柴油机废烟气驱动的热管LiBr制冷机的分析

工业过程中的废热排放造成了可用能的损失 ,又造成热污染和环境污染。针对一种利用热管回收废热的LiBr制冷机 ,采用柴油机烟气废热制冷实测后 ,对该系统的实测结果进行了火用分析 ,分析结果表明了这种新型废热LiBr制冷机有效利用了柴油机烟气余热 ,提高了系统的火用效率     

The Effect of Moisture Content in Epoxy Film Adhesives on their Performance. III: Bulk Properties

Humidity absorbed by epoxy film adhesives during low temperature storage or exposure to atmosphere may result in reversible changes and irreversible modifications. Vacuum treatment may partially remedy the reversible changes. The consequences of vacuum drying are manifested in enhancement of both the peel and shear properties of bonded joints (Part I and Part II of this series of papers) and the thermal, physical and mechanical properties of the bulk adhesive, characterized in the present study.

Experimental results have shown that the bulk properties of structural epoxy based adhesives are highly correlated with the aging processes caused by water absorption in the prepolymerized adhesive. Applying the vacuum process is harmful to fresh unaged adhesive due to devolatization of low molecular species of the film adhesive.

The characterization of bulk properties for the purpose of following the aging and recovery processes is advantageous, since the bulk is independent of geometrical and interfacial effects which dominate in the case of property evaluation of the adhesive in a bonded joint.     

Free convection heat transfer over a horizontal plate at low prandtl number

Boundary layer equations for free convection heat transfer along a semi-infinite horizontal plate are derived by giving more importance to the energy equation. The equations are obtained for low Prandtl number and two separate polynomials are used to approximate the temperature and velocity profiles in these regions. The rate of heat transfer is compared with the available analytical and numerical results based on conventional boundary layer equations.     

On the examination of recycle on heat (and mass) transfer in concentric tubes

The effect of recycle on heat (and mass) transfer in concentric circular tubes has been investigated by finite difference methods. Theoretical results show that recycle can enhance the heat transfer rate for large Graetz numbers compared with that in an open tube (without an inner tube inserted and without recycle). Competition between a preheating effect and a residence-time effect can be used to explain the heat transfer behavior. The heat transfer rate can be further augmented, with nearly no increase in total pressure drop, by employing flow pattern B instead of flow pattern A.     

Conjugate heat transfer in turbulent falling liquid films

Heat transfer characteristics for a falling turbulent liquid film flow over a fin are analyzed using the conjugate convection-conduction theory. Numerical results are obtained from a simultaneous solution of the energy equations of the fluid and the fin. Results are presented for the fin temperature distribution, dimensionless heat transfer coefficients, local heat fluxes, and fin efficiencies.     

Efficacy of tertiary butylhydroquinone on the storage and heat stability of liquid canola shortening

The sensory (odor and flavor) and physicochemical characteristics of tertiary butylhydroquinone (TBHQ) treated and butylated hydroxyanisole/toluene (BHA/BHT) treated liquid canola shortenings, subjected to accelerated storage (Schaal oven test at 65°C) and deep fat heating (at 185°C), were determined. Data for the Schaal oven test indicate that TBHQ was effective in retarding oxidative rancidity in liquid canola shortenings. However, addition of the commonly used mixture of BHA/BHT to canola shortenings resulted in only a slight decrease in oxidation during schaal oven storage. The results obtained from deep fat heating of canola liquid shortening show that neither TBHQ nor BHA/BHT was effective in enhancing oxidative and thermal stability of this product.     

微生物处理含铬(Ⅵ)废水的研究进展

文章综述了国内外微生物法处理含铬(Ⅵ)废水的研究进展，介绍了以非生物活性的微生物体为铬(Ⅵ)的吸附剂的失活微生物体吸附法及应用活体微生物的活体微生物法，活体微生物法在吸附剂的制备及处理效果等方面都具有更好的实际应用价值。文章同时指出了该法目前存在的一些问题，认为培养和应用高效工程菌是将来的发展方向。     

瓷质砖湿坯对流干燥过程的传热传质研究

引用建立于Whitaker的体积平均方程和Darcy定律基础止的多孔介质内部热质传递的等效耦合扩散模型，寻出一组关于液体饱和度、温度和气相压力的新支配方程，应用该方程组对瓷质砖坯体干燥过程进行了数值分析和实验测定。在平均含湿饱和度的变化方面，数值解与实验结果十分吻合。还改变影响坯体干燥过程的一些因素进行计算机模拟计算，通过改变这些因素的大小来考察计算结果，以期获得某些定性或定量的结论，从而用以指导实际生产过程。     

有机锡化合物的用途

有机锡化合物在工业、农业、医药和材料等方面有其极为广泛的用途，本文概述了有机锡化合物作为塑料热稳定剂、生物杀伤药剂和均相催化剂的应用。     

校园网“毒瘤”ARP病毒防治

ARP攻击是指黑客利用ARP协议缺陷的基本原理,通过在区域内一台终端或服务器上发布欺骗ARP广播包以达到进行盗取用户帐号、篡改网站内容、嵌入恶意代码、发布不良信息、监听传输数据等非法活动的目的。