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不同温度下Se-H_(2)O系电位-pH图的研究
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作者 姚浩 杨四齐 +1 位作者 白希为 张利华 《有色金属工程》 CAS 北大核心 2024年第2期49-56,共8页
针对Se-H_(2)O体系中重要的单核配合物进行计算分析,通过查询热力学手册,获得了各反应物质298 K标准态下的S0、ΔfG0、ΔfH0和CP的数据,计算得到298~573 K下Se(-Ⅱ)-H_(2)O、Se(+Ⅳ)-H_(2)O和Se(+Ⅵ)-H_(2)O体系中各溶解组分在不同pH下... 针对Se-H_(2)O体系中重要的单核配合物进行计算分析,通过查询热力学手册,获得了各反应物质298 K标准态下的S0、ΔfG0、ΔfH0和CP的数据,计算得到298~573 K下Se(-Ⅱ)-H_(2)O、Se(+Ⅳ)-H_(2)O和Se(+Ⅵ)-H_(2)O体系中各溶解组分在不同pH下的优势区域图。在此基础上,结合不同温度下各含Se物质参与氧化、还原反应的平衡热力学数据,分别构建298、373、473、573 K温度下的Se-H_(2)O系电位-pH图。结果表明:H_(2)Se和H_(2)SeO_(3)均可稳定存在于强酸性溶液中,而H_(2)SeO4仅能存在高温强酸性和溶液中。在298~573 K,单质Se能稳定存在于水溶液中。在298~473 K之间,H_(2)SeO_(3)、HSeO^(-)_(3)、SeO_(3)^(2-)全部可以直接还原成Se。因此,控制一定的pH值和电位,可以使Se以单质形式沉淀从溶液中净化除去。随着温度的升高,H_(2)O的优势区域减少,以固相存在的单质Se的优势区域也在逐渐减少,液相区以Se(+Ⅳ)存在的H_(2)SeO_(3)、HSeO^(-)_(3)及SeO_(3)^(2-)的稳定区域不断扩大。且随着温度的升高,将硒单质氧化为Se(Ⅳ)且进一步氧化为Se(Ⅵ)的氧化电位略有降低,氧化反应更易进行。 展开更多
关键词 Se-H_(2)O系 热力学 电位-ph 优势区域 氧化-还原反应
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基于24 h多通道食管腔内阻抗-pH监测的难治性胃食管反流病诊治进展 被引量:1
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作者 张海洋 张丽 《国际消化病杂志》 CAS 2024年第1期1-4,共4页
难治性胃食管反流病(RGERD)的发病率呈逐年上升趋势,部分患者伴有烧心或食管外症状。24 h多通道食管腔内阻抗-pH监测技术可以较全面、客观地监测反流,有助于分析导致RGERD的原因。RGERD包括非糜烂性反流病(NERD)、反流高敏感(RH)、功能... 难治性胃食管反流病(RGERD)的发病率呈逐年上升趋势,部分患者伴有烧心或食管外症状。24 h多通道食管腔内阻抗-pH监测技术可以较全面、客观地监测反流,有助于分析导致RGERD的原因。RGERD包括非糜烂性反流病(NERD)、反流高敏感(RH)、功能性烧心(FH)及伴有食管外症状的胃食管反流病(GERD)等,酸暴露异常、非酸反流、近端反流、气体反流等反流模式是其难治性的原因,临床可依据反流模式调整PPI的种类和剂量,辅以促动力药物、抗焦虑药物和中药治疗,或考虑转诊至精神科。 展开更多
关键词 难治性胃食管反流病 24 h多通道食管腔内阻抗-ph监测 食管外症状 平均夜间基线阻抗 治疗
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2-PH装置加氢单元废液回收工艺研究
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作者 吴桐 郭雷 贺同强 《化工设计》 CAS 2024年第1期3-6,13,1,共6页
丁烯氢甲酰化制2-PH(2-丙基庚醇)的生产工艺包含两步饱和加氢精制过程,其中前后两座精馏塔产生大量连续废液排放。本文主要研究了通过增设减压精馏系统对2-PH装置加氢精制单元排放废液进行精馏分离后回用的可行性,以期可以回收废液中的... 丁烯氢甲酰化制2-PH(2-丙基庚醇)的生产工艺包含两步饱和加氢精制过程,其中前后两座精馏塔产生大量连续废液排放。本文主要研究了通过增设减压精馏系统对2-PH装置加氢精制单元排放废液进行精馏分离后回用的可行性,以期可以回收废液中的大部分有效组分并增加2-PH产量。结果表明,通过减压精馏可回收废液中90%以上的2-PH,回收液可以加压引回至原装置加氢精制单元进行进一步加氢或者单独加氢,得到合格产品。同时,基于Aspen Plus软件进行了模拟分析,并完成投资费用估算及初步经济性测算,为国内2-PH装置同类型废液处理提供参考。 展开更多
关键词 2-ph 废液 减压精馏 模拟分析
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胃食管反流病量表与食管阻抗-pH监测在胃食管反流病诊断中的作用
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作者 朱翠翠 张霁雯 +2 位作者 罗酩 费蒙辉 吴永梅 《贵州医药》 2024年第1期118-119,共2页
目的探讨胃食管反流病量表与食管阻抗-pH监测在胃食管反流病诊断中的作用。方法将60例确诊为胃食管反流病患者作为研究组,将60例健康体检的健康人作为对照组,依次给予胃食管反流病量表与食管阻抗-pH监测,对比两组诊断结果。结果两组食... 目的探讨胃食管反流病量表与食管阻抗-pH监测在胃食管反流病诊断中的作用。方法将60例确诊为胃食管反流病患者作为研究组,将60例健康体检的健康人作为对照组,依次给予胃食管反流病量表与食管阻抗-pH监测,对比两组诊断结果。结果两组食管阻抗-pH监测结果比较差异显著(P<0.05)。研究组的胃食管反流病量表评分高于对照组,差异有统计学意义(P<0.05)。不同亚型胃食管反流病的胃食管反流病量表评分显著高于对照组,差异有统计学意义(P<0.05)。结论胃食管反流病量表与食管阻抗-pH监测均可用于胃食管反流病诊断,联合应用可进一步确诊患者的疾病,可及时辅助临床有效治疗患者疾病,改善患者的生存质量。 展开更多
关键词 胃食管反流病量表 食管阻抗-ph监测 胃食管反流病 诊断
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POTENTIAL-pH DIAGRAMS OF Al-H_2O SYSTEM
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作者 Zeng, Wenming Chen, Nianyi 《中国有色金属学会会刊:英文版》 EI CSCD 1997年第2期35-38,共4页
POTENTIALpHDIAGRAMSOFAlH2OSYSTEM①ZengWenming,ChenNianyiShanghaiInstituteofMetalurgy,ChineseAcademyofScienc... POTENTIALpHDIAGRAMSOFAlH2OSYSTEM①ZengWenming,ChenNianyiShanghaiInstituteofMetalurgy,ChineseAcademyofSciences,Shanghai200050... 展开更多
关键词 AL H 2O system POTENTIAL PH diagram THERMODYNAMICS
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E-pH diagram of ZnS-H_2O system during high pressure leaching of zinc sulfide 被引量:3
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作者 牟望重 张廷安 +5 位作者 刘燕 古岩 豆志河 吕国志 鲍丽 张伟光 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第10期2012-2019,共8页
The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and differ... The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and different temperatures were drawn through thermodynamical calculation.With the temperature increasing,the stable regions of S and Zn(Ⅱ) in the E-pH diagrams become gradually larger,but the amplification decreases over 150℃.The impacts of leaching parameters,such as temperature,liquid to solid ratio,initial acidic concentration,leaching time,oxygen partial pressure and stirring speed on the leaching rate of Zn(Ⅱ) and conversion rate of S in the single factor of high pressure leaching experiment of ZnS in autoclave,were studied.The leaching residue was examined by X-ray fluorescence(XRF) chemical composition identification and X-ray diffraction(XRD) phase identification,and the content of the leaching solution was tested by inductively coupled plasma-atomic emission spectrometry(ICP).The experimental results indicate that the leaching rate of zinc increases from 60.05% to 97.85% and the conversion rate of sulfur increases from 38.90% to 80.92% with the temperature increasing from 110℃ to 150℃,5:1 of liquid-to-solid ratio,150 g/L of initial acidic concentration,120 min of leaching time,0.8 MPa of oxygen partial pressure,and 480 r/min of stirring speed,which tend to be stable over 150℃.The experimental results correspond with theoretical calculation. 展开更多
关键词 高压浸出 硫化锌 电感耦合等离子体原子发射光谱 pH图 H2O 热力学计算 电子 X射线衍射仪
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A NEW METHOD OF COMPUTING MULTI-COMPONENT E-pH DIAGRAMS
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作者 Zhang Chuanfu Liu Haixia Zeng Dewen Li Changjun (Department of Nonferrous Metallurgy, Central South University of Technology, Changsha 410083, China) 《Journal of Central South University》 SCIE EI CAS 1999年第1期24-28,共5页
Duetothedecreaseofhighgradeores,lowgradeoresarecommonlyminedandhydrometalurgicalprocesesbecomemoreimportan... Duetothedecreaseofhighgradeores,lowgradeoresarecommonlyminedandhydrometalurgicalprocesesbecomemoreimportant.Besides,environ... 展开更多
关键词 computation algorithm of E PH diagramS component activity term M H 2O SYSTEM M S H 2O SYSTEM atom ratios
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Petrochemical eigenvalues and diagrams for the identification of metamorphic rocks'protolith,taking the host rocks of Dashuigou tellurium deposit in China as an example 被引量:1
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作者 Jianzhao Yin Shoupu Xiang +2 位作者 Yuhong Chao Yuhan Yin Hongyun Shi 《Acta Geochimica》 EI CAS CSCD 2023年第1期103-124,共22页
The Dashuigou tellurium deposit is the world’s only known independent tellurium deposit.By restoring metamorphic rocks’protolith,we seek to understand not only the development and evolution trajectory of the region ... The Dashuigou tellurium deposit is the world’s only known independent tellurium deposit.By restoring metamorphic rocks’protolith,we seek to understand not only the development and evolution trajectory of the region but also the origin of the relevant deposits.While there are many ways to restore metamorphic rocks’protolith,we take the host metamorphic rocks of Dashuigou tellurium deposit and leverage various petrochemical eigenvalues and related diagrams previously proposed to reveal the deposit’s host metamorphic rocks’protolith.The petrochemical eigenvalues include molecular number,Niggli’s value,REE parity ratio,CaO/Al_(2)O_(3)ratio,Fe^(3+) /(Fe^(3+) -+Fe^(2+) )ratio,chondrite-normalized REE value,logarithmic REE value,various REE eigenvalues including scandium,Eu/Sm ratio,total REE amount,light and heavy REEs,δEu,Eu anomaly,Sm/Nd ratio,and silicon isotope δ^(30) SiNBS-29‰,etc.The petrochemical plots include ACMs,100 mg-c-(al+alk),SiO_(2)-(Na_(2)O+K_(2)O),(al+fm)-(c+alk)versus Si,FeO+Fe_(2)O^(3+) TiO)-Al_(2)O_(3)-MgO,c-mg,Al_(2)O_(3)-(Na_(2)O+K_(2)O),chondrite-normalized REE model,La/Yb-REE,and Sm/Nd ratio,etc.On the basis of these comprehensive analyses,the following conclusions are drawn,starting from the many mantle-derived types of basalt developed in the study area of different geological ages,combined with the previously published research results on the deposit s fluid inclusions and sulfur and lead isotopes.The deposit is formed by mantle degassing in the form of a mantle plume in the late Yanshanian orogeny.The degassed fluids are rich in nano-sc ale substances including Fe,Te,S,As,Bi,Au,Se,H_(2),CO_(2),N_(2),H_(2)O,and CH_(4),which are enriched by nano-effect,and then rise to a certain part of the crust in the form of mantle plume along the lithospheric fault to form the deposit.The ultimate power for tellurium mineralization was from H_(2)flow with high energy,which was produced through radiation from the melted iron of the Earth’s outer core.The H,flow results in the Earth’s degassing,as well as the mantle and crust’s uplift. 展开更多
关键词 Petrochemical diagrams and eigenvalue PROTOLITH Metamorphic rock Independent tellurium deposit Host rock The mantle plume
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A new look atφ-pH diagram(Ⅰ)——All-equilibriumφ-pH diagram for M-H_(2)O system
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作者 刘海霞 张传福 曾德文 《中国有色金属学会会刊:英文版》 CSCD 2000年第6期808-812,共5页
A new viewpoint of computer program poubaix diagram was proposed on traditional φ pH diagrams. All equilibrium principle and activity term method were used to plot φ pH diagrams for M H 2O systems based on the therm... A new viewpoint of computer program poubaix diagram was proposed on traditional φ pH diagrams. All equilibrium principle and activity term method were used to plot φ pH diagrams for M H 2O systems based on the thermochemical database developed. And a new method——arithmetic geometric method is used to solve nonlinear equations group. The calculation procedure is proved to be efficient and convergent. The method seldom depends on artificial intervention and can extend to multi component all equilibrium φ pH diagrams such as M ligand H 2O system. [ 展开更多
关键词 Pourbaix diagram activity term method all-equilibrium nonlinear equation group Pb-H_(2)O system
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Solving Algebraic Problems with Geometry Diagrams Using Syntax-Semantics Diagram Understanding
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作者 Litian Huang Xinguo Yu +1 位作者 Lei Niu Zihan Feng 《Computers, Materials & Continua》 SCIE EI 2023年第10期517-539,共23页
Solving Algebraic Problems with Geometry Diagrams(APGDs)poses a significant challenge in artificial intelligence due to the complex and diverse geometric relations among geometric objects.Problems typically involve bo... Solving Algebraic Problems with Geometry Diagrams(APGDs)poses a significant challenge in artificial intelligence due to the complex and diverse geometric relations among geometric objects.Problems typically involve both textual descriptions and geometry diagrams,requiring a joint understanding of these modalities.Although considerable progress has been made in solving math word problems,research on solving APGDs still cannot discover implicit geometry knowledge for solving APGDs,which limits their ability to effectively solve problems.In this study,a systematic and modular three-phase scheme is proposed to design an algorithm for solving APGDs that involve textual and diagrammatic information.The three-phase scheme begins with the application of the statetransformer paradigm,modeling the problem-solving process and effectively representing the intermediate states and transformations during the process.Next,a generalized APGD-solving approach is introduced to effectively extract geometric knowledge from the problem’s textual descriptions and diagrams.Finally,a specific algorithm is designed focusing on diagram understanding,which utilizes the vectorized syntax-semantics model to extract basic geometric relations from the diagram.A method for generating derived relations,which are essential for solving APGDs,is also introduced.Experiments on real-world datasets,including geometry calculation problems and shaded area problems,demonstrate that the proposed diagram understanding method significantly improves problem-solving accuracy compared to methods relying solely on simple diagram parsing. 展开更多
关键词 Algebraic problems with geometry diagrams problem-solving geometry diagram understanding state-transformer paradigm syntax-semantics model
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Prediction and Verifcation of Forming Limit Diagrams Based on a Modifed Shear Failure Criterion
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作者 Haibo Wang Zipeng Wang +1 位作者 Yu Yan Yuanhui Xu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第5期364-373,共10页
The forming limit diagram plays an important role in predicting the forming limit of sheet metals.Previous studies have shown that,the method to construct the forming limit diagram based on instability theory of the o... The forming limit diagram plays an important role in predicting the forming limit of sheet metals.Previous studies have shown that,the method to construct the forming limit diagram based on instability theory of the original shear failure criterion is efective and simple.The original shear instability criterion can accurately predict the left area of the forming limit diagram but not the right area.In this study,in order to improve the accuracy of the original shear failure criterion,a modifed shear failure criterion was proposed based on in-depth analysis of the original shear failure criterion.The detailed improvement strategies of the shear failure criterion and the complete calculation process are given.Based on the modifed shear failure criterion and diferent constitutive equations,the theoretical forming limit of TRIP780 steel and 5754O aluminum alloy sheet metals are calculated.By comparing the theoretical and experimental results,it is shown that proposed modifed shear failure criterion can predict the right area of forming limit more reasonably than the original shear failure criterion.The efect of the pre-strain and constitutive equation on the forming limits are also analyzed in depth.The modifed shear failure criterion proposed in this study provides an alternative and reliable method to predict forming limit of sheet metals. 展开更多
关键词 Modifed shear failure criterion Sheet metal forming Forming limit diagram Loading path
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A reasoning diagram based method for fault diagnosis of railway point system
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作者 Feng Wang Yuan Cao +4 位作者 Clive Roberts Tao Wen Lei Tan Shuai Su Tao Tang 《High-Speed Railway》 2023年第2期110-119,共10页
Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing met... Railway Point System(RPS)is an important infrastructure in railway industry and its faults may have significant impacts on the safety and efficiency of train operations.For the fault diagnosis of RPS,most existing methods assume that sufficient samples of each failure mode are available,which may be unrealistic,especially for those modes of low occurrence frequency but with high risk.To address this issue,this work proposes a novel fault diagnosis method that only requires the power signals generated under normal RPS operations in the training stage.Specifically,the failure modes of RPS are distinguished through constructing a reasoning diagram,whose nodes are either binary logic problems or those that can be decomposed into the problems of the binary logic.Then,an unsupervised method for the signal segmentation and a fault detection method are combined to make decisions for each binary logic problem.Based on the results of decisions,the diagnostic rules are established to identify the failure modes.Finally,the data collected from multiple real-world RPSs are used for validation and the results demonstrate that the proposed method outperforms the benchmark in identifying the faults of RPSs. 展开更多
关键词 Railway point system Fault diagnosis Reasoning diagram SEGMENTATION Detection method
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Reliability Analysis of Satellite Turntable System under Multiple Operation Modes Based on Multi-Valued Decision Diagrams
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作者 Peng Zhang Zhijie Zhou +2 位作者 Yao Ding Dao Zhao Yijun Zhang 《Journal of Beijing Institute of Technology》 EI CAS 2023年第1期52-68,共17页
As a payload support system deployed on satellites,the turntable system is often switched among different working modes during the on-orbit operation,which can experience great state changes.In each mode,the missions ... As a payload support system deployed on satellites,the turntable system is often switched among different working modes during the on-orbit operation,which can experience great state changes.In each mode,the missions to be completed are different,consecutive and non-over-lapping,from which the turntable system can be considered to be a phased-mission system(PMS).Reliability analysis for PMS has been widely studied.However,the system mode cycle characteristic has not been taken into account before.In this paper,reliability analysis method of the satellite turntable system is proposed considering its multiple operation modes and mode cycle characteristic.Firstly,the multi-valued decision diagrams(MDD)manipulation rules between two adjacent mission cycles are proposed.On this basis,MDD models for the turntable system in different states are established and the reliability is calculated using the continuous time Markov chains(CTMC)method.Finally,the comparative study is carried out to show the effectiveness of our proposed method. 展开更多
关键词 phased-mission systems multi-valued decision diagrams continuous time Markov chains(CTMC) reliability analysis satellite turntable system
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钼酸钙浸出体系lgc-pH图的构建及其浸出行为分析
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作者 张文娟 车键勇 +4 位作者 朱纪念 陈国举 夏柳 陈军 王成彦 《Journal of Central South University》 SCIE EI CAS CSCD 2023年第2期465-476,共12页
CaMoO_(4)是钼钨钙矿的主要成分,也是钼冶金过程中重要的中间产物。目前,钼酸钙的浸出主要集中于工业实践及实验研究,而浸出过程的热力学分析较少且不够系统。本文通过绘制Ca-Mo-H_(2)O,Ca-Mo-PO_(4)-H_(2)O,Ca-Mo-SiO_(4)-H_(2)O,Ca-Mo... CaMoO_(4)是钼钨钙矿的主要成分,也是钼冶金过程中重要的中间产物。目前,钼酸钙的浸出主要集中于工业实践及实验研究,而浸出过程的热力学分析较少且不够系统。本文通过绘制Ca-Mo-H_(2)O,Ca-Mo-PO_(4)-H_(2)O,Ca-Mo-SiO_(4)-H_(2)O,Ca-Mo-CO_(3)-H_(2)O,Ca-Mo-Y(EDTA)-H_(2)O和Ca-Mo-F-H_(2)O体系的lgc-pH图,研究了钼酸钙在常用浸出体系(Na2EDTA,Na_(2)SiO_(3),Na_(3)PO_(4),Na_(2)CO_(3)和NaF)中的分解行为。结果表明,CaMoO_(4)及生成固体产物的稳定区依赖于pH值和浸出剂的浓度,适当的增加pH值和浸出剂浓度能够增加CaMoO_(4)的溶解,促进浸出反应的进行。基于热力学分析,研究了CaMoO_(4)在不同体系中的浸出行为,其结果与热力学分析完全吻合。本文构建的热力学图能够用于解释钼湿法冶金过程遇到的相关问题,并能够为CaMoO_(4)的处理提供热力学途径。 展开更多
关键词 热力学 钼酸钙 浸出 lgc-ph
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线上线下双模式教育的应用——以机械电子工程专业必修课《热力学与传热学基础》为例 被引量:1
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作者 支有冉 李果 +2 位作者 张烽 王云龙 汤巧云 《广东化工》 CAS 2024年第6期150-152,共3页
后疫情时代,为适应教学要求,逐渐衍生出线上线下双模式的教学方式。本文以机械电子工程专业的必修课《热力学与传热学基础》为例介绍了线上线下双模式教育在教学中的应用。首先介绍了《热力学与传热学基础》这门专业必修课的主要授课内... 后疫情时代,为适应教学要求,逐渐衍生出线上线下双模式的教学方式。本文以机械电子工程专业的必修课《热力学与传热学基础》为例介绍了线上线下双模式教育在教学中的应用。首先介绍了《热力学与传热学基础》这门专业必修课的主要授课内容、学习目标和考核标准,其次以理想气体基本热力学过程的p-v图和T-s图为例,说明了双模式教育的应用为教学带来的好处。 展开更多
关键词 热力学与传热学基础 双模式教育 教学应用 P-V图 T-S图
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Effects of Hydrophobicity of Ethylene Oxide-Propylene Oxide Copolymers on Phase Diagrams of Aqueous Two-Phase Systems and Partition Behaviors of Cephalexin and 7-Aminodeacetoxicephalos-poranic Acid
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作者 朱建航 魏东芝 曹学君 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第2期240-243,共4页
A series of ethylene oxide(EO)-propylene oxide (PO) random co-polymers (EOPO) were used to form aqueous two-phase systems (ATPS) with ammonium sulfate.Effects of EOPO′s properties on the phase separation behaviors an... A series of ethylene oxide(EO)-propylene oxide (PO) random co-polymers (EOPO) were used to form aqueous two-phase systems (ATPS) with ammonium sulfate.Effects of EOPO′s properties on the phase separation behaviors and on the partition of cephalexin and 7-aminodesacetoxicephalosporanic acid(7-ADCA) in ATPS were investigated.Both the molar mass and molar ratio of EO to PO of EOPO could greatly influence partition behaviors of cephalexin and 7-ADCA as well as the binodal curve of ATPS. With the increase of molar mass of co-polymer or the decrease of molar ratio of EO to PO,the critical point of ATPS decreased,the binodal curve became more asymmetry,and both cephalexin and 7-ADCA followed the same tendency to partition into the polymer-poor bottom phase.The experimental results shows that it is feasible to partition cephalexin and 7-ADCA in either the polymer-rich top phase or the polymer-poor bottom phase by choosing a specific phase-forming EOPO. 展开更多
关键词 疏水性 乙撑氧-环氧丙烷共聚物 头孢氨卡 含水丙相系统
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眩晕患者冷热实验荚形图的结果可靠性分析
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作者 李淑静 王东海 +4 位作者 王郁 杜一 刘兴健 任丽丽 吴子明 《听力学及言语疾病杂志》 CAS CSCD 北大核心 2024年第1期6-10,共5页
目的分析眩晕患者冷热实验荚形图类型,了解冷热实验结果的准确性及可靠性,为前庭系统功能评估提供更准确可靠的依据。方法总结分析眩晕诊疗中心2021年7月至2022年5月528例眩晕患者的冷热实验结果,按照荚形图形态及单侧反应减弱(unilater... 目的分析眩晕患者冷热实验荚形图类型,了解冷热实验结果的准确性及可靠性,为前庭系统功能评估提供更准确可靠的依据。方法总结分析眩晕诊疗中心2021年7月至2022年5月528例眩晕患者的冷热实验结果,按照荚形图形态及单侧反应减弱(unilateral weakness,UW)分为荚形图冷热对称组、左右对称组、单值显著异常组、双侧数值减下组以及荚形图形态不能分类组,通过比较不同组别UW的结果,对其进行解释及归纳,来辨识不可靠数据,从而减少不可靠数据对临床诊疗的干扰。结果冷热对称的荚形图(439例)表现为双侧前庭功能对称(273例)及一侧前庭功能减低(166例),同侧耳双温刺激冷热气刺激慢相角速度(SPV)差异无统计学意义(P>0.05);左右侧别对称荚形图(14例)包括双侧前庭功能对称(11例)和一侧减低(13例),同侧耳双温刺激SPV值差异有统计学意义(P<0.05);单值显著异常荚形图(36例)包括一侧前庭功能减低(25例)和双侧前庭功能对称(11例),同侧耳双温刺激SPV值差异有统计学意义(P<0.05);双侧数值减低荚形图(34例)可表现为双侧前庭功能对称(25例)及一侧减低(9例),同侧耳双温刺激SPV差异无统计学意义(P>0.05);荚形图形态不能分类(5例)提示干扰因素较多。结论冷热实验显示双耳外周前庭功能对称且正常时,要警惕荚形图中温度效应的存在,需考虑对灌注器的检视及灌注温度的校准;冷热实验提示一侧前庭功能减低时,要注意荚形图中单个数值显著增高或减低的情况,建议重复灌注,仍无改变时,建议重复另一耳此温度下的灌注,甚至重复整个冷热实验;冷热实验荚形图提示双耳外周前庭功能减低时,UW值不能真实反应双侧前庭功能的状态,可改用水灌注重复,并结合病史及其他辅助检查做出正确判断。荚形图的形态结合UW值来综合判断冷热实验的有效性有重要意义。 展开更多
关键词 温度实验 荚形图 可靠性
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应力驱动的2.5D梯度各向异性维诺多孔零件轻量化建模方法
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作者 曹伟 潘文珺 +2 位作者 刘斌 路平 江开勇 《计算机集成制造系统》 EI CSCD 北大核心 2024年第3期1036-1049,共14页
为了提高多孔零件的设计自由度、内部力学性能梯度与实际应力分布的匹配度,提出一种应力驱动的2.5D梯度各向异性维诺多孔零件轻量化设计方法。将零件有限元分析结果分解为应力标量场和应力方向场,通过加权随机采样算法将应力标量场映射... 为了提高多孔零件的设计自由度、内部力学性能梯度与实际应力分布的匹配度,提出一种应力驱动的2.5D梯度各向异性维诺多孔零件轻量化设计方法。将零件有限元分析结果分解为应力标量场和应力方向场,通过加权随机采样算法将应力标量场映射为零件设计域内的维诺站点分布,实现零件内部力学性能的梯度分布;将应力方向场映射为二维黎曼流形,提出一种基于胞元择优方向生长策略的各向异性维诺图生成算法,生成胞元沿黎曼流形分布的各向异性维诺图。在此基础上,通过偏置算法、调和距离场和拉伸算法生成光滑的梯度各向异性维诺多孔零件。最后,采用有限元分析、三点弯曲实验等方法将所设计的多孔零件和其他多孔零件进行比较分析。实验结果表明,所提出的梯度各向异性维诺多孔零件建模方法能有效提升零件内部力学性能梯度与实际应力分布的匹配度,降低材料消耗,实现轻量化设计。 展开更多
关键词 轻量化设计 多孔结构 各向异性 梯度 维诺图
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二维图纸驱动三维建模的方法
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作者 王炬成 张世超 +2 位作者 戴震 袁飞晖 朱小敏 《船海工程》 北大核心 2024年第3期23-28,共6页
针对船舶设计过程中二维图纸和三维模型之间缺乏有效关联关系的现状,开展二维图纸驱动三维模型的方法研究。开展常用二维原理图绘制软件CAD和SP P&ID的对比分析;针对CAD软件和SP P&ID两种软件输出的不同形式的二维原理图,分别... 针对船舶设计过程中二维图纸和三维模型之间缺乏有效关联关系的现状,开展二维图纸驱动三维模型的方法研究。开展常用二维原理图绘制软件CAD和SP P&ID的对比分析;针对CAD软件和SP P&ID两种软件输出的不同形式的二维原理图,分别开展二维原理图驱动三维模型的方法研究,分析二维原理图驱动三维建模的流程,研究二维原理图驱动三维建模的机理,解决二维原理图和三维模型之间数据分离的问题,提高船舶设计效率。 展开更多
关键词 二维原理图 驱动 三维模型
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读《太极图说》对人文医学的意义
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作者 王永炎 范逸品 《天津中医药》 CAS 2024年第5期545-547,共3页
宋代新儒家周敦颐改绘了当时流传的“太极图”,并撰著《太极图说》,诠释“太极图”。文章虽然是周敦颐研究易学哲理思想的心得体会,但是蕴含有深刻的宇宙自然科学哲理和广博的人文哲学精神内涵,对于当今医学工作者仍然有重要的启迪意义。
关键词 周敦颐 《太极图说》 科学 人文
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