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Morphometrics of Heliolites(Tabulata) from the Late Ordovician, Yushan, Jiangxi, South China

Acta Geologica Sinica(English Edition) 2015年第1期89卷 38-54页

作者： dai mingjian LIU Lu LEE Dong-Jin PENG Yunbiao MIAO Aisheng China University of Geosciences CNNC No.208 Geology Party Andong National University

The Upper Ordovician Xiazhen Formation in the Jiangshan-Changshan-Yushan （JCY） triangle area on the Zhejiang-Jiangxi provincial border, South China, is composed of a mixed carbonate-siliciclastic sequence representing various shallow-water platform environments. Highly diversified and abundant heliolitid coral faunas are recognized in the formation and occur over time and space in certain stratigraphic horizons and various lithofacies. Heliolites has been studied using multivariate morphometric analysis applied to differentiate species and evaluate intraspecific and interspecific variations. Ten morphological characters quantified by examination and measurement from transverse and longitudinal thin sections and statistically tested allowed selection of effective characters to discriminate species. Results of frequency histograms, correlation analysis and principle component analysis indicated that certain characters would be suitable for cluster analysis, which were performed on principle component score matrices obtained from the raw data set coordinated with coralla by all those characters. Five major clusters at a relative distance of five on the resulting dendrogram of Heliolites are regarded as morphospecies thus making valid taxa： Heliolites tashanensis Lin and Chow, 1977; Heliolites caracolica （Lin and Chow, 1977）; Heliolites columella （Lin and Chow, 1977）; Heliolites waicunensis Lin and Chow, 1977; and H. sinensis irregularis Lin and Chow, 1977. The discrimination of these morphospecies by the cluster analysis is verified by discriminant analyses and descriptive statistics.

关键词： Taxonomy tabulate corals morphometrics Ashgillian Zhejiang-Jiangxi provinces

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基于超宽频电压监测的大型水电站雷击暂态过电压分析

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浙江电力 2024年第2期43卷 40-48页

作者：庞理声丁登伟李星戴明建韦金国陈泰瑜郭海霞大唐观音岩水电开发有限公司昆明650011 清华四川能源互联网研究院成都610213

水电站出线遭受雷击时将产生严重的雷击侵入过电压,站内GIS(气体绝缘组合电器)隔离开关和断路器操作也将激发VFTO(特快速暂态过电压),严重威胁GIS及变压器设备的绝缘安全。为此,在水电站主变压器高压侧的GIS设备上增设超宽频暂态电压传... 详细信息

水电站出线遭受雷击时将产生严重的雷击侵入过电压,站内GIS(气体绝缘组合电器)隔离开关和断路器操作也将激发VFTO(特快速暂态过电压),严重威胁GIS及变压器设备的绝缘安全。为此,在水电站主变压器高压侧的GIS设备上增设超宽频暂态电压传感器,构建水电站暂态电压在线监测系统,完整记录水电站出线遭受雷击时的站内暂态响应过程。通过对暂态电压时域和频域特征分析发现:水电站出线遭受雷击接地故障时,断路器可能出现断口重燃;基于侵入水电站的雷击暂态电压波形可实现准确的故障单端定位,当线路雷击距离水电站10 km以内时,侵入水电站内部的暂态电压将威胁变压器绝缘。利用超宽频暂态电压监测系统可准确记录水电站内异常暂态事件,通过各测点暂态波形的时域和频域特征对比分析,可定位暂态激励源位置,有助于发现设备异常并及时预警,保障设备运行可靠性和水电稳定外送。

关键词：超宽频电压检测水电站出线雷击暂态电压时频分析

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A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple Subway Tunnels

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2893-2915页

作者： Shen Yan Dajiang Geng Ning dai mingjian Long Zhicheng Bai College of Civil Engineering Tongji UniversityShanghai200092China China Construction 4th Engineering Bureau 6th Corp. Ltd.Shanghai201199China Department of Civil and Architecture Engineering Hubei Polytechnic UniversityHuangshi435003China

According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.

关键词： Crossing tunnels transfer structure force mechanism simplify analysis layered soil mass

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Biohythane production from two-stage anaerobic digestion of food waste:A review

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Journal of Environmental Sciences 2024年第5期139卷 334-349页

作者： Xiaona An Ying Xu Xiaohu dai State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

The biotransformation of food waste(FW)to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal problems.To this end,a promising technique is two-stage anaerobic digestion(TSAD),in which the FW is transformed to biohythane,a gaseous mixture of biomethane and biohydrogen.This review summarises the main characteristics of FW and describes the basic principle of TSAD.Moreover,the factors influencing the TSAD performance are identified,and an overview of the research status;economic aspects;and strategies such as pre-treatment,co-digestion,and regulation of microbial consortia to increase the biohythane yield from TSAD is provided.Additionally,the challenges and future considerations associated with the treatment of FW by TSAD are highlighted.This paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment.

关键词： Two-stage anaerobic digestion(TSAD) Food waste(FW) Methane production Hydrogen production

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Neighborhood predictors of short sleep duration and bedtime irregularity among children in the United States: results from the 2019-2020 National Surveyof Children's Health

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World Journal of Pediatrics 2024年第1期20卷 73-81页

作者： Ying dai Jianghong Liu School of Nursing University of Pennsylvania418 Curie Blvd.Room 426Claire M.Fagin HallPhiladelphiaPA19104-6096USA

Background Environmental factors may contribute to short sleep duration and irregular bedtime in children.Neighborhood factors and children's sleep duration and bedtime regularity remain a less investigated area.The aim of this study was to investigate the national and state-level proportions of children with short sleep duration and irregular bedtime and their neighborhood predictors.Methods A total of 67,598 children whose parents completed the National Survey of Children's Health in 2019-2020 were included in the analysis.Survey-weighted Poisson regression was used to explore the neighborhood predictors of children's short sleep duration and irregular bedtime.Results The prevalence of short sleep duration and irregular bedtime among children in the United States(US)was 34.6%[95%confidence interval(CI)=33.8%-35.4%]and 16.4%(95%CI=15.6%-17.2%)in 2019-2020,respectively.Safe neighborhoods,supportive neighborhoods,and neighborhoods with amenities were found to be protective factors against children's short sleep duration,with risk ratios ranging between 0.92 and 0.94,P<0.05.Neighborhoods with detracting elements were associated with an increased risk of short sleep duration[risk ratio(RR)=1.06,95%CI=1.00-1.12]and irregular bedtime(RR=1.15,95%CI=1.03-1.28).Child race/ethnicity moderated the relationship between neighborhood with amenities and short sleepduration.Conclusions Insufficient sleep duration and irregular bedtime were highly prevalent among US children.A favorable neighborhood environment can decrease children's risk of short sleep duration and irregular bedtime.Improving the neighborhood environment has implications for children's sleep health,especially for children from minority racial/ethnic groups.

关键词： Child National Survey of Children's Health Neighborhood.Sleep Social determinants of health

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Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 163-178页

作者： Wu Houli Guo Endong Wang Jingyi dai Xin dai Chenxi Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much attention.This paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame structure.Different material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic performance.Floor response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical simulation.The acceleration response and displacement response of different combinations are compared.The results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes.

关键词： water supply pipe different materials shaking table test amplification factor seismic fragility

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Near-field wideband beam training for ELAA with uniform circular array

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Science China(Information Sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong dai Department of Electronic Engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

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Prenatal cadmium exposure impairs neural tube closure via inducing excessive apoptosis in neuroepithelium

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Journal of Environmental Sciences 2024年第4期138卷 572-584页

作者： Shiyong Zhu Xuenan Li Xueyan dai Jinlong Li College of Veterinary Medicine Northeast Agricultural UniversityHarbin 150030China Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment Northeast Agricultural UniversityHarbin 150030China Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine Northeast Agricultural UniversityHarbin 150030China

Birth defects have become a public health concern.The hazardous environmental factors exposure to embryos could increase the risk of birth defects.Cadmium,a toxic environmental factor,can cross the placental barrier during pregnancy.Pregnant woman may be subjected to cadmium before taking precautionary protective actions.However,the link between birth defects and cadmium remains obscure.Cadmium exposure can induce excessive apoptosis in neuroepithelium during embryonic development progresses.Cadmium exposure activated the p53 via enhancing the adenosine 5‘-monophosphate(AMP)-activated protein kinase(AMPK)and reactive oxygen species'(ROS)level.And cadmium decreases the level of Paired box 3(Pax3)and murine double minute 2(Mdm2),disrupting the process of p53 ubiquitylation.And p53 accumulation induced excessive apoptosis in neuroepithelium during embryonic development progresses.Excessive apoptosis led to the failure of neural tube closure.The study emphasizes that environmental materials may increase the health risk for embryos.Cadmium caused the failure of neural tube closure during early embryotic day.Pregnant women may be exposed by cadmium before taking precautionary protective actions,because of cadmium concentration-containing foods and environmental tobacco smoking.This suggests that prenatal cadmium exposure is a threatening risk factor for birth defects.

关键词： Cadmium Neural tube closure Excessive apoptosis p53 Embryogenesis

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How plants sense and respond to osmotic stress

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Journal of Integrative Plant Biology 2024年第3期66卷 394-423页

作者： Bo Yu dai-Yin Chao Yang Zhao Shanghai Center for Plant Stress Biology CAS Center for Excellence in Molecular Plant SciencesThe Chinese Academy of SciencesShanghai 200032China Key Laboratory of Plant Carbon Capture The Chinese Academy of SciencesShanghai 200032China National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyThe Chinese Academy of SciencesShanghai 200032China University of Chinese Academy of Sciences Beijing 100049China

Drought is one of the most serious abiotic stresses to land plants.Plants sense and respond to drought stress to survive under water deficiency.Scientists have studied how plants sense drought stress,or osmotic stress caused by drought,ever since Charles Darwin,and gradually obtained clues about osmotic stress sensing and signaling in plants.Osmotic stress is a physical stimulus that triggers many physiological changes at the cellular level,including changes in turgor,cell wall stiffness and integrity,membrane tension,and cell fluid volume,and plants may sense some of these stimuli and trigger downstream responses.In this review,we emphasized water potential and movements in organisms,compared putative signal inputs in cell wall-containing and cell wall-free organisms,prospected how plants sense changes in turgor,membrane tension,and cell fluid volume under osmotic stress according to advances in plants,animals,yeasts,and bacteria,summarized multilevel biochemical and physiological signal outputs,such as plasma membrane nanodomain formation,membrane water permeability,root hydrotropism,root halotropism,Casparian strip and suberin lamellae,and finally proposed a hypothesis that osmotic stress responses are likely to be a cocktail of signaling mediated by multiple osmosensors.We also discussed the core scientific questions,provided perspective about the future directions in this field,and highlighted the importance of robust and smart root systems and efficient source-sink allocations for generating future high-yield stress-resistant crops and plants.

关键词： cell volume drought membrane tension osmotic stress turgor

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Metagenomics reveals the microbial community and functional metabolism variation in the partial nitritation-anammox process:From collapse to recovery

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Journal of Environmental Sciences 2024年第1期135卷 210-221页

作者： Hong Wang Hui Gong Xiaohu dai Min Yang State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China BIOMATH Department of Data Analysis and Mathematical ModellingGhent UniversityGhent 9000Belgium

Mainstream partial nitritation-anammox(PNA)process easily suffers from performance instability and even reactor collapse in application.Thus,it is of great significance to unveil the characteristic of performance recovery,understand the intrinsic mechanism and then propose operational strategy.In this study,we combined long-term reactor operation,batch tests,and metagenomics to reveal the succession of microbial community and functional metabolism variation from system collapse to recovery.Proper aeration control(0.10-0.25mg O_(2)/L)was critical for performance recovery.It was also found that Candidatus Brocadia became the dominant flora and its abundance increased from 3.5%to 11.0%.Significant enhancements in carbon metabolism and phospholipid biosynthesis were observed during system recovery,and the genes abundance related to signal transduction was dramatically increased.The up-regulation of sdh and suc genes showed the processes of succinate dehydrogenation and succinyl-CoA synthesis might stimulate the production of amino acids and the synthesis of proteins,thereby possibly improving the activity and abundance of AnAOB,which was conducive to the performance recovery.Moreover,the increase in abundance of hzs and hdh genes suggested the enhancement of the anammox process.Changes in the abundance of key genes involved in nitrogen metabolism indicated that nitrogen removal pathway was more diverse after system recovery.The achievement of performance recovery was driven by anammox,nitrification and denitrification coupled with dissimilatory nitrate reduction to ammonium.These results provide deeper insights into the recovery mechanism of PNA system and also provide a potential regulation strategy for the stable operation of the mainstream PNA process.

关键词： Partial nitritation-anammox Metagenomics Microbial community Functional metabolism Recovery

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