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Mapping lineaments using Landsat 8 OLI and SRTM data;a case study of the eastern part of the Ouarzazate Basin,Morocco
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作者 MOUJANE Said ALGOUTI Ahmed +3 位作者 ALGOUTI Abdellah FARAH Abdelouahed ABOULFARAJ Abdelfatah NAFOURI Imane 《Journal of Mountain Science》 SCIE CSCD 2024年第3期987-1003,共17页
The integration of remote sensing and geographic information system(GIS)was employed in this study to delineate the structural lineaments within the eastern section of the Ouarzazate Basin,situated between the souther... The integration of remote sensing and geographic information system(GIS)was employed in this study to delineate the structural lineaments within the eastern section of the Ouarzazate Basin,situated between the southern front of the Central High Atlas and the northern slopes of the Eastern Anti-Atlas(also known as the Saghro Massif).To achieve this objective,Landsat 8 Operational Land Imager(OLI)and Shuttle Radar Topography Mission(SRTM)data were used.Principal Component Analysis(PCA)was computed and a directional filter was applied to the first PCA and the panchromatic band(B8).Additionally,shading was applied to the SRTM data in four directions;N0°,N45°,N90°,N135°.After removing of the non-geological linear structures,the results obtained,using the automatic extraction method,allowed us to produce a synthetic map that included 1251 lineaments with an average length of 1331 m and was dominated by NE-SW,ENE-WSW and E-W directions,respectively.However,the high lineament density is clearly noted in the Anti-Atlas(Saghro Massif)and at the level of the northern part,extending from the Ait Ibrirne to Arg-Ali Oubourk villages.High lineament density can always be found around the major faults affecting this area.The data collected during the field investigations and from geological maps show that the major direction of the faults and structural accidents range mostly between N45°,N70°and N75°.The correlation of remote sensing results with those collected in the field shows a similarity and coincidence with each other.From these results,it is possible to consider the automatic extraction method as a supplementary kind that can serve classical geology by quickly enriching it with additional data.As shown in this work,this method provides more information when applied in arid areas where the fields are well outcropped. 展开更多
关键词 Remote sensing GIS Landsat 8 OLI SRTM Ouarzazate Basin Central High Atlas
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Optimal Configuration of Fault Location Measurement Points in DC Distribution Networks Based on Improved Particle Swarm Optimization Algorithm
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作者 Huanan Yu Hangyu Li +1 位作者 He Wang Shiqiang Li 《Energy Engineering》 EI 2024年第6期1535-1555,共21页
The escalating deployment of distributed power sources and random loads in DC distribution networks hasamplified the potential consequences of faults if left uncontrolled. To expedite the process of achieving an optim... The escalating deployment of distributed power sources and random loads in DC distribution networks hasamplified the potential consequences of faults if left uncontrolled. To expedite the process of achieving an optimalconfiguration of measurement points, this paper presents an optimal configuration scheme for fault locationmeasurement points in DC distribution networks based on an improved particle swarm optimization algorithm.Initially, a measurement point distribution optimization model is formulated, leveraging compressive sensing.The model aims to achieve the minimum number of measurement points while attaining the best compressivesensing reconstruction effect. It incorporates constraints from the compressive sensing algorithm and networkwide viewability. Subsequently, the traditional particle swarm algorithm is enhanced by utilizing the Haltonsequence for population initialization, generating uniformly distributed individuals. This enhancement reducesindividual search blindness and overlap probability, thereby promoting population diversity. Furthermore, anadaptive t-distribution perturbation strategy is introduced during the particle update process to enhance the globalsearch capability and search speed. The established model for the optimal configuration of measurement points issolved, and the results demonstrate the efficacy and practicality of the proposed method. The optimal configurationreduces the number of measurement points, enhances localization accuracy, and improves the convergence speedof the algorithm. These findings validate the effectiveness and utility of the proposed approach. 展开更多
关键词 Optimal allocation improved particle swarm algorithm fault location compressed sensing DC distribution network
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How Sense of Ritual in Tourism Impacts Tourists’Co-Creation of Tourism Experience Values:A Study Based on the Theory of Value Co-Creation
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作者 Yi Min Zhang Guangyu Sun Genjin 《Contemporary Social Sciences》 2024年第2期67-84,共18页
Establishing a sense of ritual within tourism consumption scenarios offers tourists the opportunity for interactive engagement.Drawing upon the value co-creation theory,this study constructed an influence mechanism mo... Establishing a sense of ritual within tourism consumption scenarios offers tourists the opportunity for interactive engagement.Drawing upon the value co-creation theory,this study constructed an influence mechanism model to examine tourists'active engagement in the process of co-creating tourism experience values.It employed Partial Least Squares Structural Equation Modeling(PLS-SEM)to empirically test the proposed hypotheses.The findings demonstrate that the model constructed in the present study exhibits robust reliability,validity,and explanatory power.The perception of the sense of ritual in tourism exerts a significant positive influence on tourists’co-creation of tourism experience values,thereby significantly enhancing both the communitas and flow experienced by tourists during their travels.Moreover,such communitas and flow can mediate the influence of the sense of ritual in tourism on tourists’co-creation of tourism experience values.This study contributes to advancing the current research on tourists’co-creation of tourism experience values and the sense of ritual in tourism,thereby providing theoretical foundations for cultivating a sense of ritual within tourism consumption scenarios. 展开更多
关键词 sense of ritual in tourism tourists’co-creation of tourism experience values theory of value co-creation theory of Interaction Ritual Chains
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Preliminary report of coseismic surface rupture(part)of Türkiye's M_(W)7.8 earthquake by remote sensing interpretation
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作者 Yali Guo Haofeng Li +3 位作者 Peng Liang Renwei Xiong Chaozhong Hu Yueren Xu 《Earthquake Research Advances》 CSCD 2024年第1期4-13,共10页
Both M_(W) 7.8 and M_(W) 7.5 earthquakes occurred in southeastern Türkiye on February 6,2023,resulting in numerous buildings collapsing and serious casualties.Understanding the distribution of coseismic surface r... Both M_(W) 7.8 and M_(W) 7.5 earthquakes occurred in southeastern Türkiye on February 6,2023,resulting in numerous buildings collapsing and serious casualties.Understanding the distribution of coseismic surface ruptures and secondary disasters surrounding the epicentral area is important for post-earthquake emergency and disaster assessments.High-resolution Maxar and GF-2 satellite data were used after the events to extract the location of the rupture surrounding the first epicentral area.The results show that the length of the interpreted surface rupture zone(part of)is approximately 75 km,with a coseismic sinistral dislocation of 2-3 m near the epicenter;however,this reduced to zero at the tip of the southwest section of the East Anatolia Fault Zone.Moreover,dense soil liquefaction pits were triggered along the rupture trace.These events are in the western region of the Eurasian Seismic Belt and result from the subduction and collision of the Arabian and African Plates toward the Eurasian Plate.The western region of the Chinese mainland and its adjacent areas are in the eastern section of the Eurasian Seismic Belt,where seismic activity is controlled by the collision of the Indian and Eurasian Plates.Both China and Türkiye have independent tectonic histories. 展开更多
关键词 2023 Türkiye M_(w)7.8 earthquake Coseismic surface rupture East anatolian fault zone Eurasian seismic zone Remote sensing interpretation
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Quantification of Sand Dune Movements in the South Western Part of Egypt, Using Remotely Sensed Data and GIS 被引量:3
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作者 Islam Abou El-Magd Osman Hassan Sayed Arafat 《Journal of Geographic Information System》 2013年第5期498-508,共11页
Sand dune movement is a hazardous phenomenon in Egypt and creates major threat on the existing land use and land cover as well as developmental plans. This paper studied the sand dune morphology and quantified the rat... Sand dune movement is a hazardous phenomenon in Egypt and creates major threat on the existing land use and land cover as well as developmental plans. This paper studied the sand dune morphology and quantified the rate of sand dune movements and direction in a newly developed project in the southwest of Egypt. Two dates of satellite imageries were used to trace the Barchan dunes at various sites with different morphological properties to estimate the annual movement rate based on point to point geo-correlations. 149 dunes of the common sand dunes in the area of study including barchans and transverse dunes were studied to accurately determine their rate of movements, which ranged from 1.3 to 19.3 my-1. The direction of sand dune movements was mainly to the south and slightly southeast with range from 265 to 295 degrees. The quantification of sand dune movement and direction has, indeed, enabled to determine the major threat on the exiting land use and land cover as well as the newly developmental projects. 展开更多
关键词 SAND DUNE Natural Hazards Remote Sensing GIS EGYPT
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Participants Recruitment for Coverage Maximization by Mobility Predicting in Mobile Crowd Sensing 被引量:1
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作者 Yuanni Liu Xi Liu +2 位作者 Xin Li Mingxin Li Yi Li 《China Communications》 SCIE CSCD 2023年第8期163-176,共14页
Mobile Crowd Sensing(MCS)is an emerging paradigm that leverages sensor-equipped smart devices to collect data.The introduction of MCS also poses some challenges such as providing highquality data for upper layer MCS a... Mobile Crowd Sensing(MCS)is an emerging paradigm that leverages sensor-equipped smart devices to collect data.The introduction of MCS also poses some challenges such as providing highquality data for upper layer MCS applications,which requires adequate participants.However,recruiting enough participants to provide the sensing data for free is hard for the MCS platform under a limited budget,which may lead to a low coverage ratio of sensing area.This paper proposes a novel method to choose participants uniformly distributed in a specific sensing area based on the mobility patterns of mobile users.The method consists of two steps:(1)A second-order Markov chain is used to predict the next positions of users,and select users whose next places are in the target sensing area to form a candidate pool.(2)The Average Entropy(DAE)is proposed to measure the distribution of participants.The participant maximizing the DAE value of a specific sensing area with different granular sub-areas is chosen to maximize the coverage ratio of the sensing area.Experimental results show that the proposed method can maximize the coverage ratio of a sensing area under different partition granularities. 展开更多
关键词 data average entropy human mobility prediction markov chain mobile crowd sensing
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A novel three-step implicit iteration process for threeΦ-hemicontractive mapping in the intermediate sense
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作者 Godwin Amechi Okeke Austine Efut Ofem 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第2期248-263,共16页
In this paper,we introduce a three-step composite implicit iteration process for approximating the common fixed point of three uniformly continuous and asymptotically generalizedΦ-hemicontractive mappings in the inte... In this paper,we introduce a three-step composite implicit iteration process for approximating the common fixed point of three uniformly continuous and asymptotically generalizedΦ-hemicontractive mappings in the intermediate sense.We prove that our proposed iteration process converges to the common fixed point of three finite family of asymptotically generalizedΦ-hemicontractive mappings in the intermediate sense.Our results extends,improves and complements several known results in literature. 展开更多
关键词 xed point asymptotically genralizedΦ-hemicontractive mapping in the intermediate sense uniformly continuos implicit iteration process strong convergence Banach spaces
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Preventing Health Anxiety:The Role of Self-Evaluation,Sense of Coherence,Self-Rated Health and Perceived Social Support
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作者 Sándor Csibi Mónika Csibi József Bognár 《International Journal of Mental Health Promotion》 2023年第10期1081-1088,共8页
Background:Components of Self,completed with the perceived social support determine the individual differences in theevaluation of a stressor and the behavioral responses toward it,such as health-related anxiety.The s... Background:Components of Self,completed with the perceived social support determine the individual differences in theevaluation of a stressor and the behavioral responses toward it,such as health-related anxiety.The study set as a goal theanalysis of associations between the components of Self,such as self-evaluation,sense of coherence,perceived social support,and reported health-related anxiety in an adult sample.Methods:147 adults from the 18–73 age group(mean age 37.5)voluntarily completed the questionnaire through Qualtrics online platform containing the Short Health Anxiety Inventory,Core Self-Evaluation Scale,Social Support Assessing Scale,and one Health Self-Evaluation Item.Results:ANOVA foundrelevant differences in total scores and subscales’scores of the health anxiety scale depending on the positive self-evaluation.Linear regression shows that the analyzed variables were responsible for the prediction of a higher value on the“Perceivedprobability of becoming ill”subscale in a proportion of 45.6%and for the“Perceived consequence of illness”subscale in aproportion of 20.2%The predictive value of the linear regression model for the total score on the health anxiety scale was46.3%.Our findings show that negative Core Self-Evaluation is linked with perceived health anxiety.Conclusions:Selfevaluation,sense of coherence and perceived social support influence the perceived health and can explain the differences inthe reported health-related anxiety. 展开更多
关键词 Core self-evaluation health anxiety health self-evaluation perceived social support SELF-CONCEPT the sense of coherence
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Word Sense Disambiguation Based Sentiment Classification Using Linear Kernel Learning Scheme
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作者 P.Ramya B.Karthik 《Intelligent Automation & Soft Computing》 SCIE 2023年第5期2379-2391,共13页
Word Sense Disambiguation has been a trending topic of research in Natural Language Processing and Machine Learning.Mining core features and performing the text classification still exist as a challenging task.Here the... Word Sense Disambiguation has been a trending topic of research in Natural Language Processing and Machine Learning.Mining core features and performing the text classification still exist as a challenging task.Here the features of the context such as neighboring words like adjective provide the evidence for classification using machine learning approach.This paper presented the text document classification that has wide applications in information retrieval,which uses movie review datasets.Here the document indexing based on controlled vocabulary,adjective,word sense disambiguation,generating hierarchical cate-gorization of web pages,spam detection,topic labeling,web search,document summarization,etc.Here the kernel support vector machine learning algorithm helps to classify the text and feature extract is performed by cuckoo search opti-mization.Positive review and negative review of movie dataset is presented to get the better classification accuracy.Experimental results focused with context mining,feature analysis and classification.By comparing with the previous work,proposed work designed to achieve the efficient results.Overall design is per-formed with MATLAB 2020a tool. 展开更多
关键词 Text classification word sense disambiguation kernel support vector machine learning algorithm cuckoo search optimization feature extraction
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Comparative study of self-compassion and sense of coherence in nurses of psychiatric hospitals
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作者 Iman Nosratabadi Golnaz Forough Ameri +1 位作者 Sedigheh Iranmanesh Neda Asadi 《Frontiers of Nursing》 2023年第2期193-201,共9页
Objective:Nurses,due to the nature of their job,are subjected to various forms of stress and physical and psychological injuries.Self-compassion and a sense of coherence have attracted much attention in research in re... Objective:Nurses,due to the nature of their job,are subjected to various forms of stress and physical and psychological injuries.Self-compassion and a sense of coherence have attracted much attention in research in recent years as having high potential for improving the health and performance of people in the workplace.The present study aimed to compare self-compassion and the sense of coherence in nurses working in psychiatric hospitals and other hospitals of Kerman University of Medical Sciences.Methods:The present study was a descriptive-comparative study of applied type conducted on 100 nurses of Shahid Beheshti Psychiatric Hospital in Kerman by the census method and 100 nurses of other hospitals of Kerman University of Medical Sciences by the stratified random sampling method.The instruments included the self-compassion questionnaire and the sense of coherence questionnaire.Data were analyzed using the Statistical Package for Social Sciences software.Results:The results of the present study showed that self-compassion and sense of coherence were higher in psychiatric nurses(39.35±7.7 and 53.02±8.01)than among other nurses(36.03±5.81 and 49.76±6.30).There was a direct and moderate relationship between a sense of coherence and self-compassion(P-value<0.005).The higher the score of compassion for oneself,the higher was the score of sense of coherence.Furthermore,the sense of coherence had a direct and weak relationship with all dimensions of self-compassion,except for the extreme imitation dimension,which showed a direct and moderate relationship to other dimensions(P-value<0.001).Conclusions:Self-compassion and a sense of coherence,as a form of self-communication,increase nurses’satisfaction and reduce nurses’job stress and,as a result,job performance is improved. 展开更多
关键词 nurses psychiatric hospital SELF-COMPASSION sense of coherence COMPASSION COHERENCE
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Sensing as Knowing:Medicines,the Senses,and Practical Expertise in Late Imperial China
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作者 LIU Xiaomeng 《Chinese Medicine and Culture》 2023年第1期55-67,共13页
The development of the medicinal trade and markets in late imperial China increased anxiety among scholarly physicians about the authenticity of medicines.Even though the market was typically depicted by scholarly phy... The development of the medicinal trade and markets in late imperial China increased anxiety among scholarly physicians about the authenticity of medicines.Even though the market was typically depicted by scholarly physicians as a place full of tricks and deceptions,it was a repertoire where practical knowledge about authentication was created and circulated.The specialized knowledge was mainly transmitted through oral tradition.But in some instances,it was also written down by scholarly physicians or merchants,allowing us to reconstruct the techniques and their underlying rationales.Authentication of medicines mobilized multiple sensory perceptions of the human body,consisting of observing,tasting,smelling,touching,and performing small tests.All these techniques played different roles in the practice of authentication.Even though these sensory techniques seemed like a collection of trivial and practical records without any coherent rationales,an underlying episteme could be detected through a close investigation.Merchants and practitioners in the market did not understand the nature and materiality of medicines by any established theories.Instead,they actively engaged with the tangible form of medicines through the senses and bodily techniques.This sensory form of knowing indicates a type of practical expertise that is distant from the scholarly tradition of materia medica in late imperial China. 展开更多
关键词 Authentication Market MEDICINES senseS Practical expertise
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WHY PRACTICE MAKES PERFECT SENSE:THE PAST,PRESENT AND POTENTIAL FUTURE OF THE PPP PARADIGM IN LANGUAGE TEACHER EDUCATION
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作者 Jason Anderson 《基础教育外语教学研究》 2023年第1期29-32,共4页
Introduction Among,the many lesson planning paradigms usedin English language teacher education over the last 40 years,PPP has proven to be one of the mostpopular and most durable(see Figure 1)despite regular criticis... Introduction Among,the many lesson planning paradigms usedin English language teacher education over the last 40 years,PPP has proven to be one of the mostpopular and most durable(see Figure 1)despite regular criticism in literature emanating from the Anglophone,centre,of ELT theory.After presenting a brief history of the paradigm andoutlining the main criticisms directed at PPP,especially in the 1990s,I discuss some important rescarch findings from SLA studics sincc the turn of the century that lend support to PPP-typelesson structures. 展开更多
关键词 FIGURE sense CENTRE
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Impact of State-Owned Capital Participation on ESG Performance of Private Enterprises
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作者 Xiongwei Wu 《Proceedings of Business and Economic Studies》 2023年第6期121-127,共7页
As global investors and stakeholders increasingly prioritize environmental,social,and governance(ESG)performance,corporate social responsibility and sustainability have become crucial factors in determining corporate ... As global investors and stakeholders increasingly prioritize environmental,social,and governance(ESG)performance,corporate social responsibility and sustainability have become crucial factors in determining corporate success.In the context of China’s robust economy,the involvement of state-owned capital exerts a profound impact on the ESG performance of private enterprises.This paper,starting from the perspective of ESG,analyzes how state-owned capital participation influences the ESG performance of private enterprises.Additionally,it proposes recommendations for the involvement of state-owned enterprises in private enterprises,aiming to foster the sustainable development of private enterprises and enhance their social responsibility. 展开更多
关键词 State-owned capital Private enterprises ESG sense of social responsibility
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Air Pollution Risk Assessment Using GIS and Remotely Sensed Data in Kirkuk City,Iraq
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作者 Huda Jamal Jumaah Abed Jasim +1 位作者 Aydin Rashid Qayssar Ajaj 《Journal of Atmospheric Science Research》 2023年第3期41-51,共11页
According to World Health Organization(WHO)estimates and based on a world population review,Iraq ranks tenth among the most air-polluted countries in the world.In this study,the authors tried to evaluate the outdoor a... According to World Health Organization(WHO)estimates and based on a world population review,Iraq ranks tenth among the most air-polluted countries in the world.In this study,the authors tried to evaluate the outdoor air of Kirkuk City north of Iraq.The authors relied on two types of data:field measurements and remotely sensed data.Fifteen air quality points were determined in the study region representing the monthly average measurements im­plemented for the one-year dataset.Geographic information systems(GIS)based geo-statistic and geo-processing techniques have been applied to collected data.Spatial distribution data related to Air Quality Index(AQI),and Par­ticulate Matter(PM10 and PM2.5)were obtained by mapping collected records.Remotely sensed data of PM2.5 were analyzed and compared with the collected data.Health impacts were assessed per each air pollutant determined in the study.Spatial distribution maps revealed the hazardous air type in the study area.Overall AQI ranged between 300 and 472μg/m^(3)referring to unhealthy,very unhealthy,and hazardous classes of pollution.Also,PM10 ranged between 300 and 570μg/m^(3)indicating the same class of air pollution from unhealthy to hazardous.While PM2.5 ranged between 40 and 60μg/m^(3)which represents unhealthy air for sensitive persons and unhealthy air.The remotely sensed data re­vealed different air types for the study period ranging from 14.5 to 52.5μg/m^(3)represented in moderate and unhealthy air for sensitive persons.Significant correlations were obtained where the mean local R2(coefficient of determination)was obtained as 0.83.The assessed data were within high air pollution that requires immediate intervention for con­trolling causes and eliminating their effects. 展开更多
关键词 Air pollution risk AQI GIS particulate matter Remote sensing
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蒜芥茄SsFLS2基因的克隆及其表达分析
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作者 孙茂 吴丽艳 +4 位作者 龚亚菊 鲍锐 桂敏 黎志彬 杜光辉 《西南农业学报》 CSCD 北大核心 2024年第8期1669-1676,共8页
【目的】克隆云南野生蒜芥茄(Solanum sisymbriifolium Lam.)中的FLS2基因,并对其编码蛋白的理化性质、亚细胞定位、系统进化以及表达情况予以分析,初步探究野茄FLS2基因在黄萎病胁迫下的生物学功能。【方法】基于前期所测转录组数据(... 【目的】克隆云南野生蒜芥茄(Solanum sisymbriifolium Lam.)中的FLS2基因,并对其编码蛋白的理化性质、亚细胞定位、系统进化以及表达情况予以分析,初步探究野茄FLS2基因在黄萎病胁迫下的生物学功能。【方法】基于前期所测转录组数据(蒜芥茄接种黄萎病病原菌),克隆获取蒜芥茄FLS2基因,命名为SsFLS2;利用生物信息学分析软件对SsFLS2基因的理化性质进行分析,并通过实时荧光定量PCR(Real-time fluorescence quantitative PCR,RT-qPCR)检测其在蒜芥茄根、茎、叶的表达以及在接种黄萎病病原菌后不同时间的表达情况。【结果】蒜芥茄SsFLS2基因全长3655 bp,具有完整的ORF框,编码1126个氨基酸。其编码蛋白的分子式为C_(5596)H_(8814)N_(1494)O_(1627)S_(4),理论分子量为124.34 kD,理论等电点(pI)为7.33,总平均亲水性系数为0.081。该蛋白二级结构主要由42.81%的无规则卷曲、40.23%的α-螺旋、13.23%的延伸链以及3.73%的β-折叠组成,且存在跨膜结构,定位于细胞膜上,其中可被磷酸化且超过阈值线的位点,共计151个。SsFLS2蛋白的氨基酸序列与马铃薯(Solanum tuberosum)同源蛋白(XP 006358149.2)的关系最近。RT-qPCR检测发现,在蒜芥茄根、茎、叶中均有SsFLS2基因的表达,且根、叶中的相对表达量极显著高于茎部;接种黄萎病病原菌后72 h内,处理组和对照组均在24 h时,SsFLS2基因的相对表达量大幅度增加且极显著高于其他时间点。【结论】本研究成功克隆蒜芥茄的SsFLS2基因,并对其编码蛋白的理化性质及基因表达情况等进行分析。结果表明,SsFLS2是蒜芥茄响应黄萎病胁迫的重要基因,结果可为进一步研究该基因在蒜芥茄黄萎病抗性中的功能奠定基础。 展开更多
关键词 蒜芥茄 Flagellin sensing 2(FLS2) 基因克隆 生物信息学 基因表达
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3.0T磁共振SENSE及SPAIR技术在腹部扫描中的优势及应用 被引量:6
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作者 顾欣 袁滨 +2 位作者 袁飞 冯凯琳 龙淼淼 《医疗卫生装备》 CAS 2005年第9期51-52,共2页
目的:探讨3.0T磁共振SENSE及SPAIR技术在腹部扫描中的优势及应用.方法:收集2004年5月至2005年3月在我院进行腹部MRI检查的病人50例,采用Philips Intera 3.0T磁共振成像系统,sense-Torso腹部线圈,sSSH/TE60序列、sSSH/SPAIR序列(不同sens... 目的:探讨3.0T磁共振SENSE及SPAIR技术在腹部扫描中的优势及应用.方法:收集2004年5月至2005年3月在我院进行腹部MRI检查的病人50例,采用Philips Intera 3.0T磁共振成像系统,sense-Torso腹部线圈,sSSH/TE60序列、sSSH/SPAIR序列(不同sense因子)、sSSH/SPIR序列及sMRCP/3D胰胆管成像序列行横断面和3D扫描.结果:采用3.0TMR具有的Sense Single-Shot-TSE序列能在自由呼吸的状态下,以呼吸触发的方式,在缩短扫描时间的基础上,获得高质量的图像;sSSH/SPAIR序列与sSSH/SPIR序列相比较,具有更强的T2脂肪抑制效果,对病变具有更高的检出率,特别对胰腺病变显示清晰;SENSE与Single-Shot-TSE技术应用于超快速T2扫描可消除磁敏感伪影,应用SENSE技术与FreeBreathing结合的3D MRCP序列对胰管、肝内外胆管、胆囊病变及其细节的显示更加清晰.结论:3.0T磁共振成像系统具有的SENSE并行采集与特殊的脂肪抑制序列应用于腹部MR扫描,具有信号强度高,信噪比高的优点,可获得高密度分辨率的图像,在解决了SAR问题的基础上,具有更多的技术开发空间. 展开更多
关键词 sense SPAIR 腹部扫描 磁共振成像
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Detecting Vegetation Fractional Coverage of Typical Steppe in Northern China Based on Multi-scale Remotely Sensed Data 被引量:15
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作者 李晓兵 陈云浩 +1 位作者 史培军 陈晋 《Acta Botanica Sinica》 CSCD 2003年第10期1146-1156,共11页
One of the study objectives of global change is land use/cover change (LUCC) by using multiscale remotely sensed data on global and regional scale. In this paper, field sample, digital camera, Landsat-ETM+ (ETM+, Enha... One of the study objectives of global change is land use/cover change (LUCC) by using multiscale remotely sensed data on global and regional scale. In this paper, field sample, digital camera, Landsat-ETM+ (ETM+, Enhanced Thematic Mapper) image and the National Oceanic and Atmospheric Administration/the advanced very high resolution radiometer (NOAA/AVHRR) image were integrated to detect, simulate and analyze the vegetation fractional coverage of typical steppe in northern China. The results show: (1) Vegetation fractional coverage measured by digital camera is more precise than results measured by other methods. It can be used to validate other measuring results. (2) Vegetation fractional coverage measured by 1 m 2 field sample change fluctuantly for different observers and for different sample areas. In this experiment, the coverage is generally high compared with the result measured by digital camera, and the average absolute error is 9.92%, but two groups measure results, correlation coefficient r(2) = 0.89. (3) Three kinds of methods using remotely sensed data were adopted to simulate the vegetation fractional coverage. Average absolute errors of the vegetation fractional coverage, measured by ETM+ and NOAA, are respectively 7.03% and 7.83% compared with the result measured by digital camera. When NOAA pixel was decomposed by ETM+ pixels after geometrical registry, the average absolute errors measured by this method is 5.68% compared with the digital camera result. Correction coefficients of three results with digital camera result r(2) are respectively 0.78, 0.61 and 0.76. (4) The result of statistic model established by NOAA-NDVI (NDVI, Normalized Difference Vegetation Index) and the vegetation fractional coverage measured by digital camera show lower precision (r(2) = 0.65) than the result of statistic model established by ETM+-NDVI and digital camera coverage then converted to NOAA image (r(2) = 0.80). Pixel decomposability method improves the precision of measuring the vegetation fractional coverage on a large scale. This is a significant practice on scaling by using remotely sensed data. Integrated application of multi-scale remotely sensed data in earth observation will be an important approach to promoting measuring precision of ecological parameters. 展开更多
关键词 multi-scale remote sensing typical steppe vegetation fractional coverage
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SENSE心脏阵列线圈在前列腺MRI检查中的初步应用研究 被引量:5
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作者 刘金来 沈钧康 +6 位作者 王灌忠 杨晓春 张彩元 周丽娟 徐孝秋 王水珍 钱铭辉 《临床放射学杂志》 CSCD 北大核心 2008年第9期1234-1238,共5页
目的对灵敏度编码(SENSE)心脏阵列线圈和直肠腔内线圈在前列腺MRI检查中的图像质量进行对比研究,初步评价SENSE心脏阵列线圈在前列腺MRI检查中的价值。资料与方法选取前列腺病变患者50例。在相同扫描参数下,均使用SENSE心脏阵列线圈和... 目的对灵敏度编码(SENSE)心脏阵列线圈和直肠腔内线圈在前列腺MRI检查中的图像质量进行对比研究,初步评价SENSE心脏阵列线圈在前列腺MRI检查中的价值。资料与方法选取前列腺病变患者50例。在相同扫描参数下,均使用SENSE心脏阵列线圈和直肠腔内线圈进行前列腺MRI常规检查,对使用两种线圈所分别获得的前列腺轴位(TRA)小视野、薄层T2WI图像的均匀度、对比信噪比(CNR)进行对比分析。结果采用SENSE心脏阵列线圈所获得的图像均匀度优于采用直肠腔内线圈者(配对t检验,P<0.05);采用SENSE心脏阵列线圈所获得的图像CNR亦优于采用直肠腔内线圈者(配对t检验,P<0.05)。结论SENSE心脏阵列线圈在图像均匀度和CNR这两个图像评价指标方面都取得了较好的成像效果,在一定程度上可以替代直肠腔内线圈进行前列腺小视野、薄层、高分辨率T2W成像。 展开更多
关键词 sense心脏阵列线圈 前列腺 磁共振成像
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A highly sensitive LITES sensor based on a multi-pass cell with dense spot pattern and a novel quartz tuning fork with low frequency 被引量:3
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作者 Yahui Liu Shunda Qiao +4 位作者 Chao Fang Ying He Haiyue Sun Jian Liu Yufei Ma 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第3期26-34,共9页
A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manu... A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this manuscript.An erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further enhanced.The optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,respectively.The target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip QTF.An improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF. 展开更多
关键词 light-induced thermoelectric spectroscopy quartz tuning fork multi-pass cell gas sensing
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结合非线性GRAPPA与SENSE的并行磁共振成像 被引量:2
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作者 蒋明峰 朱礼涛 +2 位作者 汪亚明 夏灵 龚莹岚 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2014年第10期1865-1870,共6页
针对SENSE并行磁共振成像中采用补零缺失数据方法估计敏感度分布不准确性的问题,提出采用非线性GRAPPA方法估算缺失的K空间欠采样数据.计算并行线圈的敏感度分布,将这些敏感度分布应用于SENSE并行磁共振成像.采用不同加速因子的脑磁共振... 针对SENSE并行磁共振成像中采用补零缺失数据方法估计敏感度分布不准确性的问题,提出采用非线性GRAPPA方法估算缺失的K空间欠采样数据.计算并行线圈的敏感度分布,将这些敏感度分布应用于SENSE并行磁共振成像.采用不同加速因子的脑磁共振K空间欠采样数据以验证提出算法的重建性能.实验结果表明,与单一的非线性GRAPPA和SENSE重建算法相比,该混合NLGRAPPA-SENSE算法在加速因子较大时可以重建出更加准确的磁共振图像,具有更低的噪声功率(AP)和更高的信噪比(SNR)性能. 展开更多
关键词 并行磁共振成像(pMRI) 非线性GRAPPA 敏感度编码(sense) NLGRAPPA-sense
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