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Astronomical Cycles of the Late Permian Lopingian in South China and Their Implications for Third-Order Sea-Level Change

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Journal of Ocean University of China 2020年第6期19卷 1331-1344页

作者： WANG Xiuqi zhang Xunhua GAO Fei zhang minghua College of Marine Geosciences Ocean University of ChinaQingdao 266100China Qingdao Institute of Marine Geology China Geological SurveyQingdao 266071China Qingdao Jimo Municipal Transport Bureau Qingdao 266200China The Brigade of Geological Survey of Ganxi Bureau of Geologic Exploration and Mineral Development of Jiangxi ProvinceNanchang 330002China

The late Permian(Lopingian)was a crucial climate transition period from the late Paleozoic Ice Age to the early Triassic of exceptionally high ***,the origins of the third-order sea-level changes during the Lopingian Epoch remain ***,we presented astronomically calibrated gamma-ray(GR)log and non-U GR(computed gamma ray or CGR)curves from the clastic and carbonate successions of well GFD-1 in the Pingle Depression of South China for studying the sea-level oscillations during the *** analyses of the 405 kyr-calibrated GR and CGR time data revealed periodicities close to about 405,about 100,about 44.2,about 35.1,about 21,and about 17.5 kyr,supporting the existence of Milankovitch forcing in the sedimentary records.A high-resolution astronomical time scale and high-resolution sedimentation rate curve of the Lopingian from well GFD-1 were constructed by cyclostratigraphic *** eccentricity and obliquity amplitude modulation cycles suggested long periodicities of about 2.4 and about 1.2 myr,*** the Wuchiapingian greenhouse of the Lopingian,the about 2.4 myr eccentricity oscillation controlled‘weak’glacio-eustasy and/or aquifer eustatic changes related to the global third-order sea-level changes and that a lowstand(W2)was initiated by an eccentricity oscillation *** contrast,during the Changhsingian,which exhibited a cooling event,an about 1.2 myr obliquity cycle was probably strong,with the sea-level records highlighting the link between the‘icehouse’sea-level lowering(C2 and C1)and the obliquity ***,dynamic sedimentary noise model as an indicator of sea-level showed local third-order sea-level variations,the coevolution trends in the orbital power,global and local sea-level changes,and sedimentation rate had significant implications for establishing the global nature and synchronicity of these million-year-scale eustatic records and reconstructing the temporal depositional history at a region

关键词： Lopingian Milankovitch cycle third-order eustasy long-period astronomical cycle sedimentation rate

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THEORETICAL ANALYSIS ON THE NUCLEATION OF MICRO-DAMAGE IN CEMENT MORTAR UNDER COMPRESSIVE LOADING AND SULFATE ATTACK

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Acta Mechanica Solida Sinica 2013年第1期26卷 53-61页

作者： Jiankang Chen Hui Song minghua zhang Jian Ye The Faculty of Mechanical Engineering and Mechanics Ningbo University State Key Laboratory of Turbulence and Complex Systems Jiangsu Provincial Water Resources Department

Effect of uniaxial compression on the nucleation of micro-damage in cement mortar under sulfate attack is investigated. Shape and size of micro-voids in cement mortar is detected using Micro Computed Tomography techniques. The formation of delayed ettringite crystal is analyzed using scanning electron microscope and energy disperse spectrum methods. Deformation of micro-voids and the distribution of stress at the surface of a micro-void are calculated. It is found that the nucleation of micro-cracks is caused by the tensile stress at the voids＇ surface, and such damage nucleation will be speeded up by the remote uniaxial compressive load.

关键词： sulfate attack uniaxial compression micro-damage cement mortar Eshelby'smethod

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Agricultural pesticide use and food safety:California's model

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Journal of Integrative Agriculture 2015年第11期14卷 2340-2357页

作者： minghua zhang Michael R Zeiss Shu Geng Department of Land Air and Water ResourcesUniversity of California California Department of Pesticide Regulation Sino-US Joint Food Safety Research Center Northwest A&F University Department of Plant Sciences University of California

Pesticides have been an essential part of agriculture to protect crops and livestock from pest infestations and yield reduction for many decades. Despite their usefulness, pesticides could pose potential risks to food safety and the environment as well as human health. This paper reviews the positive benefits of agricultural pesticide use as well as some potential negative impacts on the environment and food safety. In addition, using the case of California, we discuss the need for both residue monitoring and effective pest management to promote food safety. Twenty years＇ pesticide residue data from California＇s pesticide residue monitoring program were analyzed. Results showed that more than 95% of food samples were in compliance with US pesticide residue standards （tolerances）. However, certain commodities from certain sources had high percentages of residues above tolerance levels. Even when residues above tolerance levels were detected, most were at levels well below 1 mg kg^-1, and most posed negligible acute health risk. However, a few detected residues had the potential to cause health effects. Therefore, establishing an effective food residue monitoring program is important to ensure food quality throughout the marketplace.

关键词： food safety food security pesticide use residue monitoring environmental impacts IPM tolerances maximum residue limits (MRLs)

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Stress-corrosion coupled damage localization induced by secondary phases in bio-degradable Mg alloys:phase-field modeling

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Journal of Magnesium and Alloys 2024年第1期12卷 361-383页

作者： Chao Xie Shijie Bai Xiao Liu minghua zhang Jianke Du The Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211P.R.China Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province Hunan University of Science and TechnologyXiangtan 411201P.R.China

In this study,a phase-field scheme that rigorously obeys conservation laws and irreversible thermodynamics is developed for modeling stress-corrosion coupled damage(SCCD).The coupling constitutive relationships of the deformation,phase-field damage,mass transfer,and electrostatic field are derived from the entropy *** SCCD localization induced by secondary phases in Mg is numerically simulated using the implicit iterative algorithm of the self-defined finite *** quantitative evaluation of the SCCD of a C-ring is in good agreement with the experimental *** capture the damage localization,a micro-galvanic corrosion domain is defined,and the buffering effect on charge migration is *** cases are investigated to reveal the effect of localization on corrosion acceleration and provide guidance for the design for resistance to SCCD at the crystal scale.

关键词： Phase field Mg alloys Stress-corrosion coupled damage Damage localization Finite element method

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Formulation of a new ocean salinity boundary condition and impact on the simulated climate of an oceanic general circulation model

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Science China Earth Sciences 2017年第3期60卷 491-500页

作者： JIN JiangBo ZENG QingCun WU Lin LIU HaiLong zhang minghua Institute of Atmospheric Physics Chinese Academy of Sciences College of Earth Sciences University of Chinese Academy of Sciences School of Marine and Atmospheric Sciences Stony Brook University

The salinity boundary condition at the ocean surface plays an important role in the stability of long-term integrations of an oceanic general circulation model （OGCM） and in determining its equilibrium solutions. This study presents a new formulation of the salt flux calculation at the ocean surface based on physical processes of salt exchange at the air-sea interface. The formulation improves the commonly used virtual salt flux with constant reference salinity by allowing for spatial correlations between surface freshwater flux and sea-surface salinity while preserving the conservation of global salinity. The new boundary condition is implemented in the latest version of the National Key Laboratory of NumericaI Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics Climate Ocean Model version 2 （LICOM2.0）. The impact of the new boundary condition on the equilibrium simulations of the model is presented. It is shown that the new formulation leads to a stronger Atlantic meridional overturning circulation （AMOC） that is closer to observational estimates. It also slightly improves poleward heat transport by the oceans in both the Atlantic and the global oceans.

关键词： OGCM Surface salinity boundary condition Virtual salinity flux Upward salt flux from oceanic surface AMOC

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EXPERIMENTAL EVALUATION ON MODULUS OF EQUIVALENT HOMOGENEOUS ETTRINGITE

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Acta Mechanica Solida Sinica 2009年第4期22卷 320-327页

作者： minghua zhang Jiankang Chen Jue Zhu Jiangying Chen Department of Mechanics and Engineering Science Ningbo University Ningbo 315211 China

In the present study, the average modulus of delayed ettringite is evaluated by an experimental method combined with theoretical analysis. Firstly, the delayed ettringite crystal is synthesized by chemical reaction of Aluminum sulfate and calcium hydroxide. Secondly, specimens are obtained by compressing the delayed ettringite crystal under different pre-loads. Thirdly, the variation of the modulus of the specimen with different pre-loads is tested using Instron material test machine and the SHPB technique, respectively. It is found that the experimental data may be suitably fitted by Boltzmann Function. Finally, the porosity of the specimen is detected using the saturation method, and the effect of the porosity on the modulus is analyzed by the Eshelby＇s equivalent inclusion method and the Mori-Tanaka＇s scheme. The static and dynamic modulli of the equivalent homogeneous ettringite obtained in present study are approximately 10.64 GPa and 24.61 GPa, respectively.

关键词： ettringite equivalent homogeneous materials Boltzmann Function modulus

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Iterative hybrid decoding algorithm for LDPC codes based on attenuation factor

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Frontiers of Electrical and Electronic Engineering in China 2012年第3期7卷 279-285页

作者： minghua LIU Lijun zhang School of Electronic and Information Engineering Beijing JiaotongUniversity Beijing 100044 China

An attenuated iterative reliability-based major- ity-logic （AIML） decoding algorithm for low-density parity-check （LDPC） codes is proposed, which pertains to hybrid decoding schemes. The algorithm is devised based on the orthogonal check-sums of one-step majority- logic （OSMLG） decoding algorithm in conjunction with certain of reliability measures of the received symbols. Computation of reliability measure of the syndrome sum is refined by introducing an attenuation factor. Simulation results show that, in binary-input additive white Gaussian noise （BI-AWGN） channel, the AIML decoding algorithm outperforms other popular iterative reliability-based major- ity-logic （IML） decoding algorithms with a slight increase in computational complexity. Within maximum iteration number of 5, the AIML algorithm can achieve almost identical error performance to sum-product algorithm （SPA）. No error floor effect can be observed for the AIML algorithm down to the bit error rate （BER） of 10- s, while error floor appears for SPA around the BER of 10 7 even with maximum iteration number of 100. Furthermore, the inherent feature of parallel procession for AIML algorithm enforces the decoding speed in contrast to those serial decoding schemes, such as weighted bit-flipping （WBF） algorithm.

关键词： attenuation factor reliability-based iterative,majority-logic low-density parity-check (LDPC) codes

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Changes in Global Vegetation Distribution and Carbon Fluxes in Response to Global Warming:Simulated Results from IAP-DGVM in CAS-ESM2

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Advances in Atmospheric Sciences 2022年第8期39卷 1285-1298,I0002-I0010页

作者： Xiaofei GAO Jiawen ZHU Xiaodong ZENG minghua zhang Yongjiu DAI Duoying JI He zhang International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China School of Marine and Atmospheric Sciences Stony Brook UniversityNY 11790USA School of Atmospheric Sciences Sun Yat-Sen UniversityGuangzhou 510275China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China

Terrestrial ecosystems are an important part of Earth systems,and they are undergoing remarkable changes in response to global *** study investigates the response of the terrestrial vegetation distribution and carbon fluxes to global warming by using the new dynamic global vegetation model in the second version of the Chinese Academy of Sciences(CAS)Earth System Model(CAS-ESM2).We conducted two sets of simulations,a present-day simulation and a future simulation,which were forced by the present-day climate during 1981-2000 and the future climate during 2081-2100,respectively,as derived from RCP8.5 outputs in ***_(2)concentration is kept constant in all simulations to isolate CO_(2)-fertilization *** results show an overall increase in vegetation coverage in response to global warming,which is the net result of the greening in the mid-high latitudes and the browning in the *** results also show an enhancement in carbon fluxes in response to global warming,including gross primary productivity,net primary productivity,and autotrophic *** found that the changes in vegetation coverage were significantly correlated with changes in surface air temperature,reflecting the dominant role of temperature,while the changes in carbon fluxes were caused by the combined effects of leaf area index,temperature,and *** study applies the CAS-ESM2 to investigate the response of terrestrial ecosystems to climate *** though the interpretation of the results is limited by isolating CO_(2)-fertilization effects,this application is still beneficial for adding to our understanding of vegetation processes and to further improve upon model parameterizations.

关键词： global warming vegetation distribution carbon flux leaf area index surface air temperature

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A novel advanced oxidation process——wet electrocatalytic oxidation for high concentrated organic wastewater treatment

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Chinese Science Bulletin 2007年第12期52卷 1724-1727页

作者： DAI QiZhou ZHOU minghua LEI LeCheng zhang XingWang Institute of Environmental Pollution Control Technologies Xixi Campus Zhejiang University Hangzhou 310028 China

A novel advanced oxidation process——wet electrocatalytic oxidation (WEO) was studied with p-nitrophenol as model pollutant and β-PbO2 electrode as the anode. Compared with the effect of the individual wet air oxidation (WAO) and electrochemical oxidation (EO), the effect of WEO showed syn- ergistic effect on COD removal under the conditions of temperature 160℃, C=1000 mg·L-1, PN2=0.50 MPa, PO2=0.9 MPa, current density = 3 mA·cm-2, Na2SO4 3 g·L-1. And the synergistic factor got the best value of 0.98 within 120 min after 180 min treatment. The synergistic factor was studied after 120 min treatment at 100℃, 120℃, 140℃ and 160℃, and the effect of 120℃ was the best with the value of 1.26. Possible mechanism for the synergistic effect was discussed based on the analysis of free-radical generation and intermediates detected by HPLC and GC/MS.

关键词：高浓度有机废水废水处理电化学氧化湿式电催化氧化协同效应

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Earthquake fault framework and seismotectonics of the Songpan-Garze region since 1900

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Earthquake Science 2012年第5期25卷 451-458页

作者： Jiasheng zhang Weijun Gan minghua zhang Xiongnan Huang Feng Liu Institute of Geology China Earthquake Administration Development Research Center of China Geological Survey

Based on 4 781 observed faults （〉2 km length） from a 1：200 000 scale digital geologic map and 5 220 recorded seismic events since the year 1900, 993 earthquake faults are identified within the triangular Songpan-Garze study region. The study area is delineated by the nearly EW-trending East Kunlun fault zone to the north, the NW-trending Xianshuihe fault to the south and the NE-trending Longmenshan thrust belt to the east. Seismicity changes along these earthquake faults, spanning four 10-year intervals since 1970, show that following a strong earthquake swarm, which occurred in the Huya area in the mid-1970s, seismic activity increased from north to south, and migrated eastward along each major strike-slip fault zone. GPS observation data before 2008 indicate a displacement rate across the Xianshuihe fault zone to the south of -6.5- 8.6 mm/a, whereas across the East Kunlun fault zone to the north it was -1.8- 2.2 mm/a. The May 12, 2008 Ms8.0 Wenchuan earthquake, which occurred in the southeast corner of the study region, was the result of stable, high-speed left-lateral displacement along the Xianshuihe fault zone, and a sharp eastward bend of the fault trend in response to the presence of crystalline rocks in the Kangding area. Therefore, the 110-year established seismotectonic framework of the Songpan-Garze region can be defined by a network of various earthquake faults and the structural relations of the local earthquake activities.

关键词： Songpan-Garze region earthquake fault GPS Wenchuan earthquake

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