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Analytic Invariant Curves for an Iterative Equation Related to Ricker-type Second-order Equation

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Acta Mathematica Sinica,English Series 2021年第7期37卷 1041-1052页

作者： hou yu ZHAO Michal FECKAN School of Mathematics Chongqing Normal UniversityChongqing 401331P.R.China Department of Mathematical Analysis and Numerical Mathematics Comenius University in BratislavaMlynska dolina84248 BratislavaSlovakia Mathematical Institute of Slovak Academy of Sciences Stefanikova 4981473 BratislavaSlovakia

In this paper,we consider the existence of analytic invariant curves of an iterative equation f(f(x))=xea-x-f(x)which arises from Ricker-type second-order *** reducing the equation with the Schr?der transformation to an auxiliary equation,the author discusses not only that the parameter at resonance,i.e.,at a root of the unity,but also the parameter near resonance under the Brjuno condition.

关键词： Difference equation invariant curves analytic solution small divisor

Heat Transfer Characteristics of a Microchannel Heat Sink with Highly-Dense Micro-Jet Arrays

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Journal of Thermal Science 2024年第3期33卷 1148-1160页

作者： ZHANG yu CHEN Xiaoyan MIAO Lin CHEN Liang hou yu State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China Beijing Aerospace Technology Institute Beijing100083China

This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the influence of structure and flow parameters on the convective heat transfer of water jet cooling in confined *** simulation results show that the optimal jet width,jet spacing and impingement distance are around 0.2 mm,0.2 mm and 0.3 mm,respectively,which can achieve a low thermal resistance as well as a relatively low pressure *** analysis of the heat transfer pathways shows that the micro-fin jet structures can extend the impinging heat transfer area and conduct a considerable proportion of heat,which can reach up to 38.9%with the Reynolds number ranging from 797.1 to *** heat transfer characteristics in the heat sink will shift from impingement dominated heat transfer to the channel-convection dominated heat transfer as the jet impingement distance increases.A correlation is proposed to predict the average Nusselt number on the stagnation area for the heat sink with different structure parameters,and the deviations of predictions from the numerical results are less than 10%.

关键词： hybrid heat sink impingement microchannel thermal management high heat flux

Novel concept of recycling sludge and dust to BOF converter through dispersed in-situ phase induced by composite ball explosive reaction

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International Journal of Minerals,Metallurgy and Materials 2017年第8期24卷 863-868页

作者： Fu-ping Tang Shu-juan yu Peng Fei hou-yu hou Feng Qian Xiao-feng Wang Ansteel Group Corporation

Recycling of iron and steelmaking dusts is a key issue in environmental protection efforts and to ensure efficient utilization. In this investigation, we developed a novel recovery process that uses a dispersed in-situ phase induced by an explosive reaction of composite balls of iron and steelmaking dusts. We designed and prepared composite balls for this function using a laboratory model batch-type balling disc(at 12 r/min) and optimized the feeding modes in 180-t and 260-t basic oxygen furnace(BOF) converters. The results indicate that feeding composite balls into BOF converters is an effective novel technology for recovering iron and steelmaking dusts. The period after hot metal charging and prior to the oxygen-blowing process is the most reasonable time to feed composite balls. Composite ball treatment is not appropriate for steel production with sulfur requirements lower than 80 ppm. The maximum composite ball feeding amount is 40 kg/t and the iron yield rate is better than 95%. Compared with the conventional recycling process of sludge and dust, this novel technology is more convenient and efficient, saving up to 309 RMB per ton of steel. Further investigation of this novel recycling technology is merited.

关键词： iron and steelmaking dusts composite balls recovery converter explosive reaction

First Digit Distributions of Gamma-Ray Bursts

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Research in Astronomy and Astrophysics 2024年第5期24卷 70-75页

作者： hou-yu Lai Jun-Jie Wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s *** this work,we perform a comprehensive investigation on the first digit distributions of the duration,fluence,and energy flux of gamma-ray bursts (GRBs) for the first *** a complete GRB sample detected by the Fermi satellite,we find that the first digits of the duration and fluence adhere to Benford’s ***,the energy flux shows a significant departure from this law,which may be due to the fact that a considerable part of the energy flux measurements is restricted by lack of spectral *** on the conventional duration classification scheme,we also check if the durations and fluences of long and short GRBs (with duration T_(90)>2 s and T_(90)≤2 s,respectively) obey Benford’s *** find that the fluences of both long and short GRBs still agree with the Benford distribution,but their durations do not follow Benford’s *** results hint that the long–short GRB classification scheme does not directly represent the intrinsic physical classification scheme.

关键词： (stars:)gamma-ray burst general-methods statistical-astronomical databases miscellaneous

A combined experimental and analytical method to determine the EHL friction force distribution between rollers and outer raceway in a cylindrical roller bearing

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Friction 2023年第8期11卷 1455-1469页

作者： yu hou Xi WANG Di YANG Zeliang XIAO School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Hunan Provincial Key Laboratory of Intelligent Manufacturing Technology for High-performance Mechanical Equipment Changsha University of Science and TechnologyChangsha 410114China

Friction force is a crucial factor causing power loss and fatigue spalling of rolling element bearings.A combined experimental and analytical method is proposed to quantitatively determine the elastohydrodynamic lubrication(EHL)friction force distribution between rollers and outer raceway in a cylindrical roller bearing(CRB).An experimental system with the instrumented bearing and housing was developed for measuring radial load distribution and friction torque of bearings.A simplified model of friction force expressed by dimensionless speed,load,and material parameters was *** inequality constrained optimization problem was established and solved by using an experimental data-driven learning algorithm for determining the uncertain parameters in the *** effect of speed,load,and lubricant property on friction force and friction coefficient was discussed.

关键词： cylindrical roller bearing(CRB) elastohydrodynamic lubrication(EHL) friction force distribution friction torque combined method

A one-pot method for controlled synthesis and selective etching of organic-inorganic hybrid perovskite crystals

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Journal of Energy Chemistry 2019年第6期28卷 149-154页

作者： yu hou Mengjiong Chen Hongwei Qiao Huagui Yang Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and Engineering East China University of Science and Technology

Organometal halide perovskites have recently emerged with a huge potential for photovoltaic applications. Moreover, preparation of high-quality perovskite crystals with controlled morphology is of great significance for the fundamental studies such as optical and electrical properties, as well as the applications. Here, we report a one-pot solvothermal process to synthesize sheet-shaped CH3NH3PbBr3 single crystals with the lateral size of 100 μm and the thickness of 3–8 μm. Furthermore, a controlled etching behavior on the crystalline surface was demonstrated, which could be the irregular collapse of the crystalline surface caused by the local accumulation of methylammonium cations. Using this technique,CH3NH3PbBr3 single crystal sheets could be used in the various optoelectronic devices, such as nanolaser,optical sensors, photodetectors and field effect transistors.

关键词： Crystal growth Perovskite Solvothermal Etching effect

Advances in immunopathogenesis of adult immune thrombocytopenia

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Frontiers of Medicine 2013年第4期7卷 418-424页

作者： Xinguang Liu yu hou Jun Peng Department of Hematology Qilu HospitalShandong UniversityJinan 250012China Shandong University School of Medicine Jinan250012China

Primary immune thrombocytopenia(ITP)is an autoimmune disorder characterized by immune-mediated accelerated platelet destruction and/or suppressed platelet *** the development of autoantibodies against platelet glycoproteins remains central in the pathophysiology of ITP,several abnormalities involving the cellular mechanisms of immune modulation have been identified,and the pathways behind the immune-mediated destruction of platelets have opened new avenues for the design of specific immunotherapies in an attempt to reduce the platelet *** review is primarily focused on the recent literature with respect to immunopathological mechanisms in patients with ITP.

关键词： primary immune thrombocytopenia B lymphocytes T lymphocytes antigen-presenting cells cytokines

小鼠胚胎脊髓神经干细胞提取与传代培养:3种常用消化酶优劣的比较与分析

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中国组织工程研究 2025年第31期29卷 6609-6615页

作者：罗丹葛志林侯永辉王万舜詹吉恒侯宇林定坤陈树东广州中医药大学第二附属医院广东省广州市510000 广东省中医药科学院广东省广州市510000 广州中医药大学广东省广州市510000

背景:在神经干细胞的研究及应用过程中,细胞的培养与传代是关键环节,直接影响到细胞的质量和实验结果。寻找一种最适宜的消化酶类,对维持胚胎小鼠脊髓神经干细胞的生物学特性并增强其传代效率,具有重要意义。目的:探讨胚胎小鼠脊髓神经... 详细信息

背景:在神经干细胞的研究及应用过程中,细胞的培养与传代是关键环节,直接影响到细胞的质量和实验结果。寻找一种最适宜的消化酶类,对维持胚胎小鼠脊髓神经干细胞的生物学特性并增强其传代效率,具有重要意义。目的:探讨胚胎小鼠脊髓神经干细胞传代最适合的消化酶。方法:显微解剖分离提取孕14 d C57BL/6胎鼠脊髓组织,用含有表皮生长因子、碱性成纤维生长因子及B27的DMEM/F12无血清培养基培养,待成球后进行Nestin与Sox2免疫荧光鉴定。神经干细胞传代培养过程中分别采用胰蛋白酶、木瓜蛋白酶以及TrypLE^(TM)Express酶消化结合吹打法制成单细胞悬液,观察细胞分散效果及成球情况,取第3代细胞进行碘化丙啶染色观察细胞死亡情况,通过计数细胞总数观察细胞增殖情况,通过免疫荧光染色、Western blot和RT-PCR检测Olig2、Tuj1、GFAP、NeuN蛋白和mRNA表达鉴定细胞分化情况。结果与结论:脊髓组织细胞培养72 h后可形成悬浮生长的神经球,5-7 d后即可传代。与胰蛋白酶、木瓜蛋白酶相比,TrypLE^(TM)Express酶结合吹打法进行传代的细胞分散率高,活性较好,分化为NeuN与Tuj1的阳性神经元细胞较多。此研究优化了神经干细胞的培养和传代过程,为进一步开展脊髓疾病的干细胞移植治疗研究奠定了基础。

关键词：神经干细胞 C57BL/6小鼠胚胎脊髓胰蛋白酶木瓜蛋白酶 TrypLE^(TM)Express酶工程化干细胞

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Effect of printing parameters on properties of 3D printing sand samples

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China Foundry 2023年第6期20卷 553-562页

作者： De-quan Shi Yin-yu hou Gui-li Gao School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China

Three-dimensional sand printing(3DSP)is widely applied in sand mold *** this study,the effects of printing parameters including the resolution of printehead holes,activator content,layer thickness,and recoating speed on the tensile and bending strengths,gas evolution,and loss-on-ignition(LOI)of 3DSP samples were investigated by changing single parameter,and the dimension deviation was also *** the resolution increases,the tensile strength,bending strength,gas evolution,LOI,and deviations at X-and Y-axis directions decrease gradually while the deviation at Z-axis direction firstly increases and then *** gas evolution and LOI drops by 13.02%and 8.13%respectively,but the strength only reduces by 2.2% when the resolution increases from 0.08 mm to 0.09 *** strengths of samples rise at first and then decline while the gas evolution and LOI rise gradually with the increasing activator content or recoating *** activator content is found to have little effect on the gas evolution as the activator increases from 0.14%to 0.34%,the gas evolution is increased by 7.3%which is far less than the LOI increment of 24.1%.As the layer thickness increases,the tensile and bending strengths firstly rise and then drop while gas evolution and LOI *** the optimal printing parameters of 0.09 mm resolution,0.18%activator,0.28 mm layer thickness and 160 mm·s^(-1) recoating speed,the tensile strengths for X-sample and Y-sample are 1.48 MPa and 1.37 MPa,the bending strengths are 1.84 MPa and 1.75 MPa,the gas evolution and LOI are 9.62 mL·g^(-1) and 1.92%,respectively.

关键词： three-dimensional sand printing printing parameters mechanical properties LOI