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Experimental investigation on the energy-saving diffuser of a main fan

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Journal of Coal Science & Engineering(China) 2012年第1期18卷 108-112页

作者： Chen, Shi-qiang Wang, Hai-qiao cheng, jian-lin School of Mining and Safety Engineering Hunan University of Science and Technology Xiangtan China College of Civil Engineering Hunan University Changsha China Hunan Province Engineering Research Center for Mine Ventilation and Dust Removal Equipment Xiangtan China

The main fan diffuser in a coal mine is an energy-recycling equipment with a dynamic energy loss for the main fan. Engineering practices and related researches show that the body structures of three types of diffusers are irrational. To solve the problem, an energy-saving diffuser is designed on the basis of the velocity potential theory. Under conditions of inlet velocity from 7 m/s to 32 m/s, 7 condition experiments using the energy-saving diffuser of 2.31 AER （area-enlarging ratio） and 5 condi- tion experiments using the energy-saving diffuser of 2.00 AER were conducted. Through a comparative analysis of the experi- ments, the results show that the COP （coefficient of performance） of the energy-saving diffuser of 2.31 AER is better than that of the energy-saving diffuser of 2.00 AER.

关键词： energy-saving diffuser mine main fan COP (coefficient of performance) model experiment

An Improved Moving Mesh Algorithm

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Wuhan University Journal of Natural Sciences 2001年第4期6卷 764-766页

作者： cheng jian,Sun Le lin,Xu Di hong School of Mathematics and Statistics, Wuhan University,Wuhan 430072,China School of Mathematics and Statistics Wuhan University Wuhan China

We consider an iterative algorithm of mesh optimization for finite element solution, and give an improved moving mesh strategy that reduces rapidly the complexity and cost of solving variational problems. A numerical ... 详细信息

关键词： adaptive method moving mesh method variational problem

The effects of beam drifts on elastic scattering measured by the large solid-angle covered detector array

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Nuclear Science and Techniques 2021年第2期32卷 24-31页

作者： Yong-Jin Yao cheng-jian lin Lei Yang Nan-Ru Ma Dong-Xi Wang Gao-Long Zhang Guang-Xin Zhang Hui-Ming Jia Feng Yang State Key Laboratory of Software Development Environment Beihang UniversityBeijing 100191China School of Physics Beihang UniversityBeijing 100191China China Institute of Atomic Energy Beijing 102413China

A new detector array characterized by compact structure and large solid-angle coverage was designed for radioactive ion beam(RIB)experiments and measuring multi-particle correlations.A Monte Carlo simulation was performed to explore the effects of beam drifts in different directions and distances on the angular distribution of the Rutherford scattering,as measured by the detector *** results indicate that when the beam drift distance is less than 2.0 mm,the symmetry of the detector array can maintain a count error of less than 5%.This confirms the property of the detector array for RIB ***,the simulation was validated through the elastic scattering angular distributions of 6;7 Li measured by the detector array in 6;7Li t209 Bi experiments at different energies.

关键词： Large solid-angle detector array Beam drift Monte Carlo simulation Elastic scattering

Numerical simulation investigations of energy-saving diffuser of main fan

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Journal of Coal Science & Engineering(China) 2010年第4期16卷 424-428页

作者： CHEN Shi-qiang WANG Hai-qiao cheng jian-lin LI Yi-qun Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines Hunan University of Science and Technology Xiangtan 411201 China School of Energy ＆ Safety Engineering Hunan University of Science and Technology Xiangtan 411201 China Hunan Mine Ventilation ＆ Dedusting Equipment Engineering Techniques Research Center Xiangtan 411201 China

Based on the boundary condition of field engineering, numerical simulations of28 conditions of existing diffusers of 3 structure types were investigated by ComputationalFluid Dynamics software package, and there were the problems of larger structure resistanceand lower diffusing efficiency of these diffusers by analysis of CFD *** outlines of the energy-saving diffuser were constructed by the application ofstream function and potential function *** the basis of numerical simulationsof energy-saving diffusers of 5 area-enlarging ratios, structural resistances and diffusingefficiencies of 5 energy-saving diffusers were comparatively analyzed, and therange from 2.00 to 2.31 of the rational area-enlarging ratio of energy-saving diffusers *** optimization area-enlarging ratio of the energy-saving diffuser was presently2.28 through comparable *** the above, the results show that the coefficient ofperformance of the energy-saving diffuser is better than 3 existing diffusers.

关键词： main fan energy-saving diffuser optimization of outlines numerical simulation

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： lin Zou Di-wei Liu jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

Aero-Hydro-Elastic-Servo Modeling and Dynamic Response Analysis of A Monopile Offshore Wind Turbine Under Different Operating Scenarios

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China Ocean Engineering 2024年第3期38卷 379-393页

作者： XIE Shuang-yi GAO jian LI Yong-ran jianG Shu-xin ZHANG cheng-lin HE Jiao College of Mechanical Engineering Chongqing University of TechnologyChongqing 400044China Beijing Institute of Precision Mechatronics and Controls Beijing 100076China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China Fishery Machinery and Instrument Research Institute Chinese Academy of Fishery SciencesShanghai 200092China School of Mechanical and Power Engineering Chongqing University of Science&TechnologyChongqing 401331China

This paper constructs a coupled aero-hydro-elastic-servo simulation framework for a monopile offshore wind turbine(OWT).In this framework,a detailed multi-body dynamics model of the monopile OWT including the gearbox,blades,tower and other components(nacelle,hub,bedplate,etc.)has been explicitly *** effects of pile−soil interaction,controller and operational conditions on the turbine dynamic responses are studied systematically in time domain and frequency *** results show that(1)a comprehensive drivetrain model has the capability to provide a more precise representation of the complex dynamic characteristics exhibited by drivetrain components,which can be used as the basis for further study on the dynamic characteristics of the drivetrain.(2)The pile−soil interaction can influence the wind turbine dynamic responses,particularly under the parked condition.(3)The effect of the pile−soil interaction on tower responses is more significant than that on blade responses.(4)The use of the controller can substantially affect the rotor characteristics,which in turn influences the turbine dynamic responses.(5)The tower and blade displacements under the operational condition are much larger than those under the parked *** model and methodology presented in this study demonstrate potential for examining complex dynamic behaviors of the monopile *** ensure accuracy and precision,it is imperative to construct a detailed model of the wind turbine system,while also taking into account simulation efficiency.

关键词： offshore wind turbine(OWT) pile−soil interaction dynamic response parked condition operating condition

Compact 16-channel integrated charge-sensitive preamplifier module for silicon strip detectors

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Nuclear Science and Techniques 2020年第5期31卷 36-43页

作者： Dong-Xi Wang cheng-jian lin Lei Yang Nan-Ru Ma Li-Jie Sun Feng Yang Hui-Ming Jia Fu-Peng Zhong Pei-Wei Wen Department of Nuclear Physics China Institute of Atomic EnergyBeijing 102413China

In this study,a compact 16-channel integrated charge-sensitive preamplifier named the smart preamplifier(SPA)was developed to support the large-scale detector array used in modern nuclear physics *** types of SPA,namely SPA02 and SPA03(with external field effect transistor),have been manufactured to match silicon detectors with small and large capacitances,*** characteristics of the SPA include fast response of typically less than 6 ns for pulse rising time and low equivalent noise of 1.5 keV at zero input *** energy sensitivity and pulse decay time can be easily adjusted by changing the feedback capacitance Cfand resistance Rfin various applications.A good energy resolution of 24.4 keV for 5.803-MeV alpha particles from 244 Cm was achieved using a small-sized Si-PIN detector;for the silicon strip detectors in the test with the alpha source,a typical energy resolution of 0.6–0.8%was *** integrated SPA has been employed in several experiments of silicon strip detectors with hundreds of channels,and a good performance has been realized.

关键词： Silicon strip detector array 16-Channel integrated charge-sensitive preamplifier Preamplifier circuit design Preamplifier performance

Energy spectrum computed tomography multi-parameter imaging in preoperative assessment of vascular and neuroinvasive status in gastric cancer

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2511-2520页

作者： Jing Wang jian-cheng Liang Fa-Te lin Jun Ma Department of Radiology Pingluo County People's HospitalShizuishan 753400Ningxia Hui Autonomous RegionChina Department of Gastrointestinal Surgery Jiangsu Provincial People's HospitalNanjing 210029Jiangsu ProvinceChina

BACKGROUND Vascular and nerve infiltration are important indicators for the progression and prognosis of gastric cancer(GC),but traditional imaging methods have some limitations in preoperative *** recent years,energy spectrum computed tomography(CT)multiparameter imaging technology has been gradually applied in clinical practice because of its advantages in tissue contrast and lesion detail *** To explore and analyze the value of multiparameter energy spectrum CT imaging in the preoperative assessment of vascular invasion(LVI)and nerve invasion(PNI)in GC *** Data from 62 patients with GC confirmed by pathology and accompanied by energy spectrum CT scanning at our hospital between September 2022 and September 2023,including 46 males and 16 females aged 36-71(57.5±9.1)years,were retrospectively *** patients were divided into a positive group(42 patients)and a negative group(20 patients)according to the presence of LVI/*** CT values(CT40 keV,CT70 keV),iodine concentration(IC),and normalized IC(NIC)of lesions in the upper energy spectrum CT images of the arterial phase,venous phase,and delayed phase 40 and 70 keV were measured,and the slopes of the energy spectrum curves[K(40-70)]from 40 to 70 keV were *** Core Tip:To investigate the application value of multiparameter energy spectrum computed tomography(CT)imaging in the preoperative assessment of vascular and nerve infiltration in patients with gastric cancer(GC).The imaging data of GC patients were retrospectively analyzed to evaluate the accuracy and sensitivity of CT for identifying and quantifying vascular and nerve infiltration and for comparison with postoperative pathological *** purpose of this study was to verify the clinical feasibility and potential advantages of multiparameter energy spectrum CT imaging in guiding preoperative diagnosis and treatment decision-making and to provide a new imaging basis for improving the diagnostic accuracy

关键词： Tomography X-ray computer Energy spectrum computed tomography Gastric cancer Vascular invasion Nerve invasion Cross-sectional study

Study of primordial deuterium abundance in Big Bang nucleosynthesis

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Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： Zhi-lin Shen jian-Jun He Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method