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Coseismic Coulomb stress changes induced by a 2020-2021 M_(W)>7.0 Alaska earthquake sequence in and around the Shumagin gap and its influence on the Alaska-Aleutian subduction interface
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作者 Lei Yang Jianjun Wang Caijun Xu 《Geodesy and Geodynamics》 EI CSCD 2024年第1期1-12,共12页
Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6... Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench. 展开更多
关键词 The 2020-2021 Alaska earthquake SEQUENCE Coseismic Coulomb stress change Mainshock-aftershock triggering The Alaska-Aleutian subduction interface The Shumagin gap
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Assessing forest cover changes and fragmentation in the Himalayan temperate region: implications for forest conservation and management
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作者 Kaleem Mehmood Shoaib Ahmad Anees +6 位作者 Akhtar Rehman Aqil Tariq Qijing Liu Sultan Muhammad Fazli Rabbi Shao’an Pan Wesam Atef Hatamleh 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第4期128-141,共14页
This study comprehensively assessed long-term vegetation changes and forest fragmentation dynamics in the Himalayan temperate region of Pakistan from 1989 to 2019.Four satellite images,including Landsat-5 TM and Lands... This study comprehensively assessed long-term vegetation changes and forest fragmentation dynamics in the Himalayan temperate region of Pakistan from 1989 to 2019.Four satellite images,including Landsat-5 TM and Landsat-8 Operational Land Imager(OLI),were chosen for subsequent assessments in October 1989,2001,2011 and 2019.The classified maps of 1989,2001,2011 and 2019 were created using the maximum likelihood classifier.Post-classification comparison showed an overall accuracy of 82.5%and a Kappa coefficient of 0.79 for the 2019 map.Results revealed a drastic decrease in closed-canopy and open-canopy forests by 117.4 and 271.6 km^(2),respectively,and an increase in agriculture/farm cultivation by 1512.8 km^(2).The two-way ANOVA test showed statistically significant differences in the area of various cover classes.Forest fragmentation was evaluated using the Landscape Fragmentation Tool(LFT v2.0)between 1989 and 2019.The large forest core(>2.00 km^(2))decreased from 149.4 to 296.7 km^(2),and a similar pattern was observed in medium forest core(1.00-2.00 km^(2))forests.On the contrary,the small core(<1.00 km^(2))forest increased from 124.8 to 145.3 km^(2) in 2019.The perforation area increased by 296.9 km^(2),and the edge effect decreased from 458.9 to 431.7 km^(2).The frequency of patches also increased by 119.1 km^(2).The closed and open canopy classes showed a decreasing trend with an annual rate of 0.58%and 1.35%,respectively.The broad implications of these findings can be seen in the studied region as well as other global ecological areas.They serve as an imperative baseline for afforestation and reforestation operations,highlighting the urgent need for efficient management,conservation,and restoration efforts.Based on these findings,sustainable land-use policies may be put into place that support local livelihoods,protect ecosystem services,and conserve biodiversity. 展开更多
关键词 Natural catastrophes Landsat change detection Forest fragmentation Landscape fragmentation tool(LFT) AFFORESTATION REFORESTATION
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Impact Assessment of Land-Use Changes on Nutrient Load in Song Cau Watershed Using Soil and Water Assessment Tool (SWAT) Model
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作者 D. B. Phan C.C. Wtu S. C. Hsieh 《Journal of Agricultural Science and Technology(B)》 2011年第2期223-231,共9页
The objective of this paper is to implement "Soil and Water Assessment Tool (SWAT)" model to assess the possible impact of land-use changes on nutrient yields from Song Cau watershed located in Northern Viet Nam. ... The objective of this paper is to implement "Soil and Water Assessment Tool (SWAT)" model to assess the possible impact of land-use changes on nutrient yields from Song Cau watershed located in Northern Viet Nam. Organic nitrogen (N) as well as phosphorus (P) output due to nonpoint source erosion was estimated through SWAT. Parameters governing the mechanics of streamflow discharge, sediment yield, nitrogen, and phosphorus output in SWAT were calibrated in a distributed fashion. A five-year period of record for nutrient was used for model calibration, while a four-year period was used for model validation. Comparing measured versus simulated average monthly total N, and P loads for the calibration and validation periods; respectively, we found that SWAT model performed reasonably well for Song Cau watershed. Simulation results showed that monthly Nash-Sutcliffe coefficient of Efficiency (NSE) ranged from 0.65 to 0.83, observation's standard deviation ratio (RSR) and percent bias (PBIAS) ranged from 0.41 to 0.58 and -36.12 to 2.78, respectively. Additionally, SWAT simulation results also showed that land-use changes caused significant percentage of changes in sediment yield, total N, and P loads within Song Cau watershed. 展开更多
关键词 Soil and Water Assessment tool (SWAT) land-use changes nutrient load.
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BH-N型不提钻换钻头钻进技术研究与应用
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作者 钱锋 罗显粱 +1 位作者 张统得 胡立 《四川地质学报》 2024年第2期312-316,共5页
地质钻探施工时起下钻更换钻头,需要占用大量时间,且存在一定的安全隐患,大大影响钻探效率,采用不提钻换钻头钻进技术可以很好的解决这个问题。以N规格绳索取心钻杆为使用平台,沿用BH-75钻具基本结构,并针对其存在问题,研制BH-N规格的... 地质钻探施工时起下钻更换钻头,需要占用大量时间,且存在一定的安全隐患,大大影响钻探效率,采用不提钻换钻头钻进技术可以很好的解决这个问题。以N规格绳索取心钻杆为使用平台,沿用BH-75钻具基本结构,并针对其存在问题,研制BH-N规格的不提钻换钻头钻具,同时根据N规格钻具的具体结构完善BH-75钻具,提高了钻具的承压能力和钻具收敛(投送)稳定性,增设了自动除沙机构等。在山东乳山金青顶金矿ZK43-1钻孔进行了现场应用,在孔深2081.20~2211.40米实现了不提钻换钻头,钻具岩心采取率达到100%,岩心质量好,最大限度减少起下钻次数,有效预防起下钻引发孔内事故。不提钻换钻头钻进技术为深孔地质勘探中钻进强研磨性、打滑、软硬频繁交替等地层,提供了及时优化钻头使用方案,降低能源消耗,有效的保护孔壁安全和减少劳动强度。 展开更多
关键词 地质钻探 不提钻换钻头 BH系列钻具 现场应用
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Numerical simulation of freezing effect and tool change of shield machine with a frozen cutterhead 被引量:6
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作者 DAI Wei XIA Yi-min +1 位作者 XU Hai-liang YANG Mei 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第4期1262-1272,共11页
A shield machine with freezing function is proposed in order to realize tool change operation at atmospheric pressure. Furthermore, the transformation project of freezing cutterhead and tool change maintenance method ... A shield machine with freezing function is proposed in order to realize tool change operation at atmospheric pressure. Furthermore, the transformation project of freezing cutterhead and tool change maintenance method are put forward. Taking the shield construction of Huanxi Power Tunnel as an example, a numerical analysis of the freezing cutter head of the project was carried out. The results show that when the brine temperature is-25 °C, after 30 d of freezing, the thickness of the frozen wall can reach 0.67 m and the average temperature drops to-9.9 °C. When the brine temperature is-30 °C, after 50 d of freezing, the thickness of the frozen wall can reach 1.01 m and the average temperature drops to-12.4 °C. If the thickness of the frozen wall is 0.5 m and the average temperature is-10 °C, as the design index of the frozen wall, the brine temperature should be lower than-28 °C to meet the excavation requirements in 30 d. Analyzing the frozen wall stress under 0.5 m thickness and-10 °C average temperature condition, the tensile safety factor and compressive safety factor are both greater than 2 at the most dangerous position, which can meet the tool change requirements for shield construction. 展开更多
关键词 shield machine CONSTRUCTION frozen cutterhead tool change maintenance finite element simulation
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Assessing the Impacts of Land Use and Land Cover Changes on Hydrology of the Mbarali River Sub-Catchment. The Case of Upper Great Ruaha Sub-Basin, Tanzania 被引量:1
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作者 Edmund Mutayoba Japhet J. Kashaigili +2 位作者 Frederick C. Kahimba Winfred Mbungu Nyemo A. Chilagane 《Engineering(科研)》 2018年第9期616-635,共20页
Intensification of agricultural land use and population growth from 1990-2017 has caused changes in land cover and land use of the Mbarali River sub-catchment which is located in the Upper Great Ruaha Sub basin, Tanza... Intensification of agricultural land use and population growth from 1990-2017 has caused changes in land cover and land use of the Mbarali River sub-catchment which is located in the Upper Great Ruaha Sub basin, Tanzania. This has affected the magnitude of the surface runoff, total water yield and the groundwater flow. This study assesses the impacts of the land cover and land use changes on the stream flows and hydrological water balance components (surface runoff, water yield, percolation and actual evapotranspiration). The land use and land cover (LULC) maps for three window period snapshots, 1990, 2006 and 2017 were created from Landsat TM and OLI_TIRS with the help of QGIS version 2.6. Supervised classification was used to generate LULC maps using the Maximum Likelihood Algorithm and Kappa statistics for assessment of accuracy. SWAT was set up and run to simulate stream flows and hydrological water balance components. The assessment of the impacts of land use and land cover changes on stream flows and hydrological water balance component was performed by comparing hydrological parameters simulated by SWAT using land use scenarios of 2006 and 2017 against the baseline land use scenario of 1990. Accuracy of LULC classification was good with Kappa statistics ranging between 0.9 and 0.99. There was a drastic increase in areal coverage of cultivated land, for periods 1990-2006 (5.84%) and 2006-2017 (12.05%) compared to other LULC. During 2006 and 2017 surface runoff increased by 4% and 9% respectively;however, water yield increased by only 0.5% compared to 1990 baseline period. This was attributed to increased proportion of cultivated land in the sub-catchment which has a high curve number (59.60) that indicates a higher runoff response and low infiltration rate. 展开更多
关键词 Geographic Information System (GIS) Mbarali River Sub-Catchment Land Use and Cover change Soil and WATER Assessment tool (SWAT) WATER Balance Stream Flow
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Oxygen Isotope Records of Core 8KL of the South China Sea and Sea - level Change 被引量:1
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作者 Qian JianxingThe Second Institute of Oceanography, SO A, Hangzhuu, Zhejiang Liu Linqun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1995年第2期209-219,共11页
Based on a comparison between the oxygen isotope records of benthic and plank tonic foraminifers from core 8KL of the South China Sea and sea-level change records derived from the Huon Peninsula, New Guinea, it is fou... Based on a comparison between the oxygen isotope records of benthic and plank tonic foraminifers from core 8KL of the South China Sea and sea-level change records derived from the Huon Peninsula, New Guinea, it is found that both records are very similar from 72 K a B.P. to the present, especially for the benthic oxygen isotope record. The linear regression shows that δ18O changes (0.9995‰ for benthic foraminifers and 1.022‰ for planktonic foraminifers) are equal to 100 m in sea-level fluctuation. After making temperature correction in the δ18O record of benthic foraminifers from 72 to 120 Ka B.P., the curve of sea-level oscillation of the South China Sea since 186 Ka B.P. has been reconstructed. The lowermost sea - level that occurred in the last glacial maximum and oxygen isotope stage 6 is approximately - 130 m. 展开更多
关键词 oxygen isotopic records of foraminifera sea - level change linear regression
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Evaluation of Thermal Effect of PCM Wallboards by Coupling Simplified Phase Change Model with Design Tool
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作者 Alain Guiavarch Denis Bruneau Bruno Peuportier 《Journal of Building Construction and Planning Research》 2014年第1期12-29,共18页
A simplified PCM wallboard model is coupled to an existing design-oriented model of multi-zone buildings. Using a reference model and a basic simulation configuration, the accuracy of the resulting PCM wallboard-build... A simplified PCM wallboard model is coupled to an existing design-oriented model of multi-zone buildings. Using a reference model and a basic simulation configuration, the accuracy of the resulting PCM wallboard-building thermal design tool is evaluated. A new performance indicator, called PCM utilization factor, is then proposed in order to estimate the thermal efficiency of using PCM wallboards in buildings. Using this PCM Utilization factor and a degrees-hours indicator, the ability of the PCM wallboard-building thermal design tool to evaluate the effect of PCM wallboards on heating loads and summer thermal comfort in the early design phase of a project is examined in two real case studies: a family house project and an existing office building. The user-friendliness of this design tool, and the short calculation times it leads to when performing a year-long simulation using a standard office computer, make it a well-adapted tool for sensibility studies or multi-criterion optimization for buildings that contain PCM wallboards. 展开更多
关键词 PHASE change Material WALLBOARD Thermal Model Dynamic Simulation SUMMER COMFORT Design toolS
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钱都去哪儿了:中央专项转移支付支持领域变迁的量化研究--基于1994-2021年政策文本的文献计量分析
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作者 周美多 肖钰琪 王馨 《南京审计大学学报》 CSSCI 北大核心 2024年第6期91-100,共10页
以1994—2021年中央颁布的专项转移支付相关的资金管理政策文本为基础进行文献计量分析发现,专项转移支付的支持领域呈阶段性扩张,资金分配管理过程中财政部和发改委的中心角色日渐明确。随着中国式现代化进程的推进,专项转移支付应当... 以1994—2021年中央颁布的专项转移支付相关的资金管理政策文本为基础进行文献计量分析发现,专项转移支付的支持领域呈阶段性扩张,资金分配管理过程中财政部和发改委的中心角色日渐明确。随着中国式现代化进程的推进,专项转移支付应当进一步完善其进入与退出机制,通过支持领域的灵活变化,积极高效地服务于现代化的国家治理目标。 展开更多
关键词 专项转移支付 资金支持领域 政策变迁 文献计量分析 财政工具 国家治理
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Effect of Land Use Change on Runoff and Sediment Yield in Da River Basin of Hoa Binh province, Northwest Vietnam 被引量:6
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作者 NGO Thanh Son NGUYEN Duy Binh Rajendra Prasad SHRESTHA 《Journal of Mountain Science》 SCIE CSCD 2015年第4期1051-1064,共14页
The objective of this study was to assess runoff discharge and sediment yield from Da River Basin in the Northwest of Vietnam using Soil and Water Assessment Tools(SWAT) model.The SWAT model was calibrated and validat... The objective of this study was to assess runoff discharge and sediment yield from Da River Basin in the Northwest of Vietnam using Soil and Water Assessment Tools(SWAT) model.The SWAT model was calibrated and validated using the observed monthly stream flows and sediment yield at selected gauging stations.The results indicated that SWAT generally performs well in simulating runoff and sediment yield according to Nash-Sutcliffe efficiency(NSE), Observation's standard deviation ratio(RSR), and percent bias(PBIAS) values.For runoff, the values of NSE, RSR, and PBIAS were 0.98,0.02, and 3.69 during calibration period and 0.99,0.01, and 1.56 during validation period, respectively.For sediment yield, the efficiency was lower than the value of NSE, RSR, and PBIAS during calibration period were 0.81, 0.19, and-4.14 and 0.84, 0.16, and-2.56 during validation period, respectively.The results of the study indicated that the vegetation status has a significant impact on runoff and sediment yield.Changes in land use type between 1995 and2005 from forest to field crop and urban strongly contributed to increasing the average annual runoff from 182.5 to 342.7 mm and sediment yield from101.3 to 148.1 ton-1 ha.Between 2005 and 2010, adecrease of both runoff(from 342.7 to 167.6 mm) and sediment yield(from 148.1 to 74.0 ton-1 ha) was due to the expansion of forested area and application of soil conservation practices.The results of this study are important for developing soil and water conservation programs, extending future SWAT modelling studies and disseminating these results to other regions in Vietnam. 展开更多
关键词 Land use change HYDROLOGY Soil erosion Soil and Water Assessment tools(SWAT) Da River Basin
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Hydrological Impacts of Climate Change on Streamflow of Dongliao River Watershed in Jilin Province,China 被引量:3
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作者 ZHANG Lei LU Wenxi +3 位作者 YANG Qingchun AN Yongkai LI Di GONG Lei 《Chinese Geographical Science》 SCIE CSCD 2012年第5期522-530,共9页
The impacts of future climate change on streamflow of the Dongliao River Watershed located in Jilin Prov-ince, China have been evaluated quantitatively by using a general circulation model (HadCM3) coupled with the ... The impacts of future climate change on streamflow of the Dongliao River Watershed located in Jilin Prov-ince, China have been evaluated quantitatively by using a general circulation model (HadCM3) coupled with the Soil and Water Assessment Tool (SWAT) hydrological model. The model was calibrated and validated against the historical monitored data from 2005 to 2009. The streamflow was estimated by downscaling HadCM3 outputs to the daily mean temperature and precipitation series, derived for three 30-year time slices, 2020s, 2050s and 2080s. Results suggest that daily mean temperature increases with a changing rate of 0.435~C per decade, and precipitation decreases with a changing rate of 0.761 mm per decade. Compared with other seasons, the precipitation in summer shows significant downward trend, while a significant upward trend in autumn. The annual streamflow demonstrates a general down-ward trend with a decreasing rate of 0.405 m^3/s per decade. The streamflow shows significant downward and upward trends in summer and in autumn, respectively. The decreasing rate of streamflow in summer reaches 1.97 m^3/s per decade, which contributes primarily to the decrease of streamflow. The results of this work would be of great benifit to the design of economic and social development planning in the study area. 展开更多
关键词 streamflow climate change Soil and Water Assessment tool (SWAT) statistical downscaling DongliaoRiver
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Characteristics and control mechanisms of coalbed permeability change in various gas production stages 被引量:5
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作者 Da-Zhen Tang Chun-Miao Deng +4 位作者 Yan-Jun Meng Zhi-Ping Li Hao Xu Shu Tao Song Li 《Petroleum Science》 SCIE CAS CSCD 2015年第4期684-691,共8页
According to dimensionless analysis of the coalbed methane (CBM) production data of Fanzhuang block in southern Qinshui basin, the dimensionless gas production rate is calculated to quantitatively divide the CBM wel... According to dimensionless analysis of the coalbed methane (CBM) production data of Fanzhuang block in southern Qinshui basin, the dimensionless gas production rate is calculated to quantitatively divide the CBM well production process into four stages, i.e., drai- nage stage, unstable gas production stage, stable gas pro- duction stage, and gas production decline stage. By the material balance method, the coal reservoir permeability change in different stages is quantitatively characterized. The characteristics and control mechanisms of change in coalbed permeability (CICP) during different production stages are concluded on five aspects, i.e., permeability trend variation, controlling mechanism, system energy, phase state compositions, and production performance. The study reveals that CICP is characterized by first decline, then recovery, and finally by increase and is controlled directly by effective stress and matrix shrinkage effects. Further, the duration and intensity of the matrix shrinkage effect are inherently controlled by adsorption and desorp- tion features. 展开更多
关键词 Production stage - Coalbed methane PERMEABILITY Dynamic change - Control mechanism
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基于RBF-SWAT的气候变化下汉江上游流域径流预测及特征分析 被引量:3
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作者 王立 翟文亮 +2 位作者 张爵宏 曹慧群 唐见 《长江科学院院报》 CSCD 北大核心 2023年第4期31-36,共6页
为研究气候变化下汉江上游流域的径流响应,基于RBF神经网络降尺度模型,利用2020—2099年CanESM2模式下RCP8.5(高温室气体排放)和RCP2.6(低温室气体排放)两种气候情景,生成未来气温与降水数据;耦合SWAT水文模型,模拟分析流域2020—2099... 为研究气候变化下汉江上游流域的径流响应,基于RBF神经网络降尺度模型,利用2020—2099年CanESM2模式下RCP8.5(高温室气体排放)和RCP2.6(低温室气体排放)两种气候情景,生成未来气温与降水数据;耦合SWAT水文模型,模拟分析流域2020—2099年径流变化对不同气候情景的响应特征。结果表明,汉江上游年径流量均呈不明显增加趋势,RCP8.5情景下的径流增加趋势比RCP2.6情景稍小,径流量年内分配与基准期大致相同,两种情景下汛期径流量稍有减小,可能是降尺度模型生成的降水量极大值偏小导致的。研究结果可为汉江流域水文气象综合管理提供一定的科学依据。 展开更多
关键词 气候变化 径流变化 SWAT RBF 降尺度模型 汉江上游流域
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Preface: The Chang'e-3 lander and rover mission to the Moon 被引量:1
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作者 Wing-Huen Ip Jun Yan +1 位作者 Chun-Lai Li Zi-Yuan Ouyang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1511-1513,共3页
The Chang'e-3 (CE-3) lander and rover mission to the Moon was an in- termediate step in China's lunar exploration program, which will be followed by a sample return mission. The lander was equipped with a number o... The Chang'e-3 (CE-3) lander and rover mission to the Moon was an in- termediate step in China's lunar exploration program, which will be followed by a sample return mission. The lander was equipped with a number of remote-sensing instruments including a pair of cameras (Landing Camera and Terrain Camera) for recording the landing process and surveying terrain, an extreme ultraviolet camera for monitoring activities in the Earth's plasmasphere, and a first-ever Moon-based ultravi- olet telescope for astronomical observations. The Yutu rover successfully carried out close-up observations with the Panoramic Camera, mineralogical investigations with the VIS-NIR Imaging Spectrometer, study of elemental abundances with the Active Particle-induced X-ray Spectrometer, and pioneering measurements of the lunar sub- surface with Lunar Penetrating Radar. This special issue provides a collection of key information on the instrumental designs, calibration methods and data processing pro- cedures used by these experiments with a perspective of facilitating further analyses of scientific data from CE-3 in preparation for future missions. 展开更多
关键词 chang'e-3 - Moon lander - rover - radar - lunar telescope
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2009-2021年我国电子健康档案政策文本量化分析 被引量:1
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作者 袁珊珊 刘智勇 《中国医院》 北大核心 2023年第7期50-54,共5页
目的:观察2009-2021年电子健康档案政策在政策工具、政策变迁和政策力度3个维度上的分布特征,总结归纳目前政策存在的不足之处,并提出相关的改善意见。方法:采用内容分析法和定量分析方法,构建“政策工具、政策目标、政策力度”的三维... 目的:观察2009-2021年电子健康档案政策在政策工具、政策变迁和政策力度3个维度上的分布特征,总结归纳目前政策存在的不足之处,并提出相关的改善意见。方法:采用内容分析法和定量分析方法,构建“政策工具、政策目标、政策力度”的三维分析框架对电子健康档案政策进行多维分析。结果:纳入56份中央和省级政策文本,共生成575条政策文本编码,供给型、环境型、需求型政策工具依次占57.22%、33.74%、9.04%;在政策变迁的3个阶段频数依次为241、120、214;电子健康档案政策平均力度为2.29。结论:电子健康档案政策工具存在使用不均衡、内部结构失衡和政策可操作性尚需加强等问题,需全面运用和优化政策工具结构和提升政策工具的可操作性。 展开更多
关键词 电子健康档案 政策工具 政策文本分析 政策变迁 政策力度
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Impacts of Land Cover Changes on Runoff and Sediment in the Cedar Creek Watershed,St.Joseph River,Indiana,United States
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作者 JIANG Xiaobo Chi-hua Huang Fushui Ruan 《Journal of Mountain Science》 SCIE CSCD 2008年第2期113-121,共9页
The relation between runoff and sediment and land cover is investigated in the Cedar Creek Watershed (CCW), located in Northeastern Indiana, United States. The major land cover types in this watershed are cultivated... The relation between runoff and sediment and land cover is investigated in the Cedar Creek Watershed (CCW), located in Northeastern Indiana, United States. The major land cover types in this watershed are cultivated land, woodland and pasture /Conservation Reserve Program (CRP), which account for approximate 90 % of the total area in the region. Moreover, land use was changed tremendously from aooo to 9004, even without regarding the effect of the crop rotation system (corn & soybean). At least 49 % of land cover types were changed into other types in this period. The land cover types, ranking by changing area from high to low series, are rye, soybean, corn, woodland and pasture/CRP. The CCW is divided into 21 subwatersheds, and soil and water loss in each sub-watershed is computed by using Soil and Water Assessment Tool (SWAT). The results indicate that the variations in runoff and sediment have positive relation to the area of crops (especially corn and soybean); sediment is more sensitive to land cover changes than runoff; more heavy rainfall does not always mean more runoff because the combination of different land cover types always modify runoff coefficient; and rye, soybean and corn are the key land cover types, which affected the variation in runoff and sediment in the CCW. 展开更多
关键词 Cedar Creek watershed Soil and Water Assessment tool land cover change RUNOFF SEDIMENT
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Use of SWAT to Model Impact of Climate Change on Sediment Yield and Agricultural Productivity in Western Oregon, USA
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作者 G. W. Mueller-Warrant C. L. Phillips K. M. Trippe 《Open Journal of Modern Hydrology》 2019年第2期54-88,共35页
Climate change predictions for the Pacific Northwest region of the United States of America include increasing temperatures, intensification of winter precipitation, and a shift from mixed snow/rain to rain-dominant e... Climate change predictions for the Pacific Northwest region of the United States of America include increasing temperatures, intensification of winter precipitation, and a shift from mixed snow/rain to rain-dominant events, all of which may increase the risk of soil erosion and threaten agricultural and ecological productivity. Here we used the agricultural/environmental model SWAT with climate predictions from the Coupled Model Intercomparison Project 5 (CMIP5) “high CO2 emissions” scenario (RCP8.5) to study the impact of altered temperature and precipitation patterns on soil erosion and crop productivity in the Willamette River Basin of western Oregon. An ensemble of 10 climate models representing the full range in temperature and precipitation predictions of CIMP5 produced substantial increases in sediment yield, with differences between yearly averages for the final (2090-2099) and first (2010-2019) decades ranging from 3.9 to 15.2 MT&middot;ha-1 among models. Sediment yield in the worst case model (CanESM2) corresponded to loss of 1.5 - 2.7 mm&middot;soil&middot;y-1, equivalent to potentially stripping productive topsoil from the landscape in under two centuries. Most climate models predicted only small increases in precipitation (an average of 5.8% by the end of the 21st century) combined with large increases in temperature (an average of 0.05&deg;C&middot;y-1). We found a strong correlation between predicted temperature increases and sediment yield, with a regression model combining both temperature and precipitation effects describing 79% of the total variation in annual sediment yield. A critical component of response to increased temperature was reduced snowfall during high precipitation events in the wintertime. SWAT characterized years with less than basin-wide averages of 20 mm of precipitation falling as snow as likely to experience severe sediment loss for multiple crops/land uses. Mid-elevation sub-basins that are projected to shift from rain-snow transition to rain-dominant appear particularly vulnerable to sediment loss. Analyses of predicted crop yields indicated declining productivity for many commonly grown grass seed and cereal crops, along with increasing productivity for certain other crops. Adaptation by agriculture and forestry to warmer, more erosive conditions may include changes in selection of crop kinds and in production management practices. 展开更多
关键词 CLIMATE change SEDIMENT Yield Soil Water Assessment tool SWAT Coupled MODEL Intercomparison Project 5 CIMP5 Nash-Sutcliffe Efficiency NSE
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Financial Support Mechanisms and Financing Instruments for Climate Change Adaptation
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作者 Shih-Fang Lo Chou-Yen Wu Chun-Hsu Lin 《Journal of Environmental Protection》 2016年第2期242-252,共11页
Extreme weather has been having an increase in frequency and severity because of global warming. Heavy financial burden on governments has been increasing as reconstruction of natural disaster and prevention of public... Extreme weather has been having an increase in frequency and severity because of global warming. Heavy financial burden on governments has been increasing as reconstruction of natural disaster and prevention of public construction spending. Unlike the climate mitigation activities, the main purpose of climate adaptation is to establish climate risk management system. We discuss several types of financing instruments and collect several cases in both developed and developing countries internationally. We find that budget reallocation or government bonds are regularly used for losses from natural disaster in developing countries while both government bonds and insurance penetration are used to against catastrophe risks in the developed countries. Finally, we also find that insurance-related instruments are feasible and have been applied in some middle-income countries with assistance from the World Bank. 展开更多
关键词 Climate change Adaptation Insurance tools Capital Market REVIEW Case Study
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Promoting Health Behavior Change in Canada: A Quality Improvement Project Integrating Prevention and Wellness in Frontline Care
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作者 Kiran Rabheru David Conn +5 位作者 Daria Parsons Ariane S. Massie Julie Mitchell Michael Vallis Claire Checkland Keri-Leigh Cassidy 《Open Journal of Psychiatry》 2021年第3期125-137,共13页
<strong>Background:</strong> The critical need for Health Behaviour Change (HBC) for preventative care has been highlighted by the COVID-19 pandemic. This quality improvement project assessed the effective... <strong>Background:</strong> The critical need for Health Behaviour Change (HBC) for preventative care has been highlighted by the COVID-19 pandemic. This quality improvement project assessed the effectiveness and acceptability of Fountain of Health HBC tools as a minimal intervention for primary and secondary prevention among Canadian clinicians and their patients. <strong>Methods:</strong> Clinicians received HBC education and tools (paper tools and app-based) to assist their patients in setting a S.M.A.R.T (Specific, Measurable, Action-oriented, Realistic, Time-limited) goal at baseline and assessed four weeks later. Primary outcome measures were: 1) patient self-report of success at goal attainment;2) patient self-reported evaluation of change in well-being and health attitudes;and 3) clinician experience and engagement. <strong>Results:</strong> A total of 2184 clinicians received HBC education. Of these, 759 clinicians registered to participate in the project. 961 patients set S.M.A.R.T. HBC goals using either the paper tools (PT) or the app format. Patient data revealed nearly all patients (89% of PT users and 90% of app users) at least partially succeeded in attaining their goal at a four-week follow-up. Most patients (85% of PT and 80% of app users) also reported improvement in their well-being. A significant difference in health beliefs and attitudes was found in both PT (p < 0.001) and app users (p = 0.003). <strong>Conclusions:</strong> HBC is challenging. Educating and providing clinicians with HBC tools as a minimal intervention was found to be a successful health prevention strategy to improve patient well-being and health attitudes, and achieve S.M.A.R.T. goals. Results show HBC tools, education, and support for clinicians are both acceptable and effective for HBC in frontline care. These findings are relevant and timely given greater reliance on virtual care in the wake of the COVID-19 pandemic. Further research with rigorous methodology is needed to implement programs to achieve sustainable HBC to promote health on a large scale. 展开更多
关键词 Behaviour Sciences Mental Health Medical Education Primary and Secondary Prevention Health Behavior change Risk Reduction tools for Health and Wellness Positive Psychiatry
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Performance analysis of thermal storage unit with possible nano enhanced phase change material in building cooling applications
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作者 Solomon G Ravikumar Ravikumar T S +1 位作者 Raj V Antony Aroul Velraj R 《储能科学与技术》 CAS 2013年第2期91-102,共12页
The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano... The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid. 展开更多
关键词 thermal storage phase change material nano particle solidification time building cooling doi.3969/j.issn.2095-4239.2013.02.002 CLC number:TK 51 Document code:A Article ID-4239(2013)02-091-12
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