基于岩土控制变形工法的公路隧道施工变形分析——以野猪山隧道为例

宁波野猪山公路隧道右线出口段埋深浅、围岩差,采用岩土控制变形工法施工。该工法在我国公路隧道施工中几乎未有使用。本文通过数值模拟和现场监测数据对比分析,得出:1)隧道地表沉降的开挖空间效应约为0.6倍跨径,并据敏感程度划分为沉降敏感区、敏感过渡区、稳定区3个区域;2)隧道拱顶沉降约60%发生在掌子面到达监测断面前,开挖空间效应稍大于单倍跨径;3)隧道掌子面挤出变形呈外凸抛物面形态,建议施工中纤维锚杆的搭接长度设为6 m,并据挤出变形发展速率划分为快速发展、稳定发展、基本稳定3个阶段。     

车联网感知技术研究进展

车联网是物联网的具体应用,车联网获取车辆运行参数和道路等交通基础设施使用状况,感知实时道路交通路况,提供丰富的智能交通综合服务.介绍了车联网相关概念及系统构成,总结了车联网的感知关键技术的研究现状,如射频识别(RFID)、无线传感网(WSN)以及两者融合等,包括近期的研究工作,理论成果及实际应用等,探讨了存在的问题和今...     

地震下城市高架桥横向偏心碰撞响应与防撞效果分析

为适应材料因温度等因素的变化而产生的横向伸缩变形及其对结构的影响,通常梁体与挡块之间会留有一定间隙。针对城市高架桥中梁体与挡块在强震作用下的横向碰撞现象,建立了考虑上部结构与挡块间偏心距和支座非线性的横桥向单墩碰撞模型。采用非线性地震反应时程分析方法,研究了初始间隙及其大小对桥梁结构横向地震反应的影响,并评估了设置橡胶缓冲垫后的防撞效果。研究结果表明：城市高架简支梁桥横向间隙处的偏心碰撞放大了桥墩的地震需求,通过在挡块内侧安装橡胶缓冲垫,可以大幅减小间隙处的碰撞力,将有效改善桥梁结构的横向抗震性能。     

基于桥梁结构的动态称重系统算法研究

基于桥梁结构影响线加载的动态称重系统（B—WIM）便携且可循环使用,近几年在国外引起了学者深刻关注,并开发了相应的商业设备,而我国对此进行相关研究见于文献的很少。该系统可为中小跨径桥梁开展汽车荷载调查提供新的思路,并为中小跨径桥梁汽车活载评估提供直接参数。详细介绍了该系统算法原理,以三轴汽车荷载作为示例介绍了影响线坐标值标定过程,并给出了汽车荷载计算的通用矩阵表达式,为下一步进行设备开发的软件程序提供了理论支持。     

β-榄香烯对肾癌细胞的体外放射增敏作用

目的　探讨 β 榄香烯对肾癌细胞GRC 1的体外放射增敏作用及机理。 方法　将GRC 1细胞分为空白组 (加培养液 2mL)、空白乳组 (加空白乳培养液 2mL)和加药组 (加 5 0mg·L -1榄香烯乳培养液 2mL) ,培养 2 4h后 ,3组细胞悬液在剂量率 4 0 0cGy·min-1时 ,分别接受来自 6MeV直线加速器不同剂量的x线照射。计数被照细胞克隆群数 ,绘制细胞放射 存活曲线图。流式细胞仪检测各组细胞的周期变化与凋亡。对 3组爬片细胞进行免疫细胞化学染色 ,成像系统灰度分析bcl 2与PCNA基因表达。结果　流式细胞术显示 ,5 0mg·L -1榄香烯乳对肾癌细胞的G2 M阻滞作用随时间增加而增强 ,2 4h时作用达高峰 ;随时间和照射剂量的增加细胞凋亡水平增高。细胞爬片的成像系统灰度分析显示加药组与空白组相比 ,bcl 2基因表达降低 2 0 % ,而两组PCNA无表达。结论　β 榄香烯乳对肾癌细胞GRC 1有放射增敏作用 ,其作用机制可能与下调bcl 2基因表达 ,诱导GRC 1细胞凋亡和对细胞G2 M期阻滞有关     

RESORBABLE HIGH-STRENGTH ROD FOR FRACTURE INTERNAL FIXATION

Objective To find an ideal biomaterial for internal fixation. Methods Forty rabbits with fracture of the femur diaphysis (superioreondyle) were treated by intramedullary nailing of femur with composites rod of resorbable DL-polylactic acid (PDLLA)-ealcium metaphosphate (CMP), while steinmann‘s pin as control. The fracture healing, the material degradation and its mechanical properties were studied by X-ray films, macroscopic, microscopic and electron microscopic observations. Results No significant inflammatory reaction was found, and all the osteotomies were healed, while material was resorbed. Conclusion The PDLLA-CMP has excellent biocompatibility and mechanical properties, and it can be a promising implant material in orthopaedics surgery.     

Remaining Useful Life Prediction of Turbofan Engine Using Hybrid Model Based on Autoencoder and Bidirectional Long Short-Term Memory

High voltage electrostatics and corona discharge are utilized for various applications in pollution and environmental control. The traditional applications have many flaws due to improper construction of electrode design and assembly that cause system failure, in particular when electrically stimulated devices are exposed to high humidity. A new innovative-patented design by Hamade, electrically stimulated catalytic converter (ESCC), eliminates such flaws and shows the wide practical applications of the new design. The new design utilized previous patented designs and work of the same inventor but retrofitted for catalytic auto exhaust emission control. The current and previous patents include: employing electrically stimulated filtration (ESF) to replace high efficiency particulate air (HEPA) filters, treatment of biological and infectious diseases, electret fabrication, and, most notably, the invention of a new electrically stimulated catalytic converter (ESCC). The electrically stimulated catalytic converter invention includes an exhaust conduit fed from the engine exhaust port with a housed corona charger apparatus. The opposite end is opened to the atmosphere outside of the vehicle or connected to a reduced-size catalytic converter. The corona charger is intrusively or non-intrusively associated with a main flow path defined by the exhaust conduit. The corona charger includes at least one electrode, which may be recessed away from, the main flow path. A plurality of corona chargers may be used in various combinations, optimally a two dimensional grid. The electrically stimulated catalytic converter is adapted to treat and eliminate auto exhaust pollution emission to air.     

A Solution Processable Flexible Transparent Conductive Graphene/PEDOT: PSS Film Fabricated by Spin and Blade Coating

Flexible transparent conductive films were made on PET substrates by spin and blade coating, using graphene sheets dispersed in PEDOT: PSS solution. Ultrasonic substrate vibration was used to improve microstructure and properties of the films. Comparing to the pristine PEDOT: PSS film, the sheet resistance is 3 to 4 orders of magnitude lower with the addition of graphene. The conductivity and reproducibility of the film are improved for two-layer films comparing to one-layer films, with a reduction in transparency. Films prepared with substrate vibration showed lower sheet resistance for one-layer films, as the size of dewetting areas is reduced. In addition, large-area flexible films with desirable conductivity and transmittance were successfully fabricated by blade coating, which is promising, as the process is low-cost, scalable and compatible with roll-to-roll manufacturing.     

数据库技术的历史及未来的发展趋势综述

本文主要讨论了数据库技术诞生以来经历的几个发展阶段及未来的发展趋势和应用领域。     

浅谈软土地基的处理方法与实践

阐述了软土地基的处理方法与实践.