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The elevation gradient of stable isotopes in precipitation in the eastern margin of Tibetan Plateau

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Science China Earth Sciences 2022年第10期65卷 1972-1984页

作者： Jie LI zhonghe pang Engineering Research Center of Groundwater Pollution Control and Remediation of Ministry of Education College of Water SciencesBeijing Normal UniversityBeijing 100875China Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy of Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing 210008China

Tibetan Plateau(TP)receives moistures from different directions,so variations of isotope elevation gradient on different sides may *** this study,we systematically monitored and modeled the elevation effect of stable isotopes in precipitation of the eastern margin of the Tibetan Plateau,where we collected 265 water samples for stable isotope(δ2H andδ^(18)O)analyses,of which 70 are eventful rainfall samples,and 195 are surface water samples,for *** lakes on the mountain peaks were used to reconstruct the average isotope composition of the local precipitation based on the evaporation *** elevation gradient of−4.2‰km^(−1)(R^(2)=0.93)was established for the eastern marginal region of *** elevation gradient was further confirmed by fractionation assessment using the Rayleigh fractionation *** is the highest ever reported for the TP and it is the highest as compared to those of all the other slopes as well as that of the interior part of the *** isotopes in the interior of TP show a lower elevation gradient,which is likely caused by significant local moisture *** paper also discusses the limitations of using river water samples to construct the elevation gradient.

关键词： Elevation gradient Stable isotopes Rayleigh fractionation Moisture recycling Tibetan Plateau

深层地热能丛式多分支U型井采热技术及传热算法

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工程地质学报 2024年第4期32卷 1397-1411页

作者：李守定张苏鹏徐涛张召彬郑博马世伟孔彦龙张文秀赫建明庞忠和李晓中国科学院地质与地球物理研究所中国科学院页岩气与地质工程重点实验室北京100029 中国科学院地质与地球物理研究所中国科学院深地资源装备技术工程实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院地球科学研究院北京100029

深层地热能是一种分布广、资源量大具有发展前景的可再生新能源,当前的主要开采方法有增强型地热系统(EGS)、环绕式井筒换热系统(AGS)、断层带流体循环开采和同轴套管开采法,但存在采热功率不稳定、地震风险高和采热效率低等难题。针对... 详细信息

深层地热能是一种分布广、资源量大具有发展前景的可再生新能源,当前的主要开采方法有增强型地热系统(EGS)、环绕式井筒换热系统(AGS)、断层带流体循环开采和同轴套管开采法,但存在采热功率不稳定、地震风险高和采热效率低等难题。针对当前深层地热开采技术面临的瓶颈问题,本文以开采过程只有能量交换而没有物质交换为原则,以深层干热岩地热规模化可持续稳定开发为目标,提出了深层地热能丛式多分支U型井采热方法(UMW-DGS)及关键技术,在此基础上建立了井筒轴对称热传导模型,以青海共和盆地恰卜恰深部干热岩储层为背景,提出了高温高压岩石热导率测试新方法,计算了在定井径条件下井周温度场和采热功率的时空演化规律,分析了温度差、热导率和井径等3个敏感因素对采热功率的影响。此外,针对UMW-DGS定解问题,研发了基于有限体积法(FVM)的三维热流固耦合数值算法,研究了UMW-DGS单水平井段换热效率和在不同泵注量条件下温度场时空演化。通过分析不同流量的有效换热量、换热时长和功率发现:泵注流量的增加会导致有效换热能量和有效换热时长的降低,并且使有效换热功率先增加后减少。研究结果表明,深层地热能开发需要在平衡换热温度和功率的条件下设计注入排量,从而得到最优的换热效果。

关键词：深层地热丛式多分支U型井高温高压岩石热导率储层-工质流固耦合热传导算法

页岩气开发的地下水环境效应评估——以贵州习水浅层页岩区块为例

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工程地质学报 2024年第4期32卷 1459-1477页

作者：利振彬黄天明李义曼李关访杨平恒龙吟赵雅静昝朝耀张芬李晓庞忠和电力规划设计总院北京100120 中国科学院地质与地球物理研究所北京100029 中国科学院大学地球与行星科学学院北京100049 西南大学地理科学学院重庆400715

大规模水力压裂可能产生一系列环境地质问题,包括了地下水污染、诱发地震以及水资源消耗。目前尚未系统地建立页岩气开发的地下水环境效应评价框架,且对地下水主要污染物来源认识不清。本文以贵州习水浅层页岩气区块为例,通过了解页岩... 详细信息

大规模水力压裂可能产生一系列环境地质问题,包括了地下水污染、诱发地震以及水资源消耗。目前尚未系统地建立页岩气开发的地下水环境效应评价框架,且对地下水主要污染物来源认识不清。本文以贵州习水浅层页岩气区块为例,通过了解页岩气开发前地下水环境背景状况、确定水力压裂中水循环过程以及地下水污染源、建立地下水敏感性监测及污染示踪指标确定方法、揭示污染溯源中关键地球化学过程对同位素污染示踪的影响,初步形成了页岩气开发的地下水环境效应评估框架。本研究确定了研究区浅层地下水背景值状况,包括水化学、同位素以及溶解性气体指标。现场水力压裂试验和具有长周期商业开采井的结果表明页岩地层水存在于整个页岩气开发和生产过程,并作为返排液和产出水的主要组成部分,是浅层地下水污染的主要来源。根据页岩地层水和浅层地下水水文地球化学特征的差异,建立了确定地下水敏感性监测和污染示踪指标的方法,识别出研究区地下水敏感性指标(Cl^(-)、Na^(+)、Ba^(2+)、Li^(+)、B、87Sr/86Sr和δ11B)。针对气体污染(甲烷作为地下水污染物),建立了浅层地下水溶解气和页岩气甲烷同位素(δ13C-CH_(4))及惰性气体同位素(3He/4He和4He/20Ne)组成的端元。同时揭示了当有黏土矿物存在的情况下,吸附-解吸对同位素示踪的影响。在研究区,黏土矿物B的解吸造成水体B含量的增加及δ11B的减少;溶解态Sr与吸附态Sr的同位素再平衡,增加了水中87Sr/86Sr比值。本项研究对于页岩气开发的地下水环境保护具有重要的意义,有助于完善页岩气开发过程中地下水环境效应的评估。

关键词：页岩气地下水背景值地下水污染同位素吸附-解吸

Groundwater circulation relative to water quality and vegetation in an arid transitional zone linking oasis, desert and river

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Chinese Science Bulletin 2013年第25期58卷 3088-3097页

作者： HUANG TianMing pang zhonghe CHEN YaNing KONG YanLong Key Laboratory of Engineering Geomechanics Institute of Geology and Geophysics Chinese Academy of Sciences State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

In groundwater-dependent ecosystems, groundwater circulation controls the overall water quality and ecosystem dynamics. Groundwater and vegetation across a 30-km groundwater transect linking oasis, desert and river in an extremely arid area were investigated with a series of soil profiles drilled into the unsaturated zone to understand groundwater circulation and its control on groundwater quality and surface vegetation in the extremely arid Lower Tarim River, NW China. Measurements have included water-table depth, water chemistry and water isotopes (2H, 18O, 3H) for 15 water samples, soil moisture and chloride content for 11 soil profiles, and vegetation investigation. Results show that the groundwater in desert zone is characterized by slow recharge rate (pre-modern water), great water-table depth (6.17-9.43 m) and high salinity (15.32-26.50 g/L), while that in oasis (uncultivated land) and riparian zone is characterized by relatively fast recharge rate (modern water), small groundwater-table depth (3.56-8.36 m) and low salinity (1.25-1.95 g/L). Stable isotopes show that secondary evaporation takes place during irrigation in oasis. The vegetation characteristics (coverage, richness, evenness and number of plants) are closely related to soil moisture and water-table depth. Groundwater recharge from irrigation in oasis and from river in riparian zone sustains a better ecosystem than that in the desert area, where lateral and vertical groundwater recharge is limited. The more evapotranspirative enrichment may occur in the vegetated and water-rich riparian zone as compared to desert. This study also demonstrates the effectiveness of environmental tracers in studying ecohydrological processes in arid regions.

关键词：地下水循环极端干旱区地表植被河流断面沙漠区绿洲连接生态系统动力学

A spaceborne advanced storage system for remote sensing microsatellites

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 600-615页

作者： Shilei TU Huiquan WANG Yue HUANG zhonghe JIN Micro-Satellite Research Center Zhejiang UniversityHangzhou 310027China Key Laboratory of Micro-Nano Satellite Research Zhejiang ProvinceHangzhou 310027China

With the development of satellite miniaturization and remote sensing,the establishment of microsatellite constellations is an inevitable *** to their limited size,weight,and power,spaceborne storage systems with excellent scalability,performance,and reliability are still one of the technical bottlenecks of remote sensing *** on the commercial off-the-shelf field-programmable gate array and memory devices,a spaceborne advanced storage system(SASS)is proposed in this *** work provides a dynamic programming,queue scheduling multiple-input multiple-output cache technique and a high-speed,high-reliability NAND flash controller for multiple microsatellite payload *** results show that SASS has outstanding scalability with a maximum write rate of 2429 Mb/s and preserves at least 78.53%of the performance when a single NAND flash *** scheduling technique effectively shortens the data scheduling time,and the data remapping method of the NAND flash controller can reduce the retention error by at least 50.73%and the program disturbance error by at least 37.80%.

关键词： Microsatellite Spaceborne advanced storage system(SASS) Scalability Performance Reliability

Geothermal data analysis at the high-temperature hydrothermal area in Western Sichuan

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中国科学：地球科学英文版 2017年第8期60卷 1507-1521页

作者： ZHANG Jian LI WuYang TANG XianChun TIAN Jiao WANG YingChun GUO Qi pang zhonghe Key Laboratory of Computational Geodynamics Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

The western Sichuan hydrothermal area is located at the northeastern margin of the eastern syntaxis of the Qinghai-Tibet Plateau, which is also the eastern end of the Mediterranean-Himalayan geothermal activity zone. There are 248 warm or hot springs in this area, and 11 have temperatures beyond the local boiling temperature. Most of these hot springs are distributed along the Jinshajiang, Dege-Xiangcheng, Ganzi-Litang, and Xianshuihe faults, forming a NW-SE hydrothermal belt. A geothermal analysis of this high-temperature hydrothermal area is an important basis for understanding the deep geodynamic process of the eastern syntaxis of the Qinghai-Tibet Plateau. In addition, this study offers an a priori view to utilize geothermal resources, which is important in both scientific research and application. We use gravity, magnetic, seismic, and helium isotope data to analyze the crust-mantle heat flow ratio and deep geothermal structure. The results show that the background terrestrial heat flow descends from southwest to northeast. The crustal heat ratio is not more than 60%. The high temperature hydrothermal active is related to crustal dynamics processes. Along the Batang-Litang-Kangding line, the Moho depth increases eastward, which is consistent with the changing Qc/Qm(crustal/mantle heat flow) ratio trend. The geoid in the hydrothermal zone is 4–6 km higher than the surroundings, forming a local "platform". The NW-SE striking local tensile stress zone and uplift structure in the upper and middle crust corresponds with the surface hydrothermal active zone. There is an average Curie Point Depth(CPD) of 19.5–22.5 km in Batang, Litang, and Kangding. The local shear-wave(S-wave) velocity is relatively low in the middle and lower crust. The S-wave shows a low velocity trap(Vs<3.2 km s.1) at 15–30 km, which is considered a high-temperature partial melting magma, the crustal source of the hydrothermal active zone. We conclude that the hydrothermal system in this area can

关键词：地热资源利用高温熔融四川西部热液区深部动力学过程上地壳结构热液活动区西藏高原

A self-centering and stiffness-controlled MEMS accelerometer

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Microsystems & Nanoengineering 2024年第1期10卷 27-40页

作者： Yiming Jin Zhipeng Ma Ziyi Ye Mingkang Li Xudong Zheng zhonghe Jin School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310013China Key Laboratory of Micro/Nano-Satellite Research of Zhejiang Province Hangzhou 310007PR China

This paper presents a high-performance MEMS accelerometer with a DC/AC electrostatic stiffness tuning capability based on double-sided parallel plates(DSPPs).DC and AC electrostatic tuning enable the adjustment of the effective stiffness and the calibration of the geometric offset of the proof mass,respectively.A dynamical model of the proposed accelerometer was developed considering both DC/AC electrostatic tuning and the temperature *** on the dynamical model,a self-centering closed loop is proposed for pulling the reference position of the forceto-rebalance(FTR)to the geometric center of *** self-centering accelerometer operates at the optimal reference position by eliminating the temperature drift of the readout circuit and nulling the net electrostatic tuning *** stiffness closed-loop is also incorporated to prevent the pull-in instability of the tuned low-stiffness accelerometer under a dramatic temperature ***-time adjustments of the reference position and the DC tuning voltage are utilized to compensate for the residue temperature drift of the proposed *** a result,a novel controlling approach composed of a self-centering closed loop,stiffness-closed loop,and temperature drift compensation is achieved for the accelerometer,realizing a temperature drift coefficient(TDC)of approximately 7μg/℃ and an Allan bias instability of less than 1μg.

关键词： stiffness electrostatic centering

Oxygen and Hydrogen Isotopes of Waters in the Ordos Basin,China:Implications for Recharge of Groundwater in the North of Cretaceous Groundwater Basin

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Acta Geologica Sinica(English Edition) 2009年第1期83卷 103-113页

作者： YANG Yuncheng SHEN Zhaoli WENG Dongguang HOU Guangcai ZHAO Zhenhong WANG Dong pang zhonghe Institute of Mineral Resources China Academy of Geological Sciences Beijing 100037 China China University of Geosciences Beijing 100083 China Xi＇an Institute of Geology and Mineral Resources Xi＇an 710054 China China Geological Survey Beijing 100011 China Institute of Geology and Geophysics the Chinese Academy of Sciences Beijing 100029 China

Hundreds of precipitation samples collected from meteorological stations in the Ordos Basin from January 1988 to December 2005 were used to set up a local meteoric water line and to calculate weighted average isotopic compositions of modern precipitation. Oxygen and hydrogen isotopes, with averages of-7.8‰ and -53.0‰ for δ^18O and δD, respectively, are depleted in winter and rich in spring, and gradually decrease in summer and fall, illustrating that the seasonal effect is considerable. They also show that the isotopic difference between south portion and north portion of the Ordos Basin are not obvious, and the isotope in the middle portion is normally depleted. The isotope compositions of 32 samples collected from shallow groundwater （less than a depth of 150 m） in desert plateau range from -10.6‰ to -6.0‰ with an average of-8.4‰ for δ^18O and from -85‰ to -46‰ with an average of-63‰ for δD. Most of them are identical with modern precipitation. The isotope compositions of 22 middle and deep groundwaters （greater than a depth of 275 m） fall in ranges from -11.6‰ to -8.8‰ with an average of -10.2‰ for δ^18O and from -89‰ to -63‰ with an average of -76‰ for δD. The average values are significantly less than those of modern precipitation, illustrating that the middle and deep groundwaters were recharged at comparatively lower air temperatures. Primary analysis of ^14C shows that the recharge of the middle and deep groundwaters started at late Pleistocene. The isotopes of 13 lake water samples collected from eight lakes define a local evaporation trend, with a relatively flat slope of 3.77, and show that the lake waters were mainly fed by modern precipitation and shallow groundwater.

关键词： groundwater lake water oxygen and hydrogen isotopes precipitation Ordos Basin

Porous TiFe_(2) intermetallic compound fabricated via elemental powder reactive synthesis

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 764-772页

作者： Qian Zhao Zhenli He Yuehui He Yue Qiu zhonghe Wang Yao Jiang State Key Laboratory of Powder Metallurgy Powder Metallurgy Research InstituteCentral South UniversityChangsha 410083China

Porous intermetallics show potential in the field of filtration and separation as well as in the field of ***,porous Ti Fe2intermetallics were fabricated by the reactive synthesis of elemental *** phase transformation and pore formation of porous TiFe2intermetallics were investigated,and its corrosion behavior and hydrogen evolution reaction(HER)performance in alkali solution were *** TiFe2intermetallics with porosity in the range of 34.4%-56.4%were synthesized by the diffusion reaction of Ti and Fe elements,and the pore formation of porous TiFe2intermetallic compound is the result of a combination of the bridging effect and the Kirkendall *** porous TiFe2samples exhibit better corrosion resistance compared with porous 316L stainless steel,which is related to the formation of uniform nanosheets on the surface that hinder further corrosion,and porous TiFe2electrode shows the overpotential of 220.6 and 295.6 mV at 10 and 100 mA·cm-2,suggesting a good catalytic *** synthesized porous Fe-based intermetallic has a controllable pore structure as well as excellent corrosion resistance,showing its potential in the field of filtration and separation.

关键词： TiFe2 intermetallic compound porous materials reactive synthesis corrosion behavior hydrogen evolution reaction