检索结果-南通市图书馆

Synthesis of Calix[4]resorcinarene Core dendrimers with Peripheral Salicylideneimine Functional Groups

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2006年第4期22卷 537-542页

作者： han Jun GE Yun yan Chao-guo College of Chemistry ＆ Chemical Engineering Yangzhou University Yangzhou 225002 P. R. China

First to third-generation calix[4] resorcinarene core dendrimers, compounds 4a, 4b, 7a, 7b, 10a and 10b, were prepared via the divergent method in seven steps with the corresponding tetraphenyl- and tetra （hydroxyphenyl） calix[4] resorcinarenes （compounds 1a, 1b） as the starting material. The repeat units of the polyamidoamines of these dendrimers were obtained by the ammonolysis of ethyl calixarylacetates 2a and 2b with 1,3-diaminopropane, that is, amide derivatives with terminal amino groups, which in turn reacted with ethyl acrylate to give a higher generation of ester derivatives. The structures of these dendrimers were characterized by IR, ^1H and ^13C NMR spoctrometries. The crystal structure of compound 2b with 12 ethoxycarbonylmethoxy groups was determined by X-ray analysis.

关键词： Calixresorcinarene dendrimer Schiffbase Amide Calixarene

Product quality prediction based on RBF optimized by firefly algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第1期35卷 105-117页

作者： han Huihui WANG Jian CHEN Sen yan Manting College of Electronics and Information Engineering Tongji UniversityShanghai 201804China

With the development of information technology,a large number of product quality data in the entire manufacturing process is accumulated,but it is not explored and used *** traditional product quality prediction models have many disadvantages,such as high complexity and low *** overcome the above problems,we propose an optimized data equalization method to pre-process dataset and design a simple but effective product quality prediction model:radial basis function model optimized by the firefly algorithm with Levy flight mechanism(RBFFALM).First,the new data equalization method is introduced to pre-process the dataset,which reduces the dimension of the data,removes redundant features,and improves the data *** the RBFFALFM is used to predict product *** expe riments conducted on real-world product quality datasets validate that the new model RBFFALFM combining with the new data pre-processing method outperforms other previous me thods on predicting product quality.

关键词： product quality prediction data pre-processing radial basis function swarm intelligence optimization algorithm

Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第6期67卷 1957-1973页

作者： GAO han SHI TingNa GAO XinMai LEI yanXiao yan Dong GUO Liyan yan yan College of Electrical Engineering Zhejiang UniversityHangzhou310027China Zhejiang University Advanced Electrical Equipment Innovation Center Hangzhou311107China State Key Laboratory of High-speed Maglev Transportation Technology Qingdao266100China CRRC Qingdao Sifang Co.Ltd. Qingdao266111China

The operating speed of the commercial electromagnetic suspension(EMS)maglev train has been over 430 km/h,making it the fastest means of land *** the increasing demands of people traveling,it is necessary to further improve the operating speed of maglev *** to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h),the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this ***,an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance,e.g.,the characteristics of phase current,the magnetic flux density,and the electromagnetic ***,the relationship between the harmonic components of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT)to reveal the mechanism of electromagnetic force ***,to address the issues of excessive armature current density and significant electromagnetic force ripple,the linear motor is re-designed by enlarging the stator slot area and reshaping the mover's main magnetic ***,the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric ***,the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA)based co-simulation.

关键词： ultra-high-speed maglev transportation electromagnetic suspension(EMS) linear motor electromagnetic force ripple suppression

Estimation of solid concentration in solid-liquid two-phase flow in horizontal pipeline using inverse-problem approach

在线全文

学校读者我要写书评

暂无评论

Particuology 2022年第3期20卷 1-13页

作者： Ji Zhang han Yuan Ning Mei Zhe yan Marine Engineering College of EngineeringOcean University of ChinaQingdao 266100China Offshore Engineering Department of CivilEnvironmental and MiningUniversity of Western Australia35 Stirling HwyCrawleyWA 6009Australia Power Engineering and Engineering Thermophysics School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In this study,an inverse-problem method was applied to estimate the solid concentration in a solid-liquid two-phase *** algebraic slip mixture model was introduced to solve the forward problem of solid-liquid convective heat *** time-average conservation equations of mass,momentum,energy,as well as the volume fraction equation were computed in a computational fluid dynamics(CFD)*** solid concentration in the CFD model was controlled using an external program that included the inversion iteration,and an optimal estimation was performed via experimental *** using a fly-ash-water mixture and sand-water mixture with different solid concentrations in a horizontal pipeline were conducted to verify the accuracy of the inverse-problem *** estimated results were rectified using a method based on the relationship between the estimated results and estimation error;consequently,the accuracy of the corrected inversion results improved *** a verification through experiments,the inverse-problem method was concluded to be feasible for predicting the solid concentration,as the estimation error of the corrected results was within 7%for all experimental samples for a solid concentration of less than 50%.The inverse-problem method is expected to provide accurate predictions of the solid concentration in solid-liquid two-phase flow systems.

关键词： Solid-liquid two-phase flow Solid concentration estimation Coupling calculation Inverse heat transfer problem Algebraic slip mixture model

Emerging low-dimensional materials for mid-infrared detection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2021年第6期14卷 1863-1877页

作者： Jiangbin Wu Nan Wang Xiaodong yan han Wang Ming Hsieh department of Electrical and Computer Engineering University of Southern CaliforniaLos AngelesCA90089USA Mork Family department of Chemical Engineering and Material Science University of Southern CaliforniaLos AngelesCA90089USA

Mid-infrared(IR)detectors based on the emerging low-dimensional(two-dimensional and quasi one-dimensional)materials offer unique characteristics including large bandgap tunability,optical polarization sensitivity and integrability with typical silicon process,which are not available in the mid-IR detectors based on traditional compound ***,we review the recent progress in study of mid-IR detectors based on the low-dimensional materials,including black phosphorus,black arsenic phosphorus,tellurene and BaTiS3,from the perspectives of crystal structure,material synthesis,optical properties,and the detector *** detector gain and detectivity are benchmarked,and the unique properties,such as the polarization sensitivity,are *** also provide our perspective about key future research directions in this field.

关键词： mid-infrared detector anisotropy low-dimensional gain detectivity

Data-driven distribution network topology identification considering correlated generation power of distributed energy resource

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2022年第1期16卷 121-129页

作者： Jialiang CHEN Xiaoyuan XU Zheng yan han WANG Key Laboratory of Control of Power Transmission and Conversion(Ministry of Education) Shanghai Jiao Tong UniversityShanghai 200240China

This paper proposes a data-driven topology identification method for distribution systems with distributed energy resources(deRs).First,a neural network is trained to depict the relationship between nodal power injections and voltage magnitude measurements,and then it is used to generate synthetic measurements under independent nodal power injections,thus eliminating the influence of correlated nodal power injections on topology ***,a maximal information coefficient-based maximum spanning tree algorithm is developed to obtain the network topology by evaluating the dependence among the synthetic *** proposed method is tested on different distribution networks and the simulation results are compared with those of other methods to validate the effectiveness of the proposed method.

关键词： power distribution network data-driven topology identification distributed energy resource maximal information coefficient

Enhanced corrosion resistance of epoxy resin coating via addition of CeO_(2) and benzotriazole

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第3期67卷 89-96页

作者： Xu han Ruijie Guo Baolong Niu Hong yan College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

The use of fillers to enhance the corrosion protection of epoxy resins has been widely *** this work,cerium dioxide(CeO_(2))and benzotriazole(BTA)were introduced into an epoxy resin to enhance the corrosion resistance of Q235 carbon *** electron microscopy results indicated that the CeO_(2) grains were rod-like and ellipsoidal in shape,and the distribution pattern of BTA was analyzed by energy dispersive *** dynamic potential polarization curve proved the excellent corrosion resistance of the composite epoxy resin with CeO_(2) and BTA co-addition,and electrochemical impedance spectroscopy test analysis indicated the significantly enhanced long-term corrosion protection performance of the composite *** the optimal protective performance was provided by the coating containing 0.3%(mass)CeO_(2) and 20%(mass)BTA,which was attributed to the barrier performance of CeO_(2) particles and the chemical barrier effect of *** formation of corrosion products was analyzed using X-ray *** addition,the corrosion resistance mechanism of the coating was also discussed in detail.

关键词： Benzotriazole Cerium dioxide Corrosion resistance Carbon steel Epoxy resin coating Preparation

density-based Global Sensitivity Analysis of Islanded Microgrid Loadability Considering Distributed Energy Resource Integration

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 94-101页

作者： Zhuoxin Lu Xiaoyuan Xu Zheng yan han Wang Key Laboratory of Control of Power Transmission and Conversion of Ministry of Education Shanghai Jiao Tong UniversityShanghaiChina

With the proliferation of renewable energy and electric vehicles(EVs),there have been increasing uncertainties in power *** the influencing random variables will reduce the effort in uncertainty modeling and improve the controllability of power *** this paper,a density-based global sensitivity analysis(GSA)method is proposed to evaluate the influence of uncertainties on islanded microgrids(IMGs).Firstly,the maximum IMG loadability evaluation model is established to assess the distance from the current operation point to the critical operation ***,the Borgonovo method,which is a density-based GSA method,is used to evaluate the influence of input variables on IMG ***,to improve GSA efficiency,a modified Kriging model is used to obtain a surrogate model of IMG loadability,and Borgonovo indices are calculated based on the surrogate ***,the proposed method is tested on a 38-bus IMG *** results are compared with those considering other methods to validate the effectiveness of the proposed *** storage systems are considered to diminish the influence of critical uncertainties on IMG operation.

关键词： Islanded microgrids(IMGs) renewable energy global sensitivity analysis uncertainty

Top-down strategy for bamboo lignocellulose-derived carbon heterostructure with enhanced electromagnetic wave dissipation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第3期35卷 360-369页

作者： Shaoxiang Cai han yan Qiuyi Wang He han Ru Li Zhichao Lou School of Textile Garment and design Changshu Institute of TechnologyChangshu 215506China Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China College of Materials Science and Engineering Nanjing Forestry UniversityNanjing 210037China department of Materials Science and Engineering Southern University of Science and TechnologyShenzhenGuangdong 518055China College of Engineering University of GeorgiaAthens 30605GAUSA

Biomass-derived residue carbonization has been an important issue for"carbon fixation"and"zero emission",and the carbonized products have multiple application ***,there have been no specific research to study the differences in macro-and micro-morphology,electrical properties and many other aspects of the products obtained from carbonization of pure cellulose,pure lignin or their complex,*** this work,lignocellulose with cellulose to lignin mass ratio of 10:1 is obtained using p-toluenesulfonic acid hydrolysis followed by homogenization process at a controlled ***,carbon heterostructure with fibers and sheets(CH-10)are obtained by pyrolysis at 1500℃.detailed results imply that the fiber-like carbon structure possesses high crystallinity and low defect density,coming from carbonization of the cellulose content in lignocellulose(LC)***,the graphite-like carbon sheet with high defect density and low crystallinity comes from carbonization of the lignin content in *** investigation indicates CH-10 possesses enhanced polarization and moderate impedance matching which makes it an ideal candidate for electromagnetic wave(EMW)***-10 exhibits an excellent EMW absorption performance with a minimum RL value of-50.05 dB and a broadest absorption bandwidth of 4.16 GHz at a coating thickness as thin as 1.3 mm.

关键词： Carbon heterostructure Conductive loss Pyrolysis Interface Bamboo lignocellulose Nanostructure