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Interplay of S and As in Mekong Delta sediments during redox oscillations

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Geoscience Frontiers 2019年第5期10卷 1715-1729页

作者： Van t.H. Phan Fabrizio Bardelli Pierre le Pape Raoul-Marie Couture Alejandro Fernandez-Martinez Delphine tisserand Rizlan Bernier-Latmani Laurent Charlet University Grenoble Alpes CNRSIRDIFSTTARISTerre38000GrenobleFrance Ho Chi Minh City University of technology (HCMUt) Vietnam National UniversityHo Chi Minh City (VNU-HCM)268 Ly Thuong KietDistrict 10Ho Chi Minh CityViet Nam Institute of Nanotechnology (CNR-Nanotec) 00186RomeItaly Institut de Mineralogie de Physique des Materiaux et de Cosmochimie (IMPMC)UMR 7590 CNRS-UPMC-IRD-MNHN4 Place Jussieu75252Paris cedex 05France Département de chimie Université Laval1045 Avenue de la MédecineQuébecQCG1V 0A6Canada Ecole Polytechnique Fédérale de Lausanne (EPFL) e Environmental Microbiology Laboratory (EML) EPFL-ENAC-IIE-EMLStation 6CH-1015LausanneSwitzerland

the cumulative effects of periodic redox cycling on the mobility of As,Fe,and S from alluvial sediment to groundwater were investigated in bioreactor *** particular sediments from the alluvial floodplain of the Mekong Delta River were investigated: Matrix A (14 m deep) had a higher pyrite concentration than matrix B (7 m deep) *** present in matrix B but absent in matrix *** the reactors,the sediment suspensions were supplemented with As(III) and SO4^2-,and were subjected to three full-redox cycles entailing phases of nitrogen/CO2,compressed air sparging,and cellobiose *** differences in As concentration and speciation were observed upon redox *** support the fact that initial sediment composition is the main factor controlling arsenic release and its speciation during the redox ***,a high pyrite content associated with a low SO4^2- content resulted in an increase in dissolved As concentrations,mainly in the form of As(III),after anoxic half-cycles;whereas a decrease in As concentrations mainly in the form of As(V),was instead observed after oxic *** addition,oxic conditions were found to be responsible for pyrite and arsenian pyrite oxidation,increasing the As pool available for *** same processes seem to occur in sediment with the presence of gypsum,but,in this case,dissolved As were sequestered by biotic or abiotic redox reactions occurring in the FeeS system,and by specific physico-chemical condition (***).the contrasting results obtained for two sediments sampled from the same core show that many complexes and entangled factors are at work,and further refinement is needed to explain the spatial and temporal variability of As release to groundwater of the Mekong River Delta (Vietnam).

关键词： Redox oscillation Pyrite oxidation Gypsum dissolution Isotope sulfur Isotope oxygen

Experimental study on the tribo-chemical smoothening process between self-mated silicon carbide in a water-lubricated surfacecontact reciprocating test

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Friction 2019年第2期7卷 181-191页

作者： le JIN Herbert SCHEERER Georg ANDERSOHN Matthias OECHSNER Dieter HELLMANN Center for Structural Materials Technische Universit?t Darmstadt KSB

Silicon carbide(SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment. As well reported in the point-contact tests, this smoothening process works well due to the abundant water as oxidant. After this smoothening process, the tribo-surface is well polished, a closely mated tribo-gap naturally forms, and an ultra-low friction state is built. However, water in the tribo-gap could be insufficient in industrial applications, e.g., the seal gap in mechanical seals. In this study, the tribo-chemical smoothening behavior in such environment was researched. A surface-contact reciprocating test was used to simulate the aqueous environment where water was insufficient. After tests, compared to the published results from the point-contact tests, the same ultra-low friction state was achieved. A part of the tribo-surface was tribo-chemically smoothened. the obtained smoothened surface microstructure was consistent with the published information. Meanwhile, severe abrasive wear occurred. A porous oxygen-rich layer was found existing beneath the abrasion-induced grooves, in which numerous smashed wear debris adhered on the worn surfaces. We concluded that the shortage of water initiated the severe abrasion, meanwhile the generated wear debris aggravated the wear condition. this understanding is instructive for developing new methods to avoid the severe abrasion in the same water insufficient environment.

关键词： silicon carbide surface-contact sliding friction tribo-chemical smoothening abrasion ultra-low friction mechanical seal

Survival outcomes and predictors of mortality,re-bleeding and complications for acute severe variceal bleeding requiring balloon tamponade

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World Journal of Hepatology 2022年第8期14卷 1584-1597页

作者： Charlotte Y Keung Aparna Morgan Suong t le Marcus Robertson Paul Urquhart Michael P Swan Department of Gastroenterology Monash HealthMelbourne 3168VictoriaAustralia Department of Gastroenterology Eastern HealthMelbourne 3128VictoriaAustralia Department of Medicine Monash UniversityMelbourne 3168VictoriaAustralia Monash Digital therapeutics and Innovation Laboratory Monash UniversityMelbourne 3168VictoriaAustralia

BACKGROUND Acute severe variceal bleeding(AVB)refractory to medical and endoscopic therapy is infrequent but associated with high *** cohort studies from 1970-1980s no longer represent the current population as balloon tamponade is no longer first-line therapy for variceal bleeding;treatments including vasoactive therapies,intravenous antibiotics,endoscopic variceal band ligation are routinely used,and there is improved access to definitive treatments including transjugular intrahepatic portosystemic ***,only a few studies from the current era exist to describe the practice of balloon tamponade,its outcomes,and predictors with a requirement for further updated *** to describe current management of AVB requiring balloon tamponade and identify the outcomes and predictors of mortality,re-bleeding and *** A retrospective multi-centre cohort study of 80 adult patients across two large tertiary health networks from 2008 to 2019 in Australia who underwent balloon tamponade using a Sengstaken-Blakemore tube(SBt)were included for *** were identified using coding for balloon *** primary outcome of this study was all-cause mortality at 6 wk after the index *** outcomes included re-bleeding during hospitalisation and complications of balloon *** of these outcomes were determined using univariate and multivariate binomial *** the all-cause mortality rates during admission and at 6-,26-and 52 wk were 48.8%,51.2%and 53.8%,*** haemostasis was achieved in 91.3%and re-bleeding during hospitalisation occurred in 34.2%.Independent predictors of 6 wk mortality on multivariate analysis included the Model for Endstage Liver disease(MELD)score(OR 1.21,95%CI 1.06-1.41,P=0.006),advanced hepatocellular carcinoma(OR 11.51,95%CI 1.61-82.20,P=0.015)and re-bleeding(OR 13.06,95%CI 3.06-55.71,Pthere were no relevant predictors of re-bleeding but a larg

关键词： Balloon tamponade Acute variceal bleeding Sengstaken-Blakemore tube Mortality Complications Haemostasis

A Sensor-Service Collaboration Approach for target tracking in Wireless Camera Networks

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China Communications 2017年第7期14卷 44-56页

作者： Shuai Zhao le Yu State Key Laboratory of Networking and Switching technology Beijing University of Posts and Telecommunications China Mobile Information Security Center

Mobile target tracking is a necessary function of some emerging application domains, such as virtual reality, smart home and intelligent healthcare. However, existing portable devices for target tracking are resource intensive and high-cost. Camera tracking is an effective location tracking way for those emerging applications which can reuse the existing ubiquitous video monitoring system. this paper proposes a dynamic community-based camera collaboration(D3C) framework for target location and tracking. the contributions of D3C mainly include that(1) nonlinear perspective projection model is selected as the camera sensing model and sequential Monte Carlo is employed to predict the target location;(2) a dynamic collaboration scheme is proposed, it is based on the local community-detection theory deriving from social network analysis. the performance of proposed approach is validated by both synthetic datasets and real-world application. the experiment results show that D3C meets the versatility, real-time and fault tolerance requirements of target tracking applications.

关键词： service collaboration camera tracking community detection sequential monte carlo

Simulation of FY-2D infrared brightness temperature and sensitivity analysis to the errors of WRF simulated cloud variables

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Science China Earth Sciences 2018年第7期61卷 957-972页

作者： Xiaokang SHI Yaodong LI Jianwen LIU Xizi XIANG le LIU Beijing Aviation Meteorological Institute Beijing 100085China Guizhou Sub-bureau of Southwest Air traffic Management Bureau of Civil Aviation of China Guiyang 550002China Guangxi Meteorological Observatory Nanning 530022China

this study simulated FY-2 D satellite infrared brightness images based on the WRF and RttOV models. the effects of prediction errors in WRF micro-and macroscale cloud variables on FY-2 D infrared brightness temperature accuracy were analyzed. the principle findings were as follows. In the t+0–48 h simulation time, the root mean square errors of the simulated brightness temperatures were within the range 10–27 K, i.e., better than the range of 20–40 K achieved previously. In the t+0–24 h simulation time, the correlation coefficients between the simulated and measured brightness temperatures for all four channels were >0.5. the simulation performance of water channel IR3 was stable and the best. the four types of cloud microphysical scheme considered all showed that the simulated values of brightness temperature in clouds were too high and that the distributions of cloud systems were incomplete, especially in typhoon areas. the performance of the tHOM scheme was considered best, followed in descending order by the WSM6, WDM6, and LIN schemes. Compared with observed values, the maximum deviation appeared in the range 253–273 K for all schemes. On the microscale, the snow water mixing ratio of the tHOM scheme was much bigger than that of the other schemes. Improving the production efficiency or increasing the availability of solid water in the cloud microphysical scheme would provide slight benefit for brightness temperature simulations. On the macroscale, the cloud amount obtained by the scheme used in this study was small. Improving the diagnostic scheme for cloud amount, especially high-level cloud, could improve the accuracy of brightness temperature simulations. these results could provide an intuitive reference for forecasters and constitute technical support for the creation of simulated brightness temperature images for the FY-4 satellite.

关键词： FY-2D RttOV WRF Simulated brightness temperature Cloud amount Cloud microphysics scheme typhoonMatmo

Properties of the Main Phases of the Super Geomagnetic Storms(ΔSYM-H≤-250 nt)with Different Heliolongitudes

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Research in Astronomy and Astrophysics 2023年第1期23卷 76-82页

作者： Ming-Xian Zhao Gui-Ming le Yong-Hua Liu Key Laboratory of Space Weather National Satellite Meteorological Center(National Center for Space Weather)China Meteorological AdministrationBeijing 100081China School of Physics Science&technology Lingnan Normal UniversityZhanjiang 524048China Innovation Center for FengYun Meteorological Satellite(FYSIC) Beijing 100081China CAS Key Laboratory of Solar Activity National Astronomical ObservatoriesBeijing 100101China Polar Research Institute of China Shanghai 200136China

We studied the properties of the main phases of 24 super geomagnetic storms(SGSs)(ΔSYM-H≤-250 nt)since *** divided the SGSs into two subgroups:SGSs-Ⅰ(-400 nt<ΔSYM-H≤-250 nt)and SGSs-Ⅱ(ΔSYM-H≤-400 nt).Of the 24... 详细信息

We studied the properties of the main phases of 24 super geomagnetic storms(SGSs)(ΔSYM-H≤-250 nt)since *** divided the SGSs into two subgroups:SGSs-Ⅰ(-400 ntt)and SGSs-Ⅱ(ΔSYM-H≤-400 nt).Of the 24 SGSs,16 are SGSs-Ⅰand eight are SGSs-Ⅱ.the source locations of SGSs were distributed in the longitudinal scope of[E37,W66].95.8%of the SGSs were distributed in the longitudinal scope of[E37,W20].East and west hemispheres of the Sun had 14 and 10 SGSs,*** durations of the main phases for six SGSs ranged from 2 to 4 *** durations of the main phases for the rest 18 SGSs were longer than 6.5 *** duration of the SGSs with source locations in the west hemisphere varied from 2.22 to 19.58 *** duration for the SGSs with the source locations in the east hemisphere ranged from 2.1 to31.88 *** averaged duration of the main phases of the SGSs in the west and east hemispheres are 8.3 hr and13.98 hr,respectively.|ΔSYM-H/Δt|for six SGSs with source locations distributed in the longitudinal area ranging from E15 to W20 was larger than 1.0 nt·minute^(-1),while|ΔSYM-H/Δt|for the rest 18 SGSs was lower than 1.0 nt·minute^(-1).|ΔSYM-H/Δt|for SGSs-Ⅰvaried from 0.18 to 3.0 nt·minute^(-1).|ΔSYM-H/Δt|for eight SGSs-Ⅱvaried from 0.37 to 2.2 nt·minute^(-1)with seven SGSs-Ⅱfalling in the scope from 0.37 to0.992 nt·minute^(-1).

关键词： the Sun-(Sun:)solar-terrestrial relations-(Sun:)solar wind

transcriptome sequencing analysis of ursolic acid-mediated proliferation suppression on cutaneous t-cell lymphoma cells

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traditional Medicine Research 2023年第2期8卷 36-44页

作者： Cheng Wang Peng-Cheng Ma Bao-le Cai Hong-Yang Li Ling-Jun Li Pharmacal Research Laboratory Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIsInstitute of DermatologyChinese Academy of Medical SciencesPeking Union Medical CollegeNanjing 210042China Department of Dermatology Zhongda Hospital Southeast UniverstiyNanjing 210009China

Background:Ursolic acid is a triterpenoid compound found in natural plants that exhibits antiproliferative effects in various cancer *** study is the first to demonstrate the strong inhibitory effects of ursolic acid on the proliferation of cutaneous t-cell lymphoma(CtCL)*** aimed to further investigate the underlying mechanism of the proliferation inhibition induced by ursolic acid in CtCL cells using transcriptome ***:Cell counting kit-8 assays were used to observe the effects of six traditional medicine monomers on the proliferation of CtCL *** sequencing was used to identify differentially expressed genes after ursolic acid *** analysis was performed to determine the potential ***-time quantitative PCR and western blotting analyses were performed to confirm the sequencing results and verify the possible mechanisms of ursolic acid-mediated proliferation inhibition in CtCL ***:Ursolic acid exhibited the strongest inhibitory effect on the proliferation of CtCL cells among the six traditional medicine *** sequencing analysis showed that 2,466 genes were significantly *** with Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis and protein-protein interaction network analysis,the interaction of various pathways and signaling molecules,such as tumor necrosis factor-α,NLR family pyrin domain containing 1,c-Jun N-terminal kinase,and melanoma differentiation-associated gene 5,accounted for the anti-tumor effects of ursolic acid in CtCL ***:Ursolic acid significantly inhibited the proliferation of CtCL cells,and our study laid a theoretical foundation for the future treatment of CtCL using ursolic acid.

关键词： ursolic acid cutaneous t-cell lymphoma transcriptome sequencing proliferation apoptosis

Rupture of a rubber sheet by a cavitation bubble:an experimental study

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Acta Mechanica Sinica 2021年第10期37卷 1489-1497,I0001页

作者： Xing-Yu Kan Jia-le Yan Shuai Li A-Man Zhang College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China

Dynamics of spark-generated cavitation bubbles near a deformable rubber sheet are experimentally investigated in this *** transient bubble–rubber interaction is captured by high-speed photography,including the expansion and collapse of the bubble,jetting behaviors,large deformation,and rupture of the rubber *** dependence of bubble behaviors and rubber response on two governing parameters(the bubble–rubber stand-off distanceγand the rubber thickness t)are systematically ***,the bubble collapse patterns or jetting directions are categorized into three *** the bubble is initially located at a largeγfrom the rubber sheet,the jet is directed towards the boundary(regime I).Unexpectedly,when the generated bubble is close to the rubber sheet,it develops a jet away from the boundary(regime III).Bubble splitting and the formation of two axial liquid jets directing in opposite directions can only be observed with an intermediateγ(regime II).A phase diagram of the bubble behaviors is given in theγ–t *** a large rubber sheet thickness(e.g.,t=5 mm),only a downward jet is *** the perspective of jet direction,the effect of such a thick rubber sheet on the bubble dynamics is similar to that of a rigid *** that the jet velocity and jet width may be slightly ***,the results reveal that bubble expansion can cause the boundary to *** strong axial jet towards the rubber sheet can damage and even rupture the rubber boundary.A parameter range within which the bubble jetting can rupture the rubber boundary is ***,for a thin rubber sheet(t≤4 mm),the rupture is more likely to occur in regime *** a thick rubber sheet(e.g.,t=5 mm),the rupture can be seen when the jet directly impacts the rubber sheet(regime I).

关键词： Bubble dynamics Rubber boundary Rupture High-speed photography

A new iterative algorithm for geolocating a known altitude target using tDOA and FDOA measurements in the presence of satellite location uncertainty

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Chinese Journal of Aeronautics 2015年第5期28卷 1510-1518页

作者： Cao Yalu Peng Li Li Jinzhou Yang le Guo Fucheng School of Internet of things (Io t) Engineering Jiangnan University College of Electronic Science and Engineering National University of Defense Technology Synergetic Innovation Center of Food Safety and Nutrition

this paper considers the problem of geolocating a target on the Earth surface whose altitude is known previously using the target signal time difference of arrival （tDOA） and frequency difference of arrival （FDOA） measurements obtained at satellites. the number of satellites available for the geolocation task is more than sufficient and their locations are subject to random errors. this paper derives the constrained Cramor-Rao lower bound （CCRLB） of the target position, and on the basis of the CCRLB analysis, an approximately efficient constrained maximum likelihood estimator （CMle） for geolocating the target is established. A new iterative algorithm for solving the CMle is then proposed, where the updated target position estimate is shown to be the globally optimal solution to a generalized trust region sub-problem （GtRS） which can be found via a simple bisection search. First-order mean square error （MSE） analysis is conducted to quantify the performance degradation when the known target altitude is assumed to be precise but indeed has an unknown but deterministic error. Computer simulations are used to compare the performance of the proposed iterative geolocation technique with those of two benchmark algorithms. they verify the approximate efficiency of the proposed algorithm and the validity of the MSE analysis.

关键词： Constrained Cram6r-Raolower bound (CCRLB):Frequency difference ofarrival (FDOA) Generalized trust regionsub-problem (GtRS):Performance analysis:time difference of arrival(tDOA)