特征含水率对轻量土基本性质的影响规律

为了研究最优含水率、流动上、下限含水率对轻量土性能的影响,通过密度、无侧限抗压强度试验研究了混合土的工程性质。结果表明：采用流动性指标 控制混合土的流动性基本可行。混合土处于流动性上、下限含水率时,无侧限应力-应变关系曲线几乎重合,流动性上、下限含水率范围内土壤性质较为接近。无侧限抗压强度随含水率增加而衰减,但流动上、下限含水率对应强度差别不大。不管含水率高低,强度随龄期增长,都可以采用双曲线模型进行预测,并且总结了7 d、90 d强度与28 d强度之间的经验关系。当含水率为最优含水率时,混合土基本不收缩;在流动性上、下限含水率范围内,线收缩率范围为1.53%～4.71%,体积收缩率范围为4.53%～13.46%,收缩性受含水率、水泥剂量等因素影响。理想密度模型可以近似预测混合土的湿密度,高含水率时预测值有一定误差,误差范围为3.834%～8.231%。     

Weathering of granite in Antarctica: I. Light penetration into rock and implications for rock weathering and endolithic communities

Where rocks are composed of translucent minerals, light penetrates the rock and, in so doing, impacts on the thermal conditions. Where minerals are not translucent all the heat transformation must be at the rock surface, and steep thermal gradients can occur. Where light does penetrate, a component of the incoming radiation is transformed to heat at differing depths within the rock, thereby decreasing the thermal gradient. Equally, light transmissive minerals facilitate endolithic communities, which can also play a role in rock weathering. The attribute of light transmission within rock and the impact this has on the resulting thermal conditions has not been considered within rock weathering studies. An attempt was made to monitor the amount of light penetrating the outer 2 mm of coarse granite under Antarctic summer conditions and to evaluate the thermal impact of this. It was found that the amount of light penetration at this site exceeded modeled or postulated values from biological studies and that it could significantly impact the thermal conditions within the outer shell of the rock. Although the resulting data highlighted a number of flaws in the experimental procedure, sufficient information was generated to provide the first assessment of the range of thermal responses due to light transmissive minerals in rock. Copyright © 2007 John Wiley & Sons, Ltd.     

津滨轻轨地磁干扰范围的实验研究

在塘沽地震台与津滨轻轨之间及向北延长线建立野外磁测剖面,对轻轨运营期间的磁场干扰变化进行了实测研究,并对实测结果进行了曲线拟合,得出满足规划中的地磁观测网的环境要求——在以津滨轻轨铁路为骚扰源的影响范围,地磁观测网的地磁固定观测台距轻轨铁路的距离应大于24km。     

“照亮”地下

本文介绍利用地震角度偏移法实现照亮地下的理论构想,并做了大量的研究工作,说明地震波角度偏移法在地下空间探测中的巨大作用和应用前景.研究中利用仿生学眼睛的功能,阐述了照亮地下的理论和方法技术,特别研究了眼睛的形觉、光觉、色觉、立体觉与地下空间探测的对比关系.最后结合研究的实测结果说明照亮地下理论的可实现性及效果.     

基于夜间灯光数据和空间回归模型的城市常住人口格网化方法研究

精确掌握常住人口的数量和分布特征有助于明确社会发展情况、提高人口管理能力。目前人口数据主要以行政区为单元统计,难以表现城市内部的人口分布特征。然而,在城市中,受道路、公共服务设施、城市亮化灯光的影响,利用夜间灯光数据对人口回归,精度降低。如何提高城市常住人口回归结果的精度,值得深入研究。上海是中国的国家中心城市之一,在快速城镇化进程中上海面临巨大人口压力。因此,本文以上海市为研究区,以NPP-VIIRS (National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite)夜间灯光数据、乡镇级常住人口统计数据为基础,提取商业和居住区的灯光数据来缓解交通、城市亮化区的影响,提高灯光累计值与常住人口数的相关性（相关系数从0.7032提高至0.8026）。然后,本文用空间回归模型对上海市2013年常住人口进行回归,相对误差为10.57%,并对回归结果进行分乡（镇、街道）修正。实验结果表明,使用空间回归模型对常住人口回归可以取得较高的精度,且格网化结果能够弥补传统统计数据空间分辨率低的缺点,更加详细地刻画常住人口的圈层特征与真实分布情况。     

The artificial night sky brightness mapped from DMSP satellite Operational Linescan System measurements

We present a method to map the artificial sky brightness across large territories in astronomical photometric bands with a resolution of approximately 1 km. This is of use in quantifying the situation regarding night sky pollution, recognizing potential astronomical sites and allowing future monitoring of trends. The artificial sky brightness present in the chosen direction at a given position on the surface of the Earth is obtained by the integration of the contributions produced by every surface area in the surroundings . Each contribution is computed via detailed models for the propagation in the atmosphere of the upward light flux emitted by the area. The light flux is measured with top-of-atmosphere radiometric observations made by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System.
We have applied the described method to Europe, obtaining maps of artificial sky brightness in the V and B bands.     

BV 690, a new bright Type II Cepheid

B andV observations of the suspected variable BV 690 = NSV 04298 are reported. The star shows light variations with a period of l^d.2400 and with amplitudes of 0^m.27, 0^m.36 and 0^m.11 inV, B, andB-V respectively. The light curves show steeper rise than decline, and there is evidence for the presence of a bump in the descending branch around the phase of 0.35. From considerations of the period, spectral type, presence of the bump and high tangential velocity we conclude that BV 690 belongs to the BL Herculis class of Typen Cepheids     

Abundances of the very light elements D,He, Li and their cosmological implications

The abundances of very light elements D,³He,⁴He and⁷Li in low-mass stars and their cosmological implications are discussed.     

A Cosmological Explanation to the Pioneer Anomaly

An earlier paper introduced a new cosmological theory based on the proposition that all four metrical coefficients of space and time change with the cosmological expansion. Such a universal scale expansion would preserve the four-dimensional spacetime geometry and therefore by general relativity most physical relationships. In addition, if the scale expansion were exponential with time, all epochs would be equivalent. The theory resolves several outstanding problems with the standard model based on the Big Bang concept and better agrees with observations. Four independent observational programs support the SEC theory, which also provides an explanation to the Pioneer anomaly. A possible resolution to the recently discovered discrepancies between optical observations of the planets and their ephemerides is proposed.