By using NCEP–NCAR daily reanalysis data for June–August of 1948–2009, the synoptic situation of the doubleblocking high pressure process over the Ural Mountains–Sea of Okhotsk region was identified objectively, a...By using NCEP–NCAR daily reanalysis data for June–August of 1948–2009, the synoptic situation of the doubleblocking high pressure process over the Ural Mountains–Sea of Okhotsk region was identified objectively, and the climatic characteristics and dynamic mechanism during the double blockings were also investigated. The results suggest that the Urals–Okhotsk double-blocking high experienced obviously an abrupt change around 1977. After the change, the occurrence frequency and number of sustained days of the blocking high reduced significantly.Moreover, the zonal spacing between the Urals blocking and the Okhotsk blocking also decreased, while their meridional locations did not change much. The double blockings became strengthened in general, and the blocking high over the Sea of Okhotsk extended northward evidently. However, during the process without double-blocking activities, the intensity and location of the double-blocking high showed no noticeable variation before and after the abrupt change. In addition, dynamic diagnosis shows that after the abrupt change, the energy of the double-blocking high mainly propagated vertically from low to high levels, and transferred horizontally from low to high latitudes; whereas, previously, before the abrupt change, this occurred from high to low latitudes. Meanwhile, the development of a low pressure system was fueled between the double blockings, which meant that the double-blocking activity was beneficial to the maintenance and development of the Northeast China cold vortex. In short, diagnosis of the wave energy has provided us with a better explanation of the life cycle characteristics of this double-blocking phenomenon before and after 1977.展开更多
Based on the concept of an integrated maintenance information system and related information environment, this paper discusses the process of troubleshooting in modern maintenance in detail, and gives a model of dynam...Based on the concept of an integrated maintenance information system and related information environment, this paper discusses the process of troubleshooting in modern maintenance in detail, and gives a model of dynamic diagnosis of faults, in which a reasoning program is designed through taking advantage of information fusion and time analysis. In the end, the authors present the logic process of dynamic diagnosis through a typical example, and proposes a dynamic diagnostic system based on information fusion.展开更多
为提高旱地小麦气候适宜程度动态分析的能力,利用黄土丘陵典型区域定西1971-2005年逐日气象资料及大田资料,建立小麦日气候适宜度模型,计算各生长阶段(营养生长阶段、营养与生殖生长并进阶段、生殖生长阶段)及全生育期综合气候适宜度,...为提高旱地小麦气候适宜程度动态分析的能力,利用黄土丘陵典型区域定西1971-2005年逐日气象资料及大田资料,建立小麦日气候适宜度模型,计算各生长阶段(营养生长阶段、营养与生殖生长并进阶段、生殖生长阶段)及全生育期综合气候适宜度,确定气候适宜性综合评价标准。通过本土化APSIM(Agricultural Production System Simulator)平台,模拟小麦逐日生物量,采用动态逼近误差平方和方法,确定气候适宜性诊断分析标准。通过等级百分比比较的方法,检验诊断分析标准,并定量、动态分析2002-2005年旱地小麦各生长阶段及全生育期气候适宜程度。结果表明,基于APSIM的诊断分析标准评价结果与基于综合评价标准的结果相比,气候适宜性等级相同和级差为1的占86%~90%;2002-2005年旱地小麦各生长阶段及全生育期诊断分析结果均为较适宜,与研究区实际情况基本相符。该优化方法为旱地小麦气候适宜性分析的动态跟踪提供了一定技术支持。展开更多
基金National Natural Science Foundation of China(41405094,41630424,and 41530531)National Basic Research and Development(973)Program of China(2013CB430204)
文摘By using NCEP–NCAR daily reanalysis data for June–August of 1948–2009, the synoptic situation of the doubleblocking high pressure process over the Ural Mountains–Sea of Okhotsk region was identified objectively, and the climatic characteristics and dynamic mechanism during the double blockings were also investigated. The results suggest that the Urals–Okhotsk double-blocking high experienced obviously an abrupt change around 1977. After the change, the occurrence frequency and number of sustained days of the blocking high reduced significantly.Moreover, the zonal spacing between the Urals blocking and the Okhotsk blocking also decreased, while their meridional locations did not change much. The double blockings became strengthened in general, and the blocking high over the Sea of Okhotsk extended northward evidently. However, during the process without double-blocking activities, the intensity and location of the double-blocking high showed no noticeable variation before and after the abrupt change. In addition, dynamic diagnosis shows that after the abrupt change, the energy of the double-blocking high mainly propagated vertically from low to high levels, and transferred horizontally from low to high latitudes; whereas, previously, before the abrupt change, this occurred from high to low latitudes. Meanwhile, the development of a low pressure system was fueled between the double blockings, which meant that the double-blocking activity was beneficial to the maintenance and development of the Northeast China cold vortex. In short, diagnosis of the wave energy has provided us with a better explanation of the life cycle characteristics of this double-blocking phenomenon before and after 1977.
文摘Based on the concept of an integrated maintenance information system and related information environment, this paper discusses the process of troubleshooting in modern maintenance in detail, and gives a model of dynamic diagnosis of faults, in which a reasoning program is designed through taking advantage of information fusion and time analysis. In the end, the authors present the logic process of dynamic diagnosis through a typical example, and proposes a dynamic diagnostic system based on information fusion.
文摘为提高旱地小麦气候适宜程度动态分析的能力,利用黄土丘陵典型区域定西1971-2005年逐日气象资料及大田资料,建立小麦日气候适宜度模型,计算各生长阶段(营养生长阶段、营养与生殖生长并进阶段、生殖生长阶段)及全生育期综合气候适宜度,确定气候适宜性综合评价标准。通过本土化APSIM(Agricultural Production System Simulator)平台,模拟小麦逐日生物量,采用动态逼近误差平方和方法,确定气候适宜性诊断分析标准。通过等级百分比比较的方法,检验诊断分析标准,并定量、动态分析2002-2005年旱地小麦各生长阶段及全生育期气候适宜程度。结果表明,基于APSIM的诊断分析标准评价结果与基于综合评价标准的结果相比,气候适宜性等级相同和级差为1的占86%~90%;2002-2005年旱地小麦各生长阶段及全生育期诊断分析结果均为较适宜,与研究区实际情况基本相符。该优化方法为旱地小麦气候适宜性分析的动态跟踪提供了一定技术支持。
