检索结果-南通市图书馆

A fast forward computational method for nuclear measurement using volumetric detection constraints

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第2期35卷 47-63页

作者： qiong Zhang Lin-Lv Lin University of Electronic Science and Technology of China Chengdu 610000China

Owing to the complex lithology of unconventional reservoirs,field interpreters usually need to provide a basis for interpretation using logging simulation *** the various detection tools that use nuclear sources,the detector response can reflect various types of information of the *** Monte Carlo method is one of the primary methods used to obtain nuclear detection responses in complex ***,this requires a computational process with extensive random sampling,consumes considerable resources,and does not provide real-time response ***,a novel fast forward computational method(FFCM)for nuclear measurement that uses volumetric detection constraints to rapidly calculate the detector response in various complex environments is ***,the data library required for the FFCM is built by collecting the detection volume,detector counts,and flux sensitivity functions through a Monte Carlo ***,based on perturbation theory and the Rytov approximation,a model for the detector response is derived using the flux sensitivity function method and a one-group diffusion *** environmental perturbation is constrained to optimize the model according to the tool structure and the impact of the formation and borehole within the effective detection ***,the method is applied to a neutron porosity tool for *** various complex simulation environments,the maximum relative error between the calculated porosity results of Monte Carlo and FFCM was 6.80%,with a rootmean-square error of 0.62 *** field well applications,the formation porosity model obtained using FFCM was in good agreement with the model obtained by interpreters,which demonstrates the validity and accuracy of the proposed method.

关键词： Nuclear measurement Fast forward computation Volumetric constraints

On Hamiltonian Property of Cayley Digraphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 547-556页

作者： Fang DUAN qiong-xiang HUANG School of Mathematics Science Xinjiang Normal UniversityUrumqi 830017China College of Mathematics and Systems Science Xinjiang UniversityUrumqi 830017China

Let G be a finite group generated by S and C(G,S) the Cayley digraphs of G with connection set *** this paper,we give some sufficient conditions for the existence of hamiltonian circuit in C(G,S),where G=Zm×H is a semiproduct of Zmby a subgroup H of *** particular,if m is a prime,then the Cayley digraph of G has a hamiltonian circuit unless G=Zm×*** addition,we introduce a new digraph operation,called φ-semiproduct of Γ1by Γ2and denoted by Γ1×Γ_φΓ2,in terms of mapping φ:V(Γ2)→{1,-1}.Furthermore we prove that C(Zm,{a})×_φ C(H,S) is also a Cayley digraph if φ is a homomorphism from H to{1,-1} ≤ Zm~*,which produces some classes of Cayley digraphs that have hamiltonian circuits.

关键词： Cayley digraphs hamiltonian circuit external semidirect product

Simulation study on the security of consensus algorithms in DAG-based distributed ledger

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第3期18卷 171-182页

作者： Shuzhe LI Hongwei XU qiong LI Qi HAN Faculty of Computing Harbin Institute of TechnologyHarbin 150001China

Due to the advantages of high volume of transactions and low resource consumption,Directed Acyclic Graph(DAG)-based Distributed Ledger Technology(DLT)has been considered a possible next-generation alternative to ***,the security of the DAG-based system has yet to be comprehensively *** at verifying and evaluating the security of DAG-based DLT,we develop a Multi-Agent based IOTA Simulation platform called *** MAIOTASim,we model honest and malicious nodes and simulate the configurable network environment,including network topology and *** double-spending attack is a particular security issue related to *** perform the security verification of the consensus algorithms under multiple double-spending attack *** simulations show that the consensus algorithms can resist the parasite chain attack and partially resist the splitting attack,but they are ineffective under the large weight *** take the cumulative weight difference of transactions as the evaluation criterion and analyze the effect of different consensus algorithms with parameters under each attack ***,MAIOTASim enables users to perform largescale simulations with multiple nodes and tens of thousands of transactions more efficiently than state-of-the-art ones.

关键词： distributed ledger IOTA Multi-Agent system simulation

An Intelligent Sensor Data Preprocessing Method for OCT Fundus Image Watermarking Using an RCNN

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2期138卷 1549-1561页

作者： Jialun Lin qiong Chen College of Biomedical Information and Engineering Hainan Medical UniversityHaikou571199China TJ-YZ School of Network Science Haikou University of EconomicsHaikou571127China Department of Earth System Science Ministry of Education Key Laboratory for Earth SystemModelingInstitute forGlobal Change StudiesTsinghua UniversityBeijing100084China

Watermarks can provide reliable and secure copyright protection for optical coherence tomography(OCT)fundus *** effective image segmentation is helpful for promoting OCT image ***,OCT images have a large amount of low-quality data,which seriously affects the performance of ***,this paper proposes an effective segmentation method for OCT fundus image watermarking using a rough convolutional neural network(RCNN).First,the rough-set-based feature discretization module is designed to preprocess the input ***,a dual attention mechanism for feature channels and spatial regions in the CNN is added to enable the model to adaptively select important information for ***,the refinement module for enhancing the extraction power of multi-scale information is added to improve the edge accuracy in *** is compared with CE-Net and MultiResUNet on 83 gold standard 3D retinal OCT data *** average dice similarly coefficient(DSC)obtained by RCNN is 6%higher than that of *** average 95 percent Hausdorff distance(95HD)and average symmetric surface distance(ASD)obtained by RCNN are 32.4%and 33.3%lower than those of MultiResUNet,*** also evaluate the effect of feature discretization,as well as analyze the initial learning rate of RCNN and conduct ablation experiments with the four different *** experimental results indicate that our method can improve the segmentation accuracy of OCT fundus images,providing strong support for its application in medical image watermarking.

关键词： Watermarks image segmentation rough convolutional neural network attentionmechanism feature discretization

Field Load Test Based SHM System Safety Standard Determination for Rigid Frame Bridge

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Structural Durability & Health Monitoring 2024年第3期18卷 361-376页

作者： Xilong Zheng qiong Wang Di Guan School of Civil and Architectural Engineering Harbin UniversityHarbin150076China

The deteriorated continuous rigid frame bridge is strengthened by external prestressing. Static loading tests wereconducted before and after the bridge rehabilitation to verify the effectiveness of the rehabilitation process. Thestiffness of the repaired bridge is improved, and the maximum deflection of the load test is reduced from 37.9 to27.6 mm. A bridge health monitoring system is installed after the bridge is reinforced. To achieve an easy assessmentof the bridge’s safety status by directly using transferred data, a real-time safety warning system is createdbased on a five-level safety standard. The threshold for each safety level will be determined by theoretical calculationsand the outcomes of static loading tests. The highest risk threshold will be set at the ultimate limit statevalue. The remaining levels, namely middle risk, low risk, and very low risk, will be determined usingreduction coefficients of 0.95, 0.9, and 0.8, respectively.

关键词： Continuous rigid frame bridge rehabilitation long-term monitoring field load test safety standard determination

Light/pH dual-responsive magnetic metal-organic frameworks composites for phosphorylated peptide enrichment

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 Chemical Letters 2024年第7期35卷 222-226页

作者： Rui Wang He Qi Haijiao Zheng qiong Jia College of Chemistry Jilin UniversityChangchun 130012China Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education School of Life SciencesJilin UniversityChangchun 130012China

Metal-organic frameworks(MOFs)combined with specific ligands are highly adaptable smart materials that can respond to external and physiological *** this study,we introduced a pyridinyl zwitterionic ligand with light/pH dual response into magnetic MOF composite(Fe_(3)O_(4)@ZW-MOF)for enrichment of phosphorylated peptides for the first *** introduction of the developed ligand gives MOF material dual response *** stimulation affects the generation/disappearance of free radicals of the pyridine derivative,resulting in a change in the charge gradient of the zwitterion,and zwitterion can also regulate the p H of the solution by adding acid or ***,the reversible capture and release of phosphorylated peptides can be easily achieved by adjusting light and *** established phosphorylated peptide enrichment platform exhibits high sensitivity(detection limit of 1 fmol),high selectivity(β-casein:BSA,1:1000),and good reusability(7 cycles).In addition,the method was applied to the enrichment of phosphorylated peptides in complex systems(non-fat milk and human serum),demonstrating the feasibility of this method for phosphoproteom *** conclusion,the synthesized Fe_(3)O_(4)@ZW-MOF is a promising MOF material,which provides the possibility to advance the application of responsive MOFs materials in proteomics.

关键词： Light pH Dual-response Metal-organic frameworks Phosphorylated peptide

Enhanced and asymmetric signatures of hybridization at climatic margins: Evidence from closely related dioecious fig species

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2024年第2期46卷 181-193页

作者： Jian-Feng Huang Clive T.Darwell Yan-qiong Peng CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China National Center for Genetic Engineering and Biotechnology(BIOTEC) 113 Thailand Science ParkPhahonyothin RoadKhlong NuengKhlong LuangPathum Thani 12120Thailand

Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of hybridization, particularly at ecological margins where parental species may exhibit reduced fitnesses. Moreover, it is unknown whether future ecosystem change will increase the prevalence of hybridization. Ficus heterostyla and F. squamosa are closely related species co-distributed from southern Thailand to southwest China where hybridization, yielding viable seeds, has been documented. As a robust test of ecological factors driving hybridization, we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range. Both species showed high population differentiation and strong patterns of isolation by distance. Admixture estimates exposed asymmetric interspecific gene *** of hybridization increase significantly towards higher latitude zones, peaking at the northern climatic margins. Geographic variation in reproductive phenology combined with ecologically challenging marginal habitats may promote this phenomenon. Our work is a first systematic evaluation of such patterns in a comprehensive, latitudinally-based clinal context, and indicates that tendency to hybridize appears strongly influenced by environmental conditions. Moreover, that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.

关键词： Hybridization Heterospecific visitation Fig Pollinator wasp Asymmetric gene flow

Current optimization-based control of dual three-phase PMSM for low-frequency temperature swing reduction

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4期34卷 238-246页

作者： Linlin Lu Xueqing Wang Luhan Jin qiong Liu Yun Zhang Yao Mao Key Laboratory of Optical Engineering Chinese Academy of SciencesChengdu 610209China Institute of Optics and Electronics Chinese Academy of SciencesChengdu 610209China University of Chinese Academy of Sciences Beijing 100049China College of Electrical Engineering Sichuan UniversityChengdu 610065China

In this paper,a control scheme based on current optimization is proposed for dual three-phase permanent-magnet synchronous motor(DTP-PMSM)drive to reduce the low-frequency temperature *** reduction of temperature swing can be equivalent to reducing maximum instantaneous phase copper loss in this ***,a two-level optimization aiming at minimizing maximum instantaneous phase copper loss at each electrical angle is ***,the optimization is transformed to a singlelevel optimization by introducing the auxiliary variable for easy *** that singleobjective optimization trades a great total copper loss for a small reduction of maximum phase copper loss,the optimization considering both instantaneous total copper loss and maximum phase copper loss is proposed,which has the same performance of temperature swing reduction but with lower total *** this way,the proposed control scheme can reduce maximum junction temperature by 11%.Both simulation and experimental results are presented to prove the effectiveness and superiority of the proposed control scheme for low-frequency temperature swing reduction.

关键词： Dual three-phase PMSM Low-frequency temperature swing Copper loss Current optimization Connected neutral points

Cationic Conjugated Oligomers for Efficient and Rapid Antibacterial Photodynamic Therapy via Both Type Ⅰ and Type Ⅱ Pathways

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第1期42卷 61-66页

作者： Huan Wang Shuwen Guo qiong Yuan Meiqi Li Yanli Tang Country Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province Key Laboratory of Applied Surface and Colloid ChemistryMinistry of EducationSchool of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'anShaanxi 710119China

Recently,photodynamic therapy(PDT)has attracted wide attention due to its less susceptibility to drug resistance,broad-spectrum biocidal activity and biosafety in normal ***,the traditional photosensitizers(Ps)face the disadvantage of poor therapeutic efficacy due to the requirement of an aerobic environment to generate ^(1)O_(2) through Type Ⅱ ***,we designed and synthesized a novel cationic conjugated oligomer oligo(phenylene vinylene)(OPV)and studied its antibacterial photodynamic activity against both Gram-negative Escherichia coli(***)and Gram-positive bacteria methicillin-resistant Staphylococcus aureus(MRSA).Importantly,the OpV can rapidly produce reactive oxygen species(ROs)through double pathways,Type Ⅰ and Ⅱ mechanism under white light irradiation,and efficiently kill *** and MRSA at a nanomolar *** dual type photosensitizing capability makes OPV promising for enhanced PDT to treat pathogens and tumors in complex environments.

关键词： Conjugated oligomers Antibacterial photodynamic therapy Oligo(phenylene vinylene) Reactive oxygen species Typelandll pathways