中国地震网格试验系统中资源管理与作业调度研究-资源管理和作业动态分配模型ProRMJS的建立me

通过分析与研究建立资源管理和作业动态分配ProRMJS模型,解决了中国地震灾害仿真网格试验系统（CEDAGrid）中网格科学计算平台在初期建设中存在的一些资源管理方面的问题. 针对网格科学计算平台默认各个计算节点均能提供计算服务的问题,ProRMJS通过ldquo;计算池rdquo;这一虚拟组织为调度器分发作业提供支撑;而调度器则根据计算池中各个节点的计算能力和状态,动态分配任务,这样就保证了计算平台的稳定性. 针对默认各个计算节点均能完成任务的问题, ProRMJS通过监控各个节点所负担作业的运行进度和设定作业时间阈值来管理作业运行. 对于各个节点计算能力大小的区别, ProRMJS通过对各个节点计算性能的权值量化,实行按ldquo;需rdquo;分配作业. 对各个节点计算性能的权值量化, ProRMJS是通过综合考虑各个因素对机器计算能力大小的影响后通过加权计算的方式完成的,从而提高了整个计算平台的工作效率. 最后通过实现地震应力触发科学计算实例验证了方案的有效性,为网格技术在地震领域内的进一步应用作了有意义的探索.      

2008年12月至2009年2月T639与ECMWF及日本模式中期预报性能检验

对2008年12月至2009年2月T639、ECMWF、日本模式的中期预报性能进行了检验和对比分析.结果表明:3种模式对大气环流的演变和调整、850hPa温度升降变化趋势均有较强的预报能力,其中尤以ECMWF模式预报误差最小.3种模式对重大灾害性、转折性天气过程也有很好的指示性能,较成功地预报了3次全国性寒潮天气过程、长江中下游地区持续阴雨天气过程的大气环流形势特征及主要影响系统.     

太阳系外行星探测方法及统计特征

太阳系外行星的探测和研究在过去十几年取得了重大进展,仅2007年就发现62颗太阳系外行星,随着行星物理学、天体生物学等学科的兴起,必将掀起对太阳系外行星研究的一次浪潮.简要回顾了太阳系外行星研究的发展历史,介绍了探测太阳系外行星的主要方法和手段,并对方法本身的特点展开分析论述,列出了各种方法应用的最新进展.对已发现的270多颗太阳系外行星进行了统计分析,得出了一些预见性的结论.     

Prediction of vegetation anomalies over an inland river basin in north‐western China

Vegetation cover plays an important role in linking the atmosphere, water, and land and is deemed as a key indicator in the terrestrial ecological system. Therefore, it is of great importance to monitor vegetation dynamics and understand the mechanisms of vegetation change, including that driven by climate change. This study examines (a) the evolution of vegetation dynamics over the Heihe River Basin in the typical arid zone in north‐western China using nonparametric Mann–Kendall test and Thiel Sen's slope; (b) the relationships between remotely sensed vegetation indices (normalized difference vegetation index [NDVI] and enhanced vegetation index [EVI]) and hydroclimatic variables based on correlation analysis; and (c) the prediction of vegetation anomalies using a multiple linear regression model. For the analysis, the Moderate Resolution Imaging Spectroradiometer NDVI/EVI product and the gridded daily meteorological data at a spatial resolution of 0.125° over the period 2001–2010 are considered. The results indicate that vegetation cover improved over a large proportion during 2001–2010, with a significant trend towards warm and wet, characterized by an increase in average annual temperature and precipitation by 0.042 °C/year and 5.8 mm/year, respectively. We test the feasibility of NDVI and EVI in quantifying the responses of vegetation anomaly to climate change and develop a statistical model to predict vegetation dynamics in the basin. The NDVI‐based model is found to be more reliable than the EVI‐based model, partly due to the vegetation characteristics and geomorphologic properties of the study region. The proposed model performs well when there is no lag time between meteorological factors and vegetation indices for grassland and cropland, whereas 1‐month lead time prediction is found to be best for forest. The soil water content is introduced as an extra explanatory variable, which effectively improves the prediction accuracy for different land use types. In general, the predictive ability of the proposed model is stable and satisfactory, and the model can provide useful early warning information for regional water resources management under changing climate.     

Geochemical characteristics of hadal sediment in the northern Yap Trench

Journal of Oceanology and Limnology - Two sediment cores were retrieved in the hadal zone of the Yap Trench, and their concentrations of six major elements Mg, Al, Ca, Ti, Mn and Fe and nine trace...     

Spatial and temporal variation of vegetation phenology and its response to climate changes in Qaidam Basin from 2000 to 2015

Based on TIMESAT 3.2 platform, MODIS NDVI data (2000–2015) of Qaidam Basin are fitted, and three main phenological parameters are extracted with the method of dynamic threshold, including the start of growth season (SGS), the end of growth season (EGS) and the length of growth season (LGS). The spatial and temporal variation of vegetation phenology and its response to climate changes are analyzed respectively. The conclusions are as follows: (1) SGS is mainly delayed as a whole. Areas delayed are more than the advanced in EGS, and EGS is a little delayed as a whole. LGS is generally shortened. (2) With the altitude rising, SGS is delayed, EGS is advanced, and LGS is shortened and phenophase appears a big variation below 3000 m and above 5000 m. (3) From 2000 to 2015, the temperature appears a slight increase along with a big fluctuation, and the precipitation increases evidently. (4) Response of phenophase to precipitation is not obvious in the low elevation humid regions, where SGS arrives early and EGS delays; while, in the upper part of the mountain regions, SGS delays and EGS advances with temperature rising, SGS arrives early and EGS delays with precipitation increasing.     

Evolution and spatial characteristics of tourism field strength of cities linked by high-speed rail (HSR) network in China

Traffic is an indispensable prerequisite for a tourism system. The “four vertical and four horizontal” HSR network represents an important milestone of the “traffic revolution” in China. It will affect the spatial pattern of tourism accessibility in Chinese cities, thus substantially increasing their power to attract tourists and their radiation force. This paper examines the evolution and spatial characteristics of the power to attract tourism of cities linked by China’s HSR network by measuring the influence of accessibility of 338 HSR-linked cities using GIS analysis. The results show the following. (1) The accessibility of Chinese cities is optimized by the HSR network, whose spatial pattern of accessibility exhibits an obvious traffic direction and causes a high-speed rail-corridor effect. (2) The spatial pattern of tourism field strength in Chinese cities exhibits the dual characteristics of multi-center annular divergence and dendritic diffusion. Dendritic diffusion is particularly more obvious along the HSR line. The change rate of urban tourism field strength forms a high-value corridor along the HSR line and exhibits a spatial pattern of decreasing area from the center to the outer limit along the HSR line. (3) The influence of the higher and highest tourism field strength areas along the HSR line is most significant, and the number of cities that distribute into these two types of tourism field strengths significantly increases: their area expands by more than 100%. HSR enhances the tourism field strength value of regional central cities, and the radiation range of tourism attraction extends along the HSR line.     

Identification of paralytic shellfish toxin-producing microalgae using machine learning and deep learning methods

Journal of Oceanology and Limnology - Paralytic shellfish poisoning (PSP) microalgae, as one of the harmful algal blooms, causes great damage to the offshore fishery, marine culture, and marine...