落叶松栲胶高度亚硫酸化改性及其产物应用性质的研究

落叶松栲胶经过高度亚硫酸化反应，小分子部分增多，产物平均分子量降低，Ｎａ２ＳＯ３ 和ＮａＨＳＯ３ 总用量为３０ ％ 时，分子量低于７１３ 的组分由３０ ％ 增加到６０ ％ ，其分布变得更均匀，色度值、粘度值、盐析值均下降，耐酸性增强，用于制革时，渗透速率增加，具有比传统方法生产的栲胶更优良的结合鞣、复鞣及填充性能。     

聚合物复合修饰电极的电化学行为研究

制备了由阳离子交换聚合物AQ和阴离子聚合物PVP组成的复合修饰电极。考察了该电极在pH为1时0.05mol.L-1H2SO4底液和含亚硝酸根H2SO4底液中的电化学行为。结果显示该电极对亚硝酸根具有明显电催化作用。     

Alumina-based Composite Materials for Prefabricated Iron Runner

The relationship between the properties of the composite and the addition of the preventing crack additives, dispersion agent, SiC, graphite, stainless steel fiber have been researched. Finally, alumina-based composite materials used for prefabricated iron runner with better ratio of properties and price has been developed by the studying of the properties and microstructure of alumina based composite materials. The best composition for the iron line is Al 2O 3-14%SiC-5%G-4%SiO 2-2%micropoeder-1%white clay-6%cement;the best composition for the slag line is Al 2O 3-16%SiC-5%G-4%SiO 2-2%micropoeder-1%white clay-6%cement;addition of both is 0.15%Na 5P 3O 10-3B aluminum powder-2%stinless steel fiber. The mechanism on the composite materials eroded by molten iron has also been discussed.     

COMPOSITE SYSTEM RELIABILITY EVALUATION CONSIDERING LOAD MODEL

The study for dealing with the load model in composite system reliability evaluation is almost at a standstill because of the inherent computational complexity. In this paper, an algorithm for composite system reliability evaluation considering load model is proposed. This method is powerful in computation because it can avoid unnecessary state enumeration by means of the relationship among basic reliability informations of load levels. As an example, the IEEE 24-node Reliability Test System is tested on VAX-11/750 computer. The average CPU time to calculate the reliability indices of the system corresponding to a load level is about 5 seconds.     

Investigation on the Pressure Head of Water Supply System with Head Tank

The water supply system with pump-head tank joint water supply is a mature technology widely used in high-rise buildings. In recent years, with widespread of new type pipe material and decoration of buildings, there is insufficient pressure head of water supplied at top floors in high-rise buildings. In this paper from the experience in engineering practice the reason for this problem and its countermeasures are investigated, then some suggestions are given.     

An Analysis of the Scaling Failure of the Nodular Iron Composite Polls

It is recognized that the scaling failure of nodular iron composite rolls in hot rolling is a problem of fatigue brittle fracture. The temperature field,stress,critical crack size as well as the interior quality of the rolls are presented. The theory of fracture mechanics is used to explain the cause of the scaling failure. At the same time, the way to extend the durability of the rolls is also studied.     

THE EFFECTS OF HEAT CONDUCTING CROSS-SECTION AREA AND AXIAL HEAT CONDUCTION ON THE HEAT TRANSFER IN THE TUBE-MOUTH REGION OF THE HIGH TEMPERATURE HEAT EXCHANGE EQUIPMENT

In this paper the heat transfer in the tube-mouth region of the high temperatur heat exchange equipment is deeply analysed. The effect; of the heat conducting cross-section area of the tube-mouth region and axial heat conduction along the tube on the temperature field is emphatically examined by numerical computation, and then the relation of the highest temperature in the tube with the elongated tube length is established. The computed results in this paper are compared with those without taking account of these two factors. It is shown that the effect can not be ignored for the corrosion-protection by controlling temperature.     

Production of mahogany sawdust reinforced LDPE wood-plastic composites using statistical response surface methodology

We produced wood–plastic composite board by using sawmill wastage of mahogany(Swietenia macrophylla) wood and low density polyethylene.We used multi-response optimization to optimize the process parameters of composite board production including mixing ratio,fire retardant(%) and pressing time(min).We investigated the effects of these three process parameters in the mechanical and physical properties of the composite board.Afterwards,Box–Behnken design was performed as response surface methodology with desirability functions to attain the optimal level of mixing ratio,fire retardant and pressing time(min).The maximum modulus of elasticity(MOE) and modulus of rupture(MOR) were achieved at the optimal conditions of wood plastic mixing ratio of60:40,pressing time of 9 min and zero fire retardant percentage.The optimized MOR and MOE were 13.12 and1,781.0 N mm-2,respectively.