聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

溶剂对PET的诱导结晶作用

应用偏光显微镜等方法,考察了12种溶剂对PET的诱导结晶作用,表明与热结晶一样存在成核和增长两过程;增长速度和形成的球晶尺寸均与熔剂分子大小、极性等有关:诱导结晶速度快于渗透扩散速度等,所以溶剂诱导结晶动力学符合扩散动力学之说是值得商榷的。溶剂诱导结晶的形态可分为表面呈球状结构和不呈现球状结构二种类型,从断面观察分析球状结构形态仅在表面形成。发现球晶脱落漂于溶剂。     

氯苄双羰基化反应动力学模型

氯苄双羰基化反应生成苯丙酮酸钙的过程是一个多相催化反应过程。通过对反应机理的研究,推导出实际操作的等温等压条件下反应动力学方程,并用实验数据加以验证。     

建筑陶瓷的装桢与软件复用技术的应用——三维虚拟展示系统的开发

在软件复用基本理论和技术的基础上，阐述了软件体系结构对软件复用的意义，提出了基于软件体系的软件复用开发方法以及在建筑陶瓷三维虚拟展示系统开发过程中的应用。     

床层不均匀对散羊毛干燥过程的影响

在均匀床层模型的基础上,用数值方法分析了羊毛床层不均匀对抽气转鼓干燥机性能的影响。提出了描述床层厚度分布的数学模型式。研究结果表明,进料不均匀分布导致产品平均湿含量增大和干燥机生产能力下降,因此进行干燥机设计时,可以在物料均匀分布模型设计的基础上,生产能力适当留有余地。     

EFFECT OF PRETREATMENT ON KINETICS OF CONVECTION DRYING OF ONION

Onion of two varieties, i.e. Oporto and Blonska was dried by convection at 60°C and 2 m/s. Prior to drying sliced onion was subjected to following treatments: soaking in water, dipping in starch solution, dipping in starch solution supplemented either with ascorbic acid or CaCl₂, and dewatering by osmosis in sucrose solution. Drying of raw onion was taken as a reference.

It has been found that both variety and pretreatment affect the course and rate of drying. Soaking in water and dipping in starch solution either increase rate of drying or have no effect on the kinetics of the process. Supplementing the starch solution with ascorbic acid or CaCl₂ adversely affects the rate of drying. Unfavorable effect on the rate of drying has also osmotic dewatering preceding convective drying.     

生物质焦分形维数计算

采用压汞法的实验数据,计算两种分形模型下生物质焦样的分形维数。其中根据Menger海绵模型计算得到的分形维数Dm的值在2．7～3．1之间,基于热力学关系的分形模型计算得到的分形维数Dr的值在2．7～2．9之间。分析认为第二种模型更好的描述了焦样的孔隙结构,Dr的值比Dm的值更为合理。实验结果表明,分形维数与生物质种类有关,树叶焦样的分形维数整体上大于稻壳焦样的分形维数。生物质焦样的平均孔径与分形维数有关。总的来看,同一生物质焦样的分形维数随着平均孔径的增大而减小。     

DEPOSITION OF AEROSOL PARTICLES ON A SURFACE COMPOSED OF DIFFERENT TYPES OF MATERIALS

Experimental and theoretical studies have been conducted on the deposition of aerosol particles on a surface composed of different types of materials (copper-polyethylene and copper-nickel). Deposition of charged particles is affected by localized electrostatic fields created by the contact potential difference between the different types of materials. The particles charged with positive polarity deposit mainly on the polyethylene or the nickel surfaces, which are negatively charged. The deposition profile has been also controlled by varying the thickness of gold layers deposited on nickel surface.     

MEASUREMENTS OF INERTIAL DEPOSITION OF AEROSOL PARTICLES IN REGULAR ARRAYS OF SPHERES

Inertial deposition of aerosol particles on single spheres and regular assemblies of spheres was investigated in the range of Stokes numbers from 0.03 to 5. Measurements were carried out on steel spheres suspended from wires in a 100 mm wide flow channel at air velocities from 5 to 28 m s^-1, using monodisperse DES (Di-II-ethyl-hexyl-sebacate) test aerosol in the size range from 1.5 to 15 μm. Experimentally determined deposition efficiencies on single spheres are in very good agreement with theoretically predicted results based on a potential flow field as well as a numerical flow simulation. Results in various types of arrays consisting of up to 12 equal-sized spheres show substantial variation of deposition efficiency from sphere to sphere which are strongly influenced by Stokes number and geometry.