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Security-constrained Transmission Maintenance Optimization Considering Generation and Operational Risk Costs

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 767-781页

作者： Dan xu zhi Cai Qian Cheng Guodong Huang Jingyang Zhou Junjie Tang Beijing Key Laboratory of Research and System Evaluation of Power Dispatching Automation Technology China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China

With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power ***,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed *** model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission ***,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution *** cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment *** electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence *** IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.

关键词： Transmission maintenance security-constrained unit commitment iterative algorithm cost feedback N−1 risk assessment

Intermittent disturbance mechanical behavior and fractional deterioration mechanical model of rock under complex true triaxial stress paths

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International Journal of Mining Science and Technology 2024年第1期34卷 117-136页

作者： zhi Zheng Hongyu xu Kai Zhang Guangliang Feng Qiang Zhang Yufei Zhao State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Key Laboratory of Disaster Prevention and Structural Safety of Ministry of EducationCollege of Civil Engineering and ArchitectureGuangxi UniversityNanning 530004China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100080China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

Mechanical excavation,blasting,adjacent rockburst and fracture slip that occur during mining excavation impose dynamic loads on the rock mass,leading to further fracture of damaged surrounding rock in three-dimensional high-stress and even causing ***,a novel complex true triaxial static-dynamic combined loading method reflecting underground excavation damage and then frequent intermittent disturbance failure is *** triaxial static compression and intermittent disturbance tests are carried out on *** effects of intermediate principal stress and amplitude on the strength characteristics,deformation characteristics,failure characteristics,and precursors of monzogabbro are analyzed,intermediate principal stress and amplitude increase monzogabbro strength and tensile fracture *** increases in microseismic parameters during rock loading can be precursors for intermittent rock *** on the experimental result,the new damage fractional elements and method with considering crack initiation stress and crack unstable stress as initiation and acceleration condition of intermittent disturbance irreversible deformation are proposed.A novel three-dimensional disturbance fractional deterioration model considering the intermediate principal stress effect and intermittent disturbance damage effect is established,and the model predicted results align well with the experimental *** sensitivity of stress states and model parameters is further explored,and the intermittent disturbance behaviors at different f are *** study provides valuable theoretical bases for the stability analysis of deep mining engineering under dynamic loads.

关键词： True triaxial static and disturbance test Mechanical properties Failure mechanism and precursor Intermittent disturbance effect Fractional mechanical model

Multiparameter Numerical Investigation of Two Types of Moving Interactions Between the Deep-Sea Mining Vehicle Track Plate and Seabed Soil:Digging and Rotating Motions

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China Ocean Engineering 2024年第3期38卷 408-423页

作者： SUN Peng-fei LYU Hai-ning YANG Jian-min xu zhi-yong State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Yazhou Bay Institute of Deepsea SCI-TECH Shanghai Jiao Tong UniversitySanya 572024China Institute of Marine Equipment Shanghai Jiao Tong UniversityShanghai 200240China

To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track *** rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed *** this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging ***,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ ***,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil *** results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed ***,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.

关键词： deep-sea mining vehicle rotating motion digging motion track plate-seabed soil interaction CEL numerical method

Low interleukin-10 level indicates a good prognosis in Salmonella enterica serovar typhimurium-induced pediatric hemophagocytic lymphohistiocytosis:A case report

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World Journal of Clinical Cases 2024年第9期12卷 1660-1668页

作者： Yuan-Yuan Chen Xiang-zhi xu Xiao-Jun xu Division/Center of Pediatric Hematology Oncology Children’s HospitalZhejiang University School of MedicineHangzhou 310003Zhejiang ProvinceChina Pediatric Intensive Care Unit Children’s Hospital of Zhejiang University School of MedicineHangzhou 310003Zhejiang ProvinceChina

BACKGROUND Secondary hemophagocytic lymphohistiocytosis(sHLH)triggered by Salmonella enterica serovar Typhimurium is rare in pediatric *** is no consensus on how to treat ***-triggered *** SUMMARY A 9-year-old boy with intermittent fever for 3 d presented to our hospital with positive results for ***,human rhinovirus,and Mycoplasma pneumoniae *** the time of admission to our institution,the patient’s T helper 1/T helper 2 cytokine levels were 326 pg/mL for interleukin 6(IL-6),9.1 pg/mL for IL-10,and 246.7 pg/mL for interferon-gamma(IFN-γ),for which the ratio of IL-10 to IFN-γwas *** this study,the patient received meropenem,linezolid,and cefoperazone/sulbactam in combination with high-dose methylprednisolone therapy(10 mg/kg/d for 3 d)and antishock supportive treatment *** careful evaluation,this patient did not receive HLH chemotherapy and recovered *** *** infection-triggered sHLH patient had a ratio of IL-10 to IFN-γ≤1.33,an IL-10 concentration≤10.0 pg/mL,and/or an IFN-γconcentration≤225 pg/mL at *** antimicrobial and supportive treatment was sufficient,and the HLH-94/2004 protocol was not necessary under these conditions.

关键词： Hemophagocytic lymphohistiocytosis Cytokine pattern Interferon gamma Interleukin-10 Salmonella enterica serovar Typhimurium Case report

Gut-targeted therapies for type 2 diabetes mellitus: A review

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World Journal of Clinical Cases 2024年第1期12卷 1-8页

作者： Tian-Cheng xu Yun Liu zhi Yu Bin xu Key Laboratory of Acupuncture and Medicine Research of Ministry of Education Nanjing University of Chinese MedicineNanjing 210023Jiangsu ProvinceChina

Type 2 diabetes mellitus(T2DM)is a chronic metabolic disorder characterized by hyperglycemia and insulin *** global prevalence of T2DM has reached epidemic proportions,affecting approximately 463 million adults worldwide in *** treatments for T2DM include lifestyle modifications,oral antidiabetic agents,and insulin ***,these therapies may carry side effects and fail to achieve optimal glycemic control in some ***,there is a growing interest in the role of gut microbiota and more gut-targeted therapies in the management of *** gut microbiota,which refers to the community of microorganisms that inhabit the human gut,has been shown to play a crucial role in the regulation of glucose metabolism and insulin *** in gut microbiota composition and diversity have been observed in T2DM patients,with a reduction in beneficial bacteria and an increase in pathogenic *** dysbiosis may contribute to the pathogenesis of the disease by promoting inflammation and impairing gut barrier *** gut-targeted therapies have been developed to modulate the gut microbiota and improve glycemic control in *** potential approach is the use of probio-tics,which are live microorganisms that confer health benefits to the host when administered in adequate *** randomized controlled trials have demonstrated that certain probiotics,such as Lactobacillus and Bifidobacterium species,can improve glycemic control and insulin sensitivity in T2DM *** may include the production of short-chain fatty acids,the improvement of gut barrier function,and the reduction of *** gut-targeted therapy is fecal microbiota transplantation(FMT),which involves the transfer of fecal material from a healthy donor to a *** has been used successfully in the treatment of Clostridioides difficile infection and is now being investigated as a potential therapy for T2DM.A recent rand

关键词： Type 2 diabetes mellitus Gastroenterology Bacteria Implanted device

Incorporating Lasso Regression to Physics-Informed Neural Network for Inverse PDE Problem

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 385-399页

作者： Meng Ma Liu Fu xu Guo zhi Zhai National Key Lab of Aerospace Power System and Plasma Technology Xi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an710049China Department of Electrical and Computer Engineering University of Massachusetts LowellLowellMA 01854USA

Partial Differential Equation(PDE)is among the most fundamental tools employed to model dynamic *** PDE modeling methods are typically derived from established knowledge and known phenomena,which are time-consuming and ***,discovering governing PDEs from collected actual data via Physics Informed Neural Networks(PINNs)provides a more efficient way to analyze fresh dynamic systems and establish *** study proposes Sequentially Threshold Least Squares-Lasso(STLasso),a module constructed by incorporating Lasso regression into the Sequentially Threshold Least Squares(STLS)algorithm,which can complete sparse regression of PDE coefficients with the constraints of l0 *** further introduces PINN-STLasso,a physics informed neural network combined with Lasso sparse regression,able to find underlying PDEs from data with reduced data requirements and better *** addition,this research conducts experiments on canonical inverse PDE problems and compares the results to several recent *** results demonstrated that the proposed PINN-STLasso outperforms other methods,achieving lower error rates even with less data.

关键词： Physics-informed neural network inverse partial differential equation Lasso regression scientific machine learning

Mechanism Design for Ancillary Service Market Considering Social Welfare and Fairness

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1000-1010页

作者： zhi Wu Yuanxi Wu Wei Gu Zheng xu Shu Zheng Jingtao Zhao School of Electrical Engineering Southeast UniversityNanjing 210096China NARI Technology Co. Ltd.Nanjing 211106China IEEE CSEE

Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the *** the ancillary service market,distribution system operator(DSO)is responsible for safety of the DN by procuring available capacities of *** existing studies,this paper proposes a novel market mechanism composed of two parts:choice rule and payment *** proposed choice rule simultaneously considers social welfare and fairness,encouraging risk-averse aggregators to participate in the ancillary service *** is then formulated as a linear programming problem,and a distributed solution using the multi-cut Benders decomposition is ***,successful implementation of the choice rule depends on each aggregator’s truthful adoption of private ***,a payment rule is also designed,which is proved to possess two properties:incentive compatibility and individual *** results demonstrate effectiveness of the proposed choice rule on improving fairness and verify properties of the payment rule.

关键词： Aggregator ancillary service market distributed mechanism fairness mechanism design

Oxidation resistant low-alloyed Ti alloys with good ductility

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Rare Metals 2024年第8期43卷 3921-3936页

作者： Meng Li Zhang-zhi Shi Jun-Yi xu Fu-zhi Dai Xiang-Min Li Zi-Lin Li Lu-Ning Wang Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advance Metals and MaterialsSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Oxidation resistance enhancement of pure Ti often comes at the cost of reduced ductility,which is frequently the problem through alloying with sole Al,Si,W,Mo and *** overcome the short coming of single element alloying,this paper proposes a multi-element low-alloying strategy to take advantage of synergistic effects and resolve the conflict between oxidation resistance and *** demonstrates that the addition of a small quantity of Ta(0.51wt%)can boost both oxidation resistance and ductility in comparison to pure ***,the combined addition of a small amount(0.54 wt%)of Ta,Nb and Si not only preserves good ductility of pure Ti,but also reduces mass gains to 14%-67%of pure Ti during 100 h oxidation at 650-850℃in *** indicates even better oxidation resistance than that obtained through the use of Ta,Nb,or Nb+Ta *** Ta+Nb+Si alloying creates an oxide layer that is less porous and more resistant to stratification and ***,a 3-μm N-rich layer can form in the Ti substrate beneath the oxide scale,in which phase transformation generates coherent Ti_(2)N with(0001)_(Ti)as the habit plane,with N atoms prefers to diffuse along■than along[0001]_(Ti).The completely transformed Ti_(2)N region or partially transformed Ti+Ti_(2)N region can effectively impede oxygen ***,the multielement low-alloying strategy is promising for enhancing both oxidation resistance and mechanical properties of metallic materials in the future.

关键词： Ti alloys Multi-element Co-alloying Oxidation resistance Mechanical properties

Optimization Design of the Multi-Layer Cross-Sectional Layout of An Umbilical Based on the GA-GLM

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China Ocean Engineering 2024年第2期38卷 247-254页

作者： YANG zhi-xun YIN xu FAN zhi-rui YAN Jun LU Yu-cheng SU Qi MAO Yandong WANG Hua-lin Institute of marine machinery College of Mechanical and Electrical EngineeringHarbin Engineering UniversityHarbin 150001China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDepartment of Engineering MechanicsDalian University of TechnologyDalian 116024China Ningbo Institube of Dalian University of Technology Ningbo 315040China

Marine umbilical is one of the key equipment for subsea oil and gas exploitation,which is usually integrated by a great number of different functional components with *** layout of these components directly affects manufacturing,operation and storage performances of the *** the multi-layer cross-sectional layout design of the umbilical,a quantifiable multi-objective optimization model is established according to the operation and storage *** the manufacturing factors,the multi-layering strategy based on contact point identification is introduced for a great number of functional ***,the GA-GLM global optimization algorithm is proposed combining the genetic algorithm and the generalized multiplier method,and the selection operator of the genetic algorithm is improved based on the steepest descent *** algorithm is used to find the optimal solution in the global space,which can converge from any initial layout to the feasible layout *** feasible layout solution is taken as the initial value of the generalized multiplier method for fast and accurate ***,taking umbilicals with a great number of components as examples,the results show that the cross-sectional performance of the umbilical obtained by optimization algorithm is better and the solution efficiency is ***,the multi-layering strategy is effective and *** design method proposed in this paper can quickly obtain the optimal multi-layer cross-sectional layout,which replaces the manual design,and provides useful reference and guidance for the umbilical industry.

关键词： umbilical cross-sectional layout multi-layers GA-GLM optimization