检索结果-南通市图书馆

DYNAMIC CHARACTERISTICS ON PRECISION NC LATHE BASED ON MULTI-BODY SYSTEM THEORY

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2005年第4期18卷 566-570页

作者： Wu Nanxing Sun Qinghong Zhang Yonghong yu dongling Department of Mechanical Engineering Jingdezhen Ceramic Institute Jingdezhen 333001 China Department of Mechanical Engineering Southeast University Nanjing 210096 China School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China Department of Mechanical Engineering Jingdezhen Ceramic Institute Jingdezhen 333001China

Based on multi-body system theory and the mainshafl system of precision NC lathe as object investigated, it is treated as a coupled rigid-flexible multi-body system which is made up of some rigid and elastic bodies in an especial linking mode. And a dynamic model is established, The problems of computing vibration characteristics are resolved by using multi-body system transfer matrix method, Resutts show that the mainshaft system of NC lathe is in the stable and reliable working area all the time. The method is simple and easy, the idea is clear. In addition, the method can be easily used and popularized in the other multi-body system.

关键词： Multi-body system Mainshaft system Transfer matrix method Dynamic characteristics NC lathe

Gas Characteristics of Pine Sawdust Catalyzed Pyrolysis by Additives

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2021年第1期30卷 333-342页

作者： yu dongling JIN Guang PANG yunji CHEN Yisheng GUO Shaopeng SHEN Shengqiang School of Energy and Environment Inner Mongolia University of Science and TechnologyBaotou 014000China School of Energy and Power Engineering Dalian University of TechnologyDalian 116023China

In order to effectively investigate the variation of gas production characteristics of biomass under normal-speed pyrolysis conditions,the gas production rate,gas production component yield and gas production calorific value of pine sawdust with adding Na_(2)CO_(3),CaO and Fe_(2)O_(3)were systematically *** the experiment,an improved tube furnace was used to research the pyrolysis process with the temperature from 350℃to 750℃.The results indicate that the gas yield rises with the increase of temperature without additives,reaching 19.59%at 750℃.The liquid yield reaches 59.38%at 450℃and then the yield change is *** increases the calorific value of the pyrolysis product gas due to the adsorption of CO_(2).Na_(2)CO_(3)is fused with inorganic substances in the biomass to form a char skeleton *** effect of Fe2O3 on H2 is more obvious at higher ***_(2)CO_(3)has the most obvious effect on the pyrolysis of pine sawdust among the discussed additives,which effectively promotes the production of H_(2).

关键词： pine sawdust pyrolysis additive catalysis gas analysis

Influence of Nozzle Orifice Shape on the Atomization Process of Si3N4 in a Dry Granulation Process

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2021年第3期17卷 569-586页

作者： dongling yu Huiling Zhang Xu Zeng Dahai Liao Nanxing Wu School of Mechanical and Electronic Engineering Jingdezhen Ceramic InstituteJingdezhen333403China National Engineering Research Center for Domestic&Building Ceramics Jingdezhen333001China

In order to reveal the intrinsic fluid-dynamic mechanisms of a pressure-swirl nozzle used for Si3N4 dry granulation,and effectively predict its external spray characteristics,the dynamics of air-atomized liquid two-phase flow is analyzed using a VOF(Volume of Fraction)method together with the modified realizable k-εturbulence *** influence of nozzle orifice shape on velocity distribution,pressure distribution is *** results show that the pressure difference in a convergent conical nozzle is the largest with a hollow air core being formed in the *** corresponding velocity of atomized liquid at nozzle orifice is the *** a self-designed atomization experiment platform,the velocity and pressure of atomized liquid and the spray cone angle are measured for three nozzles with different orifice *** micro-morphology of Si3N4 particles is also deter*** data confirm the correctness of numerical *** atomization performance of the nozzle,the contraction conical nozzle is more suitable for the atomization of Si3N4 in practical production based on the dry granulation approach.

关键词： Si_(3)N_(4)dry granulation pressure-swirl nozzle VOF method nozzle orifice shape

Effect of nozzle inlet parameters on the dry granulation atomization process of Si_(3)N_(4) ceramic bearing balls

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2021年第6期12卷 182-205页

作者： dongling yu Xiaohui Zhang Hongbin Luo Dahai Liao Nanxing Wu School of Mechanical and Electronic Engineering Jingdezhen Ceramic Institute Jingdezhen 333403 P.R.China

In this paper,the atomization characteristics of Si3N4 ceramic dry granulation affect the performance of Si3N4 ceramic bearing *** order to improve the dry granulation characteristics and the comprehensive performance of Si3N4 ceramic bearing balls,the atomization mechanism of the spinning nozzle used for Si3N4 dry granulation was studied in *** interaction between air and binder in the pressure-swirl nozzle is analyzed based on VOF method,the modified realizable k−εturbulence model is used to simulate the flow field inside and outside the pressure-swirl nozzle,the effects of nozzle inlet parameters including the number of tangential inlets and the deflection angle of tangential inlets on the binder volume fraction,velocity distribution and pressure distribution are *** results show that when the number of tangential inlets increases from 1 to 4,the swirl strength of gas–liquid two-phase in the nozzle increases,the mean diameter of air core increases from 1.51 mm to 2.01 mm,and the spray cone angle increases from 18.5◦to 26.4◦.Besides,when the deflection angle of tangential inlet increases from 0◦to 15◦,the swirl strength of gas–liquid two-phase in the nozzle with the deflection angle of tangential inlet of 10◦is the largest,and the mean diameter of air core and spray cone angle is 3.04 mm and 30.7◦,*** on the atomization experiment platform of the electric control fuel system,the mean diameter of air core and spray cone angle are measured,the micromorphology of Si3N4 particles is observed,which verifies the correctness of numerical *** the Si3N4 particles are prepared by dry granulation,taking the atomization performance of nozzle into consideration,the pressure-swirl nozzle with 4 tangential inlets and 10◦deflection angle should be selected.

关键词： Si_(3)N_(4)ceramic bearing balls pressure-swirl nozzle VOF method inlet parameters air core spray cone angle

On the Effect of the Rotating Chamber Reverse Speed on the Mixing of SiC Ceramic Particles in a Dry Granulation Process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2021年第2期17卷 487-500页

作者： dongling yu Zuoxiang Zhu Jiangen Zhou Dahai Liao Nanxing Wu School of Mechanical and Electronic Engineering Jingdezhen Ceramic InstituteJingdezhen333403China National Engineering Research Center for Domestic&Building Ceramics Jingdezhen333001China

In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is *** particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and *** numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation *** tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.

关键词： SiC ceramic dry granulation CFD method accumulate of wall surface rotating chamber reverse speed

Effect of geometric parameters at open turbine combined structure on flow field distribution of dry granulation for Si_(3)N_(4) powder

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2021年第5期12卷 59-77页

作者： dongling yu Huiling Zhang Jiangen Zhou Lijun Deng Dahai Liao Nanxing Wu School of Mechanical and Electronic Engineering Jingdezhen Ceramic Institute Jingdezhen 333403P.R.China Laboratory of Ceramic Material Processing Technology Engineering Jiangxi 333403 P.R.China National Engineering Research Center for Domestic&Building Ceramics Jingdezhen 333001 P.R.China

To improve the uniformity of the flow field and the poor axial velocity in the chamber of Si3N4 dry granulation, the influence of geometric parameters at open turbinecombined structure on the flow field distribution is studied. The Euler–Euler gas-solidtwo-phase flow model is established and the physical model of dry granulation chamberunder the combined structure is simplified. Under the same radial structure, the volumedistribution and velocity field of Si3N4 particles in the granulation chamber with a different number and angle of the axial structure at the open turbine are analyzed by theCFD method. The influence of the axial structure at the open turbine on the flow fielddistribution of Si3N4 particles under different geometric parameters is compared. Theresults show that the axial structure of the open turbine in the granulation chamber isthe most uniform when the number of blades is 6 and the inclination angle is 45◦, andthe circulating flow of the upper and lower parts of Si3N4 powder is strong.

关键词： Composite structure Si3N4 ceramic geometric parameter open turbine computational fluid dynamics method

Enterprise WeChat Groups： Their Effect on Work-Life Conflict and Life-Work Enhancement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Business Research in China 2015年第4期9卷 516-535页

作者： Shengming Liu Ye Zhang Lifan Chen Li Guo dongling yu Guanghua School of Management Peking University Beijing 100871 China

Social media technologies have made it increasingly feasible for employees to be connected to work. WeChat, a newly emerging social media platform, is widely used in daily life, yet there is still little understanding of the consequences of the use of WeChat groups in enterprise. Based on boundary theory, we suggested that the use of WeChat groups in enterprise have both pros and cons for employees. We gathered data from an online survey of 202 employees. Results show that posting work-related content in enterprise WeChat groups had a beneficial impact on work for employees but also caused work-life conflict （WLC）. However, posting life-related content in enterprise WeChat groups contributes to employees＇ life-work enhancement （LWE）. Contributions and future study directions of these findings are discussed.

关键词： social media technology WeChat groups boundary theory,work-life conflict life-work enhancement

Optimization of the in-situ growth conditions based on a novel photo-microcalorimeter for the sustainable cultivation of photosynthetic microorganisms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BIOCELL 2020年第4期44卷 703-711页

作者： YANJUAN LIAO dongling yu XIAOFANG QIN JINMEI WU HUI WEI HUI LI XIANGYING MA ZAIYIN HUANG Guangxi Key Laboratory of Utilization of Microbial and Botanical Resources Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis ChemistryGuangxi University for NationalitiesNanning530006China The Teaching and Research Department of Biotechnology Nanning UniversityNanning530200China

Despite the great potential of photosynthetic microbes in the production of renewable fuels,value-adding chemicals,and water treatment,etc.,commercial utilization of them is significantly hindered by the lack of techniques to accurately monitor the thermodynamic and kinetic characteristics of the in-situ growth of microbes under controlled light illumination for optimal ***,we demonstrated that a newly developed highly sensitive photo-microcalorimetric system successfully captured the impacts of the light wavelength and strength on the thermodynamic and kinetic parameters of the in-situ growth of Rhodopseudomonas palustris,a representative photosynthetic *** our best knowledge,this is the first time that highly precise microcalorimetry is employed to monitor exam the in-situ growth of photosynthetic microorganisms under controllable photo *** envision this technique can help for the optimization of the growth conditions of photosynthetic microorganisms for scale-up applications.

关键词： Photosynthetic microorganisms In-situ growth Photomicrocalorimetry Thermodynamics Kinetics

抑制sigma-1受体可减少神经病理性疼痛大鼠DRG细胞凋亡

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基础医学与临床 2024年第8期44卷 1101-1106页

作者：郁冬玲莫少娥傅文陈实谢酬勤蓝雨雁广西医科大学第一附属医院麻醉科广西南宁530021

目的研究抑制sigma-1受体(sig-1R)对坐骨神经慢性缩窄性损伤(CCI)介导的神经病理性疼痛大鼠背根神经节(DRG)细胞凋亡的影响。方法将行鞘内置管术的大鼠随机分为3组:假手术组(sham组)、神经病理性疼痛模型组(model组)(鞘内置管1周后行CC... 详细信息

目的研究抑制sigma-1受体(sig-1R)对坐骨神经慢性缩窄性损伤(CCI)介导的神经病理性疼痛大鼠背根神经节(DRG)细胞凋亡的影响。方法将行鞘内置管术的大鼠随机分为3组:假手术组(sham组)、神经病理性疼痛模型组(model组)(鞘内置管1周后行CCI造模)、sig-1R抑制剂组(BD1047组)CCI术后4、5、6 d,鞘内注射BD1047,每组12只。于术前1 d与术后1、3、5、7 d检测大鼠机械缩足反应阈(MWT)。用Western blot与免疫荧光法检测DRG细胞sig-1R、Bcl-2、Bax的表达;TUNEL染色法观察DRG细胞凋亡;透射电镜观察DRG细胞内质网、线粒体变化。结果与sham组比较,model组术后各时点MWT降低,DRG细胞凋亡率上调,Sig-1R、Bax上调,Bcl-2下调,DRG细胞内质网肿胀,线粒体膜破坏、线粒体嵴减少(P<0.05);与模型组比较,BD1047组术后5、7 d MWT升高,DRG细胞凋亡率下调,Sig-1R、Bax下调,Bcl-2上调,DRG细胞内质网、线粒体损伤轻微(P<0.05)。结论抑制sig-1R可上调CCI大鼠机械缩足反应阈值、减少DRG细胞凋亡。

关键词：神经病理性疼痛 sigma-1受体背根神经元(DRG) 凋亡