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Effect of Microstructure on Thermal Expansion Coeffcient of 7A09 Aluminum Alloy

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Journal of Materials Science & Technology 2011年第9期27卷 797-801页

作者： Hongzhi Ji Lin yuan Debin shan School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

The relationship between microstructure evolution and coefficient of thermal expansion （CTE） of 7A09 aluminum alloy was investigated in this paper. Differential scanning calorimetry （DSC） was combined with transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM） to investigate microstructure evolution taking place in 7A09 aluminum alloy during heating and cooling process. The corresponding CTE curves of the 7A0g alloy were recorded by thermal dilatometer. Results indicated that GPII zones and Ur phase were main precipitates in the highest strength tempered （T6） 7A09 alloy. The r/phase was the main participate in 7A09 alloy during the cooling process. The nonlinear dependency existed between CTE and temperature in both changing temperature processes. During the heating process, obvious additional contraction of alloy volume was directly caused by phase transition, such as dissolution of η＇ phase, transition from η＇ to η phase and dissolution of η phase. The additional contraction could slow down the increase of CTE greatly and be expressed in the nonlinearity of CTE curve. Volume and energy changes of alloy system influenced the variation trend of CTE directly, which was caused by the precipitation of U phase during the cooling process. These effects were revealed by the corresponding nonlinear change of CTE.

关键词： Aluminum Coefficient alloy Changing temperature process Microstructure evolution of thermal expansion

Fatigue-crack-initiation numerical modelling of a Ni-base powder metallurgy alloy

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航空动力学报 2012年第12期27卷 2778-2785页

作者： Mu, yuan-Wei Lu, shan Zhang, Hong School of Power and Energy Northwestern Polytechnical University Xi'an 710072 China

A simplified three-dimensional numerical model was presented to simulate the micro-crack nucleation and growth to some predefined dimension(approximately 0.38 mm) on the throat surface of a Ni-base powder metallurgy(PM) *** numerical simulation of micro-crack initiation was based on the Tanaka-Mura micro-crack initiation models,where individual grains of the mesoscopic model were simulated using the Voronoi *** improvements were made in the model.(1) Considering crack initiation along with 12 principal slip systems on octahedral slip planes of face centered cubic(FCC) crystal in three-dimensional(3-D) models.(2) Considering the effect of secondary phase precipitate due to impinging slip and dislocation pileup.(3) The Tanaka-Mura theory of fatigue-crack-initiation from notches was applied to simulate the crack initiation from another crack tip.(4) The coalescence of random initiated micro-cracks was simulated once they intersected with each other and a macro-crack was finally *** calculated results were in good agreement with the experimental data which verified the rationality of the simulation *** applicability of the proposed model for treating fatigue-crack-initiation life in engineering structures was preliminarily achieved.

关键词：信号模拟动力系统数字化 3D模型

Coalbed Methane Enrichment Regularity and Major Control Factors in the Xishanyao Formation in the Western Part of the Southern Junggar Basin

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Acta Geologica Sinica(English Edition) 2020年第2期94卷 485-500页

作者： yuan yuan shan Yansheng TANG Yue CAO Daiyong China University of Mining&Technology Beijing 100083China China Geological Survey Oil and Gas SurveyBeijing 100083China

There are abundant coal and coalbed methane(CBM)resources in the Xishanyao Formation in the western region of the southern Junggar Basin,and the prospects for CBM exploration and development are *** promote the exploration and development of the CBM resources of the Xishanyao Formation in this area,we studied previous coalfield survey data and CBM geological exploration ***,we analyzed the relationships between the gas content and methane concentration *** seam thickness,burial depth,coal reservoir physical characteristics,hydrogeological conditions,and roof and floor *** addition,we briefly discuss the main factors influencing CBM ***,we found that the coal strata of the Xishanyao Formation in the study area are relatively simple in structure,and the coal seam has a large thickness and burial depth,as well as moderately good roof and floor *** hydrogeological conditions and coal reservoir physical characteristics are also conducive to the enrichment and a high yield of *** believe that the preservation of CBM resources in the study area is mainly controlled by the structure,burial depth,and hydrogeological ***,on the basis of the above results,the coal seam of the Xishanyao Formation in the synclinal shaft and buried at depths of 700-1000 m should be the first considered for development.

关键词： coalbed methane enrichment regularity major control factors Xishanyao Formation western area of the southern Junggar Basin

Multi-party blind quantum computation protocol with mutual authentication in network

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Science China(Information Sciences) 2021年第6期64卷 158-171页

作者： Rui-Ting shan Xiubo CHEN Kai-Guo yuan Information Security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and Telecommunications

Blind quantum computation(BQC) can ensure a client with limited quantum capability safely delegates computing tasks to a remote quantum server. In order to resist attacks from ignoring identity authentication in BQC protocols, it is necessary to guarantee the legality of both clients and servers in a multi-party BQC network. So we propose a multi-party BQC protocol involving three phases to distribute shared keys and authenticate identities. Firstly, by using the advantages of measurement device independent quantum key distribution(MDI-QKD), the registered client and the assigned server could share the initial key safely in registration phase. Secondly, with the help of semi-honest certificate authority(CA), mutual identity authentication phase realizes the two-way authentication from both sides through the shared key simultaneously. Thirdly, in the blind quantum computing phase, a registered client can complete his computing task by just measuring the qubits from the assigned server rather than preparing the qubits. Moreover,combined with first-in-first-out(FIFO) principle, clients' authentication and blind quantum computing can be processed in parallel. The protocol can also be applied in other multi-party BQC protocols with the universality of resource states. Compared with other BQC protocols, the reliability of the protocol with identity authentication is guaranteed, and the efficiency will be significantly reflected in real experiments.

关键词： blind quantum computation mutual identity authentication load balancer semi-trust CA quantum network

Active sorting of orbital angular momentum states of light with a cascaded tunable resonator

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Light(Science & Applications) 2020年第1期9卷 1904-1913页

作者： Shibiao Wei Stuart K.Earl Jiao Lin shan shan Kou Xiao-Cong yuan Nanophotonics Research Center Shenzhen Key Laboratory of Micro-Scale Optical Information TechnologyShenzhen UniversityShenzhen 518060China Department of Chemistry and Physics La Trobe Institute for Molecular Science(LIMS)La Trobe UniversityVictoria 3086Australia School of Engineering RMIT UniversityMelbourneVictoria 3001Australia School of Physics The University of MelbourneTin AlleyMelbourneVictoria 3010Australia

The orbital angular momentum(OAM)of light has been shown to be useful in diverse fields ranging from astronomy and optical trapping to optical communications and data ***,one of the primary impediments preventing such applications from widespread adoption is the lack of a straightforward and dynamic method to sort incident OAM states without altering the ***,we report a technique that can dynamically filter individual OAM states and preserve the incident OAM states for subsequent *** the working principle of this technique is based on resonance,the device operation is not limited to a particular *** states with different wavelengths can resonate in the resonator without any additional modulation other than changing the length of the ***,we are able to demonstrate a reconfigurable OAM sorter that is constructed by cascading such optical *** approach does not require specially designed components and is readily amenable to integration into potential applications.

关键词： resonator tunable momentum

Existence of solutions for sub-linear or super-linear operator equations

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Science China Mathematics 2015年第8期58卷 1653-1664页

作者： CHEN YingYing DONG YuJun shan yuan Department of Mathematics Nanjing Normal University Department of Mathematics Nanjing University

We investigate solutions to superlinear or sublinear operator equations and obtain some abstract existence results by minimax methods. These results apply to superlinear or sublinear Hamiltonian systems satisfying several boundary value conditions including Sturm-Liouville boundary value conditions and generalized periodic boundary value conditions, and yield some new theorems concerning existence of solutions or nontrivial solutions. In particular, some famous results about periodic solutions to superlinear or sublinear Hamiltonian systems by Rabinowitz or Benci and Rabinowitz are special cases of the theorems.

关键词： superlinear sublinear operator equations existence of solutions minimax methods Hamiltoniansystems

Dual-cavity beam arrival time monitor design for the shanghai soft X-ray FEL facility

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Nuclear Science and Techniques 2019年第5期30卷 14-21页

作者： shan-shan Cao Ren-Xian yuan Jian Chen Yong-Bin Leng shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Free electron lasers provide high-power and ultrashort pulses with extreme brightness. In order to improve a facility's capabilities and explore the possibility of performing high-resolution time-resolved experiments, a beam arrival time resolution under 100 fs is required. In this article, a novel beam arrival time monitor(BAM)equipped with two cavities has been designed and a beam flight time measurement scheme based on the BAM prototype has been proposed to estimate phase jitter in the signal measurement system. The two BAM cavities work at different frequencies and the frequency difference is designed to be 35 MHz. Therefore, a self-mixing intermediate frequency signal can be generated using the two cavities. The measured beam flight time shows a temporal deviation of 37 fs(rms).

关键词： Beam arrival time monitor Dual-cavities Beam flight time Self-mixing

Does Periconceptional Fish Consumption by Parents Affect the Incidence of Autism Spectrum Disorder and Intelligence Deficiency?A Case-control Study in Tianjin,China

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Biomedical and Environmental Sciences 2016年第12期29卷 885-892页

作者： GAO Lei CUI shan shan HAN Yu DAI Wei SU yuan yuan ZHANG Xin Dept.Maternal Child&Adolescence Health of School of Public Health Tianjin Medical UniversityTianjin 300070China Department of Nutrition and Food Science Sehool of Public HealthTianjin Medical UniversityTianjin 300070China

Objective This study aimed to explore the association between periconceptional fish consumption by parents and autism spectrum disorder （ASD） and intelligence deficiency （ID）. Methods A case-control study was conducted through a questionnaire with 108 ASD cases, 79 ID cases, and 108 controls. The ASD and ID cases were students from special educational schools in Tianjin from 2012 to 2014. The age- and sex-matched controls were from a high school, three primary schools, and a kindergarten in Tianjin. Multivariate logistic regression was performed. Results Paternal habit of eating hairtail before fertilization, maternal preference for fruits during pregnancy, and maternal habit of eating grass carp during pregnancy were preventive factors for ASD. Paternal habit of drinking alcohol before fertilization was a risk factor for ID, whereas maternal preference for fruits during pregnancy and maternal habit of eating crucian carp during pregnancy were protective factors for ID. Conclusion Parental fish consumption is beneficial for the prevention of ASD and ID. Meanwhile, the protective effects of fish consumption on ASD and ID differ. More attention should be paid to the combined effect of other food when eating fish.

关键词： Parental fish consumption Periconception Autism spectrum disorder Intelligencedeficiency

Semiparametric Additive Intensity Model with Frailty for Recurrent Events

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Acta Mathematica Sinica,English Series 2011年第9期27卷 1831-1842页

作者： Yah Yah LIU yuan shan WU School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China

The seminal Cox＇s proportional intensity model with multiplicative frailty is a popular approach to analyzing the frequently encountered recurrent event data in scientific studies. In the case of violating the proportional intensity assumption, the additive intensity model is a useful alternative. Both the additive and proportional intensity models provide two principal frameworks for studying the association between the risk factors and the disease recurrences. However, methodology devel- opment on the additive intensity model with frailty is lacking, although would be valuable. In this paper, we propose an additive intensity model with additive frailty to formulate the effects of possibly time-dependent covariates on recurrent events as well as to evaluate the intra-class dependence within recurrent events which is captured by the frailty variable. The asymptotic properties for both the regression parameters and the association parameters in frailty distribution are established. Fhrthermore, we also investigate the large-sample properties of the estimator for the cumulative baseline intensity function.

关键词： Additive intensity model counting process Donsker class frailty recurrent events