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A model of crust-mantle differentiation for the early Earth

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Acta Geochimica 2022年第4期41卷 689-703页

作者： qingwen zhang Dan Zhu Wei Du Yun Liu State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang550081China International Center for Planetary Science College of Earth SciencesChengdu University of TechnologyChengdu610059China

The Archean continents,primarily composed of the felsic tonalite-trondhjemite-granodiorite(TTG)suite,were formed or conserved since~3.8 Ga,with significant growth of the continental crust since~2.7 *** difficulty in direct differentiation of the felsic crustal components from Earth’s mantle peridotite leads to a requirement for the presence of a large amount of hydrated mafic precursor of TTG in Earth’s proto-crust,the origin of which,however,remains *** mafic proto-crust may have formed as early as~4.4 Ga ago as reflected by the Hf and Nd isotopic signals from Earth’s oldest geological *** a significant time lag between the formation of the mafic proto-crust and the occurrence of felsic continental crust is not reconciled with a single-stage scenario of Earth’s early ***,inspired by the volcanism-dominated heat-pipe tectonics witnessed on Jupiter’s moon Io and the resemblances of the intensive internal heating and active magmatism between the early Earth and the present-day Io,we present a conceptual model of Earth’s early crust-mantle differentiation,which involves an Io-like scenario of efficient extraction of a mafic proto-crust from the early mantle,followed by an intrusion-dominating regime that could account for the subsequent formation of the felsic continents as Earth *** model thus allows an early formation of the preTTG proto-crust and the generation of TTG in the continent by providing the favorable conditions for its subsequent *** model is consistent with the observed early fractionation of the Earth and the late but rapid formation and/or accumulation of the felsic components in the Archean continents,thus sheds new light on the early Earth’s differentiation and tectonic evolution.

关键词： Crust-mantle differentiation Heat-pipe tectonics Plutonic squishy lid tectonics Proto-crust TTG Io

Determining nitrogen fate by hydrological pathways and impact on carbonate weathering in an agricultural karst watershed

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International Soil and Water Conservation Research 2023年第2期11卷 327-338页

作者： Zhuo Hao Yang Gao Yang Yang qingwen zhang Agricultural Clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCAsBejing10011 China Sierra Nevada Research Institute University of CalifomiaMercedCA95344USA

Identifying the nitrogen(N)fate is complicated and a great challenge in karst watersheds because of the co-existence of natural pools and anthropogenic *** objective of the study was to use stable isotopic composition of dual-isotope(δ^(15)NNitrate and δ^(18)O_(Nitrate))and LOADEST model approaches to trace N sources,pathways in karst *** study was conducted in the Houzhai watershed,which is a typical agricultural karst watershed from July 2016 to August 2018,to reveal the N fate and the coupled carbon(C)-N processes occurring in the riverine-watershed with agricultural *** found that the wet deposition of total nitrogen(TN)flux was 33.50 kg hm^(-2)·a^(-1)and dissolved nitrogen(DN)flux was 21.66 kg hm^(-2)·a^(-1).The DN runoff loss was 2.10×10^(5)kg·a^(-1)and the loss of DN during the wet season accounted for 95.4%over a *** the wet season,NO_(3)^(-)-N daily efflux was 977.62±516.66 kg ha^(-1)·day^(-1)and 248.77±57.83 kg ha^(-1)·day^(-1)in the dry *** NH_(4)^(+)-N efflux was 29.17±10.50 kg ha^(-1)·day^(-1)and 4.42±3.07 kg ha^(-1)·day^(-1)in the wet and dry seasons,*** main form output load of N was NO_(3)^(-)-N which was more than 30 times as much as NH_(4)^(+)-N output *** NO_(3)^(-)N caused by rainfall contributed11.82%-53.61%to the export *** from soil contributed over 94%of the N to Houzhai river caused by N *** addition,manure and farmland soil were the main sources of groundwater in the Houzhai watersheds,the contribution rates were 25.9%and 22.5%.The chemical N fertilizers affected carbonate weathering strongly,and the HCO_(3)^(-) flux caused by nitrifi-cation due to N fertilizers application in soil accounted for 23.5%of the entire *** study suggested that carbonate weathering may be influenced by nitrogen nitrification in the karst watershed.

关键词： Karst Agricultural watershed Hydrological pathway Nitrogen Carbonate weathering

Electrical and thermal conductivity of Earth's core and its thermal evolution——A review

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Acta Geochimica 2022年第4期41卷 665-688页

作者： Yuan Yin qingwen zhang Youjun zhang Shuangmeng Zhai Yun Liu State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang550081China International Research Center for Planetary Science College of Earth SciencesChengdu University of TechnologyChengdu610059China Institute of Atomic and Molecular Physics Sichuan UniversityChengdu610065China Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang550081China

The Earth’s core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly correlated to *** we review a large number of studies on the electrical and thermal conductivity of iron and iron alloys and discuss their implications on the thermal evolution of the Earth’s *** summary,we suggest that the Wiedemann-Franz law,commonly used to convert the electrical resistivity to thermal conductivity for metals and alloys,should be cautiously applied under extremely high pressure-temperature(P-T)conditions(e.g.,Earth’s core)because the Lorentz number may be P-T *** date,the discrepancy in the thermal conductivity of iron and iron alloys remains between those from the resistivity measurements and the thermal diffusivity modeling,where the former is systematically *** studies reconcile the electrical resistivity by first-principles calculation and direct measurements,and this is a good start in resolving this *** to an overall higher thermal conductivity than previously thought,the inner core age is presently constrained at~1.0 ***,light elements in the core would likely lower the thermal conductivity and prolong the crystallization of the inner ***,whether thermal convection can power the dynamo before the inner core formation depends on the amounts of the proper light elements in the *** works are needed to establish the thermal evolution model of the core.

关键词： Earth’s core Electrical and thermal conductivity Iron and its alloys Thermal evolution Geodynamo

Isotopic insights on quantitative assessments of interaction of eco-hydrological processes in multi-scale karst watersheds

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International Soil and Water Conservation Research 2024年第1期12卷 156-170页

作者： Zhuo Hao Yang Gao qingwen zhang Wen Wen Agricultural Clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China School of Humanities and Social Sciences Beijing Institute of TechnologyBeijing100081China

The dynamics of hydrological processes and the storage mechanisms of karst water resources are the most important issues in karst *** impact of environmental changes on water quantity,and the evaluation and quantification of eco-hydrological processes remain poorly *** this study,high-frequency continuous monitoring in multi-scale karst watersheds in Southwest China combined the approaches of water isotopes and the hybrid single-particle lagrangian integrated trajectory(HYSPLIT)model to identify the recharge mechanisms between atmospheric vapor,rainfall,surface water,and groundwater,and to reveal the interaction of eco-hydrological *** dominant moisture sources in Puding(PD)County were the Indian Ocean(43-69%)and local moisture(24-33%).Theδ^(18)O and deuterium excess(d-excess)values showed a positive correlation indicating that secondary or sub-cloud evaporation was prominent in the wet *** water line-conditioned excess(lc-excess)indicated that karst water interacted with recent precipitation,groundwater,and evaporation across *** to its specific hydrogeological structure,surface water and rainwater have a higher contribution rate to groundwater *** Chenqi stream replenished the Houzhai River mainly in the form of groundwater,with percentages ranging from 38.1 to 93.5%in the wet season,and 47.8-80.1%in the dry *** the Houzhai outlet,surface water and groundwater interconverted frequently with a percentage of 45.6-49.1%.We believe this is the first systematic study to quantify the supply relationship between water vapor transport,rainfall,surface water and groundwater in the Chinese karst zone,making a significant move forward in the field of karst hydrological processes and improving the efficiency of water resource evaluation and management.

关键词： Stable isotope Moisture sources Water cycle Karst watersheds

Simulated NH_4^+-N Deposition Inhibits CH_4 Uptake and Promotes N_2O Emission in the Meadow Steppe of Inner Mongolia, China

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Pedosphere 2017年第2期27卷 306-317页

作者： LIU Xingren zhang qingwen LI Shenggong zhang Leiming REN Jianqiang Key Laboratory of Agricultural Environment Ministry of Agriculture Agricultural Clear Watershed Group Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences Beijing 100081 (China) Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 (China) Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 (China)

Few studies are conducted to quantify the effects of enhanced N deposition on soil nitrous oxide （N2O） emission and methane （CH4） uptake in the meadow steppe of Inner Mongolia, China. A two-year field experiment was conducted to assess the effects of nitrogen （N） deposition rates （0, 10, and 20 kg N ha-1 year-1 as （NH4）2SO4） on soil N2O and CH4 fluxes. The seasonal and diurnal variations of soil N2O and CH4 fluxes were determined using the static chamber-gas chromatography method during the two growing seasons of 2008 and 2009. Soil temperature, moisture and mineral N （NH4＋-N and NO3-N） concentration were simultaneously measured. Results showed that low level of （NH4）2SO4 （10 kg N ha-1 year-1） did not significantly affect soil CH4 and N20 fluxes and other variables. High level of （NH4）2SO4 （20 kg N ha-1 year-1） significantly increased soil NO3-N concentration by 24.1% to 35.6%, decreased soil CH4 uptake by an average of 20.1%, and significantly promoted soil N2O emission by an average of 98.2%. Soil N2O emission responded more strongly to the added N compared to CH4 uptake. However, soil CH4 fluxes were mainly driven by soil moisture, followed by soil NO3--N concentration. Soil N2O fluxes were mainly driven by soil temperature, followed by soil moisture. Soil inorganic N availability was a key integrator of soil CH4 uptake and N2O emission. These results suggest that the changes of availability of inorganic N induced by the increased N deposition in soil may affect the CH4 and N2O fluxes in the cold semi-arid meadow steppe over the short term.

关键词： grassland ecosystems greenhouse gases N deposition rate nitrification denitrification mineral N

Estimating Ground Snow Load Based on Ground Snow Depth and Climatological Elements for Snow Hazard Assessment in Northeastern China

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International Journal of Disaster Risk Science 2022年第5期13卷 743-757页

作者： Huamei Mo Guolong zhang qingwen zhang H.P.Hong Feng Fan Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090China Department of Civil and Environmental Engineering University of Western OntarioLondonOntario N6A 5B9Canada

Extreme snow loads can collapse *** load is calculated based on the ground snow load(that is,the snow water equivalent on the ground).However,snow water equivalent(SWE) measurements are unavailable for most sites,while the ground snow depth is frequently measured and recorded.A new simple practical algorithm was proposed in this study to evaluate the SWE by utilizing ground snow depth,precipitation data,wind speed,and air *** the evaluation,the precipitation was clas sified as snowfall or rainfall according to the air temperature,the snowfall or rainfall was then corrected for measurement error that is mainly caused by wind-induced undercatch,and the effect of snow water loss was *** developed algorithm was applied and validated using data from57 meteorological stations located in the northeastern region of *** annual maximum SWE obtained based on the proposed algorithm was compared with that obtained from the actual SWE *** return period values of the annual maximum ground snow load were estimated and compared to those obtained according to the procedure suggested by the Chinese structural design *** comparison indicated that the use of the proposed algorithm leads to a good estimated SWE or ground snow *** use allowed the estimation of the ground snow load for sites without SWE measurement and facilitated snow hazard mapping.

关键词： Ground snow depth Ground snow load Northeastern China Precipitation data Snow hazard mapping Snow water equivalent

Molecularly Imprinted Polymer Thin Film Based Surface Plasmon Resonance Sensor to Detect Hemoglobin

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Chemical Research in Chinese Universities 2014年第1期30卷 42-48页

作者： WANG Yang zhang qingwen REN Yamin JING Lijing WEI Tianxin Key Laboratory of Cluster Science Ministry of Education Beijing Institute of Technology Beijing 100081 P. R. China

Molecularly imprinted polymer（MIP） films for hemoglobin detection were prepared onto the Au/Cr coated surface plasmon resonance（SPR） sensor chips by the in situ electropolymerization of 3-aminophenylboronic acid（3-APBA）.The formation of the films and rebinding processes of hemoglobin were monitored by in situ electrochemical-SPR（EC-SPR） spectroscopy,with allowed real-time observation of the simultaneous changes in electrochemical and optical properties of the *** electron microscopy（SEM） and atomic force microscopy（AFM）were used to characterize the surface morphologies of the MIP *** effects of pH,ion strength,different metal ions on rebinding Hb,the specific binding and the selective recognition were *** results obtained with the molecular imprinted SPR chips indicate a good adsorption of Hb in a range of 0.0005-5 mg/mL in 0.05 mol/L sodium phosphate buffer at pH=7.0.A linear calibration curve（R2=0.94） of the SPR sensor for Hb detection was obtained in a range of 0.05-5 mg/*** detection limit for hemoglobin by this method was 0.000435 mg/mL（S/N=3）.Interference studies indicate that the MIP films have a good selectivity compared with the referenced *** stability of the sensor was also *** indicate that the SPR sensor chip keeps 87.6％ of its original response after 14 d of storage under dry and ambient conditions.

关键词： Surface plasmon resonance Molecularly imprinted polymer Hemoglobin 3-Aminophenylboronic acid

Variation and driving factors of nitrous oxide emissions from irrigated paddy field in the arid and semiarid region

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International Soil and Water Conservation Research 2018年第3期6卷 245-252页

作者： qingwen zhang Hui zhang Xingren Liu Aiping zhang Meijia Xiao Zhengli Yang Agricultural Clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Ningxia Vocational and Technical College Yinchuan750002China

Agricultural pollution source as Nitrous oxide (N2O) emission from irrigated paddy field as affected by overuse of chemical fertilizer application and flooding irrigation is the primary anthropogenic source of nitrogen (N) losses in the Ningxia irrigation district. The emissions variation and driving factors of N2O emission in the large irrigation districts needs much more investigation. A static chamber-gas chromatograph method was conducted to quantify N losses from a paddy field in Lingwu Farm during 2009– 2010. Three nitrogen (N) treatments were conducted, including the conventional N application rate of 300 kg ha-1 (N300), the reducing N application rate of 240 kg ha-1 (N240) and control plot (N0). The N2O emissions due to combined effects of the fertilizer application and flood irrigation after winter dry follow was 2.86–3.27 kg ha-1 in N300. The flood irrigation at the beginning of the rice transplanting promotes N2O emissions due to nitrification–denitrification of a richer N source provided by the N fertilizer accumulation of soil NH4 + and NO3 -. During the rice growth stage when the paddy field was submerged, N2O emission was very low while intermittent irrigation before tillering and the maturation stages, frequent alteration of dry and wet soil condition enhance N2O emission. The reducing N fertilizer application improved the recovery rate in rice and resulted in a less N2O emission from irrigated paddy field in the arid and semiarid region while keeping the rice yield.

关键词： N2O emission Irrigated paddy field Flood irrigation Anthropogenic-alluvial alkaline soil

全髋关节置换后的低蛋白血症:危险因素及列线图预测模型建立

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中国组织工程研究 2025年第15期29卷 3147-3152页

作者：郑泽炜叶凯静张阔赵庆华陈秀天江禹来易艳梓张庆文广州中医药大学第三临床医学院广东省广州市510006 广州中医药大学惠州医院广东省惠州市516005 广州中医药大学第三附属医院关节中心广东省广州市510405

背景:患者接受全髋关节置换后多发低蛋白血症,影响术后愈合及康复。目的:探讨及筛选全髋关节置换后发生低蛋白血症的危险因素,建立列线图为临床中判断全髋关节置换后是否发生低蛋白血症提供指导。方法:共纳入行全髋关节置换患者355例,... 详细信息

背景:患者接受全髋关节置换后多发低蛋白血症,影响术后愈合及康复。目的:探讨及筛选全髋关节置换后发生低蛋白血症的危险因素,建立列线图为临床中判断全髋关节置换后是否发生低蛋白血症提供指导。方法:共纳入行全髋关节置换患者355例,根据术后第1天是否出现低蛋白血症分为低蛋白血症组238例、正常组117例,低蛋白血症发生率为67%。收集患者年龄、性别、糖尿病、高血压、高尿酸血症、高血脂、麻醉方式、置换前白细胞、置换前红细胞、置换前血红蛋白、置换前血小板、置换前血浆凝血酶原时间、置换前活化部分凝血酶原时间、置换前国际标准化比值、置换前凝血酶时间、置换前纤维蛋白原、置换前血沉、置换前C-反应蛋白、置换前D-二聚体、置换前平均红细胞血红蛋白含量、置换前平均红细胞体积、手术时间、体质量指数、置换前降钙素原、置换前红细胞压积等资料。利用SPSS 27.0软件进行单因素分析,随后利用R语言(4.3.1)再次对观察指标进行最小绝对收缩和选择算子回归分析及10倍交叉验证,取二者危险因素交集,使用SPSS 27.0进行多因素二元Logistic回归分析得到最终危险因素,通过R语言构建全髋关节置换后低蛋白血症的预测模型,并构建受试者特征曲线曲线、校准曲线、临床决策曲线评估预测模型预测能力。结果与结论:①经过单因素分析、最小绝对收缩和选择算子回归、多因素二元Logistic回归,筛选出年龄(OR=1.024,P=0.023)、置换前血小板(OR=0.995,P=0.028)、置换前血沉(OR=1.031,P=0.045)在判断置换后是否会发生低蛋白血症方面具有统计学意义(P<0.05);②基于多因素Logistic回归所筛选出的最终危险因素构建列线图预测模型,并通过构建受试者特征曲线评估模型预测能力,经计算受试者工作特征曲线的曲线下面积达到0.835(95%CI=0.779-0.891),C-index=0.835,经临床决策曲线计算,模型在阈值为0-0.83可带来更好的临床效能,该预测模型具有良好的灵敏度与准确性,可为医护人员及患者在全髋关节置换前更好地识别置换后发生低蛋白血症的风险。

关键词：全髋关节置换低蛋白血症危险因素预测模型列线图