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991.
分析了基于Web平台的自动气象站信息综合处理系统的设计思路、设计原则和系统特点,解析了系统的总体技术框架和功能模块结构,并就设计实现过程中的关键技术进行详细剖析。  相似文献   
992.
为满足公共气象服务的需要,利用现有GPRS网络覆盖范围广、实时在线、通信质量高和维持费用低等优势,设计并实现一种基于GPRS网络的LED显示屏气象信息发布系统。介绍系统结构和各部分功能,以及系统中远端显示控制卡的硬件结构组成和信息显示过程。阐述系统服务器3个管理程序、终端用户程序和矢量文字信息转换为点阵文字信息的方法,以及系统的实际应用情况。  相似文献   
993.
以人均国际航空CO2历史累计排放为基础,借用收入分配公平的研究思路,构造了碳洛伦兹曲线和碳基尼系数,以此来测度各国历史上国际航空碳排放权的不公平使用。对碳基尼系数计算分析表明,历史上国际航空碳排放存在巨大的不公平性,但随累计起始年的延后,不公平性被部分掩盖。国际航空碳排放权公平分配是构建国际航空全球减排机制的关键问题,本文提出的以责任-能力指数为基础构建的国际航空碳排放权分配方案,体现了公平原则。以实现“2020年碳中性”目标为例,运用本文构建的分配方案,计算出了各国2021年分配的碳减排量。  相似文献   
994.
The present research elucidates the accelerating effect of alumina minerals on metolachlor transformation using sulfur nucleophiles and also determines the metolachlor transformation mechanisms in the heterogeneous reaction systems. Metolachlor transformation was first systematically investigated under different conditions. Then, the Fourier transform infrared (FTIR) spectra were used to characterize the changes in the surface bonds of the aluminas. The transformation products were qualitatively identified using LC/MS. The results showed that bisulfide can produce efficient metolachlor transformation rates, and the presence of the aluminas can further accelerate the transformation by achieving complete transformation in <21 days. In addition, a higher pH and higher bisulfide concentration are more favorable for metolachlor transformation. When normalized to the surface area, the metolachlor transformation rates were found to follow the order of α‐Al2O3>γ‐AlOOH>γ‐Al2O3 in the presence of different aluminas. FTIR results indicated that the enhancement of metolachlor transformation rates by bisulfide with aluminas can be attributed to the surface active nucleophiles on alumina surfaces formed through Al? S and Al? O bonds. The substitution of chlorine on the metolachlor followed the SN2 mechanism by bisulfide with accelerated rate through mediating the heterogeneous reactions with aluminas.  相似文献   
995.
利用美国海军天文台提供的矢量程序包和国际天文协会提供的基础天文标准库,研究了在地球和月球上精度可以达到毫角秒的恒星和行星视位置计算,分析了恒星视位置计算中的各种改正影响。  相似文献   
996.
Lung cancer is the second most commonly diagnosed cancer in both men and women in Georgia, USA. However, the spatio-temporal patterns of lung cancer risk in Georgia have not been fully studied. Hierarchical Bayesian models are used here to explore the spatio-temporal patterns of lung cancer incidence risk by race and gender in Georgia for the period of 2000–2007. With the census tract level as the spatial scale and the 2-year period aggregation as the temporal scale, we compare a total of seven Bayesian spatio-temporal models including two under a separate modeling framework and five under a joint modeling framework. One joint model outperforms others based on the deviance information criterion. Results show that the northwest region of Georgia has consistently high lung cancer incidence risk for all population groups during the study period. In addition, there are inverse relationships between the socioeconomic status and the lung cancer incidence risk among all Georgian population groups, and the relationships in males are stronger than those in females. By mapping more reliable variations in lung cancer incidence risk at a relatively fine spatio-temporal scale for different Georgian population groups, our study aims to better support healthcare performance assessment, etiological hypothesis generation, and health policy making.  相似文献   
997.
Yao  Jiaming  Lan  Hengxing  Li  Langping  Cao  Yiming  Wu  Yuming  Zhang  Yixing  Zhou  Chaodong 《Landslides》2022,19(3):703-718

The Sichuan-Tibet railway goes across the Upper Jinsha River, along which a large number of large historical landslides have occurred and dammed the river. Therefore, it is of great significance to investigate large potential landslides along the Jinsha River. In this paper, we inspect the deformation characteristics of a rapid landsliding area along the Jinsha River by using multi-temporal remote sensing, and analyzed its future development and risk to the Sichuan-Tibet railway. Surface deformations and damage features between January 2016 and October 2020 were obtained using multi-temporal InSAR and multi-temporal correlations of optical images, respectively. Deformation and failure signs obtained from the field investigation were highly consistent. Results showed that cumulative deformation of the landsliding area is more than 50 cm, and the landsliding area is undergoing an accelerated deformation stage. The external rainfall condition, water level, and water flow rate are important factors controlling the deformation. The increase of rainfall, the rise of water level, and faster flow rate will accelerate the deformation of slope. The geological conditions of the slope itself affect the deformation of landslide. Due to the enrichment of gently dipping gneiss and groundwater, the slope is more likely to slide along the slope. The Jinsha River continuously scours the concave bank of the slope, causing local collapses and forming local free surfaces. Numerical simulation results show that once the landsliding area fails, the landslide body may form a 4-km-long dammed lake, and the water level could rise about 200 m; the historic data shows that landslide dam may burst in 2–8 days after sliding. Therefore, strategies of landslide hazard mitigation in the study area should be particularly made for the coming rainy seasons to mitigate risks from the landsliding area.

  相似文献   
998.
Feng  Wenkai  Bai  Huilin  Lan  Bing  Wu  Yiying  Wu  Zhongteng  Yan  Liangzheng  Ma  Xinjun 《Landslides》2022,19(8):1957-1970
Landslides - From June 10 to 13, 2019, continuous heavy rainfall occurred in Longchuan County, Guangdong Province, yielding a cumulative rainfall of nearly 270&nbsp;mm. The heavy rainfall...  相似文献   
999.
饱和黏土中固定锚腚拖曳锚的嵌入轨迹和承载力预测是深水系泊系统设计的关键。从固定锚腚拖曳锚在饱和黏土海床嵌土的初始状态出发,将固定锚腚拖曳锚和周围土体视作宏单元,假设在锚链拉力作用下宏单元沿土体屈服面法向运动,利用锚链方程计算锚眼拉力,基于增量迭代法建立了预测固定锚腚拖曳锚嵌入运动轨迹和锚眼拉力的模型,编制了相应的计算程序。利用程序预测了Bruce Dennla MK4固定锚腚拖曳锚、Murff算例拖曳锚在饱和黏土中的运动轨迹和承载力,结果表明:本文所建立的模型预测结果正确,可以用于预测固定锚腚拖曳锚嵌入饱和黏土全过程中板锚的运动轨迹、运动形态和锚眼拉力;固定锚腚拖曳锚嵌入过程中,锚运动形态有一个调整过程,因此,旋转角先减小,而后增加,并逐渐趋于稳定值。  相似文献   
1000.
山西神头泉域水资源管理保护区划分   总被引:1,自引:0,他引:1  
从岩溶水资源可持续利用的观点出发,深入分析了神头泉域水资源开发利用存在的问题,根据神头泉域岩溶水贮存、循环条件及人类活动影响的不同,以区域水环境自净能力、覆盖层的隔污能力及岩溶含水层的环境容量为依据,综合考虑泉域区的工业布局、社会和国民经济发展规划等多种因素,将神头泉域划分为三级水资源管理保护区,并提出了保护泉域水资源的管理对策,以保证有限的岩溶水资源可持续开发利用。   相似文献   
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