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Search Results: 1 - 10 of 129775 matches for " 杨雨图 "
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波纹管膨胀节性能试验驱动连接装置的设计
张丹丹,刘英,,李宇廷
- , 2016, DOI: 10. 13543/ j. bhxbzr. 2016. 05. 019
Abstract: 针对现有的波纹管膨胀节性能试验驱动连接装置只能满足单个且单一内径膨胀节试样的试验要求,结合机电一体化技术,提出了一种满足不同内径的复式波纹管膨胀节试样的试验驱动连接装置的设计方案与工作原理,主要包括架体、翻转机构、压紧机构、导向机构、连接法兰机构以及驱动机构。驱动连接装置实现复式波纹管膨胀节中间法兰的装夹,与试验驱动与加载机构固定连接,加载实现试样的往复运动,满足《压力管道元件型式试验规则》的试验要求。驱动机构采用西门子S7-200PLC 可编程控制,操作方便、快捷,自动化程度高,安全性能好。
Abstract:Since existing driving connection devices for bellows expansion joint performance tests can only meet the testing requirements of specimens with one single diameter bellows expansion joint, in this work we introduce electromechanical integration technology in order to fabricate a driving connection device which meets the requirements of tests on specimens with different diameters and two expansion joints. The main components of the device are a frame body, a turning mechanism, a compaction mechanism, a steering mechanism, a connecting flange and a driving mechanism. The driving connection device allows a two-bellows expansion joint to be clamped at the middle flange and has a fixed connection to the test driving and loading mechanism which can be loaded to afford a reciprocating movement of the sample, which meets the requirements for pressure piping component testing rules. The driving mechanism incorporates a Siemens S7-200 programmable controller, which offers convenient and quick operation, high automation and good safety performance.
实木板材无损检测中三维点云数据的预处理
赵乾,刘英,,胡忠康,周晓林
- , 2018, DOI: 10.13360/j.issn.2096-1359.2018.05.007
Abstract: 在实木板材检测过程中,利用激光线扫描技术,以设定的速度扫描待测木材的表面,获取三维数据,可实现实木板材无损检测、缺陷定位和三维模型重构。然而,三维激光轮廓扫描仪采集的原始数据不仅存在噪声的干扰,而且其密度一般也非常大,影响检测结果和后续重构。通过对采集到的实木板材表面轮廓点云数据进行预处理,不仅可以去除噪声干扰,降低点云密度,而且可将对后续重构无影响的背景点云数据去除,简化重构过程,保证曲面重构过程的精度、简度和速度。使用Chroma+Scan3350型激光轮廓扫描仪,配合实木板材无损检测装置,采集了赤松板材和樟子松板材图像,围绕采集到的原始点云数据进行预处理。在分析点云数据的噪声来源的基础上,对噪声数据进行分类,并依次滤除,可通过曲线检查法和弦高差法去除少量的异常点,根据线扫描点云数据特点,在对比高斯滤波、平均滤波、中值滤波和小波滤波的平滑处理结果后,最终选取小波滤波进行数据平滑,取得了良好的滤波效果,很好地保留了原始点云数据的上升沿、下降沿等特征信息和曲线的棱角特点。对比角度-弦高联合法与曲率采样精简法的点云数据精简结果,选取曲率采样精简法对数据进行精简,精简效果好,速度较快。
In recent years, 3D measurement technology has been developed rapidly, and widely used in many fields, such as surveying and reverse engineering. In the process of solid wood panel nondestructive testing, surfaces of solid wood panels could be scanned at a set of constant speed using the laser scanning technology to obtain the three-dimensional data. In this way, the nondestructive testing of solid wood panels was conducted, the defects were detected and 3D models were reconstructed. However, there was much noise in the original point cloud data acquired by the 3D laser scanner, and the density of the point cloud data was high, which affected detection results and subsequent reconstruction. Pre-processing of point cloud data collected from solid wood panels could denoise and decrease density of point cloud data. While the background point cloud data, which were not used for reconstruction, should be also removed to simplify the reconfiguration process, ensure the accuracy, simplicity and speed of reconstruction. Acquired by the Chroma+Scan3350 laser scanners with the nondestructive device, point cloud data of the original solid wood panels, such as Pinus densiflora and P. sylvestris var mongolica were pre-processed. Based on the analysis of the noise sources of the point cloud data, the noise data were classified and filtered. Curve check method and chord deviation method were used to remove the outliers. According to the characteristics of the line scanning point cloud data, a variety of point cloud was smoothened and point cloud simplification methods were used. Compared the gauss filtering, mean filtering, median filtering and wavelet filtering, the wavelet filter was finally selected for data smoothing and we achieved a great filtering outcomes. This approach could preserve angular features of curve by preserving rising edge and falling edge of original point cloud data. Comparing the angle-chord deviation method with the curvature sampling streamline method,we finally selected the curvature sampling to simplify the data. The curvature sampling
波纹管膨胀节波形曲线拟合及波距检测算法研究
崔亚飞,刘英,朱庆南,王一宁,,缑斌丽
- , 2018, DOI: 10.13543/j.bhxbzr.2018.01.014
Abstract: 由于国内波纹管膨胀节波距检测还处于手工测量阶段,存在着效率差、精度低、劳动强度大等缺点。设计了基于激光扫描技术的波纹管膨胀节波距检测系统,提出一种波纹管膨胀节波形曲线拟合及波距检测的算法,开发了一种能够自动获取波纹管膨胀节伸缩变形的波形点云数据、并能实现波形的逆向重构及波距计算的软件。该系统适用于波纹管膨胀节通径50mm~1500mm、双试验件总长1500mm~2500mm、试验压力0.1MPa~6.4MPa范围内变化的试验件波形检测,可自动调整扫描仪至膨胀节的距离,并能剔除检测过程中出现的各种干扰数据,波距测量精度达0.05mm。
Abstract:The measurement of wave pitch of bellows expansion joints is still in the manual vernier caliper measurement stage, which is not only inefficient, low precision, large labor intensity, but also many other shortcoming. In this paper, a waves pitch detection system of bellows expansion joints based on laser scanner technology was designed, a waveform fitting algorithm and wave pitch detection algorithm for bellows expansion joint was proposed, and a software automatically obtaining the point cloud data, conducting the waveform reconstruction and calculating wave distance had also been developed. The system is suitable for the bellows expansion joint test piece waveform detection, which diameter is from 50mm to 1500mm, the whole length of the double test pieces is from 1500mm-2500mm, and the test pressure is from 0.1MPa-6.4MPa, it can adjust the distance between the scanner and the expansion joints automatically, and eliminate all kinds of interference data, the measurement accuracy of wave distance is 0.05mm.
?相声话语中诗性语言的连贯策略研究——以相声《败家子》为个案研究
,,胡辉
惠州学院学报 , 2014,
Abstract:
共沉淀法制备LaFeXCo1-XO3钙钛矿的研究
Preparation of LaFeXCo1-XO3 Perovskite by Coprecipitation
 [PDF]

, 石凯
Open Journal of Nature Science (OJNS) , 2016, DOI: 10.12677/OJNS.2016.44046
Abstract:
以La(NO3)36H2O、Co(NO3)36H2O和Fe(NO3)39H2O为原料,用共沉淀法对制备LaFexCo1?xO3 (x = 0.2, 0.5, 0.8)钙钛矿进行研究。热重–差示量热分析(TG-DSC)和X射线衍射(XRD)分析表明,合成LaFexCo1?xO3钙钛矿过程有四段失重,分别在110℃之前、150℃~220℃、300℃~500℃和700℃~780℃;经过700℃~800℃煅烧后有钙钛矿形成,之后随煅烧温度提高,钙钛矿生成量逐渐增加,晶粒尺寸也缓慢增加,煅烧温度为1000℃时获得钙钛矿的量最多,但是与800℃和900℃煅烧后形成钙钛矿相比,其晶粒尺寸增加较多;随着Fe取代Co的量增加,形成钙钛矿尺寸晶粒尺寸逐渐降低。
Preparation of LaFexCo1?xO3 (x = 0.2, 0.5, 0.8) perovskite by coprecipitation using La(NO3)36H2O, Co(NO3)36H2O和Fe(NO3)39H2O and Fe(NO3)39H2O as raw materials was researched. The phenomena observed were characterized using Thermogravimetry-Differential Scanning Calorimetric (TG-DSC) and X- ray diffraction (XRD). Results showed that process of preparing LaFexCo1?xO3 perovskite appeared four period of weight loss at less than 110?C, 150?C - 220?C, 300?C - 500?C and 700?C - 780?C, respectively. The sample calcined at 700?C - 800?C has already formed perovskite, then amount of forming perovsktie and the grain size of perovskite increase gradually with the calcination temperature. When calcination temperature is at 1000?C, the most amount of perovskite is gained, but the grain size increases more than that of perovskite calcined at 800?C and 900?C. With the increase of substitute Fe for Co, perovskite particle size is gradually reduced.
飞机超低空牵引空投动力学响应研究

南京航空航天大学学报 , 2012,
Abstract:
“黑箱”与运动训练

天津体育学院学报 , 1984,
Abstract:
关于休育场馆灯光照明的几个问题

天津体育学院学报 , 1983,
Abstract:
人口问题与体育管理

天津体育学院学报 , 1985,
Abstract:
基于Bass模型的新产品潜在收益分布研究
赵骅,
科技进步与对策 , 2007,
Abstract: 通过Bass模型预测的新产品销售量和技术创新预期的新产品销售价格,获得无重复购买条件下,新产品潜在收益3种类型分布,分别代表了3种类型创新产品的收益空间;再将条件放宽到周期性重复购买,得到新产品的销售数量将趋近于潜在用户的总数,潜在收益趋于无限;根据以上两者推算出新产品在随机重复购买条件下潜在收益分布,总体呈递减趋势,最终因替代产品的出现而趋近于零。Bass模型新产品潜在收益技术创新周期性重复购买
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