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Influence of Alignment Errors on Contact Pressure during Straight Bevel Gear Meshing Process

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Chinese Journal of Mechanical Engineering 2015年第6期28卷 1089-1099页

作者： HAN Xinghui hua Lin DENG Song luo Qiuping Hubei Key Laboratory of Advanced Technology for Automotive Components School of Automotive EngineeringWuhan University of Technology

Straight bevel gears are widely applied in automotive, aerospace, chemical and many other fields as one of the most common type of gears. Currently, the researches on straight bevel gears have focused on the fields of fatigue, wear, noise and vibration, while little attention is paid to the effect of multiple alignment errors on the gear tooth wear. To study the influence of alignment errors on the gear tooth wear, a simulated model of a straight bevel gear pair is established. Then, the contact pressure on the tooth surface is analyzed under the various alignment errors according to the Archard wear relationship. The main combinations of alignment errors played vital roles on the tooth wear are investigated. The result shows that under the single alignment error, the contact pressure moves to the tooth heel and increases greatly at here when ？P=0.1 or ？G=0.1; when ？E=–0.03, the contact pressure greatly increases at the tooth heel, but it obviously increases at the tooth toe when ？E=0.03; the alignment error ？γ=1 has little effect on the contact pressure on the tooth surface. Moreover, the combination of ？P, ？G, ？E〈0 and ？γ is the most dangerous type among the multiple alignment errors. This research provides valuable guidelines for predicting the tooth wear under various alignment errors.

关键词： straight bevel gear multiple alignment errors contact pressure wear

Effect of electron beam irradiation on the degradation of monochlorophenols in aqueous solution

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Journal of Environmental Sciences 2005年第2期17卷 301-304页

作者： ADELEKEOlukunleFrancis ZHOURui-min ZuJian-hua EkokoBakamboGracien SchoolofEnvironmentalandChemicalEngineering ShanghaiUniversityShanghai200072China ShanghaiAppliedRadiationInstitute ShanghaiUniversityShanghai201800China

Electron beam was successfully used for the degradation of 2-chlorophenol(2-CP) and 4-chlorophenol(4-CP) in aqueous solutions in this research. The effect of radiation dose on substrate degradation and dechlorination of solutions with concentration of 50 mg/L was investigated. The effect of initial concentration, pH and presence of oxygen was also investigated. The concentration of 2-CP and 4-CP remaining in solution after irradiation were measured by HPLC. The results showed that increased radiation dose led to increased degradation of the chlorophenols and increased Cl - yield. Deaeration was also found to significantly increase the rate of degradation of chlorophenols in water while degradation and dechlorination under alkaline condition was lower than at low to neutral pH.

关键词： electron beam monochlorophenols degradation deaeration

Electroacupuncture improves gut barrier dysfunction in prolonged hemorrhagic shock rats through vagus anti-inflammatory mechanism

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World Journal of Gastroenterology 2013年第36期19卷 5988-5999页

作者： ming-hua Du Hong-min luo Sen Hu Yi Lv Zhi-Long Lin Li Ma Research Laboratory of Shock and Multiple Organ Dysfunction Burns Institute First Hospital Affiliated to the PLA General Hospital Medical School of Chinese PLA

AIM:To investigate whether electroacupuncture(EA)at Zusanli(ST36)prevents intestinal barrier and remote organ dysfunction following prolonged hemorrhagic shock through a vagus anti-inflammatory ***:Sprague-Dawley rats were subjected to about 45%of total blood volume loss followed by delayed fluid replacement(DFR)with Ringer lactate 3h after *** a first study,rats were randomly divided into six groups:(1)EAN:EA at non-channel acupoints followed by DFR;(2)EA:EA at ST36 after hemorrhage followed by DFR;(3)VGX/EA:vagotomy(VGX)before EA at ST36 and DFR;(4)VGX/EAN:VGX before EAN and DFR;(5)α-bungarotoxin(α-BGT)/EA:intraperitoneal injection ofα-BGT before hemorrhage,followed by EA at ST36 and DFR;and(6)α-BGT/EAN group:α-BGT injection before hemorrhage followed by EAN and *** and mean arterial pressure(MAP)were monitored over the next 12 *** a second study,with the same grouping and treatment,cytokine levels in plasma and intestine,organ parameters,gut injury score,gut permeability to 4 kDa FITC-dextran,and expression and distribution of tight junction protein ZO-1 were ***:MAP was significantly lowered after blood loss;EA at ST36 improved the blood pressure at corresponding time points 3 and 12 h after *** at ST36 reduced tumor necrosis factor-αand interleukin(IL)-6 levels in both plasma and intestine homogenates after blood loss and DFR,while vagotomy or intraperitoneal injection ofα-BGT before EA at ST36reversed its anti-inflammatory effects,and EA at ST36did not influence IL-10 levels in plasma and *** at ST36 alleviated the injury of intestinal villus,the gut injury score being significantly lower than that of EAN group(1.85±0.33 vs 3.78±0.59,P<0.05).EA at ST36 decreased intestinal permeability to FITCdextran compared with EAN group(856.95 ng/mL±90.65 ng/mL vs 2305.62 ng/mL±278.32 ng/mL,P<0.05).EA at ST36 significantly preserved ZO-1 protein expression and localization at 12 h after ***,E

关键词： Hemorrhagic shock Zusanli Electro-acupuncture Intestinal permeability Tight junction

Mixing times in single and multi-orifice-impinging transverse(MOIT) jet mixers with crossflow

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Chinese Journal of Chemical Engineering 2016年第7期24卷 825-831页

作者： Peicheng luo Yuncui Tai Yi Fang hua Wu School of Chemistry & Chemical Engineering Southeast University Nanjing 211189 China Institute for Chemical and Bioengineering Department of Chemistry and Applied Bioscience ETH Zurich 8093 Zurich Switzerland

We study the macromixing behavior of single and multi-orifice-impinging transverse(MOIT) jet mixers with crossflow, in particular, the overall mixing time and the back-splash mixing time of the injected flow with the crossflow, using the PLIF technique. It is found that for a given mixer configuration, there is a critical jet-tocrossflow velocity ratio rcat which the back-splash begins to occur. Further increase in the velocity ratio r leads to sharp increase in the back-splash mixing time, which can offset the intensification of the downstream mixing. The dimensionless overall mixing time decreases as r increases to reach either a plateau or a local minimum, and the corresponding r value represents the optimal velocity ratio roptfor the macromixing. The momentum ratio of the two liquid streams is a key factor determining rcand ropt. For a larger scale mixer, a higher momentum ratio is required to achieve the optimal macromixing with the minimum dimensionless overall mixing time.

关键词： MixingChemical reactorsMixing timeJet mixerPlanar laser induced fluorescence (PLIF)

Impact of Improving Design Factor over 0.72 on the Safety and Reliability of Gas Pipelines and Feasibility Justification

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Chinese Journal of Mechanical Engineering 2012年第1期25卷 166-172页

作者： ZHAO Xinwei ZHANG Guangli luo Jinheng ZHANG hua Tubular Goods Research Institute of China National Petroleum Corporation Xi’an 710065China Petroleumtubular engineering Key Laboratory of China National Petroleum Corporation Xi’an 710065China

Many years experience of the operation of high stress (>72% specified minimum yield strength, SMYS) gas pipelines and statistical analysis results of pipeline incidents showed that the operating pipelines at stress levels over 72% SMYS have not presented problems in USA and Canada, and design factor does not control incidents or the safety of pipelines. Enhancing pipeline safety management level is most important for decreasing incident rate. The application history of higher design factors in the U.S and Canada was reviewed. And the effect of higher factors to the critical flaw size, puncture resistance, change of reliability with time, risk level and the arrest toughness requirements of pipeline were analyzed here. The comparison of pipeline failure rates and risk levels between two design factors (0.72 and 0.8) has shown that a change in design factor from 0.72 to 0.8 would bring little effect on failure rates and risk levels. On the basis of the analysis result, the application feasibility of design factor of 0.8 in China was discussed and the related suggestions were proposed. When an operator wishes to apply design factor 0.8 to gas pipeline, the following process is recommended: stress level of line pipe hydro test should be up to 100% SMYS, reliability and risk assessment at the design feasibility or conceptual stage should be conducted, Charpy impact energy should meet the need of pipeline crack arrest; and establish and execute risk based integrity management plan. The technology of pipeline steel metallurgy, line pipe fabrication and pipeline construction, and line pipe quality control level in China achieved tremendous progresses, and line pipe product standards and property indexes have come up to international advanced level. Furthermore, pipeline safety management has improved greatly in China. Consequently, the research for the feasibility of application of design factor of 0.8 in China has fundamental basis.

关键词： gas pipeline higher design factor safety and reliability risk integrity management

Glomerular podocyte dysfunction in inherited renal tubular disease

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World Journal of Pediatrics 2021年第3期17卷 227-233页

作者： Li-min huang Jian-hua Mao Department of Nephrology National Clinical Research Center for Child HealthThe Children’s HospitalZhejiang University School of Medicine#57 Zhugan LaneHangzhou 310006China

Background Hereditary renal tubular disease can cause hypercalciuria,acid-base imbalance,hypokalemia,hypomagnesemia,rickets,kidney stones,*** these diseases are not diagnosed or treated in time,they can cause kidney damage and electrolyte disturbances,which can be detrimental to the maturation and development of the *** involvement in renal tubular disease patients has only been considered *** We screened 71 papers(including experimental research,clinical research,etc.)about Dent's disease,Gitelman syndrome,and cystinosis from PubMed,and made *** Glomerular disease was initially underestimated among the clinical signs of renal tubular disease or was treated merely as a consequence of the tubular *** tubular diseases affect glomerular podocytes through certain mechanisms resulting in functional damage,morphological changes,and glomerular *** This article focuses on the progress of changes in glomerular podocyte function in Dent disease,Gitelman syndrome,and cystinosis for the purposes of facilitating clinically accurate diagnosis and scientific treatment and improving prognosis.

关键词： Cystinosis Dent disease Gitelman syndrome Podocyte Renal tubule disease

Phenomenology of Friedberg-Lee Texture in Left-Right Symmetric Model

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Communications in Theoretical Physics 2008年第8期50卷 451-458页

作者： luo min-Jie LIU Qiu-Yu Department of Modern Physics University of Science and Technology of China Hefei 230026 China The Abdus Salams International Center for Theoretical Physics Trieste Italy

We consider that the Higgs triplet Yukawa coupling takes the Friedberg-Lee texture, and the Higgs doublet Yukawa coupling simply identifies with the diagonal Yutawa coupling of charged lepton in the context of left-right symmetric model. In this scenario, the phenomenology, including effective neutrino masses, mixings, and thermal flavor-dependent leptogenesis and lepton flavor violation decays are studied. We investigate the combined constrain of the parameters in this scenario and test its consistency with present data.

关键词： neutrino mass neutrino mixing flavor-dependent leptogenesis lepton flavor violation Friedberg-Lee texture

Electric-field-induced microstructure modulation of carbon nanotubes for high-performance supercapacitors

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Frontiers of Materials Science 2019年第3期13卷 270-276页

作者： Chengzhi luo Guanghui LIU min ZHANG School of Electronic and Computer Engineering Peking UniversityShenzhen 518055China Shenzhen China Star Optoelectronics Technology Co. Ltd.Shenzhen 518132China

The growth direction,morphology and microstructure of carbon nano-tubes(CNTs)play key roles for their potential applications in electronic and energy storage ***,effective synthesis of CNTs in high crystallinity and desired microstructure still remains a tremendous *** we introduce an electric field for controlling the microstructure formation of *** reveals that the electric field not only make CNTs aligned parallel but also improve the density of ***,the microstructures of CNTs gradually change under electrical *** is,graphite sheets are transformed from the"herringbone"structure to a highly crystalline structure,facilitating the transportation of *** to the improved aligned growth direction,high density and highly crystalline microstructure,the electrochemical performance of CNTs is greatly *** the CNTs are applied in supercapacitors,they present a high specific capacitance of 237 F/g,three times higher than that of the CNTs prepared without electrical *** microstructure modulation of CNTs by electric field would help to construct high performance electronic and energy storage devices.

关键词： carbon nanotube electric field microstructure control supercapacitor electrochemical performance

Characteristics of nonlinear evolution of wavepackets in boundary layers

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Science China(Physics,Mechanics & Astronomy) 2013年第2期56卷 250-256页

作者： YU min luo JiSheng LI Jia Department of Mechanics Tianjin University

The nonlinear evolution of a finite-amplitude disturbance in a 3-D supersonic boundary layer over a cone was investigated recently by Liu et al. using direct numerical simulation （DNS）. It was found that certain small-scale 3-D disturbances amplified rapidly. These disturbances exhibit the characteristics of second modes, and the most amplified components have a well- defined spanwise wavelength, indicating a clear selectivity of the amplification. In the case of a cone, the three-dimensionality of the base flow and the disturbances themselves may be responsible for the rapid amplification. In order to ascertain which of these two effects are essential, in this study we carried out DNS of the nonlinear evolution of a spanwise localized disturbance （wavepacket） in a flat-plate boundary layer. A similar amplification of small-scale disturbances was observed, suggesting that the direct reason for the rapid amplification is the three-dimensionality of the disturbances rather than the three-dimensional nature of the base flow, even though the latter does alter the spanwise distribution of the disturbance. The rapid growth of 3-D waves may be attributed to the secondary instability mechanism. Further simulations were performed for a wavepacket of first modes in a supersonic boundary layer and of Tollmien-Schlichting （T-S） waves in an incompressible boundary layer. The re- suits show that the amplifying components are in the band centered at zero spanwise wavenumber rather than at a finite spanwise wavenumber. It is therefore concluded that the rapid growth of 3-D disturbances in a band centered at a preferred large spanwise wavenumber is the main characteristic of nonlinear evolution of second mode disturbances in supersonic boundary layers.

关键词： boundary layer wavepacket nonlinear evolution second mode spanwise small-scale disturbance