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1.
A highly transparent and thermally stable copolymer of 1‐adamantyl methacrylate and styrene
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Thermal and optical properties of copolymers of 1‐adamantyl methacrylate (AdMA) and styrene (St) prepared by free radical polymerization in the bulk are investigated. The copolymer forms an azeotrope when the composition is AdMA/St = 55/45 mol%. The glass transition temperature and decomposition temperature of the azeotropic copolymer are 170 and ca 340 °C, respectively. The refractive index increases nonlinearly with St content from 1.522 to 1.591. The light scattering loss at 633 nm is 28.1 dB km?1, which is less than half of that of polystyrene. The total optical loss including molecular vibrational absorption, which is evaluated using a copolymer‐based optical fiber, is 292–645 dB km?1 at 500–700 nm. These values correspond to transmittances of 86–93% for a 1 m optical path length. © 2014 Society of Chemical Industry 相似文献
2.
Atsushi Narumi Kosei Kawasaki Harumi Kaga Toshifumi Satoh Naoya Sugimoto Toyoji Kakuchi 《Polymer Bulletin》2003,49(6):405-410
Summary
The potato phosphorylase-catalyzed polymerization of α-D-glucose-1-phosphate (G-1-P) onto poly[styrene-block-(4-vinylbenzyl maltohexaoside)] (1) was performed at the molar ratios of [G-l-P]0 and [maltohexaose]0 of 35, 80, and 250. The product was found to be soluble in dimethyl sulfoxide, which was a good solvent for amylose, and
showed the complex-formation with iodine, indicating that the product was assignable to poly[styrene-block-(styrene-graft-amylose)] (2). The quantitative analysis of the liberated phosphoric acid gave the average degree of polymerization o f the glucose unit
(n) as 27, 5 1, and 180 for 2-I, 2-II, and 2-III, respectively.
Received: 29 November 2002/Accepted: 22 December 2002
Correspondence to Toyoji Kakuchi 相似文献
3.
Toshimitsu Suzuki Osamu Yamada Yasuhiko Takahashi Yoshihisa Watanabe 《Fuel Processing Technology》1985,10(1):33-43
Hydroliquefaction of low-sulfur Australian coals (Wandoan and Yallourn) was studied using iron carbonyl complexes as catalyst. The addition of Fe(CO)5 (2.8 wt% Fe of coal) increased coal conversion from 48.6 to 85.2% for Wandoan coal, and from 36.7 to 69.7% for Yallourn coal in 1-methylnaphthalene at 425°C under an initial hydrogen pressure of 50 kg cm?2. When molecular sulfur was added to iron carbonyls (Fe(CO)5, Fe2(CO)9 and Fe3(CO)12), higher coal converions ( > 92%) and higher oil yields (>46%) were obtained, along with an increase in the amount of hydrogen transferred to coal from the gas phase (0.2 to 2.8%, d.a.f. coal basis). In the liquefaction studies using a hydrogen donor solvent, tetralin, Fe(CO)5S catalyst increased the amount of hydrogen absorbed from the gaseous phase and decreased the amount of naphthalene dehydrogenated from tetralin. The direct hydrogen transfer reaction from molecular hydrogen to coal fragment radicals seems to be a major reaction pathway. Organic sulfur compounds, dimethyldisulfide and benzothiophene, and inorganic FeS2 and NiS were found to be good sulfur sources to Fe(CO)5. From X-ray diffraction analyses of liquefaction residues, it is concluded that Fe(CO)5 was converted into pyrrhotite (Fe1?xS) when sulfur was present, but into Fe3O4 in the absence of sulfur. 相似文献
4.
This paper introduces the Precise Rendering Method, which generates accurately anti-aliased and highlighted images from tessellated polygons. The Precise Rendering Method first solves the aliasing problems of hidden surface removal by using the Cross Scanline Algorithm. This algorithm can exactly calculate polygon areas projected onto each pixel by using horizontal and vertical scanlines. Aliasing artifacts in shading are then prevented by the Reflection Intergration Method, which analytically integrates the intensity of reflection in the solid angle defined by surface normals at vertices of the projected area. Several synthesized images are created to show the efficiency of the Precise Rendering Method. 相似文献
5.
Harumi Yokokawa Tatsuya Kawada Masayuki Dokiya 《Journal of the American Ceramic Society》1989,72(1):152-153
It has been found that the enthalpy of formation of perovskite compounds, Δf H° (ABO3 , B = transition metais), from binary oxides can be well characterized in terms the tolerance factor, t≡(rA + ro )√2 (rB + ro ), where rA and rB are the radii of A-site ions with 12-coordination and B-site ions with 6-coordination, respectively, and Δf H°=−168 + 270(1 − t) kJ·mol−1 for AI BV O3 , Δf H°=−125 + 1000(1 − t) kJ·mol−1 for AII BIV O3 , and Δf H°=− 90 + 720(1 − t) kJ·mol−1 for AIII BIII O3 . Although the thermodynamic data of K2 NiF4 compounds are not extensive, a similar regularity can be found when use is made of the radii of A-site ions with 9-coordination for the K2 NiF4 compounds. These correlations will be quite useful in predicting. 相似文献
6.
Na-oyoshi Iwasaki Takanori Miyake Eriko Yagasaki Toshimitsu Suzuki 《Catalysis Today》2006,111(3-4):391-397
Attention has been increasingly paid to the partial oxidation of lower alkanes to synthesis gas, due to its intrinsic energy saving process. We studied the partial oxidation of ethane (POE) on Co loaded on various supports. The POE performance varied as follows: Y2O3, CeO2, ZrO2, La2O3 SiO2, Al2O3, TiO2 > MgO. Comparing Y2O3 and CeO2, the carbon deposition during the POE was negligible on CeO2 and therefore CeO2 was the most preferable support. By changing space velocity and O2 partial pressure, reaction mechanism of POE was studied and it was revealed that two-step mechanism was prevailing; combustion of ethane to H2O and CO2 and subsequent reforming of ethane with H2O and CO2 to synthesis gas. Co/CeO2 catalyst exhibited high and stable catalytic activity for 10 h; high ethane conversion of 18% (maximum ethane conversion 20% at O2/C2H6 = 0.2) with H2 and CO selectivities of 93 and 84%, respectively. 相似文献
7.
Fate of the chlorine and fluorine in a sub-bituminous coal during pyrolysis and gasification 总被引:1,自引:0,他引:1
The fate of the chlorine and fluorine present in a sub-bituminous coal from Indonesia during pyrolysis and gasification has been studied with fixed and entrained bed reactors. The rate profile for HCl evolved in the temperature programmed pyrolysis exhibits the main and shoulder peaks at 480 and 600 °C, respectively. Model experiments and subsequent Cl 2p XPS measurements show that HCl reacts with metal impurities and carbon active sites at 500 °C to be retained as inorganic and organic chlorine forms, from which HCl evolves again at elevated temperatures. It is suggested that the HCl observed in the coal pyrolysis may originate from the above-mentioned chlorine functionalities formed by secondary reactions involving the nascent char. In the CO2 gasification of the 900 °C char at 1000 °C and 2.5 MPa, any measurable amounts of HCl and HF could not be detected even at a high conversion of 75 wt% (daf), suggesting the accumulation of these halogens in the residual char. When the coal is injected into an O2-blown, entrained bed gasifier at 1200-1400 °C under 2.6 MPa, the partial oxidation proceeds to a larger extent at a higher O2/coal ratio, whereas the chlorine and fluorine are enriched in the remaining char, and the extent of the enrichment at the latter stage of gasification is larger with the fluorine. The XPS measurements of the chars reveal the presence of the broad F 1 s peak, which can cover a wide range of binding energies attributable to inorganic and organic fluorine. The halogen enrichment during gasification is discussed in terms of secondary reactions of HCl and HF with char. 相似文献
8.
Maki Itoh Toshimitsu Suzuki Yoshihiko Tsujimoto Ken-ichi Yoshii Yoshinobu Takegami Yoshihisa Watanabe 《Fuel》1983,62(1):98-102
Thermal cracking of tar-sand bitumens has been carried out using a two-stage pyrolysis reactor with temperature zones of 440°C and 750–800°C, respectively. Feedstocks were pyrolysed in the first stage into cracked oils, which were carried to the second stage for subsequent pyrolysis. Only 12–14 wt% of ethylene was obtained from tar-sand bitumens at the residence time of 1.2 s in the second stage, although 27 and 16 wt% were obtained from Taching and Iranian heavy vacuum residues, respectively. The tar-sand bitumens contain shorter paraffinic straight-chains and have more branched molecules than the vacuum residues of petroleum. A straight-chain paraffin index is proposed, with which a good correlation was obtained between ethylene yield and the fraction of straight-chain paraffin carbons in the heavy oil. 相似文献
9.
Guimes Rodrigues Filho Leandra Cardoso Toledo Daniel Alves Cerqueira Rosana Maria Nascimento de Assunção Carla da Silva Meireles Harumi Otaguro Sizue Ota Rogero Ademar Benévolo Lugão 《Polymer Bulletin》2007,59(1):73-81
Summary In this article, cellulose acetate produced through the homogeneous acetylation of sugar cane bagasse cellulose was used to
produce membranes, using poly(ethyleneglycol) 600 (PEG 600) as an admixture. The membranes were characterized using water
flux measurements (Payne’s cup), differential scanning calorimetry (DSC) and neutral red uptake (cytotoxicity). The results
showed that PEG 600 acts as a crystallinity inductor and/or pore former in the cellulose acetate matrix. The induction of
crystallinity is important for this system since it had not been reported on the literature yet. The results also demonstrated
that the studied membranes present a nontoxic behavior. 相似文献
10.
Preparation of zinc ferrite in the presence of carbon material and its application to hot-gas cleaning 总被引:3,自引:0,他引:3
In order to develop an efficient absorbent of H2S in coal gasification, zinc ferrite (ZnFe2O4) was prepared in the presence of carbon materials such as activated carbon (AC), activated carbon fiber (ACF), and Yallourn coal (YL). The absorption behavior of absorbents for H2S was examined using a fixed-bed flow type reactor equipped with a quadrupole mass spectrometer.Carbon material-supported ZnFe2O4 exhibited larger desulfurization capacity for H2S than unsupported ferrites. They could efficiently remove H2S from 4000 ppm levels in a simulated coal gasification gas to less than 1 ppm at 500 °C. The absorption capacity of H2S with ZnFe2O4/AC, ZnFe2O4/ACF, and ZnFe2O4/YL exhibited nearly 100% of stoichiometric amount of loaded metal species. They could be regenerated by an air oxidation in O2-Ar (50 vol%) at 450 °C for 30 min. The regenerated ferrite can be used for repeated absorption of H2S with a very slight decrease in the absorption capacity. 相似文献