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1.
整体穿刺是一种制造纤维立体织物的工艺技术.穿刺过程中钢针针尖与碳布之间产生顶压、摩擦作用,碳布损伤和针尖破坏是影响穿刺织物质量的主要因素.为选择合理的钢针结构形态,建立了机织布顶弯模式下钢针针尖的力学模型,提出了针尖压弯微分方程和边界条件,得出了不同曲线形状针尖临界压力的方程,并用MathCAD软件求出了临界压力的数值解,为确定合理的针尖形态提供了理论依据.  相似文献   

2.
在织物联合组织中,由于不同松紧程度的组织互相配合,使织物表面产生各种特定的外观效应,如透孔、凸条、蜂巢、网目等。本文就前三种组织形成织物相应的特殊外观效应,从受力观点进行了解释。  相似文献   

3.
提出了经编间隔织物间隔丝的排列模型,并在此基础上研究间隔织物的压缩性能.对模型进行简化并得到了不同表面组织、织物厚度、间隔丝直径的间隔丝排列加权平均倾斜角.根据间隔织物压缩方程和理论参数,由Matlab模拟得到间隔织物的理论压缩曲线,并与试验得到的压缩曲线进行比较.结果表明,根据间隔丝排列模型得到的理论压缩曲线与试验曲线拟合较好,具有较大的网孔表面和织物厚度及较小的间隔丝直径的经编间隔织物在小变形压缩下的压力较小.  相似文献   

4.
针对防弹织物的织物结构与其防弹性能之间的关系,在调研中通过对几种高性能纤维防弹织物的织物结构的分析,以及它们的防弹性能的比较,得出织物紧密指数与织物的防弹性能具有相关性。提出了在防弹织物的织物结构设计中,选用织物紧密指数ψz的方法。选用此种方法能够比较准确地把握住织物的松紧程度,为利用计算机进行仿真设计提供了一种有效的参数,增加了一条可供防弹织物设计的参考方案,为更进一步提高织物的防弹性能提供了一条思路。  相似文献   

5.
目的:评价静脉穿刺不同进针角度对患者疼痛程度的影响.方法:通过计算机检索CNKI、维普和万方三大数据库,查找静脉穿刺不同进针角度对患者疼痛程度影响的随机对照试验(Randomized controlled trial,RCT),对纳入的RCT进行质量评价,采用RevMan5.1软件进行Meta分析.结果:11个RCT被纳入,患者3 874例.Meta分析结果显示:静脉穿刺进针角度>40°与<30°相比,可降低患者疼痛程度,差异有统计学意义[OR=0.14,95%CL(0.11,0.17),P<0.01)],但对穿刺成功率无影响[OR=0.96,95%CL(0.56,1.65),P>0.05].结论:静脉穿刺新的穿刺方法(进针角度为40°~60°)在降低患者疼痛程度方面比传统穿刺方法(<30°)要好.  相似文献   

6.
针对侧脑室训练模型缺乏的问题,提出一种适用于侧脑室穿刺术的虚拟手术培训系统.将软组织与穿刺针交互过程产生的力分为3种,以模拟穿刺力的层次感,从而极大程度上还原穿刺手感.特别地,在形变力分析中构建软组织形变模型,并提出形变模型参数的转化方法.在3种力的基础上,提出穿刺力的力反馈计算模型,结合力反馈设备将其应用于侧脑室穿刺术中.选猪脑组织进行穿刺力实验,结果表明,猪脑穿刺的穿刺力与虚拟穿刺穿刺力间的最大差值为17.25 mN(<20 mN),力的两次突变以及变化趋势具有较高的一致性,能够最大程度上接近真实手术手感.  相似文献   

7.
目的:提高桡动脉穿刺采血成功率,减轻患者痛苦.方法:将60例行桡动脉穿刺患者随机分为对照组35例,观察组25例.对照组采用传统采集血气方法,观察组采用桡动脉"一"字定位法.结果:观察组桡动脉穿刺效果明显优于对照组(P<0.01),疼痛程度明显减轻(P<0.01).结论:桡动脉穿刺"一"字定位法能够提高桡动脉采血穿刺成功率,患者痛苦小.  相似文献   

8.
利用较为接近实际的织物模型,在余弦漫射和均匀漫射假设下对织物的漫反射光分布曲线进行了模拟计算.结合织物的结构因素进行了分析,并对织物的漫反射性质以及反光分布曲线中镜面反射成分和漫反射成分的划分方法进行了讨论.  相似文献   

9.
目的 离心性静脉穿刺抽血在临床上的应用.方法 离心性方式静脉穿刺与向心性静脉穿刺二种方法对比.结果 离心性静脉穿刺优于向心性静脉穿刺抽血.结论 此静脉穿刺抽血方法值得在临床上推广和使用.  相似文献   

10.
颈内静脉与锁骨下静脉穿刺置管术的比较   总被引:6,自引:0,他引:6  
目的 对颈内静脉与锁骨下静脉穿刺中心静脉置管术两种方法的成功率及并发症的发生情况进行了对比研究.方法 取临床行颈内静脉和锁骨下静脉穿刺中心静脉置管术的病例,对其成功率和各种常见并发症分别比较,统计处理用χ2检验.结果 表明颈内静脉穿刺置管术较锁骨下静脉穿刺置管术成功率高,并发症少(P<0.005),是首选的穿刺置管径路.结论 临床主张选用颈内静脉穿刺作为中心静脉置管径路.  相似文献   

11.
麻织物透气性能的研究   总被引:1,自引:0,他引:1  
从麻纤维的内部结构特征和织物紧度理论对多种麻织物透气性能的测试结果进行了深入的讨论和分析.研究表明:在苎麻、亚麻及大麻三种纤维中,苎麻纤维制成的织物透气性最好;麻织物的透气性能远比棉织物要好.  相似文献   

12.
In this paper,the protective performance of woven fab-rics against heat radiation is studied from the view offabric structure.As indices reflecting the protective per-formance against heat radiation,the heat emissivity andthe transmissivity of different fabrics are measured.It ispointed out that structure changes of common textiles af-fect their transmission to heat radiation while have littleinfluence on their absorption or reflection to heat radi-ation except fabrics surfaces are aluminized.Double-layer weave is proved to be an effective fabric weave forreducing the trasmissivity.It helps increase the densityand tightness while keeps the comfort of woven fabrics atthe same time.  相似文献   

13.
This paper examines the effects of shrink - resist treatment, washing cycle and fabric tightness on the shrinkage properties of plain knitted fabrics made from 100% wool, acrylic/wool (50/50) and acrylic/wool (70/30). It was found that shrinkages of both treated and untreated wool fabrics were negatively correlated to fabric tightness and exceeded the IWS shrinkage limits (5% in length and 8 % in area) after 2 - 5A washing cycle. The effect of tightness was not as obvious with acrylic/wool (A/W) fabrics, but the shrinkage was seen to increase with stages of washing cycle for untreated A/W fabrics with some exceeding IWS standard. By applying the DC 109 shrink - resist solvent treatment, it was identified that by with higher percentage of acrylic fibre blended with wool, shrinkage could be reduced considerably and within acceptable limits.  相似文献   

14.
通过测试各种不同规格的苎麻织物的透气、透湿性能,分析了织物厚度和织物总紧度对织物透湿性能的影响.实验证明在高湿与低湿状态下,厚度和总紧度对织物的透湿性能产生的影响是不同的.本文还提出了织物厚度与总紧度的综合影响参数,综合参数对高湿与低湿状态下织物透湿性能的影响是一致的,这为夏季服用苎麻面料的设计提供了依据.  相似文献   

15.
以纯毛织物作为亲水性织物的代表、以纯涤纶织物作为疏水性织物的代表,利用织物动态热湿舒适性能测试仪,采用定量汗液蒸发的方法,研究了两类织物的动态热湿舒适性能,并对两者的差异进行了理论分析。研究表明:在动态条件下由于皮肤要经历干燥—出汗—蒸发—干燥、织物要经历干燥—吸湿—放湿—干燥的过程,此时,亲水性的吸湿性好的织物对汗液的蒸发起了阻碍作用,因此动态条件下使用疏水性的织物比使用亲水性的织物更趋合理。  相似文献   

16.
In previous research much effort has been devoted to the geometry of woven fabrics and relat-ed problems under the assumption of constant yarn configuration in fabric.This paper will first re-port that image crimp (yarn crimp measured by an image analysis method) seems larger than actualvalue.From the explanation of this result,the variation of yarn configuration in woven fabric dueto the non-uniform flattening is revealed.The significance of this actual structure of woven fabricsis discussed.It is believed that the variation of yarn configuration is very important for fabric per-formance,and may be an advantage for fabric quality.  相似文献   

17.
提出一种基于激波管实验和理论的空气袋织物透气率的测试方法.实验中空气袋织物被固定在激波管低压段末端,与大气相通.当一道平面激波与织物相撞击时将被反射,与此同时会在织物前方形成一个高压,由于空气袋织物是一种多孔介质,此高压将导致透过织物的气流流动,此流动的流率,即透气率,可通过对反射激波速度的测试而计算得到.  相似文献   

18.
The anisotropy of magnetic susceptibility (AMS) is a quick, effective and sensitive technique used to measure the weakly deformed sedimentary rocks, and also a reliable method to reveal the deforming mechanisms of fault-related folds. In Longmenshan front belt, a typical cross-section of fault-related folds is chosen to study the AMS. A total of 224 oriented specimens have been drilled at 23 different sampling sites which were distributed at the key structural positions of this structural section developed in the Xujiahe formation of the upper Triassic. Six elementary types of magnetic fabrics are recognized and established through this AMS study: Da sedimentary fabric; 2) an initial deformation fabric; 3) a pencil structure fabric; 4) a weak cleavage fabric; 5) a strong cleavage fabric; 6) a stretching lineation fabric. It has been found that most of magnetic fabrics are characterized by fabrics of weak deformation which belong to the pure-shear results of a pre-folding layer parallel shortening (LPS). In the fault-bend fold, almost all magnetic fabrics are the initial deformation fabrics of weak deformation, and denote that the deformation in the forelimb is stronger than that in the backlimb and no finite strain is shown in the footwall. While in the fault-propagation fold, finite strains are concentrated in the trishear zone where magnetic fabric results are approximately consistent with the estimated consequences of the kinematic model. The tectonic stress field indicated by the magnetic fabrics is basically the same along the whole structural section and shows a NW to SE compression and shortening which is accordant with the regional compressive stress field of the Longmenshan fold-thrust belt.  相似文献   

19.
The anisotropy of magnetic susceptibility (AMS) is a quick, effective and sensitive technique used to measure the weakly deformed sedimentary rocks, and also a reliable method to reveal the deforming mechanisms of fault-related folds. In Longmenshan front belt, a typical cross-section of fault-related folds is chosen to study the AMS. A total of 224 oriented specimens have been drilled at 23 different sampling sites which were distributed at the key structural positions of this structural section developed in the Xujiahe formation of the upper Triassic. Six elementary types of magnetic fabrics are recognized and established through this AMS study: 1) a sedimentary fabric; 2) an initial deformation fabric; 3) a pencil structure fabric; 4) a weak cleavage fabric; 5) a strong cleavage fabric; 6) a stretching lineation fabric. It has been found that most of magnetic fabrics are characterized by fabrics of weak deformation which belong to the pure-shear results of a pre-folding layer parallel shortening (LPS). In the fault-bend fold, almost all magnetic fabrics are the initial deformation fabrics of weak deformation, and denote that the deformation in the forelimb is stronger than that in the backlimb and no finite strain is shown in the footwall. While in the fault-propagation fold, finite strains are concentrated in the trishear zone where magnetic fabric results are approximately consistent with the estimated consequences of the kinematic model. The tectonic stress field indicated by the magnetic fabrics is basically the same along the whole structural section and shows a NW to SE compression and shortening which is accordant with the regional compressive stress field of the Longmenshan fold-thrust belt.  相似文献   

20.
以气囊织物的性能要求为基准,分析了气囊织物用原料的要求,并以织物组织、经纬密度、纱线规格为主要技术参数,探讨了具有良好可织性、使用性能和工作性能的非涂层方形全成形型安全气囊织物的设计方法.  相似文献   

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