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The Development of Top-Hat Flow Field in a Circular Symmetrical Subsonic Nozzle

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Journal of Thermal Science 2019年第5期28卷 975-983页

作者： ZHANG Han JIA li CUI lishui li chunhui Beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing 100044 China National Institute of Metrology Beijing 100029 China

In this work, the numerical analysis and experimental measurements were made to investigate the development of top-hat flow field at atmospheric pressure in a circular symmetrical subsonic nozzle. Measurements were carried out over a range of inlet velocities(about 0.07–7 m/s) based on a nozzle with constant geometric parameters, which also provided verification for the numerical simulation. The objective of this study was to determine the change of top-hat flow field from the well-known pipe velocity profile to the saddle-back distribution as well as the key behaviours for the process. Results revealed a close coupling relationship between the process and the pressure gradient inside nozzle. It was concluded that the local flow direction of fluid near the edge of cross section was changed by static pressure gradient and overlapped with the mainstream. The increase in kinetic energy of each gas particle on the cross section was different contributed to the formation of top-hat flow field. The saddle-back distribution seems to occur after the appearance of the critical position. In addition, the influence of inlet velocity on the location of critical position as well as the degree of saddle-back distribution was also concerned.

关键词： top-hat flow field jet flow formation process inlet condition

Supramolecular self-assembling strategy for constructing cucurbit[6]uril derivative-based amorphous pure organic room-temperature phosphorescence complex featuring extra-high efficiency

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Chinese Chemical Letters 2022年第2期33卷 877-880页

作者： chunhui li Xiuqin li Qiaochun Wang Key Laboratory for Advanced Materials Joint International Research Laboratory of Precision Chemistry and Molecular EngineeringFeringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

The preparation of amorphous pure organic room-temperature phosphorescence materials with high efficiency is still a challenging task. Herein, we introduce a CB[6] derivative-based supramolecular selfassembling strategy. A water soluble and ellipsoidal deformed CB[6] derivative is used to self-assemble with 4-(4-bromophenyl)-1-methylpyridin-1-ium chloride, bromide and hexafluorophosphate in water. After freeze-drying, the obtained amorphous complexes exhibit brilliant green phosphorescence emission under ambient conditions, with phosphorescence efficiency up to 59%, 60% and 72%, respectively. This is the first report of amorphous non-polymeric pure organic room-temperature phosphorescence with such a high efficiency. In view of the dynamic self-assembling property, the complexes are responsive to water,which could enable information encryption.

关键词： Room temperature phosphorescence Amorphous Cucurbituril Supramolecular self-assembling Heavy-atom effect

1,8-桉叶油素干预大鼠实验性牙周炎模型的炎症反应

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中国组织工程研究 2025年第17期29卷 3605-3613页

作者：何丽任潞江小茜刘旭倩黎春晖西南医科大学附属口腔医院牙周黏膜病科四川省泸州市646000 西南医科大学附属口腔医院口腔医学研究所口颌面修复重建和再生泸州市重点实验室四川省泸州市646000

背景:研究表明,天然植物精油提取物1,8-桉叶油素具有抗炎、抗氧化、抗菌、抗肿瘤等多种药理作用,在多种疾病中表现出抗炎作用。目的:探讨1,8-桉叶油素对大鼠实验性牙周炎模型炎症反应的影响。方法:按照完全随机数字表法将30只SD大鼠随... 详细信息

背景:研究表明,天然植物精油提取物1,8-桉叶油素具有抗炎、抗氧化、抗菌、抗肿瘤等多种药理作用,在多种疾病中表现出抗炎作用。目的:探讨1,8-桉叶油素对大鼠实验性牙周炎模型炎症反应的影响。方法:按照完全随机数字表法将30只SD大鼠随机分为正常对照组、牙周炎对照组和1,8-桉叶油素组,每组10只。牙周炎对照组和1,8-桉叶油素组利用正畸钢丝结扎法构建实验性牙周炎模型。造模8周后,正常对照组和牙周炎对照组大鼠颊、腭侧牙周袋内均注射生理盐水,1,8-桉叶油素组大鼠颊、腭侧牙周袋内注射1,8-桉叶油素溶液,2次/d,连续给药4周。给药结束后,进行牙周临床指标检测、牙周组织学评估、血清炎症因子水平检测及牙龈组织中炎症因子m RNA与蛋白表达检测。结果与结论:①与正常对照组比较,牙周炎对照组大鼠牙龈出血指数、牙周探诊深度增加(P<0.05),血清中白细胞介素1β、肿瘤坏死因子α、白细胞介素6水平升高(P<0.05),血清中白细胞介素10水平降低(P<0.05),牙龈组织中白细胞介素1β、肿瘤坏死因子α、白细胞介素6mRNA与蛋白表达均升高(P<0.05),牙龈组织中白细胞介素10 mRNA与蛋白表达均降低(P<0.05);苏木精-伊红染色结果显示,牙周炎对照组大鼠牙周组织炎症明显。②与牙周炎对照组比较,1,8-桉叶油素组大鼠牙龈出血指数、牙周探诊深度减少(P<0.05),血清中白细胞介素1β、肿瘤坏死因子α、白细胞介素6水平降低(P<0.05),血清中白细胞介素10水平升高(P<0.05),牙龈组织中白细胞介素1β、肿瘤坏死因子α、白细胞介素6 mRNA与蛋白表达均降低(P<0.05),牙龈组织中白细胞介素10 mRNA与蛋白表达均升高(P<0.05);苏木精-伊红染色结果显示,1,8-桉叶油素组大鼠牙周组织炎症明显减轻。结果表明,1,8-桉叶油素治疗可减轻大鼠实验性牙周炎模型的炎症反应。

关键词： 1 8-桉叶油素植物精油牙周炎动物模型牙周组织炎症反应白细胞介素1β 肿瘤坏死因子α 白细胞介素6 白细胞介素10 工程化组织构建

Effect of swirling addition on the liquid mixing performance in a T-jets mixer

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Chinese Journal of Chemical Engineering 2022年第10期50卷 108-116页

作者： chunhui li Bin Wu Junjie Zhang Peicheng Luo School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Hubei Sanjiang Aerospace Jianghe Chemical Technology Co. LtdYichang 444200China

Swirling addition to the stream is beneficial for the fluid *** work aims to study the mixing process intensification in a conventional T-jets mixer by the swirling *** experimental verification by the planar laser-induced fluorescence technique,large eddy simulation with the dynamic kinetic energy sub-grid stress model is used to predict how the swirling strength(in terms of swirling number,S_(w))and swirling directions affect the mixing performance,*** tracer concentration distribution,mixing time,and turbulent characteristics in the T-jets mixers,Predictions show that the swirling strength is the key factor affecting the mixing efficiency of the *** overall mixing time,τ_(90),can be significantly reduced by increasing S_(w).Vortex analysis shows that more turbulent eddies appear in the collision zone and the turbulent kinetic energy dissipation rate increases obviously with the swirling *** S_(w) is kept constant,the mixing process can be accelerated and intensified by adding swirling to only one stream,to both streams with the opposite swirling directions,or to both streams with the same swirling *** of the mixing process by enlarging the mixer size or increasing the flow rates is also ***,this work provides a new strategy to improve the mixing performance of the traditional T-jets mixers by the swirling addition.

关键词： Mixing T-jets mixer Swirling Computational fluiddynamics(CFD) Large eddysimulation

Principal whitened gradient-projection algorithm for distribution control

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Science China(Information Sciences) 2013年第3期56卷 202-209页

作者： ZHANG ShiCheng Sun HuaFei li chunhui School of Mathematics Xuzhou Normal University Department of Mathematics Beijing Institute of Technology

In this paper,we use an information geometric algorithm to solve the distribution control *** new designed algorithm is called principal whitened gradient-projection *** the principal natural gradient step,we use principal whitened gradient algorithm to obtain an optimal trajectory of the weight vector on the B-spline manifold from the viewpoint of information *** the projection step,we project the selected points on B onto *** coordinates of the projections on M give the trajectory of the control input u.

关键词： principal whitened gradient distribution control Kullback divergence

Optimal control on special Euclidean group via natural gradient algorithm

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Science China(Information Sciences) 2016年第11期59卷 63-72页

作者： chunhui li Erchuan ZHANG lin JIU Huafei SUN School of Mathematics and Statistics Beijing Institute of Technology School of Mathematics and Statistics University of Western Australia Department of Mathematics Tulane University School of Mathematics and Statistics and Beijing Key Laboratory on MCAACI Beijing Institute of Technology

Considering the optimal control problem about the control system of the special Euclidean group whose output only depends on its input is meaningful in practical applications. The optimal control considered here is described as the output matrix is as close as possible to the target matrix by adjusting the system *** geodesic distance is adopted as the measure of the difference between the output matrix and the target matrix, and the trajectory of the control input obtained in the process is achieved. Furthermore, some numerical simulations are shown to illustrate our outcomes based on the natural gradient descent algorithm for optimizing the control system of the special Euclidean group.

关键词： system control natural gradient special Euclidean group geodesic distance numerical simulation

Crustal Contaminations Responsible for the Petrogenesis of Basalts from the Emeishan Large Igneous Province,NW China:New Evidence from Ba Isotopes

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Journal of Earth Science 2022年第1期33卷 109-120页

作者： Dong Yi Jing Zhao chunhui li Xiuhong Peng Department of Geochemistry College of Earth SciencesChengdu University of TechnologyChengdu 610059China

Emeishan large igneous province (EliP),one of the largest continental volcanic provinces worldwide (e.g.,Karoo),is extensively distributed along the western margin of the Yangtze *** though the consensus that the EliP is of a plume-related origin has been reached for decades,the role of crustal contamination in the petrogenesis of these basalts is still debatable so *** paper firstly reports the Ba isotopic compositions of the continental flood basalts from the lijiang,Miyi and Emeishan regions to discuss the genesis of basalts from the *** to their TiO_(2) contents and Ti/Y ratios,these basalts are divided into two groups,the low-Ti basalts from lijiang and the high-Ti basalts from Miyi and *** Ba isotopic compositions show that the low-Ti basalts have the δ^(138/134)Ba values from-0.33‰to+0.23‰with an average of-0.02‰±0.40‰,and the high-Ti basalts from -0.38‰to+0.38‰with an average of 0.038‰±0.36‰,all of which show a wider range of Ba isotopes relative to that of the primitive mantle (PM).This is unlikely to be explained by partial melting,fractional crystallization or even chemical weathering owing to little Ba isotopic fractionation during these *** contrast,variable extents of crustal contamination into the basaltic magmas more likely resulted in such isotopic *** ratios of incompatible elements (e.g.,Nb/U,La/Nb,and Nb/Y) further suggest that the low-Ti basalts experienced higher degrees of crustal contaminations than those high-Ti basalts,which is well consistent with their spatial *** general,the basaltic magmas in the EliP were probably contaminated by different degrees of crustal materials during their upwelling to the surface.

关键词： Emeishan large igneous province Ba isotope petrogenesis crustal contamination isotopes

Numerical simulation and experimental study on the leakage of continuous rotary electro-hydraulic servo motor

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High Technology Letters 2021年第3期27卷 272-281页

作者： Wang Xiaojing Peng Yiwen li chunhui Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080P.R.China

In order to study the influence of inlet and outlet pressure difference and triangular buffer groove on the internal leakage of continuous rotary electro-hydraulic servo motor,the flow field model of motor with and without triangular groove is established *** mesh model is *** pressure distribution of the internal flow field under different pressure difference is analyzed by ***,the gap leakage under different pressure difference is calculated,and the leakage curve is ***,continuous rotary electro-hydraulic servo motor experimental system is built to conduct the internal leakage test,and the leakage under different pressure difference is measured and compared with the simulation *** results show that the occurrence of leakage in the motor can be reduced by setting the triangular buffer groove on the flow plate,the simulation and experimental results are *** can be concluded that the larger the pressure difference between the inlet and the outlet of the motor,the larger the gap *** research lays foundation for the application of continuous rotary electro-hydraulic servo motor.

关键词： continuous rotary electro-hydraulic servo motor internal leakage fluent triangular buffer groove

Squeeze flow of interstitial Herschel-Bulkley fluid between two rigid spheres

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Particuology 2010年第4期8卷 360-364页

作者： chunhui Xu li Yuan Yong Xu Wenbin Hang College of Science China Agricultural University Beijing 100083 China

Interaction between two spheres with an interstitial fluid is crucial in discrete element modeling for simulating the behaviors of ＇wet＇ particulate materials. The normal viscous force of squeeze flow between two arbitrary rigid spheres with an interstitial HerscheI-Bulkley fluid was studied on the basis of Reynolds＇ lubrication theory, resulting in analytical integral expressions of pressure distribution and the viscous force between the two spheres. According to the variation of shear stress, the fluid was divided into yielding and unyielding regions, followed by a discussion on the thickness of the two regions. The result of this paper could be reduced to either the power-law fluid or the Bingham fluid case.

关键词： Wet granuleDiscrete element method Herschel-Bulldey fluid Viscous force