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Research of Temperature Tracer Method to Detect Tubular Leakage Passage in Earth-Dam

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Journal of China University of Mining and Technology 2006年第3期16卷 353-358页

作者： WANG Xin-jian chen jian-sheng Geotechnical Institute Hohai University Nanjing Jiangsu 210098 China

The location, intensity and scope of concentrated leakage must be determined in order to repair earth-Dam scoured by the leakage. In this paper, firstly, heat tracer theory and distribution laws of temperature in soil body with leakage are discussed. Then temperature tracer model is established according to stable heat conduction theory. In such model, the concentrated seepage passage is simplified into a circular pipe as a boundary condition. The location, scope and flow-velocity of the concentrated leakage are estimated via ichnography of the lowest temperature based on temperature data from detecting wells by quantitative computation and qualitative analysis. In case study, the distribution characteristic of temperature (including temperature data of water in reservoir, drainage pipes and tail pond) can be interpreted by this model. A modified model is also set up, applied for detected data at different cross-sections of the leakage passage, in which the temperature data are rectified according to distances from data locations to calculating section. Finally, the model is solved by numerical iterative method, and the possible error of this theoretical model is discussed. The permeability coefficient in leakage area is identical with that of normal soil in magnitude after anti-seepage repairing accomplished, which indicates this model is effective.

关键词： seepage concentrated leakage passage heat conduction tracer method temperature field earth-dam

Preparations of TiO_2 film coated on foam nickel substrate by sol-gel processes and its photocatalytic activity for degradation of acetaldehyde

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Journal of Environmental Sciences 2007年第1期19卷 80-85页

作者： HU Hai XIAO Wen-jun YUAN jian SHI jian-wei chen Ming-xia SHANG GUAN Wen-feng Research Center for Combustion and Environment Technology Shanghai Jiao Tong University. Shanghai 200030 China

Anatase TiO2 films were successfully prepared on foam nickel substrates by sol-gel technique using tetrabutyl titanate as precursor. The characteristics of the TiO2 films were investigated by XPS, XRD, FE-SEM, TEM and UV-Vis absorption spectra. The photocatalytic activities of TiO2 films were investigated by photocatalytic degradation reactions of gaseous acetaldehyde, an indoor pollutant, under ultraviolet light irradiation. It was found that Ni^2＋ doping into TiO2 films due to the foam nickel substrates resulted in the extension of absorption edges of TiO2 films from UV region to visible light region. The pre-heating for foam nickel substrates resulted in the formation of NiO layer, which prevented effectively the injection of photogenerated electrons from TiO2 films to metal nickel. The TiO2 films displayed high photocatalytic activity for the degradation of acetaldehyde, and were enhanced by calcining the substrates and coating TiO2 films repeatedly. The high activity was mainly attributed to the improvement of the characteristics of substrate surface and the increase of active sites on photocatalyst.

关键词： photocatalyst TiO2 films foam nickel sol-gel acetaldehyde degradation

THREE-DIMENSIONAL NUMERICAL SIMULATION OF AERATED FLOWS DOWNSTREAM SUDDEN FALL AERATOR EXPANSION-IN A TUNNEL

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Journal of Hydrodynamics 2011年第1期23卷 71-80页

作者： ZHANG jian-min chen jian-gang XU Wei-lin WANG Yu-rong LI Gui-ji State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065China

Air entrainment is known to be one of efficient and inexpensive methods to prevent cavitation damages in hydropower *** shape of sudden expansion-fall is used as a common device for mitigating cavitation *** complex flow patterns with cavitation are numerically simulated by using the realizable k-εturbulence model and the air-water mixture *** calculated results are compared well with the experimental results as well as those obtained with the k-εturbulence model with the Volume Of Fluid（VOF）*** calculated results agree well with the experimental data for the aeration cavity and wall ***,the air concentration near sidewall is simulated by a mixture *** is found that the mixture turbulence model is superior to the VOF turbulence model.

关键词： sudden expansion-fall aerator RNG k-εturbulence model realizable k-εturbulence model Volume Of Fluid (VOF)method air-water Mixture turbulence model numerical simulation

Linearly McCoy Rings and Their Generalizations

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Communications in Mathematical Research 2010年第2期26卷 159-175页

作者： CUI jian chen jian-LONG Department of Mathematics Southeast University Nanjing 210096

A ring R is called linearly McCoy if whenever linear polynomials f（x）, g（x） e R[x]／{0） satisfy f（x）g（x）： O, then there exist nonzero elements r, s ∈ R such that f（x）r ： sg（x） =0. For a ring endomorphism α, we introduced the notion of α-skew linearly McCoy rings by considering the polynomials in the skew polynomial ring R[x; α] in place of the ring R[x]. A number of properties of this generalization are established and extension properties of α-skew linearly McCoy rings are given.

关键词： linearly McCoy ring a-skew linearly McCoy ring polynomial ring,matrix ring

Role of Transarterial Chemoembolization in the Treatment of Hepatocellular Carcinoma

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Journal of Clinical and Translational Hepatology 2023年第2期11卷 480-489页

作者： Bin-Yan Zhong Zhi-cheng Jin jian-jian chen Hai-Dong Zhu Xiao-Li Zhu Department of Interventional Radiology the First Affiliated Hospital of Soochow UniversitySuzhouJiangsuChina Center of Interventional Radiology&Vascular Surgery Department of RadiologyZhongda HospitalMedical SchoolSoutheast UniversityNanjingJiangsuChina

Hepatocellular carcinoma(HCC)is one of the most common cancers *** to the Barcelona Clinic Liver Cancer(BCLC)staging system,transarterial chemoembolization(TACE)is the first-line recommendation for intermediate-stage *** real-world clinical practice,TACE also plays an important role in early-and advanced-stage *** review article by the experts from Chinese Liver Cancer Clinical Study Alliance(CHANCE)summarizes the available clinical evidence pertaining to the current application of TACE in patients with early-,intermediate-,and advanced-stage *** addition,combination of TACE with other treatment modalities,especially immunotherapy,is reviewed.

关键词： Hepatocellular carcinoma TACE Immunotherapy

The recirculation flow after different cross-section shaped high-rise buildings with applications to ventilation assessment and drag parameterization

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Building Simulation 2024年第4期17卷 509-524页

作者： Keyi chen Ziwei Mo jian Hang School of Atmospheric Sciences Sun Yat-sen University&Southern Marine Science and Engineering Guangdong LaboratoryZhuhai519082China Key Laboratory of Tropical Atmosphere-Ocean System Ministry of EducationZhuhai519000China

The building cross-section shape significantly affects the flow characteristics around buildings,especially the recirculation region behind the high-rise *** generic building shapes including square,triangle,octagon,T-shaped,cross-shaped,#-shaped,H-shaped and L-shaped are examined to elucidate their effects on the flow patterns,recirculation length L and areas A using computational fluid dynamics(CFD)simulations with Reynolds-averaged Navier-Stokes(RANS)*** sizes and positions of the vortexes behind the buildings are found to be substantially affected by the building shapes and subsequently changing the recirculation *** recirculation length L is in the range of 1.6b-2.6b with an average of *** maximum L is found for L-shaped building(2.6b)while the shortest behind octagon building(1.6b).The vertical recirculation area Av is in the range of 1.5b^(2)-3.2b^(2)and horizontal area Ah in 0.9b^(2)-2.2b^(2).The L,Av and Ah generally increase with increasing approaching frontal area when the wind direction changes but subject to the dent structures of the#-shaped and cross-shaped *** area-averaged wind velocity ratio(AVR),which is proposed to assess the ventilation performance,is in the range of 0.05 and 0.14,which is around a three-fold difference among the different building *** drag coefficient parameterized by Ah varies significantly,suggesting that previous models without accounting for building shape effect could result in large uncertainty in the drag *** findings provide important reference for improving pedestrian wind environment and shed some light on refining the urban canopy parameterization by considering the building shape effect.

关键词： recirculation region cross-section shape ventilation assessment drag parameterization computational fluid dynamics

Self-aligned dual-beam superresolution laser direct writing with a polarization-engineered depletion beam

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Photonics Research 2024年第6期12卷 1194-1200页

作者： GUOLIANG chen DEWEI MO jian chen QIWEN ZHAN School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Modern Optical System University of Shanghai for Science and TechnologyShanghai 200093China Zhangjiang Laboratory Shanghai 201204China

A fiber-based,self-aligned dual-beam laser direct writing system with a polarization-engineered depletion beam is designed,constructed,and *** system employs a vortex fiber to generate a donut-shaped,cylindrically polarized depletion beam while simultaneously allowing the fundamental mode excitation beam to pass *** results in a co-axially self-aligned dual-beam source,enhancing stability and mitigating assembly *** size of the central dark spot of the focused cylindrical vector depletion beam can be easily adjusted using a simple polarization rotation *** a depletion wavelength of 532 nm and an excitation wavelength of800 nm,the dual-beam laser direct writing system has demonstrated a single linewidth of 63 nm and a minimum line spacing of 173 *** optimization of this system may pave the way for practical superresolution photolithography that surpasses the diffraction limit.

关键词： polarization beam depletion

Data-Driven Active Disturbance Rejection Control of Plant-Protection Unmanned Ground Vehicle Prototype: A Fuzzy Indirect Iterative Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1892-1894页

作者： Tao chen Ruiyuan Zhao jian chen Zichao Zhang College of Engineering China Agricultural UniversityBeijing 100083China Key Laboratory of Smart Agricultural Technology in Tropical South China Ministry of Agriculture and Rural AffairsGuangzhou 510642China

Dear Editor,This letter proposes a fuzzy indirect iterative learning(FIIL)active disturbance rejection control(ADRC)scheme to address the impact of uncertain factors of plant-protection unmanned ground vehicle(UGV),in which ADRC is a data-driven model-free control algorithm that only relies on the input and output data of the *** on the established nonlinear time-varying dynamic model including dynamic load(medicine box),the FIIL technology is adopted to turn the bandwidth and control channel gain online,in which the fuzzy logic system is used to update the gain parameters of iterative learning in real *** and experiment show the FIIL-ADRC scheme has better control performance.

关键词： Active scheme iterative

Generalized Inverses and Units in a Unitary Ring

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1000-1014页

作者： Yu Kun ZHOU jian Long chen School of Mathematics Southeast UniversityNanjing 210096P.R.China

Let R be a unitary ring and a,b∈R with ab=*** find the 2/3 property of Drazin invertibility:if any two of a,b and a+b are Drazin invertible,then so is the third ***,we combine the 2/3 property of Drazin invertibility to characterize the existence of generalized inverses by means of *** applications,the need for two invertible morphisms used by You and chen to characterize the group invertibility of a sum of morphisms is reduced to that for one invertible morphism,and the existence and expression of the inverse along a product of two regular elements are obtained,which generalizes the main result of Mary and Patricio(2016)about the group inverse of a product.

关键词： Leftπ-regular element stronglyπ-regular element group inverse Drazin inverse inverse along an element