Analysis of heat-processed corn foods for fumonisins and bound fumonisins

Thirty retail samples of heat-processed corn foods, i.e. corn flakes, corn-based breakfast cereals, tortilla chips and corn chips, were analysed for fumonisins — fumonisin B₁ (FB₁), fumonisin B₂ (FB₂) and hydrolysed FB₁ (HFB₁) — as well as for protein- and total-bound FB₁. Bound (hidden) fumonisins cannot be detected by conventional analysis. Improved methods for the determination of bound FB₁ were developed. The protein-bound FB₁ was extracted with 1% sodium dodecylsulfate (SDS) solution. The SDS, which interfered with high-performance liquid chromatography (HPLC) analysis, was then separated from protein-bound FB₁ by complexing with methylene blue followed by solvent extraction and hydrolysis with 2 N KOH. To measure total-bound FB₁, the sample itself was hydrolysed with KOH. In both cases, clean-up was accomplished on an OASIS polymeric solid-phase extraction column and the bound fumonisins were determined by HPLC measurement of HFB₁. Fourteen of 15 samples of corn flakes and other corn-based breakfast cereals analysed contained detectable levels of FB₁ with a mean in positive samples of 67 ng g^-1 (13-237 ng g^-1). Two samples also had detectable levels of FB₂ (21-23 ng g^-1). Bound FB₁ was found in all samples; the mean protein-bound FB₁ measured was 58 ng g^-1 (22-176 ng g^-1) and the mean total-bound FB₁ measured was 106 ng g^-1 (28-418 ng g^-1), reported as FB₁ equivalents after correction for recoveries of HFB₁. There was an average of about 1.3 times more FB₁ in the bound form compared with extractable FB₁, and this was about twice as much as protein-bound FB_1. Seven of the 15 samples of alkali-processed corn-based foods, such as tortilla chips and corn chips, contained FB₁ and three contained HFB₁ with means in measurable positive samples of 78 (48-134) and 29 (13-47) ng g^-1, respectively. Five of these alkali-processed corn foods contained bound FB₁; the mean measurable protein-bound FB₁ was 42 ng g^-1 (39-46 ng g^-1) and the mean measurable total-bound FB₁ was 100 ng g^-1(54-209 ng g^-1). HFB₁ derived from bound FB₁ in selected samples was confirmed by HPLC with mass spectrometry (MS).     

钢制压力容器残余应力的Mises屈服条件确定法

利用Mises屈服条件建立了确定钢制压力容器焊接残余应力的方法,即只要测点进入屈服状态,就完全可以确定该点两个主应力方向的残余应力。并指出该方法是一种确定钢制压力容器残余应力的简易方法。     

提高4A沸石产量的有效途径

4A沸石生产过程中，水热合成反应(溶铝、混胶、结晶)在夹套反应釜中进行。结晶的4A沸石沉积于釜底。因此结晶时间成为影响产量的限制因子。该文针对性地提出增加结晶池，在反应釜中完成水热合成反应之后，转入结晶池完成结晶工艺，提高反应釜的利用率，从而提高产量。     

Simulation Techniques for the Manufacturing Test of MCMs

Simulation techniques used in the Manufacturing Test SIMulator(MTSIM) are described. MTSIM is a Concurrent Engineering tool used tosimulate the manufacturing test andrepair aspects of boards and MCMs from design concept through manufacturing release. MTSIM helps designers select assemblyprocess, specify Design For Test (DFT) features, select board testcoverage, specify ASIC defect level goals, establish productfeasibility, and predict manufacturing quality and cost goals. A newyield model for boards and MCMs which accounts for theclustering of solder defects is introduced and used topredict the yield at each test step. In addition, MTSIMestimates the average number of defects per board detected at eachtest step, and estimates costs incurred in test execution, faultisolation and repair. MTSIM models were validated withhigh performance assemblies at Hewlett-Packard (HP).     

RHZ-300YL型裂化催化剂的研制及其在印度尼西亚的应用

针对印度尼西亚SUNGAI GERONG炼油厂重油催化裂化装置的特点及对产品的要求，开发了RHZ-300YL型催化剂。该剂采用了超稳Y型分子筛的改性技术及活性担体技术，并对催化剂配方进行了优化，使该剂具有重油裂化能力强、活性稳定性好、丙烯及汽油产率高等特点。该剂在印度尼西亚SUNGAI GERONG炼油厂催化裂化装置工业应用表明。在掺炼渣油的条件下，丙烯产率达到5．65％，汽油产率达到50．5％。     

改进钢锭断面形状提高厚板成材率的变形实验

简述了钢锭断面形状对厚板成材率的作用。着重阐述模拟舞阳钢铁公司４２００ｍｍ厚板轧机的轧制工艺条件，轧制８．０ｔ镇静钢扁锭，采用正交设计法确定钢锭断面最佳尺寸。得到了在确定轧制工艺条件下，正确确定最佳钢锭断面尺寸的正交回归数学模型。在本实验最佳断面形状的锭型与合适的工艺相匹配下，厚板成材率约提高５．２７６％，边部切损率约降低３．６３５％。     

大庆蜡油掺炼渣油催化裂化多产柴油的工业开发

介绍了大庆蜡油掺炼渣油催化裂化增产柴油工业试验。标定数据表明，使用ＤＭＣ－２催化剂，选择适当的操作条件，凝点为－１０℃柴油产率可达３３％，柴汽比为０．８７。同时轻质油收率保持在７０％以上，汽油辛烷值没有明显的变化。     

天然维生素E的提取

对经酯化、脱甾醇处理后的油脂脱臭物采用简单蒸馏方法提取维生素E。结果表明维生素E的收率在87%以上,产品含量达51%以上。     

The quality of cold-smoked Atlantic salmon (Salmo salar) as affected by salting method, time and temperature

The effects of temperature (4 and 10–12 °C) and time (6, 12 and 24 h) on colorimetric parameters (Commission International de l'Eclairage (CIE) L*a*b*), carotenoid concentration, salt content and yield were investigated in brine (saturated or 50% saturation) and dry salted fillets of cold‐smoked Atlantic salmon (Salmo salar). Lightness (L*), yellowness (b*), hue (H_ab) and chroma (C*) values were lower at 10 than 4 °C (P < 0.01), whereas redness (a*) was unaffected. L* increased (P < 0.05) and a*, b*, H_ab and C* values dropped when salting time was increased (P < 0.001). Astaxanthin concentration of brine‐salted fillets decreased with increasing salting time (P < 0.05), but was unaffected by salting temperature. Increasing salting time affected colour negatively. The salt content of dry salted fillets increased with temperature and salting time. The process yield was unaffected by temperature and decreased with salting time. In conclusion, the cold smoking process is more important for variation in quality parameters than the salting process.     

A MICROMECHANICAL MODEL FOR γ-TiAl BASE PST CRYSTALS

1. Introduction Intermetallic titanium aluminides are potential new structural materials in high temperature applica- tions[1-3]. These γ-TiAl based alloy materials usually have a two-phase microstructure, composed of a γ- TiAl (L10-structure, tetragona…