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Game theoretic analysis of environmental impact assessment system in China

CHENG Hongguang, PU Xiao, GONG Li, QI Ye

《环境科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 448-453 doi: 10.1007/s11783-007-0071-8

摘要: Environmental impact assessment (EIA) system has been established in China since 1973. In present EIA cases, there are four participants in general: governments, enterprises, EIA organizations and the public. The public has held re

关键词: public     impact assessment     Environmental impact     general    

The clinical impact of tricuspid regurgitation in patients with a biatrial orthotopic heart transplant

《医学前沿(英文)》 2023年 第17卷 第3期   页码 527-533 doi: 10.1007/s11684-022-0967-5

摘要: In this study, we aim to elucidate the clinical impact and long-term course of tricuspid regurgitation (TR), taking into account its dynamic nature, after biatrial orthotopic heart transplant (OHT). All consecutive adult patients undergoing biatrial OHT (1984−2017) with an available follow-up echocardiogram were included. Mixed-models were used to model the evolution of TR. The mixed-model was inserted into a Cox model in order to address the association of the dynamic TR with mortality. In total, 572 patients were included (median age: 50 years, males: 74.9%). Approximately 32% of patients had moderate-to-severe TR immediately after surgery. However, this declined to 11% on 5 years and 9% on 10 years after surgery, adjusted for survival bias. Pre-implant mechanical support was associated with less TR during follow-up, whereas concurrent LV dysfunction was significantly associated with more TR during follow-up. Survival at 1, 5, 10, 20 years was 97% ± 1%, 88% ± 1%, 66% ± 2% and 23% ± 2%, respectively. The presence of moderate-to-severe TR during follow-up was associated with higher mortality (HR: 1.07, 95% CI (1.02–1.12), p = 0.006). The course of TR was positively correlated with the course of creatinine (R = 0.45). TR during follow-up is significantly associated with higher mortality and worse renal function. Nevertheless, probability of TR is the highest immediately after OHT and decreases thereafter. Therefore, it may be reasonable to refrain from surgical intervention for TR during earlier phase after OHT.

关键词: orthotopic heart transplant     tricuspid regurgitation     clinical impact     biatrial heart transplantation    

Dynamical analysis of droplet impact spreading on solid substrate

Zhaomiao LIU, Huamin LIU, Xin LIU,

《机械工程前沿(英文)》 2010年 第5卷 第3期   页码 308-315 doi: 10.1007/s11465-010-0020-2

摘要: This paper investigates the impact spreading of a droplet on a solid substrate using numerical simulation on the basis of a volume-of-fluid (VOF) model. The process of droplet spreading is described, the analysis of low speed and high speed droplet spreading, and more than one droplet spreading simultaneously is performed. The pressure, velocity, and spreading factor during the droplet spreading are reported. According to the spreading factor’s evolvement, the process of droplet spreading can be classified into spreading phase and recoiling phase. The spreading factors are almost the same at the low speed droplet spreading; however, the pressures on the substrate are quite different and air entrainment may be found as the impact speeds in a certain range. The impact speed impacts on the spreading factors in high speed droplet spreading. The spreading factor obviously increases with increasing impact speed; however, splashing will appear in the status when the speed is high enough in the high speed droplet spreading. The distance between the neighbor droplets affects the film’s quality, and only the distance between the static diameter and the maximum diameter can ensure the film’s quality. The results could help in understanding the process of droplet spreading and provide advice on the operation of a spray coating process.

关键词: droplet     impact spreading     numerical simulation    

Comparison of droplet distributions from fluidic and impact sprinklers

Xingye ZHU,Shouqi YUAN,Junping LIU,Xingfa LIU

《农业科学与工程前沿(英文)》 2015年 第2卷 第1期   页码 53-59 doi: 10.15302/J-FASE-2015049

摘要: To adapt to the trend toward low-energy precision irrigation, the droplet distributions for two new prototype sprinklers, outside signal sprinkler (OS) and fluidic sprinkler (FS), were compared with impact sprinkler (IS). A laser precipitation monitor was used to measure the droplet distributions. Droplet size and velocity distributions were tested under four operating pressures for nozzles 1.5 m above the ground. For the operating pressures tested, the mean OS, FS and IS droplet diameters ranged from 0 to 3.4, 0 to 3.5, 0 to 4.0 mm, respectively. The mean OS and FS droplet velocities ranged from 0 to 6.3 m·s , whereas IS ranged from 0 to 6.3 m·s . Being gas-liquid fluidic sprinklers, droplet distributions of the OS and FS were similar, although not identical. IS mostly produced a 0.5 mm larger droplet diameter and a 0.5 m·s greater velocity than OS and FS. A new empirical equation is proposed for determination of droplet size for OS and FS, which is sufficiently accurate and simple to use. Basic statistics for droplet size and velocity were performed on data obtained by the photographic methods. The mean droplet diameter (arithmetic, volumetric and median) decreased and the mean velocity increased in operating pressure for the three types of sprinkler.

关键词: outside signal sprinkler     fluidic sprinkler     impact sprinkler     sprinkler irrigation     droplet size     droplet velocity    

Mechanical properties and impact resistance of concrete composites with hybrid steel fibers

Fatih ÖZALP; Halit Dilşad YILMAZ; Burcu AKCAY

《结构与土木工程前沿(英文)》 2022年 第16卷 第5期   页码 615-623 doi: 10.1007/s11709-022-0828-y

摘要: The aim of this study is to develop concrete composites that are resistant to armor-piercing projectiles for defense structures. Different reinforcement configurations have been tested, such as short steel fibers, long steel fibers, and steel mesh reinforcement. Three different concrete mix designs were prepared as “Ultra High Performance (UHPFRC), High Performance (HPFRC) and Conventional (CFRC) Fiber Reinforced Concrete”. The content of hybrid steel fibers was approximately 5% in the UHPFRC and HPFRC mixtures, while the steel fiber content was approximately 2.5% in the CFRC mixture. In addition, a plain state of each mixture was produced. Mechanical properties of concrete were determined in experimental studies. In addition to the fracture energy and impact strength, two important indicators of ballistic performance of concrete are examined, which are the penetration depth and damage area. The results of the study show that the depth of penetration in UHPFRC was around 35% less than that in HPFRC. It was determined that the mixtures of UHPFRC and HPFRC containing 5% by volume of hybrid steel fibers showed superior performance (smaller crater diameter and the less projectile penetration depth) against armor-piercing projectiles in ballistic tests and could be used in defense structures.

关键词: projectile impact     depth of penetration     fracture energy     crater diameter     UHPFRC    

Hazard potential of zones of weakness in gravity dams under impact loading conditions

Herbert LINSBAUER

《结构与土木工程前沿(英文)》 2011年 第5卷 第1期   页码 90-97 doi: 10.1007/s11709-010-0008-3

摘要: Dam constructions worldwide are designed and constructed in view of the strictest safety aspects for all static and dynamic load cases. As experience shows, however, formation of cracks in the “homogeneos concrete” as well as unsatisfactory compound behavior of lift joints are not to be excluded. These zones of weakness especially on the upstream side of the dam— exposed to high water pressure (static and dynamic)— represent an increased risk of safety. The main investigation, apart from the computation of the dynamic effects on the dam as a global structure, focuses on the stability analysis of a pressure-water filled crack configuration subjected to “dynamic loading” in the form of seismic action on the dam-reservoir-system and alternatively by “impact spot-loading” within sectors of the reservoir. A fracture mechanics based analysis shows an excessive potential of damage for the afflicted structure.

关键词: dam-reservoir     earthquake     impact     cracking     fracture mechanics    

Buffer capacity of granular matter to impact of spherical projectile based on discrete element method

Ying YAN, Pengfei LI, Shunying JI

《结构与土木工程前沿(英文)》 2013年 第7卷 第1期   页码 50-54 doi: 10.1007/s11709-013-0186-x

摘要: Granular matter possesses impact-absorbing property due to its energy dissipation character. To investigate the impact-absorbing capacity of granular matter, the discrete element method (DEM) is adopted to simulate the impact of a spherical projectile on to a granular bed. The dynamic responses of the projectile are obtained for both thin and thick granular bed. The penetration depth of the projectile and the first impact peak are investigated with different bed thicknesses and impact velocities. Determining a suitable bed thickness is crucial to the buffering effect of granular matter. The first impact peak is independent of bed thickness when the thickness is larger than the critical thickness.

关键词: granular matter     impact peak     buffer capacity     discrete element method     critical thickness    

Water film coated composite liquid metal marble and its fluidic impact dynamics phenomenon

Yujie DING,Jing LIU

《能源前沿(英文)》 2016年 第10卷 第1期   页码 29-36 doi: 10.1007/s11708-015-0388-0

摘要: A composite liquid metal marble made of metal droplet coated with water film was proposed and its impact dynamics phenomenon was disclosed. After encapsulating the liquid metal into water droplets, the fabricated liquid marble successfully avoided being oxygenized by the metal fluid and thus significantly improved its many physical capabilities such as surface tension modification and shape control. The striking behaviors of the composite liquid metal marbles on a substrate at room temperature were experimentally investigated in a high speed imaging way. It was disclosed that such marbles could disintegrate, merge, and even rebound when impacting the substrate, unlike the existing dynamic fluidic behaviors of liquid marble or metal droplet. The mechanisms lying behind these features were preliminarily interpreted. This fundamental finding raised profound multiphase fluid mechanics for understanding the complex liquid composite which was also critical for a variety of practical applications such as liquid metal jet cooling, inkjet printed electronics, 3D printing or metal particle fabrication etc.

关键词: liquid metal marble     metallic droplet     composite fluid     impact dynamics     multiphase fluid mechanics    

Dynamic characteristics of a shrouded blade with impact and friction

Xumin GUO, Jin ZENG, Hui MA, Chenguang ZHAO, Lin QU, Bangchun WEN

《机械工程前沿(英文)》 2020年 第15卷 第2期   页码 209-226 doi: 10.1007/s11465-019-0566-6

摘要: A simplified computational model of a twisted shrouded blade with impact and friction is established. In this model, the shrouded blade is simulated by a flexible Timoshenko beam with a tip-mass, and the effects of centrifugal stiffening, spin softening, and Coriolis force are considered. Impact force is simulated using a linear spring model, and friction force is generated by a tangential spring model under sticking state and a Coulomb friction model under sliding state. The proposed model is validated by a finite element model. Then, the effects of initial gap and normal preload, coefficient of friction, and contact stiffness ratio (the ratio of tangential contact stiffness to normal contact stiffness) on system vibration responses are analyzed. Results show that resonant peaks become inconspicuous and impact plays a dominant role when initial gaps are large between adjacent shrouds. By contrast, in small initial gaps or initial normal preloads condition, resonant speed increases sharply, and the optimal initial normal preloads that can minimize resonant amplitude becomes apparent. Coefficient of friction affects the optimal initial normal preload, but it does not affect vibration responses when the contact between shrouds is under full stick. System resonant amplitude decreases with the increase of contact stiffness ratio, but the optimal initial normal preload is unaffected.

关键词: twisted shrouded blade     dynamic analysis     impact     friction     separate–stick–slip motion    

RESEARCH PROGRESS ON THE IMPACT OF NITROGEN DEPOSITION ON GLOBAL GRASSLANDS

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 425-444 doi: 10.15302/J-FASE-2022457

摘要:

● Grasslands in many regions of the world have been impacted by atmospheric nitrogen deposition.

关键词: Acidification     biomass production     critical load     eutrophication     species composition     species richness    

Corporate governance impact on banking risk

Mahdi JEMMALI, Bassem SALHI

《工程管理前沿(英文)》 2020年 第7卷 第2期   页码 182-195 doi: 10.1007/s42524-019-0034-3

摘要: This study aims to determine the relationship between several factors of governance and the level of risk in 10 Tunisian banks during an analysis period of eight years. We propose an important empirical question and examine the internal mechanisms of governance aimed at reducing financial risks. This estimation is based on a model with a single equation that examines variables relative to governance and credit risk to determine their impact on banking financials. Results demonstrate that the internal mechanisms of governance present diverging effects on the financial risk of the Tunisian banks in our case study (i.e., credit risk). Moreover, making applications work by putting together a process and model for banking risk is important. This model can be applied in any bank, and the results can be used to make decisions in real time.

关键词: bank governance     banking risk     process decision     modeling     architecture    

Parameter studies on impact in a lap joint

Amir M. RAHMANI,Elizabeth K. ERVIN

《机械工程前沿(英文)》 2015年 第10卷 第1期   页码 64-77 doi: 10.1007/s11465-014-0322-x

摘要:

To represent a loose lap joint, a beam impacting four springs with gaps is modeled. Modal analysis with base excitation is solved, and time histories of contact points are closely monitored. Using the impulse during steady state response, six influential parameters are studied: damping ratio, contact stiffness, intermediate contact position, gap, excitation amplitude and beam height. For all parameters, the system response is highly controlled by modes with two contacting springs. Each parameter’s effect on system response is presented including unstable regions, unique trend behaviours result. Recommendations for structural designers are also noted.

关键词: impact mechanics     contact     joint behaviour     modal analysis     parameter study    

Fatigue and impact analysis and multi-objective optimization design of Mg/Al assembled wheel considering

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0701-7

摘要: The multi-material assembled light alloy wheel presents an effective lightweight solution for new energy vehicles, but its riveting connection remains a problem. To address this problem, this paper proposed the explicit riveting-implicit springback-implicit fatigue/explicit impact sequence coupling simulation analysis method, analyzed the fatigue and impact performance of the punching riveting connected magnesium/aluminum alloy (Mg/Al) assembled wheel, and constructed some major evaluation indicators. The accuracy of the proposed simulation method was verified by conducting physical experiments of single and cross lap joints. The punching riveting process parameters of the assembled wheel joints were defined as design variables, and the fatigue and impact performance of the assembled wheel was defined as the optimization objective. The connection-performance integration multi-objective optimization design of the assembled wheel considering riveting residual stress was designed via Taguchi experiment, grey relational analysis, analytic hierarchy process, principal component analysis, and entropy weighting methods. The optimization results of the three weighting methods were compared, and the optimal combination of design variables was determined. The fatigue and impact performance of the Mg/Al assembled wheel were effectively improved after optimization.

关键词: magnesium/aluminum assembled wheel     riveting residual stress     fatigue analysis     impact analysis     multi-objective optimization    

Impact resistance property

Heming LIN, Dongming QI, Jian HAN, Zhiqi CAI, Minghua WU

《化学科学与工程前沿(英文)》 2009年 第3卷 第2期   页码 176-181 doi: 10.1007/s11705-009-0203-8

摘要: A novel phenolic rigid organic filler (KT) was used to modify isotactic polypropylene (iPP). The influence of KT particles on the impact resistance property of PP/KT specimens (with similar interparticles distance, 1.8 μm) was studied by notched izod impact tests. It was found that the brittle-ductile transition (BDT) of the PP/KT microcomposites took place at the filler content of about 4%, and the impact strength attains the maximum at 5% (with filler particles size of 1.5 μm), which is about 2.5 times that of unfilled iPP specimens. The impact fracture morphology was investigated by scanning electron microscopy (SEM). For the PP/KT specimens and the high-density polyethylene/KT (HDPE/KT) specimens in ductile fracture mode, many microfibers could be found on the whole impact fracture surface. It was the filler particles that induced the plastic deformation of interparticles ligament and hence improved the capability of iPP matrix on absorbing impact energy dramatically. The determinants on the BDT were further discussed on the basis of stress concentration and debonding resistance. It can be concluded that aside from the interparticle distance, the filler particles size also plays an important role in semicrystalline polymer toughening.

关键词: rigid organic filler     polypropylene     impact resistance    

Assessing the impact on groundwater safety of inter-basin water transfer using a coupled modeling approach

Haifeng JIA,Shidong LIANG,Yansong ZHANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 84-95 doi: 10.1007/s11783-014-0741-2

摘要: Surface water and groundwater always behave in a coupled manner and are major components of hydrologic cycle. However, surface water simulation models and groundwater simulation models are run separately most of the time. Few models focus on the impact of hydraulic changes in the surface water flows on the groundwater, or specifically, the impact of a water transfer project to fill a seasonally dry channel. In this study, a linked surface water and groundwater simulation model was developed to assess the impact of a trans-basin water diversion project on the groundwater. A typical plain area east of Beijing was selected as a case study, representing Beijing’s main source of groundwater used for drinking water. A surface water quality model of the Chaobai River was developed based on the Water Quality Analysis Simulation Program (WASP), and a groundwater model was developed based on the Modular Finite-Difference Groundwater Flow Model (MODFLOW) and the Modular 3-D transport model (MT3D). The results of the surface water simulation were used as input for the groundwater simulation. Water levels and four contaminants (NH -N, COD , F, As) were simulated. With the same initial and boundary conditions, scenario analyses were performed to quantify the impact of different quantities of diversion water on the groundwater environment. The results showed the water quality of the groundwater sources was not significantly affected.

关键词: surface water     groundwater     linked model     groundwater safety impact assessment     water diversion    

标题 作者 时间 类型 操作

Game theoretic analysis of environmental impact assessment system in China

CHENG Hongguang, PU Xiao, GONG Li, QI Ye

期刊论文

The clinical impact of tricuspid regurgitation in patients with a biatrial orthotopic heart transplant

期刊论文

Dynamical analysis of droplet impact spreading on solid substrate

Zhaomiao LIU, Huamin LIU, Xin LIU,

期刊论文

Comparison of droplet distributions from fluidic and impact sprinklers

Xingye ZHU,Shouqi YUAN,Junping LIU,Xingfa LIU

期刊论文

Mechanical properties and impact resistance of concrete composites with hybrid steel fibers

Fatih ÖZALP; Halit Dilşad YILMAZ; Burcu AKCAY

期刊论文

Hazard potential of zones of weakness in gravity dams under impact loading conditions

Herbert LINSBAUER

期刊论文

Buffer capacity of granular matter to impact of spherical projectile based on discrete element method

Ying YAN, Pengfei LI, Shunying JI

期刊论文

Water film coated composite liquid metal marble and its fluidic impact dynamics phenomenon

Yujie DING,Jing LIU

期刊论文

Dynamic characteristics of a shrouded blade with impact and friction

Xumin GUO, Jin ZENG, Hui MA, Chenguang ZHAO, Lin QU, Bangchun WEN

期刊论文

RESEARCH PROGRESS ON THE IMPACT OF NITROGEN DEPOSITION ON GLOBAL GRASSLANDS

期刊论文

Corporate governance impact on banking risk

Mahdi JEMMALI, Bassem SALHI

期刊论文

Parameter studies on impact in a lap joint

Amir M. RAHMANI,Elizabeth K. ERVIN

期刊论文

Fatigue and impact analysis and multi-objective optimization design of Mg/Al assembled wheel considering

期刊论文

Impact resistance property

Heming LIN, Dongming QI, Jian HAN, Zhiqi CAI, Minghua WU

期刊论文

Assessing the impact on groundwater safety of inter-basin water transfer using a coupled modeling approach

Haifeng JIA,Shidong LIANG,Yansong ZHANG

期刊论文