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Quantitative insights into the critical role of potential-dependent(electro)chemical steps in ammonia electrosynthesis via constant-potential microkinetic simulations 认领 引用
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作者 Xingshuai Lv Pei Zhao +2 位作者 Yan Liang Thomas Frauenheim Liangzhi Kou 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2026年第2期148-158,共11页
Electric fields play a pivotal role in renewable energy technologies and are essential for enabling a sustainable future.However,the regulation of macroscale catalytic behavior by electric fields has not been well dig... Electric fields play a pivotal role in renewable energy technologies and are essential for enabling a sustainable future.However,the regulation of macroscale catalytic behavior by electric fields has not been well digitally understood yet,as conventional computational models rely on reaction energy profiles that overlook the nonlinear effects of electric fields on elementary reaction steps.Here,we use advanced constant-potential microkinetic simulations to revisit the electrochemical nitrogen reduction reaction(eNRR)under operating conditions,which makes it possible to explicitly integrate both electrochemical and chemical steps and quantitatively predict the effects of electric fields on eNRR macroscale performance.The theoretical activity trends for different metals were successfully reproduced with our model,which are in good qualitative agreement with experimental observations.Furthermore,we propose a new theoretical protocol for eNRR catalyst screening where an optimal catalyst should exhibit overwhelming N2 adsorption ability over a wide potential range to sufficiently facilitate eNRR at high potentials.Interestingly,the rate-determining step undergoes dynamic evolution with potential variations,with chemical steps imposing fundamental constraints on practical ammonia(NH3)electrosynthesis.Microkinetic simulations demonstrate that incorporating *NH3 desorption steps can alter reaction rates by orders of magnitude,highlighting their critical yet often overlooked role.This work establishes a quantitative framework for achieving accurate,physically realistic theoretical simulations in heterogeneous electrochemistry. 展开更多
关键词 Electrochemistry Non-electrochemical steps Constant potential model Potential-dependent free energy Microkinetic modeling
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Key Steps and Catalyst Performance for Conversion of Cellulose to Isosorbide: AReview 认领 引用
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作者 Dan Wang Jihuan Song +2 位作者 Qiyuan Wang Chenmeng Cui Ying Yang 《Journal of Renewable Materials》 EI CAS 2025年第1期49-78,共30页
Upgrading of abundant cellulosic biomass to isosorbide can reduce the dependence on limited fossil resources and provide a sustainable way to produce isosorbide,utilized for polymers,medicine and health care product s... Upgrading of abundant cellulosic biomass to isosorbide can reduce the dependence on limited fossil resources and provide a sustainable way to produce isosorbide,utilized for polymers,medicine and health care product synth-esis.This review comprehensively examines the key steps and catalytic systems involved in the conversion of cel-lulose to isosorbide.Initially,the reaction pathway from cellulose to isosorbide is elucidated,emphasizing three critical steps:cellulose hydrolysis,glucose hydrogenation,and the two-step dehydration of sorbitol to produce isosorbide.Additionally,the activation energy and acidic sites during cellulose hydrolysis,the impact of metal particle size and catalyst support on hydrogenation,and the effects of catalyst acidity,pore structure,and reaction conditions on sorbitol dehydration have been thoroughly examined.Finally,the progress made in cellulose con-version to isosorbide is summarized,current challenges are highlighted,and future development trends are pro-jected in this review. 展开更多
关键词 Cellulose isosorbide reaction pathway key steps catalytic systems
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欧洲“Early Steps体育课程体系”的框架、特点及启示 认领 引用 被引量：2
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作者 杨希 孙佳惠 《陕西学前师范学院学报》 2025年第9期50-57,共8页
欧洲ESPEC课程遵循“在体育活动中学习和通过体育活动学习”的理念,将体育活动中的直接学习与间接学习相结合,制定了社会与健康并重的双维化课程目标,构建了从单一技能到综合能力的递进式内容体系,采用情境化与趣味性驱动的课程实施过程... 欧洲ESPEC课程遵循“在体育活动中学习和通过体育活动学习”的理念,将体育活动中的直接学习与间接学习相结合,制定了社会与健康并重的双维化课程目标,构建了从单一技能到综合能力的递进式内容体系,采用情境化与趣味性驱动的课程实施过程,注重多主体与多维反馈的课程评估。其主要特色在于依托具身认知理念,构筑多领域融合的体育学习目标;坚持儿童中心,探索高效且有趣的体育活动路径;着眼终身发展,激发幼儿主动参与体育活动的内在动机;借助动态评估,持续优化幼儿体育学习的社会支持体系。据此,我国幼儿体育教育应破解技能化、碎片化等问题,通过构建“运动+”整合型幼儿体育课程,设计递进式、游戏化的内容体系,教师角色从“指令者”转向“支持者”,建立全周期、多主体的课程反馈机制等方面,实现理念革新、内容优化、实施转型和评估完善,助力幼儿体育教育高质量发展。 展开更多
关键词 Early Steps体育课程体系 体育教育 幼儿园
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Recovery of waste rare earth fluorescent powders by two steps acid leaching 认领 引用 被引量：19
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作者 Shen-Gen Zhang Min Yang +2 位作者 Hu Liu De-An Pan Jian-Jun Tian 《Rare Metals》 SCIE EI CAS CSCD 2013年第6期609-615,共7页
The effects of the acid leaching and alkali fusion on the leaching efficiency of Y,Eu,Ce,and Tb from the waste rare earth fluorescent powders were investigated in this paper.The results show that hydrochloric acid is ... The effects of the acid leaching and alkali fusion on the leaching efficiency of Y,Eu,Ce,and Tb from the waste rare earth fluorescent powders were investigated in this paper.The results show that hydrochloric acid is better than sulfuric acid in the first acid leaching,and NaOH is better than Na2CO3in the alkali fusion.In the first acid leaching,the Wloss is 20.94%when the waste rare earth fluorescent powders are acid leached in H?concentration 3 mol L-1and S/L ratio 1:3 for 4 h due to red powders dissolved.The better results of the alkali fusion can be got at 800℃ for 2 h when the NaOH is used.The blue powders and the green powders can be dissolved into NaAlO2and oxides such as rare earth oxide(REO).The REO can be dissolved in H?concentration 5 mol L-1,S/L1:10 for 3 h in the second acid leaching.The leaching rates of the Y,Eu,Ce,and Tb are 99.06%,97.38%,98.22%,and 98.15%,respectively.The leaching rate of the total rare earth is 98.60%. 展开更多
关键词 Waste rare earth fluorescent powders Two steps acid leaching Alkali fusion
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疏散模拟软件STEPS与Pathfinder对比研究 认领 引用 被引量：47
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作者 杜长宝 朱国庆 李俊毅 《消防科学与技术》 CAS 北大核心 2015年第4期456-460,共5页
为了了解两款疏散模拟软件STEPS与Pathfinder的功能差异及适用范围,采用理论研究与实际模拟相结合的方法进行对比分析。研究发现:STEPS软件采用元胞自动机(CA)模型,疏散规则简单,人员智能化程度低,疏散时人员行为特征与现实情况不完全相... 为了了解两款疏散模拟软件STEPS与Pathfinder的功能差异及适用范围,采用理论研究与实际模拟相结合的方法进行对比分析。研究发现:STEPS软件采用元胞自动机(CA)模型,疏散规则简单,人员智能化程度低,疏散时人员行为特征与现实情况不完全相符,但路径决策系统很好地解决了上述问题,可以真实地模拟常态下人员疏散;Pathfinder软件采用Agent-based模型,人员智能化程度高,个体可以回应环境刺激,人员可以轻松规避障碍物,人群中的个体行为特征丰富且与现实情况十分相符,但在出口选择上存在缺陷,人员只能选择前方的出口而忽略后方的出口,不能模拟常态下的人员疏散。分析得出,Pathfinder模拟结果与真实情况相符程度更高,STEPS更适合模拟常态下人员疏散。 展开更多
关键词 安全疏散 STEPS 元胞自动机 Pathfinder Agent-base
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基于FDS和STEPS的大型商业综合体IMAX影厅火灾模拟与安全疏散研究 认领 引用 被引量：6
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作者 张学智 常力 +3 位作者 姜雯 谢飞 宋云龙 宋文华 《南开大学学报（自然科学版）》 CAS CSCD 北大核心 2017年第4期83-87,共5页
针对IMAX影厅面积普遍超过规范要求、火灾危险性大和人员疏散困难等因素,选取大型商业综合体的IMAX影厅为研究对象,在影厅及附近公共走道部分设计为独立防火分区,影厅内喷淋有效、排烟有效的条件下,采用FDS和STEPS软件进行厅内火灾模拟... 针对IMAX影厅面积普遍超过规范要求、火灾危险性大和人员疏散困难等因素,选取大型商业综合体的IMAX影厅为研究对象,在影厅及附近公共走道部分设计为独立防火分区,影厅内喷淋有效、排烟有效的条件下,采用FDS和STEPS软件进行厅内火灾模拟和人员疏散模拟.结果表明,影厅内烟气不会蔓延至走道等公共区域,环境未达到人员耐受极限,人员能安全疏散至公共区域,安全余量时间较大有利于消防队员的扑救和财产转移. 展开更多
关键词 大型商业综合体 IMAX影厅 FDS模拟 STEPS模拟 安全疏散
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3D anatomy and flow dynamics of net-depositional cyclic steps on the world’s largest submarine fan:a joint 3D seismic and numerical approach 认领 引用 被引量：2
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作者 Da-Li Shao Guo-Zhang Fan +5 位作者 Hai-Qiang Wang Hong-Xia Ma Guo-Ping Zuo Liang-Bo Ding Zheng Cai Wei-Qiang Li 《Petroleum Science》 SCIE EI CAS CSCD 2021年第1期10-28,共19页
Supercritical flows are ubiquitous in natural environments;however,there is rare 3D anatomy of their deposits.This study uses high-quality 3D seismic datasets from the world’s largest submarine fan,Bengal Fan,to inte... Supercritical flows are ubiquitous in natural environments;however,there is rare 3D anatomy of their deposits.This study uses high-quality 3D seismic datasets from the world’s largest submarine fan,Bengal Fan,to interpret 3D architectures and flow processes of Pliocene undulating bedforms that were related to supercritical flows.Bengal undulating bedforms as documented in this study were developed in unconfined settings,and are seismically imaged as strike-elongated,crescentic bedforms in plan view and as rhythmically undulating,upstream migrating,erosive,discontinuous reflections in section view.Their lee sides are overall 3 to 4 times steeper(0.280 to 1.19°in slope)and 3 to 4 times shorter(117 to 419 m in length)than their stoss flanks and were ascribed to faster(high flow velocities of 2.70 to 3.98 m/s)supercritical flows(Froude numbers of 1.53 to 2.27).Their stoss sides,in contrast,are overall 3 to 4 times gentler(0.120 to 0.270 in slope)and 3 to 4 times longer(410 to 1139 m in length)than their lee flanks and were related to slower(low velocities of 2.35 to 3.05 m/s)subcritical flows(Froude numbers of 0.58 to 0.97).Bengal wave-like features were,thus,created by supercriticalto-subcritical flow transformations through internal hydraulic jumps(i.e.,cyclic steps).They have crests that are positive relative to the surrounding region of the seafloor,suggesting the predominant deposition of draping sediments associated with net-depositional cyclic steps.Turbidity currents forming Bengal wave-like features were,thus,dominated by deposition,resulting in net-depositional cyclic steps.Sandy deposits associated with Bengal net-depositional cyclic steps are imaged themselves as closely spaced,strike-elongated high RMS-attribute patches,thereby showing closely spaced,long and linear,strike-elongated distribution patterns. 展开更多
关键词 Sediment waves Net-depositional cyclic steps Supercritical flows Sandy supercritical-flow deposits Bengal Fan
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Three-Steps-Meshing Based Multiple Crack Identification for Structures and Its Experimental Studies 认领 引用 被引量：4
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作者 LI Bing CHEN Xuefeng HE Zhengjia 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第2期400-405,共6页
Multiple crack identification plays an important role in vibration-based crack identification of structures. Traditional crack detection method of single crack is difficult to be used in multiple crack diagnosis. A th... Multiple crack identification plays an important role in vibration-based crack identification of structures. Traditional crack detection method of single crack is difficult to be used in multiple crack diagnosis. A three-step-meshing method for the multiple cracks identification in structures is presented. Firstly, the changes in natural frequency of a structure with various crack locations and depth are accurately obtained by means of wavelet finite element method, and then the damage coefficient method is used to determine the number and the region of cracks. Secondly, different regions in the cracked structure are divided into meshes with different scales, and then the small unit containing cracks in the damaged area is gradually located by iterative computation. Lastly, by finding the points of intersection of three frequency contour lines in the small unit, the crack location and depth are identified. In order to verify the effectiveness of the presented method, a multiple cracks identification experiment is carried out. The diagnostic tests on a cantilever beam under two working conditions show the accuracy of the proposed method： with a maximum error of crack location identification 2.7% and of depth identification 5.2%. The method is able to detect multiple crack of beam with less subdivision and higher precision, and can be developed as a multiple crack detection approach for complicated structures. 展开更多
关键词 multiple cracks structure three steps meshing
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Monte Carlo simulation on backward steps of single kinesin molecule 认领 引用 被引量：3
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作者 王宏 张勇 +1 位作者 窦硕星 王鹏业 《Chinese Physics B》 SCIE EI CAS 2008年第4期1513-1517,共5页
Kinesin is a stepping molecular motor travelling along the microtubule. It moves primarily in the plus end direction of the microtubule and occasionally in the minus-end, backward, direction. Recently, the backward st... Kinesin is a stepping molecular motor travelling along the microtubule. It moves primarily in the plus end direction of the microtubule and occasionally in the minus-end, backward, direction. Recently, the backward steps of kinesin under different loads and temperatures start to attract interests, and the relations among them are revealed. This paper aims to theoretically understand these relations observed in experiments. After introducing a backward pathway into the previous model of the ATPase cycle of kinesin movement, the dependence of the backward movement on the load and the temperature is explored through Monte Carlo simulation. Our results agree well with previous experiments. 展开更多
关键词 kinesin backward steps Monte Carlo ATPase cycle
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Half-integer Shapiro steps in MgB2 focused He ion beam Josephson junctions 认领 引用 被引量：2
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作者 殷大利 蔡欣炜 +5 位作者 徐铁权 孙瑞宁 韩颖 张焱 王越 甘子钊 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期483-489,共7页
Half-integer microwave induced steps(Shapiro steps)have been observed in many different Josephson junction systems,which have attracted a lot of attention because they signify the deviation of current phase relation(C... Half-integer microwave induced steps(Shapiro steps)have been observed in many different Josephson junction systems,which have attracted a lot of attention because they signify the deviation of current phase relation(CPR)and uncover many unconventional physical properties.In this article,we first report the discovery of half-integer Shapiro steps in MgB2focused He ion beam(He-FIB)Josephson junctions.The half-integer steps'dependence on microwave frequency,temperature,microwave power,and magnetic field is also analyzed.We find that the existence of half-integer steps can be controlled by the magnetic field periodically,which is similar to that of high temperature superconductor(HTS)grain boundary junctions,and the similarity of the microstructures between gain boundary junctions and He-FIB junctions is discussed.As a consequence,we mainly attribute the physical origin of half-integer steps in MgB2He-FIB junctions to the model that a He-FIB junction is analogous to a parallel junctions'array.Our results show that He-FIB technology is a promising platform for researching CPR in junctions made of different superconductors. 展开更多
关键词 Josephson junction half-integer Shapiro steps MgB2 focused helium ion beam
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TWO STEPS CHEMICAL-MECHANICAL POLISHING OF RIGID DISK SUBSTRATE TO GET ATOM-SCALE PLANARIZATION SURFACE 认领 引用 被引量：13
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作者 LEI Hong LUO Jianbin LU Xinchun 《Chinese Journal of Mechanical Engineering》 EI CAS 2006年第4期496-499,共4页
In order to get atomic smooth rigid disk substrate surface, ultra-fined alumina slurry and nanometer silica slurry are prepared, and two steps chemical-mechanical polishing （CMP） of rigid disk substrate in the two s... In order to get atomic smooth rigid disk substrate surface, ultra-fined alumina slurry and nanometer silica slurry are prepared, and two steps chemical-mechanical polishing （CMP） of rigid disk substrate in the two slurries are studied. The results show that, during the first step CMP in the alumina slurry, a high material removal rate is reached, and the average roughness （Ra） and the average waviness （Wa） of the polished surfaces can be decreased from previous 1.4 nm and 1.6 nm to about 0.6 nm and 0.7 nm, respectively. By using the nanometer silica slurry and optimized polishing process parameters in the second step CMP, the Ra and the Wa of the polished surfaces can be further reduced to 0.038 nm and 0.06 am, respectively. Atom force microscopy （AFM） analysis shows that the final polished surfaces are ultra-smooth without micro-defects. 展开更多
关键词 TWo steps Chemical-mechanical polishing（CMP） Rigid disk substrateAtom-scale planarization Slurry
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基于STEPS的超高层建筑人员疏散模拟研究 认领 引用 被引量：3
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作者 白磊 王刘兵 《消防科学与技术》 CAS 北大核心 2017年第6期776-779,共4页
选取某超高层写字楼,使用STEPS软件进行人员疏散模拟。按照建筑设计容量和人员密度计算各楼层的人员荷载。将楼梯、不同分布高度的电梯、避难层三种疏散设施相组合,设置5种疏散方案进行模拟研究,得出不同方案下建筑内部剩余人数随时间... 选取某超高层写字楼,使用STEPS软件进行人员疏散模拟。按照建筑设计容量和人员密度计算各楼层的人员荷载。将楼梯、不同分布高度的电梯、避难层三种疏散设施相组合,设置5种疏散方案进行模拟研究,得出不同方案下建筑内部剩余人数随时间变化的曲线以及不同方案中由电梯疏散的人数占总人数的百分比,分析各疏散方案的疏散效率。研究结果表明,"楼梯+电梯+避难层"的组合为最优疏散方案,疏散效率和安全性最高。 展开更多
关键词 超高层建筑 STEPS 人员疏散 电梯疏散 避难层 疏散效率
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“Final all possible steps”approach for accelerating stochastic simulation of coupled chemical reactions 认领 引用 被引量：1
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作者 周文 彭新俊 +2 位作者 刘祥 闫正楼 王翼飞 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第3期379-387,共9页
In this paper, we develop a modified accelerated stochastic simulation method for chemically reacting systems, called the ＂final all possible steps＂ （FAPS） method, which obtains the reliable statistics of all spec... In this paper, we develop a modified accelerated stochastic simulation method for chemically reacting systems, called the ＂final all possible steps＂ （FAPS） method, which obtains the reliable statistics of all species in any time during the time course with fewer simulation times. Moreover, the FAPS method can be incorporated into the leap methods, which makes the simulation of larger systems more efficient. Numerical results indicate that the proposed methods can be applied to a wide range of chemically reacting systems with a high-precision level and obtain a significant improvement on efficiency over the existing methods. 展开更多
关键词 ＂final all possible steps＂ approach stochastic simulation algorithm chemically reacting systems
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基于STEPS的山区高含硫气井周边居民疏散模拟研究 认领 引用 被引量：1
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作者 王丽 刘茂 孟博 《南开大学学报（自然科学版）》 CAS CSCD 北大核心 2011年第6期81-87,共7页
我国高含硫气井都位于一些远郊区或偏远山区,在生产运行中已多次因出现井喷、井口溢气等险情而疏散周边居民.以山区某高含硫气井周围1 km内的居民疏散为研究对象,针对当地山峦起伏、山路坡陡等复杂地形的特点,使用STEPS软件进行模拟.根... 我国高含硫气井都位于一些远郊区或偏远山区,在生产运行中已多次因出现井喷、井口溢气等险情而疏散周边居民.以山区某高含硫气井周围1 km内的居民疏散为研究对象,针对当地山峦起伏、山路坡陡等复杂地形的特点,使用STEPS软件进行模拟.根据NASA 2009年的全球DEM数据、航拍图和实地调研结果,提供了在软件中直接绘制山区三维地形和道路网络模型的方法.在人员属性的设置中,考虑了地形坡度对不同性别和年龄的人员移动速度的影响.最后通过STEPS模拟,研究了气井周围三条主要道路上的疏散时间、疏散效率以及不同类型人员的疏散. 展开更多
关键词 山区 高含硫气井 复杂地形 STEPS 三维疏散模拟
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基于STEPS的某高校学生宿舍楼人群疏散 认领 引用 被引量：2
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作者 王丽 任常兴 曾坚 《消防科学与技术》 CAS 北大核心 2017年第6期779-781,共3页
建立实际的宿舍楼模型,通过STEPS进行模拟,研究宿舍楼出口数量、宽度、位置等因素对人员疏散时间的影响。根据不同疏散出口的开启情况设置7个场景,分析不同时刻的人员分布、不同场景下的疏散时间以及不同场景下各出口的利用率等。建议... 建立实际的宿舍楼模型,通过STEPS进行模拟,研究宿舍楼出口数量、宽度、位置等因素对人员疏散时间的影响。根据不同疏散出口的开启情况设置7个场景,分析不同时刻的人员分布、不同场景下的疏散时间以及不同场景下各出口的利用率等。建议此宿舍楼在突发状况下至少开启2个疏散出口,并对人员疏散加以引导。 展开更多
关键词 STEPS 学生宿舍楼 疏散出口 疏散时间 出口利用率 建筑防火
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基于STEPS的音乐厅人员疏散模拟研究 认领 引用 被引量：2
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作者 李大燕 朱国庆 《消防科学与技术》 CAS 北大核心 2016年第8期1080-1083,共4页
介绍元胞自动机理论和STEPS软件。研究音乐厅人员疏散的设计,运用STEPS软件,分析火灾导致某安全出口失效的情况下音乐厅人员疏散过程,分析其他安全出口的利用率。模拟结果显示,安全出口利用不均衡,人员在疏散楼梯口以及个别直通室外的... 介绍元胞自动机理论和STEPS软件。研究音乐厅人员疏散的设计,运用STEPS软件,分析火灾导致某安全出口失效的情况下音乐厅人员疏散过程,分析其他安全出口的利用率。模拟结果显示,安全出口利用不均衡,人员在疏散楼梯口以及个别直通室外的安全出口发生拥堵。建议增大安全出口宽度,合理分流,统筹疏散;制定完善的管理制度和维护措施。将STEPS模拟结果与Pathfinder模拟结果进行对比,模拟结果基本一致。 展开更多
关键词 元胞自动机 STEPS 音乐厅 人员疏散 疏散模拟 建筑防火
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英格兰青少年足球训练理论与实践分析——基于四角模型和STEPS原则 认领 引用 被引量：7
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作者 陈志辉 梁斌 田建强 《海南师范大学学报（自然科学版）》 CAS 2017年第1期99-104,共6页
文章运用实地访谈法、文献资料法等方法对英格兰青少年足球运动员训练培养的内容与方法进行了研究.通过分析训练实例得出,四角模型能从技术、体能、心理和社交四个方面综合培养青少年足球运动员的比赛能力;STEPS原则广泛应用于英格兰青... 文章运用实地访谈法、文献资料法等方法对英格兰青少年足球运动员训练培养的内容与方法进行了研究.通过分析训练实例得出,四角模型能从技术、体能、心理和社交四个方面综合培养青少年足球运动员的比赛能力;STEPS原则广泛应用于英格兰青少年各个年龄阶段的足球训练,且不同年龄阶段培养、发展技能的侧重点十分明确;在训练内容的安排上,注重进阶,接近实战,训练内容和方法具有科学性、针对性和全面性.文章旨在为我国青少年足球运动员的训练培养提供参考. 展开更多
关键词 四角模型 STEPS原则 英格兰
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Disorder Induced Dynamic Equilibrium Localization and Random Phase Steps of Bose–Einstein Condensates 认领 引用
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作者 DUAN Ya-Fan XU Zhen +3 位作者 QIAN Jun SUN Jian-Fang JIANG Bo-Nan HONG Tao 《Chinese Physics Letters》 SCIE EI CAS CSCD 2011年第10期5-8,共4页
We numerically analyze the dynamic behavior of Bose–Einstein condensate(BEC)in a one-dimensional disordered potential before it completely loses spatial quantum coherence.We find that both the disorder statistics and... We numerically analyze the dynamic behavior of Bose–Einstein condensate(BEC)in a one-dimensional disordered potential before it completely loses spatial quantum coherence.We find that both the disorder statistics and the atom interactions produce remarkable effects on localization.We also find that the single phase of the initial condensate is broken into many small pieces while the system approaches localization,showing a counter-intuitive step-wise phase but not a thoroughly randomized phase.Although the condensates as a whole show less flow and expansion,the currents between adjacent phase steps retain strong time dependence.Thus we show explicitly that the localization of a finite size Bose–Einstein condensate is a dynamic equilibrium state. 展开更多
关键词 Einstein steps intuitive
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Direct observation of bunching of elementary steps on protein crystals under forced flow conditions 认领 引用
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作者 Gen Sazaki Guoliang Dai 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2015年第4期173-176,共4页
Bunching of elementary steps by solution flow is still not yet clarified for protein crystals. Hence, in this study, we observed elementary steps on crystal surfaces of model protein hen egg-white lysozyme （HEWL） un... Bunching of elementary steps by solution flow is still not yet clarified for protein crystals. Hence, in this study, we observed elementary steps on crystal surfaces of model protein hen egg-white lysozyme （HEWL） under forced flow conditions, by our advanced optical microscopy. We found that in the case of a HEWL solution of 99.99% purity, forced flow changed bunched steps into elementary ones （debunching） on tetragonal HEWL crystals. In contrast, in the case of a HEWL solution of 98.5% purity, forced flow significantly induced bunching of elementary steps. These results indicate that in the case of HEWL crystals, the mass transfer of impurities is more significantly enhanced by forced solution flow than that of solute HEWL molecules. We also showed that forced flow induced the incorporation of microcrystals into a mother crystal and the subsequent formation of screw dislocations and spiral growth hillocks. 展开更多
关键词 In situ observation Step bunching Step debunching Elementary steps Forced flow Protein crystal
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The Theory and Application of Upwind Finite Difference Fractional Steps Procedure for Seawater Intrusion 认领 引用
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作者 Yirang Yuan Hongxing Rui +1 位作者 Dong Liang Changfeng Li 《International Journal of Geosciences》 CAS 2012年第5期972-991,共20页
Numerical simulation and theoretical analysis of seawater intrusion is the mathematical basis for modern environmental science. Its mathematical model is the nonlinear coupled system of partial differential equations ... Numerical simulation and theoretical analysis of seawater intrusion is the mathematical basis for modern environmental science. Its mathematical model is the nonlinear coupled system of partial differential equations with initial-boundary problems. For a generic case of a three-dimensional bounded region, two kinds of finite difference fractional steps pro- cedures are put forward. Optimal order estimates in norm are derived for the error in the approximation solution. The present method has been successfully used in predicting the consequences of seawater intrusion and protection projects. 展开更多
关键词 Seawater Intrusion Three-Dimensional Region Upwind Fractional Steps Norm Estimate Numerical Simulation
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