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Understanding the local structure and thermophysical behavior of Mg-La liquid alloys via machine learning potential

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 439-449页

作者： Jia Zhao Taixi Feng Guimin Lu national engineering research center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China Joint International Laboratory for Potassium and Lithium Strategic Resources East China University of Science and TechnologyShanghai 200237China

The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained deep potential(DP) model was thoroughly evaluated through several aspects, including root-mean-square errors(RMSEs), energy and force data, and structural information comparison results;the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated,which provides new guidance for related studies.

关键词： magnesium-lanthanum liquid alloys local structure macroscopic properties thermodynamic behavior deep potential mo-lecular dynamic simulation

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Optimization on the Impeller of a Low-specific-speed Centrifugal Pump for Hydraulic Performance Improvement

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Chinese Journal of Mechanical engineering 2016年第5期29卷 992-1002页

作者： PEI Ji WANG Wenjie YUAN Shouqi ZHANG Jinfeng national research center of pumps and Pumping system Engineering and TechnologyJiangsu University

In order to widen the high-efficiency operating range of a low-specific-speed centrifugal pump, an optimization process for considering efficiencies under 1.0Qd and 1.4Qd is proposed. Three parameters, namely, the blade outlet width b2, blade outlet angle β2, and blade wrap angle φ, are selected as design variables. Impellers are generated using the optimal Latin hypercube sampling method. The pump efficiencies are calculated using the software CFX 14.5 at two operating points selected as objectives. Surrogate models are also constructed to analyze the relationship between the objectives and the design variables. Finally, the particle swarm optimization algorithm is applied to calculate the surrogate model to determine the best combination of the impeller parameters. The results show that the performance curve predicted by numerical simulation has a good agreement with the experimental results. Compared with the efficiencies of the original impeller, the hydraulic efficiencies of the optimized impeller are increased by 4.18% and 0.62% under 1.0Qd and 1.4Qd, respectively. The comparison of inner flow between the original pump and optimized one illustrates the improvement of performance. The optimization process can provide a useful reference on performance improvement of other pumps, even on reduction of pressure fluctuations.

关键词： low-specific-speed centrifugal pump optimization optimal Latin hypercube sampling surrogate model particle swarm optimization algorithm numerical simulation

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Numerical Prediction and Performance Experiment in a Deep-well Centrifugal Pump with Different Impeller Outlet Width

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Chinese Journal of Mechanical engineering 2013年第1期26卷 46-52页

作者： SHI Weidong ZHOU Ling LU Weigang PEI Bing LANG Tao national research center of pumps and Pumping system engineering and technology Jiangsu UniversityZhenjiang 212013China

The existing research of the deep-well centrifugal pump mainly focuses on reduce the manufacturing cost and improve the pump performance, and how to combine above two aspects together is the most difficult and important topic. In this study, the performances of the deep-well centrifugal pump with four different impeller outlet widths are studied by the numerical, theoretical and experimental methods in this paper. Two stages deep-well centrifugal pump equipped with different impellers are simulated employing the commercial CFD software to solve the Navier-Stokes equations for three-dimensional incompressible steady flow. The sensitivity analyses of the grid size and turbulence model have been performed to improve numerical accuracy. The flow field distributions are acquired and compared under the design operating conditions, including the static pressure, turbulence kinetic energy and velocity. The prototype is manufactured and tested to certify the numerical predicted performance. The numerical results of pump performance are higher than the test results, but their change trends have an acceptable agreement with each other. The performance results indicted that the oversize impeller outlet width leads to poor pump performances and increasing shaft power. Changing the performance of deep-well centrifugal pump by alter impeller outlet width is practicable and convenient, which is worth popularizing in the engineering application. The proposed research enhances the theoretical basis of pump design to improve the performance and reduce the manufacturing cost of deep-well centrifugal pump.

关键词： deep-well centrifugal pump impeller outlet width performance numerical simulation

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Influence of Cross-Sectional Flow Area of Annular Volute Casing on Transient Characteristics of Ceramic Centrifugal Pump

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Chinese Journal of Mechanical engineering 2019年第1期32卷 161-173页

作者： Yi Tao Shouqi Yuan Jianrui Liu Fan Zhang Wuxi Vocational Institute of Arts and technology national research center of pumps and system engineering and technology Jiangsu University

The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annular volutes are available, and there is no systematic design method for annular volutes. In this study, the influence of volute casing cross-sectional flow area on the hydraulic loss, pressure pulsations, and radial force under varying working conditions in a centrifugal ceramic pump are discussed in detail. Experimental tests were conducted to validate the numerical results. The results indicated that, when the volute casing flow area increases, the hydraulic performance decreases marginally under the rated working conditions, but increases at the o-design points, specifically under large flow condition. However, the volute casing with a larger flow area has a wider high-e ciency region. In addition, the increase in the volute casing flow area will decrease the pressure pulsations in the volute, regardless of the working condition, and decrease the radial force on the shaft, therefore, providing an improved pump operational stability. It is anticipated that this study will be of benefit during the design of annular volutes.

关键词： Annular volute Centrifugal pump Cross section Transient characteristics Pressure pulsation Radial force

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A modified interval subdividing based geometric calibration method for interior tomography

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Chinese Physics B 2014年第9期23卷 571-577页

作者：张峰闫镔李磊席晓琦江桦 national Digital Switching system engineering & technology research center

The interior tomography is commonly met in practice, whereas the self-calibration method for geometric parameters remains far from explored. To determine the geometry of interior tomography, a modified interval subdividing based method, which was originally developed by Tan et al.,^[11] was presented in this paper. For the self-calibration method, it is necessary to obtain the reconstructed image with only geometric artifacts. Therefore, truncation artifacts reduction is a key problem for the self-calibration method of an interior tomography. In the method, an interior reconstruction algorithm instead of the Feldkamp-Davis-Kress （FDK） algorithm was employed for truncation artifact reduction. Moreover, the concept of a minimum interval was defined as the stop criterion of subdividing to ensure the geometric parameters are determined nicely. The results of numerical simulation demonstrated that our method could provide a solution to the self- calibration for interior tomography while the original interval subdividing based method could not. Furthermore, real data experiment results showed that our method could significantly suppress geometric artifacts and obtain high quality images for interior tomography with less imaging cost and faster speed compared with the traditional geometric calibration method with a dedicated calibration phantom.

关键词： interior tomography geometric calibration interval subdividing minimum interval

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A Compton scattering image reconstruction algorithm based on total variation minimization

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Chinese Physics B 2012年第10期21卷 563-569页

作者：李守鹏王林元闫镔李磊刘拥军 national Digital Switching system engineering&technology research center

Compton scattering imaging is a novel radiation imaging method using scattered *** main characteristics are detectors that do not have to be on the opposite side of the source,so avoiding the rotation *** reconstruction problem of Compton scattering imaging is the inverse problem to solve electron densities from nonlinear equations,which is *** means the solution exhibits instability and sensitivity to noise or erroneous *** the theory for reconstruction of sparse images,a reconstruction algorithm based on total variation minimization is *** reconstruction problem is described as an optimization problem with nonlinear data-consistency *** simulated results show that the proposed algorithm could reduce reconstruction error and improve image quality,especially when there are not enough measurements.

关键词： Compton scattering tomography inverse problem image reconstruction sparse total variation

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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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Derivative-Hilbert-Backprojection based image reconstruction from truncated projections in helical cone-beam CT

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Nuclear Science and Techniques 2015年第2期26卷 45-53页

作者：张峰闫镔李磊席晓琦江桦魏星张翔崔进鲜 national Digital Switching system engineering & technology research center

In helical cone-beam computed tomography(CT), Feldkamp-Davis-Kress(FDK) based image reconstruction algorithms are by far the most popular. However, artifacts are commonly met in the presence of lateral projection truncation. The reason is that the ramp filter is global. To restrain the truncation artifacts, an approximate reconstruction formula is proposed based on the Derivative-Hilbert-Backprojection(DHB) framework. In the method, the first order derivative filter is followed by the Hilbert transform. Since the filtered projection values are almost zero by the first order derivative filter, the following Hilbert transform has little influence on the projection values, even though the projections are laterally truncated. The proposed method has two main advantages. First, it has comparable computational efficiency and image quality as well as the conventional helical FDK algorithm for non-truncated projections. The second advantage is that images can be reconstructed with acceptable quality and much lower computational cost in comparison to the Laplace operator based algorithm in cases with truncated projections. To point out the advantages of our method, simulations on the computer and real data experiments on our laboratory industrial cone-beam CT are conducted. The simulated and experimental results demonstrate that the method is feasible for image reconstruction in the case of projection truncation.

关键词：图像重建算法希尔伯特变换锥束CT 反投影衍生物截短螺旋锥形

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Comparison of droplet distributions from fluidic and impact sprinklers

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Frontiers of Agricultural Science and engineering 2015年第1期2卷 53-59页

作者： Xingye ZHU Shouqi YUAN Junping LIU Xingfa LIU national engineering research center of pumps and Pumping system Jiangsu University research center of Fluid Machinery engineering and technology Jiangsu University

To adapt to the trend toward low-energy precision irrigation, the droplet distributions for two new prototype sprinklers, outside signal sprinkler(OS) and fluidic sprinkler(FS), were compared with impact sprinkler(IS). A laser precipitation monitor was used to measure the droplet distributions. Droplet size and velocity distributions were tested under four operating pressures for nozzles 1.5 m above the ground. For the operating pressures tested, the mean OS, FS and IS droplet diameters ranged from 0 to 3.4, 0 to 3.5, 0 to 4.0 mm, *** mean OS and FS droplet velocities ranged from 0 to6.3 m$s–1, whereas IS ranged from 0 to 6.3 m$s–1. Being gas-liquid fluidic sprinklers, droplet distributions of the OS and FS were similar, although not identical. IS mostly produced a 0.5 mm larger droplet diameter and a 0.5 m$s–1greater velocity than OS and FS. A new empirical equation is proposed for determination of droplet size for OS and FS, which is sufficiently accurate and simple to use. Basic statistics for droplet size and velocity were performed on data obtained by the photographic methods. The mean droplet diameter(arithmetic, volumetric and median)decreased and the mean velocity increased in operating pressure for the three types of sprinkler.

关键词： outside signal sprinkler fluidic sprinkler impact sprinkler sprinkler irrigation droplet size droplet velocity

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A two-step weighted least-squares method for joint estimation of source and sensor locations: A general framework

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Chinese Journal of Aeronautics 2019年第2期32卷 417-443页

作者： Ding WANG Jiexin YIN Tao TANG Ruirui LIU Zhidong WU national Digital Switching system engineering and technology research center Zhengzhou Institute of Information Science and technology

It is well known that the Two-step Weighted Least-Squares(TWLS) is a widely used method for source localization and sensor position refinement. For this reason, we propose a unified framework of the TWLS method for joint estimation of multiple disjoint sources and sensor locations in this paper. Unlike some existing works, the presented method is based on more general measurement model, and therefore it can be applied to many different localization ***, it does not have the initialization and local convergence problem. The closed-form expression for the covariance matrix of the proposed TWLS estimator is also derived by exploiting the first-order perturbation analysis. Moreover, the estimation accuracy of the TWLS method is shown analytically to achieve the Cramér-Rao Bound(CRB) before the threshold effect takes place. The theoretical analysis is also performed in a common mathematical framework, rather than aiming at some specific signal metrics. Finally, two numerical experiments are performed to support the theoretical development in this paper.

关键词： Cramér-Rao Bound(CRB) Disjoint sources General framework Performance analysis Sensor position refinement Source localization Weighted least-squares

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