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盐城港某围海造陆工程合龙口施工工艺研究 预览
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作者 陈玉华 保长辉 《港工技术》 2019年第1期85-88,共4页
基于社会经济的发展,港区对土地的需求越来越大,需要充足的陆域作为港口发展的腹地,大量的围海造陆工程应用于工程实践,其中合龙口是整个围堤工程的关键难点。以盐城港滨海港区项目为例,为保证大堤合龙施工的成功,必须保证充足资源的投... 基于社会经济的发展,港区对土地的需求越来越大,需要充足的陆域作为港口发展的腹地,大量的围海造陆工程应用于工程实践,其中合龙口是整个围堤工程的关键难点。以盐城港滨海港区项目为例,为保证大堤合龙施工的成功,必须保证充足资源的投入,做好龙口构筑和保护工作,选择合适的时间,合理安排合龙口程序,分析合龙口过程中遇到的问题并提出相应解决措施,为以后合龙口施工提供参考。 展开更多
关键词 围海 合龙口 堵口程序 潮汐 流速
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Conditional Congruence Closure over Uninterpreted and Interpreted Symbols
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作者 KAPUR Deepak 《系统科学与复杂性学报:英文版》 SCIE EI CSCD 2019年第1期317-355,共39页
A framework for generating congruence closure and conditional congruence closure of ground terms over uninterpreted as well as interpreted symbols satisfying various properties is proposed.It is based on some of the k... A framework for generating congruence closure and conditional congruence closure of ground terms over uninterpreted as well as interpreted symbols satisfying various properties is proposed.It is based on some of the key concepts from Kapur's congruence closure algorithm (RTA97) for ground equations based on introducing new symbols for all nonconstant subterms appearing in the equation set and using ground completion on uninterpreted constants and purified equalities over interpreted symbols belonging to different theories.In the original signature,the resulting rewrite systems may be nonterminating but they still generate canonical forms.A byproduct of this framework is a constant Horn completion algorithm using which ground canonical Horn rewrite systems can be generated for conditional ground theories. New efficient algorithms for generating congruence closure of conditional and unconditional equations on ground terms over uninterpreted symbols are presented.The complexity of the conditional congruence closure is shown to be O(n*log(n)),which is the same as for unconditional ground equations. The proposed algorithm is motivated by our attempts to generate efficient and succinct interpolants for the quantifier-free theory of equality over uninterpreted function symbols which are often a conjunction of conditional equations and need additional simplification.A completion algorithm to generate a canonical conditional rewrite system from ground conditional equations is also presented.The framework is general and flexible and is used later to develop congruence closure algorithms for cases when function symbols satisfy simple properties such as commutativity,nilpotency,idempotency and identity as well as their combinations.Interesting outcomes include algorithms for canonical rewrite systems for ground equational and conditional theories on uninterpreted and interpreted symbols leading to generation of canonical forms for ground terms,constrained terms and Horn equations. 展开更多
关键词 COMPLETION CONGRUENCE CLOSURE CONDITIONAL CONGRUENCE CLOSURE intepreted SYMBOLS rewrit-ing uninterpreted SYMBOLS
基于径流过程线的调蓄池入流管设计探讨 预览
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作者 郭葵香 《陕西水利》 2019年第8期23-26,共4页
采用截流、调蓄手段提高排水系统污染控制标准在城市建设中得到了广泛应用,并取得了较好的效果。但实践发现调蓄池入流管的设计存在不合理情况,存在规模过大浪费投资或规模偏小调蓄效益不能完全发挥的情况。以某市中心城区环湖管为例,... 采用截流、调蓄手段提高排水系统污染控制标准在城市建设中得到了广泛应用,并取得了较好的效果。但实践发现调蓄池入流管的设计存在不合理情况,存在规模过大浪费投资或规模偏小调蓄效益不能完全发挥的情况。以某市中心城区环湖管为例,基于径流过程线的调蓄池入流管设计方法,从分析流域特点、管网模型、降雨特征、径流过程入手合理确定管道设计流量,得出基于径流过程线的截流管设计方法能在确保截流管达到系统设计重现期的前提下,合理确定截流管道的设计规模,在工程实际中值得推广应用。 展开更多
关键词 径流过程线 截流 调蓄 入流管
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Effects of Network Closure on Cooperative Innovation: Evidence from Dongying’s Petroleum Equipment Industry in China 预览
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作者 MA Shuang ZENG Gang 《中国地理科学:英文版》 SCIE CSCD 2019年第3期517-527,共11页
There are two opposing viewpoints on which kind of network configuration provides a more competitive advantage, namely,network closure or structural holes, with the latter occupying the dominant position in the litera... There are two opposing viewpoints on which kind of network configuration provides a more competitive advantage, namely,network closure or structural holes, with the latter occupying the dominant position in the literature. Using social network analysis and negative binomial regression methods, we graph the co-patent network of Dongying’s petroleum equipment industry in China and explore its impact on enterprise innovation. The analysis is based on 17 face-to-face interviews, 31 enterprise questionnaires, and 354 co-patent records from the China State Intellectual Property Office identifying cooperative innovation for the years 1988–2013. We find that this network is closed, controlled by state-owned enterprises, and its closure has positive effects on enterprise innovation performance. This may be related to China’s unique industrial development history, state system and policies, regional culture and circumstances, and enterprise characteristics. Therefore, for some industries in specific regions, the advantages usually attributed to structural holes and open innovation may not necessarily apply. 展开更多
关键词 NETWORK CLOSURE structural HOLES ENTERPRISE INNOVATION PETROLEUM equipment industry Dongying
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A Heterologous Fibrin Glue Enhances the Closure Effect of Surgical Suture on the Repair of Annulus Fibrous Defect in a Sheep Model 预览
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作者 Zhi-cai DU Li-xin ZHU 《当代医学科学(英文)》 SCIE CAS 2019年第4期597-603,共7页
Improving the closure effect of surgical suture for repair of annulus fibrosus defects remains an unsolved problem.A new type of porcine fibrin glue was reported for the repair of annulus fibrous defects in sheep mode... Improving the closure effect of surgical suture for repair of annulus fibrosus defects remains an unsolved problem.A new type of porcine fibrin glue was reported for the repair of annulus fibrous defects in sheep models in this study.Continuous axial loading test showed that this glue could effectively improve the closure effect of surgical suture for annulus fibrous defect.Magnetic resonance imaging (MRI) of the lumbar spine confirmed that,compared with nonfibrin glue treated intervertebral discs,it contributed to preservation of the nucleus pulposus and maintained the physiological hydration of the intervertebral discs.Moreover,histomorphology evaluation showed that the porcine fibrin glue could partially reverse degeneration of the injured intervertebral discs.Taken together,porcine fibrin glue can effectively enhance the closure effect of surgical suture on annulus fibrosus,improve the repair effect and slow down the degeneration of the intervertebral disc,and provide a potential therapeutic strategy for degenerative intervertebral disc disease. 展开更多
关键词 ANNULUS REPAIR FIBRIN glue disc degeneration CLOSURE EFFECT
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渝黔铁路新白沙沱长江特大桥钢桁梁架设技术 预览 被引量:1
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作者 邬宗平 《桥梁建设》 EI CSCD 北大核心 2019年第3期114-118,共5页
渝黔铁路新白沙沱长江特大桥为双层6线铁路钢桁梁斜拉桥,主桥桥跨布置为(81+162+432+162+81)m。主梁采用N形桁架,2片主桁,全桥钢梁总重约4.1万吨,共68个节间,其中重庆侧边跨4个节间钢梁跨越3条铁路线。为顺利跨越既有铁路线,重庆侧钢梁... 渝黔铁路新白沙沱长江特大桥为双层6线铁路钢桁梁斜拉桥,主桥桥跨布置为(81+162+432+162+81)m。主梁采用N形桁架,2片主桁,全桥钢梁总重约4.1万吨,共68个节间,其中重庆侧边跨4个节间钢梁跨越3条铁路线。为顺利跨越既有铁路线,重庆侧钢梁采用“部分顶推+散拼”的架设方案施工,在2号墩主跨侧的支架上一次性拼装完成,分多次请点将7.5个节间钢梁顶推过既有铁路线,剩余节间钢梁采用支架散拼法架设;贵阳侧钢梁采用双悬臂方案架设,在单侧墩旁托架上利用70t架梁吊机架设3号墩墩顶6个节间钢梁后,利用2台70t架梁吊机对称悬臂架设其余节间钢梁;主跨跨中采用适配法合龙。 展开更多
关键词 铁路桥 斜拉桥 钢桁梁 顶推 双悬臂架设 合龙 施工技术 桥梁施工
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10kV线路核相操作培训模拟装置浅析 预览
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作者 刘永 《电力系统装备》 2019年第13期237-238,共2页
衡量一个国家经济发达程度的标准之一就是供电可靠性,核相是提高供电可靠性的重要环节之一,10kV线路核相操作培训模拟装置的出现,使得生产人员的技能水平得到进一步提高,电网的安全、可靠、稳定运行得到了进一步的保障。
关键词 10kV配电网 合环 供电可靠性 核相操作 10kV核相操作培训模拟装置
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公路大桥钢桁拱桥施工关键技术探究——京杭运河泗阳成子河 预览
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作者 叶顺 陈文强 《工业技术创新》 2019年第3期43-48,共6页
联合应用中跨钢桁拱、三跨钢桁拱合龙、位移调整等技术,解决边跨临时支墩安装和边跨钢桁拱杆件安装等技术,实现边跨钢桁拱的架设施工。通过塔式起重机安装施工、中跨钢桁拱吊装与合龙和中跨桥面系杆安装与合龙等步骤,实现中跨钢桁拱架... 联合应用中跨钢桁拱、三跨钢桁拱合龙、位移调整等技术,解决边跨临时支墩安装和边跨钢桁拱杆件安装等技术,实现边跨钢桁拱的架设施工。通过塔式起重机安装施工、中跨钢桁拱吊装与合龙和中跨桥面系杆安装与合龙等步骤,实现中跨钢桁拱架设与合龙施工;采用从两侧边支点向跨中安装的技术方案,以及合理有效的线形控制、合龙位移调整措施,快捷高效地完成了钢桁拱桥的施工。多项技术联合应用在主桥为61.65m+152m+61.65m三跨连续钢桁拱桥的京杭运河泗阳成子河公路大桥建设中,且各项检测数据均满足设计要求。 展开更多
关键词 钢桁拱桥 线型控制 塔式起重机 合龙 中跨钢桁拱
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Safety and efficacy of three-dimensional printed patient-specific drilling templates for expansive open-door laminoplasty
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作者 Kang-Kang Huang Xin Rong +3 位作者 Hao Liu Bei-Yu Wang Hua Chen Ying Hong 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第21期2641-2643,共3页
To the Editor:Expansive open-door laminoplasty(EOLP)is commonly performed for patients with multi-level cervical myelopathy of various causes.Nevertheless,there are still several complications.Among them,displaced com... To the Editor:Expansive open-door laminoplasty(EOLP)is commonly performed for patients with multi-level cervical myelopathy of various causes.Nevertheless,there are still several complications.Among them,displaced complete fracture of the hinge side and lamina re-closure could result in neurological function deterioration.Chen et a A1*reported that the use of the mini-plate could significantly reduce the incidence of lamina re-closure compared with the traditional suture technique.Nevertheless,the complete fracture rates were around 56.8%for both the mini-plate group and the suture suspension group.Accurately locating the trough position has been reported to lower the incidence of hinge side complete fractures.121 In this study,threedimensional(3D)printed patient-specific drilling templates were fabricated to guide the trough position in EOLP,131 to validate the safety and efficacy of the 3D printed templates. 展开更多
关键词 TEMPLATE CLOSURE SUTURE
A new method of dynamic mesh used in continuous guide vane closure of a reversible pump-turbine in generating mode 预览
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作者 Xiu-li Mao Yuan Zheng +1 位作者 Giorgio Pavesi Zhan-shan Xie 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第5期976-985,共10页
In this paper,a new method of dynamic mesh based on two functional controls is used in the continuous guide vane closure,and the three-dimensional numerical simulation is carried out to investigate the transient flow ... In this paper,a new method of dynamic mesh based on two functional controls is used in the continuous guide vane closure,and the three-dimensional numerical simulation is carried out to investigate the transient flow characteristics for a Francis-type reversible pump-turbine in the turbine mode in the load regulation scenario,with the detached eddy simulation(DES)turbulent model.The transient flow characteristics during the closure of the guide vanes are illustrated by analyzing the signals of the mass flow,the torque and the pressure fluctuations in the frequency and time-frequency domains.It is shown by the simulated results that a continuous assessment of the transient flow characteristics during the guide vane closure may be made by using the new method of the dynamic mesh.Furthermore,the flow field analysis involves both the onset and the development of the unsteady phenomena progressively based on an organized guide vane closure law.The flow pattern in the return channel maintains a relatively stable flow field before the last stage of the closure,as compared with the unstable flow field in other domains.To identify the unit variation under the fluid-dynamical conditions,the influence of the three-dimensional unsteady flow structures in the passage is analyzed and its evolution during this transient process is characterized by the fluid-dynamics and the spectral analysis. 展开更多
关键词 Francis-type reversible turbine dynamic mesh guide vane closure flow characteristics
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卵圆孔未闭与不明原因脑卒中的最新诊治策略
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作者 何璐 张玉顺 《中国实用内科杂志》 CAS CSCD 北大核心 2019年第7期575-578,共4页
不明原因脑卒中(cryptogenic stroke,CS)的诊治一直是临床研究者努力的方向,而其与卵圆孔未闭(patentforamen ovale,PFO)的关系也成为近年来的研究热点,正确认识其病因并进行有针对性的治疗至关重要。文章从PFO与CS的关系以及最新诊治... 不明原因脑卒中(cryptogenic stroke,CS)的诊治一直是临床研究者努力的方向,而其与卵圆孔未闭(patentforamen ovale,PFO)的关系也成为近年来的研究热点,正确认识其病因并进行有针对性的治疗至关重要。文章从PFO与CS的关系以及最新诊治策略做出笔者的论述,旨在规范和指导PFO封堵治疗,使真正的由PFO所致CS患者从封堵治疗中获益。 展开更多
关键词 卵圆孔未闭 不明原因脑卒中 封堵
岩溶地区水库库底封堵新型坝体应力分析 预览
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作者 高强 邱珍锋 +1 位作者 黄诗渊 袁智洪 《重庆交通大学学报:自然科学版》 CAS CSCD 北大核心 2019年第6期66-71,共6页
为适应岩溶地区地形地貌条件,提出水库库底拱结构封堵的新型坝体形式,有必要对对新型坝体结构形式进行优化设计。采用三维有限元分析方法,研究了拱顶角度、拱端厚度及封拱温度等不同因素条件下的拱体在正常蓄水位、淤沙荷载和温度应力... 为适应岩溶地区地形地貌条件,提出水库库底拱结构封堵的新型坝体形式,有必要对对新型坝体结构形式进行优化设计。采用三维有限元分析方法,研究了拱顶角度、拱端厚度及封拱温度等不同因素条件下的拱体在正常蓄水位、淤沙荷载和温度应力作用下的应力变形。结果表明:拱体拉应力区域主要分布于长轴两端,适当增加拱端厚度有利于减小拉应力;通过适当增大拱顶角度可以改善拱体的受力情况,且随角度增加,拱体最大拉应力和压应力先减小后增大,在53.27°~60°范围内可取得最优拱顶角;拱结构拉应力随着封拱温度的增加而增加,建议按照9℃设计封拱施工。 展开更多
关键词 岩土工程 拱体 岩溶地区 封堵 应力变形 封拱温度
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大跨度连续梁悬臂灌筑施工线形监控技术研究 预览
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作者 刘强 《高速铁路技术》 2019年第4期38-43,共6页
蒙华铁路跨京广铁路特大桥中大跨度预应力混凝土连续梁采用单箱单室、变高度、变截面直腹板,施工工序和施工阶段较多。为确保梁体能够按设计及规范要求顺利合龙,文章利用有限元正装分析法进行模拟计算,计算出在各种外界因素影响下的梁... 蒙华铁路跨京广铁路特大桥中大跨度预应力混凝土连续梁采用单箱单室、变高度、变截面直腹板,施工工序和施工阶段较多。为确保梁体能够按设计及规范要求顺利合龙,文章利用有限元正装分析法进行模拟计算,计算出在各种外界因素影响下的梁体预拱度设置,然后通过实测数据与理论数据进行比较分析,对计算模型进行修正。通过施工线形监控、及时发现、及时调整,解决合龙前悬臂端竖向挠度的偏差,使得主梁轴线的横向位移不超过容许值,确保合龙后的梁体线形良好。 展开更多
关键词 合龙 监控 竖向挠度 位移 线形
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基于激发极化偶极勘察技术的东明矿疏干降水井布置 预览
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作者 陈俊彬 郭旭 +3 位作者 汪云川 康佳明 张峰林 钟晓勇 《露天采矿技术》 CAS 2019年第3期42-45,共4页
受特殊地理位置和构造影响,东明露天矿地下水补给强烈,边帮涌水下切侵蚀边帮,影响边帮稳定。通过开展激发极化偶极勘察,初步查明地下水的异常分布,采用靶区布井方式替代等距井排布置,优化了降水井布置方式及成井工艺参数,开展针对性降... 受特殊地理位置和构造影响,东明露天矿地下水补给强烈,边帮涌水下切侵蚀边帮,影响边帮稳定。通过开展激发极化偶极勘察,初步查明地下水的异常分布,采用靶区布井方式替代等距井排布置,优化了降水井布置方式及成井工艺参数,开展针对性降水。通过对近2年来防治水数据、截流疏干效果和成本控制等论述,进一步验证了激发极化偶极手段优化降水井布置的可行性和有效性。 展开更多
关键词 露天矿 激发极化偶极 疏干 截流 降水井
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茎乳孔附近封闭联合红外线照射治疗特发性面神经麻痹疗效观察 预览
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作者 卢铁兵 黎芫芫 +1 位作者 韦光平 牟慧丽 《右江医学》 2019年第9期691-693,共3页
目的 观察茎乳孔附近封闭联合红外线照射治疗特发性面神经麻痹的临床疗效。方法 通过随机的方式将118例特发性面神经麻痹患者分为对照组60例,治疗组58例。对照组采用静脉滴注地塞米松磷酸钠注射液治疗,治疗组给予醋酸泼尼松龙注射液+利... 目的 观察茎乳孔附近封闭联合红外线照射治疗特发性面神经麻痹的临床疗效。方法 通过随机的方式将118例特发性面神经麻痹患者分为对照组60例,治疗组58例。对照组采用静脉滴注地塞米松磷酸钠注射液治疗,治疗组给予醋酸泼尼松龙注射液+利多卡因注射液+维生素B1注射液进行茎乳孔附近封闭联合红外线照射治疗。比较两组临床疗效及不良反应。结果 治疗组总有效率为93.1%,显著高于对照组的76.7%,差异有统计学意义(P<0.05);治疗组不良反应发生率为5.2%,明显低于对照组的23.3%,差异有统计学意义(P<0.01)。结论 茎乳孔附近封闭联合红外线照射治疗特发性面神经麻痹疗效好,不良反应少,安全性高,值得临床推广。 展开更多
关键词 特发性面神经麻痹 茎乳孔 封闭 红外线
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Follow-up of percutaneous transcatheter closure of pulmonary arteriovenous fistulas
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作者 Shi-Bing Xi Yu-Mei Xie +3 位作者 Ming-Yang Qian Ji-Jun Shi Yi-Fan Li Zhi-Wei Zhang 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第8期980-983,共4页
To the Editor:Pulmonary arteriovenous fistula(PAVF)is abnormally dilated vessels that bypass the lung capillary bed,providing a direct right-to-left shunt:.The clinical manifestations of PAVF can vary from asymptomati... To the Editor:Pulmonary arteriovenous fistula(PAVF)is abnormally dilated vessels that bypass the lung capillary bed,providing a direct right-to-left shunt:.The clinical manifestations of PAVF can vary from asymptomatic to dyspnea on exertion,fatigability,cyanosis,and neurological complications.Patients with congenital PAVF are often associated with hereditary hemorrhagic telangiectasia(HHT)and congenital heart disease.The primary aim of treatment through transcatheter techniques or surgery is to reduce or abrogate abnormal shunt and to prevent severe complications.The development of medical apparatus and instruments has expanded the in dications of interventional closure of PAVF.However,data on the efficacy and safety of transcatheter closure of PAVFs is still lacking. 展开更多
关键词 PERCUTANEOUS TRANSCATHETER closure PULMONARY ARTERIOVENOUS FISTULAS PULMONARY ARTERIOVENOUS fistula(PAVF)
清代福州地区传统宫庙戏场观演空间解析——以三座宫庙戏场为例 预览
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作者 黄巍 缪远 蔡阳生 《建筑与文化》 2019年第5期42-44,共3页
庙宇戏场是传统戏场中数量最多、分布最广的戏场类型,其观演品质受观演空间与建筑声环境相互影响,也就是传统建筑保护和研究的重要内容。文章综合运用历史建筑测绘、空间分析和声学测试和分析等方法对三座清代福州庙宇戏场展开研究。从... 庙宇戏场是传统戏场中数量最多、分布最广的戏场类型,其观演品质受观演空间与建筑声环境相互影响,也就是传统建筑保护和研究的重要内容。文章综合运用历史建筑测绘、空间分析和声学测试和分析等方法对三座清代福州庙宇戏场展开研究。从测量与分析的结果可以看出,观演空间的封闭性对戏曲演出品质产生一定的影响。研究成果为传统戏场的保护和活化应用提供依据。 展开更多
关键词 庙宇戏场 观演空间 封闭性 声学品质
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经食管超声心动图在经颈内静脉可调弯鞘房间隔缺损封堵术中的应用 预览 被引量:1
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作者 孙婷 陆国梁 +2 位作者 方剑 肖霭仪 谢少波 《临床医药实践》 2019年第5期366-369,共4页
目的:总结经食管超声心动图(TEE)在经颈内静脉可调弯鞘房间隔缺损(ASD)封堵术中的应用经验。方法:回顾性分析2015年1月—2018年9月接受手术的患者43例,其中男14例,女29例,年龄1.3~67.0岁,体质量9.5~53.5kg。术前经胸超声心动图(TTE)测量... 目的:总结经食管超声心动图(TEE)在经颈内静脉可调弯鞘房间隔缺损(ASD)封堵术中的应用经验。方法:回顾性分析2015年1月—2018年9月接受手术的患者43例,其中男14例,女29例,年龄1.3~67.0岁,体质量9.5~53.5kg。术前经胸超声心动图(TTE)测量ASD直径为(10.3±5.1)mm。穿刺右侧颈内静脉,送入可调弯鞘,在TEE引导下,置入合适大小的封堵器。结果:43例患者均封堵成功。置入封堵器直径为6~30mm。术后即刻TEE证实封堵器位置良好,无残余分流。结论:TEE作为一种简便的监测手段,是经颈内静脉可调弯鞘ASD封堵术成功和安全的重要保障。 展开更多
关键词 经食管超声心动图 颈内静脉 可调弯鞘 房间隔缺损 封堵
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Progress and Applications of Visual SLAM 预览
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作者 Kaichang DI Wenhui WAN +3 位作者 Hongying ZHAO Zhaoqin LIU Runzhi WANG Feizhou ZHANG 《测绘学报(英文版)》 2019年第2期38-49,共12页
Visual simultaneous localization and mapping (SLAM) provides mapping and self-localization results for a robot in an unknown environment based on visual sensors, that have the advantages of small volume, low power con... Visual simultaneous localization and mapping (SLAM) provides mapping and self-localization results for a robot in an unknown environment based on visual sensors, that have the advantages of small volume, low power consumption, and richness of information acquisition. Visual SLAM is essential and plays a significant role in supporting automated and intelligent applications of robots. This paper presents the key techniques of visual SLAM, summarizes the current research status, and analyses the new trends of visual SLAM research and development. Finally, specific applications of visual SLAM in restricted environments, including deep space and indoor scenarios, are discussed. 展开更多
关键词 visual SLAM FEATURE extraction KALMAN filter GRAPH based optimization LOOP CLOSURE detection
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Semi-Direct Visual Odometry and Mapping System with RGB-D Camera 预览
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作者 Xinliang Zhong Xiao Luo +1 位作者 Jiaheng Zhao Yutong Huang 《北京理工大学学报:英文版》 EI CAS 2019年第1期83-93,共11页
In this paper a semi-direct visual odometry and mapping system is proposed with a RGB-D camera,which combines the merits of both feature based and direct based methods.The presented system directly estimates the camer... In this paper a semi-direct visual odometry and mapping system is proposed with a RGB-D camera,which combines the merits of both feature based and direct based methods.The presented system directly estimates the camera motion of two consecutive RGB-D frames by minimizing the photometric error.To permit outliers and noise,a robust sensor model built upon the Z-distribution and an error function mixing depth and photometric errors are used to enhance the accuracy and robustness.Local graph optimization based on key frames is used to reduce the accumulative error and refine the local map.The loop closure detection method,which combines the appearance similarity method and spatial location constraints method,increases the speed of detection.Experimental results demonstrate that the proposed approach achieves higher accuracy on the motion estimation and environment reconstruction compared to the other state-of-the-art methods.Moreover,the proposed approach works in real-time on a laptop without a GPU,which makes it attractive for robots equipped with limited computational resources. 展开更多
关键词 RGB-D simultaneous LOCALIZATION and mapping(SLAM) visual ODOMETRY LOCALIZATION 3D MAPPING loop CLOSURE detection
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