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Effect of Three-High Rotary Piercing Process on Microstructure,Texture and Mechanical Properties of Magnesium Alloy Seamless Tube

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 953-968页

作者： Xiaofeng Ding Zehao Wu Tong li Jianxun Chen Yuanhua shuang Baosheng liu Heavy Machinery Engineering Research Center of Education Ministry Taiyuan University of Science and TechnologyTaiyuan030024China College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Mg alloy seamless tubes(MASTs)were prepared through three-high rotary piercing process,effect of billet temperature,feed angle and plug advance on microstructure,texture and mechanical properties of tubes were *** effect on the deformation mechanism and improving mechanical properties mechanism of this process for MASTs were *** results show that the grain size could be refined to 11.3-31.1%of the initial grain size and the microstructure was more uniform due to the accumulation of *** formation of high strain gradient at the grain boundary activated the non-basal *** piercing process could change the grain orientation of as-extruded billet and eliminate the initial basal texture to produce new favorable *** the process could accelerate the continuous dynamic recrystallization *** piercing,yield strength of pierced tubes decreased by 6.7%,ultimate tensile strength(UTS)and elongation increased by 32.4 and 45%,respectively,at optimal *** plate-shapedβ_(1)-Mg_(17)Al_(12) orientation transformed from basal plates to prismatic plates,facilitating the increase in UTS and *** decrease size of nanoscale precipitates could reduce the cracking *** critical resolved shear stress ratios of pyramidal(10−11)slip and(11−22)slip to basal slip for the sample including prismatic plates both decreased compared to that including basal *** could enhance the ductility of tube ***,grain boundary sliding could contribute to a better ductility via coordinating deformation and reducing stress concentration during piercing process.

关键词： Mg alloy tube Rotary piercing Microstructure Texture Mechanical properties

Developing microwave-induced thermoacoustic tomography:System,application,and reconstruction

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Journal of Electronic Science and Technology 2023年第4期21卷 1-19页

作者： shuang-li liu Wan-Ting Peng Xiao-Zhang Zhu Jian Song Xin Shang Hua Zhang Zhi-Qin Zhao School of Information Engineering Southwest University of Science and TechnologyMianyang621010China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Yunnan Key Laboratory of Computer Technologies Application Kunming University of Science and TechnologyKunming650500China

A microwave-induced thermoacoustic imaging(MITAT)system is a non-destructive physical medical imaging method that combines the advantages of the high contrast of microwave imaging and the high resolution of ultrasound *** uses the microwave as the excitation source and ultrasound as the information *** different kinds of biological tissue absorb electromagnetic energy,it results in localized temperature *** thermal expansion will induce ultrasonic signals(i.e.,thermoacoustic signals),known as the thermoacoustic *** microwave absorption image of the sample can be reconstructed by algorithm *** MITAT contrast depends on different dielectric parameters of different kinds of *** introduce the developed system and its *** addition,the challenges and prospects of MITAT for further development are discussed.

关键词： Application Microwave-induced thermoacoustic tomography(MITAT) Reconstruction System

Construction of multifunctional lanthanum manganese mixed nanoparticles mediated by ionic liquids for selective aerobic oxidation of cyclohexane

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Rare Metals 2024年第5期43卷 2205-2221页

作者： Hao li Rui-Rui Zhang Ke-Xin li shuang Wei Yu-Mei liu Rui-Xia liu Beijing Key Laboratory of Ionic liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Selective oxidation of alkanes to produce highvalue chemicals is an essential strategy and means to realize efficient utilization of *** this work,a strategy of lanthanum manganese mixed metal oxides(LMMO)regulated via a facile ionic liquid(IL)-assisted hydrothermal method was proposed to construct the multifunctional catalysts,which exhibited excellent catalytic performance in the selective aerobic oxidation of *** 8.9%cyclohexane conversion with 90%KA oi(cyclohexanol and cyclohexanone)selectivity was achieved over the optimal LMMO catalyst under mild *** effects of anion type,carbon chain length and concentration of ILs on the structure and properties of catalysts were investigated through various characterizations,indicating the structure-directing and template effect of ILs on the multifunctional *** formation of self-assembled spherical nanoparticles followed the"dissolution-nucleation-proliferation"mechanism with the introduction of 1-butyl-3-methylimidazolium hydrogen sulfate,ascribing the synergistic effect between the microenvironment of ILs and the hydrothermal ***,the high reactive oxygen concentration redox capacity,and suitable basic sites of LMMO catalysts mediated by ILs enhance the activation of C-H bonds and molecular oxygen,simultaneously influencing the adsorption and desorption of the substrate.A comprehensive understanding of the high KA oil selectivity and radical reaction mechanism was elucidated based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and radical trapping *** recycling and regeneration experiments further illuminated that the removal of adsorbed cyclohexanone acting on the LMMO catalyst was the key to achieve high KA oil selectivity.

关键词： Ionic liquids Nanoparticle Multifunctional catalyst Cyclohexane oxidation

Exponential Time Differencing Method for a Reaction-Diffusion System with Free Boundary

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Communications on Applied Mathematics and Computation 2024年第1期6卷 354-371页

作者： shuang liu Xinfeng liu Department of Mathematics University of CaliforniaSan Diego9500 Gilman DriveLa JollaCalifornia92093-0112USA Department of Mathematics University of South CarolinaColumbiaSouth Carolina29208USA

For reaction-diffusion equations in irregular domains with moving boundaries,the numerical stability constraints from the reaction and diffusion terms often require very restricted time step sizes,while complex geometries may lead to difficulties in the accuracy when discretizing the high-order derivatives on grid points near the *** is very challenging to design numerical methods that can efficiently and accurately handle both *** an implicit scheme may be able to remove the stability constraints on the time step,however,it usually requires solving a large global system of nonlinear equations for each time step,and the computational cost could be *** factor(IF)or exponential time differencing(ETD)methods are one of the popular methods for temporal partial differential equations(PDEs)among many other *** our paper,we couple ETD methods with an embedded boundary method to solve a system of reaction-diffusion equations with complex *** particular,we rewrite all ETD schemes into a linear combination of specificФ-functions and apply one state-of-the-art algorithm to compute the matrix-vector multiplications,which offers significant computational advantages with adaptive Krylov *** addition,we extend this method by incorporating the level set method to solve the free boundary *** accuracy,stability,and efficiency of the developed method are demonstrated by numerical examples.

关键词： Reaction diffusion equations Free boundary Integrating factor method Level set method

MP-3 microperimeter in early primary open angle glaucoma with a new pattern

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 861-868页

作者： shuang liang li-Tao Wang Xiao-li liu Jia-liang Duan Dan-Yan liu Department of Ophthalmology of the Second Hospital of Hebei Medical University Shijiazhuang 050000Hebei ProvinceChina Department of Ophthalmology Shijiazhuang People’s HospitalShijiazhuang 050000Hebei ProvinceChina

AIM:To investigate macular microperimetry in patients with early primary open angle glaucoma(POAG)using a new custom-made pattern,and analyze the characteristics of macular ***:This case-control study included 38 patients with POAG,who were divided into pre-perimetric glaucoma(18 eyes of 18 patients),early-stage(20 eyes of 20 patients),and control(20 eyes of 20 patients)*** subjects underwent standard 24-2 humphrey visual field *** MP-3 microperimeter with a new custom-made pattern(28 testing points distributed in four quadrants,covering the central 10°of the retina)was used to evaluate macular *** cell complex(GCC)thicknesses were examined using an RS-3000 Advance OCT *** features of structure and function were analysed per ***:The pre-perimetric glaucoma group had significantly lower inferior hemifield macular sensitivity compared to controls(Plier than conventional perimetry,particularly in pre-perimetric glaucoma cases in which it might be undetectable by conventional me

关键词： early primary open angle glaucoma macular sensitivity microperimetry optical coherence tomography ganglion cell complex

Bioactivities,Mechanisms,Production,and Potential Application of Bile Acids in Preventing and Treating Infectious Diseases

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Engineering 2024年第7期38卷 13-26页

作者： shuang liu Shuo Yang Biljan Blazekovic Lu li Jidan Zhang Yi Wang Experimental Research Center China Academy of Chinese Medical SciencesBeijing 100700China Faculty of Pharmacy and Biochemistry University of ZagrebZagreb 10000Croatia

Infectious diseases are a global public health problem,with emerging and re-emerging infectious diseases on the rise ***,their prevention and treatment are still major *** acids are common metabolites in both hosts and microorganisms that play a significant role in controlling the metabolism of lipids,glucose,and *** acids have historically been utilized as first-line,valuable therapeutic agents for related metabolic and hepatobiliary ***,bile acids are the major active ingredients of cow bezoar and bear bile,which are commonly used traditional Chinese medicines(TCMs)with the therapeutic effects of clearing heat,detoxification,and relieving wind and *** recent years,the promising performance of bile acids against infectious diseases has attracted attention from the scientific *** paper reviews for the first time the biological activities,possible mechanisms,production routes,and potential applications of bile acids in the treatment and prevention of infectious *** with previous reviews,we comprehensively summarize existing studies on the use of bile acids against infectious diseases caused by pathogenic microorganisms that are leading causes of global morbidity and *** addition,to ensure a stable supply of bile acids at affordable prices,it is necessary to clarify the biosynthesis of bile acids in vivo,which will assist scientists in elucidating the accumulation of bile acids and discovering how to engineer various bile acids by means of chemosynthesis,biosynthesis,and chemoenzymatic ***,we explore the current challenges in the field and recommend a development strategy for bile-acid-based drugs and the sustainable production of bile *** presented studies suggest that bile acids are potential novel therapeutic agents for managing infectious diseases and can be artificially synthesized in a sustainable way.

关键词： Bile acids Infectious diseases Bioactivities Mechanisms Anti-infective agents

Multi-stimuli-responsive aggregation-induced emission copper iodide cluster

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Science China Chemistry 2024年第4期67卷 1193-1197页

作者： Bo li Yuan-Yuan liu Peng Luo Ye-Ru liu Ying-Jun Chen Kai li shuang-Quan Zang College of Chemistry and Pharmacy Engineering Nanyang Normal UniversityNanyang 473061China Green Catalysis Center and College of Chemistry Zhengzhou UniversityZhengzhou 450001China

Stimuli-responsive luminescent materials have attracted significant attention in the development of smart photoactive materials for both fundamental research and technological *** this work,a new copper iodide cluster(1)with aggregationinduced emission(AIE)characteristic,was obtained combining Cu_(4)I_(4) core with rhodamine B derivative ligand.1 has reversible and distinct multi-stimuli-responsive luminescence for external temperature,volatile organic compound,and mechanical ***,1 exhibited unusual large blue shift(84 nm)after being ground,which originated from the change of intermolecular ***,1 exhibits high oxygen quenching efficiency for 82.2% at 1 *** studies showed that the multi-stimuli-responsive luminescence properties of 1 can be attributed to the regulation of cluster-centered luminescence process,metal-to-ligand charge transfer process,halide-to-metal charge transfer luminescence process and aggregationinduced barrier to oxygen *** work not only reports an AIE copper iodide cluster,but also provides a new strategy to develop multi-stimuli-responsive luminescence materials.

关键词： copper iodide cluster aggregation-induced emission multi-stimuli-response

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Creep damage evolution process of asphalt binder based on viscoelastic characteristics

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 497-506页

作者： Xiaofei Qi shuang Tian liyan Shan shuang liu Yajie Wang School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150090China College of Water Conservancy&Architectural Engineering Shihezi UniversityShihezi 832003China

The creep damage evolution of asphalt binder plays a significant role in investigating the formation mechanism of *** rutting is the common distress at high temperatures for asphalt ***,the reliability of existing creep damage parameters is under questioned,and these parameters cannot accurately illustrate the change of intrinsic microstructure for asphalt *** this paper,a new test protocol was given access to study the evolution of viscoelastic parameters during creep *** was completed by inserting the frequency sweep during creep *** frequency sweep curve clusters were fitted by the generalized Kelvin-Voigt model for obtaining the change law of model *** on the change law and sensitivity analysis of model parameters,(E_(2)+E_(3))/2 was proposed as the creep damage *** to the curve of(E_(2)+E_(3))/2 versus loading time,two stages during the creep test could be identified:an approximate constant value in phase I and a linear decrease in phase *** differences about creep property of binders could be determined by this new proposed *** results not only ensure better understanding of the creep damage mechanism of binders,but also lay the theoretical foundation on predicting the anti-rutting performance of binders.

关键词： Asphalt binder Multi-stage creep test Damage variable Evolution law

Dynamic Modeling and Experimental Verification of an RPR Type Compliant Paralle Mechanism with Low Orders

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 83-94页

作者： shuang Zhang Jingfang liu Huafeng Ding Yanbin Zhang School of Mechatronics Engineering Henan University of Science and TechnologyLuoyangHenanChina Faculty of Materials and Manufacturing College of Mechanical Engineering and Applied Electronics TechnologyBeijing University of TechnologyBeijingChina Key laboratory of advanced manufacturing technology Beijing University of TechnologyBeijingChina School of Mechanical Engineering and Electronic Information China University of Geosciences(Wuhan)WuhanChina Center of Machinery Equipment Advanced Manufacturing of Henan Province LuoyangChina

Efficiency of calculating a dynamic response is an important point of the compliant mechanism for posture *** modeling with low orders of a 2R1T compliant parallel mechanism is studied in the *** mechanism with two out-of-plane rotational and one lifting degrees of freedom(DoFs)plays an important role in posture *** on elastic beam theory,the stiffness matrix and mass matrix of the beam element are established where the moment of inertia is *** improve solving efficiency,a dynamic model with low orders of the mechanism is established based on a modified modal synthesis ***,each branch of the RPR type mechanism is divided into a ***,a set of hypothetical modes of each substructure is obtained based on the C-B ***,dynamic equation of the whole mechanism is established by the substructure assembly.A dynamic experiment is conducted to verify the dynamic characteristics of the compliant mechanism.

关键词： Compliant parallel mechanism Dynamic model Modal synthesis method Dynamic experiment