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Quantifying the 2022 drought and spatiotemporal evolution of TWSA in the Dongting Lake Basin over the past two decades

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Geodesy and Geodynamics 2024年第5期15卷 516-527页

作者： Guodong Xu Sulan Liu Siyu Cheng Yu Zhang Xiaohui Wu Yunlong Wu Institute of Seismology China Earthquake Administration School of Geography and Information Engineering China University of Geosciences

Extreme hydrological events such as droughts and floods have been increasingly influenced by abnormal atmospheric disturbances caused by human activity and global warming. The Dongting Lake Basin(DLB)has experienced challenging circumstances over the past 20 years due to complex climatic variations,leading to extreme flooding and drought. This study aims to investigate the spatiotemporal variation in terrestrial water storage anomalies(TWSA) over the DLB using data from the GRACE/GRACE-FO and GLDAS spanning the latest two decades. A significant decline trend in TWSA is unveiled from July 2019 to May 2023, with the rate of change determined as-1.94.cm/year and-1.99 cm/year based on the GRACE/GRACE-FO and GLDAS, respectively. The GRACE-Drought Severity Index(DSI) is employed to identify and evaluate the severity and spatiotemporal evolution of the 2022 drought event in the DLB. The results accurately capture the drought event, which began in July 2022 and continued until March 2023, with the most severe conditions occurring in October 2022, when the GRACE-DSI value stood at-2.06 and the TWSA decreased by 15.24.cm and 33.51 cm relative to the same month in 2021 and 2020, ***, the daily water level variation at the Chenglingji hydrological gauging station in 2022 broke previous records, reaching a minimum of only 19 m. Comparing the 2022 drought event with the drought events in 2006 and 2011, the impact of drought on vegetation growth conditions was relatively small, but there was still significant vegetation degradation across the DLB.

关键词： Dongting Lake drought Terrestrial water storage GRACE-DSI NDVI GRACE

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A novel tunnel seismic prediction method based on threshold trigger

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Journal of Earth Science 2024年

作者： Peng Guan Zhenqiang Shen Cuifa Shao Yuyong Jiao Guohua Zhang Bin Li Jie Zhou Faculty of Engineering china university of geosciences

The tunnel seismic prediction method can provide information on the geological anomalous body in front of the tunnel face in a long distance (120 m)， which has become a necessary work in tunnel construction. The traditional tunnel seismic prediction methods suffer from two main issues: low data acquisition efficiency and the occurrence of signal delay traces during data gathering. These issues， in turn， impact the accuracy of calculating the velocity of the surrounding rock. To address these shortcomings， this paper proposes a new method called the threshold-triggered tunnel seismic prediction method. The effectiveness of the proposed method is validated through the analysis of measured tunnel seismic data. Firstly， when compared with the traditional short-circuit trigger method， the threshold trigger method demonstrates a significant improvement in data acquisition efficiency. Secondly， the threshold triggering mode effectively eliminates the problem of signal delay and jump that is present in the short-circuit trigger mode， thus ensuring the accuracy of the surrounding rock velocity calculation. These advantages clearly demonstrate the potential engineering application value of the threshold-triggered method.

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Real-time,single-particle chemical composition,volatility and mixing state measurements of urban aerosol particles in southwest china

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Journal of Environmental Sciences 2024年第2期136卷 361-371页

作者： Luyao Chen Junke Zhang Jiaqi Li Xiaojuan Huang Yuzheng Xiang Jing Chen Tingru Pan Wei Zhang Faculty of geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China School of Atmospheric Sciences Chengdu University of Information TechnologyChengdu 610225China Sichuan Environmental Monitoring Center Chengdu 610074China

To investigate the volatility of atmospheric particulates and the evolution of other particulate properties(chemical composition,particle size distribution and mixing state)with temperature,a thermodenuder coupled with a single particle aerosol mass spectrometer was used to conduct continuous observations of atmospheric fine particles in Chengdu,southwest *** of their complex sources and secondary reaction processes,the average mass spectra of single particles contained a variety of chemical components(including organic,inorganic and metal species).When the temperature rose from room temperature to280℃,the relative areas of volatile and semi-volatile components decreased,while the relative areas of less or non-volatile components ***(>80%)nitrate and sulfate existed in the form of NH_(4.NO_(3)and(NH_(4.)_(2)SO_(4.,and their volatilization temperatures were50–100℃and 150–280℃,*** contribution of biomass burning(BB)and vehicle emission(VE)particles increased significantly at 280℃,which emphasized the important role of regional biomass burning and local motor vehicle emissions to the core of *** the increase in temperature,the particle size of the particles coated with volatile or semi-volatile components was reduced,and their mixing with secondary inorganic components was significantly *** formation of K-nitrate(KNO_(3))and K-sulfate(KSO_(4.)particles was dominated by liquid-phase processes and photochemical reactions,*** KNO_(3)and BB particles is the key to improving *** new results are helpful towards better understanding the initial sources,pollution formation mechanisms and climatic effects of fine particulate matter in this megacity in southwest china.

关键词： Atmospheric fine particles TD-SPAMS Chemical composition Volatility Mixing state

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Temperature dependence of mechanical properties and damage evolution of hot dry rocks under rapid cooling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 645-660页

作者： Longjun Dong Yihan Zhang Lichang Wang Lu Wang Shen Zhang School of Resources and Safety Engineering Central South UniversityChangsha410083China School of geosciences and Info-physics Central South UniversityChangsha410083China

Understanding the differences in mechanical properties and damage characteristics of granitoid under high temperatures is crucial for exploring deep geothermal *** study analyzes the evolution of the acoustic emission(AE)characteristics and mechanical parameters of granodiorite and granite after heating and water cooling by uniaxial compression and variable-angle shear tests under different temperature *** identify their changes in mesostructure and mineral composition with electron probe microanalysis and scanning electron *** show that these two hot dry rocks have similar diagenetic minerals and microstructure,but show significantly different mechanical and acoustic characteristics,and even opposing evolution trends in a certain temperature *** the temperatures ranging from 100℃to 500℃,the compressive and shear mechanical properties of granodiorite switch repeatedly between weakening and strengthening,and those of granite show a continuous weakening *** 600℃,both rocks exhibit a deterioration of mechanical *** damage mode of granite is characterized by initiating at low stress,exponential evolutionary activity,and intensified energy *** contrast,granodiorite exhibits the characteristics of initiating at high stress,volatile evolutionary activity,and intermittent energy release,due to its more stable microstructure and fewer thermal defects compared to *** the temperature increases,the initiation and propagation of secondary cracks in granodiorite are suppressed to a certain extent,and the seismicity and brittleness are *** subtle differences in grain size,microscopic heterogeneity,and mineral composition of the two hot dry rocks determine the different acoustic-mechanical characteristics under heating and cooling,and the evolution trends with *** findings are of great significance for the scientific and efficient construction of rock mass engineering by rationally utilizin

关键词： Hot dry rock Acoustic emission Mechanical properties High temperature Damage

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Association between luteinizing hormone level decrease on the triggering day and pregnancy outcome for in vitro fertilization/intracytoplasmic sperm injection patients following gonadotropin-releasing hormone antagonist protocol: a retrospective cohor

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生殖与发育医学(英文) 2024年第1期08卷 8-17页

作者： Li Qing-Fang Tang Min-Yue Wang Gui-Quan Chen Xi-Jing Feng Guo-Fang Zhu Yi-Min Women’s Hospital School of Medicine 3. Zhejiang university 4. 1 Xueshi Road 5. Hangzhou 310006 6. china

Objective: Optimal luteinizing hormone (LH) levels forin vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) patients following the gonadotropin-releasing hormone (GnRH) antagonist protocol remain controversial. This study aimed to estimate the association between serum LH levels on the triggering day (LHLOT) and clinical pregnancy outcomes in IVF/ICSI patients following the GnRH antagonist ***: We enrolled 4.4. IVF/ICSI cycles using flexible or fixed GnRH antagonist protocols between January 2017 and June 2021. The patients were stratified into four groups according to the LHLOT quartiles (Q1–Q4.. Each group was further divided into two subgroups according to the median basal LH/LHLOT. The main outcomes were clinical pregnancy, birth, and miscarriage rates. Secondary outcomes were oocyte yield, number of MII, fertilized oocytes (2PN), and high-quality ***: Serum LHLOT levels were negatively correlated with oocyte yield and the numbers of MII, 2PN, and high-quality embryos. Reproductive outcomes were compared among the different quartiles and subgroups. The absolute difference in the clinical pregnancy rates between the Q4.and Q1 groups was 6.4. (4..2%vs. 4..8%,P 3.04.and ≤3.04.were 32.7% and 4..6% (P 2.14.and ≤2.14.were 50.2% and 4..9%, respectively (P 4. IU/L may result in a higher number of oocytes but reduced oocyte maturation and lower clinical pregnancy rates. A decrease in LH levels by approximately 2.14.to 3.04.times compared to basal LH levels may lead to higher clinical pregnancy rates in IVF/ICSI patients following the GnRH antagonist protocol.

关键词： GnRH antagonist IVF/ICSI Luteinizing hormone Ovarian stimulation Reproductive outcomes

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Geochronology and Geochemistry of the Xingxingxia Triassic A-type Granites in Central Tianshan,NW china:Petrogenesis and Tectonic Implications

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 337-351页

作者： HUANG Zengbao LI Xiyao ZHAO Hao LU Qing Geological Survey of Gansu Province Lanzhou 735000China Key Laboratory of Submarine geosciences and Prospecting Techniques MOE and College of Marine GeosciencesOcean University of ChinaQingdaoShandong 266100China Research Institute of Petroleum Exploration and Development Shengli OilfieldSINOPECDongyingShandong 257000China

The Triassic granitoids in Central Tianshan play a key role in determining the petrogenesis and tectonic evolution on the southern margin of the Central Asian orogenic *** this study,we present SHRIMP zircon U-Pb ages,Hf isotopic and geochemical data on the Xingxingxia biotite granite,amazonite granite and granitic pegmatite in Central Tianshan,NW *** U-Pb dating yielded formation ages of 24. Ma for the biotite granite and 24. Ma for the amazonite *** granitoid rocks have high K_(2)O with low MgO and CaO *** are enriched in Nb,Ta,Hf and Y,while being depleted in Ba and Sr,showing flat HREE patterns and negative Eu *** have typical A-type granite geochemical signatures with high Ga/A_(1)(8–13)and TFeO/(TFeO+MgO)ratios,showing an A_(2) affinity for biotite granite and an A_(1) affinity for amazonite granite and granitic *** ε_(Hf)(t)values of the granitoids are 0.4.–2.66,with Hf model ages of 0.99–1.17 *** suggests that these A-type granites originated from partial melting of the lower *** propose that Xingxingxia Triassic A-type granites formed under lithospheric extension from post-orogenic to anorogenic intraplate settings and NE-trending regional strike-slip fault-controlled magma emplacement in the upper crust.

关键词： Triassic A-type granite Xingxingxia Central Tianshan Central Asian orogenic belt

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Study on Shear Strength Characteristics of Basalt-Concrete Bonding Interface Based on in-situ Direct Shear Test

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Journal of Earth Science 2024年第2期35卷 553-567页

作者： Peng Xia Xinli Hu Chunye Ying Shuangshuang Wu Chu Xu Xuan Wang Hao Chen Hang Duan College of Harbour and Coastal Engineering Jimei UniversityXiamen361021China Faculty of Engineering China University of GeosciencesWuhan430074China china Three Gorges Construction Group Ltd.Beijing100038China

In rock engineering,the shear strength of the basalt-concrete bonding interface is a key factor affecting the shear performance of hydroelectric dam foundations,embedded rock piles and rock *** this study,30 sets of in-situ direct shear tests were conducted on the basalt-concrete bond interface in the Baihetan dam area to investigate the shear strength characteristics of the basalt-concrete bonding *** bonding interface contains two states,i.e.,the bonding interface is not sheared,termed as se(symbolic meaning see Table 1);the bonding interface is sheared with rupture surface,termed as *** effects of lithology,Joints structure,rock type grade and concrete compressive strength on the shear strength of the concrete-basalt contact surface were *** test results show that the shear strength of the bonding interface(s_(e)&s_(i))of columnar jointed basalt with concrete is greater than that of the bonding interface(s_(e)&s_(i))of non-columnar jointed one with the same rock type *** the rock type grade isⅢ_(2),fcol is 1.22 times higher than fncol and ccol is 1.13 times greater than *** shear strength parameters of the basalt-concrete bonding interface differ significantly for different *** cohesion of the bonding interface(s_(i))of cryptocrystalline basalt with concrete is 2.05 times higher than that of the bonding interface(s_(i))of breccia lava with concrete under the same rock type grade *** type grade has a large influence on the shear strength of the non-columnar jointed basalt-concrete bonding interface(s_(e)&s_(i)).cnol increases by 33%when the grade of rock type rises fromⅢ_(1)toⅡ_(1).the rock type grade has a greater effect on bonding interface(s_(i))cohesion than the coefficient of *** the rock type grade is reduced fromⅢ_(2)toⅢ_(1),f_(ncol)′increases by 2%and c_(ncol)′improves by 4.%.The shear strength of the non-columnar jointed basalt-concrete bonding interface(s_(e)&s_(i))increases wit

关键词： direct shear test basalt-concrete bonding interface shear strength parameters engineering geogolgy

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Propagation and Dispersion Characteristics of Scholte Wave in VTI Media with the Presence of Irregular Seabed

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Journal of Earth Science 2024年第2期35卷 722-725页

作者： Xiaobo Liu Yun Wang Jianlei Zhang Haifeng Chen Hua Zhang School of Ocean Sciences China University of GeosciencesBeijing 100083China Key Laboratory of Polar Geology and Marine Mineral Resources China University of GeosciencesBeijing 100083China School of Geophysics and Information Technology China University of GeosciencesBeijing 100083China Research&Development Center BGP IncCNPCZhuozhou 072751China National Engineering Research Center for Oil and Gas Exploration Computer Software Beijing 100080China

INTRODUCTION Surface waves propagating along the seafloor are general ly called Scholte waves,and were first discovered and studied in the early 1950s(Kugler et al.,2005;Buchen and Ben-Hador,1996).Scholte waves exhibit a dispersion phenomenon,which implies that their velocity varies with ***-frequency Scholte waves can propagate over long distances on the seabed with little attenuation(Bohlen et al.,2004..The particle mo tion of Scholte waves in a solid medium changes from a retro grade to a prograde ellipse(Klein et al.,2005;McMechan and Yedlin,1981).

关键词： seabed Dispersion implies

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Accurate simulations of pure-viscoacoustic wave propagation in tilted transversely isotropic media

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Petroleum Science 2024年第2期21卷 866-884页

作者： Qiang Mao Jian-Ping Huang Xin-Ru Mu Ji-Dong Yang Yu-Jian Zhang geosciences Department China University of Petroleum(East China)Qingdao266580ShandongChina Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266207ShandongChina

Forward modeling of seismic wave propagation is crucial for the realization of reverse time migration(RTM) and full waveform inversion(FWI) in attenuating transversely isotropic media. To describe the attenuation and anisotropy properties of subsurface media, the pure-viscoacoustic anisotropic wave equations are established for wavefield simulations, because they can provide clear and stable wavefields. However, due to the use of several approximations in deriving the wave equation and the introduction of a fractional Laplacian approximation in solving the derived equation, the wavefields simulated by the previous pure-viscoacoustic tilted transversely isotropic(TTI) wave equations has low accuracy. To accurately simulate wavefields in media with velocity anisotropy and attenuation anisotropy, we first derive a new pure-viscoacoustic TTI wave equation from the exact complex-valued dispersion formula in viscoelastic vertical transversely isotropic(VTI) media. Then, we present the hybrid finite-difference and low-rank decomposition(HFDLRD) method to accurately solve our proposed pure-viscoacoustic TTI wave equation. Theoretical analysis and numerical examples suggest that our pure-viscoacoustic TTI wave equation has higher accuracy than previous pure-viscoacoustic TTI wave equations in describing q P-wave kinematic and attenuation characteristics. Additionally, the numerical experiment in a simple two-layer model shows that the HFDLRD technique outperforms the hybrid finite-difference and pseudo-spectral(HFDPS) method in terms of accuracy of wavefield modeling.

关键词： Pure-viscoacoustic TTI wave equation Attenuation anisotropy Seismic modeling Low-rank decomposition method

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In situ digital testing method for quality assessment of soft soil improvement with polyurethane

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1732-1748页

作者： X.F.Wang C.J.Wang W.V.Yue Z.J.Zhang Z.Q.Yue Department of Civil Engineering China University of Geosciences (Beijing)BeijingChina Department of Water Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Geotechnical Engineering Tongji UniversityShanghaiChina Department of Civil Engineering The University of Hong KongChina

This study purposes an in situ testing method on quality assessment of soil *** drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring *** factual drilling data can characterize the degree of soil improvement by penetration injection with permeable *** from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement *** drilling time,which indicates the spatial distributions of soil *** soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky *** results of soil profile are verified by the parallel site *** constant drilling speeds profile the coring-resistant strength of drilled *** comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty *** tests,*** compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling *** show that the average predicted strengths of treated silty clay are 2.4.6.9 times higher than the average measured strength of untreated silty *** UCS-based indices of 374.5%and 34..2%verified the quality assessment(QA)results by this new in situ *** method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data.

关键词： Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement Quality assessment

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