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Precipitation Chemistry and Corresponding Transport Patterns of Influencing Air Masses at Huangshan Mountain in East China 被引量:9
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作者 SHI ChunE DENG Xueliang +2 位作者 YANG Yuanjian HUANG Xiangrong WU Biwen 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第5期1157-1166,共10页
One hundred and ten samples of rainwater were collected for chemical analysis at the summit of Huangshan Mountain, a high-altitude site in East China, from July 2010 to June 2011. The volume-weighted-mean (VWM) pH f... One hundred and ten samples of rainwater were collected for chemical analysis at the summit of Huangshan Mountain, a high-altitude site in East China, from July 2010 to June 2011. The volume-weighted-mean (VWM) pH for the whole sampling period was 5.03. SO2- and Ca2+ were the most abundant anion and cation, respectively. The ionic concentrations varied monthly with the highest concentrations in winter/spring and the lowest in summer. Evident inter-correlations were found among most ions, indicating the common sources for some species and fully mixing characteristics of the alpine precipitation chemistry. The VWM ratio of [SO]-]/[NO3] was 2.54, suggesting the acidity of rainwater comes from both nitric and sulfuric acids. Compared with contemporary observations at other alpine continental sites in China, the precipitation at Huangshan Mountain was the least polluted, with the lowest ionic concentrations. Trajectories to Huangshan Mountain on rainy days could be classified into six groups. The rainwater with influencing air masses originating in Mongolia was the most polluted with limited effect. The emissions of Jiangxi, Anhui, Zhejiang and Jiangsu provinces had a strong influence on the overall rain chemistry at Huangshan Mountain. The rainwater with influencing air masses from Inner Mongolia was heavily polluted by anthropogenic pollutants. 展开更多
关键词 precipitation chemistry air mass inter-relationship transport pattern Huangshan Mountain East China
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Transport patterns and numerical simulation of heavy metal pollutants in soils of lead–zinc ore mines 被引量:2
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作者 CAO Jie XIE Cheng-yu HOU Zhi-ru 《Journal of Mountain Science》 SCIE CSCD 2021年第9期2345-2356,共12页
Exploring transport patterns of soil contaminants is essential for solving the problem of heavy metal contamination in mine soils.In this study,contamination of Pb,Zn,and Cd in the mountain soils of the lead–zinc ore... Exploring transport patterns of soil contaminants is essential for solving the problem of heavy metal contamination in mine soils.In this study,contamination of Pb,Zn,and Cd in the mountain soils of the lead–zinc ore mines in Ganxi Township,Hengdong County,Hunan Province,China was investigated,and their transport patterns were further explored using a soil-column model and numerical simulation techniques.In total,111 mine soil samples were collected and placed into six experimental soil columns.By controlling the water flow,a control soil column group(CK),two mixed soil columns X1 with daily water flows of 1 and 5 L,and three mixed soil columns X3 with daily water flows of 2,3,and 4 L were evaluated.The results showed that the residual fraction of Pb accounted for 71.93%of the content on average,whereas the exchangeable fractions of Zn,Cd,and Fe-Mn oxide-bound fractions of Zn and Cd accounted for 28.60%,31.07%,and 43.2%and 53.54%of the content,respectively.Pb,Zn,and Cd in the soils of the CK,X1,and X3 groups mainly were accumulated at a depth from approximately 0 to 20 cm,and the content at this depth accounted for 60.09%of that at a 0~40 cm depth.The soil at a depth range of 0~10 cm was most seriously contaminated,and the proportion of content was 32.39%of that at a 0~40 cm depth.Numerical simulation showed that on the 5 th day,the pollutant transport range was 0~24 cm,and on the 9 th day,the pollutant transport range exceeded 40 cm.On the 15 th day,the transport capacity of pollutants at depths of 0~40 cm was close to the stable state,but the soil at a depth of 0~10 cm was still heavily polluted.These results reflect the transport pattern of heavy metal pollutants in the soil of lead–zinc ore mines and may provide a reliable scientific support for the prevention of heavy metal contamination in mine environments. 展开更多
关键词 MOUNTAIN Mine soil Heavy metals Numerical simulations POLLUTANTS transport patterns
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Transport patterns of micro nutrient elements from the continental shelf of the East China Sea to the Kuroshio area
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作者 Lu Saiying, Yao Qiao’er and Chen Zhen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1992年第2期219-230,共12页
On the basis of the in situ data of DO2, pH, SiO2. PO4-P, NO3-N and NO2-N collected in the north of the East China Sea during 1987-1988, the following points are mainly expounded.1.The inorgonic nutrients are obviousl... On the basis of the in situ data of DO2, pH, SiO2. PO4-P, NO3-N and NO2-N collected in the north of the East China Sea during 1987-1988, the following points are mainly expounded.1.The inorgonic nutrients are obviously affected by continent runoff in the north of the East China Sea. Their distributions are characteristic of its distribution of terrigenous materials.2.There are three transport paths of nutrients from the shelf to the Kuroshio area. The first is mixing-diffusing-advec-tion and upwelling process, the process of biology and biochemistry belongs to the second, and the sinking process is the last one.3.The swing of the Kuroshio axis affectes both the range of the migration of substances through mixing-diffusing-advec-tion process and the upwelling degree of the subsurface Kuroshio water to the shelf.4.Most part of the substances sink as macroparticles to the deep layer before reaching the Kuroshio area. 展开更多
关键词 transport patterns of micro nutrient elements from the continental shelf of the East China Sea to the Kuroshio area
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The Sources and Transport Patterns of Modern Sediments in Hangzhou Bay: Evidence from Clay Minerals 被引量:4
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作者 LIU Jinqing CAO Ke +4 位作者 YIN Ping GAO Fei CHEN Xiaoying ZHANG Yong YU Yiyong 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第6期1352-1360,共9页
Clay mineral compositions of 199 offshore surface sediment samples collected from the Hangzhou Bay have been analyzed. The clay minerals in the sediments from the Hangzhou Bay are dominated by illite(58.7%, on average... Clay mineral compositions of 199 offshore surface sediment samples collected from the Hangzhou Bay have been analyzed. The clay minerals in the sediments from the Hangzhou Bay are dominated by illite(58.7%, on average), followed by chlorite(20.3%), kaolinite(16.9%) and smectite(4.1%). Two provinces were classified by Q-mode cluster analysis. Class Ⅰ with relatively low amounts of illite and smectite is widely distributed in the Hangzhou Bay, especially concentrated in the top and mouth of the bay, and the northern and southern nearshore areas. Class Ⅱ with comparatively high amounts of illite and smectite is mainly concentrated in the central part of the bay with the water depth of 8–10 m. By comparing clay mineral compositions with the neighbouring regions, we can find that the sediments in the Hangzhou Bay are mainly influenced by the resuspension and repeated deposition of particles from the Yangtze River due to the strong dynamic environment. In particular, the clay fraction of Class Ⅰ is mainly supplied by the Yangtze River, while the sediments of Class Ⅱ are mixture of the clay minerals carried by the Yangtze River and Qiantang River. In general, the distributions of clay minerals in the northern bay are affected by Yangtze River runoff, coastal current and flood tide together, and in the southern they are mainly affected by the Qiantang River runoff and ebb tide. 展开更多
关键词 MINERAL distribution CLAY MINERAL PROVENANCE transport pattern Hangzhou BAY
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Expression Pattern of Peptide and Amino Acid Genes in Digestive Tract of Transporter Juvenile Turbot(Scophthalmus maximus L.) 被引量:3
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作者 XU Dandan HE Gen +3 位作者 MAI Kangsen ZHOU Huihui XU Wei SONG Fei 《Journal of Ocean University of China》 SCIE CAS 2016年第2期334-340,共7页
Turbot(Scophthalmus maximus L.),a carnivorous fish species with high dietary protein requirement,was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which... Turbot(Scophthalmus maximus L.),a carnivorous fish species with high dietary protein requirement,was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach,pyloric caeca,rectum,and three equal parts of the remainder of the intestine.The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns.Peptide transporter 1(Pep T1) was rich in proximal intestine while peptide transporter 2(PepT2) was abundant in distal intestine.A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B^0-type amino acid transporter 1(B^0AT1),L-type amino acid transporter 2(LAT2),T-type amino acid transporter 1(TAT1),proton-coupled amino acid transporter 1(PAT1),y^+L-type amino acid transporter 1(y^+LAT1),and cationic amino acid transporter 2(CAT2) while ASC amino acid transporter 2(ASCT2),sodium-coupled neutral amino acid transporter 2(SNAT2),and y^+L-type amino acid transporter 2(y^+LAT2) abundantly expressed in stomach.In addition,system b^(0,+) transporters(rBAT and b^(0,+)AT) existed richly in distal intestine.These findings comprehensively characterized the distribution of solute carrier family proteins,which revealed the relative importance of peptide and amino acid absorption through luminal membrane.Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract. 展开更多
关键词 碱性氨基酸 肉食性鱼类 基因表达模式 转运蛋白 消化道 多肽 中性氨基酸 少年
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Dynamic change of landscape pattern and hydrological & geochemical characteristic analysis before and after the emergency water transportation in the lower reaches of the Tarim River, China 被引量:1
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作者 Qing HUANG Ranghui WANG Shixin WU 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期274-275,共2页
关键词 水文地球化学 河流 生态环境
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The Response of Anomalous Vertically Integrated Moisture Flux Patterns Related to Drought and Flood in Southern China to Sea Surface Temperature Anomaly 被引量:2
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作者 董娜 徐祥德 +4 位作者 蔡雯悦 王春竹 赵润泽 魏凤英 孙婵 《Journal of Tropical Meteorology》 SCIE 2023年第2期179-190,共12页
With the extreme drought(flood)event in southern China from July to August in 2022(1999)as the research object,based on the comprehensive diagnosis and composite analysis on the anomalous drought and flood years from ... With the extreme drought(flood)event in southern China from July to August in 2022(1999)as the research object,based on the comprehensive diagnosis and composite analysis on the anomalous drought and flood years from July to August in 1961-2022,it is found that there are significant differences in the characteristics of the vertically integrated moisture flux(VIMF)anomaly circulation pattern and the VIMF convergence(VIMFC)anomaly in southern China in drought and flood years,and the VIMFC,a physical quantity,can be regarded as an indicative physical factor for the"strong signal"of drought and flood in southern China.Specifically,in drought years,the VIMF anomaly in southern China is an anticyclonic circulation pattern and the divergence characteristics of the VIMFC are prominent,while those are opposite in flood years.Based on the SST anomaly in the typical draught year of 2022 in southern China and the SST deviation distribution characteristics of abnormal draught and flood years from 1961 to 2022,five SST high impact areas(i.e.,the North Pacific Ocean,Northwest Pacific Ocean,Southwest Pacific Ocean,Indian Ocean,and East Pacific Ocean)are selected via the correlation analysis of VIMFC and the global SST in the preceding months(May and June)and in the study period(July and August)in 1961-2022,and their contributions to drought and flood in southern China are quantified.Our study reveals not only the persistent anomalous variation of SST in the Pacific and the Indian Ocean but also its impact on the pattern of moisture transport.Furthermore,it can be discovered from the positive and negative phase fitting of SST that the SST composite flow field in high impact areas can exhibit two types of anomalous moisture transport structures that are opposite to each other,namely an anticyclonic(cyclonic)circulation pattern anomaly in southern China and the coastal areas of east China.These two types of opposite anomalous moisture transport structures can not only drive the formation of drought(flood)in southern China but also exert its influence on the persistent development of the extreme weather. 展开更多
关键词 drought in southern China in 2022 VIMFC anomaly high impact areas of SST anomaly anomalous moisture transport circulation pattern typical drought and flood years
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Evaluation of Disparities between Transportation Needs and Trip Patterns of Men and Women in Kandahar City, Afghanistan
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作者 Mohibullah Rahmat Shoshi Mizokami 《Journal of Transportation Technologies》 2019年第1期78-94,共17页
Consideration of gender equality in transportation planning is quite a new phenomenon. However, its significance is discussed widely by several researchers, particularly, in developing countries. In Kandahar city of A... Consideration of gender equality in transportation planning is quite a new phenomenon. However, its significance is discussed widely by several researchers, particularly, in developing countries. In Kandahar city of Afghanistan, women have limited choices when it comes to using transportation services. With respect to some cultural, social, contextual, environmental, technological and physical barriers;women do not receive equal services from the current transport sectors. Using Revealed Preference and Stated Preference techniques, a survey was conducted in Kandahar city to identify the differences between trip patterns and transportation needs among men and women of the city. Our findings show distinct and clear disparities in socio-demographic characteristics of men and women of Kandahar city leading to trip disparities. Almost all of women do not own any types of personal vehicles, they are less educated and do not have jobs. Likewise, there is a considerable gap between trip characteristics and patterns of men and women. Majority of female trips are for educational purposes while male trips are more dispersed over multiple activities. Motorcycle is the most dominant and preferred mode for men, while women are mostly walking or using available public transit. Compared to men, women were recorded to have lesser trips per day over short distances. Transportation choices of women are also limited to walking, accompanying other male members of family or using public modes. However, men are generally using their private cars, motorcycles and bicycles together with all those options available for women. The results of Multinomial Logit Model showed that all selected variables such as vehicle ownership, income, travel cost and time will be significant factors for mode choice behavior of men, though for female respondents travel time and travel cost are main factors. 展开更多
关键词 TRIP patternS Gender transportATION Needs Kandahar AFGHANISTAN
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单层石墨烯微米尺度图案化和功能化:调控电子传输特性
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作者 崔苗苗 韩联欢 +7 位作者 曾兰平 郭佳瑶 宋维英 刘川 吴元菲 罗世翊 刘云华 詹东平 《电化学(中英文)》 CAS 北大核心 2024年第3期34-39,共6页
石墨烯具有优异的物理特性,如单原子厚度、极高的载流子迁移率等。然而,其零带隙的半金属特性限制了题在高性能场效应晶体管中的应用。为此,研究者们提出了石墨烯纳米化、外场诱导、掺杂以及化学图案化等策略,以调控其带隙宽度。但是,... 石墨烯具有优异的物理特性,如单原子厚度、极高的载流子迁移率等。然而,其零带隙的半金属特性限制了题在高性能场效应晶体管中的应用。为此,研究者们提出了石墨烯纳米化、外场诱导、掺杂以及化学图案化等策略,以调控其带隙宽度。但是,这些方法的可控性以及稳定性还需要进一步改善。在本研究中,我们提出采用电化学溴化并结合光刻图案化调控单层石墨烯的电子传输特性,通过这种方法,成功制备了图案化的溴化石墨烯(SLGBr)。进一步研究表明,单层石墨烯的电子传输性能可以通过溴化程度来调控。当溴化程度较小时,SLGBr表现为电阻特性,且其电导随溴化程度增加而减小;当溴化程度增加到一定值时,SLGBr表现为与半导体类似的特性。本研究将为全石墨烯器件的制备提供可行的技术路线,拓展其在微电子领域的应用。 展开更多
关键词 石墨烯图案化 电子传输 电化学溴化 光刻 全石墨烯器件
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微通道换热器拓扑结构优化与性能研究
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作者 陈彦松 阮达 +3 位作者 刘渊博 郑通 张帅帅 马学虎 《化工学报》 EI CSCD 北大核心 2024年第3期823-835,共13页
换热器结构拓扑优化可将传热强化设计问题转化为数学优化问题进行求解,对于设计新颖高效换热器具有重要价值。然而,拓扑优化数学模型难以直接解释优化结果的几何特征及相应强化机理。以传热量为目标,对微通道换热器进行拓扑优化设计,研... 换热器结构拓扑优化可将传热强化设计问题转化为数学优化问题进行求解,对于设计新颖高效换热器具有重要价值。然而,拓扑优化数学模型难以直接解释优化结果的几何特征及相应强化机理。以传热量为目标,对微通道换热器进行拓扑优化设计,研究了不同参数对换热器强化结构特征和换热器性能的影响。结果表明,拓扑优化换热器的通道结构呈现多级分叉构型,分叉的数量随着入口Reynolds数、翅片传热效率和流体Prandtl数的增大而增多。在此基础上,采用耗散和边界层理论分析了拓扑优化分叉通道与流体边界层厚度的内在联系,为换热器结构强化设计提供了新的思路。 展开更多
关键词 优化设计 微通道 传递过程 分级通道结构 边界层理论
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缢蛏ABC转运蛋白基因家族成员全基因组鉴定及表达模式分析
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作者 杨凡 李治平 +1 位作者 董迎辉 任建峰 《渔业科学进展》 CSCD 北大核心 2024年第1期172-184,共13页
腺苷三磷酸结合盒转运蛋白(ATP binding cassette transporter,ABC transporter)家族是最古老的膜蛋白家族之一,广泛存在于原核生物和真核生物体内,利用ATP水解释放的能量对氨基酸、脂质、抗生素等物质进行跨膜运输,参与生物体内多种生... 腺苷三磷酸结合盒转运蛋白(ATP binding cassette transporter,ABC transporter)家族是最古老的膜蛋白家族之一,广泛存在于原核生物和真核生物体内,利用ATP水解释放的能量对氨基酸、脂质、抗生素等物质进行跨膜运输,参与生物体内多种生理活动。目前,对软体动物ABC转运蛋白家族的鉴定,仅在虾夷扇贝(Patinopecten yessoensis)、栉孔扇贝(Chlamys farreri)和长牡蛎(Crassostrea gigas)3种双壳类中有系统研究,对缢蛏(Sinonovacula constricta)ABC转运蛋白家族的鉴定和表达模式分析尚未见报道。利用缢蛏基因组和转录组数据,运用本地及NCBI在线BLAST程序、FGENESH+、SMART、Ex PASy、MEGA X、Mev 4.90和MapInspect等生物信息学分析工具,在全基因组水平系统地鉴定出52个缢蛏ABC转运蛋白,并对转运蛋白基因外显子数目、染色体定位等信息进行分析;通过系统进化分析,将缢蛏ABC转运蛋白家族分为8个亚家族,即ABCA~ABCH;通过比较分析不同物种ABC转运蛋白家族,推测基因串联复制事件对软体动物ABC转运蛋白家族成员数目的增加有影响。ABC转运蛋白基因在缢蛏不同发育时期和组织的表达分析显示,ABCC和ABCG亚家族多个基因在缢蛏稚贝时期表达量达到最高值,ABC转运蛋白基因在鳃、肝胰腺和性腺中表达种类较多。软体动物作为第二大动物类群,目前仅有3个物种的ABC转运蛋白得到了系统分类,缢蛏ABC转运蛋白基因家族的系统鉴定与表达模式分析为研究软体动物ABC转运蛋白基因的进化和缢蛏ABC转运蛋白功能提供了基础资料。 展开更多
关键词 缢蛏 ABC转运蛋白 序列分析 表达模式
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基于城市公共交通可达性的医疗服务空间评价——以成都市金牛区为例
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作者 聂书君 唐相龙 《黑龙江科学》 2024年第11期20-22,27,共4页
医疗服务可达性是城市居民就医便利程度的重要影响因素。利用ArcGIS网络分析模式与空间点格局分析法评估成都市金牛区医院与居住区的空间分布特征及就医平均可达时间,讨论私家车与公交车关于可达性水平的高低与空间聚集现状。研究结果表... 医疗服务可达性是城市居民就医便利程度的重要影响因素。利用ArcGIS网络分析模式与空间点格局分析法评估成都市金牛区医院与居住区的空间分布特征及就医平均可达时间,讨论私家车与公交车关于可达性水平的高低与空间聚集现状。研究结果表明,金牛区医院整体可达性较强,91.26%的居住区基本满足30 min的就医需求,顶峰时段公共交通工具更具优势。金牛区的医疗服务设施等资源存在8.3%的重叠及分配不均现象,可对相应医院的设施及配置进行优化,提升各医院的基础服务水平,扩大服务范围,开通快速直达道路,避免因交通拥堵而造成不必要损失。金牛区的居住区与医院分布方向大致相同,圈层密度由核心到边缘逐渐减少,但密度较低区域部分居民就医需求无法得到满足。应优化可达性较弱居住区周边的公共交通基础设施,更深层次维护多种公共交通间的联系。 展开更多
关键词 医疗服务 交通可达性 GIS 空间格局 成都市
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基于夜光遥感的我国春运人口流动时空特征研究
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作者 王白羽 于泉洲 +4 位作者 林英华 姜杰 张宏立 栾志理 张二勋 《测绘与空间地理信息》 2024年第5期68-70,74,共4页
基于2013、2019和2021年的NPP/VIIRS夜间灯光数据,构建春节夜光差值指数,在省域尺度上证明了差值指数与流动人口量具有显著相关性(R=0.61,P<0.01),并以该指数研究了全国春运期间人口流动的时空特征。结果发现:1)我国春运强度在胡焕... 基于2013、2019和2021年的NPP/VIIRS夜间灯光数据,构建春节夜光差值指数,在省域尺度上证明了差值指数与流动人口量具有显著相关性(R=0.61,P<0.01),并以该指数研究了全国春运期间人口流动的时空特征。结果发现:1)我国春运强度在胡焕庸线两侧差异明显,东南地区人口流动是西北地区的6倍左右。春运在东南地区呈现连片式特征,在西北地区呈现离散零星式的流动特征。2)2013—2021年间,我国春运期间总体人口流动格局大致稳定,但流入地和流出地在空间上存在一定变化。3)经济发展状况和新冠疫情可能导致了这种格局演化特征的发生。尤其新冠疫情防疫和“就地过年”政策的推出,导致2021年春节期间大规模人口流动的减少,春运强度的下降。 展开更多
关键词 春运 人口流动 空间格局 夜光遥感 新冠疫情
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福建省沿海港口货运职能识别及结构演变研究
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作者 齐永杰 叶士琳 +1 位作者 王佳韡 吴祖安 《福建师范大学学报(自然科学版)》 CAS 北大核心 2024年第1期131-139,共9页
精准识别港口货运职能及其演变规律,是推动港口群协同发展的重要环节。采用货种区位商、货物离散指数、港口分工系数等方法,定量分析福建省沿海港口群货物吞吐量增长态势、货运职能及结构演变趋势。结果表明:2000—2020年,福建省沿海港... 精准识别港口货运职能及其演变规律,是推动港口群协同发展的重要环节。采用货种区位商、货物离散指数、港口分工系数等方法,定量分析福建省沿海港口群货物吞吐量增长态势、货运职能及结构演变趋势。结果表明:2000—2020年,福建省沿海港口群货物吞吐量整体呈增长趋势,但年增长速度趋于放缓;沿海港口群的主要职能以煤炭、钢铁、粮食等传统货物运输为主,其中福州港主要职能最多,具有一定的综合功能;沿海港口群的港口分工系数明显下降,各港间货种结构差异缩小,货运职能特征由单一向多样化转变。今后应优化福建省沿海港口群空间布局,明确港口功能定位,促进沿海港口协同发展。 展开更多
关键词 港口职能 职能结构 时空格局 港口转型 货物运输 福建省
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基于FP-Growth算法的运毒嫌疑车辆智能推荐研究
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作者 陈柏翰 罗安飞 《贵州警察学院学报》 2024年第3期84-91,共8页
毒品运输是毒品犯罪的重要环节,虽然毒品运输的手段越来越多样化,但公路运输仍然是主要的运输方式之一,而运毒人员有着各自经典的运毒模式。文中对运毒模式进行特征挖掘,发现存在前后车伴随的规律,根据实际业务中前后车行为以半小时为... 毒品运输是毒品犯罪的重要环节,虽然毒品运输的手段越来越多样化,但公路运输仍然是主要的运输方式之一,而运毒人员有着各自经典的运毒模式。文中对运毒模式进行特征挖掘,发现存在前后车伴随的规律,根据实际业务中前后车行为以半小时为时间间隔导向,建模时选择PostgreSQL数据库。在数据库中建立过往车辆前半小时中间表、后半小时中间表、中间跨度表,运用人工智能数据挖掘技术实现从大量的通行车辆中抽取车辆伴随信息,采用FP-Growth算法挖掘频繁项集,查找高频出现车牌号,通过设定阈值并找到对应的关联规则,经过缉毒民警提供的黑名单进行过滤并排序,最后进行车辆嫌疑度的推荐,为民警拦截嫌疑车辆提供支持,能够在一定程度上提高对嫌疑车辆排查的针对性、准确性和有效性。 展开更多
关键词 毒品运输 运毒模式 特征挖掘 FP-GROWTH算法 关联规则
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适应客流波动的高铁运力动态调整策略与实践
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作者 高瀚 单仕平 +1 位作者 杨阳 张琦 《中国铁路》 北大核心 2024年第3期96-104,共9页
高速铁路网的拓展和动车组运载工具数量的增加,使我国高铁客流呈现愈加复杂的变化规律。为了灵活、快速、精准地响应不同时期动态变化的客流需求,基于现阶段运力配置模式,首先揭示平峰时期以及包含季节性假期和国家法定节假日的高峰时... 高速铁路网的拓展和动车组运载工具数量的增加,使我国高铁客流呈现愈加复杂的变化规律。为了灵活、快速、精准地响应不同时期动态变化的客流需求,基于现阶段运力配置模式,首先揭示平峰时期以及包含季节性假期和国家法定节假日的高峰时期客流波动规律;其次剖析客运生产环节中涉及运力调整的原则、流程、资源和措施;最后根据不同时期、不同场景的客流波动规律,针对性地提出可适应平峰时期客流需求的“三批次”运力动态调整策略与高峰时期的“梯次投放”运力动态调整策略。该高铁运力动态调整策略,可满足市场化背景下客流需求的波动性与复杂性,为进一步完善复合场景下铁路运力精准配置策略提供参考。 展开更多
关键词 高速铁路 运力配置 需求波动 客流规律 动态调整
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Identification of AtENT3 as the main transporter for uridine uptake in Arabidopsis roots 被引量:7
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作者 Kun Ling Chen Min Xin Xu +6 位作者 Guang Yong Li Hui Liang Zong Liang Xia Xin Liu Ji Shu Zhang Ai Min Zhang Dao Wen Wang 《Cell Research》 SCIE CAS CSCD 2006年第4期377-388,共12页
当在酵母细胞生产了,差别在 Arabidopsis 器官被表示时,以前的研究证明了 Arabidopsis equilibrative nucleoside 运输 ers (AtENTs ) 拥有运输活动。此处,我们在 nucleoside 运输活动和 AtENT 成员的 transcriptional 模式报导进一... 当在酵母细胞生产了,差别在 Arabidopsis 器官被表示时,以前的研究证明了 Arabidopsis equilibrative nucleoside 运输 ers (AtENTs ) 拥有运输活动。此处,我们在 nucleoside 运输活动和 AtENT 成员的 transcriptional 模式报导进一步的分析。AtENTs 3 的 recombinant 蛋白质, 6,和 7,然而并非那些 AtENTs 1, 2, 4,和 8,被发现与高亲密关系搬运 thymidine。与以前的建议相反,那 AtENT1 不能搬运 uridine,这个工作证明 recombinant AtENT1 是 uridine 的 pH 依赖、高亲密关系的 transporter。当在 MS 盘子上成长时, AtENT3 猛烈植物比野类型的植物和 AtENT1 或 AtENT6 的猛烈植物对细胞毒素的 uridine 类似物 5-fluorouridine 更容忍。与这观察一致, AtENT3 猛烈的线展出了一个显著地减少的能力收起[(3 ) H ] 经由根的 uridine 什么时候与有变异的 AtENT1 或 AtENT6 的野类型的植物和植物相比。这显示那 AtENT3,然而并非 AtENTs 1 并且 6,是为在 Arabidopsis 根的 uridine 举起的主要 transporter。AtENTs 1 的抄写, 3, 4, 6, 7,和 8 在叶开发和老朽期间以一种复杂方式被调整。相反,六个 AtENT 成员并列地在种子萌芽期间被劝诱。这个工作为未来研究在 recombinant AtENT 蛋白质和新线索的运输性质上提供新信息在里面 vivo 运输活动和在 Arabidopsis 工厂的不同 ENT 蛋白质的生理的功能。 展开更多
关键词 尿嘧啶核苷 植物药 药物治疗 生物
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平陆运河建设对西南部地区货运出海格局的影响
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作者 刘晓玲 王桃 吴晓磊 《水运工程》 北大核心 2023年第11期15-22,共8页
平陆运河对外直接沟通北部湾港,对内直接连通珠江水系高等级航道,是一条通江达海的水运新通道,其建设将对西南部地区货运出海格局产生深远影响。全面分析西南部地区现状货运出海通道总体格局,结合平陆运河—北部湾港江海联运通道与东南... 平陆运河对外直接沟通北部湾港,对内直接连通珠江水系高等级航道,是一条通江达海的水运新通道,其建设将对西南部地区货运出海格局产生深远影响。全面分析西南部地区现状货运出海通道总体格局,结合平陆运河—北部湾港江海联运通道与东南向、东向出海通道及南向通道现有路径综合运输成本比较,提出平陆运河建设的影响将主要集中在广西、云南、贵州3省区,辐射影响川渝地区。平陆运河的建设将优化西南部地区出海货运方式,改变出海货运流向,提高西南部地区南向通道出海货运量比重,提升环北部湾港口群综合竞争力,为西南部地区提前围绕平陆运河建设完善物流体系提供决策参考。 展开更多
关键词 平陆运河 江海联运 西南部地区 货运出海格局
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中国新型城镇化与低碳交通耦合协调时空格局及其驱动因素 被引量:2
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作者 张帅 《生态经济》 北大核心 2023年第10期115-123,共9页
构建新型城镇化和低碳交通评价体系,借助耦合协调模型、空间自相关分析、空间计量模型研究分析了两者耦合协调水平的时空演变特征及其驱动因素。结果显示:(1)2010—2019年新型城镇化与低碳交通耦合协调水平呈现日益递增的良好态势,但依... 构建新型城镇化和低碳交通评价体系,借助耦合协调模型、空间自相关分析、空间计量模型研究分析了两者耦合协调水平的时空演变特征及其驱动因素。结果显示:(1)2010—2019年新型城镇化与低碳交通耦合协调水平呈现日益递增的良好态势,但依然整体处于过渡发展区间,协调水平相对较低,且存在明显的空间分异特征,逐渐形成了以东部为轴带、向内陆扩散的“川”字梯度分布格局。(2)各地区新型城镇化与低碳交通耦合协调发展存在明显的空间正相关性,且呈现出高、低水平集聚趋于东、西两级分布的空间特征。(3)空间结构、公共交通、科技创新、信息数字化和政府干预对两者的耦合协调发展具有明显催化作用。 展开更多
关键词 新型城镇化 低碳交通 耦合协调 时空格局 驱动因素
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扁果枸杞表皮蜡质转运相关基因LbABCG11的克隆及其表达特征分析
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作者 袁惠君 张瑞艳 +4 位作者 关玉晨 余诗曼 徐琰莹 马倩国 鲍婧婷 《华北农学报》 CSCD 北大核心 2023年第6期45-54,共10页
为研究ATP结合转运蛋白G亚家族蛋白11(ABCG11)在旱生经济灌木扁果枸杞中的功能,以扁果枸杞为试验材料,利用逆转录(RT-PCR)技术和RACE法克隆了扁果枸杞LbABCG11基因的cDNA序列,通过生物信息学分析该序列特征,并用实时荧光定量PCR法(qRT-P... 为研究ATP结合转运蛋白G亚家族蛋白11(ABCG11)在旱生经济灌木扁果枸杞中的功能,以扁果枸杞为试验材料,利用逆转录(RT-PCR)技术和RACE法克隆了扁果枸杞LbABCG11基因的cDNA序列,通过生物信息学分析该序列特征,并用实时荧光定量PCR法(qRT-PCR)研究了LbABCG11在盐处理、渗透胁迫和脱落酸(ABA)处理下不同器官的转录水平。结果表明,LbABCG11基因全长为2971 bp,开放阅读框长2130 bp,编码710个氨基酸,有6个跨膜区,预测蛋白质分子质量为79.39 ku,理论等电点8.42,脂肪指数为89.63,不稳定系数为35.52,平均亲水性为0.070,其编码蛋白质分子式为C _(3590) H_( 5577) N _(935) O _(1027) S_( 35),属于性质稳定的碱性疏水蛋白,含有核苷酸结合域(NBD)以及跨膜结构域(TMD),并以NBD-TMD的形式排列,是一种WBC型(WBC)半分子转运蛋白。该蛋白质二级结构主要由α-螺旋及无规则卷曲组成,分别占45.21%和33.66%,与三级结构预测结果相符。系统进化树分析发现,LbABCG11蛋白与茄科番茄SlABCG11和辣椒CbABCG11的亲缘关系较近,与拟南芥AtABCG11、藜麦CqABCG11同源性较低。LbABCG11基因在叶、茎、根中均表达,其表达量受NaCl、渗透胁迫和ABA诱导,表明LbABCG11参与旱生植物盐和干旱等多种胁迫的调控。 展开更多
关键词 扁果枸杞 蜡质转运 LbABCG11 基因克隆 生物信息学 表达模式
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