Treatment of Drilling Wastewater by Combined Coagulation-Ultraviolet/Fenton-Pressurized Biological Processes

An integrated technique containing coagulation, ultraviolet/Fenton oxidation, and pressurized biological processes was provided for the treatment of wastewater generated from drilling operation where sulfonated muds were used. Ultraviolet/Fenton oxidation process was used to improve biodegradability of effluent after coagulation [assessed through a ratio of biological oxygen demand to chemical oxygen demand (COD) (B/C) index]. Pressurized biological experiments were used to further remove COD so as to meet the wastewater discharge standard. The results showed that coagulation pretreatment could help remove most of CODs (70–80%) in drilling wastewater. A 57% reduction in COD was obtained in the ultraviolet/Fenton oxidation process with 0.8 Qth H2O2 (in 30 min), and the biodegradability was significantly improved (B/C was increased from 0.03 to 0.47). The pressurized biological process could help speed up the reaction process with a saved aeration time of 66.7% under a system pressure of 0.2 MPa (in comparison with the condition of a normal pressure). The overall COD removal efficiency was about 95% and the COD level in the final effluent was less than 100 mg/L, which satisfied the wastewater discharge standard.     

针对全空子数据体的GPU体绘制方法

体绘制是三维数据可视化的主要方法之一。用于体绘制的数据体中包含有大量的空体素,导致光线投射算法进行没有意义的重采样计算,必然降低绘制算法效率。针对全空子数据体体绘制低效问题,本文提出基于GPU体高效绘制方法。利用八叉树数据结构组织数据,有效管理包含许多空体素的子数据体。通过绘制八叉树非全空叶子结点子数据体表面,使光线投射算法中起始和终止重采样位置更接近数据体中的可视部分,同时根据八叉树全空结点子数据体判定纹理查询结果,计算合适的跳跃步长,快速跳过八叉树中全空结点子数据体,减少无效重采样点。当数据体中空体素较多时,实现对原基于体包围盒表面绘制的GPU光线投射算法的加速。设计不透明度函数,凸显数据体中层位面,并将算法成功应用于地震数据可视化,取得很好应用效果。     

A comparison of techniques for preparing fish fillet for ICP-AES multielemental analysis and the microwave digestion of whole fish.

Four catfish fillet homogenate treatments before multielemental metal analysis by simultaneous inductively coupled plasma/atomic emission spectroscopy were compared in triplicate. These treatments were: nitric acid wet-ashing by Parr bomb digestion; nitric acid wet-ashing by microwave digestion; tetramethylammonium hydroxide/nitric acid wet digestion; and dry-ashing. The tetramethylammonium hydroxide/nitric acid method was imprecise (coefficients of variation > 20%). The dry-ashing method was fast and sensitive but had low recoveries of 50% for spiked Pb and Al and was not as precise as the Parr bomb or microwave treatments. The Parr bomb method was the most precise method but was less sensitive than the microwave method which had nearly the same precision. The microwave method was then adapted to homogenates of small whole fish < or = 3 cm in length. The whole fish homogenate required more vigorous digestion conditions, and addition of more acid after the evaporative step because of the presence of less oxidizable and acid-soluble components than fillet. The whole fish homogenate was also more heterogeneous than catfish fillet. A quality assurance protocol to demonstrate homogenate uniformity is essential. The use of a non-specialized microwave oven system allowed precise results for fillet and whole fish homogenates.     

天然裂缝性储层的特征

天然裂缝性储层给开采带来了一个矛盾难题。这类储层包括低油气采收率储层,这些储层最初可能表现出高产,但产能下降得非常快。此外,这类储层还经常出现早期见气或见水等问题。而另一方面,一些天然裂缝性储层也是全球最大、产量最高的储层。这类储层的这种矛盾特性激发业界尽力去深入了解其特征,以便更有把握地对其进行模拟分析。     

渣油中硫和硫类型分布对热转化产物中硫分布的影响

考察了热转化反应条件对胜利和孤岛渣油热转化产品中硫分布的影响。在研究原料中硫、硫醚硫、噻酚硫分布和残分布的基础上，探讨了原料硫分布与热转化产品中硫分布的关系。     

真丝重绉织物性能与服装选料、加工的关系

通过对真丝重绉类织物试样的性能测试，结合服装对真丝重磅面料服用性能的要求，对所测数据进行系统聚类分析与综合评分计算，并进行缝制试验，为真丝重绉织物的设计和 服装的选料与加工提供参考。     

LABORATORY STUDY OF REAL-TIME OPTICAL MICROSCOPE TRACKING OF THERMAL REACTION PROGRESS OF VACUUM RESIDUA II: CHEMICAL RELEVANCE OF PHYSICAL PROCESSES IN THERMAL REACTION SYSTEMS OF VACUUM RESIDUA

It has been indicated from analyses of the vicissitude of chemical states and their comparisons with the occurring physical processes in the thermal reaction systems of vacuum residua that the first characteristic state point coincides with the induction period of coke formation, and the third characteristic state point, immediately after which a large amount of coke is yielded, manifests the critical point at which concentration of the neo-asphaltenes generated in-situ by the fast-reaction resins is high enough to approach its phase separation. The industrial implication of the second characteristic state point is not clear enough. It is accordingly pointed out, in combination with the conclusions drawn in the first part of the serial, that the real-time optical microscope tracking of the thermal reaction progress of vacuum residua based on the first and third characteristic state points is feasible on the laboratory scale for forecasting the sudden changes of the physical and/or chemical states of the thermal reaction systems of vacuum residua, and is expected to find applications in the industrial visbreaking process.     

Investigation of texturization for monocrystalline silicon solar cells with different kinds of alkaline

In this paper, monocrystalline silicon was textured with different kind of etchants for solar cells, respectively. It was found that, only with sodium hydroxide (NaOH) or sodium acetate anhydrous (CH₃COONa) solution, the textural results were very weak, resulting in high reflectance of silicon surface. However, if using the mixture solution of NaOH and CH₃COONa, the reflectance was noticeably decreased. Moreover, the dependence of reflectance on the etching time showed that longer etching time was necessary for texturization in the NaOH+CH₃COONa+H₂O system. And it was also found that the addition of isopropyl alcohol (IPA) to this mixture solution had a detrimental effect on the texturization. All these results suggested that acetate (CH₃COO⁻) plays a similar role as IPA for alkaline texturization, but they cannot coexist. Finally, the mechanisms of texturization with different kinds of etchant were discussed in detail.     

The 2-His-1-carboxylate facial triad--an emerging structural motif in mononuclear non-heme iron(II) enzymes

PURPOSE: To determine in-line pressures generated in small-bore central venous catheters during power injection of computed tomographic (CT) contrast media. MATERIALS AND METHODS: Five 3.0-7.0-F central venous catheters for pediatric patients were tested at full and half lengths in vitro. In-line pressures were measured during power injection of three contrast media. Rates of injection were increased in steps from 0.1 to 5.0 mL/sec or until a peak pressure of 100 psi (700 kPa) was achieved. The maximum tolerated flow rate was determined with reference to the manufacturer's suggested operating pressure limit for each catheter. RESULTS: At full length, the maximum tolerated flow rates were as follows: 2-3 mL/sec for the large lumen and 1-1.4 mL/sec for the small lumen of the 7.0-F double-lumen catheter; 0.2-0.4 and 0.8-1.2 mL/sec for the 3.0- and 4.0-F peripherally inserted central catheters, respectively; 0.7-1.2 mL/sec for the 6.6-F catheter; and only 0.2 mL/sec for the 4.2-F catheter, which ruptured during testing at higher flow rates. CONCLUSION: Flow rates were documented at which certain small-bore central venous catheters should tolerate power injection of CT contrast media with peak pressures remaining below the manufacturer's recommended operating pressure limits. These data may serve as a guide for clinical use.     

山西省汾河二库枢纽工程建设简介

本文较系统地介绍汾河二库枢纽工程建设的基本情况，并就工程采用的新技术、新工艺、新设备、新材料以及工程建设的主要经济和教训作了简要分析和介绍。