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Experimental study and numerical simulation of the characteristics of a percussive gas-solid separator

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Particuology 2018年第1期16卷 96-105页

作者： Xuecheng Wu xiao wang Yonggang Zhou State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

The presence of solid particles in the flow of hypersonic wind tunnels damages the appearance of the experiment models in the wind tunnel and influences the accuracy of experimental results. The design of a highly efficient gas-solid separator was therefore undertaken, Particle trajectory imaging methods were used to measure trajectories under different conditions. The flow field and particle movement characteristics for different head angles （HAs） and separation tooth angles （STAs）, inlet velocities, and the exhaust gas outlet pressures in the separator, were calculated using simulations based on the discrete phase model. The particle separation efficiency, pressure loss, and flow loss resulting from different structural parameters were also studied. In line with experimental observations, the characteristic angle of particle movements in the separator and the separation efficiency of the separator were found to increase with decreasing HA and with increasing STA. Separation efficiency improves with increasing inlet velocity and with increasing negative pressure of the exhaust gas outlet; however, the corresponding pressure loss and the flow rate of the waste gas also increased.

关键词： Gas-soIid separation Trajectory imaging Collision of particles Numerical simulation Efficiency of separation

EFFECT OF A MOVING BOUNDARY ON THE FLUID TRANSIENT FLOW IN LOW PERMEABILITY RESERVOIRS

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Journal of Hydrodynamics 2012年第3期24卷 391-398页

作者： LUO Wan-Jing wang xiao-dong School of Energy Resources China University of Geosciences Beijing 100083 China

In a low permeability reservoir, the existence of a moving boundary is considered in the study of the transient porous flow with threshold pressure gradient. The transmission of the moving boundary directly indicates the size of the drainage area as well as the apparent influences on the pressure behavior. The nonlinear transient flow mathematical model in which the threshold pressure gradient and the moving boundary are incorporated is solved by advanced mathematical methods. This paper presents some new analytical solutions describing the pressure distribution at a constant rate and the production decline in a constant pressure production with the boundary propagation. It is shown that the greater the threshold pressure gradient, the slower the transmission of the moving boundary, the larger the pressure loss will be, and there is no radial flow in the middle and later phases of the wellface pressure for a well at a constant rate. We have the the maximum moving boundary at a specific drawdown pressure for a low permeability reservoir The greater the threshold pressure gradient, the smaller the maximum moving boundary distance, the quicker the production decline for a well in a constant pressure production will be. The type curve charts for the modern well test analysis and the rate transient analysis with a moving boundary are obtained and the field test and the production data are interpreted as examples to illustrate how to use our new results.

关键词： threshold pressure gradient moving boundary well test analysis low permeability reservoir rate transient analysis

SIMULATION OF THE TWO PHASE FLOW OF DROPLET IMPINGEMENT ON LIQUID FILM BY THE LATTICE BOLTZMANN METHOD

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Journal of Hydrodynamics 2012年第2期24卷 292-297页

作者： GUO Jia-hong wang xiao-yong Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics andMechanicsShanghai UniversityShanghai 200072China

A Lattice Boltzmann Method （LBM） with two-distribution functions is employed for simulating the two-phase flow induced by a liquid droplet impinging onto the film of the same liquid on solid *** model is suitable for solution of twophase flow problem at high density and viscosity ratios of liquid to vapor and phase transition between liquid and its *** roles of the vapor flow,the density ratio of liquid to vapor and the surface tension of the droplet in the splashing formation are *** is concluded that the vapour flow induced by the droplet fall and splash in the whole impinging process may affect remarkably the splash *** the case of large density ratio of liquid to vapor a crown may engender after the droplet collides with the ***,for the case of small density ratio of liquid to vapor a ＂bell＂ like splash may be observed.

关键词： droplet impact film two-phase flow Lattice Boltzmann Method (LBM) numerical simulation

Differences of aroma development and metabolic pathway gene expression between Kyoho and 87-1 grapes

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Journal of Integrative Agriculture 2021年第6期20卷 1525-1539页

作者： JI xiao-hao W ANG Bao-liang wang xiao-di W ANG xiao-long LIU Feng-zhi wang Hai-bo Research Institute of Pomology Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(Germplasm Resources Utilization)Ministry of Agriculture/Key Laboratory of Mineral Nutrition and Efficient Fertilization for Deciduous FruitsLiaoning ProvinceXingcheng 125100P.R.China

Aroma is an important quality trait of grapes and often the focus of consumers,viticulturists and grapevine *** is a hybrid between Vitis vinifera and Vitis labrusca with a strawberry-like scent,while 87-1 is an early-ripening mutant of Muscat hamburg,belonging to Vitis vinifera,with a rose *** this study,we compared their aroma compositions and concentrations during berry development by headspace-SPME combined with gas chromatography-mass spectrometry(GC-MS),and analyzed the expression differences of enzyme-encoding genes in the LOX-HPL,MEP and MVA metabolic pathways by *** esters were detected in Kyoho during the whole berry development and they were abundant after veraison,but no esters were detected in 87-1 *** was the dominant terpene among the 14 terpenes detected in 87-1 berries,while limited amounts of terpenes were detected in Kyoho ***-PCR analysis indicated that the low expression of VvAAT might explain the low content of ester volatiles in 87-1 berries,and the low expression of coding genes in the MEP pathway,especially VvPNLin Ner1,might be the reason for the low content of volatile terpenes in Kyoho *** results from this work will promote our understanding of aroma metabolic mechanisms of grapes,and offer some suggestions for grape aromatic quality improvement.

关键词： grape Kyoho 87-1 aroma LOX-HPL MEP gene expression

Continuous-wave lasing in halide perovskites

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Science China Materials 2018年第9期61卷 1243-1244页

作者： xiaoxia wang xiao wang Anlian Pan Key Laboratory for Micro-Nano Physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and Chemometrics and College of Materials Science and Engineering Hunan University

Continuous-wave(c.w.)lasing means that the laser is operated under continuous optical pumping,which is believed to be a key stepping stone on the path to an electrically pumped laser diode and to applications in high density integrated optoelectronic systems[1].Achieving continuous-wave lasing was thought to be challenging due to the intrinsic thermal damage

关键词：激光二极管集成光电子系统理论研究

Phase transition of Ni_(55-x)Co_(x)Mn_(20)Ga_(25)(8.5≤x≤11.0)alloys with different compositions and magnetic fields

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Rare Metals 2023年第2期42卷 572-578页

作者： xiao wang Jing-Min wang Hui Hua Cheng-Bao Jiang Key Laboratory of Aerospace Materials and Performance(Ministry of Education) School of Materials Science and EngineeringBeihang UniversityBeijing100191China

Studies on Co-doped Ni–Mn–Ga ferromagnetic shape memory alloys(FSMAs)have been quite active topics in recent *** previous reports where the amount of Co doping was generally less than 8 at%,in this work Ni_(55-x)Co_(x)Mn_(20)Ga_(25)(8.5≤x≤11.0)alloys were studied with high Co *** effects of both composition and magnetic field on phase transitions were *** the increase in substitution of Co for Ni,the magnetic transition temperatures increase gradually but the martensitic transformation temperature decreases quite *** particular,the average decrease in the martensitic transformation temperatures is up to 100 K which is nearly twice that in the case of Co content of less than 8 at%.Further,under an applied magnetic field ranging from 0.03 to 0.60 T,abnormal stabilization of a martensite phase with lower magnetization was *** entropy change of 1.6 J·kg^(−1)·K^(−1)was induced at the martensitic transformation of Ni46.5Co8.5Mn20Ga25 alloy by an applied field of 1 *** magnetic contributions,including the magnetocrystalline anisotropy and the Zeeman energy,to the thermodynamics of the martensitic transformation are considered to understand the observed unusual *** work results in new insights into the understanding of Co-doped Ni–Mn-based ferromagnetic shape memory alloys.

关键词： Ni-Mn-Ga Ferromagnetic shape memory alloys Martensitic transformation Magnetic properties Magnetocaloric effect

Effects of Staggered Magnetic Field on Entanglement in the Anisotropic XY Model

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Communications in Theoretical Physics 2006年第1期45卷 61-66页

作者： SUN Zhe wang xiao-Guang Zhejiang Institute of Modern Physics Department of Physics Zhejiang University Hangzhou 310027 China

We investigate effects of staggered magnetic field on thermal entanglement in the anisotropic XY model. The analytic results of entanglement for the two-site cases are obtained. For the general case of even sites, we show that when the anisotropic parameter is zero, the entanglement in the XY model with a staggered magnetic field is the same as that with a uniform magnetic field.

关键词： thermal entanglement staggered magnetic field anisotropic XY model

Crop residue incorporation and nitrogen fertilizer effects on greenhouse gas emissions from a subtropical rice system in Southwest China

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Journal of Mountain Science 2018年第9期15卷 1972-1986页

作者： wang xiao-guo LUO Yong Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Key laboratory of Geological Spatial information Technology of Ministry of Land and Resource Chengdu University of Technology

Crop residue incorporation has been widely accepted as a way to increase soil carbon(C) sequestration and sustain soil fertility in agroecosystems. However, effect of crop residue incorporation on greenhouse gas(GHG) emissions in rice paddy soils remains uncertain. A field experiment was conducted to quantify emissions of CH_4 and N_2O and soil heterotrophic respiration(RH) from a paddy rice field under five different crop residue treatments(i.e., 150 kg N ha^(-1) of synthetic N fertilizer application only [NF], 150kg N ha^(-1) of synthetic N fertilizer plus 5.3 Mg ha^(-1) wheat residue [NF-WR1], 150 kg N ha^(-1) of synthetic N fertilizer plus 10.6 Mg ha^(-1) wheat residue [NF-WR2], 75 kg N ha^(-1) of synthetic N fertilizer plus 10.6 Mg ha^(-1) wheat residue [50%NF-WR2] and 150 kg N ha^(-1) of synthetic N fertilizer plus 21.2 Mg ha^(-1) wheat residue [NF-WR3]) in southwest China. Our results showed that crop residue incorporation treatments(NF-WR1, NF-WR2, 50%NF-WR2, NF-WR3) significantly increased CH_4 emissions by at least 60%, but N_2O emissions were not enhanced and even suppressed by 25% in the NF-WR3 treatment as compared to the NF treatment. Soil RH emissions were comparable among experimental treatments, while crop residue incorporation treatments significantly increased soil carbon sequestrations relative to the NF treatment. Overall, CH_4 emissions dominated total global warming potentials(GWP) across all experimental treatments. The average yieldscaled GWPs for the NF and NF-WR1 treatments were significantly lower than for the NF-WR2, 50%NFWR2 and NF-WR3 treatments. Given the comparable yield-scaled GWPs between the NF and NF-WR1 treatments, the NF-WR1 treatment could gain net carbon sequestration as compared with the NF treatment with net soil carbon loss. Our findings suggest that the NF-WR1 treatment should be an effective option to sustain rice production while mitigating GHG emissions from the rice field in China.

关键词： Methane Nitrous oxide Crop residueSoil carbon sequestration Global warming potentialPaddy field

Asymptotic controllability of a class of discrete-time systems with disturbances

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1296-1300页

作者： Cai Xiushan wang xiao Xu Xiuling Coll. of Mathematics Physics and Information Engineering Zhejiang Normal Univ. Jinhua 321004 P. R. China

This article deals with the uniformly globally asymptotic controllability of discrete nonlinear systems with *** is shown that the system is uniformly globally asymptotic controllability with respect to a closed set if and only if there exists a smooth control Lyapunov ***, it is obtained that the control Lyapunov function may be used to construct a feedback law to stabilize the closed-loop *** addition, it is proved that for periodic discrete systems, the resulted control Lyapunov functions are also time periodic.

关键词： nonlinear systems asymptotic controllability control Lyapunov functions discrete time disturbances.