原状冻结砂土阻尼比的综合影响因素探究

对青藏铁路清水河DK1 047+000段原状冻结砂土进行室内动三轴试验研究,采用Tablecurver3D数据处理软件对阻尼比试验结果进行三维曲面生成,结果表明:当试验温度为-0.6~-10℃、围压为0.1~0.5 MPa、荷载振动频率为1~5Hz条件下,原状冻结砂土阻尼比分别与温度和加载频率呈单调增函数和单调减函数的关系,随围压的变化其值较为分散.阻尼比随温度和围压的综合作用呈片状微卷上升趋势,其中温度影响较为显著;温度—围压—阻尼比三维曲面为单调递增曲面;在频率和围压的综合作用下,阻尼比曲面近似呈螺旋上升状     

影响冷藏集装箱温度的因素

<正> 冷藏货在运输过程中,为了防止货物变质及保持货物的鲜度,需要保持一定的温度,即运输温度。根据具体货种的要求来确定运输温度值的大小,即使同一种货物,由于运输时间长短、冻结状态和货物成熟度的不同,对运输温度的要求也不一样。冷冻货物是在货物冻结状态下进行运输的货物,运输温度要求的范围一般在-10℃至-18℃之间,冷却货物是货物未冻结或货物表面有一层薄冰的状态下进行运输的货物,一般允许的温度调整范围在2℃至-2℃之间。所需运输温度要求由托运人提出,冷藏集装箱应适于拟装各种冷藏货物所需的运输温度。     

用强制循环冻结法开展桥梁冬期施工

在寒冷地区，桥梁冬季施工特别是基础施工，利用强制循环冻结法，是一个极好的办法。文章具体介绍了此办法的实施，并考虑了在动水区和静水区的措施。     

DGA技术在电力机车充油电气设备故障诊断中的问题探讨

文章对DGA技术在电力机车充油电气设备故障诊断中存在的问题进行了研究讨论，提出了如何处理注意值及综合诊断电力机车充油电气设备故障的方法。     

人工地层冻结法在地铁联络通道中的应用

随着城市地铁规模的不断发展,区间隧道联络通道在防灾、排水、联络等方面的功能日渐突出,人工地层冻结法(以下简称冻结法)在地铁区间联络通道中的应用越来越受到人们的关注,其设计、施工技术和质量控制要点更成为人们关注的重点.以上海市轨道交通某区间联络通道为例,就冻结法在地铁区间联络通道中的应用作一浅析,以期得到更多业内资深人士的关注,使冻结法的设计施工技术和质量控制要点更趋完善.     

EFFECTS OF THROMBOLYSIS WITH ULTRASOUND ON THE STRUCTURE OF ERYTHROCYTE AND ITS SAFETY THRESHOLD

The study was to investigate thrombolysis in vitro with ultrasound, and to discuss effects of thrombolysis with ultrasound on the structure of erythrocyte and its safety threshold under different ultrasound intensity and exposure time. The structure of erythrocyte in thrombus was evaluated under light microscope. The relationship between the structure of erythrocyte in thrombus and ultrasound intensity and exposure time was obtained. The results showed that ultrasound eliminated the thrombus. According to the change of the structure of erythrocyte in thrombus and ultrasound intensity and exposure time, the effects of thrombolysis with ultrasound could be divided into three kinds of areas： the A, B, C area. The area A was the safe area, the area B was the relatively safe area, and the area C was the irreversible damage area. The study suggested that ultrasound intensity and exposure time had significant impact on the structure of erythrocyte. Stronger ultrasound intensity or longer exposure time could cause erythrocytes irreversible damage. It could accelerate thrombolysis and shorten the exposure time that the ultrasound intensity was little bit increased. The study of effects of thrombolysis with ultrasound on the structure of erythrocyte and its safety threshold were important for practical applications.     

聚氯乙烯盐水冻结管在盾构进洞中的工艺性能分析

在地铁隧道盾构进出洞采用冻结法加固工程中,由于盾构机多为软土盾构,刀盘无法切除打入土体的钢质冻结管.为了解决盾构进出洞免拔管问题,采取PVC(聚氯乙烯)管作为冻结管,进行盾构进洞免拔管盐水冻结加固工艺性试验.分析了冻结过程中PVC冻结管在低温盐水冷冻下的渗漏性,冻结管管壁和冻土壁的温度分布规律,以及盾构推进过程中PVC冻结管的可切割性.获得了PVC管作为盐水冻结管的可行性.     

长江隧道盾构始发端头冻结加固施工技术

盾构始发施工事关隧道施工成败,软土地层盾构始发施工难度及风险大大高于其他地层。南京纬三路过江通道N线盾构始发施工采用端头冻结加固技术取得了良好的效果。详细阐述了盾构隧道始发端头冻结加固法设计、施工关键技术及施工效果,可供类似工程借鉴。