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NUMERICAL SIMULAtION OF CAStING PROCESS

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Acta Metallurgica Sinica(English Letters) 2000年第2期13卷 764-769页

作者： L.L. Chen, R.X. Liu and h.t. lin College of Materials Science and Engineering, huazhong University of Science and technology, Wuhan 430074, China

In this paper, the development status of casting numerical simulation technology is introduced. In additional, mathematical model, solution method, initial condition, boundary condition and defect predicting scheme of foundry process are also analyzed, which include the mold filling process, solidification process and the process coupling fluid flow with heat transfer. Finally, a practical casting is taken out to show how to predict defects and optimize foundry process with numerical simulation technology.

关键词： foundry numerical simulation temperature field fluid field coupling fluid flow with heat transfer

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI h.GhANDVAR E.JUMAEV S.Kh.t.R t.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. the strain potential and kinetic energies of each beam along with.t.e work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with.t.e force vector. the curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through.t.e comparison of the obtained results with.t.ose of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

关键词： double curved beam finite element method functionally graded porous (FGP) material intermediate straight beam O313 vibration analysis

Soil colloids can significantly enhance spreading of polybromodiphenyl ethers in groundwater by serving as an effective carrier

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Journal of Environmental Sciences 2025年第1期147卷 93-100页

作者： lin Duan Min Li Jiameng Liu Wei Chen College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybromodiphenyl ethers(PBDEs),the widely used flame retardants,are common contaminants in surface soils at e-waste recycling *** association of PBDEs with soil colloids has been observed,indicating the potential risk to groundwater due to colloid-facilitated ***,the extent to which soil colloidsmay enhance the spreading of PBDEs in groundwater is largely ***,we report the co-transport of decabromodiphenyl ester(BDE-209)and soil colloids in saturated porous *** colloids released froma soil sample collected at an e-waste recycling site in tianjin,China,contain high concentration of PBDEs,with BDE-209 being the most abundant conger(320±30 mg/kg).the colloids exhibit relatively high mobility in saturated sand columns,under conditions commonly observed in groundwater ***,under all the tested conditions(i.e.,varying flow velocity,ph,ionic species and ionic strength),the mass of eluted BDE-209 correlates linearly with.t.at of eluted soil colloids,even though.t.e mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions ***,the mass of BDE-209 retained in the columns also correlates strongly with.t.emass of retained ***,the PBDEs remain bound to soil colloids during transport in porous *** in this study indicate th.t.soil colloidsmay significantly promote the transport of PBDEs in groundwater by serving as an effective *** might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.

关键词： Polybromodiphenyl ethers Soil colloids E-waste recycling sites Groundwater Facilitated transport

Estimating transient Stability Regions of Large-scale Power Systems Part Ⅱ: Reduced-order Stability Region with Computational Efficiency

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CSEE Journal of Power and Energy Systems 2025年第1期11卷 38-50页

作者： Yuqing lin tianhao Wen Lei Chen Yang Liu Q. h. Wu School of Electric Power Engineering South China University of TechnologyGuangzhou510640China

Part Ⅱ of this paper presents a reduced-order stability region (ROSR) based method to estimate the full-order stability region (FOSR) of a large-scale power system. First, we introduce the definitions of FOSR and ROSR, followed by a comprehensive theory th.t.reveals the relationships between them. Since the full-order system can be rewritten as a standard two timescale model and the reduced-order system is regarded as the slow subsystem of it, the proposed theory is derived based on the idea of singular perturbation. With rigorous mathematical proof, the properties of FOSR and ROSR are revealed. Moreover, a modified Energy Augmented Dynamic (EAD) algorithm and a constrained equidistant projection (CEP) approach are employed to estimate the ROSR and FOSR, respectively. the modified EAD algorithm and CEP form a so-called reduced-order stability region mapping (ROSRM) method. Finally, the proposed ROSRM method is applied to the IEEE 10-machine-39-bus power system, and simulation studies confirm its superiority to the traditional energy function method in terms of computational speed and reliability of results.

关键词： Large-scale power system singular perturbation theory stability region sum of squares transient stability

Estimating transient Stability Regions of Large-Scale Power Systems Part I: Koopman Operator and Reduced-Order Model

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CSEE Journal of Power and Energy Systems 2025年第1期11卷 24-37页

作者： Yuqing lin tianhao Wen Lei Chen Q. h. Wu Yang Liu School of Electric Power Engineering South China University of Technology Guangzhou China

this paper presents an estimation of transient stability regions for large-scale power systems. In Part I, a Koopman operator based model reduction (KOMR) method is proposed to derive a low-order dynamical model with reasonable accuracy for transient stability analysis of large-scale power systems. Unlike traditional reduction methods based on linearized models, the proposed method does not require linearization, but captures dominant modes of the original nonlinear dynamics by employing a Koopman operator defined in an infinite-dimensional observable space. Combined with.t.e Galerkin projection, the obtained dominant Koopman eigenvalues and modes produce a reduced-order nonlinear model. to approximate the Koopman operator with sufficient accuracy, we introduce a Polynomial-based Multi-trajectory Kernel Dynamic Mode Decomposition (PMK-DMD) algorithm, which outperforms traditional DMD in various scenarios. In the end, the proposed method is applied to the IEEE 10-machine-39-bus power system and IEEE 16-machine-68-bus power system, which demonstrates th.t.our method is significantly superior to the modal analysis method in both qualitative and quantitative aspects.

关键词： Power system stability Reduced order systems Nonlinear dynamical systems Eigenvalues and eigenfunctions Power system dynamics Kernel transient analysis Analytical models Accuracy Modal analysis

Selenium deficiency exacerbates ROS/ER stress mediated pyroptosis and ferroptosis induced by bisphenol A in chickens thymus

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Journal of Environmental Sciences 2025年第2期148卷 13-26页

作者： Kun Wang Xu Shi hongjin lin tong Xu Shiwen Xu College of Veterinary Medicine Northeast Agricultural UniversityHarbin 150030China Key Laboratory of the Provincial Education Department of heilongjiang for Common Animal Disease Prevention and treatment Harbin 150030China

Bisphenol A(BPA)is an industrial pollutant th.t.can cause immune *** acts as an antioxidant,as selenium deficiency often accompanies oxidative stress,resulting in organ *** study is the first to demonstrate th.t.BPA and/or selenium deficiency induce pyroptosis and ferroptosis-mediated thymic injury in chicken and chicken lymphoma cell(MDCC-MSB-1)via oxidative stress-induced endoplasmic reticulum(ER)*** established a broiler chicken model of BPA and/or selenium deficiency exposure and collected thymus samples as research subjects after 42 *** results demonstrated th.t.BPA or selenium deficiency led to a decrease in antioxidant enzyme activities(t-AOC,CAt,and GSh-Px),accumulation of peroxides(h2O2 and MDA),significant upregulation of ER stress-relatedmarkers(GRP78,IER 1,PERK,EIF-2α,AtF4,and ChOP),a significant increase in iron ion levels,significant upregulation of pyroptosis-related gene(NLRP3,ASC,Caspase1,GSDMD,IL-18 and IL-1β),significantly increase ferroptosis-related genes(tFRC,COX2)and downregulate GPX4,hO-1,Fth,*** vitro experiments conducted in MDCC-MSB-1 cells confirmed the results,demonstrating th.t.the addition of antioxidant(NAC),ER stress inhibitor(tUDCA)and pyroptosis inhibitor(Vx765)alleviated oxidative stress,endoplasmic reticulum stress,pyroptosis,and ***,this study concludes th.t.the combined effects of oxidative stress and ER stress mediate pyroptosis and ferroptosis in chicken thymus induced by BPA exposure and selenium deficiency.

关键词： Bisphenol A Selenium deficiency ROS/ER stress Pyroptosis Ferroptosis thymic injury

Numerical Study of Flow and heat transfer Characteristics of Shell-and-tube Molten Salt Electric heater with Circularly Perforated Baffles

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Journal of thermal Science 2025年第1期34卷 24-33页

作者： lin Yongjie ZhANG Cancan WU Yuting ZhANG Yi LU Yuanwei Key Laboratory of heat transfer and Energy Conversion National User-Side Energy Storage Innovation Research and Development CenterBeijing University of TechnologyBeijing 100124China

Numerical simulations of the flow and heat transfer characteristics of four shell-and-tube molten salt electric heaters with different perforation rates was ***-and-tube electric heaters have the same geometry and tube arrangement,and all of them use single segmental baffles,but there exist four different baffle openings(φ),i.e.,0%,2.52%,4.06%,and 6.31%.the results indicated th.t.the reasonable baffle opening could significantly reduce the shell-side pressure drop,effectively decreasing the shell-side flow dead zone *** can eliminate the local high.t.mperature phenomenon on the surface of electric heating tubes,but the heat transfer coefficient is slightly *** perforated schemes significantly reduce shell-side pressure drop compared to the baseline solution without open *** particular,the φ=6.31% scheme exhibits the optimal performance among all the schemes,with a maximum reduction of up to 50.50% in shell-side pressure drop relative to the unopened holes *** heat transfer coefficient is the highest for φ=0%,exhibiting a range of5.26% to 5.73%,5.14% to 5.99%,and 7.31% to 8.54% higher than φ=2.52%,4.06%,and 6.31%,respectively,within the calculated *** composite index h/(Δp)^(1/3)was higher for all open-hole solutions than th.t.for the unopened-hole *** best overall performance was for φ=6.31%,which improved the composite index by15.29%to 17.18%over the unopened-hole solution.

关键词： molten salt electric heater perforated baffles heat transfer

Nanostructured ZnO/BiVO_(4)I-scheme h.t.rojunctions for piezocatalytic degradation of organic dyes via harvesting ultrasonic vibration energy

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 488-497页

作者： Yiling Li Xiaoyao Yu Yingjie Zhou Yao lin Ying Wu Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004China

BiVO_(4)porous spheres modified by ZnO were designed and synthesized using a facile two-step *** resulting ZnO/BiVO_(4)composite catalysts have shown remarkable efficiency as piezoelectric catalysts for degrading Rhodamine B(RhB)unde mechanical vibrations,they exhibit superior activity compared to pure *** 40wt%ZnO/BiVO_(4)h.t.rojunction composite displayed the highest activity,along with good stability and *** enhanced piezoelectric catalytic activity can be attributed to the form ation of an I-scheme h.t.rojunction structure,which can effectively inhibit the electron-hole ***,hole(h+)and superoxide radical(·O_(2)^(-))are proved to be the primary active ***,ZnO/BiVO_(4)stands as an efficient and stable piezoelectric catalyst with broad potential application in the field of environmental water pollution treatment.

关键词： piezoelectric catalytic h.t.rojunction dye degradation ultrasonic vibration

hMGB2 knockdown ameliorates retinal ganglion cell injury by inhibiting NLRP3 inflammasome activation after retinal ischemia

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International Journal of Ophthalmology(English edition) 2025年第1期18卷 39-50页

作者： lin-Ping Xue hai-Song Feng hubei University of Chinese Medicine Wuhan 430065Hubei ProvinceChina Department of Encephalopathy Hubei Provincial Hospital of Traditional Chinese MedicineWuhan 430070Hubei ProvinceChina

AIM:to explore the neuroprotective effects of high mobility group box 2(hMGB2)knockdown on retinal ganglion cells(RGCs)in the retinal ischemia-reperfusion injury(RIRI).MEthODS:Oxygen-glucose deprivation(OGD)-injured RGCs from postnatal three-day C57BL/6 mice pups and high intraocular pressure(IOP)-induced RIRI mice were used as cellular and animal models of *** expression of hMGB2 in the retina of RIRI mice and OGD-injured RGCs was detected through reverse transcription-polymerase chain reaction(Rt-qPCR)and Western *** effects of hMGB2 silencing on the morphological changes,RGCs survival,and cell apoptosis in mouse retinal tissues were observed through h&E staining,immunofluorescence staining with RNA-binding protein with multiple splicing(RBPMS)antibody,and tUNEL staining,*** viability and apoptosis were examined by CCK-8 and flow cytometry *** levels of proteins associated with NOD-like receptor thermal protein domain associated protein 3(NLRP3)-mediated pyroptosis[NLRP3,Caspase-1,GSDMD-N,interleukin(IL)-1β,IL-18]in vivo and in vitro were measured by Western ***:hMGB2 protein and NLRP3 were upregulated in the retina of RIRI mice and OGD-injured RGCs(Pthe retina was edematous,accompanied by disorganized cell arrangement and decreased thickness of all layers,and obvious vacuoles in ganglion cell ***2 silencing alleviated the reduction in total retinal thickness and the severity of retinal tissue damage as well as suppressed RGC loss and retinal cell apoptosis in RIRI ***-induced RGC apoptosis was ameliorated after downregulation of hMGB2 in *** injection of the AAV-sh-hMGB2 and si-hMGB2 resulted in significantly decrease of NLRP3,Caspase-1,GSDMD-N,IL-1β,and IL-18 protein levels in the retinal tissues of RIRI mice and OGD-injured RGCs,respectively(all PhMGB2 knockdown protects against RGC apoptosis and pyroptosis after RIRI through suppressing NLRP3 inflammasome activ

关键词： hMGB2 retinal ischemia-reperfusion injury retinal ganglion cell apoptosis pyroptosis NLRP3 mice