Electro-osmotic permeability model based on ions migration     

Zhou  Jian  Gan  Qiyun  Tao  Yanli 《Acta Geotechnica》2022,17(6):2379-2393

Acta Geotechnica - Electro-osmotic permeability is a very important parameter in soil drainage and electrochemical remediation. The present widely used equation for calculating the electro-osmotic...  相似文献   

Climate change impact to Mackenzie river Basin projected by a regional climate model     

Kuo  Chun-Chao  Gan  Thian Yew  Wang  Jingwen 《Climate Dynamics》2020,54(7):3561-3581

Climate Dynamics - A regional climate model, WRF (Weather Research and Forecasting model), was set-up and fine-tuned to simulate the possible impacts of climate change to the Mackenzie River Basin...  相似文献   

Climate change in the 21st century simulated by HadGEM2-AO under representative concentration pathways   总被引：2，自引：0，他引：2  

Hee-Jeong Baek  Johan Lee  Hyo-Shin Lee  Yu-Kyung Hyun  ChunHo Cho  Won-Tae Kwon  Charline Marzin  Sun-Yeong Gan  Min-Ji Kim  Da-Hee Choi  Jonghwa Lee  Jaeho Lee  Kyung-On Boo  Hyun-Suk Kang  Young-Hwa Byun 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(5):603-618

We present climate responses of Representative Concentration Pathways (RCPs) using the coupled climate model HadGEM2-AO for the Coupled Model Intercomparison Project phase 5 (CMIP5). The RCPs are selected as standard scenarios for the IPCC Fifth Assessment Report and these scenarios include time paths for emissions and concentrations of greenhouse gas and aerosols and land-use/land cover. The global average warming and precipitation increases for the last 20 years of the 21st century relative to the period 1986-2005 are +1.1°C/+2.1% for RCP2.6, +2.4°C/+4.0% for RCP4.5, +2.5°C/+3.3% for RCP6.0 and +4.1°C/+4.6% for RCP8.5, respectively. The climate response on RCP 2.6 scenario meets the UN Copenhagen Accord to limit global warming within two degrees at the end of 21st century, the mitigation effect is about 3°C between RCP2.6 and RCP8.5. The projected precipitation changes over the 21st century are expected to increase in tropical regions and at high latitudes, and decrease in subtropical regions associated with projected poleward expansions of the Hadley cell. Total soil moisture change is projected to decrease in northern hemisphere high latitudes and increase in central Africa and Asia whereas near-surface soil moisture tends to decrease in most areas according to the warming and evaporation increase. The trend and magnitude of future climate extremes are also projected to increase in proportion to radiative forcing of RCPs. For RCP 8.5, at the end of the summer season the Arctic is projected to be free of sea ice.  相似文献   

白光连续谱与模型大气     

甘为群  方成 《中国天文和天体物理学报》1988,(1)

本文依据白光耀斑连续发射谱的一般观测事实,通过对一系列模型大气的非局部热动平衡计算,从半经验角度探讨了白光连续发射与模型大气的关系。结果表明:光球深层的温度增加或者过渡区存在平台结构均可解释观测到的白光辐射增强。对如何从理论上来解释这些大气结构本文也提出了一些看法。  相似文献   

Selection of environmental conditions for nearshore structure design     

DONGSheng GANBuhong HAOXiaoli 《中国海洋大学学报(英文版)》2004,3(1):111-114

1　Introduction　InChina ,coastalcitiesaremostlyregionaleconomicdevelopmentcenters.Becauseoftheirspecialgeogra phiclocations ,typhoonsandassociatedstormsurgescauseheavylossesoflivesandproperties.In 1 992 Qing daowasfloodedduetothecoincidenceoftheastrono m…  相似文献   

大型射电望远镜背架精密安装技术     

李干  李宗春  高德军  邓勇 《测绘工程》2012,21(4):65-69

对65 m射电望远镜的背架安装做了尝试,取得较满意的结果.针对天线背架尺寸大、质量重、焊接变形大、几何精度要求高等特性,采用全站仪工业测量系统实现背架的快速、无接触、高精度定位测量,点位测量精度优于1 mm;采用独特的施工工艺和焊接技术,最大限度控制焊接变形,最终点位偏差优于1.5 cm.提出基于设计坐标系建立安装测量...  相似文献   

2005年6月桂南沿海降水异常偏多成因分析   总被引：1，自引：0，他引：1  

甘静  邢维东  李一忠  李永平 《气象研究与应用》2009,30(2):31-33,110

2005年6月桂南沿海降水异常偏多,通过分析气候背景,环流形势特征,并将其与历史多雨年和少雨年做对比分析得出:2005年6月桂南沿海降水偏多是在多雨的大气候变化周期中发生的;西太平洋副热带高压强度偏强、西伸脊点位置偏西、脊线位置偏南是2005年6月桂南沿海降水异常偏多的主要原因.  相似文献   

提高暗筒式日照纸感光质量的技巧   总被引：1，自引：0，他引：1  

甘灿明 《气象研究与应用》2008,29(4):68-69

暗筒式日照计日照纸所用药品品质好坏、配药比例和涂药方法是否得当,是造成日照纸感光质量好坏的主要原因。本文针对部分测报员在日照纸配药、涂药和浸漂操作处理过程中存在的问题提出相关改进措施和建议。  相似文献   

Magnetic connection and current distribution in black hole accretion discs     

Cheng-Xuan Zhao  Ding-Xiong Wang  Zhao-Ming Gan 《Monthly notices of the Royal Astronomical Society》2009,398(4):1886-1890

We discuss one of the possible origins of large-scale magnetic fields based on a continuous distribution of toroidal electric current flowing in the inner region of the disc around a Kerr black hole (BH) in the framework of general relativity. It turns out that four types of configuration of the magnetic connection (MC) are generated, i.e. MC of the BH with the remote astrophysical load (MCHL), MC of the BH with the disc (MCHD), MC of the plunging region with the disc (MCPD) and MC of the inner and outer disc regions (MCDD). It turns out that the Blandford–Znajek process can be regarded as one type of MC, i.e. MCHL. In addition, we propose a scenario for fitting the quasi-periodic oscillations in BH binaries based on MCDD associated with the magnetic reconnection.  相似文献   

东北地区农业结构转型时期土地利用变化的成因与效应     

刘彦随  甘红  Jay GAO  DENG Xusheng 《地理学报(英文版)》2004,14(4):488-494

During the last decade of the 20th century, extensive conversion in agricultural land use took place in Northeast China. The goal of this study is to ascertain its spatial distribution and regional differentiation, determine its causes, and analyze its environmental impact, Especially we attempt to elucidate how institutional constraints have facilitated the change at a time of agrarian restructuring when newly emerging free market was hybridized with the former planned economy. Information on six categories of land use was mapped from interpretation of Landsat TM images recorded in 1990,1995 and 2000. Most of land use changes took place during the first half of the decade, coinciding with abrupt and chaotic changes in government directives. Farmland was changed mainly to woodland,water body and built-up areas while woodland and grassland were converted chiefly to farmland.Spatially, the change from farmland to woodland was restricted to the west of the study area. The change from grassland to farmland took place in the grazing and farming interlocked west. These chaotic and occasionally conflicting changes were largely caused by lack of stability and consistency in agricultural land use policies promulgated. They have exerted adverse impacts on the local environment, including land degradation, increased flooding, and modified climate regime.  相似文献