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Effect of proximal contact strength on the three-dimensional displacements of implant-supported cantilever fixed partial dentures under axial loading

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第6期14卷 526-532页

作者： zhen-zhen peng Xin-min CHEN Jun WANG Ai-jie LI Zu-jie XU State Key Laboratory of Oral Diseases West China Hospital of StomatologySichuan University

Objective:This study investigated the effect of proximal contact strength on the three-dimensional displacements of cantilever fixed partial denture(CFPD) under vertically concentrated loading with digital laser speckle(DLS) ***:Fresh mandible of beagle dog was used to establish the implant-supported CFPD for *** technique was employed for measuring the three-dimensional displacement of the prosthesis under vertically concentrated loading ranging from 200 to 3 000 *** effect of the contact tightness on the displacement of CFPD was investigated by means of changing the contact ***:When an axial concentrated loading was exerted on the pontic of the implant-supported CFPD,the displacement of the CFPD was the *** displacement of the prosthesis decreased with the increase of contact *** the contact strength was 0,0.95,and 3.25 N,the displacement of the buccolingual direction was smaller than that of the mesiodistal direction but greater than that of the occlusogingival *** the force on the contact area was 6.50 N,the mesiodistal displacement of the prosthesis was the biggest while the buccolingual displacement was the ***:The implant supported CFPD is an effective therapy for fully or partially edentulous *** restoration of the contact area and the selection of the appropriate contact strength can reduce the displacement of the CFPD,and get a better stress *** most appropriate force value is 3.25 N in this study.

关键词： Cantilever fixed partial denture Digital laser speckle technique Contact strength Three-dimensional displacement

Novel strategy of nitrogen removal from domestic wastewater using pilot Orbal oxidation ditch

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Journal of Environmental Sciences 2006年第5期18卷 833-839页

作者： GAO Shou-you peng Yong-zhen WANG Shu-ying YAN Jun School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China. College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China

A pilot-scale Orbed oxidation ditch was operated for 17 months to optimize nitrogen removal from domestic wastewater of average COD to total nitrogen ratio of 2.7, with particular concern about the roles of dissolved oxygen （DO）, mixed liquor suspended solids （MLSS） and return activated sludge （RAS） recycle ratio. Remarkable simultaneous nitrification and denitrification （SND） was observed and mean total nitrogen （TN） removal efficiency up to 72.1% was steadily achieved, at DO concentration in the out, middle and inner channel of 0.1, 0.4 and 0.7 mg/L, respectively, with an average M LSS of 5.5 g/L and RAS recycle ratio of 150%. Although the out channel took the major role in TN removal, the role of middle channel should never be ignored. The denitrification potential could be fully developed under low DO, high MLSS with adequate RAS ratio. The sludge settleability was amazingly improved under low DO operation mode, and some explanations were tried. In addition, a scries of simplified batch tests were done to determine whether novel microorganisms could make substantial contribution to the performance of nitrogen removal. The results indicated that the SND observed in this Orbal oxidation ditch was more likely a physical phenomenon.

关键词： nitrogen removal simultaneous nitrification and denitrification low DO MLSS novel bacterial

An Inexact Affine Scaling Levenberg-Marquardt Method Under Local Error Bound Conditions

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Acta Mathematicae Applicatae Sinica 2019年第4期35卷 830-844页

作者： Zhu-jun WANG Li CAI Yi-fan SU zhen peng School of Computational Science and Electronics Hunan Institute of Engineering Xiangtan 411104 China Shanghai Research Institute of Microwave Equipment Shanghai 200063 China School of Mathematics and Computational Science Xiangtan University Xiangtan 411104 China

We propose an inexact affine scaling Levenberg-Marquardt method for solving bound-constrained semismooth equations under the local error bound assumption which is much weaker than the standard nonsingularity condition. The affine scaling Levenberg-Marquardt equation is based on a minimization of the squared Euclidean norm of linearized model adding a quadratic affine scaling matrix to find a solution which belongs to the bounded constraints on variable. The global convergence and the superlinear convergence rate are *** results show that the new algorithm is efficient.

关键词： semismooth equation Levenberg-Marquardt method inexact method affine scaling local error bounds

Amorphous urchin-like copper@nanosilica hybrid for efficient CO_(2) electroreduction to C2+ products

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Journal of Energy Chemistry 2021年第10期30卷 290-296,I0009页

作者： Rui Yang Zipeng Zeng zhen peng Jiafang Xie Yiyin Huang Yaobing Wang CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsState Key Laboratory of Structural ChemistryKey Laboratory of Optoelectronic Materials Chemistry and PhysicsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002FujianChina Dalian National Laboratory for Clean Energy Dalian 116023LiaoningChina

Currently most of research efforts for selective electrocatalysis CO_(2) reduction to C2+products have relied on crystalline Cu-based catalysts;amorphous Cu with abundant low-coordinated atoms holds greater promise for this conversion yet remains relatively *** we report an amorphous urchin-like Cu@nanosilica hybrid synthesized by electrostatic coupling Si polyanions with Cu salt in hydrothermal *** Cu@nanosilica electrocatalyst displays excellent CO_(2) electroreduction activity and selectivity with a Faradic efficiency of 70.5%for C2+product production,and higher stability compared to the crystalline Cu *** solar-driven CO_(2) electrolysis yields an energy efficiency of 20%for C2+product *** study reveals that the urchin-like Cu@nanosilica catalyst with amorphous Cu/Cu^(+)dispersion enhances CO_(2) adsorption and activation to facilitate generation of CO_(2)^(-)*and possible CO^(*)intermediates,and suppresses hydrogen evolution *** combined effects of both aspects promote efficient C2+product production from CO_(2) electroreduction.

关键词： Copper Amorphous Catalyst CO_(2)electroreduction C2+products

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国人全膝置换术股骨远端截骨面解剖参数测量

中国矫形外科杂志 2024年第10期32卷 954-957页

作者：杨波陈明吴学元常彦海雷鹏真陕西省人民医院骨科陕西西安710068

[目的]应用三维CT重建测量正常国人膝关节股骨远端截骨面解剖形态学参数,为国产人工膝关节股骨假体的设计提供参考依据。[方法]2022年3月—2022年10月对187例(男94例,女93例)汉族正常膝关节进行CT三维重建,测量股骨内外径(medial-latera... 详细信息

[目的]应用三维CT重建测量正常国人膝关节股骨远端截骨面解剖形态学参数,为国产人工膝关节股骨假体的设计提供参考依据。[方法]2022年3月—2022年10月对187例(男94例,女93例)汉族正常膝关节进行CT三维重建,测量股骨内外径(medial-lateral,ML)、股骨前后径(anterior-posterior,AP)、股骨内侧髁宽度(medial condyle width,MCW)、股骨外侧髁宽度(lateral condyle width,LCW)、股骨髁间窝宽度(width of intercondylar fossa,WICF)、股骨髁间窝高度(height of intercondylar fossa,HICF),并计算ML/AP比值,比较各参数性别差异及相关性。[结果]股骨远端各解剖数据测量值男性均显著大于女性(P<0.05)。股骨远端截骨面测量值中除MCW与WICF(r=0.087,P=0.236)、LCW与WICF(r=0.052,P=0.478)、HICF与ML/AP(r=0.023,P=0.757)之间无显著的相关关系,其余各测量值均存在显著正相关(P<0.05)。股骨远端ML/AP与AP成显著负相关(P<0.05),随着AP的增大ML/AP减小。在相同AP值下,男性股骨ML/AP显著大于女性(P<0.05)。[结论]国人股骨远端截骨面男性和女性存在尺寸和形态的差异,在设计股骨假体时,ML/AP应该考虑作为参考设计性别差异性股骨假体。

关键词：股骨远端膝关节置换 CT三维重建性别差异

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不同船体破口对水流出流特性影响研究

舰船科学技术 2024年第1期46卷 21-27页

作者：何振鹏刘明远李敏堂姚连峥中国民航大学航空工程学院天津300300 陆军军事交通学院军事交通运输研究所天津300161

利用冲击动力学仿真,构建多种类型的船体破口,将冲击仿真所得的船体破口形状耦合进构建的多相流计算模型中,按照069型和067型登陆艇面临的实际堵漏环境,分析不同形状船体破口、不同尺寸船体破口、不同翻边船体破口的水流出流特性。研究... 详细信息

利用冲击动力学仿真,构建多种类型的船体破口,将冲击仿真所得的船体破口形状耦合进构建的多相流计算模型中,按照069型和067型登陆艇面临的实际堵漏环境,分析不同形状船体破口、不同尺寸船体破口、不同翻边船体破口的水流出流特性。研究表明,翻边撕裂较深的破口形状出流距离要远;外翻边破口的水流出流距离呈现先小于后大于内翻边破口的规律;400 mm、300 mm和200 mm破口相比同时刻下的出流距离相差较小,但冲击压强的稳定值相差较大,400 mm破口为34700 Pa,比300 mm破口大1300 Pa,比200 mm破口大5700 Pa。研究可为船体破损后的堵漏密封作业提供精准的数据支撑,也可为新型堵漏器材的设计提供技术指导。

关键词：船体破口水流出流水动力学

Accounting for CO2 Variability over East Asia with a Regional Joint Inversion System and Its Preliminary Evaluation

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Journal of Meteorological Research 2017年第5期31卷 834-851页

作者： xingxia kou xiangjun tian meigen zhang zhen peng xiaoling zhang institute of urban meteorology china meteorological administrationBeijing 100089 state key laboratory of atmospheric boundary layer physics and atmospheric chemistry institute of atmospheric physicschinese academy of sciencesBeijing 100029 international center for climate and environment sciences institute of atmospheric physicschinese academy of sciencesNanjing 210093 school of atmospheric sciences nanjing university school of atmospheric sciences chengdu university of information technologyChengdu 610225

A regional surface carbon dioxide （C02） flux inversion system, the Tan-Tracker-Region, was developed by incor- porating an assimilation scheme into the Community Multiscale Air Quality （CMAQ） regional chemical transport model to resolve fine-scale CO2 variability over East Asia. The proper orthogonal decomposition-based ensemble four-dimensional variational data assimilation approach （POD-4DVar） is the core algorithm for the joint assimilation framework, and simultaneous assimilations of CO2 concentrations and surface CO2 fluxes are applied to help reduce the uncertainty in initial CO2 concentrations. A persistence dynamical model was developed to describe the evolu- tion of the surface CO2 fluxes and help avoid the ＂signal-to-noise＂ problem; thus, CO2 fluxes could be estimated as a whole at the model grid scale, with better use of observation information. The performance of the regional inversion system was evaluated through a group of single-observation-based observing system simulation experiments （OSSEs）. The results of the experiments suggest that a reliable performance of Tan-Tracker-Region is dependent on certain assimilation parameter choices, for example, an optimized window length of approximately 3 h, an ensemble size of approximately 100, and a covariance localization radius of approximately 320 km. This is probably due to the strong diurnal variation and spatial heterogeneity in the fine-scale CMAQ simulation, which could affect the perform- ance of the regional inversion system. In addition, because all observations can be artificially obtained in OSSEs, the performance of Tan-Tracker-Region was further evaluated through different densities of the artificial observation net- work in different CO2 flux situations. The results indicate that more observation sites would be useful to systematic- ally improve the estimation of CO2 concentration and flux in large areas over the model domain. The work presented here forms a foundation for future research in w

关键词： surface CO2 flux inversion proper orthogonal decomposition (PDO) four-dimensional variational dataassimilation (4DVar) joint assimilation regional transport model

Association discovery and outlier detection of air pollution emissions from industrial enterprises driven by big data

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Data Intelligence 2023年第2期5卷 438-456页

作者： zhen peng Yunxiao Zhang Yunchong Wang Tianle Tang China University of Geosciences Beijing School of Economics and ManagementBeijing 100038China Beijing Institute of Petrochemical Technology School of Economics and ManagementBeijing 102617China

Air pollution is a major issue related to national economy and people's *** present,the researches on air pollution mostly focus on the pollutant emissions in a specific industry or region as a whole,and is a lack of attention to enterprise pollutant emissions from the micro *** by the amount and time granularity of data from enterprises,enterprise pollutant emissions are stll *** by big data of air pollution emissions of industrial enterprises monitored in Beijing-Tianjin-Hebei,the data mining of enterprises pollution emissions is carried out in the paper,including the association analysis between different features based on grey association,the association mining between different data based on association rule and the outlier detection based on *** results show that:(1)The industries affecting NOx and SO2 mainly are electric power,heat production and supply industry,metal smelting and processing industries in Beijing-Tianjin-Hebei;(2)These districts nearby Hengshui and Shijiazhuang city in Hebei province form strong association rules;(3)The industrial enterprises in Beijing-Tianjin-Hebei are divided into six clusters,of which three categories belong to outliers with excessive emissions of total vOCs,PM and NH3 respectively.

关键词： Air Pollution Emissions of Enterprises Outlier detection based on clustering Association Rule Mining Grey Association Analysis Big data

The Aerosol Radiative Effect on a Severe Haze Episode in the Yangtze River Delta

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Journal of Meteorological Research 2017年第5期31卷 865-873页

作者： Kai SUN Hongnian LIU Xueyuan WANG zhen peng Zhe XIONG School of Atmospheric Sciences Nanjing University Key Laboratory of Climate–Environment for East Asia Institute of Atmospheric Physics Chinese Academy of Sciences

Due to increased aerosol emissions and unfavorable weather conditions, severe haze events have occurred fre- quently in China in the last 10 years. In addition, the interaction between the boundary layer and the aerosol radiative effect may be another important factor in haze formation. To better understand the effect of this interaction, the aero- sol radiative effect on a severe haze episode that took place in December 2013 was investigated by using two WRF- Chem model simulations with different aerosol configurations. The results showed that the maximal reduction of re- gional average surface shortwave radiation, latent heat, and sensible heat during this event were 88, 12, and 37 W m2, respectively. The planetary boundary layer height, daytime temperature, and wind speed dropped by 276 m, I^C, and 0.33 m s-l, respectively. The ventilation coefficient dropped by 8%-24% for in the central and northwestern Yangtze River Delta （YRD）. The upper level of the atmosphere was warmed and the lower level was cooled, which stabilized the stratification. In a word, the dispersion ability of the atmosphere was weakened due to the aerosol radi- ative feedback. Additional results showed that the PM2.5 concentration in the central and northwestern YRD in- creased by 6-18 p.g m3, which is less than 15% of the average PM2.5 concentration during the severely polluted peri- od in this area. The vertical profile showed that the PM2.5 and PM10 concentrations increased below 950 hPa, with a maximum increase of 7 and 8 gg m-3, respectively. Concentrations reduced between 950 and 800 hPa, however, with a maximum reduction of 3.5 and 4.5 p.g rn-3, respectively. Generally, the aerosol radiative effect aggravated the level of pollution, but the effect was limited, and this haze event was mainly caused by the stagnant meteorological condi- tions. The interaction between the boundary layer and the aerosol radiative effect may have been less important than the large-scale static weather condit

关键词： haze aerosol radiative effect Yangtze River Delta ventilation coefficient PM2.5 WRF-Chem