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Price prediction of power transformer materials based on CEEMD and GRU
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作者 Yan Huang Yufeng Hu +2 位作者 Liangzheng Wu Shangyong Wen Zhengdong Wan 《Global Energy Interconnection》 EI CSCD 2024年第2期217-227,共11页
The rapid growth of the Chinese economy has fueled the expansion of power grids.Power transformers are key equipment in power grid projects,and their price changes have a significant impact on cost control.However,the... The rapid growth of the Chinese economy has fueled the expansion of power grids.Power transformers are key equipment in power grid projects,and their price changes have a significant impact on cost control.However,the prices of power transformer materials manifest as nonsmooth and nonlinear sequences.Hence,estimating the acquisition costs of power grid projects is difficult,hindering the normal operation of power engineering construction.To more accurately predict the price of power transformer materials,this study proposes a method based on complementary ensemble empirical mode decomposition(CEEMD)and gated recurrent unit(GRU)network.First,the CEEMD decomposed the price series into multiple intrinsic mode functions(IMFs).Multiple IMFs were clustered to obtain several aggregated sequences based on the sample entropy of each IMF.Then,an empirical wavelet transform(EWT)was applied to the aggregation sequence with a large sample entropy,and the multiple subsequences obtained from the decomposition were predicted by the GRU model.The GRU model was used to directly predict the aggregation sequences with a small sample entropy.In this study,we used authentic historical pricing data for power transformer materials to validate the proposed approach.The empirical findings demonstrated the efficacy of our method across both datasets,with mean absolute percentage errors(MAPEs)of less than 1%and 3%.This approach holds a significant reference value for future research in the field of power transformer material price prediction. 展开更多
关键词 power transformer material Price prediction Complementary ensemble empirical mode decomposition Gated recurrent unit Empirical wavelet transform
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ASYMPTOTIC ANALYSIS OF MODE Ⅱ STATIONARY GROWTH CRACK ON ELASTIC-ELASTIC POWER LAW CREEPING BIMATERIAL INTERFACE
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作者 唐立强 李永东 刘长海 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第2期228-235,共8页
A mechanical model was established for modeⅡinterfacial crack static growing along an elastic_elastic power law creeping bimaterial interface. For two kinds of boundary conditions on crack faces, traction free and fr... A mechanical model was established for modeⅡinterfacial crack static growing along an elastic_elastic power law creeping bimaterial interface. For two kinds of boundary conditions on crack faces, traction free and frictional contact, asymptotic solutions of the stress and strain near tip_crack were given. Results derived indicate that the stress and strain have the same singularity, there is not the oscillatory singularity in the field; the creep power_hardening index n and the ratio of Young's module notably influence the crack_tip field in region of elastic power law creeping material and n only influences distribution of stresses and strains in region of elastic material. When n is bigger, the creeping deformation is dominant and stress fields become steady,which does not change with n. Poisson's ratio does not affect the distributing of the crack_tip field. 展开更多
关键词 elastic-elastic power law creeping material mode Ⅱinterfacial crack crack-tip field
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The crack tip fields of Mode Ⅱ stationary growth crack on bimaterial interface
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作者 TANG Li-qiang,LIU Chang-hai, and ZHENG Gui School of Civil Engineering, Harbin Engineering University, Harbin 150001 , China 《Journal of Marine Science and Application》 2003年第2期11-16,共6页
A mechanical model is established for mode II interfacial crack static growing along an elastic-elastic power law creeping bimaterial interface. For frictional contact of boundary conditions on crack faces, asymptotic... A mechanical model is established for mode II interfacial crack static growing along an elastic-elastic power law creeping bimaterial interface. For frictional contact of boundary conditions on crack faces, asymptotic solutions of the stresses and strains of near tip-crack are got. It was shown that in stable creep growing phase, elastic deformation and viscous deformation are equally dominant in the near-tip field, the stress and strain have the same singularity and there is not the oscillatory singularity the field. Through numerical calculation , it is shown that the frictional coefficient η notably influence the crack-tip field. 展开更多
关键词 an elastic-elastic power law creeping material near-tip field of mode interfacial crack the frictional effect
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Titanylphthalocyanine as hole transporting material for perovskite solar cells
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作者 Mengna Sun Shirong Wang +2 位作者 Yin Xiao Zhihao Song Xianggao Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第6期756-761,共6页
Titanylphthalocyanine (TiOPc) as hole transporting material (HTM) was successfully synthesized by a simple process with low cost. Perovskite solar cells using the TiOPc as HTM were fabricated and characterized. Ti... Titanylphthalocyanine (TiOPc) as hole transporting material (HTM) was successfully synthesized by a simple process with low cost. Perovskite solar cells using the TiOPc as HTM were fabricated and characterized. TiOPc as HTM plays an important role in increasing the power conversion efficiency (PCE) by minimizing recombi- nation losses at the perovskite/Au interface because TiOPc as HTM can extract photogenerated holes from the perovskite and then transport quickly these charges to the back metal electrode. In the research, the β-TiOPc gives a higher PCE than α-TiOPc for the devices due to sufficient transfer dynamics, The β-TiOPc was applied in perovskite solar cells without clopping to afford an impressive PCE of 5.05% under AM 1.5G illumination at the thickness of 40 nm which is competitive with spiro-OMeTAD at the same condition. The present work suggests a guideline for optimizing the photovoltaic properties ofperovskite solar cells using the TiOPc as the HTM. 展开更多
关键词 Perovskite Solar cell Titanylphthalocyanine Hole transporting material power conversion efficiency
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Analysis of bulging process of aluminum alloy by overlapping sheet metal and its formability 被引量:8
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作者 高铁军 刘洋 +1 位作者 陈鹏 王忠金 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第4期1050-1055,共6页
The influences of strength coefficient K, work hardening exponent n and thickness t of the overlapping sheet on bulging process are analyzed based on hardening material model. Also, bulging experiments are carried out... The influences of strength coefficient K, work hardening exponent n and thickness t of the overlapping sheet on bulging process are analyzed based on hardening material model. Also, bulging experiments are carried out by taking the aluminum alloy LF21 as formed sheet metal, and selecting overlapping sheet with different thicknesses and material properties, by which accuracy of the above analysis result is verified in the aspects of geometric shape, thickness distribution and limit bulging height. The results show that higher strength coefficient K, larger work hardening exponent n and proper thickness of the overlapping sheet are helpful to improve the formability and forming uniformity of formed sheet metal. 展开更多
关键词 overlapping sheet aluminum alloy BULGING power hardening material FORMABILITY
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Vibrational power flow analysis on combined plates partially covered layer of discontinuous material
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作者 LI Tianyun LIU Tuguang ZHANG Xiaoming (Department of Naval Architecture & Ocean Engineering, Huazhong University of Science & Technology Wuhan 430074) 《Chinese Journal of Acoustics》 1998年第2期110-119,共10页
Vibrational power flow on combined plates with a change in mass and stiffness or with viscoelastic damping layer used widely in engineering is studied. The expressions of flexural displacement and other physical quan... Vibrational power flow on combined plates with a change in mass and stiffness or with viscoelastic damping layer used widely in engineering is studied. The expressions of flexural displacement and other physical quantities are obtained using Laplace transformation and transfer matrix approach, then influences of changes in mass and stiffness of discontinuous material and the free damping layer on the input power flow and the transmitted power flow are discussed. The conclusions provide theory basis for structural optimization design and reducing noise and vibration 展开更多
关键词 flow Vibrational power flow analysis on combined plates partially covered layer of discontinuous material
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On the use of ferroelectric material LiNbO3 as novel photocatalyst in wastewater-fed microbial fuel cells 被引量:3
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作者 N.Touach V.M.Ortiz-Martinez +5 位作者 M.J.Salar-Garcia A.Benzaouak F.Hernandez-Fernandez A.P.de Rios M.El Mahi E.M.Lotfi 《Particuology》 SCIE EI CAS CSCD 2017年第5期147-155,共9页
In this work, the use of lithium niobate (LiNbO3), a ferroelectric and photocatalyst material, is investi- gated as a new type of cathode catalyst for wastewater-fed single-chamber microbial fuel cells (MFCs). Car... In this work, the use of lithium niobate (LiNbO3), a ferroelectric and photocatalyst material, is investi- gated as a new type of cathode catalyst for wastewater-fed single-chamber microbial fuel cells (MFCs). Carbon cloth electrodes coated with LiNbO3 were studied with and without UV-vis irradiation to assess its photocatalytic behavior in these devices. The synthesized phase of LiNbO3 was characterized by X- ray diffraction, differential scanning calorimetry, particle size distribution, and transmission electron microscopy analyses. The MFC containing a LiNbO3-based cathode exhibited a maximum open circuit potential and power output of 400 mV and 131 mW/m^3, respectively, under irradiation. This cathode configuration also achieved the maximum chemical oxygen demand removal of 84% after 120 h of MFC operation. These results show that ferroelectric materials such as LiNbO3 could be used as cathode cat- alysts in MFC devices. As a complementary analysis, the removal of the heavy metals detected in the wastewater was also monitored. 展开更多
关键词 Lithium niobate Ferroelectric material Photocatalyst Microbial fuel cell (MFC)power outputWastewater treatment
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D-A structural protean small molecule donor materials for solution-processed organic solar cells 被引量:1
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作者 Qiong WU Dan Deng +1 位作者 Kun Lu Zhi-Xiang Wei 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第11期2065-2077,共13页
Under the synergistic effect of molecular design and devices engineering, small molecular organic solar cells have presented an unstoppable tendency for rapid development with putting forward donor- acceptor (D-A) s... Under the synergistic effect of molecular design and devices engineering, small molecular organic solar cells have presented an unstoppable tendency for rapid development with putting forward donor- acceptor (D-A) structures. Up to now, the highest power conversion efficiency of small molecules has exceeded 11%, comparable to that of polymers. In this review, we summarize the high performance small molecule donors in various classes of typical donor-acceptor (D-A) structures and discuss their relationships briefly. 展开更多
关键词 Small molecule donor materials Bulk heterojunction solar cells Donor-acceptor structures Molecule design power conversion efficiency
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Organic functional materials based buffer layers for efficient perovskite solar cells
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作者 Fateh Ullah Hongzheng Chen Chang-Zhi Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第3期503-511,共9页
In this review, we highlight the recent development of organic π-functional materials as buffer layers in constructing efficient perovskite solar cells(PVSCs). By following a brief introduction on the PVSC developm... In this review, we highlight the recent development of organic π-functional materials as buffer layers in constructing efficient perovskite solar cells(PVSCs). By following a brief introduction on the PVSC development, device architecture and material design features, we exemplified the exciting progresses made in field by exploiting organic π-functional materials based hole and electron transport layers(HTLs and ETLs) to enable high-performance PVSCs. 展开更多
关键词 Perovskite solar cells Organic functional material Hole transport layer Electron transport layer power conversion efficiency
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