检索结果-南通市图书馆

Five-plane lancet needle design for soft PVC phantom tissue cutting

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bio-Design and manufacturing 2018年第3期1卷 195-202页

作者： Yancheng Wang Deqing Mei State key lab of Fluid Power and Mechatronic Systems School of Mechanical Engineering Zhejiang UniversityHangzhou 310027 China key laboratory of advanced manufacturing technology ofzhejiang province School of Mechanical EngineeringZhejiang University Hangzhou 310027 China

Lancet needle, having three planes at the tip to generate a sharp lancet point, is the most common needle tip geometry and used for medical procedures. This research presents two five-plane lancet needle designs, the five-plane lancet needle with two back bevels （FLN-B） and five-plane lancet needle with two front bevels （FLN-F）, to study the effects of two additional bevel planes on the reduction of soft tissue cutting force. Mathematical models to calculate the inclination angle and rake angle along the cutting edges of FLN-B and FLN-F are developed. By using the grinding process, the prototype FLN-B and FLN-F needles are fabricated. And their inclination and rake angles along the cutting edges are investigated and compared to that of regular lancet needle. Needles insertion tests were conducted on soft PVC phantom which mimics the soft tissue. The initial peak insertion force and steady-state cutting force during needle insertion were identified, and the effect of cutting edge on needle soft tissue cutting force was studied. Compared to lancet needle, FLN-B and FLN-F both have higher inclination and rake angles at the tip cutting edge, could reduce the initial peak needle insertion force and tissue cutting forces, and thus can efficiently cut the soft tissue for medical applications.

关键词： Lancet needle Needle insertion force Rake angle Inclination angle Bevels Five plane

Multi-physical Modeling and Adjusting for Ultrasonic Assisted Soft Abrasive Flow Processing

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2023年第4期36卷 111-124页

作者： Yesha Ni Yunfeng Tan Dapeng Tan key lab of E&M Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China Collaborative Innovation Center of High-end Laser manufacturing Equipment Zhejiang Province&Ministry of EducationHangzhou 310014China

The polishing efficiency of the soft abrasive flow(SAF)method is low,which is not in line with the concept of carbon emission reduction in industrial *** address the above issue,a two-phase fluid multi-physics modeling method for ultrasonic-assisted SAF processing is *** acoustics-fluid coupling mechanic model based on the realizable k-ε model and Helmholtz equation is built to analyze the cavitation *** results show that the pro-posed modeling and solution method oriented to ultrasonic-assisted SAF processing have better revealed the flow field evolution *** turbulence kinetic energy at different ultrasonic frequencies and amplitudes is *** results show that the ultrasonic vibration can induce a cavitation effect in the constrained flow chan-nel and promote the turbulence intensity and uniformity of the abrasive flow.A set of comparative polishing experiments with or without ultrasonic vibration are conducted to explore the performance of the proposed *** can be found that the ultrasonic-assisted SAF method can improve the machining efficiency and uniformity,to achieve the purpose of carbon emission *** relevant result can offer a helpful reference for the SAF method.

关键词： Soft abrasive flow Ultrasonic vibration Cavitation effect Polishing efficiency Turbulent kinetic energy

Mechanically Robust Polylactide Fibers with Super Heat Resistance via Constructing in situ Nanofibrils

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第6期41卷 962-971,I0011页

作者： Jun Lu Li-Xiang Yi Yong-Huan Zhao Yang Meng Peng-Xiang Yu Juan-Juan Su Jian Han College of Materials and Textiles Zhejiang Sci-Tech UniversityHangzhou 310018China The key lab of Industrial Textile Material and manufacturing technology Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China

All-PLA fibers with excellent comprehensive performance and recycling convenience are realized *** molecular weight poly(D-lactide)(HPDLA)is incorporated into poly(L-lactide)(PLLA)matrix to construct in situ nanofibrils structure by taking advantages of the microphase separation between HPDLA and *** tensile strength of HPDLA/PLLA composite fibers(HDL-8)is enhanced from 2.1 cN/dtex of neat PLLA-8 fibers up to 2.9 cN/*** boiling water shrinkage(BWS)and shrinkage in hot air(HAS)significantly decrease to 7.8%and 2.8%,*** abundance of in situ nanofibrils creates a grille-like structure that is crucial for both heat and hydrolysis *** strikingly,a hybrid shish-kebab structure induced by the in situ nanofibrils serves as a mechanical *** work paves a new way for heat resistance and self-reinforcement modification of PLA materials.

关键词： materials. fibers lactide

Build orientation determination of multi-feature mechanical parts in selective laser melting via multi-objective decision making

在线全文

学校读者我要写书评

暂无评论

机械工程前沿:英文版 2023年第2期18卷 227-251页

作者： Hongsheng SHENG Jinghua XU Shuyou ZHANG Jianrong TAN Kang WANG Engineering Research Center for Design Engineering and Digital Twin of zhejiang province Zhejiang UniversityHangzhou 310027China State key laboratory of Fluid Power and Mechatronic Systems Hangzhou 310027China key laboratory of advanced manufacturing technology of zhejiang province Hangzhou 310027China

Selective laser melting(SLM)is a unique additive manufacturing(AM)category that can be used to manufacture mechanical *** has been widely used in aerospace and automotive using metal or alloy *** build orientation is crucial in AM because it affects the as-built part,including its part accuracy,surface roughness,support structure,and build time and cost.A mechanical part is usually composed of multiple surface *** surface features carry the production and design knowledge,which can be utilized in SLM *** study proposes a method to determine the build orientation of multi-feature mechanical parts(MFMPs)in ***,the surface features of an MFMP are recognized and grouped for formulating the particular optimization ***,the estimation models of involved optimization objectives are established,and a set of alternative build orientations(ABOs)is further obtained by many-objective ***,a multi-objective decision making method integrated by the technique for order of preference by similarity to the ideal solution and cosine similarity measure is presented to select an optimal build orientation from those *** weights of the feature groups and considered objectives are achieved by a fuzzy analytical hierarchy *** case studies are reported to validate the proposed method with numerical results,and the effectiveness comparison is *** manufacturing is conducted to prove the performance of the proposed *** measured average sampling surface roughness of the most crucial feature of the bracket in the original orientation and the orientations obtained by the weighted sum model and the proposed method are 15.82,10.84,and 10.62μm,*** numerical and physical validation results demonstrate that the proposed method is desirable to determine the build orientations of MFMPs with competitive results in SLM.

关键词： selective laser melting(SLM) build orientation determination multi-feature mechanical part(MFMP) fuzzy analytical hierarchy process multi-objective decision making(MODM)

Microstructure and mechanical properties of AZ91-Ca magnesium alloy cast by different processes

在线全文

学校读者我要写书评

暂无评论

China Foundry 2018年第4期15卷 263-269页

作者： xiao-yang chen yang zhang ya-lin lu xiao-ping li key lab of advanced Materials Design and Additive manufacturing of Jiangsu province Jiangsu University of TechnologyChangzhou 213001China

The microstructure and mechanical properties of magnesium （Mg） alloys are significantly influenced by the casting process. In this paper, a comparative study on microstructure and mechanical properties at ambient and elevated temperatures of AZ91-2wt.% Ca （AZX912） Mg alloy samples prepared by gravity casting （GC）, squeeze casting （SC） and rheo-squeeze casting （RSC）, respectively, was carried out. The results show that mMg grains in SC and RSC samples are significantly refined compared to the GC sample. The average secondary dendritic arm spacing of AZX912 alloy samples decreases in the order of GC, SC and RSC. As testing temperature increases from 25 ~C to 200 ~C, strength of AZX912 alloy samples is reduced, while their elongation is increased continuously. Compared to GC and SC processes, RSC process can improve the mechanical properties of AZX912 alloy at both ambient and elevated temperatures. The enhancement of mechanical properties of RSC sample over GC and SC samples mainly results from grain refinement in the as-cast microstructure of AZX912 alloy.

关键词： magnesium alloys casting process microstructure mechanical properties

在线全文

学校读者我要写书评

暂无评论

水系合成δ相甲脒铅碘钙钛矿粉末

Science China Materials 2024年第5期67卷 1621-1630页

作者：潘逸宁王镛皓邓明欣曾强李林鸿廖响张茗珺王伟谢锋刘芳洋 School of Metallurgy and Environment Central South UniversityChangsha410083China School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan430070China Department of Research and Development Zhejiang Yitai Technology Co.Ltd.Changsha410205China advanced Battery Materials Engineering Research Center of the Ministry of Education Changsha410083China School of Metallurgy Northeastern UniversityShenyang110819China National Energy Metal Resources and New Materials key laboratory Changsha410083China

近年来,甲脒基钙钛矿太阳能电池的光电转换效率取得了显著进展,其商业化前景日益明朗.随着钙钛矿电池商业化的快速发展,对于环境友好、成本低廉的钙钛矿前驱体的需求不断增长.甲脒铅碘钙钛矿材料遇水易分解,因此传统钙钛矿粉末合成方法... 详细信息

近年来,甲脒基钙钛矿太阳能电池的光电转换效率取得了显著进展,其商业化前景日益明朗.随着钙钛矿电池商业化的快速发展,对于环境友好、成本低廉的钙钛矿前驱体的需求不断增长.甲脒铅碘钙钛矿材料遇水易分解,因此传统钙钛矿粉末合成方法依赖于有机溶剂和惰性气氛手套箱,不具备成本优势.在此背景下,本文提出了一种经济高效的水系合成高纯度δ相甲脒铅碘(δ-FAPbI_(3))粉末的策略.在水溶液中加入过量氢碘酸,碘离子可使不溶性PbI_(2)转化为可溶性[PbI_(2)+n]n-络合物,将FAPbI_(3)的遇水分解转化为溶解,从而使水系合成成为可能.水系合成的甲脒铅碘粉末具有高纯度、低成本优势,可作为钙钛矿薄膜前驱体材料.与以PbI_(2)和FAI的混合物作为前驱体制备的钙钛矿薄膜相比,以水系合成的δ-FAPbI_(3)粉末为前驱体制备的钙钛矿薄膜具有良好的结晶性,降低了缺陷密度,并有效抑制了有害的离子输运和降解过程,从而增强了载流子传输性能和电池稳定性.在环境空气中以合成粉末为前驱体制备的钙钛矿太阳能电池,最高转化效率可达23.24%.

关键词： perovskite microcrystal powder aqueous synthesis perovskite solar cells

Surface plasmons interference nanogratings:wafer-scale laser direct structuring in seconds

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第7期11卷 1607-1614页

作者： liao Geng Wei Yan Liping Shi Min Qiu key laboratory of 3D Micro/Nano Fabrication and Characterization of zhejiang province School of EngineeringWestlake University18 Shilongshan RoadHangzhou 310024 Zhejiang ProvinceChina Institute of advanced technology Westlake Institute for Advanced Study18 Shilongshan RoadHangzhou 310024 Zhejiang ProvinceChina

It is always a great challenge to bridge the nano-and macro-worlds in nanoscience,for instance,manufacturing uniform nanogratings on a whole wafer in seconds instead of hours even ***,we demonstrate a single-step while extremely high-throughput femtosecond laser scanning technique to obtain wafer-scale,highly regular nanogratings on semiconductor-on-metal thin *** technique takes advantage of long-range surface plasmons-laser interference,which is regulated by a self-initiated *** controlling the scanning speed,two types of nanogratings are readily manufactured,which are produced by either oxidation or *** achieve a record manufacturing speed(>1 cm^(2)s^(-1)),with tunable periodicity of∧<1μ*** fractional variation of their periodicity is evaluated to be as low as△∧/∧≈0.5%.Furthermore,by utilizing the semiconductor-on-metal film-endowed interference effects,an extremely high energy efficiency is achieved via suppressing light reflection during femtosecond laser *** the fabricated nanogratings exhibit multi-functionality,we exemplify their practical applications in highly sensitive refractive index sensing,vivid structural colors,and durable superhydrophilicity.

关键词： utilizing wafer refractive

Surface accuracy optimization of mechanical parts with multiple circular holes for additive manufacturing based on triangular fuzzy number

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2021年第1期16卷 133-150页

作者： Jinghua XU Hongsheng SHENG Shuyou ZHANG Jianrong TAN Jinlian DENG State key laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China key laboratory of advanced manufacturing technology of zhejiang province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China zhejiang Institute of Mechanical and Electrical Engineering Hangzhou 310053China

Surface accuracy directly affects the surface quality and performance of mechanical *** hole,especially spatial non-planar hole set is the typical feature and working surface of mechanical *** with traditional machining methods,additive manufacturing(AM)technology can decrease the surface accuracy errors of circular holes during ***,an accuracy error may still exist on the surface of circular holes fabricated by AM due to the influence of staircase *** study proposes a surface accuracy optimization approach for mechanical parts with multiple circular holes for AM based on triangular fuzzy number(TFN).First,the feature lines on the manifold mesh are extracted using the dihedral angle method and normal tensor voting to detect the circular ***,the optimal AM part build orientation is determined using the genetic algorithm to optimize the surface accuracy of the circular holes by minimizing the weighted volumetric error of the ***,the corresponding weights of the circular holes are calculated with the TFN analytic hierarchy process in accordance with the surface accuracy ***,an improved adaptive slicing algorithm is utilized to reduce the entire build time while maintaining the forming surface accuracy of the circular holes using digital twins via virtual *** effectiveness of the proposed approach is experimentally validated using two mechanical models.

关键词： surface accuracy optimization multiple circular holes additive manufacturing(AM) part build orientation triangular fuzzy number(TFN) digital twins

key technologies and development trends of the soft abrasive flow finishing method

在线全文

学校读者我要写书评

暂无评论

Journal of zhejiang University-Science A(Applied Physics & Engineering) 2023年第12期24卷 1043-1064页

作者： Yunfeng TAN Yesha NI Weixin XU Yuanshen XIE Lin LI Dapeng TAN key lab of E&M Ministry of Education&Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China State key laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China Collaborative Innovation Center of High-end Laser manufacturing Equipment Zhejiang Province&Ministry of EducationHangzhou 310014China

This paper reviews recent developments of the soft abrasive flow finishing(SAF)method in constraint *** multiphase fluid dynamics modeling,material removal mechanism,auxiliary strengthening finishing techniques,and observation of surface impact effects by abrasive particles and cavitation bubbles are presented in *** prospects and challenges are given for four aspects:thin-walled curved surfaces,biomedical functions,electronic information,and precise optical components.

关键词： Soft abrasive flow finishing(SAF) Dynamic modeling Material removal mechanism Processing optimization Strengthening finishing control technology