大豆水溶性膳食纤维提取的研究

豆渣是多种膳食纤维原料中质高价廉的一种,本文研究了在碱性条件下豆渣中水溶性膳食纤维（SDF）的提取工艺。研究表明豆渣中SDF提取的最佳工艺条件为：碳酸钠浓度为4％,浸泡时间为1．5h,浸泡处理温度为60℃,料液比为1：30。以此最佳条件提取的水溶性膳食纤维产率可达33．8％,具有良好的产业化应用前景。     

板蓝根水溶性多糖的提取纯化工艺条件研究

目的研究板蓝根水溶性多糖的提取纯化工艺条件。方法通过正交实验,考察液料比、提取时间、提取温度、醇沉时间、醇液比对多糖得率的影响。结果液料比是影响提取工艺的主要因素,最佳工艺条件为：液料比30：1,提取温度90℃,提取时间6h。三氯乙酸法脱蛋白,葡聚糖凝胶柱层析纯化分离。结论板蓝根多糖得率25．63％,多糖含量76．42％。纯化后的板蓝根多糖为分子大小均一的单一组分多糖,不含核酸和蛋白质。     

超声-微波辅助酶法对小米SDF提取和物理性质的影响

目的为了提高小米中水溶性膳食纤维(SDF)的得率,实验采用超声-微波(U-M)辅助酶法提取小米SDF,并对提取工艺进行优化。方法以小米SDF的得率为测定指标,对微波功率、提取温度、提取时间、料液比等4个因素进行单因素试验,并利用正交试验对以上4个因素进行优化。对此条件下提取的SDF和采用传统酶法提取的SDF得率及其物理性质进行研究。结果得到了提取小米粉SDF的最优条件,微波功率为550 W,料液比(g/mL)为1:25,微波温度为55℃,微波时间为20 min,提取率为13.63%,比传统酶法提取的SDF含量提高了46.88%;通过对小米SDF物理性质的测定,发现超声-微波处理对小米SDF的持水力、膨胀力、持油力均有显著提高,分别提高了24.79%,25.16%,15.74%。结论通过超声-微波辅助酶法可以提高小米SDF的得率,对其物理性质影响显著。     

荸荠多糖的超声波辅助提取工艺

为提高荸荠多糖的得率,采用超声波辅助法提取荸荠多糖。通过单因素试验研究超声波功率、料液比、提取温度、超声处理时间、乙醇浓度对荸荠多糖得率的影响,确定荸荠多糖的最佳提取工艺。单因素试验结果表明,在本试验条件下,超声波功率为300W、料液比1：10、提取温度为50℃、超声时间25min时荸荠多糖得率最高。     

基于响应曲面法的桑叶萃余物多糖提取工艺优化

以提取生物碱和黄酮的桑叶萃余物为原料,采用响应曲面分析法(RSM)优化桑叶萃余物多糖的超声提取工艺。在单因素实验的基础上,选取对实验结果影响较大的因素:提取时间、提取温度、水料比,根据中心组合(BoxBenhnken)实验设计原理对桑叶多糖的超声提取工艺进行优化,苯酚-硫酸比色法测定桑叶多糖的含量。在分析各个因素的显著性和交互作用的基础上,得到最佳提取工艺条件为:提取温度79.29℃、超声波时间35.90min、水料比8.78mL/g。采用该工艺条件,桑叶多糖的提取得率达到2.97%。与模型预测值相符。     

黄精多糖的提取工艺对比研究

目的以黄精为原料,对比不同提取工艺对黄精多糖提取率的影响,以确定黄精多糖的最佳提取工艺。方法对黄精多糖的水提醇沉法和复合酶解法等2种提取方法进行对比分析。结果得到了水提醇沉法最佳的实验条件,料液比(g/mL)为1∶25,pH值为6,温度为80℃,提取时间为2 h,乙醇的体积分数为70%,在该最佳条件下多糖的提取率为8.84%;得到了复合酶解法提取黄精多糖最佳复合酶组合条件,纤维素酶与木瓜蛋白酶的质量比为3∶7,pH值为5.0,酶解温度为50℃,料液比(g/mL)为1∶20,加酶量(质量分数)为5%,酶解2 h,在该条件下,黄精多糖的提取率可达22%。结论采用复合酶解法得到的多糖得率远高于采用水提醇沉法得到的多糖得率;实验提供了黄精多糖的最优提取工艺,为其开发利用提供了理论参考。     

超声强化溶剂提取车前草中总黄酮的研究

采用超声技术对车前草中总黄酮提取进行强化,选择料液比、超声提取时间、提取温度、超声功率四因素进行正交实验,得出影响总黄酮提取率大小的次序先后为：提取温度〉超声功率〉超声提取时间〉料液比。在实验参数的基础上,为了获得较高的提取率和节省溶剂用量,各因素的优化工艺参数为：料液比1：20,超声提取时间30min,超声提取温度为50℃,超声功率为200W,在这个最佳条件下试验,总黄酮的提取率为0．645％。相对常规回流提取法而言,采用超声法提取具有快速、节省溶剂、节省时间、提取的有效成分含量较高等优点。     

超声波-乙醇法提取树莓酮及抗脂质过氧化研究

目的为了探究天然树莓酮提取的最佳工艺条件,以及树莓酮的抗脂质过氧化作用。方法以红树莓为原料,选用超声辅助乙醇提取法提取树莓酮,采用气相色谱法测定树莓酮含量。基于单因素实验结果,以料液比、乙醇浓度、超声时间和温度为影响因子,树莓酮得率为响应值,设计响应曲面优化实验,并研究树莓酮的抗脂质过氧化作用。结果得到树莓酮最佳提取条件,料液比(g/mL)为1∶15、乙醇体积分数为85%、超声时间为50 min,超声温度为40℃。在此条件下验证了实验,得出树莓酮含量为2.803μg/g,抗蛋黄卵磷脂脂质过氧化能力趋势为Vc溶液>树莓酮粗提液>树莓酮标准溶液。结论超声波辅助乙醇提取法可有效应用于红树莓中树莓酮的提取,且树莓酮粗提液对由Fe^2+诱导的脂质过氧化有一定的抑制作用。     

枸杞色素的闪式提取和超声-微波协同提取工艺

目的 以枸杞为原料,比较不同提取工艺对枸杞色素吸光值的影响,以确定枸杞色素的最佳提取工艺.方法 通过单因素试验和响应面法对枸杞色素的闪式提取和超声-微波协同提取工艺进行研究.结果 闪式提取枸杞色素的最佳工艺条件为料液比(g/mL)1︰13,提取电压113 V,提取时间112 s,该条件下枸杞色素吸光度为0.457;超声-微波协同提取枸杞色素的最佳工艺条件为料液比(g/mL)1︰16,微波功率613 W,提取温度55℃,提取时间32 min,该条件下枸杞色素吸光度为0.502.结论 对2种提取方法在最佳工艺条件下进行比较,超声-微波协同提取法提取枸杞色素的效果优于闪式提取法.     

蒸汽爆破预处理白芦笋下脚料多糖提取工艺

目的研究蒸汽爆破预处理白芦笋下脚料多糖提取的最佳工艺,分析蒸汽爆破预处理对多糖得率的影响。方法以白芦笋加工下脚料为原料,采用蒸汽爆破预处理提取多糖,探讨物料粒径、汽爆压力、维压时间、料腔比(物料与料腔体积的比值)对多糖得率的影响,利用响应面优化设计筛选白芦笋下脚料多糖的最佳提取工艺。结果汽爆压力对白芦笋下脚料多糖得率的影响最大,其次为物料粒径、维压时间、料腔比。得到了响应面优化蒸汽爆破预处理的最佳提取条件,物料粒径为30目,维压时间为128 s,汽爆压力为1.50 MPa,在此条件下多糖得率的实测值达到8.86%,较直接热水浸提法的多糖得率增加了22.88%。结论蒸汽爆破预处理对提升多糖得率具有一定的促进作用。     

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.     

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.……     

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.     

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.     

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.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

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.