塔式起重机市场高速增长 变频器应用潜力巨大

塔式起重机定义及分类 塔式起重机是动臂装在高耸塔身上部的旋转起重机。作业空间大，主要用于房屋建筑施工中物料的垂直和水平输送及建筑构件的安装。塔机的主要机构有起升机构、变幅机构、小车牵引机构、回转机构和大车走行机构。按塔机能否移动又分为：走行式塔机和固定式塔机。动臂式塔机设臂架变幅机构，兼有架设及变幅两种功能。小车变幅水平臂架塔机设小车牵引机构，或称小车变幅机构。     

螺旋型光纤传感软体操作臂状态测量及特性分析

微创手术软体操作臂是微创外科和机器人领域的科学前沿和研究热点,对提升微创手术水平至关重要。现有视觉、电子和光电等传感方法尚未解决软体操作臂的状态测量问题,以直线型布设在软体操作臂中的光纤传感器,在柔性操作臂伸展和弯曲等运动时存在易断裂和可重复性差等问题,未能实现手术操作臂的闭环控制,限制了其手术应用。为此,提出了一种基于螺旋型光纤传感的软体操作臂状态测量方法,并对其传感特性进行了研究。不同于直线布设光纤的传感方法,螺旋型布设光纤的传感方法可以实现可伸缩软体操作臂的测量,防止光纤在软体操作臂中的错位,满足可伸缩弯曲软体操作臂的测量需求。通过理论分析气动驱动软体操作臂伸缩和弯曲的运动特性,利用光纤上刻写的布拉格光栅传感点,建立软体操作臂中螺旋型光纤光栅的传感模型,推导出光纤光栅中心波长漂移量和软体操作臂弯曲曲率之间的关系。最后,为了验证螺旋型光纤光栅在软体操作臂中的传感性能,对其传感灵敏度和稳定性等进行了实验测试。实验结果表明:提出的螺旋型光纤传感方法可实现操作臂伸长10%、弯曲角度达到180°时的状态测量,且操作臂理论弯曲角度和光纤传感的误差最大为9%,传感灵敏度可达12.55 pm/(°),满足软体操作臂伸缩和各向弯曲操作时的测量需求。     

新型内河航道水上作业和检修一体船设计与应用研究

在内河航道桥梁的检测过程中,目前通过在桥墩上或者船舶上搭建脚手架建立检测平台开展检修作业,对部 分桥梁也可采用桁架式桥梁检测车,将设备和人员送到桥梁底面开展检测。 搭建脚手架所需时间较长,存在较大安全隐 患,而采用桥梁检测车方式需要封锁道路,无法适用于缆索桥、斜拉桥等桥梁。 针对这些问题,提出了一种适用于内河航道 水上作业和检修一体船设计与应用技术,在专用船舶上集成了大吨位折叠臂起重机和模块化高空作业平台,在一条船上 可以完成护岸吊装和桥底检测施工,在安全性、效率、适用性等方面有较大提升,具有较大应用推广价值。     

基于仿真优化的甲板作业站位选择指标策略研究

针对在甲板资源配置一定的条件下，资源分配策略影响航母作战效率的问题，对甲板作业站位选择策略展开了研究。从调运时间和排队时间两项特征参数的计算模型出发，提出了一种基于站位指标的动态选择策略。该策略可根据当前作业条件动态求解适合的站位选择方案，以甲板作业时长为优化目标，利用遗传算法对最佳的站位特征参数权重进行搜索求解。通过仿真实验，以甲板作业时长为评价指标将该策略与其他常见策略进行对比分析，结果表明在该问题背景下，站位指标策略优于其他几种站位选择策略，采用所提策略可获得更佳的舰载机甲板作业时长，提升舰载机出动架次率。     

基于3ds MAX双台起重机道路桥台吊装仿真实现

为了减少双台汽车起重机吊装过程中由于双机载荷分配不合理、协同策略不当等因素带来的不安全问题,根据吊装的具体场景及吊装的要求,对进行吊装作业的起重机进行吊装点载荷受力分析,基于一个具体的道路桥台吊装问题,分析吊装过程中额定起重量与工作幅度的影响关系,建立关系模型。并结合吊装过程的需求分析,然后利用3ds MAX这个三维动画制作及渲染的软件对吊装过程进行了三维建模仿真,通过起重机吊装的分析,查询起重机的载荷参数,完成起重机协同作业的选型过程。实验表明选用3ds MAX可以快速有效地完成双台起重机选型、站位和空间的校验。     

轮椅机器人异构主从臂关节空间中的运动映射研究

轮椅机器人系统是一种用于帮助有肢体运动困难的老年人/残疾人完成各种日常生活操作的辅助机器人,研究异构主从臂之间的运动映射算法有助于提高此类机器人系统控制操作的便捷性和直观性.本文以人手臂作为通用主臂,异构的7DOF机械臂作为从臂,采用穿戴式人体运动运动捕捉系统获取人手臂的关节运动数据,然后根据从机械臂的构型特征将其关节分为肩、肘、腕3组,研究在关节空间中由主臂到从臂的运动映射算法以及从臂的自主避障算法,最终实现符合操作者日常习惯的异构从臂运动控制.本算法具有如下两个突出的优点：（1）老年人/残疾人可以根据生活直觉和日常习惯来控制机械从臂的运动,操作疲劳程度和出错率得到显著降低;（2）轮椅机器人在家庭等非结构化和受限空间中作业时的自身安全性得到显著提高.上述优点对于轮椅机器人系统在助老助残中的应用具有非常重要的意义.     

嵌入式视频编码器量化算法优化

通过构造合适的量化矩阵，实现了快速量化，解决了通用嵌入式处理器实现视频压缩标准量化算法存在效率差、量化器结构复杂等问题：同时，对不同的视频编码块类型，采用不同的量化策略，避免了统一量化引起的图像质量下降。实验结果表明：不仅提高了编码器在通用嵌入式处理器上的量化效率，而且明显改善了编码图像的主、客观质量。     

基于随动天线的雷达主瓣干扰抑制

针对雷达系统主瓣干扰问题,本文提出了一种基于随动天线的干扰抑制算法。假设雷达站配置了一个主天线和一个随动天线,其中随动天线仅配备了接收机。主瓣干扰抑制算法是分两步进行的,第一步是基于特征值分解和特征子空间,完成初步干扰对消;第二步是将预处理后的随动天线的信号作为参考信号完成二次对消。通过仿真实验比较了本文提出的算法和已有算法的性能,结果显示本文提出的基于随动天线的算法可有效地对抗多个主瓣干扰源。     

ATV71 Plus柜式变频器在高炉卷扬上料中的应用

高炉上料卷扬系统为高炉的核心设备,负责原料的输送,是高炉连续生产的基础。松汀钢铁6#高炉卷扬小车采用单台三相交流异步电机拖动,电气传动系统选用法国施耐德电气的12脉冲整流工程型变频器ATV71 Plus柜式变频器,解决了传统卷扬主-从方案因机械耦合失败引起变频器故障而造成的休风、停产问题,提高了卷扬上料系统的稳定性,同时ATV71 Plus不对工厂电网产生谐波污染,实现了高炉的稳产高产和绿色节能。     

现代电装作业效率提升路径探析

本文分析现代电装作业存在的库存管理、最短路径以及CAK车间生产流水线问题,建立标准化物资采购周期流程,引入GA中交叉和变异进化策略,实现现代电装作业效率提升路径算法设计。实验结果表明,设计的现代电装作业效率提升路径算法能够有效提高现代电装作业效率,加快现代电装作业进程。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.