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Multi-blade rubbing characteristics of the shaft-disk-blade-casing system with large rotation

Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 111-136页

作者： Zhiyuan WU Linchuan ZHAO han yan Ge yan Ao CHEN Wenming ZhanG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Aerospace Systems Engineering Shanghai 201108China

Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.

关键词： shaft-disk-blade-casing(SDBC) large rotation spin and whirl multi-blade rubbing rotational effect

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In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

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中华医学杂志(英文版) 2024年第8期137卷 2023 Aug 22页

作者： han Yu Shao Zehua Sun Zirui han yan Xu Hongdang Song Shubo Pan Xiangbin de Jaegere Peter P. T. Fan Taibing Zhang Gejun Department of Cardiology Erasmus MC Rotterdam 3015 GD Netherlands Department of Structure Heart Disease Central China Fuwai Hospital of Zhengzhou University Zhengzhou Henan 451460 China Children’s Heart Center Department of Anesthesiology Fuwai Hospital Chinese Academy of Medical Sciences Beijing 100037

Background: Due to the wide variety of morphology, size, and dynamics, selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation (PPVI). This study aimed to report our experience within vitro bench testing using patient-specific three-dimensional (3D)-printed models for planning PPVI with the Venus P-valve.Methods: Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results: 3D model bench testing altered treatment strategy in all patients (100%). One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly. In the remaining 14 patients, valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery. In four patients, it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract (RVOT) (n = 2) or risk of compression coronary artery (n = 2). Concerning sizing, we found that an oversize of 2-5 mm suffices. Anchoring of the valve was dictated by the flaring of the in- and outflow portion in the pulmonary artery. PPVI was successful in all 14 patients (absence of valve migration, no coronary compression, and none-to-mild residual pulmonary regurgitation [PR]). The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group (36 [2]vs. 32 [4],Z = -3.77,P <0.001).Conclusions: In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique, as 2-5 mm sufficed.

关键词： Heart valve prosthesis implantation Percutaneous pulmonary valve intervention Pulmonary regurgitation In vitro bench testing 3D printing Venus P-valve

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Engineered plant extracellular vesicles for autoimmune diseases therapy

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Nano Research 2024年第4期17卷 2857-2873页

作者： Ruina han yan Wu Yafei han Xiangfei Liu han Liu Jiacan Su Institute of Translational Medicine Shanghai UniversityShanghai 200444China Organoid Research Center Shanghai UniversityShanghai 200444China National Center for Translational Medicine(Shanghai)SHU Branch Shanghai UniversityShanghai 200444China Department of Orthopedics Shanghai Zhongye HospitalShanghai 200941China Department of Orthopedics Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092China

Autoimmune diseases(AID)encompass a diverse array of conditions characterized by immune system dysregulation,resulting in aberrant responses of B cells and T cells against the body’s own healthy tissues.Plant extracellular vesicles(PEVs)are nanoscale particles enclosed by phospholipid bilayers,secreted by plant cells,which facilitate intercellular communication by transporting various bioactive molecules.Due to their nanoscale structure,safety,abundant sources,low immunogenicity,high yield,biocompatibility,and effective targeting of the colon and liver,PEVs are regarded as a promising platform for the treatment of AID.This review provides a comprehensive summary of PEV biogenesis,physicochemical and biological properties,internalization mechanisms,isolation methods,and their applications in various diseases,with a specific focus on their potential roles in AID.Additionally,we propose engineering approaches and administration methods for PEVs.Finally,we present an overview of the advantages and challenges associated with utilizing PEVs for the treatment of AID.By gaining a comprehensive understanding of PEVs,we anticipate the development of innovative therapeutic strategies for AID.Natural and engineered PEVs hold substantial promise as a valuable resource for innovative technologies in AID treatment.

关键词： autoimmune diseases plant extracellular vesicles extracellular vesicles engineering modification

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Sobolev Mapping of the Bergman Projections on Generalized Hartogs Triangles

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Acta Mathematica Sinica,English Series 2024年第2期40卷 451-466页

作者： Hong yan LIU Zhen han TU School of Mathematics and Statistics Wuhan UniversityWuhan 430072P.R.China

In this paper,we investigate Sobolev mapping properties of the Bergman projection.Th domain we focus on is defined byΩm/n:={(z,w)∈C^(1+N):|w1|<|z|m1/n1<1,…|wN|<|z|/m_(N)/n_(N)<1},where m=(m1,…mN)∈(Z^(+))^(N),n=(n1,…nN)∈(Z^(+))N,N∈Z^(+).Sobolev irregularity of the Bergman projections on 2 is shown.We also prove some Sobolev regularity results of the Bergman projections onΩm/n for m=(1,…1).

关键词： Bergman projections generalized Hartogs triangles Sobolev spaces

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Product quality prediction based on RBF optimized by firefly algorithm

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Journal of Systems Engineering and Electronics 2024年第1期35卷 105-117页

作者： han Huihui WANG Jian CHEN Sen yan Manting College of Electronics and Information Engineering Tongji UniversityShanghai 201804China

With the development of information technology,a large number of product quality data in the entire manufacturing process is accumulated,but it is not explored and used effectively.The traditional product quality prediction models have many disadvantages,such as high complexity and low accuracy.To overcome the above problems,we propose an optimized data equalization method to pre-process dataset and design a simple but effective product quality prediction model:radial basis function model optimized by the firefly algorithm with Levy flight mechanism(RBFFALM).First,the new data equalization method is introduced to pre-process the dataset,which reduces the dimension of the data,removes redundant features,and improves the data distribution.Then the RBFFALFM is used to predict product quality.Comprehensive expe riments conducted on real-world product quality datasets validate that the new model RBFFALFM combining with the new data pre-processing method outperforms other previous me thods on predicting product quality.

关键词： product quality prediction data pre-processing radial basis function swarm intelligence optimization algorithm

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Enhanced corrosion resistance of epoxy resin coating via addition of CeO_(2) and benzotriazole

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Chinese Journal of Chemical Engineering 2024年第3期67卷 89-96页

作者： Xu han Ruijie Guo Baolong Niu Hong yan College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

The use of fillers to enhance the corrosion protection of epoxy resins has been widely applied.In this work,cerium dioxide(CeO_(2))and benzotriazole(BTA)were introduced into an epoxy resin to enhance the corrosion resistance of Q235 carbon steel.Scanning electron microscopy results indicated that the CeO_(2) grains were rod-like and ellipsoidal in shape,and the distribution pattern of BTA was analyzed by energy dispersive spectroscope.The dynamic potential polarization curve proved the excellent corrosion resistance of the composite epoxy resin with CeO_(2) and BTA co-addition,and electrochemical impedance spectroscopy test analysis indicated the significantly enhanced long-term corrosion protection performance of the composite coating.And the optimal protective performance was provided by the coating containing 0.3%(mass)CeO_(2) and 20%(mass)BTA,which was attributed to the barrier performance of CeO_(2) particles and the chemical barrier effect of BTA.The formation of corrosion products was analyzed using X-ray diffraction.In addition,the corrosion resistance mechanism of the coating was also discussed in detail.

关键词： Benzotriazole Cerium dioxide Corrosion resistance Carbon steel Epoxy resin coating Preparation

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Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

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Science China Technological Sciences 2024年第6期67卷 1957-1973页

作者： GAO han SHI TingNa GAO XinMai LEI yanXiao yan Dong GUO Liyan yan yan College of Electrical Engineering Zhejiang University Zhejiang University Advanced Electrical Equipment Innovation Center State Key Laboratory of High-speed Maglev Transportation Technology CRRC Qingdao Sifang Co.Ltd.

The operating speed of the commercial electromagnetic suspension(EMS) maglev train has been over 430 km/h, making it the fastest means of land transportation. With the increasing demands of people traveling, it is necessary to further improve the operating speed of maglev trains. Aiming to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h), the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this article. First, an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance, e.g., the characteristics of phase current, the magnetic flux density, and the electromagnetic force. Second, the relationship between the harmonic components of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT) to reveal the mechanism of electromagnetic force ripple. Third, to address the issues of excessive armature current density and significant electromagnetic force ripple, the linear motor is re-designed by enlarging the stator slot area and reshaping the mover's main magnetic poles. Furthermore, the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric motor. Finally, the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA) based co-simulation.

关键词： ultra-high-speed maglev transportation electromagnetic suspension (EMS) linear motor electromagnetic force ripple suppression

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Clinical characteristics and treatment of splenic infarction in children with systemic lupus erythematosus

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World Journal of Pediatrics 2024年第5期20卷 525-531页

作者： yan Li Yu-Rong Piao Tong-Xin han Hua-Wei Mao Department of Immunology Ministry of Education Key Laboratory of Major Diseases in ChildrenBeijing Key Laboratory for Genetics of Birth DefectsNational Center for Children’s HealthBeijing Children’s HospitalCapital Medical UniversityNo.56 Nan Li Shi LuBeijing100045China

Splenic infarction(SI)is a rare clinical phenomenon that occurs when the blood supply to the spleen is interrupted,resulting in tissue ischemia and necrosis[1].There are many causes of SI;in adult patients,cardioembolism,hematological malignancy,and infectious disease are the most common[2].Rheumatic diseases,especially systemic lupus erythematosus(SLE)and granulomatosis with polyangitis,can also lead to SI[3];however,only a few cases have been reported.There are currently no statistically meaningful data on the etiology of SI in children.Although most patients with SI can recover after conservative treatment,a small number of patients develop complications,such as splenic abscess,splenic rupture,splenic hemorrhage,and hemoperitoneum,and may even undergo splenectomy in severe cases.

关键词： erythematosus lupus treatment

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Constructing porous ZnFC-PA/PSF composite spheres for highly efficient Cs^(+) removal

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Journal of Environmental Sciences 2024年第9期143卷 126-137页

作者： Senjian han Chao Gao Wenfeng yan Yafei Guo Shiqiang Wang Tianlong Deng College of Marine and Environmental Sciences Tianjin University of Science and TechnologyTianjin 300457China Key Laboratory of Marine Resource Chemistry and Food Technology Ministry of EducationTianjin 300457China

Radioisotope leaking from nuclear waste has become an intractable problem due to its gamma radiation and strong water solubility.In this work,a novel porous ZnFC-PA/PSF composite sphere was fabricated by immobilization of ferrocyanides modified zinc phytate into polysulfone(PSF)substrate for the treatment of Cs-contaminated water.The maximum adsorption capacity of ZnFC-PA/PSF was 305.38 mg/g,and the removal efficiency of Cs+was reached 94.27%within 2 hr.The ZnFC-PA/PSF presented favorable stability with negligible dissolution loss of Zn^(2+)and Fe^(2+)(hanism was inferred to be the ion-exchange between Cs^(+)and K^(+).What’s more,ZnFC-PA/PSF worked well in the fixed-bed adsorption(E=91.92%),indicating the application potential for the hazardous Cs^(+)removal from wastewater.

关键词： Adsorption Cesium Metal ferrocyanide Composite adsorbent

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A deoxidation thermodynamic model for 304 stainless steel considering multiple-components coupled reactions

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Journal of Iron and Steel Research(International) 2024年第1期31卷 74-91页

作者： yan yan Guang-hao Shang Li-ping Zhang Shao-ying Li han-jie Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Henan Jinhui Stainless Steel Industry Group Co. Ltd.Xuchang461500HenanChina Changge Jinhui Recycling Metal R&D Co. Ltd.Xuchang461500HenanChina

A thermodynamic model for predicting the equilibrium oxygens of 304 stainless steel was developed based on the theory of slag-steel equilibrium,the law of mass conservation,and the ion and molecule coexistence theory.In the developed model,the Fe-Cr-Mn-Si-Al-S-O-melts reaction system and CaO-MgO-CaF_(2)-FeO-MnO-Al_(2)O_(3)-SiO_(2)-Cr2O_(3)slags were considered.The oxygen contents calculated by the model are in good agreement with experimental results and reference data.The equilibrium oxygen contents in 304 stainless steel mainly decrease with increasing binary basicity(w(CaO)/w(SiO_(2)),where w(i)is the mass percentage of component i)and decreasing temperature.Controlling binary basicity at 2.0 while maintaining temperatures lower than 1823 K will keep the oxygen contents in the 304 stainless steel lower than 15×10^(-6).The equilibrium oxygen contents may also be decreased with increasing content of MgO in slags,which is more significant at lower binary basicity.Besides,a small amount of FeO,MnO,and Al_(2)O_(3)(about 0-2.5 wt.%)in slags has little effect on equilibrium oxygen contents.Furthermore,it is found that the[C]-[O]reaction may occur during refining process but will not significantly affect the equilibrium oxygen contents.

关键词： Complex deoxidation Thermodynamic model Ion and molecule coexistence theory 304 stainless steel Slag-steel reaction

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