木材微波干燥的应用与研究动态

分析了木材微波干燥的机理和优点，介绍了国内外木材微波干燥的研究与应用情况，指出木材微波干燥是一项具有广阔发展前景的新技术。建议今后加强木材微波干燥理论、干燥设备、干燥工艺、微波联合干燥技术等的研究工作。     

ZKY-01型箱式木材真空干燥机及干燥工艺的试验研究

介绍了ZKY-01型箱式木材真空干燥机的结构，采用浮压手段对榆木和酸枝木进行真空干燥试验。试验结果表明，ZKY-01型箱式木材真空干燥机的干燥效果与常规干燥相比，干燥速度大大提高，其干燥时间仅为常规干燥时间的15％左右；干燥质量好，没有发生端裂、表裂与变形等干燥缺陷；被干锯材的应力试片其齿条基本通直，应力指标为0．42％-0．76％。箱式木材真空干燥机具有一定的发展潜力。     

蒸汽与热泵联合干燥木材的匹配分析

对单独的常规蒸汽干燥、热泵(除湿)干燥以及二者联合干燥三种工况进行了能耗分析，结果以联合干燥能耗最低，热泵(除湿)干燥次之，常规蒸汽干燥能耗最高。文中还就相应干燥条件下蒸汽-热泵(除湿)联合干燥的匹配条件作了研究。     

热泵干燥木材的技术现状与发展趋势

热泵与常规热风干燥的区别在于前者的干燥系统中空气为闭式循环，依靠制冷原理对空气降湿；后者为开式循环，依靠换气使空气降湿。对热泵干燥木材进行了节能分析，其节能率在40％～70％之间。文中介绍了热泵在木材干燥工业中的国内外应用概况，分析了热泵干燥的优点、局限性与适用范围，指出了今后热泵干燥木材的发展趋向是与常规能源联合干燥或作为二段干燥中的预干燥。同时还指出，热泵也宜推广用于干燥种子、水产品及热敏类化工原料等适于低温干燥的物料。     

木材干燥的国内外现状与发展趋势

阐述了常规蒸汽（热风）干燥、除湿（热泵）干燥、真空干燥、微波与高频干燥等各种木材干燥技术的国内外现状以及我国木材干燥技术与国际水平的差距；介绍了国内外木材干燥的理论研究动态；指出了今后木材干燥技术的发展趋势。     

荆芥不同干燥加工方法药材质量变化研究

比较不同干燥加工方法引起荆芥药材的质量变化。选用传统的阴干、晒干干燥和3种温度的恒温烘干干燥方法,以水分含量,挥发油含量与挥发油中两种主要成分的含量与相互比例为指标进行观察。结果:与传统干燥方法相比,恒温烘干干燥能较快地去除水分,控制温度在一定范围也有助于减少挥发油的损失。但加工后药材挥发油中两种主要成分薄荷酮与胡薄荷酮的含量与相互比例均有显著改变。将恒温干燥方法用于荆芥药材加工可能对其质量有较大影响。     

太阳能与热泵联合干燥木材特性的实验研究

介绍了国内外利用太阳能干燥木材的概况、太阳能与热泵联合干燥系统的组成与工作原理、太阳能与热泵联合干燥木材的特性和干燥木材的工艺实验。实验结果显示。太阳能与热泵联合供热可以弥补太阳能或热泵单独供热的缺点。太阳能比联合干燥节能3．8％,而联合干燥比热泵干燥节能11．8％;联合干燥比太阳能干燥时间缩短了14．9％。从能耗及生产效率综合考虑。太阳能与热泵联合干燥是值得推荐的一种干燥方法。     

材性法制定木材干燥基准的探索

提出了一种新的木材干燥基准制定法——材性法。与常用的百度法相比,材性法更省时、简易、准确。采集简单易测的待干木材材性数据,如基本密度、厚度、初含水率等,材性法可以快速地制定出木材干燥基准。介绍了材性法的理论基础、制定方法及试验验证。     

我国木材干燥技术与研究动态

阐述了我国木材干燥技术应用状况及面临的问题,介绍了我国木材干燥学术活动的情况和理论研究动态。指出以蒸汽为热源的常规干燥仍将占木材干燥的主导地位,约在80％以上;真空干燥、热泵除湿干燥、微波与高频干燥、高温干燥、加压干燥等其它干燥方法都在各自适用的范围内有一定的发展。木材的渗透性、木材干燥过程的水分迁移机理等有关木材干燥的传热传质方面的基础理论研究正在加强;高效节能的木材干燥技术是目前研究的重点课题。我国木材干燥技术正由经验型转向以干燥理论为基础的科学型方向发展。     

利用热泵对木材常规干燥窑进行废热回收的初步探讨

介绍了利用热泵对木材常规干燥窑进行废热回收装置的设备构成,计算了空气和制冷剂的各状态点参数,对冷热负荷和压缩机耗功进行了分析,提出并比较了废热回收的三种方案,为系统的进一步设计和实验提供了参考依据。     

太阳能-除湿-常规分段组合木材干燥工艺优化

为降低木材干燥能耗,通过对杨木进行太阳能-除湿-常规分段组合干燥,即含水率40%以上采用太阳能进行预干,25%—40%采用除湿干燥,25%以下采用常规干燥,并与常规干燥进行干燥能耗和木材质量的对比。结果表明,分段组合干燥比常规干燥节能19%左右,而且干燥质量和常规干燥基本一致。分段组合干燥充分利用了三者各自的优势,从而达到节能的目的。     

Spray Drying of Yogurt: Optimization of Process Conditions for Improving Viability and Other Quality Attributes

Plain yogurt was subjected to spray drying to determine the optimum processing conditions that yield maximum survival ratio of lactic acid bacteria, maximum overall sensory attributes, minimum color change, and acceptable moisture content. The inlet (150–180°C) and outlet air temperatures (60–90°C) and the feed temperature (4–30°C) were the independent factors. A pilot-scale spray dryer was used to conduct a set of drying experiments where the process conditions were selected according to central composite rotatable design (CCRD). The resulting yogurt powder at each condition was also subjected to the measurement of some physical properties (water activity, titratable acidity [lactic acid, %] and pH) to determine the effects of spray-drying conditions. The morphological structure of the powder was inspected by scanning electron microscopy (SEM) analysis. Optimization by the application of the desirability function method resulted in air inlet temperature of 171°C, air outlet temperature of 60.5°C, and feed temperature of 15°C as the optimum processing condition. The mathematical optimum condition was experimentally verified.     

我国木材干燥设备制造业概况与存在的问题

介绍了我国木材干燥的市场需求与设备制造企业的概况,指出了我国木材干燥设备制造企业目前存在着技术规范还不够健全、缺乏质量监督机构、检测控制系统精度差、零部件质量差及干燥设备的能耗偏高等问题,并对提高木材干燥设备质量提出了几点建议。     

Energy and Quality Aspects of Food Drying

High energy consumption and increasing consumers interest in new products are two problems worthy of note in the drying of food. Difficulties in producing high-quality food and degrading transformations of the material during drying are mentioned. The kinetics of quality degradation due to drying is described. The role of water activity in maintaining product quality is emphasized. Examples of drying methods and tendencies toward a reduction in quality degradation of dried food products are shown.     

A Comparison of the Drying Simulation Codes Transpore and Wood2D which are used for the Modelling of Two-Dimensional Wood Drying Processes

ABSTRACT

This study is devoted to investigating the heat and mass transfer phenomena that occur during the convective drying of wood at high temperatures. A comparison will be made between an existing two-dimensional computer code known as Transpore. which was developed by Perre in France, and another two-dimensional code which was developed independently by Turner in Australia. Both numerical codes use a comprehensive set of macroscopic equations to describe the drying process, and most importantly treat the anisotropic behaviour of the wood. The porous medium is defined by three state variables: temperature, moisture content and gaseous pressure and the numerical simulation codes allow the evolution of the distributions of these state variables to be analysed throughout the drying process. The numerical investigation presented in this research work will compare the results obtained from both simulation codes and comments will be made on their consistencies. The influence that the drying air characteristics (moist air and super-heated stream) have on the overall drying kinetics, together with the effect that varying the mesh structure or changing the relative permeability curves have on the results will be throughly scrutinised.     

Color Changes of Birch Wood During High-Temperature Drying

In low-temperature drying, a high drying rate has been found to be adequate for silver birch (Betula pendula) and European white birch (B. pubescens) timber as far as wood colour is concerned. During high-temperature drying, however, birch timber darkens significantly if steam is used as the drying medium. The objective of this research was to study the effects of drying force (wet-bulb depression), timber thickness, and initial moisture content on the color of high-temperature-dried birch wood. The reflectance spectrum of wood was measured and transformed to the CIEL?a?b? color scale.

The increase in drying force increased the lightness and decreased the redness and the yellowness of wood. At the same time, the difference in color between the surface layer and the interior of boards increased. Increase in thickness and in initial moisture content increased the difference in color between the surface and the interior of boards. Pretreatment of timber with water soaking decreased the difference in color between the surface layer and the interior of boards when low drying force was used, but this difference was increased when high drying force was used.     

低碳经济推动车用工程塑料的研发与应用

介绍了工程塑料的性能特点：适用于汽车零部件领域里的工程塑料种类：并指出汽车以塑代钢的轻量化亟待研发与应用趋势。     

低碳经济与煤的清洁高效利用

煤炭是中国的主要能源,实现低碳经济的关键是煤的清洁高效利用。提出煤炭洗选、煤制合成天然气和煤基多联产作为短、中、长期的对策建议。     

加强低碳经济教育以提高大学生的环保意识

强化高校低碳经济教育,让大学生理解低碳经济是指温室气体排放量尽可能低的经济发展方式,尤其是要有效控制CO2的排放量,是以低能耗、低排放、低污染为基础,核心是技术、制度创新和发展观的改变。只有当人们尤其是作为跨世纪建设者的大学生普遍树立起低碳环保意识时,才能形成社会力量来共同保护人类生存环境。可见,推广低碳生活,加强低碳经济教育是必要的。     

PE木塑复合材料配方中润滑剂对物理性能和加工性能的影响

讨论了两种润滑体系在PE(聚乙烯)木塑复合材料中的应用,测试了材料的物理性能和加工性能,结果发现不同润滑剂对PE木塑复合材料的影响。