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Observer-based robust high-order fully actuated attitude autopilot design for spinning glide-guided projectiles 被引量:1
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作者 Wei Wang Yuchen Wang +2 位作者 Shiwei Chen Yongcang Guo Zhongjiao Shi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期282-294,共13页
This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external disturbances.Based on fixed-time stable theor... This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external disturbances.Based on fixed-time stable theory,a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects,irrespective of initial conditions.By introducing an error integral signal,the dynamics of the SGGP are transformed into two separate second-order fully actuated systems.Subsequently,employing the high-order fully actuated approach and a parametric approach,the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system,ensuring that the projectile's attitude asymptotically tracks the given goal with the desired eigenstructure.Under the proposed composite control framework,the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov method.Validation of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations. 展开更多
关键词 spinning glide-guided projectile Attitude control Sliding mode disturbance observer Fixed-time stable theory High-order fully actuated approach
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Dynamic characteristics of multi-span spinning beams with elastic constraints under an axial compressive force
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作者 Xiaodong GUO Zhu SU Lifeng WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第2期295-310,共16页
A theoretical model for the multi-span spinning beams with elastic constraints under an axial compressive force is proposed.The displacement and bending angle functions are represented through an improved Fourier seri... A theoretical model for the multi-span spinning beams with elastic constraints under an axial compressive force is proposed.The displacement and bending angle functions are represented through an improved Fourier series,which ensures the continuity of the derivative at the boundary and enhances the convergence.The exact characteristic equations of the multi-span spinning beams with elastic constraints under an axial compressive force are derived by the Lagrange equation.The efficiency and accuracy of the present method are validated in comparison with the finite element method(FEM)and other methods.The effects of the boundary spring stiffness,the number of spans,the spinning velocity,and the axial compressive force on the dynamic characteristics of the multi-span spinning beams are studied.The results show that the present method can freely simulate any boundary constraints without modifying the solution process.The elastic range of linear springs is larger than that of torsion springs,and it is not affected by the number of spans.With an increase in the axial compressive force,the attenuation rate of the natural frequency of a spinning beam with a large number of spans becomes larger,while the attenuation rate with an elastic boundary is lower than that under a classic simply supported boundary. 展开更多
关键词 multi-span spinning beam elastic constraint improved Fourier series free vibration semi-analytical solution
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Photocatalytic ozonation-based degradation of phenol by ZnO—TiO_(2)nanocomposites in spinning disk reactor
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作者 Xueqing Ren Jiahao Niu +5 位作者 Yan Li Lei Li Chao Zhang Qiang Guo Qiaoling Zhang Weizhou Jiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第8期74-84,共11页
Spinning disk reactor(SDR)has emerged as a novel process intensification photocatalytic reactor,and it has higher mass transfer efficiency and photon utilization for the degradation of toxic organic pollutants by adva... Spinning disk reactor(SDR)has emerged as a novel process intensification photocatalytic reactor,and it has higher mass transfer efficiency and photon utilization for the degradation of toxic organic pollutants by advanced oxidation processes(AOPs).In this study,ZnO—TiO_(2)nanocomposites were prepared by solgel method,and coated on the disk of SDR by impregnation-pull-drying-calcination method.The performance of catalyst was characterized by X-ray diffraction,scanning electron microscope,X-ray photoelectron spectroscopy,photoluminescence and ultraviolet—visible diffuse reflectance spectroscopy.Photocatalytic ozonation in SDR was used to remove phenol,and various factors on degradation effect were studied in detail.The results showed that the rate of degradation and mineralization reached 100%and 83.4%under UV light irradiation after 50 min,compared with photocatalysis and ozonation,the removal rate increased by 69.3%and 34.7%,and mineralization rate increased by 56.7%and 62.9%,which indicated that the coupling of photocatalysis and ozonation had a synergistic effect.The radical capture experiments demonstrated that the active species such as photogenerated holes(h^(+)),hydroxyl radicals(·OH),superoxide radical(·O_(2)-)were responsible for phenol degradation,and·OH played a leading role in the degradation process,while h+and·O_(2)^(-)played a non-leading role. 展开更多
关键词 spinning disk reactor Photocatalytic ozonation ZnO-TiO_(2)nanocomposites Advanced oxidation processes
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Carrageenan Fiber Prepared by a New Process Route of Ba^(2+)Ion Pre-Crosslinking in the Spinning Solution
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作者 Liting Jia Xiao Han +3 位作者 Cuixia Qiao Gang Zhao Yanzhi Xia Zhixin Xue 《Journal of Renewable Materials》 EI CAS 2024年第3期427-441,共15页
Ba^(2+)pre-crosslinked carrageenan fiber(Ba/CAF)was prepared by adding a small amount of Ba^(2+) to the carrageenan(CA)solution as the spinning solution.Ba/CAF-n/A,Ba/CAF-n/B and Ba/CAF-n/C were prepared with ethanol ... Ba^(2+)pre-crosslinked carrageenan fiber(Ba/CAF)was prepared by adding a small amount of Ba^(2+) to the carrageenan(CA)solution as the spinning solution.Ba/CAF-n/A,Ba/CAF-n/B and Ba/CAF-n/C were prepared with ethanol solution(combine A),high concentration BaCl_(2)solution(combine B)and low concentration BaCl_(2)solution(combine C),as coagulation bath and stretch bath,respectively.The combination of coagulation bath and stretch bath suitable for Ba^(2+) pre-crosslinking wet spinning was screened.The results showed that Ba^(2+) can induce the birefringence of the CA molecular chain,and the Ba^(2+) pre-crosslinking effect is the best when the CA mass fraction is 8.0 wt%.From the perspective of production safety,fiber performance and spinning cost,the coagulation bath of 3.5 wt%BaCl_(2)solution and stretch bath of 1.7 wt%BaCl_(2)solution,that is,combination C with low concentration BaCl_(2)solution,is the best choice.Ba/CAF-8.0/C was obtained under the best conditions.The linear intensity,water absorption and flame retardancy study showed that the breaking strength of Ba/CAF-8.0/C is as high as 1.61 cN/dtex,the water absorption was 649.2%and 574.3%,in deionized water and normal saline,respectively,and the LOI value reached 32. 展开更多
关键词 Carrageenan fiber Ba^(2+)ion pre-crosslinking wet spinning flame retardancy
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Preparation of Regenerated Silk Fibroin Hybrid Fibers with Hydrogen Peroxide Sensing Properties by Wet Spinning
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作者 Song Lu Jianjun Guo +3 位作者 Richard Ansah Herman Xinyi Wu Lin Ma Guohua Wu 《Journal of Renewable Materials》 EI CAS 2024年第6期1043-1055,共13页
Silk is widely used in the production of high-quality textiles.At the same time,the amount of silk textiles no longer in use and discarded is increasing,resulting in significant waste and pollution.This issue is of gr... Silk is widely used in the production of high-quality textiles.At the same time,the amount of silk textiles no longer in use and discarded is increasing,resulting in significant waste and pollution.This issue is of great concern in many countries where silk is used.Hydrogen peroxide as a naturally occurring compound is an important indicator of detection in both biology and the environment.This study aims to develop a composite fiber with hydrogen peroxide-sensing properties using discarded silk materials.To achieve this goal,firstly,polydopamine(PDA)was used to encapsulate the ZnFe_(2)O_(4) NPs to achieve the improvement of dispersion,and then regenerated silk fibroin(RSF)and PDA@ZnFe_(2)O_(4)/RSF hybrid fibers are prepared by wet spinning.Research has shown that PDA@ZnFe_(2)O_(4)/RSF demonstrates exceptional sensitivity,selectivity,and stability in detecting hydrogen peroxide,while maintaining high mechanical strength.Furthermore,the complete hybridization of PDA@ZnFe_(2)O_(4) with silk fibroin not only results in the combination of the durability of silk fibroin and PDA@ZnFe_(2)O_(4)’s rigidity,ensuring a reliable service life,but also makes PDA@ZnFe_(2)O_(4)/RSF exhibit excellent catalytic activity and biocompatibility.Therefore,the composite fiber exhibits exceptional mechanical properties and reliable hydrogen peroxide sensing capabilities,making it a promising material for biological and medical applications. 展开更多
关键词 Regenerated silk fibroin modified zinc ferrite nanoparticles composite fiber hydrogen peroxide sensor wet spinning
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Reduce waste and boost profits in spinning:Uster presents FiberQ and RSO 3D
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《China Textile》 2024年第3期42-43,共2页
Coinciding with World Water Day celebrations and unSpinners seeking profitable investments for sustainable mill operations would do well to check out Uster FiberQ and RSO 3D.Both these systems offer attractive ROI.The... Coinciding with World Water Day celebrations and unSpinners seeking profitable investments for sustainable mill operations would do well to check out Uster FiberQ and RSO 3D.Both these systems offer attractive ROI.They also help spinners control the most expensive stages in the mill process,cutting waste and boosting profits. 展开更多
关键词 spinning USTER BOOST
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Effects of Spinning Process on Intergranular Corrosion Behavior of 5A06 Aluminum Alloy 被引量:1
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作者 张谦君 付永康 +4 位作者 ZHAO Wenlong 李青 ZHANG Rulin GUO Yong LI Rongbin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第1期231-236,共6页
Aluminum alloy tubes were prepared by tube spinning.The intergranular and electrochemical corrosion tests were used to investigate the intergranular corrosion behavior of the 5A06 aluminum alloy blank sample and the s... Aluminum alloy tubes were prepared by tube spinning.The intergranular and electrochemical corrosion tests were used to investigate the intergranular corrosion behavior of the 5A06 aluminum alloy blank sample and the spinning sample.Results showed that the intergranular corrosion resistance of the spinning sample was higher than that of the blank sample.In addition,the electrochemical corrosion resistance of the spinning sample was higher than that of the blank sample.The EDS maps indicated a uniform element distribution pattern of aluminum and magnesium.Moreover,the phase composition and lattice constant of the samples were obtained by XRD analysis.The differences in microstructure between the aluminum alloy subjected to the spinning process and the untreated aluminum alloy were determined by EBSD.The differences were mainly attributed to the complex interactions among grain size,dislocations and grain boundaries. 展开更多
关键词 spinning process 5A06 aluminum alloy intergranular corrosion EBSD
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Study on Licker-In and Flat Speeds of Carding Machine and Its Effects on Quality of Cotton Spinning Process 被引量:1
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作者 Md. Mominul Motin Ayub Nabi Khan Md. Obaidur Rahman 《Journal of Textile Science and Technology》 2023年第3期198-214,共17页
Spinning has a significant influence on all textile processes. Combinations of all the capital equipment display the process’ critical condition. By transforming unprocessed fibers into carded sliver and yarn, the ca... Spinning has a significant influence on all textile processes. Combinations of all the capital equipment display the process’ critical condition. By transforming unprocessed fibers into carded sliver and yarn, the carding machine serves a critical role in the textile industry. The carding machine’s licker-in and flat speeds are crucial operational factors that have a big influence on the finished goods’ quality. The purpose of this study is to examine the link between licker-in and flat speeds and how they affect the yarn and carded sliver quality. A thorough experimental examination on a carding machine was carried out to accomplish this. The carded sliver and yarn produced after experimenting with different licker-in and flat speed combinations were assessed for important quality factors including evenness, strength, and flaws. To account for changes in material qualities and machine settings, the study also took into consideration the impact of various fiber kinds and processing circumstances. The findings of the investigation showed a direct relationship between the quality of the carded sliver and yarn and the licker-in and flat speeds. Within a limited range, greater licker-in speeds were shown to increase carding efficiency and decrease fiber tangling. On the other hand, extremely high speeds led to more fiber breakage and neps. Higher flat speeds, on the other hand, helped to enhance fiber alignment, which increased the evenness and strength of the carded sliver and yarn. Additionally, it was discovered that the ideal blend of licker-in and flat rates varied based on the fiber type and processing circumstances. When being carded, various fibers displayed distinctive behaviors that necessitated adjusting the operating settings in order to provide the necessary quality results. The study also determined the crucial speed ratios between the licker-in and flat speeds that reduced fiber breakage and increased the caliber of the finished goods. The results of this study offer useful information for textile producers and process engineers to improve the quality of carded sliver and yarn while maximizing the performance of carding machines. Operators may choose machine settings and parameter adjustments wisely by knowing the impacts of licker-in and flat speeds, which will increase textile industry efficiency, productivity, and product quality. 展开更多
关键词 spinning Process Carding Machine Yarn Count FLAT Licker-In Sliver Hank
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Study on Licker-In and Flat Speeds of Carding Machine and Its Effects on Quality of Cotton Spinning Process
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作者 Md. Mominul Motin Ayub Nabi Khan Md. Obaidur Rahman 《Journal of Flow Control, Measurement & Visualization》 2023年第3期198-214,共17页
Spinning has a significant influence on all textile processes. Combinations of all the capital equipment display the process’ critical condition. By transforming unprocessed fibers into carded sliver and yarn, the ca... Spinning has a significant influence on all textile processes. Combinations of all the capital equipment display the process’ critical condition. By transforming unprocessed fibers into carded sliver and yarn, the carding machine serves a critical role in the textile industry. The carding machine’s licker-in and flat speeds are crucial operational factors that have a big influence on the finished goods’ quality. The purpose of this study is to examine the link between licker-in and flat speeds and how they affect the yarn and carded sliver quality. A thorough experimental examination on a carding machine was carried out to accomplish this. The carded sliver and yarn produced after experimenting with different licker-in and flat speed combinations were assessed for important quality factors including evenness, strength, and flaws. To account for changes in material qualities and machine settings, the study also took into consideration the impact of various fiber kinds and processing circumstances. The findings of the investigation showed a direct relationship between the quality of the carded sliver and yarn and the licker-in and flat speeds. Within a limited range, greater licker-in speeds were shown to increase carding efficiency and decrease fiber tangling. On the other hand, extremely high speeds led to more fiber breakage and neps. Higher flat speeds, on the other hand, helped to enhance fiber alignment, which increased the evenness and strength of the carded sliver and yarn. Additionally, it was discovered that the ideal blend of licker-in and flat rates varied based on the fiber type and processing circumstances. When being carded, various fibers displayed distinctive behaviors that necessitated adjusting the operating settings in order to provide the necessary quality results. The study also determined the crucial speed ratios between the licker-in and flat speeds that reduced fiber breakage and increased the caliber of the finished goods. The results of this study offer useful information for textile producers and process engineers to improve the quality of carded sliver and yarn while maximizing the performance of carding machines. Operators may choose machine settings and parameter adjustments wisely by knowing the impacts of licker-in and flat speeds, which will increase textile industry efficiency, productivity, and product quality. 展开更多
关键词 spinning Process Carding Machine Yarn Count FLAT Licker-In Sliver Hank
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Microstructure Distribution Characteristics of High-Strength Aluminum Alloy Thin-Walled Tubes during Multi-Passes Hot Power Backward Spinning Process
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作者 Yuan Tian Ranyang Zhang +1 位作者 Gangyao Zhao Zhenghua Guo 《Journal of Materials Science and Chemical Engineering》 2023年第7期114-121,共8页
The microstructure of the thin-walled tubes with high-strength aluminum alloy determines their final forming quality and performance. This type of tube can be manufactured by multi-pass hot power backward spinning pro... The microstructure of the thin-walled tubes with high-strength aluminum alloy determines their final forming quality and performance. This type of tube can be manufactured by multi-pass hot power backward spinning process as it can eliminate casting defects, refine microstructure and improve the plasticity of the tube. To analyze the microstructure distribution characteristics of the tube during the spinning process, a 3D coupled thermo-mechanical FE model coupled with the microstructure evolution model of the process was established under the ABAQUS environment. The microstructure evolution characteristics and laws of the tube for the whole spinning process were analyzed. The results show that the dynamic recrystallization is mainly produced in the spinning deformation zone and root area of the tube. In the first pass, the dynamic recrystallization phenomenon is not obvious in the tube. With the pass increasing, the trend of dynamic recrystallization volume percentage gradually increases and extends from the outer surface of the tube to the inner surface. The fine-grained area shows the states of concentration, dispersion, and re-concentration as the pass number increases. . 展开更多
关键词 Cast High-Strength Aluminum Alloy Tube Multi-Pass Hot Power Backward spinning FE Simulation Microstructure Evolution
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ANALYSIS OF MECHANICS IN BALL SPINNING OF THIN-WALLED TUBE 被引量:18
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作者 JIANG Shuyong REN Zhengyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第1期25-30,共6页
Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain proble... Ball spinning is applied to manufacturing thin-walled tube with high precision and high mechanical properties. On the basis of plastic mechanics, by simplifying ball spinning of thin-walled tube as plane strain problem, slab method is used for the purpose of calculating the contact deformation pressure. The spinning force components, the torsional moment, the deformation power and the deformation work are calculated further as well. The influence of the two important process parameters such as the feed ratio and the ball diameter on the spinning force components is analyzed in order to further control the spinning force components by regulating the two process variables during the ball spinning process. The stress and strain state in deformable zone as well as mechanics boundary conditions in ball spinning are obtained. The effect of the three spinning force components on the formability of the spun part is analyzed and validated through the ball spinning experiments. The theoretical and experimental results show that the radial spinning component plays a significant role in ball spinning of thin-walled tube, and the mechanics situation in backward ball spinning contributes to enhancing the plasticity of the metal material, but that in forward ball spinning contributes to advancing the axial flow of the metal material. 展开更多
关键词 Power spinning Tube spinning Ball spinning spinning force Slab method
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Spinning Deformation Criteria of Thin-walled Tubular Part with Longitudinal Inner Ribs 被引量:2
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作者 江树勇 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第4期169-172,共4页
As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation... As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation theoo,, the application of yield criterion to the spinning process and the influence of the radial spinning force component on the formability of inner ribs were analyzed. Based on yield criterion and plastic mechanics, the stable flow rule of metal material and forming criteria of the inner ribs were obtained aad conformed to the experimental results so as to contribute greatly to improving the ball spinning process and optimizing the process variables, such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank, which have a significant influenee on the formability of the inner ribs. The knowledge of the influence of the process variables such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank on the spinning process is essential to preventing the quality defects of the spun parts and obtaining the desired spun parts. 展开更多
关键词 ball spinning power spinning spinning force CRITERION
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一种基于Contourlet递归Cycle Spinning的图像去噪方法 被引量:38
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作者 梁栋 沈敏 +2 位作者 高清维 鲍文霞 屈磊 《电子学报》 EI CAS CSCD 北大核心 2005年第11期2044-2046,共3页
综合利用Contourlet变换和递归Cycle Spinning,提出一种新的图像去噪方法.由于Contourlet变换缺乏平移不变性,直接进行Contourlet系数阈值图像去噪会产生伪吉布斯现象(导致图像失真),本文引入递归Cycle Spinning来有效地消除这种由于Con... 综合利用Contourlet变换和递归Cycle Spinning,提出一种新的图像去噪方法.由于Contourlet变换缺乏平移不变性,直接进行Contourlet系数阈值图像去噪会产生伪吉布斯现象(导致图像失真),本文引入递归Cycle Spinning来有效地消除这种由于Contourlet变换缺乏平移不变性而产生的图像失真.实验结果显示,与小波递归Cycle Spinning图像去噪等方法相比,该方法明显改善图像视觉效果,显著提高图像的PSNR值. 展开更多
关键词 小波变换 CONTOURLET变换 递归Cycle spinning 图像去噪
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Effect of Nd content on electrochemical performances of nanocrystalline and amorphous (Mg_(24)Ni_(10)Cu_2)_(100-x)Nd_x(x=0-20) alloys prepared by melt spinning 被引量:10
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作者 张羊换 杨泰 +3 位作者 卜文刚 蔡颖 张国芳 赵栋梁 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3668-3676,共9页
The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of (Mg24Ni10Cu2)100-xNdx (x=0, 5, 10, 15, 20) were fabricated by melt spinning technology. The effects of spinning rate on the struct... The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of (Mg24Ni10Cu2)100-xNdx (x=0, 5, 10, 15, 20) were fabricated by melt spinning technology. The effects of spinning rate on the structure and electrochemical hydrogen storage performance of the alloys were investigated. The as-spun Nd-free alloy displays an entire nanocrystalline structure, whereas the as-spun Nd-added alloys hold a nanocrystalline and amorphous structure, suggesting that the addition of Nd facilitates the glass forming of the Mg2Ni-type alloys. Increasing the spinning rate from 0 to 40 m/s gives rise to the discharge capacity growing from 42.5 to 100.6 mA·h/g for the x=0 alloy and from 86.4 to 452.8 mA·h/g for the x=10 alloy. And the cycle stability (S20) rises from 40.2%to 41.1%for the x=0 alloy and from 53.2%to 89.7%for the x=10 alloy, respectively. 展开更多
关键词 hydrogen storage alloy Mg2Ni-type alloy ND melt spinning structure
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Review on hot spinning for difficult-to-deform lightweight metals 被引量:14
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作者 詹梅 杨合 +1 位作者 郭靖 王贤贤 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第6期1732-1743,共12页
Hot spinning process has attracted significant attention because it can be used to manufacture complex parts, extend the forming limit of materials, decrease forming forces and reduce process chains. In this paper, we... Hot spinning process has attracted significant attention because it can be used to manufacture complex parts, extend the forming limit of materials, decrease forming forces and reduce process chains. In this paper, we review researches on lightweight metals spun at elevated temperatures since they are difficult to deform at room temperature. These metals include light alloys, such as titanium, magnesium and aluminum alloys, and metal composites. Then, the heating methods used in the hot spinning process and the treatment methods employed for the temperature boundary condition in finite element analyses for the process were discussed. Finally, the future development directions for the hot spinning process of lightweight but difficult-to-deform alloys were highlighted. 展开更多
关键词 hot spinning lightweight metal heating method temperature boundary condition future develonment direction
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基于小波-Contourlet变换的Cycle spinning硬阈值图像去噪方法 被引量:4
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作者 任洪娥 王海丰 赵鹏 《光学技术》 CAS CSCD 北大核心 2008年第6期854-857,861,共5页
综合考虑小波变换的特点以及Contourlet变换对二维光滑图像有很好的近似特性和对曲线有更好的"稀疏"表示的特点,提出了一种基于小波-Contorlet变换的图像硬阈值去噪方法,并用Cycle spinning去除图像中小波-Con- tourlet变换... 综合考虑小波变换的特点以及Contourlet变换对二维光滑图像有很好的近似特性和对曲线有更好的"稀疏"表示的特点,提出了一种基于小波-Contorlet变换的图像硬阈值去噪方法,并用Cycle spinning去除图像中小波-Con- tourlet变换平移变异性而产生的伪吉布斯现象。实验结果表明:该方法与采用Cycle spinning的小波和Contourlet去嗓算法相比,PSNR分别提高了0.4~1.6和0.2~1.0。与其它去噪算法相比,这种方法能有效地去除图像中的噪声,具有更高的PSNR值,能更好地保留图像的纹理和细节。 展开更多
关键词 信息光学 图像处理 图像去噪 小波-CONTOURLET变换 Cycle spinning
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Variable-based Ramberg-Osgood constitutive model of power spinning bushing 被引量:8
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作者 赵俊生 顾元通 樊文欣 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第9期3080-3087,共8页
The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carr... The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carried out.Based on the experimental data,a ternary quadratic regression equation was established by orthogonal experiment.The Ramberg-Osgood constitutive model of tin-bronze connecting rod bushing was obtained.Referred to the constitutive relation of macroscopic incremental,the incremental elastoplastic constitutive relation of spinning parts was deduced based on the Mises yield criterion and kinematic hardening model.The results can be applied to the elastoplastic analysis in finite element numerical simulation. 展开更多
关键词 power spinning connecting rod bushing constitutive model technical parameter mechanical properties
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Finite element simulation of ball spinning of NiTi shape memory alloy tube based on variable temperature field 被引量:2
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作者 江树勇 张艳秋 +2 位作者 赵亚楠 唐明 李春峰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第3期781-787,共7页
As a new attempt,ball spinning was used to manufacture the nickel-titanium shape memory alloy(NiTi SMA) tube at elevated temperature.The NiTi bar with a nominal composition of Ni50.9Ti49.1(mole fraction,%) was sol... As a new attempt,ball spinning was used to manufacture the nickel-titanium shape memory alloy(NiTi SMA) tube at elevated temperature.The NiTi bar with a nominal composition of Ni50.9Ti49.1(mole fraction,%) was solution treated and was used as the original tube blank for ball spinning.Based on the variable temperature field and the constitutive equation,rigid-viscoplastic finite element method(FEM) was applied in order to simulate the ball spinning of NiTi SMA tube.The temperature field,the stress field,the strain field and the load prediction were obtained by means of FEM.FEM results reveal that there is a temperature increase of about 160 ℃ in the principal deformation zone of the spun part.It can be found from the stress fields and the strain fields that the outer wall of NiTi SMA tube is easier to meet the plastic yield criterion than the inner wall,and the plastic deformation zone is caused to be in a three-dimensional compressive stress state.The radial strain and the tangential strain are characterized by the compressive strain,while the axial strain belongs to the tensile strain.The variation of spinning loads with the progression of the ball is of great importance in predicting the stable flow of the spun part. 展开更多
关键词 NiTi alloy NiTi tube shape memory alloy finite element method ball spinning
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基于广义交叉验证和Cycle Spinning的SAR图像相干斑抑制 被引量:3
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作者 杨晓慧 金海燕 焦李成 《电子与信息学报》 EI CSCD 北大核心 2007年第8期1779-1783,共5页
该文基于SAR图像的统计特性,提出了一种相干斑抑制算法。该算法在不需要估计噪声能量的情况下,采用广义交叉验证准则构造目标函数,自适应获取近似最优阈值;然后基于小波阈值收缩完成SAR图像滤波;并引入Cycle Spinning策略有效去除边缘... 该文基于SAR图像的统计特性,提出了一种相干斑抑制算法。该算法在不需要估计噪声能量的情况下,采用广义交叉验证准则构造目标函数,自适应获取近似最优阈值;然后基于小波阈值收缩完成SAR图像滤波;并引入Cycle Spinning策略有效去除边缘存在的振铃效应。实验结果表明:基于该文算法的相干斑抑制在视觉效果和客观衡量指标上都取得了较好的、鲁棒的效果,有效地抑制了相干斑噪声,均匀区域平滑,且能同时保持边缘和细节清晰。 展开更多
关键词 合成孔径雷达 广义交叉验证 CYCLE spinning 相干斑
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小波-Contourlet与迭代Cycle Spinning相结合的SAR图像去噪 被引量:3
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作者 方敬 肖扬 王东 《应用科学学报》 CAS CSCD 北大核心 2014年第6期605-610,共6页
通过分析合成孔径雷达图像的相干斑噪声模型,提出一种小波-Contourlet与迭代Cycle spinning相结合的SAR图像去噪方法.小波-Contourlet比小波变换、Contourlet变换能更稀疏地表达图像,更好地获得图像结构特征.Contourlet变换缺乏移不变性... 通过分析合成孔径雷达图像的相干斑噪声模型,提出一种小波-Contourlet与迭代Cycle spinning相结合的SAR图像去噪方法.小波-Contourlet比小波变换、Contourlet变换能更稀疏地表达图像,更好地获得图像结构特征.Contourlet变换缺乏移不变性,导致小波-Contourlet也是缺乏移不变性的,对系数进行阈值处理会产生伪吉布斯现象.Cycle spinning算法可以有效地减少伪吉布斯现象,但不是最优的.为此,用小波变换代替LP(Laplacian pyramid)变换作子带分解,以迭代Cycle spinning代替多次移位取平均值.仿真结果表明,该方法不仅可以显著去除相干斑噪声,达到较高的峰值信噪比,而且还保留了图像的细节,改善了视觉效果. 展开更多
关键词 合成孔径雷达图像 去噪 CONTOURLET 小波-Contourlet 迭代Cycle spinning
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