资源类型

期刊论文 334

会议视频 6

年份

2023 28

2022 24

2021 26

2020 25

2019 24

2018 18

2017 22

2016 15

2015 21

2014 15

2013 5

2012 8

2011 7

2010 9

2009 12

2008 11

2007 12

2006 11

2005 10

2004 4

展开 ︾

关键词

养殖模式 4

可持续发展 4

信息处理 3

发展模式 3

人工智能 2

发展战略 2

开发模式 2

战略 2

材料 2

模式 2

滑模控制 2

生态文明 2

管理模式 2

资源化利用 2

AD9954 1

ANSYS 1

BPSK 1

BP神经网络 1

CBC-MAC模式 1

展开 ︾

检索范围:

排序: 展示方式:

Fundamental frequency and testing mode of complicated elastic clamped-plate vibration

QI Hongyuan, GUAN Yiduo

《机械工程前沿(英文)》 2008年 第3卷 第4期   页码 360-364 doi: 10.1007/s11465-008-0084-4

摘要: Aimed at the modal analysis of complicated elastic clamped-plates, a trigonometric interpolation method of conformal mapping is applied to set up the mapping function between a complicated region and a unit dish region, and the fundamental frequency of the complicated vibrating region is analyzed with the help of the Galerkin method. Taking an elastic rectangle-plate with arc radius as an example, the testing mode frequency band of plates is determined by analyzing the fundamental frequency; meanwhile, according to hamming testing method of multi-point excitation to the single-point response, and by signal processing technology and its software programming, modal parameter recognition of the elastic clamped-plate is completed. Comparing the first order modal frequency with the theoretical fundament frequency, the validity of the testing mode method and theoretical analysis are verified.

关键词: multi-point excitation     rectangle-plate     single-point     processing technology     trigonometric interpolation    

Cryogenic minimum quantity lubrication machining: from mechanism to application

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 649-697 doi: 10.1007/s11465-021-0654-2

摘要: Cutting fluid plays a cooling–lubrication role in the cutting of metal materials. However, the substantial usage of cutting fluid in traditional flood machining seriously pollutes the environment and threatens the health of workers. Environmental machining technologies, such as dry cutting, minimum quantity lubrication (MQL), and cryogenic cooling technology, have been used as substitute for flood machining. However, the insufficient cooling capacity of MQL with normal-temperature compressed gas and the lack of lubricating performance of cryogenic cooling technology limit their industrial application. The technical bottleneck of mechanical–thermal damage of difficult-to-cut materials in aerospace and other fields can be solved by combining cryogenic medium and MQL. The latest progress of cryogenic minimum quantity lubrication (CMQL) technology is reviewed in this paper, and the key scientific issues in the research achievements of CMQL are clarified. First, the application forms and process characteristics of CMQL devices in turning, milling, and grinding are systematically summarized from traditional settings to innovative design. Second, the cooling–lubrication mechanism of CMQL and its influence mechanism on material hardness, cutting force, tool wear, and workpiece surface quality in cutting are extensively revealed. The effects of CMQL are systematically analyzed based on its mechanism and application form. Results show that the application effect of CMQL is better than that of cryogenic technology or MQL alone. Finally, the prospect, which provides basis and support for engineering application and development of CMQL technology, is introduced considering the limitations of CMQL.

关键词: cryogenic minimum quantity lubrication (CMQL)     cryogenic medium     processing mode     device application     mechanism     application effect    

Review on flexible perovskite photodetector: processing and applications

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-023-0749-z

摘要: Next-generation optoelectronics should possess lightweight and flexible characteristics, thus conforming to various types of surfaces or human skins for portable and wearable applications. Flexible photodetectors as fundamental devices have been receiving increasing attention owing to their potential applications in artificial intelligence, aerospace industry, and wise information technology of 120, among which perovskite is a promising candidate as the light-harvesting material for its outstanding optical and electrical properties, remarkable mechanical flexibility, low-cost and low-temperature processing methods. To date, most of the reports have demonstrated the fabrication methods of the perovskite materials, materials engineering, applications in solar cells, light-emitting diodes, lasers, and photodetectors, strategies for device performance enhancement, few can be seen with a focus on the processing strategies of perovskite-based flexible photodetectors, which we will give a comprehensive summary, herein. To begin with, a brief introduction to the fabrication methods of perovskite (solution and vapor-based methods), device configurations (photovoltaic, photoconductor, and phototransistor), and performance parameters of the perovskite-based photodetectors are first arranged. Emphatically, processing strategies for photodetectors are presented following, including flexible substrates (i.e., polymer, carbon cloth, fiber, paper, etc.), soft electrodes (i.e., metal-based conductive networks, carbon-based conductive materials, and two-dimensional (2D) conductive materials, etc.), conformal encapsulation (single-layer and multilayer stacked encapsulation), low-dimensional perovskites (0D, 1D, and 2D nanostructures), and elaborate device structures. Typical applications of perovskite-based flexible photodetectors such as optical communication, image sensing, and health monitoring are further exhibited to learn the flexible photodetectors on a deeper level. Challenges and future research directions of perovskite-based flexible photodetectors are proposed in the end. The purpose of this review is not only to shed light on the basic design principle of flexible photodetectors, but also to serve as the roadmap for further developments of flexible photodetectors and exploring their applications in the fields of industrial manufacturing, human life, and health care.

关键词: photodetector     perovskite     flexible     processing     application    

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode

Abdelkarim AMMAR,Amor BOUREK,Abdelhamid BENAKCHA

《能源前沿(英文)》 2020年 第14卷 第4期   页码 836-849 doi: 10.1007/s11708-017-0444-z

摘要: This paper proposes a design of control and estimation strategy for induction motor based on the variable structure approach. It describes a coupling of sliding mode direct torque control (DTC) with sliding mode flux and speed observer. This algorithm uses direct torque control basics and the sliding mode approach. A robust electromagnetic torque and flux controllers are designed to overcome the conventional SVM-DTC drawbacks and to ensure fast response and full reference tracking with desired dynamic behavior and low ripple level. The sliding mode controller is used to generate reference voltages in stationary frame and give them to the controlled motor after modulation by a space vector modulation (SVM) inverter. The second aim of this paper is to design a sliding mode speed/flux observer which can improve the control performances by using a sensorless algorithm to get an accurate estimation, and consequently, increase the reliability of the system and decrease the cost of using sensors. The effectiveness of the whole composed control algorithm is investigated in different robustness tests with simulation using Matlab/Simulink and verified by real time experimental implementation based on dS pace 1104 board.

关键词: induction motor     direct torque control (DTC)     space vector modulation (SVM)     sliding mode control (SMC)     sliding mode observer (SMO)     dS1104    

Assessment of popular techniques for co-processing municipal solid waste in Chinese cement kilns

《环境科学与工程前沿(英文)》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1485-4

摘要:

• Municipal solid waste (MSW) was fermented, screened, gasified, then co-processed.

关键词: Cement kiln     Co-processing     Environmental risk assessment     By-pass system    

基于双重分组和密钥计数的并行认证模式

黄玉划,胡爱群,宋宇波

《中国工程科学》 2004年 第6卷 第7期   页码 70-74

摘要:

由于CBC-MAC模式不可并行处理,提出了一种基于双重分组的并行认证模式(PKCB)。PKCB模式同并行认证模式PMAC相比,安全性和速率都有显著提高,PKCB认证模式与CTR(计数器)加密模式结合可构成分组密码算法的一种全工作模式。在此基础上提出了一种基于密钥计数的并行认证模式(KCTR-MAC)。KCTR-MAC模式安全性比PMAC模式高得多,而速率未降低,KCTR-MAC认证模式和CTR加密模式结合也可构成分组密码算法的一种全工作模式(2CTR),2CTR模式的综合性能不亚于标准模式CCM(CTR with CBC-MAC),是一种安全快速的实用模式。

关键词: 认证模式     CBC-MAC模式     PMAC模式     CTR模式     CCM模式    

zone-layered trimming method for ceramic core of aero-engine blade based on an advanced reconfigurable laser processing

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0675-5

摘要: Ceramic structural parts are one of the most widely utilized structural parts in the industry. However, they usually contain defects following the pressing process, such as burrs. Therefore, additional trimming is usually required, despite the deformation challenges and difficulty in positioning. This paper proposes an ultrafast laser processing system for trimming complex ceramic structural parts. Opto-electromechanical cooperative control software is developed to control the laser processing system. The trimming problem of the ceramic cores used in aero engines is studied. The regional registration method is introduced based on the iterative closest point algorithm to register the path extracted from the computer-aided design model with the deformed ceramic core. A zonal and layering processing method for three-dimensional contours on complex surfaces is proposed to generate the working data of high-speed scanning galvanometer and the computer numerical control machine tool, respectively. The results show that the laser system and the method proposed in this paper are suitable for trimming complex non-datum parts such as ceramic cores. Compared with the results of manual trimming, the method proposed in this paper has higher accuracy, efficiency, and yield. The method mentioned above has been used in practical application with satisfactory results.

关键词: ceramic parts trimming     computer-aided laser manufacturing     3D vision     reconfigurable laser processing system    

Probabilistic stability of uncertain composite plates and stochastic irregularity in their buckling mode

《结构与土木工程前沿(英文)》   页码 179-190 doi: 10.1007/s11709-022-0888-z

摘要: In this study, the mechanical properties of the composite plate were considered Gaussian random fields and their effects on the buckling load and corresponding mode shapes were studied by developing a semi-analytical non-intrusive approach. The random fields were decomposed by the Karhunen−Loève method. The strains were defined based on the assumptions of the first-order and higher-order shear-deformation theories. Stochastic equations of motion were extracted using Euler–Lagrange equations. The probabilistic response space was obtained by employing the non-intrusive polynomial chaos method. Finally, the effect of spatially varying stochastic properties on the critical load of the plate and the irregularity of buckling mode shapes and their sequences were studied for the first time. Our findings showed that different shear deformation plate theories could significantly influence the reliability of thicker plates under compressive loading. It is suggested that a linear relationship exists between the mechanical properties’ variation coefficient and critical loads’ variation coefficient. Also, in modeling the plate properties as random fields, a significant stochastic irregularity is obtained in buckling mode shapes, which is crucial in practical applications.

关键词: uncertain composite plate     stochastic assume mode method     Karhunen−Loève theorem     polynomial chaos approach     plate buckling     irregularity in buckling mode shapes    

Wheat gluten protein and its impacts on wheat processing quality

Wujun MA, Zitong YU, Maoyun SHE, Yun ZHAO, Shahidul ISLAM

《农业科学与工程前沿(英文)》 2019年 第6卷 第3期   页码 279-287 doi: 10.15302/J-FASE-2019267

摘要:

Before the advent of the wheat genomic era, a wide range of studies were conducted to understand the chemistry and functions of the wheat storage proteins, which are the major determinants of wheat flour the suitability of wheat flour for various end products, such as bread, noodles and cakes. Wheat grain protein is divided into gluten and non-gluten fractions and the wheat processing quality mainly depends on the gluten fractions. Gluten provides the unique extensibility and elasticity of dough that are essential for various wheat end products. Disulfide bonds are formed between cysteine residues, which is the chemical bases for the physical properties of dough. Based on the SDS-extractability, grain protein is divided into SDS-unextractable polymeric protein (UPP) and SDS-extractable polymeric protein. The percentage of UPP is positively related to the formation of disulfide bonds in the dough matrix. In the wheat genomic era, new glutenins with long repetitive central domains that contain a high number of consensus hexapeptide and nonapeptide motifs as well as high content of cysteine and glutamine residues should be targeted.

关键词: wheat gluten     consensus motifs     disulfide bonds     SDS-unextractable polymeric protein     glutenins     gliadins     processing quality     storage protein    

Chromium steel from chromite ore processing residue----A valuable construction material from a waste

Jay N. MEEGODA, Wiwat KAMOLPORNWIJIT

《环境科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 159-166 doi: 10.1007/s11783-011-0325-3

摘要: As species we humans generate excessive amounts of waste and hence for sustainability we should explore innovative ways to recover them. The primary objective of this study is to demonstrate an efficient and optimum way to recover chromium and iron from chromite ore processing residues (COPR) for the production of chrome steel and stainless steel. In Hudson County, New Jersey, there are more than two million tons of leftover COPR. Part of COPR was used as fill materials for construction sites, which spread the problem to a larger area. With high solubility along with their toxicity leached chromate from COPR is threatening the environment as well as human health. In this research, COPR was thermally treated to recover iron with chromium by applying techniques used in steel manufacturing. An extensive experimental program was performed using a Thermo-Gravimetric Analyzer (TGA) and bench scale tests to thermally treat the processed chromium contaminated soils with carbon and sand at varying temperatures and under reducing environment. The optimum chemical composition of COPR and additives to be used in the melts were evaluated based upon the thermodynamic properties of the mixture to ensure good phase separation, least amounts of iron and chromium oxides in the slag and minimum variability of final product (steel or iron with chromium). The impact of other oxides on the steel making process was evaluated to minimize the adverse impact on the process. The research demonstrated the feasibility of recovering a valuable construction material (chrome steel) from a waste (COPR).

关键词: chromite ore processing residue     chromium steel     reduction     thermal treatment     beneficial use    

Experimental investigation of evolutive mode-I and mode-II fracture behavior of fiber-reinforced cemented

《结构与土木工程前沿(英文)》 2023年 第17卷 第2期   页码 256-270 doi: 10.1007/s11709-022-0924-z

摘要: The curing temperature-dependent cement hydration causes the nonlinear evolution of fracture behavior and properties of fiber-reinforced cemented paste backfill (CPB) and thus influences the stability of mine backfill materials in deep mines. Therefore, the coupled effect of curing temperature (20, 35, and 45 °C) and cement hydration at different curing times (3, 7, and 28 d) on the mode-I and mode-II fracture behavior and properties of fiber-reinforced CPB is investigated. A comprehensive experimental testing program consisting of semicircular bend tests, direct shear tests, measurement of volumetric water content and matric suction, TG/DTG tests, and SEM observation is carried out. The results show that the coupled thermochemical effect results in strongly nonlinear development of pre- and post-peak behavior of fiber-reinforced CPB. Moreover, the results discover a positive linear correlation between fracture toughness and shear strength parameters and also reveal the vital role played by matric suction in the formation of fracture toughness. Furthermore, predictive functions are developed to estimate the coupled thermochemical effect on the development of KIc and KIIc. Therefore, the findings and the developed mathematical tools have the potential to promote the successful application of fiber-reinforced CPB technology in deep underground mines.

关键词: fiber reinforcement     cemented paste backfill     fracture behavior     underground mine     cement hydration    

材料的成形加工与凝固技术

介万奇

《中国工程科学》 2002年 第4卷 第6期   页码 1-4

摘要:

从对材料成形加工技术进步的分析入手,论述了凝固技术在材料先进成形加工技术中的应用及其重要性。结合对几种凝固新技术的实例的分析指出,不论是传统材料加工过程“控形—控性(控制组织)—控制成本—控制污染”一体化新技术,还是作为新材料研制手段,凝固技术的重要性均是非常突出的。进而分析了近年来受到广泛重视的凝固过程研究的新课题及其由此可能带来的技术进步。

关键词: 材料     成形加工     凝固技术    

Novel slack-based robust scheduling rule for a semiconductor manufacturing system with uncertain processing

Juan LIU, Fei QIAO, Yumin MA, Weichang KONG

《工程管理前沿(英文)》 2018年 第5卷 第4期   页码 507-514 doi: 10.15302/J-FEM-2018045

摘要:

The NP-hard scheduling problems of semiconductor manufacturing systems (SMSs) are further complicated by stochastic uncertainties. Reactive scheduling is a common dynamic scheduling approach where the scheduling scheme is refreshed in response to real-time uncertainties. The scheduling scheme is overly sensitive to the emergence of uncertainties because the optimization of performance (such as minimum make-span) and the system robustness cannot be achieved simultaneously by conventional reactive scheduling methods. To improve the robustness of the scheduling scheme, we propose a novel slack-based robust scheduling rule (SR) based on the analysis of robustness measurement for SMS with uncertain processing time. The decision in the SR is made in real time given the robustness. The proposed SR is verified under different scenarios, and the results are compared with the existing heuristic rules. Simulation results show that the proposed SR can effectively improve the robustness of the scheduling scheme with a slight performance loss.

关键词: semiconductor manufacturing system     uncertain processing time     dynamic scheduling     slack-based robust scheduling rule    

Atomistic understanding of interfacial processing mechanism of silicon in water environment: A ReaxFF

《机械工程前沿(英文)》 2021年 第16卷 第3期   页码 570-579 doi: 10.1007/s11465-021-0642-6

摘要: The interfacial wear between silicon and amorphous silica in water environment is critical in numerous applications. However, the understanding regarding the micro dynamic process is still unclear due to the limitations of apparatus. Herein, reactive force field simulations are utilized to study the interfacial process between silicon and amorphous silica in water environment, exploring the removal and damage mechanism caused by pressure, velocity, and humidity. Moreover, the reasons for high removal rate under high pressure and high velocity are elucidated from an atomic perspective. Simulation results show that the substrate is highly passivated under high humidity, and the passivation layer could alleviate the contact between the abrasive and the substrate, thus reducing the damage and wear. In addition to more Si-O-Si bridge bonds formed between the abrasive and the substrate, new removal pathways such as multibridge bonds and chain removal appear under high pressure, which cause higher removal rate and severer damage. At a higher velocity, the abrasive can induce extended tribochemical reactions and form more interfacial Si-O-Si bridge bonds, hence increasing removal rate. These results reveal the internal cause of the discrepancy in damage and removal rate under different conditions from an atomic level.

关键词: silicon     ReaxFF     molecular dynamics     friction     damage    

塑料加工成型技术的最新研究进展

瞿金平

《中国工程科学》 2011年 第13卷 第10期   页码 58-68

摘要:

依据塑料工业发展低耗、高效、环保型“绿色”加工成型技术的重大需求,随着塑料塑化输运方法的不断演变与创新,在塑料动态加工成型方法和设备的基础上提出和研究了基于拉伸流变的塑料加工成型方法和技术,着重讨论了拉伸形变支配的叶片挤压系统中塑料塑化输运过程、叶片挤压系统的技术特征和叶片塑化输运技术的应用。研究结果表明,与传统技术及设备相比较,这种新技术及设备具有加工历程缩短50 %以上、加工能耗降低30 %左右、混合混炼效果好、制品质量提高、对物料适应性广等优异的技术性能。同时发现,新技术及设备在多相多组份复合材料、剪切热敏感高分子材料等物料体系的加工方面具有独特优势。

关键词: 塑料     加工成型     拉伸形变     塑化输运    

标题 作者 时间 类型 操作

Fundamental frequency and testing mode of complicated elastic clamped-plate vibration

QI Hongyuan, GUAN Yiduo

期刊论文

Cryogenic minimum quantity lubrication machining: from mechanism to application

期刊论文

Review on flexible perovskite photodetector: processing and applications

期刊论文

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode

Abdelkarim AMMAR,Amor BOUREK,Abdelhamid BENAKCHA

期刊论文

Assessment of popular techniques for co-processing municipal solid waste in Chinese cement kilns

期刊论文

基于双重分组和密钥计数的并行认证模式

黄玉划,胡爱群,宋宇波

期刊论文

zone-layered trimming method for ceramic core of aero-engine blade based on an advanced reconfigurable laser processing

期刊论文

Probabilistic stability of uncertain composite plates and stochastic irregularity in their buckling mode

期刊论文

Wheat gluten protein and its impacts on wheat processing quality

Wujun MA, Zitong YU, Maoyun SHE, Yun ZHAO, Shahidul ISLAM

期刊论文

Chromium steel from chromite ore processing residue----A valuable construction material from a waste

Jay N. MEEGODA, Wiwat KAMOLPORNWIJIT

期刊论文

Experimental investigation of evolutive mode-I and mode-II fracture behavior of fiber-reinforced cemented

期刊论文

材料的成形加工与凝固技术

介万奇

期刊论文

Novel slack-based robust scheduling rule for a semiconductor manufacturing system with uncertain processing

Juan LIU, Fei QIAO, Yumin MA, Weichang KONG

期刊论文

Atomistic understanding of interfacial processing mechanism of silicon in water environment: A ReaxFF

期刊论文

塑料加工成型技术的最新研究进展

瞿金平

期刊论文