检索结果-内蒙古大学图书馆

SSRN 2023年

作者： Wang, Wei Luo, Zhen Liu, Xia Dai, Yanhui Hu, Guoqing Zhao, Jian Yue, Tongtao Institute of Coastal Environmental Pollution Control Key Laboratory of Marine Environment and Ecology Ministry of Education Ocean University of China Qingdao266100 China Department of Engineering Mechanics State of Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou310027 China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology Qingdao266237 China

Inhaled nanoparticles (NPs) can deposit in alveoli where they interact with the pulmonary surfactant (PS), potentially inducing toxicity. Although nano-bio interactions are influenced by the physicochemical properties of NPs, isolated NPs used in previous studies cannot accurately represent those found in atmosphere. Here we used molecular dynamics simulations to investigate the interplay between two types of NPs associated with benzo[a]pyrene (BaP) at the PS film. Silicon NPs (SiNPs), regardless of aggregation and adsorption, directly penetrated through the PS film with minimal disturbance. Meanwhile, BaPs adsorbed on SiNPs were rapidly solubilized by PS, increasing the BaP’s bioaccessibility in alveoli. Carbon NPs (CNPs) showed aggregation and adsorption-dependent effects on the PS film. Compared to isolated CNPs, which extracted PS to form biomolecular coronas, aggregated CNPs caused more pronounced PS disruption, especially around irregularly shaped edges. SiNPs in mixture exacerbated the CNP-induced PS perturbation by piercing PS film around the site of CNP interactions. BaPs adsorbed on CNPs were less solubilized and suppressed PS extraction, but aggravated biophysical inhibition and prompted film collapse under compression. These results suggest that for proper assessment of inhalation toxicity of airborne NPs, it is imperative to consider their heterogeneous aggregation and adsorption of pollutants under atmospheric conditions. © 2023, The Authors. All rights reserved.

关键词： Adsorption

来源：评论

学校读者我要写书评

暂无评论

Fast control Strategy of Grid-forming Inverter Based on power Feedforward

Fast Control Strategy of Grid-forming Inverter Based on Powe...

引用

Chinese control Conference (CCC)

作者： Sheng Zhang Zhijian Fang Qine Liu Muchao Xiang Dingbang Huang School of Automation China University of Geosciences Wuhan China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan China Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education Wuhan China State Grid Hubei Electric Power Co. Ltd Xiangyang Power Supply Company Xiangyang China Electric Power Scientific Research Institute of State Grid Hubei Electric Power Co. Ltd Wuhan China

Grid-forming inverter is widely used in grid-connected systems of distributed generation because of its frequency and voltage support capacity and good stability in microgrid, but its large inertia will affect the dynamic response speed of grid-forming inverter. In order to solve this problem, this paper introduces the loop that affects the dynamic response of grid-forming inverter, and carries out small signal modeling for active loop, analyzes the dynamic performance indicators and determinants of typical second-order system. Thus, a method of adding power feedforward coefficient to the forward channel of the power loop is designed, and the response speed of the system with or without feedforward coefficient under the unit step response is compared. Finally, the simulation results show that adding the power feedforward coefficient can improve the response speed of the grid-forming inverter during startup and power switching, then achieves the effect of fast control.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Optimal Allocation Research of Distribution Network with DGs and SCs by Improved Sand Cat Swarm Optimization Algorithm

IAENG International Journal of Computer Science

引用

IAENG International Journal of Computer Science 2023年第2期50卷 646页

作者： Long, Hongyu He, Yuqiang Xu, Yuansen You, Chun Zeng, Diyang Lu, Hu Chongqing Key Laboratory of Complex Systems and Bionic Control Chongqing University of Posts and Telecommunications Chongqing400065 China Economic and Technology Research Institute of State Grid Chongqing Electric Power Company Chongqing401120 China School of Electric Power Engineering Nanjing Institute of Technology Nanjing211167 China Chongqing Jiangbeizui Water Air Conditioning Co. Ltd Chongqing211167 China

The contemporary paradigm for developing novel distribution grids is centered on the integration of distributed generations (DGs) and shunt capacitors (SCs) within the distribution infrastructure. Unreasonable DG and SC configurations may have a negative impact on grid line loss and voltage quality. The goal of optimal allocation research of distribution network (OARDN) is to allocate distributed generators (DGs) and shunt capacitors (SCs) in the distribution network in a rational manner to minimize power losses, enhance voltage quality, and ensure secure and stable power supply to the loads. Aiming at the critical OARDN problems, such as minimizing power loss and improving voltage quality, this paper proposes an improved sand cat swarm optimization algorithm (ISCSO). To address the issue of the original SCSO being prone to local optima and low search accuracy, this method introduces a tent map-based chaotic strategy and reverse learning approach to augment the precision of the optimization, and proposes a cross-learning mechanism to expand the global search ability, and this method is used to solve the single-objective problem. Based on ISCSO, the sensitivity analysis method and pareto non-inferior sorting method are introduced, which is extended to the MOISCSO algorithm to solve multi-objective OARDN problem. © 2023, IAENG International Journal of Computer Science. All Rights Reserved.

关键词： Sensitivity analysis

来源：评论

学校读者我要写书评

暂无评论

Sensitivity analysis for AC/DC hybrid power systems

引用

Dianli Xitong Zidonghua/Automation of Electric power systems 2007年第12期31卷 45-49页

作者： Liu, Chongru Zhang, Boming Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control North China Electric Power University Beijing 102206 China State Key Lab. of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China

The interactions between AC and DC systems in the steady-state condition of power systems are investigated. Through a sensitivity analysis, the influence of DC control parameters on the operation of AC/DC systems and that of AC control parameters on other AC parameters with the DC system existing are discussed. The sensitivity matrices and the influence factors between AC and DC systems are analyzed from various points of view. The sensitivity analysis made in this paper is expected to be of practical significance in such problems as load flow control, parameter regulation, voltage estimation, etc.

关键词： Electric power transmission networks

来源：评论

学校读者我要写书评

暂无评论

Wind turbine failure detection based on SCADA data and data mining method

Wind turbine failure detection based on SCADA data and data ...

引用

8th Renewable power Generation Conference (RPG 2019)

作者： SiYu Tao Zheng Qian Yan Pei AnQi Wang FangHong Zhang School of Instrumentation and Optoelectronic Engineering Beihang University Beijing China State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems China Electric Power Research Institute Haidian Dist. Beijing China CSIC HaiZhuang Windpower Co. Ltd Chongqing China

ISBN: (数字)9781839531248

ISBN: (纸本)9781839531255

WTFD (Wind Turbine Failure Detection) system is important for improving wind turbine reliability and reducing operation & maintenance cost. A WTFD method using only SCADA data and data mining algorithm is proposed. Firstly, select representative variables from a wide variety of SCADA variables using ARD (Automatic Relevance Determination) method. Then, the denoising autoencoders (DAE) model using the selected variables with sliding window is developed to capture nonlinear correlations among multiple variables and autocorrelation of each variable. Finally, using the Mahalanobs distance (MD) of reconstruction error to make the WTFD. Real world dataset is used to validate the efficiency of the proposed method. The results show that the proposed method can provide advanced failure alarm for wind turbines many hours before failure happens. The results of our proposed WTFD method can reduce operation & maintenance cost and improve wind turbine reliability.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Regional Frequency Dynamics Modeling of power systems Incorporating Frequency Support from HVDC Links and Renewable Energy Sources

Regional Frequency Dynamics Modeling of Power Systems Incorp...

引用

IEEE General Meeting power& Energy Society

作者： Jianguo Zhou Ye Guo Zichao Meng Lun Yang Hongbin Sun Tsinghua-Berkeley Shenzhen Institute Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen China School of Automation Science and Engineering Xi’an Jiaotong University Xi’an China State Key Laboratory of Power Systems Operation and Control (Tsinghua University) Tsinghua University Beijing China

ISBN: (数字)9798350381832

ISBN: (纸本)9798350381849

The increasing penetration of Renewable Energy Sources (RESs) and High Voltage Direct Current (HVDC) challenges the system frequency stability and the frequency shows distinct spatial-temporal characteristics. A Physical-Informed Neural Network (PINN)-based Regional Frequency Security Metrics (RFSM) is proposed for power systems with frequency support from HVDC and RESs. First, the RFSM models are modeled based on the physical principle. Then, neural networks are used to determine the parameters informed with the developed physical models. The proposed model can be utilized to establish frequency constraints implemented in the scheduling model. This type of constraints can be easily integrated into the optimization model due to its linearity. Moreover, the proposed model enables the system operators to find the optimal location and frequency response to be procured to guarantee the frequency stability in every region of the power system, and make pricing schemes for the corresponding ancillary services. The case study shows that the model has better physical interpretation and higher accuracy.

关键词： Measurement Renewable energy sources HVAC HVDC transmission Optimization models power system dynamics Pricing power system stability Stability analysis Frequency control

来源：评论

学校读者我要写书评

暂无评论

Improved NSGA-Ⅲ Algorithm and BP Fuel-cost Prediction Network for Many-objective Optimal power Flow Problems

引用

IAENG International Journal of Applied Mathematics 2021年第2期51卷 1页

作者： Qian, Jie Long, Hongyu Long, Yi Zhao, Chenxu School of Computer Science and Technology Chongqing University of Posts and Telecommunications Chongqing400065 China Key Laboratory of Complex Systems and Bionic Control Chongqing University of Posts and Telecommunications Chongqing400065 China State Grid Chongqing Electric Power Company Marketing Service Center Chongqing401123 China Co. Ltd Inner Mongolia Power Economy and Technology Research Institute Hohhot010010 China

To effectively handle the many-objective optimal power flow (MOOPF) problems considering the simultaneous reduction of power loss, emission and fuel cost, an improved NSGA-Ⅲ (INSGA-Ⅲ) algorithm is put forward in this paper. In detail, the proposed INSGA-Ⅲ algorithm adopts the competitive solutions preliminarily optimized by traditional NSGA-Ⅲ method as the initial population and integrates the novel adaptive dominant (NAD) strategy. Comparing with the original NSGA-Ⅲ algorithm, INSGA-Ⅲ obtains the more preferable Pareto front (PF) with uniform distribution. More significantly, an entirely new BP fuel-cost prediction network is proposed to explore the potential elite power flow (EPL) solutions. These EPL solutions determined around the best compromise solution (BCS) of INSGA-Ⅲ algorithm provide decision-makers with more and better scheduling schemes. The effectiveness and superiorities of proposed INSGA-Ⅲ algorithm and BP fuel-cost prediction model are verified by both dual-objective and triple-objective MOOPF simulation experiments. In general, this paper presents an innovative way to solve the complex engineering problems by computer technologies represented by intelligent algorithms and neural networks. © 2021. All Rights Reserved.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

Chlorine Degradation of Semi-Aromatic Polypiperazine-Amide Membranes and the Mechanisms

SSRN

引用

SSRN 2023年

作者： Li, Meng-Fei Yang, Shao-Xia Fu, Wen-Jie Wang, Xiao-Mao Liu, Shu-Ming Huang, Xia Li, Jun State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China School of Water Conservancy and Hydropower Engineering North China Electric Power University Beijing102206 China College of Environment and Resources Guangxi Normal University Guangxi Guilin541004 China Department of Chemistry Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Tsinghua University Beijing100084 China

Semi-aromatic polypiperazine-amide (PPA) nanofiltration (NF) membranes are widely used in water treatment applications, but the resistance to free chlorine and other biocidal agents need to be improved. Understanding the chlorination mechanisms of PPA NF membranes is of great significance for avoiding membrane degradation and developing new chlorine-resistant membranes. In this paper, the effects of chlorination on the rejection selectivity as well as the surface charge, hydrophilicity and roughness, and pore size distribution of PPA NF membranes are presented. In addition, the chlorination mechanisms of the membranes are proposed through functional groups characterization of the stripped PPA active layer, element composition analysis, quantum mechanical calculations based on density-functional theory, and use of model compound ((3,5-dimethylphenyl)(4-methylpiperazin-1-yl)methanone) for PPA material. The molecular active chlorine species, HOCl, predominantly induces the cleavage of C-N bonds, whereas the primary reaction pathway caused by the ionic active chlorine species, ClO-, involves the ring-opening of benzene. Under the same chlorination conditions, HClO has a more severe impact on membrane properties and performance than ClO-. NF membranes with a looser polyamide layer are more susceptible to the attack by active chlorine species. © 2023, The Authors. All rights reserved.

关键词： Chlorination

来源：评论

学校读者我要写书评

暂无评论

Low-Order Frequency Response Modeling for Offshore Wind Farm-MTDC systems

Low-Order Frequency Response Modeling for Offshore Wind Farm...

引用

IEEE Conference on Energy Internet and Energy System Integration (EI2)

作者： Jianguo Zhou Ye Guo Zichao Meng Lun Yang Hongbin Sun Tsinghua-Berkeley Shenzhen Institute Tsinghua Shenzhen International Graduate School Tsinghua University Shenzhen China School of Automation Science and Engineering Xi'an Jiaotong University Xi'an China State Key Laboratory of Power Systems Operation and Control (Tsinghua University) Tsinghua University Beijing China

The increasing penetration of Renewable Energy Sources (RES) and (Multi-Terminal) High Voltage Direct Current (HVDC) is challenging the system frequency stability. The RES such as Wind Turbine Generators (WTGs) are being required to automatically provide frequency regulation support for the main grid. A Low-Order Frequency Response Model (LOFRM) is proposed for the complete Wind Farm (WF)-MTDC system in this paper. First, a high-order model that can be regarded as the virtual governor turbine is developed for the WF-MTDC system whose structure is similar to that of conventional generators. An LOFRM is then proposed to surrogate approximately the high-order model, whose parameters are determined by using a regression-based numerical method. The results show that the proposed LOFRM can properly approximate the complicated high-order model, and be acceptable if used for stability analysis and even maybe optimization problems.

关键词：

来源：评论

学校读者我要写书评

暂无评论

An Active and Adaptive Image Enhancement Method for Applications in Low-Light and Narrow Environment

An Active and Adaptive Image Enhancement Method for Applicat...

引用

Chinese Automation Congress (CAC)

作者： Mingrui Luo En Li Rui Guo Shengchuan Li Cunfeng Kang The State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China School of Artificial Intelligence University of Chinese Academy of Sciences Beijing China State Grid Shandong Electric Power Company Jinan China State Grid Liaoning Electric Power Company Limited Shenyang China Mechanical engineering and Applied Electronic Technology Beijing University of Technology Beijing China

ISBN: (数字)9781728176871

ISBN: (纸本)9781728176888

The images in the low-light and narrow environment generally have the problems of non-uniform illumination, low contrast, and large random noise. Existing algorithms are mostly subject to the imaging effect of the original image, and are prone to failure in extremely weak light or strong reflective environments. This paper proposes an active and adaptive image enhancement method. First of all, this paper combines the distributed light source model and the difference in brightness between frames to complete active feedback fill light, which improves the quality of the input image. Then gamma correction, contrast limited adaptive histogram equalization and bilateral filter are designed to enhance image details and suppress noise amplification. Combined with fuzzy inference parameter self-adjustment method, algorithm adaptability is improved. Finally, through experimental verification, the method proposed in this paper can effectively enhance the images in the low-light and narrow environment.

关键词： Light sources Histograms Adaptive equalizers Filtering algorithms Brightness Image color analysis Image enhancement

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：