苹果真空冷冻干燥工艺参数对耗电量影响的研究

研究了苹果真空冷冻干燥工艺参数（干燥室压力、物料厚度、加热温度）对耗电量的影响规律。试验结果表明，影响试验指标的主要因素是物料厚度，试验因素主次排列为物料厚度、干燥室压力、加热温度。其较优组合为干燥室压力为140Pa、物料厚度为12mm、加热温度为30℃。     

真空冷冻干燥过程参数对扇贝冻干升华干燥时间的影响

通过采用二次正交回归组合试验,建立了真空冷冻干燥升华时间和单位厚度升华时间的二次多元回归模型,利用降维法分析了真空冷冻干燥过程中物料厚度、干燥室压强和加热板温度三个主要过程参数对扇贝真空冷冻干燥升华干燥时间的影响。结果表明,物料厚度、干燥室压强和加热板温度对冻干时间影响呈二次函数规律变化,影响的主次因素依次为：物料厚度、干燥室压强、加热板温度。对单位厚度冻干时间进行岭嵴分析,给出了在本试验三因素取值范围内的冻干过程优化参数：物料厚度为9mm;干燥室压强为50Pa;加热板温度为39℃,优化的物料单位厚度升华干燥时间为0.146h。     

真空冷冻干燥升华干燥时间的实验研究

本文以扇贝为研究对象,采用二次正交回归组合试验,建立了真空冷冻干燥升华时间和单位厚度升华时间的二次多元回归模型,利用降维法分析了干燥室压强、物料厚度和加热板温度三个主要过程参数对真空冷冻升华干燥时间的影响。结果表明,干燥室压强、物料厚度和加热板温度对升华干燥时间影响显著,呈二次函数规律变化,影响的主次因素依次为:物料厚度、干燥室压强、加热板温度。对单位厚度升华干燥时间进行岭嵴分析,给出了在本试验三因素取值范围内的冻干过程优化参数:干燥室压强为50Pa;物料厚度为9mm;加热板温度为39℃,优化的物料单位厚度升华干燥时间为0.146h。     

真空冷冻干燥升华干燥时间的实验研究

以扇贝为研究对象，采用二次正交回归组合试验，建立了真空冷冻干燥升华时间和单位厚度升华时间的二次多元回归模型；利用降维法分析了干燥室压强、物料厚度和加热板温度三个主要过程参数对真空冷冻升华干燥时间的影响。结果表明，干燥室压强、物料厚度和加热板温度对升华干燥时间影响显著，呈二次函数规律变化，影响的主次因素依次为：物料厚度、干燥室压强、加热板温度。对单位厚度升华干燥时间进行岭嵴分析，给出了在本试验三因素取值范围内的冻干过程优化参数：干燥室压强为50Pa；物料厚度为9mm；加热板温度为39℃，优化的物料单位厚度升华干燥时间为0.146h。     

基于图像处理优化真空冷冻干燥工艺参数

通过三因素二次通用旋转组合试验设计,考察了物料厚度、加热板温度和干燥室压力对真空冷冻干燥人参面积收缩率的影响,得出了人参面积收缩率与各因素间的回归模型.试验结果表明,影响试验指标的主要因素是物料厚度,试验因素主次排列为物料厚度、加热温度、干燥室压力.其较优组合为物料厚度为12 mm、加热温度为40℃、干燥室压力为40 Pa.     

冻干香蕉过程参数优化的研究

对香蕉冻干生产工艺中的物料厚度、冻结方法、加热板温度、干燥室真空度等过程参数进行比较试验，结果表明：各过程参数的不同处理水平对香蕉冻干品质量和产量均有显著的影响。香蕉物料厚度取5nml～7mm，采用速冻方法冻结，加热板温度设定45℃，干燥室真空度控制于20Pa～30Pa范围，是香蕉冻干过程参数较佳的工艺条件。     

真空冷冻干燥过程参数对酸化纸质文献冻干过程的影响

以酸化纸质文献为对象,研究了真空冷冻干燥过程参数(加热板温度、纸质文献厚度、干燥室压强)对其冻干时间和品质的影响,并采用L9(33)正交实验得出各过程参数影响的主次顺序和除水比例。结果表明:各过程参数的不同处理水平对纸质文献冻干时间和品质均有显著的影响,且各过程参数影响主次顺序均为:纸质文献厚度、加热板温度、真空室压强。本实验三因素取值范围内的冻干过程优化参数分别为:纸质文献厚度7 mm,加热板温度25℃,真空室压力10~20 Pa。     

变温变压的优化组合对扇贝真空冷冻干燥过程影响的实验研究

为了获得调压调温的优化组合对栉孔扇贝真空冷冻干燥过程的品质、能耗和时间的综合影响,在前期研究的基础上,本文对两次变温和一次变压的温度和压力组合参数进行了五因素四水平的正交组合试验,并以能耗、冻干时间和复水率等三指标的综合加权平分值为指标,得出了各温度和压力条件影响冻干能耗及品质的主次关系为:加热板高温2>干燥室低压>加热板高温1>加热板低温>干燥室高压,各因素的最佳组合是加热板高温1为42℃,高温2为30℃,干燥室低压为25Pa,加热板低温为25℃,干燥室高压为80 Pa,在这个优化组合工艺条件下,扇贝的复水率达到83.7%,与16组实验中的最佳相比,复水率提高了12.20%,能耗下降了2.17%,干燥时间缩短了20%。     

苹果冷冻干燥过程的实验研究

本对苹果的冷冻干燥过程进行了实验研究,分析了冻干曲线的特征,比较了降温速率、真空度、加热板温度以及冷阱温度对冷冻干燥和冻干品质量的影响,对实际冷冻干燥生产具有一定的指导作用。     

真空冷冻干燥过程参数对玫瑰的冻干过程影响的试验研究

真空冷冻干燥技术是将含水物料在低温状态下冻结,然后在真空条件下,使冰直接升华成水蒸气并排掉脱水物料中的水分使物料干燥.因此真空冷冻干燥产品可以最大限度的保持新鲜物料的原有色、香、味.形和营养成分.本文通过对玫瑰花的真空冷冻干燥实验的分析,对影响真空冻干的过程参数进行了试验研究.试验表明隔板温度、干燥室真空度是很重要的两个参数;冻结速率对总冻干时间没影响.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.