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Fiber optic sensing and performance evaluation of a water conveyance tunnel with composite linings under super-high internal pressures

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第8期15卷 1997-2012页

作者： Deyang Wang Honghu Zhu Jingwu Huang Zhenrui Yan Xing Zheng Bin Shi School of Earth Sciences and Engineering Nanjing UniversityNanjing210023China Nanjing University High-Tech institute at Suzhou Suzhou215123China Guangdong Hydropower planning and design institute Guangzhou510635China Zhejiang Huadong Construction Engineering Co.Ltd. Hangzhou310012China

For long-distance water conveyance shield tunnels in operation,the high internal water pressure may cause excessive deformation of composite linings,affecting their structural integrity and ***,the deformation and failure characteristics of lining structures under internal water pressure are not well investigated in the literature,particularly for three-layer composite *** study presents an in situ experimental investigation on the response of two types of composite linings(*** and combined lining structures)subjected to internal pressures,in which a fiber optic nerve system(FONS)equipped with distributed strain and displacement sensing nerves was employed to monitor the performance of the two composite linings during *** experimental results clearly show that the damage of the tunnel lining under different internal pressures was mainly located in the self-compaction concrete *** separated lining structure responded more aggressively to the variations in internal pressures than the combined ***,two evaluation indices,*** displacement and effective stiffness coefficient,are proposed for describing the changes in the structural bearing *** effective stiffness coefficients of the two types of lining structures were reduced by 39.4%and 29.5%,*** the convenience of field monitoring,it is suggested that the average strains at different layers can be used as characteristic parameters for estimating the health conditions of lining structures in *** analysis results provide a practical reference for the design and health evaluation of water conveyance shield tunnels with composite linings.

关键词： Water conveyance tunnel Composite lining interface Strain measurement Geotechnical monitoring Fiber optic nerve system(FONS)

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PS-G-GERT Effectiveness Evaluation Model of Link-Based GEO Satellite Communication Constellation under Poor Information Background

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China communications 2022年第12期19卷 176-196页

作者： Ruirui Shao Zhigeng Fang Su Gao Sifeng Liu Weiqing You College of Economics and Management Nanjing University of Aeronautics&AstronauticsNanjing 211106China institute of Telecommunication Satellite China Academy of Space Technology(CAST) Beijing 100094China National Cryptography Administration of jiangsu province Nanjing 210013China

The effectiveness evaluation of GEO satellite communication constellation not only characterizes the communication capability of the constellation but also provides a basis for optimizing the constellation *** due to information poverty or the complexity of the system,the impact of uncertain information on the effectiveness evaluation needs to be considered to ensure the accuracy of the evaluation *** address this issue,this paper develops a model for evaluating the GEO satellite communication constellation’s effectiveness in the context of poor ***,it analyses the GEO satellite communication constellation plus system based on communication links with an in-depth analysis of the constellation ***,an equivalent transfer function algorithm based on the characteristic function and transfer probability is proposed with the help of graphical evaluation and review ***,by analyzing the communication link importance connotation,the algorithm formula of communication link effectiveness and its importance is derived,and the constellation effectiveness and variance are ***,the model constructed in this paper is used to evaluate the effectiveness of a GEO satellite communication constellation,further verifying the accuracy and validity of the *** comparative analysis,it is shown that the model can not only solving the effectiveness of the constellation but also analyzing the variation of its *** lays a theoretical foundation for the analysis and optimization of the GEO satellite communication constellation effectiveness.

关键词： poor information graphical evaluation and review technique(GERT) plus system(PS) effectiveness evaluation

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A low-floor bit-mapping scheme for LDPC coded BICM for 5G and beyond systems

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Science China(Information Sciences) 2023年第10期66卷 263-277页

作者： Mingyang ZHU Ming JIANG Chunming ZHAO Lijie HU Xiaodong XU National Mobile communications Research Laboratory Southeast University Purple Mountain Laboratories China Mobile Research institute

This paper proposes a low-floor bit-mapping(LFBM) scheme for bit-interleaved coded modulation(BICM) systems to meet more stringent quality of service requirements of 5G and beyond. For highefficiency transmissions, we consider the 5G low-density parity-check codes with high-order 2m-quadrature amplitude modulations(QAMs). The proposed LFBM scheme overcomes plenty of trapping sets induced by the bit interleaver, which focuses on the waterfall performance too aggressively. When the high-order QAM is used, the row-column interleaver specified by the 5G standard is such a bit interleaver. The LFBM scheme only optimizes the rule of mapping an m-bit tuple output by the row-column interleaver to a modulation symbol, rather than the entire bit interleaver. Therefore, the optimized bit mapper is actually an m-bit permutation module concatenated with the original bit interleaver employed in the current 5G BICM *** simulation results confirm that the LFBM scheme can lower the error floor of the 5G BICM system by approximately two orders of magnitude, while with negligible performance loss in the waterfall region.

关键词： bit-interleaved coded modulation low-density parity-check codes error floors bit mapping high-order modulation

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Experimental Investigation on Fracture Performance of Short Basalt Fiber Bundle Reinforced Concrete

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Structural Durability & Health Monitoring 2022年第4期16卷 291-305页

作者： Jinggan Shao Jiao Ma Renlong Liu Ye Liu Pu Zhang Yi Tang Yunjun Huang School of Water Conservancy and Civil Engineering Zhengzhou UniversityZhengzhou450001China Henan Traffic Engineering Technology Co. Ltd.Zhengzhou450015China Key Laboratory of Deep Underground Science and Engineering(Ministry of Education) College of Architecture and EnvironmentSichuan UniversityChengdu610065China Henan Provincial communications planning&design institute Co. Ltd.Zhengzhou450015China

In this paper,a notched three-point bending test is used to study the fracture performance of the short basalt fiber bundle reinforced concrete(SBFBRC).To compare and analyze the enhancement effect of different diameters and different content of basalt fiber bundles on the fracture performance of concrete,some groups are set up,and the P-CMOD curves of each group of specimens are measured,and the fracture toughness and fracture energy of each control group are *** fracture toughness and fracture energy are two important fracture performance parameters to study the effect and law of the new basalt fiber bundles on the fracture performance of *** research results show that the diameter and content of the new basalt fiber bundles have a certain effect on the fracture performance of *** the increase of the content of basalt fiber bundles,the peak load,crack initiation toughness,instability toughness and fracture energy of SBFBRC are greatly improved compared with the benchmark *** the fiber bundle diameter is 0.2 mm,the peak load increases by 69.5%compared with the reference *** instability toughness reaches its maximum value at 0.2 mm diameter,which is 59.7%higher than the benchmark.

关键词： Basalt fiber bundle fracture toughness fracture energy fiber concrete

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General design of Sutong Bridge

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Engineering Sciences 2009年第1期7卷 6-11页

作者： Zhang Xigang Yuan Hong Pei Minshan Dai Jie Xu Lin CCCC Highway Consultants Co. Ltd. Beijing 100088 China jiangsu province communications planning and design institute Nanjing 210005 China

The main span of Sutong Bridge is a double-pylon,double-plane cable-stayed bridge with steel box girder,which has the world's longest central span of 1 088 m within cable-stayed *** overcome problems caused by severe meteorological conditions,perplexing hydrological conditions,deep buried bedrock and higher navigation level,many new technics and methods were *** including structural system,steel box girder,stayed cable,tower,pier,tower foundation,collision avoidance system,wind-resistance,seismic-resistance,structural nonlinear response and structural static stability were presented individually in this paper.

关键词： cable-stayed bridge structural system steel box girder stayed cable tower tower foundation

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On the effects of urban-like intersections on ventilation and pollutant dispersion

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Building Simulation 2022年第3期15卷 419-433页

作者： Xin Guo Riccardo Buccolieri Zhi Gao Mingjie Zhang Tong Lyu Liyan Rui Jialei Shen School of Architecture and Urban planning Nanjing University22 Hankou RoadNanjing 210093Jiangsu ProvinceChina Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali Laboratory of MicrometeorologyUniversity of SalentoS.P.6 Lecce-Monteroni73100LecceItaly Department of Green Building and Low-Carbon Development Shanghai Research Institute of Building Sciences568 Shenfu RoadShanghai201108China Department of Mechanical and Aerospace Engineering Syracuse UniversitySyracuseNY13210USA

Focusing on the effect of street morphology on the ventilation efficiency,this paper presents 3D computational fluid dynamics(CFD)simulations of airflow and pollutant dispersion within urban-like three-way intersections,four-way intersections and *** steady-state Reynolds-averaged Navier-Stokes(RANS)k-εturbulence model is adopted and eight directions of the approaching wind are *** ventilation efficiency is evaluated using the ventilation indices purging flow rate(PFR)and the net escape velocity(NEV).Results show the sensitivity of the ventilation efficiency to the type of intersection,to the wind direction and to the number of ***,the ventilation efficiency of the investigated three-way intersections is found to be better than that of the other intersections,especially when the angle between the streets is large,while that of roundabouts is also considerable,even with a similar average wind velocity,among the cases evaluated in this ***,the influence of the wind direction for the three-way and four-way intersections is greater than that on *** on the ventilation efficiency at urban intersections are not common in the literature and this work may help urban planners to better design such hub nodes of urban traffic,where traffic-related pollutants are not easily dispersed,thus avoiding harm to the health of pedestrians and surrounding residents.

关键词： urban-like intersections ventilation efficiency CFD simulations traffic-related pollutants

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Understanding groundwater table using a statistical model

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Water Science and Engineering 2018年第1期11卷 1-7页

作者： Shao-feng Yan Shuang-en Yu Yu-bai Wu De-feng Pan Jia-gen Dong Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China Ministry of EducationHohai UniversityNanjing 210098China Hubei Provincial Water Resources and Hydropower planning Survey and design institute Wuhan 430064China jiangsu Water Conservancy Research institute Nanjing 210017China jiangsu Coastal Water Conservancy Research institute Dongtui 224200China jiangsu province Hydrology and Water Resources Investigation Bureau Nanjing 210008China

In this study, a statistical model was established to estimate the groundwater table using precipitation, evaporation, the river stage of the Liangduo River, and the tide level of the Yellow Sea, as well as to predict the groundwater table with easily measurable climate data in a coastal plain in eastern China. To achieve these objectives, groundwater table data from twelve wells in a farmland covering an area of 50 m ~ 150 m were measured over a 12-month period in 2013 in Dongtai City, jiangsu province. Trend analysis and correlation analysis were conducted to study the patterns of changes in the groundwater table. In addition, a linear regression model was established and regression analysis was conducted to understand the relationships between precipitation, evaporation, river stage, tide level, and groundwater table. The results are as follows：（1） The groundwater table was strongly affected by climate factors （e.g., precipitation and evaporation）, and river stage was also a significant factor affecting the groundwater table in the study area （p 〈 0.01, where p is the probability value）. （2） The groundwater table was especially sensitive to precipitation. The significance of the factors of the groundwater table were ranked in the following descending order： precipitation, evaporation, and river stage. （3） A triple linear regression model of the groundwater table, precipitation, evaporation, and river stage was established. The linear relationship between the groundwater table and the main factors was satisfied by the actual values versus the simulated values of the groundwater table （R^2 = 0.841, where R^2 is the coefficient of determination）.

关键词： Groundwater table Precipitation Evaporation Climate factors Regression statistics Coastal plain

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Optimal experimental methods of the large-scale mathematical programming and applications

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Science China(Technological Sciences) 1998年第5期41卷 465-470页

作者：程吉林郭元裕金兆森陶长生陈宝华 Department of Hydraulogy Yangzhou University Yangzhou China Wuhan University of Hydraulic & Electric Engineering Wuhan China Hydraulic Bureau of jiangsu province Nanjing China planning institute of Taihu Suzhou China

The optimal experimental methods of a multidimensional dynamic programming, a large-scale linear and a complex nonlinear system are presented, which achieve a great step forward in the field of systems science. And ex... 详细信息

关键词： a large scale system optimization technique experimental method mathematical programming.

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Effect of Sludge Retention Time on the Fate of Proteins and Polysaccharides in AAO Process

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Journal of Donghua University(English Edition) 2015年第3期32卷 401-405页

作者：杜勇立黄满红郑宇 School of Civil and Architectural Engineering Central South University Hunan Provincial communications planning Survey & Design Institute School of Environmental Science and Engineering Donghua University

Effect of sludge retention time( SRT) on the removal of potential and polysaccharides in an anaerobic / anoxic / aerobic( AAO) process was investigated. The Lowry method and anthrone method were used to detect proteins and polysaccharides. Total removal efficiency of proteins at SRT of 10 to 25 d in the AAO system was higher than 90%. Polysaccharides removal efficiencies were above 80% when SRT was increased from 15 to 25 d,whereas only 81% of polysaccharides was removed at SRT of 10 d. The biodegradation part of proteins and polysaccharides increased from87. 40% to 93% and from 74. 22% to 86. 94% with increasing *** ratios of polysaccharides and proteins in extracellular polymer substances( EPSs) were around 1. 5-3 in different SRTs. As SRT increasing,polysaccharides and proteins discharged with residual sludge decreased gradually. The amount of EPSs decreased with increasing SRTs.

关键词： protein polysaccharide sludge retention time(SRT) anaerobic / anoxic / aerobic(AAO) system extracellular polymer substances(EPSs)

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Uncertainty analysis of seawater intrusion forecasting

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Water Science and Engineering 2013年第4期6卷 380-391页

作者： Zhong-wei ZHAO Jian ZHAO Chang-sheng FU State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Water Conservancy and Hydropower Engineering Hohai University jiangsu Provincial Communication planning and design institute

In order to describe the importance of uncertainty analysis in seawater intrusion forecasting and identify the main factors that might cause great differences in prediction results, we analyzed the influence of sea level rise, tidal effect, the seasonal variance of influx, and the annual variance of the pumping rate, as well as combinations of different parameters. The results show that the most important factors that might cause great differences in seawater intrusion distance are the variance of pumping rate and combinations of different parameters. The influence of sea level rise can be neglected in a short-time simulation （ten years, for instance）. Retardation of seawater intrusion caused by tidal effects is obviously important in aquifers near the coastline, but the influence decreases with distance away from the coastline and depth away from the seabed. The intrusion distance can reach a dynamic equilibrium with the application of the sine function for seasonal effects of influx. As a conclusion, we suggest that uncertainty analysis should be considered in seawater intrusion forecasting, if possible.

关键词： Key words: seawater intrusion forecasting uncertainty analysis deterministic model uncertainty model factorial design

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