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Contributions of adsorption, bioreduction and desorption to uranium immobilization by extracellular polymeric substances

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Frontiers of Environmental Science & Engineering 2023年第9期17卷 125-135页

作者： Chen Zhou Ermias Gebrekrstos Tesfamariam Youneng Tang ang Li Biodesign Swette Center for Environmental Biotechnology Arizona State UniversityTempeAZ 85281USA Department of Civil and Environmental Engineering FAMU-FSU College of EngineeringFlorida State UniversityTallahasseeFL 32310USA State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

Hexavalent uranium(U(VI))can be immobilized by various *** role of extracellular polymeric substances(EPS)in U(VI)immobilization has not been *** work provides a model framework to quantify the contributions of three processes involved in EPS-mediated U(VI)immobilization:adsorption,bioreduction and *** associated EPS was extracted from a pure bacterial strain,Klebsiella sp.j1,and then exposed to H_(2) and O_(2)(no bioreduction control)to immobilize U(VI)in batch experiments.U(VI)immobilization was faster when exposed to H_(2) than O_(2) and stabilized at 94%for H_(2) and 85%for O_(2),*** non-equilibrium data from the H_(2) experiments were best simulated by a kinetic model consisting of pseudo-second-order adsorption(ka=2.87×10^(−3) g EPS·(mg U)^(−1)·min^(−1)),first-order bioreduction(kb=0.112 min−1)and first-order desorption(kd=7.00×10^(−3) min^(−1))and fitted the experimental data with R^(2) of *** adsorption was dominant in the first minute of the experiments with H_(2),bioreduction was dominant from the second minute to the 50th *** 50 min,adsorption was negligible,and bioreduction was balanced by *** work also provides the first set of equilibrium data for U(VI)adsorption by EPS *** equilibrium experiments with O_(2) were well simulated by both the Langmuir isotherm and the Freundlich isotherm,suggesting multiple mechanisms involved in the interactions between U(VI)and *** thermodynamic study indicated that the adsorption of U(VI)onto EPS was endothermic,spontaneous and favorable at higher temperatures.

关键词： Adsorption Bioreduction Desorption Kinetics Isotherm Uranium

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Phenotypic nutrient up-take differences in an alley cropping system in semi-arid Machakos, Kenya

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journal of Environmental Sciences 2001年第2期13卷 164-169页

作者： D.N. Mungai C.L.Coulson C.j. Stigter j.K. Ng’ang’a D.N.Mugendi Department of Geography University of NairobiNairdbiKenya Department of Botany University of NairobiNairobiKenya Department of Enviromnental Sciences Graduate School of Productian EcologyWageningen UniversityDuivendaal 26701 APThe Netherlands Department of Meteorology University of NairobiNairobiKenya Kenya Forestry Research Instiute(KEFRI NairobiKanya)

Alley cropping of Cassia siamea and maize was studied in semi arid Kenya for soil fertility improvement. Katumani composite maize was planted except in the short rains of 1988 (SR88) when a hybrid variety was sown. Therefore the grain yield per row increased differently in the alley cropped maize (CM). Sole maize (SM) and CM yields were higher in SR88 than in the long rains of 1988 (LR88) by 62% and 38%, while yields from the same treatments in LR89 were only 21% and 45% of those in SR88 These differences in relative maize yields are attributed to differences between the two maize varieties in competition under nutrient stress conditions.

关键词： alley cropping Cassia siamea maize nutrients maize yield semi arid condition soil moisture Kenya

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Fast Marching Method for Microseismic Source Location in Cavern-Containing Rockmass: Performance Analysis and Engineering Application

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Engineering 2021年第7期7卷 1023-1034页

作者： Ruochen j.ang Feng Dai Yi Liu ang Li State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China School of Highway Chang’an UniversityXi’an 710064China

Microseismic(MS)event locations are vital aspect of MS monitoring technology used to delineate the damage zone inside the surrounding rock ***,complex geological conditions can impose significantly adverse effects on the final location *** achieve a high-accuracy location in a complex cavern-containing structure,this study develops an MS location method using the fast marching method(FMM)with a second-order difference approach(FMM2).Based on the established velocity model with three-dimensional(3D)discrete grids,the realization of the MS location can be achieved by searching the minimum residual between the theoretical and actual first arrival ***,based on the calculation results of FMM2,the propagation paths from the MS sources to MS sensors can be obtained using the linear interpolation approach and the Runge–Kutta *** methods were validated through a series of numerical *** addition,our proposed method was applied to locate the recorded blasting and MS events that occurred during the excavation period of the underground caverns at the Houziyan hydropower *** location results of the blasting activities show that our method can effectively reduce the location error compared with the results based on the uniform velocity ***,the obtained MS location was verified through the occurrence of shotcrete fractures and spalling,and the monitoring results of the in-situ multipoint *** proposed method can offer a more accurate rock fracture location and facilitate the delineation of damage zones inside the surrounding rock mass.

关键词： Fast marching method Microseismic event location Cavern-containing complex rock mass Runge-Kutta method

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A novel dense descriptor based on structure tensor voting for multi-modal image matching

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Chinese journal of Aeronautics 2020年第9期33卷 2408-2419页

作者： jiazhen LU Maoqing HU jing DONG Songlai HAN ang SU School of Aeronautics and Astronautics Central South UniversityChangsha 410083China Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Automatic and robust matching of multi-modal images can be challenging owing to the nonlinear intensity differences caused by radiometric variations among these *** address this problem,a novel dense feature descriptor and improved similarity measure are proposed for enhancing the matching *** proposed descriptor is built on a voting scheme of structure tensor that can effectively capture the geometric structural properties of *** is not only illumination and contrast invariant but also robust against the degradation caused by significant ***,the similarity measure is improved to adapt to the reversal of orientation caused by the intensity inversion between multi-modal *** proposed dense feature descriptor and improved similarity measure enable the development of a robust and practical templatematching algorithm for multi-modal *** verify the proposed algorithm with a broad range of multi-modal images including optical,infrared,Synthetic Aperture Radar(SAR),digital surface model,and map *** experimental results confirm its superiority to the state-of-the-art methods.

关键词： Dense feature descriptor Remote sensing images Similarity measurement Structure tensor Template matching

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Numerical simulation of the three-dimensional flow-path in a ram-rotor

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航空动力学报 2010年第6期25卷 1358-1365页

作者： HAN ji-ang ZHONG jing-jun YAN Hong-ming Marine Engineering College Dalian Maritime UniversityDalian 116026China School of Energy Science and Engineering Harbin institute of TechnologyHarbin 150001China

A kind of three-dimensional flow-path of the ram-rotor was designed in this paper according to the design method of the typical supersonic intake of aircraft and missiles,especially the design method of the compression ramp,the throat and the subsonic *** design Mach number of the flow-path was based on the averaged relative Mach number,regardless of the change of incoming Mach number along radial direction of the ***,the flowfield of the designed flow-path was simulated numerically with computational fluid dynamics software at design *** purpose of simulation was to obtain the details of the flowfield,including the structure of the shock wave system,position of flow separation zone,and so *** performance of the ram-rotor was also *** numerical results show the structure of the shock wave system in the flow-path is similar to that in the supersonic *** improve the overall performance of the ram-rotor,the reasonable compromise between the total pressure ratio and the isentropic adiabatic efficiency should be *** structure optimization of the flow-path and the configuration of the shock wave system have great influence on the performance of the ram-rotor.

关键词： ram-rotor flow-path supersonic intake numerical simulation design point

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Modeling and flapping vibration suppression of a novel tailless flapping wing micro air vehicle

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Chinese journal of Aeronautics 2022年第3期35卷 309-328页

作者： Siqi Wang Bifeng SONG ang CHEN Qiang FU jin CUI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang 215400China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

This paper establishes and analyzes a high-fidelity nonlinear time-periodic dynamic model and the corresponding state observer for flapping vibration suppression of a novel tailless Flapping Wing Micro Air Vehicle(FWMAV),named ***,a complete modeling of NPU-Tinybird is determined,including the aerodynamic model based on the quasi-steady method,the kinematic and dynamic model about the mechanism of flapping and attitude control,combined with the single rigid body dynamic *** on this,a linearized longitudinal pitch dynamic cycle-averaged model is obtained and analyzed through the methods of neural network fitting and system identification,preparing for the design of flapping vibration suppression *** vibration is an inherent property of the tailless FWMAV,which arises from the influence of time-periodic aerodynamic forces and *** can be captured by attitude and position sensors on the plane,which impairs the flight performance and efficiency of flight controller and *** deal with this problem,a novel state observer for flapping vibration suppression is designed.A robust optimal controller based on the linear quadratic theory is also designed to stabilize the closed-loop *** results are given to verify the performance of the observer,including the closed loop responses combined with robust optimal controller,the comparison of different parameters of observer and the comparison with several classic methods,such as Kalman filter,H-infinity filter and low-pass filter,which prove that the novel observer owns a fairly good suppression effect on flapping vibration and benefits for the improvement of flight performance and control efficiency.

关键词： Flapping vibration Flapping wing Linear quadratic theory Robust control State observer

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Numerical investigation on the caving mechanism with different standard deviations of top coal block size in LTCC

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International journal of Mining Science and Technology 2020年第5期30卷 583-591页

作者： jiachen Wang Weijie Wei jinwang Zhang Brijes Mishra ang Li State Key Laboratory Coal Resources and Safe Mining China University of Mining and Technology-BeijingBeijing 100083China School of Energy and Mining Engineering China University of Mining and Technology-BeijingBeijing 100083China Coal Industry Engineering Research Center of Top-coal Caving Mining Beijing 100083China Department of Mining Engineering West Virginia UniversityMorgantownWV 26505USA

The size distribution of the broken top coal blocks is an important factor,affecting the recovery ratio and the efficiency of drawing top coal in longwall top coal caving(LTCC)mining *** standard deviation of top coal block size(dt)is one of the main parameters to reflect the size distribution of top *** find the effect of dt on the caving mechanism,this study simulates experiments with 9 different dt by using discrete element software *** dt is divided into two stages:uniform distribution stage(UDS)whose dt is less than 0.1(Schemes 1–5),and nonuniform distribution stage(NDS)whose dt is more than 0.1(Schemes 6–9).This research mainly investigates the variation of recovery ratio,drawing body shape,boundary of top coal,and contact force between particles in the two stages,*** results showed that with the increasing dt,the recovery ratio of the panel increases first and then decreases in *** is the largest in Scheme 3,which mainly increases the drawing volume at the side of starting drawing ***,the recovery ratio decreases first and then increases quickly in NDS,and it is the largest in Scheme 9,where the drawing volume at the side of finishing drawing end are relatively *** UDS,the major size of top coal is basically medium,while in NDS,the size varies from medium to small,and then to large,with a distinct difference in shape and volume of the drawing *** the major size of top coal is medium and small,the cross-section width of the initial boundary of top coal at each height is relatively ***,when the top coal size is large,the initial boundary of top coal has a larger opening range,the rotating angle of lower boundary is relatively small in the normal drawing stage,which is conducive to the development of drawing body and reduces the residual top coal,and the maximum particle velocity and the particles movement angle are both *** study lays a foundation for the prediction of recovery ratio,and sug

关键词： Longwall top coal caving mining Standard deviation of top coal size Recovery ratio Drawing body Boundary of top coal Contact force

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Real-time mosaicking for infrared videos from an oblique sweeping camera

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Chinese journal of Aeronautics 2021年第1期34卷 309-319页

作者： jiazhen LU Fangde SUN jing DONG Songlai HAN ang SU School of Aeronautics and Astronautics Central South UniversityChangsha 410083China Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Image mosaicking is widely used in Geographic Information Systems(GISs)for largescale ground surface ***,most existing mosaicking methods can only be used in offline processing due to the enormous amounts of *** this paper,we propose a novel and practical algorithm for real-time infrared video *** achieve this,a novel fast template matching algorithm based on Sum of Cosine Differences(SCD)is proposed to coarsely match the sequential *** high speed of the proposed template matching algorithm is obtained by computing correlation with Fast Fourier Transform(FFT).We also propose a novel fast Least Squares Matching(LSM)algorithm for inter-frame fine registration,which can significantly reduce the computation without degrading the matching *** addition,the proposed fast LSM can effectively adapt for noise degradation and geometric *** on the proposed fast template matching algorithm and fine registration algorithm,we develop a practical real-time mosaicking approach which can produce seamless mosaic image highly *** on synthetic and real-world datasets demonstrate that the proposed algorithm is not just computationally efficient but also robust against various noise distortions.

关键词： Fast Fourier transform Least squares matching Map fusion Mosaic Real-time Template matching

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Prognostic effect analysis of molecular subtype on young breast cancer patients

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Chinese journal of Cancer Research 2015年第4期27卷 428-436页

作者： Hong-Liang Chen ang Ding Fu-Wen Wang Department of Breast Surgery Obstetrics and Gynecology Hospital of Fudan University

Objective： To make a prognostic effect analysis of molecular subtype on young breast cancer ***： Totally 187 cases of young breast cancer patients less than 40 years old treated in Obstetrics and Gynecology Hospital of Fudan University between june 2005 and june 2011 were included in our study. We described their clinical-pathological characteristics, disease-free survival（DFS） rate, and overall survival（OS） rate after a median follow-up period of 61 months. The factors associated with prognosis were also evaluated by univariate and multivariate ***： All patients were premenopausal, with an average age of 35.36±3.88 years old. The mean tumor size was 2.43±1.53 cm. Eighty-one cases had lymph node metastasis（43.3%）, 126 cases had lymphovascular invasion（67.4%）, and 125 cases had histological grade III（66.8%） disease. Twenty-seven cases（14.4%） were Luminal A subtype, 99 cases（52.9%） were Luminal B subtype, 29 cases（15.5%） were human epidermal growth factor receptor 2（HER-2） overexpression subtype, while 32 cases（17.1%） were triple negative breast cancer（TNBC） subtype according to 2013 St Gallen expert consensus. One hundred and thirty-five cases underwent mastectomy whereas 52 cases had breast-conserving surgery. One hundred and seventy-eight cases underwent adjuvant or neoadjuvant chemotherapy. Recurrence or metastasis occurred in 29 cases, 13 of which died. The 5-year DFS and OS rates were 84% and 92%. Multivariate analysis showed that nodal status（P=0.041） and molecular subtype（P=0.037） were both independent prognostic factors of DFS, while nodal status（P=0.037） and TNBC subtype（P=0.048） were both independent prognostic factors of OS. Conclusions： Molecular subtype is an independent prognostic factor of young breast cancer patients. TNBC has a high risk of relapse and death.

关键词： Molecular subtype young breast cancer prognosis

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Strange star candidates revised within a quark model with chiral mass scaling

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Research in Astronomy and Astrophysics 2011年第4期11卷 482-490页

作者： ang Li Guang-Xiong Peng ju-Fu Lu Department of Physics and Institute of Theoretical Physics and Astrophysics Xiamen University Xiamen 361005 China Department of Physics Graduate University Chinese Academy of Sciences Beijing 100049 China

We calculate the properties of static strange stars using a quark model with chiral mass scaling. The results are characterized by a large maximum mass （-1.6 M⊙） and radius （-10km）. Together with a broad collection of modern neutron star models, we discuss some recent astrophysical observational data that could shed new light on the possible presence of strange quark matter in compact stars. We conclude that none of the present astrophysical observations can prove or confute the existence of strange stars.

关键词： dense matter -- elementary particles -- equation of state -- stars: inte-riors

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