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Sharp upper bounds for the adjacency and the signless Laplacian spectral radius of graphs 预览
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作者 WU Xian-zhang LIU Jian-ping 《高校应用数学学报:英文版(B辑)》 SCIE CSCD 2019年第1期100-112,共13页
Let G be a simple graph with n vertices and m edges.In this paper,we present some new upper bounds for the adjacency and the signless Laplacian spectral radius of graphs in which every pair of adjacent vertices has at... Let G be a simple graph with n vertices and m edges.In this paper,we present some new upper bounds for the adjacency and the signless Laplacian spectral radius of graphs in which every pair of adjacent vertices has at least one common adjacent vertex.Our results improve some known upper bounds.The main tool we use here is the Lagrange identity. 展开更多
关键词 graph SPECTRAL RADIUS signless LAPLACIAN SPECTRAL RADIUS upper bound
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肘关节常见骨折的相关问题探讨 预览
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作者 公茂琪 蒋继乐 蒋协远 《中国骨伤》 CAS CSCD 2019年第4期293-295,共3页
肘关节骨折是临床常见的损伤,但因肘关节自身的结构特点,术后并发症较高,特别是处理不当时容易发生肘关节僵硬,给患者生活带来很大困难。尽管近几年肘关节治疗的热点集中在肘关节复杂骨折脱位和肘关节创伤性不稳定等方面,但就发生率而言... 肘关节骨折是临床常见的损伤,但因肘关节自身的结构特点,术后并发症较高,特别是处理不当时容易发生肘关节僵硬,给患者生活带来很大困难。尽管近几年肘关节治疗的热点集中在肘关节复杂骨折脱位和肘关节创伤性不稳定等方面,但就发生率而言,肱骨髁间骨折、尺骨鹰嘴骨折和桡骨头骨折仍是最多见的几种损伤,而且这些常见骨折处理不当发生的并发症很多,值得广大的创伤骨科医生细化治疗以减少并发症,使患者获得更好的功能。其中肱骨远端骨折的治疗相对而言更复杂,并发症也更高。来自瑞典的全国性调查发现,肘部损伤中的肱骨远端骨折发病率约为8.3/100000[1],并随着年龄的增加而升高,其中老年女性最为常见。 展开更多
关键词 肘关节 肱骨 尺骨鹰嘴 桡骨 骨折
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掌侧入路与背侧入路锁定钢板内固定治疗桡骨远端不稳定骨折的比较研究
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作者 刘鹏 《中国实用乡村医生杂志》 2019年第8期52-54,共3页
目的比较掌侧入路与背侧入路锁定钢板内固定治疗桡骨远端不稳定骨折的效果.方法收集开原市中心医院2014年6月—2018年6月收治的成人桡骨远端不稳定骨折患146例,随机分为掌侧入路组和背侧入路组各73例.两组分别采用掌侧入路和背侧入路进... 目的比较掌侧入路与背侧入路锁定钢板内固定治疗桡骨远端不稳定骨折的效果.方法收集开原市中心医院2014年6月—2018年6月收治的成人桡骨远端不稳定骨折患146例,随机分为掌侧入路组和背侧入路组各73例.两组分别采用掌侧入路和背侧入路进行手术,比较两组手术情况、术后6个月腕关节形态学和术后1年腕关节灵活度.结果掌侧入路组手术时间短于背侧入路组,术中出血量少于背侧入路组,并发症发生率低于背侧入路组,背伸活动度高于背侧入路组,差异均有统计学意义(P<0.05).结论相比于背侧入路治疗桡骨远端不稳定骨折,掌侧入路在手术时间、并发症发生率和背伸活动度上具有一定优势,可作为临床首选手术入路. 展开更多
关键词 桡骨 远端 骨折 掌侧入路 背侧入路
Assessing the oscillation of channel geometry and meander migration cardinality of Bhagirathi River,West Bengal,India
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作者 Rakhohori Bag Ismail Mondal Jatisankar Bandyopadhyay 《地理学报:英文版》 SCIE CSCD 2019年第4期613-634,共22页
Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal,India.The Bhagirathi River flows SW for-67.30 km betwee n the confluenee point of Ajay and Jalangi rivers in E... Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal,India.The Bhagirathi River flows SW for-67.30 km betwee n the confluenee point of Ajay and Jalangi rivers in East Burdwan and Nadia districts of West Bengal.The course of Bhagirathi is notably migration prone and cultivates problematic changes along its course over time.In the study,we have looked into its migration tendency and unpredictability for past 238 years and then predicted the lateral shifting of river centerline using temporal satellite imageries-Landsat-5(TM)of 1987(8,December),1995(28,January),2005(7,January)and LISS-IV satellite imagery(2017,5 January);SOI Toposheet-1968-1969(79A/2,79A/3,79A/6 and 79A/7)and RennelPs map of 1779.Other highlights are the quest of fluvial features,oxbow lakes,mid-channel bars,channel migration rate,meander geometry,channel sinuosity in different parts of river course and the parts that experience intensive bank erosion.The entire river course has been subdivided into three segments;viz.reaches A,B and C.Investigation displays that degree of sinuosity decreases from its anterior course(1968)to the existing course(2017).Reach-specific outputs display that reach B is highly sinuous(SI value 1.94 in 2017)and SI increases temporarily,whereas for reaches A and C it decreases with time.The rate of migration is higher in reach B than that in reaches C and A.The study displays a notably decreasing trend of migration in comparison with its previous lateral migration and shows that the migration nature over time is intensively inconsistent and unpredictable except very few portions of the river course.The nature of deposition within the river channel shows an unstable behavior during the entire period of the study.Meander geometry depicts a rapid change of river course innate to meander bends and shows a higher rate of migration by meander loop cut-off rather than lateral migration that reflects the inconsistency,erosion vulnerability and unpredictable nature of migration.Th 展开更多
关键词 channel GEOMETRY sinuosity INDEX BRAIDING INDEX MEANDER GEOMETRY radius of curvature bend TIGHTNESS INDEX linear regression GIS
High-Q, low-mode-volume microsphere-integrated Fabry–Perot cavity for optofluidic lasing applications
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作者 XIAOQIN Wu YIPEI WANG +4 位作者 QIUSHU CHEN YU-CHENG CHEN XUZHOU LI LIMIN TONG XUDONG FAN 《光子学研究:英文版》 CSCD 2019年第1期50-60,共11页
We develop a hybrid optofluidic microcavity by placing a microsphere with a diameter ranging from 1 to 4 μm in liquid-filled plano-plano Fabry–Perot(FP) cavities, which can provide an extremely low effective mode vo... We develop a hybrid optofluidic microcavity by placing a microsphere with a diameter ranging from 1 to 4 μm in liquid-filled plano-plano Fabry–Perot(FP) cavities, which can provide an extremely low effective mode volume down to 0.3–5.1 μm^3 while maintaining a high Q-factor up to 1 × 10^4–5 × 10^4 and a finesse of ~2000. Compared to the pure plano-plano FP cavities that are known to suffer from the lack of mode confinement, diffraction, and geometrical walk-off losses as well as being highly susceptible to mirror misalignment, our microsphere-integrated FP(MIFP) cavities show strong optical confinement in the lateral direction with a tight mode radius of only 0.4–0.9 μm and high tolerance to mirror misalignment as large as 2°. With the microsphere serving as a waveguide, the MIFP is advantageous over a fiber-sandwiched FP cavity due to the open-cavity design for analytes/liquids to interact strongly with the resonant mode, the ease of assembly, and the possibility to replace the microsphere. In this work, the main characteristics of the MIFP, including Q-factor, finesse, effective mode radius and volume, and their dependence on the surrounding medium’s refractive index, mirror spacing, microsphere position inside the FP cavity, and mirror misalignment, are systematically investigated using a finite-element method.Then, by inserting dye-doped polystyrene microspheres of various sizes into the FP cavity filled with water, we experimentally realize single-mode MIFP optofluidic lasers that have a lasing threshold as low as a few microjoules per square millimeter and a lasing spot radius of only ~0.5 μm. Our results suggest that the MIFP cavities provide a promising technology platform for novel photonic devices and biological/chemical detection with ultra-small detection volumes. 展开更多
关键词 mirror radius diameter optical devices down EASE spot
负极性直流电压作用下SF6气体中极不均匀电场局部放电特性研究
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作者 庞培川 孙泽明 +3 位作者 张芊 韩旭涛 侯志强 李军浩 《高电压技术》 EI CAS CSCD 北大核心 2019年第4期1093-1100,共8页
随着特高压直流输电技术(HVDC)的发展,以SF6作为主要绝缘介质的直流气体绝缘输电线路(GIL)受到越来越多的关注和研究。直流GIL中金属尖端缺陷会造成局部电场集中,引发局部放电,因此研究直流电压作用下SF6气体中极不均匀电场局部放电特... 随着特高压直流输电技术(HVDC)的发展,以SF6作为主要绝缘介质的直流气体绝缘输电线路(GIL)受到越来越多的关注和研究。直流GIL中金属尖端缺陷会造成局部电场集中,引发局部放电,因此研究直流电压作用下SF6气体中极不均匀电场局部放电特性可为直流GIL的建设提供试验依据,具有重要意义。通过搭建负直流高压局放试验平台,研究了SF6气体中气压、电场不均匀系数对起始放电电压(PDIV)的影响,并分析流注发展过程的放电特性。结果表明:随着气压的上升,PDIV增加,尖端曲率半径较小时,SF6气体对气压敏感程度随气压上升而增加,尖端曲率半径较大时SF6气体对气压敏感程度随气压增加而减小;随着电场不均匀系数的增加,PDIV减小,低气压下,SF6气体对电场不均匀程度敏感性较大,且随电场不均匀系数增加而降低,高气压下,SF6气体对电场不均匀程度敏感性较小,且随电场不均匀程度增加,敏感程度降低;放电过程可分为放电起始、流注发展和间歇击穿3个阶段。 展开更多
关键词 GIL 金属尖端 SF6 气压 曲率半径 PDIV 放电过程
RADIUS协议专题问答 预览
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作者 陈沪娟 《网络安全和信息化》 2019年第4期165-170,共6页
网络管理人员配置设备时需要熟悉一些网络协议,本文列举了Radius协议的一些知识以及可能遇到的问题,希望对大家的工作有所帮助。
关键词 认证协议 属性参数 字符串 服务器端 RADIUS 端口号码 服务器组
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Diagnosis and Treatment of a Case of Radius and Ulna Fracture in Dog 预览
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作者 Shasha ZHAO Lijun DING 《农业生物技术:英文版》 CAS 2019年第2期116-118,共3页
60% of a dog s body weight is supported by its fore limbs, while the hind limbs mainly play the role of power, so the probability of dog s radius and ulna fracture is greatly increased. This paper mainly introduced th... 60% of a dog s body weight is supported by its fore limbs, while the hind limbs mainly play the role of power, so the probability of dog s radius and ulna fracture is greatly increased. This paper mainly introduced the diagnosis and treatment of a case of radius and ulna fracture in dog, with an attempt to provide reference for clinical practice. 展开更多
关键词 RADIUS and ULNA FRACTURE Diagnosis Treatment POSTOPERATIVE CARE
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Upper bounds for signless Laplacian Z-spectral radius of uniform hypergraphs
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作者 Jun HE Yanmin LIU +1 位作者 Junkang TIAN Xianghu LIU 《中国数学前沿:英文版》 SCIE CSCD 2019年第1期17-24,共8页
Let ■ be a k-uniform hypergraph on n vertices with degree sequence △= d1≥…≥ dn =δ. In this paper, in terms of degree di , we give some upper bounds for the Z-spectral radius of the signless Laplacian tensor (Q(... Let ■ be a k-uniform hypergraph on n vertices with degree sequence △= d1≥…≥ dn =δ. In this paper, in terms of degree di , we give some upper bounds for the Z-spectral radius of the signless Laplacian tensor (Q(■)) of ■. Some examples are given to show the efficiency of these bounds. 展开更多
关键词 HYPERGRAPH ADJACENCY TENSOR signless LAPLACIAN TENSOR spectral RADIUS
陈旧性桡骨头前脱位儿童患侧尺骨三维畸形的研究
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作者 姜海 苗武胜 +4 位作者 吴革 汪兵 吴永涛 屈继宁 李敏 《中华小儿外科杂志》 CSCD 北大核心 2019年第1期45-47,共3页
目的探讨和分析陈旧性桡骨头前脱位儿童患侧尺骨的三维畸形,以期能对临床治疗提供病理改变基础,指导临床手术。方法2016年6月至2017年1月收治7例陈旧性桡骨头前脱位患儿,男5例,女2例。年龄范围3~11岁,平均8岁。均为BadoⅠ型。受伤到测... 目的探讨和分析陈旧性桡骨头前脱位儿童患侧尺骨的三维畸形,以期能对临床治疗提供病理改变基础,指导临床手术。方法2016年6月至2017年1月收治7例陈旧性桡骨头前脱位患儿,男5例,女2例。年龄范围3~11岁,平均8岁。均为BadoⅠ型。受伤到测量时间为1~4年,平均2年5个月。通过双侧尺桡骨全段三维CT扫描,导入MIMICS10.01软件,重建出双侧尺骨三维图像。再通过镜像技术,将患侧尺骨与对侧尺骨进行矢状位、冠状位、轴位的对比测量。结果7例桡骨头前脱位儿童患侧尺骨与对侧尺骨比较,存在矢状位、冠状位、轴位的三维畸形改变。矢状位的过伸畸形最为明显,为12.14°~20.83°,平均为16.26°。冠状位的外翻畸形为5.44°~12.90°,平均为10.24°。轴位存在旋后畸形为6°~23°,平均为13.14°。结论陈旧性桡骨头前脱位儿童患侧尺骨存在明显的三维畸形,提示在临床不能单纯行尺骨近端后成角截骨治疗,可能需要同时矫正患侧尺骨的外翻和旋转畸形,这样才能完全矫正患侧尺骨的畸形,防止术后的桡骨头再脱位。 展开更多
关键词 桡骨 脱位 尺骨 儿童
基于有限元模型分析伸直型桡骨远端骨折的生物力学特点 预览
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作者 张朝驹 何川 +5 位作者 陈洪卫 庞启雄 万安 刘道东 Tsang WWN 李孝林 《中国组织工程研究》 CAS 北大核心 2019年第12期1898-1902,共5页
背景:老年人跌倒所致桡骨远端骨折临床发生率较高,从生物力学上分析受伤机制、预防骨折发生的研究非常重要但相对不足。目的:探讨伸直型桡骨远端骨折的生物力学特性。方法:选取29岁健康男性志愿者1名,对其前臂、腕关节、手进行CT扫描。... 背景:老年人跌倒所致桡骨远端骨折临床发生率较高,从生物力学上分析受伤机制、预防骨折发生的研究非常重要但相对不足。目的:探讨伸直型桡骨远端骨折的生物力学特性。方法:选取29岁健康男性志愿者1名,对其前臂、腕关节、手进行CT扫描。将扫描获得的CT图像导入三维成像软件Mimics 10.01建立腕关节背伸损伤的有限元模型,约束模型的手掌面,给予模型一个大小为2 m/s、方向垂直向下的速度载荷,观测载荷作用后腕关节软组织、骨骼的应力分布。结果与结论:建立了真实有效的腕关节背伸位有限元模型,载荷作用后软组织应力主要集中于手掌小鱼际以及腕背侧,骨骼应力背侧主要集中于尺桡骨下端,桡骨下端的应力最大、最集中,掌侧应力主要集中于尺桡骨中下段交界偏下处以及腕中部,尺桡骨的应力分布不对称。研究结果可用于伸直型桡骨远端骨折损伤机制的解释,可为腕关节背伸跌倒损伤的预防提供一定的生物力学依据。 展开更多
关键词 伸直型桡骨远端骨折 有限元分析 应力分布 CT数据重建 腕关节背伸跌倒 腕关节背伸位模型 腕关节 桡骨 组织工程
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A New Class AOR Preconditioner for L-Matrices
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作者 Reza BEHZADI 《数学研究及应用:英文版》 CSCD 2019年第1期101-110,共10页
Hadjidimos(1978) proposed a classical accelerated overrelaxation(AOR) iterative method to solve the system of linear equations, and discussed its convergence under the conditions that the coefficient matrices are irre... Hadjidimos(1978) proposed a classical accelerated overrelaxation(AOR) iterative method to solve the system of linear equations, and discussed its convergence under the conditions that the coefficient matrices are irreducible diagonal dominant, L-matrices, and consistently orders matrices. Several preconditioned AOR methods have been proposed to solve system of linear equations Ax = b, where A ∈ Rn×n is an L-matrix. In this work, we introduce a new class preconditioners for solving linear systems and give a comparison result and some convergence result for this class of preconditioners. Numerical results for corresponding preconditioned GMRES methods are given to illustrate the theoretical results. 展开更多
关键词 AOR iterative method L-MATRIX IRREDUCIBLE MATRIX spectral radius PRECONDITIONER ITERATION MATRIX
Ipsilateral proximal and distal radius fractures with unstable elbow joint: Which should we address first?
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作者 Nur Azuatul Akma Kamaludin Nur Azree Ferdaus Kamudin +1 位作者 Shalimar Abdullah Jamari Sapuan 《中华创伤杂志:英文版》 CAS CSCD 2019年第1期59-62,共4页
Simultaneous ipsilateral fractures involving radial head and distal end of radius are uncommon. We present our thoughts on which fracture should be addressed first. A 68-year-old lady sustained an ipsilateral fracture... Simultaneous ipsilateral fractures involving radial head and distal end of radius are uncommon. We present our thoughts on which fracture should be addressed first. A 68-year-old lady sustained an ipsilateral fracture of the right radial head and distal end of radius following a fall. Clinically her right elbow was posteriorly dislocated and right wrist was deformed. Plain radiographs showed an intraarticular fracture of the distal end of radius and a comminution radial head fracture with a proximally migrated radius. Magnetic resonance imaging (MRI) showed no significant ligament injuries. We addressed her distal radius first with an an atomical lock ing plate followed by her radial head with a radial head replacement. Our rationale to treat the distal end radius: first was to obtain a correct alignment of Lister's tubercle and correct the distal radius height. Lister's tubercle was used to guide for the correct rotation of the radial head prosthesis. Correcting the distal end fracture radial height helped us with length selection of the radial head prosthesis and address the proximally migrated radial shaft and neck. Postoperative radiographs showed an acceptable reduction. The Cooney score was 75 at 3 months postoperatively, which was equivalent to a fair functional outcome. 展开更多
关键词 Simultaneous IPSILATERAL FRACTURES Radius FRACTURES IRREDUCIBLE elbow dislocation RADIAL HEAD RADIAL HEAD ARTHROPLASTY
Doping radius effects on an erbium-doped fiber amplifier
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作者 Md.Ziaul Amin Khurram Karim Qureshi Md.Mahbub Hossain 《中国光学快报:英文版》 SCIE EI CAS CSCD 2019年第1期14-19,共6页
In an erbium-doped fiber amplifier(EDFA), erbium ions act as a three-level system. Therefore, much higher pump energy is required to achieve the population inversion in an erbium-doped fiber(EDF). This higher pump ene... In an erbium-doped fiber amplifier(EDFA), erbium ions act as a three-level system. Therefore, much higher pump energy is required to achieve the population inversion in an erbium-doped fiber(EDF). This higher pump energy requirement complicates the efficient design of an EDFA. However, efficient use of the pump power can improve the EDFA performance. The improved performance of an EDFA can be obtained by reducing the doping radius of the EDF. A smaller doping radius increases pump–dopant interactions and subsequently increases the pump–photon conversion efficiency. Decreasing the doping radius allows a larger proportion of dopant ions,which are concentrated near the core, to interact with the highest pump intensity. However, decreasing the doping radius beyond a certain limit will bring the dopant ions much closer and introduce detrimental ion–ion interaction effects. In this Letter, we show that an optimal doping radius in an EDF can provide the best gain performance. Moreover, we have simulated the well-known numerical aperture effects on EDFA gain performance to support our claim. 展开更多
关键词 DOPING RADIUS EFFECTS ERBIUM-DOPED FIBER AMPLIFIER
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桡骨茎突狭窄性腱鞘炎的治疗进展 预览
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作者 赵杰 戴小宇 何双华 《中国骨伤》 CAS CSCD 2019年第4期387-390,共4页
桡骨茎突狭窄性腱鞘炎,是一种常见的慢性运动系统损伤疾病,多引起关节处疼痛并伴活动时加重,对人们的日常生活造成影响。目前针对此病的治疗方法较多且各有疗效,可以分为保守治疗和手术治疗两种。本病的治疗难点在于根治,保守治疗常常... 桡骨茎突狭窄性腱鞘炎,是一种常见的慢性运动系统损伤疾病,多引起关节处疼痛并伴活动时加重,对人们的日常生活造成影响。目前针对此病的治疗方法较多且各有疗效,可以分为保守治疗和手术治疗两种。本病的治疗难点在于根治,保守治疗常常能在急性期缓解疼痛,改善腕部功能,但其远期作用甚微,容易复发。手术治疗能够提高本病的治愈率,但作为有创治疗,存在一系列风险,当遇到顽固性桡骨茎突狭窄性腱鞘炎时才建议选用。笔者认为,患者教育为治疗中重要一环,并且对本病进行分级,根据疾病发展的不同情况合理选用多种手法综合治疗本病,能够有效治愈本病。 展开更多
关键词 桡骨 腱鞘炎 狭窄性 治疗
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切开复位钢板内固定与闭合复位外固定支架固定治疗桡骨远端骨折:评分及线性回归分析 预览 被引量:1
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作者 柯巍 李珂 +5 位作者 王思博 杜新辉 邱忠鹏 康治林 王维山 李刚 《中国组织工程研究》 CAS 北大核心 2019年第8期1196-1202,共7页
背景:目前无确切的循证医学证据证明掌侧锁定钢板内固定对于治疗桡骨远端骨折比其他治疗方式更有效,也无证据证明某种手术方式为金标准。目的:比较钢板与外固定支架治疗桡骨远端骨折的康复疗效。方法:回顾性分析2014年6月至2017年12月... 背景:目前无确切的循证医学证据证明掌侧锁定钢板内固定对于治疗桡骨远端骨折比其他治疗方式更有效,也无证据证明某种手术方式为金标准。目的:比较钢板与外固定支架治疗桡骨远端骨折的康复疗效。方法:回顾性分析2014年6月至2017年12月采用钢板与外固定支架治疗桡骨远端骨折的64例患者资料,其中钢板内固定组34例,随访时间(19.15±8.92)个月;外固定支架组30例,随访时间(17.9±11.34)个月。比较两组Gartland-Werley评分、COONEY评分、DASH评分、腕关节活动度、握力及桡骨远端影像学结果,采用线性回归分析尺骨变异、桡骨高度等与前臂旋前及腕关节尺偏之间的相关性。结果与结论:①随访各评分结果:64例患者均顺利完成手术并获得随访。末次随访时,钢板内固定组:Gartland-Werley评分优21例,良13例;COONEY评分优20例,良12例,可2例;DASH评分(5.744±4.055)分。外固定支架组:Gartland-Werley评分:优24例,良6例;COONEY评分:优24例,良6例;DASH评分(4.872±3.174)分。两组各评分差异无显著性意义;②骨折康复效果:两组患者掌屈、背伸、桡偏、旋后、握力、尺骨变异、桡厚及掌倾角差异无显著性意义。外固定支架组尺偏及旋前角度、桡骨高度及桡骨茎突尺倾角大于内固定组(P=0.000),桡宽小于内固定组(P=0.001)。桡骨茎突尺倾角对外固定支架组的患者旋前角度有影响,旋前角度随着桡骨茎突尺倾角的增加而变大(P=0.018);③结果证实,钢板与外固定支架治疗桡骨远端骨折均有较好的疗效,闭合复位外固定支架技术具有切口小、不破坏桡骨远端的生物学机制的优点。 展开更多
关键词 桡骨 骨折 外固定器 内固定器 组织工程 桡骨远端骨折 钢板内固定 闭合复位外固定 旋前角度 DASH评分 COONEY评分 Gartland-Werley评分 腕关节活动度 握力
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二氧化碳爆破采掘装备及技术研究 预览
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作者 张永政 《世界有色金属》 2019年第9期161-162,共2页
本文为了解决煤矿巷道掘进中的问题,研制了一套完整的二氧化碳掘进设备,提出了二氧化碳爆破巷道掘进技术,并在现场进行应用。研究表明,二氧化碳爆破器可用于煤矿井下巷道开挖,它具有安全性高、爆破效果好和工作环境好、开挖成本低等诸... 本文为了解决煤矿巷道掘进中的问题,研制了一套完整的二氧化碳掘进设备,提出了二氧化碳爆破巷道掘进技术,并在现场进行应用。研究表明,二氧化碳爆破器可用于煤矿井下巷道开挖,它具有安全性高、爆破效果好和工作环境好、开挖成本低等诸多优势。 展开更多
关键词 二氧化碳爆破技术 半径 环境质量
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Sphere decoder for polar codes concatenated with cyclic redundancy check
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作者 Yongrun YU Zhiwen PAN +1 位作者 Nan LIU Xiaosi TAN 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第8期155-167,共13页
The existing cyclic redundancy check(CRC)-aided successive cancellation list(CA-SCL) decoder partitions the decoding process into two steps, where an SCL is followed by a CRC check. An SCL decoder can approach the max... The existing cyclic redundancy check(CRC)-aided successive cancellation list(CA-SCL) decoder partitions the decoding process into two steps, where an SCL is followed by a CRC check. An SCL decoder can approach the maximum-likelihood(ML) decoding performance of the inner polar codes using a sufficiently large list;however, in this case, CRC is only used for performing error detection. Therefore, the decoding performance of the outer CRC is different from that of ML because the errors are not rectified, which degrades the performance of the entire concatenated codes. In this study, we propose a sphere decoder(SD) that can achieve the ML performance of polar codes concatenated with CRC to address the suboptimality of CASCL decoding. The proposed SD performs joint decoding of the CRC-polar codes in a single step, thereby avoiding the polar decoding and CRC detection decoding scheme. Because the proposed SD guarantees the ML decoding performance of the CRC-polar concatenated codes, the simulation results demonstrate that the block error rate(BLER) of the proposed SD acts as the lower bound of the CA-SCL decoding performance. Further, a new initial radius selection method is proposed for the SD to reduce the average decoding complexity. The simulations demonstrate that the proposed initial radius selection method reduces more amount of decoding complexity when compared with that reduced using sequential step size methods. 展开更多
关键词 POLAR codes SPHERE DECODER MAXIMUM-LIKELIHOOD DECODING optimal DECODING radius search
右桡骨远端骨巨细胞瘤1例误诊分析
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作者 郭杨 董博 +3 位作者 袁普卫 康武林 杨锋 姚洁 《世界临床药物》 CAS 2019年第6期442-446,共5页
患者,男,30岁。主诉:右腕部加重疼痛13年余,劳累后疼痛加剧伴局部肿胀和关节活动受限3个月。影像学检查提示良性骨肿瘤。既往体健,无急、慢性疾病史及外伤史。临床表现:右腕部疼痛肿胀和活动受限,右腕关节背侧可触及一囊性物,质软,活动... 患者,男,30岁。主诉:右腕部加重疼痛13年余,劳累后疼痛加剧伴局部肿胀和关节活动受限3个月。影像学检查提示良性骨肿瘤。既往体健,无急、慢性疾病史及外伤史。临床表现:右腕部疼痛肿胀和活动受限,右腕关节背侧可触及一囊性物,质软,活动度差。组织病理示:肿瘤组织由圆形、多角形或梭形单核细胞及分布其间的破骨样巨细胞。诊断:右桡骨远端骨巨细胞瘤。5年前因疼痛加剧就诊外院,以"右腕关节软组织损伤"予盐酸氨基葡萄糖片口服治疗8周,未见好转。提示临床医生要加强对本病的鉴别诊断,避免误诊漏诊。 展开更多
关键词 骨巨细胞瘤 桡骨 误诊
手术和石膏外固定治疗桡骨远端不稳定骨折的效果对比 预览
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作者 林宇生 黄永翔 丁文彬 《中国现代药物应用》 2019年第5期8-10,共3页
目的探究手术和石膏外固定对于桡骨远端不稳定骨折的治疗效果,指导临床应用.方法100例桡骨远端不稳定骨折患者,随机分为观察组和对照组,各50例.观察组患者应用手术治疗,对照组患者接受石膏外固定治疗.比较两组患者术后1年患肢活动情况,... 目的探究手术和石膏外固定对于桡骨远端不稳定骨折的治疗效果,指导临床应用.方法100例桡骨远端不稳定骨折患者,随机分为观察组和对照组,各50例.观察组患者应用手术治疗,对照组患者接受石膏外固定治疗.比较两组患者术后1年患肢活动情况,术后1年影像学恢复情况,术后1年功能恢复情况,术后1、3、6个月及1年的疼痛视觉模拟评分法(VAS)评分.结果术后1年,观察组患者的背伸、掌曲、旋后及旋前活动度分别为(65.25±11.35)、(64.32±11.40)、(74.29±11.46)、(69.24±12.16)°,均显著优于对照组的(41.64±10.53)、(43.62±9.78)、(43.51±13.59)、(47.22±10.69)°,差异均具有统计学意义(P<0.05).影像学检查,观察组患者的尺偏角、掌倾角和桡腕关节面平整度分别为(18.46±4.16)°、(11.35±3.76)°、(1.73±0.54)mm,均显著优于对照组的(14.53±4.67)°、(8.57±4.05)°、(2.62±0.63)mm,差异均具有统计学意义(P<0.05).观察组优良率为84.00%,高于对照组的64.00%,差异有统计学意义(P<0.05).观察组术后1、3个月的VAS评分分别为(2.10±0.42)、(1.86±0.32)分,显著低于对照组的(3.68±0.37)、(2.64±0.35)分,差异均具有统计学意义(P<0.05).结论桡骨远端不稳定骨折患者接受手术治疗,其治疗效果较石膏外固定更佳,疼痛较轻且活动度明显较高. 展开更多
关键词 桡骨 石膏外固定 疼痛 不稳定骨折
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