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New kind of subarea-parallel scanning mode for laser metal deposition shaping

BIAN Hongyou, LIU Weijun, ZHAO Jibin

《机械工程前沿（英文）》 2007年第2卷第4期页码 417-422 doi: 10.1007/s11465-007-0071-1

摘要： A scanning mode is the key technology in a laser metal deposition shaping (LMDS) fabrication process. On the basis of the analysis of existing scanning modes and their influences on the fabrication efficiency and the quality of parts, some disadvantages of them are pointed out. A new kind of subarea-parallel scanning mode for LMDS based on a subdividing profiled outline into monotonous polygon subareas is presented. First, based on the principle of point visibility, inner loops are eliminated, and simple polygons are subdivided into monotonous polygons with the minimal zones. Second, the parallel scanning paths of all monotonous polygon subareas are finished, which diminishes the length of the scanning line. The practical application shows that the scanning mode can enhance the fabrication efficiency and quality.

关键词： scanning parallel scanning practical application fabrication efficiency LMDS

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Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Wenyuan LI, Yu HUANG, Youmin RONG, Long CHEN, Guojun ZHANG, Zhangrui GAO

《机械工程前沿（英文）》 2021年第16卷第1期页码 97-110 doi: 10.1007/s11465-020-0600-8

摘要： Cutting quality and efficiency have always been important indicators of glass laser cutting. Laser scanning modes have two kinds, namely, the spiral and concentric circle scanning modes. These modes can achieve high-performance hole cutting of thick solar float glass using a 532-nm nanosecond laser. The mechanism of the glass laser cutting under these two different scanning modes has been described. Several experiments are conducted to explore the effect of machining parameters on cutting efficiency and quality under these two scanning modes. Results indicate that compared with the spiral scanning mode, the minimum area of edge chipping (218340 µm ) and the minimum Ra (3.01 µm) in the concentric circle scanning mode are reduced by 9.4% and 16.4% respectively. Moreover, the best cutting efficiency scanning mode is 14.2% faster than that in the spiral scanning mode. The best parameter combination for the concentric circle scanning mode is as follows: Scanning speed: 2200 mm/s, number of inner circles: 6, and circle spacing: 0.05 mm. This parameter combination reduces the chipping area and sidewall surface roughness by 8.8% and 9.6% respectively at the same cutting efficiency compared with the best spiral processing parameters. The range of glass processing that can be achieved in the concentric circle scanning mode is wider than that in the spiral counterpart. The analyses of surface topography, white spots, microstructures, and sidewall surface element composition are also performed. The study concluded that the concentric circle scanning mode shows evident advantages in the performance of solar float glass hole cutting.

关键词： laser cutting solar float glass scanning mode surface quality cutting efficiency

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Review of MEMS differential scanning calorimetry for biomolecular study

Shifeng YU, Shuyu WANG, Ming LU, Lei ZUO

《机械工程前沿（英文）》 2017年第12卷第4期页码 526-538 doi: 10.1007/s11465-017-0451-0

摘要：

Differential scanning calorimetry (DSC) is one of the few techniques that allow direct determination of enthalpy values for binding reactions and conformational transitions in biomolecules. It provides the thermodynamics information of the biomolecules which consists of Gibbs free energy, enthalpy and entropy in a straightforward manner that enables deep understanding of the structure function relationship in biomolecules such as the folding/unfolding of protein and DNA, and ligand bindings. This review provides an up to date overview of the applications of DSC in biomolecular study such as the bovine serum albumin denaturation study, the relationship between the melting point of lysozyme and the scanning rate. We also introduce the recent advances of the development of micro-electro-mechanic-system (MEMS) based DSCs.

关键词： differential scanning calorimetry biomolecule MEMS thermodynamic

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一种飞机装配用便携式非接触轮廓扫描系统

梁冰, 刘巍, 刘坤, 周孟德, 张洋, 贾振元

《工程（英文）》 2022年第15卷第8期页码 207-214 doi: 10.1016/j.eng.2020.09.017

摘要：

在大型飞机装配过程中，三维轮廓扫描对于装配质量检测具有关键作用。为实现大型飞机零部件高反光曲面轮廓的扫描测量，本文提出一种兼顾精度与效率的非接触式自动化测量系统和方法。首先，以距离传感器辅助摄影测量，建立一种非接触式三维坐标复合测量系统，避免被测表面高反光对摄影测量精度的影响。同时，建立一种蕴含距离传感器一维测距信息与视觉全局转换关系的复合式坐标测量模型，高精度解算被测量点的三维坐标。其次，构建一种轮廓信息驱动的形面自动扫描方法和策略，在距离传感器有效量程内实现形面的非接触快速扫描与轮廓重建。最后，在某型号飞机平尾升降舵（尺寸约1760 mm × 460 mm）装配过程中对所提系统及方法进行现场试验与精度分析。实验表明：整个测量过程用时仅208 s，形面轮廓重建精度优于0.121 mm，因此，鉴于大型飞机装配过程中形面轮廓的高精度和高效率测量要求，所提系统及方法具有广阔应用前景。

关键词：飞机测试三坐标测量轮廓重建自动扫描扫描策略

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互联微电网可编程自适应安全扫描 Article

姜自民, 唐泽帆, 张鹏, 秦彦源

《工程（英文）》 2021年第7卷第8期页码 1087-1100 doi: 10.1016/j.eng.2021.06.007

摘要：

现代微电网的重要特征是其核心的分布式能源和控制系统普遍依赖网络通信和软件系统。信息与物理系统的集成使得微电网获得了极佳的分布可控性、可扩展性和可观性；然而，恶意网络攻击者由此亦可以利用微电网信息物理系统中各种潜在的漏洞对微电网实施破坏。本文提出一种可编程自适应安全扫描（PASS）技术，用以保护电力电子化微电网系统免受各类电力机器人（power bot）的攻击。这一新技术尤其可以有效抵御三种危害性较大的攻击，即控制器操纵攻击、重放攻击和注入攻击。可编程自适应扫描融合软件定义网络与新的协同检测方法；这一新的安全措施可以使得微电网的互联具有超高的弹性和安全性、低成本与高度自动化等优点。协同检测结合了主动同步扫描和混沌检测两类新技术，可以有效识别电力机器人攻击的类型并对各类攻击快速定位，且不会中断或影响互联微电网的正常运行。可编程自适应安全扫描技术的有效性和实用性在大量实验中得到了确证。

关键词：互联微电网可编程自适应安全扫描协同检测软件定义网络

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大面积扫描探针显微镜研制

路小波,陆祖宏,周庆,王国著

《中国工程科学》 2004年第6卷第9期页码 50-55

摘要：

介绍了一种大面积扫描探针显微镜。仪器采用大范围扫描与高精度微动扫描相分离、X-Y扫描与纵向检测相分离的方案，同时具备较大扫描范围和较高的分辨率，扫描重复性好，大面积扫描范围220mm×290mm×60mm，重复性2～3 μm，并可实现探针的自动逼近、光学显微镜自动聚焦和图像自动拼接。

关键词：扫描探针显微镜自动逼近自动聚焦图像拼接

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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

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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

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用于5G的毫米波宽角扫描天线 Article

Raj Mittra, Abdelkhalek Nasri, Ravi Kumar Arya

《工程（英文）》 2022年第11卷第4期页码 60-73 doi: 10.1016/j.eng.2021.10.017

摘要：

第五代（5G）网络通信系统主要工作在毫米波波段，预计可以提供数千兆的数据速率，这是目前使用无线服务（包括低于6 GHz的频段）所无法实现的。本文简要综述了几种现有的用于5G应用的毫米波相控阵设计。首先，介绍了低剖面天线阵列设计，包括固定波束和仅在一个平面上扫描波束的两种设计类型。随后，介绍了具有二维（2D）扫描能力的阵列系统，该系统对于大多数5G应用而言具有重要意义。接下来，在本文的主体部分，讨论了两种不同的扫描阵列设计策略，这两种策略都规避了用传统移相器来实现波束扫描。值得注意的是，因为在毫米波波段传统的移相器损耗高且价格昂贵，所以找到一个能替代传统移相器的器件是非常必要的；此外，诸如包括射频放大器在内的有源移相器等替代品也是既昂贵又耗电的。在此背景下，本文提出了两种不同的天线系统，这两种天线系统在毫米波范围内具有理想的2D扫描性能。第一种天线系统是龙伯透镜，该透镜由2D波导阵列或微带贴片天线阵列激励，以实现2D扫描能力。第二种天线系统是相控阵设计，该设计采用可切换的PIN二极管或变容二极管取代传统移相器，并将二极管插入波导中的辐射槽之间，从而为扫描提供所需的相移。最后，讨论了几种通过修改传统阵列配置来提高阵列增益的方法。本文还介绍了通过使用可重构的超表面类型的面板来实现一维（1D）和2D扫描的新技术。

关键词：龙伯透镜扫描阵列毫米波天线可切换移相器可重构超表面

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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

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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 K_Ic and K_IIc. 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

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海洋二号卫星扫描辐射计海洋参数反演算法研究

王振占,鲍靖华,李芸,谌华

《中国工程科学》 2014年第16卷第6期页码 70-82

摘要：

针对海洋二号（HY-2）卫星扫描辐射计，利用辐射传射方程模拟，建立了海面温度、海面风速、大气水汽含量、大气液态水含量和雨率的反演算法，并利用扫描辐射计在轨数据对上述参数进行反演。经过对反演的海面温度和风速全球产品的真实性检验表明，算法合理可行，能够反演大气海洋参数，反演精度满足设计指标需求。目前，其他参数的反演产品的检验还在进行，而且反演算法还要根据对辐射计测量值定标的深入而进一步优化。

关键词： HY-2 卫星微波辐射计海洋参数反演算法

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Crystal modification of rifapentine using different solvents

Kun ZHOU, Jun LI, Jianhong LUO, Dongsheng ZHENG,

《化学科学与工程前沿（英文）》 2010年第4卷第1期页码 65-69 doi: 10.1007/s11705-009-0302-6

摘要： Rifapentine crystals with different habits were prepared by recrystallization from selected solvents, such as methanol, ethanol, chloroform, and acetic acid. Scanning electron microscopy, X-ray powder diffractometry, infrared spectrometry, and differential scanning calorimetry were used to investigate the physicochemical characteristics of the prepared crystals. The comparative dissolution behaviors of the newly developed crystals and of rifapentine without being treated were also studied. Results show that the newly developed crystals were different from each other with respect to physical properties but were identical chemically. Needle-shaped crystals were obtained from methanol, ethanol, and chloroform solvents, and the block-shaped crystals were obtained from acetic acid solvent. X-ray diffraction spectra and differential scanning calorimetry investigation on those developed crystals clearly indicate that rifapentine has different crystal structure modification. When the crystal was obtained from acetic acid, the change of crystal habit was originated from the crystal structure modification. The dissolution rate of newly developed crystals was found to be higher than that of rifapentine without being treated. However, the modified crystal obtained from acetic acid shows the lower dissolution rate than crystals obtained from other solvents.

关键词： identical scanning calorimetry different comparative dissolution structure modification

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Experimental flexural behavior of SMA-FRP reinforced concrete beam

Adeel ZAFAR, Bassem ANDRAWES

《结构与土木工程前沿（英文）》 2013年第7卷第4期页码 341-355 doi: 10.1007/s11709-013-0221-y

摘要： The most critical drawback in currently used steel reinforcement in reinforced concrete (RC) structures is susceptibility to accumulation of plastic deformation under excessive loads. Many concrete structures due to damaged (yielded) steel reinforcement have undergone costly repairs and replacements. This research presents a new type of shape memory alloy (SMA)-based composite reinforcement with ability to withstand high elongation while exhibiting pseudo-elastic behavior. In this study, small diameter SMA wires are embedded in thermoset resin matrix with or without additional glass fibers to develop composite reinforcement. Manufacturing technique of new proposed composite is validated using microscopy images. The proposed SMA-FRP composite square rebars are first fabricated and then embedded in small scale concrete T-beam. 3-point bending test is conducted on manufactured RC beam using a cyclic displacement controlled regime until failure. It is found that the SMA-FRP composite reinforcement is able to enhance the performance of concrete member by providing re-centering and crack closing capability.

关键词： re-centering shape memory alloys concrete composite fiber reinforced polymer scanning electron microscopy

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海洋二号扫描微波辐射计冷空定标和地球物理参数反演研究

周武,林明森,李延民,王振占,黄磊

《中国工程科学》 2013年第15卷第7期页码 75-80

摘要：

本文研究了海洋二号（HY-2A）扫描微波辐射计冷空定标方法和数据反演算法。针对HY-2A扫描微波辐射计对地观测和定标扫描的设计原理和观测几何，基于微波辐射计的对地观测数据修正进入冷空反射器的地球信号，建立地面观测亮温的冷空反射器权重系数矩阵修正冷空观测信号；基于海面温度、海面风速、水汽含量和云液态含量的微波辐射计辐射传输模型，计算HY-2A扫描微波辐射计不同条件下的各频率极化方式下的理论亮温，建立线性回归模型，拟合不同地球物理参数的反演系数，采用多元线性回归算法反演HY-2A微波扫描辐射计地球物理参数，对比国外成熟微波辐射计数据，得到产品精度。

关键词：扫描微波辐射计多元线性回归星星交叉冷空定标