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Combined effects of obstacle and fine water mist on gas explosion characteristics

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Chinese Journal of Chemical Engineering 2021年第12期34卷 131-140页

作者： Xiaoping Wen Mengming wang fahui wang Minggao Yu Haoxin Deng School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454003China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China

Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated *** this study,the diameter of the water mist,the location,and the number of obstacles was *** results demonstrated that 5 μm water mist present a significant suppression affected while 45 μm shows a slight promotion effected on a gas explosion of the condition without *** the presence of an obstacle,however,the inhibitory effect of 5 μm water veils of mist dropped significantly during flame propagation,and the effect of 45 μm water veils of mist changed from the enhancement of inhibition,and its inhibitory effect was *** inhibitory effect of 45 μm water veils of mist on gas explosion weakened firstly and then enhanced with the increasing distance between obstacle location from the ignition location as well as in several obstacles.

关键词： Fine water mist Gas explosion suppression Obstacle Couple effects

Numerical Investigation on Porous Media Quenching Behaviors of Premixed Deflagrating Flame using RANS/LES Model

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Journal of Thermal Science 2019年第4期28卷 780-788页

作者： WEN Xiaoping SU Tengfei LIU Zhigang XIE Maozhao wang fahui LIU Zhichao School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454003China Henan Key Laboratory for Green and Efficient Mining & Comprehensive Utilization of Mineral Resources Henan Polytechnic UniversityJiaozuo 454003China The Boiler & Pressure Vessel Safety Inspection Institute of Henan Province Jiaozuo 454000China School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China

To understand the mechanism of premixed flame quenching by porous media,a zonal hybrid RANS/LES model was employed,in which the LES flow solver was used to resolve the large turbulent structures within the non-porous region,while RANS was applied to porous media *** predicted results were compared with previous experimental *** it was evident that the premixed flame propagation rates and structure as well as quenching behaviors were reproduced by this numerical approach with a better *** to the inherently higher heat transfer coefficients between the solid and gas phases in porous media,the gas phase temperature has been decreased ***,upstream obstacles can cause the flame propagating faster and thus reduce the axial gas temperature gradients,resulting in the invalidity of the operation of premixed flame *** comparison with the case without upstream obstacle,the values of reaction rate attained in the case with three pairs of obstacles are higher,which makes a positive impact on the flame passing through the porous *** addition,the porous media with greater pore density has an excellent flame quenching property mainly owing to both the larger volumetric heat transfer and higher quenching temperature.

关键词： RANS/LES model porous media quenching flame propagation

Effect of Oxygen-Rich Combustion on Flame Propagation of Syngas in a Half-Open Pipe at Elevated Temperatures

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Journal of Thermal Science 2024年第5期33卷 1920-1934页

作者： LI Ningning DENG Haoxin XU Zhuangzhuang YAN Mengmeng WEI Shengnan SUN Guangzhen WEN Xiaoping GAN Haowen wang fahui School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454003China

The investigation of syngas flame propagation has great benefits for the effective use of gas *** essay sets out to study the flame propagation of premixed oxygen-rich combustion(oxygen enrichment coefficient in volumeΩ:0.21,0.27,0.32,0.37)of syngas(H_(2):CO=2:8)in half-closed rectangular ducts at elevated temperatures(T:300 K,400 K,500 K)and evaluate the effects of initial temperature and oxygen enrichment coefficient on the LBV from sensitivity analysis and kinetic *** paper presents the effect of the expansion effect on laminar burning velocity for the first time,and separates the effect of the expansion effect on laminar burning velocity by a new *** shows that as the initial temperature goes up,the faster the exponential growth phase of the flame front velocity,the slower the slow growth *** smaller and earlier the maximum flame front velocity arrives,the slower the average flame speed *** the oxygen enrichment coefficient goes up,the peak value of the flame front velocity gradually ***-rich combustion and increasing initial temperature inhibit flame propagation in a half-open tube,but promote laminar burning velocity,which increases the key chemical bond and adiabatic flame *** net reaction rate shows that oxygen-rich combustion mainly promotes the combustion reaction of H_(2)(R2).However,increasing the initial temperature mainly promoted the oxidation of CO(R29).Analysis of the reaction path showed that oxygen-rich combustion and increased initial temperature promoted the reaction of H_(2)and CO with key chemical bonds,increased OH concentration,and inhibited OH cracking reaction.

关键词： gas turbines oxyfuel combustion numerical simulation combustion kinetics fire and flame

Gd_(2)O_(3) nanoparticles modified g-C_(3)N_(4) with enhanced photocatalysis activity for degradation of organic pollutants

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Journal of Rare Earths 2021年第11期39卷 1353-1361,I0002页

作者： Yipeng Zhou Fanshan Zeng Chaoyang Sun Jun Wu Yu Xie Fayun Zhang Senlin Rao fahui wang Jinbing Zhang Jinsheng Zhao Shiqian Li School of New Energy Science and Engineering Xinyu UniversityXinyu 338004China College of Environment and Chemical Engineering Nanchang Hangkong UniversityNanchang 330063China College of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China School of Materials and Environmental Engineering Fujian Polytechnic Normal UniversityFuqing 350300China

Gd_(2) O_(3) nanoparticles modified g-C_(3) N_(4) photocatalytic composites were synthesized by a simple one-step hydrothermal *** structure,morphology,optical properties of the prepared photocatalyst were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),field emission transmission electron microscopy(FETEM) and X-ray photoelectron spectroscopy(XPS).The result demonstrates that gadolinium is mainly dispersed on the surface of g-C_(3) N_(4) in the form of Gd_(2) O_(3),and does not destroy the lattice structure of g-C_(3) N_(4).Besides,the gadolinium can cause the red shift of the absorption edge of light,narrow the band gap,and increase the separation efficiency of the photogenerated electron and hole of g-C_(3) N_(4).Especially,the specific surface area of g-C_(3) N_(4) can be significantly ***,g-C_(3) N_(4)/Gd-0.05 displays the highest photodegradation performance when it is used for degradation of methyl orange(MO),methylene blue(MB) and Rhodamine B(RhB).The photodegradation rate of g-C_(3) N_(4)/Gd-0.05 composites is 72.4% for MO,95.5% for RhB,100% for MB after120 min under visible light(λ> 420 nm) *** band gap promotes the separation of photogenerated electron and hole,which enhances the photocatalytic activity of g-C_(3) N_(4).It is noted that g-C_(3) N_(4)/Gd-0.05 exhibits excellent photocatalytic stability by the photocurrent and the cyclic photodegradation of MO.

关键词： Gd_(2)O_(3) g-C_(3)N_(4) Photocatalysis activity Visible light Hydrothermal method Rare earths

基于变权重PSO-Elman神经网络的路面附着系数估计

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浙江大学学报（工学版） 2024年第3期58卷 622-634页

作者：王骏骋王法慧浙江理工大学机械工程学院浙江杭州310018

针对传统神经网络权值更新不稳定导致路面附着系数预估精度不高的问题,提出基于变权重粒子群优化(PSO)-Elman神经网络的路面附着系数估计方法.搭建基于7自由度汽车动力学模型的神经网络模型,在Elman神经网络模型中引入粒子群算法降低训... 详细信息

针对传统神经网络权值更新不稳定导致路面附着系数预估精度不高的问题,提出基于变权重粒子群优化(PSO)-Elman神经网络的路面附着系数估计方法.搭建基于7自由度汽车动力学模型的神经网络模型,在Elman神经网络模型中引入粒子群算法降低训练绝对误差,并使用线性权重递减策略对粒子群算法中的权重进行改变,平衡粒子全局和局部搜索能力,实现网络权值矩阵优化;采用傅里叶函数方法拟合出理想滑移率-路面附着系数相关曲线;通过理论分析和仿真验证,证明采用该方法能够提升路面附着系数预估精度.仿真结果表明:在定附和变附路面行驶工况下,相比于传统Elman神经网络,采用变权重PSO-Elman神经网络的路面附着系数估计方法获得的路面附着系数均方根误差分别平均降低了35.62%和19.20%,有效提升了防抱死控制效果.

关键词：车辆状态路面附着系数神经网络粒子群防抱死控制

Population distribution patterns and changes in China 1953–2010: A regionalization approach

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Journal of Geographical Sciences 2019年第11期29卷 1908-1922页

作者： LIU Cuiling XU Yaping wang fahui Department of Geography and Anthropology Louisiana State University

This study uses six censuses (1953,1964,1982,1990,2000,and 2010) at the county level since the foundation of the People’s Republic of China to examine the changes of population density pattern in China's Mainland over *** on the Gini coefficient,the change of disparity in population density followed a “U-shaped” trend,i.e.,decreasing during 1953–1982 and increasing during 1982–*** shrinking disparity in the pre-reform periods was largely attributable to various ill-conceived political movements,and the enlarging gap in population growth rates in the post-reform era reflected a natural outcome of urbanization,which will continue in the foreseeable *** addition,this research employs a GIS-automated regionalization method,REDCAP,to uncover a natural demarcation line like the classic “Hu Line” that divides China into two regions of similar area sizes but a strong contrast in *** results show that the regionalization-derived lines were largely consistent with the Hu Line over ***,the disparity between the high-density southeast and low-density northwest regions is likely due to differing physical environments that form a natural *** public policy to overcome this barrier at a large scale is destined to be a vain attempt.

关键词： regional population distribution temporal change disparity Gini coefficient regionalization GIS Hu Line China

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社会科学和公共政策的空间化和GIS的应用

地理学报 2011年第8期66卷 1089-1100页

作者：王法辉美国路易斯安那州立大学地理与人类学系 usa70803

近年来社会科学的发展出现三大潮流,即"科学化"(强调借用自然科学的计量分析方法和模型)、"空间化"(关注社会经济现象的空间变化和相互作用)和"应用化"(侧重于政策性规划性强的实用课题)。空间化的社会科学,尤其是应用研究离不开地理信... 详细信息

近年来社会科学的发展出现三大潮流,即"科学化"(强调借用自然科学的计量分析方法和模型)、"空间化"(关注社会经济现象的空间变化和相互作用)和"应用化"(侧重于政策性规划性强的实用课题)。空间化的社会科学,尤其是应用研究离不开地理信息系统(GIS)方法的应用,因为GIS在整合、分析各种数据尤其是空间数据方面有独特优势。本文举例演示GIS在相关领域(如经济学、语言历史、社会学特别是犯罪学、公共卫生和规划)的广泛应用。选取的案例来源于笔者多年研究的经验,包括美国联邦政府多家研究机构(NSF、NIH、NIJ)资助的多项研究成果,旨在说明GIS在社会科学和公共政策研究中的应用价值。

关键词： GIS空间分析方法空间综合社会科学公共政策

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大数据驱动的人类移动模式和模型研究

武汉大学学报（信息科学版） 2014年第6期39卷 660-666页

作者：刘瑜康朝贵王法辉北京大学遥感与地理信息系统研究所北京100871 路易斯安那州立大学地理与人类学系巴吞鲁日路易斯安那州70803

大数据时代的到来使得基于个体粒度的海量时空轨迹获取人类移动模式成为可能。来自不同领域的学者基于手机通话数据、公交卡刷卡记录、社交网站签到数据、出租车轨迹、银行刷卡记录等进行了人类移动模式的研究,这些研究丰富了地理信息... 详细信息

大数据时代的到来使得基于个体粒度的海量时空轨迹获取人类移动模式成为可能。来自不同领域的学者基于手机通话数据、公交卡刷卡记录、社交网站签到数据、出租车轨迹、银行刷卡记录等进行了人类移动模式的研究,这些研究丰富了地理信息系统的时空分析方法,为从个体角度审视人与地理环境之间的交互关系提供了一个新视角,并可以应用于交通、公共卫生等领域。总结了基于大数据的人类移动模式研究流程,归纳了人类移动模式的基本度量方法,探讨了解释所观测移动模式的模型构建方法,指出了地理环境对于移动模型建立的影响。

关键词：大数据人类移动模式移动模型地理环境影响

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减压渣油的分离与评价

石油化工高等学校学报 2013年第1期26卷 33-35,67页

作者：王奎王法辉中国神华煤制油化工有限公司鄂尔多斯煤制油分公司内蒙古鄂尔多斯017209 中石化洛阳工程有限公司河南洛阳471003

采用超临界流体萃取分馏技术,将减压渣油分离成6个窄馏分和1个萃余残渣,对窄馏分的组成分布和结构进行了研究,为减压渣油的的合理加工提供重要基础数据。结果表明,随着窄馏分收率的增加,饱和分质量分数减小,胶质质量分数增大,芳香分质... 详细信息

采用超临界流体萃取分馏技术,将减压渣油分离成6个窄馏分和1个萃余残渣,对窄馏分的组成分布和结构进行了研究,为减压渣油的的合理加工提供重要基础数据。结果表明,随着窄馏分收率的增加,饱和分质量分数减小,胶质质量分数增大,芳香分质量分数先增大,达到最大值,再减小,各窄馏分中基本不含沥青质,残炭值、及金属元素含量逐渐增加,金属在最后几个窄馏分和残渣中有富集现象。用改进的Brown-Ladner法计算了各个窄馏分和原料的结构参数。

关键词：超临界减压渣油组成结构