检索结果-南通市图书馆

Streaming Histogram Publication Over Weighted Sliding Windows Under Differential Privacy

TSINGHUA SCIENCE AND TECHNOLOGY 2024年第6期29卷 1674-1693页

作者： wang, xiujun Mo, Lei Zheng, Xiao Dang, Zhe Anhui Univ Technol Sch Comp Sci & Technol Maanshan 243032 Peoples R China Inst Artificial Intelligence Hefei Comprehens Natl Sci Ctr Hefei 230088 Peoples R China Baosight Software Anhui Co Ltd Maanshan 243000 Peoples R China Washington State Univ Sch Elect Engn & Comp Sci Pullman WA 99164 Australia

Continuously publishing histograms in data streams is crucial to many real-time applications, as it provides not only critical statistical information, but also reduces privacy leaking risk. As the importance of elements usually decreases over time in data streams, in this paper we model a data stream by a sequence of weighted sliding windows, and then study how to publish histograms over these windows continuously. The existing literature can hardly solve this problem in a real-time way, because they need to buffer all elements in each sliding window, resulting in high computational overhead and prohibitive storage burden. In this paper, we overcome this drawback by proposing an online algorithm denoted by Efficient Streaming Histogram Publishing (ESHP) to continuously publish histograms over weighted sliding windows. Specifically, our method first creates a novel sketching structure, called Approximate-Estimate Sketch (AESketch), to maintain the counting information of each histogram interval at every time instance;then, it creates histograms that satisfy the differential privacy requirement by smartly adding appropriate noise values into the sketching structure. Extensive experimental results and rigorous theoretical analysis demonstrate that the ESHP method can offer equivalent data utility with significantly lower computational overhead and storage costs when compared to other existing methods.

关键词： Histograms Differential privacy Costs Publishing Noise Clustering algorithms Reinforcement learning differential privacy randomized algorithm streaming data publication weighted sliding window approximate statistics data usability computational complexity

来源：

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

Copper-cobalt Bimetallic Oxides-doped Alumina Hollow Spheres: a Highly Efficient Catalyst for Epoxidation of Styrene

引用

Chemical Research in Chinese Universities 2019年第1期35卷 125-132页

作者： LI Baitao HUANG Jing wang xiujun Key Laboratory of Fuel Cell Technology of Guangdong Province School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640P.R.China

Copper-cobalt bimetallic oxides-doped alumina hollow spheres(CuCo/AHS)were labricatcd through the sacrificial carbonaceous template *** dependence of the physicochemical properties and morphologies of CuCo/AHS on the composition of copper and cobalt in CuxCoy/AHS(x/y=9/1,7/3,5/5,and 3/7)was characterized bv means of X-ray powder diffraction,nitrogen physisorption,atomic adsorption spectroscopy,scanning electron microscopy,transmission electron microscopy and X-ray photoelectron *** these catalysts, Cu7-Co3/AHS catalyst exhibited perfect hollow sphere structure,thin wall,and big pore *** calcined catalysts were examined for the epoxidation of styrene with tert-butyl hydroperoxide as *** with the monometallic counterparts(Cu/AHS and Co/AHS)and other CuxCoy/AHS catalysts,Cu7Co3/AHS catalyst showed higher performance,yielding a styrene conversion of 64.6% with 93.0% selectivity toward styrene *** addition,the strong interaction of Cu^2+or Co^2+ with AHS ensured good stability after four consecutive reactions.

关键词： Alumina hollow sphere Styrene epoxidation Cu-Co bimetallic catalyst Styrene oxide

来源：

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

Preparation of an amphoteric flocculant having both high polymer content and low viscosity and its polymerization kinetics

引用

Chinese Journal of Chemical Engineering 2019年第1期27卷 130-135页

作者： Shenwen Fang Manlin wang Zipei Xu Lei Zhai xiujun wang Yan Xiong School of Chemistry and Chemical Engineering Southwest Petroleum University Oil&Gas Applied Chemistry Key Laboratory of Sichuan Province Beijing Research Center of China National Offshore Oil Corporation

It is not easy for liquid cationic flocculant diallyldimethyl-ammonium chloride(DM) homopolymer to simultaneously exhibit both low viscosity and high polymer content, which limited its application in offshore *** this paper, sodium allylsulfonate(XS) and sodium formate were used in the aqueous solution polymerization of *** amphoteric flocculant(PDMXS) with the properties of high polymer content(about 55 wt%) and low viscosity(efflux time measured by an Apply 4 viscometer was less than 100 s) was *** optimum reaction conditions were identified as follows: the mass ratio of XS/DM was 10 wt%, the concentration of sodium formate was 2000 mg·L^(-1), reaction temperature was 55 ℃, the concentration of KPS was 0.5 wt% and the reaction time was 4 *** polymerization kinetics was *** results showed that R_p∝ [M]^(1.97)[I]^(0.68)[CTA]^(0.71) and the apparent activation energy was 72.55 kJ·mol^(-1).

关键词： diallyldimethyl-ammonium chloride(DM) PDMXS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Counteracting effects on ENSO induced by ocean chlorophyll interannual variability and tropical instability wave-scale perturbations in the tropical Pacific

引用

Science China Earth Sciences 2024年第2期67卷 387-404页

作者： Rong-Hua ZHANG Feng TIAN Qidong SHI xiujun wang Tongwen WU School of Marine Sciences Nanjing University of Information Science and TechnologyNanjing210044China Laoshan Laboratory Qingdao266237China Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao266071China University of Chinese Academy of Sciences Beijing101408China Faculty of Geographical Sciences Beijing Normal UniversityBeijing100875China Earth System Modeling and Prediction Centre China Meteorological AdministrationBeijing100081China

Large perturbations in chlorophyll(Chl)are observed to coexist at interannual and tropical instability wave(TIW)scales in the tropical Pacific;at present,their combined effects on El Ni?o-Southern Oscillation(ENSO)through ocean biologyinduced heating(OBH)feedbacks are not understood ***,a hybrid coupled model(HCM)for the atmosphere and ocean physics-biogeochemistry(AOPB)in the tropical Pacific is adopted to quantify how ENSO can be modulated by Chl perturbations at interannual and TIW scales,individually or collectively,*** HCM-based sensitivity experiments demonstrate a counteracting effect on ENSO:the bio-climate feedback due to large-scale Chl interannual variability acts to damp ENSO through its impact on upper-ocean stratification and vertical mixing,whereas that due to TIW-scale Chl perturbations tends to amplify *** ENSO simulations are sensitively dependent on the ways Chl effects are represented at these different scales,it is necessary to adequately take into account these related differential Chl effects in climate modeling.A bias source for ENSO simulations is illustrated that is related with the Chl effects in the tropical Pacific,adding in a new insight into interactions between the climate system and ocean ecosystem on different scales in the *** results reveal a level of complexity of ENSO modulations resulting from Chl effects at interannual and TIW scales,which are associated with ocean biogeochemical processes and their interactions with physical processes in the tropical Pacific.

关键词： Ocean chlorophyll Bio-climate feedbacks Interannual variability Tropical instability waves Counteracting effects A hybrid coupled model

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The electrocatalytic activity of BaTiO3 nanoparticles towards polysulfides enables high-performance lithium-sulfur batteries

引用

Journal of Energy Chemistry 2020年第9期29卷 208-216,I0007页

作者： Hongcheng Gao Shunlian Ning Jiasui Zou Shuang Men Yuan Zhou xiujun wang Xiongwu Kang New Energy Research Institute School of Environment and EnergySouth China University of TechnologyGuangzhou 510006GuangdongChina School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640GuangdongChina

The slow redox dynamics and dissolution of polysulfides in lithium-sulfur(Li-S)batteries result in poor rate performance and rapid decay of battery capacity,thus limiting their practical *** barium titanate(BT)nanoparticles have been reported to effectively improve the electrochemical performance of Li-S batteries due to the inherent self-polarization and high adsorption capacity of the BT nanoparticles towards *** in this paper,BT nanoparticles,behave as highly efficient electrocatalyst and demonstrate much higher redox dynamics towards the conversion reaction of polysulfides and Li2S than TiO2,as shown by both electrochemical measurements and density functional theory *** coupling of the sulfur host of the hollow and graphitic carbon flakes(HGCF)and the BT nanoparticles(HGCF/S-BT)enable excellent electrochemical performance of Li-S batteries,delivering a0.047%capacity decay per cycle in 1000 cycles at 1 C,788 mAh g^-1 at 2 C and a reversible capacity of613 mAh g^-1 after 300 cycles at a current density of 0.5 C at a S loading of 3.4 mg cm^-***/S-BT also shows great promise for practical application in flexible devices as demonstrated on the soft-packaged Li-S batteries.

关键词： Electrocatalysis Redox reaction Li-S battery Polysulfide DFT calculation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impacts of land use and salinization on soil inorganic and organic carbon in the middle-lower Yellow River Delta

引用

Pedosphere 2021年第6期31卷 839-848页

作者： Yang GUO xiujun wang Xianglan LI Minggang XU Yuan LI Haonan ZHENG Yongming LUO Pete SMITH College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875(China) Institute of Agricultural Resources and Regional Planning Chinese Academy of Agriculture SciencesBeijing 100081(China) Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003(China) Institute of Biological and Environmental Sciences University of AberdeenAberdeen AB243UU(UK)

Soil inorganic carbon(SIC)is an important reservoir of carbon(C)in arid,semi-arid,and semi-humid ***,knowledge is incomplete on the dynamics of SIC and its relationship with soil organic C(SOC)under different land use types in the semi-humid region,particularly in coastal zones impacted by soil *** collected 170 soil samples from 34 profiles across various land use types(maize-wheat,cotton,paddy,and reed)in the middle-lower Yellow River Delta(YRD),*** measured soil pH,electrical conductivity(EC),water-soluble salts,and SOC and SIC *** results showed significant differences in both SOC and SIC among land use *** dry cropland(maize-wheat and cotton)soils had significantly higher SOC and SIC densities(4.71 and 15.46 kg C m^(-2),respectively)than the paddy soils(3.28 and 14.09 kg C m^(-2),respectively)in the 0–100 cm *** with paddy soils,reed soils contained significantly higher SOC(4.68 kg C m^(-2))and similar SIC(15.02 kg C m^(-2))*** was a significant positive correlation between SOC and SIC densities over a 0–100 cm soil depth in dry cropland soils,but a negative relationship in the paddy *** average,SOC and SIC densities under maize-wheat cropping were 15%and 4%lower,respectively,in the salt-affected soils in the middle-lower YRD than the upper *** study indicated that land use types had great influences on both SOC and SIC and their relationship,and salinization had adverse effect on soil C storage in the YRD.

关键词： C densities C stocks land use type salt-affected soil soil salinization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Realizing a“solid to solid”process via in situ cathode electrolyte interface(CEI)by solvent-in-salt electrolyte for Li-S batteries

引用

Nano Research 2023年第4期16卷 5018-5025页

作者： Jiajun Huang Mengli Tao Weifeng Zhang Guangli Zheng Li Du Zhiming Cui xiujun wang Zhenxing Liang Shijun Liao Huiyu Song Guangdong Provincial Key Laboratory of Fuel Cell Technology Guangzhou 510641China School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510641China

Lithium-sulfur batteries(LSBs)are regarded as the most promising next-generation energy system due to their high theoretical energy ***,LSBs suffer the“shuttle effect”if undergoing the solid-liquid-solid sulfur conversion process during ***,we design a solvent-in-salt(SIS)electrolyte with co-solvent vinylene carbonate(VC)to synthesize an in situ dense cathode electrolyte interface(CEI)and successfully change sulfur conversion into a solid-solid way to avoid shuttle effect by separating the contact of sulfur and ether *** CEI is formed at the beginning of first discharge by the combined action of SIS electrolyte and filmogen *** and simulations show that SIS electrolyte controls the initial formed lithium polysulfides(LiPSs)to stay very closely on the cathode surface,and then converts them into a dense CEI *** a result,Coulombic efficiency(above 99%)and cycling performance of LSBs are ***,the in situ dense CEI can nearly stop the self-discharge of LSBs,and enable the LSBs to work under a pretty lean electrolyte condition.

关键词： lithium-sulfur battery solid-solid conversion cathode electrolyte interface no-shuttle-effect

来源：

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

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

引用

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Density functional theory study of methane dehydrogenation on the Pt/TiO2（101） surface

Density functional theory study of methane dehydrogenation o...

引用

第十三届全国量子化学会议

作者： wang xiujun South China University of Technology

The activation barriers of elementary-like reactions pertaining to methane dehydrogenation over single atom platinum（Pt） supported on anatase TiO（101） surface（Pt/TiO） was studied using periodic density functional theory（DFT） calculation. A clear clue for inhibiting carbon deposition over the Pt/TiO surface was elucidated. The possible intermediates（CHx, x = 0-3） involved in the methane dehydrogenation were calculated to determine the optimum adsorption sites. The results showed that methane（CH）, methyl（CH）, and methylidyne（CH）preferred to adsorb on the top of Pt atom, while the most stable sites of methlene（CH）, hydrogen（H）, and carbon（C） were the bridge *** CH and C were adsorbed on the surface, the Pt atom could be pulled out of the original site. The adsorption energies of methane and the dissociation species followed the order: CH < CH < H < CH < CH< C. On the Pt/TiO（101） surface, CH dehydrogenation proceeded with the highest barrier of 1.538 eV, showing that CH → C+H was the rate-limiting step. The carbon formation was much more difficult than the other reaction steps, and CH was identified as the most stable intermediate, indicating that Pt/TiO processes the excellent ability for inhibiting carbon deposition.

关键词： methane dehydrogenation density functional theory platinum anatase TiO2(101)

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

装配式梁柱外环板高强螺栓连接节点抗弯承载力及节点刚度研究

引用

天津大学学报（自然科学与工程技术版） 2019年第A02期52卷 75-82页

作者：王修军王燕安琦青岛理工大学土木工程学院青岛266033 青岛理工大学蓝色经济区工程建设与安全协同创新中心青岛266033

提出一种装配式梁柱外环板高强螺栓连接节点,针对节点力学性能进行了理论分析和数值模拟研究,分析节点失效破坏模式,推导节点极限抗弯承载力及节点初始转动刚度计算公式,提出装配式梁柱外环板高强螺栓连接节点弯矩-转角曲线计算方法.建... 详细信息

提出一种装配式梁柱外环板高强螺栓连接节点,针对节点力学性能进行了理论分析和数值模拟研究,分析节点失效破坏模式,推导节点极限抗弯承载力及节点初始转动刚度计算公式,提出装配式梁柱外环板高强螺栓连接节点弯矩-转角曲线计算方法.建立5个十字形节点有限元数值计算模型,运用ABAQUS有限元软件进行静力加载数值模拟,研究节点构造参数对节点力学性能影响.研究结果表明:柱宽厚比及外环板厚度对节点破坏模式有一定影响,柱宽厚比增大,节点承载力、初始转动刚度均增加,建议柱宽厚比控制在16~20;随外环板厚度增加,节点刚度有所增加,建议外环板厚度比梁翼缘厚度增加2 mm;节点弯矩-转角曲线理论计算值与数值计算值吻合较好,验证了节点弯矩-转角曲线理论计算方法的有效性.

关键词：外环板高强螺栓梁柱连接节点弯矩-转角曲线节点刚度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：