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Volume-averaged modeling of multiphase solidification with equiaxed crystal sedimentation in a steel ingot

China Foundry 2024年第3期21卷 229-238页

作者： Xiao-lei Zhu Shuang Cao Rui Guan Ji Yang Zhe Ning Xin-gang Ai sheng-li li Xin-cheng Miao The key Laboratory of Material Forming and Structure Property Control Anshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

Macrosegregation is a critical factor that limits the mechanical properties of *** impact of equiaxed crystal sedimentation on macrosegregation has been extensively studied,as it plays a significant role in determining the distribution of alloying elements and impurities within a *** improve macrosegregation in steel connecting shafts,a multiphase solidification model that couples melt flow,heat transfer,microstructure evolution,and solute transport was established based on the volume-averaged Eulerian-Eulerian *** this model,the effects of liquid phase,equiaxed crystals,columnar dendrites,and columnar-to-equiaxed transition(CET)during solidification and evolution of microstructure can be considered *** sedimentation of equiaxed crystals contributes to negative macrosegregation,where regions between columnar dendrites and equiaxed crystals undergo significant A-type positive macrosegregation due to the ***,noticeable positive macrosegregation occurs in the area of final solidification in the *** improvement in macrosegregation is beneficial for enhancing the mechanical properties of connecting *** mitigate the thermal convection of molten steel resulting from excessive superheating,reducing the superheating during casting without employing external fields or altering the design of the ingot mold is indeed an effective approach to control macrosegregation.

关键词： ingot casting multiphase solidification model equiaxed crystal sedimentation microstructure macrosegregation

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有机物鉴别方法融合于医药应用的探索

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化学教育（中英文） 2024年第2期45卷 98-103页

作者：向广艳李利生姚秋丽遵义医科大学药学院贵州遵义563000

对有机物的鉴别是有机化学课程的重点内容之一。然而,当前的有机化学教材针对上述内容的阐述多停留在化学原理层面,教学过程亦缺乏融入应用领域的现实案例,此现状不利于基础学科与应用学科的交叉融合,不利于学生构建前后衔接的知识体系... 详细信息

对有机物的鉴别是有机化学课程的重点内容之一。然而,当前的有机化学教材针对上述内容的阐述多停留在化学原理层面,教学过程亦缺乏融入应用领域的现实案例,此现状不利于基础学科与应用学科的交叉融合,不利于学生构建前后衔接的知识体系。在此背景下,将有机物鉴别原理与药物分析、法医鉴定、食品毒物分析、临床检测等领域的应用案例结合起来,从而推动有机化学案例版教材的编写,促进教育的多学科交叉融合。

关键词：有机化学鉴别反应案例教学课程融合医药领域

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在线分析仪在盐水系统中的应用

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中国氯碱 2024年第3期 29-35,64页

作者：李胜利张友平陕西北元化工集团股份有限公司化工分公司陕西榆林

介绍了盐水系统2035系列在线分析仪的原理、分析步骤以及优化改进措施,并论证了仪器的可靠性。

关键词：在线分析仪钙镁含量过碱量游离氯含量优化改进可行性论证

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新农科背景下设施农业科学与工程专业的实践教学体系研究

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教育教学论坛 2024年第14期 105-108页

作者：李严曼陈菲李胜利河南农业大学园艺学院河南郑州450046 河南农业职业学院园艺园林学院河南郑州451450

随着产业的发展,对于人才的要求也在不断提高。实践教学在应用型人才培养的过程中起着至关重要的作用,是培养学生动手和创新能力的重要途径,尤其是对于应用性较强的设施农业科学与工程专业。通过对该专业实践教学中的一些问题进行分析,... 详细信息

随着产业的发展,对于人才的要求也在不断提高。实践教学在应用型人才培养的过程中起着至关重要的作用,是培养学生动手和创新能力的重要途径,尤其是对于应用性较强的设施农业科学与工程专业。通过对该专业实践教学中的一些问题进行分析,然后从课程教材建设、教学基地、教学团队、教学方式、教学评价等几个方面对实践教学体系优化进行探讨,希望可以提高学生的实践动手能力,提高人才培养质量,增强毕业生就业竞争力,适应新农科发展需要。

关键词：设施农业科学与工程新农科人才培养实践教学

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Characterization of Phase Transition in Heisenberg Fluids from Density Functional Theory

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Communications in Theoretical Physics 2009年第2期51卷 287-292页

作者： li liang-sheng li li CHEN Xiao-Song Institute of Theoretical Physics Chinese Academy of Sciences P.O. Box 2735 Beijing 100190 China

The phase transition of Heisenberg fluid has been investigated with the density functional theory in mean-field approximation （MF）. The matrix of the second derivatives of the grand canonical potential Ω with respect to the particle density fluctuations and the magnetization fluctuations has been investigated and diagonalized. The smallest eigenvalue being 0 signalizes the phase instability and the related eigenvector characterizes this phase transition. We find a Curie line where the order parameter is pure magnetization and a spinodal where the order parameter is a mixture of particle density and magnetization. Along the spinodal, the character of phase instability changes continuously from predominant condensation to predominant ferromagnetic phase transition with the decrease of total density. The spinodal meets the Curie line at the critical endpoint with the reduced density p＊=pσ3=0.224 and the reduced temperature T＊ =kT/ε=1.87 （σ is the diameter of Heisenberg hard sphere and e is the coupling constant）.

关键词： critical phenomena order-disorder magnetic liquid

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Effects of Ni Content and Ball Milling Time on the Hydrogen Storage Thermodynamics and Kinetics Performances of La–Mg–Ni Ternary Alloys

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Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 961-971页

作者： Zhen-Yang li sheng-li li Ze-Ming Yuan Yang-Huan Zhang School of Materials Science and Engineering Shandong UniversityJinan 250061China Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010China Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China

The eifects of Ni content and ball milling time on the hydrogen storage thermodynamics and kinetics performances of asmilled La5Mg95-xNix(x=5,10,15)ternary alloys have been *** evolution of microstructure and phase of experimental alloys in the absorption/desorption process has been characterized by XRD,SEM and *** hydrogen storage kinetics and thermodynamics performances and PCI curves have been tested using the Sievert *** is found that the rising of Ni content remarkably improves the hydrogen storage kinetic performance,but reduces hydrogen storage *** with the increase in milling time,hydrogen desorption activation(Ea)value decreases firstly and then increases;the minimum value is 47.6 kJ/mol,and the corresponding milling time is 10 h for La5Mg85Ni10 *** for the thermodynamics properties,the hydrogenation enthalpy(△H)and hydrogenation entropy(△S)both decrease firstly and then increase with the rising of Ni content and milling *** composite La5Mg85Ni10 alloy milled for 10 h exhibits the best thermodynamics and kinetics performances,the lowest Ea of 47.6 kJ/mol,absorption of 5.4 wt.%within 5 min and desorption of 5.2 wt.%within 3 min at 360℃and the lowest△H and△S of 72.1 kJ/mol and 123.2 J/mol/K.

关键词： Hydrogen storage Mg-based alloys Thermodynamics and kinetics Ni content Milling time

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Optimization of flow uniformity control device for six-stream continuous casting tundish

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Journal of Iron and Steel Research International 2020年第9期27卷 1035-1044页

作者： Xin-gang Ai Dong Han sheng-li li Hong-bo Zeng Hui-ya li Key Laboratory of Chemical Metallurgy Engineering liaoning Province University of Science and Technology LiaoningAnshan 114051LiaoningChina

For a multistream tundish,the uniformity among the streams plays a significant role in the quality of molten *** to analyze the uniformity quantitatively and optimize structures of a multistream tundish is an important research content for a multistream tundish.A new approach was proposed to quantify the uniformity among the *** a physical study and a numerical study were carried out to optimize the structure of the diversion hole based on the prototype of a six-stream tundish in a steel *** the basis of average residence time,the uniformity of each flow was considered fully and then the optimal structure of the diversion hole was obtained by means of the comprehensive analysis of temperature field and velocity *** results show that the optimum structural parameters adopted for diversion holes are height of 20 mm,angle of 15°and diameter of 80 mm.

关键词： Multistream tundish Uniformity Diversion hole Physical simulation Numerical simulation

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Giant submucosal lipoma located in the descending colon: A case report and review of the literature

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World Journal of Gastroenterology 2007年第42期13卷 5664-5667页

作者： li Jiang li-sheng Jiang Fu-Yu li Hui Ye Ning li Nan-sheng Cheng Yong Zhou The First Department of General Surgery West China Hospital of Sichuan University Chengdu610041 Sichuan Province China

Colonic lipoma is an uncommon tumor of the gastrointestinal tract. Most cases are asymptomatic, with a small tumor size, and do not need any special treatment. However, we encountered one patient with a giant submucosal lipoma, with a maximum diameter of 8.5 cm, which exhibited symptoms such as intermittent lower abdominal pain, changes in bowel habits with passage of fresh blood and mucus per rectum, abdominal distension, anorexia and weight loss. Unfortunately, the possibility of colonic malignancy could not be precluded and leffc hemicolectomy was planned. The exact diagnosis of this special case was accomplished by intraoperative pathology. In the end, local resection was performed instead of left hemicolectomy. To the best of our knowledge, colonic lipoma exceeding 8 cm in diameter has not been previously reported. We, therefore, present this case and discuss age and sex factors, clinical and histopathological findings, diagnostic methods and treatment by reviewing the available literature, to serve as a reminder that colonic lipoma can also exist in patients with significant symptoms. In addition, intraoperative pathology should be investigated in those doubtful cases, so as to guide the exact diagnosis and treatment plan.

关键词： Colon lipoma Age, Diagnosis Therapy

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A Multi-step Thermodynamic Model for Alumina Formation during Aluminum Deoxidation in Fe–O–Al Melt

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Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 272-280页

作者： Guo-Cheng Wang Qi Wang sheng-li li Xin-Gang Ai Da-Peng li Key Laboratory of Chemical Metallurgy Engineering Liaoning Province University of Science and Technology Liaoning Jiangxi University of Science and Technology Benxi Steel Group Corporation

Based on the two-step nucleation mechanism, a multi-step thermodynamic model for alumina inclusion for- mation during aluminum deoxidation process was proposed in Fe-O-Al melt. Thermodynamic properties of metastable intermediates including （Al2O3）n clusters for prenucleation and α-Al2O3 nanoparticle for growth process were calculated using density functional theory. Furthermore, Gibbs free energy change of forming the intermediate by reaction between the dissolved aluminum （Al） and oxygen （O） in the melt was calculated. The results indicated that the thermodynamics of （Al2O3）n at steelmaking temperature are dependent on their structures, while that of α-Al2O3 nanoparticle are dependent on their size. The nuclei of α-Al2O3 which was originated from （Al2O3）n aggregated under a high supersaturation ratio of Al and O（Rs） in the melt. There existing excess oxygen because of the low Rs, but the secondary inclusions will be formed during the cooling process due to the excess oxygen. The nuclei lager than 20 nm can grow up spontaneously and instantaneously into primary inclusions because of thermodynamic drive. It is difficult to control the size of α-Al2O3 to be less than 20 nm, in the aluminum deoxidation process of the current conditions of steelmaking.

关键词： Multi-step thermodynamics Fe-O-AI melt Aluminum deoxidation DFT Nano-α-Al2O3

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Prevalence of Thrombocytopenia among Chinese Adult Antiretroviral-na（i）ve HIV-positive Patients

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Chinese Medical Journal 2015年第4期128卷 459-464页

作者： Hong-Wei Fan Fu-Ping Guo Yi-Jia li Ning li Tai-sheng li Department of Infectious Diseases Peking Union Medical College Hospital Chinese Academy of Medical Sciences Beijing 100730 China

Background：The prevalence ofthrombocytopenia among Chinese antiretroviral therapy （ART）-na（i）ve HIV-infected adults has not been *** aim of this study was to investigate the prevalence and associated risk factors of thrombocytopenia among Chinese ART-na（i）ve HIV-infected ***：We performed a cross-sectional study of Chinese adult ART-na（i）ve HIV-infected patients from September 2005 through August ***-demographic variables and laboratory results including platelets,CD4＋ cell count,and viral load were obtained from medical *** and outcomes associated with thrombocytopenia were assessed using logistic ***：A total of 1730 adult ART-na（i）ve HIV-infected patients was *** mean age was 38 *** prevalence of thrombocytopenia was 4.5％.There were significant differences in the prevalence of thrombocytopenia between patients ＜30 years of age （2.8％） and 30-39 years （4.0％） compared with patients greater than 50 years （7.0％）（P =0.006 and P =0.044,respectively）.The prevalence of thrombocytopenia was also significantly different between patients with CD4＋ counts of 200-349 cells/mm3 （3.3％） and ＞350 cells/mm3 （2.8％） compared with patients with CD4＋ counts of50-199 cells/mm3 （7.1％）（P =0.002 and P =0.005,respectively）.The prevalence of thrombocytopenia was significantly different by hepatitis C virus antibody （HCV-Ab） seropositivity （10.2％ for HCV-Ab positive vs.3.9％ for HCV-Ab negative,P =0.001）.We observed differences in prevalence of thrombocytopenia by mode of transmission of HIV infection：Blood transmission （10.7％） versus men who have sex with men （3.9％）（P =0.002） and versus heterosexual transmission （3.9％）（P =0.001）.In binary logistic regression analyses,age ≥＞50 years,HCV-Ab positivity and having a CD4＋ cell count of 50-199 cells/mm3 were significantly associated with thrombocytopenia with adjusted odds ratio of 2.482 （95％ confidence interval [CI]：1.167,5.281,P=0.018）,2.091 （95％ CI：1.078,4.055,P =0.029）

关键词： HIV Prevalence Thrombocytopenia

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