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171.
Dr. Surjyakanta Rana Dr. Suresh Maddila Dr. Kotaiah Yalagala Suryanarayana Maddila Prof. Sreekantha B. Jonnalagadda 《ChemistryOpen》2015,4(6):703-707
The surface of graphene oxide (GO) was modified using [3‐(2‐aminoethylamino)propyl]trimethoxysilane (diamine), which exhibited excellent catalytic activity for one‐pot multicomponent reactions. The newly synthesized material was fully characterized by various instrumental techniques including Fourier‐transfer infrared (FTIR) and Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The instrumental analysis confirmed the successful grafting of organic amine functional groups onto the graphene oxide surface. The diamine‐functionalized GO proved to be an excellent catalyst for the synthesis of pyrazolo‐pyranopyrimidine derivatives with 93 % yield and high selectivity. The catalytic activity almost remained unaltered up to three cycles. The newly synthesized pyrazolo‐pyranopyrimidine derivatives have potential use as scaffolds in designing new pharmaceutical products. 相似文献
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Polycrystalline materials of rare earth-substituted (La, Sm, Gd and Dy) 5-layered compound of Bi6Fe2Ti3O18 were prepared by solid state sintering method. Dielectric measurements were made on these samples, which reveal the occurrence of diffuse phase transitions. The Curie temperatures of these materials have been found to be strongly dependent on the size of the rare earth ion. Pyroelectric and P vs. E measurements at room temperature confirm their ferroelectric nature. 相似文献
176.
Reetuparna Ghosh Sylvia Badwar Bioletty Mary Lawriniang Vibha Vansola Haladhara Naik Yeshwant Naik SaraswatulaVenkata Suryanarayana Nilesh Subhash Tawade Sapna Padmakumar Suresh Chand Sharma Shri Krishna Gupta Betylda Jyrwa Srinivasan Ganesan Pitamber Singh Ashok Goswami 《Journal of Radioanalytical and Nuclear Chemistry》2016,307(2):1481-1487
177.
Mamta Sharma D. Raghavender Goud A. K. Gupta M. V. S. Suryanarayana 《Magnetic resonance in chemistry : MRC》2010,48(5):403-408
The complete multinuclear 1H, 13C, 31P and 19F NMR data of symmetrically substituted amines containing N,N‐dialkyl‐P‐alkyl phosphonamidic fluorides are presented. Assignment was achieved, using various one‐and two‐dimensional NMR experiments. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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M. Chandra Sekhar B. Gopalakrishna M. M. Kumar S. V. Suryanarayana 《Crystal Research and Technology》1995,30(3):345-352
Samples with the stoichiometric composition Bi2−xPbxSr2Ca2Cu3−yByOz (x = 0.3, y = 0.2, 0.25, 0.3, 0.4) ceramics were prepared by a solid state reaction method. The samples were annealed at 850 °C for 100 hours (treatment A), and the other at 850 °C for 200 hours (treatment B). From the X-ray diffraction data of a ceramic sample it is revealed that all the samples were mixed phases of 2212 and 2223. The variation of the lattice parameters with the dopant level are represented. From the D.C. four-probe electrical resistivity data it was found that for the samples subjected to treatment B the Tc(0) values were higher than those with treatment A. The A.C. susceptibility data were collected by change in the inductance method. The effect of boron doping on the phase formation and Tc(0) is presented and the volume fraction of the phases estimated from the X-ray data. The presence of boron in the samples was confirmed by the inductive coupled plasma method. The microstructure of the samples was studied by scanning electron microscopy. 相似文献
180.
Summary A new method for the photometric determination of micro quantities of molybdenum through the thiocyanate method has been developed. The reduction of Mo VI to Mo V is achieved by photochemical reaction at 2 N acidity without the addition of an extraneous reducing agent. The coloured complex is stable for about 36 hrs. in 2.0N acid concentration. The method is accurate to about ±1.0% and Beer's Law is obeyed within the limits of 0 to 100 g.
Zusammenfassung Ein Verfahren zur photometrischen Bestimmung von Mikromengen MolybdÄn mit der Thiocyanatmethode wird beschrieben. Die Reduktion von MoVI zu MoV wird durch photochemische Reaktion in 2 n saurem Medium ohne Zusatz eines weiteren Reduktionsmittels erreicht. In diesem SÄuremedium ist der Farbkomplex etwa 36 Std lang stabil. Die erhaltenen Werte sind auf ±1,0% genau und das Beersche Gesetz wird von 0–100 g befolgt.相似文献