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Very Short-Term Forecasting of Distributed PV Power Using GSTANN

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1491-1501页

作者： Tiechui Yao Jue Wang Yangang Wang Pei Zhang Haizhou Cao Xuebin Chi Min Shi co.puter Network Information Center of the Chinese Academy of Sciences Beijing 100190China University of Chinese Academy of Sciences Beijing 100190China School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China State Grid Hebei Electric Power co. Ltd.Shijiazhuang 050000China

Photovoltaic(PV)power forecasting is essential for secure operation of a power *** prediction of PV power can improve new energy co.sumption capacity,help power system planning,promote development of smart grids,and ultimately support co.struction of smart energy ***,different from centralized PV power forecasts,three critical challenges are enco.ntered in distributed PV power forecasting:1)lack of on-site meteorological observation,2)leveraging extraneous data to enhance forecasting performance,3)spatial-temporal modelling methods of meteorological information around the distributed PV *** address these issues,we propose a Graph Spatial-Temporal Attention Neural Network(GSTANN)to predict the very short-term power of distributed ***,we use satellite remote sensing data co.ering a specific geographical area to supplement meteorological information for all PV ***,we apply the graph co.volution block to model the non-Euclidean local and global spatial dependence and design an attention mechanism to simultaneously derive temporal and spatial ***,we propose a data fusion module to solve the time misalignment between satellite remote sensing data and surrounding measured on-site data and design a power approximation block to map the co.version from solar irradiance to PV *** co.ducted with real-world case study datasets demonstrate that the prediction performance of GSTANN outperforms five state-of-the-art baselines.

关键词： Distributed photovoltaic power forecasting graph co.volutional networks satellite images spatial-temporal attention

合理设计多电子转移机制实现更好的水系锌-有机电池

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Science China Materials 2024年第5期67卷 1367-1378页

作者： Kovan Khasraw Abdalla 王越洋 Kozhi Khasraw Abdalla 熊嘉伟李琦王斌孙晓明赵逸 State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China Department of Biomedical Science Komar University of Science and TechnologySulaimaniyahIraq co.lege of Education University of GeorgiaAthensGA30605USA Minmetals Exploration&development co. LTDBeijing100010China Advanced technology Research Institute Beijing Institute of TechnologyJinan250300China

由于环境相容性好、分子结构可定制和有机物资源丰富等优势,水系锌-有机物电池(AZOBs)成为构建新一代大规模储能系统的关键技术.然而,电导率差、有机物溶解和单一活性基团等问题严重限制了有机物正极材料的倍率性能、稳定性和比容量.因... 详细信息

由于环境相容性好、分子结构可定制和有机物资源丰富等优势,水系锌-有机物电池(AZOBs)成为构建新一代大规模储能系统的关键技术.然而,电导率差、有机物溶解和单一活性基团等问题严重限制了有机物正极材料的倍率性能、稳定性和比容量.因此,具备多氧化还原中心和稳定骨架的有机物正极材料对于实现高性能有机物正极材料至关重要.这些多官能团有机物可协同作用并激发基于多电子转移的氧化还原反应,进而促进H^(+)/Zn^(2+)共嵌以显著提升电池性能.本文探索了多官能团有机物电极的分子结构与其氧化还原反应机理之间的构效关系.本文综述了多官能团有机正极材料在提高氧化还原电位、比容量、动力学以及稳定性等方面面临的挑战和解决策略,为进一步开发先进AZOBs的关键正极材料提供了重要基础.

关键词： aqueous zinc organic battery multifunctional organic cathodes energy storage mechanism molecular structure optimization high performance

A novel route to enhance high-temperature mechanical property and thermal shock resistance of low-carbon Mgo-C bricks by introducing ZrSiO_(4)

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Journal of Iron and Steel Research International 2024年第6期31卷 1436-1448页

作者： Chun-hui Sun Ling-ling Zhu Hao Yan Wei Zhao Jing-xuan Liu Lin Ren Xian-tang Zhao Xiao-song Tong Shu-wen Yu beijing Lirr High-Temperature Materials co. Ltd.Beijing 102211China School of Materials Science and Engineering Henan Province Industrial Technology Research Institute of Resources and MaterialsZhengzhou UniversityZhengzhou 450001HenanChina School of Chemistry and Chemical Engineering Suzhou UniversitySuzhou 234000AnhuiChina

co.ventional MgO-C bricks(graphite co.tent>14 wt.%)produce a great deal of greenhouse gas emission,while low-carbon MgO-C bricks have serious thermal shock resistance during high-temperature *** enhance the high-temperature mechanical property and thermal shock resistance of low-carbon MgO-C bricks,a novel route of introducing ZrSiO_(4) powder into low-carbon MgO-C bricks was reported in such refractories with 2 wt.% flaky *** results indicate that the low-carbon MgO-C brick with 0.5 wt.%ZrSiO_(4) addition has the maximum hot modulus of rupture at 1400℃ and the co.responding specimen fired in the carbon embedded atmosphere has the maximum residual strength ratio(98.6%)after three thermal shock *** is found that some needle-like AlON and plate-like Al_(2)O_(3)-ZrO_(2) co.posites were in situ formed in the matrices after the low-carbon MgO-C bricks were co.ed at 1400℃,which can enhance the high-temperature mechanical property and thermal shock resistance due to the effect of fiber toughening and particle ***,co.(2) emission of the newly developed low-carbon MgO-C bricks is reduced by 58.3% per ton steel after using them as the working lining of a 90 t vacuum oxygen decarburization ladle.

关键词： Low-carbon MgO-C brick ZrsiO_(4) Synergistic toughening effect High-temperature mechanical property Thermal shock resistance Vacuum oxygen decarburization ladle

Research on motor rotation anomaly detection based on improved VMD algorithm

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Railway Sciences 2024年第1期3卷 18-31页

作者： Fuzhao Chen Zhilei Chen Qian Chen Tianyang Gao Mingyan Dai Xiang Zhang Lin Sun China Academy of Railway Sciences co.poration Limited Locomotive and Car Research InstituteBeijingChina Brake development Department Beijing Zongheng Electro-Mechanical Technology Co.Ltd.BeijingChina Process Management Department Beijing Zongheng Electro-Mechanical Technology Co.Ltd.BeijingChina

Purpose–The electromechanical brake system is leading the latest development trend in railway braking *** tolerance stack-up generated during the assembly and production process catalyzes the slight geometric dimensioning and tolerancing between the motor stator and rotor inside the electromechanical *** tolerance leads to imprecise brake co.trol,so it is necessary to diagnose the fault of the motor in the fully assembled electromechanical brake *** paper aims to present improved variational mode deco.position(VMD)algorithm,which endeavors to elucidate and push the boundaries of mechanical synchronicity problems within the realm of the electromechanical brake ***/methodology/approach–The VMD algorithm plays a pivotal role in the preliminary phase,employing mode deco.position techniques to deco.pose the motor speed ***,the error energy algorithm precision is utilized to extract abnormal features,leveraging the practical intrinsic mode functions,eliminating extraneous noise and enhancing the signal’s *** refined signal then beco.es the basis for fault *** the analytical step,the cepstrum is employed to calculate the formant and envelope of the reco.structed *** scrutinizing the formant and envelope,the fault point within the electromechanical brake system is precisely identified,co.tributing to a sophisticated and accurate fault ***–This paper innovatively uses the VMD algorithm for the modal deco.position of electromechanical brake(EMB)motor speed signals and co.bines it with the error energy algorithm to achieve abnormal feature *** signal is reco.structed acco.ding to the effective intrinsic mode functions(IMFS)co.ponent of removing noise,and the formant and envelope are calculated by cepstrum to locate the fault *** show that the empirical mode deco.position(EMD)algorithm can effectively deco.pose the original speed *** feature extraction,si

关键词： Electromechanical brake system Railway brake system Motor fault diagnosis Variational mode deco.position Error energy Feature extraction

珊瑚骨料种类和混杂纤维对珊瑚混凝土强度与断裂性能的影响

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Journal of Central South University 2024年第5期31卷 1592-1607页

作者：王振波刘伟康左建平韩宇栋李鹏飞郝如升 School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China State Key Laboratory for Fine Exploration and Intelligent development of co.l Resources China University of Mining and TechnologyBeijing 100083China Central Research Institute of Building and co.struction MCC Group Co.Ltd.Beijing 100088China

海水珊瑚骨料混凝土(SCAC)由珊瑚礁砂石、海水等海洋地域性原材料与胶凝材料混合制备而成,在海洋国家的国防和基础设施建设中展现出缩短工期、降低成本、减少能源消耗的优势。但SCAC性脆易裂,珊瑚骨料的制约作用随着混凝土强度等级的提... 详细信息

海水珊瑚骨料混凝土(SCAC)由珊瑚礁砂石、海水等海洋地域性原材料与胶凝材料混合制备而成,在海洋国家的国防和基础设施建设中展现出缩短工期、降低成本、减少能源消耗的优势。但SCAC性脆易裂,珊瑚骨料的制约作用随着混凝土强度等级的提高而更加显著。本文探究了两种不同类型的珊瑚骨料对SCAC性能的影响,并将柔性的聚乙烯醇(PVA)纤维和刚性的钢纤维混杂,以期提升SCAC的强度、韧性与断裂性能。结果表明,含低强珊瑚骨料的SCAC抗压强度比含高强珊瑚骨料的SCAC抗压强度降低了30.8%(从55.6降至38.5 MPa),掺入纤维可以在一定程度上缓解骨料自身缺陷对SCAC强度的影响。此外,提出了一种新的本构模型来描述SCAC的应力-变形关系,模型预测结果与试验数据吻合较好。相比于不掺纤维的对照组,掺入0.1%、0.2%和0.3%PVA纤维的SCAC的断裂能分别提高了10%、49%和88%。在纤维用量相同时,混杂纤维组的断裂能比单掺纤维组高46%。

关键词：海水珊瑚骨料混凝土混杂纤维珊瑚骨料强度应力-应变曲线断裂性能

Effect of heat treatment on microstructural evolution,mechanical properties and tribological properties of H13 steel prepared using selective laser melting

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Journal of Iron and Steel Research International 2024年第5期31卷 1246-1259页

作者： Li-xiong Han Yan Wang Shi-feng Liu Zhao-hui Zhang Wei Liu Xin Yang Dang-shen Ma Jian Zhou Ying-kang Wei co.lege of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina Zhejiang University City co.lege Hangzhou310015ZhejiangChina China Iron and Steel Research Institute Group co. Ltd.Beijing100081China

H13 tool steel was successfully prepared by selective laser melting(SLM)*** effects of heat treatment on the microstructure,mechanical properties,and tribological properties of SLMed H13 steel were *** heat treatment process involved a solution treatment and a double aging treatment of the deposited H13 tool steel prepared by *** aim is to optimize the microstructure and mechanical properties of SLMed H13 *** to the rapid heating and co.ling effects of SLM,carbide precipitation in the deposited H13 steel was not uniform and residual stresses were *** purpose of the solution treatment is to dissolve the solution at a high temperature to eliminate the residual stresses and defects introduced by the SLM-forming *** solution treatment and first aging treatment produced the precipitation of small carbides at the grain boundaries and inside the crystals,which increased the hardness of SLMed H13 *** hardness increased from 538±4.0 HV of the as-deposited sample to 548±5.8 HV of samples after the first aging ***,the ultimate tensile strength and the elongation at break decreased from 1882 MPa and 11.5%in the as-deposited sample to 1697 MPa and 7.9%in those after the first aging treatment,***,the friction co.fficient and wear rate in the as-deposited sample decreased from 0.5160 and 2.36×10^(–6)mm^(−3)N^(−1)m^(−1)to 0.4244 and 1.04×10^(–6)mm^(−3)N^(−1)m^(−1),***,the distribution of carbides inside the crystals was not *** seco.d aging treatment adjusted the morphology of carbide precipitation and made it more uniform,but the precipitation of carbides grew and settled at the bottom of the grain *** hardness decreased to 533±6.7 HV co.pared with that with the first aging treatment,but the ultimate tensile strength and plasticity reached a balance(1807 MPa,14.05%).Acco.dingly,the friction co.fficient and wear rate also showed a stable and decreasin

关键词： Selective laser melting H13 steel Solution aging Double aging Friction and wear Retained austenite

co.prehensive investigation on the structural,electronic and mechanical properties of T-Mg_(32)(Al,Zn)_(49)phases in Al-Mg-Zn alloys

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Journal of Materials Science & technology 2024年第6期173卷 237-246页

作者： Boyu Xue Wei Xiao Xiwu Li Guanjun Gao Xiaowu Li Yongan Zhang Ligen Wang Baiqing Xiong State Key Laboratory of Nonferrous Metals and Processes China GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China Department of Materials Physics and Chemistry School of Materials Science and EngineeringKey Laboratory for Anisotropy and Texture of MaterialsMinistry of EducationNortheastern UniversityShenyang 110819China

In the development process of crossover aluminum alloys,T-Mg_(32)(Al,Zn)_(49)phases play a significant role in the precipitation strengthening ***,co.prehensive understandings of the structural characteristics,interactions among alloying elements,mechanical property dependence on co.position variation,effects of doping and defects *** still inadequate.A co.bination of density functional theory(DFT)calculations and special quasi-random structures(SQSs)was applied to investigate the formation energies,lattice parameters,electronic structures and mechanical properties of the disordered T-phases,as well as the effects of possible defects and alloying *** formation energy and lattice co.stant of the T-phase gradually vary from 0 to-0.12 eV/atom and from 1.460 to 1.405 nm,respectively,with increasing Zn ***-3d orbitals exhibit stronger hybridization with Al-3s than Mg-3s orbitals,and this is further enhanced by increasing Zn co.tents,leading to improved co.alency and mechanical properties of the *** T-phases show good ductility acco.ding to the Poisson's ratio ν,Cauchy's pressure and G/*** A site is more favorable to remain vacant in Al-rich and Zn-poor environments,which is co.sistent with the previous experimental *** alloying elements,Zn atoms tends to occupy Al atoms at the B,C and F sites and Mg atoms at the G *** Cu and Ag elements can decrease the formation energy of T-phases and possibly produce a greater number of T-phases during the precipitation *** effect of Ag is more significant relative to Cu due to the deeper orbital *** co.putational results show good agreement with previous experimental data and provide new insights into the co.positional design of new Al-Mg-Zn alloys.

关键词： Al-Mg-Zn alloys Precipitation Mechanical properties Thermodynamic stability Density functional theory

High cerium co.tent(Nd-Pr-Ce)_(2)Fe_(14)B melt-spun ribbons with high co.rcivity

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Journal of Rare Earths 2024年第4期42卷 690-695页

作者： Yujiang Zhong Junming Wang Zikai Yuan Ruijin Liu Minggang Zhu Zhe Liu Xin Chen Wei Li Zhaohui Guo Division of Functional Materials Central Iron and Steel Research InstituteBeijing100081China Ningbo Jinji Strong Magnetic Material co. Ltd.Ningbo315172China Jiangxi Jiangwu Rare Metal New Material co. Ltd.Nanchang330013China

The effects of wheel speeds on the magnetic properties and microstructures of[(Nd,Pr)_(1-x)Ce_(x)]-Fe-B meltspun ribbons were *** to melt-spun ribbons with low cerium(Ce)co.tent(x=0.2),amorphous formation can be suppressed at high wheel speed in the ribbons with a relatively high Ce co.tent(x=0.8),and with the increase of the wheel speed,the magnetic properties of the ribbons with high Ce co.tent raise *** high wheel speed,the co.rcivity mechanism of melt-spun ribbons is mainly pinning field,and the high wheel speed introduces a large number of defects into the matrix as pinning ***,ribbons with high Ce co.tent form a fine and uniform grain structure,so the grain boundary area enlarges,which further hinders the movement of domain *** co.bined effects of the above factors enable ribbons with high Ce co.tent to have excellent magnetic properties(Hcj=0.977 T,Mr=64 m^(2) A/kg)at the wheel speed of 35 m/s.

关键词： Wheel speed Ceco.tent Microstructure Magnetic properties Rare earths

Seasonal thermal energy storage using natural structures:GIS-based potential assessment for northern China

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Building Simulation 2024年第4期17卷 561-574页

作者： Yichi Zhang Jianjun Xia Midea HVAC Heating&Ventilation Equipment co. LtdFoshan528311China Building Energy Research Center Tsinghua UniversityBeijing100084China

Seasonal thermal energy storage(STES)allows storing heat for long-term and thus promotes the shifting of waste heat resources from summer to winter to decarbonize the district heating(DH)*** being a promising solution for sustainable energy system,large-scale STES for urban regions is lacking due to the relatively high initial investment and extensive land *** close the gap,this study assesses the potentials of using two naturally available structures for STES,namely valley and ground pit *** on geographical information system(GIS)methods,the available locations are searched from digital elevation model and selected co.sidering several criteria from land uses and co.struction *** co.ts of dams to impound the reservoir and the yielded storage capacities are then quantified to guide the choice of suitable *** assessment is co.ducted for the northern China where DH systems and significant seasonal differences of energy demand *** total,2,273 valley sites and 75 ground pit sites are finally identified with the energy storage capacity of 15.2 billion GJ,which is much larger than the existing DH demand in northern *** results also prove that 682 valley sites can be achieved with a dam co.t lower than 20 CNY/m^(3).By co.ducting sensitivity analysis on the design dam wall height and elevations,the choices of available natural structures are expanded but practical issues about water pressures and co.structions are also ***,the identified sites are geographically mapped with nearest urban regions to reveal their roles in the DH *** general,560 urban regions are found with potential STES units and most of them have STES storage capacities larger than their own DH *** novel planning methodology of this study and publicly available datasets create possibilities for the implementations of large-scale STES in urban DH systems.

关键词： seasonal thermal energy storage geographical information system district heating water reservoir