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Assessment of shallow groundwater vulnerability in Dahei River Plain based on AHP and DRASTIC

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Journal of Groundwater Science and Engineering 2017年第3期5卷 266-277页

作者： ZHU Yu-chen ZHANG Yi-long hao qi-chen Institute of Hydrogeology and Environmental Geology Chinese Academy of Geosciences Shijiazhuang 050061 China

Based on the special hydrogeological conditions of the Dahei River Plain in the Inner Mongolia area, assessment of shallow groundwater vulnerability is conducted based on DRASTIC model. Each evaluation indicator weight is determined by using analytic hierarchy process(AHP). The most important indicators are lithology in soil media and vadose zone. Assessment model of shallow groundwater vulnerability of the Dahei River plain is constructed. Distribution map of vulnerability index in this area is made with the spatial analysis function of ARCGIS. The results show that the particularly sensitive area is the piedmont of the Daqing Mountain, where the upstream place of the groundwater and the south-central place of the plain has the lowest vulnerability. The assessment results are more in accordance with the actual vulnerability conditions of this area by using analytic hierarchy process, and is helpful for groundwater protection.

关键词： Groundwater vulnerability DRASTIC model AHP Dahei River Plain ARCGIS

Effect of Ultrasound on Heterogeneous Nucleation in TIG Welding of Al–Li Alloy

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Acta Metallurgica Sinica(English Letters) 2016年第12期29卷 1081-1088页

作者： qi-hao chen San-Bao Lin Chun-Li Yang cheng-Lei Fan Hong-Liang Ge State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

The effect of ultrasound on heterogeneous nucleation in a tungsten inert gas （TIG） weld pool of 2195 Al-Li alloy has been investigated by a series of experiments. An ultrasonic vibration was imposed on the surface of base material before turning off the welding arc during the TIG welding implemented at a fixed point. The results suggest that ultrasound could promote heterogeneous nucleation in the TIG weld pool of 2195 Al-Li alloy. The grain around the fusion zone is changed from a column grain to an equiaxed grain after applying the ultrasonic treatment. To study the influencing mechanism of ultrasound on heterogeneous nucleation, further investigations were implemented where the welding arc was turned off after turning off the ultrasonic power. The results show that the equiaxed grain around the fusion zone disappeared gradually with an increase in heat input after turning off the ultrasonic power. It suggests that ultrasound could promote the heterogeneous nucleation particle to nucleate in advance before turning off the welding arc and the crystal nucleus could again be melted with an increase in heat input after turning off the ultrasonic power. Moreover, the effects of the welding current and ultrasonic amplitude on heterogeneous nucleation in the weld pool of 2195 Al-Li alloy were also investigated. Possible influencing mechanism of the welding current and ultrasonic amplitude on heterogeneous nucleation was discussed.

关键词： Ultrasound TIG welding Grain Al-Li alloy

Numerical simulation of response of groundwater flow system in inland basin to density changes

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Journal of Groundwater Science and Engineering 2018年第1期6卷 7-17页

作者： LI Lu-lu SU chen hao qi-chen Shao Jing-li School of Water Resources & Environment China University of Geosciences in Beijing The Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological Science

The developmental characteristics of groundwater flow system are not only controlled by formation lithology and groundwater recharge conditions,but also influenced by the physical properties of *** simulation is an effective way to study groundwater flow *** this paper,the ideal model is generalized according to the fundamental characteristics of groundwater system in inland basins of Western *** simulation method of variable density flow on the development of groundwater system in inland basins is established by using EOS9 module in TOUGHREACT numerical simulation *** accordance with the groundwater streamline,the groundwater flow system is divided into three levels,which are regional groundwater flow system,intermediate groundwater flow system and local groundwater flow *** on the calculation of the renewal rate of groundwater,the analysis shows that the increase of fluid density in the central part of the basin will restrain the development of regional groundwater flow system,resulting in a decrease of the circulation rate from 32.28% to 17.62% and a certain enhancement to the local groundwater flow system,which increased from 37.29% to 51.94%.

关键词： Inland basin Groundwater Flow System TOUGHREACT Fluid density

The drainage of the aquitard and its implication for groundwater exploitation in Hengshui City

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Journal of Groundwater Science and Engineering 2018年第2期6卷 84-91页

作者： SU chen WANG Ying ZHENG Zhao-xian chenG Zhong-shuang chen Jiang hao qi-chen Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological Sciences

The deformation and the drainage of the aquitard is the main concern in the North China Plain(NCP), and the water released from aquitard compaction may be a large portion of the exploited groundwater. The skeletal specific storage of aquitard is the element parameter to the drainage of aquitard, and the undisturbed core samples are the best choice for the measurement of the physical parameters. In this study, the consolidation test was employed to analyze the skeleton specific storage of the clay sample drilled from Hengshui City, and the contribution from the drainage of aquitard to the groundwater exploitation. The results suggest the consolidation test can be utilized to understand the skeletal specific storage of aquitard, which is about 3.92×10-4 m-1 in the Hengshui. The water-saturation content of the aquitard was less than 100%, and the amount of the drainage of the aquitard was about 69% of the volume of land subsidence. The water released from aquitard compaction was about 35% of the groundwater exploitation to the deep aquifers.

关键词： Hengshui City North China Plain Land subsidence Skeleton specific storage Aquitard

Genetic model and exploration target area of geothermal resources in Hongtang Area, Xiamen, China

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Journal of Groundwater Science and Engineering 2022年第2期10卷 128-137页

作者： Chun-lei Liu chen-ming Lu Ya-song Li qi-chen hao Sheng-wei Cao Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes Xiamen 361000Fujian ProvinceChina

The geothermal resources in Fujian Province are mainly hydrothermal resources of medium-low *** better understand the whole process and conditions of heat control in the middle and deep crust,this study focuses on the analysis of heat accumulation model in Hongtang Area of Xiamen,and the main conditions of the model such as faults and sags are explored and interpreted in detail by using gravity and wide-field electromagnetic methods.4 main faults(F33,F2,F12 and HT-F1)and 10 secondary faults(HT-F2,HT-F3,HT-F4,HT-F5,HT-F6,HT-F7,HT-F8,HT-F9,HT-F10 and HT-F11)were inferred,and the distribution range of sags was *** convective geothermal system is composed of four components:Heat source,geothermal reservoir,heat-conductive fault and heat retaining cover,which form a quaternary heat accumulation *** to the model,the intersection of the main faults F12,HTF1 and F33 can be delineated as the primary target area of geothermal exploration,while the intersection of the secondary faults(F12 and HT-F6;F12 and HT-F2;HT-F9,HT-F10 and F12;F12 and HT-F11;F33 and HT-F3;HT-F8 and HT-F3;HT-F2,HT-F10 and HT-F1)can be delineated as the secondary target *** DR01,which is located in the primary target area,shows that the water temperature increases from fast to slow in the depth range of 0–500 m,and stays at 36℃below 500 *** reliability of the heat accumulation model and the target area was tested via geothermal boreholes,which is of great significance to the exploitation and utilization of geothermal resources in Hongtang Area of Xiamen.

关键词： Geotherm Gravity method Wide-field electromagnetic method Target area of geothermal exploration Heat accumulation model Hongtang Area

First-Principles Study of Two Dimensional Transition Metal Phthalocyanine-Based Metal-Organic Frameworks in Kagome Lattice

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Chinese Journal of Chemical Physics 2019年第5期32卷 563-571页

作者： hao-qi chen Huan Shan Ai-di Zhao Bin Li Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Tech- nology of China Hefei 230026 China Synergetic Innovation Center of Quantum Information & Quantum Physics University of Science and Technology of China Hefei 230026 China

Transition metal phthalocyanines (TMPc) and relevant derivatives can act as pervasive molecules for their electronic, magnetic, and optical applications. Numerous researches based on TMPc are carried out, attempting to synthesize novel two-dimensional (2D) metal-organic frameworks. Recently, some 2D poly-TMPc frameworks including FePc [J. Am. Chem. Soc. 133, 1203 (2011)], CoPc [Chem. Commun. 51, 2836 (2015)], and Ni-NiPc [J. Mater. Chem. A 6, 1188 (2018)] frameworks have been successfully synthesized experimentally. Meanwhile, potential applications in catalysis, gas storage, and spintronics were predicted by theoretical studies. Here, we propose a new kind of 2D poly-TMPc frameworks with kagome lattice (denoted as kag-TMPc) and systematically investigate their electronic and magnetic properties by employing first-principles calculations. We have demonstrated that the 2D kag-MnPc framework displays quite stable ferromagnetic ordering with Curie temperature about 125 K as indicated by Monte Carlo simulations based on Heisenberg model and prefers out-of-plane easy-magnetization axis. The 2D kag-CrPc framework is an ideal candidate for S=2 kagome antiferromagnet with RT3 magnetic order. Particularly, the investigations on optical absorption suggest that when the TMPc molecules are self-assembled into 2D kag- TMPc frameworks, their absorption wave bands are broadened, especially in visible region.

关键词： Transition metal phthalocyanine Metal-organic framework Kagome Curie temperature Magnetic order Optical absorption

NiNC Catalysts in CO_(2)-to-CO Electrolysis

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Nano-Micro Letters 2025年第4期17卷 363-366页

作者： hao Zhang Menghui qi Yong Wang Department of Chemical Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA Department of Chemistry University of OxfordOxford OX13TAUK Advanced Materials and Catalysis Group Department of ChemistryInstitute of CatalysisZhejiang UniversityHangzhou 310058People’s Republic of China

CO_(2)-to-CO electrolyzer technology converts carbon dioxide into carbon monoxide using electrochemical methods,offering significant environmental and energy benefits by aiding in greenhouse gas mitigation and promoting a carbon circular *** study by Strasser et *** Nature Chemical Engineering presents a high-performance CO_(2)-to-CO electrolyzer utilizing a NiNC catalyst with nearly 100%faradaic efficiency,employing innovative diagnostic tools like the carbon crossover coefficient(CCC)to address transport-related failures and optimize overall ***’s research demonstrates the potential of NiNC catalysts,particularly NiNC-IMI,for efficient CO production in CO_(2)-to-CO electrolyzers,highlighting their high selectivity and ***,challenges such as localized CO_(2)depletion and mass transport limitations underscore the need for further optimization and development of diagnostic tools like *** for optimizing catalyst structure and operational parameters offer avenues for enhancing the performance and reliability of electrochemical CO_(2)reduction catalysts.

关键词： NiNC catalysts CO_(2)-to-CO electrolyzer Faradaic efficiency Carbon crossover coefficient(CCC) Mesoporous structures

Analysis on the situation and countermeasures of water resources supply and demand in the cities of small and medium-sized river basins along southeast coast of China-taking Xiamen City as an example

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Journal of Groundwater Science and Engineering 2021年第4期9卷 350-358页

作者： Chun-lei Liu Jian-hua Zheng Zheng-hong Li Ya-song Li qi-chen hao Jian-feng Li Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang 050061China Key Laboratory of Groundwater Sciences and Engineering Ministry of Natural ResourcesShijiazhuang 050061China Xiamen Institute of Environment Science Xiamen 361000FujianChina.

The small and medium-sized river basins along southeast coast of China hold comparatively abundant water ***,the rapid resources urbanization in recent years has produced a series of water problems such as deterioration of river water quality,water shortage and exacerbated floods,which have constrained urban economic *** applying the principle of triple supply-demand equilibrium,this paper focuses on the estimation of levels of water supply and demand in 2030 at different guarantee probabilities,with a case study of Xiamen *** results show that water shortage and inefficient utilization are main problems in the city,as the future water supply looks daunting,and a water shortage may hit nearly 2×10^(8)m^(3)in an extraordinarily dry *** on current water supply-demand gap and its trend,this paper proposes countermeasures and suggestions for developing and utilizing groundwater resources and improving the utilization rate of water resources,which can supply as a reference for other southeast middle-to-small-sized basin cities in terms of sustainable water resources and water environment protection.

关键词： Xiamen City Water resources Triple equilibrium Probability Supply and demand forecast

New Taub-NUT black holes with massive spin-2 hair

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 51-58页

作者： Yu-qi chen Hai-Shan Liu Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China

We consider Einstein gravity extended with quadratic curvature invariants,within which the well-known Ricci-flat Taub-NUT black hole remains a *** analysis of the unstable Lichnerowicz modes in the Taub-NUT background enables us to identify the mass and NUT parameters(m,n)where new Taub-NUT black holes can *** then adopt numerical techniques to construct these new Taub-NUT black holes,which bifurcate away from the Ricci-flat *** the Ricci-flat Taub-NUT,there can exist two new black holes for an appropriate given temperature,making it a total of three if we include the Ricci-flat one.

关键词： higher derivative gravity black hole solution Taub-NUT spacetime