双进双出钢球磨煤机双可调式动静态分离器研发与应用

双进双出钢球磨煤机双可调式动、静态分离器可实现磨煤机分离器的双向调节;具有结构紧凑、系统阻力低,煤粉颗粒均匀的特点;其动态叶轮传动系统采用同轴布置,且叶轮转轴依靠三档支承,轴承部位采取了完善的润滑和密封措施,使得整个分离器结构简单、运行安全可靠。     

高精度平面加工—“分离器”技术

本文通过对高精度光学平面加工——“分离器”技术的系统工艺研究及长期实践,总结了各种“分离器”的加工形式、特点与最佳技术参数,监指出了各种“分离器”在加工中必须注意的几个共性技术问题。这在加工高精度光学平面、提高工效方面已取得了明显的经济效果。     

旋流分离器在石油化工中的应用

液-固、液-液分离在从工艺液流回收产品和液体净化中占有重要的地位,大多数工业分离是基于固体和液体的重度差,所用妹的主要设备之一是旋液分离器,亦称旋流器.简要介绍了旋流分离器的工作原理与特点,探讨了旋流分离器在石化工程中的应用方式与注意事项.     

基于Fluent的旋风分离器气固两相流数值模拟

旋风分离器内部流场较为复杂,属于典型的三维湍流强旋流场,具有非线性、时变性等特点,而颗粒在旋风分离器内的运动则更为复杂。应用Fluent软件来对旋风分离器内气固两相流进行数值模拟研究,以期能够更加深入、更加全面地认识旋风分离器内部流动规律,进而实现模拟与工业应用的良好结合。     

导叶式气液旋流分离器试验研究

根据气井井下工况特点设计了一种直径为50mm的新型导叶式气液旋流分离器,并进行了模拟分离试验。试验中重点分析了导叶式气液旋流分离器的叶道出口角度、锥体角度、叶道出口速度以及人口含液浓度对其分离性能的影响规律。     

催化裂化装置旋风分离器失效原因分析

针对催化裂化装置旋风分离器普遍存在的由于器壁开裂、冲刷穿孔等失效的现象,通过对其工作环境、工作特点、制造选用的材料进行分析,为旋风分离器的动态分析及设计制造提供参考。     

油田注汽锅炉汽水分离器的优化

分析目前我国油田开采中使用的注汽锅炉中的重要组成部分-油田注汽炉汽水分离器的应用和优化,优化后的汽水分离器具有分离效率高、干度高、阻力小的特点。     

双级分离旋风分离器计算机仿真设计与应用

采用SIMPLE算法,利用修正的k-ε湍流模型和非交错网格压力插值法对旋风分离器的流场进行了三维两相流动的数值模拟,通过分析流场的特点,提出了优化的分离器改造设计方案,并进行了工业性试验,实际效果良好。     

ADSL话音分离器幅频特性检测仪的研制

根据ADSL话音分离器快速检测的特殊要求,设计了一种综合应用MCU、DDS、LPF、自动控制、高频小信号放大等技术实现ADSL分离器多项幅频特性参数快速检测的仪器。经过与传统检测方法进行对比表明,所设计的检测仪具有检测速度快、准确性高、检测数据后期使用方便和检测成本低等特点。     

惯性粒子分离器流场特性的PIV试验研究

惯性粒子分离器因具有流动损失小、砂尘分离效果明显的特点而成为直升机发动机进气道的标准配置。论文采用PIV测速技术对惯性粒子分离器矩形截面模型进口、中心体驼峰区域、清除流(包括分叉区域)、主气流流场在高速进气状态下,进行分段测量,研究了该模型流道在设计型线下的流动特性;对比数值计算,显示出该流场的局部流动细节结构。进一步地验证了湍流模型数值计算方法可应用于惯性粒子分离器流道流场特性的研究。     

Face Detection from Four Captured Images Related to Intelligent Room for the Deaf

The intelligent environment needs Human-Computer Interactive technology (HCI) and a projector projects screen on wall in the intelligent environments.We propose the front-face detection from four captured images related to the intelligent room for the deaf.Our proposal purpose is that a deaf user faces wall displaying everywhere.The system gets the images from four cameras,and detects the user region from a silhouette image using a different method,detects and cuts a motion body region from a different image,and cuts the vertexchest region from the cut body region image.The system attempts to find front-face using Haar-like feature,and selects a detected frontface image from the vertex-chest region.We estimate the front-face detection of recognition rate,which shows somewhat successfully.     

Operation of a model of a transducer with a 2D-phased array in the transmission mode

Signals from a normal transducer with a phased array, whose shape was varied from linear to square, were simulated. The results of calculating the change in the normalized signal amplitude from a 2D-phased-array transducer as a function of the distance along the acoustic axis were compared using an analytical expression and via numerical summation of signals from transmitting elements with consideration of their focusing and their coincidence was shown. As a result of the comparative simulation of a signal from a linear phased array and a signal from a standard transducer with comparable directivity characteristics, it was established that the latter amplitude is 10 dB larger. The influence of incomplete focusing and focusing at a fixed distance was studied.     

Electron microscopy and diffraction of icosahedral and decagonal quasicrystals in aluminium-manganese alloys

Electron microscopic observations on the morphology of icosahedral and decagonal quasicrystals in aluminium-manganese alloys have been interpreted in favour of a heterogenous nucleation mode. The transition of icosahedral quasicrystals from nonfacetted dendrites to facetted particles occurs as a function of composition. While the variety of electron diffraction patterns to be expected from icosahedral quasicrystals has been demonstrated for a number of alloys, subtle intensity differences exist among analogous patterns from Al-Mn, Al-Cr, Al-Mn-Si and Mg-Al-Zn-Cu alloys. Electron diffraction patterns from decagonal quasicrystals can be understood on the basis of an edge-centred icosahedron as opposed to a vertex-centred icosahedron for icosahedral quasicrystals. Truncation from two-dimensional quasicrystals is discussed.     

Large-area, high-resolution image analysis of composite materials

An image analysis system based on a small network of parallel processors hosted within a PC has been developed to measure the orientations of glass and carbon fibres in a polymer matrix from a polished section using optical microscopy. A computer-controlled XY translation stage is used to scan a large sample area (mm × mm), at a high magnification to minimize measurement errors. The distance that the stage moves between adjacent image frames is accurately measured allowing partial images at the edges of image frames to be reconstructed and so produce a continuous area. By removing a small amount of material from the sample by polishing and rescanning the same sample area, data from a number of serial sections can be obtained. Pattern matching is then used to correlate the fibre images from each section, allowing full three-dimensional orientation data to be extracted, overcoming the limitations of measurements from a single, two-dimensional section plane.     

The use of model systems prepared from tobacco BY-2 cells for studies of the plant cytoskeleton

Model systems, such as plasma membrane-permeabilized cells, isolated phragmoplasts and membrane ghosts, were prepared from tobacco BY-2 cells and used for studies of the plant cytoskeleton. The use of membrane-permeabilized cells enabled us to demonstrate the occurrence in the phragmoplast of the translocation of microtubules away from the equatorial plane and led us to the isolation of a kinesin-like microtubule-translocating protein from phragmoplasts. Autoradiographic experiments using preparations of isolated phragmoplasts revealed that 1,3-β-glucan was synthesized at the equatorial plane of isolated phragmoplasts and xyloglucan was synthesized in the Golgi apparatus. Membrane ghosts from which pre-existing cortical microtubules had been removed by a cold solution of CaCl₂ bound microtubules that had polymerized in vitro , but those from which pre-existing microtubules had been removed by KCl did not. We used membrane ghosts that had been pretreated with KCl in an attempt to identify a microtubule-plasma membrane cross-linking activity in a fraction of a cell extract. We found that a fraction solubilized by KCl from isolated cortical microtubules had such activity.     

A combination of topographical contrast and stereoscopy for the reconstruction of surface topographies in SEM

The reconstruction of three-dimensional surface topographies can be done in two principally different ways: conventional stereoscopy and ‘shape from shading’. In conventional stereoscopy the depth information is obtained from two perspective views of the specimen. For that, perspectively corresponding features have to be identified in both views to determine depth from perspective shift. Conventional stereoscopy normally results in a relatively sparse set of irregularly distributed points whose elevations are known precisely. The shape-from-shading approach determines the local surface orientation from the local surface luminosity. Over a limited range of surface inclinations the emission of secondary (SE) and back-scattered (BSE) electrons depends uniquely on the angle between electron beam and local surface normal of the specimen. Shape from shading uses this relationship to determine the surface normal with multiple detectors mounted in different take-off directions. Contrary to conventional stereoscopy shape from shading yields depth information from each surface point, but this method is less accurate than stereoscopy. In this paper we propose a combination of both approaches, in which the dense, but less accurate results from shape from shading are used to fill the gaps in the sparsely distributed, but very accurately known, depth information obtained from stereoscopy.     

A comparative study between light extinction and direct sampling methods for measuring volume fractions of twin-hole sprays using tomographic reconstruction

The spatially resolved spray volume fractions from both line-of-sight data of direct measuring cells and a laser diffraction particle analyzer (LDPA) are tomographically reconstructed by the Convolution Fourier transformation, respectively. Asymmetric sprays generated from a twinhole injector are tested with 12 equiangular projections of measurements. For each projection angle, a line-of-sight integrated injection rate was measured using a direct sampling method and also a liquid volume fraction from a set of line-of-sight Fraunhofer diffraction measurements was measured using a light extinction method. Interpolated data between the projection angles effectively increase the number of projections, significantly enhancing the signal-to-noise level in the reconstructed data. The reconstructed volume fractions from the direct sampling cells were used as reference data for evaluating the accuracy of the volume fractions from the LDPA.     

Fourier-ratio deconvolution techniques for electron energy-loss spectroscopy (EELS)

We discuss several ways of using Fourier-ratio deconvolution to process low-loss spectra. They include removal of the tail arising from the zero-loss peak, extraction of the spectrum of a particle from data recorded from the particle on a substrate, separation of the bulk and surface components in spectra recorded from samples of the same composition but different thickness, and investigation of interface energy-loss modes. We also demonstrate the use of a Bayesian-equivalent procedure based on the Richardson–Lucy algorithm.     

哲学自何处来？

数学和哲学的繁荣是全民族繁荣中不可缺少的重要部分，因此有必要追问和思考：哲学来自何处？数学与哲学最大的共同点在于都来自人的心灵。心灵中之所以能产生如此美丽的东西，是因为追求美与追求真是联系在一起的。真知并非源自“感性物质活动”，虽然有一些知识与物质的关系很密切。但数学和哲学都来自精神、来自心灵。这就是亚里士多德主张“闲暇”的原因。     

Wear of paper slitting blades: an examination of worn blades from paper mills

Examination of worn rotary slitting blades from several paper mills showed that the predominant wear mechanism is abrasion by a two-body mechanism, in which carbide particles are plucked from the surface of the blades, and a three-body mechanism with hard particles released from the paper as dust. The dimensions of abrasion tracks suggest that the three-body mechanism is more common. Quartz, a minor constituent of paper additives, is identified as a hard material in paper dust. Fatigue cracking is a minor factor in blade wear, causing chipping at blade tips, and is attributed to high cyclical stresses in the early stages of wear. Loss of cut quality during wear is attributed to a transition from shear cutting to tensile cutting which pulls out fibres from the paper web. This tranition is a function of changes in wear angle and wear depth at the blade tip, which in turn are affected by slitter machine settings