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Prospects of 3D Printing Technology in Dental Medicine
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作者 Ye Sun 《Journal of Clinical and Nursing Research》 2024年第6期398-403,共6页
With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and fut... With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and future potential of 3D printing technology in dental medicine and to analyze its benefits and challenges.It first introduces the current state of 3D printing technology in dental implants,crowns,bridges,orthodontics,and maxillofacial surgery.It then discusses the potential applications of 3D printing technology in oral tissue engineering,drug delivery systems,personalized dental prosthetics,and surgical planning.Finally,it analyzes the benefits of 3D printing technology in dental medicine,such as improving treatment accuracy and patient comfort,and shortening treatment times,while also highlighting the challenges faced,such as costs,material choices,and technical limitations.This article aims to provide a reference for professionals in the field of dental medicine and to promote the further application and development of 3D printing technology in this area. 展开更多
关键词 3D printing technology Dental medicine Dental implants CROWNS Bridges ORTHODONTICS Maxillofacial surgery Tissue engineering Drug delivery systems Personalized dental prosthetics Surgical planning
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3D-ASL技术在高级别脑胶质瘤术后复发诊断中的价值分析
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作者 王艳芹 石礼廷 《影像研究与医学应用》 2024年第9期61-64,共4页
目的:分析在高级别脑胶质瘤术后复发诊断中应用3D动脉自旋标记(3D-ASL)技术的临床价值。方法:选取2017年11月—2023年10月于山东第一医科大学附属省立医院就诊的疑似高级别脑胶质瘤复发的患者共计50例。均应用MRI、MRI增强、3D-ASL检测... 目的:分析在高级别脑胶质瘤术后复发诊断中应用3D动脉自旋标记(3D-ASL)技术的临床价值。方法:选取2017年11月—2023年10月于山东第一医科大学附属省立医院就诊的疑似高级别脑胶质瘤复发的患者共计50例。均应用MRI、MRI增强、3D-ASL检测,以手术病理结果为金标准,分析不同检查方式的诊断效果。结果:手术病理结果显示,阳性36例,阴性14例;MRI平扫+增强方式检出真阳性29例,真阴性7例;MRI平扫+增强+3D-ASL检测方式检出真阳性35例,真阴性12例。MRI平扫+增强+3D-ASL联合检测高级别脑胶质瘤复发的诊断灵敏度、增强率、特异度均高于MRI平扫+增强扫描,差异有统计学意义(P<0.05)。经病理诊断,50例疑似高级别脑胶质瘤患者中,共有36例确认为术后肿瘤复发,余14例为术后放射性脑损伤者。不同类型患者病灶各项最大相对脑血流量比较,差异有统计学意义(P<0.05)。结论:在高级别脑胶质瘤术后复发诊断中,在应用MRI平扫、MRI增强扫描基础上联合应用3D-ASL技术,可提升级别脑胶质瘤术后复发诊断准确率,可推广。 展开更多
关键词 高级别 脑胶质瘤 复发诊断 3d-asl
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磁共振3D-ASL技术联合DWI在脑缺血性疾病中的应用
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作者 张庆国 《影像研究与医学应用》 2024年第12期92-94,共3页
目的:分析脑缺血性疾病诊断中采取磁共振动脉自旋标记(3D-ASL)技术联合弥散加权成像(DWI)的应用效果。方法:选取瓮安县人民医院2021年1月—2023年10月期间收治的40例急性缺血性脑梗死(AICI)患者,采取磁共振3D-ASL技术联合DWI诊断,分析... 目的:分析脑缺血性疾病诊断中采取磁共振动脉自旋标记(3D-ASL)技术联合弥散加权成像(DWI)的应用效果。方法:选取瓮安县人民医院2021年1月—2023年10月期间收治的40例急性缺血性脑梗死(AICI)患者,采取磁共振3D-ASL技术联合DWI诊断,分析诊断结果。结果:40例AICI患者DWI特征为异常高信号。经3D-ASL脑血流(CBF)图像显示,梗死区血流灌注异常情况为,低血流灌注者35例、高血流灌注者3例、无明显异常者2例,同时梗死高血流灌注者可见梗死区域大量缺血半暗带和合并对侧半球灌注减弱者2例;梗死区的表观弥散系数(ADC)值低于对侧,差异有统计学意义(P<0.05)。梗死区的CBF值低于梗死对侧区,差异有统计学意义(P<0.05)。IP区的CBF值低于IP区对侧区,差异有统计学意义(P<0.05)。梗死区的CBF值低于IP区,差异有统计学意义(P<0.05)。结论:脑缺血性疾病采取磁共振3D-ASL技术联合DWI诊断具有重要的意义,能够从不同方面表达脑缺血性疾病的特征。 展开更多
关键词 磁共振3d-asl DWI 脑缺血性疾病 应用效果
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全脑3D-ASL灌注成像联合DTI对脑胶质瘤患者的诊断价值
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作者 李晶 《医疗装备》 2024年第11期13-16,共4页
目的 分析全脑磁共振三维动脉自旋标记(3D-ASL)灌注成像联合核磁共振弥散张量成像(DTI)对脑胶质瘤的诊断价值。方法 选择2021年1月至2023年12月医院收治的40例脑胶质瘤患者为研究对象,根据肿瘤分级分为高级别组(22例)和低级别组(18例)... 目的 分析全脑磁共振三维动脉自旋标记(3D-ASL)灌注成像联合核磁共振弥散张量成像(DTI)对脑胶质瘤的诊断价值。方法 选择2021年1月至2023年12月医院收治的40例脑胶质瘤患者为研究对象,根据肿瘤分级分为高级别组(22例)和低级别组(18例)。所有患者术前均行3D-ASL灌注成像和DTI扫描,分析不同分级患者的各项检查参数[各向异性指数(rFA)、相对表观扩散系数(rADC)、脑血流量最大值(TBF_(max))、相对脑血流量(rCBF)]。结果 高级别组病灶、周围水肿带、正常区的rFA值与低级别组比较,差异无统计学意义(P>0.05)。高级别组病灶区、周围水肿带的rADC值低于低级别组(P<0.05)。高级别组TBF_(max)分别与对侧白质、灰质、半球的比值及rCBF值均高于低级别组(P<0.05)。受试者工作特征(ROC)曲线显示,3D-ASL灌注成像联合DTI技术诊断高、低级别肿瘤的曲线下面积[AUC(0.965)]、约登指数(0.864),灵敏度(100.00%)、特异度(86.40%)均高于单一指标。结论 全脑3D-ASL灌注成像联合DTI诊断脑胶质瘤有较高的价值,可准确鉴别肿瘤分级程度,为临床治疗提供客观的参考依据。 展开更多
关键词 3d-asl灌注成像 DTI 脑胶质瘤
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Review of Digital Campus Construction Led by Virtual Reality Technology
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作者 Jiaxuan Tang Yalin Lin Xinmin Hu 《Journal of Electronic Research and Application》 2024年第3期148-154,共7页
In recent years,the government has issued a series of documents to promote the construction of digital campuses.This initiative serves to encourage the deep integration of information technology and intelligent techno... In recent years,the government has issued a series of documents to promote the construction of digital campuses.This initiative serves to encourage the deep integration of information technology and intelligent technology education and digital reform,the combination of virtual reality and campus management is the need for innovative thinking and economic and social development,and then better change our learning style and living environment.The construction of the digital campus is based on virtual reality technology,BIM,GIS,and three-dimensional modeling technology to provide an immersive platform for students,promote the integration of virtual reality technology and education,help teachers,students,and parents to understand all kinds of education information and resources,to achieve their interoperability.From the off-campus environment to the school teaching equipment,teachers to teaching quality certification,and learning,to extracurricular entertainment,opening ceremonies to graduation parties,to bring more efficient,convenient,and safe campus life for teachers,students,and staff in school,and break the traditional information restrictions. 展开更多
关键词 Digital campus Virtual reality technology BIM GIS 3D modeling
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Anisotropic creep behavior of soft-hard interbedded rock masses based on 3D printing and digital imaging correlation technology
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作者 TIAN Yun WU Fa-quan +5 位作者 TIAN Hong-ming LI Zhe SHU Xiao-yun HE Lin-kai HUANG Man CHEN Wei-zhong 《Journal of Mountain Science》 SCIE CSCD 2023年第4期1147-1158,共12页
Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent... Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research. 展开更多
关键词 3D printing Soft-hard interbedded rock mass Digital imaging correlation technology Weak interlayer Anisotropic creep
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Research on 3D Laser Scanning Reconstruction of Ancient Buildings Combined with BIM Technology
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作者 Ensheng Liu Chunyong Luo +1 位作者 Chunbaixue Yang Yuhua Huang 《Journal of Computer and Communications》 2023年第7期233-240,共8页
After more than 30 years of scientific and social development, surveying and mapping technology by leaps and bounds, engineering surveying technology has undergone tremendous changes. In the process of protecting anci... After more than 30 years of scientific and social development, surveying and mapping technology by leaps and bounds, engineering surveying technology has undergone tremendous changes. In the process of protecting ancient buildings, it is necessary to obtain the precise dimensions of architectural details. In this study, the path of 3D laser scanning combined with BIM technology is explored. Taking the observation and protection of the ancestral hall of the Liu family as an example, this study aims to draw drawings that reflect the relevant information about the ancient buildings, the accurate three-dimensional model of ancient buildings is established with BIM technology, which provides new methods and ideas for the research and protection of ancient buildings. . 展开更多
关键词 Liu Ancestral Hall 3D Laser Scanning technology BIM technology Point Cloud Processing
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Research on the Application of Virtual Simulation and 3D Animation Technology in the Teaching of Road and Bridge Majors in Higher Vocational Colleges
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作者 Wei Liu 《Journal of Contemporary Educational Research》 2023年第9期67-73,共7页
The informatization of higher vocational education is the future development trend,and it is also encouraged and promoted by the Ministry of Education.This article focuses on the road and bridge major,combined with th... The informatization of higher vocational education is the future development trend,and it is also encouraged and promoted by the Ministry of Education.This article focuses on the road and bridge major,combined with the author’s experience in introducing virtual simulation and three-dimensional(3D)animation technology into relevant course teaching in recent years,discusses the application of virtual simulation and 3D animation technology in higher vocational education and promotes classroom revolution,to obtain better teaching effect. 展开更多
关键词 Virtual simulation technology 3D animation technology Higher vocational education Classroom revolution
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工业CuBi/MgSiO_(3)催化剂再生技术研究
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作者 薛斌 马彩梅 +1 位作者 刘婷婷 刘志威 《山西化工》 CAS 2024年第3期15-17,43,共4页
以1,4丁二醇生产过程中的催化剂再生技术为研究对象,探讨了对废铜铋催化剂再生后,与新鲜铜铋催化剂在整体成型法工艺下的复配技术。通过表征催化剂的粒径分布、比表面积、形貌特征、元素组成和物相组成,确定了乙炔合成丁炔二醇铜铋催化... 以1,4丁二醇生产过程中的催化剂再生技术为研究对象,探讨了对废铜铋催化剂再生后,与新鲜铜铋催化剂在整体成型法工艺下的复配技术。通过表征催化剂的粒径分布、比表面积、形貌特征、元素组成和物相组成,确定了乙炔合成丁炔二醇铜铋催化剂的最优再生处理工艺流程。通过正交试验和强度测试仪分析了成型铜铋催化剂的机械强度可靠性和耐磨性能,为工业CuBi/MgSiO_(3)催化剂的再生提供了新的思路,也为其他催化剂的再生提供了借鉴。 展开更多
关键词 再生技术 工业CuBi/MgSiO_(3)催化剂 复配技术
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双参数3D-ASL联合DWI对急性脑梗死侧支循环及预后的评估 被引量:2
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作者 胡玉明 邓凌 张靓婧 《影像研究与医学应用》 2023年第19期45-47,共3页
目的:评估双参数三维动脉自旋标记(3D-ASL)联合弥散加权成像(DWI)对急性脑梗死侧支循环及预后的影响。方法:选取2021年1月—2022年1月佛山市三水区人民医院接收的60例急性脑梗死患者为研究对象,采用3D-ASL双参数(PLD 1.5 s和2.5 s)的方... 目的:评估双参数三维动脉自旋标记(3D-ASL)联合弥散加权成像(DWI)对急性脑梗死侧支循环及预后的影响。方法:选取2021年1月—2022年1月佛山市三水区人民医院接收的60例急性脑梗死患者为研究对象,采用3D-ASL双参数(PLD 1.5 s和2.5 s)的方式,结合DWI技术,对急性脑梗死患者进行影像学检查,测量患者的梗死核心区、缺血半暗带和对侧正常脑组织在不同标记后延迟时间下的脑血流量,并根据相对脑血流值将患者分为高灌注组、正常灌注组和低灌注组,每组20例。采用美国国立卫生研究院卒中量表(NIHSS),记录入院当天和治疗后15天的NIHSS评分,比较三组患者的NIHSS评分以及相对脑血流值,评估患者脑血流情况与预后的关系。结果:双参数3D-ASL和DWI联合评估结果显示,高灌注组患者脑血流量下降较为明显,正常灌注组脑血流量无明显降低,两组差异有统计学意义(P <0.05);低灌注组脑血流量下降相对明显,但降低幅度低于高灌注组,差异有统计学意义(P <0.05);NIHSS评分结果显示,正常灌注组的治疗效果更好,在治疗后1 d、7 d、14 d均有明显降低,差异具有统计学意义(P <0.05)。高灌注组的治疗效果最差,在治疗后1 d、7 d、14 d降低幅度较小,差异具有统计学意义(P <0.05)。低灌注组治疗效果要优于高灌注组,低于正常灌注组,治疗后1 d、7 d、14 d有较为明显的降低,但降低幅度小于正常灌注组,差异具有统计学意义(P <0.05)。结论:双参数3D-ASL联合DWI可以有效评估急性脑梗死患者的侧支循环情况及预后。侧支循环良好的患者具有较小的脑梗死体积和较好的预后,而侧支循环不良的患者则脑梗死体积较大且预后较差。联合方法有望帮助医生早期准确评估患者的脑梗死严重程度和预后风险,并制定个体化的治疗方案,提高患者的生存和康复率。这些结果将为急性脑梗死患者的诊断和治疗提供精确的影像学信息,为医生提供有效的指导。 展开更多
关键词 双参数3d-asl DWI 急性脑梗死 侧支循环 预后
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双参数3D动脉自旋标记灌注成像对大脑中动脉慢性闭塞患者血供情况评价及与脑梗死面积关系研究
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作者 王丽坤 尹继磊 +1 位作者 刘海静 郑园园 《中国医学装备》 2024年第2期64-69,共6页
目的:探讨双参数3D动脉自旋标记灌注成像(3D-ASL)对大脑中动脉慢性闭塞(CMCAO)患者血供情况的评价及与脑梗死面积的关系。方法:选取2019年4月至2021年12月邯郸市中心医院收治的112例单侧CMCAO患者,根据数字减影血管造影(DSA)检查结果将... 目的:探讨双参数3D动脉自旋标记灌注成像(3D-ASL)对大脑中动脉慢性闭塞(CMCAO)患者血供情况的评价及与脑梗死面积的关系。方法:选取2019年4月至2021年12月邯郸市中心医院收治的112例单侧CMCAO患者,根据数字减影血管造影(DSA)检查结果将其分为大脑前动脉(ACA)脑膜支代偿(LMA)的代偿组(50例)和无代偿组(62例)。分析弥散张量成像(DWI)、磁共振血管成像(MRA)以及双参数3D-ASL检测结果,对比两组临床资料、3D-ASL参数及脑梗死发生情况,分析代偿情况影响因素,根据脑血流量值[标记后延迟时间(PLD)=1.5 s、2.5 s]绘制CMCAO患者LMA诊断价值的受试者工作特征(ROC)曲线,对比不同脑梗死面积患者3D-ASL参数,并分析3D-ASL参数与脑梗死面积的关系。结果:CMCAO患者患侧表观弥散系数(ADC)为0.31±0.10、脑血流量值1.5 s和2.5 s分别为25.67±4.25和54.09±4.49,且均低于健侧,差异有统计学意义(t=27.591、34.210、3.913,P<0.05);代偿组患者的脑血流量值分别为1.5 s和2.5 s,与无代偿组相比,差异有统计学意义(t=5.584、4.090,P<0.05);logistic回归分析显示年龄、卒中、脑梗死面积、脑血流量值1.5 s和2.5 s均为CMCAO患者LMA情况的影响因素(OR=4.187、6.604、0.482、5.681、5.807,P<0.05);ROC曲线显示,PLD为1.5 s和2.5 s时,3D-ASL诊断LMA的曲线下面积(AUC)分别为0.720、0.812;代偿组正常及腔隙性脑梗死比例高于无代偿组,中小梗死及大面积脑梗死比例低于无代偿组,差异有统计学意义(t=28.062,P<0.05);不同脑梗死面积患者脑血流量值(1.5 s)相比,差异有统计学意义(t=0.202,P<0.05);3D-ASL参数脑血流量值(1.5 s)与脑梗死面积呈负相关(r=-0.261,P<0.05)。结论:双参数3D-ASL可无创、直观地评估单侧CMCAO患者LMA代偿状况,患侧大脑中动脉(MCA)血流灌注与脑梗死面积相关,PLD为1.5 s时,可对此进行敏感反应,为临床诊治及疗效判断提供客观可靠的依据。 展开更多
关键词 双参数 3D动脉自旋标记灌注成像(3d-asl) 大脑中动脉慢性闭塞(CMCAO) 标记后延迟时间 脑梗死面积
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Assessment and Risk Zonation of Landslides in Panxi Area Based on 3S Technology 被引量:3
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作者 ZHANG Baolei SONG Shujun +1 位作者 FENG Wenlan ZHOU Wancun 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第4期793-800,共8页
Based on field survey located by GPS, it is obtained landslides' location and distribution information by the method of remote sensing in this paper. The vector data of environmental factors that breed and induce lan... Based on field survey located by GPS, it is obtained landslides' location and distribution information by the method of remote sensing in this paper. The vector data of environmental factors that breed and induce landslides such as the elevation, the slope, the vegetation cover, the lithology, the rainfall and so on are gained using GIS(geographical information system) techniques of spatial analysis. All the data obtained are managed through building landslide management system. At the same time, the system is made the platform to appraise the relationship between the distribution of landslides and the environmental factors. The results indicate: landslides take place relatively easily in the slope range between 10° and 25°; most landslides are in the mixed area of bush and grass with a coverage degree of from 20° to 65°; the distribution of landslides has a positive relationship with the distribution of annual rainfall. The risk degree of Panxi Area is zoned and mapped by the model of liner stack using GIS technique, and the result indicates: the place of high risk degree is the belt of Panzhihua-Miyi-Dechang-Mugu and southeast of Huili county and Huidong county,and area is about 512 707 hm^2. 展开更多
关键词 LANDSLIDE 3S technology risk zonation Panxi Area
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足月新生儿缺氧缺血性脑病3D-ASL灌注成像与扩散加权成像的相关性研究
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作者 林国太 罗树君 +1 位作者 陈东 罗树存 《中国CT和MRI杂志》 2023年第12期1-2,共2页
目的探析3D-ASL灌注成像联合DWI技术能否揭示足月新生儿HIE微观病理生理学的改变。方法选择2015年6月—2022年5月49例足月新生儿HIE作为研究对象分别进行颅脑3D-ASL及DWI序列扫描并进行图像分析,然后选取双侧丘脑、额叶白质、顶叶白质... 目的探析3D-ASL灌注成像联合DWI技术能否揭示足月新生儿HIE微观病理生理学的改变。方法选择2015年6月—2022年5月49例足月新生儿HIE作为研究对象分别进行颅脑3D-ASL及DWI序列扫描并进行图像分析,然后选取双侧丘脑、额叶白质、顶叶白质、基底节区、小脑半球、小脑蚓部为感兴趣区(ROI)分别测量ADC、rCBF值,并通过对各ROI的rCBF值与ADC值进行相关性分析。结果足月新生儿HIE的双侧丘脑、双侧顶叶白质、双侧基底节区rCBF值与ADC值呈负相关,但双侧额叶白质、双侧小脑半球、小脑蚓部的rCBF值与ADC值无相关性。结论3D-ASL灌注成像联合DWI技术可反映不同病理情况下的HIE微观病理生理学的演变规律,对足月新生儿HIE的早期诊断、治疗方案制定提供更充分的证据。 展开更多
关键词 3d-asl DWI 足月新生儿HIE 相关性 病理生理学
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Evaluation of reservoir connectivity using whole-oil gas chromatographic fingerprint technology: A case study from the Es_3~3 reservoir in the Nanpu Sag, China 被引量:1
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作者 Xu Yaohui Shen Xianda +2 位作者 Chen Nengxue Yang Cuimin WangQiaoli 《Petroleum Science》 SCIE CAS CSCD 2012年第3期290-294,共5页
In this study, whole-oil gas chromatographic fingerprint analyses were performed on oils from the Es3^3 reservoir in the Liubei area of the Nanpu Sag. The gas chromatographic peaks of cyclic and branched alkanes with ... In this study, whole-oil gas chromatographic fingerprint analyses were performed on oils from the Es3^3 reservoir in the Liubei area of the Nanpu Sag. The gas chromatographic peaks of cyclic and branched alkanes with relatively high resolution from nCl0 to nC25 were selected to establish a database of whole-oil gas chromatographic peak height ratio fingerprints. Reservoir fluid connectivity was identified by using clustering analysis. This method can reflect the gas chromatography fingerprint information accurately and entirely, and avoid the one-sidedness of the star diagram method which only selects several fixed gas chromatographic peaks. 展开更多
关键词 Whole-oil gas chromatographic fingerprint technology reservoir connectivity Nanpu Sag Es3^3 reservoir clustering analysis
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Methods of extracting change information and updating land use/cover map based on 3S technology 被引量:1
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作者 YANG Gui-jun~(1,2), ZHANG Ji-xian~2, WU Wen-bo~1, ZHAO Hong~1 (1. Liaoning Technical Chiversity, Fuxin, 123000, China 2. Academy of China Surveying and Mapping Science, Beijing 100039, China) 《中国有色金属学会会刊:英文版》 CSCD 2005年第S1期38-41,共4页
A fully automated approach for detecting land use/cover change using remote sensing data, GIS data, GPS data is presented. The integrating raster with vector methods of updating the basic land use/land cover map based... A fully automated approach for detecting land use/cover change using remote sensing data, GIS data, GPS data is presented. The integrating raster with vector methods of updating the basic land use/land cover map based on 3S technology is becoming one of the most important developing directions in 3S application fields, land-use and cover change fields over the world. It has been successful applied in two tasks of the Ministry of Land and Resources of China, and takes some benefit. 展开更多
关键词 3S technology land-use and COVER CHANGE OBJECT-ORIENTED
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Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology 被引量:2
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作者 Linyi Li Junsheng Yang +3 位作者 Jinyang Fu Shuying Wang Cong Zhang Maolong Xiang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第5期1470-1485,共16页
In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor... In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test. 展开更多
关键词 Operating railway tunnels Invert stability Tunnel drainage system Three-dimensional(3D)printing technology Model test
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Ni/γ-Al_(2)O_(3)催化苯乙烯-异戊二烯-苯乙烯嵌段共聚物加氢
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作者 周浩浩 郭方 +2 位作者 荣泽明 侯召民 苏东宁 《精细化工》 EI CAS CSCD 北大核心 2024年第4期872-880,共9页
以γ-Al_(2)O_(3)为原料、碳酸铵为沉淀剂,采用沉积-沉淀法制备了Ni/γ-Al_(2)O_(3)催化剂,将其应用于苯乙烯-异戊二烯-苯乙烯(SIS)嵌段共聚物催化加氢。通过XRD、TEM、XPS、1HNMR和DSC对催化剂和产物进行了表征。考察了载体种类、Ni理... 以γ-Al_(2)O_(3)为原料、碳酸铵为沉淀剂,采用沉积-沉淀法制备了Ni/γ-Al_(2)O_(3)催化剂,将其应用于苯乙烯-异戊二烯-苯乙烯(SIS)嵌段共聚物催化加氢。通过XRD、TEM、XPS、1HNMR和DSC对催化剂和产物进行了表征。考察了载体种类、Ni理论负载量(以载体质量为基准,下同)、反应条件对SIS加氢反应的影响。结果表明,以γ-Al_(2)O_(3)为载体并负载10%的Ni为催化剂、环己烷为溶剂、反应温度为140℃、反应压力为1MPa、反应时间3.0 h的条件下,催化剂具有最优活性,聚异戊二烯嵌段加氢度达到85%,副反应苯环的加氢度<10%。 展开更多
关键词 苯乙烯-异戊二烯-苯乙烯嵌段共聚物 Ni/γ-Al_(2)O_(3) 非均相催化 催化技术
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Application of 3D stereoscopic visualization technology in casting aspect 被引量:1
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作者 Kang Jinwu Zhang Xiaopeng +1 位作者 Zhang Chi Liu Baicheng 《China Foundry》 SCIE CAS 2014年第4期308-313,共6页
3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research... 3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research.The history,fundamental principle,and devices of 3D stereoscopic visualization technology are reviewed in this paper.The authors’research achievements on the 3D stereoscopic visualization technology in the modeling and simulation of the casting process are presented.This technology can be used for the observation of complex 3D solid models of castings and the simulated results of solidification processes such as temperature,fluid flow,displacement,stress strain and microstructure,as well as the predicted defects such as shrinkage/porosity,cracks,and deformation.It can also be used for other areas relating to 3D models,such as assembling of dies,cores,etc.Several cases are given to compare the illustration of simulated results by traditional images and red-blue 3D stereoscopic images.The spatial shape is observed better by the new method.The prospect of3D stereoscopic visualization in the casting aspect is discussed as well.The need for aided-viewing devices is still the most prominent problem of 3D stereoscopic visualization technology.However,3D stereoscopic visualization represents the tendency of visualization technology in the future;and as the problem is solved in the years ahead,great breakthroughs will certainly be made for its application in casting design and modeling and simulation of the casting processes. 展开更多
关键词 3D stereoscopic visualization technology CASTING modeling and simulation observation and analysis
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3D-ASL灌注技术联合MRA诊断脑缺血疾病的价值
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作者 陈雯婷 《影像研究与医学应用》 2023年第11期64-66,共3页
目的:分析三维动脉自旋标记(three-dimentional arterial spin labeling,3D-ASL)灌注技术及磁共振血管成像(magnetic resonance angiography,MRA)联合应用在脑缺血疾病诊断中的价值。方法:选取2021年9月—2022年12月于中山大学肿瘤防治... 目的:分析三维动脉自旋标记(three-dimentional arterial spin labeling,3D-ASL)灌注技术及磁共振血管成像(magnetic resonance angiography,MRA)联合应用在脑缺血疾病诊断中的价值。方法:选取2021年9月—2022年12月于中山大学肿瘤防治中心就诊的脑缺血疾病患者80例作为研究组,另选取28名健康志愿者作为对照组,均予以3D-ASL灌注技术及MRA检查,分析两组图像表现,测量相对脑血流量(relative cerebral blood flow,rCBF)值,判断灌注区rCBF值与血管狭窄程度及缺血程度的关联。结果:对照组rCBF值(1.052±0.037),ASL图左右对称,没有显著的异常灌注区;研究组包括30例短暂性脑缺血发作(transient ischemic attack,TIA),22例大面积梗死,28例小面积梗死,rCBF值在(0.752±0.109),差异有统计学意义(P<0.05);80例患者中,包括灌注正常者25例,灌注异常者55例,其中有灌注增高5例,灌注减低50例;脑缺血性疾病患者患侧平均rCBF值(0.78±0.17),比健侧的(0.97±0.13)更低,差异有统计学意义(P<0.05)。结论:将3D-ASL灌注技术及MRA联合应用在脑缺血疾病的诊断中价值高,能够为病情的诊断提供重要依据,值得在临床中推广。 展开更多
关键词 3d-asl灌注技术 MRA 脑缺血疾病 诊断价值
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Advancing Wound Filling Extraction on 3D Faces:An Auto-Segmentation and Wound Face Regeneration Approach
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作者 Duong Q.Nguyen Thinh D.Le +2 位作者 Phuong D.Nguyen Nga T.K.Le H.Nguyen-Xuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期2197-2214,共18页
Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical applications.In this paper,we propose an efficient approach for automating 3D facial wound seg... Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical applications.In this paper,we propose an efficient approach for automating 3D facial wound segmentation using a two-stream graph convolutional network.Our method leverages the Cir3D-FaIR dataset and addresses the challenge of data imbalance through extensive experimentation with different loss functions.To achieve accurate segmentation,we conducted thorough experiments and selected a high-performing model from the trainedmodels.The selectedmodel demonstrates exceptional segmentation performance for complex 3D facial wounds.Furthermore,based on the segmentation model,we propose an improved approach for extracting 3D facial wound fillers and compare it to the results of the previous study.Our method achieved a remarkable accuracy of 0.9999993% on the test suite,surpassing the performance of the previous method.From this result,we use 3D printing technology to illustrate the shape of the wound filling.The outcomes of this study have significant implications for physicians involved in preoperative planning and intervention design.By automating facial wound segmentation and improving the accuracy ofwound-filling extraction,our approach can assist in carefully assessing and optimizing interventions,leading to enhanced patient outcomes.Additionally,it contributes to advancing facial reconstruction techniques by utilizing machine learning and 3D bioprinting for printing skin tissue implants.Our source code is available at https://github.com/SIMOGroup/WoundFilling3D. 展开更多
关键词 3D printing technology face reconstruction 3D segmentation 3D printed model
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