鄂西高原地文期辨析

本文认为鄂西地区已不存在多级剥夷面。喜山运动期间,区内差异性升降运动剧烈,先前形成的剥夷面被分置于不同高程,并基本上已为后期作用完全破坏。目前所存在剥夷面是早更新世形成的。元谋运动以后,地壳以同步间歇性抬升为特征,形成了遍布本区的峡谷地貌。不同高程面上的岩溶形态并非形成于不同剥夷期,各高程面上均不存在独具特征的岩溶地貌组合形态,即:不同高程面上可出现相同岩溶组合形态,而同一高程面上又可出现不同的岩溶组合形态。      

Material records for Mesozoic destruction of the North China Craton by subduction of the Paleo-Pacific slab

It is well known that the destruction of the North China Carton(NCC) is closely related to subduction of the PaleoPacific slab, but materials recording such subduction has not been identified at the peak time of decratonization. This paper presents data of whole-rock major and trace elements and Sr-Nd-Hf isotopes and zircon U-Pb ages and Hf-O isotopes for Mesozoic volcanic rocks from the Liaodong-Jinan region in the northeastern NCC, in order to trace the subduction-related materials in their source and origin. The Mesozoic volcanic rocks in the Liaodong-Jinan region are mainly composed of two series of rocks, including alkaline basaltic trachyandesite, trachyandesite and trachyte, and subalkaline trachyandesite and andesite. Zircon U-Pb dating yields eruption ages of 129–124 Ma for these rocks. The Early Cretaceous volcanic rocks are all enriched in LILEs(such as Rb, Sr, Ba and Th) and LREEs, depleted in HFSEs(such as Nb, Ta and Ti), indicating that they were originated from mantle sources that had been modified by subducted crustal materials. However, they have relatively heterogeneous and variable isotopic compositions. The alkaline basaltic trachyandesite, trachyandesite and trachyte have enriched whole-rock Sr-Nd-Hf and zircon Hf isotopic compositions and mantle-like δ~(18)O values, suggesting that they were derived from low-degree partial melting of an isotopically enriched lithospheric mantle source. In contrast, the subalkaline trachyandesite and andesite have relatively depleted isotopic compositions with zircon ε_(Hf)(t) values up to +5.2 and heavy zircon O isotopic compositions with δ~(18)O values of +8.1‰ to +9.0‰, indicating that they were originated from a lithospheric mantle source that had been metasomatized by melts/fluids derived from the recycled low-T altered oceanic basalt. All of these geochemical features suggest that the Early Cretaceous volcanic rocks in the Liaodong-Jinan region would result from mixing of mafic magmas with different compositions. Such magmas were originated from the enriched lithospheric mantle and the young metasomatized mantle, respectively, with variable extents of enrichment and depletion in trace elements, radiogenic isotopes and O isotopes. Importantly, the identification of the low-T altered oceanic crust component in the origin of Early Cretaceous volcanic rocks by the zircon Hf-O isotopes provides affirmative isotopic evidence and direct material records for Mesozoic subduction of the Paleo-Pacific slab that induced decratonization of the North China Craton.     

Eco-districts in France: What tools to ensure goals achievement?

Globally, to build cities and communities more inclusive, safe, resilient and sustainable is one of the most important sustainable development goals. Eco-districts in cities emerged as an answer to current global environmental concerns and have been developed in France since the 1990s. The objective of this work is to gather operational feedback from sustainable neighborhood projects owners to better understand the key barriers of such projects and how to overcome them. A case study of the eco-district Les Tanneries, Lingolsheim showed that the carbon footprint of each inhabitant annually amounted to 4 tons CO_2 equivalent, more than half of the French average. Rooms for improvements were clearly identified regarding transports and food carbon footprint. Indicators for energy consumption, social diversity and density reached the level of the eco-districts average. A governance review pointed out some superior practices such as the formalization of a specification requirements handbook, a competition between project management teams, and the use of neighborhood sustainability assessment tools to measure and track changes in performance. The validated tools and obtained results can be useful in building sustainable cities and even China's ecological civilization.     

基于5G RCS UP1.0标准的天气消息支撑系统设计与实现

气象短信服务在气象部门已有十多年的历史并有较广的覆盖面，由于一直以来受运营商传统短信网关的技术能力限制，仅能提供70个字的文字服务。2020年随着三大运营商联合发布《5G消息（5GMC）白皮书》,推出了RCS（Rich Communication Suite, 富媒体通信）,该技术具备融合语音、消息、视频、社区网络等多种功能，为传统短信业务的全面升级提供了技术支撑。本文立足现阶段手机终端普遍支持的RCS UP1.0标准，研究建立“5G天气罗盘制作发布支撑系统”提供以图片、视频等形式的服务内容将天气消息多媒体化，并通过Chatbot的NFS（Network File System）回落技术实现非5G用户以彩信回落的方式接收5G消息，对传统气象短信进行迭代升级，取得了较好的运行效果。