检索结果-内蒙古大学图书馆

Pacific-Rim laser Damage 2023: Optical Materials for High-Power lasers

作者： Kuang, Weiquan Zheng, Yu Chen, Jie Liu, Wenwen Peng, Wenhai Ye, Zongyi Cao, Yu Zhejiang Provincial Key Laboratory of Laser Processing Robotics China International Science and Technology Cooperation Base for Laser Processing Robot College of Mechanical and Electrical Engineering Wenzhou University Wenzhou325035 China Zhejiang Wuma Reducer Co. Ltd. Zhejiang Wenzhou325019 China Zhejiang Qidi Technology Co. Ltd. Zhejiang Wenzhou325035 China Wenzhou University Rui'an Graduate College Rui'an Zhejiang325200 China

ISBN: (纸本)9781510672826

laser continuous/dispersed quenching techniques were used for surface hardening Cr8 cold work die steel, and its metallographic microstructures and mechanical properties are investigated in this work. Typical mixed structure which composed of carbides in different morphologies and acicular martensite can be obtained by laser quenching. The excellent wear resistance and surface hardness of Cr8 die steel are attributed to the synergistic effect of solid solution strengthening, grain refinement and high dislocation density. Meanwhile, the phase change hardening layer structure and residual tensile stress induced by full area coverage scanning (LCQ) are the main factors to deteriorate the impact toughness and bending performance after laser quenching. The soft substrate-hardened unit structure with laterally spaced distribution (LDQ) obtained by graphical scanning reduces the heat accumulation effect on the surface, which reduces concentration of deformation near the hardened layer. The bending property and fracture mechanism are studied. Compared with the forging die material treated by LCQ, the impact energy and bending resistances of forging die materials treated by LDQ are enhanced significantly. Consequently, Cr8 die steel takes into account the same wear resistance, and scanning strategy should be controlled to retain more interval distribution hardening units in layer structure for superior impact toughness and bending properties. © 2023 SPIE.

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

A Novel Method to Estimate Mean Lifetime with Censoring in the Context of Reliability Improvement with Design of Experiments 9

A Novel Method to Estimate Mean Lifetime with Censoring in t...

引用

9th International Conference on Dependable Systems and Their Applications, DSA 2022

作者： Jiang, Renyan Zhu, Xiaowei Xue, Wei Wu, Rangda Cao, Yu College of Mechanical and Electrical Engineering Wenzhou University Zhejiang Provincial Key Laboratory of Laser Processing Robotics China China International Science & Technology Cooperation Base for Laser Processing Robotics Wenzhou University China Co. Ltd. Zhejiang Wenzhou325000 China

ISBN: (数字)9781665488778

ISBN: (纸本)9781665488778

Design of experiments has been widely applied to improve product quality and reliability. When the objective is to improve the reliability, the response of experiments is usually a life observation, and experiment is often stopped at a pre-specified time (i.e., type-I censoring) so that the gathered life data are incomplete. In this case, the traditional methods such as the Taguchi and response surface methods cannot be applied, and some assumptions have to be made so that the data can be analyzed using those methods. A typical assumption is that a right-censored time is treated as a failure time. This assumption is obviously unrealistic. To address this issue, this paper proposes a novel method to estimate mean lifetime with censoring of a right-censored time, which is used to replace the censored time. The proposed method first sorts the data in ascending order. Then, a weighted least squares method is used to fit the ordered data to a power-law model of the order number. Finally, the fitted model is used to extrapolate the mean lifetime with censoring. Three examples are included to illustrate the appropriateness and usefulness of the proposed method. © 2022 IEEE.

关键词： Design of experiments

来源：评论

学校读者我要写书评

暂无评论

Effects of laser Non-Uniform Shock Peening on the Microstructure and Fatigue Performance of Sus 304 Stainless Steel Welded Joints

SSRN

引用

SSRN 2024年

作者： Sheng, Yongqi Feng, Aixin Cao, Xiangguang Lin, Guanhan Ronaldo, Chedo Ngankam College of Mechanical and Electrical Engineering Wenzhou University Wenzhou325035 China Rui’an Graduate College Wenzhou University Wenzhou Ruian325200 China Zhejiang Provincial Key Laboratory of Laser Processing Robots Machinery Industry Key Laboratory of Laser Processing and Testing Wenzhou325035 China Wenzhou Zhisen Industrial Co. Ltd Wenzhou Ruian325200 China

Residual tensile stresses and microstructural heterogeneity in welded joints are primary factors that degrade fatigue performance. Addressing this issue, this paper leverages the precise control and customizability of laser Shock Peening (LSP) to propose a technique called laser Non-Uniform Shock Peening (LNUSP) for welded joints. This method precisely controls stress and microstructure in specific regions to enhance fatigue performance. Results indicate that LNUSP transforms residual tensile stresses on the weld surface into compressive stresses. Compared to original, uniformly LSP, and locally LSP samples, LNUSP-treated samples exhibit more uniform surface morphology, residual stress, and hardness distribution. LNUSP significantly increases surface hardness, with the highest hardness reaching 308.3 HV. Additionally, LNUSP induces martensitic transformation in the Base Material (BM) and Weld Zone (WZ) areas, changes grain orientation, and promotes dislocation movement, leading to dislocation tangling, dislocation networks, and twin structures, which refine the grain size. Consequently, LNUSP markedly improves joint fatigue performance, delaying fatigue crack propagation and increasing fatigue life by 25.41% compared to original samples. This enhancement is attributed to the strengthening effects of the microstructure, and the state and distribution of residual stresses. © 2024, The Authors. All rights reserved.

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

High Performance Soft Electrochemical Actuators Based on Hierarchical Conductive Polymer Ionogels

引用

Journal of Bionic Engineering 2023年第6期20卷 2755-2763页

作者： Hongwei Hu Shengtao Zhang Yan Li Xinghao Hu Lin Xu Aixin Feng Guanggui Cheng Jianning Ding Zhejiang Provincial Key Laboratory of Laser Processing Robotics College of Mechanical and Electrical EngineeringWenzhou UniversityWenzhou325035China Institute of Intelligent Flexible Mechatronics Jiangsu UniversityZhenjiang212013China School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang212100China School of Mechanical Engineering Yangzhou UniversityYangzhou225127China Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering Changzhou UniversityChangzhou213164China Ruian Graduate School of Wenzhou University Ruian325207ZhejiangChina

Electrochemical actuators based on conductive polymers are emerging as a strong competitive in the field of soft actuators because of their intrinsically conformable/elastic nature,low cost,low operating voltage and air-working *** development has shown that adding electroactive materials,such as CNT and graphene,can improve their actuation *** the complex material systems used,their output strains(one of the key factors)are generally lower than 1%,which limited further applications of them in multiple ***,we report soft electrochemical actuators based on conductive polymer ionogels by embedding polyaniline particles between the PEDOT:PSS *** show that such a hierarchical structure not only leads to a high conductivity(1250 S/cm)but also improved electrochemical *** a low operating voltage of 1 V,the maximum strain of these soft actuators reaches an exceptional value of 1.5%,with a high blocking force of 1.3 *** these high-performance electrochemical actuators,we demonstrate soft grippers for manipulating object and a bionic flower stimulated by an electrical *** work sets an important step towards enabling the enhanced performance of electrochemical actuators based on conductive polymers with designed microstructures.

关键词： Conductive polymer Soft actuator Polyaniline PEDOT:PSS Bioinspired actuator

来源：评论

学校读者我要写书评

暂无评论

Fabrication of Cf/SiC composites by direct selective laser sintering and liquid silicon infiltration

引用

Materials Today Communications 2025年 46卷

作者： Wan, Changjie Geng, Yanfei Chen, Xizhang Zhang, Shuai Lin, Xiao Lin, Dingan Xue, Wei Fang, Tiehui Lang, Wenchang Zhejiang Provincial Key Laboratory of Laser Processing Robotics College of Mechanical and Electrical Engineering Wenzhou University China China International Science & Technology Cooperation Base for Laser Processing Robotics Wenzhou University China YUSHI Film Technology Co. Ltd. Jiangsu Huaian China Zhejiang Wenzhou China Key Laboratory of Surface Modification School of Intelligent Manufacturing Wenzhou Polytechnic Wenzhou325035 China

Selective laser Sintering (SLS) technology has demonstrated significant potential in the production of high-precision, complex Cf/SiC ceramic matrix composites. However, traditional additive manufacturing methods typically require the incorporation of binders, such as resins, into the raw powders. These processes are often complex, and the removal of binders during debinding can lead to volumetric shrinkage, which negatively affects the dimensional accuracy of the final product. To address this, a novel approach based on SLS technology for manufacturing Cf/SiC composites has been developed. By directly laser sintering a mixture of carbon fiber and silicon carbide powders, Cf/SiC ceramic preforms were successfully fabricated. These preforms were then infiltrated with liquid silicon (LSI) to produce Cf/SiC ceramic composites. Experimental results indicate that the addition of carbon fiber significantly enhanced the physical properties of the preforms, which in turn influenced the microstructure and mechanical properties of the final Cf/SiC composites. The maximum density, flexural strength, and fracture toughness of the fabricated Cf/SiC composites were 2.620 ± 0.127 g/cm³, 143.59 ± 6.51 MPa, and 3.43 ± 0.20 MPa·m1/2, respectively, demonstrating the feasibility of this method for producing near-net-shape Cf/SiC ceramic matrix composite parts with complex structures. © 2025 Elsevier Ltd

关键词： Fracture toughness

来源：评论

学校读者我要写书评

暂无评论

A Mode-based Approach for Lognormal Parameter Estimation on Heavily Censored Data 13

A Mode-based Approach for Lognormal Parameter Estimation on ...

引用

13th International Conference on Reliability, Maintainability, and Safety, ICRMS 2022

作者： Jiang, R.Y. Qi, F.Q. Cao, Y. China International Science and Technology Cooperation Base for Laser Processing Robotics Wenzhou University Wenzhou China College of Mechanical and Electrical Engineering Wenzhou University Wenzhou China Zhejiang Provincial Key Laboratory of Laser Processing Robotics College of Mechanical and Electrical Engineering Wenzhou University Wenzhou China

ISBN: (数字)9781665486903

ISBN: (纸本)9781665486903

The density function of the lognormal distribution is unimodal and its mode is always smaller than its median life. For the type-I censoring test, if the censoring time is not larger than the median life, the censoring degree of the dataset obtained in this way will be larger than 50% on average, implying that the dataset is heavily censored. In this case, the classical parameter estimation methods generally cannot provide stable estimates, but a relatively accurate estimate of the mode can be obtained. According to this argument, this paper proposes a mode-based approach for estimating the parameters of the lognormal distribution on heavily censored data. The proposed approach first uses the midpoint Kaplan-Meier estimator to augment the data;then uses the lognormal Q-Q plot to estimate the mode of the density function, from which the scale parameter can be expressed as a function of the shape parameter;and finally uses a single-parameter maximum likelihood method to estimate the shape parameter. Six datasets are analyzed to illustrate the proposed approach and its appropriateness. © 2022 IEEE.

关键词： Parameter estimation

来源：评论

学校读者我要写书评

暂无评论

Enhanced photonic nanojets for submicron patterning

引用

Journal of Central South University 2022年第10期29卷 3323-3334页

作者： ZHOU Zhuang-zhuang ALI Hassan HOU Zhi-shan XUE Wei CAO Yu Zhejiang Provincial Key Laboratory of Laser Processing Robotics College of Mechanical and Electrical EngineeringWenzhou UniversityWenzhou 325035China Oujiang Laboratory(Zhejiang Lab for Regenerative Medicine Vision and Brain Health)Wenzhou UniversityWenzhou 325000China China International Science&Technology Cooperation Base for Laser Processing Robotics Wenzhou UniversityWenzhou 325035China

Photonic nanojets(PNJs) have a wide range of applications in laser processing, nanolithography, optical highdensity storage, super-resolution microscopy, and other fields due to their processing capacity to overcome the diffraction limit. Herein, we control static microsphere be developed into the motion state to fabricate vector graphics *** microspheres roll on the substrate while the laser is kept synchronously irradiated, and the overlapping PNJ ablated craters form patterned grooves on the indium-tin oxide(ITO) substrate. Thus, PNJ has been expanded from “point”processing to “line” processing. The fabricated nano grooves have high continuity and consistency. Whereas, the precise customization of critical groove dimension can be achieved via modulation in diameter and kinetics of dielectric microshperes. Furthermore, by etching vectographs on an ITO conductive glass substrate, we demonstrated the advantages and potential of the proposed method in nanopatterning. The proposed method effectively reduces the cost and complexity of photonic nanojets applied in nanopatterning. The proposed nanopatterning methodology will play a vital role in the fabrication of semiconductor materials, sensors, microfluidic devices, surface-enhanced Raman scattering(SERS), biomedicine, nanoscience and nanoengineering.

关键词： photonic nanojets nano-grooves synchronously irradiated nanoengineering

来源：评论

学校读者我要写书评

暂无评论

Super‑elastic Scintillating Fibers and Fabrics for Efficient and Visual Radiation Detection

引用

Advanced Fiber Materials 2023年第4期5卷 1493-1504页

作者： Minghui Du Jin Wang Sijia Xu Hongwei Li Zhihao Zhang Yankun Qi Shichao Lv Jianrong Qiu Yurong Yan Shifeng Zhou State Key Laboratory of Luminescent Materials and Devices School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641China Institute of Photonics Technology Jinan UniversityGuangzhou 510632China National Engineering Research Center of Novel Equipment for Polymer Processing School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510641China Key Lab Guangdong High Property&Functional Polymer Materials School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641China Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and DevicesGuangzhou 510641China College of Optical Science and Engineering State Key Laboratory of Modern Optical InstrumentationZhejiang UniversityHangzhou 310027China

The fabrication of advanced radiation detectors is an important subject due to the wide use of radiation sources in scientific instruments,medical services,security check,non-destructive inspection,and nuclear ***,the manufacture of flexible and stretchable radiation detectors remains a ***,we report the scalable fabrication of super-elastic scintillating fibers and fabrics for visual radiation detection by thermal drawing and melt-spinning methods using styrene-b-(ethylene-co-butylene)-b-styrene,and scintillating Gd_(2)O_(2)S:Tb(GOS).Microstructure evolution,rheological properties,and radiation-composite interaction are studied to reveal the excellent processability,elasticity,and radiation detection ability of the fabricated *** from the physical crosslinking structural features of the polymer matrix and the excellent radiation absorption capacities of GOS,the resulting fiber can sustain high strains of 765%with a high content of GOS dopants(2 wt.%)and has excellent X-ray detection performance with the limit down to 53 nGy_(air)s^(-1).Furthermore,stretchable fabrics are constructed,and their applications in various fields,such as radiation warning,and X-ray imaging,are *** work not only provides a new type of super-elastic scintillating fibers and fabrics for smart textiles but also demonstrates their potential applications in the nuclear field.

关键词： Elastic fiber Radiation detection Optical materials X-ray imaging

来源：评论

学校读者我要写书评

暂无评论

Research on Preparation and Water Collection Characteristics of Bionic Pattern Surface for Multi-Order Combination - Multi-Segment Transport

SSRN

引用

SSRN 2022年

作者： Zhu, Yunhu Feng, Aixin Zhang, Chenglong Pan, Xiaoming Yu, Jinhai Zhao, Pu College of Mechanical & Electrical Engineering Wenzhou University Wenzhou325035 China Zhejiang Provincial Key Laboratory of Laser Processing Robots Key Laboratory of Laser Precision Processing ＆ Detection Wenzhou325035 China Ruian Graduate School of Wenzhou University Wenzhou325206 China Zhejiang Jinlong Automatic Control Equipment Co. Ltd Wenzhou325299 China

Collecting water from the atmosphere is seen as a potential way to alleviate global water shortages. Although the large and complex water collecting pattern can quickly transport and collect droplets on the surface where the pattern is located, the collection of droplets is limited by the large-area transport distance and the preparation of complex patterns, and the water collecting pattern cannot completely cover the surface of the material and cannot collect droplets outside the pattern. Therefore, flexible application and amplification cannot be obtained. Aiming at the problem of large-area directional transportation, the characteristics of bionic triangular channel (BTC)and linear channel (LC) are studied in this paper. Combined with their characteristics, the water collection pattern surface of multi-order combination - multi-segment transport(MC-MT) is prepared by laser direct writing technology. This paper systematically describes the water collection process and explores the influence of parameters of BTC and LC on the water collection efficiency, and compares the water collection efficiency of single superhydrophobic, superhydrophilic and mixed wettability surfaces. The experimental results show that the BTC has the characteristics of directional liquid collection, and the optimal interval of the linear channel is 0.3 mm, and the angle is 15°. The mixed wettability surface prepared by combining the two characteristics is 125.9% and 242.9% higher than a single superhydrophobic and superhydrophilic surface, respectively. The surfaces have strong self-transport and directional transport capabilities, and can still collect well into the designed water collection area even over large surface distances, which is expected to provide a reference for the design of efficient water collection systems and micro-titration directional manipulation. © 2022, The Authors. All rights reserved.

关键词： Wetting

来源：评论

学校读者我要写书评

暂无评论

Droplet Transfer Characteristics in High Power laser-Mag Hybrid Welding: Influence of Energy Parameters

SSRN

引用

SSRN 2024年

作者： Zheng, Yafeng An, Yuanlong Yu, Jia Wang, Liang Zhang, Qunli Zhang, Huaxia Wu, Rangda Yao, Jianhua College of Mechanical Engineering Zhejiang University of Technology Zhejiang Hangzhou310023 China Institute of Laser Advanced Manufacturing Zhejiang University of Technology Zhejiang Hangzhou310023 China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang Province Zhejiang Hangzhou310023 China Co. Ltd. Zhejiang Wenzhou325000 China Zhejiang Provincial Innovation Center for Laser Intelligent Equipment Technology Zhejiang Wenzhou325000 China

High-power laser-arc hybrid welding (LAHW) experiments were carried out on Q345 low-alloy steel with a thickness of 10 mm, and the effects of energy parameters such as high-power laser, arc power, the distance between laser and arc (DLA), and welding speed on the droplet transfer behavior were investigated by means of high-speed imaging system. The distance between the droplet falling position and the keyhole of the continuous transfer was statistically investigated to determine the effect of the change of the droplet transfer trajectory on the weld stability. Results reveal that a strong metal vapor reaction force is generated as laser power exceeds 6.5 kW, causing the droplet transfer trajectory to shift, which enhances the welding stability, and the stability of the keyhole gets worse when the laser power increases to 9.5 kW. As the arc power increases from 4096 W to 6860W, the droplet transfer mode appears in sequence as a mixed transfer mode dominated by globular droplet transfer, projected droplet transfer, and spray droplet transfer. A single spray droplet transfer mode is discerned when the arc power exceeds 7394 W. In this regard, the increased arc power will enhance the stability of the welding process. Excessively large or small DLA values will lead to poor welding stability. In the former case, it may be attributed to strong mutual interference between laser and arc. Regarding the latter case, it is caused by the weakened attraction of the laser to the arc. It is also found that arc stability and droplet transfer frequency decrease with increasing welding speed. © 2024, The Authors. All rights reserved.

关键词： Stability

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：