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Influence of volar margin of the lunate fossa fragment fixation on distal radius fracture outcomes:A retrospective series

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World Journal of Clinical Cases 2021年第24期9卷 7022-7031页

作者： Hua Meng Jia-Zhi Yan Bing Wang zong-bo ma Wei-bo Kang Bao-Ge Liu Department of Orthopedic Surgery Beijing Tiantan HospitalCapital Medical UniversityBeijing 100050China

BACKGROUND Distal radius fractures accompanied by the volar margin of the lunate fossa(VMLF)lesions are often overlooked or inadequately reduced in clinical *** To investigate the impact of VMLF fragment in distal radius fractures on the stability and function of the wrist *** This was a retrospective study of patients with distal radius fractures who underwent surgical treatment between January 2013 and December *** patients were divided into two groups according to whether the VMLF fragments were fixed or not.X-rays and computed tomography were performed before surgery,immediately postoperatively,and at 1,3,and 6 mo to measure the scapholunate angle,radiolunate angle,capitolunate angle,and effective radiolunate flexion(ERLF).The mayo wrist score and disabilities of the arm,shoulder,and hand(DASH)score were determined at 1 *** Thirty-five patients were *** were 15 males and 20 *** mean age was 52.5±14.3(range:19-70)*** were 38 wrists(17 on the left side,15 on the right,and three bilateral;16 in the fixed group,and 22 in the unfixed group).The interval between trauma and surgery was from 1 h to 1 *** incidence of postoperative wrist instability in the unfixed group(86.4%)was higher than in the fixed group(25.0%)(P≤0.001).Ten patients had ERLF>25°in the unfixed group and none in the fixed group(P=0.019).The mayo wrist score was 94±5.7 in the fixed group and 68±15.1 in the unfixed group(Pmall fractures,might damage the radial-lunar ligament,leading to postoperative wrist instability,sagittal force line imbalance,and poor recovery of wrist joint function.

关键词： Radius fractures Lunate bone Reduction Disability Wrist function

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Catalysis by subsurface metal atoms in Al(001) through electron transfer

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National Science Review 2024年第4期11卷 12-13页

作者： bo Sun Ding ma Beijing National Laboratory for Molecular Science New Cornerstone Science Laboratory College of Chemistry and Molecular Engineering Peking University

Heterogeneous catalysis plays a crucial role in the chemical industry, which has evolved from the investigation of chemisorption to an electronic structure[1]. Diverse strategies, such as alloying,doping, and confining, have been applied to enhance the catalytic properties of active sites through electronic modulation. The electron transfer between active sites and substrates profoundly influences catalytic activity [2].

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Short-term Association of Meteorological Elements on COVID-19 Pandemic in a Semi-arid City of Northwest China,2021-2022

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Biomedical and Environmental Sciences 2024年第5期37卷 537-542页

作者： FENG Feng Liu ma Yu Xia CHENG bo Wen LIU zong Rui ZHAO Yu Han YANG Jie College of Atmospheric Sciences Key Laboratory of Semi-Arid Climate ChangeMinistry of EducationLanzhou UniversityLanzhou 730000GansuChina Minhe Meteorological Bureau Minhe 810800QinghaiChina

The coronavirus disease 2019(COVID-19)outbreak in late 2019 significantly impacted global *** virus’s rapid spread,with its long incubation period and high infection level,caused substantial disruption to regular social frameworks,production,and lifestyles^([1]).COVID-19 is primarily transmitted through close contact,long-range contaminants,and airborne routes.

关键词： Northwest COV primarily

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Access to High-Molecular-Weight Polyethylenes through High Temperature Ethylene Polymerization Catalysed by Ethylene-Bridged ansa-(3-R-Cyclopentadienyl)(Fluorenyl) Zirconocene Complexes

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Chinese Journal of Polymer Science 2024年第1期42卷 42-51,I0007页

作者： bo Li Haiyan ma Jiling Huang Shanghai Key Laboratory of Functional materials Chemistry and Laboratory of Organometallic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of C1-symmetric ethylene-bridged ansa-(3-R-cyclopentadienyl)(fluorenyl) metallocene complexes(Zr: 1-5;Hf: 6) have been synthesized, characterized and investigated as catalyst precursors for the high temperature ethylene polymerization. Using methylaluminoxane(maO) as the cocatalyst, zirconium complexes 1-5 bearing a bulky substituent on the 3-position of the cyclopendienyl ring showed high catalytic activities up to 1.48×10^(7) g PE·mol_(Zr)^(-1)·h^(-1) toward the polymerization of ethylene and afforded polyethylenes with high molecular weights(1.49×10^(5)-6.31×10^(5) g/mol), meanwhile exhibting great thermal stability at high temperatures up to 120 ℃ together with a long catalytic life time up to 2 h. By adopting low Al/Zr ratios, such as 125, polyethylenes with ultra high molecular weights up to 2.86×106 g/mol were obtained. It is worthy of noting that zirconium complexes 1-4 bearing a substituent with an aryl pendant showed temperature-dependent activities, which increased rapidly with the increase of polymerization temperature, thus weak interaction of the pendent aryl group with the cationic active center is proposed to account for the very low activities displayed at low temperatures. In contrast to zirconocene complexes 1-5, hafnocene complex 6 only displayed very low catalytic activities toward the polymerization of ethylene and afforded polyethylenes with molecular weights ten times smaller than those obtained by zirconocene complexes 1-5. Zirconocene complexes 1-5 were also able to catalyse the polymerization of propylene at high temperatures, but only afforded waxes with low molecular weights.

关键词： ansa-Metallocene Ethylene Propylene Polymerization High temperature

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Catalytic recycling of polyesters via a binuclear catalyst

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Science China Chemistry 2024年第2期67卷 426-427页

作者： bo Sun Ding ma Beijing National Laboratory for Molecular Science New Cornerstone Science LaboratoryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

Plastics play a crucial role in modern society life. While the increasing use of plastics and rapid accumulation of plastic waste in nature environment have caused severe environmental crisis and the waste of carbon resources. Catalytic upcycling is a promising approach to transform plastic waste into high value-added chemicals to achieve a sustainable circular economy.

关键词： Catalytic polyester catalyst

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Development of a convolutional neural network based geomechanical upscaling technique for heterogeneous geological reservoir

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2111-2125页

作者： Zhiwei ma Xiaoyan Ou bo Zhang Earth and Environmental Sciences Division Los Alamos National LaboratoryLos AlamosUSA Civil and Environmental Engineering University of AlbertaEdmontonCanada

Geomechanical assessment using coupled reservoir-geomechanical simulation is becoming increasingly important for analyzing the potential geomechanical risks in subsurface geological ***,a robust and efficient geomechanical upscaling technique for heterogeneous geological reservoirs is lacking to advance the applications of three-dimensional(3D)reservoir-scale geomechanical simulation considering detailed geological ***,we develop convolutional neural network(CNN)proxies that reproduce the anisotropic nonlinear geomechanical response caused by lithological heterogeneity,and compute upscaled geomechanical properties from CNN *** CNN proxies are trained using a large dataset of randomly generated spatially correlated sand-shale realizations as inputs and simulation results of their macroscopic geomechanical response as *** trained CNN models can provide the upscaled shear strength(R^(2)>0.949),stress-strain behavior(R^(2)>0.925),and volumetric strain changes(R^(2)>0.958)that highly agree with the numerical simulation results while saving over two orders of magnitude of computational *** is a major advantage in computing the upscaled geomechanical properties directly from geological realizations without the need to perform local numerical simulations to obtain the geomechanical *** proposed CNN proxybased upscaling technique has the ability to(1)bridge the gap between the fine-scale geocellular models considering geological uncertainties and computationally efficient geomechanical models used to assess the geomechanical risks of large-scale subsurface development,and(2)improve the efficiency of numerical upscaling techniques that rely on local numerical simulations,leading to significantly increased computational time for uncertainty quantification using numerous geological realizations.

关键词： Upscaling Lithological heterogeneity Convolutional neural network(CNN) Anisotropic shear strength Nonlinear stressestrain behavior

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Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization

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Rare Metals 2024年第5期43卷 2093-2102页

作者： bo Peng Zi-Hao Zhou Ping Xuan Jie Xu Lian-bo ma School of materials Science and Engineering Anhui University ofTechnologyMa'anshan 243002China Anhui Product Quality Supervision&Inspection Research Institute Hefei 230051China

Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered ***,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle *** study prepared a multitude of Na_(x)MnO_(2)(x=0.7,0.8,0.9)cathode materials with varying P2/O'3 ratios and further investigated their electrochemical *** optimized Na_(0.8)MnO_(2) comprising 69.9 wt%O'3 and 30.1 wt%P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle ***,it achieved a high specific capacity of 128.9 mah·g^(-1) with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na_(0.8)MnO_(2)//hard carbon full cell also achieved a high specific capacity of 126.7 mah·g^(-1) with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray *** findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关键词： Sodium-ion batteries Cathode materials Mn-based layered oxides P2/0'3 composites

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Extreme precipitation detection ability of four high-resolution precipitation product datasets in hilly area:a case study in Nepal

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Advances in Climate Change Research 2024年第3期15卷 390-405页

作者： Sunil Subba Yao-Ming ma Wei-Qiang ma Cun-bo Han Land-Atmosphere Interaction and its Climatic Effects Group State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Atmospheric Science Lanzhou UniversityLanzhou 730000China National Observation and Research Station for Qomolongma Special Atmospheric Processes and Environmental Changes Dingri 858200China Kathmandu Center of Research and Education Chinese Academy of SciencesBeijing 100101China China-Pakistan Joint Research Center on Earth Sciences Chinese Academy of SciencesIslamabad 45320Pakista

Given Nepal's vulnerability to extreme precipitation(EP),it is imperative to conduct a comprehensive analysis to comprehend the historical trends of such ***,acquiring precise precipitation data for EP remains challenging in mountainous countries like Nepal owing to the scarcity of densely gauged *** limitation impedes the dissemination of knowledge pertaining to EP variability events in *** current research on this topic is deficient for two main reasons:1)there is a lack of studies leveraging recently released high-resolution precipitation products to identify their EP detection capabilities,which further hinders the usability of those products in data-scarce regions like Nepal,and 2)most studies have focused on the characterisation of EP events in Nepal rather than their spatial and temporal *** address these issues,this study evaluated the EP detection capabilities of four high-resolution precipitation product datasets(PPDs)across Nepal from 1985 to *** datasets include the ERA5 Land reanalysis data,satellite-based precipitation data(PERSIANN_CCS_CDR and CHIRPS_V2.0)and a merged dataset(TPHiPr).We used various statistical and categorical indices to assess their ability to capture the spatial and temporal variability of EP *** annual EP events were characterised by 11 indices divided into frequency and intensity *** TPHiPr merged dataset offered a robust depiction of monthly precipitation estimates,achieving the highest critical success index,accuracy,probability of detection and a low false alarm ratio for daily precipitation detection of 0.1 mm in ***,the PERSIANN_CCS_CDR dataset exhibited poor *** PPDs showed increasing trends in EP ***,the TPHiPr dataset showcased those trends with fewer errors and stronger correlations for many frequency(R10mm,R20mm and R25mm)and intensity(RX1day,RX5day,PRCPTOT and R99p)*** results indicate that TPHiPr outperformed ot

关键词： Extreme precipitation Precipitation product Nepal TPHiPr ERA5 land PERSIANN_CCS_CDR CHIRPS_V2.0

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Detecting the distribution of and public attitudes to charismatic alien species based on media coverage

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Avian Research 2024年第3期15卷 379-384页

作者： Yuexuan Liu Ruichang Sun bo Li Zhijun ma Shanghai Institute of Infectious Disease and Biosecurity Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringNational Observations and Research Station for Wetland Ecosystems of the Yangtze Estuaryand Institute of Eco-Chongming(SIEC)School of Life SciencesFudan UniversityShanghai200433China Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology Institute of BiodiversitySchool of Ecology and Environmental ScienceYunnan UniversityKunming650504YunnanChina

Charismatic species are often reported by the media,providing information for detecting population status and public *** identify the number and distribution of free-living Black Swan(Cygnus atratus),a charismatic alien species in Chinese mainland and to detect the public and the media attitudes to the species,we analyzed the reports and emotional tendency from media coverage in 2000-2022 using manual reading,crawler extraction and latent Dirichlet allocation.A total of 6654 Black Swans were reported at 711 sites,including 147 individuals at 30 nature *** breeding was reported at one-fourth of the total sites,including five nature *** proportion of positive emotional tendency to Black Swans was overwhelming in the reports and was higher than that to alien species in general,suggesting that the public and the media are unaware of the risk of biological *** management of invasive species requires the media clarifies the invasion risk of charismatic alien *** the unity between the harmfulness of abstract concept of alien species and the charisma of a specific alien species among the public help effective management.

关键词： Alien species Biological invasion Cygnus atratus Emotional tendency Invasive species Media coverage Public perception

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Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

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Petroleum Science 2024年第2期21卷 1149-1170页

作者： Yu-Fei Chen Hui Zhang Wen-Xin Wu Jun Li Yong Ouyang zong-Yu Lu De-Xin ma Yong-Chuan Wu Jun-bo Liu Ke-Rou Liu Zhuo-Xin Dong China University of Petroleum(Beijing) Beijing102249China Beijing Normal University at Zhuhai Experimental and Practical Education Innovation CenterZhuhai519087GuangdongChina Oil&Gas Technology Research Institute of PetroChina Changqing Oilfield Company Xi'an710016ShaanxiChina PetroChina Xinjiang Oilfield Company Karamay834002XinjiangChina China Oilfield Services Ltd. Tianjin300459China

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(borehole near the step surface and causes a stuck pipe directly. If the flow rate increases to the “low flow rate” interval(33-35 L/s in Case 4), a smaller flow rate instead facilitates borehole cleaning. If the flow rate is large enough to be in the “high flow rate” interval(>35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than

关键词： Backreaming Stuck pipe Hole cleaning Transient solid transport Multiple flow patterns

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