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Forming process chain for manufacturing complex conical-section profiled rings:On a co-design method

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Chinese journal of Aeronautics 2024年第6期37卷 485-503页

作者： Lei liang Chaojiang ZOU lianggang gUO State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China guizhou Aviation technology Development Co.Ltd Guiyang 550081China

the final quality of complex conical-section rings depends on co-design of multiple processes in forming process *** this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the *** profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is *** the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the *** on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed *** view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design *** is demonstrated that the proposed design method has significant advantages in improving forming ***,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming *** corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.

关键词： Complex conical-section ring Co-design of forming process chain Profiled ringrolling Preformed blank Loose tooling forging

research on Credit Default Swaps Pricing Considering Moral hazard Incentive under reduce-Form Model

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journal of Systems Science and Systems Engineering 2024年第3期33卷 311-329页

作者： liang Wu Kangjie he Zhe guo School of Mathematical Science Henan Institute of Science and TechnologyXinxiang453003China Public Front Office Department Industrial and Commercial Bank of ChinaZhengzhou450000China

Equilibrium pricing of credit default swaps(CDS)promotes efficient identification of credit risk in the market,which in turn leads to efficient allocation of ***,even when CDS have been priced in equilibrium,i.e.,when premiums are equal to anticipated payments,the moral hazard incentives of CDS buyers increase with CDS ***,it becomes an interesting research direction to study the impact of moral hazard incentives on the trading mechanism or pricing of derivatives(CDS).Most of the existing literature on the impact of moral hazard incentives in CDS pricing on derivatives trading mechanisms takes a macro perspective and focuses on the agreement risk *** literature exploring the analysis of the impact of moral hazard on the probability of agreement default from a micro perspective is not yet *** this in mind,this paper focuses on the mechanisms by which“fraud”,an extreme manifestation of micro-moral hazard incentives,affects the probability of *** paper introduces for the first time the concept of“claiming fraud”by credit protection buyers,which is different from the macro perspective of moral hazard incentives,and thus defines a specific extreme form of moral hazard ***,to address the intrinsic feature of the lack of economic explanatory power of the reduce-form model,this paper introduces a moral hazard incentive factor into the reduce-form model,and proposes a moral hazard state variable as a function of the asset value of the reference entity,which gives the reduce-form model strong economic explanatory power,and the default predictability is reduced by the description of the reduce-form *** terms of the object of study,this paper considers the issue of moral hazard incentives in the presence of claiming fraud in two reference entities to further explore the impact of moral hazard incentives on default protection at the micro level in terms of cyclic ***,based on the

关键词： Financial engineering moral hazard incentive claiming fraud reduce-form model probability of default calculation CDS pricing

Stereoselective synthesis of substituted 1,3-dienes from propargylic esters: electrophilic-metal or redox catalysis?

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Science China Chemistry 2024年第5期67卷 1384-1396页

作者： Mengfu Dai liangliang Song liang-An Chen jiangsu Collaborative Innovation Center of Biomedical Functional Materials Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest resources International Innovation Center for Forest Chemicals and MaterialsCollege of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China

1,3-Diene architectures are not only widely present in natural products, pharmaceuticals, and functional organic materials but also serve as versatile building blocks to furnish important functionalized molecules in synthetic chemistry due to conjugated repeating C=C units. Accordingly, various strategies to access substituted 1,3-dienes in a stereoselective manner have been developed. however, chemo-, regio-and stereoselective synthesis of highly substituted 1,3-dienes still remains elusive and challenging. readily available propargylic esters have emerged as an appealing class of synthetic intermediates for accessing functionalized 1,3-dienes, especially challenging tri-or tetrasubstituted variants, via transition-metal catalysis, including electrophilic metal and redox neutral catalysis. this review, for the first time, systematically highlights recent advances in transitionmetal catalyzed synthesis of substituted 1,3-dienes from propargylic esters, discusses the mechanisms and synthetic utilities, and gives the remaining challenges and potential opportunities in this field.

关键词： 1 3-diene propargylic ester Lewis acid redox catalysis transition metal

remote sensing image encryption algorithm utilizing 2D Logistic memristive hyperchaotic map and ShA-512

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Science China(technological Sciences) 2024年第5期67卷 1553-1566页

作者： LAI Qiang LIU yuan yANg liang School of Electrical and Automation Engineering East China Jiaotong UniversityNanchang330013China

the two-dimensional Logistic memristive hyperchaotic map(2D-LMhM)and the secure hash ShA-512 are the foundations of the unique remote sensing image encryption algorithm(rS-IEA)suggested in this *** proposed map is formed from the improved Logistic map and the memristor,which has wide phase space and hyperchaotic range and is exceptionally excellent to be utilized in specific *** proposed image algorithm uses the permutation-assignment-diffusion *** generates two position matrices in a progressive manner to achieve an efficient random exchange of pixel positions,assignment is carried through on the image pixels of the permutated image to entirely remove the original image information,strengthening the relationship between permutation and diffusion,and loop diffusion in two different directions can use subtle changes of pixels to affect the whole *** random key and plain-image ShA-512 hash values are used to produce an additional key,which is then utilized to figure out the permutation parameters and the initial value of a chaotic *** experimental results with the average NPCr=99.6094%(NPCr:number of pixels change rate),average UACI=33.4638%(UACI:unified average changing intensity),100%pass rate of the targets in the test set,the average correlation coefficient is 0.00075,and the local information entropy is 7.9025,which shows that the algorithm is able to defend against a variety of illegal attacks and provide more trustworthy protection than some of the existing state-of-the-art algorithms.

关键词： chaos memristive hyperchaotic map remote sensing ShA-512 image encryption rS-IEA

Encroachment drives facilitation at alpine shrublines

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Forest Ecosystems 2024年第1期11卷 62-72页

作者： yafeng Wang Eryuan liang j.julio Camarero College of Ecology and Environment Nanjing Forestry UniversityNanjing210037China State Key Laboratory of tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China Instituto Pirenaico de Ecología(IPE-CSIC) Zaragoza50080Spain

Ongoing encroachment is driving recent alpine shrubline dynamics globally,but the role of shrub-shrub interactions in shaping shrublines and their relationships with stem density changes remain poorly ***,the size and age of shrubs from 26 Salix shrubline populations along a 900-km latitudinal gradient(30°-38°N)were measured and mapped across the eastern tibetan *** pattern analyses were used to quantify the spatial distribution patterns of juveniles and adults,and to assess spatial associations between *** intensity of univariate and bivariate spatial patterns was related to biotic and abiotic *** mark correlation functions with a quantitative mark(shrub height,basal stem diameter,crown width)were also employed to investigate the spatial relationships between shrub traits of juveniles and *** equation models were used to explore the relationships among conspecific interactions,patterns,shrub traits and recruitment dynamics under climate *** shrublines showed clustered patterns,suggesting the existence of conspecific *** patterns of juveniles and conspecific interactions(potentially facilitation)tended to intensify with increasing soil moisture *** warming before 2010 triggered positive effects on population interactions and spatial patterns via increased shrub ***,summer warming after2010 triggered negative effects on interactions through reduced shrub ***,shrub recruitment shifts under rapid climate change could impact spatial patterns,alter conspecific interactions and modify the direction and degree of shrublines responses to *** changes would have profound implications for the stability of alpine woody ecosystems.

关键词： Alpine shrubline Positive interactions Facilitation Spatial clustering Point pattern analyses

Seasonal increase in nest defense,but not egg rejection,in a cuckoo host

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Avian research 2024年第1期15卷 50-54页

作者： Bo Zhou Wei liang Ministry of Education Key Laboratory for Ecology of tropical Islands Key Laboratory of Tropical Animal and Plant Ecology of Hainan ProvinceCollege of Life SciencesHainan Normal UniversityHaikou 571158China Institute of Biological resources Jiangxi Academy of ScienceNanchang 330096China

the interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying *** brood parasitism reduces the reproductive success of hosts,and thus,hosts have evolved anti-parasitic strategies,such as rejecting parasitic eggs and adopting aggressive nest defense strategies,to avoid the cost brought on by brood *** test whether host anti-parasitic strategies are adjusted with the risk of being parasitized when the breeding seasons of brood parasites and hosts are not synchronous,we conducted a field experiment assessing nest defense and egg recognition behaviors of the Isabelline Shrike(Lanius isabellinus),a host of the Common Cuckoo(Cuculus canorus).In the local area,the host Isabelline Shrike begins to breed in April,whereas the summer migratory Common Cuckoo migrates to the local area in May and begins to lay parasitic *** showed that nest defense behaviors of the Isabelline Shrike increases significantly after cuckoo arrival,showing higher aggressiveness to cuckoo dummies,with no significant difference in attack rates among cuckoo,sparrowhawk and dove dummies,but their egg rejection did not change *** results imply that Isabelline Shrikes may adjust their nest defense behavior,but not egg rejection behavior,with seasonality.

关键词： Aggression Anti-parasite strategy Egg rejection Mismatch cuckoo parasitism Nest defense

the low Mach number limit of non-isentropic magnetohydrodynamic equations with large temperature variations in bounded domains

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Science China Mathematics 2024年第4期67卷 787-818页

作者： Min liang yaobin Ou School of Mathematics Renmin University of ChinaBeijing 100872China

this paper verifies the low Mach number limit of the non-isentropic compressible magnetohydrodynamic(MhD)equations with or without the magnetic diffusion in a three-dimensional bounded domain when the temperature variation is large but *** uniform estimates of strong solutions are established in a short time interval independent of the Mach number,provided that the slip boundary condition for the velocity and the Neumann boundary condition for the temperature are imposed and the initial data is well-prepared.

关键词： low Mach number limit non-isentropic compressible magnetohydrodynamic equations large temperature variations bounded domains

Analysis of the one-decoy-state SArg04 quantum cryptography protocol in the presence of afterpulse effects

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Communications in theoretical Physics 2024年第6期76卷 66-71页

作者： hu Nian ya-Feng Nie Chun-Mei Zhang liang-liang Lu Key Laboratory of Optoelectronic technology of jiangsu Province School of Physical Science and TechnologyNanjing Normal UniversityNanjing 210023China Institute of Quantum Information and technology Nanjing University of Posts and TelecommunicationsNanjing 210003China hefei National Laboratory Hefei 230088China

the SArg04 quantum key distribution protocol can offer greater robustness against photon number splitting attacks than the BB84 protocol that is implemented with weak *** this paper,we propose a tight key analysis for the SArg04 protocol,by considering the one-decoy method and investigating its performance under the influence of a detector *** results demonstrate that an increase in block size leads to a slight increase in both the secure key rate and the maximum transmission ***,the detector afterpulse plays a crucial role in practical applications and has a more pronounced effect on the SArg04 protocol compared to the BB84 protocol.

关键词： Quantum key distribution SArg04 protocol one decoy afterpulse

hgaNets:Fusion of Visual Data and Skeletal heatmap for human gesture Action recognition

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Computers, Materials & Continua 2024年第4期79卷 1089-1103页

作者： Wuyan liang Xiaolong Xu School of Internet of things Nanjing University of Posts and TelecommunicationsNanjing210023China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing210023China

recognition of human gesture actions is a challenging issue due to the complex patterns in both visual andskeletal features. Existing gesture action recognition (gAr) methods typically analyze visual and skeletal data,failing to meet the demands of various scenarios. Furthermore, multi-modal approaches lack the versatility toefficiently process both uniformand disparate input ***, in this paper, an attention-enhanced pseudo-3Dresidual model is proposed to address the gAr problem, called hgaNets. this model comprises two independentcomponents designed formodeling visual rgB (red, green and blue) images and 3Dskeletal heatmaps, *** specifically, each component consists of two main parts: 1) a multi-dimensional attention module forcapturing important spatial, temporal and feature information in human gestures;2) a spatiotemporal convolutionmodule that utilizes pseudo-3D residual convolution to characterize spatiotemporal features of gestures. then,the output weights of the two components are fused to generate the recognition results. Finally, we conductedexperiments on four datasets to assess the efficiency of the proposed model. the results show that the accuracy onfour datasets reaches 85.40%, 91.91%, 94.70%, and 95.30%, respectively, as well as the inference time is 0.54 s andthe parameters is 2.74M. these findings highlight that the proposed model outperforms other existing approachesin terms of recognition accuracy.

关键词： gesture action recognition multi-dimensional attention pseudo-3D skeletal heatmap