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Filling gap of combination of gauge and analytical method in KFR-like theory

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Chinese Physics B 2020年第4期29卷 267-271页

作者： jian Li feng-Cai Ma School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China Department of Science Shenyang Aerospace UniversityShenyang 110036China Department of Physics Liaoning UniversityShenyang 110036China

Bauer recently presented a formula for the ionization rate of a hydrogen atom in a strong linearly polarized laser field[***.B 49145601(2016)].He started from the Keldysh probability amplitude in the length gauge and utilized Reiss’s method in the velocity ***,according to the Reiss probability amplitude in the velocity gauge and Keldysh’s derivation for the length gauge,we derive a formula for the ionization rate of a ground-state hydrogen atom or a hydrogenlike atom in a strong linearly polarized laser *** compare the numerical results of the total ionization rate and the photoelectron energy distribution calculated from our formula with the results from Keldysh,Reiss,and *** find that the apparent discrepancies in the ionization rate are caused not only by different gauges,but also by different analytical methods used to derive the ionization rate.

关键词： velocity gauge ionization rate energy spectra

ROBUST INEXACT ALTERNATING OPTIMIZATION FOR MATRIX COMPLETION WITH OUTLIERS

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Journal of Computational Mathematics 2020年第2期38卷 337-354页

作者： Ji Li jian-feng Cai Hongkai Zhao Beijing Computational Science Research Center Beijing 100193China Department of Mathematics Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong Department of Mathematics University of CaliforniaIrvineCAUSA

We investigate the problem of robust matrix completion with a fraction of observation corrupted by sparsity outlier *** propose an algorithmic framework based on the ADMM algorithm for a non-convex optimization,whose objective function consists of an l1 norm data fidelity and a rank *** reduce the computational cost per iteration,two inexact schemes are developed to replace the most time-consuming step in the generic ADMM *** resulting algorithms remarkably outperform the existing solvers for robust matrix completion with outlier *** the noise is severe and the underlying matrix is ill-conditioned,the proposed algorithms are faster and give more accurate solutions than state-of-the-art robust matrix completion approaches.

关键词： Matrix completion ADMM Outlier noise Inexact projection

Fulvic acid degradation using nanoparticle TiO_2 in a submerged membrane photocatalysis reactor

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Journal of Environmental Sciences 2005年第6期17卷 942-945页

作者： FU jian-feng JI Min AN Ding-nian School of Environmental Science and Engineering Tianjin University Tianjin 300072 China

The degradation of fulvic acid（FA） by nanoparticle TiO2 in a submerged membrane photocatalysis（SMPC） reactor was studied. In this reactor, photocatalytic oxidation and membrane separation co-occured. The continuous air supplier provided O2 for the photocatalytical reaction and mixed the solution through an airflow controller. The particle TiO2 could automatically settle due to gravity without particle agglomeration so it could be easily separated by microfiltration（MF） membrane. It was efficient to maintain high flux of membranes. The effects of operational parameters on the photocatalytic oxidation rate of FA were investigated. Results indicated that photocatalyst at 0.5 g/L and airflow at 0.06 m^3/h were the optimum condition for the removal of fulvic acid, the removal efficiency was higher in acid media than that in alkaline media. The effects of different filtration duration on permeate flux rate of MF with P25 powder and with nanoparticle TiO2 were compared. Experimental results indicated that the permeate flux rate of MF was improved and the membrane fouling phenomenon was reduced with the addition of nanoparticle TiO2 catalyst compared with conventional P25 powder. Therefore, this submerged membrane photocatalysis reactor can faciliate potential application of photocatalytic oxidation process in drinking water treatment.

关键词： fulvic acid microfiltration membrane nanoparticle TiO2 photocatalytic oxidation reactor

Stability of soil organic carbon changes in successive rotations of Chinese fir(Cunninghamia lanceolata(Lamb.) Hook) plantations

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Journal of Environmental Sciences 2009年第3期21卷 352-359页

作者： ZHANG jian WANG Silong feng Zongwei WANG Qingkui Huitong Experimental Station of Forest Ecology Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China Department of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Huitong National Research Station of Forest Ecosystem Huitong 418307 China Graduate University of Chinese Academy of Sciences Beijing 100039 China

The importance of soil organic carbon （SOC） under forests in the global carbon cycle depends on the stability of the soil carbon and its availability to soil microbial biomass. We investigated the effects of successive rotations of Chinese fir （Cunninghamia lanceolata （Lamb.） Hook） plantations on the stability of SOC and its availability to microbes by adopting the two-step hydrolysis with H2SO4 and density fractionation. The results showed that successive rotations of Chinese fir decreased the quantity of total SOC, recalcitrant fraction, and carbohydrates in Labile Pool I （LPI）, and microbial properties evidently, especially at 0-10 cm horizon. However, cellulose included in Labile Pool Ⅱ （LP Ⅱ） and the cellulose/total carbohydrates ratio increased in successive rotations of Chinese fir. The noncellulose of carbohydrates included in LPI maybe highly available to soil microbial biomass. Hence the availability of SOC to microbial biomass declined over the successive rotations. Although there was no significant change in recalcitrance of SOC over the successive rotations of Chinese fir, the percentage of heavy fraction to total SOC increased, suggesting that the degree of physical protection for SOC increased and SOC became more stable over the successive rotations. The degradation of SOC quality in successive rotation soils may be attributed to worse environmental conditions resulted from disturbance that related to ＂slash and burn＂ site preparation. Being highly correlated with soil microbial properties, the cellulose/total carbohydrates ratio as an effective indicator of changes in availability of SOC to microbial biomass brought by management practices in forest soils.

关键词： Chinese fir plantation forest soils organic carbon microbial property biochemical quality density fractionation

Guest Editorial Special Issue on Mid-Infrared Lasers and Applications

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Journal of Electronic Science and Technology 2015年第4期13卷 289-290页

作者： jian-feng Li University of Electronic Science and Technology of China

Mid-infrared （mid-IR） lasers, generally defined as having an operation wavelength in the spectral region of 2μm to 20μm, have attracted great scientific and technological interests owing to their widespread applications. This wavelength range not only contains some strong vibration transitions of many important molecules, thus, exhibiting enormous potential in medical, spectroscopy.

关键词： Guest Editorial Special Issue on Mid-Infrared Lasers and Applications IR

Speciation characterization and coagulation of poly-silica-ferric-chloride:The role of hydrolyzed Fe(Ⅲ) and silica interaction

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Journal of Environmental Sciences 2011年第5期23卷 749-756页

作者： jian Shi Yan Zhang Kaiyun Zou feng Xiao Nantong University Nantong 226007 China. E-mail: shijianchuyu @ *** Key Laboratory of Environmental Water Chemistry Ecological Environment Research Center of Chinese Academy of Science Beijing 100085 China

The highly efficient inorganic polymer flocculants （IPFs） of the ferric-silica system is a new and promising coagulant. Interactions between ferric species and silica play a large part in the coagulation of suspensions. These effects are quite distinct from those associated with polymeric or colloid silica. However, although these species are key to coagulation efficiency, they have not been comprehensively discussed. A new type of coagulant, poly-silica-ferric-chloride （PFSC）, was synthesized by co-polymerization and characterized by time complexation spectroscopy and photon correlation spectroscopy. Compared with traditional ferric salt, the results indicated that PFSC had a higher molecular weight, lesser positive charge, lower Feb and higher Fec. The higher the Si/Fe ratio, the higher the silica and lower the silicac found. The PFSC with appropriate polysilica acid not only obtained better coagulation/flocculation efficiency in turbidity removal, enhanced the flocculation index （FI） and provided less residual ferric, it also lowered water treatment costs compared to traditional ferric salt. Results showed that PFSC could remove colloid particles in water by charge neutralization and sweeping, adsorption bridging mechanism.

关键词： coagulation inorganic polymer flocculant PFSC species distribution residual ferric

Exploratory study of logistics service quality scale based on online shopping malls

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 926-931页

作者： feng Yi-xiong ZHENG Bing TAN jian-rong State Key Lab. of CAD ＆ CG Zhejiang University Hangzhou 310027 China College of Economics ＆ Management Dalian University Dalian 116622 China

Online shopping has already become the new mode that a lot of customers try to adopt. At the same time, the online shopping could not be successfully completed without logistics service. Logistics service quality (LSQ) has significant impact on revenue and profitability. This paper presents the issue from the perspective of the customer, and explores the initial factors of LSQ based on the online shopping through in-depth interview and the Delphi method. The survey uses a standard 7-point Likert-type scale to measure the LSQ. Empirical research results are shown in detail to confirm seven LSQ dimensions with Chinese characteristics, including timeliness quality, personal contact quality, order quality, order discrepancy handling, order condition and convenience. Statistical analyses of the investigation were conducted to test the reliability and validity of the LSQ evaluation model.

关键词： Online shopping Logistics service Logistics service quality (LSQ) Dimensions of LSQ

Simulation of turbulent combustion in DLR Scramjet

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第7期8卷 1053-1058页

作者： ZOU jian-feng ZHENG Yao LIU Ou-zi School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China

Turbulent combustion in a DLR (German Aerospace Center) Scramjet engine was simulated using the newly-proposed Partially Resolved Numerical Simulation (PRNS) procedure. The PRNS procedure uses temporal filtering to define large-scale turbulence, and the model developed to account for unresolved scales is grid independent. No problem about inner commutation error and inconsistencies will arise from the PRNS, while such issues are of concern in traditional Large Eddy Simulation (LES) methods. The mean results have good agreement with the experiment data and the flow structures with small scales are well resolved.

关键词： Scramjet Turbulent combustion Unstructured grid Finite volume method

Effects of moss-dominated biocrusts on soil detachment by overland flow in the Three Gorges Reservoir Area of China

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Journal of Mountain Science 2020年第10期17卷 2418-2431页

作者： ZHANG Guan-hua DING Wen-feng PU jian LI jian-ming QIAN feng SUN Bao-yang Soil and Water Conservation Department Changjiang River Scientific Research InstituteWuhan430010China Research Center on Mountain Torrent&Geologic Disaster Prevention of Ministry of Water Resources Wuhan430010China

Biological soil crusts(biocrusts)are important landscape components that exist in various climates and *** roles of biocrusts in numerous soil processes have been predominantly recognized in many dryland regions ***,little is known about their effects on soil detachment process by overland flow,especially in humid *** study quantified the effects of moss-dominated biocrusts on soil detachment capacity(Dc)and soil erosion resistance to flowing water in the Three Gorges Reservoir Area which holds a subtropical humid *** factors driving soil detachment variation and their influencing mechanism were analyzed and *** designed five levels of coverage treatments(1%–20%,20%–40%,40%–60%,60%–80%,and 80%–100%)and a nearby bare land as control in a mossdominated *** soil samples were taken and subjected to water flow scouring in a hydraulic flume under six shear stresses ranging from 4.89 to 17.99 *** results indicated that mean Dc of mosscovered soil varied from 0.008 to 0.081 kg m^-2 s^-1,which was 1.9 to 21.0 times lower than that of bare soil(0.160 kg m^-2 s^-1).Rill erodibility(Kr)of mosscovered soil ranged from 0.0095 to 0.0009 s m^-1,which was 2 to 20 times lower than that of bare soil(0.0187 s m^-1).Both relative soil detachment rate and Kr showed an exponential decay with increasing moss coverage,whereas the critical shear stress(τc)for different moss coverage levels did not differ *** coverage,soil cohesion,and sand content were key factors affecting Dc,while moss coverage and soil bulk density were key factors affecting Kr.A power function of flow shear stress,soil cohesion,and moss coverage fitted well to estimate Dc(NSE=0.947).Our findings implied that biocrusts prevented soil detachment directly by their physical cover and indirectly by soil properties *** could be rehabilitated as a promising soil conservation measure during ecological recovery to enhance so

关键词： Soil detachment Soil erosion resistance Rill erodibility Biological soil crusts Yangtze River