Residual and Fully Softened Strength Evaluation of Soils using Artificial Neural Networks

A backpropagation artificial neural network (ANN) model is developed to predict the secant friction angle of residual and fully softened soils, using data reported by Stark et al. (J Geotech Geoenviron Eng ASCE 131:575–588, 2005). In the ANN model, index properties such as liquid limit, plastic limit, activity, clay fraction and effective normal stress are used as input variables while secant residual friction angle is used as output variable. The model is verified using data that were not used for model training and testing. The results also indicate that the secant residual friction angle of cohesive soils can be predicted quite accurately using liquid limit, clay fraction and effective normal stress as input variables with R ² = 0.93. The sensitivity analysis results indicate that plastic limit and activity have no appreciable effect on ANN predicted secant friction angles. The secant friction angle predictions of the ANN model were also compared with those of Stark’s et al. (2005) curves and the empirical formulas suggested for the same data sets by Wright (Evaluation of soil shear strengths for slope and retaining wall stability with emphasis on high plasticity clays, 2005). The comparison shows that the ANN model predictions are very close to those suggested by the Stark et al. (2005) curves but much better than the prediction of Wright’s (2005) empirical equations. The results also show that ANN is an alternative powerful tool to predict the secant friction angle of soils.     

海气耦合随机动力模式的Fokker-Planck方程

将描写海温和气温交互作用的随机动力模式化为一个Fokker-Planck方程(FPE),然后用矩阵连分法进行求解,并对二氧化碳增温效应进行了计算。当CO₂从330ppm增加到660ppm时增温1.2℃,模式中存在的优势周期为3～4年,当CO₂倍增时各周期有延长的趋势。     

扩散系数和源函数的同时反演

本文讨论了线性扩散方程：Ｕｔ（ｘ，ｔ）＝ａ（ｔ）Ｕｘｘ（ｘ，ｔ）＋ｆ（ｔ）ｇ（ｘ）在区域０≤ｘ≤１，０≤ｔ＜Ｔ上确定未知国数组｛ｕ（ｘ，ｔ），ａ（ｔ），ｆ（ｔ）｝的反问题，证明了反问题解的存在性和唯一性。     

基于数据挖掘及网络药理学探讨射血分数保留性心力衰竭的用药规律及作用机制

目的：探讨中医药治疗射血分数保留性心力衰竭（HFPEF）的用药规律及作用机制。方法：收集中国知网2003年1月31日至2022年12月31日期间收录的中医药治疗HFPEF的相关文献,使用中医传承辅助平台V2.50进行用药规律分析,将核心药物进行网络药理学分析。结果：数据挖掘共纳入112个有效方剂,涉及127味中药,使用频次由高到低依次为黄芪、丹参、人参等,药性以温、寒、平为主,药味多甘、苦、辛,多归心、脾、肺经,共得到17个频次≥23次的药物组合,包括9味中药,7个新方组合;核心药物包括丹参、黄芪、葶苈子、人参、桂枝等。网络药理学分析得出核心药物共108个活性成分,可能作用靶点91个,与HFPEF共有52个交集靶点,主要包括肿瘤坏死因子（TNF）、白细胞介素-6(IL-6)、细胞肿瘤抗原p53（TP53）、白细胞介素-1β（IL-1β）、表皮生长因子受体（EGFR）等。核心药物主要作用于胞外、调控细胞增殖及凋亡、通过炎症反应及抗动脉粥样硬化以延缓HFPEF进程。结论：中医药治疗HFPEF的总治则为益气养阴、化瘀行水;网络药理学分析表明核心药物通过多成分、多靶点、多通路共同治疗HFPEF。     

Effects of rainy season on mobilization of contaminants from tsunami deposits left in a coastal zone of Thailand by the 26 December 2004 tsunami

Study on contamination of tsunami sediments deposited on 26 December 2004 conducted shortly after the tsunami in coastal zone of Thailand revealed elevated contents of salts in water-soluble and some heavy metals and arsenic in bioavailable fractions (Szczuciński et al. in Env Geol 49:321–331, 2005). Few months later rainy season started and effected in total rainfall of over 3,300 mm. This paper presents results of survey repeated 1 year after the tsunami. To assess the effects of rainy season on mobilization of previously determined potential contaminants, the same locations were sampled again and analysed with the same methods. The tsunami deposit layer was well preserved but in many locations the sediments were coarser than just after tsunami due to washing out of finer fractions. The water-soluble salts contents were strongly reduced after the rainy season. However, the concentrations of acid leachable heavy metals and metalloids were still elevated in comparison to reference sample from an area not impacted by tsunami. It is possible that the metals and metalloids are successively moved to more bioavailable fraction from forms which were more resistant to mobilization.     

城市建设对地面沉降影响的原因分析

在地下水开采引起的地面沉降得到初步控制之后,沿海地区城市工程建设引起的地面沉降就显得日益突出。人们发现上海城区建筑规模及其增长速度直接导致工程性地面沉降同步增长。建筑密度越大,建筑容积率越高,地面沉降越显著。分析了一定间距的荷载共同作用的宏观效应,提出了等效影响荷载的概念,进而揭示了城市工程建筑与大面积等效影响荷载的关系。据此对文献中观测得到的上海城市建设与地面沉降的关系进行了较好的解释。有关分析对软土地基上城市建设规划具有一定参考意义。     

风成沙地地形1/10定律的研究与敦煌鸣沙山成因的猜想

 以风成沙地地形的共性—— 同一性作为切入点,探索了风成沙地地形高长比和深长比的变化范围以及它与气流流速结构的关系。通过调查发现,尽管沙积物尺度有大有小,形态繁简差异悬殊,但绝大多数风积地形,尤其在主风向单一地区,它们的高长比Kg存在着明显的变化范围,其界阈Kg≤1/10;而风蚀地形的深长比Ks也有相同的属性,只是Ks≥ -1/10。如果用K代表沙区正负两种风成地形的共同属性,则K=Kg=-Ks,即K≤|±1/10|。研究认为,风成沙地地表形态之所以具有这种共同特征,主要在于气流与沙质地表的相互作用中,地形的高长比同气流垂直分速与其水平纵向分速之比这两个比例之间相互制衡相互顺应的结果。野外试验证明高长比K≤1/10的沙质地表地形阻力最小、最适宜风沙流通过,因而形态比较稳定,且具有自修复功能,并在治沙工程中已经得到验证和广泛应用。因此称这种比例关系为1/10定律。以高长比1/10为界,对于比值远大于1/10的特殊的沙积物地形,我们以敦煌鸣沙山为例,根据外界山体对气流场的影响以及由此而产生的风速结构的变化,提出对鸣沙山成因的猜想。鸣沙山的形成从反面、从更广阔和更深的层次上证明了1/10定律的存在。     

长偏移距瞬变电磁测深甚晚期响应及视电阻率的数值计算

文中讨论了提高长偏移距瞬变电磁测深甚晚期响应计算精度及相应的全区视电阻率的计算方法。在频率域 ,利用直接数值积分结合连分式展开提高低频段响应的计算精度 ,从而提高时间域甚晚期响应的计算精度。同时 ,利用连分式渐进展开 ,将均匀半空间电阻率表示为该模型长偏移距瞬变电磁测深响应的反函数 ,利用迭代方法求出适合全时间段的全区视电阻率。数值结果表明 ,文中的方法可有效地提高长偏移距瞬变电磁测深 (甚 )晚期数据的模拟与解释精度     

Climate change and sustainable development: towards dialogue

The consequences of climate change and sustainable development remaining as separate discourses are explored, both in general and in the Canadian context. One of these consequences is the difference in emission and economic development scenarios generated by the two groups. A second is that strategies to reduce greenhouse gas emissions are designed and assessed in a narrow technical context, divorced from the economic and social forces that underlie them. We identify the need for climate change and sustainable development to be represented in a more explicit manner in each other's research agendas, and for integrated assessment of climate change to incorporate alternative methodologies that complement global scale integrated assessment models. These methodologies should include greater involvement of stakeholders as partners with researchers in a shared learning experience.     

乌努格吐山斑岩铜钼矿床土壤测量方法技术试验研究

文章论述了在乌努格吐山斑岩铜钼矿床上进行的土壤测量方法采样深度、样品粒级以及方法技术的适用性和有效性试验研究。采用的工作方法为土壤剖面测量法。确定了合适的采样深度和样品粒级，在已知矿上方获得了清晰、明显的土壤测量异常。为采用土壤测量方法进行航空物探（电／磁）异常查证工作提供了可靠的依据。