玻璃纤维混凝土抗折性能及弯曲韧性试验研究

为研究玻璃纤维对混凝土的抗折性能及弯曲韧性的影响,以玻璃纤维掺量、玻璃纤维长度和混凝土基体强度等级为主要参数,对玻璃纤维混凝土小梁试件进行弯拉试验。结果表明:玻璃纤维掺入混凝土后,破坏形态得到改善,破坏后试件整体性能良好,抗折强度以及弯曲韧性均有显著提高;0.5%~1.5%时抗折强度随玻璃纤维掺量的增加而提高,1.5%~2.0%时随玻璃纤维掺量的增加而降低;抗折强度与弯曲韧性随玻璃纤维长度与基体强度的增加而增加。玻璃纤维可有效改善混凝土的抗折性能与弯曲韧性。

基于光纤声发射的局部放电信号识别方法分析

局部放电(PD)是电气设备绝缘退化的主要原因,相较于传统的检测方法,光纤声发射检测技术具有不影响设备运行方式、抗电磁干扰能力强等优点。设计并制作了尖端放电、气泡放电、悬浮放电和沿面放电4种典型局部放电模型,搭建了基于光纤声发射的局部放电声发射信号采集试验平台,采集了梯度施加电压下的局部放电声发射信号并对其进行了参量统计分析,提出了将去噪后信号时频图作为卷积神经网络特征输入的识别模型。试验结果表明,该识别模型对于淹没在噪声中的微弱局部放电信号具有良好的识别效果,识别准确率可达98%。

基于取向纤维基底和图案化双相金属层的高灵敏应变传感器

为了提高液态金属基应变传感器的灵敏度,研究了一种高灵敏度、可拉伸的应变传感器,该传感器由取向的静电纺热塑性聚氨酯纤维基底和图案化双相金属传感层构成。以液态金属Galinstan为“岛”,固体金属银为“海”,构建了图案化双相金属传感层。银“海”可阻止连续的液态金属导电路径的形成,基于银导电区域的裂纹扩展机制,传感器的灵敏度显著提高。此外,纤维取向(水平或垂直)削弱了在受力时纤维的重新排列,增强了传感层的变形。结果表明,对于单一液态金属层或Ag层组成的传感器,基底纤维垂直取向与随机排列比较,灵敏度分别提高1.09倍和33.19倍。最终制成的基于垂直取向纤维基底和图案化双相金属层的应变传感器具有超高的灵敏度(灵敏度系数高达952.20)和宽传感范围(高达59.33%)。这种设计有望在可穿戴设备中显示良好的应用潜力。

黎陶包装的主题性设计创新研究

目的立足“道器”造物思想探究黎陶包装的主题性设计逻辑和方法,并拓展包装设计要素的主题性深化导向。方法通过梳理原始黎陶技艺以探究其困境,进而结合黎族原生文化和图纹提炼出可对接现代生活语境的主题类型,并采用事件化方法细化主题属性,使其转为设计因素以便设定主题包装的体验与功能,从而得出可实践的黎陶包装主题性设计方案,由此针对包装设计要素进行主题性深化探究。结果基于黎族原生文化和图纹提炼出福寿、多子、婚恋、丰饶、平安的主题,并将“道器”作为设计理念以引申出黎陶包装的主题性设计逻辑导图,进而开发出将主题事件化的黎陶包装设计方法,并基于主题深化造型、结构、视觉、材料的包装设计要素,配以黎陶包装概念设计效果图呈现。结论当前黎陶包装设计过于秉持“原始”属性,造成黎陶本体和外包装在设计层面被忽视,导致黎陶在工艺技法、设计逻辑、包装理念上出现故步自封的现象。因此提出黎陶包装的主题性设计逻辑与方法以带动包装设计的系统性升级。

基于光栅动画图案合成光纤织物的设计及其实现

通过光栅原理将动态画面用于织物设计时,易出现织物的双层结构复杂、色彩难以精准控制等问题,提出基于光栅动画图案合成原理设计动态图案光纤织物,利用提花工艺将光纤和纱线织造成图案织物,使用发光二极管作为光源,通过热塑管将其分别与聚合物光纤耦合连接,利用发光控制器,使得二极管依次间隔发光,显示相邻动作的静态图案。还分析了合成图片个数、切分用光栅细度、分组发光频率等对图案动态效果的影响。以光纤和棉纱为原料,采用提花织机设计和织造聚合物光纤织物,结果表明:当以直径为0.25 mm的聚合物光纤作为最小发光单元时,5帧数合成的光纤发光织物能够同时兼顾动画呈现的识别度和流畅度;间隔条纹宽度在0.25 mm时,动态效果呈现时,物体轮廓越清晰;当发光频率为0.2 s时,其呈现的动态效果最好。该思路开拓了织物上动态图案呈现的全新实现方法。

西部矿区深埋厚煤层采动覆岩离层发育规律数值模拟研究

为了丰富离层发育规律的研究方法,以石拉乌素矿221_上08工作面为对象,通过分布式光纤(BOTDR)及定点光纤对离层位置进行综合确定,结合颗粒流PFC^(2D)数值模拟,对大采高、大采深条件下采动覆岩离层发育规律进行研究。结果表明:随着工作面推进,离层空间在关键层底部自下而上向主关键层底部发育,离层发育埋深在440、396、376、331、321、296 m附近,层位止于粗砂岩主关键层底部;覆岩运移主要经历下位关键层沉降、上位亚关键层快速沉降、向粗砂岩主关键层底部发展、主关键层运移阶段;离层层位与工作面推进距离呈正比,且离层发育主要分为孕育(Ⅰ)-加速扩容(Ⅱ)-压密阶段(Ⅲ)3个阶段。

纤维桩联合不同冠部修复方式修复穿髓型非龋性颈部缺损牙体的力学分析

背景:使用纤维桩修复穿髓型非龋性颈部缺损可以改变牙齿的应力分布,显著降低患牙折裂风险,但关于纤维桩改善牙体抗折性的力学机制及穿髓型非龋性颈部缺损的最佳冠部修复方式尚有争论。目的:综述纤维桩修复穿髓型非龋性颈部缺损后的应力分布模式,在各种受力状态下的抗折能力与断裂模式,以及纤维桩联合不同冠部修复方式的最新研究进展。方法:应用计算机在PubMed和中国知网数据库中检索2008年9月至2023年9月发表的相关文献,英文检索词为“non-carious cervical lesions,endodontically treated teeth restoration,endodontically treated teeth stress distribution”,中文检索词为“非龋性颈部缺损,根管治疗后牙体修复,根管治疗后牙齿应力分布”,最终纳入56篇文献进行分析。结果与结论:穿髓型非龋性颈部缺损根管治疗后,应用纤维桩修复可部分改善牙齿颈部应力,同时不会增加牙根纵裂的风险;使应力分布更加均匀,提高牙齿的抗折性。使用纤维桩修复的非龋性颈部缺损牙齿若折断,其断裂模式显示出有利的、可恢复的或可修复的断裂模式。纤维桩联合瓷贴面或贴面式嵌体可能会成为修复穿髓型非龋性颈部缺损的一种较理想微创修复方法。

Toward Flexible and Wearable Embroidered Supercapacitors from Cobalt Phosphides-Decorated Conductive Fibers

Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.

Molecular Cloning and Characterization of an Allene Oxide Cyclase Gene Associated with Fiber Strength in Cotton

Allene oxide cyclase （AOC） is one of the most important enzymes in the biosynthetic pathway of the plant hormone jasmonic acid （JA）. AOC catalyzes the conversion ofallene oxide into 12-oxo-phytodienoic acid （OPDA）, a precursor of JA. Using 28K cotton genome array hybridization, an expressed sequence tag （EST; GenBank accession no. ES792958） was investigated that exhibited significant expression differences between lintless-fuzzless XinWX and linted-fuzzless XinFLM isogenic lines during fiber initiation stages. The EST was used to search the Gossypium EST database （http：//www.ncbi.nlm.nih.gov/） for corresponding cDNA sequences encoding full-length open reading frames （ORFs）. Identified ORFs were confirmed using transcriptional and genomic data. As a result, a novel gene encoding AOC in cotton （Gossypium hirsutum AOC; GenBank accession no. KF383427） was cloned and characterized. The 741-bp GhAOC gene comprises three exons and two introns and encodes a polypeptide of 246 amino acids. Two homologous copies were identified in the tetraploid cotton species G. hirsutum acc. TM-1 and G. barbadense cv. Hai7124, and one copy in the diploid cotton species G. herbaceum and G. raimondii, qRT-PCR showed that the GhAOC transcript was abundant in cotton fiber tissues from 8 to 23 days post anthesis （DPA）, and the expression profiles were similar in the two cultivated tetraploid cotton species G. hirsutum acc. TM- 1 and G. barbadense cv. Hai7124, with a higher level of transcription in the former. One copy of GhAOC in tetraploid cotton was localized to chromosome 24 （Chr. D8） using the subgenome-specific single nucleotide polymorphism （SNP） marker analysis, which co-localized GhAOC to within 10 cM of a fiber strength quantitative trait locus （QTL） reported previously. GhAOC was highly correlated with fiber quality and strength （P=0.014） in an association analysis, suggesting a possible role in cotton fiber development, especially in secondary cell wall thickening.

Tire Grip Performance Simulation and Improving Method Considering the Influence of Tread Pattern Stiffness

The grip performance of radial tires on dry roads was simulated with the software ABAQUS. A sliding-velocity.dependent friction coefficient on the contact behavior at the tire-pavement interface was selected to describe friction phenomenon for fire and road interface. Anti-lock brake system （ABS） process was achieved by controlling the tire angular velocity to obtain the relationship between friction force and slip rate, while the maximum friction forces were used to evaluate tire grip performance. Physical mechanism of tire grip performance was also analyzed through the frictional force generated from the adhesion region and sliding region by considering the contact differences between the longitudinal slip and the lateral slip, and the deformation characteristics of tire pattern were also investigated. In order to improve tire grip performance, carbon fiber material was added to the tread pattern grooves. The results show that carbon fiber has a significant influence on stiffness distribution of tread patterns and friction force vector in the contact zone. Tire grip performance can be improved by controlling the stiffness distribution and deformation direction of the tread pattern.

Fractal geometry and topology abstracted from hair fibers

Based on the concepts of fractal super fibers, the （3, 9＋2）-circle and （9＋2, 3）-circle binary fractal sets are abstracted form such prototypes as wool fibers and human hairs, with the （3）-circle and the （9＋2）-circle fractal sets as subsets. As far as the （9＋2） topological patterns are concerned, the following propositions are proved： The （9＋2） topological patterns accurately exist, but are not unique. Their total number is 9. Among them, only two are allotropes. In other words, among the nine topological patterns, only two are independent （or fundamental）. Besides, we demonstrate that the （3, 9＋2）-circle and （9＋2, 3）-circle fractal sets are golden ones with symmetry breaking.

Fiber diameters and parallel patterns:proliferation and osteogenesis of stem cells

Due to the innate extracellular matrix mimicking features,fibrous materials exhibited great application potential in biomedicine.In developing excellent fibrous biomaterial,it is essential to reveal the corresponding inherent fiber features’effects on cell behaviors.Due to the inevitable‘interference’cell adhesions to the background or between adjacent fibers,it is difficult to precisely reveal the inherent fiber diameter effect on cell behaviors by using a traditional fiber mat.A single-layer and parallel-arranged polycaprolactone fiber pattern platform with an excellent non-fouling background is designed and constructed herein.In this unique material platform,the‘interference’cell adhesions through interspace between fibers to the environment could be effectively ruled out by the non-fouling background.The‘interference’cell adhesions between adjacent fibers could also be excluded from the sparsely arranged(SA)fiber patterns.The influence of fiber diameter on stem cell behaviors is precisely and comprehensively investigated based on eliminating the undesired‘interference’cell adhesions in a controllable way.On the SA fiber patterns,small diameter fiber(SA-D1,D1 means 1μm in diameter)may seriously restrict cell proliferation and osteogenesis when compared to the middle(SA-D8)and large(SA-D56)ones and SA-D8 shows the optimal osteogenesis enhancement effect.At the same time,the cells present similar proliferation ability and even the highest osteogenic ability on the densely arranged(DA)fiber patterns with small diameter fiber(DA-D1)when compared to the middle(DA-D8)and large(DA-D56)ones.The‘interference’cell adhesion between adjacent fibers under dense fiber arrangement may be the main reason for inducing these different cell behavior trends along with fiber diameters.Related results and comparisons have illustrated the effects of fiber diameter on stem cell behaviors more precisely and objectively,thus providing valuable reference and guidance for developing effective fibrous biomaterials.

Numerical Study on Optical Solitons Transmission System with 40 Gbit/s in the Photonic Crystal Fiber

The 40 Gbit/s optical solitons transmission system in photonic crystal fiber was investigated by fast Fourier transform method, and the maximum transmission distance of system was calculated numerically. By the eye pattern of system, the transmission performances of system were studied. Results show that when polarization mode dispersion coefficient Dp is smaller than , the influence of the PMD on the transmission distance was neglectable. When the dispersion coefficient D is larger than 1.5 ps/km/nm, the transmission distance decreases rapidly. The positive or negative of three order group-velocity dispersion makes no differences on the system transmission.

Perimeter Security System Based on Ultra-Weak Fiber Bragg Grating Array

A perimeter security system based on ultra-weak fiber Bragg grating high-speed wavelength demodulation was proposed. The demodulation system for signal acquisition and high-speed wavelength calculation was designed based on field programmable gate array (FPGA) platform. The principle of ultra-weak fiber Bragg grating high-speed demodulation and signal recognition method were analyzed theoretically, and the Support Vector Machine model was introduced to optimize the event recognition accuracy of the system. A perimeter security experimental system containing 1000 ultra-weak fiber Bragg gratings, ultra-weak fiber Bragg grating sense optical cables with a diameter of 2.0 mm and a reflectivity of 0.01%, steel space frames and demodulation equipments was built to recognize four typical events such as knocking, shaking, wind blowing and rainfall. The experimental resulted show that the system has a spatial resolution of 1m and an acquisition frequency of 200 Hz. The joint time-frequency domain detection method is used to achieve 99.2% alarm accuracy, and 98% recognition accuracy of two intrusion events, which has good anti-interference performance.

不同种植模式对机采棉产量和纤维品质的影响

为考察不同种植模式对机采棉的产量和纤维品质的影响,并优化机采棉的种植模式,开展了田间小区试验。试验设置了1膜3行、1膜4行、1膜6行等3个处理,每个处理重复3次。结果表明:1膜6行处理的皮棉产量最高,1膜3行处理在单株铃数、单铃质量、衣分等方面具有一定优势,不同处理间纤维品质性状变异不大。1膜6行种植模式具有稳产、高产的特点;建议优化1膜3行种植模式的种植密度,改进栽培方式,选择适宜种植的棉花品种。

种植模式与灌溉定额对机采长绒棉产量及纤维品质形成的影响

【目的】研究种植模式与灌溉定额对机采长绒棉产量及纤维品质形成的影响,为促进机采长绒棉产量与品质协同提供理论依据。【方法】试验在田间微区控制条件下进行,采用裂区试验设计,选择同一最适密度,以机采种植模式为主区:1膜3行(S_(3))、1膜4行(S_(4))和1膜6行(S_(6));灌溉定额为副区:3150 m^(3)/hm^(2)[W_(1),重度亏缺(田间持水量50%)]、4050 m^(3)/hm^(2)[W_(2),轻度亏缺(田间持水量75%)]和4980 m^(3)/hm^(2)[W_(3),充分灌溉(田间持水量100%)],分析种植模式与灌溉定额对机采长绒棉干物质积累、产量构成及机采品质的影响。【结果】棉花干物质的积累符合Logistic生长函数模型。同一灌溉定额下,随平均行距的扩大可提早进入干物质快速积累时期,S_(3)处理最大干物质积累速率平均分别比S_(4)和S_(6)处理增加0.62和0.77 g/(株·d)。在同一种植模式下,干物质积累速度和持续时长随着灌溉定额的增加而增加。平均行距和灌溉定额的增加,显著提高了单株结铃数与单铃质量及产量。同一灌溉定额下,随平均行距的扩大,化学脱叶效率显著提高,挂枝率显著降低,棉纤维半均长、整齐度和纺织参数得到显著改善;同一种植模式下,随着灌溉定额的增加,产量与纤维品质指标同样显著提高,但对纤维品质的影响未达到显著水平。【结论】等行距处理和轻度亏缺灌溉组合(S_(3)W_(2)),有利于干物质积累量向生殖器官的转移,单株结铃数和单铃重显著提高,且机采品质较好。

基于分布式光纤振动传感技术的地下管廊入侵监测系统

针对目前地下综合管廊的安全防控需求,设计研制了一种基于分布式光纤振动传感技术的地下管廊入侵监测系统。系统采用分布式光纤马赫曾德尔-萨格纳克混合干涉结构,结合振动传递装置将井盖开关行为转化成对光缆的振动冲击,再利用一维卷积神经网络算法对振动冲击信号做模式识别,通过监测井盖开关实现对地下管廊人为入侵行为的监测。对所设计的系统进行实地测试,采集1573组扰动数据进行模式识别,模式识别正确率在99%以上,识别实时性高,表明该系统能够满足地下综合管廊实际应用的需求,有利于拓展光纤传感技术在地下管廊领域的应用。

光纤光栅光谱与雷达方向图特性分析

光纤光栅在雷达领域发挥着重要作用,与此同时光纤Bragg光栅的反射光谱和雷达方向图间也存在一定的相似性,如光栅的光谱切趾和雷达的方向图加权有类似的作用,都是为了抑制信号的旁瓣或者副瓣。基于耦合模理论对均匀光栅、相移光栅、切趾光栅、啁啾光栅等光纤Bragg光栅的反射光谱进行了仿真分析,同时,根据上述光栅的结构模型,构建了一维阵列雷达模型,并对相应阵列的方向图进行了分析和仿真。仿真结果表明,相关构型能够起到方向图调制的效果,如实现对副瓣抑制的效果等。研究内容促进了光纤光学和雷达领域的相关成果转化和交叉学科发展。

“宽早优”植棉模式下不同株距配置对棉花生长及产量和纤维品质的影响

【目的】探究适于新疆生产建设兵团第七师“宽早优”植棉模式的最佳株距和种植密度,从而为当地建立高产高效的棉花栽培技术体系提供理论依据。【方法】2021―2022年开展田间试验,采用“宽早优”(76 cm等行距,地膜宽2.05 m)种植模式,1膜3行3带。采用裂区试验设计:主区为棉花品种(新陆早61号和K07-12),副区为株距处理(设置5.5 cm、7.5 cm、9.5 cm、11.5 cm、13.5 cm和15.5 cm共6个水平)。研究不同处理对棉花的生育期、农艺性状、叶绿素含量(soil and plant analyzer development,SPAD值)、干物质质量、冠层结构、产量以及纤维品质的影响。【结果】随着株距的增加,供试棉花品种的生育期缩短,单株果枝数、株高、茎粗整体呈增加趋势,第1果枝节位高度呈波动降低趋势。不同株距处理对SPAD值无显著影响。2022年盛花期、盛铃期和吐絮期,随着株距的增大,生殖器官干物质质量呈先升高后降低趋势,叶面积指数呈波动减小趋势,冠层开度呈波动增加趋势。2021年,同一棉花品种在不同株距下的衣分、籽棉产量和皮棉产量均无显著差异。2022年9.5 cm株距配置下,新陆早61号和K07-12的籽棉产量和皮棉产量较高,纤维品质也较好。新陆早61号的纤维品质更加稳定,不同株距处理间的纤维上半部平均长度、长度整齐度指数、马克隆值、断裂比强度和断裂伸长率差异均不显著。【结论】“宽早优”植棉模式下,株距为9.5 cm(理论种植密度为13.85万株·hm-2)时,新陆早61号和K07-12可获得较理想的叶面积指数与干物质质量,籽棉产量和皮棉产量较高,也可保持较好的纤维品质。

抗菌、消臭功能纤维的研究进展(1)——机理与前景

本文以抗菌、消臭功能纤维的研制方法分类 ,并详细讨论了其抗菌消臭作用的方式和机理。概述了近几年国内外在抗菌、消臭功能纤维研究方面的进展 ,对抗菌、消臭功能纤维现存的问题加以分析 ,提出高效、安全、耐久和适用性广是未来抗菌、消臭功能纤维研发的重点。