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21.
苏明浩  高毅  程鹏 《隧道建设》2019,39(3):444-450
为研究结构分割转换工法(CC工法)中不同结构分割方式对设计、施工的影响,丰富CC工法的相关研究,首先对CC工法跨中设缝和柱顶设缝2种典型分割方式相应的结构体系、受力特性进行分析和比较,并采用数值分析的方法,研究2种分割方式下不同节点位置和节点性质对结构受力的影响。然后对施工环节2种不同分割方式施工步序、节点施工质量控制、经济状况进行分析比较。结果表明: 1)柱顶设缝时,节点的设计、施工较为困难,施工措施费较高; 2)跨中设缝时,节点处理较为简单,经济优势较为突出,但跨中节点的性质在设计时较难把握,宜视构造特点具体考虑。  相似文献   
22.
庞立  朱莉莉 《船电技术》2019,39(4):36-38,64
本文针对电焊机分布式工作时不便集中监测其工作参数的问题,设计了电焊机互联网在线监测系统。该系统以SimpleLinkCC3220MCU为核心控制器,在控制器上移植FreeRTOS实时操作系统进行任务分解,利用CC3220内置的网络协议栈及HTTP服务器。经Wi-Fi连接互联网,用户通过访问web页面实现对不同电焊机工作状态的在线监测。  相似文献   
23.
Absolute values of chlorophyll a concentration and its spatial and seasonal variations in the Black Sea were assessed by using satellite CZCS and in situ data. Since the satellite CZCS had operated for the 1978–1986 period, CZCS data was used for assessing the past state of the Black Sea just before the onset of drastic changes observed in late 1980s. The approach used for the calculation of the absolute values of chlorophyll a concentration from CZCS data was based on the direct comparison of in situ chlorophyll a data and those of CZCS and by applying the algorithm developed for the transformation of CZCS data into chlorophyll a values. CZCS Level 2 data related with pigment concentration having a spatial resolution of 1 km at nadir were used. The daily Level 3 files were derived by binning Level 2 values into 4-km grid cells and the monthly and seasonal Level 3 files were created by averaging the daily Level 3 files over the corresponding period. In situ chlorophyll a data were obtained by spectrophotometric and fluorometric methods in 15 scientific cruises over the 1978–1986 period. Total number of ship-measured data used for the comparison with those CZCS values was 590.Chlorophyll a concentration (Chl) was derived from CZCS values (C) with regression equations Chl=kC; the coefficient of transformation k was calculated from six different data sets by taking into account distinctions between subregions and seasons. The reasons for difference in the k values have been analyzed.Statistical comparison of the chlorophyll a values measured in situ and those derived from CZCS data was based on log-transformed data and gave the following results: regression SLOPE=0.842, regression INTERCEPT=−0.081, coefficient of determination (R2)=0.806, root–mean–square ERROR=0.195. The mean monthly chlorophyll a distributions derived from CZCS data over 1978–1986 have been constructed and the mean seasonal chlorophyll a values in different regions have been calculated and analyzed. The significant difference in chlorophyll concentration between the western shelf regions and the open part of the Black Sea has been demonstrated, especially in warm season. At almost all seasons, the highest chlorophyll concentration is observed in the western interior shelf region which is under strong influence of Danube. The summer mean chlorophyll concentration in this region is 18 times higher than that in the open parts and about nine times higher than in the eastern shelf region. The greatest seasonal variations are observed in the open part of the Black Sea: chlorophyll concentration in cold season is four to six times higher than in summer and three to five times higher than in April and October. To the contrary, in the western interior shelf regions, the concentration is higher in May–October (about twice than that in November–March). Seasonal variations in the western outer shelf regions are smoothed out as compared with both the western interior shelf and the open regions.  相似文献   
24.
This paper is based on research undertaken for CPRE (Council for the Protection of Rural England) arising from concern at the inadequacy of current road planning procedures to address the issue of local development effects. The paper puts forward a number of arguments of principle in support of this proposition before recounting the planning and development experience of sites in the vicinity of the original (London-Oxford) section of M40 motorway built 20–30 years ago. This experience points to quite different outcomes in areas of open countryside as distinct from the periphery of the major intermediate town (High Wycombe), paricularly enclaves of enclosed land near to motorway junctions. With the latter the experience points to the failure of the planning system to anticipate and cope satisfactorily with development pressures. Since the provisions of development plans are used as the basis for assessing the impact of new road proposals this situation is not merely inefficient but conflicts with the basic purpose of the public planning system to give full consideration to the likely effects of proposals before they are committed.  相似文献   
25.
基于虚拟试验的汽车40%偏置碰撞抗撞性分析   总被引:2,自引:1,他引:1  
建立并验证了偏置变形壁障块模型、某轿车全宽碰撞模型的有效性,按照欧洲ECE R94.01法规建立该轿车的40%偏置碰撞有限元模型,基于虚拟试验技术对该轿车进行40%偏置碰撞抗撞性分析,确定该轿车40%偏置碰撞抗撞性改进方向和改进对策。  相似文献   
26.
试验车数据采集是机车牵引试验中最重要的环节之一,针对试验车数据采集系统的要求,将ZigBee无线传感网络技术应用于试验车数据采集系统,组建ZigBee无线传感网络,详细设计了该系统的硬件结构和软件结构.此系统与以前有线的试验车数据采集系统相比,节省布线,降低成本,并对ZigBee无线传感网络用于铁路运输做了展望.  相似文献   
27.
大型化集装箱船的诞生,对岸边集装箱机械提出了更高要求。简单介绍了Stinis分离上架吊具的组成和功能。着重介绍了Stinis上架吊具在岸桥上的实际应用情况以及岸桥的设计需要注意的问题。  相似文献   
28.
ADS40数字航摄仪在铁路航测中的生产试验   总被引:1,自引:0,他引:1  
介绍了ADS40数字摄影仪在既有铁路航测应用中的试验情况,着重说明了各工序的工作方法,并阐述了与常规摄影不同的地方。精度指标统计结果表明,本次试验工作方法满足大比例尺地形图的要求。  相似文献   
29.
目的 探讨重组促性腺激素释放激素 绿脓杆菌外毒素 4 0 (LHRH PE4 0 )与正常肝脏组织和肝癌细胞表面受体结合特性的差异。方法 用放射性配基结合分析的方法测定亲和力和受体容量。结果 LHRH PE4 0与肝癌细胞HEPG细胞的亲和力Kd为 (0 .4 3± 0 .12 )nmol·L-1,受体容量Bmax为 (0 .37± 0 .15 )nmol·mg-1,与正常肝脏组织未见结合。结论 重组毒素LHRH PE4 0和肝癌细胞HEPG的表面受体有较强的结合 ,而和正常肝脏组织无特异性结合。  相似文献   
30.
IntroductionRecently,the Ti Al based alloy has emerged asone of the structural materials with good prospectsin space,aviation,automotive and power genera-tion industries owing to their unique high- tempera-ture properties such as high specific strength andmodulus,good creep and oxidation resistance[1~3 ] .It has become well known for its excellent perfor-mance in turbine blades and engine valves for hightemperature service.These Ti Al made parts areconventionally jointed to the main body of…  相似文献   
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