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Analysis of Mixed Model in Gear Transmission Based on ADAMS

Chinese Journal of Mechanical Engineering 2012年第5期25卷 968-973页

作者： LI Xiufeng WANG Yabin National key laboratory on Electromechanical Dynamic control Beijing Institute of TechnologyBeijing 100081China

The traditional method of mechanical gear driving simulation includes gear pair method and solid to solid contact method. The former has higher solving efficiency but lower results accuracy; the latter usually obtains higher precision of results while the calculation process is complex, also it is not easy to converge. Currently, most of the researches are focused on the description of geometric models and the definition of boundary conditions. However, none of them can solve the problems fundamentally. To improve the simulation efficiency while ensure the results with high accuracy, a mixed model method which uses gear tooth profiles to take the place of the solid gear to simulate gear movement is presented under these circumstances. In the process of modeling, build the solid models of the mechanism in the SolidWorks firstly; Then collect the point coordinates of outline curves of the gear using SolidWorks API and create fit curves in Adams based on the point coordinates; Next, adjust the position of those fitting curves according to the position of the contact area; Finally, define the loading conditions, boundary conditions and simulation parameters. The method provides gear shape information by tooth profile curves; simulates the mesh process through tooth profile curve to curve contact and offer mass as well as inertia data via solid gear models. This simulation process combines the two models to complete the gear driving analysis. In order to verify the validity of the method presented, both theoretical derivation and numerical simulation on a runaway escapement are conducted. The results show that the computational efficiency of the mixed model method is 1.4 times over the traditional method which contains solid to solid contact. Meanwhile, the simulation results are more closely to theoretical calculations. Consequently, mixed model method has a high application value regarding to the study of the dynamics of gear mechanism.

关键词： mixed model contact gear transmission runaway escapement

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Effects of SO2 on the low temperature selective catalytic reduction of NO by NH3 over CeO2-V2O5-WO3/TiO2 catalysts

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Frontiers of Environmental Science & Engineering 2017年第4期11卷 153-159页

作者： Quanming Liang Jian Li Hong He Wenjun Liang Tiejun Zhang Xing Fan key laboratory of beijing on Regional Air Pollution control Beijing University of Technology Beijing 100124 China beijing key laboratory for Green Catalysis and Separation Beijing University of Technology Beijing 100124 China

The CeO2-V2O5-WO3/TiO2 （CeO2-VWT） catalysts were prepared by one-step and two-step impregnation methods. The effects of different loading of CeO2 and different preparation methods on De-NOx activity of catalysts had been investigated. CeO2 helped to improve the De-NOx activity and sulfur resistance. The optimal loading of CeO2 was 3% with the De-NOx efficiency reached 89.9% at 140℃. The results showed that the De-NOx activity of 3% CeO2-VWT catalysts by one-step method was the same as two-step method basically and reached the level of industrial applications, the N2 selectivity of catalysts was more than 99.2% between 110℃ and 320℃. In addition, CeO2 promoted the oxidation of NO to NO2, which adsorbed on the Lewis acid site （V5＋-O） to form V5＋-NO3 and inspired the fast SCR reaction. Not only the thermal stability but also the De-NOx activity of catalysts decreased with excess CeO2 competed with V2O5. Characterizations of catalysts were carried out by XRF, BET, XRD, TG and FT-IR. BET showed that the specific surface area of catalysts decreased with the loading of CeO2 increased, the active components content and specific surface area of catalysts decreased slightly after entering SO2. Ammonium sulfate species were formed in poisoned catalyst which had been investigated by XRF, BET, TG and FT-IR. The largest loss rate of weight fraction was 0.024%.℃-1 at 380℃ 390℃, which was in accordance with the decomposition temperature of NH4HSO4 and （NH4）2SO4,

关键词： Low temperature SCR De-NOx activity Sulfur resistance Ammonium sulfate

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NO oxidation over Co-La catalysts and NOx reduction in compact SCR

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Frontiers of Environmental Science & Engineering 2017年第2期11卷 67-75页

作者： Tiejun Zhang Jian Li Hong He Qianqian Song Quanming Liang key laboratory of beijing on Regional Air Pollution control Beijing University of Technology Beijing 100124 China beijing key laboratory for Green Catalysis and Separation Beijing University of Technology Beijing 100124 China

A series of Co-La catalysts were prepared using the wet impregnation method and the synthesis of catalysts were modified by controlling pH with the addition of ammonium hydroxide or oxalic solution. All the catalysts were systematically investigated for NO oxidation and S02 resistance in a fixed bed reactor and were characterized by Brunanuer-Emmett-Teller （BET） method, Fourier Transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD）, Thermogravimetric （TG） and Ion Chromatography （IC）. Among the catalysts, the one synthesized at pH = 1 exhibited the maximum NO conversion of 43% at 180℃. The activity of the catalyst was significantly suppressed by the existence of SO2 （300 ppm） at 220℃. Deactivation may have been associated with the generation of cobalt sulfate, and the SO2 adsorption quantity of the catalyst might also have effected sulfur resistance. In the case of the compact selective catalytic reduction （SCR）, the activity increased from 74% to 91% at the highest gas hourly space velocity （GHSV） of 300000 h I when the NO catalyst maintained the highest activity, in excess of 50% more than that of the standard SCR.

关键词： NO catalytic oxidationpH effectLow temperatureSulfur dioxideHigh space velocitySCR

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Potential acute effects of suspended aluminum nitride (AlN) nanoparticles on soluble microbial products (SMP) of activated sludge

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Journal of Environmental Sciences 2017年第7期29卷 284-292页

作者： Lijie Zhou Weiqin Zhuang Xin Wang Ke Yu Shufang Yang Siqing Xia State Environmental Protection key laboratory of Drinking Water Source Management and Technology Shenzhen Key Laboratory of Drinking Water Source Safety ControlShenzhen Key Laboratory of Emerging Contaminants Detection & Control in Water EnvironmentShenzhen Academy of Environmental Sciences State key laboratory of Pollution control and Resource Reuse College of Environmental Science and EngineeringTongji University Department of Civil and Environmental Engineering University of Auckland School of Environment and Energy Peking University Shenzhen Graduate School Shenzhen Municipal Design & Research Institute Co. Ltd

The study aims to identify the potential acute effects of suspended aluminum nitride（Al N）nanoparticles（NPs） on soluble microbial products（SMP） of activated *** activated sludge loaded with 1,10,50,100,150 and 200 mg/L of Al N NPs were carried out in this *** results showed,Al N NPs had a highly inverse proportionality to bacterial dehydrogenase and OUR,indicating its direct toxicity to the activated sludge *** toxicity of Al N NPs was mainly due to the nano-scale of Al N *** SMP,Al N NPs led to the decrease of polysaccharide and humic compounds,but had slight effects on *** decrease of tryptophan-like substances in SMP indicated the inhibition of Al N NPs on the bacterial ***,Al N NPs reduced obviously the molecular weight of SMP,which might be due to the nano-scale of Al N.

关键词： Aluminum nitride nanoparticles Topic Soluble microbial products(SMP) Activated sludge Bacterial viability

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Assessing the persistence of pharmaceuticals in the aquatic environment:Challenges and needs

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emerging contaminants 2016年第3期2卷 145-147页

作者： Qingwei Bu Xiao Shi Gang Yu Jun Huang Bin Wang School of Chemical&Environmental Engineering China University of Mining&Technology-BeijingBeijing 100083PR China School of Environment State Key Joint Laboratory of Environmental Simulation and Pollution ControlBeijing Key Laboratory for Emerging Organic Contaminants ControlTsinghua UniversityBeijing 100084PR China

Chemical’s persistence is known to be an important parameter applied for decades to identify persistent organic pollutants in hazard and/or risk *** it is greatly challenged in the case of emerging contaminants such as pharmaceuticals because the persistence of these chemicals could be more affected by environmental *** fact brings more challenges to the current system for evaluating the persistence of chemical *** this paper,challenges in assessing the persistence of pharmaceuticals were identified,and more importantly research needs were addressed based on the existing data and knowledge.

关键词： Persistence Pharmaceuticals Transformation half-life

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Inhibiting ceramide synthase 5 expression in microglia decreases neuroinflammation after spinal cord injury

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Neural Regeneration Research 2025年第10期20卷 2955-2968页

作者： Wei Zhang Yubao Lu Ruoqi Shen Yingjie Wu Chenrui Liu Xingxing Fang Liangming Zhang Bin Liu Limin Rong Department of Spine Surgery The Third Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina National Medical Products Administration(NMPA)key laboratory for Quality Research and Evaluation of Cell Products GuangzhouGuangdong ProvinceChina Guangdong Provincial Center for Quality control of Minimally Invasive Spine Surgery GuangzhouGuangdong ProvinceChina Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery GuangzhouGuangdong ProvinceChina

Microglia,the resident monocyte of the central nervous system,play a crucial role in the response to spinal cord ***,the precise mechanism remains *** investigate the molecular mechanisms by which microglia regulate the neuroinflammatory response to spinal cord injury,we performed single-cell RNA sequencing dataset analysis,focusing on changes in microglial *** found that the MG1 subpopulation emerged in the acute/subacute phase of spinal cord injury and expressed genes related to cell pyroptosis,sphingomyelin metabolism,and neuroinflammation at high ***,we established a mouse model of contusive injury and performed intrathecal injection of siRNA and molecular inhibitors to validate the role of ceramide synthase 5 in the neuroinflammatory responses and pyroptosis after spinal cord ***,we established a PC12-BV2 cell co-culture system and found that ceramide synthase 5 and pyroptosis-associated proteins were highly expressed to induce the apoptosis of neuron *** ceramide synthase 5 expression in a mouse model of spinal cord injury effectively reduced ***,ceramide synthase 5-induced pyroptosis was dependent on activation of the NLRP3 signaling *** ceramide synthase 5 expression in microglia in vivo reduced neuronal apoptosis and promoted recovery of neurological ***2g7 formed a“bridge”between sphingolipid metabolism and ceramide synthase 5-mediated cell death by inhibiting the NLRP3 signaling ***,these findings suggest that inhibiting ceramide synthase 5 expression in microglia after spinal cord injury effectively suppressed microglial pyroptosis mediated by NLRP3,thereby exerting neuroprotective effects.

关键词： ceramide synthase 5 gasdermin D microglia neuroinflammation NLRP3 nuclear factor kappa B Pla2g7 pyroptosis sphingomyelin metabolism spinal cord injury

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Sewage sludge disintegration by high-pressure homogenization: A sludge disintegration model

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Journal of Environmental Sciences 2012年第5期24卷 814-820页

作者： Yuxuan Zhang Panyue Zhang panyue_zhang@*** Boqiang Ma Hao Wu Sheng Zhang Xin Xu beijing key laboratory for Source control Technology of Water Pollution Beijing Forestry University Beijing 100083 China

High-pressure homogenization （HPH） technology was applied as a pretreatment to disintegrate sewage sludge. The effects of homogenization pressure, homogenization cycle number, and total solid content on sludge disintegration were investigated. The sludge disintegration degree （DDCOD）, protein concentration, and polysaccharide concentration increased with the increase of homogenization pressure and homogenization cycle number, and decreased with the increase of sludge total solid （TS） content. The maximum DDCOD of 43.94% was achieved at 80 MPa with four homogenization cycles for a 9.58 g/L TS sludge sample. A HPH sludge disintegration model of DDCOD= kNaPb was established by multivariable linear regression to quantify the effects of homogenization parameters. The homogenization cycle exponent a and homogenization pressure exponent b were 0.4763 and 0.7324 respectively, showing that the effect of homogenization pressure （P） was more significant than that of homogenization cycle number （N）. The value of the rate constant k decreased with the increase of sludge total solid content. The specific energy consumption increased with the increment of sludge disintegration efficiency. Lower specific energy consumption was required for higher total solid content sludge.

关键词： high-pressure homogenization sludge disintegration homogenization pressure homogenization cycle number total solid content

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Formation of disinfection byproducts from accumulated soluble products of oleaginous microalga after chlorination

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Frontiers of Environmental Science & Engineering 2017年第6期11卷 1-7页

作者： Yu Liu Qiao Zhang Yu Hong beijing key laboratory for Source control Technology of Water Pollution Beijing Forestry University Beijing 100083 China

When microalgae are simultaneously applied for wastewater treatment and lipid production, soluble algal products （SAP） should be paid much attention, as they are important precursors for formation of disinfection byproducts （DBPs）, which have potential risks for human health. Chlorella sp. HQ is an oleaginous microalga that can generate SAP during growth, especially in the exponential phase. This study investigated the contribution of SAP from Chlorella sp. HQ to DBP formation after *** predominant DBP precursors from SAP were identified with the 3D excitation-emission matrix fluorescence. After chlorination, a significant reduction was observed in the fluorescence intensity of five specific fluorescence regions, particularly aromatic proteins and soluble microbial by-product-like regions, accompanied with slight shifting of the peak. The produced DBPs were demonstrated to include trihalomethanes and haloacetic acids. As the algal cultivation time was extended in wastewater, the accumulated SAP strengthened the formation of DBPs. The trend for DBP formation was as follows： chloroform〉dichloroacetic acid〉trichloroacetic acid.

关键词： Chlorella sp. HQ Chlorination Disinfection byproducts Fluorescence spectroscopy Soluble algal products

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Efficient Humoral and Cellular Immune Responses Induced by a Chimeric Virus-like Particle Displaying the Epitope of EV71 without Adjuvant

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Biomedical and Environmental Sciences 2018年第5期31卷 343-350页

作者： LIANG Pu YI Yao SU Qiu Dong QIU Feng FAN Xue Ting LU Xue Xin BI Sheng Li National Institute for Viral Disease control and Prevention Chinese Center for Disease Control and PreventionBeijing 102206China Institute of Infectious Diseases Beijing Ditan HospitalCapital Medical UniversityBeijing Key Laboratory of Emerging Infectious DiseasesBeijing 100015China

Objective To eliminate the side effects of aluminum adjuvant and His-tag,we constructed chimeric VLPs displaying the epitope of EV71（SP70） without *** evaluating whether the VLPs could efficiently evoke not only humoral but also cellular immune responses against EV71 without *** The fusion protein was constructed by inserting SP70 into the MIR of truncated HBc Ag sequence,expressed in ***,and purified through ion exchange chromatography and density gradient *** were immunized with the VLPs and sera were collected *** specific antibody titers,Ig G subtypes and neutralizing efficacy were detected by ELISA,neutralization assay,and EV71 lethal ***-γ and IL-4 secreted by splenocytes were tested by ELISPOT *** HBc-SP70 proteins can self-assemble into empty *** immunization with HBc-SP70 VLPs,the detectable anti-EV71 antibodies were effective in neutralizing EV71 and protected newborn mice from EV71 lethal *** was no significant difference for the immune efficacy whether the aluminum adjuvant was added or *** specific Ig G subtypes were mainly IgG1 and IgG2 b and splenocytes from the mice immunized produced high levels of IFN-γ and *** The fusion proteins without His-tagged was expressed and purified as soluble chimeric HBc-SP70 VLPs without *** the absence of adjuvant,they were efficient to elicit high levels of Th1/Th2 mixed immune response as well as assisted by aluminum ***,the chimeric VLPs have potential to prevent HBV and EV71 infection simultaneously.

关键词： Virus-like particles Enterovirus 71 Neutralizing antibody Humoral and cellular immunity Adjuvant Vaccine

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Regression model for daily passenger volume of high-speed railway line under capacity constraint

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Journal of Central South University 2015年第9期22卷 3666-3676页

作者：骆泳吉刘军孙迅赖晴鹰 State key laboratory of Rail Traffic control and Safety (beijing Jiaotong University)

A non-linear regression model is proposed to forecast the aggregated passenger volume of beijing-Shanghai high-speed railway(HSR) line in China. Train services and temporal features of passenger volume are studied to have a prior knowledge about this high-speed railway line. Then, based on a theoretical curve that depicts the relationship among passenger demand, transportation capacity and passenger volume, a non-linear regression model is established with consideration of the effect of capacity constraint. Through experiments, it is found that the proposed model can perform better in both forecasting accuracy and stability compared with linear regression models and back-propagation neural networks. In addition to the forecasting ability, with a definite formation, the proposed model can be further used to forecast the effects of train planning policies.

关键词： high-speed rail Jinghu high-speed railway(HSR) demand capacity forecasting

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