Causes and Predictability of the 2021 Spring Southwestern China Severe Drought

In the spring of 2021, southwestern China (SWC) experienced extreme drought, accompanied by the highest seasonal-mean temperature record since 1961. This drought event occurred in the decaying phase of a La Ni?a event with negative geopotential height anomalies over the Philippine Sea, which is distinct from the historical perspective. Historically, spring drought over SWC is often linked to El Ni?o and strong western North Pacific subtropical high. Here, we show that the extreme drought in the spring of 2021 may be mainly driven by the atmospheric internal variability and amplified by the warming trend. Specifically, the evaporation increase due to the high temperature accounts for about 30% of drought severity, with the contributions of its linear trend portion being nearly 20% and the interannual variability portion being about 10%. Since the sea surface temperature forcing from the tropical central and eastern Pacific played a minor role in the occurrence of drought, it is a challenge for a climate model to capture the 2021 SWC drought beyond one-month lead times.     

配电变压器雷电防护“三点一地”接线方式分析及应用

从高、低压侧避雷器接地、变压器中性点及外壳接地的形式和作用等方面展开分析了"三点一地"配电变压器雷电防护方式的原理,并指出安装注意要点.     

Floods in the IPCC TAR Perspective

Recent floods have become more abundant and more destructive than ever in many regions of the globe. Destructive floods observed in the 1990s all over the world have led to record-high material damage, with total losses exceeding one billion US dollars in each of two dozen events. The immediate question emerges as to the extent to which a sensible rise in flood hazard and vulnerability can be linked to climate variability and change. Links between climate change and floods have found extensive coverage in the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC). Since the material on floods is scattered over many places of two large volumes of the TAR, the present contribution - a guided tour to floods in the IPCC TAR – may help a reader notice the different angles from which floods were considered in the IPCC report. As the water-holding capacity of the atmosphere grows with temperature, the potential for intensive precipitation also increases. Higher and more intense precipitation has been already observed and this trend is expected to increase in the future, warmer world. This is a sufficient condition for flood hazard to increase. Yet there are also other, non-climatic, factors exacerbating flood hazard. According to the IPCC TAR, the analysis of extreme events in both observations and coupled models is underdeveloped. It is interesting that the perception of floods in different parts of the TAR is largely different. Large uncertainty is emphasized in the parts dealing with the science of climate change, but in the impact chapters, referring to sectors and regions, growth in flood risk is taken for granted. Floods have been identified on short lists of key regional concerns.     

星座图贴近度方法在广西北海近海水质监测优化布点上的应用

本文将星座图聚类、欧几里得距离贴近度、中国近海水质评价及t检验方法结合起来,对广西北海近海水质监测点进行分类、择优布点及检验。结果表明,这是一种实用的优化布点方法。     

海平面长期变化对推算多年一遇极值水位的影响

利用乳山口24a的年极值高、低水位和年平均海平面,分析讨论了平均海平面长期变化对推算多年一遇极值水位的影响.同时讨论了消除平均海平面中长期变化的途径.比较了消除平均海平面长期变化和保留这种变化情况下推算出的两种多年一遇极值水位,可以发现,对多年一遇高水位来说,保留平均海平面长期变化所得结果高于消除了的,而对多年一遇低水位而言,情况正好相反.     

关于“不动点的单调原理”的条件的修正(英文)

Taskovic,M R于1985年建立的“不动点的单调原理”,经作者证明是错误的。本文以另外的条件来代替“不动点的单调原理”中的所谓“AT—型条件”,建立了相应的不动点定理。该定理是某些重要结果的进一步推广。