通信网络运维多维评估模型设计及应用

通信网络运行维护工作是电信运营商的一项基础性重要工作。当前,世界各运营商网络运维工作公开披露的信息相对较少,缺乏评估各运营商电信网络运维水平的有效模型。以平衡积分卡方法为基础,结合长期通信网络运维体系研究及工作实践,创新性地提出了通信网络运维多维评估模型,并应用该模型对国际大型电信运营商、创新型电信运营商、高增长型电信运营商3种不同类型的运营商进行对比分析,以期对国内运营商网络运维工作发展提供有效的评估和指引。

Timing and structural controls on skarn-type and vein-type mineralization at the Xitian tin-polymetallic deposit, Hunan Province, SE China

Xitian tin-polymetallic deposit, located in the eastern Hunan Province, SE China, hosts quartz vein and skarn in the contact zone between carbonate and two stages granites. Critical geodynamic questions for South China are whether different types of mineralization form in the same time and how the magmatism–tectonic system controls the ore-forming process. Based on the distribution of the orebodies, six cassiterite samples from different types of mineralization are collected for dating. In-situ LA-MCICP-MS U–Pb isotopic data yielded concordia low intercept ages between 154 and 157 Ma, indicating that different types of mineralization belong to the same magmatism–mineralization system. Coupled with the study of the kinematic indicators, it suggests that the structural control of the wall rocks constrain the types of mineralization. These results provide further evidence of a close temporal link between the structure and the tin-polymetallic mineralization in Xitian deposit. Considering the structure in the district, granite dome plays an important role in the ore-forming process. The age and structural signatures in Xitian deposit are the response to the subduction of Pacific Plate.

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 Paleo-Pacific 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-likeδ18O 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 zirconεHf(t)values up to+5.2 and heavy zircon O isotopic compositions with δ18O 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.