Abstract: This paper studied some problems of multivariate geostatistics which involve four parts: 1, Bas;c hypothesis of multivariate geostatistics, include coregionalized variable, cross-variogram, cross-covariance, the statio-narity of order 2 and the intrinsic hypothesis of coregionalized variables; 2, coregionalization matrices; 3, Linear model of coregionalization; 4, The best estima ted methods for multivariate geostatistics include estimation of the regionalized variables with cokriging, estimation of the spatial components and estimation of the regionalized factors.
Abstract: On the basis of the chevron, notched short-rod specimen for fracture toughness test suggested by ISRM, a designed wedge and two semi-circle slices were used to enable compressive force to be applied on the wedge, whereas the crack tip remained loaded in tension. Thus, fracture toughness of rock could be determined by this metaod. Especially, dynamic fracture toughness of rock could be conveniently measured by the method with the wedge and slices, and the effect of loading rates on the fracture toughness of rock could be studied through this way. Finally, some measuring results of static /dynamic fracture toughness for marble were shown.
Abstract: Split Hopkinson's Pressure Bar (SHPB) has been used to study the dynamic behavior of three hinds of magnetics and one granite at strain rates rangingfrom 300 to 1000 s-1. Some results including the dynamic fracture strength, Yaung's modulus, stress-strain curve and constitutive equations of the rocks are given.
Abstract: A rational process of integral iron and steel production can beconstituted by the four processes-full oxygen blast furnace, decarbonizationof granulated pig iron, electric furnace of steelmaking and horizontal continuous casting. This procese is especially suitible for small scale works. Because it can give high technical index and solve the technical difficulty of steelmaking with small scale. In addition, a effective energy balance in the interior of integral works is formed due to the higher calorific gas produced from blast furnace and using of effective power station.
Abstract: Differential thermal analysis (DTA) tests were used to measure the effect of nitrogen on phase transformation temperature of primary austenite of Fe-C-Si and Fe-C-Si-Mn grey cast irons. The results were discussed with ther-modynamic theory.
Abstract: The paper introduces the progress of intersitial-free steel for extra-deep drawing (IF steel). Its developing trend and technology of production, its developing prospect are also discussed.
Abstract: Based on Hill's yield condition and its related flow rule, the plane stress characteristics equations have been developed for the first time. By using these equations, the analysis and simulation for the deep drawing process of normal anisotropic and irregular parts have been realized. In the paper, the plane stress characteristic theory is adopted to calculate and analyse the stress distribution within the flange region and along the die opening during the deep drawing process of square boxes. Furthermore, with the application of the plane stress characteristic theory founded, the optimum design for the blank shapes and its loading conditions have also been researched in this paper.
Abstract: Being aimed to developing intermetallic base structural materials to be worked at above 1000℃, a systematic investigation has been performed of the fundamental crystallographic structure, phase constitution map, density-composition dependence, oxidation resistance and general mechanical behaviour for the ternary intermetallic alloys in the Nb-Ti-Al system. Promissing results have been obtained at the initial stage in the current program. The 1100℃ high temperature strength at the strain rate of 10-2/s and 10-5/s for the ternary compound NbTiAl3 （γ1） base alloys are generally much higher than that of the binary compound TiAl （γ）, especially in the γ1 + α2 phase region, it is as high as twice as that of TiAl. The densities are 4.1-4.79g/cm3, depending on relative amount of the intermetallics involved and the density difference between the intermetallics. The oxidation resistance at the temperature of 900-1200℃ of the compound NbTiAl3 is relatively low but still acceptable. However, by adjusting the relative amount of constituents and adding a small amount of alloying elements it can be singnificantly improved. The room temperature brittleness remains to be solved.
Abstract: Low temperature deposition of diamond thin films in the range of 700-300℃ has been successfully carried out by microwave plasma assisted CVD technique. It was found that the introduction of oxygen into the system of CH4-H2 not only lowered or even eliminated the diffused peak at 1550cm-1 caused by non-diamond phases, but also reduced the half height width of the diamond peak at 1332cm-1. It was because that the atomic oxygen did have a much stronger etching effect on graphite and diamond-like carbon than that of atomic hydrogen at relatively low temperatures, could the low temperature growth of diamond from the vapour phase become possible. Low temperature deposition and characterization of the resultant diamond films are reported in detail. An attempt to link the low temperature deposition data to the C-H-O phase diagram recently proposed by Bachmann et al. has also been made.
Abstract: This paper presents a multivariable self-optimization pole assignment, self-tuning control algorithm. It can sslf search closed-loop poles and be located on approprate positions in the allowing scale of control measure. This algorithm not only implements optimization control, but also has still robustness of pole assignment.
Abstract: By applying hypergraph theory, Algorithm RFCMHGT is presented for determing the realizability of a given directed fundamental cutset matrix Qf and synthesizing its corresponding directed graph G layer by layer from its tree path submatrix Qfp. Its principle is intuitive, and its computational complexity is O(nl2), where n and l are the numbers of rows and columns of Qfp. Example 2 shows that Tutte's condition is not the sufficient condition for Qf to he realizable.
Abstract: Evaluations of three different types of temperature measurement system have been made. Especially a newly developing JW-11 type Infrared Coke Cake Temperature Measurement System, its working principles, system organization and results of practical tests are described in detail. The formation of cracks of coke cake, the characteristics of a special portable data storage and the merits of the system are also mentioned.
Abstract: This paper presents the vector strsam function-vorticity (Ψ-ω) methed for computing gas-particles 3-dimensional turbulent reacting flow: the gas-phase governing equations and the related turbulence models, the properties of vector stream function, the results obtained from computation of pulverized coal combustors and industrial boiler, and discussions on a lot of work for further research.
Abstract: The displacive phase transformation in an appoximately equiatomic Ti-Ni alloy and Fe-Ni-V-C alloy has been studied by TEM. The results show that the stress has strong effects on the lattice instability. A tensile stress promotes soft modes which relate to the nucleation of the R-phase and the Martensite phase. It has been identified that the diffuse streaks in the electron diffraction arise from the softening of phonons which <111>olarization vectors which results from the softening of Coff<111>. The R-phase nucleus formed on the plate of Ti11Ni14 where a tensile stress field was good to R-transfor-mation. The regular shape of the R-phase is the comprehensive effect of strain energy and interface energy. The special dislocation constitution has been observed in Fe-Ni-V-C alloy. An array of shorter dislocation which b =1/2 [011]fcc piled up within long envelope dislocation with b = 1/2[110]fcc. It provide necessary atomic displacement (in double-shear) and can transform into butterfly martensite.
Abstract: That stress corrosion cracking (SCC) is belong to hydrogen induced cracking (HIC) or the anodic preferential dissolution can be solved based on a synthetical study using the following methods, i.e, electrochemistry, the activation energy, the effect of loading modes, comparing the threshold value, initiation site and fracture of SCC to these of HIC, cracking initiation under compressive stress and the correlation between the local plastic deformation and crack nucle-ation. During SCC of austenitic stainless steel in MgCl2 solution, hydrogen can enter into the specimen and enrich and then facilitate the anodic dissolution but does not control the SCC, therefore the mechanism of the SCC is belong to the anodic dissolution. The effects of hydrogen and stress on anodic dissolution are synergistic rather than simply additive. The normal stress instead of shear stress pays a controlled role in SCC of anodic dissolution.
Abstract: the electrode process of Y(Ⅲ) on nickel electrode in NaCl-KCl-YCl3 molten salts has been investigated by means of cyclic voltammetry, X-ray diffraction and SEM. The results show that intermetallic compound (Ni5Y and NiY) are formed first, then metallic yttrium is reduced.
Abstract: When the ratio of RE/S in steel reachs to a certain value, for example RE/S =2.2 in 16Mn steel, RE/S = 2.0 in 20MnVB steel, RE/S = 1.5 in MnTiB steel, RE/S = 1.2 in 09CuPTi steel, the best effect purifying malden steel is obtained. The modification of oxides by RE addition is important to the improvement of fatigue resistance and it depends on the ratio of aco·aS/aAl·ao and aCe/aAl in steel. When RE/S ratio is 2.5, 1.8 or 1.5 in steel 16Mn or 20MnVB, 25MnTiB and 09CuPTi respectively, the all sulfide and oxide modification will be achieved. Therefore the optimal ratio range of RE/S in steel must be controlled.
Abstract: The effectiveness of small amount silicon (1,5%, 2.5%) on the high temperature sulfidation properties of Fe-25Cr alloy in H2S-H2 mixtures has been investigated. The addition of silicon enhanced the sulfidation resistance of Fe-25Cr alloy by varying degree above 800℃. The sulfidation kinetics of alloys with Si followed the parabolic law unperfectly because of the cracking of sulfide scale during sulfidizing process. A dense and integrated inner-layer but of poor protection formed on the alloys bearing Si. On the basis of analysis of sulfidation kinetics curves, structure and construction of sulfide scale, uhe sulfidation mechanism of Fe-25Cr-(1.5%, 2.5%) Si alloys has been proposed and the effectiveness of Si discussed.
Abstract: A new set of scratching electrode apparatus has been designed to investigate the repassivation behavior of electroless amorphous Ni-P alloy in 3.5% NaCl solution. The results show that the repassivation kinetics obeys the equation, i (t)=-A1exp (-C1t) + A2 exp (-c2t). In the lower potential, the oxidation of Ni occurs quickly and the stable oxide NiOOH forms on the surface. The oxide film growth follows the ionic conduct mechanism of high electric field. And, in the higher potential, the adsorption process is rapid, and the adsorbed monolayer on the interface makes the bare surface current decrease quickly. The adsorbed anion H2PO2- effectively inhibits the dissolution of Ni site.
Abstract: The paper presents a Heuristic method which can be used to determine the control parameters for a two-echelon inventory system. The system under consideration consists of one central warehouse and N local ones. Steady stochestic demands occur at local warehouses which order from the central warehouse and it is. the central warehouse's responsibility to order from outside supplier. Both the central and local warehouses are controlled under (T, S) policy. The system seeks the minimum expected total inventory cost under the constraint of satisfying a specified service level.
Abstract: By simultaneously sampling the roll-bar speed and estimating the tension by electric current-torque method, the forward slip model for continuous shape rolling can be identified on-line. More exact roll speed can be predicted by introducing the adaptive control in mill set-up system.
Abstract: In this paper, the methodology of design and the technology of design and the technology of implementation for a new type of computer-based management system-Intelligent Management System (IMS) are discussed.
Abstract: According to the theory and methodology of Intelligent Management System (IMS), the paper have developed the Oil-mine Intelligent Managenent System (OIMS) in Daging., The system structure and function, the methods and technology of design and implementation of OIMS are discussed.
Abstract: Gd3+, Ce3+ and Tb3+ in (La1-xGdx OBr: Tb0.0075, Cey can be excited with different wavelengths in ultra-violet region. Ce3+ and Tb3+ radiate. No Gd3+ characteristic luminescence has been observed, yet the energy of excited Gd3+transfers to Ce3+ and Tb3+, thus contributes to their radiations conssque-rtly. Energy transfer may be reversible to some extent between Ce3+ and Tb3+. The existance of Gd changes the crystal field distribution makes some red shift of the Ce3+ excited band and causes more Tb3+5D3→Ce3+→Tb3+5D4 energy transfer. These energy transfer processes result in the strengthen of greenish luminescence to which the naked eye is most sensitive, also result in the improvements of temperature stability of both Ce3+ and Tb3+ luminescence.
Abstract: Ultrasonic pulse are generated by irradiation with a Q-switched Nd: YAG laser. The effects of the laser power density and the conditions of the metal surface on the intensity of the ultrasonic pulse are studied. The effects of a simulated defect in the metal sample on the propagation of the ultrasonic pulse are also studied.
Abstract: The electrochemical behaviours of the Al (Ⅲ)-Chromazol KS complex and the ligand have been investigated in HAc-NH Ac buffer solution (pH 6.1). The mechanism of related reactions is discussed. A new simple and sensitive single-sweep polarographic method is established for the determination of trace aluminium. The peak height of adsorptive complex wave is directly proportional to the concentration of Al(Ⅲ) in the range from 0.004 to 0.200 μg/ml, and the detection limit is 1.0ng/ml. The results of direct determination of trace aluminium in alloy steels are very satisfactory.
Abstract: The elementary properties and sensitivity of Green's function in application to fault diagnosis of equipment are described. Taking a ball bearing as an example, the quantitative standard for fault diagnosis with Green's function was explored.
Abstract: High-Resolution Electron-Microscopic Images (HREM) and Electron-Diffraction Patterns (EDP) are strong tools for researching matter structures. By using computer only, it can effectively analyze and deal with HREM and EDP. The application of computer in researching new matter state-‘quasicrystal phase’. The diagram flow-chart of the computer is given. Some practical example for researching quasicrystal structures are presented by observing HREMs and EDPs of quasicrytals.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
