Distribution of microbes in supercritical CO2 extraction of sea buckthorn (Hippopha? rhamnoides) oils

 The distribution of vegetative microbial cells and their spores in a supercritical CO₂ extraction process was studied. The seed and flesh/skin fractions of the press residue of sea buckthorn berries (Hippopha? rhamnoides) from a juice factory were used as raw materials. A pilot-scale extraction plant was operated at 30 MPa at temperatures of 40 and 60°C. The number of yeasts, moulds and bacteria in the pulp/skin fraction, in the extraction residues, in the extracted oils as well as in the water phases separated from the extracted oils was estimated by the spread plate technique. The microbial content of the flesh/skin material was increased in some extractions by the addition of bacterial spores. In general, the extraction process led to a decrease in the bacterial count of the extracted material, whereas no microbial growth was detected in the oils extracted or in the water phases separated from them. Neither yeasts nor moulds were found in any samples after the extraction process. The microbial status of seed oil and flesh/skin oil obtained by industrial-scale CO₂ extraction at 40°C and at 30 MPa before and after gelatine encapsulation remained unchanged. This proves that supercritical CO₂ can be used to manufacture edible oil products free of living micro-organisms and their spores. Received: 14 May 1996     

NC-OFDM系统基于最小功率的导频设计

以导频总功率最小化为准则,提出了一种适用非连续正交频分复用系统的导频设计方法.与传统的子载波总功率受限的导频设计方法相比,对给定的导频辅助信道估计最小均方误差指标,需要较小的导频总功率,从而提高了数据传输的功率利用率,这也响应了当今社会提倡的节能减排的号召.仿真结果证明了该结论.     

A DYNAMIC MODEL WITH ON-LINE IDENTIFICATION FOR ROTARY SUGAR DRYING PROCESSES

A dynamic modelling methodology, which combines on-line variable estimation and parameter identification with physical laws to form an adaptive model for rotary sugar drying processes, is developed in this paper. In contrast to the conventional rate-based models using empirical transfer coefficients, the heat and mass transfer rates are estimated by using on-line measurements in the new model. Furthermore, a set of improved sectional solid transport equations with localized parameters is developed in this work to replace the global correlation for the computation of solid retention time. Since a number of key model variables and parameters are identified on-line using measurement data, the model is able to closely track the dynamic behaviour of rotary drying processes within a broad range of operational conditions. This adaptive model is validated against experimental data obtained from a pilot-scale rotary sugar dryer. The proposed modelling methodology can be easily incorporated into nonlinear model based control schemes to form a unified modelling and control framework.     

塑闪墙在束性能测试

在HIRFL通用散射室的终端调试时完成了0°附近Pilot U塑闪墙的性能测量,给出了位置分辨为Δx=3cm,时间分辨为600ps,并能分辨出Z≤6的几种主要粒子,测得100×5×1cm~3的Pilot U有效光速为16.37cm/ns,有效衰减长度为92.4cm,并解决了同一条塑闪在0°附近的粒子多击问题。     

Characteristics of Oil and Skim in Enzyme-Assisted Aqueous Extraction of Soybeans

The economic viability of enzyme-assisted aqueous extraction processing (EAEP) of soybeans depends on properties and potential applications of all fractions (skim and insolubles as well as oil). EAEP oil contained lower free fatty acid, phosphorus, and tocopherol contents, similar unsaponifiable matter levels, and higher degrees of oxidation (peroxide and p-anisidine values) than hexane-extracted oil. The phospholipid profile of EAEP fractions was mainly composed of phosphatidic acid, followed by phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine. Most of phospholipids were present in the skim, except for phosphatidic acid, which was the major phospholipid in the cream fraction. Skim and cream contained 55 and 3 % of the soluble carbohydrates in the original extruded flakes, respectively. Soluble carbohydrates of the skim were mainly composed of stachyose (5.8 ± 0.8 mg/mL) and sucrose (9.9 ± 0.8 mg/mL), which were hydrolyzed into glucose, galactose, and fructose after addition of α-galactosidase. Skim and cream peptides contained <20 kDa MW molecules. About 71 % of the skim peptides were <20 kDa MW, with 49 % being <1.35 kDa MW, 22 % being 17–1.35 kDa MW, and 29 % being 44–670 kDa MW. Skim protein and carbohydrate contents make this fraction suitable for replacing water in ethanol fermentations, thereby improving the fermentation rate/production and the nutritional quality of distiller’s dried grains with solubles.     

抗菌建筑卫生陶瓷的试制和展望

本文介绍了抗菌建筑卫生陶瓷的基本概念和国内外的发展简况;抗菌剂及制品的性能评价;无机抗菌剂型和纳米材料型抗菌建筑卫生陶瓷的试验和检测情况;讨论了发展抗菌建筑卫生陶瓷方面的几个问题并对它的发展前景作了预测和展望。     

工业企业新产品试制过程管理的研究

本文从提高微观经济效益的角度,研究了工业企业新产品试制过程管理的问题。文中指出：企业新产品试制过程管理是企业管理系统的一个重要组成部分,要运用现代化手段管理新产品试制过程。     

50W1300冷轧无取向电工钢带的工业试制

采用40 t氧气顶吹转炉-180 mm×495 mm板坯连铸-连轧工艺流程,试制了0.5 mm×480 mm 3 t 50W1300冷轧电工钢带(铸坯成分%:0.04～0.06C、0.82～0.96Si、0.35～0.40Mn、0.015～0.017P、0.014～0.019S)。通过钢包吹氩,控制钢水终点温度1650～1670℃,钢中氧含量由72.9×10^-6降至22.9×10^-6。试制的冷轧无取向电工钢带成品的电磁性能和力学性能均达到GB/T2521-1996中50W1300标准要求,适用于小型电动机转子的制造。