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51.
Lilu?Zhang Abdul?Waheed Richard?A.?JonesEmail author Vincent?M.?Lynch 《Journal of chemical crystallography》2005,35(9):673-677
The crystal structure of the bis-amido complex of Ti(IV) (η5-C5H5)2Ti(NH(2,4-(C
CSiMe3)2C6H3))2 is reported. This complex was prepared in 52% yield from the reaction of (η5-C5H5)2TiCl2 with two equivalents of LiNH(2,4-(C
CSiMe3)2C6H3) (prepared in situ in THF at −78∘C). The substituted aniline H2N(2,4-(C
CSiMe3)2C6H3) was prepared in 70% yield from the reaction of 2,4-dibromoaniline with Me3SiC
CH using conventional Pd/Cu coupling methodology. The molecular structure of (η5-C5H5)2Ti(NH(2,4-(C
CSiMe3)2C6H3))2 (monoclinic, space group C2/c, Z = 4, a = 29.7523(5) Å, b = 9.5339(2) Å, c = 15.8864(3) Å, β = 93.022(1)∘ features a titanium (IV) center with a distorted tetrahedral geometry which lies on a crystallographic twofold axis. The amido units are arranged so that steric interactions are minimized. The Ti– N distance is 2.016(2) Å. 相似文献
52.
微波复合直流等离子体转化天然气制乙炔的研究 总被引:4,自引:0,他引:4
利用微波复合直流等离子体对天然气转化制乙炔反应进行了研究. 考察了氢烷比、气体流量、功率等参数对装置的能量利用率以及天然气转化反应的影响, 并考核了微波复合直流等离子体转化天然气制乙炔工艺的稳定性. 实验结果表明: 微波复合直流等离子体装置的能量利用率随等离子体工作气体的流量的增加而提高; 由于微波的作用使传统直流柱状等离子体分化为多根丝状等离子体, 从而使得电极的烧蚀方式由传统的点烧蚀变为面烧蚀, 并大幅度提高等离子体转化天然气工艺的稳定性和电极寿命; 甲烷的转化率和乙炔的收率随功率的增加而提高, 随CH4/H2比和气体流量的增加而降低, 在氢烷比为0.9、总气体流量为760 L/min、微波源输出电功率6 kW、直流电源输出功率90 kW时, 甲烷转化率可达84.4%, 乙炔选择性为75.6%, 乙炔收率为63.8%, 乙炔能耗达10.8 kWh•kg-1; 电极寿命超过200 h. 相似文献
53.
J. Nassar J. Goldbach 《International journal of environmental analytical chemistry》2013,93(2):145-159
Abstract The problem of determining the concentration changes of reactive hydrocarbon immissions as a function of time was solved by means of an automatic gas chromatograph which, without enrichment, could record ethylene and acetylene in ppb concentrations. At the same time various other pollutants were covered, so that by a mutual allocation of the individual components it was possible to identify certain emitter groups. The results clearly show that ethylene and acetylene primarily originate from the combustion processes of the automobiles, while the handling and storage of petroleum products and their processing do not exert any influence on the immission of the two components. By way of time series measurements during a summer week in 1976 with very intensive solar radiation it was possible to show indirect secondary photochemical reactions. 相似文献
54.
《Journal of Coordination Chemistry》2012,65(14):2357-2364
A new series of bimetallic bis(diphenylphosphino)acetylene-bridged copper(I) 1,10-phenanthroline complexes, [Cu2(dppa)2(L)2](BF4)2; L?=?1,10-phenanthroline (1); 4-methyl-1,10-phenanthroline (2); 4,7-dimethyl-1,10-phenanthroline (3); and 2,9-dimethyl-1,10-phenanthroline (4), have been prepared and characterized by spectroscopic methods. The X-ray structures of 1 and 4 were determined. The structures consist of centrosymmetric bimetallic 10-membered chair-like dimetallacycles. In 1, intermolecular C–H?π interactions result in bending of the phenanthroline ligand and sterically induced lengthening of one Cu–P bond. In 1–4, the 31P NMR downfield coordination shift, relative to the free ligand, correlates with the basic strength of the 1,10-phenanthroline ligands. 相似文献
55.
Manoj K. Kolel‐Veetil Kenan P. Fears Syed B. Qadri Christopher A. Klug Teddy M. Keller 《Journal of polymer science. Part A, Polymer chemistry》2012,50(15):3158-3170
A semicrystalline inorganic–organic hybrid crosslinked network containing polyhedral oligomeric silsesquioxane (POSS) cores was constructed by the unusual hydrosilylation of the terminal vinyl groups of an internal acetylene‐containing silane linker by a POSS monomer. Products from the thermal treatments of this network in either argon or air at 250, 550, and 1000 °C, respectively, were characterized by Fourier transform infrared, Solid‐state 13C and 29Si magic angle spinning NMR, X‐ray diffraction and XPS analyses. The highly symmetrically functionalized POSS silica clusters, in the fluorite silica phase, in the network were found to remain unchanged on thermal treatment possibly due to the shielding of the silica core by the functionalities and a cancellation of thermal stresses on the silica core. Stabilization of the metastable α‐cristobalite phase, which is typically formed on cooling by a β‐ to α‐transition of the β‐cristobalite phase formed above 1400 °C, was observed in the amorphous regions in the network sample treated only to 1000 °C in air. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
56.
Yi Peng Junhui Xu Jia Zhao Bailin Hu Shengshui Hu 《Russian Journal of Electrochemistry》2008,44(2):206-212
The electrochemical response of phenol at acetylene black (AB)-dihexadecyl hydrogen phosphate (DHP) composite modified glassy
carbon electrode in the presence of cetyltrimethylammonium bromide (CTAB) was investigated. In this system, a sensitive oxidation
peak at 0.62 V (SCE) was obtained. The electrode process and the influence of CTAB on the oxidation of phenol were explored
by chronocoulometry and linear sweep voltammetry (LSV). Experimental conditions for the determination of phenol were optimized.
In the range of 5.0 × 10−7 to 1.2 × 10−5 M, the phenol concentration was linear with the oxidation peak current and the detection limit was found to be 1.0 × 10−7 M for 3 min accumulation. The method was applied for the determination of phenol in lake water and the results were satisfactory.
Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 2, pp. 222–229.
The text was submitted by the authors in English. 相似文献
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富氧条件下乙炔选择催化还原NOx 总被引:1,自引:0,他引:1
Acetylene as a reducing agent of metal exchanged HY catalysts, for selective catalytic reduction of NO in the reaction system of 0.16% NO, 0 (C2H2-SCR) was investigated over a series 08% C2H2, and 9.95% O2 (volume percent) in He. 75% of NO conversion to N2 with hydrocarbon efficiency about 1.5 was achieved over a Ce-HY catalyst around 300 ℃. The NO removal level was comparable with that of selective catalytic reduction of NOx by C3H6 reported in literatures, although only one third of the reducing agent in carbon moles was used in the C2H2-SCR of NO. The protons in zeolite were crucial to the C2H2-SCR of NO, and the performance of HY in the reaction was significantly promoted by cerium incorporation into the zeolite. NO2 was proposed to be the intermediate of NO reduction to N2, and the oxidation of NO to NO2 was rate-determining step of the C2H2-SCR of NO over Ce-HY. The suggestion was well supported by the results of the NO oxidation with O2, and the C2H2 consumption under the conditions in the presence or absence of NO. 相似文献