Influence of fines content on the anti-frost properties of coarse-grained soil

This paper aims to determine the optimal fines content of coarse-grained soil required to simultaneously achieve weaker frost susceptibility and better bearing capacity. We studied the frost susceptibility and strength properties of coarse-grained soil by means of frost heaving tests and static triaxial tests, and the results are as follows:(1) the freezing temperature of coarse-grained soil decreased gradually and then leveled off with incremental increases in the percent content of fines; (2) the fines content proved to be an important factor influencing the frost heave susceptibility and strength properties of coarse-grained soil. With incremental increases in the percent content of fines, the frost heave ratio increased gradually and the cohesion function of fines effectively enhanced the shear strength of coarse-grained soil before freeze-thaw, but the frost susceptibility of fines weakened the shear strength of coarse-grained soil after freeze-thaw; (3) with increasing numbers of freeze-thaw cycles,the shear strength of coarse-grained soil decreased and then stabilized after the ninth freeze-thaw cycle, and therefore the mechanical indexes of the ninth freeze-thaw cycle are recommended for the engineering design values; and (4) considering frost susceptibility and strength properties as a whole, the optimal fines content of 5% is recommended for railway subgrade coarse-grained soil fillings in frozen regions.     

辽宁陆东凹陷前河油田水下扇沉积粒度特征及水流强度分析

前河油田九佛堂组为一套水下扇沉积。通过对不同层位取心井粒度资料分析及对比,分析其差异的原因,确定各层位搬运方式及沉积作用形式,并运用霍姆斯水流强度图分析从湖盆边缘向湖盆内的水流强度变化。根据岩性组合及测井曲线特征,识别出扇根、扇中前缘及扇端3种微相。并认为沿水流及砂体发育方向为部署有利区带。     

附加系统参数的多时相InSAR时空建模和形变估计

轨道误差和长波大气延迟组成的系统误差是影响InSAR形变监测精度的重要因素之一.传统方法在空间域对干涉图的系统误差建模,容易导致长波形变和系统误差相混淆.本文在时空域利用附加系统参数对系统误差建模,同时根据观测值质量对差分相位观测值定权,采用附加系统参数的加权最小二乘法估计形变参数和系统误差,实现了长波形变和系统误差的分离.模拟实验结果表明,在形变与系统误差的空间变化特性完全一致的极端情况下,本文方法能实现两者的有效分离,估计的形变速率均方根误差比传统方法降低了98.8%.ASAR数据实验显示当形变尺度较小且分散分布时,本文方法和传统方法得到的结果相似;当形变在研究区内表现为长波变化时,本文方法比传统方法估计的形变结果更为稳健.     

动力因子对地形影响下的四川暴雨落区的诊断分析

本文分析了2010年7月16～18日地形作用下四川盆地的一次持续性暴雨过程,指出此次暴雨过程是在高低层系统配置较好的情况下发生的。并以NCEP资料为初值场对此次暴雨过程进行了数值模拟,结合实况对模拟结果进行对比分析。分析表明:模式对本次四川暴雨过程的模拟较为成功,能很好地再现此次暴雨的降水落区以及强降水中心。运用广义湿位温、广义对流涡度矢量垂直分量的垂直积分和质量垂直螺旋度对受大巴山脉影响的四川东北部的暴雨落区进行了诊断分析。分析指出,广义湿位温纬向平均的垂直剖面图上,等湿位温线的倒Ω区域与四川东北部的强降水落区吻合较好,等湿位温线的倾斜程度以及湿位温异常的高度可以定性地指示降水的强弱;对广义湿位温从800 hPa到500 hPa垂直积分,用得到的湿位温的水平分布来指示东北部的暴雨落区效果较 好;用改进垂直积分区间后的广义对流涡度矢量垂直分量比用传统的对流涡度矢量垂直分量来示踪四川东北部的暴雨落区效果更好;质量垂直螺旋度能有效刻画出四川东北部地区强降水系统的典型动力场垂直结构,因此与四川东北部的地面强降水具有很好的对应关系。     

Time‐series high‐resolution spectroscopy and photometry of ε Aurigae from 2006–2013: Another brick in the wall

We present continuous and time‐resolved R = 55 000 optical échelle spectroscopy of ε Aurigae from 2006–2013. Data were taken with the STELLA Echelle Spectrograph of the robotic STELLA facility at the Observatorio del Teide in Tenerife. Contemporaneous photometry with the Automatic Photoelectric Telescopes at Fairborn Observatory in Arizona is presented for the years 1996–2013. Spectroscopic observations started three years prior to the photometric eclipse and are still ongoing. A total of 474 high‐resolution échelle spectra are analyzed and made available in this paper. We identify 368 absorption lines of which 161 lines show the characteristic sharp disk lines during eclipse. Another 207 spectral lines appeared nearly unaffected by the eclipse. From spectrum synthesis, we obtained the supergiant atmospheric parameters T_eff = 7395 ± 70 K, log g ≈ 1, and [Fe/H] = +0.02 ± 0.2 with ξ_t = 9 km s^–1, ζ_RT = 13 km s^–1, and v sin i = 28 ± 3 km s^–1. The residual average line broadening expressed in km s^–1 varies with a period of 62.6 ± 0.7 d, in particular at egress and after the eclipse. Two‐dimensional line‐profile periodograms show several periods, the strongest with ≈110 d evident in optically thin lines as well as in the Balmer lines. Center‐of‐intensity weighted radial velocities of individual spectral lines also show the 110‐d period but, again, additional shorter and longer periods are evident and are different in the Balmer lines. The two main spectroscopic Hα periods, ≈ 116 d from the line core and ≈ 150 d from the center‐of‐intensity radial velocities, appear at 102 d and 139 d in the photometry. The Hβ and Johnson V I photometry on the other hand shows two well‐defined and phase‐coherent periods of 77 d and 132 d. We conclude that Hα is contaminated by changes in the circumstellar environment while the Hβ and V I photometry stems predominantly from the non radial pulsations of the F0 supergiant. We isolate the disk‐rotation profile from 61 absorption lines and found that low disk eccentricity generally relates to low disk rotational velocity (but not always) while high disk eccentricity always relates to high velocity. There is also the general trend that the disk‐absorption in spectral lines with higher excitation potential comes from disk regions with higher eccentricity and thus also with higher rotational velocity. The dependency on transition probability is more complex and shows a bi‐modal trend. The outskirts of the disk is distributed asymmetrically around the disk and appears to have been built up mostly in a tail along the orbit behind the secondary. Our data show that this tail continues to eclipse the F0 Iab primary star even two years after the end of the photometric eclipse. High‐resolution spectra were also taken of the other, bona‐fide, visual‐binary components of ε Aur (ADS 3605BCDE). Only the C‐component, a K3‐4‐giant, appears at the same distance than ε Aur but its radial velocity is in disagreement with a bound orbit. The other components are a nearby (≈ 7 pc) cool DA white dwarf, a G8 dwarf, and a B9 supergiant, and not related to ε Aur. The cool white dwarf shows strong DIB lines that suggest the existence of a debris disk around this star. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

中国淡水和近海鱼类的生态对策研究

通过渐近体长（Ｌ∞），渐近体重（Ｗ∞）、生长系数（Ｋ）、初次性成熟年龄（Ｔｍ）、最大年龄（Ｔｍａｘ）、瞬时自然死亡率（Ｍ）和种群繁殖力（ＰＦ）等七个生态学参数的比较，研究１９种淡水鱼类和１５种近海鱼类的生态对策。根据ｒ—选择和ｋ—选择的典型特征以及各参数间相互关系的显著性，３种鲟鱼类属ｋ—选择；牙鲆等５种近海鱼类偏向ｋ—选择；青鱼、勒氏笛鲷等９种鱼类偏向ｒ—选择；鲤、黄鲫等１７种鱼类为ｒ—选择。对ｒ－ｋ选择的资源特征及其对捕捞的反应做了分析，只有合理控制捕捞强度和起捕年龄，才能保护资源，获得较好的经济效益。