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Numerical research on adverse effect of muzzle flow formed by muzzle brake considering secondary combustion

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Defence Technology（防务技术） 2021年第4期17卷 1178-1189页

作者： Peng-fei Li xiao-bing Zhang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094PR China

The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device,muzzle brake,on the muzzle hazard phenomena,such as flash and blast *** correlation of the chemical reactions with the characteristics of the muzzle flow field is analyzed by the simulation for a further understanding of the secondary combustion phenomenon of the muzzle *** novel structure of muzzle flow caused by the muzzle brake is presented by the simultaneous solution of the interior ballistics model and multi-species Navier-Stokes equations in order to analyze the influence of the muzzle brake structure on the chemical *** secondary combustion of the muzzle flow due to the oxygen-supplement chemical reactions is obtained by the chemical reaction kinetic *** interaction of the blast waves released from the muzzle brake is illustrated in detail and the mechanism of the formation of muzzle flash is *** research provides a reference for the studies on the suppression of the muzzle flash.

关键词： Muzzle flow Muzzle brake Secondary combustion Chemical reaction

Modeling the redshift and energy distributions of fast radio bursts

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Research in Astronomy and Astrophysics 2017年第2期17卷 22-28页

作者： xiao-Feng Cao Ming xiao fei xiao Department of Physics and Engineering Hubei University of Education Wuhan 430205 China

Abstract Fast radio bursts （FRBs） are one of the most mysterious astronomical phenomena nowadays. The identification of their origin requires more observations in the future and, importantly, deep un- derstandings of the existing observational data. By fitting the redshift and energy distributions of 15 Parkes FRBs, we try to derive their intrinsic energy function and the cosmic evolution of their burst rates. Specifically, while the energy function is assumed as usual to have a single-power-law form, the burst rates are considered to be proportional to the cosmic star formation rates by a redshift-dependent coefficient. Some plausible fittings are obtained, which indicate the power-law assumptions are feasible and effective. The values of the power-law indices could be used to independently constrain candidate FRB models, although parameter degeneracies still exist.

关键词： radio continuum general

Synthesis of amphiphilic tri-block copolymerpoly(vinylpyrrolidone)-b-poly(methyl methacrylate)-b-poly(vinylpyrrolidone) for the modification of polyethersulfone membrane

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Chinese Chemical Letters 2011年第3期22卷 370-373页

作者： sheng Qiang Nie Fen Ran Chao He Peng fei Zhao xiao Hong Wei Jie Li Chang sheng Zhao College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan Universiry Chengdu 610065 China State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China

Well-defined amphiphilic tri-block copolymer PVP-b-PMMA-b-PVP was prepared for the first time via successive reversible addition fragmentation chain transfer（RAFT） polymerization using carboxyl-terminated trithiocarbonate as the RAFT *** structure of the copolymer was characterized using FTIR,GPC and ~1H *** block copolymer could be directly blended with polyethersulfone（PES） as a macromolecule additive using N-methyl-2-pyrrolidone（NMP） as the solvent to prepare membranes. The water contact angles for the modified membranes decreased obviously,and therefore,the protein adsorption amount on the membrane surface decreased.

关键词： Polyethersulfone membrane Protein adsorption Surface modification PVP-b-PMMA-b-PVP

In vitro Transient Expression System of Latex C-serum was used for Analysis of Hevein Promoter in Response to Abscisic Acid in Hevea brasiliensis

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Journal of Integrative Plant Biology 2008年第3期50卷 338-344页

作者： xiao-Wen fei xiao-Dong Deng Institute of Tropical Bioscience and Biotechnology Chinese Agricultural Academy for Tropical Crops Haikou 571101 China Department of Biochemistry Hainan Medical College Haikou 571101 China

Hevein has been found to be an essential element in coagulation of rubber particles in latex of rubber trees. In a previous study, we cloned a 1 241-bp fragment of a 5＇ upstream region of the hevein gene by genome walking. This fragment was analyzed by a 5＇ end nested deletion method in the present study, fused with a uidA （gus） gene to produce a series of tested constructs, which were transferred into C-serum of latex and the Gus activities were detected. Results showed that the fragment from -749 to -292 was sufficient for expression of gus gene in latex, and the fragment from -292 to -168 was crucial in response to abscisic acid inducement. In a transient transgenic test of rubber leaf with particle bombardment, construct Hev749 conferred gus-specific expression in veins, in which the latex tubes mainly distributed. This implies that the fragment from -749 to -292 was laticiferous-specific.

关键词： abscisic acid gus (beta-glucuronidase) gene hevein promoter rubber tree (Hevea brasiliensis)

Template-free preparation of porous Co microfibers from spent lithium-ion batteries as a promising microwave absorber

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Rare Metals 2022年第10期41卷 3475-3485页

作者： xiao-Min Wu fei Xie Yong-Lin Yao Yue Sun Zhong-sheng Hua Zhuo Zhao Yong-Xiang Yang Anhui Province Key Laboratory of Metallurgical Engineering&Resources Recycling School of Metallurgical EngineeringAnhui University of TechnologyMaanshan243002China Department of Materials Science and Engineering Delft University of TechnologyDelft2628CDNetherlands

In order to take full advantage of the secondary resources,in this paper,we reported a template-free process to prepare porous Co microfibers from spent lithiumion batteries(LIBs).First,the waste LiCoO_(2) powders were leached by oxalic acid at a suitable temperature,and rodlike cobalt oxalate powders were ***,the porous Co microfibers were prepared by using the cobalt oxalate as precursors through a thermal decomposition at420 ℃ under nitrogen *** prepared Co microfibers possess diameters of 1-2 μm,and each microfiber consists of small particles with size of100-200 *** Co microfibers(25 wt%)/paraffin composite exhibited excellent microwave absorption *** the sample thickness is 4.5 mm,the reflection losses reach-36.14 and-38.20 dB at 4.16 and 17.60 GHz,respectively,and the effective bandwidth reaches up to 5.52 *** indicates that the Co microfibers can be used as a promising microwave ***,this paper demonstrates a novel process to make a high value-added product through recycling from the spent lithium-ion *** addition,it is advantageous to eliminate the hazard of spent lithium-ion batteries and electromagnetic radiation to environment and human health.

关键词： Spent lithium-ion batteries(LIBs) Co microfibers Recycling Oxalic acid leaching Microwave absorption

Novel application of multispectral refraction topography in the observation of myopic control effect by orthokeratology lens in adolescents

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World Journal of Clinical Cases 2021年第30期9卷 8985-8998页

作者： Ning-Jun Ni fei-Yan Ma xiao-Mei Wu xiao Liu Hong-Yan Zhang Yi-fei Yu Mei-Chen Guo sheng-Yong Zhu Department of Technology Zigong Yuan-Xin Energy Saving Technology Co.LtdZigong 643030Sichuan ProvinceChina Department of Ophthalmology The Second Hospital of Hebei Medical UniversityShijiazhuang 050000Hebei ProvinceChina Department of Ophthalmology The First People’s Hospital of ZigongZigong 643000Sichuan ProvinceChina Department of Optometry North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina

BACKGROUND Myopia,as one of the common ocular diseases,often occurs in *** addition to the harm from itself,it may also lead to serious ***,prevention and control of myopia are attracting more and more *** research revealed that single-focal glasses and orthokeratology lenses(OK lenses)played an important part in slowing down myopia and preventing high *** To compare the clinical effects of OK lenses and frame glasses against the increase of diopter in adolescent myopia and further explore the mechanism of the OK *** Changes in diopter and axial length were collected among 70 adolescent myopia patients(124 eyes)wearing OK lenses for 1 year(group A)and 59 adolescent myopia patients(113 eyes)wearing frame glasses(group B).Refractive states of their retina were inspected through multispectral refraction *** obtained hyperopic defocus was analyzed for the mechanism of OK lenses on slowing down the increase of myopic diopter by delaying the increase of ocular axis length and reducing the near hyperopia *** Teenagers in groups A and B were divided into low myopia(0 D--3.00 D)and moderate myopia(-3.25 D--6.00 D),without statistical differences among gender and *** 1-year treatment,the increase of diopter and axis length and changes of retinal hyperopic defocus amount of group A were significantly less than those of group *** to the multiple linear analysis,the retinal defocus in the upper,lower,nasal,and temporal directions had almost the same effect on the total *** amount of peripheral retinal defocus(15°-53°)in group A was significantly lower than that in group *** Multispectral refraction topography is progressive and instructive in clinical prevention and control of myopia.

关键词： Multispectral refraction topography Myopia Retinal hyperopic defocus Eye axis Diopter Orthokeratology lens Frame glasses

Current and recent cigarette smoking in relation to cardiovascular and non-cardiovascular mortality in an elderly male Chinese population

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Journal of Geriatric Cardiology 2023年第8期20卷 567-576页

作者： Wen-Yuan-Yue WANG xiao-fei YE Chao-Ying MIAO Wei ZHANG Chang-sheng sheng Qi-Fang HUANG Ji-Guang WANG School of Public Health Shanghai Jiaotong University School of MedicineShanghaiChina Department of Cardiovascular Medicine The Shanghai Institute of HypertensionRuijin HospitalShanghai Jiaotong University School of MedicineShanghaiChina

OBJECTIVE To investigate the association between current and former smoking and the risk of mortality in elderly Chinese *** Our study participants were elderly(≥60 years)men recruited in a suburban town of *** smoking status was categorized as never smoking,remote(cessation>5 years)and recent former smoking(cessation≤5 years),and light-to-moderate(≤20 cigarettes/day)and heavy current smoking(>20 cigarettes/day).Cox proportional hazards models and restricted cubic splines were used to examine the associations of *** The 1568 participants had a mean age of 68.6±7.1 *** all participants,311 were never smokers,201 were remote former smokers,133 were recent former smokers,783 were light-to-moderate current smokers and 140 were heavy current *** a median follow-up of 7.9 years,all-cause,cardiovascular and non-cardiovascular deaths occurred in 267,106 and 161 participants,*** current smokers had the highest risk of all-cause and non-cardiovascular mortality,with an adjusted hazard ratio(HR)of 2.30(95%CI:1.34-4.07)and 3.98(95%CI:2.03-7.83)versus never smokers,*** former smokers also had a higher risk of all-cause(HR=1.62,95%CI:1.04-2.52)and non-cardiovascular mortality(HR=2.40,95%CI:1.32-4.37)than never *** regression restricted cubic spline models showed the highest risk of all-cause and non-cardiovascular mortality within 5 years of smoking cessation and decline *** subgroup analyses showed interaction between smoking status and pulse rate(≥70 beats/min vs.<70 beats/min)in relation to the risk of all-cause and non-cardiovascular mortality,with a higher risk in current versus never smokers in those participants with a pulse rate below 70 beats/*** Cigarette smoking in elderly Chinese confers significant risks of mortality,especially when recent former smoking is considered together with current smoking.

关键词： relation cubic restricted

Microstructural evolution and mechanical properties of Ni-45Ti-5Al-2Nb-1Mo alloy subjected to different heat treatments

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Rare Metals 2023年第8期42卷 2774-2780页

作者： xiao-Yun Song Yan Li fei Zhang State Key Laboratory of Nonferrous Metals and Processes GRIMAT Engineering Institute Co.LtdBeijing 101407China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The effects of solution and aging heat treatment on microstructural evolution and room temperature tensile properties for as-forged Ni-45Ti-5Al-2Nb-1Mo alloy were investigated through scanning electron microscopy(SEM),transmission electron microscopy(TEM)and tensile *** results show that the microstructure of solution-treated alloy comprises NiTi matrix,Ti_(2)Ni and(Nb,Ti)ss *** aging treatment at 700℃for 6 and100 h,the distribution of Ti_(2)Ni and(Nb,Ti)ss precipitates increases in *** new type of precipitate is observed in the specimen aged at 700℃.After aging at800℃for 100 h,numerous nanosized Ni_(2)TiAl phases are precipitated within the *** and aging treatments improve the tensile properties at room *** strength and ductility are improved after solution treatment at 1100℃plus aging treatment at 800℃for 6 h or 700℃for 100 *** aging time prolonging to 100 h at 800℃,the precipitation of fine Ni2TiAl particles leads to the improvement in tensile strength and deterioration of elongation.

关键词： NiTi-Al-based alloy Intermetallics Microstructure Mechanical properties Heat treatment

Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 499-512页

作者： Yue-Hui Dang sheng-Lin Liu xiao-Lei Ai xiao-Wei Feng Bo Feng Zhuo Tian Ying-fei Lin Huan-Tao Chen Kai-Hong Zheng School of Materials Science and Engineering Chang’an UniversityShaanxi 710064China Guangdong Key Laboratory of Metal Toughening Technology and Application Institute of New MaterialsGuangdong Academy of SciencesGuangzhou 510650China

In this study,microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied,with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite *** rule of mixtures(ROM)for elongation was also *** results show that when there is no or thin diffusion layer with thickness of about 3μm,Mg-based bimetal plates have a good plasticity with elongation of about 19-24%,and the ROM predicted elongations are very close to the experimental *** contrast,with a diffusion layer about 95-155μm thick,Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11-17%,and the experimental elongations largely deviate from the ROM *** plasticity of Mg-based bimetal plates increases with increasing sleeve *** study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.

关键词： Mg-based composites Co-extrusion Microstructure Mechanical behavior Plastic deformation