The curve of ion exchange ratio(%)-pH of the interaction between suspended particles with Cd(II) in the Yellow River

The curve of ion exchange ratio(%)-pH of the interactionbetween suspended particles with Cd(II) in the Yellow River wasstudied. The effects of lysine on this curve have been alsoinvestigated. The results showed that (1) Cadmium in Cd(OH)+ formin the suspended particles exchanges with the cations.The exchangeratio of Cd2+ is nearly at its greatest value in the range of pH(8.0-8.5) in natural aquatic system; (2) Ion exchange ratiodecreases as the concentration of Cd2+ raises from 8.9×10-6 mol/L to 2x8.9 x 10-6mol/L; (3) At the lysine concentration of 6.8x10-6 mol/L, it can promote the ion exchange ratio; (4) Adsorption of thesuspended particles to cadmium is weaker in seawater and Jin ShaRiver than in the Yellow River.     

武汉城市圈土地利用变化系统仿真模拟与驱动力分析

土地利用变化是全球环境变化与可持续研究的重要内容,驱动力研究是土地利用变化研究中的核心问题。现有土地利用变化驱动力研究多针对单一的城市区域展开,无法解释城市群地区,城市一体化战略指导下城市交互作用对土地利用变化的影响。运用系统动力学(SD)方法,综合考虑经济、人口、城市化、政策等主要人文因素,并将城市交互作用因素引入SD,以武汉城市圈为例,构建土地利用变化系统SD模型,运用1997~2006年的历史数据进行检验,并对武汉城市圈2010~2020年不同情景下的土地利用变化进行模拟。结果表明,建立的SD模型是有效的,两种情景下土地利用变化表现出差异性,说明城市交互作用是除经济、人口城市化等社会经济因素外,土地利用变化的又一重要影响因素。     

Conservation Strategies for Species Affected by Apparent Competition

Apparent competition is an indirect interaction between 2 or more prey species through a shared predator, and it is increasingly recognized as a mechanism of the decline and extinction of many species. Through case studies, we evaluated the effectiveness of 4 management strategies for species affected by apparent competition: predator control, reduction in the abundances of alternate prey, simultaneous control of predators and alternate prey, and no active management of predators or alternate prey. Solely reducing predator abundances rapidly increased abundances of alternate and rare prey, but observed increases are likely short‐lived due to fast increases in predator abundance following the cessation of control efforts. Substantial reductions of an abundant alternate prey resulted in increased predation on endangered huemul (Hippocamelus bisulcus) deer in Chilean Patagonia, which highlights potential risks associated with solely reducing alternate prey species. Simultaneous removal of predators and alternate prey increased survival of island foxes (Urocyon littoralis) in California (U.S.A.) above a threshold required for population recovery. In the absence of active management, populations of rare woodland caribou (Rangifer tarandus caribou) continued to decline in British Columbia, Canada. On the basis of the cases we examined, we suggest the simultaneous control of predators and alternate prey is the management strategy most likely to increase abundances and probabilities of persistence of rare prey over the long term. Knowing the mechanisms driving changes in species’ abundances before implementing any management intervention is critical. We suggest scientists can best contribute to the conservation of species affected by apparent competition by clearly communicating the biological and demographic forces at play to policy makers responsible for the implementation of proposed management actions. Estrategias de Conservación para Especies Afectadas por Competencia Aparente     

土-地下结构的非线性动力相互作用——理论及应用

基于土-结构动力相互作用理论，阐述了土-地下结构非线性动力相互作用的基本原理及其建模方法。根据这一方法，对1995年日本阪神地震中震害最为严重的大开地铁车站进行了成灾机理有限元数值模拟分析。分析结果表明：在地震动作用下，车站结构顶板与侧墙的交叉部位，和中柱的顶底端首先发生弯曲破坏而形成塑性铰，使得顶板上覆土的大部分重量传递到由中柱来承担；在由顶板破坏后传来的上覆土重力和地震动在中柱中引起的压应力的共同作用下，中柱发生压曲和弯曲的双重破坏，导致中柱倒塌，进而导致车站顶板塌陷；同时还表明，水平向地震作用仍是造成大开地铁站结构破坏的主要因素。     

Biospheric influence on carbon dioxide measurements in Italy

The study concerning carbon dioxide measurements taken during the 1997, 1998 and 1999 summer campaigns at two different altitude stations and biospheric conditions are presented. The higher station (Mt. Cimone, 2165 m a.s.l.) is characterised by 360° free horizon and is located on a rocky mountain while the lower (Ninfa lake, 1550 m a.s.l.) is located inside the red spruce and beech forest. The different behaviour of CO₂ at the two mountain stations has been registered. It shows the strong effect of nighttime soil emission and vegetation respiration on CO₂ mixing ratio increases and of diurnal vegetative activity on CO₂ concentration decreases at the lower measurement site. The baseline character of the higher measurement site has been confirmed by comparison of CO₂ diurnal amplitudes recorded at the two stations.     

气泡雾化细水雾灭火有效性实验研究

气泡雾化技术是一种双流体的细水雾发生方法。作者根据气泡雾化的雾化机理自行设计了一种气泡雾化喷嘴,并通过先进的实验诊断手段和模拟实验,对该喷嘴产生的细水雾的雾场特性进行了测量,研究了其熄灭煤油火和酒精火的有效性,为发展新型的细水雾发生方法积累了必要的实验数据。     

基于深度学习的不安全因素识别和交互分析

为解决行为安全领域不安全因素识别和交互分析困难的问题,构建基于深度学习的不安全因素识别和交互分析模型。首先,从“人-机-环”3方面构建不安全因素识别层,分别采用不同的深度学习结构识别作业人员行为属性、工作环境场景和操作设备工作状态的不安全因素;然后,通过因素交互层,采用关联和回归多值算法完成对不安全因素的交互分析;最后,通过输出显示层实现分析结果的表征。以某煤矿综采、掘进、通风3个生产活动类别的视频音频数据为例,通过Matlab操作平台选取最优深度学习结构,进行模型交互分析。结果表明,用该模型能实现对采煤面空顶作业、喷浆机故障仍然加料、主要通风机异常响动未停机检查等不安全因素的识别和交互分析,完成不安全行为的描述以及风险分级、行为痕迹的分类。     

金堆城超大型钼矿床水-岩δD-δ~(18)O同位素交换体系理论模型及成矿流体来源

基于水-岩δD-δ18O同位素交换体系理论模型的建立和计算，对金堆城超大型斑岩钼矿四个不同成矿期中成矿流体的演化和来源进行了研究，发现在成矿前期和早期，成矿流体为岩浆水与围岩在较低水／岩比值（0．1W／R＞0．001）和中、高温（t=250～500℃）条件下反应后的残余流体，而主成矿期和成矿晚期的成矿流作为大气降水在相对较高水／岩比值（0．5＞W／R0．1）和中、低温（t＝150～310℃）条件下与围岩反应后的残留流体。大气降水在金堆城钼矿成矿过程中起了重要作用。在主成矿期水／岩比值达到最高。     

中国交通运输碳排放强度时空交互特征及跃迁机制

采取多种空间分析的方法,对2002～2020年交通运输业碳排放强度的时空交互特征进行剖析,通过得到的时空跃迁类型与面板分位数模型进行嵌套来探究其跃迁机制,最后根据不同的跃迁机制引入地理探测器模型来考察影响交通运输业碳排放强度的不同因素之间的交互作用效应.结果表明：(1)中国30个省区的交通运输业碳排放强度整体呈波动下降态势,在空间上的聚集水平也相对稳定.(2)ESTDA的时空交互特征表明,西北地区和周边邻接空间单位的关系不稳定,变化和波动较大.而东部沿海城市等经济发达地区已经形成了成熟的交通运输网络,因此局部空间格局也相对稳定,但仍有部分地区存在时空竞争性.(3)交通运输业碳排放强度时空跃迁可分为4类驱动或制约模式（人口-经济-城镇化制约模式;人口-经济-城镇化-设施制约模式;技术-消费-产业驱动模式和技术-产业-规制驱动模式）.大部分省份受低分位制约和高分位驱动两种模式的影响,仅有少部分省份受高分位制约和低分位驱动的作用影响,且绝大多数属于西北或西南地区.(4)根据得出的交通运输业碳排放强度跃迁机制进一步引入地理探测器模型,注重多因子的协调发展,加强区域间协同治理.     

The role of remote sensing in hydrological modelling of the Okavango Delta, Botswana

A coupled surface water-groundwater model of the Okavango Delta has been built based on the United States Geological Survey software MODFLOW 2000 including the SFR2 package for stream-flow routing. It will provide a new tool for evaluating water management and climate change scenarios. The delta's size and limited accessibility make direct, on the ground data acquisition difficult. Remote sensing methods are the most promising source of acquiring spatially distributed data for both model input parameters and calibration. Topography, aquifer thickness, channel positions, evapotranspiration and precipitation data are all based on remote sensing. Simulated flooding patterns are compared to patterns derived from visible to thermal NOAA-AVHRR data and microwave radar ENVISAT-ASAR data.