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International Journal of Minerals,Metallurgy and Materials 2013年第11期20卷 1115-1121页

作者： Shan-jie Yi Hai-qing Yin Ke Chen Dil-Faraz Khan Qing-jun Zheng Xuan-hui Qu School of Materials Science and Engineering University of Science and Technology Beijing Department of Physics University of Science and Technology Bannu Kennametal inc. 1600 Technology Way Latrobe

Powder injection molding （PIM） and die pressing were employed to fabricate nano-TiN modified Ti（C,N）- based cermets. The shrinkage behavior, microstructure, porosity, and mechanical properties of the samples with and without nano-TiN addition fabricated by PIM and die pressing were analyzed. It is demonstrated that for either PIM or die pressing, the porosities are obviously reduced, the mechanical properties are significantly improved after adding nano-TiN, and the hard particles are refined; the rim phase thickness obviously becomes thinner, and the number of dimples in fracture also inc.eases. Compared the samples fabricated by die pressing, it is difficult for PIM to obtain dense Ti（C,N）-based cermets. Due to the too much existence of pores and isolated carbon, the mechanical properties of the sintered samples by PIM are inferior to those of the sintered ones by die pressing.

关键词： cermets powder injection molding die pressing titanium nitride nanoparticles mechanical properties

100-Gb/s undersea transmission with high spectral efficiency using pre-filtered QPSK modulation format

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Chinese Optics Letters 2010年第9期8卷 831-836页

作者： J.-X. Cai Y. Cai C. R. Davidson D. G. Foursa A. Lucero O. Sinkin W. Patterson A. Pilipetskii G. Mohs Neal S. Bergano Tyco Electronics Subsea Communications LLC ("TE SubCom" formerly known as ~co Telecommunications (US) inc.) 250 Industrial Way West Eatontown NJ 07724 USA

We provide a review of our recent 100-Gb/s, high spectral efficiency （SE） experiment targeting transoceanic and regional undersea transmission distances. We demonstrated that simple pre-filtering at the transmitter together with a maximum a posteriori probability （MAP） detection algorithm can significantly improve SE. We transmitted 96×100-Gb/s pre-filtered polarization division multiplexed return-to-zero quadrature phase shift keyed （PDM-RZ-QPSK） channels with 300% SE over 10608 km using 52-km spans of 150-μm 2 fiber and simple single-stage erbium-doped fiber amplifiers （EDFAs）. We also achieved 400% SE over 4368 km using similar techniques.

关键词： Bit error rate Erbium doped fiber amplifiers Modulation Optical signals Quadrature phase shift keying Signal processing

SERS detection of arsenic in water:A review

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Journal of Environmental Sciences 2015年第10期27卷 152-162页

作者： Jumin Hao Mei-Juan Han Songman Han Xiaoguang Meng Tsan-Liang Su Qingwu K.Wang Center for Environmental Systems Stevens Institute of Technology Agiltron inc. 15 Presidential WayWoburnMA 01801USA Department of Chemical Engineering Renai College of Tianjin University

Arsenic（As） is one of the most toxic contaminants found in the environment. Development of novel detection methods for As species in water with the potential for field use has been an urgent need in recent years. In past decades, surface-enhanced Raman scattering（SERS）has gained a reputation as one of the most sensitive spectroscopic methods for chemical and biomolecular sensing. The SERS technique has emerged as an extremely promising solution for in-situ detection of arsenic species in the field, particularly when coupled with portable/handheld Raman spectrometers. In this article, the recent advances in SERS analysis of arsenic species in water media are reviewed, and the potential of this technique for fast screening and field testing of arsenic-contaminated environmental water samples is discussed. The problems that remain in the field are also discussed and an outlook for the future is featured at the end of the article.

关键词： Arsenic SERS Detection Speciation Nanoparticles Nanofilms

Challenges of mining the first right-handed longwall panel in a new reserve block in Pittsburgh Seam

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International Journal of Mining Science and Technology 2019年第1期29卷 145-149页

作者： Jun Lu Greg Hasenfus CONSOL Energy inc.

In this paper, the mining experience and challenges for the first right-handed longwall panel in the Pittsburgh Seam are introduced. The longwall headgate T-junction experienced very high face convergence(up to 61 cm), accompanied by roof sag, floor heave, and rib loading. The headgate convergence was so large that, in a few places, it threatened longwall retreat and ultimately required the bottom to be re-graded. Different underground instruments, such as a roof scope, de-gas drill, tell-tale, laser meter,and borehole pressure Cell(BPC), were employed to explore the roof geology and to monitor the entry convergence and the stress changes in the pillar. In addition, the impact of other geologic factors, such as large overburden depth, laminated sandstone roof geology, soft floor, and large headgate equipment,were also analyzed. Subsequently, geotechnical solutions were provided to avoid or mitigate the impact of these challenging geologic factors.

关键词： Coal mining Horizontal stress Ground control Roof convergence

Comparative evaluation for catalytic gasification of petroleum coke and asphaltene in subcritical and supercritical water

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Journal of Energy Chemistry 2019年第4期28卷 107-118页

作者： Rachita Rana Sonil Nanda Aimee Maclennan Yongfeng Hu Janusz A.Kozinski Ajay K.Dalai Department of Chemical and Biological Engineering University of Saskatchewan Department of Chemical and Biochemical Engineering University of Western Ontario soft X-Ray Micro-Characterization Beamline Canadian Light Source Inc. New Model in Technology & Engineering

Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures(350–650°C),feed concentrations(15–30 wt%)and reaction times(15–60 min).Nickel-impregnated activated carbon(Ni/AC)was synthesized as a catalyst for enhancing syngas yields at optimal gasification conditions(650°C,15 wt%and 60 min).Structural chemistry of precursors and chars developed at different gasification temperatures was studied using physicochemical and synchrotronbased approaches such as carbon–hydrogen–nitrogen–sulfur(CHNS)analysis,thermogravimetric and differential thermogravimetric analysis(TGA/DTA),scanning electron microscopy(SEM),Fourier-Transform Infrared spectroscopy(FTIR),Raman spectroscopy,X-ray diffraction(XRD)and X-ray absorption spectroscopy(XAS).Asphaltene testified to be a better precursor for catalytic hydrothermal gasification leading to 11.97 mmol/g of total gas yield compared to petroleum coke(8.04 mmol/g).In particular,supercritical water gasification using 5 wt%Ni/AC at 650°C with 15 wt%feed concentration for 60 min resulted in 4.17 and 2.98 mmol/g of H_2from asphaltene and petroleum coke,*** the same conditions,the respective CH_4yields from catalytic gasification of asphaltene and petroleum coke were 2.54and 1.07 mmol/***,asphaltene also seemed to an attractive feedstock for the production of highly aromatic chars through hydrothermal gasification.

关键词： Asphaltene Petroleum coke Subcritical water Supercritical water Gasification Char

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF BUBBLE AUGMENTED WATERJET PROPULSION

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Journal of Hydrodynamics 2012年第5期24卷 635-647页

作者： CHOI Jin-Keun SINGH Sowmitra HSIAO Chao-Tsung CHAHINE Georges L DYNAFLOW inc. JessupMarylandUSA

This contribution presents experimental and numerical investigations of the concept jet propulsion augmentation using bubble injection. A half-3D （D-shaped cylindrical configuration to enable optimal visualizations） divergent-convergent nozzle was designed, built, and used for extensive experiments under different air injection conditions and thrust measurement schemes. The design, optimization, and analysis were conducted using numerical simulations. The more advanced model was based on a two-way coupling between an Eulerian description of the flow field and a Lagrangian tracking of the injected bubbles using our Surface Averaged Pressure （SAP） model. The numerical results compare very favorably with nozzle experiments and both experiments and simulations validation the thrust augmentation concept. For a properly designed nozzle and air injection system, air injection produces net thrust augmentation, which inc.eases with the rate of bubble injection. Doubling of thrust was measured for a 50% air injection rate. This beneficial effect remains at 50% after account for liquid pump additional work to overcome inc.eased pressure by air injection.

关键词： waterjet propulsion bubble dynamics multi-phase flow

DEM analysis of the influence of stirrer design on die filling with forced powder feeding

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Particuology 2024年第5期88卷 107-115页

作者： Chao Zheng Edward Yost Ariel R.Muliadi Nicolin Govender Ling Zhang Chuan-Yu Wu School of Chemistry and Chemical Engineering University of SurreyGuildfordGU2 7XHUnited Kingdom Small Molecule Pharmaceutics GenentechInc.One DNA WaySouth San FranciscoCA94080USA

Die filling is a critical stage during powder compaction,which can significantly affect the product quality and *** this paper,a forced feeder is introduced attempting to improve the filling performance of a lab-scale die filling *** die filling process is analysed with a graphics processing units(GPU)enhanced discrete element method(DEM).Various stirrer designs are assessed for a wide range of process settings(i.e.,stirrer speed,filling speed)to explore their influence on the die filling performance of free-flowing *** results show that die filing with the novel helical-ribbon(i.e.,type D)stirrer design exhibits the highest filling ratio,implying that it is the most robust stirrer design for the feeder configuration ***,die filling performance with the type D stirrer design is a function of the stirrer speed and the filling speed.A positive variation of filling ratio(ηf>0%)can be ensured over the whole range of filling speed by adjusting the stirrer speed(i.e.,inc.easing the stirrer speed).The approach used in this study can not only help understand how the stirrer design affects the die filling performance but also guide the optimization of feeder system and process settings.

关键词： Discrete element method Die filling Forced feeding Stirrer design GPU computing

SUSTAINABLE SITE DEVELOPMENT

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Journal of Green Building 2006年第1期1卷 9-20页

作者： Bruce A.Hendee BHA Design inc.

INTRODUCTION Two weeks ago I went for a trail run at Coyote *** about five miles south of Fort Collins,the Coyote Ridge trail is about a seven mile round trip and takes runners up a geological hogback and then down into a pristine *** I was in a system perfectly balanced but not static;one in which all systems were in a state of dynamic interaction but always shifting in a way that ensured *** was moving in a balanced *** was enough food,water,and shelter produced,but there was no *** I,standing in the valley,had an opportunity to add to the balance.

关键词： trail valley shifting

COMPARISON OF EMITTED EMISSIONS BETWEEN TRENCHLESS PIPE REPLACEMENT AND OPEN CUT UTILITY CONSTRUCTION

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Journal of Green Building 2009年第2期4卷 126-140页

作者： Samuel T.Ariaratnam Shaik S.Sihabuddin Ira A.Fulton School of Engineering Arizona State UniversityTempeAZ Metcalf Builders inc. 751 Basque WayCarson CityNV

Currently,there is a worldwide trend towards reducing emissions into the environment generated by human *** emissions into the atmosphere are a major measure of the impact on *** construction indus-try is a major producer of such emissions due in part to the magnitude of operations and the vast array of *** urbanization has resulted in a need for the installation of an expanded underground network of infrastruc-ture that inc.udes gas,water,wastewater,pipelines,power,and communications ***,engineers are faced with engaging the construction option that not only provides the best cost advantage,but also considers environmental sensitivities to create the most sustainable *** of pollutants such as carbon dioxide(CO_(2)),carbon monoxide(CO),nitrogen oxide(NO_(X)),total organic compounds(TOC),and sulfur oxide(SO_(X))have been identiﬁed by the United States Environmental Protection Agency as critical to sustainable *** paper describes an approach for quantifying airborne emissions that is demonstrated through a comparison of two construction methods for installing a wastewater *** was discovered that the option involving a traditional open cut method resulted in an overall average of about 80%greater emissions compared to trenchless pipe ***ﬁndings of this paper should assist the utility construction industry in technology selection to minimize environmental impacts.

关键词： environmental trenchless technology emissions underground construction

NUMERICAL SIMULATION OF BUBBLE FLOW INTERACTIONS

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Journal of Hydrodynamics 2009年第3期21卷 316-332页

作者： CHAHINE Georges L. DYNAFLOW inc. 10621-J Iron Bridge RoadJessup

Bubble flow interaction can be important in many practical engineering applications. For instance, cavitation is a problem of interaction between nuclei and local pressure field variations inc.uding turbulent oscillations and large scale pressure variations. Various types of behaviours fundamentally depend on the relative sizes of the nuclei and the length scales of the pressure variations as well as the relative importance of bubble natural periods of oscillation and the characteristic time of the field pressure variations. Similarly, bubbles can significantly affect the performance of lifting devices or propulsors. We present here some fundamental numerical studies of bubble dynamics and deformation, then a practical method using a multi-bubble Surface Averaged Pressure （DF-Multi-SAP ） to simulate cavitation inc.ption and scaling, and connect this with more precise 3-D simulations. This same method is then extended to the study of two-way coupling between a viscous compressible flow and a bubble population in the flow field.

关键词： cavitation bubble flow interaction numerical simulation