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971.
Dong Ju Moon 《Catalysis Surveys from Asia》2008,12(3):188-202
Hydrogen has been attracting great interest as a major energy source in near future. The lack of an infrastructure has led to a research effort to develop fuel processing technology for production of hydrogen. In this review, we are reporting the catalytic reforming of gaseous hydrocarbons carried out in our research group, covering dry-reforming of CH4, tri-reforming of CH4, the electrocatalytic reforming of CH4 by CO2 in the SOFC (solid oxide fuel cell) system and steam reforming of LPG. Especially, we have focused on our work, though the related work from other researchers is also discussed wherever necessary. It was found that tri-reforming of CH4 over NiO–YSZ–CeO2 catalyst was more desirable than dry-reforming of CH4 due to higher reforming activity and less carbon formation. The synthesis gas produced by tri-reforming of CH4 can be used for the production of dimethyl ether, Fischer–Tropsch synthesis fuels and high valued chemicals. To improve the problem of deactivation of catalyst due to carbon formation in the dry reforming of CH4, the internal reforming of CH4 by CO2 in SOFC system with NiO–YSZ–CeO2 anode catalyst was suggested for cogeneration of a syngas and electricity. It was found that Rh-spc-Ni/MgAl catalyst showed long term stability for 1,100 h in the steam reforming of LPG under the tested conditions. The addition of Rh to spc-Ni/MgAl catalyst restricted the deactivation of catalyst due to carbon formation in the steam reforming of LPG and diesel under the tested conditions. The result suggested that the developed reforming catalysts can be used in the reforming process of CH4, LNG and LPG for application to hydrogen station and fuel processor system. 相似文献
972.
Jochen A. Kerres Danmin Xing Frank Schönberger 《Journal of Polymer Science.Polymer Physics》2006,44(16):2311-2326
In this study, the properties of novel acid-base blend membranes from polybenzimidazole PBI and self-prepared sulfonated nonfluorinated and partially fluorinated arylene main chain polymers from the polymer classes of aromatic polyethers, polyetherketones, polyethersulfones, and polyphosphine oxides are comparatively discussed. The aims of this study were to (1) determine the influence of the chemical structure of the polymers on their thermal and chemical stabilities and to identify polymeric structures having stabilities as high as possible, and (2) determine the effect of the addition of PBI to sulfonated arylene ionomers in terms of improving of their chemical, thermal, and dimensional stabilities. The working hypothesis of the study was that partially fluorinated arylene main-chain ionomers should have better chemical and thermal stabilities than the F-free ionomers, due to the much higher stability of C F bonds, compared to that of C H bonds. Improved procedures have been used for the polycondensation reactions, by applying an excess of K2CO3 deprotonation compound; the use of a dehydration agent like toluene or benzene was not required. Further, reactions could be performed at lower temperatures than is usually required for such polycondensation reactions; most of the polycondensations were made in a temperature range between 80 and 130 °C. The following properties of the polymers and blend membranes have been determined: proton conductivity, water uptake, swelling, thermal stability including thermal stability of sulfonic acid groups and of the polymer backbone, and oxidative stability by H2O2 treatment. The result of these investigations was that polymers containing fluorinated building blocks and/or phosphine oxide building blocks had the best stabilities. Selected acid-base blend membranes were made from PBI and these aromatic polymers showed proton conductivities of up to 0.1 S/cm, water uptake values of not more than 40%, and starting temperatures for SO3H group splitting-off approaching 290 °C. Moreover, PBI-sulfonated polymer blend membranes showed much less weight loss after H2O2 treatment than does the sulfonated polymers alone, indicating a radical attack-stabilizing effect of PBI. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2311–2326, 2006 相似文献
973.
974.
L. Michael Hayden Won‐Kook Kim Andrew P. Chafin Geoffrey A. Lindsay 《Journal of Polymer Science.Polymer Physics》2001,39(9):895-900
Second harmonic generation (SHG) was used to measure the temperature dependence of the reorientation activation volume (ΔV*) of a syndioregic main‐chain hydrazone (SMCH) nonlinear optical polymer. The decay of the SHG signal from poled films of SMCH was recorded at hydrostatic pressures up to 2924 atm and at temperatures between 25 °C below the glass‐transition temperature (Tg) to 20 °C above it. ΔV* for pressures less than 500–1000 atm and T > Tg decreased as the temperature was increased. For pressures greater than 1000 atm, ΔV* was essentially constant for all temperatures. In addition, the size of ΔV* indicated that the chromophore in this main chain was internally flexible. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 895–900, 2001 相似文献
975.
976.
977.
Dr. Tsuyoshi Taniguchi Prof. Dr. Dennis P. Curran 《Angewandte Chemie (International ed. in English)》2014,53(48):13150-13154
Arynes were generated in situ from ortho‐silyl aryl triflates and fluoride ions in the presence of stable N‐heterocyclic carbene boranes (NHC? BH3). Spontaneous hydroboration ensued to provide stable B‐aryl‐substituted NHC‐boranes (NHC? BH2Ar). The reaction shows good scope in terms of both the NHC‐borane and aryne components and provides direct access to mono‐ and disubstituted NHC‐boranes. The formation of unusual ortho regioisomers in the hydroboration of arynes with an electron‐withdrawing group supports a hydroboration process with hydride‐transfer character. 相似文献
978.
Dr. Thomas P. Robinson Daniel M. De Rosa Prof. Dr. Simon Aldridge Prof. Dr. Jose M. Goicoechea 《Angewandte Chemie (International ed. in English)》2015,54(46):13758-13763
The synthesis of a phosphorus(III) compound bearing a N,N‐bis(3,5‐di‐tert‐butyl‐2‐phenoxy)amide ligand is reported. This species has been found to react with ammonia and water, activating the E? H bonds in both substrates by formal oxidative addition to afford the corresponding phosphorus(V) compounds. In the case of water, both O? H bonds can be activated, splitting the molecule into its constituent elements. To our knowledge, this is the first example of a compound based on main group elements that sequentially activates water in this manner. 相似文献
979.
Prof. Philip N. Bartlett Jennifer Burt Dr. David A. Cook Dr. Charles Y. Cummings Prof. Michael W. George Prof. Andrew L. Hector Mahboba M. Hasan Dr. Jie Ke Prof. William Levason Dr. David Pugh Prof. Gillian Reid Dr. Peter W. Richardson Prof. David C. Smith Joe Spencer Norhidayah Suleiman Dr. Wenjian Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(1):302-309
For the first time, a versatile electrolyte bath is described that can be used to electrodeposit a wide range of p‐block elements from supercritical difluoromethane (scCH2F2). The bath comprises the tetrabutylammonium chlorometallate complex of the element in an electrolyte of 50×10?3 mol dm?3 tetrabutylammonium chloride at 17.2 MPa and 358 K. Through the use of anionic ([GaCl4]?, [InCl4]?, [GeCl3]?, [SnCl3]?, [SbCl4]?, and [BiCl4]?) and dianionic ([SeCl6]2? and [TeCl6]2?) chlorometallate salts, the deposition of elemental Ga, In, Ge, Sn, Sb, Bi, Se, and Te is demonstrated. In all cases, with the exception of gallium, which is a liquid under the deposition conditions, the resulting deposits are characterised by SEM, energy‐dispersive X‐ray analysis, XRD and Raman spectroscopy. An advantage of this electrolyte system is that the reagents are all crystalline solids, reasonably easy to handle and not highly water or oxygen sensitive. The results presented herein significantly broaden the range of materials accessible by electrodeposition from supercritical fluid and open up the future possibility of utilising the full scope of these unique fluids to electrodeposit functional binary or ternary alloys and compounds of these elements. 相似文献
980.
Dr. Kai‐Oliver Feldmann Dr. Thomas Wiegand Dr. Jinjun Ren Prof. Dr. Hellmut Eckert Joachim Breternitz Matthias F. Groh Ulrike Müller Prof. Dr. Michael Ruck Dr. Boris Maryasin Prof. Dr. Christian Ochsenfeld Dr. Oliver Schön Prof. Dr. Konstantin Karaghiosoff Prof. Dr. Jan J. Weigand 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9697-9712
Although a fairly large number of binary group 15/16 element cations have been reported, no example involving phosphorus in combination with a group 16 element has been synthesized and characterized to date. In this contribution is reported the synthesis and structural characterization of the first example of such a cation, namely a nortricyclane‐type [P3Se4]+. This cation has been independently discovered by three groups through three different synthetic routes, as described herein. The molecular and electronic structure of the [P3Se4]+ cage and its crystal properties in the solid state have been characterized comprehensively by using X‐ray diffraction, Raman, and nuclear magnetic resonance spectroscopies, as well as quantum chemical calculations. 相似文献