Experiment on Qinghai-Tibet railroad subgrade temperature monitoring based on FBG sensors

Qinghai-Tibet Railway is the longest and highest plateau railway in the world. A long term monitoring system of the stability of the subgrade in the permafrost regions should be put forward immediately to prevent damage to the railway. As it's very difficult to set up the long-distance automatic monitoring system which contains a lot of measure points along the 550 kilometers railway in the permafrost area, we present a subgrade temperature monitor system based on fiber Bragg grating (FBG). In this paper the principles of the FBG was presented, and the feasibility of the FBG sensors in the permafrost area of Qinghai-Tibet plateau was analysized. We embedded fifteen FBG temperature sensors and thermal resistance temperature sensors. A contrast experiment is made while the two kinds of sensors are arranged in the same position. The result of the experiment shows that the accuracy of the FBG temperature sensors is less than 0.1 degrees C. and the FBG sensors can do well in the measurement of pattern which the temperature varies with the depth of the permafrost soil. The result also shows the stability of the FBG sensors in the bad environmental condition of Qinghai-Tibet plateau, which proves the feasibility of the application of FBG sensors and our monitoring system on the Qinghai-Tibet railway.

Study on Mechanics Parameters of Unloaded Rock Mass about the Underground Powerhouse of Jin-ping Hydroelectric Station

After the excavation of Jinping underground cavern, a strong expansion appears along the unloading direction of the rock mass, mainly in the type of tensile rupture, accompanied by shear destruction, unloading resulted in significant deterioration of mechanical properties of rock. Based on the in-site investigation of rock mass structure, via analyzing the acoustic testing data, we identify the unloading range of the side walls and the division of rock types, and carry out with the solution of rock mechanical parameters about different unloading zone, providing geological foundation for the supporting design of the following design of the side walls, at the same time, providing reference for the selection of mechanical parameters of other underground excavation engineering with similar geological conditions.

Rapid automated in-situ monitoring of total dissolved iron and total dissolved manganese in underground water by reverse-flow injection with chemiluminescence detection during the process of water treatment

Measurement of iron and manganese is very important in evaluating the quality of natural waters. We have constructed an automated Fe(II), total dissolved iron(TDI), Mn(II), and total dissolved manganese(TDM) analysis system for the quality control of underground drinking water by reverse flow injection analysis and chemiluminescence detection(rFIA-CL), The method is based on the measurement of the metal-catalyzed light emission from luminol oxidation by potassium periodate. The typical signal is a narrow peak, in which the height is proportional to light emitted and hence to the concentration of metal ions. The detection limits were 3 x 10(-6) mu g ml(-1) for Fe(II) and the linear range extents up to 1.0 x 10(-4) and 5 x 10(-6) mu g ml(-1) for Mn(II) cover a linear range to 1.0 x 10(-4) mu g ml(-1). This method was used for automated in-situ monitoring of total dissolved iron and total dissolved in underground water during water treatment. (C) 1997 Elsevier Science B.V.

地下结构震动响应数值方法研究

随着计算机技术的飞速发展，数值计算已经成为模拟在各种介质中的爆炸过程及其近场波动效应的重要研究手段。针对目前爆炸技术在工程的重要应用课题之一，即地下结构在爆炸载荷作用下的震动响应数值方法进行了较深入的研究，研究了适用于松动爆破的爆破震动的等效模型，该模型简单可行，基本反映了爆破震动过程的物理特征。利用该模型对爆炸载荷作用下地下结构的震动过程进行了模拟，分析爆破在介质中激发的瞬态扰动及其传播的特征，如频率特征、振幅变化规律等，通过与实验数据进行对比，解释了近场爆炸现象并为实验提供理论依据。通过场地模拟实验的数值模拟验证了方法的有效性，为后续工作打下了良好的基础。

32m跨简支铁路桥梁横向振动的研究分析

基于频谱的概念,考虑列车行车的水平载荷的性质以及桥梁自振特性,通过理论分析以及实际的测试数据,得到32 m跨度的简支混凝土桥梁在行车时的振动情况,对结果进行了详细分析。提出32 m跨度桥梁的横向振动主要由桥墩的自振特性控制。最后,就避免铁路桥梁行车时的共振现象进行了初步分析,提出了可行的解决方案。

运用爆破震动来识别地下裂隙和软弱夹层

从爆破震动信号主要来源于爆破区邻近范围内地质结构的自振的观点出发，提出了一种探测地下裂隙和软弱夹层的新技术：把震源布置在裂隙和软弱夹层附近进行爆破，由于介质中裂隙和软弱夹层的存在使得局部结构的刚度减小。直接影响到爆破介质振动的速度幅值和频率，因此可以通过地表接收器接收的振动信号(包括振动速度的幅值和频率)识别出裂隙和软弱夹层的大小和形状等特征．通过无网格的数值算例分别从水平裂隙和斜裂隙的情况下总结规律说明了这种方法的可行性．

中国广西原花鳅属穴居盲鱼一新种——多鳞原花鳅

2006年5月从广西武鸣县城5km的地下龙潭中发现了原花鳅属的一个新种.该新种被命名为多鳞原花鳅(Protocobitis polylepis),与该属唯一已知种无眼原花鳅(Protocobitis typhlops)的豁别特征如下:1) 体背和体侧具淡的色素vs.色素完全退化;2) 除头和腹部外身体其余部分被稀疏鳞片vs.稀疏鳞片仪见于体侧中线;头长为体长24.1%-24.8% vs.19.8%-22.1%;体高为体长16.2%-16.3% vs.11.5%-13.0%:内侧吻须长为头长19.8%-21.O% vs.9.4%-11.8%;外侧吻须长为头长28.6%-30.2% vs.1513%-21.8%;颌须长为头长44.6%-46.0% vs.22.4%-31.8%.

Taxonomic review of the genus Sinocrossocheilus Wu (Teleostei : Cyprinidae), with a description of four new species

All Sinocrossocheilus species, except S. microstomatus, are reviewed. Four new species, S. labiata, S. papillolabra, S. nigrovittata, and S. longibulla, are described. The genus Sinocrossocheilus differs from other genera of Cyprinidae by the last simple dorsal fin ray being unserrated and unossified, the last unbranched anal fin ray being unserrated and unossified, the 5-branched anal fin rays, the mouth gap being inferior, the rostral cap covering the lower jaw and connecting directly with the lower lip, a row of fleshy lobes on the lower jaw, and a cloudy black spot above the pectoral fin. Sinocrossocheilus labiata is small and has 22 predorsal scales; S. longibulla has a very large air bladder; S. papillolabra possesses a well-developed ventral fin and a wide band covered by fleshy papillae on the lower lip; and S. nigrovittata possesses black longitudinal stripes along the lateral line. Crossocheilus bamaensis and Crossocheilus liuchengensis are transferred to the genus Sinocrossocheilus. Sinocrossocheilus species are endemic to the central and eastern Yunnan-Guizhou Plateau of China, where river systems are anfractuous, including seasonal rivers, cave rivers, underground rivers, and streamlets between mountains. These separated rivers probably provide conditions for the allopatric speciation of the Sinocrossocheilus.