云桂铁路老石山隧道浅层天然气成因模式研究

云桂铁路老石山隧道在穿越非煤层系地层施工时,发生了天然气溢出及燃烧现象。文章针对该隧道病害形成原因及天然气来源,对天然气的成因模式进行了研究;在收集区域油气地质背景的基础上,从生油气层、油气储层和油气层构造三方面进行分析得出,隧道出口的背斜构造是油气运移的指向区和逸散浸染带,隧道下伏的多套生油气地层均存在一定的生油气能力,油气有通过断裂构造向上运移至浅部富集的可能性;结合隧道开挖前后天然气浓度检测结果分析表明,浅层天然气主要来源于隧道底板下深部岩层,而隧道洞身岩层可能已受油气浸染,在个别地段有富集的可能;最后通过对天然气分布特征及形成模式的分析研究得出,老石山隧道浅层天然气的成因模式,即气体来源于深部志留系和寒武系筇竹寺组的页岩天然气,沿龙泉寺断裂带向上运移至隧道溢出。     

A new algorithm to automatically extract the drainage networks and catchments based on triangulation irregular network digital elevation model

A new algorithm to automatically extract drainage networks and catchments based on triangula- tion irregular networks （TINs） digital elevation model （DEM） was developed. The flow direction in this approach is determined by computing the spatial gradient of triangle and triangle edges. Outflow edge was defined by comparing the contribution area that is separated by the steepest descent of the triangle. Local channels were then tracked to build drainage networks. Both triangle edges and facets were considered to con- struct flow path. The algorithm has been tested in the site for Hawaiian Island of Kaho＇olawe, and the results were compared with those calculated by ARCGIS as well as terrain map. The reported algorithm has been proved to be a reliable approach with high efficiency to generate well-connected and coherent drainage networks.     

Lesion segmentation and identification of breast tumor on dynamic contrast-enhanced magnetic resonance imaging

Dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） can show subtle lesion morphol- ogy, improve the display of lesion definitions, and objectively reflect the blood supply of breast tumors; it can also reflect different strengthening patterns of normal tissues and lesion areas after medical tracer injection. DCE-MRI has become an important basis for the clinical diagnosis of breast cancer. To DCE-MRI data acquired from several hospitals across multiple provinces, a series of in-silico computational methods were applied for lesion segmentation and identification of breast tumor in this paper. The image segmentation methods include Otsu segmentation of subtraction images, signal-interference-ratio segmentation method and an improved variational level set method, each has its own application scope. After that, the distribution of benign and malignant in lesion region is iden- tified based on three-time-point theory. From the experiment, the analysis of DCE-MRI data of breast tumor can show the distribution of benign and malignant in lesion region, provide a great help for clinicians to diagnose breast cancer more expediently and lay a basis for medical diagnosis and treatment planning.     

基于龙芯的Windows软件运行环境的设计与实现

龙芯处理器在国产处理器市场占有重要地位。由于龙芯采用的是MIPS指令集且主要支持Linux操作系统,然而目前在该平台上的应用软件还相对匮乏,且很多传统Windows软件也无法在该平台上直接运行,这使得龙芯处理器的推广与应用受到了影响。针对这一问题,提出了一种在龙芯平台上基于Wine来提供Windows 虚拟执行环境,并通过将Wine和Bochs模拟器相结合完成X86指令集到MIPS指令集翻译的解决方案。该方案能够实现Windows程序在零修改情况下直接运行在龙芯平台上,可支持Delphi ,C,C＋＋等多种语言开发的程序,以及网络、数据库等多种功能。测试表明：该系统运行稳定,但还存在不可忽略的性能影响。     

Current publications

Despite the European Union (EU) efforts promoting policies that encourage short sea shipping (SSS) based on its advantages in terms of intermodality and environment, this mode has not yet reached a significant market share compared to land transport. In this paper, we establish a thesis that suggests that funding programs (such as Marco Polo I and II) have not properly offered the right incentives to promote SSS, and aspects such as the key role of port infrastructure and its characteristics, have not been taken into consideration. In a departure from traditional transport cost models, to prove our thesis, we use a theoretical intermodal competition model to compare alternative modes—road transport vs. SSS. We reach the conclusion that the EU needs to focus on ports and transport system efficiency as a whole in order to compete effectively in the freight transport market.     

钢-混凝土双面组合箱梁日照温度场研究

自然环境中的钢-混凝土双面组合箱梁受到日照作用影响,在梁体内部会产生温度应力。对某地的日气温变化及日照辐射量进行计算;利用有限元软件ANSYS进行仿真分析,计算双面组合箱梁截面在日照条件下的温度分布,对比分析正负弯矩区截面温度分布的异同,得到组合梁表面日温度变化规律;选取温差最大时的数值结果进行分析,用多项式拟合沿梁截面高度温度梯度分布。     

Effects of cooling rates on microstructures and mechanical properties of Nb-Ti microalloyed steel

The mechanical properties and microstructure of as-cast Nb-Ti microalloyed steel at different temperatures and cooling rates are investigated in this paper. The III brittle zone (700?C900°C) is revealed. The reduction of the hot ductility is due to the film-like proeutectoid ferrite or the Nb(C, N) precipitates along the austenitic grain boundaries. In the temperature range of 850?C1 000°C, with the increase of the cooling rate, the hot ductility decreases. However, in the range of 650?C850°C, the appearance of large volume fractions of ferrite on austenite grain boundaries minimizes the effect of cooling rate on hot ductility. When the cooling rate is 10°C/s, austenite transforms more quickly to ferrite and at a lower temperature a larger amount of ferrite nucleates and precipitates in the grain, which leads to a sharper improvement in the hot ductility at 650°C.     

大断面浅埋黄土隧道锚杆轴力差异分析

以郑西铁路客运专线上的贺家庄隧道为例,研究了大断面黄土隧道中系统锚杆的受力状况,得出了拱部和边墙锚杆的受力特点,从径向位移的衰减规律和围岩压力分布形式两个角度分析了系统锚杆受力差异较大的原因,相关研究结论对黄土隧道的设计和施工具有参考价值和指导意义。     

一种仿生水下机器人的研究进展

近年来仿生技术在水下机器人上的应用已经成为水下机器人的重要研究方向之一.本文介绍了哈尔滨工程大学研制的"仿生-Ⅰ"号水下机器人.该机器人以蓝鳍金枪鱼为模本,长2.4m,前体固定,后体(约1/3体长)为具有3个节点的摆动装置,采用月牙形尾鳍.水动力计算和水池实验表明,仿鱼推进和操纵方式比传统的桨舵具有高效性和高机动性.     

地铁列车运行再生能利用的研究

先进的地铁信号及车辆系统,提供了列车再生制动的能力.论述了地铁列车制动系统提供的再生制动节能方式.在现有的条件下,通过合理编制运行图是提高再生能利用率的有效方法.介绍了提高再生能利用率的时刻表编制方法.按新运行图运营后,平均每日每列车公里可节约牵引用电0.95 kWh.