检索结果-南通市图书馆

An efficient online histogram publication method for data streams with local differential privacy

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第8期25卷 1096-1109页

作者： Tao TAO funan zhang Xiujun WANG Xiao ZheNG Xin ZHAO School of Computer Science and Technology Anhui University of TechnologyMaanshan 243032China Anhui Engineering Research Center for Intelligent Applications and Security of Industrial Internet Maanshan 243032China Engineering Research Institute Anhui University of TechnologyMaanshan 243032China Shengli No.1 Middle School of Dongying City Dongying 257000China

Many areas are now experiencing data streams that contain privacy-sensitive *** the sharing and release of these data are of great commercial value,if these data are released directly,the private user information in the data will be ***,how to continuously generate publishable histograms(meeting privacy protection requirements)based on sliding data stream windows has become a critical issue,especially when sending data to an untrusted third *** histogram publication methods are unsatisfactory in terms of time and storage costs,because they must cache all elements in the current sliding window(sW).Our work addresses this drawback by designing an efficient online histogram publication(EOHP)method for local differential privacy data ***,in the EOHP method,the data collector first crafts a histogram of the current SW using an approximate counting ***,the data collector reduces the privacy budget by using the optimized budget absorption mechanism and adds appropriate noise to the approximate histogram,making it possible to publish the histogram while retaining satisfactory data *** experimental results on two different real datasets show that the EOHP algorithm significantly reduces the time and storage costs and improves data utility compared to other existing algorithms.

关键词： Data stream Differential privacy Sliding windows Approximate counting

Subnatural-linewidth fluorescent single photons

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第4期12卷 625-637页

作者： he-bin zhang GAO-XIANG LI YONG-CHUN LIU State Key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Department of Physics Huazhong Normal UniversityWuhan 430079China Frontier Science Center for Quantum Information Beijing 100084China

Subnatural-linewidth single photons are of vital importance in quantum optics and quantum information *** to previous research, it appears difficult to utilize resonance fluorescence to generate single photons with subnatural linewidth. here we propose a universally applicable approach to generate fluorescent single photons with subnatural linewidth, which can be implemented based on Λ-shape and similar energy ***, the general condition to obtain fluorescent single photons with subnatural linewidth is *** single-photon linewidth can be easily manipulated over a broad range by external fields, which can be several orders of magnitude smaller than the natural linewidth. Our study can be easily implemented in various physical platforms with current experimental techniques and will significantly facilitate the research on the quantum nature of resonance fluorescence and the technologies in quantum information science.

关键词： quantum utilize optics

Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 55-66页

作者： Zhiyuan zhang Hanyu Deng Wenhe Liao bin yu Zai yu Nanjing University of Science and Technology Nanjing 210094China

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano ***,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical *** conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition *** this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was *** detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were *** ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition *** results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition ***,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of *** the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,*** rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition *** to direct injection scheme,swirlin

关键词： Micro/nano satellite hybrid propulsion Arc ignition Charring conductive polymer Ignition mechanism Ignition characteristic Repeated ignition

Urea-induced interfacial engineering enabling highly reversible aqueous zinc-ion battery

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1599-1609页

作者： bin-Rui Xu Quan-An Li Yong Liu Guang-bin Wang Zi-he zhang Feng-zhang Ren School of Material Science and Engineering Henan University of Science and TechnologyLuoyang471023China School of Information Engineering Henan University of Science and TechnologyLuoyang471023China Longmen Laboratory Luoyang471023China Provincial and Ministerial Co-Construction of Collaborative Innovation Center for Non-Ferrous Metal New Materials and Advanced Processing Technology Luoyang471023China

Aqueous zinc-ion batteries(AZIBs)have been regarded as prospective rechargeable energy storage devices because of the high theoretical capacity and low redox potential of Zn ***,the uncontrollable formation of dendrites and the water-induced side reactions at the Zn/electrolyte interface,and the poor reversibility under a high current density(>2 mA·cm^(-2))and large area capacity(>2 mAh·cm^(-2))still limit the practical applications of ***,a strategy that can overcome these difficulties is urgently ***,we introduce an environmentally friendly and low-cost additive,namely urea,to the electrolyte of AZIBs to induce uniform Zn deposition and suppress the side *** of the adsorption behavior,electrochemical characterization,and observations of the morphology revealed the interfacial modification induced by urea on the Zn/electrolyte interface,demonstrating its huge potential in ***,the long-term cycling stability(over2100 h)of a Zn/Zn symmetric cell under a high current density of 5 mA·cm^(-2)and a capacity of 5 mAh·cm^(-2)was achieved with a 1 mol·L^(-1)ZnSO_(4)electrolyte with the urea ***,the assembled Zn/NH_4V_4O_(10)full cell with urea exhibited excellent cycling performance and an outstanding average Coulombic efficiency of 99.98%.These results indicate that this is a low-cost and effective additive strategy for realizing highly reversible AZIBs.

关键词： Zn anode Urea additive Interface engineering Dendrite growth Side reaction

Numerical analysis of wind effects on aerodynamic characteristics of a ducted fan

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 263-280页

作者： Yiwei LUO Tianfu AI yuhang he bin XU yuping QIAN Yangjun zhang State Key Laboratory of Intelligent Green Vehicle and Mobility School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Key Laboratory of Conveyance and Equipment Ministry of Education East China Jiaotong UniversityNanchang 330013China Vehicle Research Center School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Ducted fans have been extensively used in Unmanned Aerial Vehicles(UAVs)for a variety of missions because of high efficiency,high safety and low ***,as a kind of typical meteorological condition,brings significant aerodynamic interference to the ducted fan,which seriously threatens flight stability and *** this work,the numerical simulation with the Unsteady Reynolds Averaged Navier-Stokes(URANS)method and the sliding mesh technique is performed to evaluate the steady wind *** results show that the wind will lead to serious unsteady effects in the flow field,and the thrust fluctuates at the blade passing frequency of 200 *** the wind speed increases,the rotor thrust increases,the duct thrust decreases,and the total thrust changes *** instability may occur when the wind speed exceeds 8 m/*** the angle of low-speed wind increases,the rotor thrust changes little,the duct thrust increases,and the total thrust *** addition,we figure out that cases with the same crosswind ratio are similar in results,and increasing the rotating speed or fan radius is beneficial to performance improvement in *** findings are essential to the ducted fan design and UAV flight control design for stable and safe operations in wind conditions.

关键词： Unmanned Aerial Vehicle(UAV) Ducted fan Wind effect Thrust fluctuations Computational Fluid Dynamics(CFD)

Effective Supply,Consumption Upgrade,and Expanding Domestic Demand

在线全文

学校读者我要写书评

暂无评论

Frontiers of Economics in China-Selected Publications from Chinese Universities 2024年第1期19卷 106-127页

作者： he Jingtong zhang bin School of Economics Nankai UniversityTianjin 300071China

Addressing the prolonged stagnation in household consumption growth in China is crucial for the successful implementation of the strategy to expand domestic *** constructing the upgrading index of consumption structure from 2002 to 2018,it is found that the overall upgrading trend of household consumption structure in China is accelerated after *** analysis and empirical results indicate that,as household consumption structures rapidly upgrade with rising incomes in China,the primary factor limiting reasonable growth in household consumption is the insufficient effective supply resulting from a mismatch between the supply structure and the demand *** the adjustment of the supply structure depends on the continuous optimization of investment flow,expanding effective investment is the key driving force to improve effective supply,and it is also the existing component of expanding domestic *** research shows that weakening investment convergence can significantly alleviate the insufficient effective supply caused by consumption *** the scientific anticipation of policy regulations and increasing the effectiveness of investments will be beneficial for realizing the strategy of expanding domestic demand.

关键词： expanding domestic demand consumption upgrade insufficient effective supply investmentconvergence

On the two-layer high-level Green-Naghdi model in a general form

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 Hydrodynamics 2024年第1期36卷 78-86页

作者： bin-bin Zhao Tian-yu zhang Zhan Wang Wen-yang Duan Alexander Chesnokov Natalia Shmakova College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Qingdao Innovation and Development Center of Harbin Engineering University Qingdao266000China Lavrentyev Institute of Hydrodynamics NovosibirskRussia

The traditional high-level Green-Naghdi(HLGN)model,which uses the polynomial as the shape function to approximate the variation of the horizontal-and vertical-velocity components along the vertical direction for each-fluid layer,can accurately describe the large-amplitude internal waves in a two-layer system for the shallow configuration(h_(2)/λ■1,h_(1)/λ■1).However,for the cases of the deep configuration(h_(2)/λ■1,h_(1)/λ=O(1)),higher-order polynomial is needed to approximate the variation of the velocity components along the vertical direction for the lower-fluid ***,however,introduces additional unknowns,leading to a significant increase in computational *** paper,for the first time,derives a general form of the HLGN model for a two-layer fluid system,where the general form of the shape function is used during the *** obtaining the general form of the two-layer HLGN equations,corresponding solutions can be obtained by determining the reasonable shape ***-amplitude internal solitary waves in a deep configuration are studied by use of two different HLGN *** of the two HLGN models shows that the polynomial as the shape function for the upper-fluid layer and the production of exponential and polynomial as the shape function for the lower-fluid layer is a good *** comparing with Euler’s solutions and the laboratory measurements,the accuracy of the two-layer HLGN model is verified.

关键词： High-level Green-Naghdi(HLGN)model general form internal waves deep configuration

Establishing Modular Cell-Free Expression System for the Biosynthesis of Bicyclomycin from a Chemically Synthesized Cyclodipeptide

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第4期42卷 384-390页

作者： Yi-Pei Liu yu-heng Zhao Wen-Qi zhang Lian Wu Linjuan Huang Gong-Li Tang Jun-bin he Shaanxi Natural Carbohydrate Resource Engineering Research Center College of Food Science and TechnologyNorthwest UniversityXi'anShaanxi710069 China State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of Sciences(CAS)CASShanghai200032 China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of CAS1 Sub-lane XiangshanHangzhouZhejiang310024 China

Cell-free expression systems have emerged as a versatile and powerful platform for metabolic engineering,biosynthesis and synthetic biology ***,successful examples of the synthesis of complex natural products using this system are still ***,a structurally unique and complex diketopiperazine alkaloid,is a clinically promising antibiotic that selectively inhibits the transcription termination factor ***,we established a modular cell-free expression system with cascade catalysis for the biosynthesis of bicyclomycin from a chemically synthesized *** six cell-free expressed biosynthetic enzymes,including five iron-andα-ketoglutarate-dependent dioxygenases and one cytochrome P450 monooxygenase,were active in converting their substrates to the corresponding *** co-expressed enzymes in the cell-free module were able to complete the related partial *** vitro biosynthesis of bicyclomycin was also achieved by reconstituting the entire biosynthetic pathways(i.e.,six enzymes)using the modular cell-free expression *** study demonstrates that the modular cell-free expression system can be used as a robust and promising platformforthe biosynthesis of complex antibiotics.

关键词： Natural products Bicyclomycin Biosynthesis Iron-andα-ketoglutarate-dependent dioxygenases Cytochrome P450 monooxygenase Cell-freeprotein synthesis Enzyme catalysis

Acute Bacillus cereus endophthalmitis caused by ocular perforation injury and occult intravitreal cilium implantation:a case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第5期17卷 976-978页

作者： Ling zhang bin Chen Wei-Min he Department of Ophthalmology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Ophthalmology the People’s Hospital of LeshanLeshan 614000Sichuan ProvinceChina

Dear Editor,We present a case of acute Bacillus cereus(***)endophthalmitis in a patient with an intraocular perforation injury combined with occult intravitreal cilium *** endophthalmitis is a severe intraocular infection commonly caused by post-traumatic *** often leads to significant vision loss or even eye loss within 12-48h[1].The presence of an intraocular foreign body(IOFB)increases the risk of infection,while early surgical removal of IOFBs can prevent endophthalmitis,some IOFBs are difficult to detect *** Medical Ethics Review Board of West China Hospital of Sichuan University waived application for a clinical study because this was a retrospective report of a single patient based on imaging and because no human experimentation was *** patient provided written informed consent to use the imaging data for publication.

关键词： endophthalmitis ilium injuries