核桃缝合力测试系统的研究

针对目前各国对核桃缝合线紧密度分级标准各异、缺乏量值化这一现状,提出了一种基于虚拟仪器的核桃缝合力测试系统的方案。本系统能实现对数据的实时显示及存储,测试结果直观、可靠。这种新的分级方法更加接近实际,将对核桃坚果品质的优选和发展生产提供有利的数据支持。

带材缝合机的缝合力计算

缝合力计算是带材缝合机设计的关键。本文结合作者在生产调试过程中的实践,并通过理论分析,提出了新的缝合力计算方法,其计算结果与实测值基本一致。

缝合线拉力与小梁网扩张宽度的仿真分析与实验研究

黏小管成形术是治疗青光眼较为安全有效的新型手术方式,医生通过向患者施莱姆氏管中递送缝合线一周并张紧的方法,使小梁网和施莱姆氏管处于扩张状态,恢复房水自然流出通路从而降低眼内压。为了研究缝合线上张紧力与组织扩张的关系,文中采用有限元方法,进行了黏小管成形术的仿真分析,并开展了猪眼球实验验证。结果表明:施莱姆氏管和小梁网由松弛变形至术后扩张状态的过程中,扩张宽度随着缝合线拉力的增加而逐渐增大,仿真中拉力为43.5~57.3m N时,扩张宽度为300~390μm;实验中拉力在34.1~66.6 m N范围时,扩张宽度为297.8~404.6μm,实验结果与仿真结果呈现相同趋势。这种方法可以辅助医生进行决策,提升手术的精准性。

黏小管成形术中缝合线扩张小梁网过程的有限元分析与实验研究

黏小管成形术是治疗青光眼较为安全有效的新型手术方式,医生通过向患者施莱姆氏管(Schlemm’s canal,SC)中递送缝合线一周并张紧的方法,使患者小梁网(trabecular meshwork,TM)和施莱姆氏管处于扩张状态,恢复房水自然流出通路从而降低眼内压。然而,缝合线张紧力是组织扩张的直接因素,过大会导致组织损伤,医生往往通过经验或出血进行扩张程度判断。为了研究缝合线上张紧力与组织扩张的关系,采用有限元方法建立了包含巩膜、施莱姆氏管、小梁网和缝合线的数值计算模型,进行了黏小管成形术的仿真分析,并开展了猪眼球实验验证。结果表明:施莱姆氏管和小梁网由松弛变形至术后扩张状态的过程中,扩张宽度随着缝合线拉力的增加而逐渐增大,仿真中拉力为43.5~57.3 mN时,扩张宽度为300~390μm;实验中拉力在34.1~66.6 mN范围时,扩张宽度为297.8~404.6μm,实验结果与仿真结果呈现相同趋势。所提方法可以用于实时预测术中施莱姆氏管和小梁网的扩张程度,辅助医生进行决策,提升手术精准性。

“四个最严”全程无缝 合力监管织密网格

食品药品安全关系人民群众的生命健康安全,近年来,福州市鼓楼区市场监管局严格按照“四个最严”要求,坚持示范创建、日常监管、多方联动、宣传教育,以“排头兵”的标准全力推进食品药品安全工作,坚决以实际行动把好人民群众饮食用药安全的每一道关口,取得一定成效。

Coupled thermo-hydro-mechanical process in buffer material and self-healing effects with joints

Within the multi-barrier system for high-level waste disposal,the technological gap formed by combined buffer material block becomes the weak part of buffer layer.In this paper,Gaomiaozi bentonite buffer material with technological gap was studied,the heat transfer induced by liquid water flow and water vapor was embedded into the energy conservation equation.Based on the Barcelona basic model,the coupled thermo-hydro-mechanical model of unsaturated bentonite was established by analyzing the swelling process of bentonite block and the compression process of joint material.The China-Mock-up test was adopted to compare the numerical calculation results with the test results so as to verify the rationality of the proposed model.On this basis,the effect of joint self-healing on dry density,thermal conductivity and permeability coefficient of buffer material was further analyzed.The results show that,with bentonite hydrating and swelling,the joint material gradually increases in dry density,and exhibits comparatively uniform hydraulic and thermal conductivity properties as compacted bentonite block.As a result,the buffer material gradually shifts to homogenization due to the coordinated deformation.

A New Method for Measuring the Stitch Length of Weft Knitted Fabric in a Static Environment

It is essential to measure the stitch length of weft knitted fabric in a static environment for economy and improving productivity. The image inputted was dealt with the digital image processing techniques： the paper carried out the transformation of grey scale; then removed impurities with filtering; the characteristic of the stitch structure was abstracted by using the Fourier transform technique. To obtain the stitch length more accurately, we should establish ageometric medal of the stitch lined on the digital image processing, which provides a way to transform the stitch length in the two-dimenslon space into a three-dimension space. This study provides a new methed for measuring the stitch length without damaging the fabric.

Fatigue Magnification Factors of Arc-Soft-Toe Bracket Joints

Arc-soft-toe bracket(ASTB), as a joint structure in the marine structure, is the hot spot with significant stress concentration, therefore, fatigue behavior of ASTBs is an important point of concern in their design. Since macroscopic geometric factors obviously influence the stress flaws in joints, the shapes and sizes of ASTBs should represent the stress distribution around cracks in the hot spots. In this paper, we introduce a geometric magnification factor for reflecting the macroscopic geometric effects of ASTB crack features and construct a 3D finite element model to simulate the distribution of stress intensity factor(SIF) at the crack endings. Sensitivity analyses with respect to the geometric ratio Ht/Lb, R/Lb, Lt/Lb are performed, and the relations between the geometric factor and these parameters are presented. A set of parametric equations with respect to the geometric magnification factor is obtained using a curve fitting technique. A nonlinear relationship exists between the SIF and the ratio of ASTB arm to toe length. When the ratio of ASTB arm to toe length reaches a marginal value, the SIF of crack at the ASTB toe is not influenced by ASTB geometric parameters. In addition, the arc shape of the ASTB slope edge can transform the stress flowing path, which significantly affects the SIF at the ASTB toe. A proper method to reduce stress concentration is setting a slope edge arc size equal to the ASTB arm length.

Test evaluation for vertical fracture wells in low permeability reservoir

As flow environment is poor in low permeability reservoirs, wells are always fractured in order to gain better economic benefits. Well testing analysis is very necessary for fracturing wells. However, available test analysis methods are of slow fitting speed and low fitting precision. In this paper, we first use a comprehensive evaluation method of analytical well testing, numerical well testing and well testing design. Many dynamic parameters such as fracture length, fracture conductivity, skin factor, etc are obtained. An example to illustrate accurate results of this method is given.

基于化学改性和切割方法的介入瓣瓣膜力学性能相关研究

本文探索了介入瓣瓣膜膜片的制备方法和瓣膜化学改性和切割方法对瓣膜膜片拉伸性能和缝合力力学性能的影响。本研究通过采集新鲜猪心包材料并应用碳化亚胺溶液和戊二醛溶液作为固定液的方法合成介入瓣瓣膜膜片材料;通过茚三酮法检测瓣膜膜片材料的交联度情况;应用拉伸及缝合力力学实验测试介入瓣瓣膜膜片材料的生物力学性能;通过场发射扫描电镜表征瓣膜膜片材料在经过缝合线拉伸作用后的胶原纤维取向分布。结果表明:经过化学改性后,介入瓣瓣膜膜片材料的交联度达到93.78%±3.2%;瓣膜膜片材料的拉伸强度达到(8.24±0.79)MPa;缝合力强度增加了102%。介入瓣瓣膜膜片材料具有较强的生物力学性能,有望发展成为的一种较好的介入瓣瓣膜膜片材料。

Comparison of a new single-donor human fibrin adhesive with suture for posterior tibial nerve repair in rat： biomechanical resistance and functional analysis

Objective： The use of fibrin adhesives has a broad background in nerve repair. Currently the suboptimal physical properties of singledonor fibrin adhesives have restricted their usage. The present experiment studies the performance and physical characteristics of a modified fibrin glue prepared from single-donor human plasma in the repair of posterior tibial nerve of rat. Methods： Forty Wistar rats were divided into 5 groups; in the control group, tibial nerve was completely transected and no treatment was done, while in the four experimental groups the nerve stumps were reconnected by one suture, three sutures, one suture with fibrin glue and fibrin glue alone respectively. During 8 weeks of follow-up, Tibial Function Index was measured weekly and adhesive strength, inflammation and scar formation were assessed at the end of the study. Results： Nerve stumps dehiscence rate and adhesive strength were similar in all experimental groups and significantly differed from control group （P〈0.05）. By the end of the eighth follow-up week, functional recovery of one and three sutures groups were significantly higher than groups in which fibrin glue was used for repair （P〈0.05）. The amount of inflammation and scar tissue formation was similar among all groups. Conclusion： The study results show that the prepared single-donor fibrin adhesive has acceptable mechanical properties which could provide required adhesiveness and hold nerve stumps in the long term; yet, we acknowledge that more studies are needed to improve functional outcome ofsinszle donor fibrin adhesive repair.