检索结果-南通市图书馆

Study on Sealing Characteristics of Sliding Seal Assembly of Aircraft Hydraulic Actuator

在线全文

学校读者我要写书评

暂无评论

Instrumentation 2024年第1期11卷 18-29页

作者： Weinan Li Saixin Shi Hongxia Tang Liang Chen Jiawei Zhang Hao Tang Jianhua Zhao shijiazhuang haishan industrial development co.poration shijiazhuang 050200 China Heavy Machinery Fluid Power Transmission and co.trol Laboratory Yanshan UniversityQinhuangdao 066004China

The hydraulic actuator,known as the"muscle"of military aircraft,is responsible for flight attitude adjustment,trajectory co.trol,braking turn,landing gear retracting and other actions,which directly affect its flight efficiency and safety.However,the sealing assembly often has the situation of over-aberrant aperture fit clearance or critical over-aberrant clearance,which increases the failure probability and degree of movable seal failure,and directly affects the flight efficiency and safety of military aircraft.In this paper,the simulation model of hydraulic actuator seal co.bination is established by ANSYS software,and the sealing principle is described.The change curve of co.tact width and co.tact pressure of co.bination seal under the action of high-pressure fluid is drawn.The effects of different oil pressure,fit clearance and other parameters on the sealing performance are analyzed.Finally,the accelerated life test of sliding seal co.ponents is carried out on the hydraulic actuator accelerated life test rig,and the surface morphology is co.pared and analyzed.The research shows that the O-ring is the main sealing element and the role of the check ring is to protect and support the O-ring to prevent damage caused by squeezing into the fit clearance,so the check ring bears a large load and is prone to shear failure.Excessive fit clearance is the main factor affecting the damage of the check ring,and the damage parts are mainly co.centrated at the edge of the sealing surface.This paper provides a theoretical basis for the design of hydraulic actuator and the improvement of sealing performance.

关键词： hydraulic actuator co.tact stress sealing characteristics maximum shear stress

Research on static characteristic of double redundance double nozzle flapper valve based on AMESim

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2024年第2期30卷 164-169页

作者：孙亚南 LIANG Qiuhui WANG Wentao YANG Guang ZHANG Wei shijiazhuang haishan industrial development co.Ltd Shijiazhuang 050200P.R.China Fluid Power Transmission and co.trol Laboratory Yanshan UniversityQinhuangdao 066004P.R.China

The feedback spring rod of the armature assembly is cancelled in the double redundance double nozzle flapper valve(DRDNFV),and the difficulty of valve co.e displacement co.trol is increased.Therefore,this paper intends to study the static characteristic of DRDNFV through the AMESet and AMESim simulation.It is explored under the circumstance of the fixed orifices being clogged and experimentally verified on the test bench.The results show that the pressure gain increases and the flow gain decreases with the increasing clogged degree of the fixed orifices on both sides.The zero bias increases synchronously with the increasing clogged degree of the unilateral fixed orifice.The experimental results are basically co.sistent with the theoretical curves and the theoretical co.rectness of the simulation model is effectively verified.The results can provide the theoretical reference for design,debugging,maintenance and fault diagnosis of DRDNFV.

关键词： double redundance double nozzle flapper valve(DRDNFV) AMESet torquemotor armature assembly fault diagnosis

Research of transient rotor dynamic characteristic of magnetic liquid double suspension bearing in double co.lision state

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2024年第2期30卷 146-157页

作者：刘洪美 LI Shengguo SUN Chao SUN Yanan ZHAO Jianhua shijiazhuang Rail Transit Group co.Ltd Shijiazhuang 050011P.R.China shijiazhuang haishan industrial development co.Ltd Shijiazhuang 050200P.R.China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and co.trol Yanshan UniversityQinhuangdao 066004P.R.China

During the operation of magnetic liquid double suspension bearing(MLDSB),due to rotor resonance,assembly error and other factor,the vibration amplitude of the rotor in resonance state exceeds the original design clearance,resulting in the co.lision damage between the rotor and the stator,the rotor and the casing.This paper presents a method to simulate the influence of different factors on the dynamic characteristics of 5 degrees of freedom(DOF)rotor based on the dynamic model of MLDSB.Firstly,acco.ding to the seco.d Lagrange equation,the dynamic equation of 5 DOF rotor is derived,and the mathematical model is established.Then,based on 5 DOF rotor dynamic equation,the rotor transient dynamic equation under co.lision state is obtained,and the rotor transient co.lision dynamic simulation model is established.Finally,the key influencing factors of rotor dynamic characteristics are extracted,and the influence mapping relationship of rotor displacement,axis locus and stress distribution under different factors is simulated by using ANSYS Workbench software.The experimental results show that this method can effectively reflect the influence of various factors on the dynamic characteristics of the rotor.This method can provide theoretical reference for the design and co.trol of MLDSB.

关键词： displacement response axis trajectory radial excitation peak radial excitationtimes transient dynamic characteristics

Tuning interaction strength between CeO_(2) and iridium to promote co.oxidation over Ir/TiO_(2)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 651-659页

作者： Lu Dai Binghua Li Yuhan Peng Xianwei Hao Runquan Xuan Hua Huang Yiming Bi Liping Xu Yanhui Zhang Yun Guo Fangqi Du Li Wang Hui Wang Technology Center China Tobacco Zhejiang Industrial Co.Ltd.Hangzhou310024China Research Institute of industrial Catalysis East China University of Science and TechnologyShanghai200237China

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis design.However,how to tune metal support interactions to optimize the activity still needs further exploration.CeO_(2) was introduced to promote co.oxidation ove r Ir/TiO_(2) by adjusting the interaction strength between iridium(Ir)and CeO_(2).The strong interaction between Ir and CeO_(2) blocks co.adsorption and causes low co.oxidation activity.However,introducing CeO_(2) on Ir/TiO_(2) produces localized interaction between Ir and CeO_(2),which can tune the surface electronic state of Ir,so a"volcano curve"relationship between co.oxidation activity and electronic state is built.Limited amount of CeO_(2) on Ir/TiO_(2)(Ir/Ce_(0.2)Ti)leads to co.co.plete oxidization at 22℃,and a new pathway for co.oxidation was explored.The study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

关键词： co.oxidation CeO_(2) Localized interaction Interaction strength Supported Ir catalysts Rareearths

Effect of titanium on the sticking of pellets based on hydrogen metallurgy shaft furnace:Behavior analysis and mechanism evolution

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 282-291页

作者： Jinge Feng Jue Tang Zichuan Zhao Mansheng Chu Aijun Zheng Xiaobing Li Xiao’ai Wang School of Metallurgy Northeastern UniversityShenyang 110819China Institute for Frontier Technologies of Low-carbon Steelmaking Northeastern UniversityShenyang 110819China Liaoning Low-carbon Steelmaking Technology Engineering Research Center Northeastern UniversityShenyang 110819China Engineering Research Center of Frontier Technologies for Low-carbon Steelmaking(Ministry of Education Shenyang 110819China Zhang Xuan Technology of HBIS Group co. Ltd.Shijiazhuang 050000China Xuanhua Iron and Steel Group co. Ltd.Shijiazhuang 050000China Iron and Steel Research Institute of HBIS Group co. Ltd.Shijiazhuang 050000China

Direct reduction based on hydrogen metallurgical gas-based shaft furnace is a promising technology for the efficient and low-carbon smelting of vanadium-titanium magnetite.However,in this process,the sticking of pellets occurs due to the aggregation of metal-lic iron between the co.tact surfaces of adjacent pellets and has a serious negative effect on the co.tinuous operation.This paper presents a detailed experimental study of the effect of TiO2 on the sticking behavior of pellets during direct reduction under different co.ditions.Results showed that the sticking index(SI)decreased linearly with the increasing TiO2 addition.This phenomenon can be attributed to the increase in unreduced FeTiO3 during reduction,leading to a decrease in the number and strength of metallic iron interco.nections at the sticking interface.When the TiO2 addition amount was raised from 0 to 15wt%at 1100°C,the SI also increased from 0.71%to 59.91%.The co.nection of the slag phase co.ld be attributed to the sticking at a low reduction temperature,co.responding to the low sticking strength.Moreover,the interco.nection of metallic iron became the dominant factor,and the SI increased sharply with the increase in re-duction temperature.TiO2 had a greater effect on SI at a high reduction temperature than at a low reduction temperature.

关键词： titanium sticking index hydrogen metallurgy direct reduction pellets

In Situ Analysis of Tobacco.Leaves Based on Microwave Plasma Torch Desorption Ionization Mass Spectrometry

在线全文

学校读者我要写书评

暂无评论

Journal of Analysis and Testing 2024年第1期8卷 9-15页

作者： He Tang Yonggang Zhang Zhiguang Reng Junchen Zhu Yue Xie Xiaobin Zhang Hongru Feng Kailong Yuan Yuanjiang Pan Department of Chemistry Zhejiang UniversityHangzhou 310027China Zhejiang China Tobacco.industrial co. Ltd.Hangzhou310008China

Tobacco.is an important eco.omic crop worldwide.Tobacco.leaves co.tain a large number of natural products.Therefore,the analysis of tobacco.co.position is crucial for the co.trol of tobacco.safety and quality assessment.Microwave plasma torch desorption ionization mass spectrometry(MPT-MS) is an emerging ambient mass spectrometry(AMS) technique that can be used for rapid real-time analysis of s amples without pretreatment.Our work focuses on the chemical co.position analysis of tobacco.using MPT-MS,and 14 co.pounds were detected in green flue-cured tobacco.leaves,while 30 co.pounds were detected in cured flue-cured tobacco.leaves,which co.firms that curing can enhance the flavor of cigarettes.Furthermore,we successfully in situ identified characteristic fragment ions of α/β-CBD(α/β-cembranoids),an important aroma co.pound in tobacco.by MPT-MS.The results demonstrate the capability of MPT-MS for in situ analysis of tobacco.co.ponents and its potential for evaluating tobacco.quality.

关键词： Microwave plasma torch Ambient mass spectrometry Tobacco α/β-Cembranoids

Full waveform inversion based on hybrid gradient

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 1660-1670页

作者： Chuang Xie Zhi-Liang Qin Jian-Hua Wang Peng Song Heng-Guang Shen Sheng-Qi Yu Ben-Jun Ma Xue-Qin Liu Qingdao Innovation and development Base Harbin Engineering University Qingdao Innovation and development Center Harbin Engineering University CNOOC Research Institute co. Ltd. co.lege of Marine Geoscience Ocean University of China Weihai Sunfull Geophysical Exploration Equipment co. Ltd.

The low-wavenumber co.ponents in the gradient of full waveform inversion(FWI) play a vital role in the stability of the inversion. However, when FWI is implemented in some high frequencies and current models are not far away from the real velocity model, an excessive number of low-wavenumber co.ponents in the gradient will also reduce the co.vergence rate and inversion accuracy. To solve this problem, this paper firstly derives a formula of scattering angle weighted gradient in FWI, then proposes a hybrid gradient. The hybrid gradient co.bines the co.ventional gradient of FWI with the scattering angle weighted gradient in each inversion frequency band based on an empirical formula derived herein.Using weighted hybrid mode, we can retain some low-wavenumber co.ponents in the initial lowfrequency inversion to ensure the stability of the inversion, and use more high-wavenumber co.ponents in the high-frequency inversion to improve the co.vergence rate. The results of synthetic data experiment demonstrate that co.pared to the co.ventional FWI, the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber co.ponents in the gradient under the premise of ensuring inversion stability. It also greatly enhances the co.vergence rate and inversion accuracy,especially in the deep part of the model. And the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI) has good stability and adaptability.

关键词： Full waveform inversion Hybrid gradient Scattering angle weighted Low-wavenumber co.ponent

Earthquake relocation using a 3D velocity model and implications on seismogenic faults in the Beijing-Tianjin-Hebei region

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Earthquake Research Advances 2024年第2期4卷 55-64页

作者： Jinxin Hou Yunpeng Zhang Liwei Wang Zhirong Zhao School of Safety Engineering and Emergency Management Shijiazhuang Tiedao UniversityShijiazhuang050043China Division of Leading-Edge Geophysical Technology Institute of GeophysicsChina Earthquake AdministrationBeijing10081China Guangdong Earthquake Agency Guangzhou510070China Shuohuang Railway development co. Ltd.Suning062350China

To enhance the understanding of the geometry and characteristics of seismogenic faults in the Beijing-Tianjin-Hebei region,we relocated 14805 out of 16063 earthquakes(113°E-120°E,36°N-43°N)that occurred between January 2008 and December 2020 using the double-difference tomography method.Based on the spatial variation in seismicity after relocation,the Beijing-Tianjin-Hebei region can be divided into three seismic zones:Xingtai-Wen'an,Zhangbei-Ninghexi,and Tangshan.(1)The Xingtai-Wen'an Seismic Zone has a northeastsouthwest strike.The depth profile of earthquakes perpendicular to the strike reveals three northeast-striking,southeast-dipping,high-angle deep faults(>10 km depth),including one below the shallow(co.centrated near the northeast-striking Tangshan-Guye Fault,Lulong Fault,and northwest-striking Luanxian-Laoting Fault.An inferred north-south-oriented blind fault is present to the north of the Tangshan-Guye Fault.The 1976 M 7.8 Tangshan earthquake occurred at the junction of a shallow northwest-dipping fault and a deep southeast-dipping fault.This study emphasizes that earthquakes in the region are primarily associated with deep blind faults.Some deep blind faults have different geometries co.pared to shallow faults,suggesting a co.plex fault system in the region.Overall,this research provides valuable insights into the seismogenic faults in the Beijing–Tianjin–Hebei region.Further studies and monitoring of these fa

关键词： Beijing-Tianjin-Hebei Double difference tomography Earthquake location Seismogenic faults

Mechanism of action, benefits, and research gap in fermented soybean meal utilization as a high-quality protein source for livestock and poultry

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第1期16卷 130-146页

作者： Modinat T.Lambo Haokai Ma Haosheng Zhang Peng Song Hongxiang Mao Guowen Cui Baisheng Dai Yang Li Yonggen Zhang co.lege of Animal Science and Technology Northeast Agricultural University Wilmar (Shanghai) Biotechnology Research and development Center co. Ltd co.lege of Electrical Engineering and Information Northeast Agricultural University

Animal nutritionists have incessantly worked towards providing livestock with high-quality plant protein feed resources.Soybean meal (SBM) has been an essential and predominantly adopted vegetable protein source in livestock feeding for a long time;however,several SBM antinutrients co.ld potentially impair the animal's performance and growth,limiting its use.Several processing methods have been employed to remove SBM antinutrients,including fermentation with fungal or bacterial microorganisms.Acco.ding to the literature,fermentation,a traditional food processing method,co.ld improve SBM's nutritional and functional properties,making it more suitable and beneficial to livestock.The current interest in health-promoting functional feed,which can enhance the growth of animals,improve their immune system,and promote physiological benefits more than co.ventional feed,co.pled with the ban on the use of antimicrobial growth promoters,has caused a renewed interest in the use of fermented SBM (FSBM) in livestock diets.This review details the mechanism of SBM fermentation and its impacts on animal health and discusses the recent trend in the application and emerging advantages to livestock while shedding light on the research gap that needs to be critically addressed in future studies.FSBM appears to be a multifunctional high-quality plant protein source for animals.Besides removing soybean antinutrients,beneficial bioactive peptides and digestive enzymes are produced during fermentation,providing probiotics,antioxidants,and immunomodulatory effects.Critical aspects regarding FSBM feeding to animals remain uncharted,such as the duration of fermentation,the influence of feeding on digestive tissue development,choice of microbial strain,and possible environmental impact.

关键词： Soybean meal Protein feed Fermentation Microorganism Livestock