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Control of petroleum-hydrocarbon contaminated groundwater by intrinsic and enhanced bioremediation

Journal of Environmental Sciences 2010年第6期22卷 864-871页

作者： Chih-Ming Kao Rao y.Surampalli Mu-Sheng lee Institute of Environmental Engineering "National" Sun Yat-Sen University U.S.Environmental Protection Agency Environmental Protection Bureau Kaohsiung City Government

In the first phase of this study, the effectiveness of intrinsic bioremediation on the containment of petroleum hydrocarbons was evaluated at a gasoline spill site. Evidences of the occurrence of intrinsic bioremediation within the BtEX （benzene, toluene, ethylbenzene, and xylenes） plume included （1） decreased BtEX concentrations; （2） depletion of dissolved oxygen （DO）, nitrate, and sulfate; （3） production of dissolved ferrous iron, methane, and CO2; （4） deceased pH and redox potential; and （5） increased methanogens, total heterotrophs, and total anaerobes, especially within the highly contaminated areas. In the second phase of this study, enhanced aerobic bioremediation process was applied at site to enhance the BtEX decay rates. Air was injected into the subsurface near the mid-plume area to biostimulate the naturally occurring microorganisms for BtEX biodegradation. Field results showed that enhanced bioremediation process caused the change of BtEX removal mechanisms from anaerobic biodegradation inside the plume to aerobic biodegradation. this variation could be confirmed by the following field observations inside the plume due to the enhanced aerobic bioremediation process：（1） increased in DO, CO2, redox potential, nitrate, and sulfate, （2） decreased in dissolved ferrous iron, sulfide, and methane, （3） increased total heterotrophs and decreased total anaerobes. Field results also showed that the percentage of total BtEX removal increased from 92% to 99%, and the calculated total BtEX first-order natural attenuation rates increased from 0.0092% to 0.0188% per day, respectively, after the application of enhanced bioremediation system from the spill area to the downgradient area （located approximately 300 m from the source area）.

关键词： petroleum hydrocarbon groundwater natural attenuation intrinsic bioremediation

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Influence of Carrier Gas on Analysis of MgO Powders by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

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Journal of Materials Science & technology 2009年第3期25卷 333-335页

作者： J.S. lee y.S. lee C.J. Park H.S. lee D.S. lee Department of Chemistry Yonsei University Material Analysis team Korea Testing Laboratory Korea Research Institute of Standards and Science School of Material Science and Engineering Pusan National Univirsity

Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） has been widely adopted for the direct multi-elemental analysis with high sensitivity. Especially analysis of fine ceramics by LA-ICP-MS without time-consuming sample decomposition process has been one of the most expecting application field. Small additive elements in MgO powders were analyzed by LA-ICP-MS. For precise and accurate analysis influence of carrier gas （Ar or He） was presented by the signal intensities of ICP-MS, relative standard deviation of signal intensities and ablated particle size distribution. Ablated particles were collected and analyzed by scanning electron microscopy （SEM） to investigate the particle size distribution, and the ablated sample surface was examined by camscope. In He gas atmosphere, the signal was more stable than in Ar gas atmosphere. the signal intensity was higher in Ar than in He. Examination of ablated particles and sample surface reveals that more particles were generated in Ar atmosphere and the distribution of particle size was larger.

关键词： Laser ablation MgO powders Carrier gas ICP-MS

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Relation between etching profile and voltage-current shape of sintered SiC etching by atmospheric pressure plasma

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Plasma Science and technology 2019年第4期21卷 137-144页

作者： D C SEOK S R yOO K I lee y S CHOI y H JUNG Plasma technology Research Center National Fusion Research InstituteGunsan City 54004Republic of Korea

Sintered silicon carbide(SiC)was etched by a dielectric barrier discharge source.A high voltage bipolar pulse was used with helium gas for the plasma *** stable filament plasma was generated and could be used for SiC *** the processing gas(NF3)mixing rate increased,the width and depth of the etching profile became narrower and *** differentiated V-Q Lissajous method was used for measuring the capacitances(Ceq)of the electrode after the plasma turned *** width of the etching profile was proportional to *** the current peak value/smx of the substrate current in creased,the volume removal rate of SiC *** etch depth was proportional to the ratio of/smx to ***,because of the different characteristics of the plasma disks on SiC substrate by the voltage polarity,the etching profile was ***,in high NF3 mixing process,the etching profile became stable and deeper.

关键词： dielectric barrier discharge silicon carbide plasma etching、filament discharge,surface charge

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Experimental and finite element analysis for fracture of coating layer of galvannealed steel sheet

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transactions of Nonferrous Metals Society of China 2011年第A1期21卷 111-116页

作者： S.I.KIM J.U.HER y.C.JANG y.lee Sheet Products and Process Research Group POSCO Techology Research Laboratory Department of Mechanical Engineering Chung-Ang University

Mechanical properties of galvannealed (GA) steel sheet used for automotive exposed panel and predicted failure phenomenon of its coating layer were evaluated using finite element method. V-bending test was performed to understand better the fracture of coating layer of GA steel sheet during plastic deformation. yield strength of the coating layer was calculated by using a relative difference between hardness of coating layer measured from the nano-indentation test and that of substrate. to measure shearing strength at the interface between substrate and coating layer, shearing test with two specimens attached by an adhesive was carried out. Using the mechanical properties measured, a series of finite element analyses coupled with a failure model was performed. Results reveal that the fracture of coating layer occurs in an irregular manner at the region where compressive deformation is dominant. Meanwhile, a series of vertical cracks perpendicular to material surface are observed at the tensile stressed-region. It is found that 0.26-0.28 of local equivalent plastic strain exists at the coating and substrate at the beginning of failure. the fracture of coating layer depends on ductility of the coating layer considerably as well.

关键词： galvannealed steel sheet fracture simulation coating layer finite element analysis, failure model

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Model with strong γ_4 t-violation

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Chinese Physics C 2008年第12期32卷 939-944页

作者： R. Friedberg t. D. lee Physics Department Columbia University New York NY 10027 U.S.A. China Center of Advanced Science and technology (CCASt/World Lab.) P.O. Box 8730

eAbstract We extend the t violating model of the paper on ＂Hidden symmetry of the CKM and neutrinomapping matrices＂ by assuming its t-violating phases X↑ and X↓ to be large and the same, with X = X↑ = X↓. In this case, the model has 9 real parameters： at, α↑,β↑,ξ↑,η↑t for the t-quark sector, α↓,β↓,ξ↓,η↓, for the sector and a common X- We examine whether these nine parameters are compatible with ten observables： the six quark masses and the four real parameters that characterize the CKM matrix （i.e., the Jarlskog invariant and three Eulerian angles）. We find that this is possible only if the t violating phase X is large, between -120^o to -135^o. In this strong t violating model, the smallness of theJarlskog invariant 3 × 10^-5 ismainly accounted for by the large heavy quark masses, with mc/mt〈ms/mb≈0.02, as well as the near completeoverlap of t and b quark, with （c｜b）=-0.04.

关键词： Jarlskog invariant CKM matrix strong γ4 t-violation

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Dynamic stiffness for thin-walled structures by power series

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1351-1357页

作者： ZHU Bin LEUNG A.y.t. Department of Civil Engineering Zhejiang University Hangzhou 310027 China Department of Building and Construction City University of Hong Kong Hong Kong China

the dynamic stiffness method is introduced to analyze thin-walled structures including thin-walled straight beams and spatial twisted helix beam. A dynamic stiffness matrix is formed by using frequency dependent shape functions which are exact solutions of the governing differential equations. With the obtained thin-walled beam dynamic stiffness matrices, the thin-walled frame dynamic stiffness matrix can also be formulated by satisfying the required displacements compatibility and forces equilib-rium, a method which is similar to the finite element method (FEM). then the thin-walled structure natural frequencies can be found by equating the determinant of the system dynamic stiffness matrix to zero. By this way, just one element and several elements can exactly predict many modes of a thin-walled beam and a spatial thin-walled frame, respectively. Several cases are studied and the results are compared with the existing solutions of other methods. the natural frequencies and buckling loads of these thin-walled structures are computed.

关键词： Dynamic stiffness method thin-wall structures Power series Buckling

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CONStRUCtION OF QUANtUM FIELD tHEORy OF DISLOCAtIONS BASED ON tHE NON-RIEMANNIANPLAStICIty

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Acta Metallurgica Sinica(English Letters) 1998年第6期11卷 405-411页

作者： t.Hasebe y.Imaida Doshisha Univ Kyoto Japan

A new microscopic approach was proposed, which bridges the order gap between the dislocation theory and the crystalline plasticity based on the quantum field theory of dislocations. the Ginzburg-Landau equation was derived rigorously from the quantized Hamiltonian for a crystal body containing a large number of dislocations, which gives the reaction-diffusion (RD) type differential equations. the RD equation describes periodic patterning shown in PSBs, etc.. relationship between the proposed theory and the concepts appeared in the non-Riemannian plasticity was extensively discussed by introducing the gauge field of dislocations. (Edited author abstract) 15 Refs.

关键词： crystalline plasticity field theory Non-Riemannian plasticity,dislocation theory gauge field

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Processing and Performance of Alumina Fiber Reinforced Alumina Composites

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Journal of Materials Science & technology 2003年第4期19卷 337-340页

作者： P.y.leet t.Uchijima t.yano Research Laboratory for Nuclear Reactors Tokyo Institute of Technology2-12-1O-okayamaMeguro-kuTokyo152-8550JapanResearch Laboratory for Nuclear ReactorsTokyo Institute of Technology2-12-1O-okayamaMeguro-kuTokyo152-8550JapanResearch Laboratory for Nuclear ReactorsTokyo Institute of Technology2-12-1O-okayamaMeguro-kuTokyo152-8550Japan

Processing of alumina fiber-reinforced alumina matrix composites by hot-pressing was described. the mechanical properties of the composites fabricated by different sintering conditions including temperature and pressure have been investigated. the results indicated that the higher sintering temperature and pressure corresponded to the higher bulk density and higher maximum strength of the composite, whereas the pseudo-ductility of the composite was lower. the preliminary results of the composite with monazite-coated fibers showed that maximum strength could be improved up to 35% compared with the noncoated fiber composite in the same sintering condition. Moreover, the fracture behavior of the composite changed from completely brittle fracture to non-brittle fracture under the suitable sintering conditions. SEM observation of the fracture surface indicated that the coating worked as a protective barrier and avoided sintering of the fibers together even at high temperature and pressure during densification process.

关键词： Al2O3/Al2O3 composites Mechanical properties Hot-pressing Fiber reinforced composites

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γ"variant-sensitive deformation behaviour of Inconel 718 superalloy

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Journal of Materials Science & technology 2022年第31期126卷 169-181页

作者： R.y.Zhang H.L.Qin Z.N.Bi y.t.tang J.Araújo de Oliveira t.L.lee C.Panwisawas S.y.Zhang J.Zhang J.Li H.B.Dong Centre of Excellence for Advanced Materials Dongguan 523808China School of Engineering University of LeicesterUniversity RoadLeicester LE17RHUnited Kingdom Beijing Key Laboratory of Advanced High temperature Materials Central Iron and Steel Research InstituteBeijing 100081China Department of Materials University of OxfordParks RoadOxford OX13PHUnited Kingdom StressMap Engineering and Innovation DepartmentThe Open UniversityWalton HallMilton Keynes MK76AAUnited Kingdom ISIS Neutron Source Rutherford Appleton LaboratoryHarwell Science and Innovation CampusChiltonOxfordshire OX110QXUnited Kingdom School of Material Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Strengthening in Inconel 718 superalloy is derived from dislocation interaction withγ"precipitates,which exist in disk-shaped three possible orientation variants with theirthabit plane normal to each *** interactions between dislocations andγ"precipitates vary according to theγ"orienta-tion variants,which makes the deformation behaviour complicated and difficult to reveal *** this work,γ"variant distributions of Inconel 718 samples were tailored by ageing heat treatment under either tensile or compressive ***γ"variant-sensitive deformation behaviours were then studied by in situ tensile tests via neutron diffraction at room *** is demonstrated that yield-ing first takes place in grains oriented withparallel to the loading *** identical lattice strain response to applied stress of both theγmatrix and theγ"precipitates was observed during yield-ing,suggesting that dislocations shearing through theγ"precipitates is predominant at this ***-ations in yield strength for samples with differentγ"variant distributions were observed,which can be attributed to different strengthening that arises from interactions between dislocation and differentγ"variants.

关键词： Ni-base superalloys Precipitation strengthening Neutron diffraction Lattice strains Plastic deformation

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Different fundus imaging modalities and technical factors in AI screening for diabetic retinopathy:a review

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Eye and Vision 2020年第1期7卷 201-213页

作者： Gilbert Lim Valentina Bellemo yuchen Xie Xin Q.lee Michelle y.t.yip Daniel S.W.ting School of Computing National University of SingaporeSingaporeSingapore Singapore Eye Research Institute Singapore National Eye CentreSingaporeSingapore Duke-NUS Medical School National University of Singapore11 Third Hospital Road AvenueSingapore 168751Singapore Vitreo-Retinal Service Singapore National Eye Center11 Third Hospital Road AvenueSingapore 168751Singapore Artificial Intelligence in Ophthalmology Singapore Eye Research Institute11 Third Hospital Road AvenueSingapore 168751Singapore

Background:Effective screening is a desirable method for the early detection and successful treatment for diabetic retinopathy,and fundus photography is currently the dominant medium for retinal imaging due to its convenience and *** screening using fundus photographs has however involved considerable costs for patients,clinicians and national health systems,which has limited its application particularly in less-developed *** advent of artificial intelligence,and in particular deep learning techniques,has however raised the possibility of widespread automated *** text:In this review,we first briefly survey major published advances in retinal analysis using artificial *** take care to separately describe standard multiple-field fundus photography,and the newer modalities of ultrawide field photography and smartphone-based ***,we consider several machine learning concepts that have been particularly relevant to the domain and illustrate their usage with extant ***:In the ophthalmology field,it was demonstrated that deep learning tools for diabetic retinopathy show clinically acceptable diagnostic performance when using colour retinal fundus *** intelligence models are among the most promising solutions to tackle the burden of diabetic retinopathy management in a comprehensive ***,future research is crucial to assess the potential clinical deployment,evaluate the cost-effectiveness of different DL systems in clinical practice and improve clinical acceptance.

关键词： Artificial intelligence Deep learning Diabetic retinopathy Fundus photographs Retinal imaging modalities Survey

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