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71.
采用静态法测定了自行研制的吸热型碳氢燃料ZH-100在加强氧化条件下的热氧化安定性能,用红外光谱检测ZH-100热氧化前后官能团的变化.结果表明,在160℃下加强氧化5h后燃料组分中除了原有的-CH3和-CH2-官能团外,还明显检出了羟基、羰基和碳碳双键3种官能团,红外分析结果很好地解释了燃料经加强氧化后颜色发生变化的原因.通过碘量比色法对氧化过程中生成的过氧化物进行定量分析,解释了燃料的热氧化反应机理,评价了3种抗氧化剂的效果.结果显示合适的抗氧化剂可以使燃料的热氧化安定性有一定程度的提高. 相似文献
72.
采用超临界反应装置测定了吸热型碳氢燃料HDF-1的氧化安定性能.结合吸光度分析结果、红外谱图以及氧化沉积量的测定结果,考察了2,6-二叔丁基对甲酚(BHT)对燃料氧化安定性能的影响.结果表明,如果反应时间为3h,BHT能够将燃料的氧化沉积量降低64%,有效地提高燃料的氧化安定性能,但BHT对缓解燃料颜色变化并无明显效果. 相似文献
73.
ANDON J. BLAKE 《Natural Resource Modeling》2013,26(1):66-90
Abstract A numerical model is proposed for the testing of distortions caused by petroleum fiscal systems on the exploration and extraction activities of a profit‐maximizing firm. Traditional models have not been capable of testing for the distortions caused by the complex tax structures most often used by governments. Two tax combinations, as well as certain other taxes, are analyzed for distortions in the model. The model is parameterized using generic data because specific jurisdictions are not considered. The distortions due to rentals and royalties are as expected by theory. Property taxes show a new distortion result where production tilting is ambiguous. 相似文献
74.
Comparative Plasma Chemical Reaction Studies of CH4/Ar and C2Hm/Ar (m = 2,4,6) Gas Mixtures in a Dielectric Barrier Discharge 下载免费PDF全文
Plasma chemical reactions in CH4/Ar and C2Hm/Ar (m = 2, 4, 6) gas mixtures in a dielectric barrier discharge at medium pressure (300 mbar) have been investigated. From mass spectrometry the production of H2 and formation of larger hydrocarbons such as CnHm with up to n = 12 is inferred. Hydrogen release is most pronounced for CH4 and C2H6 gas mixtures. Fourier Transform InfraRed (FTIR) spectroscopy reveals the formation of substituted alkane (sp3), alkene (sp2), and alkyne (sp) groups from the individual gases which are used in this work. Abundant formation of acetylene occurs from C2H4 and to a lesser extent from C2H6 and CH4 precursor gases. The main reaction pathway of acetylene leads to the formation of large molecules via C4H2 and, eventually, to nano‐size particles. The experimental results are in reasonable agreement with simulations which predict a pronounced electron temperature and gas pressure dependency. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
75.
Roy E. Hoffman Noach Treitel Mordecai Rabinovitz 《Magnetic resonance in chemistry : MRC》2001,39(8):489-494
Isotope shifts are a well-established tool for structural analysis by NMR. The substitution of a protium with a deuterium is the most widely studied of these effects. However, such studies call for specific deuteration that requires complex synthetic techniques owing to the low natural abundance of deuterium. 13C occurs at a higher natural abundance and couples strongly with its attached proton. We have developed and refined a method to reliably observe these much smaller shifts without needing to resort to chemical synthesis. We show that carbon induced isotope shifts reflect structural features. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
76.
Proton affinities are calculated at all reactive positions for the normal benzenoid hydrocarbons, benzene, naphthalene, phenanthrene
and anthracene, a strained benzenoid hydrocarbon, biphenylene, and a nonalternant hydrocarbon, fluoranthene, and the results
are compared to experimental protodetritiation rates. Methods used include PM3 and Hartree-Fock calculations at the STO-3G,
3-21G*, 6-31G* and MP2//6-31G* levels. Generally good agreement is found between theory and experiment with 6-31G* giving
the best correlations.
Received: 11 June 1998 / Accepted: 3 September 1998 / Published online: 23 February 1999 相似文献
77.
J.M. Ramos-Fernndez M. Martínez-Escandell F. Rodríguez Reinoso 《Journal of Analytical and Applied Pyrolysis》2007,80(2):477-484
The co-pyrolysis of a petroleum residue with two different sources of titanium (tetrabutyl-ortotitanate (TBO) or titanium carbide nano-powder) was carried out to obtain mesophase pitches containing TiO2 or TiC nanoparticles. Co-pyrolysis is an appropriate technique to achieve a good dispersion and low particle size. In the case of TBO, TiO2 nanoparticles (5–20 nm) are observed, which are forming aggregates, the largest of them being 1–2 μm. In the case of TiC nano-particles, they are more difficult to disperse and larger aggregates are formed, although the final material is rather homogenous. The chemistry of pyrolysis for the production of doped and undoped mesophase pitches has been followed by means of solvent insolubility, XRD, XPS, FTIR and elemental analysis. They show evidences of promotion of the formation of mesophase in the presence of the titanium-containing particles, especially in the presence of TiO2. The final materials can be of great value as precursors to produce high density titanium doped graphites for nuclear and space applications. 相似文献
78.
79.
吸热型碳氢燃料的结焦研究Ⅰ含硫抑制剂 总被引:3,自引:2,他引:3
在连续进样微反测焦系统上考察了二硫化碳、噻酚等含硫化合物添加前后碳氢燃料S-1裂解结焦速率的变化。结果显示,两种含硫抑制剂均可明显降低燃料裂解时的结焦速率,二硫化碳的抑制效果较好,可以使初始结焦速率降低90%。同时,气相色谱的分析结果显示,含硫抑制剂对燃料裂解产物的分布情况有一定影响,促进了烯烃选择性的提高,有利于改善燃料的吸热能力。利用扫描电镜以及元素分析手段对焦形态结构和元素组成的研究结果显示,含硫抑制剂还有利于改善焦的形态结构以及氢碳元素组成,对清焦工作有一定帮助。 相似文献
80.
YU Biao HUI Yong-ZhengState Key Laboratory of Bio-organic Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai China 《中国化学》1996,14(2):171-179
Three types of single-chain hydrocarbon fluorocarbon hybrid bolaamphiphiles were synthesized.They readily formed different kinds of organized supramolecular assemblies,including vesicles,tapes,and micellar fibers,in aqueous solution.The aggregates morphology was characterized by transmission electron microscopy (TEM) after negative staining.The superstructures of these aggregates seemed to be determined by the geometry and the head group's properties of the corresponding amphiphiles. 相似文献