基于粒子群-高斯过程回归耦合算法的滑坡位移时序分析预测智能模型

高斯过程回归(GPR)学习机有着容易实现、超参数自适应获取及预测输出具有概率意义等优点。通常采用共轭梯度法获取GPR超参数,但其存在优化效果对初值依赖性太强,迭代次数难以确定,易陷入局部最优的缺点。改用粒子群优化 (PSO)算法进行最优超参数搜索,形成粒子群-高斯过程回归耦合算法(PSO-GPR)。将该算法引入三峡永久船闸高边坡、卧龙寺新滑坡、链子崖滑坡3个不同的典型滑坡变形时序分析中,对每个滑坡分别采用稳态核及一种新式神经网络（NN）、平方指数（SE）、有理二次型（RQ）3种单一核函数进行外推预报测试。工程应用表明,基于3种不同单一核函数的粒子群-高斯过程回归算法（PSO-GPR）均能完全适应不同滑坡时序分析,其中以NN核函数外推预测效果最佳,平均相对误差分别为6.37%、7.62%、1.07%,从而改善了在进行不同滑坡变形时序分析时采用单一核函数的核机器外推能力存在较大差异性的问题,提高了单一核函数对不同数据类型的兼容性     

基于不确定型层次分析法的边坡稳定模糊评判方法

针对边坡稳定性影响因素众多复杂,且存在模糊不确定性和层次性的特点,首先引入锚固边坡稳定性分析二级模糊综合评判模型,并基于模糊数学理论建立评价指标隶属度确定方法和模糊运算规则,从而建立出锚固边坡稳定性分析的二级模糊综合评判方法;然后,考虑评价指标重要程度取值的不确定性、专家判断的模糊性以及群组决策的优势,建立基于群组决策的不确定型层次分析（AHP）方法确定权重,进而建立出基于AHP的锚固边坡稳定模糊评判方法,最后通过工程实例分析和计算,表明文中方法的可行性与合理性。     

城市避震疏散能力评价方法研究

综合考虑人口、建筑、绿地、道路、疏散场所和重大危险源等各类影响因素,提出了街区疏散能力综合评价指数CEIEC,用层次分析法(AHP)通过各因素权重,对街区避震疏散能力进行了量化表达,能够给出各研究单元的避震疏散能力的相对水平,从而对城市社区避震疏散能力进行综合评价。本方法有利于揭示城市内避震疏散的薄弱环节,对城市规划等部门的工作,尤其对城市防灾规划的编制具有明显的指导性意义。     

Pretreatment of Olive Oil Mill Wastewater by Two Different Applications of Fenton Oxidation Processes

The removal of chemical oxygen demand (COD) and phenol from olive oil mill wastewaters (OOMW) was investigated experimentally by using conventional Fenton (CFP) and Fenton type processes (FTP) with zero valent iron (ZVI). Different operational parameters such as initial pH, Fe²⁺, Fe⁰, and H₂O₂ concentrations were examined. Kinetic studies in terms of COD and phenol removals for both CFP and FTP were performed. The original pH value (4.6) of OOMW for CFP was found as the optimum pH. The determined optimum conditions are [Fe²⁺] = 1500 mg L^?1, [H₂O₂] = 1750 mg L^?1, and pH = 4.6 for CFP; [Fe⁰] = 2000 mg L^?1, [H₂O₂] = 2000 mg L^?1, and pH = 3 for FTP. 82.4% COD and 62% phenol removals were performed under the optimum conditions by CFP, while 82% COD and 63.4% phenol were removed by FTP. According to the results of kinetic studies, it was observed that COD and phenol were removed by FTP more rapidly, compared to CFP. Consequently, it was determined that both CFP and FTP were effective processes for the pretreatment of OOMW.     

济阳坳陷桩海地区下古生界硅化岩溶储集层空间分布模式

基于岩心描述和镜下观察,分析了研究区下古生界硅化岩溶储集层的岩性特征。通过对沟通潜山 断块和古近纪洼陷的边界断层产状、潜山断块内下古生界产状的分析,认为下古生界碳酸盐岩具备埋藏岩溶作 用条件,提出了古近纪沉积物压释酸性水向潜山断块运移的3种方式,即：翘倾端断面补给畅流运移模式、倾 没端断面补给畅流运移模式和背斜凸起两侧双向渗入补给对流循环模式。利用这 3种模式可以合理解释研究区 下古生界潜山硅化岩溶储集层空间分布的特点和规律。翘倾端断面补给畅流运移模式可以解释潜山断块高部位 硅化岩溶层段储集层的发育情况,倾没端断面补给畅流运移模式和背斜凸起两侧纵向渗入补给对流循环模式, 可以解释潜山断块的低部位硅化岩溶层段储集层的发育情况。该模式还可以合理地解释硅化岩溶储集层在下古 生界赋存层位的 “ 穿层性”特点,同时也能够合理解释潜山断块周缘发育硅化岩溶层段,而潜山断块中心地带 很少出现硅化岩溶层段等现象。     

Challenges to the representation of suspended sediment transfer using a depth‐averaged flux

The sediment saturation recovery process (i.e. the adaptation of suspended sediment concentration [SSC] to local forcing) is the main feature of the non‐equilibrium suspended sediment transport (SST) frequently occurring in fluvial, estuarine and coastal waters. In order to quantitatively describe this phenomenon, a series solution is analytically derived, including the evolution of both vertical SSC profile and near‐bed sediment flux (NBSF), and is verified by net erosion and net deposition experiments, respectively. The results suggest that the sediment saturation recovery process involves vertically varying fluxes that are not represented correctly by depth‐averaging. Consequently, a vertical two‐dimensional (2D) combined scheme is established and applied respectively in to a dredged trench and to a sand wave feature to demonstrate this argument. By analyzing the variations of the calculated depth‐averaged SSC and NBSF we reveal that the equilibrium state presented by the sediment carrying capacity (SCC) form of the NBSF, which is usually applied in depth‐integrated SST models, lags behind the actual dynamic bed equilibrium state. Moreover, the key factor α, the so‐called saturation recovery coefficient within this form, is not only a function of local Rouse number but also is influenced by the local SSC profile. Finally, a three‐dimensional (3D) non‐orthogonal curvilinear body‐fitted SST model is developed and validated in the Yangtze estuary, China, combined with the in situ hourly hydrographic data from August 14–15, 2007 during spring tide in the wet season. Model results confirm that the vertically varying sediment saturation recovery process, the discrepancies between the actual and SCC form of NBSF and non‐constant value of α are significant in actual real geomorphic cases. The quantitative morphological change resulting from variations in environmental conditions may not be correctly represented by uncorrected depth‐integrated SST models if they do not treat the effects of vertical motion on the sediment saturation recovery process. Copyright © 2016 John Wiley & Sons, Ltd.     

High-resolution crustal structure of the Yinchuan basin revealed by deep seismic reflection profiling: implications for deep processes of basin

The Yinchuan basin, located on the western margin of the Ordos block, has the characteristics of an active continental rift. A NW-striking deep seismic reflection profile across the center of Yinchuan basin precisely revealed the fine structure of the crust. The images showed that the crust in the Yinchuan basin was characterized by vertical stratifications along a detachment located at a two-way travel time(TWT) of 8.0 s.The most outstanding feature of this seismic profile was the almost flat Mohorovicˇic′ discontinuity(Moho) and a high-reflection zone in the lower crust. This sub-horizontal Moho conflicts with the general assumption of an uplifted Moho under sedimentary basins and continental rifts, and may indicate the action of different processes at depth during the evolution of sedimentary basins or rifts.We present a possible interpretation of these deep processes and the sub-horizontal Moho. The high-reflection zone, which consists of sheets of high-density, mantlederived materials, may have compensated for crustal thinning in the Yinchuan basin, leading to the formation of a sub-horizontal Moho. These high-density materials may have been emplaced by underplating with mantlesourced magma.     

导线覆冰自动观测实验与覆冰过程分析

在贵州重冰区3个气象站和海拔2500m的梅花山野外观测点开展了3a冬季的导线覆冰自动观测实验,利用观测实验获取的大量连续覆冰过程数据,对导线覆冰重量及其气象条件逐小时演变特征进行了深入分析.结果表明:一次完整的连续导线覆冰过程包括覆冰开始、增长、维持、减弱、消融到结束五个不同的阶段,持续时间较长的覆冰过程中间可能出现间断,而覆冰增长、维持、减弱几个阶段可能重复交替出现.覆冰过程开始一般以气温下降到0℃以下且相对湿度90%以上为标志,当出现浓雾或降水时覆冰出现增长,当既无降水也无雾时覆冰进入维持阶段;整个覆冰过程中温度均低于0℃且维持很高的湿度,中途若温度上升且无雾和降水则覆冰有明显减弱,当气温稳定上升到0℃以上同时湿度下降时覆冰过程结束.覆冰过程的开始和增长一般持续时间较长,而覆冰的消融和结束则十分迅速.在气象站观测到的覆冰以雨雾混合冻结为主,降水对覆冰过程的开始和增长有重要作用,而在梅花山野外观测到的多为雾凇覆冰,降水对覆冰的作用不如地势较低地区显著.     

掺砾黏土拉伸断裂细观特性研究

掺砾黏土在高心墙堆石坝工程中的应用越来越广泛,其拉伸断裂特性对心墙的安全至关重要。将掺砾黏土视作四相复合材料,基于图像处理和随机投放建立了考虑真实砾石形态的细观数值模型,结合物理试验的结果验证了其有效性,并分析了掺砾黏土拉伸断裂的宏细观特性。应力位移曲线的宏观非线性是细观非均质性的体现,砾石的掺入大幅减低了抗拉强度,但提高了峰后抗拉性能;土石界面是微裂缝发展的源头,拉伸断裂是一个微裂缝萌生、扩展以至汇集形成宏观裂缝的过程;拉伸断裂发生在一个区域,即断裂过程区,该区域的形成与砾石的随机分布有关。最后,采用数值试验分析了随机砾石投放和掺砾量对掺砾黏土宏细观力学行为的影响。     

基于Burgers模型考虑损伤的非定常岩石蠕变模型

Burgers模型只能描述岩石蠕变的前两个阶段,为了描述蠕变全过程,考虑蠕变参数的时间效应及损伤带来的影响,采用非定常黏性元件取代Burgers模型中串联的定常黏性元件,使其能描述加速蠕变阶段。根据损伤变量的变化特征,假定了一个函数,经过Lemaitre应变等效原理,代入Kelvin模型可得到能描述蠕变衰减阶段的模型。试验数据拟合结果显示,改进的Burgers模型能很好地描述加速蠕变阶段,模型拟合曲线与试验曲线基本吻合,相关系数高,参数取值也在合理范围内;非定常Burgers模型更适合描述不同应力下的岩石蠕变特征曲线。