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Painlevé Property and Integrability of Polynomial Dynamical Systems

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Communications in Mathematical Research 2014年第4期30卷 358-368页

作者： li wen-lei Shi Shao-yun School of Mathematics Jilin University Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University

The main purpose of this paper is to investigate the connection between the Painlev′e property and the integrability of polynomial dynamical systems. We show that if a polynomial dynamical system has Painlev′e property, then it admits certain class of first integrals. We also present some relationships between the Painlev′e property and the structure of the differential Galois group of the corresponding variational equations along some complex integral curve.

关键词： Painlev′e property integrability differential Galois group

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基于改进金枪鱼群算法PMSM自抗扰控制

电力电子技术 2024年第1期58卷 27-31,35页

作者：阎馨李文磊屠乃威侯利民辽宁工程技术大学电气与控制工程学院辽宁葫芦岛125105

针对传统永磁同步电机(PMSM)调速系统在受到外部环境干扰、参数易变等不确定性因素的影响下系统鲁棒性变差的问题,提出一种基于改进金枪鱼群优化(ITSO)算法的PMSM自抗扰控制(ADRC)策略。首先,针对ADRC中fal函数在拐点处不平滑的问题,提... 详细信息

针对传统永磁同步电机(PMSM)调速系统在受到外部环境干扰、参数易变等不确定性因素的影响下系统鲁棒性变差的问题,提出一种基于改进金枪鱼群优化(ITSO)算法的PMSM自抗扰控制(ADRC)策略。首先,针对ADRC中fal函数在拐点处不平滑的问题,提出了一种改进fal函数,减小了系统的高频抖振。其次,由于ADRC中参数多且不易整定,利用ITSO算法对参数进行寻优整定。为了避免电流环在采用比例积分(PI)控制时电流控制存在抗负载能力差、响应速度慢等问题,将降低电感权值后的改进型无差拍预测控制应用到电流环。最后,进行仿真和半实物实验验证,结果表明所提控制策略具有良好的系统响应和控制精度,明显提高了系统的鲁棒性。

关键词：永磁同步电机自抗扰控制金枪鱼群优化算法

Metallothionein 1E Alleviates Cadmium-induced Renal Cytotoxicity through Promoting Mitochondrial Functional Recovery

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Biomedical and Environmental Sciences 2024年第1期37卷 117-121页

作者： wen Si Hui li Lu Bei HUANG Hui Dan XIE Ying LUO lei Key Laboratory of Molecular Epidemiology of Hunan Province School of MedicineHunan Normal UniversityChangsha 410081HunanChina Department of Occupational Health Changsha Centre for Disease Control and PreventionChangsha 410004HunanChina The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province Hunan Normal University School of MedicineChangsha 410013HunanChina

The pervasive utilization of industrial substances has escalated human exposure to cadmium(Cd),a metal associated with long-term negative health outcomes such as renal dysfunction,neurological disorders,and various cancers^([1]).Once ingested by humans,Cd interacts with cysteine-rich metallothioneins(MTs)which have metal-binding and antioxidant properties and is subsequently transported to the kidney^([2]).

关键词： Renal kidney cadmium

Study of the blocking mechanism in gravel packing based on CFD-DEM

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Particuology 2024年第7期90卷 164-178页

作者： Fucheng Deng lei wen Gang li Baitao Fan Ning Gong Shenghong Chen Yangtze University Jingzhou434023China Guangzhou Institute of Energy Conversion Chinese Academy of Sciences510640China CNOOC Research Institute Ltd Beijing100028China Tianjin Branch of CNOOC Ltd Tianjin300459China CNOOC Ener Tech-Drilling&Production Co Tianjin300457China

Gravel packing sand control(GPSC),as the optimization of mechanical sand control technology,is widely used in the deep water completion and sand control of loose sandstone heavy oil reservoirs and highly argillaceous.To explore the blocking mechanism of GPSC,the influence of its structural parameters on the blocking of GPSC is investigated.This paper establishes a particle element model based on computational fluid dynamics-discrete element method coupling using the discrete element method and establishes a fluid flow model combined with computational fluid dynamics to realize their full coupling solution.And sand control experiments were carried out using a micro visual sand control simulation device to verify the blocking model.The blocking mechanism is analyzed from the microscopic point of view,and then,the influence of sand control structure parameters on the blocking in GPSC design is evaluated.The results show the following:(1)the blocking process of GPSC can be divided into three stages:an initial stage,sand accumulation stage,and equilibrium stage.(2)There are two main types of gravel packing blockage.The first type of blocking is blocking on the surface of the gravel layer.Sand particles on the surface of gravel layer mainly exist in the form of large particle size blocking gravel pores and sand particles bridging each other.The second type of blockage is the blockage inside the gravel layer.Sand particles mainly exist in the form of internal mud cakes and adsorption on gravels inside the gravel layer.(3)To ensure the sand control performance of the gravel layer,the gravel layer thickness is designed between 23 and 28 mm.The displacement or pressure of the on-site packing pump should be increased to ensure that the gravel layer packing solidity ranges between 59%and 62%.In the design of GPSC,it should be ensured that the median particle size of gravel is 5–6 times the median particle size of sand.This study provides an effective technical reference for the design of gravel structural parameters in on-si

关键词： CFD-DEM Blocking the process Blocking mechanism Structural parameter

N-glycan biosignatures as a potential diagnostic biomarker for earlystage pancreatic cancer

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 659-669页

作者： Yan-Rong wen Xia-wen lin Yu-wen Zhou lei Xu Jun-li Zhang Cui-Ying Chen Jian He Department of Nuclear Medicine Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Department of Research and Development Sysdiagno(Nanjing)Biotech Co.LtdNanjing 210008Jiangsu ProvinceChina

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)has a poor prognosis,with a 5-year survival rate of less than 10%,owing to its late-stage diagnosis.Early detection of pancreatic cancer(PC)can significantly increase survival rates.AIM To identify the serum biomarker signatures associated with early-stage PDAC by serum N-glycan analysis.METHODS An extensive patient cohort was used to determine a biomarker signature,in-cluding patients with PDAC that was well-defined at an early stage(stages I and II).The biomarker signature was derived from a case-control study using a case-cohort design consisting of 29 patients with stage I,22 with stage II,4 with stage III,16 with stage IV PDAC,and 88 controls.We used multiparametric analysis to identify early-stage PDAC N-glycan signatures and developed an N-glycan sig-nature-based diagnosis model called the“Glyco-model”.RESULTS The biomarker signature was created to discriminate samples derived from patients with PC from those of controls,with a receiver operating characteristic area under the curve of 0.86.In addition,the biomarker signature combined with cancer antigen 19-9 could discriminate patients with PDAC from controls,with a receiver operating characteristic area under the curve of 0.919.Glyco-model demonstrated favorable diagnostic performance in all stages of PC.The diagnostic sensitivity for stage I PDAC was 89.66%.Core Tip:This study employed a patient cohort to investigate the N-glycan signature of early-stage pancreatic cancer(PC).Serum N-glycans analysis was conducted to identify the serum biomarker signature associated with early-stage pancreatic ductal adenocarcinoma(PDAC),resulting in the identification of nine early-stage PDAC N-glycan signatures.Subsequently,utilizing these biosignatures,a diagnostic model named the“Glyco-model”was developed,demonstrating promising diagnostic performance across all stages of PC.The study revealed that the diagnostic sensitivity for stage I PDAC was determined to be 89.66%.Consequently,this diagnostic model exhibits potent

关键词： Glycomics N-glycans Biomarkers Pancreatic cancer Predictive modeling

Mo@PANI-catalyzed oxidative deoximation reaction

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Chinese Chemical Letters 2024年第2期35卷 407-410页

作者： Yiyang Zhang wen li Zuofeng Hu Xiaobi Jing lei Yu School of Mechanical Engineering Yangzhou UniversityYangzhou 225127China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China Yangzhou Yangzi Auto Interior & Exterior Co. Ltd.Yangzhou 225119China

Deoximation is an important transformation in synthetic industry.It can be employed in protection,characterization and purification of the carbonyls,and in the synthesis of ketones from non-carbonyl molecules.In the field,oxidative deoximation reaction can utilize the driving force caused by the oxidation process so that the reaction can occur under relatively mild conditions.Recently,we designed and prepared polyaniline-supported molybdenum(Mo@PANI)just by immersing PANI into the EtOH/H_(2)O solution of MoCl_(5).The material was successfully applied as the efficient catalyst for oxidative deoximation reactions,which were performed in ethanol using H_(2)O_(2)as the clean oxidant.The substrate scope of the reaction was wide.It could be applied on heterocycle-containing substrates,making this protocol preferable for pharmaceutical intermediate synthesis.Since Mo is a necessary trace element for both animals and plants,this method is environment-friendly and is suitable for large-scale preparation.This work as the first example of Mo-catalyzed oxidative deoximation reaction may inspire novel ideas for both catalyst design and synthetic process development.

关键词： Molybdenum Polyaniline Oxidation Deoximation Carbonyl

A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics

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Petroleum Science 2024年第1期21卷 327-342页

作者： Qian Zhang wen-Dong Wang Yu-liang Su Wei Chen Zheng-Dong lei lei li Yong-Mao Hao Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Oil Development Branch Changqing Oilfield CompanyPetroChinaQingyang745708GansuChina PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China

A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation.

关键词： Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory

Layered niobium carbide enabling excellent kinetics and cycling stability of li-Mg-B-H hydrogen storage material Layered niobium carbide enabling excellent kinetics

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Rare Metals 2024年第3期43卷 1153-1166页

作者： li-wen Lu Hui Luo Guang-Xu li Yun li Xin-Hua Wang Cun-Ke Huang Zhi-QiangLan wen-Zheng Zhou Jin Guo Mohammad Ismail Hai-Zhen liu Guangxi Novel Battery Materials Research Center of Engineering Technology Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science and TechnologyGuangxi UniversityNanning530004China State Key Laboratory of Featured Metal Materials and life-Cycle Safety for Composite Structures Nanning530004China School of Mechanical and Electrical Engineering Quzhou College of TechnologyQuzhou324000China Department of Materials Science and Engineering Zhejiang UniversityHangzhou310027China Faculty of Ocean Engineering Technology and Informatics Universiti Malaysia Terengganu21030Kuala NerusTerengganuMalaysia Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin300071China

The li-Mg-B-H composite(2liBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage material.However,the slow kinetics and poor cycling stability severely restrict its practical applications.In this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the li-Mg-B-H composite.The milled 2liH+MgB_(2)composites were initially hydrogenated to obtain the 2liBH_(4)+MgH_(2)composites.The 2liBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2liBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and liBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2liBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th cycle.Nb_(2)C keeps stable in the composite and acts as an efficient catalyst for the li-Mg-B-H composite.It is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the li-Mg-B-H composite.This work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.

关键词： Hydrogen storage lithium borohydride Magnesium hydride Nb_(2)C MXene

Dynamic simulation analysis of molten salt reactor-coupled air-steam combined cycle power generation system

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Nuclear Science and Techniques 2024年第2期35卷 222-233页

作者： Jing-lei Huang Guo-Bin Jia li-Feng Han wen-Qian liu li Huang Zheng-Han Yang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power system.This model considers the impact of thermal properties of fluid variation on accuracy and has been validated with Simulink.This study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet parameters.Meanwhile,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also analyzed.The results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial values.This simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.

关键词： Molten salt reactor Combined cycle Dynamic characteristic Control