Modelling of Melt Flow and Solidification in the Twin‐Roll Strip Casting Process

A three‐dimensional mathematical model has been developed to simulate turbulent fluid flow, heat transfer and solidification in the pool of a twin‐roll strip caster. A Darcy‐porosity approach was used to study the fluid flow within the mushy solidification zone in the pool. The effect of the heat transfer coefficient and permeability constant on the flow and solidification was also predicted. It was shown that an even flow and temperature distribution of the pool can be obtained by using a suitable feeding system. The heat transfer between the rolls and the solidifying metal has a big influence on the location of the solidification end point. The permeability of the mushy zone is a key factor which affects the flow and solidification in the twin‐roll strip casting process.     

术前口服依他昔布对妇科手术后病人自控镇痛的影响

目的: 观察妇科开腹手术患者术前给予依他昔布120 mg 对术后自控镇痛(PCA) 吗啡用量的影响及其副作用。方法: 随机选取全麻下接受妇科开腹全子宫(双附件) 切除患者40 例, 术前分别给予安慰剂或依他昔布120 mg 口服。在手术后观察24 h 患者PCA 吗啡用量, 同时记录患者的疼痛评分和满意度评分, 并观察不良反应。结果: 术后PCA 吗啡24h 消耗量在依他昔布组为9.4±7.6 mg, 显著低于安慰剂组15.7±8.9 mg。两组患者24 h 内对PCA 的按压次数依他昔布组也低于安慰剂组(P <0.05)。其中术后3、6、8 和12 h PCA 吗啡消耗量在两组间无显著差异。两组患者术后24 h 疼痛评分和对镇痛治疗的满意度也无差异。两组患者不良反应的发生率亦无差别。结论: 在妇科开腹手术患者术前应用依他昔布120 mg 可使患者术后PCA 吗啡消耗量降低, 且在术后12 h 后下降明显。未发现与依他昔布应用相关的副作用。     

Acid adaptation and temperature effect on the survival of E. coli O157:H7 in acidic fruit juice and lactic fermented milk product.

In this study, two strains of Escherichia coli O157:H7, (ATCC 43889 and ATCC 43895) were acid adapted at pH 5.0 in tryptic soy broth (TSB) for 4 h. Commercial products of mango juice (pH 3.2), asparagus juice (pH 3.6), Yakult--a diluted milk fermented drink (pH 3.6), and low-fat yoghurt (pH 3.9) were inoculated with acid-adapted or nonadapted cells of E. coli O157:H7. Survival of the inoculated E. coli O157:H7 in these commercial food products during storage at 25 or 7 degrees C was examined. It was found that although survival of the acid-adapted and nonadapted E. coli O157:H7 ATCC 43895 in asparagus juice during storage at 7 degrees C did not show marked difference, in general, acid adaptation and low temperature enhanced the survival of E. coli O157:H7 in both the commercial fruit juices tested. On the contrary, acid adaptation reduced the survival of both the strains of the test organism in Yakult and low-fat yoghurt stored at 7 degrees C. Besides, E. coli O157:H7 ATCC 43895 survived longer than ATCC 43889 in all the products examined, regardless of the storage temperature and acid adaptation.     

Comprehensive study on a novel bidirectional tunnelingprogram/erase NOR-type (BiNOR) 3-D flash memory cell

In this paper a recently proposed bidirectional tunneling program/erase (P/E) NOR-type (BiNOR) flash memory is extensively investigated. With the designated localized p-well structure, uniform Fowler-Nordheim (FN) tunneling is first fulfilled for both program and erase operations in NOR-type array architecture to facilitate low power applications. The BiNOR flash memory guarantees excellent tunnel oxide reliability and is provided with fast random access capability. Furthermore, a three-dimensional (3D) current path in addition to the conventional two-dimensional (2D) conduction is proven to improve the read performance. The BiNOR flash memory is thus promising for low-power, high-speed, and high-reliability nonvolatile memory applications     

EFFECT OF OSMOTIC PRE-TREATMENT AND INFRARED RADIATION ON DRYING RATE AND COLOR CHANGES DURING DRYING OF POTATO AND PINEAPPLE

A combination of intermittent infrared and continuous convection heating was used to dry various osmotically pretreated sample of potato (in solutions of 10%, 20% and 30% NaCl) and pineapple (in solutions of 30%, 50%, 70% Brix). The effect of drying conditions on color changes of potato and pineapple was investigated. The Hunter color scale parameters (redness, yellowness and lightness) were measured to quantify the color changes. With appropriate choice of infrared intermittency as well as osmotic pretreatment, it is possible to reduce the overall color change while maintaining high drying rates. As expected, osmotic pretreatment resulted in a shift in the sorption isotherms for both products.     

向外排废水要效益

我公司的工业废水大部分回收利用但仍有７０００ｔ／ｄ废水因无用场而不得不外排。近年缴纳放费１３０～１５０万元／ａ。外高三度放心水,不仅毒化了生态环境,且抬高了生成成本。本文创议出“置换”水洗新工艺,在生产特种氧化铝过程中,以废水替代高价（３．０元／ｔ）优质水作生产工艺用水取得成功,已用于生产,经济效益显著,这是我公司依靠技术进步向“三废”要效益所获得的新进展。     

Development of a Stereolithography File Interface with ArtCAM™

This paper presents the technique used for converting a 3D ArtCAM™ relief file into the stereolithography (STL) format. This 3D file is obtained from a 2D picture using a 3D CNC engraving software called ArtCAM™. The problem is to convert the 3D relief files into an STL format without compromising the accuracy and details of therelief. This paper discusses the size of the files which have been converted, and steps taken to reduce the file size by reducing the number of triangles or facets in the STL file. The discussion involves the verification of the converted model by comparing it with the original relief. The problems associated with the reduction of triangles when the file has been converted to STL format are also discussed.     

过程装备多媒体CAI应用软件的开发

以创作软件３ Ｄ Ｓｔｕｄｉｏ ４．０ 及 Ｍｉｃｒｏｓｏｆｔ Ｐｏｗ ｅｒｐｏｉｎｔ ９５ 与著作软件 Ａｕｔｈｏｒｗ ａｒｅ Ｐｒｏｆｅｓｓｉｏｎａｌ３．５ 为开发工具,开发了过程装备多媒体 Ｃ Ａ Ｉ应用软件,它涵盖了《化工设备设计》课程,并增加了生物流化床反应器等方面的内容,动画效果逼真、生动、形象地反映了单元操作设备零部件之间的结构关系。完善的交互设计,界面设计和导航设计极大地方便了用户的使用,尤其适合于课堂教学。     

中温太阳集热器系统热状态特性数值模拟的三维动态热网络实验验证

以中温太阳集热器系统单元段分节点热阻、热容网络概念,建立腔体式吸收器－槽形抛物镜中温太阳集热器系统的热性能动态模型。利用所建立的集热器单元测试系统对模型进行实验验证。