层状地基端承桩扭转动力阻抗研究

本文采用Novak薄层法推导粘弹性地基的扭转动力阻抗,并将其用于考虑桩土相互作用的单桩扭转动力阻抗,又通过传递矩阵法将此公式推广到求取层状地基单桩扭转动力阻抗。而且本文以工程中常用的端承桩为例,推导了层状地基中端承桩扭转动力阻抗的简化计算公式。根据此公式,分析了频率、上覆软土层厚度、上覆软土层刚度等因素对单桩扭转动力阻抗的影响,分析结果表明,随着振动频率提高,层状地基中端承单桩的扭转动力阻抗的实部有缓慢下降的趋势,而虚部则增大;随着上覆土层厚度的增加,层状地基中端承单桩的扭转动力阻抗的实部和虚部均减小;随着上覆土层刚度的减小,层状地基中端承单桩的扭转动力阻抗的实部减小,虚部在低频段减小,而在较高频率段则增大。     

折射层析成像法测试隧道围岩松动圈

通过应用折射层析成像法在乌鞘岭特长隧道中的测试,说明该方法对于横向速度变化不均一,过渡带速度渐变的地质情况具有分辨率高、图像直观、易于解释,适合对隧道围岩松动圈的测试.     

新疆及中亚地区斜坡灾害研究现状与展望

新疆和中亚五国山河相连,都是"一带一路"建设的重要支点,但也是滑坡、泥石流等斜坡灾害的高发区,且两地的地质灾害发育有着明显的共性.本文对新疆和中亚地区的斜坡灾害研究现状进行综述,分析了两地斜坡灾害形成机理、发育规律,即中高山地分布集中,受降雨和冰雪融水影响很大,黄土滑坡发育.新疆的斜坡灾害研究多围绕公路、水利等工程设施...     

BoxCox multi-output linear regression for 10.7 cm solar radio flux prediction

We consider the problem of predicting the mid-term daily 10.7 cm solar radio flux(F10.7),a widely-used solar activity index.A novel approach is proposed for this task,in which BoxCox transformation with a proper parameter is first applied to make the data satisfy the property of homoscedasticity that is a basic assumption of regression models,and then a multi-output linear regression model is used to predict future F10.7 values.The experiment shows that the BoxCox transformation significantly improves the predictive performance and our new approach works substantially better than the prediction from the US Airforce and other alternative methods like Auto-regressive Model,Multi-layer Perceptron,and Support Vector Regression.     

山门银矿黄铁矿的找矿矿物学研究及其地质意义

本文对山门银矿矿体及围岩中黄铁矿进行了成因和找矿矿物学特征的研究,并在矿床研究方面和找矿方面得到应用。     

Simultaneous monochromatic and spectral observations of two large loop prominence groups

Using the solar tower telescope of Nanjing University, we observed the two large loop prominence groups of 1982 Dec. 20 and 1983 Feb. 9. Hα photographs and spectra around the Hα and H and K lines were obtained simultaneously. From these data, we derived a line of sight velocity distribution, which agrees perfectly with the distribution for matter falling freely without viscosity. From the widths of the Hα and the K lines, we found the loop material to have a uniform kinetic temperature and a turbulent velocity that increases with height. From the central intensities of the lines we derived a density of n(H) ? 1.3 ? 2.6 × 10¹⁰cm^?3. A possible mechanism of the formation of loop prominence groups and their relation with flares are discussed.     

A statistical study on relationship of El Niño events to the hydrography along 137 °E in winter

Principal component analysis (PCA) as used by meteorologists and oceanographers is a powerful tool for analysis of the spatial and temporal variability of physical fields. This study was aimed at applying “quasi-local PCA for singular factor” to make the cumulative percentage for the first principal component as great as possible, so that a multi-dimensional problem can be reduced to a single-dimensional one, and then stepwise regression analysis can be used to parameterize the relationship between El Niño events and the hydrographic factor anomalies along 137 °E in winter. The results show that the salinity anomalies on 30 m level, the sigmat on 250 m level, and the temperature on 300 m level at 8 °N are most closely related with El Niño events because of thermocline movement caused by enhanced upwelling in this area during El Niño years.     

生物传感器综述

本文介绍当前国际、国内生物传感器的发展及应用概况,并对生物传感器的市场前景和生物传感器技术的未来发展作了简单地论述。     

山东西南地区早第三纪介形类

本文研究了山东西南地区早第三纪介形类化石。记述了12个属35个种,其中7个新种。可划分为四个介形类化石组合:(1)早、中古新世Cypridea—Candona hubeiensis组合;(2)早始新世Cypris henanensis—Eucypris wutuensis组合;(3)中、晚始新世Cyprinotus altilis—Austrocypris levis组合;(4)渐新世Xiyingia组合。     

彰武盆地地质发展及构造聚煤控煤研究

从侏罗纪到新生代彰武盆地构造发展可分为８个阶段。早新华夏系属成盆期构造体系，控制了以八道壕煤系为代表的晚侏罗世九佛堂组的聚煤作用；北西构造系同沉积构造控制了彰武盆地早白垩世小型断陷盆地的聚煤作用；中新华夏系等成盆后构造通过后期形变控制了盆地内现今煤层的分布。