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Asymptotic solution for EI Nino-southern oscillation of nonlinear model

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Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 251-255页

作者： MO jia-qi LIN Wan-tao Dept. of Math. Anhui Normal Univ. Wuhu 241000 China LASG Institute of Atmos. Phys. Chinese Academy of Sciences Beijing 100029 China

A class of nonlinear coupled system for EI Nino-Southern Oscillation （ENSO） model is considered. Using the asymptotic theory and method of variational iteration, the asymptotic expansion of the solution for ENSO mod... 详细信息

关键词： nonlinear asymptotic theory EI Nino-Southern Oscillation model

Development of rocking constraint device with vertical damping capacity for three-dimensional base-isolated frame structures

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Frontiers of Structural and Civil Engineering 2023年第3期17卷 350-367页

作者： Yundong SHI qi WANG Wenqing dong Bo ZHAO Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation (Ministry of Emergency Management)Harbin 150080China School of Civil Engineering Tianjin UniversityTianjin 300072China

A new rocking constraint device(RCD)is developed for three-dimensional(3D)base-isolated frame structures by connecting a custom-designed cylinder pair to provide vertical damping with replaceable damping components installed outside the cylinders when the superstructure undergoes translational motion,and rocking constraint capacity when the superstructure is susceptible to *** formulas for calculating the damping and rocking constraint stiffness of the RCD are *** series of sinusoidal loading tests are conducted at different loading frequencies and amplitudes to verify the damping and rocking constraint performance of the *** test results show that the cylinder without orifices on its piston can provide the desired damping with a replaceable damping component,and that the RCD can effectively suppress *** the vertical stiffness of an individual cylinder is affected by the location of the replaceable damping component and loading frequency,the average vertical stiffness of the two cylinders,which determines the rocking constraint stiffness of the RCD,is independent of the two *** of the test and theoretical results indicate that the errors of the proposed formulas for calculating the damping and rocking constraint stiffness of the RCD do not exceed 12.9%and 11.0%,respectively.

关键词： three-dimensional isolation rocking behavior rocking constraint device replaceable damping component sinusoidal test

NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma

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Current Medical Science 2024年第1期44卷 168-179页

作者： Wei XUE Ting WANG Wen-jing TIAN Si-qi PANG Hua-feng ZHANG Wei-dong jia Department of General Surgery The First Affiliated Hospital of University of Science and Technology of ChinaDivision of Life Science and MedicineUniversity of Science and Technology of ChinaHefei 230027China Institute of Health and Medicine Hefei Comprehensive National Science CenterHefei 230601China The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease School of Basic Medical SciencesDivision of Life Science and MedicineUniversity of Science and Technology of ChinaHefei 230027China

Objective Hepatocellular carcinoma(HCC)is the third leading cause of cancer-associated death *** a first-line drug for advanced HCC treatment,lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients,and the underlying mechanism remains largely *** present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC,explore the potential molecular mechanism,and propose combinatorial therapeutic targets for HCC *** Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and ***-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant(LR)*** upregulated genes were analyzed by GO and KEGG ***,qPCR and Western blotting were employed to determine the relative gene expression ***,the intracellular reactive oxygen species(ROS)and apoptosis were detected by flow *** PLC-LR and Hep3B-LR were *** was a total of 116 significantly upregulated genes common to both LR cell *** GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities,and reactive oxygen species ***,NAD(P)H:quinone oxidoreductase 1(NQO1)was highly expressed in LR cells,and was involved in the lenvatinib *** high expression of NQO1 decreased the production of ROS induced by lenvatinib,and subsequently suppressed the *** combination of lenvatinib and NQO1 inhibitor,dicoumarol,reversed the resistance of LR *** The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels,thereby promoting lenvatinib resistance in HCC cells.

关键词： hepatocellular carcinoma lenvatinib resistance NAD(P)H quinone oxidoreductase 1 reactive oxygen species apoptosis dicoumarol

Efficient optimization method for variable-specific-impulse low-thrust trajectories with shutdown constraint

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Science China(Technological Sciences) 2022年第3期65卷 581-594页

作者： jia FeiDa qiAO dong HAN HongWei LI XiangYu School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Autonomous Navigation and Control for Deep Space Exploration Ministry of Industry and Information TechnologyBeijing 100081China

This paper develops a sequential convex programming(SCP)-based method to solve the minimum-fuel variable-specific-impulse low-thrust transfer problem considering shutdown constraint,with emphasize on improving the computational *** variable parameter engine is more applicable for many low-thrust scenarios,therefore,both a continuously variable model and a ladder variable model are ***,the original problem is convexified by processing the constraint feasible domain,which is composed of the nonlinear dynamic equations and second-order equality constraint,into convex ***,the approximation is generated to close the optimal solution of the low-thrust problem by iteratively solving the convexified ***,the switching self-detection and adaptive node refinement methods are presented,which can improve the accuracy of the solution and accelerate the convergence during the approximation process and is especially necessary and effective in the scenarios with shutdown *** numerical simulations,the comparison with the homotopic approach shows that the proposed method only needs 4%computational time as that of the homotopic approach,and two variable-specificimpulse examples further demonstrate the effectiveness and efficiency of the proposed method.

关键词： low-thrust trajectory variable-specific-impulse shutdown constraint sequential convex programming switching self-detection and adaptive node refinement

Distributed collaborative complete coverage path planning based on hybrid strategy

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Journal of Systems Engineering and Electronics 2024年第2期35卷 463-472页

作者： ZHANG jia DU Xin dong qichen XIN Bin School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Autonomous Intelligent Unmanned Systems Beijing Institute of TechnologyBeijing 100081China

Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm is proposed for the urban rescue search or military search in outdoor *** to flexible control of small UAVs, it can be considered that all UAVs fly at the same altitude, that is, they perform search tasks on a two-dimensional plane. Based on the agents’ motion characteristics and environmental information, a mathematical model of CCPP problem is established. The minimum time for UAVs to complete the CCPP is the objective function, and complete coverage constraint, no-fly constraint, collision avoidance constraint, and communication constraint are considered. Four motion strategies and two communication strategies are designed. Then a distributed CCPP algorithm is designed based on hybrid strategies. Simulation results compared with patternbased genetic algorithm(PBGA) and random search method show that the proposed method has stronger real-time performance and better scalability and can complete the complete CCPP task more efficiently and stably.

关键词： multi-agent cooperation unmanned aerial vehicles(UAV) distributed algorithm complete coverage path planning(CCPP)

Effect of Heat Flux Distribution on Entropy Generation and Irreversibility of Lead-Bismuth Eutectic(LBE)Forced Convective Heat Transfer

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Journal of Thermal Science 2023年第1期32卷 223-236页

作者： ZHANG dong ZHANG Haochun WANG qi SUN Wenbo School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Investigations on entropy generation and thermal irreversibility analysis are conducted for liquid lead-bismuth eutectic(LBE)in an annular *** find better performance in convective heat transfer,the computational fluid dynamics(CFD)code based on the finite volume method(FVM)is adopted to solve this *** elevated temperature LBE flows in the annular pipe,and four types of heat flux,including constant,linear increase and decrease,and parabolic distributions are imposed at the inside wall of the annular *** investigations are conducted for the specific average heat input of 200 kW/m^(2),and the different Peclet number Pe is set from 1200 to *** SST k-ωturbulent model and Cheng-Tak Prt model are *** mesh independence validation and models verification are also conducted and the maximum Nu error is 5.43%compared with previous experimental *** results from the local and system scales,respectively,including volumetric dimensionless entropy generation,Ns,Be,and Ep,are *** results indicate that the viscous friction and heat transfer caused by entropy generation can be found in the viscous sub-layer and buffer layer *** transfer is the primary factor that leads to irreversible ***,the results show that the best thermodynamic performance occurs under parabolic distributed heat flux in the research scope.

关键词： liquid lead-bismuth eutectic entropy generation analysis annular pipe CFD

Large cystic-solid pulmonary hamartoma:A case report

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World Journal of Clinical Cases 2022年第8期10卷 2650-2656页

作者： Xiao-Wan Guo Xu-dong jia A-Dan Ji Dan-qing Zhang De-Zhao jia qi Zhang qiu Shao Yang Liu Department of Radiology Hebei General HospitalShijiazhuang 050000Hebei ProvinceChina Departments of Urology The Second Hospital of Hebei Medical UniversityShijiazhuang 050005Hebei ProvinceChina Department of Medical Record Statistics Hebei General HospitalShijiazhuang 050000Hebei ProvinceChina Department of Pathology Hebei General HospitalShijiazhuang 050000Hebei ProvinceChina

BACKGROUND It now seems that all pulmonary hamartomas(PHs)are large cystic-solid lesions that are difficult to ***,few cases of large cystic-solid PHs have been *** present case report presents a large cystic-solid PH and provides a literature review of the imaging features,formation mechanism and histopathological basis of *** SUMMARY A 53-year-old woman with no clinical symptoms underwent a chest computed tomography(CT)examination at our *** CT images revealed a large,flat tumor with multiple air-containing cysts in the left thoracic cavity and a cystic part confined to the medial side of the tumor;the solid part of the tumor showed abundant fat and lamellar soft tissue *** small blood vessels were detected in the solid part of the tumor on contrast-enhanced CT *** the large size of the lesion,the patient elected to undergo *** examination revealed PH.A detailed review of the patient’s CT imaging showed that the lesion had a small vascular pedicle to the left lower lobe,which was a clue to its lung tissue histological *** to immunohistochemical staining,the confined multiple air-containing cysts were caused by the entrapment of respiratory/alveolar *** This case shows the imaging manifestations of a large *** awareness of its formation mechanism and histopathological basis may alert radiologists to consider this diagnosis in their daily workflow.

关键词： Lung Lung benign lesion Hamartoma Computed tomography Case report

GGC:Gray-Granger Causality Method for Sensor Correlation Network Structure Mining on High-Speed Train

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Tsinghua Science and Technology 2022年第1期27卷 207-222页

作者： Jie Man Honghui dong Limin jia Yong qin the State Key Laboratory of Rail Traffic Control and Safety and Beijing Research Center of Urban Traffic Information Sensing and Service TechnologiesBeijing Jiaotong UniversityBeijing 100044China

Vehicle information on high-speed trains can not only determine whether the various parts of the train are working normally,but also predict the train’s future operating *** to obtain valuable information from massive vehicle data is a difficult ***,we divide the vehicle data of a high-speed train into 13 subsystem datasets,according to the functions of the collection ***,according to the gray theory and the Granger causality test,we propose the Gray-Granger Causality(GGC)model,which can construct a vehicle information network on the basis of the correlation between the collection *** using the complex network theory to mine vehicle information and its subsystem networks,we find that the vehicle information network and its subsystem networks have the characteristics of a scale-free *** addition,the vehicle information network is weak against attacks,but the subsystem network is closely connected and strong against attacks.

关键词： vehicle information network structure mining gray theory Granger causality theory complex network theory high-speed train

Involvement of phosphatidate phosphatase in the biosynthesis of triacylglycerols in Chlamydomonas reinhardtii

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第12期14卷 1121-1131页

作者： Xiao-dong DENG jia-jia CAI Xiao-wen FEI Key Laboratory of Tropical Crop Biotechnology Ministry of Agriculture Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences School of Science Hainan Medical College

Lipid biosynthesis is essential for eukaryotic cells, but the mechanisms of the process in microalgae remain poorly understood. Phosphatidic acid phosphohydrolase or 3-sn-phosphatidate phosphohydrolase(PAP) catalyzes the dephosphorylation of phosphatidic acid to form diacylglycerols and inorganic orthophosphates. This reaction is integral in the synthesis of triacylglycerols. In this study, the mRNA level of the PAP isoform CrPAP2 in a species of Chlamydomonas was found to increase in nitrogen-free conditions. Silencing of the CrPAP2 gene using RNA interference resulted in the decline of lipid content by 2.4%–17.4%. By contrast, over-expression of the CrPAP2 gene resulted in an increase in lipid content by 7.5%–21.8%. These observations indicate that regulation of the CrPAP2 gene can control the lipid content of the algal cells. In vitro CrPAP2 enzyme activity assay indicated that the cloned CrPAP2 gene exhibited biological activities.

关键词： Phosphatidate phosphohydrolase 2 Triacylglycerol biosynthesis RNAi Chlamydomonas reinhardtii Nitrogen deprivation Over-expression