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Architecture,Key Technologies and Applications of Load Dispatching in China Power Grid

Journal of Modern Power Systems and Clean Energy 2022年第2期10卷 316-327页

作者： yu dong Xin Shan Yaqin Yan Xiwu Leng Yi Wang State Grid Corporation of China Beijing 100031China NARI Group Corporation(State Grid Electric Power Research Institute) Nanjing 211000China

With the development of renewable energy and the changes in the characteristics of power grid,it is becoming increasingly difficult to balance power supply and demand in space and *** addition,the requirement for improved dispatching capability of power grid is ***,the potential of flexible load dispatching should be realized,which can promote the large-scale consumption of renewable energy and the construction of new power *** on the analysis of existing load dispatching studies and the differences in the characteristics of domestic and foreign load dispatchings,a technical architecture and several key technologies are proposed for load resources to participate in power grid dispatching under the new situation,i.e.,the autonomous collaborative control system of load *** system implements the multi-layer coordinated control of main,distribution and micro grids(load aggregators).Adjustable load resources are aggregated through an aggregator operation platform and connected with a dispatcher load regulator platform to realize real-time data interaction with dispatching agencies as well as the monitoring,con-trol,and marketing of *** supports the load resources to participate in network-wide dispatching optimization via continuous power *** key technologies such as the control mode,load modeling,dispatching strategy,and safety protection are also *** the closed-loop control of orderly charging piles and energy storage clusters in the North China Power Grid,the feasibility of the proposed architecture and key technologies is *** route has successively supported multiple adjustable load aggregators to partici-pate in the ancillary services market of North China Power Grid for ***,the technical challenges of load resources participating in power grid dispatching under the dual carbon goals are discussed and prospected.

关键词： Automatic power control(APC) load modeling load dispatching renewable energy accommodation situation awareness.

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Interaction of multicomponent disilicate(Yb_(0.2)Y_(0.2)Lu_(0.2)Sc_(0.2)Gd_(0.2))_(2)Si_(2)O_(7)with molten calcia-magnesia-aluminosilicate

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Journal of Advanced Ceramics 2022年第1期11卷 66-74页

作者： yu dong Ke REN Qiankun WANG Gang SHAO Yiguang WANG Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China Henan Province Industrial Technology Research Institute of Resources and Materials Zhengzhou UniversityZhengzhou 450001China

Environmental barrier coating(EBC)materials that are resistant against molten calcia-magnesia-aluminosilicate(CMAS)corrosion are urgently ***,multicomponent rare-earth(RE)disilicate((Yb_(0.2)Y_(0.2)Lu_(0.2)Sc_(0.2)Gd_(0.2))_(2)Si_(2)O_(7),(5RE)_(2)Si_(2)O_(7))was investigated with regard to its CMAS interaction behavior at 1400°*** with the individual RE disilicates,the(5RE)2Si2C>7 material exhibited improved resistance against CMAS *** dominant process involved in the interaction of(5RE)_(2)Si_(2)O_(7)with CMAS was reaction-recrystallization.A dense and continuous reaction layer protected the substrate from rapid corrosion at high *** results demonstrated that multicomponent strategy of RE species in disilicate can provide a new perspective in the development of promising EBC materials with improved corrosion resistance.

关键词： environmental barrier coating(EBC)materials rare-earth(RE)disilicates multicomponent ceramics calcia-magnesia-aluminosilicate(CMAS)interaction

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NUMERICAL SIMULATION OF TWO-DIMENSIONAL DAM-BREAK FLOWS IN CURVED CHANNELS

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Journal of Hydrodynamics 2007年第6期19卷 726-735页

作者： BAI yu-chuan XU dong LU dong-qiang Institute for Sediment on River and Coast 300072 China Shanghai Institute of Applied Mathematics Engineering School of Civil Engineering Tianjin University Tianjin and Mechanics Shanghai University Shanghai 200072 China

Two-dimensional transient dam-break flows in a river with bends were theoretically studied. The river was modeled as a curved channel with a constant width and a flat bottom. The water was assumed to be an incompressible and homogeneous fluid. A channel-fitted orthogonal curvilinear coordinate system was established and the corresponding two-dimensional shallow-water equations were derived for this system. The governing equations with well-posed initial and boundary conditions were numerically solved in a rectangular domain by use of the Godunov-type finite-difference scheme, which can capture the hydraulic jump of dam-break flows. The comparison between the obtained numerical results and the experimental data of Miller and Chaudry in a semicircle channel shows the validity of the present numerical scheme. The mathematical model and the numerical method were applied to the dam-break flows in channels with various curvatures. Based on the numerical results, the influence of river curvatures on the dam-break flows was analyzed in details.

关键词： dam-break flow shallow-water equations,channel bend curvilinear coordinate Godunov-type finite-difference scheme

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Effects of hydrogen sulfide on storage quality, water mobility and cell wall metabolism of strawberry fruit

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International Journal of Agricultural and Biological Engineering 2018年第6期11卷 201-207页

作者： Huanhuan Zhi Qiqi Liu yu dong College of Food and Bioengineering Zhengzhou University of Light IndustryZhengzhou 450002HenanChina Department of Horticulture Oregon State UniversityMid-Columbia Agricultural Research and Extension Center3005 Experiment Station DriveHood RiverOR 97031USA

The effects of hydrogen sulfide(H_(2)S)on storage quality,cellular water distribution,and cell wall metabolism of strawberry fruit after subjected to shelf or cold storage were *** were fumigated with a range of aqueous NaHS solution(0.4-3.2 mmol/L),then stored at 20℃ for 3 d or 0℃ for 9 d.H_(2)S-treated fruit significantly maintained higher fruit firmness(FF)and titratable acidity(TA)as well as lower decay compared to the control ***,H_(2)S inhibited the loss in extractable juice(EJ)and improved storage quality that not only resulted from the suppressing of respiration rate,but also from the modification of water mobility and cell wall *** FF and EJ in H_(2)S-treated fruit were closely associated with lower exchanges of free water between vacuole and cytoplasm/free space or cell wall,water-soluble polysaccharides(WSP),and activities of cell wall-modifying ***,a potential benefit of H_(2)S on retarding softening was that the H2S can reinforce the hydrogen bonding in polysaccharides and reduce activities of cell wall-modifying enzymes,causing a stabilization of cell wall *** approval of the use of H_(2)S on foods has not yet been granted,an alternative reducing agent gas based on H2S tended to be more effective in improving strawberry quality.

关键词： hydrogen sulfide strawberry softening water mobility cell wall metabolism

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Failure evaluation mechanism of cement sheath sealing integrity under casing eccentricity during multistage fracturing

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Petroleum Science 2024年第5期21卷 3428-3445页

作者： Yan Xi yu Yao Xue-Li Guo Jun Li yu-dong Tian Gong-Hui Liu Beijing University of Technology Beijing100124China CNPC Engineering Technology R&D Company Ltd. Beijing102200China China University of Petroleum-Beijing at Karamay Karamay834000XinjiangChina China University of Petroleum-Beijing Beijing102249China CNPC Daqing Drilling Engineering Corporation Daqing163311HeilongjiangChina

A microannulus(MA) is the primary reason for sustained casing pressure in multi-stage fractured-shale gas wells. However, the effect of the casing eccentricity on the long horizontal section has not been considered. In this study, a full-scale integrity tester for cement sheaths is adopted to measure the cumulative plastic deformation. Numerical models are applied to evaluate the development of the cumulative plastic deformation and quantify the MA width considering casing centralization and eccentricity in the context of multiple loading and unloading cycles. Subsequently, the influences of the eccentricity distance and angle, cement-sheath mechanical variables, and different well depths on the cumulative sheath plastic deformation and sheath MA development are explored. The research results demonstrate that casing eccentricity significantly increases the cumulative sheath plastic deformation compared with that of the casing-centered condition. Consequently, the risk of sealing integrity failure increases. The accumulated plastic deformation increases when the eccentricity distance increases. In contrast, the initial plastic deformation increases as the eccentricity angle increases. However, the cumulative plastic deformation decreases after a specific loading and unloading cycle count. Affected by the coupled influence of the internal casing pressure and fracturing stages, the width of the MA in the horizontal section increased from the toe to the heel, and the casing eccentricity significantly increased the MA width at each stage, thus increasing the risk of gas channeling. Finally, an engineering case is considered to study the influence of casing eccentricity. The results show that cement slurries that form low and high elastic moduli can be applied to form a cement sheath when the fracturing stage is lower or higher than a specific value, respectively. The results of this study offer theoretical references and engineering support for the integrity control of c

关键词： Cement sheath Microannulus Casing eccentricity Numerical simulation

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Real-time transient stability assessment in power system based on improved SVM

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Journal of Modern Power Systems and Clean Energy 2019年第1期7卷 26-37页

作者： Wei HU Zongxiang LU Shuang WU Weiling ZHANG yu dong Rui yu Baisi LIU State Key Laboratory of Power system Department of Electrical Engineering Tsinghua University State Grid Hunan Electric Power Company Limited Southwest Branch State Grid Corporation of China

Due to the strict requirements of extremely high accuracy and fast computational speed, real-time transient stability assessment(TSA) has always been a tough problem in power system ***, the development of artificial intelligence and big data technologies provide the new prospective methods to this issue, and there have been some successful trials on using intelligent method, such as support vector machine(SVM) ***, the traditional SVM method cannot avoid false classification, and the interpretability of the results needs to be strengthened and *** paper proposes a new strategy to solve the shortcomings of traditional SVM,which can improve the interpretability of results, and avoid the problem of false alarms and missed *** this strategy, two improved SVMs, which are called aggressive support vector machine(ASVM) and conservative support vector machine(CSVM), are proposed to improve the accuracy of the *** two improved SVMs can ensure the stability or instability of the power system in most *** the small amount of cases with undetermined stability, a new concept of grey region(GR) is built to measure the uncertainty of the results, and GR can assessment the instable probability of the power *** studies on IEEE 39-bus system and realistic provincial power grid illustrate the effectiveness and practicability of the proposed strategy.

关键词： Power system Transient stability assessment(TSA) Intelligent method Support vector machine Grey region

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A Survey of Convolutional Neural Network in Breast Cancer

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 2127-2172页

作者： Ziquan Zhu Shui-Hua Wang yu-dong Zhang School of Computing and Mathematical Sciences University of LeicesterLeicesterLE17RHUK

Problems:For people all over the world,cancer is one of the most feared *** is one of the major obstacles to improving life expectancy in countries around the world and one of the biggest causes of death before the age of 70 in 112 *** all kinds of cancers,breast cancer is the most common cancer for *** data showed that female breast cancer had become one of themost common ***:A large number of clinical trials have proved that if breast cancer is diagnosed at an early stage,it could give patients more treatment options and improve the treatment effect and survival *** on this situation,there are many diagnostic methods for breast cancer,such as computer-aided diagnosis(CAD).Methods:We complete a comprehensive review of the diagnosis of breast cancer based on the convolutional neural network(CNN)after reviewing a sea of recent ***,we introduce several different imaging *** structure of CNN is given in the second *** that,we introduce some public breast cancer data ***,we divide the diagnosis of breast cancer into three different tasks:***;***;***:Although this diagnosis with CNN has achieved great success,there are still some limitations.(i)There are too few good data sets.A good public breast cancer dataset needs to involve many aspects,such as professional medical knowledge,privacy issues,financial issues,dataset size,and so on.(ii)When the data set is too large,the CNN-based model needs a sea of computation and time to complete the diagnosis.(iii)It is easy to cause overfitting when using small data sets.

关键词： Breast cancer convolutional neural network deep learning review image modalities

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Effects of Nitric Oxide on the Quality and Pectin Metabolism of Yali Pears During Cold Storage

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Agricultural Sciences in China 2011年第7期10卷 1125-1133页

作者： LIU Li-qin dong yu GUAN Jun-feng College of Life Science Hebei Normal University Shijiazhuang 050016 P.R.China Institute of Genetics and Physiology Hebei Academy of Agricultural and Forestry Sciences Shijiazhuang 050051 P.R.China

The effect of fumigation with 10, 20, and 30 μL L-1 nitric oxide （NO） was investigated to study the effects of NO on the quality of Yali pears during cold storage. The ethylene production, composition of cell walls, and cell-wall-modifying enzyme activities were measured on fruits which were fumigated with NO （20 μL L-1）. The results showed that NO not only reduced the peak value of ethylene production rate, the soluble sugar, soluble solid content, maintained higher firmness, starch, and NO content, but also retarded the degradation of covalent soluble pectin, accumulation of ionic soluble pectin and water soluble pectin. Moreover, NO fumigation decreased the activities of polygalacturonase （PG） and b-galactosidase（b-Gal） and delayed the peak of PG activity of fruits. Therefore, it indicated that NO fumigation could delay the softening and ripening of Yali pears.

关键词： pear nitric oxide cell wall material fruit softening

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Effects of 1-Methylcyclopropene on NO Content,NOS Activity,and H_2O_2 Content in Postharvest Suli Pears

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Agricultural Sciences in China 2011年第5期10卷 797-804页

作者： dong yu LIU Li-qin GUAN Jun-feng Institute of Genetics and Physiology Hebei Academy of Agricultural and Forestry Sciences Shijiazhuang 050051 P.R.China College of Life Science Hebei Normal University Shijiazhuang 050016 P.R.China

Studies were conducted over the effects of 1-methylcycolpropene （1-MCP） treatment on postharvest life of Suli pears （Pyrus bretschneideri Rehd.） stored at room and cold temperatures on nitric oxide （NO）,nitric oxide synthase （NOS） activity,and hydrogen dioxide （H2O2）.Results showed that the 1-MCP treatment had little effect on total soluble solids （TSS） at both room and cold temperatures.1-MCP delayed softening of Suli pear fruits,decreased respiratory rate and H2O2 accumulation,and increased NO and NOS activity at room temperature storage,while the effect of cold temperature storage was relatively *** was a significant positive correlation between NOS activity and NO *** is concluded that 1-MCP had effects on endogenous NO content and accumulation of ***,H2O2 acting as a signaling molecule via regulating NO level affects the ripening and senescence of Suli pears.

关键词： pear 1-MCP NO NOS H2O2

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Nonexistence and Longtime Behaviors of Solutions to a Class of Nonlinear Degenerate Parabolic Equations Not in Divergence Form

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Acta Mathematicae Applicatae Sinica 2016年第2期32卷 327-332页

作者： yu-dong SUN Yi-min SHI MIN WU School of Science Guizhou Minzu University Department of Applied Mathematics Northwestern Polytechnical University

In this paper, we study the nonexistence and longtime behavior of weak solution for the degenerate parabolic equation σtun=umdiv（｜▽um｜p-2▽um）＋γ｜▽um｜p＋βun with zero boundary condition. Blow-up time is der... 详细信息

关键词： nonexistence nonlinear degenerate parabolic equations weak solution blow-up

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