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31.
通过对火场常见塑料载体与助燃剂混合燃烧残留物的分析,发展一种适用此类燃烧残留物的火灾物证鉴定方法,对火场中是否存在助燃剂进行判断,避免漏检情况的发生。应用热分析技术确定合适的闪蒸温度,在此温度下对塑料载体与助燃剂混合燃烧残留物进行闪蒸分析,并从实验条件选择、可行性分析、定性分析三方面对闪蒸技术进行评价。结果表明,闪蒸气相色谱-质谱(Flash GC-MS)技术可以检测到热塑性聚合物塑料载体与助燃剂混合燃烧残留物中残留的助燃剂特征组分,可对火场中是否存在过助燃剂进行辨别。闪蒸气相色谱-质谱技术丰富了现代火灾物证鉴定技术,能进一步辅助火灾物证鉴定工作,使鉴定结论更准确、可靠。 相似文献
32.
A new algorithm to find the phase equilibrium conditions in systems with specified values of internal energy, volume, and number of moles of each component present (isochoric–isoenergetic flash problem) is proposed. The core of the procedure consists of maximizing the system entropy by iterating on the values, in each phase, of internal energy, volume, and number of moles of each component. Analytical expressions for the physical properties and derivatives required by the calculations were generated by computer algebra. The algorithm tests for the possible need to add or remove phases during the course of iterations. The paper discusses possible numerical difficulties during application of the procedure and how to overcome them. The algorithm has shown to be robust and capable of solving multiphase equilibrium problems, avoiding trivial solutions. 相似文献
33.
LI Chao FANG Mengxiang XIAO Ping SHI Zhenghai CEN Jianmeng YAN Qike WANG Qinhui LUO Zhongyang 《高等学校化学研究》2016,32(6):1019-1027
The evolution behavior of the light tar fraction of tar during large bituminous coal particle pyrolysis in a fluidized bed reactor at 500-900℃ was investigated to optimize the industrial process. The coal residence time was varied from 30 s to 150 s. The crude tar obtained was distilled and separated into the light fraction and the heavy fraction through an evaporator under conditions of 280℃ and 104 Pa. The light tar was subjected to GC-MS analysis, and the 300 main species in each spectrum were determined and analyzed. The experimental results showed that the evolution behavior of the light tar fraction and the heavy tar fraction presented spectacularly different variation trends with pyrolysis temperature and coal residence time. The molecular weight and number of rings per aromatic compound molecule contained in the light tar fraction increased with increasing pyrolysis temperature because of polymerization. It was also observed that the amount of methyl substituents decreased with an increasing number of rings per molecule of poly-aromatic ring compounds. The chain aliphatic compound evolution was suppressed and underwent heterocyclization with increasing temperature. 相似文献
34.
强流脉冲相对论电子束加速器:—闪光二号 总被引:3,自引:1,他引:2
本文介绍了在西北核技术研究所建成的一台低阻抗脉冲电子束加速器——闪光二号。它主要用于核辐射效应模拟。加速器系统由Marx发生器、水介质同轴线和二极管三大主机部件以及十几个配套设备所组成。文中给出了在允电电压±55kV和±70kV两个电压等级下调试和运行的结果。最大输出电流600kA,管电压1.2MV。目前该加速器已用于电子束和X射线的实验研究。 相似文献
35.
利用间隙技术并靠一个专用模板,就能仅通过一次试验而对爆轰波面轮廓进行记录,辽河对其不同对称程度和旋转对称性加以详细分析. 相似文献
36.
Azafulvenium methides generated by the thermal extrusion of SO2 from 1-methyl- and 1,1-dimethyl-1H,3H-pyrrolo[1,2-c]thiazole-2,2-dioxides undergo [1,8]H sigmatropic shifts to give vinylpyrroles. Flash vacuum pyrolysis of the C-vinylpyrroles affords 5-oxo-5H-pyrrolizines or C-allyl-1H-pyrroles. 相似文献
37.
A set of vapor-flow calorimeter has been constructed on the basis of Power's adiabatic calorimeter and Clarke s flash boiler. It can determine the heat capacities of mono-or multi-component vapors from vaporizing temperature to 600 K and 10—600 kPa pressures. For the calibration of the instrument, the heat capacities of benzene have been measured under 51.1, 101.3, 309.3 and 495.2 kPa and 370—600 K tempera-tures. For multicomponent vapor, benzene-cyclohexane has been determined. The results showed that the calorimeter has both the precision and accuracy better than 1.0% for either pure or mixtural vapors. 相似文献
38.
Summary A sensitive and simplified method is described for the determination of barbital (B) and pentobarbital (PB) in blood using
gas chromatography with a nitrogen-specific flame ionization detector. After a simple one-step extraction, B and PB were reconstituted
in trimethylanilinium hydroxide and introduced directly into the gas chromatograph. Lower limits of detection was 0.14 μg/ml
for B and PB in either water or blood solutions. The recoveries for B from water and blood were 90 and 88%, respectively;
for PB they were essentially complete. The average between-run and within-run coefficients of variation for B from water and
blood were lower than 7.8%, whereas those of PB were lower than 3.0%. The scale and sensitivity of detection for B and PB
were found to be suitable for use in pharmacokinetic studies in the rat. 相似文献
39.
40.
This paper describes a novel analytical method, flash gas chromatography (FGC), for the analysis of volatile compounds from Houttuynia cordata Thunb. This method does not demand time-consuming extraction process. The ground powder of the plant material can be directly applied for the analysis and only a few milligrams of sample are needed. The identification of the components was made by FGC-MS. The results between FGC and ordinary GC (using the extracted essential oil as sample) were compared and found that FGC offered a similar number and types of the components with GC. FGC is a novel and feasible method for the quality control of traditional Chinese medicines (TCMs). 相似文献