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Symplectic schemes and symmetric schemes for nonlinear Schr¨odinger equation in the case of dark solitons motion

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第6期12卷 150-167页

作者： yiming yao Miao Xu Beibei Zhu Quandong Feng College of Science Beijing Forestry University Beijing 100083P.R.China School of Mathematics and Physics University of Science and Technology Beijing Beijing 100083 P.R.China

In this paper,symplectic schemes and symmetric schemes are presented to simulate Nonlinear Schrodinger Equation(NLSE)in case of dark soliton ***,by Ablowitz–Ladik model(A–L model),the NLSE is discretized into a non-canonical Hamiltonian ***,different kinds of coordinate transformations can be used to standardize the non-canonical Hamiltonian ***,the symplectic schemes and symmetric schemes can be employed to simulate the solitons motion and test the preservation of the invariants of the A–L model and the conserved quantities approximations of the original *** numerical experiments show that symplectic schemes and symmetric schemes have similar simulation effect,and own significant superiority over non-symplectic and non-symmetric schemes in long-term tracking the motion of solitons,preserving the invariants and the approximations of conserved ***,it is obvious that coordinate transformations with more symmetry have a better simulation effect.

关键词： Symplectic schemes symmetric schemes nonlinear Schr¨odinger equation dark solitons motion Ablowitz–Ladik model

Property and Oxidation Behaviours of (Mo,Cr)Si2 + ZrO2 Composite Produced by Pressure-Less Sintering

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Journal of Materials Science and Chemical Engineering 2016年第7期4卷 15-21页

作者： yiming yao Erik Ström Xin-Hai Li Qin Lu Department of Materials and Manufacturing Technology Chalmers University of Technology Gothenburg Sweden Heating Systems Division Sandvik Heating Technology AB Hallstahammar Sweden Material Technology Siemens Industrial Turbomachinery AB Finspong Sweden

A composites of (Mo0.9Cr0.1)Si2 + 15vol% ZrO2 was prepared with powder metallurgy and Pressure- Less Sintering (PLS) method, aiming at applications of high temperature structural materials. Mechanical properties of the composites were assessed with hardness, indentation fracture toughness Kc and KIC tested using SEVNB, flexure strength at room temperature and 1200?C, and isothermal oxidation at 1400?C. The results showed that the native silica oxide and molybdenum-oxides on the silicide feedstock surface were significantly reduced in terms of Cr-alloying. (Mo0.9Cr0.1)Si2 and its composite also exhibited improved sinterability and grain growth, owing to the presence of (Cr, Mo)5Si3 at grain boundaries. Fracture toughness of the composite was increased by a factor of 1.6 to that in the monolithic silicide. Mechanical property of the composite at high temperature was not affected by Cr addition. However, the high temperature oxidation resistance was greatly improved in the (Mo0.9Cr0.1)Si2 + 15vol% ZrO2 compared with the non Cr-alloyed counterpart. The Cr-alloying effects on the microstructure, fracture behaviour, and high temperature oxidation resistance were discussed.

关键词： MoSi2 Composite Fracture Toughness Mechanical Property Microstructure High Temperature Oxidation

Microstructure of Plasma Sprayed Al2O3-3wt%TiO2 Coating Using Freeze Granulated Powder

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Journal of Materials Science and Chemical Engineering 2016年第7期4卷 8-14页

作者： yiming yao Ola Lyckfeldt Aurélien Tricoire Aurélien Tricoire Department of Materials and Manufacturing Technology Chalmers University of Technology Gothenburg Sweden Swerea IVF AB Material Applications-Ceramics M?lndal Sweden GKN Aerospace Sweden AB Trollh?ttan Sweden

This study is aiming at controlling the microstructure of plasma sprayed Al2O3-TiO2 composite coatings using freeze granulated powders. As sprayed and sintered Al2O3 + 3wt%TiO2 powders were air plasma sprayed with industry process parameters and compared with a commercial powder. The resulting coatings were investigated with respect to powder flowability, porosity and microstructure of the granules. The results showed that microstructure and melting fraction in the coatings could be tailored with the freeze granulation process and heat treatment conditions.

关键词： Al2O3-TiO2 Freeze Granulation Plasma Spray Microstructure

Thyroid Hormone Biomonitoring:A Review on Their Metabolism and Machine-Learning Based Analysis on Effects of Endocrine Disrupting Chemicals

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Environment & Health 2024年第6期2卷 350-372页

作者： Shijie Chen Mengjie Yu yiming yao Yongcheng Li Ana He Zijun Zhou Liyang Pan Nan Xiao Haining Luo Hongwen Sun MOE Key Laboratory of Pollution Processes and Environmental Criteria College of Environmental Science and EngineeringNankai UniversityTianjin 300071China Tianjin Tianshi College Tianjin 301700China Dalian Center for Disease Control and Prevention DalianLiaoning Province 116000China Department of Center for Reproductive Medicine Tianjin Central Hospital Of Gynecology Obstetrics/Tianjin Key Laboratory Of Human Development And Reproductive RegulationTianjin 300052China

The thyroid is an essential endocrine organ in human body,and thyroid hormones(THs)are pivotal signaling molecules and mediators in various physiological ***,particularly in their free form,play a critical role in regulating body temperature and in the metabolism of lipid and glucose,making the maintenance of TH levels crucial for human *** undergo a series of metabolic processes,producing TH metabolites(THMs).THMs are significant in endocrine regulation,such as 3,5-diiothyronine(3,5-T2)and 3-iodothyronamine(3-T1AM),which exhibit activities akin to *** production and distribution of THMs are intricately linked to the function of specific organs and tissues,highlighting the need for advanced research into the determination and mechanisms of THMs in *** to endocrine disrupting chemicals(EDCs)can significantly affect the levels of thyroid stimulating hormone(TSH)and *** review utilizes machine learning to analyze epidemiological data,identifying potential EDCs that pose risks of hyperthyroidism and ***,it delves into the toxicological mechanisms of these EDCs,examining their effects on TH production,binding processes,related proteins,and metabolic *** approach effectively bridges the gap between epidemiological studies and toxicological researches,laying the groundwork for future research *** integrating epidemiological studies with machine learning,this review offers insightful perspectives on the potential risks associated with chemical exposure and underscores the necessity for further research in understanding the impact of EDCs on TH metabolism and TH-related health effects.

关键词： Thyroid stimulating hormone Emerging contaminants Data mining Thyroxine 3,3′,5-Triiodothyronine Homeostasis

WEAK BOUNDS FOR ROUGH SQUARE AND MAXIMAL OPERATORS

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Applied Mathematics(A Journal of Chinese Universities) 2001年第2期16卷 161-170页

作者： Ying yiming  yao KuiDept.ofMath.,ZhejiangUniv.(XiXiCampus),Hangzhou310028.InstituteofSciences,PLAUniv.ofScienceandTechnology,Nanjing211101. Dept. of Math. Zhejiang Univ. (XiXi Campus) Hangzhou Institute of Sciences PLA Univ. of Science and Technology Nanjing

With Ω ∈ L (log + L)(S n-1 ) and suitable h ∈ L γ (R 1)(1<γ≤2),the weak type (1,1) of the square function g(f)(x) =k｜ψ k*f｜ 2 12(x) and the maximal operator M ψ(f)(x) = sup... 详细信息

With Ω ∈ L (log + L)(S n-1 ) and suitable h ∈ L γ (R 1)(1<γ≤2),the weak type (1,1) of the square function g(f)(x) =k｜ψ k*f｜ 2 12(x) and the maximal operator M ψ(f)(x) = sup k｜ψ k｜*｜f｜(x) where ψ(x)=｜x｜ -n Ω(x)h(｜x｜),ψ k(x)=ψ 2 k (x), are studied in this *** a corollary,the weak bounds of M Ω(f) proved by Christ in 1988 are given and the previous weak type results for M ψ(f)(x) are *** addition,the weighted weak type (1,1) estimates of the Littlewood Paley function g ψ(f) with power weights is also proved.

关键词： Square functions maximal operators rough kernel power weight.

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公路建设项目土地经济损失的定量评价

环境污染与防治 1999年第6期21卷 25-27页

作者：姚炎明王英浙江大学海洋科学与工程系杭州310028 浙江省环境保护科学设计研究院杭州310007

公路建设项目中，长距离、大范围的土地征用会带来一系列的社会环境问题，世界银行贷款组织对此提出要求，必须在公路建设获取发展交通运输效益的同时，对项目的土地损失作出评价，提出相应的补偿措施。通过引用投资项目经济评价中的土... 详细信息

公路建设项目中，长距离、大范围的土地征用会带来一系列的社会环境问题，世界银行贷款组织对此提出要求，必须在公路建设获取发展交通运输效益的同时，对项目的土地损失作出评价，提出相应的补偿措施。通过引用投资项目经济评价中的土地机会成本概念及有关模式参数，分析计算所征用土地的原有价值。并由此提出所征用土地经济损失评价的定量方法，用于预测公路建设中因土地损失引起的经济影响。

关键词：公路建设项目土地经济损失定量评价征用土地

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解吸附可降解乳液型降阻剂研究

钻井液与完井液 2024年第4期41卷 537-545页

作者：黄静姚奕明中石化石油工程技术研究院有限公司北京102206

针对浅层常压页岩气吸附气含量高,难以提高产量实现有效开采及常规聚合物降阻剂难以实现自然降解的问题,通过水相分散聚合合成无油相乳液型降阻剂。通过摩阻仪、磁悬浮天平等对降阻剂及其形成的降阻水体系进行性能评价,实验结果表明,利... 详细信息

针对浅层常压页岩气吸附气含量高,难以提高产量实现有效开采及常规聚合物降阻剂难以实现自然降解的问题,通过水相分散聚合合成无油相乳液型降阻剂。通过摩阻仪、磁悬浮天平等对降阻剂及其形成的降阻水体系进行性能评价,实验结果表明,利用该降阻剂配制的0.6%~1.0%降阻水体系实验室降阻率均达到70%以上,现场降阻率84%,解吸附实验结果表明产品解吸率达到85%,远超常规乳液降阻剂产品,具有较高的工程实用性,可以满足施工的要求;使用特性黏数法评价了降阻剂的自然降解能力,其在95℃下330 h能够实现自然降解,降解率达到86%,岩心伤害率远低于胍胶体系,IC50测试结果表明该降阻剂在使用浓度下无毒环保。为开发浅层常压页岩气提供了技术借鉴和新的产品思路。

关键词：降阻剂分散聚合降阻水丙烯酰胺

出口退税政策效用的实验性评估——基于倍差法分析的再检验

同方期刊数据库博看期刊评论

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北京理工大学学报（社会科学版） 2016年第6期18卷 99-105页

作者：魏艺明姚博西安交通大学经济与金融学院西安710061

选取2007年7月退税率调低政策事件作为实验环境,研究出口退税率调低对贸易商品的月度同比增长率的影响。结果表明:退税率调低对初级品类商品的贸易增长率有较大的负向效果,对资源类商品贸易增长率影响并不明显。稳健性检验显示出口退税... 详细信息

选取2007年7月退税率调低政策事件作为实验环境,研究出口退税率调低对贸易商品的月度同比增长率的影响。结果表明:退税率调低对初级品类商品的贸易增长率有较大的负向效果,对资源类商品贸易增长率影响并不明显。稳健性检验显示出口退税率调整对贸易增长率影响具有一定的连续性和滞后性,对不同商品产生的作用有很大差异,经由调整窗宽、反事实检验和引入3次大规模政策调整扩展分析,印证了文中结论。政策制定者对贸易涉及产品的市场环境以及行业特点等因素有正确评估,选择恰当的退税率调整政策商品贸易组合,会有助于实现其目标。

关键词：退税率出口增长率倍差法

基于轮轨非Hertz接触的影响系数的有限元计算方法

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同济大学学报（自然科学版） 2017年第10期45卷 1476-1482页

作者：杨新文姚一鸣周顺华同济大学道路与交通工程教育部重点实验室上海201804

采用非Hertz接触理论求解轮轨接触问题时,影响系数对轮轨接触应力与接触斑大小产生重要影响.由于当车轮轮缘与钢轨在轨距角处发生接触时,非Hertz接触理论中基于弹性半空间条件下的影响系数已不适用,所以利用有限元方法求解了全空间内轮... 详细信息

采用非Hertz接触理论求解轮轨接触问题时,影响系数对轮轨接触应力与接触斑大小产生重要影响.由于当车轮轮缘与钢轨在轨距角处发生接触时,非Hertz接触理论中基于弹性半空间条件下的影响系数已不适用,所以利用有限元方法求解了全空间内轮轨非Hertz接触的影响系数,并对Kalker的非Hertz接触理论做了修正.在保证计算效率的前提下,以30t轴重重载铁路CHN75钢轨和LM磨耗车轮踏面为例,采用修正的非Hertz理论及轮轨接触分区模型P_M(partition model)分别计算了轮对横移量为0~8mm时的轮轨接触斑面积及接触斑应力.研究结果表明,用有限元法计算出的影响系数大于Bossinisqe-Cerruti公式求出的影响系数,并且在轨距角处的影响系数大于轨顶处.修正的非Hertz理论计算出的法向应力和接触斑面积始终要比P_M模型计算出的法向应力略大一些,且随轮对横移量的增加,两种轮轨法向接触模型计算出的法向应力和接触斑趋势一致.当横移量为0~4mm时,最大接触斑面积可达173.75mm2,轮轨型面较为匹配;当横移量持续增大时,由于车轮与钢轨轨距角接触,接触面积急剧降低,同时法向应力急剧增大.

关键词：重载铁路轮轨接触 Bossinisqe—Cerruti公式分区模型