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基于离散元法的茶叶抖筛机结构参数优化与试验

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农业工程学报 2024年第5期40卷 337-343页

作者：李兵朱勇方赛弟方立旭朱焕成邹亚刚安徽农业大学工学院合肥230036 茶树生物学与资源利用国家重点实验室合肥230036

茶叶抖筛机是茶叶精加工的关键装备,传统抖筛装备主要通过经验设计,筛分性能较差,主要表现在筛净率较低、误筛率较高。该研究结合抖筛机的筛分原理,运用solidworks构建虚拟样机,利用EDEM软件建立茶叶颗粒离散元仿真模型,通过单因素仿真... 详细信息

茶叶抖筛机是茶叶精加工的关键装备,传统抖筛装备主要通过经验设计,筛分性能较差,主要表现在筛净率较低、误筛率较高。该研究结合抖筛机的筛分原理,运用solidworks构建虚拟样机,利用EDEM软件建立茶叶颗粒离散元仿真模型,通过单因素仿真试验对茶叶颗粒进行动力学分析,结果表明,连杆长度、曲柄半径和筛面倾角是茶叶抖筛机筛分性能的主要影响因素。以筛净率、误筛率为评价指标,设计三因素三水平二次旋转正交试验,并运用DesignExpert软件对试验数据进行回归分析,当连杆长度为1 977 mm、曲柄半径为25 mm、筛面倾角为2.8°时,茶叶筛净率为94.5%、误筛率为4.61%,筛分性能最优。以最优结构参数进行验证试验,筛净率为93.8%,误筛率为4.73%,生产效率为319 kg/h,较优化前筛净率提高3.42%,误筛率降低7.62%,生产效率提高8.87%。该研究结果可为茶叶筛分装备的优化提供理论依据。

关键词：茶叶正交试验抖筛机筛分 DEM

Combining GLP-1 receptor agonists and SGLT-2 inhibitors for cardiovascular disease prevention in type 2 diabetes:A systematic review with multiple network meta-regressions

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World Journal of Diabetes 2024年第10期15卷 2135-2146页

作者： Jing-Jing zhu John P H Wilding Xiao-Song Gu Department of Endocrinology and Metabolic Medicine The Second Affiliated Hospital of Soochow UniversitySuzhou 215004Jiangsu ProvinceChina Department of Cardiovascular and Metabolic Medicine University of LiverpoolLiverpool L697ZXUnited Kingdom Clinical Sciences Centre Liverpool University Hospitals NHS Foundation TrustLiverpool L97ALUnited Kingdom Department of Cardiovascular Medicine The Second Affiliated Hospital of Soochow UniversitySuzhou 215004Jiangsu ProvinceChina

BACKGROUND Glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are associated with significant cardiovascular benefit in type 2 diabetes(T2D).However,GLP-1RA or SGLT-2I alone may not improve some cardiovascular outcomes in patients with prior cardiovascular *** To explore whether combining GLP-1RA and SGLT-2I can achieve additional benefit in preventing cardiovascular diseases in *** The systematic review was conducted according to PRISMA *** protocol was registered on PROSPERO(ID:42022385007).A total of 107049 participants from eligible cardiovascular outcomes trials of GLP-1RA and SGLT-2I were included in network meta-regressions to estimate cardiovascular benefit of the combination *** modification of prior myocardial infarction(MI)and heart failure(HF)was also explored to provide clinical insight as to when the INTRODUCTION The macro-and micro-vascular benefits of glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are independent of their glucose-lowering effects[1].In patients with type 2 diabetes(T2D),the major cardiovascular outcome trials(CVOT)showed that dipeptidyl peptidase-4 inhibitors(DPP-4I)did not improve cardiovascular outcomes[2],whereas cardiovascular benefit of GLP-1RA or SGLT-2I was significant[3,4].Further subgroup analyses indicated that the background cardiovascular risk should be considered when examining the cardiovascular outcomes of these newer glucose-lowering *** instance,prevention of major adverse cardiovascular events(MACE)was only seen in those patients with baseline atherosclerotic cardiovascular disease[3,4].Moreover,a series of CVOT conducted in patients with heart failure(HF)have demonstrated that(compared with placebo)SGLT-2I significantly reduced risk of hospitalization for HF or cardiovascular death,irrespective of their history of T2D[5-8].However,similar car

关键词： Type 2 diabetes Glucagon-like peptide-1 receptor agonist Sodium-glucose co-transporter-2 inhibitor Combination treatment Cardiovascular outcome Systematic review Network meta-regression

Preparation of Ag@AgCl-doped TiO_2/sepiolite and its photocatalytic mechanism under visible light

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Journal of Environmental Sciences 2017年第10期29卷 43-52页

作者： Shaomin Liu Dinglong zhu Jinglin zhu Qing yang Huijun Wu School of Earth Science and Environmental Engineering Anhui University of Science and Technology

A cube-like Ag@Ag Cl-doped TiO2/sepiolite（denoted Ag@Ag Cl–TiO2/sepiolite） was successfully synthesized via a novel method. X-ray diffraction, scanning electron microscopy, energy dispersion X-ray fluorescence, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy were performed to determine the structure and physicochemical properties of Ag@Ag Cl–TiO2/sepiolite. SEM micrographs revealed that Ag@Ag Cl nanoparticles and TiO2 film are well deposited on the surface of tube-like sepiolite. As a result, Ag@Ag Cl–TiO2/sepiolite exhibits a red shift relative to TiO2/sepiolite. Photocatalytic experiments demonstrated that the dosage of catalysts plays an important role during photocatalysis. The photoelectrochemical activities of Ag@Ag Cl–TiO2/sepiolite and TiO2/sepiolite were also investigated. Photocurrent responses confirmed that the ability of Ag@Ag Cl–TiO2/sepiolite to separate photo-generated electron–hole pairs is stronger than that of TiO2/sepiolite. Methylene Blue degradation is also improved under alkaline conditions and visible light irradiation because more UOH is produced by visible light *** excellent catalytic ability is mainly attributed to the formed Ag nanoparticles and the Schottky barrier at the Ag/TiO2 interface. Active species analysis indicated that UO2-and h＋are implicated as active species in photocatalysis. Therefore, catalysts are excited to produce abundant electron–hole pairs after they absorb photons in photocatalysis.

关键词： Ag@AgCl Sepiolite Photocatalyst Photocurrent

Role of local coordination in bimetallic sites for oxygen reduction: A theoretical analysis

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Journal of Energy Chemistry 2020年第5期29卷 131-137页

作者： Yuqi yang hao Zhang Zhaofeng Liang Yaru Yin Bingbao Mei Fei Song Fanfei Sun Songqi Gu Zheng Jiang Yuen Wu Zhiyuan zhu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201204China Shanghai Synchrotron Radiation Facility Zhangjiang LaboratoryShanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China Department of Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleiChEM(Collaborative Innovation Center of Chemistry for Energy Materials)University of Science and Technology of ChinaHefei 230026AnhuiChina ShanghaiTech University Shanghai 201210China

Understanding of the oxygen reduction reaction(ORR)mechanism for single atom catalysts is pivotal for the rational design of non-precious metal cathode materials and the commercialization of fuel ***,a series of non-precious metal electrocatalysts based on nitrogen-doped bimetallic(Fe and Co)carbide were modeled by density functional theory calculations to predict the corresponding reaction *** study elucidated prior oxygen adsorption on the Fe atom in the dual site and the modifier role of Co atoms to tune the electronic structures of *** reaction activity was highly correlated with the bimetallic center and the coordination environment of the adjacent ***,the preadsorption of*OH resulted in the apparent change of metal atoms'electronic states with the d-band center shifting toward the Fermi level,thereby boosting reaction *** result should help promote the fundamental understanding of active sites in ORR catalysts and provide an effective approach to the design of highly efficient ORR catalysts on an atomic scale.

关键词： Non-precious metal catalysts Bimetallic-sites Oxygen reduction reaction Density functional theory

Receptivity and structural sensitivity study of the wide vaneless diffuser flow with adjoint method

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Chinese Journal of Aeronautics 2018年第8期31卷 1679-1690页

作者： Xiaocheng zhu Chenxing HU Zezhao LIU hao LIU Zhaohui DU School of Mechanical Engineering/2011 Aero-Engine Collaborative Innovation Center Shanghai Jiao Tong University College of Politics and Law Hebei University

The stability of the flow in the vaneless diffuser of a centrifugal compressor is studied with the linear theory. The characteristics of direct and adjoint perturbation modes are investigated,and the receptivity of the instability mode to momentum forcing or mass injection is identified based on the adjoint modes. Analysis shows that the perturbation with the largest amplitude is located at the outlet of the vaneless diffuser, while the highest-receptivity region is located in the middle of the vaneless diffuser along the radial direction. The large difference between the direct and adjoint modes indicates that the instability mechanism cannot be identified from a study of either eigenmode separately. Therefore, the structural sensitivity analysis is adopted to study the feedback of the instability mode. The structural sensitivity of the eigenvalue which is proportional to the perturbation pressure and velocity is used to explain the mechanism of flow control for the vaneless diffuser.

关键词： Adjoint method Receptivity Rotating stall Structural sensitivity Vaneless diffuser

Crack Growth Rate Model Derived from Domain Knowledge-Guided Symbolic Regression

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 286-301页

作者： Shuwei Zhou Bing yang Shoune Xiao Guangwu yang Tao zhu State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China

Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue ***,most ML methods are inexplicable black-box models that are difficult to apply in engineering *** regression(SR)is an interpretable machine learning method for determining the optimal fitting equation for *** this study,domain knowledge-guided SR was used to determine a new fatigue crack growth(FCG)rate *** terms of the variable subtree ofΔK,R-ratio,andΔK_(th)were obtained by analysing eight traditional semi-empirical FCG rate *** on the FCG rate test data from other literature,the SR model was constructed using *** was subsequently extended to other alloys(Ti-10V-2Fe-3Al,Ti-6Al-4V,Cr-Mo-V,LC9cs,Al-6013-T651,and Al-2324-T3)using multiple linear *** with the three semi-empirical FCG rate models,the SR model yielded higher prediction *** result demonstrates the potential of domain knowledge-guided SR for building the FCG rate model.

关键词： Fatigue crack growth rate Stress intensity factor range Threshold stress intensity factor range R-ratio Symbolic regression Machine learning

轴心射流收油环内部油气流动特性的数值模拟研究

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推进技术 2024年第2期45卷 63-72页

作者：朱泽韬吕亚国朱鹏飞姜乐刘振侠西北工业大学动力与能源学院陕西西安710129

为研究环下润滑结构内部油膜迁移及流动特性,针对轴心射流收油环采用VOF (Volume of fluid)方法开展了数值计算,获得了收油环端面油膜动态形成过程,在分析流场特征的基础上,讨论了收油环运转工况及结构参数对内部油膜形态、滑油体积分... 详细信息

为研究环下润滑结构内部油膜迁移及流动特性,针对轴心射流收油环采用VOF (Volume of fluid)方法开展了数值计算,获得了收油环端面油膜动态形成过程,在分析流场特征的基础上,讨论了收油环运转工况及结构参数对内部油膜形态、滑油体积分数、油膜速度和供油孔输油能力的影响规律。结果表明:收油环端面油膜呈圆盘状迁移,边缘破碎形成油滴、油带甩至侧壁面,在供油孔内以“月牙形”分布加速流动,收油环端面油膜厚度随主轴转速增大而减小,随喷嘴流量上升而增加;提高转速降低了供油孔内滑油含量,使孔内油膜加速流动,孔内滑油含量随喷嘴流量的上升而增大,随供油孔径的增加而下降;喷嘴流量与供油孔径的改变对孔内流速影响较小;增加孔径与提高收油环转速可加强供油孔输运能力,8 kr/min下提高喷嘴流量使无量纲输油量Cq平均降低了40.71%,提高孔径使Cq最大提高了57.14%,转速的增加使Cq平均增加25.87%。

关键词：环下润滑收油环轴心射流两相流动特性 VOF方法

Interatomic electron transfer promotes electroreduction CO_(2)-to-CO efficiency over a CuZn diatomic site

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Nano Research 2023年第7期16卷 8863-8870页

作者： Jican hao Han zhu Qi Zhao Jiace hao Shuanglong Lu Xiaofan Wang Fang Duan Mingliang Du Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China School of Biological and Chemical Sciences Queen Mary University of LondonLondon E14NSUK

Diatomic site catalysts(DACs)with two adjacent atomic metal species can provide synergistic interactions and more sophisticated functionalities to break the bottleneck of intrinsic drawbacks of single atom catalysts(SACs).Herein,we have designed a CuZn diatomic site(CuZn-DAS)electrocatalyst with unique coordination structure(CuN_(4)-ZnN_(4))by anchoring and ordering the spatial distance between the metal precursors on the carbon nitride(C_(3)N_(4))derived N-doped carbon(NC)*** CuZn-DAS/NC shows high activity and selectivity for electroreduction CO_(2)into *** Faradaic efficiency for CO of CuZn-DAS/NC(98.4%)is higher than that of Cu single atomic site on NC(Cu-SAS/NC)(36.4%)and Zn single atomic site on NC(Zn-SAS/NC)(66.8%)at-0.6 V versus reversible hydrogen electrode(***).In situ characterizations reveal that the CuZn-DAS is more favorable for the formation and adsorption of^(*)COOH than those of the electrocatalysts with single atomic *** calculations show that the charge redistribution of Zn site in CuZn-DAS/NC caused by the considerable electron transfers from Zn atoms to the adjacent Cu atoms can reduce the adsorption energy barriers for^(*)COOH and^(*)CO production,improving the activity and CO selectivity.

关键词： CuZn diatomic site CO_(2)electroreduction reaction interatomic electron transfer in situ characterizations

Van der Waals epitaxy of ultrathin crystalline PbTe nanosheets with high near-infrared photoelectric response

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Nano Research 2021年第6期14卷 1955-1960页

作者： Xinxin Zhao Qing Yin hao Huang Qiang Yu Bo Liu Jie yang zhuo Dong Zhenjiang Shen Benpeng zhu Lei Liao Kai Zhang School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei230026China Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou215123China Key Laboratory of Nanodevices and Applications i-LabSuzhou Institute of Nano-Tech and Nano-Bionics(SINANO)Chinese Academy of SciencesSuzhou215123China School of Physics and Technology Wuhan UniversityWuhan430072China The Institute of Scientific and Industrial Research Osaka UniversityOsaka567-0047Japan College of Physics and Electronic Engineering Hainan Normal UniversityHaikou571158China School of Optical and Electronic Information Wuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhan430074China

Lead telluride(PbTe)is one of the reliable candidates for infrared(IR)optoelectronics with optimum band-gap as well as excellent photoelectric *** interests had been paid on the growth and device applications with PbTe for the development of high-performance IR photodetectors especially those working in the near-infrared *** a great deal of effort had been made to prepare PbTe nanostructures for miniaturized detectors,it is difficult to synthesize high-quality two-dimensional(2D)PbTe crystals due to its rock-salt non-layered ***,a facile strategy for controllable synthesis of ultrathin crystalline PbTe nanosheets by van der Waals epitaxy is *** an optimized growth temperature,which determines the morphology transit from triangular pyramid islands to regular square 2D planars,PbTe nanosheets in lateral size of tens of microns with thickness down to~7 nm are ***,ultrasensitive near-infrared detectors(NIRDs)based on the as-grown 2D PbTe nanosheets have been demonstrated with an ultrahigh responsivity exceeding 3,847 A/W at the wavelength of 1,550 nm under room *** approach demonstrates that 2D PbTe nanosheets have great latent capacity of developing high-performance miniaturized IR optoelectronic devices.

关键词： two-dimensional materials van der Waals epitaxy lead telluride near-infrared photodetector