THE DEVELOPMENT OF ALUMINIUM MATRIX MICRO -GLASSBALL COMPOSITE AND THE ANALYSIS ON ITS FORMING MECHANISMS

The problem that the micro-glassball is not wettable in molten aluminium alloys can be solved by a special technology that is different from rheocasting and squeezecasting methods. The metten metal can fill the cavity of the glass ball through the broken place on its wall, and an original micro -structure will be formed. This material has good comprehensive mechanical proper ties and this method can be used to other kinds of ceramic powders. The mechanisms of the formation of this materials have been discussed as well.     

ANALYSIS FOR VIBRATION OF ARCHES BY TRANSFER MATRIX METHOD

This paper presents a transfer matrix method for analysing dynamiccharacteristics of arches.The calculation models are the broken-line rigidframes with a series of mass points,which are simplified from the criginalstructures.The geometric stiffness and the axial deformation of arch are consi-dered in formulating its vibration transfer equation.Through application ofthe method,the vibration modes and the relative values of internal forces canbe obtained simultaneously as soon as the vibration frequencies of arch areknown.The simple and direct method developed may be easily calculated withmicrocomputer,and it has extensive usage with high precision.     

喷油抑尘杀虫剂的研究

本文对抑尘杀虫剂的配方进行了研究 ,将马拉硫磷、白油和表面活性剂在一定条件下混合 ,使马拉硫磷完全增溶于白油中。通过响应曲面分析得出最佳增溶条件为 :花生色拉油∶白油 =2∶3,最佳表面活性剂用量为 16.6% ,助表面活性剂用量为 1.9%。     

THE USE OF ION BOMBARDMENT IN DEPOSITION OF EVAPORATINC THIN METAL FILMS ON GLASS

This paper presents a new method in the producton of glass deposition byevaporation,and the principle of ion bonibardment.The effect of ion bombardment to the filmadhesion is estimated by the observation of cross-sectiun sweep electron micrcocope.     

散粮储藏喷油抑尘装置的研究和开发

本文主要研究了散粮储藏喷油抑尘技术和装置，解决散粮储运过程中粉尘大、粮食损耗高等技术问题。介绍了散粮储藏喷油抑尘装置的研制过程，并对其结构和工作原理进行了详细说明和介绍。     

Present Statue and Future of the In-situ Reaction Synthesis Technology for Metal Matrix Composites Fabricated

Among the methods of fabrication of ceramic particles reinforced Metal Matrix Composites, the in-situ reaction synthesis technology has obvious technical and economical advantages over other traditional methods. The in-situ reactive technology has become the leading direction in composites research area in the past decade. The main in-situ reaction synthesis methods include XD, VLS, SHS, DIMOX, PRIMEX, RSD, CR, MA, etc. The principles, properties and prospective application of the main in-situ reaction synthesis methods are reviewed. The Metal Matrix Composites, prepared by in-situ reaction composite technology, can normally achieve higher mechanical properties than other traditionally prepared composites under the same condition. The in-situ reaction synthesis technology, with its wide raw material resources, low price, relatively simple processes, low cost preparation and application feasibility in large-scale industry process, is of great future.     

AN EXTENDED TRANSFER MATRIX AND BOUNDARY ELEMENT METHOD

A combination of extended transfer matrix and boundary element method is proposed for solving two dimentional statics problems of complicated nonhomogeneous structure. It is explained with the theory and the example. The method can get greater numerical accuray and shorten computation time in small amount of computer storage without getting involved with large matrices.     

Recent Development of Solid/Liquid Reaction Synthesis Technology for Metal Matrix Composites

TheSolid/liquidReactionSynthesisTechnologyforMetalMatrixCompositeshasattractedanincreasinginterest, andalotofimportantprogresseshavebeenmadeinrecentyears.Fivetypicalprocesses ,exothermicdispersion ,coatingtech nologybycontactreaction ,liquidcontactreaction ,meltinfiltrationandreactivespraydeposition ,havebeenreviewed .More attentionhasbeenpaidtorecentdevelopmentoftheresearchworkontheexothermicdispersion ,coatingtechnologybycontact reactionandliquidcontactreaction .Thecharacteristicsoftheseprocessesareanalysed ,andtheexistedproblemsonthereac tionsynthesistechnologiesarediscussed .     

A STRUCTURAL NON-LINEAR DYNAMIC STABILITY AND A MATRIX FUNCTION METNOD

This paper presents a mathematical and mechanic model for non-linear dynamicstability analysis of structures on the basis of Liapunov's stability criteria. Due to the complexityand difficulty in numerical calculation,a matrix function to this type of stability problems is selectedand the programing formulations are derived.Applying the method to beam or frame structures un-der the axial period loadings,the geometric non-linear dynamic stability results are obtained.Fromthe results,the basic characteristics of this type of probtems,especially the non-linear effect areshown.The model and matrix function method are valtiable both in theory and in practice for struc-tural non-linear dynamic stability.     

THE MANUFACTURE OF SELFGROWING A1_2O_3 -Al COMPOSITE AND ITS FORMING MECHANISM

The A12O3 layer on moten aluminium alloys can be damaged in some technological conditions. By capillarity the molten metal will rise to the surface through the broken place on the loyer and form a new A12O3 layer which is not compact and can be passed by molten metal too. This is a self-organic process by which a self growing A12O3-A1 composite with some thickness will be formed on the surface of the molten metal. The proportion of A12O3 in the material can be controlled from 20%-80% while the qualities especially the hardness and tensile strength, are all higher than thoses of the powder metallurgy materials.     

A STUDY OF THE MECHANISM OF HEAT-TRANSFER DURING METAL HEATING WITH IMPINGING JET

The mechanism of heat transfer during sheet metals heating with impinging jet in a rapid heating furnace is studied with experiments and mathematical simulating methods. It is shown that the heat exchange between metals and impinging jet occurs mainly in the lower region of the hearth,most of which is carried out in the manner of convective heat transfer,and the convective portion of the total heat fluxing to metal is up to 80%. Furthermore,it is also found that the reverse heat flux from metals to the wall, which is a new heat transfer phenomenon, takes place in the late heating period, and the intenser the convective heat transfer in the furnace is, the earlier the reverse radiation occurs.     

A NEW APPROACH OF LOAD FREQUENCY DECENTRALIZED CONTROL-OPTIMIZATION OF WEIGHT MATRIX Q

As the optimization and coordination of weight matrix Q and feedback gain matrix K are taken into account, the dynamic performance of the decentralized controller designed by this method is as good as that of the optimal controller. This method can be used in the strong or weak coupled systems, and various controllers can be designed according to the demand. An example is given to prove the validity and advantage of this method.     

Advance in Research on Interfacial Reaction in SiCp/Al Composites

Researchers aronnd the world conducted experiments according to the aspects of interfacial reaction principle, contributing factors, control approaches, etc. In the aspect of interfacial reaction principle, possibly existing interfacial chemical reaction between Al alloy liquid and SiC particles, interfacial reaction process and model, phases in the interface, etc. , have been researched. In the aspect of contributing factors to interfacial reaction, the relationship among interfacial reaction and process, parameters of fabrication such as effect of Mg, Si content, SiC pretreatment, temperature, cooling speed to interfacial reaction has been investigated. In the aspect of efficient control approaches to interfacial reaction, matrix alloying, surface treatment to SiC particles, process selection and process parameters control have been studied. Research direction of interfacial reaction for the future can be generalized as the following aspects; interfacial fine structure, chemical thermodynamics and kinetics of interfacial reaction, establishment and optimization of heat and mass transfer model to interfacial reaction and new efficient control approaches to interfacial reaction.     

基于灰度-梯度共生矩阵的大米加工精度的机器视觉检测方法

提出了基于灰度-梯度共生矩阵结合机器视觉技术检测大米加工精度的方法。使用实验碾米机制备不同加工精度的大米样品,设计大米加工精度机器视觉检测系统获取不同加工精度大米样品图像,再利用灰度-梯度共生矩阵提取大米图像的纹理特征,采用逐步判别分析法构建Fisher判别函数组对大米样品的加工精度进行检测。试验结果表明:该方法对4种不同加工精度大米样品检测的平均准确率达到94.00%。     

INVESTIGATION ON THE DITERMINATION OF METAL IRON IN SLAG CONTAINING VANADIUM TITANIUM ( IODIN-ALCOHOL FOR SEPARATION EDTA FOR DITERMINATION)

Great accuracy can be obtained when metal iron is determined with bromine for dissolution K2Cr2O7 for titration. Unfortunately, harmful substances such as Br2, CH3OH, HgCl2, K2Cr2O7 etc. must be used when this method. But these harmful substances can be avoided when I2-C2H5OH is used for dissolution and EDTA for titration as discussed in this paper. As this method is simple with good reapetability, it is suitable for the diterminat ion of metal iron slag containing V.Ti, in slag containing high Ti, and in common slags.     

The Numerical Simulations of the Casting Process for Making Fiber-reinforced Metal Matrix Composite

The numerical simulations of the casting process for making metal matrix composite by infiltrating melting alloys into a fiber preform arestudied. The evaluation of the infiltration flow, the thermal conduction, the stress and strains of the matrix are studied with finite element method, and the corresponding finite element program for axi-symmetry condition is programmed. The influences of the controllable initial and boundary conditions on the casting process, residual stress and residual plastic strains, and selection of optimal technological parameters are researched. The reliability of the numerical simulation is analyzed by comparison between the calculated results andsimilar experimental data.[WT5HZ]     

杭州市典型茶园土壤与茶叶中重金属的积累与来源分析

为了解杭州市茶园土壤与茶叶中重金属的污染状况及其重金属的可能污染来源,选择杭州市典型茶园20个,按区位与施肥的不同分为城郊-化肥、城郊-有机肥、山区-化肥和山区有机肥等4种类型,采集了0~15、45~60 cm分层土样及茶树新叶和老叶样品,分析土样和茶叶样品中Pb、Zn、Cu、Cd、Hg、Cr和Co等重金属含量。结果表明,研究土壤Pb、Zn、Cu、Cd、Hg、Cr和Co污染程度较轻,其含量均低于土壤环境质量二级标准。除老叶样中Pb有25%样品超标外,新叶及老叶的其他重金属元素都在限值以下。城郊区茶园土壤的Pb、Cd和Hg含量普遍高于山区茶园。施用化肥的茶园土壤Cd略高于施用有机肥的茶园,施有机肥的茶园土壤Hg略高于施用化肥的茶园。施用有机肥的茶园土壤Zn和Cu明显高于施化肥的茶园。施用有机肥可轻微提高茶园土壤中Cr的积累;土壤中Co的积累受人为影响较小。研究认为,研究区茶园土壤中重金属Pb、Cd和Hg的积累主要与大气沉降有关,而Zn和Cu的积累主要与有机肥料的施用有关。     

Current Status of DIMOX in Synthesizing Al/Al2O3 by Aluminum Alloy

The processes, microstructures, properties and mechanisms of DIMOX in synthesizing Al/Al 2O 3 by Al-Mg-Si alloy are reviewed and their problems are considered mainly as following:non_homogeneous oxidation growth of Al/Al 2O 3 at the surface of melts and the porosity of Al/Al 2O 3 limites structural application of Al/Al 2O 3 composite. The mechanisms and models of microchannel,magnesium action,silicon action,and induction are outlined. Several problems which need to be noticed are pointed out,which are diffusion and transfer of oxygen in aluminium melts;the role of MgO and MgAl 2O 4 at outer layer;the reaction feature of solid_gas in the oxidation microstructures of Al_Mg_Si alloy;SiO 2 induction mechanism of silicon and its correlation with the mechanism of magnesium action in Al_Mg_Si alloy.