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Retrieval of Ozone Profiles Using a Weighted Multiplicative Algebraic Reconstruction Technique from SCIAMACHY Limb Scattering Observations
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作者 Fang Zhu Fuqi Si +3 位作者 Ke Dou Kai Zhan Haijin Zhou Yuhan Luo 《Journal of Earth Science》 2025年第1期314-326,共13页
This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer f... This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer for atmospheric chartography(SCIAMACHY).This technique is based on SaskMART(the combination of the multiplicative algebraic reconstruction technique and SaskTRAN radiative transfer model),which was originally developed for optical spectrometer and infrared imaging system(OSIRIS)data.One of the objectives of this study was to obtain consistent ozone profiles from the two satellites.In this study,the WMART algorithm is combined with a radiative transfer model(SCIATRAN),as well as a set of measurement vectors comprising five Hartley pairing vectors(HPVs)and one Chappuis triplet vector(CTV),to retrieve ozone profiles in the altitude range of 10–69 km.Considering that the weighting factors in WMART have a significant effect on the retrievals,we propose a novel approach to calculate the pair/triplet weighting factors using wavelength weighting functions.The results of the application of the proposed ozone retrieval scheme are compared with the SCIAMACHY v3.5 ozone product by University of Bremen and validated against profiles derived from other passive satellite observations or measured by ozonesondes.Between 18 and 55 km,the retrieved ozone profiles typically agree with data from the SCIAMACHY ozone product within 5%for tropics and middle latitudes,whereas a negative deviation exists between 35 and 50 km for northern high latitudes,with a deviation of less than 10%above 50 km.Comparison of the retrieved profiles with microwave limb sounder(MLS)v5.0 indicates that the difference is within±5%between 18 and 55 km,and an agreement within 10%is achieved in other altitudes for tropics and middle latitudes.Comparison of the retrieved profiles with OSIRIS v7.1 indicates that the average deviation is within±5%between 20 and 59 km,and difference of approximately 10%is achieved below 20 km.Compared with ozonesondes data,a general validity of the retrievals is no more than 5%between 15 and 30 km. 展开更多
关键词 RETRIEVALS OZONE profiles WMART SCIAMACHY LIMB
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Grain morphology and plasticizing mechanism of AZ31 magnesium alloy curved profiles by staggered extrusion
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作者 CHEN Zi-yu LI Feng +2 位作者 LI Yuan-qi LI Chao SUN Lu 《Journal of Central South University》 2025年第2期319-331,共13页
Traditional manufacturing processes for lightweight curved profiles are often associated with lengthy procedures,high costs,low efficiency,and high energy consumption.In order to solve this problem,a new staggered ext... Traditional manufacturing processes for lightweight curved profiles are often associated with lengthy procedures,high costs,low efficiency,and high energy consumption.In order to solve this problem,a new staggered extrusion(SE)process was used to form the curved profile of AZ31 magnesium alloy in this paper.The study investigates the mapping relationship between the curvature,microstructure,and mechanical properties of the formed profiles by using different eccentricities of the die.Scanning electron microscopy(SEM)and electron backscatter diffraction techniques are employed to examine the effects of different eccentricity values(e)on grain morphology,recrystallization mechanisms,texture,and Schmid factors of the products.The results demonstrate that the staggered extrusion method promotes the deep refinement of grain size in the extruded products,with an average grain size of only 15%of the original billet,reaching 12.28μm.The tensile strength and elongation of the curved profiles after extrusion under the eccentricity value of 10 mm,20 mm and 30 mm are significantly higher than those of the billet,with the tensile strength is increased to 250,270,235 MPa,and the engineering strain elongation increased to 10.5%,12.1%,15.9%.This indicates that staggered extrusion enables curvature control of the profiles while improving their strength. 展开更多
关键词 staggered extrusion ECCENTRICITY curved profiles MICROSTRUCTURE mechanical properties
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Fluid Resonance in a Moonpool Coupling with Heave Motion Response of Hulls with Sharp and Convex Edge Profiles
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作者 TANG Peng LAN Jun-jie +2 位作者 HUANG Yong-qiang JIANG Sheng-chao ZHANG Hong-sheng 《China Ocean Engineering》 2025年第2期225-231,共7页
Numerical simulations on the coupling actions between the free surface oscillation in the moonpool and the heave motion response of hulls with vertical mooring stiffness are carried out in this study,where the influen... Numerical simulations on the coupling actions between the free surface oscillation in the moonpool and the heave motion response of hulls with vertical mooring stiffness are carried out in this study,where the influences of edge profiles,including sharp and convex edge profiles,on the coupling actions are considered.Two-peak variations in the free surface oscillations in the moonpool with incident wave frequencies can be observed,which are defined as the first and second peak frequencies.The free surface oscillations and heave motion responses show in-phase and out-of-phase relationships at the first and second peak frequencies,respectively.The convex edge profiles are able to generate effective suppressing actions at the second peak frequencies.However,it is only efficient for large vertical stiffness at the first peak frequency.The relative velocity between the fluid flow along the moonpool bottom and the heave motion of the hulls is the essential reason. 展开更多
关键词 fluid resonance moonpool heave motion response edge profiles coupling actions OPENFOAM
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Characterization of metabolic profiles of Lanqin Oral Liquid in rats by ultra-high-performance liquid chromatography tandem time-of-flight mass spectrometry
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作者 Yue-Yue Tan Meng-Yuan Wang +6 位作者 Yu-Nuo Fan Ya-Liu Fan Ye Zhang Bin Li Yong-Xiang Wang Hua Yang Ping Li 《Acupuncture and Herbal Medicine》 2025年第1期76-88,共13页
Objective:Lanqin oral liquid(LOL),as a traditional Chinese medicine prescription,has obvious clinical efficacy in the treatment of pharyngeal inflammation.Exploring the distribution of LOL prototype components and met... Objective:Lanqin oral liquid(LOL),as a traditional Chinese medicine prescription,has obvious clinical efficacy in the treatment of pharyngeal inflammation.Exploring the distribution of LOL prototype components and metabolites in plasma is of great significance for understanding potentially effective compounds.The aim of this study is to elucidate the metabolites and main metabolic pathways of LQL in vivo.Methods:In this study,a reliable approach integrated background subtraction and mass defect filtering(MDF),based on quadrupole time-of-flight mass spectrometry(QTOF-MS)technology,was performed to systematically scan the metabolites of LOL in rat plasma.In addition,according to the prototype mass spectrometry fragmentation pattern and combined with metabolic pathway analysis,a biotransformation oriented analysis strategy was established and applied to the identification of metabolites in LOL in vivo.Results:As a result,159 compounds(58 prototypes and 101 metabolites)were identified or tentatively characterized in drug-containing plasma,including 74 flavonoids,30 alkaloids,34 terpenoids,five phenylpropanoids,six phenolic acids,five fatty acids,and five other type components.The main metabolic pathways include methylation,demethylation,hydroxylation,hydrogenation,glucuronidation,and sulfation.Conclusions:This study provides an overall characterization of the metabolites of LOL in vivo for the first time,providing a solid material basis for exploring the therapeutic effects and pharmacological mechanisms of LOL. 展开更多
关键词 Background subtracts Lanqin Oral Liquid Mass defect filtering Metabolic profiles UHPLC-QTOF-MS
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Deep learning on chromatin profiles reveals the cis-regulatory sequence code of the rice genome
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作者 Xinkai Zhou Zhonghao Ruan +2 位作者 Chenlu Zhang Kerstin Kaufmann Dijun Chen 《Journal of Genetics and Genomics》 2025年第6期848-851,共4页
Rice(Oryza sativa)is a staple food for more than half of the world's population and a critical crop for global agriculture.Understanding the regulatory mechanisms that control gene expression in the rice genome is... Rice(Oryza sativa)is a staple food for more than half of the world's population and a critical crop for global agriculture.Understanding the regulatory mechanisms that control gene expression in the rice genome is fundamental for advancing agricultural productivity and food security.In mechanism,cis-regulatory elements(including promoters,enhancers,silencers,and insulators)are key DNA sequences whose activities determine the spatial and temporal expression patterns of nearby genes(Yocca and Edger,2022;Schmitz et al.,2022). 展开更多
关键词 cis regulatory elements deep learning chromatin profiles agricultural productivity rice genome cis regulatory sequence code gene expression food security
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Individual and mixture effects of BTEX occupational exposure with hematologic and hepatic profiles in petrochemical workers and the metabolic mechanism
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作者 Rujian He Hongjie Zhong +5 位作者 Chang He Hailing Li Zhanxiang Wang Jing Zheng Guiying Li Taicheng An 《Journal of Environmental Sciences》 2025年第8期163-173,共11页
Evidence on the association of occupational exposure to benzene,toluene,ethylbenzene,and xylene(BTEX)with hematologic and hepatic profiles were equivocal,and few studies have investigated overall effect of BTEX mixtur... Evidence on the association of occupational exposure to benzene,toluene,ethylbenzene,and xylene(BTEX)with hematologic and hepatic profiles were equivocal,and few studies have investigated overall effect of BTEX mixtures.Herein,significant higher concentrations(p<0.05)of hippuric acid,1,2-dihydroxybenzene,mandelic acid,trans,trans-muconic acid and phenylglyoxylic acid were found in petrochemical workers than the controls,in accordance with higher levels of hematologic and hepatic profiles found in petrochemical workers(p<0.05).Occupational exposure to individual BTEX was associated with elevated levels of white blood cell(WBC),lymphocyte(LYMPH),alanine aminotransferase(ALT),and gamma-glutamyl transferase(GGT).Further,the Weighted Quantile Sum Regression model and Bayesian Kernel Machine Regression model consistently identified a positive associa-tion between BTEX mixture exposure and WBC,LYMPH,and GGT.Xylene was the primary contributor to increased WBC,LYMPH,and GGT levels.Furthermore,BTEX exposure resulting in the increased inflammation indices were mainly related to perturbations of sphingolipid metabolism,biosynthesis of unsaturated fatty acids,and primary bile acid biosynthesis.Whereas metabolites mediated the correlation between BTEX exposure and liver function indiceswere related to the perturbations of biosynthesis of unsaturated fatty acids,arachidonic acid metabolism,sphingolipid metabolism,primary bile acid biosynthesis,etc.Our findings revealed potential health risk of occupational exposure to BTEX andmight help one to understand the link between BTEX exposure and hematologic and hepatic profiles. 展开更多
关键词 Petrochemical industry pollution Occupational co-exposure BTEX Serum metabolomics Hematologic and hepatic profiles
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Research on Constructing Personalized Learner Profiles Based on Multi-Feature Fusion
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作者 Xing Pan Meixiu Lu 《Journal of Electronic Research and Application》 2025年第2期274-284,共11页
This study proposes a learner profile framework based on multi-feature fusion,aiming to enhance the precision of personalized learning recommendations by integrating learners’static attributes(e.g.,demographic data a... This study proposes a learner profile framework based on multi-feature fusion,aiming to enhance the precision of personalized learning recommendations by integrating learners’static attributes(e.g.,demographic data and historical academic performance)with dynamic behavioral patterns(e.g.,real-time interactions and evolving interests over time).The research employs Term Frequency-Inverse Document Frequency(TF-IDF)for semantic feature extraction,integrates the Analytic Hierarchy Process(AHP)for feature weighting,and introduces a time decay function inspired by Newton’s law of cooling to dynamically model changes in learners’interests.Empirical results demonstrate that this framework effectively captures the dynamic evolution of learners’behaviors and provides context-aware learning resource recommendations.The study introduces a novel paradigm for learner modeling in educational technology,combining methodological innovation with a scalable technical architecture,thereby laying a foundation for the development of adaptive learning systems. 展开更多
关键词 Learner profile Multi-feature fusion Dynamic features Personalized recommendation Educational technology
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Profiles of Parent-Child Attachment and Peer Attachment among Adolescents and Associations with Internalizing Problems
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作者 Chao Qu Xiaoshan Jia Haidong Zhu 《International Journal of Mental Health Promotion》 2025年第3期401-420,共20页
Objectives:Attachment is a profound and enduring connection to the emotion children progressively form with their parents as they mature.It significantly impacts the social and psychological development of kids and te... Objectives:Attachment is a profound and enduring connection to the emotion children progressively form with their parents as they mature.It significantly impacts the social and psychological development of kids and teenagers.This study aimed to explore the latent profiles and longitudinal transition patterns of parent-child and peer attachments among adolescents.Methods:A cohort of 914 participants from China completed the measures with a twelve-month interval.There were 46.8%boys and 53.2%girls in this survey.Latent profile analysis(LPA)was adopted to explore the distinct profiles reflecting different parent-child and peer attachment response patterns at each time point.Latent transition analysis(LTA)was used to examine the membership of distinct latent profiles and how individuals move between profiles over time.Results:Three latent profiles were found:the poor parent-child communication profile,the moderate attachment profile,and the good attachment profile.It was shown that the transition probability from the poor parent-child communication and good attachment profiles to the moderate attachment profile was higher than the transition probability between the poor parent-child communication and good attachment profiles.Patterns of parent-child and peer attachments were associated with depression and anxiety.Conclusion:This study demonstrates differences in adolescents’attachment to fathers,mothers,and peers and the need for targeted interventions for groups of adolescents with moderate levels of parent-child and peer attachment. 展开更多
关键词 Parent-child attachment peer attachment ADOLESCENCE latent profile analysis latent transition analysis
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Adjustment of thalweg longitudinal profiles in response to sediment silting in cascade reservoirs:A case study of the lower Jinsha River
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作者 WANG Suiji 《Journal of Geographical Sciences》 2025年第7期1497-1515,共19页
How the strong segmentation of cascade reservoir dams and the spatiotemporal changes of sediment retention volume affect the river morphology adjustment in the reservoir area is a scientific issue worthy of exploratio... How the strong segmentation of cascade reservoir dams and the spatiotemporal changes of sediment retention volume affect the river morphology adjustment in the reservoir area is a scientific issue worthy of exploration.This study aims to reveal the adjustment mechanism of the thalweg longitudinal profile of cascade reservoirs.This study focuses on the Xiangjiaba and Xiluodu reservoirs located in the lower reaches of the Jinsha River.Utilizing multi-period observational data of thalweg elevation in reservoir reaches both before and after dam construction,the research employs statistical,geomorphological,and sedimentological methodologies to analyze variation characteristics in the measured curves,trend curves,and theoretical fitting curves of the thalweg longitudinal profile.The investigation ultimately reveals two distinct adjustment patterns in the longitudinal profiles of these cascade reservoirs:the concave curve type and the convex curve type.The former is characterized by weak riverbed scouring and silting changed to rapid aggradation in the upstream section of the reservoir area after dam closure,then changed to slow aggradation in the whole reservoir area,which is the common feature of reservoirs that were built earlier and are relatively located in the downstream(such as the Xiangjiaba Reservoir).The latter is characterized by a straight line or concave curve type with weak riverbed scouring and silting before the dam closure changed to a convex curve type with strong siltation after dam closure,which is the characteristic of reservoirs that were built later and are relatively located in the upstream(such as the Xiluodu Reservoir).The adjustment of the cascade reservoir longitudinal profile is controlled by the spatiotemporal changes of the sediment deposition volume and sedimentation rate in the reservoir area,and the alternating changes of the hydrodynamic gradient and regulation mode affect the spatial heterogeneity of the sedimentation rate.The research results are helpful for understanding the adjustment mechanism of the cascade reservoir longitudinal profile in similar areas and have a guiding role in predicting the adjustment trend of the cascade reservoir longitudinal profile without observation data. 展开更多
关键词 cascade reservoirs longitudinal profile adjustment pattern sediment silting lower Jinsha River
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Changes in factor profiles deriving from photochemical losses of volatile organic compounds:Insight from daytime and nighttime positive matrix factorization ana
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作者 Baoshuang Liu Tao Yang +9 位作者 Sicong Kang Fuquan Wang Haixu Zhang Man Xu Wei Wang Jinrui Bai Shaojie Song Qili Dai Yinchang Feng Philip K.Hopke 《Journal of Environmental Sciences》 2025年第5期627-639,共13页
Substantial effects of photochemical reaction losses of volatile organic compounds(VOCs)on factor profiles can be investigated by comparing the differences between daytime and nighttime dispersion-normalized VOC data ... Substantial effects of photochemical reaction losses of volatile organic compounds(VOCs)on factor profiles can be investigated by comparing the differences between daytime and nighttime dispersion-normalized VOC data resolved profiles.Hourly speciated VOC data measured in Shijiazhuang,China from May to September 2021 were used to conduct study.The mean VOC concentration in the daytime and at nighttime were 32.8 and 36.0 ppbv,respectively.Alkanes and aromatics concentrations in the daytime(12.9 and 3.08 ppbv)were lower than nighttime(15.5 and 3.63 ppbv),whereas that of alkenes showed the opposite tendency.The concentration differences between daytime and nighttime for alkynes and halogenated hydrocarbonswere uniformly small.The reactivities of the dominant species in factor profiles for gasoline emissions,natural gas and diesel vehicles,and liquefied petroleum gas were relatively low and their profiles were less affected by photochemical losses.Photochemical losses produced a substantial impact on the profiles of solvent use,petrochemical industry emissions,combustion sources,and biogenic emissions where the dominant species in these factor profiles had high reactivities.Although the profile of biogenic emissions was substantially affected by photochemical loss of isoprene,the low emissions at nighttime also had an important impact on its profile.Chemical losses of highly active VOC species substantially reduced their concentrations in apportioned factor profiles.This study results were consistent with the analytical results obtained through initial concentration estimation,suggesting that the initial concentration estimation could be the most effective currently availablemethod for the source analyses of active VOCs although with uncertainty. 展开更多
关键词 Volatile organic compounds Dispersion normalization Photochemical loss Factor profile Positive matrix factorization
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Adaptive multi-view learning method for enhanced drug repurposing using chemical-induced transcriptional profiles, knowledge graphs, and large language models
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作者 Yudong Yan Yinqi Yang +9 位作者 Zhuohao Tong Yu Wang Fan Yang Zupeng Pan Chuan Liu Mingze Bai Yongfang Xie Yuefei Li Kunxian Shu Yinghong Li 《Journal of Pharmaceutical Analysis》 2025年第6期1354-1369,共16页
Drug repurposing offers a promising alternative to traditional drug development and significantly re-duces costs and timelines by identifying new therapeutic uses for existing drugs.However,the current approaches ofte... Drug repurposing offers a promising alternative to traditional drug development and significantly re-duces costs and timelines by identifying new therapeutic uses for existing drugs.However,the current approaches often rely on limited data sources and simplistic hypotheses,which restrict their ability to capture the multi-faceted nature of biological systems.This study introduces adaptive multi-view learning(AMVL),a novel methodology that integrates chemical-induced transcriptional profiles(CTPs),knowledge graph(KG)embeddings,and large language model(LLM)representations,to enhance drug repurposing predictions.AMVL incorporates an innovative similarity matrix expansion strategy and leverages multi-view learning(MVL),matrix factorization,and ensemble optimization techniques to integrate heterogeneous multi-source data.Comprehensive evaluations on benchmark datasets(Fdata-set,Cdataset,and Ydataset)and the large-scale iDrug dataset demonstrate that AMVL outperforms state-of-the-art(SOTA)methods,achieving superior accuracy in predicting drug-disease associations across multiple metrics.Literature-based validation further confirmed the model's predictive capabilities,with seven out of the top ten predictions corroborated by post-2011 evidence.To promote transparency and reproducibility,all data and codes used in this study were open-sourced,providing resources for pro-cessing CTPs,KG,and LLM-based similarity calculations,along with the complete AMVL algorithm and benchmarking procedures.By unifying diverse data modalities,AMVL offers a robust and scalable so-lution for accelerating drug discovery,fostering advancements in translational medicine and integrating multi-omics data.We aim to inspire further innovations in multi-source data integration and support the development of more precise and efficient strategies for advancing drug discovery and translational medicine. 展开更多
关键词 Drug repurposing Multi-view learning Chemical-induced transcriptional profile Knowledge graph Large language model Heterogeneous network
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Analysis of the distribution of sound velocity profiles and sound propagation laws based on a global high-resolution ocean reanalysis product
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作者 Shiyuan Tao Yi Yu +2 位作者 Wenbin Xiao Weimin Zhang Yanlai Zhao 《Acta Oceanologica Sinica》 2025年第5期131-149,共19页
Ocean reanalysis data,compared to traditional observational data,possess stronger continuity and higher data accuracy.The globally high-resolution ice-ocean coupled reanalysis product China Ocean ReAnalysis,Version 2.... Ocean reanalysis data,compared to traditional observational data,possess stronger continuity and higher data accuracy.The globally high-resolution ice-ocean coupled reanalysis product China Ocean ReAnalysis,Version 2.0(CORA v2.0),independently developed by the National Marine Information Center,has attracted considerable attention since its release in 2020.This study selected six representative points of sound velocity profiles in different global ocean regions and conducted comparative analysis between the 2014 momentary data from CORA v2.0 and Argo data.Additionally,the monthly average data of CORA v2.0 in 2013 were compared and studied against General Digital Environmental Model(GDEM)and World Ocean Atlas(WOA)data.Metrics such as Root Mean Square Error(RMSE)and Mean Error(ME)were introduced to evaluate the differences between datasets.The result reveals that,in a comparison of single moment data,the sound velocity profiles of CORA v2.0 data and Argo data exhibit high consistency,with ME generally within 2 m/s.Regarding a comparison of monthly average data,the consistency between CORA v2.0 data and WOA data is higher,while the error relative to GDEM data is relatively larger,but their RMSE and ME exhibit high similarity in temporal trends.Based on the 2014 data of CORA v2.0,the temporal and spatial evolutionary laws of global seawater sound velocity profiles and sound speed fields were analyzed.On the time scale,the variation of seawater sound speed is mainly influenced by seasons,with significant differences between winter and summer seasons.On the daily scale,there are certain differences in sound velocity profiles mainly in the early morning and afternoon.On the spatial scale,analysis was conducted from both horizontal and vertical perspectives.The distribution of sound speed exhibits evident regularity with latitude,with shallow seawater sound speed being greatly influenced by external factors while deep seawater is relatively stable.Using the Range-dependent Acoustic Model for Geoacoustics(RAMgeo)model to solve the underwater acoustic field at three specific points,the characteristic changes of sound velocity profiles at different times of the day and their impact on under water sound propagation losses were obtained.This paper provides valuable information for the application of CORA v2.0 data products. 展开更多
关键词 ocean reanalysis products sound velocity profile temporal and spatial distribution characteristics
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Use of generated artificial road profiles in road roughness evaluation 被引量:2
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作者 Giuseppe Loprencipe Pablo Zoccali 《Journal of Modern Transportation》 2017年第1期24-33,共10页
In the evaluation of road roughness and its effects on vehicles response in terms of ride quality, loads induced on pavement, drivers' comfort, etc., it is very common to generate road profles based on the equation p... In the evaluation of road roughness and its effects on vehicles response in terms of ride quality, loads induced on pavement, drivers' comfort, etc., it is very common to generate road profles based on the equation provided by ISO 8608 standard, according to which it is possible to group road surface profiles into eight different classes. However, real profiles are significantly different from the artificial ones because of the non-stationary fea- ture of the first ones and the not full capability of the ISO 8608 equation to correctly describe the frequency content of real road profiles. In this paper, the international roughness index, the frequency-weighted vertical acceleration awz according to ISO 2631, and the dynamic load index are applied both on artificial and real profiles, highlighting the different results obtained. The analysis carried out in this work has highlighted some limitation of the ISO 8608 approach in the description of performance and conditions of real pavement profiles. Furthermore, the different sensitivity of the various indices to the fitted power spectral density parameters is shown, which should be taken into account when performing analysis using artificial profiles. 展开更多
关键词 Ride quality International roughness indexDynamic load index Road surface irregularities - ISO2631 ISO 8608 Real road profiles Artificial roadprofiles
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Dynamics of Soil CO_2 Profiles of Pinus sylvestris var. sylvestriformis Seedlings Under CO_2 Concentration Doubled
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作者 韩士杰 张军辉 +1 位作者 周玉梅 邹春静 《Acta Botanica Sinica》 CSCD 2002年第7期852-857,共6页
The gas_well system permanently installed in the soil was adopted for studying the dynamic relationship between CO 2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis (Takenouchi) Che... The gas_well system permanently installed in the soil was adopted for studying the dynamic relationship between CO 2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis (Takenouchi) Cheng et C. D. Chu. The study was conducted in the Open Research Station of Changbai Mountain Forest Ecological System, The Chinese Academy of Sciences from 1999 to 2001. Four treatments were arranged in the rectangular open_top chambers (OTCs): ambient CO 2+no_seedling, 700 μmol/mol CO 2+no_seedling, ambient CO 2 +seedlings, 700 μmol/mol CO 2+seedlings. By collecting and analyzing soil gas synchronously, it was found that the dynamics of CO 2 profiles were related to the biological activity of seedlings. There were more roots distributed in the top soil and the boundary layer across soil and sand, which made more contributions to the CO 2 profiles due to respiration root. Compared with the ambient CO 2, elevated CO 2 led to the peak of CO 2 concentration distribution shifted from soil surface layer to the boundary layer as seasonally growing of seedling roots. It is suggested the gas_well system is an inexpensive, non_destructive and relatively sensitive method for study of soil CO 2 concentration profiles. 展开更多
关键词 CO 2_doubled soil CO 2 profiles gas well Pinus sylvestris var. sylvestriformis seedlings root distribution
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MPEG-4中的Profiles及适用场合 被引量:1
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作者 卢官明 《南京邮电学院学报》 2000年第4期84-86,90,共4页
MPEG 4提供了极其丰富的工具集用于对音 /视频对象编码。在实现MPEG 4标准时 ,可以根据应用领域的不同有选择地使用合适的视频、音频、图形和场景描述工具子集 ,这样可提高编解码器的工作效率。那些面向不同应用的工具子集就称为Profil... MPEG 4提供了极其丰富的工具集用于对音 /视频对象编码。在实现MPEG 4标准时 ,可以根据应用领域的不同有选择地使用合适的视频、音频、图形和场景描述工具子集 ,这样可提高编解码器的工作效率。那些面向不同应用的工具子集就称为Profiles(档次 ) ,它们限定了一个解码器必须实现的工具集。描述了MPEG 4标准中的Profiles及适用场合。 展开更多
关键词 MPEG-4 profiles 多媒体通信 图像通信
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基于蓝牙Profiles的互连测试系统的研究和实现 被引量:1
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作者 陈瑜 王凤至 《北方交通大学学报》 CSCD 北大核心 2002年第2期40-42,共3页
对蓝牙通信软件的互连性测试进行了研究 。
关键词 蓝牙技术 互连测试系统 测试模型 测试用例 profiles
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Dynamics of profiles and storage of carbon dioxide in broadleaved/Korean forest in Changbai Mountain 被引量:3
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作者 韩士杰 林丽莎 +4 位作者 于贵瑞 张军辉 吴家兵 赵晓松 关德新 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第4期275-279,共5页
CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, A... CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected dada, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 mmolmol-1, but had a significant change in July, with a difference of 60 mmolmol-1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 mmolmol-1. The calculated total storage (ΔC/Δt ) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE. 展开更多
关键词 CO2 concentration CO2 profile CO2 storage Broadleaved/Korean pine forest Vertical distribution Concentration gradient
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Organochlorine compounds and polycyclic aromatic hydrocarbons in surface sediment from Baiyangdian Lake,North China:Concentrations,sources profiles and potential risk 被引量:45
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作者 Guocheng Hu Xiaojun Luo +6 位作者 Fengchao Li Jiayin Dai Jianyang Guo Shejun Chen Cao Hong Bixian Mai Muqi Xu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第2期176-183,共8页
Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) were determined in nineteen surface sediment samples collected from Baiyangdian Lake and its inflow... Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) were determined in nineteen surface sediment samples collected from Baiyangdian Lake and its inflowing river (Fuhe River) in North China. Total concentrations of OCPs, PCBs and PAHs in sediments ranged from 5.4 to 707.6 ng]g, 2.3 to 197.8 ng/g, and 101.3 to 6360.5 ng]g, respectively. The levels of contaminants in Fuhe River were significantly higher than those in Baiyandian Lake. For hexachlorocyclohexane (HCHs) and dichlorodiphenytrich/oroethanes (DDTs), α-HCH and p,p'-DDT were predominant isomers; while for PCBs, PCB 28/31, PCB 40/103, PCB 60, PCB 101, and PCB 118 were predominant congeners. Possible sources derived from historical usage for OCPs and incomplete combustion fuel, wood, and coal and exhaustion of boats or cars for PAHs. Risk assessment of sediment indicated that sediments in Fuhe River were likely to pose potential biological adverse impact. 展开更多
关键词 persistent organic pollutants CONCENTRATIONS profiles risk assessment Baiyangdian Lake
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Effects of Malnutrition on Economic Productivity in China As Estimated by PROFILES 被引量:21
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作者 JAYROSS CHUN-MINGCHEN +4 位作者 WuHE GANGFU YU-YINGWANG ZHEN-YINGFU MING-XIACHEN 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2003年第3期195-205,共11页
Objective To calculate the effects of malnutrition on economic productivity in China. Methods PROFILES was used to quantify the function consequences of malnutrition in term of protein energy malnutrition, iron defici... Objective To calculate the effects of malnutrition on economic productivity in China. Methods PROFILES was used to quantify the function consequences of malnutrition in term of protein energy malnutrition, iron deficiency and iodine deficiency. Results Productivity gained due to improved iodine nutrition. The reduction in the TGR in 1992 to 2001 increased the net present value of further economic productivity by $142 billion. Reduction of the TGR rate to 5% over next 10 years would result in future productivity gains with value of $40 billion. Productivity gain due to reductions in child stunting would result in future economic productivity gains with the value of $101 billion. Reducing stunting further over the next 10 years would gain $20 billion. Productivity gain due to reduction of iron deficiency anemia reduced by 30% over the next 10 years would gain worth $107 billion and if childhood anemia reduced by 30% over next 10 years would gain $348 billion. Conclusion These interventions have huge economic payoff. That is likely to exceed their costs many times over. 展开更多
关键词 profiles MALNUTRITION Economic productivity Iodine nutrition Iron deficiency
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Retrieving Atmospheric Temperature Profiles from AMSU-A Data with Neural Networks 被引量:15
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作者 姚志刚 陈洪滨 林龙福 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2005年第4期606-616,共11页
Back propagation neural networks are used to retrieve atmospheric temperature profiles from NOAA-16 Advanced Microwave Sounding Unit-A (AMSU-A) measurements over East Asia. The collocated radiosonde observation and AM... Back propagation neural networks are used to retrieve atmospheric temperature profiles from NOAA-16 Advanced Microwave Sounding Unit-A (AMSU-A) measurements over East Asia. The collocated radiosonde observation and AMSU-A data over land in 2002-2003 are used to train the network, and the data over land in 2004 are used to test the network. A comparison with the multi-linear regression method shows that the neural network retrieval method can significantly improve the results in all weather conditions. When an offset of 0.5 K or a noise level of ±0.2 K is added to all channels simultaneously, the increase in the overall root mean square (RMS) error is less than 0.1 K. Furthermore, an experiment is conducted to investigate the effects of the window channels on the retrieval. The results indicate that the brightness temperatures of window channels can provide significantly useful information on the temperature retrieval near the surface. Additionally, the RMS errors of the profiles retrieved with the trained neural network are compared with the errors from the International Advanced TOVS (ATOVS) Processing Package (IAPP). It is shown that the network-based algorithm can provide much better results in the experiment region and comparable results in other regions. It is also noted that the network can yield remarkably better results than IAPP at the low levels and at about the 250-hPa level in summer skies over ocean. Finally, the network-based retrieval algorithm developed herein is applied in retrieving the temperature anomalies of Typhoon Rananim from AMSU-A data. 展开更多
关键词 AMSU-A neural network temperature profiles RETRIEVAL
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