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Nonlinear system identification framework of folding fins with freeplay using backbone curves

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Chinese Journal of Aeronautics 2022年第10期35卷 183-194页

作者： Shuaishuai liU rui ZHAO Kaiping YU Bowen zheng Department of Astronautical Science and Mechanics Harbin Institute of TechnologyHarbin 150001China

Due to wear and manufacturing tolerance,the freeplay is unavoidable in the hinges of folding fins,which exerts significant effects on the aerodynamic *** paper proposes a backbone-curve-based framework for the dynamical identification of folding fins containing the freeplay *** no need to measure the input force signal and the response signals of nonlinear related Degrees of Freedom(DOFs),the proposed method is more direct and elegant than most existing nonlinear identification approaches,and it contains three steps:Firstly,the underlying linear model of the folding fin structure is obtained through the modal test on its linear sub-parts,and then,the harmonic approximation solves the analytical expressions of the backbone curves of measurable ***,response data measured from the sine-sweep test are used to extract the fitting points of backbone curves for these ***,the curve fitting approach is applied to identify the freeplay parameters.A series of numerical experiments verify the effectiveness of the proposed method.A real-life folding fin structure is also employed to illustrate how the method can be *** examples demonstrate that the identification framework can give an accurate dynamic model of the folding fin structure.

关键词： Backbone curves Folding fin Freeplay nonlinearity Harmonic approximation Indirect estimation Output-only identification

A Z-scheme LaFeO_(3)-CuFe_(2)O4 composite for sulfate radical-based photocatalytic process:Synergistic effect and mechanism

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Chinese Journal of Chemical Engineering 2024年第9期73卷 256-269页

作者： Wenwen Gao Yuhuan Wang Wang li Zhifang Zhang Ting Su Miao Mu Ying Gong rui Dang rui Bai E zheng Wei Zhao Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization School Chemistry and Chemical EngineeringYulin UniversityYulin 71900China Key Laboratory of Coal Processing and Efficient Utilization Ministry of EducationChina University of Mining&TechnologyXuzhou 221116China High Value Utilization of Coal Based Semi-coke Derivatives of Shaanxi University Engineering Research Center Yulin UniversityYulin 71900China

The sulfate radical-based photocatalytic process is supposed to be the most promising way to degrade organic ***,the development of a suitable and efficient photocatalyst is very *** 40LaFeO_(3)-CuFe_(2)O_(4)(40LFO-CFO)nanocomposite was constructed and its catalytic performance was studied using Rhodamine B(RhB)as the target pollutant.40LFO-CFO exhibited excellent RhB degradation by the persulfate(PS)-assisted photocatalytic process compared to the pristine LFO and *** degradation rate constant for RhB by 40LFO-CFO in the Vis/PS system was 2.22h^(-1)which is 3.04 times and 5.05 times higher than the pristine LFO(0.73 h^(-1))and CFO(0.44h^(-1)),***,the trapping experiments and EPR spectra proved that h^(+) plays a leading role in the bleaching of RhB for the 40LFO-CFO/PS/Vis *** enhanced photocatalytic oxidation activity of 40LFO-CFO could be attributed to the unique charge carriers flow in 40LFO-CFO due to the Z-scheme and the cooperation effect between photocatalysis and PS *** recycle tests confessed the stability of ***,the intermediates and products of RhB are detected by liquid chromatographymass spectrometry(LC-MS),and the photocatalytic degradation routes of RhB for the 40LFO-CFO/Vis/PS system were ***,the 40LFO-CFO nanocomposite has a superior catalytic performance for other organics,suggesting that it is a promising heterocatalyst because of its high catalytic activity and stability for the PS-assisted photocatalytic process.

关键词： Interfacial charge transfer Sulfate radical-based photocatalytic process Z-scheme electron transfer Enhanced charge pair separation Organic pollutants degradation

Community-acquired pneumonia complicated by rhabdomyolysis: A clinical analysis of 11 cases

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World Journal of Clinical Cases 2019年第24期7卷 4218-4225页

作者： Bo Zhao rui zheng Department of Respiratory Medicine Shengjing Hospital of China Medical University

BACKGROUND In clinical practice, community-acquired pneumonia(CAP) can be complicated by rhabdomyolysis(RM), and RM symptoms are mild and easily missed during diagnosis. Moreover, available data on RM induced by CAP are mainly from case reports. Due to the relatively low incidence of CAP-induced RM, more systematic studies are required to understand the characteristics of CAP-induced RM to improve its diagnosis and *** To investigate the clinical characteristics of patients with CAP-induced *** This was a retrospective study of 11 patients with CAP-induced RM. Baseline characteristics, diagnostic work-up, and laboratory test results were summarized and compared with those of 48 patients with exercise-induced RM admitted during the same *** CAP-induced RM was more common in men, and affected older patients compared to those with exercise-induced RM. However, the average age of the patients in this study was lower than the age of peak incidence of CAP in adults in China. The major clinical manifestations were high fever and respiratory symptoms. RM symptoms were mild and often overlooked. Patients with CAP-induced RM had elevated inflammatory parameters, respiratory alkalosis,relatively low serum potassium levels and often had abnormalities in hepatic and renal function and cardiac enzymes. Compared with the exercise group, the pneumonia group had lower levels of creatine kinase and myoglobin, a higher incidence of acute kidney injury, and worse renal function and *** events were mainly related to the severity of *** CAP-induced RM has different clinical characteristics from those of exerciseinduced RM. Early detection and treatment could reduce complications and consequently shorten the treatment course.

关键词： Community-acquired pneumonia Rhabdomyolysis Exercise Acute kidney injury

Contaminant transport in heterogeneous aquifers: A critical review of mechanisms and numerical methods of non-Fickian dispersion

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Science China Earth Sciences 2021年第8期64卷 1224-1241页

作者： Zhilin GUO rui MA Yong ZHANG Chunmiao zheng State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China School of Environmental Studies China University of GeosciencesWuhan 430074China Department of Geological Sciences University of AlabamaTuscaloosa AL 35487USA

Natural aquifers usually exhibit complex physical and chemical heterogeneities,which are key factors complicating kinetic processes,such as contaminant transport and transformation,posing a great challenge in the remediation of contaminated *** heterogeneity usually leads to a distinct feature,the so-called“anomalous transport”in groundwater,which deviates from the phenomenon described by the classical advection-dispersion equation(ADE)based on Fick’s *** transport,also known as non-Fickian dispersion or“anomalous dispersion”in a broad sense,can explain the hydrogeological mechanism that leads to the temporally continuous deterioration of water quality and rapid spatial expansion of pollutant *** enter and then are retained in the low-permeability matrix from the high-permeability zone via molecular diffusion,chemical adsorption,and other mass exchange *** process can be reversed when the concentration of pollutants in high-permeability zones is relatively *** contaminants slowly return to the high-permeability zones through reverse molecular diffusion,resulting in sub-dispersive anomalous transport leading to the chronic gradual deterioration of water ***,some contaminants are rapidly transported along the interconnected preferential flow paths,resulting in super-dispersive anomalous transport,which leads to the rapid spread of *** heterogeneity is also an important factor that constrains the efficacy of groundwater remediation,while the development,application,and evaluation of groundwater remediation technologies are usually based on the Fickian dispersion process predicted by the ADE *** studies of the impacts of non-Fickian dispersion on contaminant transport and remediation are still *** article reviews the non-Fickian dispersion phenomenon caused by the heterogeneity of geological media,summarizes the processes and current understanding of contamin

关键词： Aquifer heterogeneity Contaminant transport Contamination remediation Non-Fickian dispersion Anomalous transport Small-scale preferential flow paths

3-D numerical simulation of curved open channel confluence flow with partially non-submerged rigid vegetation

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Journal of Hydrodynamics 2021年第5期33卷 992-1006页

作者： zheng-rui Shi Cong-fang Ai Sheng Jin School of Civil and Hydraulic Engineering Dalian University of TechnologyDalian 116024China

For the study of the effects of partially non-submerged rigid vegetation on the free-surface confluence flow in a curved open channel,a numerical simulation is carried out by using the Volume of Fluid model combined with the porous media model with the software *** model is first validated by using available experimental measurement data with a good ***,the characteristics of the separation zone generated by the centrifugal forces and the confluence flow are *** to the resistance created by the vegetation,the velocities in the separation zone are more chaotic and the separation zone becomes smaller and more *** reduction of the separation zone area of the vegetated flow in the convex bank is more significant than that in the concave *** velocities in the vegetated region become much smaller and remains so in the downstream flow after the vegetation ***,the vegetation compresses and divides the circulations in the flow area,rebuilding a structure with smaller circulations in the main flow and unclear circulations in the vegetation *** addition,the bed wall shear stresses are significantly smaller in the vegetation region and the separation zone compared to the non-vegetated *** implies that the vegetation can have the effect of protecting the river bed from erosion.

关键词： Curved open channel confluence flow porous media model non-submerged rigid vegetation separation zone

Metathesis of 1-butene and 2-butene to propene over Re_2O_7 supported on macro-mesoporous γ-alumina prepared via a dual template method

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Journal of Natural Gas Chemistry 2012年第2期21卷 105-108页

作者： Lei Sang Sheng-li Chen Guimei Yuan Min zheng Ju You Aicheng Chen rui li Lanjing Chen State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of PetroleumBeijing 102249China

Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,*** had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 ***2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular *** result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3.

关键词： butene metathesis propene rhenium oxide polystyrene microspheres macro-mesoporous alumina

Particle Deposition in Oral-tracheal Airway Models with Very Low Inhalation Profiles

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Journal of Bionic Engineering 2012年第2期9卷 252-261页

作者： zheng li International Biomedical 8206 Cross Park Dr Austin TX 78754 USA

Considerable progress has been made on modeling particle deposition in the oral-tracheal airway under some normal breathing conditions, i.e., resting, light activity and moderate exercise. None of these standard breathing patterns correspond to very low inhalation profiles. It is known that particle deposition in the oral-tracheal airway is greatly influenced by flow and particle inlet conditions. In this work, very low inhalation flow rates are considered. Particle deposition is numerically investigated in different oral-tracheal airway models, i.e., circular, elliptic and realistic oral-tracheal airway models. Both micro- and nano-particles that are normally present in cigarette smoke are considered. Results show that inhalation profiles greatly influence the particle deposition. Due to relatively low flow rate, for ultra-fine particles, the oral deposition is enhanced due to longer residence time in oral cavity and stronger Brownian motion. However, for larger particles, less particles deposit in the oral-tracheal airway due to the weaker impaction. The transition happens when particle size changes from 0.01 μm to 0.1 μm. The influence of the limited entrance area is shown and discussed. Under the low inhalation profiles, the highest deposition fraction could be in either circular or realistic models depending on the particle property and the geometric characteristic of oral cavity. The knowledge obtained in this study may be beneficial for the design of bionic inhaler and understanding of health effect from smoke particle on human being.

关键词： particle deposition airway airflow CFD low inhalation profile

Metallurgical Source of Cryogenic Intergranular Fracture of Fe-38Mn Austenitic Alloy

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Journal of Iron and Steel Research International 2000年第1期7卷 31-35页

作者： FU rui-dong zheng Yang-zeng li Shao-hua ZHOU Hui-hua Yanshan University Central Iron & Steel Research Institute Tsinghua University

SEM and Field emitting TEM-EDAX were used to investigate the fracture surface of series impact specimens and the grain boundary chemistries of VIM(vacuum-inductionmelted) Fe-38 Mn austenitic alloy before and after ESR(electroslag remelting,).The quantity and the size of inclusions were also *** results show that the VIM Fe-38 Mn austenitinic alloy water-quenched from 1 100 C undergoes an obvious ductile-to-brittle transition,and the impact work at ambient temperature is 242 J,the corresponding fracture surface exhibits a dimple ***,the impact work at 77 K of VIM alloy is only 25 J and the fracture mode is IGF(intergranular fracture).After ESR,the impact work at ambient temperature is 320 J and the fracture surface exhibits a character of "volcano lava"(meaning excellent toughness);The impact work at 77 K is up to 300 J and the fracture mode is micro void coalescence mixed with *** segregation of Mn is not found in all specimens,but the segregation of S is observed,and the S segregation is decreased after *** examined results of inclusions show that ESR reduces the quantity and improves the morphology of *** the above results it can be seen that the cryogenic IGF of VIM Fe-38 Mn austenitic alloy is related to the S segregation at grain *** ESR the decrease in the quantity and size of inclusion results in the increase of the impact work at ambient temperature,while the restriction of IGF is related to the decrease in the total level,and hence in the grain boundary segregation of S.

关键词： rich Mn austenitic alloy cryogenic intergranular fracture grain boundary segregation electroslag remelting

Characteristics of structural loess strength and preliminary framework for joint strength formula

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Water Science and Engineering 2014年第3期7卷 319-330页

作者： Rong-jian li Jun-ding liU rui YAN Wen zheng Sheng-jun SHAO Institute of Geotechnical Engineering Xi'an University of Technology Open Research Laboratory of Geotechnical Engineering Ministry of Land and ResourcesChang'an University

The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress （ Kf line）, and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests： the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural loess comprehensively and reasonably, a joint strength formula for structural loess was established. This formula comprehensively considers tensile and shear properties. Studies have shown that the tensile strength exhibits a decreasing trend with increasing water content. When the water content is constant, the tensile strength of the structurally intact soil is greater than that ofremolded soil. In the studies, no loss of the originally cured cohesion in the structurally intact soil samples was observed, given that the soil samples did not experience loading disturbance during the uniaxial compressive strength test, meaning there is a high initial structural strength. The results of the conventional triaxial shear strength test show that the water content is correlated with the strength of the structural loess. When the water content is low, the structural properties are strong, and when the water content is high, the structural properties are weak, which means that the water content and the ambient pressure have significant effects on the stress-strain relationship of structural loess. The established joint strength formula of structural loess effectively avoids overestimating the role of soil tensile strength in the traditional theory of Mohr-Coulomb strength.

关键词： structurally intact loess, remolded loess, tensile strength shear strength stress path failure envelope of principal stress ( Kf line) strength failure envelope joint strength formula