检索结果-南通市图书馆

Quantum vector DC magnetometry via selective phase accumulation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 12-22页

作者： min Zhuang Sijie chen Jiahao Huang Chaohong Lee Institute of Quantum Precision Measurement State Key Laboratory of Radio Frequency Heterogeneous IntegrationCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China Laboratory of Quantum Engineering and Quantum Metrology School of Physics and AstronomySun Yat-sen University(Zhuhai Campus)Zhuhai 519082China

Precision measurement of magnetic fields is a crucial issue in both fundamental scientific research and practical sensing *** sensitive detection of a vector magnetic field poses a significant challenge in quantum magnetometry,particularly in estimating a vector DC magnetic field with high ***,we propose a comprehensive protocol for quantum vector DC magnetometry,utilizing selective phase accumulation in both non-entangled and entangled quantum *** upon the principles of Ramsey interferometry,our protocol enables the selective accumulation of phase for a specific magnetic field component by incorporating a meticulously designed pulse *** the individual measurement scheme,we employ three individual quantum interferometries to independently estimate each of the three magnetic field ***,in the simultaneous measurement scheme,the application of a pulse sequence along different directions enables the simultaneous estimation of all three magnetic field components using only one quantum ***,by employing an entangled state(such as the Greenberger-Horne-Zeilinger state)as the input state,the measurement precisions of all three components may reach the Heisenberg *** study not only establishes a general protocol for measuring vector magnetic fields using quantum probes,but also presents a viable pathway for achieving entanglement-enhanced multi-parameter estimation.

关键词： magnetometry quantum interferometry entanglement-enhanced quantum metrology

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第2期21卷 185-196页

作者： Wei-li Wu Chang-gui cheng Yang Li Shi-fa Wei De-li chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

Genomic analysis of Nypa fruticans elucidates its intertidal adaptations and early palm evolution

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第4期66卷 824-843页

作者： Weihong Wu Xiao Feng Nan Wang Shao Shao min Liu fa Si Linhao chen Chuanfeng Jin Shaohua Xu Zixiao Guo Cairong Zhong Suhua Shi Ziwen He State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources School of Life SciencesSun Yat-sen UniversityGuangzhou 510275China Greater Bay Area Institute of Precision Medicine School of Life SciencesFudan UniversityGuangzhou 511462China Hainan Academy of Forestry(Hainan Academy of Mangrove) Haikou 571100China

Nypa fruticans(Wurmb),a mangrove palm species with origins dating back to the Late Cretaceous period,is a unique species for investigating long-term adaptation strategies to intertidal environments and the early evolution of ***,we present a chromosome-level genome sequence and assembly for *** integrated the genomes of *** and other palm family members for a comparative genomic analysis,which confirmed that the common ancestor of all palms experienced a whole-genome duplication event around 89 million years ago,shaping the distinctive characteristics observed in this *** also inferred a low mutation rate for the *** genome,which underwent strong purifying selection and evolved slowly,thus contributing to its stability over a long evolutionary ***,ancient duplicates were preferentially retained,with critical genes having experienced positive selection,enhancing waterlogging tolerance in ***,we discovered that the pseudogenization of Early Methionine-labelled 1(EM1)and EM6 in *** underly its crypto-vivipary characteristics,reflecting its intertidal *** study provides valuable genomic insights into the evolutionary history,genome stability,and adaptive evolution of the mangrove *** results also shed light on the long-term adaptation of this species and contribute to our understanding of the evolutionary dynamics in the palm family.

关键词： crypto-vivipary genome stability long-term adaptation mangrove Nypa fruticans palm

Potentially Practical Catalytic Systems for Olefin-Polar Monomer Coordination Copolymerization

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第4期6卷 882-897页

作者： chen Tan min chen chen Zou Changle chen Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationKey Laboratory of Environment-Friendly Polymeric Materials of Anhui ProvinceAnhui UniversityHefeiAnhui 230601 CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026

Studies on transition-metal catalyzed olefin-polar monomer coordination copolymerization and their resulting polar-functionalized polyolefin materials have attracted attention from both academia and *** decades of research,recent developments in a variety of high-performance catalytic systems have shown that this field is on the brink of *** review summarizes representative olefin-polar monomer coordination copolymerization catalyst systems that may be suitable for industrial polyolefin production via homogeneous solution-phase processes or heterogeneous gas-phase/slurry-phase processes.

关键词： olefin copolymerization polar monomer catalyst solution polymerization heterogeneous

Hydrodynamics and OCM reaction performance in a bubbling fluidized bed reactor and a riser reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第3期86卷 188-204页

作者： min Cai Shuangzhu Kong Sheng chen Mengxi Liu Chunxi Lu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China China Special Equipment Inspection and Research Institute Beijing102249China

The reasonable reactor design is of great importance for increasing the C_(2) yield(C2H4 and C2H6)of the oxidative coupling of methane(OCM),and the OCM reactor should remove the heat released in reactions quickly and efficiently and minimize the consecutive reaction of ethylene to carbon *** fluidized bed reactor is characterized by excellent heat transfer,superior mass transport,and large handling capacity,while fewer studies focused on large-scale fluidized bed reactors for the OCM ***,large cold-model experiments and computational fluid dynamics simulations were conducted to investigate hydrodynamics and the OCM reaction performance in a large-scale bubbling fluidized bed(BFB)and a large-scale *** the BFB reactor,consecutive reactions of ethylene are acute because of the strong gas back-mixing,high solids holdup,and non-uniform solids *** the consecutive reactions of ethylene are negligible due to the plug flow structure and low solids holdup in the riser ***,both reactors can achieve isothermal operation for the OCM *** C_(2) selectivity of 45.4% and C_(2) yield of 21.1% are obtained in the riser reactor,increasing by 20.3% and 5.8% individually than that in the BFB *** study provides useful information and reference to the OCM reactor designandcommercialization.

关键词： Oxidative coupling of methane Bubbling fluidized bed reactor Riser reactor Hydrodynamics Isothermal operation

Ultrahigh performance passive radiative cooling by hybrid polar dielectric metasurface thermal emitters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2024年第4期7卷 17-25页

作者： Yinan Zhang Yinggang chen Tong Wang Qian Zhu min Gu Institute of Photonic Chips University of Shanghai for Science and TechnologyShanghai 200093China Centre for Artificial-Intelligence Nanophotonics School of Optical-Electrical and Computer EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China

Real-world passive radiative cooling requires highly emissive,selective,and omnidirectional thermal emitters to maintain the radiative cooler at a certain temperature below the ambient temperature while maximizing the net cooling *** various selective thermal emitters have been demonstrated,it is still challenging to achieve these conditions sim-ultaneously because of the extreme difficulty in controlling thermal emission of photonic structures in *** we demonstrated hybrid polar dielectric metasurface thermal emitters with machine learning inverse design,en-abling a high emissivity of~0.92 within the atmospheric transparency window 8-13μm,a large spectral selectivity of~1.8 and a wide emission angle up to 80 degrees,*** selective and omnidirectional thermal emitter has led to a new record of temperature reduction as large as~15.4°C under strong solar irradiation of~800 W/m2,signific-antly surpassing the state-of-the-art *** designed structures also show great potential in tackling the urban heat island effect,with modelling results suggesting a large energy saving and deployment area *** research will make significant impact on passive radiative cooling,thermal energy photonics and tackling global climate change.

关键词： radiative cooling dielectric metasurfaces machine learning thermal emitters

Body-force modeling considering induced upstream effects for a transonic compressor with total temperature distortion

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 7-19页

作者： Jiahui QIU chen YANG Wenqiang ZHANG min ZHANG Juan DU Digital Twin Research Center Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Engineering and Science University of Chinese Academy of SciencesBeijing 100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Chinese Academy of SciencesBeijing 100190China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

To numerically study the impact of total temperature distortion on a transonic compressor with reduced computational costs,a Body-Force Model(BFM)is ***,the interactions between the distorted flow and the compressor are analyzed using full-annulus Unsteady Reynolds-Averaged Navier-Stokes(URANS)results and the orbit *** is found that the induced swirl distortion and the mass flux nonuniformity are intensified in the compressor upstream flow field.A correction factor is thus added to the BFM to account for the effect of the induced swirl,which is crucial for the accurate representation of distortion transfer in the ***,steady simulations with large-amplitude 180circumferential total temperature distortion are performed using the developed *** is shown that the distorted compressor map simulated with the BFM matches well with URANS *** circumferential phase shift of total temperature and the generation of the additional total pressure distortion across the rotor are in line with the time-averaged URANS flow *** compressor upstream effects on the distorted inflow can also be exactly *** above-mentioned results demonstrate the BFM developed in this paper can effectively capture the distorted flow features inside the compressor,and significantly reduce the computational costs by five orders of magnitude compared with URANS.

关键词： Upstream effect Orbit method Induced swirl distortion Body force model Correction factor Time-averaged URANS

Aerodynamic Performance of Three Flapping Wings with Unequal Spacing in Tandem Formation

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第4期21卷 1662-1676页

作者： min Chang Ziyi Xu Zengshuang chen Li Li Xueguang Meng Unmanned System Research Institute National Key Laboratory of Unmanned Aerial Vehicle TechnologyNorthwestern Polytechnical UniversityXi’an710072People’s Republic of China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049People’s Republic of China Xi’an Aeronautics Computing Technique Research Institute Aviation Industry Corporation of ChinaXi’an710076People’s Republic of China

To better understand the aerodynamic reasons for highly organized movements of flying organisms,the three-flapping wing system in tandem formation was studied numerically in this *** from previous relevant studies on the multiple flapping wings that are equally spaced,this study emphasizes the impact of unequal spacing between individuals on the aerodynamics of each individual wing as well as the whole *** is found that swapping the distance between the first and second wing with the distance between the second wing and the rearmost wing does not affect the overall aerodynamic performance,but significantly changes the distribution of aerodynamic benefits across each *** the whole flapping cycle,three effects are at *** narrow channel effect and the downwash effect can promote and weaken the wing lift,respectively,while the wake capture effect can boost the *** also shows that these effects could be manipulated by changing the spacing between adjacent *** findings provide a novel way for flow control in tandem formation flight and are also inspiring for designing the formation flight of bionic aircraft.

关键词： Three flapping wings Unequal spacing Aerodynamic performance Tandem formation

Brominated flame retardants in surface sediment from Western Guangdong,South China:Occurrence,distribution and toxicity in Caenorhabditis elegans

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 Environmental Sciences 2024年第11期145卷 97-106页

作者： Xiaoxia chen Ping Ding Haibo chen Tingzhen Li min Zhang Yunjiang Yu Guocheng Hu State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment South China Institute of Environmental SciencesMinistry of Ecology and EnvironmentGuangzhou 510655China Institute for Environmental pollution and health School of Environmental and Chemical EngineeringShanghai UniversityShanghai 200444China Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir Chongqing Three Gorges UniversityChongqing 404000China

Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong *** study assessed the content and distribution of brominated flame retardants in *** acute toxicity effects of tetrabromobisphenol A(TBBPA)and hexabromocyclododecane(HBCDs)in sediments were evaluated using Caenorhabditis elegans as model *** concentration of TBBPA in sediments ranged from not detected(ND)to 12.59μg/kg andwas mainly distributed in the central area,whichwas affected by the emission of TBBPA from residential and *** concentration of HBCDs ranged from ND to 6.31μg/kg,and the diastereoisomer distribution was consistent,showing a trend close to the South China *** composition pattern of HBCDs in the surface sediments from rivers were 41.73%-62.33%,7.89%-25.54%,and 18.76%-40.65%forα-,β-,andγ-HBCD,respectively,and in the sediments from reservoirs were 26.15%-45.52%,7.44%-19.23%,and 47.04%-61.89%forα-,β-,andγ-HBCD,*** the sum of concentrations of TBBPA and HBCD in sediments were above high levels,reactive oxygen species in nematodes significantly increased,resulting in an oxidative stress *** permeabilitywas also enhanced,causing intestinal *** addition,in terms of this study,TBBPA had a greater impact on biotoxicity compared to HBCDs,and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City,Guangdong *** study can complement the pollution database in the study area and provide basic data for pollution control.

关键词： Tetrabromobisphenol A(TBBPA) Hexabromocyclododecane(HBCDs) Sediment Caenorhabditis elegans Biotoxicity