圆形截面纤维皮芯结构对其内部反光性能的影响

借助纤维内部反射光中的笛卡尔线,针对纤维皮层厚度及皮芯层折射率差异对内部反射光的影响,从理论上进行分析,认为纤维皮芯结构中仍存在笛卡儿线.在薄壁玻璃管中加入一定折射率的液体,对其二维漫反射光强进行测试,验证了理论分析的结论.研究表明:纤维皮芯层折射率差异对笛卡儿线出射角的影响,大于纤维皮层厚度变化对纤维笛卡儿线出射角的影响.纤维皮芯层折射率差异的增大会使纤维笛卡儿线的出射角增大,反光强度变小.     

蜘蛛丝的结晶结构及其取向

研究和分析了大腹园蛛的牵引丝、内层包卵丝的结晶结构及其取向,探索了大腹园蛛丝纤维分子链的排列状态、结晶结构和蜘蛛丝力学性能间的关系。     

超高相对分子质量聚乙烯纤维的表面粘结性能研究

在萃取阶段用表面改性剂溶液对超高相对分子质量聚乙烯（UHMWPE）冻胶纤维进行表面处理，然后经过多级热拉伸制得改性纤维。对萃取液进行了紫外吸光度分析，并对改性前后纤维的表面化学结构、力学性能和表面粘结性能进行了比较。结果表明；经表面处理的纤维表面引入许多极性基团，纤维粘结强度随拉伸倍数增加而提高，纤维粘结性能得到较大改善；表面处理对纤维的力学性能影响不大。其中EVA的改性效果最为明显，3级拉伸后纤维的粘结强度提高了100％．     

考虑组分相互作用的飞艇蒙皮材料力学模型

平流层空间空气稀薄,昼夜温差变化剧烈,巡航状态的平流层飞艇需要承受较大的循环压差载荷。蒙皮作为平流层飞艇的主要承力结构,其材料力学性能直接影响着飞艇的使用性。针对蒙皮材料层压结构特点,构建其细观结构模型。通过研究拉伸过程中纤维纱束与基体和膜层的相互作用,指出承力方向纤维纱束的变形过程分为弯曲状态逐步拉直和产生伸长形变两个阶段。建立了蒙皮材料拉伸过程的非线性力学模型;并通过与准静态拉伸试验获得的材料应力-应变曲线进行对比分析,校验了模型的准确性并分析了模型参数的改变对材料力学性能的影响,为平流层飞艇蒙皮材料结构优化设计提供依据。     

大腹圆珠牵引丝的结构与性能分析

以大腹圆珠牵引丝为研究对象,分析了蜘蛛丝的聚集态结构特征和形态结构特征。在结构研究的基础上,探索和分析了蜘蛛丝高强度和超收缩性能的形成机理。     

经编人造血管的制备工序对管壁性能均匀性的影响

从人造血管整体层面和单纤维层面的纺织结构和力学性能，对经不同制备工房的系列经编人造血管的管壁结构和性能的变化进行了研究。管壁沿周向分成3部分：基础部位(BL)、连接部位(RL)和指示部位(GL)。线圈结构和纤维的线密度分析显示管壁三部位存在不均匀性。在管道承受周向拉伸时，该系列人造血管在连接部位呈现出断裂的选择性，连接部位的薄弱结构源自经编的双针床加工。此外，所考察的技分解自管壁3部位的单纤维的拉伸特性也被证实存在总统计意义上的差异，即不均匀性。可以预测人造血管在体内承受反复脉动等生理负荷下，破损可能首先出现在相对薄弱的部位。     

甲壳胺纤维的结构与性能

研究了甲壳胺纤维的形态结构、超分子结构及力学性能、热性能、保水值.研究表明:甲壳胺纤维的形态结构、超分子结构与纺丝原液浓度、凝固浴组成、拉伸率有关.甲壳胺纤维的抗张强度可达1.5cN/dtex,热分解温度为288℃,保水值高达130%.     

赛络纺复合纱线结构及其拉伸力学模型

在对赛络纺复合纱线工艺、组分特点以及结构分析的基础上,从复合纱线组分纤维的拉伸性能着手,结合有关短纤维纱和股线的结构力学经典理论,计算并建立了非对称复合纱线的理论拉伸方程,并用几种组分纤维及其复合纱线性能参数的实验结果与理论拉伸方程进行了验证,两者的结果相符,利用此模型很容易计算并预测在既定成纱参数下的赛络纱线力学性能,并进一步揭示了赛络纺复合纱线的结构机理和拉伸性能之间的内在联系.     

浅谈蜘蛛丝的研究进展情况

蜘蛛丝纤维的来源与组成、性能,在医疗、军事、纺织制衣的应用,综述了国内外利用生物技术和基因工程对蜘蛛丝的研究进展。     

纤维网格增强混凝土复合材力学性能

纤维网格增强混凝土（TRC）是以纤维编织网格为加强材料，以聚合物砂浆为基体的新型复合材料，其力学性能受到不同纤维网格股数和层数的明显影响。为研究这种新型复合材料的力学性能和与其所加固混凝土间的黏结滑移性能，进行了不同股数和不同层数的纤维网格拉伸试验和TRC复合材拉伸试验，以及不同网格层数的TRC?混凝土界面黏结滑移试验，建立了随层数和股数变化的纤维网格拉伸本构模型、TRC复合材拉伸本构模型、TRC?混凝土界面黏结滑移本构模型，为后续研究和工程应用提供理论依据。     

成丝的速度与方式和蜘蛛丝力学性能的关系

为了分析蜘蛛丝的力学性能和成丝条件间的关系,研究了不同速度下人工卷取的蜘蛛牵引丝以及蜘蛛垂直下落时分泌的牵引丝的力学性能.研究结果表明,随着卷取速度的增大,蜘蛛丝的断裂强度有一极大值,在高速卷取时强度的变化较低速时平缓.垂直下落时蜘蛛分泌的牵引丝的综合力学性能优异,但断裂强度不一定大于人工卷取的丝.成丝速度和成丝方式都对蜘蛛丝的性能有很大影响.     

Molecular Fundaments of Mechanical Properties of Spider Silk

Dragline, framework and cocoon silk fibers of Araneus Ventricosus were used for this study. To investigate the microstructure mechanisms of stress-strain behavior of spider silk, firstly, amino acid compositions were analyzed and molecular conformations and crystallinity were measured with Raman spectra and X-ray diffraction respectively. The results showed that there were more amino acids with large side groups and polar ones in spider silk than those of Bombyx silk, and the amino acid distribution varied with different spider silk. The molecular structures were mainlyα-helix and β-sheet, and random coil andβ-turn existed as well. The proportions and arrangement of these conformations of dragline silk were different from framework and cocoon silk fibers. Microstructure was one of important factors of excellent mechanical properties of spider silk. Crystallinity of spider silk was very low, which implied that the roles of crystal on spider silk were not as great as other protein fibers.     

蜘蛛丝应力—应变行为的分子结构机理

利用激光拉曼光谱技术研究了大腹园蛛牵引丝、蛛网框丝和内层包卵丝的分子构象,分析了蜘蛛丝的分子构象差异对其应力-应变行为的影响,探索了蜘蛛丝优异力学性能的分子结构机理。     

Surprising strength of silkworm silk

Commercial silkworm silk is presumed to be much weaker and less extensible than spider dragline silk, which has been hailed as a 'super-fibre'. But we show here that the mechanical properties of silkworm silks can approach those of spider dragline silk when reeled under controlled conditions. We suggest that silkworms might be able to produce threads that compare well with spider silk by changing their spinning habits, rather than by having their silk genes altered.     

Morphology and Microstructure of Spider Dragline Silk from Araneus Ventricosus

The spider dragline silk has excellent mechanical properties. The stress- strain curves of dragline silk fibers have intraspecific and intraindividual variability because of the spiders active control during spinning process. To investigate the relationship between the morphology of dragline silk fibers and spinning conditions, four samples were made at the reeling rates of 1mm/s, 20mm/s, 43.5mm/s and 110mm/s from the major ampullate glands of Araneus Ventricosus and the other two of dragline silks were prepared from a crawling or dropping spider. The surface microstructure and nanofibril characteristic were analyzed with atomic force microscopy (AFM). AFM images of 2000nm*2000nm and 500nm*500nm of these samples showed that the spinning condition influenced the surface roughness and fibril size, while AFM images of 200nm*200nm clearly displayed that dragline silk of Araneus Ventricosus included sheet macro-conformation structure. These results can facilitate the further investigation of the spinning mechanism of a spider in order to understand mechanical properties and macromolecular structures of dragline silk.     

大腹圆蛛包卵丝的化学组成与物理机械性能

分析了大腹圆蛛包卵丝的氨基酸组成，包卵丝中极性氨基酸含量较高，小侧基氨基酸含量较少，利用SEM及计算机图像处理技术分析了大腹圆蛛包卵丝的形态结构特征，包卵丝的断面形状基本为圆形，包层包卵丝的细度约为内层包卵丝的2倍，并且外层包卵丝的纤维断面内有许多无规分布的纳米级孔隙，经冷冻干燥后，孔隙率增加了2倍左右，在此基础上，研究了大腹圆蛛包卵丝的拉伸机械性能，光泽和热性能，初步探索了性能的形成机理，大腹圆蛛内层包卵丝具有比其他功能蜘蛛丝和丝素纤维好得多的力学性能，其强度高，伸长率大，韧性好，包卵丝在光泽和热性能方面与蚕丝丝素纤维有一定的差异。     

Nonlinear material behaviour of spider silk yields robust webs

Natural materials are renowned for exquisite designs that optimize function, as illustrated by the elasticity of blood vessels, the toughness of bone and the protection offered by nacre. Particularly intriguing are spider silks, with studies having explored properties ranging from their protein sequence to the geometry of a web. This material system, highly adapted to meet a spider's many needs, has superior mechanical properties. In spite of much research into the molecular design underpinning the outstanding performance of silk fibres, and into the mechanical characteristics of web-like structures, it remains unknown how the mechanical characteristics of spider silk contribute to the integrity and performance of a spider web. Here we report web deformation experiments and simulations that identify the nonlinear response of silk threads to stress--involving softening at a yield point and substantial stiffening at large strain until failure--as being crucial to localize load-induced deformation and resulting in mechanically robust spider webs. Control simulations confirmed that a nonlinear stress response results in superior resistance to structural defects in the web compared to linear elastic or elastic-plastic (softening) material behaviour. We also show that under distributed loads, such as those exerted by wind, the stiff behaviour of silk under small deformation, before the yield point, is essential in maintaining the web's structural integrity. The superior performance of silk in webs is therefore not due merely to its exceptional ultimate strength and strain, but arises from the nonlinear response of silk threads to strain and their geometrical arrangement in a web.     

AN-g-Casein纤维的结构与性能的研究

利用扫描电镜(SEM)观察,发现AN-g-Casein纤维截面形成了皮芯型结构;芯层Casein组分相畴约20～60nm,拉断时,芯层易产生原纤化;皮层结构致密,断面平整;纤维表面形成细长条纹。AN-g-Casein纤维中二组分的结晶度基本不随酪素含量而变。AN-g-Casein纤维吸湿性、染色性优异,且能采用酸性染料、阳离子染料染色,AN-g-Casein纤维力学性能良好,是一种值得推广应用的新型改性仿真丝纤维。     

Molecular architecture and engineering of spider dragline silk protein

Spider dragline silk, which is produced in spider major ampullate gland, is a composite proteinacious fiber with highly repetitive Ala-Gly-rich domain. The unique combination of both high tensile strength and high elasticity makes spider dragline silk superior to almost any other natural or synthetic fibers. Cloning of the genes reveals that the silk is composed of at least two major proteins. Each protein component contains multiple repeats of modular structures that alternate between Ala-rich domains and Gly-rich domains. Molecular engineering not only opens a door to the production of spidroins but also provides a valuable experimental system to test and further establish the relationship between modular structures and mechanical properties. Here, based on our own studies, we review the latest progress of the modular structure and genetic engineering and outline the future prospects.