检索结果-南通市图书馆

NFT Security Matrix:Towards Modeling NFT Ecosystem Threat

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3255-3285页

作者： Peng Liao Chaoge Liu Jie yin Zhi wang Xiang Cui Key Laboratory of Trustworthy Distributed Computing and Service Beijing University of Posts and TelecommunicationsBeijing100876China Zhongguancun Laboratory Beijing100094China Institute of Information Engineering Chinese Academy of SciencesBeijing100085China

Digital assets have boomed over the past few years with the emergence of Non-fungible Tokens(NFTs).To be specific,the total trading volume of digital assets reached an astounding$55.5 billion in ***,numerous security concerns have been raised by the rapid expansion of the NFT *** holders are exposed to a plethora of scams and traps,putting their digital assets at risk of being ***,academic research on NFT security is scarce,and the security issues have aroused rare *** this study,the NFT ecological process is comprehensively *** process falls into five different stages encompassing the entire lifecycle of ***,the security issues regarding the respective stage are elaborated and analyzed in depth.A matrix model is proposed as a novel contribution to the categorization of NFT security *** data are collected from social networks,the Ethereum blockchain,and NFT markets to substantiate our claims regarding the severity of security concerns in the NFT *** this comprehensive dataset,nine key NFT security issues are identified from the matrix model and then subjected to qualitative and quantitative *** study aims to shed light on the severity of NFT ecosystem security *** findings stress the need for increased attention and proactive measures to safeguard the NFT ecosystem.

关键词： Non-fungible token blockchain cyber security

Preparation and performance improvement of a dual-component microcapsule self-healing system for silicone rubber insulating material

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2024年第2期9卷 453-465页

作者： Mingzhe Li Bin Cao Fanghui yin Hongwei Mei Liming wang Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhenChina

A key factor limiting the development of silicone rubber insulating materials is their short service life in harsh operating *** establishment of a self-healing system is desired to improve the long-term operational performance of silicone rubber and effectively extend its service *** this study,poly(urea-formaldehyde)microcapsules containing polydimethylsiloxane healing agents are prepared and a dual-component microcapsule self-healing system for silicone rubber material is established and *** addition,the key factors affecting the self-healing performance(such as microcapsule size,rupture rate,and microcapsule doping amount)are *** is found that when SYLGARDTM 184 is used as the healing agent and matrix,with a 4:6(A:B)doping ratio of dual-component microcapsules and 20 phr doping amount,the self-healing efficiency is approximately 51%.Furthermore,increasing the microcapsule rupture rate and the interface strength between the healing agent and the matrix can effectively improve the self-healing *** relationships between key factors and self-healing performance are theoretically *** on the relationships,the microcapsule self-healing system can be appropriately *** results of this paper can provide a reference for the development of long-life silicone rubber insulating materials.

关键词： service rubber performance

Flashover Characteristics of Dry Band-water band on Hydrophobic Surfaces

在线全文

维普期刊数据库

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 392-400页

作者： Xiaohan Wu Fanghui yin Bin Cao Daiming Yang Shichao Shao Liming wang Tsinghua-Berkeley Shenzhen Institute(TBSI) Shenzhen 518055China Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China Shenzhen Polytechnic School Shenzhen 518055China

Due to their outstanding anti-flashover characteristics,composite insulators have been extensively applied in power systems.A lot of research has investigated flashover characteristics of hydrophobic specimens with artificial water ***,the phenomenon is not consistent with that of the contaminated composite *** the test specimens covered with water droplets,there is no obvious leakage current before the flashover and no obvious relationship between flashover voltage and the conductivity of water *** the contaminated composite insulator surface,there are short continuous arcs on the insulators before critical flashover,making insulators look like a luminous *** that under these two conditions,the proportion of water along the insulation distance is different,the flashover characteristic of“dry band-water band”on a hydrophobicity surface is analyzed in the present *** influence of the water band parameter(including length,width,and conductivity)as well as the length of dry band is *** this basis,the arc generation and development process of the surface covered with“dry band-water band”is *** research results improve the understanding of the flashover process on contaminated composite insulators.

关键词： Flashover characteristics hydrophobicity partial arc water band

Structural parameter optimization of a furrow opener based on EDEM software

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 Agricultural and Biological Engineering 2024年第3期17卷 115-120页

作者： Longjie wang Bin Zhou Chang Wan ling Zhou College of Mechanical and Electrical Engineering Tarim UniversityAlar 843300XinjiangChina Modern Agricultural Engineering Key Laboratory at Universities of Education Department of Xinjiang Uygur Autonomous Region Alar 843300XinjiangChina Xinjiang Production and Construction Corps(XPCC)Key Laboratory of Utilization and Equipment of Special Agricultural and Forestry Products in Southern Xinjiang Alar 843300XinjiangChina

To reduce the ditching resistance of a furrow opener during operation,single-factor and multiple-factor combinations were used to explore the influence of the furrow opener’s advance speed,blade opening angle,and width on the ditching resistance based on the discrete element method(DEM).A DEM simulation of the furrow opener was *** changing these influencing factors,the parameters with the least resistance to operation were *** openers were fabricated according to the optimized results,and soil trench tests were carried *** and soil groove tests showed that the minimum ditching resistance was 58.54 N when the current advance speed was 4.47 m/s,the blade opening angle was 32.02°,and the furrow opener width was 51.45 *** error between the simulated value of the ditching resistance and the soil trench test was within 10%,and the trends of resistance change were essentially the same,indicating that it is feasible to optimize the structural parameters of a trench furrow opener using *** research results can provide a reference for the parameter optimization of furrow openers.

关键词： furrow opener discrete element optimization ditching resistance

The effect of bladder function on the efficacy of transurethral prostatectomy in patients with benign prostatic hyperplasia:a retrospective,single-center study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2024年第1期26卷 112-118页

作者： Jin Li Xian-Yan-ling Yi Ze-Yu Chen Bo Chen yin Huang Da-Zhou Liao Pu-Ze wang De-Hong Cao Jian-Zhong Ai Liang-Ren Liu West China School of Medicine Sichuan UniversityChengdu 610041China Department of Urology Institute of UrologyWest China HospitalSichuan UniversityChengdu 610041China

We investigated the impact and predictive value of bladder function in patients with benign prostatic hyperplasia(BPH)on the efficacy of transurethral ***,imaging,and urodynamic data of patients who underwent transurethral prostatectomy at West China Hospital of Sichuan University(Chengdu,China)from July 2019 to December 2021 were ***-up data included the quality of life(QoL),International Prostate Symptom Score(IPSS),and IPSS storage and voiding(IPSS-s and IPSS-v).Moreover,urinary creatinine(Cr),nerve growth factor(NGF),brain-derived neurotrophic factor(BDNF),and prostaglandin estradiol(PGE2)were measured in 30 patients with BPH and 30 healthy *** indicators were determined by subgroup analyses and receiver operating characteristic(ROC)curve *** the 313 patients with BPH included,patients with severe micturition problems had more improvements but higher micturition grades postoperatively than those with moderate ***,good bladder sensation,compliance,and detrusor contractility(Dc)were predictors of low postoperative IPSS and *** urinary concentrations of BDNF/Cr,NGF/Cr,and PGE2/Cr in patients were significantly higher than those in healthy participants(all P<***1).After evaluation,only DC was significantly related to both urinary indicators and postoperative recovery of *** with good DC,as predicted by urinary indicators,had lower IPSS and IPSS-v than those with reduced DC at the 1st month postoperatively(both P<0.05).In summary,patients with impaired bladder function had poor *** combined levels of urinary BDNF/Cr,NGF/Cr,and PGE2/Cr in patients with BPH may be valid predictors of preoperative bladderfunction and postoperative recovery.

关键词： BPH function of bladder IPSS:urodynamics

Chemoselective and Living/Controlled Polymerization of Alkenyl Methacrylates by the Phosphonium Ylide/Organoaluminum Lewis Pairs

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 Polymer Science 2024年第2期42卷 159-167,I0005页

作者： Zhi-Kang Chen Wu-Chao Zhao Yi-ling Zhao Cong-Lei Liu Liu-yin Jiang Yue-Tao Zhang Hong-Ping Zhu State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun130012China

Chemoselective,living/controlled polymerizations of allyl methacrylate(AMA) and vinyl methacrylate(VMA) with/without methyl methacrylate(MMA) by using the phosphonium ylide/organoaluminum based Lewis pairs(LPs) have been *** P-ylide-2/AIMe(BHT)_(2)(Pylide-2=Ph_(3)P=CHMe and BHT=2,6-iBu_(2)-4-MeC_(6)H_(2)O) was demonstrated to be superior by which homopolymers PAMAs(M_(n)=27.6-111.5kg/mol and ■=1.14-1.25) and PVMAs(M_(n)=28.4-78.4 kg/mol and ■=1.12-1.18) and block copolymers PMMA-b-PAMA,PAMA-b-PVMA,PAMA-bPMMA,PMMA-b-PAMA-b-PMMA,PAMA-b-PMMA-b-PAMA,and PAMA-b-PVMA-b-PAMA were *** the polymerizations,all of the monomers were reacted by the conjugated ester vinyl groups leaving intactly the nonconjugated acryloxy *** pendant acryloxy groups attached to the main chain enable further to post-functionalization by the AIBN-induced radical "thiol-ene" reaction using PhCH_(2)*** thiolether side group-containing polymers PAMA-SCH_(2)Ph and PAMA-SCH_(2)Ph-b-PMMA-b-PAMA-SCH_(2)Ph were thus prepared.

关键词： Phosphonium ylide Alkenyl methacrylate Chemoselectivity Living/controlled polymerization Post-functionalization

Broadband high-efficiency plasmonic metalens with negative dispersion characteristic

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

Photonics Research 2024年第4期12卷 813-820页

作者： YONG-QIANG LIU YONG ZHU HONGCHENG yin JINHAI SUN YAN wang YONGXING CHE National Key Laboratory of Scattering and Radiation Beijing 100854China

Controlling the dispersion characteristic of metasurfaces(or metalenses) along a broad bandwidth is of great importance to develop high-performance broadband metadevices. Different from traditional lenses that rely on the material refractive index along the light trajectory, metasurfaces or metalenses provide a new regime of dispersion control via a sub-wavelength metastructure, which is known as negative chromatic ***, broadband metalenses design with high-performance focusing especially with a reduced device dimension is a significant challenge in society. Here, we design, fabricate, and demonstrate a broadband highperformance diffractive-type plasmonic metalens based on a circular split-ring resonator metasurface with a relative working bandwidth of 28.6%. The metalens thickness is only 0.09λ0(λ0is at the central wavelength),which is much thinner than previous broadband all-dielectric metalenses. The full-wave simulation results show that both high transmissive efficiency above 80%(the maximum is even above 90%) and high average focusing efficiency above 45%(the maximum is 56%) are achieved within the entire working bandwidth of 9–12 ***, an average high numerical aperture of 0.7(NA = 0.7) of high-efficiency microwave metalens is obtained in the simulations. The broadband high-performance metalens is also fabricated and experimental measurements verify its much higher average focusing efficiency of 55%(the maximum is above 65% within the broad bandwidth) and a moderate high NA of 0.6. The proposed plasmonic metalens can facilitate the development of wavelength-dependent broadband diffractive devices and is also meaningful to further studies on arbitrary dispersion control in diffractive optics based on plasmonic metasurfaces.

关键词： resonator dispersion high

A Matching Algorithm with Reinforcement Learning and Decoupling Strategy for Order Dispatching in On-Demand Food Delivery

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

Tsinghua Science and Technology 2024年第2期29卷 386-399页

作者： Jingfang Chen ling wang Zixiao Pan Yuting Wu Jie Zheng Xuetao Ding Department of Automation Tsinghua UniversityBeijing 100084China Department of Delivery Technology MeituanBeijing 100102China

The on-demand food delivery(OFD)service has gained rapid development in the past decades but meanwhile encounters challenges for further improving operation *** order dispatching problem is one of the most concerning issues for the OFD platforms,which refer to dynamically dispatching a large number of orders to riders reasonably in very limited decision *** solve such a challenging combinatorial optimization problem,an effective matching algorithm is proposed by fusing the reinforcement learning technique and the optimization ***,to deal with the large-scale complexity,a decoupling method is designed by reducing the matching space between new orders and ***,to overcome the high dynamism and satisfy the stringent requirements on decision time,a reinforcement learning based dispatching heuristic is *** be specific,a sequence-to-sequence neural network is constructed based on the problem characteristic to generate an order priority ***,a training approach is specially designed to improve learning ***,a greedy heuristic is employed to effectively dispatch new orders according to the order priority *** real-world datasets,numerical experiments are conducted to validate the effectiveness of the proposed *** results show that the proposed algorithm can effectively solve the problem by improving delivery efficiency and maintaining customer satisfaction.

关键词： order dispatching on-demand delivery reinforcement learning decoupling strategy sequence-to-sequence neural network

Towards Domain-agnostic Depth Completion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第4期21卷 652-669页

作者： Guangkai Xu Wei yin Jianming Zhang Oliver wang Simon Niklaus Simon Chen Jia-wang Bian Zhejiang University Hangzhou 310058China DaJiang Technology Shenzhen 518057China Adobe Research California 95110USA University of Oxford Oxford OX12JDUK

Existing depth completion methods are often targeted at a specific sparse depth type and generalize poorly across task *** present a method to complete sparse/semi-dense,noisy,and potentially low-resolution depth maps obtained by various range sensors,including those in modern mobile phones,or by multi-view reconstruction *** method leverages a data-driven prior in the form of a single image depth prediction network trained on large-scale datasets,the output of which is used as an input to our *** propose an effective training scheme where we simulate various sparsity patterns in typical task *** addition,we design two new benchmarks to evaluate the generalizability and robustness of depth completion *** simple method shows superior cross-domain generalization ability against state-of-the-art depth completion methods,introducing a practical solution to highqualitydepthcapture onamobile device.

关键词： Monocular depth estimation depth completion zero-shot generalization scene reconstruction neural network.