检索结果-南通市图书馆

Chiral electron transporting material for circularly polarized organic light-emitting diode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第11期67卷 3777-3784页

作者： Peihao Huo Tianyu Yang Peiyu Fang Yujia Li Nanlong Zheng Min Gong Zuqiang bian Zhiwei Liu Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular Engineering Peking University

Circularly polarized organic light-emitting diode(CP-OLED) has attracted increasing interest for its efficient ability to generate circularly polarized light directly. So far, many CP-OLEDs were successfully fabricated with chiral emitters or chiral hosts. In this study, a new strategy based on chiral electron transporting layer is proposed to construct CP-OLEDs. A pair of chiral electron transporting materials, 1,3,5-tris((R/S)-4-isopropyl-4,5-dihydrooxazol-2-yl)benzene((R/S)-TOxiPr), are firstly designed and synthesized. The crystalline films of(R/S)-TOxiPr show circularly polarized photoluminescence with photoluminescence dissymmetry factors of-0.067 and +0.041, respectively. The CP-OLEDs based on(R/S)-TOxiPr and three types of achiral emitters all exhibit circularly polarized electroluminescence, showing feasibility and strong versatility of this new strategy. The mechanism is attributed to in-situ electrical excitation instead of simply light filtering of non-circularly polarized light. This work demonstrates a new approach for realizing circularly polarized electroluminescence which may provide a valuable strategy to develop CP-OLEDs.

关键词： circularly polarized organic light-emitting diodes chiral electron transporting layer trisoxazolinylbenzene circularly polarized electroluminescence

VLBI with SKA:Possible Arrays and Astrometric Science

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第7期24卷 1-33页

作者： Yingjie Li Ye Xu Jingjing Li Shuaibo bian Zehao Lin Chaojie Hao Dejian Liu Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China University of Science and Technology of China Hefei 230026China

The next generation of very long baseline interferometry(VLBI)is stepping into the era of microarcsecond(μas)astronomy,and pushing astronomy,especially astrometry,to new *** with the Square Kilometre Array(SKA),SKA-VLBI,will increase current sensitivity by an order of magnitude,and reach astrometric precision routinely below 10μas,even challenging 1μ*** advancement allows precise parallax and proper motion measurements of various celestial *** improvements can be used to study objects(including isolated objects,and binary or multiple systems)in different stellar stages(such as star formation,main-sequence stars,asymptotic giant branch stars,pulsars,black holes,white dwarfs,etc.),unveil the structure and evolution of complex systems(such as the Milky Way),benchmark the international celestial reference frame,and reveal cosmic ***,the theory of general relativity can also be tested with SKA-VLBI using precise measurements of light deflection under the gravitational fields of different solar system objects and the perihelion precession of solar system objects.

关键词： astrometry-parallaxes-stars kinematics and dynamics-ISM kinematics and dynamics-Galaxy kinematics and dynamics-galaxies kinematics and dynamics-gravitation

维普期刊数据库

Red algal evidence for a marine regression during closure of the Paleo-Asian Ocean in the Junggar Basin and its linkage to hydrocarbon generation

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第9期67卷 2845-2863页

作者： Ruijie ZHANG Jian CAO Lizeng bian Wenxuan HU Liuwen XIA Bin ZHANG Yong TANG Wenjun HE School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China PetroChina Xinjiang Oilfield Company Karamay 834000China

The closure of the Paleo-Asian Ocean was a significant geological event in northern Pangea during the *** had a significant effect on climate,biota,and environmental conditions of the Late Paleozoic Ice Age,and resulted in the development of vast energy *** paper reports on the first discovery of marine red algal fossils in the Junggar Basin and its linkage to hydrocarbon *** algae occur mainly in the Fengcheng Formation(ca.300 Ma)and provide direct fossil evidence for closure of the Paleo-Asian *** red algal fossils contain well-preserved reproductive organs,such as cystocarps and *** concentrations of C_(27) steranes(C_(27) regular steranes/sum of C_(27)-C_(29) regular steranes×100=14.30%-21.30%)and the marine biomarker 24-n-propylcholesterane(C_(30) diasterane[βα20S]/sum of C_(27)-C_(30) diasteranes[βα20S]×100=1.15%-1.85%)were detected in the red-algae-bearing hydrocarbon source *** experiments that simulate hydrocarbon generation show that the oil generation potential of the red-algae-bearing source rocks is 363.71 mg g^(-1) total organic *** result,combined with oil-source rock correlations,indicates these rocks contributed to the formation of oil and gas resources,particularly in the marginal areas of the *** lake basin inherited the water and biological conditions of the Paleo-Asian Ocean during a marine regression,which was an important factor in the development of these high-quality hydrocarbon source rocks in an alkaline saline *** results advance our understanding of the evolution of the Paleo-Asian Ocean,interactions between the ocean and a lake during the deposition of terrestrial hydrocarbon source rocks,and whether red algae can effectively generate hydrocarbons.

关键词： Biotic precursor 24-n-propylcholesterane Regressive lake basin Fengcheng Formation Junggar Basin

维普期刊数据库

Synergistic Promotion of Electrical, Mechanical and Thermal Properties for Silicone Rubber-based Field Grading Material via Compound Modification

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第1期10卷 337-350页

作者： Jiale Wu Yangzhi Gong Peiqi Xiong Zexi Xing Xiaofeng Xue Xiao Yang Boyang Shen Xingming bian State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University102206 BeijingChina State Grid Fuzhou Electric Power Supply Company Fuzhou 350009Fujian ProvinceChina Electrical Engineering Division University of CambridgeCambridge CB30FAUK

Use of nonlinearconductive SiC/silicone rubber(SR)field grading material(FGM)can improve the local field concentration of composite *** large volume fraction and large-size SiC particles(SiCp)into SR can obtain a good field grading effect,but it is accompanied by the deterioration of mechanical *** SiC with different shapes can solve this *** incorporating one-dimensional SiC whiskers(SiCw)to synergize with granular SiCp,SiC/SR FGM with better field-dependent conductivity,mechanical properties and thermal conductivity than large-size SiCp and large volume fraction filling case can be obtained by using smaller size SiCp and lower filling *** simulations of 500 kv line insulators show that the modified SiC/SR FGM can reduce the maximum field strength along the insulator surface and at sheath-core rod interfaces by 55%and 71.4%,*** combined application of FGM and grading ring can achieve a complementary *** FGM to partially replace the role of the grading rings,the field strength indicators can still meet the operational requirements after the tube radius and shielding depth of the grading rings at both ends are reduced by 36.2%and 40%separately,which is a benefit to alleviating the problems of high weight and large volume faced by traditional field grading methods.

关键词： Compound modification electric field regulation field grading material field-dependent conductivity mechanical properties thermal conductivity

Source-Load Coordinated Optimal Scheduling Considering the High Energy Load of Electrofused Magnesium and Wind Power Uncertainty

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2024年第10期121卷 2777-2795页

作者： Juan Li Tingting Xu Yi Gu Chuang Liu Guiping Zhou Guoliang bian School of Electrical Engineering Northeast Electric Power UniversityJilin132013China Ministry of Science and Technology Communication State Grid Liaoning Electric Power Co.Ltd.Shenyang110000China

In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional units obviously can not solve the new energy as the main body of the scheduling *** enhance the systemscheduling ability,based on the participation of thermal power units,incorporate the high energy-carrying load of electro-melting magnesiuminto the regulation object,and consider the effects on the wind unpredictability of the ***,the operating characteristics of high energy load and wind power are analyzed,and the principle of the participation of electrofusedmagnesiumhigh energy-carrying loads in the elimination of obstructedwind power is ***,a two-layer optimization model is suggested,with the objective function being the largest amount of wind power consumed and the lowest possible cost of system *** the upper model,the high energy-carrying load regulates the blocked wind power,and in the lower model,the second-order cone approximation algorithm is used to solve the optimizationmodelwithwind power uncertainty,so that a two-layer optimizationmodel that takes into account the regulation of the high energy-carrying load of the electrofused magnesium and the uncertainty of the wind power is ***,the model is solved using Gurobi,and the results of the simulation demonstrate that the suggested model may successfully lower wind abandonment,lower system operation costs,increase the accuracy of day-ahead scheduling,and lower the final product error of the thermal electricity unit.

关键词： High energy load of electrofused magnesium wind energy consumption thermal power unit wind power uncertainty two-layer optimization

Total process of fault diagnosis for wind turbine gearbox,from the perspective of combination with feature extraction and machine learning:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI 2024年第1期15卷 356-373页

作者： Xinhua Xu Xinyu Huang Haibin bian Jiani Wu Chen Liang Feiyun Cong Huadian(Ningxia)Energy Co.Ltd.New Energy Branch No.55Xihu StreetNingchuan 750016China State Key Laboratory of Fluid Power&Mechatronic System Zhejiang UniversityZhejiangHangzhou 310027China Huadian Zhengzhou Machinery Design&Research Institute Co.Ltd. No.28Huxinhuandao RdZhengzhou 450046China

With the increasing of the installed capacity of wind power,the condition monitoring and maintains technique is becoming more *** Turbines(WT)gearbox is one of the key wind power components as it plays the role of power transmission and speed *** this,a number of scholars have pay attention to the fault diagnosis of WT *** efficiency of Machine Learning(ML)algorithms is highly correlated with signal type,data quality,and extracted features *** implementation of ML techniques has proven to be advantageous in simplifying the comprehension prerequisites for fault diagnosis technology concerning fault *** and more current studies predominantly concentrate on the utilization and fine-tuning of ML algorithms,while providing limited insights into the features of the acquired ***,it is necessary to review the research in recent years from the perspective of the combination of feature extraction and ML algorithms,and provide a detailed direction for future WT gearbox fault diagnosis technology *** this paper,data processing algorithms and typical fault diagnosis methods based on ML methods for WT gearbox are *** the using of ML method in WT gearbox fault diagnosis,the data prepared for training is very *** paper firstly reviewed the data analysing method which will support the ML *** data analysing methods include data acquisition,data preprocessing and feature extraction *** extraction plays a pivotal role in the realm of gearbox fault diagnosis,as it serves as the essence of effective *** review will primarily focus on exploring methods that enable the utilization of efficient features in combination with ML techniques to achieve accurate gearbox fault *** typical ML method for WT gearbox fault diagnosis are carefully ***,some prospects for future research directions are discussed in the end.

关键词： Wind turbine gearbox Machine learning Fault diagnosis Artificial neural network

A comprehensive analysis of formation conditions,intrinsic properties,and mechanical responses of gas hydrate-bearing sediments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第2期3卷 39-62页

作者： Hualin Zhang Hanbing bian Shuangxing Qi Jijing Wang Univ.Lille IMT Lille DouaiUniv.ArtoisJUNIAULR 4515-LGCgELaboratoire de Genie Civil et Geo-EnvironnementF-59000LilleFrance China National Chemical Southern Construction&Investment(Jiangxi)Co. LtdGanzhou 341499JiangxiChina School of Traffic&Transportation Engineering Changsha University of Science&TechnologyChangsha 410114HunanChina

Natural gas hydrates(NGH)stored in submarine deposits are a promising energy resource,Yet,the deterioration in sediment strength can trigger geological disasters due to drilling-induced hydrate ***,an in-depth investigation on geo physical-mechanical performance of gas hydrate-bearing sediments(GHBS)is crucial for recovery hydrates safely and *** paper provides a comprehensive assessment of the research progress on formation conditions,intrinsic properties,and mechanical responses of *** key findings have been presented:gas composition,inhibitors and promoters alter hydrate formation by modifying the thermodynamic equilibrium of temperature and ***,we identified the key determinants of porosity of GHBS and revealed the correlation between permeability,hydrate saturation,and hydrate ***,we highlighted the differences in mechanical behavior between hydrate-free sediments and GHBS along with their underlying ***,we examined the methods for GHBS preparation as well as the employed test apparatuses,providing critical insights into the limitations and *** synthe-sizing data from existing literature,we conducted a comprehensive analysis of the dependence of mechanical parameters of GHBS on factors such as hydrate saturation,effective confining stress,and temperature,and dis-cussed the mechanical responses subjected to various hydrate dissociation ***,we offer a perspective for future research to focus on the micro-scale aspects,heterogeneous distribution,and long-term stability of *** discerned patterns and mechanical mechanisms are expected to guide the improvement of predictive model for geo physical-mechanical behavior of GHBS and establish a reference for developing effective strategies for recovery hydrates.

关键词： Gas hydrate-bearing sediments Hydrate formation and dissociation Hydrate morphology Geo physical-mechanical performance Recovery hydrates

Design and Implementation of NOMA Backscatter Communication with Low-Precision Oscillators

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2024年第3期9卷 286-295页

作者： Kun Zhang Zhongye Cao Huixin Dong Zhiqing Luo Luanjian bian Wei Wang School of Electronic Information and Communications Huazhong University of Science and TechnologyWuhan 430074China ZTE Corporation Shenzhen 518057China

Recent years have witnessed increasing demands for the large-scale deployment of Internetof-things(IoT)*** technologies are promising to meet these demands with the notable low power consumption and ***,the conventional designs of backscatter prioritize energy efficiency at the cost of multiple access schemes with low spectral efficiency,which hinders its large-scale *** this paper,we propose a new non-orthogonal multiple access backscatter(NOMA-Backscatter)system to meet high spectral-efficiency *** implement the NOMA-Backscatter system for the first time with resource-constrained low-cost and low-power hardware and eliminate the affects of unstable oscillators during the successive interference cancellation(SIC)demodulation process in real *** demonstrate that NOMA-Backscatter can achieve 1.38 Mbit/s throughput with 200%tag load,and the spectral efficiency is 1.73×higher than state-of-the-art backscatter systems.

关键词： backscatter communication NOMA spectral efficiency multiple access

Heterogeneous integration of 2D materials on Si charge-coupled devices as optical memory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第6期67卷 190-197页

作者： Zheng bian Feng TIAN Zongwen LI Xiangwei SU Tianjiao ZHANG Jialei MIAO Bin YU Yang XU Yuda ZHAO College of Integrated Circuits Hangzhou Global Scientific and Technological Innovation CentreZhejiang University

Optical memory integrates the function of optical sensing in memory devices, remarkably promoting the interconnection between sensory and memory terminals. Silicon charge-coupled photodetectors and floating gate memory have been widely used in imaging and storage technologies, respectively. However,the heterogeneous integration of the two devices requires technological innovation and complex electrical connections. In this work, we adopt a three-dimensional layer stacking method to design a novel optical memory device. On the top of Si charge-coupled photodetectors, we successively deposit two-dimensional graphene,hexagonal boron nitride, and molybdenum disulfide as a floating gate layer, a tunneling layer, and a readout layer, respectively. By applying a gate bias on lightly doped Si, a deep depletion layer is formed with a high voltage potential drop. Under dark conditions, the depletion layer cannot be filled, and the electric field across the h-BN tunnel barrier is relatively small. Under light irradiation, the deep depletion layer is gradually filled, and the h-BN tunneling layer withstands the increasing electric field, resulting in charge storage in the floating gate layer. Based on this mechanism, the device exhibits a gate voltage-dependent operation mode, including an integrated optical sensing-memory mode and an electrically driven storage mode. Under moderate gate voltage, the device can effectively detect the optical information with varied intensity and store the optical information in the floating gate, displaying optically controlled memory characteristics. Our work demonstrates a compact device structure for optical memory and displays excellent optically controlled memory performance, which can be applied in artificial vision systems.

关键词： heterogeneous integration charge-coupled device floating gate optical memory molybdenum disulfide lightly doped silicon