most energetically favorable one available to V(2)O(5)(+) and V(4)O(10)(+) via a radical-cation mechanism.The association and replacement reaction pathways were found to be the optimal channels for V(2)O(4)(+) and V(2)O(6)(+), respectively. These results are in agreement with the experimental results reported previously. Experiments were also conducted for the reactions between V(2)O(5)(+) and ethylene to include an energetic analysis at increasing pressures. It was found that the addition of energy depleted the production of V(2)O(4)(+), confirming that a more involved reaction rather than a collisional process is responsible for the observed phenomenon. In this contribution we show that investigation of reactions involving gas-phase cationic vanadium oxide clusters with small hydrocarbons is suitable for the identification of reactive centers responsible for selectivity in heterogeneous catalysis. 相似文献
9.
10.