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Modified artificial neural network model with an explicit expression to describe flow behavior and processing maps of Ti2AlNb-based superalloy

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Journal of Iron and Steel Research International 2021年第11期28卷 1451-1462页

作者： Yan-qi Fu Qing Zhao Man-qian Lv zhen-shan cui School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Institute of Forming Technology and Equipment Shanghai Jiao Tong UniversityShanghai 200030China

The elevated-temperature deformation behavior of Ti2AlNb superalloy was observed by isothermal compression experiments in a wide range of temperatures(950–1200°C)and strain rates(0.001–10 s^(-1)).The flow behavior is nonlinear,strongly coupled,and *** constitutive models,namely the double multivariate nonlinear regression model,artificial neural network model,and modified artificial neural network model with an explicit expression,were applied to describe the Ti2AlNb superalloy plastic deformation *** comparative predictability of those constitutive models was further evaluated by considering the correlation coefficient and average absolute relative *** comparative results show that the modified artificial network model can describe the flow stress of Ti2AlNb superalloy more accurately than the other developed constitutive *** explicit expression obtained from the modified artificial neural network model can be directly used for finite element *** modified artificial neural network model solves the problems that the double multivariate nonlinear regression model cannot describe the nonlinear,strongly coupled,and multivariable flow behavior of Ti2AlNb superalloy accurately,and the artificial neural network model cannot be embedded into the finite element software ***,the modified artificial neural network model is mainly dependent on the quantity of high-quality experimental data and characteristic variables,and the modified artificial neural network model has not physical ***,the processing maps were applied to obtain the optimum processing parameters.

关键词： Modified artificial neural network model Ti2AlNb superalloy Double multivariate nonlinear regression model Explicit expression Processing map

Stereoselective metabolic disruption of cypermethrin by remolding gut homeostasis in rat

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Journal of Environmental Sciences 2023年第4期126卷 761-771页

作者： Quan Zhang Sijia gu YanWang Shitao Hu Siqing Yue cui Wang Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province College of EnvironmentZhejiang University of TechnologyHangzhou 310032China School of Life Science Zhejiang Chinese Medical UniversityHangzhou 310053China

Cypermethrin(CYP), a prototypical synthetic pyrethroid, reportedly causes metabolic disruption, while its stereoselective impact remains elusive. This study initially revealed that only α-CYP caused significant weight loss at 8.5 mg/(kg·day) in rats. All three CYP isomers caused the accumulation of hepatic glycogen, and hyperlipemia phenotype as the increment of total triglyceride. Rats treated with α-CYP had markedly high blood glucose levels and homeostasis model assessment of insulin resistance index. The systematic inflammation of θ-CYP group rats was evidenced by high lipopolysaccharide-binding protein levels and abnormalities of leukocytes indices. By examining the gut microbiome, we found thatα-CYP-treated rats had low contents of Firmicutes and high levels of Verrucomicrobia while Elusimicrobia was enriched in the β-CYP group. The increasing alpha diversity in the θ-CYP group may be due to the dominance of pathogenic bacteria and the increase of probiotics to counteract adverse effects. Exclusively, the α-CYP group enriched total short-chain fatty acids(SCFAs), whereas most SCFAs depleted in the θ-CYP group. The correlation analysis further found Firmicutes, an energy storage modulator, was positive to body weight(BW),while SCFAs exerted the opposite, confirming the low BW in α-CYP. Blood glucose that correlated well with SCFAs and Verrucomicrobia can be accounted for the discrepancy betweenα-CYP and θ-CYP. Overall, the three isomers exerted stereoselective glycolipid disruption in rats, and gut homeostasis acted as vital indicators.

关键词： Cypermethrin Stereoisomeric selectivity gut microbiota Short-chain fatty acids Glycolipid metabolism

Closer:Scalable Load Balancing Mechanism for Cloud Datacenters

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China Communications 2021年第4期18卷 198-212页

作者： Zixi cui Pengshuai cui Yuxiang Hu Julong Lan Fang Dong Yunjie gu Saifeng Hou School of Electronic Engineering Information Engineering UniversityZhengzhou 450001China Science and Technology on Communication Networks Laboratory Shijiazhuang 050081China 61660 Unit of PLA Beijing 100089China

Cloud providers(e.g.,Google,Alibaba,Amazon)own large-scale datacenter networks that comprise thousands of switches and links.A loadbalancing mechanism is supposed to effectively utilize the bisection *** Equal-Cost Multi-Path(ECMP),the canonical solution in practice,and alternatives come with performance limitations or significant deployment *** this work,we propose Closer,a scalable load balancing mechanism for cloud *** complies with the evaluation of technology including the deployment of Clos-based topologies,overlays for network virtualization,and virtual machine(VM)*** decouple the system into centralized route calculation and distributed route decision to guarantee its flexibility and stability in large-scale *** In-band Network Telemetry(INT)to obtain precise link state information,a simple but efficient algorithm implements a weighted ECMP at the edge of fabric,which enables Closer to proactively map the flows to the appropriate path and avoid the excessive congestion of a single *** achieves 2 to 7 times better flow completion time(FCT)at 70%network load than existing schemes that work with same hardware environment.

关键词： cloud datacenters load balancing programmable network INT overlay network

Controlling Airy-Bessel Light Bullets in an Optically Induced Potential

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Communications in Theoretical Physics 2019年第6期71卷 741-745页

作者： zhen-Kun Wu Yu-Zong gu Institute of Micro/Nano Photonic Materials and Applications School of Physics and Electronics Henan University

We investigate numerically the curious evolution of self-decelerating Airy-Bessel light bullets carrying different topological charges(TC), launched in the three-dimensional(3 D) Schr?dinger equation with an induced parabolic potential. We present their spatiotemporal profile during propagation. In our paper, the number of TC, the modulation depth, and the induced potential are considered simultaneously. The propagation properties of light bullets result from a combination of these effects. Our scheme is distinctly different from the linear light bullets in free space, in which the localized wave packets propagate in a self-consistent trapping potential.

关键词： Airy-Bessel light bullet self-decelerating optically induced potential topological charges 3D Schrodinger equation

Breakdown Behavior of Eutectic Carbide in High Speed Steel During Hot Compression

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Journal of Iron and Steel Research International 2011年第1期18卷 41-48页

作者： ZHOU Bin SHEN Yu CHEN Jun cui zhen-shan National Engineering Research Center of Die and Mold CAD Shanghai Jiao Tong University Shanghai 200030 China

The evolution of euteelie carbide in as CaSl M2 high speed steeL was invesligated with hot compression test and metallographic examination. Initial rodlike or irregular eutectic carbides were broken into smaller particles during hot deformation by thermomechanical disintegration, while diffusion controlled phase transformation was not remarkable. Combining with numerical simulation, the relationship between breakdown ratio of carbide network and deformation parameters was obtained. Strain was the most important driving force to shatter euteclic carbides and disperse products. Furthermore, critical strain values were obtained, beyond which carbide network disappeared, and fractured carbides kept a stable profile and they were deformed with matrix coordinately. A higher temperature or lower strain rate resulted in a lower crilical strain.

关键词： hol compression high speed steel eulectic earbidc breakdown mechanism

Existence and Nonexistence of Global Positive Solutions for a Weakly Coupled P-Laplacian System

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Acta Mathematicae Applicatae Sinica 2013年第3期29卷 541-554页

作者： Xian-zhong ZENG zhen-hai LI Yong-geng gu School of Mathematics and Computing Science Hunan University of Science and Technology College of Science Guangxi University for Nationalities Department of Mathematics Hunan Normal University

In this paper, we deal with a weakly coupled evolution P-Laplacian system with inhomogeneous terms. We obtain a critical criterion concerning existence and nonexistence of its global positive solutions. Such a criterion is different from that of the weakly coupled evolution P-Laplacian system with homogeneous terms. Further, we demonstrate existence and nonexistence of its global positive solutions.

关键词： the evolution P-Laplacian system inhomogeneous terms blow-up global existence

Moisture-induced degradation of the narrow-band red-emitting SrLiAl3N4:Eu2+phosphor

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Journal of Rare Earths 2018年第4期36卷 341-345页

作者： Wenxia Li zhen Song Dianpeng cui Zhiguo Xia Quanlin Liu The Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The degradation of materials plays an important role in their application and service process. In this work, the moisture-induced degradation of SrLiAl3 N4：Eu2＋（SLAN）, a very promising narrow-band redemitting phosphor, was comprehensively investigated by treating it in two different moisture conditions in order to reveal the potential mechanism and optimize the luminescence properties. The degradation rate gradually slows down with the decreasing environmental humidity indicating that water plays a key role in the degradation. Moreover, we take the other option with 100% humidity at different temperatures for rapid degradation. In the rapid degradation, the luminescence of SLAN is quenched quickly and the phase and micro structure change obviously, with the phosphor being bleached. The host turns into NH_3, Al_2 O_3, Sr_3 Al_2（OH）_（12） and LiAl_2（OH）_7 finally. It is further confirmed that the rapid degradation occurs with the help of water and the phosphor is oxidized during this process.

关键词： Degradation Narrow-band Phosphor Mechanism Rare earths

Calculation and Regulation of Residual Stress Distributionfor Superhybrid Composites

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Journal of Materials Science & Technology 1999年第2期15卷 128-132页

作者： Zhong, Weihong cui, Deyu gu, Zhifen Chen, Changqi Li, Hongyun Beijing Univ Aeronaut & Astronaut Beijing 100083 Peoples R China

The distribution of residual stresses of ARALL with different prestress was calculated by finite element theory. A new method for regulating the residual stress, that is, introducing interim layer between aramid and Al layers, was given out. Applying prestress to the laminate has strong effects on the distribution of normal stress along the fiber direction. The interim layer in fiber direction presents a state with gradient distribution. (Edited author abstract) 7 Refs.

关键词： Laminated composites

A Genetic Algorithm for Simultaneous Determination of Thin Films Thermal Transport Properties and Contact Resistance

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Journal of Materials Science & Technology 2006年第3期22卷 339-341页

作者： zhengxing HUANG zhen＇an TANG Ziqiang XU Haitao DING Yuqin gu Department of Electronic Engineering Microsystem Resarch Center Dalian University of Technology Dalian 116024 China School of Mechanic Engineering Dalian University of Technology Dalian 116024 China Department of Engineering Mechanics Tsinghua University Beijing 100084 China

A genetic algorithm （GA） was studied to simultaneously determine the thermal transport properties and the contact resistance of thin films deposited on a thick substrate. A pulsed photothermal reflectance （PPR） system was employed for the measurements. The GA was used to extract the thermal properties. Measurements were performed on SiO2 thin films of different thicknesses on silicon substrate. The results show that the GA accompanied with the PPR system is useful for the simultaneous determination of thermal properties of thin films on a substrate.

关键词： Thin film Thermal transport properties Thermal contact resistance Genetic algorithm