光及补料条件对室内管道光反应器中三角褐指藻生长和岩藻黄素积累的影响

【目的】制备富含岩藻黄素的三角褐指藻(Phaeodactylum tricornutum)生物质。【方法】采用470 L室内管道光生物反应器系统,研究自养培养下光源、调光策略、补料培养操作条件对于细胞生长、生物量浓度和岩藻黄素积累的影响。【结果】在采用LED灯、梯度提升照度及重复补料半连续培养模式下,三角褐指藻细胞密度、生物量和岩藻黄素产率最高分别可达3.16×10⁷mL^-1、1.64 g/L和1.90 mg/(L·d),分别是日光灯为光源条件下的2.77倍、3.09倍和2.38倍(P<0.01)。【结论】在管道光生物反应器中获得的自养培养条件,可强化三角褐指藻生物量和岩藻黄素积累,为三角褐指藻积累岩藻黄素的室内可控规模化技术开发提供指导。     

近20年东莞市城市扩张的时空特征分析

深入分析建设用地演变过程,掌握城市扩张不同阶段的时空特征,对科学推进国土空间规划编制实施具有重要意义.基于多时相卫星遥感影像来解译东莞市建设用地,使用重心空间轨迹模型及空间扩张象限分析法,实现对东莞市近20年来城市扩张的时空特征分析.结果表明:2000—2020年,东莞市建设用地面积增加显著,城市扩张明显,部分区域的建...     

Effect of Penetration Rates on the Piezocone Penetration Test in the Yellow River Delta Silt

Partial drainage often occurs during piezocone penetration testing on Yellow River Delta silt because of its intermediate physical and mechanical properties between those of sand and clay.Yet,there is no accurate understanding for the range of penetra-tion rates to trigger the partial drainage of silt soils.In order to fully investigate cone penetration rate effects under partial drainage condi-tions,indoor 1 g penetration model tests and numerical simulations of cavity expansion at variable penetration rates were carried out on the Yellow River Delta silt.The boundary effect of the model tests and the variation of key parameters at the different cavity ex-pansion rates were analyzed.The 1 g penetration model test results and numerical simulations results consistently indicated that the penetration rate to trigger the partially drainage of typical silt varied at least three orders of magnitude.The numerical simulations also provide the reference values for the penetration resistance corresponding to zero dilation and zero viscosity at any given normalized penetration rate for silt in Yellow River Delta.These geotechnical properties can be used for the design of offshore platforms in Yel-low River Delta,and the understanding of cone penetration rate effects under the partially drained conditions would provide some technical support for geohazard evaluation of offshore platforms.     

基于最小二乘配置法的优化GM（1,1）预测模型及其应用

针对灰色GM(1,1)预测模型预测结果精度低、模型缺乏稳定性的问题,基于最小二乘配置理论的GM（1,1)预测优化模型,首先通过使得生成序列新预测值的误差在最小二乘意义下最小,选取GM(1,1)模型的最优初值,利用指数函数法构造新的背景值;然后将优化的GM(1,1)模型和最小二乘配置理论有机结合,进一步对优化的GM(1,1)模型进行改进,构建优化的灰色最小二乘配置预测模型;最后通过对建筑物的沉降数据进行定量分析与预报,与其他模型进行对比分析。     

最优非负变权组合模型在卫星钟差预报中的应用

针对单一卫星钟差预报模型自身存在的缺陷,提出基于二次多项式、灰色GM（1,1）和ARIMA等三种单一模型的最优非负变权组合预报模型。通过与各单一模型和经典权组合模型进行对比分析表明,该模型预报残差RMS值最小,精度更高,能够根据各模型预报效果赋予不同的权值,在一定程度上综合了多种单一模型的优点,可降低预报风险,提高模型预报的可靠性。     

基于GIS分析的泰安市地质灾害风险评价

泰安市地处鲁中山区,山地丘陵广泛分布,崩塌、滑坡、泥石流和岩溶塌陷等地质灾害较为发育。本次研究依托新一轮1∶5万地质灾害风险普查,基于ArcGIS平台空间分析功能对高精度DEM、构造、工程地质和水文地质、降雨及植被等数据分析和提取,利用信息量法和层次分析法分别对崩滑泥石流和岩溶塌陷易发性评价,以降雨作为危险性评价因子,综合考虑人口和经济因素选择用地类型作为易损性条件进行风险区划,最终划分为地质灾害风险高、中、低3个等级,为今后有效开展自然灾害综合防治、衔接国土空间规划和保障经济社会可持续发展提供基础依据。     

二次灌浆在电解槽沉降基础加固复位中的应用

广西某电解铝车间电解槽沉降基础在采用直孔帷幕灌浆加固的基础上,利用斜孔在有限空间进行二次灌浆加固复位,通过合理控制灌浆压力和灌浆量或间歇灌浆等措施,实行测量跟踪观测控制每次灌浆的抬升量,成功地将电解槽沉降基础抬升复位。     

Influence of Indian Ocean Dipole on Tropical Cyclone Activity over Western North Pacific in Boreal Autumn

In this study, we investigated the influence of the Indian Ocean Dipole(IOD) on the interannual variability of tropical cyclone(TC) activity over the western North Pacific(WNP) during autumn(September–November) from 1961–2015. We found the number of TCs making landfall in China to be significantly negatively correlated with the IOD index, which can be attributed to shifts in the location of TC formation together with the abnormal steering flow at 500 hPa. During negative IOD autumns, TC genesis regions move obviously westward due to the westward retreat of the WNP monsoon trough. The TC activity is remarkably enhanced near South China coastal areas, which is due to a contiguous 500-hPa subtropical ridge. In contrast, during positive IOD autumns, TC genesis positions obviously shift eastward and more TCs tend to exhibit recurvature around 130?E or a westward path south of 15?N led by an equatorward movement of the 500-hPa subtropical ridge with a break near 125?E. In our examination of large-scale circula-tion, we found a pair of equator-symmetric anticyclones in the lower troposphere resulting from variations in the large-scale Walker circulation induced by the anomalous sea surface temperature(SST) associated with a positive IOD. The resulting Philippines anti-cyclonic anomalies are closely related to the variability of the monsoon trough over the WNP region. Furthermore, the variations in the steering flow can be explained by the suppressed(enhanced) convective activities around the Philippines and the weakened(strengthened) local meridional circulation over East Asia in positive(negative) IOD years.     

论秦岭造山带的成矿作用

对秦岭造山带区域成矿背景、矿床的时空分布、典型矿床矿田赋存部位、区域成矿元素地球化学背景、多重岩片控矿理论,构造成矿体系、成矿物质来源、矿床成因类型、矿床区域成矿模式进行了讨论,在对大量资料研究的基础上提出了新认识。最后指出秦巴地区进一步寻找大型矿床的地区。     

一种改进的车头SURF特征提取和匹配

通过对加速鲁棒性算法特征关键点提取和匹配的研究,提出一种改进的车头加速鲁棒性特征点提取方法,该方法在车头图像像素梯度变化较大的范围内提取关键点,然后采用最近邻比例算法进行特征点匹配。实验结果表明,提出的改进方法不仅能够筛选出鲁棒性较强的关键点,同时提高了特征的提取速度和匹配效率,在总时间上比尺度不变特征变换算法提高了3~6倍;比加速鲁棒性算法提高了近1/4。