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71.
大庆渣油族组分非等温热反应的研究 总被引:2,自引:0,他引:2
采用动态热重分析法在升温速率为6.2K·min ̄(-1)及惰性气流量100cm ̄3·min ̄(-1)的条件下,对大庆渣油族组分的热转化行为进行了考察,获得了族组分的热转化速率峰值、速率峰值处的反应温度、转化率和剧裂分解温度区间等动力学基本数据以及各族组分的生焦性能。数据分析表明,族组分的热反应活性顺序为:饱和分>胶质>芳香分>沥青质。在大庆渣油族组分热转化的两个温区内,采用分段一级动力学模型较好地拟合了实验数据,确定了各族组分在两个温区内的热反应动力学参数。 相似文献
72.
73.
The double-T injector design employed in many microchip capillary electrophoresis devices allows for the formation of very small (50-500 pL) sample plugs for subsequent analysis on-chip. In this study, we show that sample plugs formed at the channel junction can be geometrically defined. The channel width and injector symmetry prove to be of great importance to good performance. A unique pushback of solvent into the side channels can be induced when the side channels have a very low resistance to flow, and this helps to better define the injected sample plug. Samples and running buffers of differing ionic strength (e.g., 10 mM KCl buffer and 20 mM KCl sample) can yield widely variable results in terms of plug shape and amount injected (variations of 1.5 to 10x). Applying bias voltages to all the intersecting channels aids in controlling the plug shape. However, when the ionic strengths of buffer and sample are not matched, the actual amount injected (up to 10x variations) can be inconsistent with the appearance of the plug formed in the injector (up to only 30 % variations). Operating at constant pH and ionic strength produced the most consistent results. This report examines the effects of altering the injector geometry and solution ionic strengths, and presents the results of using bias voltages to control plug formation. The observed results should provide a benchmark for modeling of the fluid dynamics in channel intersections. 相似文献
74.
75.
Annals of Global Analysis and Geometry - In this paper, we study a problem of finding compact hypersurfaces of prescribed mean curvature with free boundary in a ball. We transform the problem to an... 相似文献
76.
X. Y. Zhang S. Jin Y. C. Liang Y. F. Ming L. H. Yu M. G. Fan W. F. Wang S. D. Yao 《Research on Chemical Intermediates》1995,21(1):17-24
Photochromic reactions of four indolinospirooxazine derivatives have been studied using nanosecond laser flash photolysis
techniques. Photolysis of the four compounds in acetonitrile and in cyclohexane all leads to the formation of the short-lived
CT intermediates as the predominant photoproducts. In certain circumstances few photomerocyanines (PMC) can be observed. From
the absorption bands and the lifetimes of CT intermediates, it has been speculated that the substituents at the nitrogen atom
of the indole ring influence the structural characteristics of CT intermediates mainly through steric hindrance effects, whereas
the substituents at the 5 position of the indoline ring influence mainly through electron effects. A potential energy surface
model is established to explain the results. 相似文献
77.
Science China Mathematics - Let w be a permutation of {1, 2, …, n}, and let D(w) be the Rothe diagram of w. The Schubert polynomial ${\mathfrak{S}_w}\left(x \right)$ can be realized as the... 相似文献
78.
Abe K Abt I Ahn CJ Akagi T Ash WW Aston D Bacchetta N Baird KG Baltay C Band HR Barakat MB Baranko G Bardon O Barklow T Bazarko AO Ben-David R Benvenuti AC Bienz T Bilei GM Bisello D Blaylock G Bogart JR Bolton T Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Busza W Calcaterra A Caldwell DO Calloway D Camanzi B Carpinelli M Cassell R Castaldi R Castro A Cavalli-Sforza M Church E Cohn HO Coller JA Cook V Cotton R Cowan RF Coyne DG D'Oliveira A Damerell CJ Dasu S 《Physical review letters》1995,74(9):1512-1516
79.
80.
Abe K Abt I Ahn CJ Akagi T Allen NJ Ash WW Aston D Baird KG Baltay C Band HR Barakat MB Baranko G Bardon O Barklow T Bazarko AO Ben-David R Benvenuti AC Bienz T Bilei GM Bisello D Blaylock G Bogart JR Bolton T Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Busza W Calcaterra A Caldwell DO Calloway D Camanzi B Carpinelli M Cassell R Castaldi R Castro A Cavalli-Sforza M Church E Cohn HO Coller JA Cook V Cotton R Cowan RF Coyne DG D'Oliveira A Damerell CJ Daoudi M 《Physical review D: Particles and fields》1995,52(7):4240-4244