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Quantitative redox imaging biomarkers for studying tissue metabolic state and its heterogeneity

Journal of Innovative Optical Health Sciences 2014年第2期7卷 109-128页

作者： He N.Xu lin z.li Department of RadiologyBrtton Chance Laboratory of Redoa Imaging Johnson Research Foundation Departmentof Biochemistry and BiophysicsPerelman School of MedicineUniversity of Pennsyluania PhiladelphiaPAUSA

NAD+/NADH redox state has been implicated in many diseases such as cancer and diabetes aswell as in the regulation of embryonic development and aging,To fluorimetrically sssthemitochondrial redox state,*** and co-workers measured the fluorescence of NADH andoxidized flavoproteins(Fp)including favin-adenine-dinucleotide(FAD)and demonstrated theirratio(*** redox ratio)is a sensitive indicator of the mitochondrial redox states.,The Chanceredox sca mer was built to simult aneously measure NADH and Fp in tisue at submilimeter scalein 3D using the freeze-trap *** paper summarizes our recent research experience,development and new applications of the redox scanning technique in collaboration with *** beginning in *** initiated or actively involved in many of the projectsduring the last several years of his *** advanced the redox scanning technigue by measuringthe nominal concentrations(in reference to the frozen solution standards)of the endogenousfuorescent analy tes,i.e.,[NADH]and[rp]to quantify the redox ratios in various *** advancement has enabled us to identify an array of the redox indices as quantitativeimaging,biomarkers(including[NADH],[Fp],[Fp]/[NADH]+[Fp],[NADH]/[Fp],and theirstandard deviations)for studying some important biological questions on cancer and normaltsue *** found that the redox indices were asociated or changed with(NADH)tumorigenesis(cancer versus non-cancer of human breast tisue biopsies);(2)tumor metastaticpotential;(3)tumor glucose uptake;(4)tumor p53 stat us;(5)PI3K pathway activation in pre-malignant tissue;(6)therapeutic ffects on tumors;(7)embryonic stem cell diferentiation;(8)the heart under fasting,Together,our work demonstrated that the tisue redox indices obtainedfrom the redox scanning technique may provide usefil information about tisue met abolism and physiology status in normal and diseased *** Chance redox scanner and other redoximaging techniques may ha

关键词： Tumor progresion mitochondria met astasis met astatic potential pre-malignancy NADH Fp FAD redox ratio

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A NOVEL METHOD FOR EVALUATIng PLANE STRESS DYNAMIC FRACTURE TOUGHNESS OF 0Cr18Ni10Ti STAINLESS STEEL WELDED JOINTS

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 303-312页

作者： z.J. Xu Y.L. li School of Aeronautics Northwestern Polytechnical University Xi＇an 710072 China

A novel method was proposed for the evaluation of Mode I dynamic fracture toughness （DFT） under plane stress and small scale yielding conditions for welded joints of stainless steel （SS）, 0Cr18Ni10Ti. In a hybrid experimental-numerical approach, the experiments were carried out on the Hopkinson pressure bar apparatus, and three dimensional （3D） transient numerical simulations were performed by a finite element （FE） computer program. Macroscopical plastic deformation was observed at the loading and supporting points, on the specimens, after the test, which could cause a large error if omitted in the numerical simulation. Therefore, elustic-viscoplustic analysis was performed on the specimen by adopting the Johnson-Cook （J-C） model to describe the rate-dependent plastic flow behavior of the material. The material heterogeneity in the mismatched welded joints, induced by the difference in the base metal （BM） and the weld metal （WM） in yield stress, has also been taken into consideration by using the J-C models separately. Good accordance was obtained between the experimental and the computational results by the present approach. The relationship between plane stress DFT and loading rate was also obtained on the order of 108 MPa.m^1/2.s^-1.

关键词： 0Cr18Ni10Ti Welded joint High strain rate Dynamic fracture Plane stress

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REAL-TIME FLOOD FORECASTIng MODEling OF 1D UNSTEADY CHANNEL FLOW AND KALMAN FILTER

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Journal of Hydrodynamics 2001年第1期13卷 64-69页

作者： li, z.J. Weng, M.H. Coll. of Water Res. and Environ. Hohai Univ. Nanjing 210024 China

The model of 1D unsteady channel flow combined with the Kalman filter for real-time channel flood forecasting was attempted. The suitable upstream and downstream boundary conditions were suggested. The system equation was given by the linearization of the finite difference equations of the mass conservation and momentum equations as well as the boundary conditions. In the Kalman filter updating model, because the number of measurement variable is less than that of state-space variables, the measurement error covariance matrix could be estimated in real time through the innovation sequence, and the system error covariance matrix needs to be estimated preliminarily. A real example of flood forecasting in the Huaihe River was given to explain how the method works. The results show that the model is reasonable and effective.

关键词： Channel flow Computer simulation Kalman filtering Unsteady flow

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Absorption Spectroscopy of （8,1） Band in d^3△-a^3П System of CS Radical

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Chinese Journal of Chemical Physics 2012年第5期25卷 513-518,I0003页

作者： Chuan-liang li Lun-hua Deng Yan zhang Ji-lin Wei Ya ng-qin Chen Department of Physics School of Applied ScienceTaiyuan University of Science and TechnoloEyTaiyuan 030024China State Key Laboratory of Precision Spectroscopy and Department of Physics East China NormalUniversityShanghai 200052China

The CS radical was generated by discharging the mixture gas of CS2 and Helium. The Doppler limited spectra of CS were recorded in the region of 12350-12950 cm^-1 using optical heterodyne concentration modulation absorption spectroscopy. Three hundred and twenty-six lines were recorded and assigned to the d^3△-a^3П （8,1） band, in which eighty-three transitions were first observed. A set of improved molecular constants for the d^3△（v=8） and a^3П（v=1） levels were determined by a non-linear least-squares fitting of all the lines to the effective Hamiltonian.

关键词： CS radical Concentration modulation absorption spectroscopy Molecularconstant

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Surface Characterisation of Silicon Based MEMS

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Chemical Research in Chinese Universities 2004年第4期20卷 407-410页

作者： li J. CUI z M. A. Baker The Surface Analysis Laboratory School of Engineering University of SurreyRutherford Appleton LaboratoryThe Surface Analysis Laboratory School of Engineering University of Surrey Guildford GU2 7XH UKChilton Didcot UKGuildford GU2 7XH UK

Polysilicon Microelectromechanical systems(MEMS) are the subject of intensive researches. Surface chemistry and topography of a MEMS test structure fabricated at Sandia National Laboratory, USA, were studied by means of scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM). XPS C_ 1sand Si_ 2pspectra from the polysilicon components, silicon nitride substrate and a reference silicon wafer were compared. The results confirm the presence of a self-assembled monolayer(SAM) on the MEMS surface. An island-like morphology was found on both polysilicon and silicon nitride surfaces of the MEMS. The islands take the form of caps, being up to 0.5 μm in diameter and 20 nm in height. It is concluded that the co-existence of columnar growth and equiaxed growth during the low pressure chemical vapor deposition(LPCVD) of these layers leads to the observed morphology and the islands are caps to the columnar structures.

关键词： Microelectromechanical systems XPS Atomic force microscopy

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New insights into hydraulic fracturing fluids used for hightemperature wells

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Petroleum 2021年第1期7卷 70-79页

作者： Tariq Almubarak Leiming li Jun Hong ng Hisham Nasr-El-Din Mohammed AlKhaldi Texas A&M University USA Aramco Services Company Saudi Arabia Saudi Aramco EXPEC ARC Saudi Arabia

Current interest in deep,low-permeability formations(<10 md)demands accelerated development of high-temperature hydraulic fracturing *** guar systems break down above 300°F and require higher polymer loadings to main... 详细信息

Current interest in deep,low-permeability formations(lic fracturing *** guar systems break down above 300°F and require higher polymer loadings to maintain thermal ***,higher polymer loadings generate more residue and damage to the proppant pack and the *** resolve these problems,a variety of high-temperature stabilizers are added to enhance the thermal stability of these fracturing fluids at temperatures above 300*** focus of this work is to:(1)identify those additives that best enhance temperature stability of fracturing fluids and(2)study the rheological influence of incorporating these additives on the fracturing fluid *** experimental fracturing-fluid solutions were prepared at a total polymer concentration of 30 and 40 lb/1000 *** such as synthetic polymer,oxygen scavengers,crosslinkers,crosslinker delay additives,and pH buffers were examined in this *** polymer solutions were crosslinked with a metallic crosslinker between 200 and 400°*** measurements were carried out in a highpressure/high-temperature(HP/HT)rheometer to evaluate rheology and thermal *** show that adding a synthetic polymer and a crosslinker with the slowest reaction rate improves the fracturing fluid thermal *** the three other additives tested,oxygen scavengers showed the greatest enhancement to thermal stability while pH buffers showed the *** the addition of high-temperature stabiliz.ng additives,the fracturing fluid in this work was able to maintain a stable performance at temperatures up to 400°*** the thermal stability of fracturing fluids at a lower polymer loading remains a challenge in the *** work proposes techniques that can be used to enhance the thermal stability of fracturing *** knowledge about these different techniques will allow for better additive development and a

关键词： Oxygen scavenger Crosslinker Crosslinker delay Shear tolerance High temperature Synthetic polymer CMHPG Buffers

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Correlation between Porosity and Fracture Mechanism in High Pressure Die Casting of AM60B Alloy

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Journal of Materials Science & Technology 2016年第1期32卷 54-61页

作者： X.li S.M.Xiong z.Guo School of Materials Science and Engineering Tsinghua University State Key Laboratory of Automobile Safety and Energy Tsinghua University

X-ray tomography was used to characterize the porosity in high pressure die casting of AM60B alloy. In situ tensile deformation was performed to observe the change of porosities and their influences on crack initiation, propagation and subsequent fracture of specimen. Results showed that four types of porosi- ties, including gas-shrinkage pore, gas pore, net-shrinkage and island-shrinkage, could be identified according to the formation mechanism and morphology characterization. During tensile deformation, it was shown that the gas-shrinkage pore and net-shrinkage, rather than gas pore or island-shrinkage, were the main sources for crack initiation. In addition, the crack propagated by interconnecting the po- rosities at the cross section with minimum efficient force bearing area. At these locations where externally solidified crystals （ESCs） were present, the crack would propagate along the ESC boundaries in an inter- granular mode, while at these locations without ESCs, the crack would propagate roughly along the direction perpendicular to the tensile stress in a combination of trans-granular and inter-granular modes.

关键词： High pressures die casting AM60B alloy Fracture mechanism Porosity

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PREPARATION AND XRD STUDY OF liTHIUM DEFICIENT liB COMPOUND

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 667-671页

作者： z.J.liu B.Y.Huang z.Y.li StateKeyLaboratoryforPowderMetallurgy CentralSouthUniversityChangsha410083China

The liB compounds in lithium deficient state were prepared by three methods and its crystal structure was investigated by using XRD. It is found that the lattice constant c of the compound will increase step by step with decreasing li content from 0.2796nm of the normal liB to 0.2886, 0.2981 and 0.3118nm of the lithium deficient liB. The change of the lattice constant is reversible.

关键词： liB compound crystal structure electrode materials X-ray diffraction

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Influence of plasma condition on carbon nanotube growth by rf-PECVD

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Nano-Micro Letters 2010年第1期2卷 37-41页

作者： Y.H.Man z.C.li z.J.zhang Advanced Materials Laboratory Department of Materials Science and Engineering Tsinghua University

Carbon nanotubes(CNTs)have been synthesized from Ar-CH_4 mixtures using rf-plasma enhanced chemical vapor deposition(rf-PECVD)at *** gases such as H_2 and NH_3 were found unnecessary for carbon nanotube formation compared to thermal *** relationship between the growth of CNTs and the plasma condition in PECVD has been investigated by in situ self bias *** conditions were controlled by changing the interelectrode distance,rf power and the applied substrate negative *** increasing the interelectrode distance and rf power,the spatial density of CNTs was on a rise as a result of the increase in ions density and self *** the applied substrate negative bias increased,the spatial density of CNTs decreased possibly due to the positive ions over bombarding effect.

关键词： Carbon nanotube Plasma enhanced CVD Plasma condition

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Diagnosing the Dynamic and Thermodynamic Effects for the Exceptional 2020 Summer Rainy Season in the Yangtze River Valley

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Journal of Meteorological Research 2022年第1期36卷 26-36页

作者： Na WEN Shujie liU Laurent z.X.li College of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science&TechnologyNanjing 210044China Qingdao Engineering Technology Research Center for Meteorological Disaster Prevention Qingdao Meteorological BureauQingdao 266003China Laboratoire de Météorologie Dynamique Centre National de la Recherche ScientifiqueSorbonne UniversitéEcole Normale SupérieureEcole PolytechniqueParis 75252France

An exceptional rainy season occurred in the Yangtze River valley of eastern China in June-July *** relative importance of the dynamic and thermodynamic effects on this unusual event is evaluated through the budget equations of moisture and moist static energy(MSE).The moisture budget analysis suggests that the thermodynamic effect contributes to the precipitation anomaly by 8.5%through the advection of abnormal water vapor by mean vertical motion,while the dynamic effect,related to water vapor advection by anomalous vertical motion,has the dominant *** MSE budget analysis further reveals that the anomalous vertical motion is both constrained by the dynamic effect related to changes in atmospheric circulation and the thermodynamic effect related to changes of the atmospheric thermal state,with a ratio of thermodynamic versus total effects estimated at 45.3%.The dynamic effect is linked to the advection of warm and humid air by the abnormal southwesterly wind,which is related with an anomalous anticyclone over the Philippine *** thermodynamic effect is partly induced by the positive advection of anomalous MSE(mainly latent energy)by the mean vertical *** analysis of the dynamic and thermodynamic effects is useful to understand the underlying physical mechanisms leading to the unusual rainy season in the Yangtze River valley in summer *** is also helpful to put forward a few speculations on the potential role of global warming whose primary effect is,after all,to change the thermal state of the atmosphere.

关键词： exceptional rainfall Yangtze River valley global warming dynamic and thermodynamic effects

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