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文章速递Designing multilayer diamond like carbon coatings for improved mechanical properties 认领
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作者 Mohammad Sharear Kabir Zhifeng Zhou +1 位作者 Zonghan Xie Paul Munroe 《材料科学技术:英文版》 SCIE EI CAS CSCD 2021年第6期108-117,共10页
New multilayer coatings were produced by incorporating alternating soft and hard DLC layers enabled by varying the bias voltage during deposition process while maintaining a constant hard-to-soft layer thickness ratio... New multilayer coatings were produced by incorporating alternating soft and hard DLC layers enabled by varying the bias voltage during deposition process while maintaining a constant hard-to-soft layer thickness ratio.These coatings were deposited onto a Cr/Cr Cxgraded layer by closed field unbalanced magnetron sputtering(CFUBMS).The cross-sectional analysis of the coatings showed that the multilayer coatings possess sharp interfaces between the soft and hard layers with the hard to soft layer thickness ratio(1:1.33)constant in all the coatings.Raman analysis uncovered the increasing sp^(3)character of the DLC coatings as a result of decreasing ID/IGratio and increasing full width at half maximum(FWHM)values of the G band peak induced supposedly by an increase in bias voltage during hard layer deposition.Nanoindentation tests showed an increase in hardness of the DLC coatings which can be correlated with the increase in the sp^(3)content of the coatings as well as decreasing sp^(2)-C cluster size,as calculated from the ID/IGratio.Furthermore,the coatings exhibited excellent plastic deformation resistance and adhesion strength upon microindentation and scratch testing,respectively.Although further investigations are required to assess coating durability,the multilayer design could offer the DLC coatings with a rare opportunity to combine the high hardness with damage resistance with a constant bilayer thickness and without the need to introduce complex multilayer system. 展开更多
关键词 Diamond like carbon(DLC) Closed field unbalanced magnetron sputtering(CFUBMS) sp^(3)Character Nanoindentation Plastic deformation resistance Scratch adhesion behaviour
文章速递封闭冷通道在数据机房中的应用 认领
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作者 王涛 《信息与电脑》 2021年第3期44-46,共3页
企业的机房机柜一般采用开放式成列摆放,根据机房设计规范,机柜为面对面式或背对背式,机器产生的热气流和空调产生的冷气流分别位于机柜两侧,冷热气流无明显分界点,在空气中交织,导致冷气流不能被全部利用.为提高冷气流的利用率和空调... 企业的机房机柜一般采用开放式成列摆放,根据机房设计规范,机柜为面对面式或背对背式,机器产生的热气流和空调产生的冷气流分别位于机柜两侧,冷热气流无明显分界点,在空气中交织,导致冷气流不能被全部利用.为提高冷气流的利用率和空调的制冷效率,有必要对空气气流进行优化,采用封闭冷通道技术将冷热气流隔离开。基于此,本文重点探讨了封闭冷通道在数据机房中的应用. 展开更多
关键词 热气流 封闭 冷通道 能耗
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冷水机组在电力电子水冷却系统中的应用研究 认领
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作者 张辉亮 刘金革 《电气技术》 2021年第1期71-74,共4页
现有电力电子设备水冷却系统中,通常使用空气冷却器或冷却塔作为外冷设备,该种设备不适合在常年高温缺水的地区应用。本文通过对目前换流站中电力电子设备水冷却系统的分析和研究,提出了将冷水机组应用于外冷却系统的新思路,即采用冷水... 现有电力电子设备水冷却系统中,通常使用空气冷却器或冷却塔作为外冷设备,该种设备不适合在常年高温缺水的地区应用。本文通过对目前换流站中电力电子设备水冷却系统的分析和研究,提出了将冷水机组应用于外冷却系统的新思路,即采用冷水机组直接冷却去离子水。通过实际工程应用,验证了该方案的可行性,为高温缺水地区大功率电力电子阀的冷却提供了技术支持。 展开更多
关键词 电力电子 密闭式 水冷却系统 冷水机组
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Recent Advances in Closed Loop Spray Cooling and its Application in Airborne Systems 认领
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作者 XU Xinjie WANG Yu +2 位作者 JIANG Yanlong LIU Jinxiang YUAN Xiaolei 《热科学学报:英文版》 SCIE EI CAS 2021年第1期32-50,共19页
In recent years,the problem of heat dissipation in airborne directed energy weapons has attracted considerable research interest.Spray cooling can be applied to cool airborne directed energy weapons,owing to its sever... In recent years,the problem of heat dissipation in airborne directed energy weapons has attracted considerable research interest.Spray cooling can be applied to cool airborne directed energy weapons,owing to its several advantages such as a large heat transfer coefficient,absence of boiling hysteresis and uniform surface temperature.To examine the potential of an airborne spray cooling system,the typical high heat flux dissipation methods were compared,and the state of the art research on spray cooling was reviewed.This review was focused on studies related to the spray cooling hydrodynamic mechanism,experimental studies of closed loop spray cooling,numerical simulation studies about spray cooling and the identification of the factors influencing spray cooling systems,and investigations related to the multiple nozzle spray cooling technology and heat transfer correlation predictions.Overall,there is a need for further research to investigate the failure phenomenon after the critical state,matching operation of the total system and microscopic characteristics of airborne specific parameters. 展开更多
关键词 spray cooling closed loop heat transfer performance influencing factor CORRELATIONS
Process optimization of a closed-chamber distillation system for the recovery of FLiNaK molten salt 认领
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作者 Jun-Xia Geng Yang Yang +3 位作者 Hai-Ying Fu Yan Luo Qiang Dou Qing-Nuan Li 《核技术:英文版》 SCIE EI CAS 2021年第1期17-26,共10页
Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel.A closed-chamber distillation system,in which the pump is stopped and pressurein... Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel.A closed-chamber distillation system,in which the pump is stopped and pressureinduced salt distillation is performed,was arranged for fluoride salt treatment.A stair-step optimization process was demonstrated to improve the recovery efficiency by up to 99%.The pressure change curve was feasible for estimating the distillation process,and a method for displaying the pressure value online in order to determine the endpoint was also developed.The decontamination factor of Nd in the condensate salt was deduced to be greater than 100 with 1 wt%NdF3–FLiNaK distillation.The optimal conditions developed in this study showed a high recovery ratio for the fluoride carrier salt and a high separation efficiency for rare earth products. 展开更多
关键词 Low-pressure distillation Closed chamber Fluoride molten salt Recovery ratio
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急性闭合性阴茎损伤的MRI临床应用 认领
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作者 张效杰 张杰 卜庆丰 《中国临床研究》 CAS 2021年第1期95-98,101,共5页
目的分析急性闭合性阴茎损伤的MRI表现,探讨其在阴茎损伤中的临床应用价值。方法回顾性分析2015年1月至2019年12月收治的、并经MRI平扫检查的12例阴茎闭合性损伤患者的临床及MRI影像资料。结果2例单纯阴茎皮下血肿,MRI表现为阴茎皮层肿... 目的分析急性闭合性阴茎损伤的MRI表现,探讨其在阴茎损伤中的临床应用价值。方法回顾性分析2015年1月至2019年12月收治的、并经MRI平扫检查的12例阴茎闭合性损伤患者的临床及MRI影像资料。结果2例单纯阴茎皮下血肿,MRI表现为阴茎皮层肿胀,不同范围的皮下血肿在T1WI表现为等或稍高信号,T2WI为高信号。8例阴茎海绵体及白膜破裂(阴茎折断),其中1例合并尿道海绵体轻度损伤,MRI表现为低信号白膜连续性中断,裂隙间可见长短不一的高信号影,以T2WI及T2-FS(T2压脂序列)显示清晰;相应阴茎海绵体内可见不同程度的血肿,T1WI等信号为主,T2WI及T2-FS混杂等高信号为主,部分可见低信号区;Buck筋膜下可见范围不同的血肿。2例海绵体、白膜破裂合并Buck筋膜破裂,MRI除了显示白膜及Buck筋膜中断,以及海绵体内、Buck筋膜下血肿之外,还可见沿着皮下浅筋膜层广泛水肿或血肿信号达阴囊、会阴部及耻骨联合周围软组织。与临床手术结果对照,本组MRI诊断定位及定性准确度均为100%。结论MRI检查可以清楚显示闭合性阴茎损伤的部位和范围,为临床治疗提供精确依据。 展开更多
关键词 阴茎 海绵体 阴茎损伤 闭合性 急性 磁共振成像 血肿
封闭性凝析气藏开发指标预测新方法 认领
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作者 康博韬 张迎春 +3 位作者 陈国宁 李晨曦 姜彬 邹婧芸 《石油化工应用》 CAS 2021年第1期36-39,46,共5页
中低含凝析油的气藏多采用衰竭式开发,其开发指标同时受到地下能力和下游市场两个方面的限制,开发指标预测难度大。通过实际生产动态资料分析并结合物质平衡理论,考虑组分变化后形成衰竭开发的封闭性凝析气藏动态规律性认识;基于典型凝... 中低含凝析油的气藏多采用衰竭式开发,其开发指标同时受到地下能力和下游市场两个方面的限制,开发指标预测难度大。通过实际生产动态资料分析并结合物质平衡理论,考虑组分变化后形成衰竭开发的封闭性凝析气藏动态规律性认识;基于典型凝析气藏试井资料分析,建立了气井无阻流量随地层压力变化的定量预测图版;兼顾地下能力与市场需求两个方面,建立了一种更为合理的封闭性凝析气藏衰竭开发的指标量化评价方法,为此类气藏的现场生产提供更为有力的指导。研究表明:(1)由于受到组分变化的影响,凝析气藏衰竭开发过程中地层压力多呈两段式递减,随着地层压力下降,气井的绝对无阻流量呈指数递减;(2)衰竭式开发的封闭凝析气藏开发前期主要受到下游市场约束,后期主要受到地下能力的限制;(3)研究方法考虑因素全面,评价结果更为准确合理,可以为后续生产决策提供更为准确可靠的支撑。 展开更多
关键词 凝析气藏 封闭性 衰竭开发 组分变化 开发指标
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第一跖骨基底闭合楔形截骨联合远端软组织平衡手术治疗中重度[母]外翻25例 认领
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作者 顾鸿程 梁杰 崔恒燕 《中国中医骨伤科杂志》 CAS 2021年第2期60-63,共4页
目的:总结采用第一跖骨基底闭合楔形截骨联合远端软组织平衡手术治疗中重度[母]外翻的疗效。方法:自2012年1月至2019年12月,对25例(28足)中重度[母]外翻患者采用第一跖骨基底楔形截骨联合远端软组织平衡手术治疗,测量手术前后[母... 目的:总结采用第一跖骨基底闭合楔形截骨联合远端软组织平衡手术治疗中重度[母]外翻的疗效。方法:自2012年1月至2019年12月,对25例(28足)中重度[母]外翻患者采用第一跖骨基底楔形截骨联合远端软组织平衡手术治疗,测量手术前后[母]外翻角(HAA)及跖间角(IMA)变化情况,并采用美国足踝外科协会(AOFAS)第一跖骨、趾骨及跖趾关节、趾间关节功能评分标准评定手术前后功能。结果:切口均Ⅰ期愈合,无感染,无内固定失败,无截骨部延迟愈合或不愈合。患者外翻畸形纠正明显,[母]囊炎、转移性跖痛症均明显改善,未见畸形复发。术后测量HAA(9.643°±2.041°)及IMA(6.714°±1.357°)均较术前(分别为(43.286°±6.531°)和(20.464°±3.144°))明显减小,差异有统计学意义(P<0.01);AOFAS评分也从术前(49.786±9.480)分显著提高为末次随访的(91.750±4.169)分,差异有统计学意义(P<0.01)。结论:采用第一跖骨基底闭合楔形截骨联合远端软组织平衡手术治疗中重度[母]外翻,是一种安全有效的治疗方法。 展开更多
关键词 [母]外翻 楔形截骨 闭合 中重度 远端软组织平衡手术
A screw dislocation near one open inhomogeneity and another closed inhomogeneity both permitting constant interior stresses 认领
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作者 Xu WANG Ping YANG P.SCHIAVONE 《应用数学和力学:英文版》 SCIE EI 2021年第2期173-182,共10页
We prove that the interior stresses within both a non-parabolic open inhomogeneity and another interacting non-elliptical closed inhomogeneity can still remain constant when the matrix is simultaneously under the acti... We prove that the interior stresses within both a non-parabolic open inhomogeneity and another interacting non-elliptical closed inhomogeneity can still remain constant when the matrix is simultaneously under the action of a screw dislocation and uniform remote anti-plane stresses. The constancy of interior stresses is realized through the construction of a conformal mapping function for the doubly connected domain occupied by the surrounding matrix. The mapping function is endowed with the information describing the screw dislocation via the incorporation of two specifically defined logarithmic terms. The constant interior stress fields are observed to be independent of the specific open and closed shapes of the two inhomogeneities and the existence of the screw dislocation. In contrast, the existence of the neighboring screw dislocation significantly affects the open and closed shapes of the two inhomogeneities. 展开更多
关键词 constant stress field open inhomogeneity closed inhomogeneity screw dislocation conformal mapping
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Closed External Subtalar Dislocation: A Case Report 认领
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作者 Achegri Abderrahim Mohamed Nassiri +4 位作者 Yassine Chaouqui Rachid Chafik Mohamed Madhar Hanane Elhaoury Youssef Najeb 《矫形学期刊(英文)》 2020年第7期137-142,共6页
Subtalar dislocation is described as the simultaneous dislocation of the talo-calcaneal and talo-navicular joints without any tibio-talar or talar neck associated fractures. This injury is rare, and represents 1% of d... Subtalar dislocation is described as the simultaneous dislocation of the talo-calcaneal and talo-navicular joints without any tibio-talar or talar neck associated fractures. This injury is rare, and represents 1% of dislocations. We report the case of 28-year-old male patient, without any medical history, who had been involved in a sport accident causing a rare closed external subtalar dislocation without any bone fracture. An open reduction was indicated after failure of closed reduction and the X-ray control showed good joint congruence;the fixation was maintained for 6 weeks and then the rehabilitation was started. The evaluation was favorable, and we noted good functional results after a decline of 12 months. 展开更多
关键词 Closed External Dislocation Subtalar Joint Sport Injury
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Pure Talocrural Dislocation without Associated Malleolar Fracture 认领
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作者 Souleymane Diao Amadou Ndiassé Kasse +6 位作者 Jean Claude Sane Joseph Davy Diouf Abdoulaye Keita Pape Matar Fall Pape Alkaly Diouf Ndiaga Dieye Mouhamadou Habib Sy 《矫形学期刊(英文)》 2020年第1期13-20,共8页
Pure talocrural dislocation is an uncommon injury of the ankle. Malleolar fracture is usually associated. We report two cases of pure talocrural dislocation, to describe its therapeutic and prognostic clinical aspects... Pure talocrural dislocation is an uncommon injury of the ankle. Malleolar fracture is usually associated. We report two cases of pure talocrural dislocation, to describe its therapeutic and prognostic clinical aspects through a review of the literature. 展开更多
关键词 Talocrural PURE DISLOCATION CLOSED Reduction
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Techniques of High Tibial Osteotomy: A Review 认领
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作者 Mohammad Jawed Aqil Liyong Gang +2 位作者 Abdul Qadir Nawabi Jinan Wei Nasir Ahmad Haidari 《矫形学期刊(英文)》 2020年第5期93-109,共17页
Main intention of the research is to understand about significance of techniques associated with HTO. This research reviewed the techniques of high tibial osteotomy namely high tibial osteotomy, open wedge high tibial... Main intention of the research is to understand about significance of techniques associated with HTO. This research reviewed the techniques of high tibial osteotomy namely high tibial osteotomy, open wedge high tibial osteotomy, closedhigh tibial osteotomy. Patients who are suffering from knee arthritis, high tibial osteotomy assists to prevent or delay the requirement for total or partial replacement of knee to preserve damaged tissue of joint. High tibial osteotomy technique is mainly suitable for active and young patients with knee osteoarthritis. Age plays a main factor in success rate of high tibial osteotomy technique. It could be done in open wedge or closed wedge high tibial osteotomy. For some cases, surgery could be done in combined method (open wedge and closed wedge high tibial osteotomy). When compared with clinical outcomes of closed wedge high tibial osteotomy and open wedge high tibial osteotomy, open wedge high tibial osteotomy performs well in reducing the pain, duration of weight-bearing and return to normal life as soon as possible. 展开更多
关键词 HIGH TIBIAL OSTEOTOMY Open WEDGE HIGH TIBIAL OSTEOTOMY KNEE OSTEOARTHRITIS Closed WEDGE HIGH TIBIAL OSTEOTOMY
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微创技术与开放手术治疗SandersⅡ、Ⅲ型跟骨骨折的疗效比较 认领 被引量:1
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作者 马超 王成伟 唐国柱 《中华骨科杂志》 CAS CSCD 北大核心 2020年第21期1443-1452,共10页
目的探讨跗骨窦小切口结合空心拉力螺钉或小钢板内固定治疗SandersⅡ型、Ⅲ型跟骨骨折的临床疗效。方法回顾性分析2015年09月至2017年04月收治并获得随访的50例闭合性跟骨骨折(sanderⅡ、Ⅲ型)患者的相关资料。根据手术方式不同分为两组... 目的探讨跗骨窦小切口结合空心拉力螺钉或小钢板内固定治疗SandersⅡ型、Ⅲ型跟骨骨折的临床疗效。方法回顾性分析2015年09月至2017年04月收治并获得随访的50例闭合性跟骨骨折(sanderⅡ、Ⅲ型)患者的相关资料。根据手术方式不同分为两组,采用跗骨窦小切口结合空心拉力螺钉或小钢板内固定术者为微创组;采用传统外侧“L”型入路结合传统钢板内固定术者为开放组。微创组30例,男20例,女10例;年龄(44.53±13.74)岁(范围,19~78岁)。开放组20例,男13例,女7例;年龄(45.35±12.93)岁(范围,19~70岁)。两组患者采用不同的方式进行手术治疗,术中均纠正跟骨内翻及恢复跟骨长度、宽度和高度,但以不同方式进行骨折端固定。术前及术后均行X线及CT检查,评价骨折类型及复位、骨折愈合情况。末次随访时测量Bohler角、Gissane角,并记录术后并发症,采用Maryland足部评分系统评价临床疗效。结果两组患者一般资料的差异无统计学意义,具有可比性。微创组中7例行异体骨植骨,17例采用微型钢板、13例采用空心拉力螺钉固定;开放组中5例行异体骨植骨,均采用常规跟骨外侧钢板固定。微创组手术时间为(48.23±5.56)min,开放组为(54.25±5.09)min;微创组术中出血量为(53.10±8.5)ml,开放组为(61.75±7.13)ml,两组差异均有统计学意义(t=3.75,t=3.87,均P<0.01)。微创组骨折愈合时间为(9.60±1.52)周,开放组为(11.05±2.33)周,两组差异有统计学意义(t=2.67,P<0.05)。末次随访时微创组Maryland评分优良率为80.00%,开放组为50%。术后影像学显示两组患者跟骨术后关节面塌陷复位,跟骨高度、宽度和长度恢复,跟骨轴线得到纠正。微创组Bohler角术前为15.50°±4.18°,术后改善为31.03°±3.35°(t=15.88,P<0.001),微创组Gissan角术前为101.87°±9.94°,术后改善为129.17°±4.85°(t=13.52,P<0.001);开放组Bohler角术前为15.00°±4.22°,术后改善为30.75°±3.39°(t=13.0 展开更多
关键词 跟骨 骨折 闭合性 骨折固定术 外科手术 微创性
石化园区封闭管理探究 认领
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作者 王广庆 《黑龙江科学》 2020年第12期150-151,共2页
为强化石化园区的安全管理工作,实现对外来车辆、人员的有效监控,保证石化园区安全生产环境,分析了石化园区封闭管理面临的挑战,提出了石化园封闭管理规划建设的原则以及封闭管理系统的功能定位策略。
关键词 石化园区 封闭式 管理
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The Fuzzy Neural Network Control Scheme With H∞ Tracking Characteristic of Space Robot System With Dual-arm After Capturing a Spin Spacecraft 认领
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作者 Jing Cheng Li Chen 《自动化学报:英文版》 SCIE EI CSCD 2020年第5期1417-1424,共8页
In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At f... In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At first,the pre-impact dynamic equations of open chain dual-arm space robot are established by Lagrangian approach,and the dynamic equations of a spacecraft are obtained by Newton-Euler method.Based on the results,with the process of integral and simplify,the response of the dual-arm space robot impacted by the spacecraft is analyzed by momentum conservation law and force transfer law.The closed chain system is formed in the post-impact phase.Closed chain constraint equations are obtained by the constraints of closed-loop geometry and kinematics.With the closed chain constraint equations,the composite system dynamic equations are derived.Secondly,the recurrent fuzzy neural network control scheme is designed for calm motion of unstable closed chain system with uncertain system parameter.In order to overcome the effects of uncertain system inertial parameters,the recurrent fuzzy neural network is used to approximate the unknown part,the control method with H∞tracking characteristic.According to the Lyapunov theory,the global stability is demonstrated.Meanwhile,the weighted minimum-norm theory is introduced to distribute torques guarantee that cooperative operation between manipulators.At last,numerical examples simulate the response of the collision,and the efficiency of the control scheme is verified by the simulation results. 展开更多
关键词 Capturing operation calm motion control closed chain system dual-arm space robot recurrent fuzzy neural network H∞tracking characteristic
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巴拉干建筑中的“自然之影” 认领
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作者 金秋野 《风景园林》 2020年第6期22-29,共8页
探讨路易斯·巴拉干在亲人尺度的日常空间中塑造"深远感",实现"空旷寂寥"场景氛围的方法、发展过程和来源。从分析巴拉干自宅入手,建筑经过改造,逐渐实现对市井和自然的双重屏蔽。通过调节光线的层次、空间界... 探讨路易斯·巴拉干在亲人尺度的日常空间中塑造"深远感",实现"空旷寂寥"场景氛围的方法、发展过程和来源。从分析巴拉干自宅入手,建筑经过改造,逐渐实现对市井和自然的双重屏蔽。通过调节光线的层次、空间界面的差异化处理、半高墙体的设置以及人和更高的两重空间尺度并存,制造"受控的昏暗",带来空间的深远感,使自宅内部成为"自然之影"的容器。然后通过梳理巴拉干不同时期的设计作品,讨论他面对"自然"的态度的变化,及其设计语言的改变。建筑不断变得"封闭",成为"光的盒子",让自然的信息经过一层过滤,将具体的"复杂"转变为抽象的"微妙",使其陌生化地显现。重点强调石头城住宅区对巴拉干审美理想转向原始雄浑的深刻影响,进而指出,这一变化与巴拉干对北美大陆孤寂感的逐步深入认识有关。 展开更多
关键词 路易斯·巴拉干 封闭 光线 两重尺度 间接自然 信息过滤器
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距骨定位法微创治疗复杂Pilon骨折43例报告 认领 被引量:1
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作者 赵航 陈戈 +2 位作者 陈仲 欧艺 毕鑫 《中国骨与关节杂志》 CAS 2020年第2期119-124,共6页
目的探讨通过距骨作为踝关节力线和胫骨远端关节面复位标志,微创复位固定复杂Pilon骨折的方法及疗效。方法 2016年7月至2018年7月收治46例R(u|")edi-AllgowerⅡ、Ⅲ/AO分型C型闭合Pilon骨折患者,以距骨定位法微创复位固定复杂Pilo... 目的探讨通过距骨作为踝关节力线和胫骨远端关节面复位标志,微创复位固定复杂Pilon骨折的方法及疗效。方法 2016年7月至2018年7月收治46例R(u|")edi-AllgowerⅡ、Ⅲ/AO分型C型闭合Pilon骨折患者,以距骨定位法微创复位固定复杂Pilon骨折。术后43例获12~24个月随访,平均16.5个月;3例失访。采用B urwell和Charnley放射评价标准和AOFAS评分评价患者骨折复位质量和愈合功能情况。结果本组均随访的43例,均获骨性愈合,骨折复位质量按Burwell和Charnley放射评价标准:解剖复位38例,一般4例,差1例,优良率88.4%。临床功能评价按AOFAS评分:优30例,良6例,可6例,差1例,优良率83.7%。结论距骨定位法微创治疗复杂Pilon骨折恢复踝关节正常力线好,固定可靠、损伤小,可减少踝关节创伤性关节炎的发生,功能恢复良好,疗效满意。 展开更多
关键词 骨折 闭合性 距骨 踝骨折 骨折 骨折固定术
Protocol Format Extraction Based on an Improved CFSM Algorithm 认领
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作者 Peihong Lin Zheng Hong +2 位作者 Lifa Wu Yihao Li Zhenji Zhou 《中国通信:英文版》 SCIE CSCD 2020年第11期156-180,共25页
As the information technology rapidly develops,many network applications appear and their communication protocols are unknown.Although many protocol keyword recognition based protocol reverse engineering methods have ... As the information technology rapidly develops,many network applications appear and their communication protocols are unknown.Although many protocol keyword recognition based protocol reverse engineering methods have been proposed,most of the keyword recognition algorithms are time consuming.This paper firstly uses the traffic clustering method F-DBSCAN to cluster the unknown protocol traffic.Then an improved CFSM(Closed Frequent Sequence Mining)algorithm is used to mine closed frequent sequences from the messages and identify protocol keywords.Finally,CFGM(Closed Frequent Group Mining)algorithm is proposed to explore the parallel,sequential and hierarchical relations between the protocol keywords and obtain accurate protocol message formats.Experimental results show that the proposed protocol formats extraction method is better than Apriori algorithm and Sequence alignment algorithm in terms of time complexity and it can achieve high keyword recognition accuracy.Additionally,based on the relations between the keywords,the method can obtain accurate protocol formats.Compared with the protocol formats obtained from the existing methods,our protocol format can better grasp the overall structure of target protocols and the results perform better in the application of protocol reverse engineering such as fuzzing test. 展开更多
关键词 flow clustering CFSM algorithm closed frequent sequences keyword recognition CFGM algorithm keyword relations format categorization
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Strain concentration caused by the closed end contributes to cartridge case failure at the bottom 认领
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作者 Song Cai Jie Feng +3 位作者 Hui Xu Kun Liu Zhong-xin Li Zhi-lin Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第6期1151-1159,共9页
Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial defor... Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial deformation of a cartridge,considering the radial constraint of the closed end at the bottom of the cartridge.Owing to the influence of the closed end,the bottom of a cartridge does not establish complete contact with the chamber.Owing to strain concentration in the non-contact area,this area is more amenable to the occurrence of cartridge rupture.This theory predicts the location of the fracture more accurately than the traditional theory.The maximum axial deformation of a cartridge comprises bending and friction deformation.The maximum strain at the bottom of the cartridge increased by 135%owing to the introduction of bending strain caused by the closed end.The strain distribution of a cartridge was measured using digital image correlation technology,and the measured result was consistent with the predicted results of the bending deformation theory and rupture case.The effects of wall thickness,radial clearance,friction coefficient,and axial clearance on the axial deformation of the cylinder were studied.Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation;furthermore,lubrication and reduction in axial clearance reduce frictional deformation,which in turn reduce cartridge rupture. 展开更多
关键词 Closed end Cartridge case failures Strain concentration Bending deformation
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The Closed Orbits of a Class of Cubic Vector Fields in R^3 认领
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作者 Hong Yan YIN Da ZHOU Xing An ZHANG 《数学学报:英文版》 SCIE CSCD 2020年第12期1429-1440,共12页
In this paper,we investigate the isolated closed orbits of two types of cubic vector fields in R^3 by using the idea of central projection transformation,which sets up a bridge connecting the vector field X(x)in R^3 w... In this paper,we investigate the isolated closed orbits of two types of cubic vector fields in R^3 by using the idea of central projection transformation,which sets up a bridge connecting the vector field X(x)in R^3 with the planar vector fields.We have proved that the cubic vector field in R^3 can have two isolated closed orbits or one closed orbit on the invariant cone.As an application of this result,we have shown that a class of 3-dimensional cubic system has at least 10 isolated closed orbits located on 5 invariant cones,and another type of 3-dimensional cubic system has at least 26 isolated closed orbits located on 13 invariant cones or 26 invariant cones. 展开更多
关键词 Closed orbit central projection transformation tangent vector field invariant cone
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