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金属热处理 2002年第7期27卷 39-44页

作者： h.M.Tensi A.haas K.Lainer g.E.Totten g.M.Webster Department of Materials and Processing Technical University of MunichDepartment of Materials and ProcessingTechnical University of MunichDepartment of Materials and ProcessingTechnical University of MunichThe Dow Chemical CompanyTarrytownThe Dow Ch

淬火槽中复杂的液流形态会明显影响淬硬结果 ,因此开发一套结构紧凑的液流测量装置就显得很重要了。一个典型的淬火过程包括把已奥氏体化了的钢浸没在淬火槽中 ,这一过程势必影响液流的循环 ,使其形成不均匀的液流和热波动 ,由此而引起... 详细信息

淬火槽中复杂的液流形态会明显影响淬硬结果 ,因此开发一套结构紧凑的液流测量装置就显得很重要了。一个典型的淬火过程包括把已奥氏体化了的钢浸没在淬火槽中 ,这一过程势必影响液流的循环 ,使其形成不均匀的液流和热波动 ,由此而引起传热变化 ,导致零件的不均匀淬火。

关键词：测定淬火槽对流强度热流速仪探头优化设计

NEXT NEAREST NEIghBOR EFFECT ON TETRAhEDRAL FERROUS AND OCTAhEDRAL FERRIC IRON IN ChROMITE

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Science China Chemistry 1986年第8期29卷 889-896页

作者：李哲,J.g.STEVENS Institute of geology Academia Sinica Beijing Mssbauer Effect Data Center University of North Carolina Asheville U. S. A.

Four chromites have been studied by using Mssbauer spectroscopy. Of the spectra of four chromites studied, three spectra aro fitted to three or four Fe2+doublets in the tetrahedral A sites and one or two Fe3+doublets in the tetrahedral A sites and octahedral B sites. The fourth spectrum is fitted to one Fe3+doublet in the A sites and two Fe3+doublets in tho B sites. Constant isomer shifts of approximately 0.9 mm/s for Fe2+ions in the A sites and 0.3 mm/s for Fe3+ions in the B sites as well as gradual changing quadrupole splitting for both of the A sites and the B sites are obtained. The binomial distributions in the B sites are ealeulated. Next nearest neighbor effect is used to explain the multiple doublets caused by Fe2+ions in the A sites in the spectra of chromites Ⅰ, Ⅱ, Ⅲ and by Fe3+ions in the B sites in the spectrum of chromite Ⅳ.

关键词： tetrahedral octahedral fitted NEXT neighbor explain nearest splitting fourth umber

Conventional approaches for assessment of caving behaviour and support requirement with regard to strata control experiences in longwall workings

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Journal of Rock Mechanics and geotechnical Engineering 2015年第3期7卷 291-297页

作者： g.S.P.Singh Department of Mining Engineering Indian Institute of Technology (Banaras Hindu University)

Effective control of roof strata is very important for trouble free operation and regular face advance in mechanised longwall workings. It is now technically possible to exploit coal seams in difficult geomining conditions with the help of newer innovations in longwall face machineries. A reliable assessment of caving behaviour and support capacity requirement helps in selecting supports of adequate capacity and making operational preparedness for timely and confident solution of impending *** paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support requirement in the context of major strata control experiences gained worldwide. The review shows that a number of approaches are being used for advance prediction of caving behaviour and support capacity requirement in a variety of geo-mining conditions. The theoretical explanation of the mechanism of roof caving and the design function of roof supports have been worked out through staged development of approaches, their evaluation followed by their gradual modification and enrichment of synthesized findings. This process is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata analysis and monitoring techniques. These attempts have contributed significantly to improving the level of understanding and reducing the gap of uncertainty in planning and design of longwall operation in a given geo-mining condition.

关键词： Longwall Caving behaviour Main fall Periodic caving Support capacity Convergence

A PRELIMINARY STUDY ON FORMATION OF ThE SAND DUNE SYSTEMS IN ThE NORThERN AUSTRALIAN COASTAL ZONE

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Chinese Science Bulletin 1992年第7期37卷 587-592页

作者： BRIAN g.LESS 卢演俦 Department of geography Australian National University Box 4 Canberra ACT 2601 Australia Xi'an Laboratory of Loess and Quaternary geology Academia Sinica Xi'an 710061 PRC Institute of Geology State Seismological BureauBeijing 100029 China

Ⅰ. INTRODUCTIONDune activity across northern Australia is currently the focus of a joint research project between the Australian National University and the Xi’an Laboratory of Loess and Quaternary geology, Academia Sinica. Although the project is not yet completed, there is sufficient data available to allow discussion of the general setting of the dune fields studied to date. These include the dune fields near Shelbume Bay and Cape Flattery, eastern Cape York, Cobourg Peninsula, Arnhemland, and groote Eylandt, gulf of Carpentaria(Fig. 1).

关键词： northern Australia formation of the coastal sand dune systems activity phases.

TIME-INDEPENDENT ANISOTROPIC PLASTIC BEhAVIOR BY MEChANICAL SUBELEMENT MODELS

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Applied Mathematics and Mechanics(English Edition) 1984年第4期5卷 1425-1435页

作者： Theodore h. h. Pian (Massachusetts Institute of Technology) Massachusetts Institute of Technology USA

The paper describes a procedure for modelling the anisotropic elastic-plastic behavior of metals in plane stress state by the mechanical sub-layer model. In this model the stress-strain curves along the longitudinal and transverse directions are represented by short smooth segments which are considered as piecewise linear for simplicity. The model is incorporated in a finite element analysis program which is based on the assumed stress hybrid element and the viscoplasticity theory.

关键词： TIME-INDEPENDENT ANISOTROPIC PLASTIC BEhAVIOR BY MEChANICAL SUBELEMENT MODELS

Chemokine expression in hepatocellular carcinoma versus colorectal liver metastases

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World Journal of gastroenterology 2006年第41期12卷 6627-6633页

作者： Claudia Rubie Vilma Oliveira Frick Mathias wagner Christina Weber Bianca Kruse Katja Kempf Jochen Knig Bettina Rau Martin Schilling Department of general- Visceral-Vascular-and Paediatric SurgeryUniversity of the SaarlandHomburg/Saar 66421Germany Institute of Pathology University of the SaarlandHomburg/Saar 66421Germany Institute of Medical Biometrics Epidemiologyand Medical InformaticsUniversity of the SaarlandHomburg/ Saar 66421Germany

AIM： To evaluate and compare the expression profiles of CXCL12 （SDF-1）, CCL19 （MIP-3β）, CCL20 （MIP-3a） and CCL21 （6Ckine, Exodus2） and their receptors on RNA and protein levels in hepatocellular carcinoma （hCC） versus colorectal liver metastases （CRLM） and to elucidate their impact on the carcinogenesis and progression of malignant liver diseases. METhODS： Chemokine expression was analyzed by RT-PCR and ELISA in 11 cases of hCC specimens and in 23 cases of CRLM and corresponding adjacent nontumorous liver tissues, respectively. Expressions of their receptors CXCR4, CCR6 and CCR7 were analyzed by RT- PCR and Western blot analysis in the same cases of hCC and CRLM. RESULTS： Significant up-regulation for CCL20/CCR6 was detected in both cancer types. Moreover, CCL20 demonstrated significant overexpression in CRLM in relation to the hCC tissues. Being significantly up-regulated only in CRLM, CXCR4 displayed an aberrant expression pattern with respect to the hCC tissues. CONCLUSION： Correlation of CXCR4 expression with CRLM suggests CXCR4 as a potential predictive factor for CRLM. high level expression of CCL20 and its receptor CCR6 in hCC and CRLM with marked up-regulation of CCL20 in CRLM in relation to hCC tissues indicates involvement of the CCL20/CCR6 ligand-receptor pair in the carcinogenesis and progression of hepatic malignancies.

关键词： Chemokines Chemokine receptors gene expression hepatocellular carcinoma Colorectal liver metastases

Microstructure and mechanical properties of TiAl/TiAl joints brazed with a newly developed Ti–Ni–Nb–Zr quaternary filler alloy

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Progress in Natural Science:Materials International 2022年第6期32卷 758-768页

作者： h.S.Ren Y.L.Shang X.Y.Ren Y.J.Jing h.P.Xiong Y.Y.Cheng Welding and Plastic Forming Division Beijing Institute of Aeronautical Materials

A novel Ti-Ni-Nb-Zr quaternary filler alloy with the composition of Ti-(19～25)Ni-(15～25)(Nb+Zr)(wt.%) was *** filler alloy was composed of(Ti,Nb)ss,(Ti,Zr,Nb)ss+(Ti,Zr)2Ni,α-Ti and Ti2Ni *** was fabricated into filler foil with a thickness of about 45 μm by a rapid solidification *** results indicate that the liquidus temperature of the Ti-Ni-Nb-Zr brazing alloy was about 978℃,and the brazing alloy presented excellent wettability on TiAl *** TiAl joint mainly consisted of β/B2 phase,Ti2Al,Ti2AlNi and α2-Ti3Al *** diffusion of Al atom from base metal to brazed seam led to the formation of Ti2Al and *** that no previously references on XRD pattern of Ti2AlNi compound can be found,Ti2AlNi cast alloy specimen was specially prepared and XRD peaks were specially *** micro-hardness and bending strength tests of the Ti2AlNi phase were carried out,and the results were 761 hV and 192 MPa,*** brazing parameters of 1010 ℃/10 min offered the joint shear strength of 280 MPa at room temperature,and the joints exhibited tensile strength of 372 MPa at room temperature and 340 MPa at 750 ℃,indicating that the newly developed filler alloy could offer a stable high-temperature strength.

关键词： TiAl Brazing Filler alloy Microstructure Mechanical properties

Fast laser surface texturing of spherical samples to improve the frictional performance of elasto-hydrodynamic lubricated contacts

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Friction 2021年第5期9卷 1227-1241页

作者： g.BOIDI P.g.gRÜTZMAChER A.KADIRIC F.J.PROFITO I.F.MAChADO C.gAChOT D.DINI Department of Mechanical Engineering Imperial College LondonSouth Kensington CampusLondon SW72AZUK AC2T research gmbh Wiener Neustadt 2700Austria Polytechnic School University of São Paulo–USPSão Paulo 05508-030Brazil Department of Engineering Design and Product Development TU WienWien 1060Austria Department of Material Science and Engineering Saarland UniversitySaarbrücken 66123Germany

Textured surfaces offer the potential to promote friction and wear reduction by increasing the hydrodynamic pressure,fluid uptake,or acting as oil or debris ***,texturing techniques often require additional manufacturing steps and costs,thus frequently being not economically feasible for real engineering *** experimental study aims at applying a fast laser texturing technique on curved surfaces for obtaining superior tribological performances.A femtosecond pulsed laser(Ti:Sapphire)and direct laser interference patterning(with a solid‐state Nd:YAg laser)were used for manufacturing dimple and groove patterns on curved steel surfaces(ball samples).Tribological tests were carried out under elasto‐hydrodynamic lubricated contact conditions varying slide‐roll ratio using a ball‐on‐disk ***,a specific interferometry technique for rough surfaces was used to measure the film thickness of smooth and textured *** steel samples were used to obtain data for the reference *** results showed that dimples promoted friction reduction(up to 20%)compared to the reference smooth specimens,whereas grooves generally caused less beneficial or detrimental *** addition,dimples promoted the formation of full film lubrication conditions at lower *** study demonstrates how fast texturing techniques could potentially be used for improving the tribological performance of bearings as well as other mechanical components utilised in several engineering applications.

关键词： surface laser texturing elasto‐hydrodynamic lubrication bearings friction film thickness

Research of Neural Network Based on Improved PSO Algorithm for Carbonation Depth Prediction of Concrete

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武汉理工大学学报 2010年第17期32卷 170-175页

作者： DAI W ShUI Z h School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China School of Economics and Management Huangshi Institution of TechnologyHuangshi 435003China

Firstly,neural network based on improved particle swarm optimization (PSO)algorithm is introduced in this paper. Based on the data collected from projects in typical areas,the concrete carbonation depth is assessed with consideration of various factors such as unit cement consumption (C),unit water consumption (W),binder material content (B),water binder ratio (W/B ),concrete strength (MPa),rapid carbonization days (D),fly ash consumption of unit volume concrete(FA),fly ash percentage of total cementitious materials (FA%),expansion agent consumption of unit volume concrete(EA),expansion agent percentage of total cementitious materials (FA%).gaining the data from project-experiment,a model is presented to calculate and forecast carbonation depth using neural network based on improved PSO algorithm. The calculation results indicate that this algorithm accord with the prediction carbonation depth of concrete accuracy requirements and has a better convergence and generalization,worth being popularized.

关键词： PSO BP neural network concrete carbonation depth prediction