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Microstructure and mechanical properties of GTA-based wire arc additive manufactured AZ91D magnesium alloy

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Journal of Magnesium and Alloys 2024年第8期12卷 3180-3192页

作者： Xiaoyu Cai Fukang Chen Bolun Dong Sanbao Lin chunli yang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Wire arc additive manufacturing offers advantages in producing large metal *** current research on GTA-based wire arc additive manufacturing(GTA-WAAM)of magnesium alloys is focused on deformed magnesium alloys,mainly on the Mg-Al alloy ***,there is little research on GTA-WAAM for casting magnesium *** study investigates the microstructural characteristics and mechanical properties of AZ91D magnesium alloy(AZ91D-Mg)deposited by ***-pass multilayer thin-walled components were successfully *** results show that equiaxed grains dominate the microstructure of the deposited *** the remelting process,the precipitated phases dissolve into the matrix,and they precipitate and grow from the matrix under the thermal effect of the subsequent thermal *** mechanical properties in the vertical and horizontal directions are similar,showing higher overall mechanical properties than the casting *** average yield strength is 110.5 MPa,the ultimate tensile strength is 243.6 MPa,and the elongation is 11.7%.The overall hardness distribution in the deposited sample is relatively uniform,and the average microhardness is 59.6 HV_(0.2).

关键词： GTA Additive manufacturing AZ91D magnesium alloy Microstructure Mechanical properties

Strength Prediction of Aluminum–Stainless Steel-Pulsed TIG Welding–Brazing Joints with RSM and ANN

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1012-1017页

作者： Huan He chunli yang Zhe Chen Sanbao Lin Chenglei Fan State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

Pulsed TIG welding–brazing process was applied to join aluminum with stainless steel dissimilar metals. Major parameters that affect the joint property significantly were identified as pulsed peak current, base current, pulse on time,and frequency by pre-experiments. A sample was established according to central composite design. Based on the sample,response surface methodology（RSM） and artificial neural networks（ANN） were employed to predict the tensile strength of the joints separately. With RSM, a significant and rational mathematical model was established to predict the joint *** ANN, a modified back-propagation algorithm consisting of one input layer with four neurons, one hidden layer with eight neurons, and one output layer with one neuron was trained for predicting the strength. Compared with RSM, average relative prediction error of ANN was ／10% and it obtained more stable and precise results.

关键词： Welding–brazing Aluminum Stainless steel Response surface methodology(RSM) Artificial neural networks(ANN) Prediction

A lattice-based signcryption scheme without random oracles

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Frontiers of Computer Science 2014年第4期8卷 667-675页

作者： Xiuhua LU Qiaoyan WEN Zhengping JIN Licheng WANG chunli yang State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China Mathematics and Information Science Langfang Teachers University Langfang 065000 China Information Security Center Beijing University of Posts and Telecommunications Beijing 100876 China

In order to achieve secure signcryption schemes in the quantum era, Li Fagen et al. [Concurrency and Computation： Practice and Experience, 2012, 25（4）： 2112-2122] and Wang Fenghe et al. [Applied Mathematics ＆ Information Sciences, 2012, 6（1）： 23-28] have independently extended the concept of signcryption to lattice-based cryptography. However, their schemes are only secure under the random or- acle model. In this paper, we present a lattice-based signcryp- tion scheme which is secure under the standard model. We prove that our scheme achieves indistinguishability against adaptive chosen-ciphertext attacks （IND-CCA2） under the learning with errors （LWE） assumption and existential unforgeability against adaptive chosen-message attacks （EUF- CMA） under the small integer solution （SIS） assumption.

关键词： signcryption standard model lattice-based cryptography learning with errors problem small integer solution problem

Research on the Mechanism of Penetration Increase by Flux in A-TIG Welding

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Journal of Materials Science & Technology 2003年第Z1期19卷 225-227页

作者： chunli yang Sanbao LIN Fengyao LIU Lin WU Qingtao ZHANG State Key Lab.of Advanced Welding Production Technology Harbin Institute of TechnologyHarbin 150001China

The mechanism of penetration depth increased by activating flux in activating tungsten inert gas(A-TIG)weldingwas studied by measuring the distribution of trace element Bi in the weld and monitoring the change of arc voltageduring A-TIG welding of stainless steel 0Crl8Ni9 with fluxes SiO_(2)and TiO_(2).The results show that the mechanismof penetration depth in A-TIG welding depends on the sort of flux *** weld pool convection after coating theflux SiO_(2)and flux TiO_(2)is changed inversely compared with convectional TIG welding without *** arc voltageis increased by flux SiO_(2)whilst flux TiO_(2)does not have effect on the arc *** reason of penetration depthincrease for SiO_(2)is due to the constriction of arc plasma and the change of surface tension *** increaseof weld penetration depth with TiO_(2)only ascribes to the change of surface tension gradient.

关键词： TIG welding Activating flux Surface tension Arc voltage

Research on droplet transfer in oscillating arc narrow gap GMA welding

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China Welding 2014年第2期23卷 12-16页

作者： Xu Wanghui Fan Chenglei Lin Sanbao yang chunli State Key Laboratory of Advanced Welding and Joining Harbin Institute ofTechnology Harbin 150001

In this paper, the droplet transfer in oscillating arc narrow gap gas metal arc （ GMA ） welding was studied. According to the experimental results, the oscillating arc has effect on the droplet transfer mode. The droplet transfer frequency in narrow gap groove is higher than that in bead-on-plate welding. Because of the change of arc location in narrow gap groove, the droplet transfer in oscillating arc narrow gap changes regularly. The droplet transfer frequency near groove sidewall is higher than that at the middle of narrow gap groove.

关键词： narrow gap welding oscillating arc droplet transfer GMA welding

Creep behaviour and constitutive model of coal filled with gas

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International Journal of Mining Science and Technology 2017年第5期27卷 847-851页

作者： Li Xiangchun yang chunli Ren Ting Nie Baisheng Zhao Caihong Liu Shuiwen Jiang Tao School of Resource and Safety Engineering China University of Mining & Technology Occupational Hazards Control Technology Center Beijing Municipal Institute of Labour Protection Faculty of Engineering and Information Sciences University of Wollongong

Coal exhibits different creep behaviours when filled with different amounts of gas. Creep tests of coal filled with 0 and 0.5 MPa gas were performed, and strain under different axial stress was *** three creep constitutive models which were analysed using the method fitting experimental data for determining which creep model can reflect the creep process of the test best. The results show that the deformation of coal filled with 0.5 MPa gas is more higher than that of coal filled with 0 MPa gas under the same axial stress. Gas plays a positive effect on the deformation of coal process and will accelerate creep process. And gas will reduce coal intensity and change coal creep *** with Nishihara Model and Extensional Nishihara Model, Burgers Model can reflect the three stages of creep process of coal filled with gas better. The research results can contribute to reveal coal and gas outburst mechanism.

关键词： Coal Gas Creep Constitutive model

MAGNETIC AND ^(57)Fe MÖSSBAUER STUDY OF YFe_(12-x)Vx COMPOUNDS

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Chinese Physics Letters 1990年第8期7卷 373-376页

作者： yang chunli ZHOU Rongjie LI Fashen ZHONG Wending LAN Jian Department of Physics Lanzhou UniversityLanzhou 730000 Department of Physics Peking UniversityBeijing 100871

Using Mössbauer spectroscopy and magnetic measurement,the hyperfine coupling coefficient of YFe_(12-x)Vx(x=2,3,4)was determined approximately A=14.85T/μ*** reasons of changes of the hyperfine parameters depending on ... 详细信息

关键词： vanadium approximate

Classification and Application of Landscape Agriculture in Rural Leisure Tourism

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当代农业（中英文版） 2019年第1期7卷 32-35页

作者： yang chunli Guo Meibin Leshan Normal University Sichuan 614000 China

The core content of beautiful countryside construction is to construct and implement modern landscape agriculture planning. The basic work of landscape agriculture planning and management is to classify landscape agriculture. In view of the requirements of new rural construction and the characteristics of agricultural land consolidation in China, this paper is based on the functions of landscape agriculture, location and farmers' economic behavior modification methods and topographic position index. A rural scale functional classification method for landscape agriculture was proposed, which is a secondary classification system using landscape and landscape subcategories. The method takes into account the dominant functions and spatial morphological characteristics of landscape agriculture, and can meet the needs of landscape agriculture planning in beautiful rural construction.

关键词： Rural Leisure Tourism Landscape Agriculture Classification

Characteristics of the electrode melting phenomena in narrow gap MAG high-rotating-speed arc welding

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Rare Metals 2007年第S1期26卷 291-295页

作者： ZHAO Bo,FAN Chenglei,and yang chunli State Key Laboratory of Advanced Welding Production Technology,Harbin Institute of Technology,Harbin 150001,China Harbin Inst Technol State Key Lab Adv Welding Prod Technol Harbin 150001 Peoples R China

The influence of rotating speed on metal transfer and the wire metal speed was studied in the high rotating speed arc narrow gap *** results indicate that the high rotating speed arc has benefit on the metal transfer,and that with the rotating speed increasing,the droplet volume *** is shown that the rotating speed has little influence on the wire metal speed with DC electrode positive polarity(DCEP),but the melting speed decreases with increasing of rotating speed in DC electrode negative polarity(DCEN).

关键词： narrow gap welding DCEN MAG welding high-rotating-speed arc melting speed