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Phase equilibria relations in the V_(2)O_(5)-rich part of the Fe_(2)O_(3-)TiO_(2)-V_(2)O_(5) system at 1200℃ related to converter vanadium-bearing slag
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作者 Junjie Shi Yumo Zhai +6 位作者 Yuchao Qiu Changle Hou Jingjing Dong Maoxi Yao Haolun Li Yongrong Zhou Jianzhong Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第9期2017-2024,共8页
The efficient recycling of vanadium from converter vanadium-bearing slag is highly significant for sustainable development and circular economy.The key to developing novel processes and improving traditional routes li... The efficient recycling of vanadium from converter vanadium-bearing slag is highly significant for sustainable development and circular economy.The key to developing novel processes and improving traditional routes lies in the thermodynamic data.In this study,the equilibrium phase relations for the Fe_(2)O_(3)-TiO_(2)-V_(2)O_(5)system at 1200℃in air were investigated using a high-temperature equilibrium-quenching technique,followed by analysis using scanning electron microscopy-energy dispersive X-ray spectrometer and X-ray photoelectron spectroscopy.One liquid-phase region,two two-phase regions(liquid-rutile and liquid-ferropseudobrookite),and one three-phase region(liquid-rutile-ferropseudobrookite)were determined.The variation in the TiO_(2)and V_(2)O_(5)contents with the Fe_(2)O_(3)content was examined for rutile and ferropseudobrookite solid solutions.However,on further comparison with the predictions of FactSage 8.1,significant discrepancies were identified,highlighting that greater attention must be paid to updating the current thermodynamic database related to vanadium-bearing slag systems. 展开更多
关键词 vanadium-bearing slag thermodynamics FactSage phase equilibria recovery
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Helically symmetric equilibria for some ideal and resistive MHD plasmas with incompressible flows
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作者 S.M.Moawad O.H.El-Kalaawy H.M.Shaker 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第2期192-209,共18页
In this paper, the problem of finding exact solutions to the magnetohydrodynamic(MHD) equations in the presence of incompressible mass flows with helical symmetry is considered. For ideal flows, a similarity reduction... In this paper, the problem of finding exact solutions to the magnetohydrodynamic(MHD) equations in the presence of incompressible mass flows with helical symmetry is considered. For ideal flows, a similarity reduction method is used to obtain exact solutions for several MHD flows with nonlinear variable Mach number. For resistive flows parallel to a magnetic field, the governing equilibrium equation is derived. The MHD equilibrium state of a helically symmetric incompressible flow is governed by a second-order elliptic partial differential equation(PDE) for the helical magnetic flux function. Exact solutions for the latter equation are obtained. Also, the equilibrium equations of a gravitating plasma with incompressible flow are derived. 展开更多
关键词 MAGNETOHYDRODYNAMICS helical symmetry resistivity incompressible ows exact equilibria
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Investigation on small molecule-aptamer dissociation equilibria based on antisense displacement probe
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作者 Lei Wang Lili Yao +3 位作者 Qihui Ma Yu Mao Hao Qu Lei Zheng 《Food Science and Human Wellness》 SCIE CSCD 2023年第4期1257-1264,共8页
Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target m... Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target molecules with high affinity and specificity represent an attractive tool for the recognition of food hazardous substances,which play an important role in the development and application of new food safety detection technology.But current assays for characterizing small molecule-aptamer binding are limited by either the mass sensitivity or the size differentiation ability.Herein,we proposed a comprehensive method for assessing the dissociation equilibria of small molecule-aptamer,which is immobilized-free under ambient conditions.The design employs the Le Chatelier’s principle and could be used to effectively measure small molecule-aptamer interactions.ATP binding aptamer and anti-aflatoxin B1 aptamer were used as the model system to determine their affinity,in which their dissociation equilibria measurements are in excellent close to their previous work.Due to the simplicity and sensitivity of this new method,we believe that it could be recommended as an effective tool for characterizing small molecule-aptamer interactions and promote the further application of small molecular aptamer in food safety. 展开更多
关键词 APTAMER Small molecule Dissociation equilibria Antisense displacement probe Le Chatelier’s principle
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CO_(2)-海水水合物生成强化方法研究
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作者 杨明军 宋维 +3 位作者 张磊 凌铮 陈兵兵 宋永臣 《化工学报》 EI CSCD 北大核心 2024年第8期2939-2948,共10页
海水中的盐离子成分阻碍水合物成核进程,使得水合物法海洋碳封存耗时长、封存比率低。结合水合物非均相成核特征考虑,认为在局部区域内实现水合物优先成核,进而带动大片海域内水合物扩展生成的封存方法极具工业可行性。因而,开展海水水... 海水中的盐离子成分阻碍水合物成核进程,使得水合物法海洋碳封存耗时长、封存比率低。结合水合物非均相成核特征考虑,认为在局部区域内实现水合物优先成核,进而带动大片海域内水合物扩展生成的封存方法极具工业可行性。因而,开展海水水合物强化生成方法基础研究是推进水合物法海洋碳封存应用落地的基础。基于此,以高效、高转化率生成水合物为目标,在实验室尺度分别探究了高过冷度、添加剂四丁基溴化铵(TBAB)以及变温速率对海水水合物生成特性的影响。结果表明,受到盐离子抑制作用,400 m深度海水中水合物自然生成难度极大,而提高生成过程的过冷度可增强水合物生成驱动力;热力学添加剂TBAB难以显著改善海水水合物的生成条件,但可使生成速率有所提高;0.3 K/min降温速率下的水合物转化率分别是过冷度作用和添加剂作用下的1.28倍和1.19倍。在后续研究中,应考虑多种强化生成方法的耦合作用效果,开发更能缓解海水水合物生成难题的技术手段。 展开更多
关键词 二氧化碳 水合物 成核 相平衡
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废锌基脱硫剂与铜锌基催化剂协同真空碳热提取锌
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作者 马红周 党煜博 +3 位作者 王耀宁 曾劲阳 赵小军 史建伟 《化工进展》 EI CAS CSCD 北大核心 2024年第9期5275-5281,共7页
针对废锌基脱硫剂及铜锌基催化剂中金属提取工艺流程长、污染物产生量大的问题,提出了利用真空碳热还原方法将两种物料中铜和锌实现高效、清洁协同分离利用的技术思路。在对废脱硫剂、铜锌基催化剂化学成分及主要物相检测的基础上进行... 针对废锌基脱硫剂及铜锌基催化剂中金属提取工艺流程长、污染物产生量大的问题,提出了利用真空碳热还原方法将两种物料中铜和锌实现高效、清洁协同分离利用的技术思路。在对废脱硫剂、铜锌基催化剂化学成分及主要物相检测的基础上进行了真空碳热协同提取分离铜和锌的实验研究,通过调整加热温度、保温时间、配料比等获得了较优的锌挥发工艺条件,并深入分析了工艺机理。研究结果表明,以ZnS为主要物相的废脱硫剂和以CuO和ZnO为主要物相的废铜锌基催化剂协同在真空碳热还原时可有效地将两种物料中的锌充分还原挥发。铜锌基催化剂、脱硫剂及碳以C∶(ZnO+CuO)=1∶1 (摩尔比)、CuO∶ZnS=2∶1 (摩尔比)的配料组成混合物料,加热至1100℃保温60min,锌的还原挥发率可达到99.56%,还原渣中铜品位可达到59.46%,还原渣中铜主要为Cu_(1.96)S,可作为冰铜吹炼原料使用。 展开更多
关键词 锌基脱硫剂 铜锌基催化剂 真空碳热还原 协同利用 回收 相平衡 催化剂
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基于稳定性分析的含酸/醇烃水体系相平衡计算
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作者 陈好奇 史博会 +6 位作者 彭琪 康琦 宋尚飞 姚海元 陈海宏 吴海浩 宫敬 《化工学报》 EI CSCD 北大核心 2024年第3期789-800,共12页
油气开发的井流物多以油气水混相形式存在。对于酸性油气田,还常伴有硫化氢或二氧化碳等酸性气体。为了避免水合物生成堵塞管道,加注醇类防冻剂是常用的方法。因而油气田井流物易于呈现含酸、含醇的多相烃水混输状态。含酸/醇烃水体系... 油气开发的井流物多以油气水混相形式存在。对于酸性油气田,还常伴有硫化氢或二氧化碳等酸性气体。为了避免水合物生成堵塞管道,加注醇类防冻剂是常用的方法。因而油气田井流物易于呈现含酸、含醇的多相烃水混输状态。含酸/醇烃水体系相平衡的准确计算,是预测其物性特征的基础,也是支持该复杂体系多相混输流动仿真的关键。但目前被广泛应用的基于经典立方型状态方程计算油气水体系相平衡的方法,存在对液烃及水相分布预测准确性不高的问题。为此,引入稳定性分析的方法,构建适用于含酸/醇烃水体系的稳定性检验方式,结合SRK-HV状态方程,建立了耦合稳定性分析的含酸/醇烃水多相多组分相平衡计算模型及算法。经多角度验证,本研究所提模型具有较高的准确性与稳定性。 展开更多
关键词 相平衡 热力学 状态方程 稳定性分析 闪蒸计算
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锂钠镁共存硫酸盐体系多温相图及其应用
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作者 赵志星 姚智豪 +3 位作者 于雪峰 杨游胜 曾英 于旭东 《化工学报》 EI CSCD 北大核心 2024年第6期2123-2133,F0002,共12页
针对硫酸钠亚型盐湖卤水钠锂比高、镁锂比高带来的锂分离难题,通过开展锂钠镁共存硫酸盐体系多温相图研究,获取锂钠镁硫酸盐之间的作用关系和结晶析出规律,并应用于指导降低卤水中钠镁含量工艺设计。采用等温溶解平衡法获取了四元体系Li... 针对硫酸钠亚型盐湖卤水钠锂比高、镁锂比高带来的锂分离难题,通过开展锂钠镁共存硫酸盐体系多温相图研究,获取锂钠镁硫酸盐之间的作用关系和结晶析出规律,并应用于指导降低卤水中钠镁含量工艺设计。采用等温溶解平衡法获取了四元体系Li_(+),Na_(+),Mg^(2+)//SO_(4)2--H_(2)O 303.2、318.2 K固液相平衡数据,采用X射线粉晶衍射法(XRD)测定了共饱点的平衡固相类型。复盐分析:采用XRD、扫描电镜(SEM)和热重分析法(TG-DSC)进行了各复盐的晶体结构分析、晶体形貌表征和热分析。研究发现,四元体系Li_(+),Na_(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O303.2、318.2 K下均为复杂体系,相图均包含4个四元共饱点、9条单变量曲线和6个结晶区。303.2 K时,该体系相图结晶区为:Na_(2)SO_(4)、Na_(2)SO_(4)·10H_(2)O、Li_(2)SO_(4)·H_(2)O、MgSO_(4)·7H_(2)O、Na_(2)SO_(4)·MgSO_(4)·4H_(2)O、Li_(2)SO_(4)·3Na_(2)SO_(4)·12H_(2)O;318.2 K时,该体系相图结晶区为:Na_(2)SO_(4)、MgSO_(4)·7H_(2)O、Li_(2)SO_(4)·H_(2)O、Na_(2)SO_(4)·MgSO_(4)·4H_(2)O、Li_(2)SO_(4)·Na_(2)SO_(4)、Li_(2)SO_(4)·3Na_(2)SO_(4)·12H_(2)O。对比该四元体系288.2、298.2、303.2、318.2、323.2 K多温相图发现,温度对体系的影响主要表现在水合盐和含锂复盐的结晶形式及各盐类结晶区面积的变化。根据四元体系多温相图中含锂复盐(Li_(2)SO_(4)·Na_(2)SO_(4)、Li_(2)SO_(4)·3Na_(2)SO_(4)·12H_(2)O)、白钠镁矾(Na_(2)SO_(4)·MgSO_(4)·4H_(2)O)和三元体系Na_(+),Mg^(2+)//SO_(4)2--H_(2)O多温相图中盐类的结晶规律,给出了硫酸钠亚型盐湖脱钠镁及白钠镁矾的分离加工建议。 展开更多
关键词 相平衡 溶液 溶解性 白钠镁矾 含锂复盐
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六氟化铀及氟化物汽液相平衡数据预测及精馏过程模拟
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作者 杨同 王欢 邓春 《化工学报》 EI CSCD 北大核心 2024年第2期463-474,共12页
精馏技术提纯六氟化铀是铀转化工艺的重要环节,该精馏工艺的模拟可为工艺设计及操作优化提供关键支撑。然而,由于六氟化铀及氟化物汽液相平衡数据及物性数据的缺乏,六氟化铀提纯精馏工艺的建模和模拟难以开展。为此,利用COSMOtherm和Tur... 精馏技术提纯六氟化铀是铀转化工艺的重要环节,该精馏工艺的模拟可为工艺设计及操作优化提供关键支撑。然而,由于六氟化铀及氟化物汽液相平衡数据及物性数据的缺乏,六氟化铀提纯精馏工艺的建模和模拟难以开展。为此,利用COSMOtherm和Turbomole软件,预测UF_(6)与TiF_(4)二元体系汽液相平衡数据。通过预测已知的WF_(6)-UF_(6)二元体系汽液相平衡实验数据以间接验证COSMO-RS模型预测的准确性。利用Aspen Plus软件的物性常数估算系统(property constant estimation system),估算出缺失的无限稀释水溶液Gibbs生成能等物性参数。文献中UF_(6)饱和蒸气压实验数据与模拟值进行对比,相对误差在1.76%以内。根据文献中的实验数据和预测的汽液相平衡数据,利用Aspen Plus软件回归NRTL模型的二元交互作用参数。针对六氟化铀及氟化物的分离,设计直接分离序列和间接分离序列提纯UF_(6)的两种方案。设定UF_(6)产品纯度,以总年度费用(TAC)最小化为目标,采用灵敏度分析对塔板数、进料位置和回流比的关键参数进行优化,结果表明,间接分离序列提纯UF_(6)方案的TAC更低。 展开更多
关键词 氟化物 物性估算 汽液平衡 精馏
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三元混合制冷剂R290+R600a+N2汽液相平衡实验研究
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作者 韩树康 祁影霞 +4 位作者 杨瀚宁 徐小雷 陶杰 王飞 刘业凤 《原子与分子物理学报》 北大核心 2024年第6期161-169,共9页
在氢气液化工艺中,预冷循环是重要的一环,其中混合制冷剂(mixed refrigerant,MR)预冷循环是单位能耗比较低的,故对MR性能的优化显得尤为重要.为此利用液相单相循环法搭建汽液相平衡(Vapor-liquid equilibrium,VLE)实验系统,研究了R290+R... 在氢气液化工艺中,预冷循环是重要的一环,其中混合制冷剂(mixed refrigerant,MR)预冷循环是单位能耗比较低的,故对MR性能的优化显得尤为重要.为此利用液相单相循环法搭建汽液相平衡(Vapor-liquid equilibrium,VLE)实验系统,研究了R290+R600a+N_(2)三元体系的VLE性质,在273.15 K~323.15 K的温度范围内,对三元混合工质R290+R600a+N_(2)进行实验研究,并获得18组实验数据.同时使用Peng-Pobinson-Stryjek-Vera (PRSV)状态方程结合van der Waals(vd W)混合法则对R290+R600a、R290+N_(2)、R600a+N_(2)三组二元体系的VLE文献数据进行了拟合计算,得到二元交互作用系数,拟合结果与文献数据吻合良好.以此为基础,推算该三元体系的VLE性质.最后将实验数据与计算结果对比表明,体系压力平均相对偏差AARDp为0.85%,系统组分R290、R600a和N_(2)的气相平均绝对偏差AADy_(1)、AADy_(2)和AADy_(3)分别为0.0064、0.0027和0.0063,证明实验结果数据合理可靠,可以满足工程上的应用. 展开更多
关键词 混合制冷剂 汽液平衡 热力学性质 仪器标定
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三元体系Na+(Mg^(2+)),Ca^(2+)//Cl^(-)-H_(2)O 278.2 K稳定相平衡研究
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作者 冯霞 于雪峰 +4 位作者 姚智豪 罗军 任思颖 赵志星 于旭东 《无机盐工业》 CAS CSCD 北大核心 2024年第1期47-52,共6页
含钠镁钙水盐体系的多温相平衡研究,可为含钙镁盐湖资源的持续开发提供数据支撑。因此,采用等温溶解法开展了两个三元体系Na+,Ca^(2+)//Cl^(-)-H_(2)O和Mg^(2+),Ca^(2+)//Cl^(-)-H_(2)O在278.2 K下的相平衡研究,测定了溶解度、折射率和... 含钠镁钙水盐体系的多温相平衡研究,可为含钙镁盐湖资源的持续开发提供数据支撑。因此,采用等温溶解法开展了两个三元体系Na+,Ca^(2+)//Cl^(-)-H_(2)O和Mg^(2+),Ca^(2+)//Cl^(-)-H_(2)O在278.2 K下的相平衡研究,测定了溶解度、折射率和密度,并绘制了相应的相图。结果表明,三元体系Na+,Ca^(2+)//Cl^(-)-H_(2)O和Mg^(2+),Ca^(2+)//Cl^(-)-H_(2)O在278.2 K时均为简单体系,无复盐或固溶体生成。三元体系Na+,Ca^(2+)//Cl^(-)-H_(2)O在278.2 K时的氯化钠结晶区远大于氯化钙,对比该体系273.2、278.2、298.2、348.2 K多温相图可知,随温度升高,氯化钠结晶区增大,氯化钙结晶形式由CaCl_(2)·6H_(2)O转变为CaCl_(2)·2H_(2)O。三元体系Mg^(2+),Ca^(2+)//Cl^(-)-H_(2)O在278.2 K时的MgCl_(2)·6H_(2)O结晶区大于CaCl_(2)·6H_(2)O,对比该体系273.2、278.2、303.2、308.2、348.2、383.2 K多温相图发现:303.2、308.2、348.2、383.2 K时体系中形成复盐2MgCl_(2)·CaCl_(2)·12H_(2)O,且其结晶区随温度升高而增大;383.2 K时体系中同时存在两种复盐2MgCl_(2)·CaCl_(2)·12H_(2)O和MgCl_(2)·2CaCl_(2)·6H_(2)O。 展开更多
关键词 相平衡 相图 溶解度 水合盐
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NaHCO_(3)溶液浓度改变引起的支配质子转移反应变化:从HCO_(3)^(-)质子自递反应到HCO_(3)^(-)水解反应
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作者 柳青 刘建宇 王海水 《大学化学》 CAS 2024年第1期305-308,共4页
NaHCO_(3)水溶液中存在多个质子转移反应和多重化学平衡。随溶液浓度改变,各质子反应所占的相对比重将发生变化,与质子转移相关的产物H_(2)CO_(3)、H^(+)、OH^(-)和CO_(3)^(2-)的相对含量也会发生变化。绘制了[H_(2)CO_(3)]、[H^(+)]、[... NaHCO_(3)水溶液中存在多个质子转移反应和多重化学平衡。随溶液浓度改变,各质子反应所占的相对比重将发生变化,与质子转移相关的产物H_(2)CO_(3)、H^(+)、OH^(-)和CO_(3)^(2-)的相对含量也会发生变化。绘制了[H_(2)CO_(3)]、[H^(+)]、[OH^(-)]和[CO_(3)^(2-)]随溶液浓度c变化的动态图。从动态图上,可以直观地观察到哪些酸碱组分是主要组分,哪些组分是次要组分。较浓溶液中,[H_(2)CO_(3)]≈[CO_(3)^(2-)]>>[OH^(-)]>>[H^(+)],表明能够产生H^(+)或OH^(-)的质子反应占据次要地位,质子反应HCO_(3)^(-)+HCO_(3)^(-)-H_(2)CO_(3)+CO_(3)^(2-)占据支配地位。9.1×10^(-6) mol-L^(-1)溶液中,[OH^(-)]≈[H_(2)CO_(3)]>>[H^(+)]≈[CO_(3)^(2-)],表明质子反应H_(2)O+HCO_(3)^(-)-H_(2)CO_(3)+OH^(-)占据支配地位。极稀溶液中,[OH^(-)]≈[H^(+)]>>[H_(2)CO_(3)]>[CO_(3)^(2-)],表明H_(2)O-H^(+)+OH^(-)占据支配地位。溶液的酸碱性质主要由起支配作用的质子转移反应控制。 展开更多
关键词 碳酸氢钠溶液 多重平衡 支配反应 反应产物含量图
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甲烷在乳液中溶解度的计算
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作者 王娟 严红超 《当代化工》 CAS 2024年第10期2468-2471,共4页
甲烷水合物相平衡研究在水合物储运和可燃冰开采领域有着非常重要的意义。首先利用Patel-Teja状态方程迭代计算甲烷在气相中的逸度,然后以Krichevsky-Kasarnovsy方程为基础,建立体系相平衡时甲烷在乳液中溶解度的数学模型,并对所建数学... 甲烷水合物相平衡研究在水合物储运和可燃冰开采领域有着非常重要的意义。首先利用Patel-Teja状态方程迭代计算甲烷在气相中的逸度,然后以Krichevsky-Kasarnovsy方程为基础,建立体系相平衡时甲烷在乳液中溶解度的数学模型,并对所建数学模型进行验证,发现不同压力和温度条件下的计算结果与相同条件下文献实验测量结果之间误差较小(小于4%)。因此,当实验条件不满足或需要的数据物性手册没有时,所建的溶解度计算模型对乳液中甲烷溶解度具有一定预测价值。 展开更多
关键词 甲烷 水合物 溶解性 相平衡 逸度 模型 数学模拟
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Theoretical Assessment of Environmental Factors and Untreated Infectious Individuals in the Transmission Dynamics of Buruli ulcer
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作者 Codjo Cesaire Yadouleton Myriam Djoukwe Tapi +1 位作者 Judicael Deguenon Ghislain Emmanuel Sopoh 《Applied Mathematics》 2024年第8期477-498,共22页
Buruli ulcer is the third most common mycobacterial disease worldwide, posing a significant public health burden, especially in impoverished regions of West and Central Africa, such as Benin. The management of Buruli ... Buruli ulcer is the third most common mycobacterial disease worldwide, posing a significant public health burden, especially in impoverished regions of West and Central Africa, such as Benin. The management of Buruli ulcer (BU) in Africa is often hindered by limited resources, delays in treatment, and inadequate medical facilities. Additionally, a portion of the population does not seek hospital care, which facilitates the continued presence of the pathogen in the environment. This paper aims to investigate the role of environmental factors in the transmission of Buruli ulcer. We develop a mathematical model to describe the dynamics of Buruli ulcer transmission, incorporating the presence of the bacterium in the environment. Theoretical results are presented to demonstrate that the model is well-posed. We compute the equilibria, including the disease-free equilibrium and the endemic equilibrium, and study their stability. To achieve this, we derive a threshold parameter called the basic reproduction number ℛ0, which determines whether the disease will persist in a human population. If ℛ0is less than one, the disease will eventually die out;if ℛ0is greater than one, the disease will persist. Sensitivity analysis is performed to understand the impact of various parameters on the dynamics of Buruli ulcer transmission and to identify the parameters that influence the basic reproduction number ℛ0. Finally, numerical simulations are conducted to validate the theoretical results obtained from the mathematical analysis. 展开更多
关键词 Buruli Ulcer Mathematical Models equilibria STABILITY
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Thermodynamic model for deoxidation of liquid steel considering strong metal-oxygen interaction in the quasichemical model framework
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作者 Yong-Min Cho Youn-Bae Kang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期988-1002,共15页
Herein,a thermodynamic model aimed at describing deoxidation equilibria in liquid steel was developed.The model provides explicit forms of the activity coefficient of solutes in liquid steel,eliminating the need for t... Herein,a thermodynamic model aimed at describing deoxidation equilibria in liquid steel was developed.The model provides explicit forms of the activity coefficient of solutes in liquid steel,eliminating the need for the minimization of internal Gibbs energy preliminarily when solving deoxidation equilibria.The elimination of internal Gibbs energy minimization is particularly advantageous during the coupling of deoxidation equilibrium calculations with computationally intensive approaches,such as computational fluid dynamics.The model enables efficient calculations through direct embedment of the explicit forms of activity coefficient in the computing code.The proposed thermodynamic model was developed using a quasichemical approach with two key approximations:random mixing of metallic elements(Fe and oxidizing metal) and strong nonrandom pairing of metal and oxygen as nearest neighbors.Through these approximations,the quasichemical approach yielded the activity coefficients of solutes as explicit functions of composition and temperature without requiring the minimization of internal Gibbs energy or the coupling of separate programs.The model was successfully applied in the calculation of deoxidation equilibria of various elements(Al,B,C,Ca,Ce,Cr,La,Mg,Mn,Nb,Si,Ti,V,and Zr).The limitations of the model arising from these assumptions were also discussed. 展开更多
关键词 deoxidation equilibria THERMODYNAMICS quasichemical approach computational fluid dynamics
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VAPOR-LIQUID EQUILIBRIA FOR PROPYLENE -METHANOL-WATER SYSTEM
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作者 陈晓晖 王春艳 +1 位作者 许锡恩 陈宪 《Transactions of Tianjin University》 EI CAS 1999年第1期101-104,共4页
In this article VLE data for a ternary system (propylene-methanol-water) under 30~60 C,0. 3~0. 9 MPa with a mass ratio of methanol to water of 9:1, 8: 2, 7: 3 were determined with a static equilibrium still, and wer... In this article VLE data for a ternary system (propylene-methanol-water) under 30~60 C,0. 3~0. 9 MPa with a mass ratio of methanol to water of 9:1, 8: 2, 7: 3 were determined with a static equilibrium still, and were correlated by using Peng-Robinson model. The average relative error ofpropylene concentration in liquid phase is 1. 46 %. The results indicate that the models are very suitablefor the ternary system and the data are reliable. 展开更多
关键词 propylene methanol water vapor-liquid phase equilibria Peng-Robinson model
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Modeling analysis of cobalt-based Fischer-Tropsch catalyst particles
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作者 Huashuai Wu Gang Wang +1 位作者 Yong Yang Yongwang Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期82-92,共11页
The influences of particle size,shape,and catalyst distribution on the reactivity and hydrocarbon product selectivity of a cobalt-based catalyst for Fischer-Tropsch synthesis were investigated in the present work.A se... The influences of particle size,shape,and catalyst distribution on the reactivity and hydrocarbon product selectivity of a cobalt-based catalyst for Fischer-Tropsch synthesis were investigated in the present work.A self-consistent kinetic model for Fischer-Tropsch reaction proposed here was found to correlate experimental data well and hence was used to describe the consumption rates of reactants and formation rates of hydrocarbon products.The perturbed-chain statistical associating fluid theory equation of state was used to describe vapor-liquid equilibrium behavior associated with Fischer-Tropsch reaction.Local interaction between intraparticle diffusion and Fischer-Tropsch reaction was investigated in detail.Results showed that in order to avoid the adverse influence of intraparticle diffusional limitations on catalyst reactivity and product selectivity,the use of small particles is necessary.Large eggshell spherical particles are shown to keep the original catalyst reactivity and enhance the selectivity of heavy hydrocarbon products.The suitable layer thickness for a spherical particle with a diameter of 2 mm is nearly 0.15 mm.With the same outer diameter of 2 mm,the catalyst reactivity and heavy product selectivity of hollow cylindrical particles with a layer thickness of 0.25 mm are found to be larger than eggshell spherical particles.From the viewpoint of catalytic performance,hollow cylindrical particles are a better choice for industrial applications. 展开更多
关键词 Fischer-Tropsch synthesis Kinetic modeling Vapor-liquid equilibria Numerical simulation Intraparticle diffusion Particle shapes
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Distributed Optimal Variational GNE Seeking in Merely Monotone Games
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作者 Wangli He Yanzhen Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1621-1630,共10页
In this paper, the optimal variational generalized Nash equilibrium(v-GNE) seeking problem in merely monotone games with linearly coupled cost functions is investigated, in which the feasible strategy domain of each a... In this paper, the optimal variational generalized Nash equilibrium(v-GNE) seeking problem in merely monotone games with linearly coupled cost functions is investigated, in which the feasible strategy domain of each agent is coupled through an affine constraint. A distributed algorithm based on the hybrid steepest descent method is first proposed to seek the optimal v-GNE. Then, an accelerated algorithm with relaxation is proposed and analyzed, which has the potential to further improve the convergence speed to the optimal v-GNE. Some sufficient conditions in both algorithms are obtained to ensure the global convergence towards the optimal v-GNE. To illustrate the performance of the algorithms, numerical simulation is conducted based on a networked Nash-Cournot game with bounded market capacities. 展开更多
关键词 Distributed algorithms equilibria selection generalized Nash equilibrium(GNE) merely monotone games
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锂电添加剂FEC-VC二元体系固液平衡数据的测定及回归
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作者 向瑞 艾波 +4 位作者 吴高胜 李瑜哲 宗睿 许保云 杜丽君 《化工进展》 EI CAS CSCD 北大核心 2024年第8期4246-4252,共7页
针对熔融结晶技术分离锂电池电解液添加剂存在缺少基础理论数据的问题,本文采用差示扫描量热法(DSC),测定了氟代碳酸乙烯酯(FEC)-碳酸亚乙烯酯(VC)二元固液平衡数据,实验数据表明该二元物系为低共熔型物系。在此基础上采用活度系数法进... 针对熔融结晶技术分离锂电池电解液添加剂存在缺少基础理论数据的问题,本文采用差示扫描量热法(DSC),测定了氟代碳酸乙烯酯(FEC)-碳酸亚乙烯酯(VC)二元固液平衡数据,实验数据表明该二元物系为低共熔型物系。在此基础上采用活度系数法进行分析计算,得到了二元体系活度系数数据。借助AspenPlus流程模拟软件的数据回归功能,使用vanlaar、NRTL、Redlich-Kister模型对固液平衡数据进行回归,得到了各模型的回归参数。根据模型计算二元固液平衡数据,并绘制出相应的低共熔型二元固液相图。对各模型回归结果进行对比,结果显示vanlaar模型回归结果偏差较大,Redlich-Kister模型回归所得结果与实验数据较为相符,其平衡温度标准差小于0.005、平均偏差小于1.0K。为FEC-VC的结晶分离技术提供了固液平衡数据和热力学参数。 展开更多
关键词 氟代碳酸乙烯酯 结晶 热力学 相平衡 活度系数 回归
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三层液精炼法提纯多晶硅的研究
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作者 李翔 袁亮 +3 位作者 李克帆 纪睿 展亦馨 唐恺 《有色金属工程》 CAS 北大核心 2024年第10期67-72,共6页
在高温下利用密度差别,以熔硅、熔渣和熔铁(或铜)构建Si/Slag/Me三层液体系。冶金硅中的B和P杂质扩散到熔渣和底层金属中,达到提纯冶金硅的目的。热力学计算结果证明了这种方法具有可行性。实验研究分析了底层金属类型、炉渣成分及反应... 在高温下利用密度差别,以熔硅、熔渣和熔铁(或铜)构建Si/Slag/Me三层液体系。冶金硅中的B和P杂质扩散到熔渣和底层金属中,达到提纯冶金硅的目的。热力学计算结果证明了这种方法具有可行性。实验研究分析了底层金属类型、炉渣成分及反应温度对B和P去除率的影响。结果表明:底层金属可有效吸收冶金硅中的P,其中铁比铜有更好的P吸收效果。底层金属对B的吸收效果不佳,B的去除主要归功于造渣提纯过程。在炉渣中加入10 wt%的CaF_(2),降低了渣黏度,可显著提高B和P的去除率。1600~1700℃温度范围内,提高反应温度有利于B的去除,对P的去除无显著作用。 展开更多
关键词 三相平衡 多晶硅 提纯 热力学模拟
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考虑医疗资源影响下的SIS模型动力学性态分析
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作者 张婷婷 《兰州文理学院学报(自然科学版)》 2024年第6期20-23,共4页
研究了医疗资源影响下的SIS动力学模型.首先,求出了模型的基本再生数.其次,讨论了平衡点的存在性,即若R_(1)<1,R_(0)>1+βb_(0)(d+α)/d(d+α+μ_(0))时,系统有两个正平衡点或者没有正平衡点;当R_(1)>1时,系统存在一个正平衡点... 研究了医疗资源影响下的SIS动力学模型.首先,求出了模型的基本再生数.其次,讨论了平衡点的存在性,即若R_(1)<1,R_(0)>1+βb_(0)(d+α)/d(d+α+μ_(0))时,系统有两个正平衡点或者没有正平衡点;当R_(1)>1时,系统存在一个正平衡点,并且证明了平衡点的稳定性.最后,对参数进行了敏感性分析. 展开更多
关键词 医疗资源 平衡点 稳定性
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