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Updated Lagrangian Particle Hydrodynamics (ULPH)Modeling of Natural Convection Problems

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 151-169页

作者： Junsong Xiong Zhen Wang Shaofan Li Xin lai Lisheng Liu Xiang Liu Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan430070China Department of Engineering Structure and Mechanics Wuhan University of TechnologyWuhan430070China Department of Civil and Environmental Engineering The University of CaliforniaBerkeleyCA 94720USA

Natural convection is a heat transfer mechanism driven by temperature or density differences,leading to fluid motion without external *** occurs in various natural and engineering phenomena,influencing heat transfer,climate,and fluid mixing in industrial *** work aims to use the Updated Lagrangian Particle Hydrodynamics(ULPH)theory to address natural convection *** Navier-Stokes equation is discretized using second-order nonlocal differential operators,allowing a direct solution of the Laplace operator for temperature in the energy *** numerical simulations,including cases such as natural convection in square cavities and two concentric cylinders,were conducted to validate the reliability of the *** results demonstrate that the proposed model exhibits excellent accuracy and performance,providing a promising and effective numerical approach for natural convection problems.

关键词： Updated Lagrangian particle hydrodynamics(ULPH) natural convection meshless methods higher order Laplacian model

Synthesis and Enhanced Acetone-sensing Properties of Ordered Large-pore Mesoporous Nickel Oxides with Ultrathin Crystalline Frameworks

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Chemical Research in Chinese Universities 2024年第3期40卷 521-528页

作者： SHAO Chen GUO Ru LI Hui WANG Xiaozhong YANG Qingfeng lai Xiaoyong State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering School of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021P.R.China

Acetone is a tracer for monitoring air quality and a potential breath maker for diabetes. It remains a great challenge for current portable sensors to sensitively and selectively detect acetone at low-ppb (part per billion) level. Herein, we present an ordered mesoporous nickel oxide (NiO) with both large mesopores and ultrathin crystalline frameworks for the detection of low-ppb acetone. The ordered mesoporous NiO replicas with predominant large mesopores of 11 nm, high specific surface areas of 121–128 m2/g and ultrathin crystalline frameworks of 5 nm were synthesized by the nanocasting method and the crystalline properties of NiO frameworks were adjusted by changing the annealing temperature from 300℃ to 750℃, which resulted in different contents of oxygen deficient on the surface of ultrathin frameworks. The gas-sensing properties for all the NiO samples were investigated and the ordered large-pore mesoporous NiO (NiO-600) with maximum oxygen deficient obtained at 600℃ exhibited the highest response (R_(gas)/R_(air)−1=2.9) toward acetone (1 ppm, ppm: part per million), which is 3.4 and 30 times larger than those for common mesoporous NiO obtained at 300℃ and bulk NiO. Notably, a low detection limit (2 ppb), good selectivity and cycling stability were also observed in NiO-600.

关键词： Mesoporous semiconductor NiO Gas sensing Acetone

Regulation role of miR-204 on SIRT1/VEGF in metabolic memory induced by high glucose in human retinal pigment epithelial cells

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1232-1237页

作者： Qiao-Ling lai Ting Xie Wei-Dong Zheng Yan Huang Department of Ophthalmology Renmin Hospital of Wuhan UniversityWuhan 460060Hubei ProvinceChina Department of Ophthalmology The First Affiliated Hospital of Fujian Medical UniversityFuzhou 350004Fujian ProvinceChina Department of Ophthalmology&Optometry Fujian Medical UniversityFuzhou 350004Fujian ProvinceChina

AIM:To examine the regulatory role of microRNA-204(miR-204)on silent information regulator 1(SIRT1)and vascular endothelial growth factor(VEGF)under highglucose-induced metabolic memory in human retinal pigment epithelial(hRPE)***:Cells were cultured with either normal(5 mmol/L)or high D-glucose(25 mmol/L)concentrations for 8d to establish control and high-glucose groups,*** induce metabolic memory,cells were cultured with 25 mmol/L D-glucose for 4d followed by culture with 5 mmol/L D-glucose for *** addition,exposed in 25 mmol/L D-glucose for 4d and then transfected with 100 nmol/L miR-204 control,miR-204 inhibitor or miR-204 mimic in 5 mmol/L D-glucose for *** reverse transcription-polymerase chain reaction(RT-qPCR)was used to detect miR-204 mRNA ***1 and VEGF protein levels were assessed by immunohistochemical and Western *** cytometry was used to investigate apoptosis ***:It was found that high glucose promoted miR-204 and VEGF expression,and inhibited SIRT1 activity,even after the return to normal glucose culture *** of miR-204 promoted apoptosis inhibiting SIRT1 and increasing VEGF ***,downregulation of miR-204 produced the opposite ***:The study identifies that miR-204 is the upstream target of SIRT1and VEGF,and that miR-204 can protect hRPE cells from the damage caused by metabolic memory through increasing SIRT1 and inhibiting VEGF expression.

关键词： human retinal pigment epithelial metabolic memory microRNA-204 silent information regulator 1 vascular endothelial growth factor high-glucose

An Elastoplastic Fracture Model Based on Bond-Based Peridynamics

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2349-2371页

作者： Liping Zu Yaxun Liu Haoran Zhang Lisheng Liu Xin lai Hai Mei Department of Engineering Structure and Mechanics Wuhan University of TechnologyWuhan430070China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics Wuhan University of TechnologyWuhan430070China

Fracture in ductile materials often occurs in conjunction with plastic ***,in the bond-based peridynamic(BB-PD)theory,the classic mechanical stress is not defined *** makes it difficult to describe plasticity directly using the classical plastic *** address the above issue,a unified bond-based peridynamics model was proposed as an effective tool to solve elastoplastic fracture *** to the existing models,the proposed model directly describes the elastoplastic theory at the bond level without the need for additional calculation *** results obtained in the context of this model are shown to be consistent with FEM results in regard to force-displacement curves,displacement fields,stress fields,and plastic deformation *** model exhibits good capability of capturing crack propagation in ductile material failure problems.

关键词： Ductile materials plastic deformation bond-based peridynamics isotropic hardening fracture analysis

Comparison of different preoperative objective nutritional indices for evaluating 30-d mortality and complications after liver transplantation

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 143-154页

作者： Chuan Li Hong-Xia Chen Yan-Hua lai Department of Transplantation People’s Hospital of Guangxi Zhuang Autonomous RegionNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Clinical Pharmacy People’s Hospital of Guangxi Zhuang Autonomous RegionNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND The nutritional status is closely related to the prognosis of liver transplant re-cipients,but few studies have reported the role of preoperative objective nutri-tional indices in predicting liver transplant *** To compare the predictive value of various preoperative objective nutritional indicators for determining 30-d mortality and complications following liver transplantation(LT).METHODS A retrospective analysis was conducted on 162 recipients who underwent LT at our institution from December 2019 to June *** This study identified several independent risk factors associated with 30-d mor-tality,including blood loss,the prognostic nutritional index(PNI),the nutritional risk index(NRI),and the control nutritional *** 30-d mortality rate was 8.6%.Blood loss,the NRI,and the PNI were found to be independent risk factors for the occurrence of severe postoperative *** NRI achieved the highest prediction values for 30-d mortality[area under the curve(AUC)=0.861,P<0.001]and severe complications(AUC=0.643,P=0.011).Compared to those in the high NRI group,the low patients in the NRI group had lower preoperative body mass index and prealbumin and albumin levels,as well as higher alanine aminotransferase and total bilirubin levels,Model for End-stage Liver Disease scores and prothrombin time(P<0.05).Furthermore,the group with a low NRI exhibited significantly greater incidences of intraabdominal bleeding,primary graft nonfunction,and *** The NRI has good predictive value for 30-d mortality and severe complications following *** NRI could be an effective tool for transplant surgeons to evaluate perioperative nutritional risk and develop relevant nutritional therapy.

关键词： Liver transplantation Nutritional indicator Complications Prognosis Nutrition assessment

Optimal Strategy for Aircraft Pursuit-evasion Games via Self-play Iteration

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Machine Intelligence Research 2024年第3期21卷 585-596页

作者： Xin Wang Qing-lai Wei Tao Li Jie Zhang State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100049China Institute of Systems Engineering Macao University of Science and TechnologyMacao999078China

In this paper,the pursuit-evasion game with state and control constraints is solved to achieve the Nash equilibrium of both the pursuer and the evader with an iterative self-play *** the condition where the Hamiltonian formed by means of Pontryagin’s maximum principle has the unique solution,it can be proven that the iterative control law converges to the Nash equilibrium ***,the strong nonlinearity of the ordinary differential equations formulated by Pontryagin’s maximum principle makes the control policy difficult to figured *** the system dynamics employed in this manuscript contains a high dimensional state vector with *** practical applications,such as the control of aircraft,the provided overload is ***,in this paper,we consider the optimal strategy of pursuit-evasion games with constant constraint on the control,while some state vectors are restricted by the function of the *** address the challenges,the optimal control problems are transformed into nonlinear programming problems through the direct collocation ***,two numerical cases of the aircraft pursuit-evasion scenario are given to demonstrate the effectiveness of the presented method to obtain the optimal control of both the pursuer and the evader.

关键词： Differential games pursuit-evasion games nonlinear control optimal control Nash equilibrium solution

26-electrons redox-active polyoxovanadate clusters for aqueous zincion batteries

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Nano Research 2024年第5期17卷 4047-4054页

作者： Yimin Xing Wen Yan Haiyang Wu Peng Huang Chao Wang Chao lai School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhou 221116China

Aqueous zinc-ion batteries(ZIBs)are attaining increasing attention for their high safety and low *** significant progresses in realizing high-performance cathode material for ZIBs,simultaneously endowing them with high capacity and fast-charging capability,the long-term cycling stability remains a major unsolved *** this work,a polyoxovanadate cluster of(NH_(4))_(8)[V_(19)O_(41)(OH)_(9)]·11H_(2)O(NOV)is defined as a cathode material for ZIBs that contains mixed-valence vanadium sites(V^(4+)and V^(5+)).A maximum of 26 electrons can be accommodated in one[V_(19)O_(41)(OH)_(9)]^(8-){V_(19)O_(50)}cluster,contributing to the high theoretical specific capacity of 328 mA·h·g^(-1).The Ti_(3)C_(2)T_(x) MXene nanosheets are incorporated into NOV with the help of ionic liquid(IL)linkers to restrain the dissolution of vanadium species and facilitate electron transport across the *** interfacial bonding,anion exchange,and electrostatic interactions among NOV and MXene are provided by IL *** nanohybrid of NOV-IL-MXene endows excellent contact between MXene and NOV,thereby enhanced charge transfer is observed at ***,the as-synthesized NOV-IL-MXene cathodes exhibit high discharge capacity of 413 mA·h·g^(-1) at 0.2 A·g^(-1) even at high mass loading of 5.2 mg·cm^(-2),remarkable rate performance of 182 mA·h·g^(-1) at 10 A·g^(-1),and impressive cycling stability of 94%capacity retention after 2000 *** work opens up new opportunities to develop advanced polyoxovanadate hybrid cathodes for low-cost and high-performance aqueous ZIBs.

关键词： polyoxovanadate MXene composite materials cathodes zinc-ion batteries

Analysis of amino acid enantiomers in ambient aerosols:Effects and removal of coexistent aerosol matrix

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Journal of Environmental Sciences 2024年第3期137卷 732-740页

作者： Ying Li Xiaoying Li Libin Wu Luhan Shi ShanWang Pingqing Fu Yingyi Zhang Senchao lai The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China now at Hong Kong University of Science and Technology Hong Kong 00852China

Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient *** to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution *** this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution *** results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample *** pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by *** recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers *** suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.

关键词： Amino acid enantiomers Atmospheric aerosol Organic carbon Ammonia Chiral ratio

Realization of Low in-Band Harmonic for Compact 6–18-GHz T/R Module Under TX-Mode Operation

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Chinese Journal of Electronics 2024年第2期33卷 380-384页

作者： Jinming lai Zhiyou LI Chaojie WANG Hailong WANG Xiaohua MA School of Microelectronics Xidian University CETC 29th Research Institute

Wideband high power amplifier(PA) with poor harmonic suppression will degrade the performance of the active electronically scanned array(AESA) due to its harmonic products falling into the operating bandwidth of a wideband T/R module. In view of this, a compact reconfigurable harmonic suppress circuit(HSC) is proposed to achieve low in-band harmonic for compact T/R module with multiple octaves under TX-mode operation. The HSC consists of eight microstrip resonant stubs with high impedance and multiple p-i-n switches. By controlling the p-i-n switches, the HSC can work in three states. When six of the used p-i-n switches are “ON” state, the corresponding microstrip resonant stubs are loaded onto the 50 Ω transmission line, which performs a bandstop filter(BSF). For verification, the HSC with bandwidth of 12–15 GHz/15–18 GHz is designed to apply to a 6–18 GHz T/R module. As a result, the second harmonic of 6–9 GHz transmitting signal can be suppressed below 32 d Bc when compared to the PA's fundamental output. While the p-i-n switches are “OFF” state, the HSC is almost the same as a 50 Ω transmission line, which will have a little effect on the 9–18 GHz transmitting signal. The measurement results approximately agree with the calculated results and simulated results, which demonstrate the validity of the proposed HSC.

关键词： Microstrip filters Harmonics suppression Power transmission lines PIN photodiodes Switches Harmonic analysis Transmission line measurements