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94篇 您的检索式:作者名="HU Junhui"
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1Impact of Typical Steady-state Conditions and Transient Conditions on Flow Ripple and Its Test Accuracy for Axial Piston Pump显示文摘The current research about the flow ripple of axial piston pump mainly focuses on the effect of the structure of parts on the flow ripple. Therein, the structure of parts are usually designed and optimized at rated working conditions. However, the pump usually has to work in large-scale and time-variant working conditions. Therefore, the flow ripple characteristics of pump and analysis for its test accuracy with respect to variant steady-state conditions and transient conditions in a wide range of operating parameters are focused in this paper. First, a simulation model has been constructed, which takes the kinematics of oil film within friction pairs into account for higher accuracy. Afterwards, a test bed which adopts Secondary Source Method is built to verify the model. The simulation and tests results show that the angular position of the piston, corresponding to the position where the peak flow ripple is produced, varies with the different pressure. The pulsating amplitude and pulsation rate of flow ripple increase with the rise of pressure and the variation rate of pressure. For the pump working at a constant speed, the flow pulsation rate decreases dramatically with the increasing speed when the speed is less than 27.78% of the maximum speed, subsequently presents a small decrease tendency with the speed further increasing. With the rise of the variation rate of speed, the pulsating amplitude and pulsation rate of flow ripple increase. As the swash plate angle augments, the pulsating amplitude of flow ripple increases, nevertheless the flow pulsation rate decreases. In contrast with the effect of the variation of pressure, the test accuracy of flow ripple is more sensitive to the variation of speed. It makes the test accuracy above 96.20% available for the pulsating amplitude of pressure deviating within a range of ?6% from the mean pressure. However, with a variation of speed deviating within a range of ?2% from the mean speed, the attainable test accuracy of flow ripple is above 93.07%. The model constructed in this research proposes a method to determine the flow ripple characteristics of pump and its attainable test accuracy under the large-scale and time-variant working conditions. Meanwhile, a discussion about the variation of flow ripple and its obtainable test accuracy with the conditions of the pump working in wide operating ranges is given as well.XU Bing HU Min ZHANG Junhui 2015Chinese Journal of Mechanical Engineering2015,28,5:14
2High-Sensitivity Temperature Sensor Based on Polarization Maintaining Fiber Sagnac Loop显示文摘A high-sensitivity all-fiber temperature sensor based on a Sagnac interferometer is demonstrated by splicing a section of polarization maintaining fiber(PMF)between two sections of standard single mode fibers(SMFs).In this sensor,the SMF-PMF-SMF structure in the Sagnac loop is bent into a circle to enhance the sensitivity.The length and curvature of the PMF in the loop are investigated and can be optimized to further increase the temperature sensitivity of the sensor. Results show that the radius of the circle has an important effect upon temperature sensitivity due to the bend-induced birefringence variation of the PMF.The SMF-PMF-SMF structure bent into a circle with a radius of 30mm exhibits a high-sensitivity temperature of 1.73nm/℃.The sensor is provided with the advantages of easy fabrication,low-insertion loss,and high sensitivity,which may find potential applications in the field of high precision temperature measurement.Laipeng SHAO Junhui HU Hanglin LU Jing DU Tianyin WU Yiping WANG 2019Photonic Sensors2019,9,1:10
3Microscopic examination of intracellular organisms in bronchoalveolar lavage fluid for the diagnosis of ventilator-associated pneumonia:a prospective multi-center study显示文摘Liu Chang Du Zhaohui Zhou Qing Hu Bo Li Zhifeng Yu Li Xu Tao Fan Xuepeng Yang Junhui Li Jianguo 2014Chinese Medical Journal2014,,10:6
4Analysis of humidity-dependent adhesion between a probe tip and a surface显示文摘Li Yang Junhui Hu Huapeng Xiao Wenwen Quan 2017Particuology2017,15,4:4
5Principle and Experimental Verification of Novel Dual Driving Face Rotary Ultrasonic Motor显示文摘Existing rotary ultrasonic motors operating in extreme environments cannot meet the requirements of good environmental adaptability and compact structure at same time,and existing ultrasonic motors with Langevin transducers show better environmental adaptability,but size of these motors are usually big due to the radial arrangement of the Langevin transducers.A novel dual driving face rotary ultrasonic motor is proposed,and its working principle is experimentally verified.The working principle of the novel ultrasonic motor is firstly proposed.The 5th in-plane flexural vibration travelling wave,excited by the Langevin transducers around the stator ring,is used to drive the rotors.Then the finite element method is used in the determination of dimensions of the prototype motor,and the confirmation of its working principle.After that,a laser Doppler vibrometer system is used for measuring the resonance frequency and vibration amplitude of the stator.At last,output characteristics of the prototype motor are measured,environmental adaptability is tested and performance for driving a metal ball is also investigated.At room temperature and 200 V(zero to peak) driving voltage,the motor's no-load speed is 80 r/min,the stalling torque is 0.35 N·m and the maximum output power is 0.85 W.The response time of this motor is 0.96 ms at the room temperature,and it decreases or increases little in cold environment.A metal ball driven by the motor can rotate at 210 r/min with the driving voltage 300 V(zero to peak).Results indicate that the prototype motor has a large output torque and good environmental adaptability.A rotary ultrasonic motor owning compact structure and good environmental adaptability is proposed,and lays the foundations of ultrasonic motors' applications in extreme environments.LU Xiaolong HU Junhui YANG Lin ZHAO Chunsheng 2013Chinese Journal of Mechanical Engineering2013,26,5:4
6Influence of Metallic Modification on Ethylbenzene Dealkylation over ZSM-5 Zeolites显示文摘A series of metal-modified HZSM-5 catalysts were prepared by impregnation and were used for ethylbenzene dealkylation of the mixed C8 aromatics(ethylbenzene,m-xylene and o-xylene).The effects of different supported metals(Pt,Pd,Ni,Mo)on catalytic performance,including reaction conditions,were investigated.The physicochemical properties of catalysts were characterized by means of XRD,BET,TEM and NH_(3)-TPD.Experimental results showed that metallic modification obviously increased the ethylbenzene conversion and reduced the coke deposition,greatly improving the catalyst stability.The distinction of ethylbenzene conversion depended on the interaction between hydrogenation reactivity and acidic cracking of bifunctional metal-modified zeolites.Compared with Pt and Ni,Pd and Mo were easier to disperse into HZSM-5 micropores during loading metals.The acidic density of different metal-modified HZSM-5 declined in the following order:HZSM-5>Pt/HZSM-5>Pd/HZSM-5>Ni/HZSM-5>Mo/HZSM-5.The activity of ethylene hydrogenation decreased with Pt/HZSM-5>Pd/HZSM-5>Ni/HZSM-5>Mo/HZSM-5.In comparison,Pd/HZSM-5 showed the best catalytic performance with both high activity and high selectivity,with less cracking loss of m-xylene and o-xylene.Moreover,the following reaction conditions were found to be preferable for ethylbenzene dealkylation over Pd/HZSM-5:340℃,1.5 MPa H2,WHSV 4 h^(−1),H_(2)/C84 mol/mol.Chao Hu Junhui Li Wenzhi Jia Min Liu Zhixian Hao Zhirong Zhu 2015Chinese Journal of Chemistry2015,33,2:3
7A novel in-plane mode rotary ultrasonic motor显示文摘Ultrasonic motors have the merits of high ratio of torque to volume, high positioning precision, intrinsic holding torque, etc., compared to the conventional electromagnetic motors. There have been several potential applications for this type of motor in aerospace exploration, but bearings and bonding mechanism of the piezoelectric ring in the motors limit the performance of them in the space operation conditions. It is known that the Langevin type transducer has excellent energy efficiency and reliability. Hence using the Langevin type transducer in ultrasonic motors may improve the reliability of piezoelectric motors for space applications. In this study, a novel in-plane mode rotary ultrasonic motor is designed, fabricated, and characterized. The proposed motor operates in in-plane vibration mode which is excited by four Langevin-type bending vibrators separately placed around a ring-shaped stator. Two tapered rotors are assembled to the inner ring of the stator and clamped together by a screw nut. In order to make the motor more stable and convenient to fix, a thin cylindrical support is placed under the stator ring. Due to its no-bearing structure and Langevin transducer excitation, the prototype ultrasonic motor may operate well in aeronautic and astronautic environments.Lu Xiaolong Hu Junhui Yang Lin Zhao Chunsheng 2014Chinese Journal of Aeronautics2014,27,2:3
8Optical superoscillatory waves without side lobes along a symmetric cut显示文摘Optical superoscillation refers to an intriguing phenomenon of a wave packet that can oscillate locally faster than its highest Fourier component,which potentially produces an extremely localized wave in the far field.It provides an alternative way to overcome the diffraction limit,hence improving the resolution of an optical microscopy system.However,the optical superoscillatory waves are inevitably accompanied by strong side lobes,which limits their fields of view and,hence,potential applications.Here,we report both experimentally and theoretically a new superoscillatory wave form,which not only produces significant feature size down to deep subwavelength,but also completely eliminates side lobes in a particular dimension.We demonstrate a new mechanism for achieving such a wave form based on a pair of moonlike sharp-edge apertures.The resultant superoscillatory wave exhibits Bessel-like forms,hence allowing long-distance propagation of subwavelength structures.The result facilitates the study of optical superoscillation and on a fundamental level eliminates the compromise between the superoscillatory feature size and the field of view.Yanwen Hu Shiwang Wang Junhui Jia Shenhe Fu Hao Yin Zhen Li Zhenqiang Chen 2021Advanced Photonics2021,3,4:3
9Effect of external surface of HZSM-5 zeolite on product distribution in the conversion of methanol to hydrocarbons显示文摘The external surface of HZSM-5 zeolite was passivated by liquid siliceous deposition and by acidic sites poisoning with lepidine, respectively.Then methanol-to-hydrocarbons(MTH) reaction was investigated over the above as-prepared catalysts and the dissoluble coke on these used catalysts was analyzed by GC-MS, to study the role of the external surface of HZSM-5 in the catalytic reaction. Comparison with the experimental results based on parent ZSM-5 showed that the product distribution of MTH reaction was obviously influenced by the external surface.Evidences were listed as follows:(1) the final product on parent HZSM-5 showed higher aromatic selectivity, lower olefin selectivity, lower ratio of C2/C3+aliphatics and higher ratio of C3/C4+aliphatics than the reaction mixture produced by the sole catalysis of acidic sites in HZSM-5channel;(2) a little of pentamethylbenzene and hexamethylbenzene in the product on parent HZSM-5, was produced via multi-methylation of methylbenzene on the external surface. The above conclusion may also be suitable for MTH reaction over other zeolites with 10-ring channel.Junhui Li Yanan Wang Wenzhi Jia Zhiwen Xi Huanhui Chen Zhirong Zhu Zhonghua Hu 2014Journal of Energy Chemistry2014,23,6:2
10Interactive response of photosynthetic characteristics in Haloxylon ammodendron and Hedysarum scoparium exposed to soil water and air vapor pressure deficits显示文摘C4 plants possess better drought tolerance than C3 plants. However, Hedysarum scoparium, a C3 species, is dominant and widely distributed in the desert areas of northwestern China due to its strong drought tolerance. This study compared it with Haloxylon ammodendron, a C4 species, regarding the interactive effects of drought stress and different leaf–air vapor pressure deficits. Variables of interest included gas exchange, the activity levels of key C4 photosynthetic enzymes, and cellular anatomy. In both species, gas exchange parameters were more sensitive to high vapor pressure deficit than to strong water stress, and the net CO2 assimilation rate(A n) was enhanced as vapor pressure deficits increased. A close relationship between A n and stomatal conductance(g s) suggested that the species shared a similar response mechanism. In H. ammodendron, the activity levels of key C4 enzymes were higher, including those of phosphoenolpyruvate carboxylase(PEPC) and nicotinamide adenine dinucleotide phosphate-malate enzyme(NADP-ME), whereas in H. scoparium, the activity level of nicotinamide adenine dinucleotide-malate enzyme(NAD-ME) was higher.Meanwhile, H. scoparium utilized adaptive structural features, including a larger relative vessel area and a shorter distance from vein to stomata, which facilitated the movement of water. These findings implied that some C4 biochemical pathways were present in H. scoparium to respond to environmental challenges.Chunmei Gong Jiajia Wang Congxia Hu Junhui Wang Pengbo Ning Juan Bai 2015Journal of Environmental Sciences2015,27,8:2
11Structure transition comparison between the amorphous nanosize particles and coarse - grained polycrystailine of cobalt显示文摘Changsheng Xie Junhui Hu Run Wu 0,,:1
12Modeling and analysis of dual-output piezoelectric transformer operating at the thickness-shear vibration mode显示文摘Du Jinlong Hu Junhui Tseng K J 2006IEEE Transactions on Ultrasonics Ferroelectrics and FrequencyControl2006,53,3:1
13A plate - shaped high power- density piezoelectric transformer with dual outputs 显示文摘Du Jinlong Hu Junhui Tseng King Jet 2004Ceramics International2004,30,:1
14The law of ultrasonic energy conversion in thermosonic flip chip bonding interfaces显示文摘Li Junhui Wang Ruishan He Hu Wang Fuliang Han Lei Zhong Jue 2009Microelectronic Engineering2009,,10:1
15Analyses of an ultrasonic motor driving fluid directly显示文摘Junhui Hu Tohgo Yamazaki Kentaro Nakamra 1995Jpn J Appl Phys1995,34,5:1
16An analysis of a noncontact ultrasonic motor with an ultrasonically levitated rotor 显示文摘Junhui Hu Kentaro Nakamra Sadauki Ueha 1997Ultrasonics1997,,35:1
17Analysis of an ultrasonic motor driving fluid directly显示文摘Hu Junhui Tohgo Yamazaki 1995Jpn J Appl Phys1995,34,5:1
18Cardiac proteomics reveals the potential mechanism of microtubule associated protein 4 phosphorylation-induced mitochondrial dysfunction显示文摘Background:Our previous work suggested that microtubule associated protein 4(MAP4)phosphorylation led to mitochondrial dysfunction in MAP4 phosphorylation mutant mice with cardiomyopathy,but the detailed mechanism was still unknown.Thus,the aim of this study was to investigate the potential mechanism involved in mitochondrial dysfunction responsible for cardiomyopathy.Methods:The present study was conducted to explore the potential mechanism underlying the mitochondrial dysfunction driven by MAP4 phosphorylation.Strain of mouse that mimicked constant MAP4 phosphorylation(S737 and S760)was generated.The isobaric tag for relative and absolute quantitation(iTRAQ)analysis was applied to the heart tissue.Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG),and protein-protein interaction(PPI)were all analyzed on the basis of differential expressed proteins(DEPs).Results:Among the 72 cardiac DEPs detected between the two genotypes of mice,12 were upregulated and 60 were downregulated.GO analysis showed the biological process,molecular function,and cellular component of DEPs,and KEGG enrichment analysis linked DEPs to 96 different biochemical pathways.In addition,the PPI network was also extended on the basis of DEPs as the seed proteins.Three proteins,including mitochondrial ubiquitin ligase activator of NF-κB 1,reduced form of nicotinamide adenine dinucleotide(NADH)-ubiquinone oxidoreductase 75 kDa subunit,mitochondrial and growth arrest,and DNA-damage-inducible proteins-interacting protein 1,which play an important role in the regulation of mitochondrial function,may correlate with MAP4 phosphorylationinduced mitochondrial dysfunction.Western blot was used to validate the expression of the three proteins,which was consistent with iTRAQ experiments.Conclusions:These findings revealed that the DEPs caused by MAP4 phosphorylation in heart tissue using iTRAQ technique and may provide clues to uncover the potential mechanism of MAP4 phosphorylation-induced mitochondrial dysfunction.Lingfei Li Junhui Zhang Qiong Zhang Yuesheng Huang Jiongyu Hu 2019Burns & Trauma2019,7,1:1
19Junction plakoglobin regulates and destabilizes HIF2α to inhibit tumorigenesis of renal cell carcinoma显示文摘Background:Increased hypoxia-inducible factor 2α(HIF2α)activation is a common event in clear cell renal cell carcinoma(ccRCC)progression.However,the function and underlying mechanism of HIF2α in ccRCC remains uninvestigated.We conducted this study to access the potential link between junction plakoglobin(JUP)and HIF2αin ccRCC.Methods:Affinity purification and mass spectrometry(AP-MS)screening,glutathione-s-transferase(GST)pull-down and co-immunoprecipitation(Co-IP)assays were performed to detect the interacting proteins of HIF2α.Quantitative PCR(qPCR)and Western blotting were used to detect the expression of JUP in human ccRCC samples.Luciferase reporter assays,chromatin immunoprecipitation(ChIP),cycloheximide chase assays,and ubiquitination assays were conducted to explore the regulation of JUP on the activity of HIF2α.Cell Counting Kit-8(CCK-8)assays,colony formation assays,transwell assays,and xenograft tumor assays were performed to investigate the effect of JUP knockdown or overexpression on the tumorigenicity of renal cancer cells.Results:We identified JUP as a novel HIF2α-binding partner and revealed an important role of JUP in recruiting von Hippel-Lindau(VHL)and histone deacetylases 1/2(HDAC1/2)to HIF2α to regulate its stability and transactivation.JUP knockdown promoted and overexpression suppressed the tumorigenicity of renal cell carcinoma in vitro and in vivo.Importantly,the low expression of JUP was found in clinical ccRCC samples and correlated with enhanced hypoxia scores and poor treatment outcomes.Conclusion:Taken together,these data support a role of JUP in modulating HIF2α signaling during ccRCC progression and identify JUP as a potential therapeutic target.Ke Chen Jin Zeng Yi Sun Wei Ouyang Gan Yu Hui Zhou Yangjun Zhang Weimin Yao Wei Xiao Junhui Hu Jinchun Xing Kefeng Xiao Lily Wu Zhiqiang Chen Zhangqun Ye Hua Xu 2021Cancer Communications2021,41,4:1
20Analyses of ultrasonic motor driving fluid directly显示文摘Hu Junhui Tohgo Yamazaki 1995Jpn J Appl Phys1995,,:1
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