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Biogeographic affinitypartly shapes woody plant diversity along an elevational gradient in subtropical forests
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作者 Zhaochen Zhang Fang Wang +13 位作者 Xiaoran Wang Mufan Sun Pu Zheng Jingchao Zhao Junhong Chen Min Guan Pengcheng Liu Xiaofan Shang Yaoshun Lu Qingpei Yang Qingni Song Lin Chen Quying Zhong Jian Zhang 《Plant Diversity》 2025年第5期784-792,共9页
The ecological and evolutionary mechanisms underlying montane biodiversity patterns remain unresolved.To understand which factors determined community assembly rules in mountains,biogeographic affinity that represents... The ecological and evolutionary mechanisms underlying montane biodiversity patterns remain unresolved.To understand which factors determined community assembly rules in mountains,biogeographic affinity that represents the biogeographic and evolutionary history of species should incorporate with current environments.We aim to address two following questions:1)How does plant taxonomic and phylogenetic diversity with disparate biogeographic affinitiesvary along the subtropical elevational gradient?2)How do biogeographic affinityand environmental drivers regulate the community assembly?We collected woody plant survey data of 32 forest plots in a subtropical mountain of Mt.Guanshan with typical transitional characteristics,including 250 woody plant species belonging to 56 families and 118 genera.We estimated the effects of biogeographic affinity,climate and soil properties on taxonomic and phylogenetic diversity of plant communities employing linear regression and structural equation models.We found that the richness of temperate-affiliated species increased with elevations,but the evenness decreased,while tropical-affiliatedspecies had no significantpatterns.Winter temperature directly or indirectly via biogeographic affinityshaped the assemblage of woody plant communities along elevations.Biogeographic affinityaffected what kind of species could colonize higher elevations while local environment determined their fitnessto adapt.These results suggest that biogeographic affinityand local environment jointly lead to the dominance of temperate-affiliated species at higher elevations and shape the diversity of woody plant communities along elevational gradients.Our findingshighlight the legacy effect of biogeographic affinityon the composition and structure of subtropical montane forests. 展开更多
关键词 Taxonomic diversity Phylogenetic diversity Biogeographic affinity Cold tolerance Phylogenetic niche conservatism
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Ion coordination affinity and its application in mineral flotation
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作者 Hong-liang ZHANG Xin RAO +4 位作者 Chen-yang ZHANG Jian-hua CHEN Yang-ge ZHU Rong WANG Wei SUN 《Transactions of Nonferrous Metals Society of China》 2025年第10期3468-3479,共12页
The ion coordination affinities of the commonly found metal ions were evaluated using DFT calculations.The results indicate that the lowest unoccupied molecular orbital(LUMO)energy of metal ions correlates positively ... The ion coordination affinities of the commonly found metal ions were evaluated using DFT calculations.The results indicate that the lowest unoccupied molecular orbital(LUMO)energy of metal ions correlates positively with their binding energies with O(S)ligands,and some metal ions with various valence states also present different affinities.Besides,due to the steric hindrance effects,the mono-and hexa-coordinated metal ions may exhibit different affinities,and the majority of the studied hexa-coordinated metal ions exhibit oxophilicity.These affinity differences perfectly illustrate the activation flotation practice in which the oxyphilic ions are applied to activating oxide minerals,while thiophilic ions are applied to activating sulfide minerals. 展开更多
关键词 ion coordination affinity mineral flotation coordination chemistry density functional theory
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Self-optimized H-adsorption affinity of CuRu alloy cocatalysts towards efficient photocatalytic H_(2)evolution 被引量:2
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作者 Meiya Wang Ping Wang +2 位作者 Xuefei Wang Feng Chen Huogen Yu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第7期168-175,共8页
In addition to the electron transfer,the appropriate H-adsorption affinity of active centers on the metal cocatalyst surface is quite important for high hydrogen-production activity of cocatalyst-modified photo-cataly... In addition to the electron transfer,the appropriate H-adsorption affinity of active centers on the metal cocatalyst surface is quite important for high hydrogen-production activity of cocatalyst-modified photo-catalysts.The typical Cu and Ru metal cocatalysts clearly exhibit a weak Cu-H bond and a strong Ru-H bond,respectively,resulting in limited activity for photocatalytic H_(2)evolution.In this work,an ingenious strategy of self-optimized H-adsorption affinity in CuRu alloy cocatalyst is developed to simultaneously reinforce the Cu-H bond and weaken the Ru-H bond by the intrinsic electron transfer from Cu to Ru atom.The CuRu alloy nanoparticles(2-3 nm)were deposited on the TiO_(2)surface to prepare CuRu/TiO_(2)through a one-step photoreduction method.Photocatalytic tests exhibited that the highest H_(2)-production rate of CuRu/TiO_(2)photocatalyst reached up to 5.316 mmol h^(-1)g^(-1),which was 24.80,1.86,and 2.60 times higher than that of the TiO_(2),Cu/TiO_(2),and Ru/TiO_(2),respectively.Based on the characterization results and theoretical calculations,the CuRu alloy cocatalyst exhibits excellent self-optimized H-adsorption affinity via the spontaneous electron transfer from Cu to Ru atom,which can greatly accelerate the photocatalytic H_(2)-production rate of TiO_(2).This work provides a feasible idea for the self-optimized H-adsorption affinity of metal active sites in the photocatalytic H_(2)-generation field. 展开更多
关键词 TiO_(2) CuRu alloy Cocatalyst Self-optimized H-adsorption affinity Photocatalytic H_(2)generation
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多体非完全经典态的基于Affinity的关联测度
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作者 闫栋华 王银珠 《太原科技大学学报》 2024年第1期101-103,108,共4页
在量子信息理论中,量子关联是一种极其重要的物理资源。文章首先定义了多体非完全经典态基于Affinity的一种量子关联测度,它可以量化多体非完全经典态的关联程度;接下来证明了该关联测度满足量子关联度的一些必要物理性质,包括非负性、... 在量子信息理论中,量子关联是一种极其重要的物理资源。文章首先定义了多体非完全经典态基于Affinity的一种量子关联测度,它可以量化多体非完全经典态的关联程度;接下来证明了该关联测度满足量子关联度的一些必要物理性质,包括非负性、局部酉操作下的不变性、局部量子操作下的单调性、凸性以及连续性。 展开更多
关键词 多体复合系统 完全经典态 投影测量 量子关联度 affinity
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Comparative study of trastuzumab modification analysis using mono/ multi-epitope affinity technology with LC-QTOF-MS
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作者 Chengyi Zuo Jingwei Zhou +10 位作者 Sumin Bian Qing Zhang Yutian Lei Yuan Shen Zhiwei Chen Peijun Ye Leying Shi Mao Mu Jia-Huan Qu Zhengjin Jiang Qiqin Wang 《Journal of Pharmaceutical Analysis》 CSCD 2024年第11期1675-1685,共11页
Dynamic tracking analysis of monoclonal antibodies(mAbs)biotransformation in vivo is crucial,as certain modifications could inactivate the protein and reduce drug efficacy.However,a particular challenge(i.e.immune rec... Dynamic tracking analysis of monoclonal antibodies(mAbs)biotransformation in vivo is crucial,as certain modifications could inactivate the protein and reduce drug efficacy.However,a particular challenge(i.e.immune recognition deficiencies)in biotransformation studies may arise when modifications occur at the paratope recognized by the antigen.To address this limitation,a multi-epitope affinity technology utilizing the metal organic framework(MOF)@Au@peptide@aptamer composite material was proposed and developed by simultaneously immobilizing complementarity determining region(CDR)mimotope peptide(HH24)and non-CDR mimotope aptamer(CH1S-6T)onto the surface of MOF@Au nanocomposite.Comparative studies demonstrated that MOF@Au@peptide@aptamer exhibited significantly enhanced enrichment capabilities for trastuzumab variants in comparison to mono-epitope affinity technology.Moreover,the higher deamidation ratio for LC-Asn-30 and isomerization ratio for HCAsn-55 can only be monitored by the novel bioanalytical platform based on MOF@Au@peptide@aptamer and liquid chromatography-quadrupole time of flight-mass spectrometry(LC-QTOF-MS).Therefore,multi-epitope affinity technology could effectively overcome the biases of traditional affinity materials for key sites modification analysis of mAb.Particularly,the novel bioanalytical platform can be successfully used for the tracking analysis of trastuzumab modifications in different biological fluids.Compared to the spiked phosphate buffer(PB)model,faster modification trends were monitored in the spiked serum and patients'sera due to the catalytic effect of plasma proteins and relevant proteases.Differences in peptide modification levels of trastuzumab in patients'sera were also monitored.In summary,the novel bioanalytical platform based on the multi-epitope affinity technology holds great potentials for in vivo biotransformation analysis of mAb,contributing to improved understanding and paving the way for future research and clinical applications. 展开更多
关键词 Monoclonal antibody Multi-epitope affinity technology Biotransformation analysis LC-QTOF-MS Breast cancer
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Strategies for Enhancing the Affinity of College Ideological and Political Course Teachers
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作者 WANG Na 《Cultural and Religious Studies》 2024年第2期113-117,共5页
This article aims to explore effective ways to enhance the affinity of ideological and political course teachers in universities.By analyzing the connotation of affinity,the factors that affect the affinity of ideolog... This article aims to explore effective ways to enhance the affinity of ideological and political course teachers in universities.By analyzing the connotation of affinity,the factors that affect the affinity of ideological and political course teachers are analyzed,and corresponding improvement strategies are proposed.Research suggests that strengthening the construction of teacher ethics and conduct,improving teaching skills,enhancing emotional engagement,and enhancing practical training are key paths to enhance the affinity of ideological and political course teachers.The implementation of these paths will help improve the teaching quality and effectiveness of ideological and political courses,and promote the comprehensive development of students. 展开更多
关键词 ideological and political courses in universities teacher affinity improvement path teaching quality
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Characteristics and Affinity of Tropical Flora in Southern China 被引量:7
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作者 朱华 M.C.Roos 《Forestry Studies in China》 CAS 2002年第1期18-24,共7页
The tropical flora in southern China is represented mainly by three regional flora, i.e. southern Yunnan (southwestern China), southwestern Guangxi (southwestern China) and Hainan Island (southern China). The floristi... The tropical flora in southern China is represented mainly by three regional flora, i.e. southern Yunnan (southwestern China), southwestern Guangxi (southwestern China) and Hainan Island (southern China). The floristic composition of each is concisely enumerated. Their geographical elements at generic level are analyzed. Furthermore, a comparison of floristic similarities between southern Yunnan and Hainan Island and Malay Peninsula and Brunei of western Malesia is made, based on existing regional flora treatments. The following is concluded: (1) The flora of southern China consists mainly of tropical floristic elements which contribute about 60% at the family level and more than 80 % at the generic level of its total flora. The dominant distribution type of the flora of southern China at the generic level is the tropical Asian distribution pattern. This reveals that the flora of southern China is of tropical nature with a strong tropical Asian affinity; (2) Most of the dominant families from the flora of southern China are also dominant in the Malesian flora. The floristic similarities between the regional flora of southern China and the regional flora of western Malesia are over 70% at the family level and more than 50% at the generic level. This suggests that the tropical flora of southern China belongs to the Malesian floristic region; (3) Situated at the northern margin of tropical Asia, on the other hand it is also obvious that the flora of southern China comprises less strictly tropical elements compared to the Malesian flora, and is consequently only a marginal type of the latter; (4) The close affinity of the flora of southern China to the Malesian flora can be explained by the geological history of southeast Asia. 展开更多
关键词 southern China FLORA floristic composition affinity
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Affinity Chromatography Purification of Recombinant Human Interleukin-6 from Its Fusion Protein with GST
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作者 吴蕾 甘一如 +1 位作者 林峰 黄鹤 《Transactions of Tianjin University》 EI CAS 2002年第2期106-109,共4页
Recombinant E.coli JM109, containing pHZ1818 plasmid which included the fused gene encoding human interleukin 6(IL 6), expressed a fusion protein with glutathion S transferase(GST). The fusion protein existed both... Recombinant E.coli JM109, containing pHZ1818 plasmid which included the fused gene encoding human interleukin 6(IL 6), expressed a fusion protein with glutathion S transferase(GST). The fusion protein existed both in the supernatant and inside the bacterial cell,but the insoluble protein had no biological activity and could not be refolded. The rotative speed of the shaker and the temperature of induction were optimized to maximize the expression of the soluble fusion protein. From the supernatant of the cell sonicates Glutathion Sephrose 4B affinity column chromatography was employed to isolate the fusion protein which could be purified to >80 0 0 in a single step. The yield of soluble GST IL 6 was about 10 mg per liter culture. The GST was site specifically cloven by 6 hours of treatment with thrombin and from the thrombin digest mixture IL 6 was purified by Q high performance ion exchange chromatography. From 1 liter of E.coli culture 2 mg refined IL 6 was obtained. The purified IL 6 had a purity of more than 95 0 0 and a biological activity of 1.02×10 8 IU/mg. 展开更多
关键词 affinity purification human interleukin 6 fusion protein GST
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Identification and characterization of GIP1,an Arabidopsis thaliana protein that enhances the DNA binding affinity and reduces the oligomeric state of G-box binding factors
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作者 Paul C.SEHNKE Beth J.LAUGHNER +2 位作者 Carla R.LYERLY LINEBARGER William B.GURLEY Robert J.FERL 《Cell Research》 SCIE CAS CSCD 2005年第8期567-575,共9页
Environmental control of the alcohol dehydrogenase(Adh)and other stress response genes in plants is in part brought about by transcriptional regulation involving the G-box cis-acting DNA element and bZIP G-box Binding... Environmental control of the alcohol dehydrogenase(Adh)and other stress response genes in plants is in part brought about by transcriptional regulation involving the G-box cis-acting DNA element and bZIP G-box Binding Factors(GBFs).The mechanisms of GBF regulation and requirements for additional factors in this control process are not well understood.In an effort to identify potential GBF binding and control partners,maize GBF1 was used as bait in a yeast two-hybrid screen of an A.thaliana cDNA library.GBF Interacting Protein 1(GIP1)arose from the screen as a 496 amino acid protein with a predicted molecular weight of 53,748 kDa that strongly interacts with GBFs.Northern analysis of A.thaliana tissue suggests a 1.8-1.9 kb GIP1 transcript,predominantly in roots.Immunolocalization studies indicate that GIP1 protein is mainly localized to the nucleus.In vitro electrophoretic mobility shift assays using an Adh G-box DNA probe and recombinant A.thaliana GBF3 or maize GBF1,showed that the presence of GIP1 resulted in a tenfold increase in GBF DNA binding activity without altering the migration,suggesting a transient association between GIP1 and GBF.Addition of GIP1 to intentionally aggregated GBF converted GBF to lower molecular weight macromolecular complexes and GIP1 also refolded denatured rhodanese in the absence of ATP.These data suggest GIP1 functions to enhance GBF DNA binding activity by acting as a potent nuclear chaperone or crowbar,and potentially regulates the multimeric state of GBFs,thereby contributing to bZIP-mediated gene regulation. 展开更多
关键词 G-box binding factor interacting protein nuclear chaperone DNA binding affinity.
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High-throughput and intelligent design of potential GRK2 inhibitor candidates using deep learning and mathematical programming methods
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作者 Yujing Zhao Qilei Liu +3 位作者 Jian Du Qingwei Meng Liang Sun Lei Zhang 《Chinese Journal of Chemical Engineering》 2025年第8期11-22,共12页
G protein coupled receptor kinase 2 (GRK2) is a kinase that regulates cardiac signaling activity. Inhibiting GRK2 is a promising mechanism for the treatment of heart failure (HF). Further development and optimization ... G protein coupled receptor kinase 2 (GRK2) is a kinase that regulates cardiac signaling activity. Inhibiting GRK2 is a promising mechanism for the treatment of heart failure (HF). Further development and optimization of inhibitors targeting GRK2 are highly meaningful. Therefore, in order to design GRK2 inhibitors with better performance, the most active molecule was selected as a reference compound from a data set containing 4-pyridylhydrazone derivatives and triazole derivatives, and its scaffold was extracted as the initial scaffold. Then, a powerful optimization-based framework for de novo drug design, guided by binding affinity, was used to generate a virtual molecular library targeting GRK2. The binding affinity of each virtual compound in this dataset was predicted by our developed deep learning model, and the designed potential compound with high binding affinity was selected for molecular docking and molecular dynamics simulation. It was found that the designed potential molecule binds to the ATP site of GRK2, which consists of key amino acids including Arg199, Gly200, Phe202, Val205, Lys220, Met274 and Asp335. The scaffold of the molecule is stabilized mainly by H-bonding and hydrophobic contacts. Concurrently, the reference compound in the dataset was also simulated by docking. It was found that this molecule also binds to the ATP site of GRK2. In addition, its scaffold is stabilized mainly by H-bonding and π-cation stacking interactions with Lys220, as well as hydrophobic contacts. The above results show that the designed potential molecule has similar binding modes to the reference compound, supporting the effectiveness of our framework for activity-focused molecular design. Finally, we summarized the interaction characteristics of general GRK2 inhibitors and gained insight into their molecule-target binding mechanisms, thereby facilitating the expansion of lead to hit compound. 展开更多
关键词 Mathematical modeling Optimal design Product design GRK2 Mathematical programmingmethod Binding affinity
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Fe^(3+) ion quantification with reusable bioinspired nanopores
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作者 Yanqiong Wang Yaqi Hou +1 位作者 Fengwei Huo Xu Hou 《Chinese Chemical Letters》 2025年第2期179-184,共6页
Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmenta... Excessive Fe^(3+) ion concentrations in wastewater pose a long-standing threat to human health.Achieving low-cost,high-efficiency quantification of Fe^(3+) ion concentration in unknown solutions can guide environmental management decisions and optimize water treatment processes.In this study,by leveraging the rapid,real-time detection capabilities of nanopores and the specific chemical binding affinity of tannic acid to Fe^(3+),a linear relationship between the ion current and Fe^(3+) ion concentration was established.Utilizing this linear relationship,quantification of Fe^(3+) ion concentration in unknown solutions was achieved.Furthermore,ethylenediaminetetraacetic acid disodium salt was employed to displace Fe^(3+) from the nanopores,allowing them to be restored to their initial conditions and reused for Fe^(3+) ion quantification.The reusable bioinspired nanopores remain functional over 330 days of storage.This recycling capability and the long-term stability of the nanopores contribute to a significant reduction in costs.This study provides a strategy for the quantification of unknown Fe^(3+) concentration using nanopores,with potential applications in environmental assessment,health monitoring,and so forth. 展开更多
关键词 Bioinspired nanopores Fe^(3+)ion quantification Chemical binding affinity Tannic acid REUSABILITY
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Combining label-free quantitative proteomics and 2D-DIGE to identify the potential targets of Sini Decoction acting on myocardial infarction
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作者 Fei Feng Weiyue Zhang +4 位作者 Yan Cao Diya Lv Yifeng Chai Dandan Guo Xiaofei Chen 《Chinese Journal of Natural Medicines》 2025年第8期1016-1024,共9页
Sini Decoction(SNT)is a traditional formula recognized for its efficacy in warming the spleen and stomach and dispersing cold.However,elucidating the mechanism of action of SNT remains challenging due to its complex m... Sini Decoction(SNT)is a traditional formula recognized for its efficacy in warming the spleen and stomach and dispersing cold.However,elucidating the mechanism of action of SNT remains challenging due to its complex multiple components.This study utilized a synergistic approach combining two-dimensional fluorescence difference in gel electrophoresis(2D-DIGE)-based drug affinity responsive target stability(DARTS)with label-free quantitative proteomics techniques to identify the direct and indirect protein targets of SNT in myocardial infarction.The analysis identified 590 proteins,with 30 proteins showing significant upregulation and 51 proteins showing downregulation when comparing the SNT group with the model group.Through the integration of 2D-DIGE DARTS with proteomics data and pharmacological assessments,the findings indicate that protein disulfide-isomerase A3(PDIA3)may serve as a potential protein target through which SNT provides protective effects on myocardial cells during myocardial infarction. 展开更多
关键词 Sini Decoction Myocardial infarction Drug affinity response target stability Label-free quantitative proteomics
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Based on DAP⁃seq method: exploring target genes and regulatory network of SmWRKY69
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作者 ZHANG Ke TAN Jingfu +4 位作者 YANG Xu LIU Yiru CAO Jiajia LI Yajing CHEN Junfeng 《上海中医药大学学报》 2025年第4期25-34,共10页
Objective:Salvia miltiorrhiza is widely used in traditional Chinese medicine for treating cardiovascular and cerebrovascular diseases,with tanshinones being its major active components.This study aims to systematicall... Objective:Salvia miltiorrhiza is widely used in traditional Chinese medicine for treating cardiovascular and cerebrovascular diseases,with tanshinones being its major active components.This study aims to systematically elucidate the core transcriptional circuitry controlling tanshinone production,thereby establishing a mechanistic framework to optimize phytochemical yield and advance sustainable cultivation strategies for this pharmaceutically vital species.Methods:Transcriptome profiling revealed that the transcription factor SmWRKY69 is specifically expressed in the root periderm of S.miltiorrhiza.DNA affinity purification sequencing(DAPseq)was used to identify its potential target genes,and cis-element analysis predicted W-box motifs in the promoters of SmCPS1 and SmKSL1.Yeast one-hybrid(Y1H)assays were employed to validate its regulatory interactions with candidate gene promoters.Results:SmWRKY69 was found to directly bind to the promoters of SmCPS1 and SmKSL1,key genes in the tanshinone biosynthetic pathway,through W-box elements,indicating its role as a transcriptional regulator.Conclusion:SmWRKY69 regulates tanshinone biosynthesis by directly targeting SmCPS1 and SmKSL1,providing a valuable genetic target for metabolic engineering to enhance the therapeutic quality of S.miltiorrhiza. 展开更多
关键词 TANSHINONE transcriptional regulation WRKY transcription factors DNA affinity purification sequencing
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Advances in small molecule representations and AI-driven drug research:bridging the gap between theory and application
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作者 Junxi Liu Shan Chang +2 位作者 Qingtian Deng Yulian Ding Yi Pan 《Chinese Journal of Natural Medicines》 2025年第11期1391-1408,共18页
Artificial intelligence(AI)researchers and cheminformatics specialists strive to identify effective drug precursors while optimizing costs and accelerating development processes.Digital molecular representation plays ... Artificial intelligence(AI)researchers and cheminformatics specialists strive to identify effective drug precursors while optimizing costs and accelerating development processes.Digital molecular representation plays a crucial role in achieving this objective by making molecules machine-readable,thereby enhancing the accuracy of molecular prediction tasks and facilitating evidence-based decision making.This study presents a comprehensive review of small molecular representations and AI-driven drug discovery downstream tasks utilizing these representations.The research methodology begins with the compilation of small molecule databases,followed by an analysis of fundamental molecular representations and the models that learn these representations from initial forms,capturing patterns and salient features across extensive chemical spaces.The study then examines various drug discovery downstream tasks,including drug-target interaction(DTI)prediction,drug-target affinity(DTA)prediction,drug property(DP)prediction,and drug generation,all based on learned representations.The analysis concludes by highlighting challenges and opportunities associated with machine learning(ML)methods for molecular representation and improving downstream task performance.Additionally,the representation of small molecules and AI-based downstream tasks demonstrates significant potential in identifying traditional Chinese medicine(TCM)medicinal substances and facilitating TCM target discovery. 展开更多
关键词 Small molecular representation Drug-target interaction prediction Drug-target affinity prediction Drug property prediction De novo drug generation Traditional Chinese medicine
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Fault Detection of Yarn Congestion in Sizing Machine Based on Machine Vision
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作者 LI Jingwei ZOU Kun ZHAO Chen 《Journal of Donghua University(English Edition)》 2025年第3期292-300,共9页
During the sizing process,yarn congestion fault occurs at the reed teeth of a sizing machine.At present,the yarn congestion fault is generally handled by manual detection.The sizing production line operates on a large... During the sizing process,yarn congestion fault occurs at the reed teeth of a sizing machine.At present,the yarn congestion fault is generally handled by manual detection.The sizing production line operates on a large scale and runs continuously.Untimely handling of the yarn congestion fault causes a large amount of yarn waste.In this research,a machine vision-based algorithm for yarn congestion fault detection is developed.Through the analysis of the congestion fault and interference contour characteristics,the basic idea of image phase subtraction to identify the congestion fault is determined.To address the interference information appearing after image phase subtraction,the image pre-processing methods of Canny edge extraction and mean filtering are employed.According to the fault size and location characteristics,the fault contour detection algorithm based on inter-frame difference is designed.To mitigate the camera vibration interference,the anti-vibration interference algorithm based on affine transformation is studied,and the fault detection algorithm for the total yarn congestion fault is determined.The detection of 20 sets of field data is carried out,and the detection rate reaches 90%.This fault detection algorithm realizes the automatic detection of yarn congestion fault of sizing machine with certain real-time performance and accuracy. 展开更多
关键词 machine vision yarn congestion fault detection inter-frame difference affine transformation
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Distributed predefined-time estimator-based affine formation target-enclosing maneuver control for cooperative underactuated quadrotor UAVs with fault-tolerant capabilities
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作者 Yang XU Yuanfang QU +2 位作者 Delin LUO Haibin DUAN Zhengyu GUO 《Chinese Journal of Aeronautics》 2025年第1期471-490,共20页
The paper presents a two-layer,disturbance-resistant,and fault-tolerant affine formation maneuver control scheme that accomplishes the surrounding of a dynamic target with multiple underactuated Quadrotor Unmanned Aer... The paper presents a two-layer,disturbance-resistant,and fault-tolerant affine formation maneuver control scheme that accomplishes the surrounding of a dynamic target with multiple underactuated Quadrotor Unmanned Aerial Vehicles(QUAVs).This scheme mainly consists of predefinedtime estimators and fixed-time tracking controllers,with a hybrid Laplacian matrix describing the communication among these QUAVs.At the first layer,we devise predefined time estimators for leading and following QUAVs,enabling accurate estimation of desired information.In the second layer,we initially devise a fixed-time hybrid observer to estimate unknown disturbances and actuator faults.Fixedtime translational tracking controllers are then proposed,and the intermediary control input from these controllers is used to extract the desired attitude and angular velocities for the fixed-time rotational tracking controllers.We employ an exact tracking differentiator to handle variables that are challenging to differentiate directly.The paper includes a demonstration of the control system stability through mathematical proof,as well as the presentation of simulation results and comparative simulations. 展开更多
关键词 Affine formation maneuver control Target tracking Fixed-time control Quadrotor unmanned aerial vehicle Target enclosing Predefined-time estimation
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一类虚拟纽结的Affine Index多项式
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作者 郭兴博 《应用数学进展》 2025年第1期462-468,共7页
纽结理论是拓扑学的一个重要分支,虚拟纽结理论是经典纽结理论的推广,对它的研究是通过一种图解理论来展开的。虚拟纽结多项式是一类以多项式表达的虚拟纽结不变量,例如Arrow多项式和Wriggle多项式。Affine index多项式是以虚拟纽结图... 纽结理论是拓扑学的一个重要分支,虚拟纽结理论是经典纽结理论的推广,对它的研究是通过一种图解理论来展开的。虚拟纽结多项式是一类以多项式表达的虚拟纽结不变量,例如Arrow多项式和Wriggle多项式。Affine index多项式是以虚拟纽结图的整数标记定义的单变量多项式。本文主要计算一类特殊虚拟纽结的Affine index多项式。按照Cheng着色的规则,对虚拟纽结图的每一段弧进行整数标记,计算每个经典交叉点的指标值,进而得到这类特殊虚拟纽结的Affine index多项式的表达式。Knot theory is an important branch of topology. Virtual knot theory is a generalization of classical knot theory, and its research is carried out through a graphic theory. The virtual knot polynomial refers to a class of virtual knot invariant expressed by polynomials, such as the Arrow polynomial and the Wriggle polynomial. The affine index polynomial is a univariate polynomial defined by the integer label of a virtual knot graph. In this paper, we mainly calculate affine index polynomials for a special class of virtual knots. According to the rules of Cheng coloring, we will integer label each arc of the virtual knot graph and calculate the index value of each classical crossings, and then get the expression of the affine index polynomial of this special virtual knot. 展开更多
关键词 虚拟纽结 Affine Index多项式 Cheng着色 纽结不变量
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ARCHIMEDES'PRINCIPLE OF FLOTATION AND FLOATING BODIES:CONSTRUCTION,EXTENSIONS AND RELATED PROBLEMS
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作者 Chunyan LIU Elisabeth M.WERNER +1 位作者 Deping YE Ning ZHANG 《Acta Mathematica Scientia》 2025年第1期237-256,共20页
In this article,we explain how the famous Archimedes’principle of flotation can be used to construct various floating bodies.We survey some of the most important results regarding the floating bodies,including their ... In this article,we explain how the famous Archimedes’principle of flotation can be used to construct various floating bodies.We survey some of the most important results regarding the floating bodies,including their relations with affine surface area and projection body,their extensions in different settings such as space forms and log-concave functions,and mention some associated open problems. 展开更多
关键词 flfoating body affine surface area log-concave functions
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The Varieties of Semi-Conformal Vectors of Rank-One Even Lattice Vertex Operator Algebras
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作者 CHU Yan-jun GAO Yi-bo 《Chinese Quarterly Journal of Mathematics》 2025年第1期36-48,共13页
In this paper,we shall study structures of even lattice vertex operator algebras by using the geometry of the varieties of their semi-conformal vectors.We first give the varieties of semi-conformal vectors of a family... In this paper,we shall study structures of even lattice vertex operator algebras by using the geometry of the varieties of their semi-conformal vectors.We first give the varieties of semi-conformal vectors of a family of vertex operator algebras V_(√kA_(1)) associated to rank-one positive definite even lattices √kA_(1) for arbitrary positive integers k to characterize these even lattice vertex operator algebras.In such a family of lattice vertex operator algebras V_(√kA_(1)),the vertex operator algebra V_(√2A_(1)) is different from others.Hence we describe the varieties of semi-conformal vectors of V_(√2A_(1)) and the fixed vertex operator subalgebra V^(+)√2A_(1).Moreover,as applications,we study the relations between vertex operator algebras V_(√kA_(1) )and L_(sl_(2))(k,0)for arbitrary positive integers k by the viewpoint of semi-conformal homomorphisms of vertex operator algebras.For case k=2,in the series of rational simple affine vertex operator algebras L_(sl_(2))(k,0)for positive integers k,we show that L_(sl_(2))(2,0)is a unique frame vertex operator algebra with rank 3. 展开更多
关键词 Vertex operator algebra Semi-conformal vector Affine variety
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Research on feature matching strategy based on adaptive affine transformation
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作者 CAO Hengrui QIN Danyang +2 位作者 ZHANG Xiao CHEN Yuhong ZHAO Bojia 《High Technology Letters》 2025年第2期144-153,共10页
The inherent challenges arising from variations in user-captured viewpoints and object orientation disparities in real-world scenarios pose significant difficulties in establishing robust correspondence relationships ... The inherent challenges arising from variations in user-captured viewpoints and object orientation disparities in real-world scenarios pose significant difficulties in establishing robust correspondence relationships between image pairs.Methods based on geometric transformation estimation usually perform affine transformation of the global image for viewpoint correction,which not only increases the time complexity but also generates a large number of redundant features.To solve this problem,this paper proposes an adaptive affine transformation model(AATM)to achieve robust image matching by dividing special regions with pixel information and employing feature extraction algorithms with different granularities.First,the input image is divided into significant and non-significant regions by an adaptive algorithm.Second,for the salient region,the feature point extraction is accelerated by optimizing the longitude angle sampling algorithm and constructing the affine invariant nonlinear scale space,introducing the Hessian integral image and box filter.Then,for the non-significant region of the weak texture scene through the uniform step sampling algorithm,a dense feature description can be obtained in the weak texture scenes,so that more robust features are extracted for both significant and non-significant regions.The results of extensive experiments on two datasets show that the AATM algorithm outperforms similar algorithms in terms of the number of correctly matched pairs,elapsed time,and root mean square error(RMSE),indicating that the AATM can obtain more robust matches in scenes with large angle tilting and scale transformations. 展开更多
关键词 adaptive affine transformation optimizing the longitude angle sampling weak texture scene large angle tilting
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