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71.
张庆华  吴周安  钟军  黄钢 《浙江化工》2007,38(8):30-32,3
研究了色谱柱柱温对柱流失、分离效果的影响,采用低柱温技术显著降低了柱流失造成的背景,有利于痕量组分的分析;低柱温技术还明显提高了色谱柱分离效率,有利于在复杂成分样品中低沸点物质的测定。研究了在测定痕量全氟异丁烯中采用ECD检测器与相匹配的色谱柱问题,发现采用交联聚甲基硅氧烷类色谱柱比较适宜。利用本技术测定废水、环境气体中的痕量全氟异丁烯得到了满意的效果。  相似文献   
72.
为解决长江高填方护岸深厚覆盖层地基的抗滑稳定问题,采用振冲置换法对地基进行加固处理。计算分析表明,振冲碎石桩处理范围、桩间距、桩长等参数应结合地形、地质条件进行设计,振冲置换法与其他地基处理方式进行有机结合能够取得更好的处理效果;护岸地基通过振冲置换处理后,抗滑稳定性能够满足规范要求。采用振冲碎石桩对软弱地基进行置换形成复合地基,能够有效解决地基砂土液化问题、承载力问题及抗剪强度问题。  相似文献   
73.
研制了一种从石灰釉中分离出来的缺陷釉—气泡釉。气泡釉由于其特殊的性质,不适用于强度要求高的建陶,一般用于普通的日用瓷或艺术瓷。主要利用长石、高岭土、方解石、白云石和石英等常用原料,通过调整各种原料的用量,改变釉层厚度、烧成制度等方法来寻求最佳的气泡釉效果。  相似文献   
74.
以某工程为算例,分别选取合理板柱与梁板结构计算模型,按照相关规范进行大型广场在平时工况与战时工况顶板各构件承载力计算,并对其两种结构型式的受力性能分析对比,以总结出地下人防结构顶板的适用原则,为实际工程设计提供参考依据。  相似文献   
75.
Air bubble – bitumen attachment is a critical step in the flotation of bitumen from mined oil sand. In this study, single bubble – bitumen drop attachment was observed directly using a novel experimental technique. Induction time is determined and used as an indication of bubble‐bitumen attachment potency for both hydrogen and oxygen bubbles. The attachment tests were conducted in deaerated municipal water (City of Edmonton tap water) at temperatures ranging from 22–50°C. Induction times measured for hydrogen bubble attachment were shorter than those for oxygen bubbles. Coalescence tests were also conducted in the absence of bitumen, and showed that hydrogen bubbles coalesced more rapidly than oxygen bubbles in both deaerated municipal water and clear (solids‐free) process water.  相似文献   
76.
以填充柱气相色谱对 3 氯 1 丙醇进行了分析研究 ,方法变异系数 0 .5 % ,回收率99.5 0 %~ 10 0 .6 7%  相似文献   
77.
Volumetric mass transfer coefficients in liquid and vapour phases in distillation column were measured by the method consisting of a fitting of the concentration profile of liquid phase along the column obtained by the integration of a differential model to the experimental one. The mathematical model of distillation process includes mass and energy balances and the heat and mass transfer equations. The film model flux expressions with the convective transport contributions have been considered in the transfer equations. Vapour and liquid phases are supposed to be at their saturated temperatures along the column. Effect of changes of phase flows and physical properties of phases on the mass transfer coefficients along the column and non-ideal thermodynamic behaviour of the liquid phase have been taken into account. The concentration profiles of liquid phase are measured in the binary distillation of the ethanol-water and methanol-ethanol systems at total reflux on metal Pall Rings and Intalox saddles 25 mm in the column with diameter of 150 mm. The distillation mass transfer coefficients obtained by the fitting procedure are compared with those calculated from absorption data using Onda's, Billet's and Linek's correlations. The distillation heat transfer coefficients calculated from the model assuming saturated temperatures in both phases are compared with those calculated from the Chilton-Colburn and penetration model analogy between mass and heat transfer. The results have confirmed an agreement neither between distillation and from absorption correlations calculated mass transfer coefficients nor between analogy and from enthalpy balance calculated heat transfer coefficients. Also the concentration profiles obtained by the integration of the differential model of the distillation column using the coefficients from absorption correlation have differed from the experimental profiles considerably.  相似文献   
78.
针对传统的帽罩式浓硝酸漂白塔存在的缺点和不足,找出原因并予以改进,开发研制出螺旋式浓硝酸漂白塔,改进了工艺状况,减少了维修工作量,达到了节能降耗的目的,确保了直接法浓硝酸装置的长周期运行。  相似文献   
79.
This paper presents a comparative study how reactor configuration, sludge loading and air flowrate affect flow regimes, hydrodynamics, floc size distribution and sludge solids-liquid separation properties. Three reactor configurations were studied in bench scale activated sludge bubble column reactor (BCR), air-lift reactor (ALR) and aerated stirred reactor (ASR). The ASR demonstrated the highest capacity of gas holdup and resistance, and homogeneity in flow regimes and shearing forces, resulting in producing large numbers of small and compact flocs. The fluid dynamics in the ALR created regularly directed recirculation forces to enhance the gas holdup and sludge flocculation. The BCR distributed a high turbulent flow regime and non-homogeneity in gas holdup and mixing, and generated large numbers of larger and looser flocs. The sludge size distributions, compressibility and settleability were significantly influenced by the reactor configurations associated with the flow regimes and hydrodynamics.  相似文献   
80.
In order to supplement the literature data on VLE, isobaric bubble temperature data were collected for the binary systems phenol-i-amyl alcohol and phenol-n-amyl alcohol over the entire composition range by indirect method using a standard Swietoslawski type ebulliometer. The measurements were made at three sub-atmospheric pressures. The experimental t-x data were correlated with both equation of state method and gamma-phi methods. In the former approach, the Soave equation of state is used, whereas in the latter case Wilson, NRTL and UNIQUAC equations are used.  相似文献   
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