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Equivalent linear model for seismic damage evaluation of single-degree-of-freedom systems representing reinforced concrete structures considering cyclic degradation behavior

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 637-648页

作者： Lulu Yan Ding-Hao Yu research center for Geotechnical and Structural Engineering Technology of Liaoning Province Dalian UniversityDalian116622China State Key Laboratory of coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

In this study,a novel equivalent damping ratio model that is suitable for reinforced concrete(RC)structures considering cyclic degradation behavior is developed,and a new equivalent linearization analysis method for implementing the proposed equivalent damping ratio model for use in seismic damage evaluation is *** this end,Ibarra’s peak-oriented model,which incorporates an energy-based degradation rule,is selected for representing hysteretic behavior of RC structure,and the optimized equivalent damping for predicting the maximum displacement response is presented by using the empirical method,in which the effect of cyclic degradation is ***,the relationship between the hysteretic energy dissipation of the inelastic system and the elastic strain energy of the equivalent linear system is established so that the proposed equivalent linear system can be directly integrated with the Park-Ang seismic model to implement seismic damage *** to the simplicity of the equivalent linearization method,the proposed method provides an efficient and reliable way of obtaining comprehensive insight into the seismic performance of RC *** verification demonstrates the validity of the proposed method.

关键词： degrading system equivalent linear system equivalent damping seismic damage RC structures

Reproductive biology of Hemitripterus villosus in the Bohai Strait,China

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Journal of Oceanology and Limnology 2024年第3期42卷 881-892页

作者： Ping SUN Song QIN Zhengyi LIU Longchuan ZHUANG Key Laboratory of coastal Biology and Biological Resource Utilization Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China University of Chinese Academy of Sciences Beijing 100049China center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species,a year-round detail study was conducted for the first *** total,263 individuals were randomly sampled off the coasts of the Bohai *** show that and the overall female-to-male ratio(1.35:1)did not differ significantly from the 1:1 sex *** length and weight relationship for females and males were regressed,depicting an isometric growth for both *** reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were *** monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to *** average diameter of eggs ranged from 2.10 to 3.57 *** length at first sexual maturity was 224.87 mm for females and 241.26 mm for *** positive relationships between absolute fecundity and fish size,and also gonadal weight were *** from the Bohai Strait exhibited smaller body size,smaller egg diameter,lower gonadosomatic index,lower absolute fecundity,and higher population extinction risk than the other populations’studied *** findings contribute to understanding the status of this isolated westernmost population,and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait.

关键词： Hemitripterus villosus Bohai Strait fecundity length at first maturity reproductive seasonality

Wmic-GMTS and Wmic-GMERR criteria for micron-scale crack propagation in red-bed soft rocks under hydraulic action

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3641-3660页

作者： Guangjun Cui Chunhui Lan Cuiying Zhou Zhen Liu Chang Xia Institute of Estuarine and coastal research School of Ocean Engineering and TechnologySun Yat-sen UniversityGuangzhou510275China Guangdong Provincial Engineering research center of Coasts Islands and ReefsSun Yat-sen UniversityGuangzhou510275China Guangdong Engineering research center for Major Infrastructure Safety Sun Yat-sen UniversityGuangzhou510275China The Hong Kong Polytechnic University Hong KongChina

Micron-scale crack propagation in red-bed soft rocks under hydraulic action is a common cause of engineering disasters due to damage to the hard rockesoft rockewater *** studies have not provided a theoretical analysis of the length,inclination angle,and propagation angle of micron-scale cracks,nor have they established appropriate criteria to describe the crack propagation *** propagation mechanism of micron-scale cracks in red-bed soft rocks under hydraulic action is not yet fully understood,which makes it challenging to prevent engineering disasters in these types of *** address this issue,we have used the existing generalized maximum tangential stress(GMTS)and generalized maximum energy release rate(GMERR)criteria as the basis and introduced parameters related to micron-scale crack propagation and water *** GMTS and GMERR criteria for micronscale crack propagation in red-bed soft rocks under hydraulic action(abbreviated as the Wmic-GMTS and Wmic-GMERR criteria,respectively)were established to evaluate micron-scale crack propagation in redbed soft rocks under hydraulic *** influence of the parameters was also *** process of micron-scale crack propagation under hydraulic action was monitored using uniaxial compression tests(UCTs)based on digital image correlation(DIC)*** study analyzed the length,propagation and inclination angles,and mechanical parameters of micron-scale crack propagation to confirm the reliability of the established *** findings suggest that the Wmic-GMTS and Wmic-GMERR criteria are effective in describing the micron-scale crack propagation in red-bed soft rocks under hydraulic *** study discusses the mechanism of micron-scale crack propagation and its effect on engineering disasters under hydraulic *** covers topics such as the internal-external weakening of nano-scale particles,lateral propagation of micron-scale cracks,weakening of the mechanical properties

关键词： Red-bed soft rocks Hydraulic action Micron-scale cracks Generalized maximum tangential stress (GMTS)criterion Generalized maximum energy release rate (GMERR)criterion Digital image correlation(DIC)

Summer Atmospheric Water Cycle under the Transition Influence of the Westerly and Summer Monsoon over the Yarlung Zangbo River Basin in the Southern Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第5期41卷 830-846页

作者： Qianhui MA Chunyan ZHANG Donghai WANG Zihao PANG School of Atmospheric Sciences Sun Yat-sen UniversityGuangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesKey Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Guangdong Meteorological Data center Guangdong Meteorological ServiceGuangzhou 510080China National Observation and research Station of coastal Ecological Environments in Macao Macao Environmental Research InstituteMacao University of Science and TechnologyMacao SAR 999078China National Meteorological Information center China Meteorological AdministrationBeijing 100081China

This study compares the summer atmospheric water cycle,including moisture sources and consumption,in the upstream,midstream,and downstream regions of the Yarlung Zangbo River Basin in the southern Tibetan *** evolutions of moisture properties under the influence of the westerly and summer southerly monsoon are examined using 5-yr multi-source measurements and ERA5 reanalysis *** that moisture consumption in this study is associated with clouds,precipitation,and diabatic *** to the midstream and downstream regions,the upstream region has less moisture,clouds,and precipitation,where the moisture is brought by the *** early August,the vertical wet advection over this region becomes enhanced and generates more high clouds and *** midstream region has moisture carried by the westerly in June and by the southerly monsoon from July to *** higher vertical wet advection maximum here forms more high clouds,with a precipitation peak in early *** downstream region is mainly affected by the southerly-driven wet *** rich moisture and strong vertical wet advection here produce the most clouds and precipitation among the three regions,with a precipitation peak in late *** height of the maximum moisture condensation is different between the midstream region(325 hPa)and the other two regions(375 hPa),due to the higher upward motion maximum in the midstream *** diabatic heating structures show that stratiform clouds dominate the upstream region,stratiform clouds and deep convection co-exist in the midstream region,and deep convection systems characterize the downstream region.

关键词： Yarlung Zangbo River Basin atmospheric water cycle constrained variational analysis moisture source and consumption

Current observation and analysis based on mooring systems in the Andaman Sea

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Journal of Oceanology and Limnology 2024年第2期42卷 484-491页

作者： Yimeng WANG Jingsong GUO Dapeng QU Zhixin ZHANG Chalermrat SANGMANEE Varintha VASINAMEKHIN Binghuo GUO First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Shandong Key Laboratory of Marine Science and Numerical Modeling Qingdao 266061China Phuket Marine Biological center Department of Marine and Coastal ResourcesPhuket 83000Thailand Marine and coastal Resources research&Development Institute Department of Marine and Coastal ResourcesBangkok 10210Thailand

The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean currents of the Andaman Sea was investigated by combining observational and satellite *** observations show that rapid changes of current speed and direction occurred in May and June,with a significant increase in current velocity at the C1 *** the second half of the year,southward flow dominated at the C1 mooring,and alternating northward and southward flows were evident at the C5 mooring during the same period but the northward flow prevailed in boreal *** addition,analysis of the power spectra of the upper currents revealed that the tidal period at both moorings is primarily semidiurnal with weaker energy than that of the low-frequency *** upper ocean currents at the C1 and C5 moorings exhibited intraseasonal variation of 30-60 d and 120 d,while the zonal current at the C1 mooring exhibited a notable period of approximately 180 *** analysis indicated that the variability of currents in the Andaman Sea is influenced primarily by equatorial Kelvin waves and Rossby wave ***,our results suggest that equatorial Kelvin waves from the eastern Indian Ocean entered the Andaman Sea in the form of Wyrtki Jets and propagated primarily along two distinct pathways during the observation *** addition to coastal boundary Kelvin waves,it was found that a branch of the Wyrtki Jet that directly enters the Andaman Sea and flows northward along the slope of the continental shelf,and reflected Rossby wave packets by topography.

关键词： mooring observation Wyrtki Jet Rossby waves intraseasonal variation

Insight into the microbial community of denitrification process using different solid carbon sources: Not only bacteria

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Journal of Environmental Sciences 2024年第10期144卷 87-99页

作者： Congyu Li Yu Ling Yanjie Zhang Haiyan Wang Huan Wang Guokai Yan Weiyang Dong Yang Chang Liang Duan State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China College of Environmental Science and Engineering Tongji UniversityShanghai 200092China College of Water Sciences Beijing Normal UniversityBeijing 100875China research center of Environmental Pollution Control Technology Chinese Research Academy of Environmental ScienceBeijing 100012China State Environmental Protection Key Laboratory of Estuarine and coastal Environment Chinese Research Academy of Environmental SciencesBeijing 100012China

There is a lack of understanding about the bacterial,fungal and archaeal communities’composition of solid-phase denitrification(SPD)*** investigated four SPD systems with different carbon sources by analyzing microbial gene sequences based on operational taxonomic unit(OTU)and amplicon sequence variant(ASV).The results showed that the corncob-polyvinyl alcohol sodium alginate-polycaprolactone(CPSP,0.86±0.04 mg NO_(3)^(−)-N/(g·day))and corncob(0.85±0.06 mg NO_(3)^(−)-N/(g·day))had better denitrification efficiency than polycaprolactone(PCL,0.29±0.11 mg NO_(3)^(−)-N/(g·day))and polyvinyl alcoholsodium alginate(PVA-SA,0.24±0.07 mg NO_(3)^(−)-N/(g·day)).The bacterial,fungal and archaeal microbial composition was significantly different among carbon source types such as Proteobacteria in PCL(OTU:83.72%,ASV:82.49%)and Rozellomycota in PVA-SA(OTU:71.99%,ASV:81.30%).ASV methods can read more microbial units than that of OTU and exhibit higher alpha diversity and classify some species that had not been identified by OTU such as Nanoarchaeota phylum,unclassified_f_Xanthobacteraceae genus,etc.,indicating ASV may be more conducive to understand SPD microbial *** co-occurring network showed some correlation between the bacteria fungi and archaea species,indicating different species may collaborate in SPD *** KEGG function prediction results were obtained in two bioinformatic methods generally and some fungi and archaea functions should not be ignored in SPD *** results may be beneficial for understanding microbial communities in SPD systems.

关键词： Solid-phase denitrification Solid carbon source Microbial community ASV analysis OTU analysis

Production traits and fertility of reciprocal hybrids between Argopecten irradians irradians and ***

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Journal of Oceanology and Limnology 2024年第1期42卷 304-315页

作者： Jinjing WANG Junhao NING Xia LU Min CHEN Guilong LIU Xin XU Quanchao WANG He XU Chunde WANG research and Development center for Efficient Utilization of coastal Bioresources Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China College of Marine Science and Engineering Qingdao Agricultural UniversityQingdao 266109China University of Chinese Academy of Sciences Beijing 100049China Yantai Spring-Sea AquaSeed Co. Ltd.Yantai 264006China Jiangsu Baoyuan Biotechnology Co. Ltd.Lianyungang 222144China Jiangsu Haitai MariTech Co. Ltd.Lianyungang 222144China

The two bay scallop subspecies,Argopecten irradians irradians(NN)and ***(SS),are fast growing and major cultured bivalves in ***,their relatively small sizes and decreasing production traits caused by long-term inbreeding have been major concerns to the industry in the last two *** between the two bay scallop subspecies may provide a new approach to breed a new variety with superior production traits for the *** this end,in this study,we hybridized the two bay scallop subspecies in order to obtain a new strain that incorporates the genes of both *** significant difference was found in fertilization rate,hatching rate and metamorphosis rate between the purebred and crossbred cohorts(NN♀×SS♂,denoted as NS;SS♀×NN♂,denoted as SN).Both mating strategy(***-population crosses)and egg origin had significant effects on growth and survival at the larval *** was observed in the crossbred and was more pronounced in older *** diversity of the reciprocal hybrids,especially that of SN,was increased compared with the purebred *** all hybrids were completely fertile and able to reproduce by selffertilization or by backcrossing with either ***,male sterile individuals whose gonads were fully occupied by the ovary part at mature stage were found in the hybrids for the first *** hybrids,especially SN,may provide precious germplasm resources for the production of ternary hybrids with the Peruvian scallop,***.

关键词： bay scallop hybridization growth survival heterosis fertility ternary hybrids

Improving landscape connectivity through habitat restoration:application for Asian elephant conservation in Xishuangbanna Prefecture,China

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Integrative Zoology 2024年第2期19卷 319-335页

作者： Bin WAN Wenwen LI Peng LIU Nian YANG Shang CHEN Xianming GUO Bin WANG Li ZHANG Key Laboratory for Biodiversity Science and Ecological Engineering Ministry of EducationCollege of Life SciencesBeijing Normal UniversityBeijingChina research center for coastal Zone Science and Marine Development Strategy First Institute of OceanographyMinistry of Natural ResourcesQingdaoChina School of Biological Sciences The University of Hong KongPokfulamHong KongChina research Institute of Xishuangbanna National Nature Reserve JinghongChina Xishuangbanna Asian Elephant Conservation and Management center JinghongChina

Habitat restoration is an effective method for improving landscape connectivity,which can reduce habitat *** landscape connectivity could promote connections between habitat,which is extremely essential to preserve gene flow and population *** study proposes a methodological framework to analyze landscape connectivity for Asian elephant habitat conservation,aiming to provide practical options for reducing habitat fragmentation and improving habitat *** approach involved combining a species distribution model using MaxEnt and landscape functional connectivity models using graph theory to assess the impact on connectivity improvement via farmland/plantation restoration as *** results showed that:(1)there were 119 suitable habitat patches of Asian elephant covering a total area of 1952.41 km^(2).(2)The connectivity between habitats improved significantly after vegetation restoration and the gain first decreased and then increased with the increase of dispersal distance.(3)The first few new habitat patches that were identified played an important role in improving connectivity,and the variation rate of connectivity gradually leveled off as the number of new habitats increased.(4)Prioritization of the 25 best new habitat patches increased connectivity from 0.54%to 5.59%as the dispersal distance increased and mainly was located between two Asian elephant distribution regions and two *** of new habitat patches was effective for improving or restoring *** findings can be used as guidance for improving the studied fragmented Asian elephant habitats,and they can also be used as a reference for the habitat restoration of other endangered species heavily affected by habitat fragmentation.

关键词： Asian elephant connectivity habitat restoration habitat suitability landscape graphs

Differences in Precipitation and Related Wind Dynamics and Moisture and Heat Features in Separate Areas of the South China Sea before and after Summer Monsoon Onset

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Advances in Atmospheric Sciences 2024年第8期41卷 1643-1660页

作者： Chunyan ZHANG Donghai WANG Kaifeng ZHANG Wanwen HE Yanping ZHENG Yan XU Guangdong Meteorological Data center Guangdong Meteorological BureauGuangzhou 510640China School of Atmospheric Sciences Sun Yat-sen UniversityGuangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesKey Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China National Observation and research Station of coastal Ecological Environments in Macao Macao Environmental Research InstituteMacao University of Science and TechnologyMacao SAR 999078China Foshan Meteorological Service Foshan 528000China Ningjiang District Meteorological Bureau Songyuan 138000China

Using surface and balloon-sounding measurements, satellite retrievals, and ERA5 reanalysis during 2011–20, this study compares the precipitation and related wind dynamics, moisture and heat features in different areas of the South China Sea(SCS) before and after SCS summer monsoon onset(SCSSMO). The rainy sea around Dongsha(hereafter simply referred to as Dongsha) near the north coast, and the rainless sea around Xisha(hereafter simply referred to as Xisha) in the western SCS, are selected as two typical research subregions. It is found that Dongsha, rather than Xisha, has an earlier and greater increase in precipitation after SCSSMO under the combined effect of strong low-level southwesterly winds, coastal terrain blocking and lifting, and northern cold air. When the 950-h Pa southwesterly winds enhance and advance northward, accompanied by strengthened moisture flux, there is a strong convergence of wind and moisture in Dongsha due to a sudden deceleration and rear-end collision of wind by coastal terrain blocking. Moist and warm advection over Dongsha enhances early and deepens up to 200 h Pa in association with the strengthened upward motion after SCSSMO, thereby providing ample moisture and heat to form strong precipitation. However, when the 950-h Pa southwesterly winds weaken and retreat southward, Xisha is located in a wind-break area where strong convergence and upward motion centers move in. The vertical moistening and heating by advection in Xisha enhance later and appear far weaker compared to that in Dongsha, consistent with later and weaker precipitation.

关键词： Dongsha Xisha South China Sea summer monsoon onset precipitation wind dynamics moisture heat