Evaluating relationships between soil chemical properties and vegetation cover at different slope aspects in a reclaimed dump

Conducting research about the relationships between soil chemical properties and vegetation coverage at different slope aspects is especially important in reconstructed ecosystems of vulnerable ecological regions. This study was conducted in the first reclaimed dump within the Pingshuo mining area of Shanxi Province, China, to analyze patterns of soil chemical properties (soil organic matter (SOM), soil total nitrogen (STN), soil available phosphorus (SAP) and soil available potassium (SAp) and vegetation coverage (NDVI) and their correlations at different slope aspects. In the reclaimed dump, 26 quadrats were established along four slope aspects (i.e., shady, semi-shady, sunny and semi-sunny slopes). There was no significant difference in SOM or STN among different slope aspects, while SAP differed between shady slopes compared to semi-shady, sunny and semi-sunny slopes; SAP differed significantly between semi-shady and semi-sunny slopes. The NDVI of semi-sunny slopes differed significantly from that of the other three aspects. There was variation in the relationships between NDVI and soil chemical properties, depending on the slope aspects. The logarithm of SOM and NDVI was related linearly on shady and semi-shady slopes, while NDVI was inversely related to the natural logarithm of the logarithm of SOM on sunny and semi-sunny slopes. STN and NDVI had a first-order function relationship on shady and semi-shady slopes, yet a quadratic function relationship on sunny and semi-sunny slopes. The relationships between SAP and NDVI were inverse on all types of slopes. On shady and semi-shady slopes, NDVI had a quadratic relationship with the logarithm of SAp, but it was well fitted by using a cubic function on sunny and semi-sunny slopes. The sensitivity coefficients of soil chemical properties and NDVI were different, and soil chemical properties changed differently depending on changes in NDVI at different slope aspects.     

震(前)兆远场异常与德令哈6.6级地震临震特征分析

简要叙述了2003年4月17日发生在青海德令哈6．6级地震及异常台站概况。采用甘肃省内11个地电台共61个测项(其中电阻率28个测项、自然电位28个测项、大地电场5个测项)及地震活动空间扫描图像(频度场、6值、GL值)进行筛选,从中检索到了15项异常指标。经对数据的处理与临震异常特征分析,结果表明：震(前)兆异常信息的出现为6．6级地震事件的发生提供了临震异常判据;这些异常判据也可为将来地震的预测预报提供一定的参考依据。     

Dynamic responses under the excitation of pulse sequences

This paper studies the dynamic responses of SDOF system under pulse-dominant excitations. The purpose of the study is to prepare for scrutiny of some near-field pulse-dominant ground motions and their potential to cause structural damage. Extending the single pulse dynamics, we consider the effect of pulse sequences. This kind of excitation was particularly obvious in some of previous earthquakes such as Northridge (1994) and Chi-Chi (1995). Based on the duration,peak and rise and decay era of the main pulse as well as its relationship with the predecessor and successor pulses, we propose a classification for the pulse sequences. Consequent studies have been carried out for acceleration, velocity and displacement response spectra of the main pulse with either a predecessor or a successor pulse. The analysis also includes general response behaviors in different fundamental period segments and special aspects of response at certain points (e.g., the corresponding peak points).     

南梁煤矿多煤层开采地下水系统演化规律

煤层开采对所在矿区地下水系统有着重要影响.以往研究单煤层开采对地下水系统的影响较多,而对多煤层的影响研究甚少,特别对于我国西部缺水矿区.以南梁煤矿为例,运用地下水系统演化理论和岩石力学模拟等,对该矿井水文地质结构、矿井涌水变化规律、矿井地下水流场演变、矿井地下水化学成分变化等方面进行了综合分析研究,重构了多煤层开采条件...     

渤、黄海冬季海冰对大气环流及气候变化的响应

受全球气候变暖影响,渤、黄海冬季气候呈明显的变暖趋势。在1951-2010年共60年中,后30年较前30年,气温升高了1.6℃,升幅异常显著。与此相对应,渤、黄海冬季海冰的冰级下降了0.6级。渤、黄海冰情持续偏轻与全球气候变暖趋势相当一致。冬季渤、黄海气温异常是对全球大气环流变化的响应,直接受同期东亚大气环流制约。研究表明,渤海海冰和大气环流的关系是清楚的,这对预测渤、黄海海冰具有重要意义。     

Composition and Useful Properties of Tailings of Marine Manganese Nodules and Crusts

ABSTRACT

Marine manganese nodules and crusts, when processed, yield tailings which may be utilized for environmental and economic benefit. The key to the reasonable and effective utilization of these tailings lies in making a systematic appraisal of their composition and properties. This article gives an introduction to the investigation of manganese tailings properties. The tailings have a high iron and/or manganese content, high surface area, high porosity, and fine grain size. Some tailings have a high rare earth element content which is valuable. They may also have high SO₃, arsenic, and uranium contents which are harmful. Depending on the process used to produce the tailings, there will likely be some differences in chemical composition, mineral assemblages, surface area and adsorption capability, pore diameter and volume, density and pH. In assigning potentially beneficial applications for these tailings, these differences should be taken into account to optimize utilization.     

土壤碳储量计算中不同插值方法对比研究——以吉林省大安市为例

土壤碳储量问题是大气温室效应和全球变化研究的热点问题。本文采用“单位土壤碳量”方法,计算了吉林省大安市表层土壤有机碳总储量和平均土壤有机碳储量,以为全球碳循环研究提供精确的基础数据。分析和比较了反距离加权、全局多项式、局部多项式、径向基函数和普通克里格等不同插值模型对表层单位土壤有机碳储量空间插值结果的影响,结果表明全局多项式插值的均差最小,径向基函数中张力样条法的平均绝对误差最小,普通克里格法的标准差最小。综合分析来看,普通克里格的有理二次方程式模型插值精度最高。      

巴西坎波斯盆地和桑托斯盆地油气分布差异及主控因素

巴西坎波斯盆地和桑托斯盆地均为典型的被动陆缘盆地。随着勘探程度的增加和近年来在桑托斯盆地深水区盐下油气的重大发现,坎波斯盆地和桑托斯盆地之间的构造-沉积演化和油气地质特征的差异性越来越明显。通过对坎波斯盆地和桑托斯盆地区域地质特征和油气成藏条件差异性的比较,总结出两个盆地油气分布特征的截然不同。研究表明,盐窗比较发育的坎波斯盆地中已发现的油气主要富集于盐上浊积砂岩,而连续盐岩发育的桑托斯盆地已发现的油气则主要富集于盐下湖相碳酸盐岩。对于盐下层系,连续分布的盐岩和圣保罗高地的发育控制了盐下层系油气的分布;对于盐上层系,盐相关构造的发育则为油气垂向运移提供了有利通道,从而控制了盐上油气藏的形成与分布。