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排序方式: 共有276条查询结果,搜索用时 15 毫秒
1.
LZ建筑结构胶的研制和应用 总被引:1,自引:0,他引:1
介绍了LZ建筑结构胶配方优化及性能指标 ,应用LZ结构胶粘贴钢板及碳纤维织物对小梁加固的结构试验和结构胶在工程中补强加固的应用 相似文献
2.
Rotational fretting which exist in many engineering applications has incurred enormous economic loss. Thus, accessible methods are urgently needed to alleviate or eliminate damage by rotational fretting. Surface engineering is an effective approach that is successfully adopted to enhance the ability of components to resist the fretting damage. In this paper, using a high-velocity oxygen fuel sprayed(HVOF) technique WC-17 Co coating is deposited on an LZ50 steel surface to study its properties through Vickers hardness testing, scanning electric microscope(SEM), energy dispersive X-ray spectroscopy(EDX), and X-ray diffractrometry(XRD). Rotational fretting wear tests are conducted under normal load varied from 10 N to 50 N, and angular displacement amplitudes vary from 0.125° to 1°. Wear scars are examined using SEM, EDX, optical microscopy(OM), and surface topography. The experimental results reveal that the WC-17 Co coating adjusted the boundary between the partial slip regime(PSR) and the slip regime(SR) to the direction of smaller amplitude displacement. As a result, the coefficients of friction are consistently lower than the substrate's coefficients of friction both in the PSR and SR. The damage to the coating in the PSR is very slight. In the SR, the coating exhibits higher debris removal efficiency and load-carrying capacity. The bulge is not found for the coating due to the coating's higher hardness to restrain plastic flow. This research could provide experimental bases for promoting industrial application of WC-17 Co coating in prevention of rotational fretting wear. 相似文献
3.
为了对实际信号进行监测,设计了以W77E58微控制器为核心的多路数据采集系统,介绍了系统总体结构,阐明了模拟量采集的硬件和软件设计方法,给出了具体的电路图和软件程序,经实际测试表明,该系统具有采集精度高、功耗低、抗干扰能力强、通用性好的特点。 相似文献
4.
In the field of lossless compression,most kinds of traditional software have some shortages when they face the mass data.Their compressing abilities are limited by the data window size and the compressing format design.This paper presents a new design of compressing format named ’CZ format’ which supports the data window size up to 4 GB and has some advantages in the mass data compression.Using this format,a compressing shareware named ’ComZip’ is designed.The experiment results support that ComZip has better compression ratio than WinZip,Bzip2 and WinRAR in most cases,especially when GBs or TBs of mass data are compressed.And ComZip has the potential to beat 7-zip in future as the data window size exceeds 128 MB. 相似文献
5.
苏77-5-8H井大斜度穿煤层安全钻井技术 总被引:2,自引:1,他引:1
苏77-5-8H井为苏里格气田苏77区块第一口利用水平井提高山23组开发效益的大斜度穿煤层水平井,目的层山23储集砂岩上部发育厚度25~30 m的碳质泥岩和煤层段,由于煤系地层的特殊性,钻进过程中易坍塌,且煤系地层正好处于入靶前的造斜井段,钻井施工难度大、风险高。在分析了煤层井壁稳定机理基础上,针对苏77区块地层特性和水平井钻井施工的难点,分析了该井主要技术难点,重点从井眼轨迹轨道设计优化、轨迹控制及施工技术措施和钻井液技术等方面对该井安全技术进行了全面的介绍,为今后同类井钻井提供可参考的经验。 相似文献
6.
介绍了苏77井区的储层特征,并指出压裂改造过程中面临的主要难题:粘土含量高、压力系数低、返排困难、残渣伤害。针对难题,苏里格气田普遍采用液氮伴注水基泡沫压裂液技术,增压助排,减少储层伤害。该压裂液100℃剪切稳定性好,能有效防止粘土膨胀运移,液氮泡沫稳定,有助于增加地层能量,提高自喷返排率。通过现场使用表明,采用液氮伴注水基泡沫压裂液技术,适当提高平均砂比、变排量施工、提高液氮伴注比例以及全程伴注等措施,不断优化施工参数,有效满足了苏77井区低压低渗气藏的压裂试气施工,并取得一定成效。 相似文献
7.
大规模的云渲染技术带来了大量的三维图形渲染数据。为了减小集群渲染产生的图像序列数据的传输以及存储代价,针对渲染图像序列低熵的特点,基于字典编码技术提出了降低数据局部复杂性的无损数据压缩方案。该方案通过数据重排技术来大大提高数据的局部冗余度,从而提高数据无损压缩效率。为了进一步解决大规模图像序列的压缩耗时问题,提出了一种云计算平台上的分布式图像压缩处理方案,充分利用现有云计算中Map/Reduce计算模型实现了分布式编码方案。实验结果证明,对于渲染产生的大规模低熵图像序列,提出的方案能够有效提高编码率并减少编码时间。 相似文献
8.
在Gleeble-1500热模拟实验机上测定高碳钢SWRH77B的连续冷却转变(CCT)曲线,并利用光学显微镜和透射电镜分析其终轧温度、冷却速度下的组织演变和相变规律。结果表明,随着冷却速度的加快,高碳钢SWRH77B在950℃变形时,其珠光体的片层间距变细;冷却速度达到5℃/s时,有马氏体组织析出。高碳钢SWRH77B在终轧温度为950℃、冷却速度约为4℃/s时,其珠光体的片层间距约为97 nm,索氏体含量达到95.7%左右,表明此时的组织为最佳索氏体组织。 相似文献
9.
A. D. Morrison-Low 《History of Photography》2013,37(1):99-103
Abstract This is a difficult conference to review. It is particularly difficult as your reviewer comes from the margins of the discipline of his tory of photography; but then, all reviews are from a single, personal viewpoint (as are most photographs) and may not necessarily reflect an audience consensus. So, I shall begin by saying that this was not what I had expected. Had I been a mainstream art historian, still flushed with youthful enthusiasm, I might have loved it; but age, experience and a profound uneasiness about my own lack of wisdom left me with the distinct impression of the curate's egg. This conference was ‘good in parts’. 相似文献
10.
C. Galacho M.M.L. Ribeiro Carrott P.J.M. Carrott 《Microporous and mesoporous materials》2007,100(1-3):312-321
A study of the pore structural properties and catalytic activity of MCM-41 containing titanium, prepared by direct synthesis at ambient temperature and pressure, using tetraethoxysilane, titanium alcoxides, cationic surfactants and ammonia is presented. The influence of different metal sources (titanium ethoxide, isopropoxide or n-butoxide), alcohols (ethanol or propan-2-ol), metal content (2 Si/Ti 100) and surfactants (tetra-, hexa- or octadecyltrimethylammonium bromide) is considered. The materials were characterised by X-ray diffraction, nitrogen adsorption at 77 K and diffuse reflectance UV–Vis spectroscopy. The catalytic activity was evaluated in the model reaction of oxidation of cyclohexene with anhydrous tert-butylhydroperoxide, for representative samples. It is concluded that this method allows the preparation in a short period of time of well structured and catalytically active Ti–MCM-41. Down to Si/Ti = 10 the materials have high pore volumes and very uniform pore size, with highest conversion and excellent selectivity demonstrated in the compositional range 30 Si/Ti 100, corresponding to materials containing predominantly isolated and tetracoordinated Ti. The increase in Ti content to Si/Ti ratios of 10 and 5 implied a reduction both in conversion and selectivity, although the MCM-41 structure was still observed for Si/Ti = 2. 相似文献