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Application of GNSS-PPP on Dynamic Deformation Monitoring of Offshore Platforms

China Ocean Engineering 2024年第2期38卷 352-361页

作者： YU Li-na XIONG Kuan GAO Xi-feng LI Zhi FAN Li-long ZHANG Kai Institute of Ocean Energy and Intelligent Construction Tianjin University of TechnologyTianjin 300384China China Railway Construction Bridge Engineering bureau Group Co.LTD Tianjin 300300China School of Civil Engineering Tianjin UniversityTianjin 300072China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Precision Blasting Jianghan UniversityWuhan 430056China

The real-time dynamic deformation monitoring of offshore platforms under environmental excitation is crucial to their safe *** Global Navigation Satellite System-Precise Point Positioning(GNSS-PPP)has been considered for this purpose,its monitoring accuracy is relatively ***,the influence of background noise on the dynamic monitoring accuracy of GNSS-PPP remains ***,it is imperative to further validate the feasibility of GNSS-PPP for deformation monitoring of offshore *** address these concerns,vibration table tests with different amplitudes and frequencies are *** results demonstrate that GNSS-PPP can effectively monitor horizontal vibration displacement as low as±30 mm,which is consistent with ***,the spectral characteristic of background noise in GNSS-PPP is similar to that of GNSS-RTK(Real Time Kinematic).Building on this observation,an improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)has been proposed to de-noise the data and enhance the dynamic monitoring accuracy of *** monitoring application research is also undertaken,successfully extracting and analyzing the dynamic deformation of an offshore platform structure under environmental excitation using GNSS-PPP monitoring in conjunction with improved CEEMDAN *** comparing the de-noised dynamic deformation trajectories of the offshore platform during different periods,it is observed that the platform exhibits reversible alternating vibration responses under environmental excitation,with more pronounced displacement deformation in the direction of load *** research results confirm the feasibility and potential of GNSS-PPP for dynamic deformation monitoring of offshore platforms.

关键词： GNSS-PPP offshore platform dynamic deformation monitoring improved CEEMDAN de-noising

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Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt,Northwest China

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Acta Geochimica 2024年第1期43卷 72-86页

作者： Jiao-Long Zhao Xiao-Jun Huang Pei-Qing Hu Zhen-Xi Yang Ying Fan Er-Teng Wang Fu-Bo Yang Jing-Yu Zhang School of Earth Sciences Key Laboratory of Mineral Resources in Western China(Gansu Province)Lanzhou UniversityLanzhou 730000China Nuclear Industry 247 Brigade Tianjin North China Geological Survey BureauTianjin 301800China Fourth Institute of Geological and Mineral Exploration of Gansu Provincial bureau of Geology and Mineral Resources Jiuquan 735000China

Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline *** are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.

关键词： Silurian adakitic granitoids Petrogenesis Tectonic setting Qilian Orogenic Belt

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Astronomic background of global huge earthquakes at beginning of 21st century

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Applied Geophysics 2024年第3期21卷 423-432,616页

作者： Hu Hui Su You-Jin Yunnan Observatory Chinese Academy of SciencesKunming 650011China seismological bureau of Yunnan Province Kunming 650224China

Since the beginning of the 21st century,major earthquakes have frequently occurred *** explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is used to systematically analyze the effects of astronomical factors,such as solar activity,Earth’s rotation,lunar declination angle,celestial tidal force,and other phenomena on M≥8 global earthquakes at the beginning of the 21st *** regard to solar activity,this study focuses on the analysis of the 11-year and century cycles of solar *** causal relationship of the Earth’s rotation is not obvious in this work and previous works;in contrast,the valley period of the solar activity century cycle may be an important astronomical factor leading to the frequent occurrence of global earthquakes at the beginning of the 21st *** topic warrants further study.

关键词： M≥8.0 earthquake astronomical factors solar activity Earth’s rotation lunar declination angle tidal force phenomena

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Improving the Forecasts of Coastal Wind Speeds in tianjin,China Based on the WRF Model with Machine Learning Algorithms

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Journal of Meteorological Research 2024年第3期38卷 570-585页

作者： Weihang ZHANG Meng TIAN Shangfei HAI Fei WANG Xiadong AN Wanju LI Xiaodong LI Lifang SHENG College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao266100China tianjin Key Laboratory for Oceanic Meteorology Tianjin Institute of Meteorological ScienceTianjin300074China CMA Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing100081China Qingdao Meteorological bureau Qingdao266003China

Characterized by sudden changes in strength,complex influencing factors,and significant impacts,the wind speed in the circum-Bohai Sea area is relatively challenging to *** the western side of Bohai Bay,as the economic center of the circum-Bohai Sea,tianjin exhibits a high demand for accurate wind *** this study,three machine learning algorithms were employed and compared as post-processing methods to correct wind speed forecasts by the Weather Research and Forecast(WRF)model for *** results showed that the random forest(RF)achieved better performance in improving the forecasts because it substantially reduced the model bias at a lower computing cost,while the support vector machine(SVM)performed slightly worse(especially for stronger winds),but it required an approximately 15 times longer computing *** back propagation(BP)neural network produced an average forecast significantly closer to the observed forecast but insufficiently reduced the *** regard to wind speed frequency forecasting,the RF method commendably corrected the forecasts of the frequency of moderate(force 3)wind speeds,while the BP method showed a desirable capability for correcting the forecasts of stronger(force>6)*** addition,the 10-m u and v components of wind(u_(10)and v_(10)),2-m relative humidity(RH_(2))and temperature(T_(2)),925-hPa u(u925),sea level pressure(SLP),and 500-hPa temperature(T_(500))were identified as the main factors leading to bias in wind speed forecasting by the WRF model in tianjin,indicating the importance of local dynamical/thermodynamic processes in regulating the wind *** study demonstrates that the combination of numerical models and machine learning techniques has important implications for refined local wind forecasting.

关键词： machine learning Weather Research and Forecast(WRF)model wind speed forecasting coastal region

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Investigation and measurement of old building response to the overlapped shield tunnel of multiple schemes in the sandy cobble stratum

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Underground Space 2024年第2期15卷 260-274页

作者： Xue Li Aopeng Geng School of Geoscience and Technology Southwest Petroleum UniversityChengduSichuan 610500China China Railway Construction Bridge Engineering bureau Group Co. Ltd.Tianjin 300300China

Ground movements due to tunneling are becoming increasingly critical as buildings are located around construction *** study proposes a new combined reinforcement method using a foundation grouting oblique pipe *** former improves the bearing capacity of the subsoil,and the latter blocks the transmission of soil deformation,which weakens the influence of construction during overlapped tunnel *** on this new method,a case study of the shield tunneling response to an old building in Line 6 of China’s Chengdu Metro is ***,three-dimensional numerical models without reinforcement,traditional foundation grouting reinforcement,and the new combined reinforcement schemes were *** numerical simulation performance was verified using a set of field instrumentation data,which demonstrated that the old building response to the overlapped tunnels was under control,and the maximum deformation,angular distortion,and principal tensile strain of the building were 5.25 mm,5.1010–6 rad/m,and 0.0081%,*** with the traditional reinforcement scheme,the deformation,angular distortion,and principal tensile strain in the combined reinforcement scheme were reduced by 54.78%,71.02%,and 70.22%,*** results have important implications for the design and construction of shield tunnels and their response to old buildings.

关键词： Overlapped tunnels Reinforcement schemes Under-crossing Old building Numerical simulation

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Construction of daily precipitation series and the observational characteristics of extreme precipitation in tianjin,China during 1888-2022

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Advances in Climate Change Research 2024年第1期15卷 52-61页

作者： Peng SI Qing-Xiang LI Xiao-Yang CHEN Min WANG Chuan-Jun LUO tianjin Meteorological Information Center Tianjin Meteorological BureauTianjin 300074China Research Centerfor Ecology and Environment of Central Asia Chinese Academy of SciencesWulumuqi 830011China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China Key Laboratory of Tropical Amosphere-Ocean System Ministry of EducationZhuhai 528478China Shaoguan Meteorological Service Shaoguan 512028China

Given the difficulties in rescuing and ensuring the quality of long-term climate data,current studies on century-scale climate change are usually limited to annual and monthly data,resulting in the poor detection of extreme climate events and their changes before *** this study,we reconstructed a daily precipitation series for tianjin from 15 September 1887 to 31 December 2022 on the basis of the most comprehensive daily precipitation records collected from the tianjin Meteorological Archive,China,and in reference to the precipitation analysis results based on the datasets developed by the Climatic Research Unit Time-Series version 4.06,Global Precipitation Climatology Centre and University of Delaware along with the application of various homogenisation methods for climate *** approach provides a complete and reliable century-long daily precipitation series for the study of regional or local extreme weather and climate *** reconstructed daily dataset reveals that the annual precipitation amount and R95 intensity in tianjin during 1888-2022 lack significant trends and have values of 0.74±6.99 and-1.84±3.22 mm per decade,*** the annual and seasonal scales,the precipitation amount and R95 intensity,particularly those in autumn,have increased since the latter half of the 20th century relative to those in ***,the increase in precipitation amount and R95 intensity is relatively limited compared with that in atmospheric water vapour content due to surface warming,indicating the highly sensitive response of extreme precipitation events to *** addition,the estimates for the return periods of 5,10,20,50 and 100 years covering 1888-2022,1888-1950 and 1951-2022 depict that the intensity of heavy rain and above magnitude was highest in 1888-1950 and decreased in 1951-2022.

关键词： Over a century-long timescale Daily precipitation series Extreme precipitation Return period

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PRRSV degrades MDA5 via dual autophagy receptors P62 and CCT2 to evade antiviral innate immunity

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Virologica Sinica 2024年第2期39卷 264-276页

作者： Ruiqi Sun Yanyu Guo Lilin Zhang Huixia Zhang Boxuan Yin Xiaoyang Li Changyan Li Liu Yang Lei Zhang Zexing Li Jinhai Huang School of Life Sciences Tianjin UniversityTianjin300072China

Porcine reproductive and respiratory syndrome virus(PRRSV)is a major economically devastating pathogen that has evolved various strategies to evade innate *** of antiviral interferon largely promotes PRRSV immunoevasion by utilizing cytoplasmic melanoma differentiation-associated gene 5(MDA5),a receptor that senses viral *** this study,the downregulated transcription and expression levels of porcine MDA5 in PRRSV infection were observed,and the detailed mechanisms were *** found that the interaction between P62 and MDA5 is enhanced due to two factors:the phosphorylation modification of the autophagic receptor P62 by the upregulated kinase CK2αand the K63 ubiquitination of porcine MDA5 catalyzed by the E3 ubiquitinase TRIM21 in PRRSV-infected *** a result of these modifications,the classic P62-mediated autophagy is ***,porcine MDA5 interacts with the chaperonin containing TCP1 subunit 2(CCT2),which is enhanced by PRRSV *** interaction promotes the aggregate formation and autophagic clearance of MDA5-CCT2-nsp3 independently of *** summary,enhanced MDA5 degradation occurs in PRRSV infection via two autophagic pathways:the binding of MDA5 with the autophagy receptor P62 and the aggrephagy receptor CCT2,leading to intense innate immune *** research reveals a novel mechanism of immune evasion in PRRSV infection and provides fundamental insights for the development of new vaccines or therapeutic strategies.

关键词： Porcine reproductive and respiratory syndrome virus(PRRSV) nsp3 Autophagy MDA5

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Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease

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World Journal of Gastroenterology 2024年第10期30卷 1393-1404页

作者： Ming-Hui Zeng Qi-Yu Shi Liang Xu Yu-Qiang Mi Clinical School of the Second People’s Hospital Tianjin Medical UniversityTianjin 300192China Department of Gastroenterology Cangzhou People’s HospitalCangzhou 061000Hebei ProvinceChina Department of Hepatology Tianjin Second People’s HospitalTianjin 300192China tianjin Research Institute of Liver Diseases Tianjin 300192China

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is the most common liver disease worldwide,affecting about 1/4th of the global population and causing a huge global economic *** date,no drugs have been approved for the treatment of NAFLD,making the correction of unhealthy lifestyles the principle method of *** patients with poor adherence to lifestyle correction and attempting to improve their adherence are therefore very *** To develop and validate a scale that can rapidly assess the adherence of patients with NAFLD to lifestyle *** The Exercise and Diet Adherence Scale(EDAS)was designed based on com-pilation using the Delphi method,and its reliability was subsequently *** and laboratory indicators were measured,and patients completed the EDAS questionnaire at baseline and after 6 *** efficacy of the EDAS was evaluated in the initial ***,the efficacy of the EDAS was internally verified in a validation *** The EDAS consisted of 33 items in six dimensions,with a total of 165 *** EDAS score correlated significantly with daily number of exercise and daily reduction in calorie intake(P500 kacl/d),(sensitivity/specificity was 100.0%/75.8%),while patients score below 97 could nearly rule out the possibility of daily exercise(sensitivity/specificity was 89.5%/44.4%).Total EDAS scores≥116,97-115,and<97 points were indicative of good,average,and poor adherence,respectively,to diet and exercise *** The EDAS can reliably assess the adherence of patients with NAFLD to lifestyle interventions and have clinical application in this population.

关键词： Fatty liver Lifestyle intervention Behavioral change Patient adherence Compliance

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Theoretical researches on three-dimensional coda wave scattering problem

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Acta Seismologica Sinica(English Edition) 1995年第1期8卷 83-87页

作者：聂永安曾健冯德益 seismological bureau of tianjin Tianjin China seismological bureau of Sichuan Province Chengdu China

Based on the previous researches on scattering theory, a model of single and multiple scattering in a three-dimensional infinite medium with non-zero hypocentral distance is proposed in this paper. According to the assumptionof three-dimensional medium with numerous, statistically isotropic and uniformly distributed scatterers, we obtain the analytic form of power spectrum of coda waves for single scattering and the integral form of power spectrum of coda waves for multiple scattering.

关键词： coda wave three-dimensional model

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Comparison　and　analysis　of　the　stress　field　in　the　source　region　of　Tangshan　and　Lancang　earthquake　sequences

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Acta Seismologica Sinica(English Edition) 1995年第3期8卷 379-386页

作者：刁桂苓于利民李钦祖 seismological bureau of tianjin Tianjin China seismological bureau of Hebei Province Shijiazhuang China seismological bureau of Yunnan Province Kunming China

The state of the stress fields in the source region is analysed systematically, on the basis of the focal mechanismsof 167 events with Ms≥4. 0 of Tangshan sequence and 163 moderate-small events of Lancang sequence respectively. The result indicates that the directions of the stress field in the source region are generally stable and thevariation is not obvious after the occurrence of strong shock. The dominant orientations of focal mechanisms ofthe aftershocks are consistent with that of the mainshock, there is still a small difference between some mechanisms of aftershocks and the mechanism of mainshock, and the difference decreases as time goes on. The numbers of solutions with dominant direction of Tangshan and Lancang sequences are similar to each other, it indicates that the controls of the strong earthquake sequences from the tectonic stress field are similar to each othertoo. Through the hierarchical clustering analysis of focal mechanism,it is found that the number of clusters ofTangshan sequence is larger than that of Lancang sequence,and their orientations are relatively disordered. Itmay be the cause that the tectonics in the Tangshan region are more complicated than those in the Lancang region.

关键词： focal mechanism stress field Tangshan earthquake sequence Lancang earthquake sequence

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