期刊文献+
共找到26篇文章
< 1 2 >
每页显示 20 50 100
A Bogus Typhoon Scheme and Its Application to a Movable Nested Mesh Model
1
作者 王国民 王诗文 李建军 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第1期103-114,共12页
A bogus typhoon scheme,designed for the initialization of a typhoon track prediction model,is developed in thispaper.This scheme includes both effects of axisymmetric wind and asymmetric wind.Experimental forecasts us... A bogus typhoon scheme,designed for the initialization of a typhoon track prediction model,is developed in thispaper.This scheme includes both effects of axisymmetric wind and asymmetric wind.Experimental forecasts using atwo-way interactive movable nested mesh model show that the forecast skill of typhoon tracks has clearly improvedafter introducing the bogus typhoon into the initial fields. 展开更多
关键词 Bogus typhoon Track forecast nested mesh model
在线阅读 下载PDF
A Regional Spectral Nested Multilevel Primitive Equation Model
2
作者 廖洞贤 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第1期27-35,共9页
By means of vertical normal modes a regional nested multilevel primitive equation model can be reduced to several sets of shallow water equations characterized by various equivalent depths. Therefore, time integration... By means of vertical normal modes a regional nested multilevel primitive equation model can be reduced to several sets of shallow water equations characterized by various equivalent depths. Therefore, time integration of the model in spectral form can be performed in the manner similar to those used in the spectral nested shallow water equation model case. 展开更多
关键词 A Regional Spectral nested Multilevel Primitive Equation model
在线阅读 下载PDF
A Regional Spectral Nested Shallow Water Equation Model
3
作者 廖洞贤 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1989年第4期393-402,共10页
A method to expand meteorological elements in terms of finite double Fourier series in a limited-region and a spectral nested shallow water equation model based upon the method with conformal map projection in rectang... A method to expand meteorological elements in terms of finite double Fourier series in a limited-region and a spectral nested shallow water equation model based upon the method with conformal map projection in rectangular coordinates, have been proposed, and computational stability and efficiency of time integration have been discussed. 展开更多
关键词 A Regional Spectral nested Shallow Water Equation model
在线阅读 下载PDF
长白山北坡植物群落β多样性及其组分驱动因素分析
4
作者 丛明珠 刘琪璟 +2 位作者 孙震 董淳超 钱尼澎 《南京林业大学学报(自然科学版)》 北大核心 2025年第2期99-106,共8页
【目的】探究长白山北坡植物群落β多样性及其组分的格局与环境驱动因素,为长白山生物多样性保护和生态系统管理提供理论依据。【方法】采用R语言betapart工具包对长白山北坡植物群落β多样性进行组分(周转和嵌套)分解,使用广义相异性模... 【目的】探究长白山北坡植物群落β多样性及其组分的格局与环境驱动因素,为长白山生物多样性保护和生态系统管理提供理论依据。【方法】采用R语言betapart工具包对长白山北坡植物群落β多样性进行组分(周转和嵌套)分解,使用广义相异性模型(GDM)探讨β多样性及其组分与环境因子之间的关系。【结果】据β多样性及其组分计算结果,长白山北坡植物群落β多样性以周转组分为主,即物种更替导致群落间物种组成的差异。本研究GDM模型输出结果表明,用于建模的13个环境因子可解释长白山北坡植物群落β多样性及其周转组分的32.63%~66.52%;年均气温对乔木β多样性影响显著。此外,当年降水量>710.00 mm、土壤容重>1.07 g/cm^(3)时,年降水量和土壤容重对其产生显著影响;乔木周转组分主要受年均气温、土壤容重和坡度的影响,超过阈值后随其值的增大,周转速率增加;随着气温季节性变化、坡度和年均气温的增加,灌木β多样性及其周转组分的增长速率分别呈减缓、不变和加快的趋势;而草本β多样性及其周转组分随主要影响因子的梯度变化表现为:随海拔的升高而增大,随等温性的升高而减小,随土壤有机碳含量的升高先增大后减小。【结论】整体上长白山北坡植物群落物种组成以周转模式变化,启示生物多样性保护工作应多物种、多区域展开。环境因子是长白山北坡植物群落β多样性格局的关键影响因素,其中乔木β多样性及其周转组分主要受年均气温的影响,灌木β多样性及其周转组分主要受气温季节性变化的影响,而草本β多样性及其周转组分主要受海拔的限制。 展开更多
关键词 Β多样性 周转 嵌套 广义相异性模型(GDM) 环境异质性
原文传递
Numerical simulation study on the properties and source tracing of swells in the Gulf of Guinea
5
作者 Fumin Xu Hanzheng Ya Donglin Zhu 《Acta Oceanologica Sinica》 2025年第2期1-13,共13页
Swells are critical concerns regarding safety,marine transportation,and coastal engineering construction of coastal countries along the Gulf of Guinea and have been scientific problems due to the lack of systematic th... Swells are critical concerns regarding safety,marine transportation,and coastal engineering construction of coastal countries along the Gulf of Guinea and have been scientific problems due to the lack of systematic theoretical,numerical,and observational research.In this study,a double nesting numerical model was constructed and validated from the Atlantic Ocean to the Gulf of Guinea based on simulating waves nearshore(SWAN)to explore the swell characteristics and source tracing in the Gulf of Guinea in winter and summer seasons from 2020 to 2021.Simulation results reveal that swells are stronger and deflect more to the west in winter than summer,even though they dominate in both seasons in the Gulf of Guinea in the S-SW directional range.Simulated two-dimensional(2D)wave spectral patterns not only clarify wave composition,variation,and propagation properties from the central South Atlantic Ocean to the Gulf of Guinea,but also distinguish swell strength and directional range in winter and summer.The NW wind events induce swells which spread toward the SSE-ESE direction from the North Atlantic Ocean,big wind source generates sustained and stable S-SW swells from the South Atlantic Ocean,and corresponding swell-influenced areas are discussed.The strongest swell event in the Gulf of Guinea during the simulation was used as a case study to trace its source.A strong clockwise wind vortex within the Roaring Forties induced these large swells in the Gulf of Guinea approximately 5.5 days later,and swell propagation formed a regular isoline of peak period distribution from the South Atlantic Ocean to the Gulf of Guinea in the SSW-SW direction. 展开更多
关键词 swells simulating waves nearshore double nesting numerical model Gulf of Guinea Atlantic Ocean 2D wave spectra
在线阅读 下载PDF
Ensemble Cloud Model Application in Simulating the Catastrophic Heavy Rainfall Event
6
作者 Vlado Spiridonov Mladjen Curic +1 位作者 Marija Grcic Boro Jakimovski 《Journal of Atmospheric Science Research》 2022年第4期35-49,共15页
An attempt has been made in the present research to simulate a deadly flash-flood event over the City of Skopje,Macedonia on 6 August 2016.A cloud model ensemble forecast method is developed to simulate a super-cell s... An attempt has been made in the present research to simulate a deadly flash-flood event over the City of Skopje,Macedonia on 6 August 2016.A cloud model ensemble forecast method is developed to simulate a super-cell storm’s initiation and evolutionary features.Sounding data are generated using an ensemble approach,that utilizes a triple-nested WRF model.A three-dimensional(3-D)convective cloud model(CCM)with a very fine horizontal grid resolution of 250-m is initialized,using the initial representative sounding data,derived from the WRF 1-km forecast outputs.CCM is configured and run with an open lateral boundary conditions LBC,allowing explicit simulation of convective scale processes.This preliminary study showed that the ensemble approach has some advantages in the generation of the initial data and the model initialization.The applied method minimizes the uncertainties and provides a more qualitative-quantitative assessment of super-cell storm initiation,cell structure,evolutionary properties,and intensity.A high-resolution 3-D run is capable to resolve detailed aspects of convection,including high-intensity convective precipitation.The results are significant not only from the aspect of the cloud model’s ability to provide a qualitative-quantitative assessment of intense precipitation but also for a deeper understanding of the essence of storm development,its vortex dynamics,and the meaning of micro-physical processes for the production and release of large amounts of precipitation that were the cause of the catastrophic flood in an urban area.After a series of experiments and verification,such a system could be a reliable tool in weather services for very short-range forecasting(now-casting)and early warning of weather disasters. 展开更多
关键词 WRF triple nested model Convective cloud model Ensemble initialization 3-D numerical simulation Flash-flood event Super-cell storm
在线阅读 下载PDF
Recognizing Expression Variant and Occluded Face Images Based on Nested HMM and Fuzzy Rule Based Approach 被引量:1
7
作者 Parvathi Ramalingam Shanthi Dhanushkodi 《Circuits and Systems》 2016年第6期983-994,共12页
The face recognition with expression and occlusion variation becomes the greatest challenge in biometric applications to recognize people. The proposed work concentrates on recognizing occlusion and seven kinds of exp... The face recognition with expression and occlusion variation becomes the greatest challenge in biometric applications to recognize people. The proposed work concentrates on recognizing occlusion and seven kinds of expression variations such as neutral, surprise, happy, sad, fear, disgust and angry. During enrollment process, principle component analysis (PCA) detects facial regions on the input image. The detected facial region is converted into fuzzy domain data to make decision during recognition process. The Haar wavelet transform extracts features from the detected facial regions. The Nested Hidden markov model is employed to train these features and each feature of face image is considered as states in a Markov chain to perform learning among the features. The maximum likelihood for the input image was estimated by using Baum Welch algorithm and these features were kept on database. During recognition process, the expression and occlusion varied face image is taken as the test image and maximum likelihood for test image is found by following same procedure done in enrollment process. The matching score between maximum likelihood of input image and test image is computed and it is utilized by fuzzy rule based method to decide whether the test image belongs to authorized or unauthorized. The proposed work was tested among several expression varied and occluded face images of JAFFE and AR datasets respectively. 展开更多
关键词 Face Recognition Fuzzy Rule Based Method Expression and Occlusion Variation Baum Welch Algorithm nested Hidden Markov model
在线阅读 下载PDF
Overview on high-resolution ocean modeling in JAMSTEC
8
作者 Michio Kawamiya 《Engineering Sciences》 EI 2014年第2期43-44,共2页
In view of the importance of ocean component for representing climate change,efforts are underway to implement a high-resolution nesting model system in Model for Interdisciplinary Research on Climate(MIROC) for the N... In view of the importance of ocean component for representing climate change,efforts are underway to implement a high-resolution nesting model system in Model for Interdisciplinary Research on Climate(MIROC) for the North Pacific using the same ocean model as used in the coupled model MIROC5. By comparing double(10 km for the northwestern Pacific,50 km for the rest of the Pacific) and triple(double nesting plus 2 km resolution near Japan) nesting,it turns out that relative vorticity is drastically enhanced near Japan with 2 km resolution. It is hoped that such an elaborated nesting system will reveal detailed processes for the ocean heat uptake by,e.g.,intermediate water and mode water formation for which the"perturbed region"near Japan is the key region. 展开更多
关键词 K computer earth simulator II eddy-resolving ocean model nesting model
在线阅读 下载PDF
Influence of land use characteristics and trip attributes on commuting mode choice: a case of Nanjing 被引量:5
9
作者 刘志伟 邓卫 季彦婕 《Journal of Southeast University(English Edition)》 EI CAS 2014年第1期107-112,共6页
The effects of socio-demographics, land use characteristics and trip attributes on the commute mode choice are studied with a nested logit (NL) model. Based on the random utility maximum theory, the NL model is form... The effects of socio-demographics, land use characteristics and trip attributes on the commute mode choice are studied with a nested logit (NL) model. Based on the random utility maximum theory, the NL model is formulated. The analysis is carried out in the main area of Nanjing. Direct and cross elasticities are calculated to analyze the effects of travel time and travel cost on the selection of travel mode choice. The results reveal that the non-motorized travel modes are more attractive in the areas with higher housing and employment accessibility and car owners are found to be more likely to commute to work by car. The bus and subway choice probabilities are more sensitive to changes in travel times than to changes in travel costs. In conclusion, a comprehensive public transit system and effective integration of land use and transportation policies help to relieve the traffic congestion levels caused by the increasing urban sprawl. 展开更多
关键词 traffic engineering land use travel mode choice nested logit model elasticity analysis
在线阅读 下载PDF
Numerical simulation of the structure and variation of upwelling off the east coast of Hainan Island using QuikSCAT winds 被引量:5
10
作者 李毅能 彭世球 +1 位作者 杨威 王东晓 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第6期1068-1081,共14页
The spatial structure and variation of the upwelling in the waters east and northeast of Hainan Island, China during 2000-2007 were investigated using a nested high-resolution Princeton Ocean Model (POM) forced by Qui... The spatial structure and variation of the upwelling in the waters east and northeast of Hainan Island, China during 2000-2007 were investigated using a nested high-resolution Princeton Ocean Model (POM) forced by QuikSCAT winds. The model produced good simulations of the summer upwelling and the seasonal and annual variability. Strong upwelling occurs from mid-July to mid-August with a peak east of Hainan Island associated with the southwesterly monsoon in the South China Sea. Sensitivity experiments indicated that when the local wind stress controls the variability of the upwelling, the large-scale circulation significantly enhances the upwelling northeast of Hainan Island by inducing a local upwelling and transporting cold water northeast-ward along the island's east coast. The joint effects of the local wind stress and large-scale circulation result in stronger upwelling northeast of Hainan Island. This implies that the annual variation of the upwelling northeast of Hainan Island is controlled not only by the local alongshore wind stress but also by the large-scale circulation. This result will help us investigate the decadal variation of the upwelling in this region in the future. 展开更多
关键词 UPWELLING high-resolution nested model South China Sea QuikSCAT winds
原文传递
Computational Techniques of 2D Tidal Flow in Estuaries and Bays 被引量:4
11
作者 Xin Wenjie Senior Engineer, River and Harbour Department, Nanjing Hydraulic Research Institute, Nanjing 210024 《China Ocean Engineering》 SCIE EI 1995年第4期395-404,共10页
Some problems in the numerical calculation of tidal flow in estuaries and bays, such as distribution bed roughness, relationship between model moving boundary and water volume balance, remedy of certain shortage under... Some problems in the numerical calculation of tidal flow in estuaries and bays, such as distribution bed roughness, relationship between model moving boundary and water volume balance, remedy of certain shortage under open boundary conditions, smooth transfer of the controlling message for the inner boundaries of nested model, can not be solved usually by means of the fundamental equations and computing mode adopted in the numerical model, but can be done by the measures which not only satisfy the physical features but also are convenient for operation. Based on the calculated samples of some areas of Modaomen, Lingdingyang and Huangmaohai of the Pearl River Estuary, and Shuidong Bay (a typical barrier- lagoon tidal channel) in Guangdong Province, method and process of calculation for the above mentioned problems are briefly presented in this paper. 展开更多
关键词 numerical model bed roughness moving boundary problems open boundary nested model
在线阅读 下载PDF
南亚热带河流底栖硅藻β多样性及其对空间距离与环境梯度的响应——基于广义非相似性模拟的分析 被引量:4
12
作者 谭琳 陈慈 +3 位作者 朱昆鹏 韩诺 王璐 韩博平 《生态学报》 CAS CSCD 北大核心 2023年第10期4176-4189,共14页
β多样性指不同生境间群落物种组成的差异,其空间格局及影响因素是生物多样性维持研究的重要内容。以典型的南亚热带中小型河流—广州流溪河为对象,在对底栖硅藻进行季节调查的基础上,采用Baselga对β多样性的分解框架,基于Sørense... β多样性指不同生境间群落物种组成的差异,其空间格局及影响因素是生物多样性维持研究的重要内容。以典型的南亚热带中小型河流—广州流溪河为对象,在对底栖硅藻进行季节调查的基础上,采用Baselga对β多样性的分解框架,基于Sørensen相异性系数将底栖硅藻的β多样性分解为周转和嵌套两个组分,运用广义非相似性模拟(Generalized Dissimilarity Modelling,GDM)分析了空间与环境因子对β多样性及其组分的影响。结果表明:底栖硅藻β多样性、物种周转和嵌套组分无明显季节差异,物种周转是流溪河底栖硅藻β多样性的主要组分(>75%);环境与空间过程共同影响流溪河底栖硅藻β多样性和物种周转组分格局,但环境选择是主要的驱动因子;与枯水期相比,丰水期的空间因素对β多样性和物种周转组分的影响程度降低。作为一种非线性距离回归方法,GDM能较好地识别底栖硅藻β多样性及其组分对环境梯度和空间距离的响应。 展开更多
关键词 Β多样性 周转 嵌套 广义非相似性模拟 环境选择 扩散限制
在线阅读 下载PDF
网络分析在宿主植物与菌根真菌共生关系研究中的应用 被引量:3
13
作者 林力涛 马克明 《菌物学报》 CAS CSCD 北大核心 2019年第11期1826-1839,共14页
菌根共生体是生物界最广泛的互惠共生体,共生关系多样性是生物多样性的重要组成部分,当前群落尺度菌根共生关系研究才刚刚起步,但发展迅速。网络分析作为生态学研究的重要手段逐渐在菌根共生关系中得以应用,网络分析为群落尺度探究菌根... 菌根共生体是生物界最广泛的互惠共生体,共生关系多样性是生物多样性的重要组成部分,当前群落尺度菌根共生关系研究才刚刚起步,但发展迅速。网络分析作为生态学研究的重要手段逐渐在菌根共生关系中得以应用,网络分析为群落尺度探究菌根真菌多样性分布规律、共生机制研究提供新观点和途径,对菌根真菌群落结构、生态功能研究具有重要意义。本文总结了网络分析方法在单点式、双点式和多点式菌根共生关系网络研究中的优势和局限性,同时还阐述了零模型选择和构建网络大小对关系网络度量指数的影响,为菌根真菌群落结构、生态功能研究提供新思路,为后续群落尺度菌根共生关系格局研究提供借鉴。 展开更多
关键词 共生关系网络 网络分析 嵌套性 零模型 群落尺度
原文传递
A Generalized Comfort Function of Subway Systems Based on a Nested Logit Model 被引量:2
14
作者 Yichen Zheng Wei Guo +1 位作者 Yi Zhang Jianming Hu 《Tsinghua Science and Technology》 SCIE EI CAS 2014年第3期300-306,共7页
With rapid urbanization,subway systems are widely acknowledged as one of the best solutions to urban transportation problems.The operators or managers of subway systems should pay more attention to passenger's percep... With rapid urbanization,subway systems are widely acknowledged as one of the best solutions to urban transportation problems.The operators or managers of subway systems should pay more attention to passenger's perceptions of service quality to maintain its competitive position.Taking the traffic state,efficiency,and environmental impact into consideration,the concept of generalized comfort is proposed in this paper.Based on a nested logit model,the selection probability for each factor in a generalized comfort function can be estimated using a nested structure.A certain factor is considered to be more significant in a generalized comfort function than others,when the corresponding probability of this factor is higher in value.Using stated preference and revealed preference data about passenger travel behavior obtained from the Beijing subway,the parameters of generalized comfort function are estimated by maximum likelihood techniques. 展开更多
关键词 generalized comfort subway system nested logit model
原文传递
菌根共生网络嵌套性判定的零模型选择 被引量:3
15
作者 林力涛 马克明 《植物生态学报》 CAS CSCD 北大核心 2019年第7期611-623,共13页
零模型是判定网络嵌套性的重要依据,菌根共生关系网络经常出现高度非对称性,该文通过探究矩阵非对称变化对基于不同零模型构建方法的网络嵌套性的影响,试图为非对称网络零模型的选择提供依据。结果表明:不同零模型保守性不同,增加限定... 零模型是判定网络嵌套性的重要依据,菌根共生关系网络经常出现高度非对称性,该文通过探究矩阵非对称变化对基于不同零模型构建方法的网络嵌套性的影响,试图为非对称网络零模型的选择提供依据。结果表明:不同零模型保守性不同,增加限定条件减少零模型构建过程中的自由空间,高度限定条件易导致第II类错误。高度非对称网络会增加基于完全随机(r00)零模型的矩阵温度(NT)偏离、降低配对重叠度(NODF)偏离,标准化指数z-score值显示网络非对称增加后有助于NT和NODF显著性判定。行或列限定对非对称网络嵌套性判定的影响存在差异,列限定(c0)的网络嵌套性判定对网络非对称性变化的响应规律与r00零模型的响应趋势基本一致,具有更低的嵌套性偏离和标准差值。行限定(r0,包括行列限定(backtrack))零模型NT值和NT偏移随矩阵非对称性的变化保持稳定,较之c0零模型在高度非对称网络中呈现更低的NODF偏离值。选用完全随机和限定零模型相结合的方法,有助于更加准确判断非对称网络是否具有嵌套结构。高度非对称网络嵌套性判定中对行属性特征比较敏感,不同非对称性网络间嵌套性水平相比较时选用r0零模型要优于r00和c0零模型。 展开更多
关键词 关系网络 嵌套性 零模型 网络非对称性
原文传递
嵌套分布格局研究进展:分析方法、影响机制及保护应用 被引量:8
16
作者 王彦平 张敏楚 詹成修 《生物多样性》 CAS CSCD 北大核心 2023年第12期78-94,共17页
基于物种分布或群落组成的嵌套格局(嵌套分布格局)是岛屿生物地理学和群落生态学的重要前沿研究领域和核心问题之一。嵌套分布格局最初起源于岛屿物种组成的研究,是指物种较贫乏岛屿中的物种是物种较丰富岛屿中的物种的一个适当子集的... 基于物种分布或群落组成的嵌套格局(嵌套分布格局)是岛屿生物地理学和群落生态学的重要前沿研究领域和核心问题之一。嵌套分布格局最初起源于岛屿物种组成的研究,是指物种较贫乏岛屿中的物种是物种较丰富岛屿中的物种的一个适当子集的分布模式。深入了解嵌套分布格局及其影响机制对生物多样性保护具有重要意义,并可用于指导管理工作。近40年来,嵌套分布格局备受生态学家和保护生物学家的关注,并且在分析方法、影响机制、生物多样性保护应用等方面都取得了一系列重要进展。本文通过对文献的系统检索和归纳总结,从4个方面对嵌套分布格局的最新研究进展进行了综述:(1)发展历史及其研究现状;(2)分析方法,包括各个嵌套指数和零模型的优点与局限;(3)影响机制及其检验方法;(4)在生物多样性保护与管理中的应用。最后,我们对该领域进行了归纳总结并对以后的发展方向提出了针对性建议,包括选择最适合的嵌套指数和零模型进行嵌套分析、同时对多种嵌套理论假说进行验证、开展更多关于功能嵌套和谱系嵌套的研究、推动嵌套分布格局与其他相关领域的融合。本文对于深入了解嵌套分布格局的前沿进展,以及推动国内该领域的快速发展将有重要意义。 展开更多
关键词 岛屿生物地理学 群落生态学 嵌套格局 嵌套分析 嵌套指数 功能嵌套 谱系嵌套 零模型 影响机制
原文传递
Probabilistic Approach of Coastal Defense Against Typhoon Attacks for Nuclear Power Plant 被引量:1
17
作者 刘德辅 韩凤亭 +3 位作者 庞亮 李华军 谢波涛 王风清 《China Ocean Engineering》 SCIE EI 2010年第2期265-275,共11页
With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power pla... With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power plant should be calibrated because of the increasing threat of typhoon disaster and severe consequences. This paper discusses the probabilistic approach of definitions about "probable maximum typhoon" and "probable maximum storm surge" in nuclear safety regulations of China and has made some design code calibrations by use of a newly proposed Double Layer Nested Mtdti-objective Probability Model (DLNMPM). 展开更多
关键词 TYPHOON nuclear power plant coastal engineering code calibration double layer nested multi-objective probability model
在线阅读 下载PDF
Improved atmospheric mercury simulation using updated gas-particle partition and organic aerosol concentrations
18
作者 Kaiyun Liu Qingru Wu +8 位作者 Shuxiao Wang Xing Chang Yi Tang Long Wang Tonghao Liu Lei Zhang Yu Zhao Qin’geng Wang Jinsheng Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第9期106-118,共13页
The gaseous or particulate forms of divalent mercury(HgⅡ) significantly impact the spatial distribution of atmospheric mercury concentration and deposition flux(FLX). In the new nested-grid GEOS-Chem model, we try to... The gaseous or particulate forms of divalent mercury(HgⅡ) significantly impact the spatial distribution of atmospheric mercury concentration and deposition flux(FLX). In the new nested-grid GEOS-Chem model, we try to modify the HgⅡ gas-particle partitioning relationship with synchronous and hourly observations at four sites in China. Observations of gaseous oxidized Hg(GOM), particulate-bound Hg(PBM), and PM 2.5 were used to derive an empirical gas-particle partitioning coefficient as a function of temperature( T) and organic aerosol(OA) concentrations under different relative humidity(RH). Results showed that with increasing RH, the dominant process of HgⅡ gas-particle partitioning changed from physical adsorption to chemical desorption. And the dominant factor of HgⅡ gas-particle partitioning changed from T to OA concentrations. We thus improved the simulated OA concentration field by introducing intermediate-volatility and semi-volatile organic compounds(I/SVOCs) emission inventory into the model framework and refining the volatile distributions of I/SVOCs according to new filed tests in the recent literatures. Finally, normalized mean biases(NMBs) of monthly gaseous element mercury(GEM), GOM, PBM, WFLX were reduced from-33%–29%, 95%–300%, 64%–261%, 117%–122% to-13%–0%,-20%–80%,-31%–50%,-17%–23%. The improved model explains 69%–98% of the observed atmospheric Hg decrease during 2013–2020 and can serve as a useful tool to evaluate the effectiveness of the Minamata Convention on Mercury. 展开更多
关键词 nested GEOS-Chem model HgⅡgas-particle partitioning Organic aerosol Atmospheric mercury Mercury deposition flux
原文传递
Towards an Ecological Understanding of Translation Etemality in the Context of Iran
19
作者 Maryam Shirdel Majid Elahi Shirvan 《Sino-US English Teaching》 2016年第6期468-491,共24页
This study attempted to investigate the similarities and differences regarding the conceptions of translation eternality among a small group of Iranian people of different social positions and different ages. Sixty-tw... This study attempted to investigate the similarities and differences regarding the conceptions of translation eternality among a small group of Iranian people of different social positions and different ages. Sixty-two participants were selected based on the maximum variation sampling. To gather data, semi-structured interview was utilized. The participants were asked a list of 11 questions collected from the existing literature on the similar topics. Then, the interviews were transcribed for analyzing the data. Besides, Erikson's (1959) theory of development was used to classify participants of different ages in four groups of teenager, young, middle age, and old. The high frequency factors were found and analyzed with the use of Bronfenbrenner's (1979) nested ecological model. Moreover, the participants were classified in 11 groups based on their social positions and their conceptions were analyzed with the same method. Broadly speaking, 17 central tendencies in the interviews were obtained: People mainly focused on subjects of the books, translation fluency, author's competence in writing, and translator's competence, translations which have common grounds with social events of Iran, advertisement, existence of movie or cartoon adaptation of the book, translator's awareness of the content of the book, existence of cultural similarities between the source and target culture, popularity of the translator, author, and the original book, conversational language in translation, translation fidelity, being both translator and author, and effect of censorship on translation. Besides, old participants seemed to have more precise view on translation eternality and teenager's concerns were mostly about the appearance-related issues. 展开更多
关键词 translation etemality ecological understanding nested ecological model translation competence translation fidelity
在线阅读 下载PDF
Passenger Choice Behavior between Direct and Transit Flights——A Case Study on Passengers Using Hub Airports in the Northeast Asian Region
20
作者 Se-Yeon Jung Baek-Jae Kim Kwang-Eui Yoo 《Journal of Traffic and Transportation Engineering》 2017年第5期260-270,共11页
This study analyzes air passenger route choice behavior for long-haul inter-continental travel. It employs the SP (state preference) technique and logit modeling to investigate the impact of route development via ne... This study analyzes air passenger route choice behavior for long-haul inter-continental travel. It employs the SP (state preference) technique and logit modeling to investigate the impact of route development via neighboring countries in the region. With the Japanese government pursuing an increase in international routes at Haneda International Airport, and the Chinese government planning to construct Beijing Capital Second International Airport by 2019, the competition among airports to serve as hubs in Northeast Asia will increase significantly. Korean passengers will have a greater number of route choices when traveling to North America or Europe, utilizing not only direct flights from Incheon International Airport but also flights via Tokyo or Beijing area airports including Haneda International Airport, Narita International Airport, Beijing Capital International Airport and Beijing Capital Second International Airport. Accordingly, passengers will choose among the alternatives by considering fares and flight times. As such, it is essential for airports to offer flights with competitive prices for transit passengers to become successful competitive airports in the region. Therefore, it will become more important for market decision makers to strive toward more attractive ticket prices and better route network quality. 展开更多
关键词 Passenger route choice behavior SP technique multinomial logit model nested logit model competitive airports inNortheast Asia.
在线阅读 下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部