Influence of Waveguide Properties on Wave Prototypes Likely to Accompany the Dynamics of Four-Wave Mixing in Optical Fibers

In this article, we study the impacts of nonlinearity and dispersion on signals likely to propagate in the context of the dynamics of four-wave mixing. Thus, we use an indirect resolution technique based on the use of the iB-function to first decouple the nonlinear partial differential equations that govern the propagation dynamics in this case, and subsequently solve them to propose some prototype solutions. These analytical solutions have been obtained;we check the impact of nonlinearity and dispersion. The interest of this work lies not only in the resolution of the partial differential equations that govern the dynamics of wave propagation in this case since these equations not at all easy to integrate analytically and their analytical solutions are very rare, in other words, we propose analytically the solutions of the nonlinear coupled partial differential equations which govern the dynamics of four-wave mixing in optical fibers. Beyond the physical interest of this work, there is also an appreciable mathematical interest.

Functionalized Fiber-Based Strain Sensors:Pathway to Next-Generation Wearable Electronics

Wearable strain sensors are arousing increasing research interests in recent years on account of their potentials in motion detection,personal and public healthcare,future entertainment,man-machine interaction,artificial intelligence,and so forth.Much research has focused on fiber-based sensors due to the appealing performance of fibers,including processing flexibility,wearing comfortability,outstanding lifetime and serviceability,low-cost and large-scale capacity.Herein,we review the latest advances in functionalization and device fabrication of fiber materials toward applications in fiber-based wearable strain sensors.We describe the approaches for preparing conductive fibers such as spinning,surface modification,and structural transformation.We also introduce the fabrication and sensing mechanisms of state-of-the-art sensors and analyze their merits and demerits.The applications toward motion detection,healthcare,man-machine interaction,future entertainment,and multifunctional sensing are summarized with typical examples.We finally critically analyze tough challenges and future remarks of fiber-based strain sensors,aiming to implement them in real applications.

Fabrication and study of supercapacitor electrodes based on oxygen plasma functionalized carbon nanotube fibers

Dry-spun Carbon Nanotube(CNT)fibers were surface-modified by atmospheric pressure oxygen plasma functionalization using a well controlled and continuous process.The fibers were characterized by scanning electron microscopy(SEM),Raman spectroscopy,and X-ray Photoelectron Spectroscopy(XPS).It was found from the conducted electrochemical measurements that the functionalized fibers showed a 132.8% increase in specific capacitance compared to non-functionalized fibers.Dye-adsorption test and the obtained Randles-Sevcik plot demonstrated that the oxygen plasma functionalized fibers exhibited increased surface area.It was further established by Brunauer-Emmett-Teller(BET)measurements that the surface area of the CNT fibers was increased from 168.22 m^2/g to 208.01 m^2/g after plasma functionalization.The pore size distribution of the fibers was also altered by this processing.The improved electrochemical data was attributed to enhanced wettability,increased surface area,and the presence of oxygen functional groups,which promoted the capacitance of the fibers.Fiber supercapacitors were fabricated from the oxygen plasma functionalized CNT fiber electrodes using different electrolyte systems.The devices with functionalized electrodes exhibited excellent cyclic stability(93.2% after 4000 cycles),flexibility,bendability,and good energy densities.At 0.5 m A/cm^2,the EMIMBF4 device revealed a specific capacitance,which is 27% and 65%greater than the specific capacitances of devices using EMIMTFSI and H2SO4 electrolytes,respectively.The practiced in this work plasma surface processing can be employed in other applications where fibers,yarns,ribbons,and sheets need to be chemically modified.

Mechanism of Functional Responses to Loading of Carbon Fiber Reinforced Cement-based Composites

Single fiber pull-out testing was conducted to study the origin of the functional responses to loading of carbon fiber reinforced cement-based composites. The variation of electrical resistance with the bonding force on the fiber-matrix interface was measured. Single fiber electromechanical testing was also conducted by measuring the electrical resistance under static tension. Comparison of the results shows that the resistance increasing during single fiber pull-out is mainly due to the changes at the interface. The conduction mechanism of the composite can be explained by the tunneling model. The interfacial stress causes the deformation of interfacial structure and the interfacial debonding, which have influences on the tunneling effect and result in the change of resistance.

Axonotmesis-evoked plantar vasodilatation as a novel assessment of C-fiber afferent function after sciatic nerve injury in rats

Quantitative assessment of the recovery of nerve function, especially sensory and autonomic nerve function, remains a challenge in the field of nerve regeneration research. We previously found that neural control of vasomotor activity could be potentially harnessed to evaluate nerve function. In the present study, five different models of left sciatic nerve injury in rats were established: nerve crush injury, nerve transection/ suturing, nerve defect/autografting, nerve defect/conduit repair, and nerve defect/non-regeneration. Laser Doppler perfusion imaging was used to analyze blood perfusion of the hind feet. The toe pinch test and walking track analysis were used to assess sensory and motor functions of the rat hind limb, respectively. Transmission electron microscopy was used to observe the density of unmyelinated axons in the injured sciatic nerve. Our results showed that axonotmesis-evoked vasodilatation in the foot 6 months after nerve injury/repair recovered to normal levels in the nerve crush injury group and partially in the other three repair groups;whereas the nerve defect/non-regeneration group exhibited no recovery in vasodilatation. Furthermore, the recovery index of axonotmesis-evoked vasodilatation was positively correlated with toe pinch reflex scores and the density of unmyelinated nerve fibers in the regenerated nerve. As C-fiber afferents are predominantly responsible for dilatation of the superficial vasculature in the glabrous skin in rats, the present findings indicate that axonotmesis-evoked vasodilatation can be used as a novel way to assess C-afferent function recovery after peripheral nerve injury. This study was approved by the Ethics Committee for Laboratory Animals of Nantong University of China (approval No. 20130410-006) on April 10, 2013.

Cloning GhSCFP Gene and Its Function in Cotton Fiber Development

As a major raw material for the textile industry and the most important fiber crop in the world,cotton is of great significance in Chinese economy.The development of cotton fiber can be divided

Effects of cereal fiber on bowel function: A systematic review of intervention trials

AIM: To comprehensively review and quantitatively summarize results from intervention studies that examined the effects of intact cereal dietary fiber on parameters of bowel function. METHODS: A systematic literature search was conducted using Pub Med and EMBASE. Supplementary literature searches included screening reference lists from relevant studies and reviews. Eligible outcomes were stool wet and dry weight, percentage water in stools, stool frequency and consistency, and total transit time. Weighted regression analyses generated mean change(± SD) in these measures per g/d of dietary fiber. RESULTS: Sixty-five intervention studies among generally healthy populations were identified. A quantitative examination of the effects of non-wheat sources of intact cereal dietary fibers was not possible due to an insufficient number of studies. Weighted regression analyses demonstrated that each extra g/d of wheat fiber increased total stool weight by 3.7 ± 0.09 g/d(P < 0.0001; 95%CI: 3.50-3.84), dry stool weight by 0.75 ± 0.03 g/d(P < 0.0001; 95%CI: 0.69-0.82), and stool frequency by 0.004 ± 0.002 times/d(P = 0.0346; 95%CI: 0.0003-0.0078). Transittime decreased by 0.78 ± 0.13 h per additional g/d(P < 0.0001; 95%CI: 0.53-1.04) of wheat fiber among those with an initial transit time greater than 48 h.CONCLUSION: Wheat dietary fiber, and predominately wheat bran dietary fiber, improves measures of bowel function.

Functional Investigation of a Cotton Fiber HOX Gene

Most of the plant homeodomain-containing proteins play important roles in regulating cell differentiation and organ development,and Arabidopsis GLABRA2(GL2),a member of the class IV homeodomain-Leucine zipper(HD-ZIP) proteins,is a trichome and non-root hair cell regulator.We

Multi-functional optical fiber sensor system based on a dense wavelength division multiplexer

We propose a novel and efficient multi-functional optical fiber sensor system based on a dense wavelength division multiplexer(DWDM).This system consists of an optical fiber temperature sensor, an optical fiber strain sensor, and a 48-channel DWDM.This system can monitor temperature and strain changes at the same time.The ranges of these two sensors are from-20℃ to 100℃ and from-1000 με to 2000 με, respectively.The sensitivities of the temperature sensor and strain sensor are 0.03572 nm/℃ and 0.03808 nm/N, respectively.With the aid of a broadband source and spectrometer,different kinds and ranges of parameters in the environment can be monitored by using suitable sensors.

Research on the behavior of fiber orientation probability distribution function in the planar flows

The equation of two-dimensional fiber direction vector was solved theoretically to give the fiber orientation distri- bution in simple shear flow, flow with two direction shears, extensional flow and arbitrary planar incompressible flow. The Fok- ker-Planck equation was solved numerically to validify the theoretical solutions. The stable orientation and orientation period of fiber were obtained. The results showed that the fiber orientation distribution is dependent on the relative not absolute magnitude of the matrix rate-of-strain of flow. The effect of fiber aspect ratio on the orientation distribution of fiber is insignificant in most conditions except the simple shear case. It was proved that the results for a planar flow could be generalized to the case of 3-D fiber direction vector.

Enhanced gas separation performance of mixed matrix hollow fiber membranes containing post-functionalized S-MIL-53

Mixed matrix hollow fiber membranes（MMHFMs）filled with metal-organic frameworks（MOFs）have great potential for energy-efficient gas separation processes,but the major hurdle is polymer/MOFs interfacial defects and membrane plasticization.Herein,lab-synthesized MIL-53 was post-functionalized by aminosilane grafting and subsequently incorporated into Ultem-1000 polymer matrix to fabricate high performance MMHFMs.SEM,DLS,XRD and TGA were performed to characterize silane-modified MIL-53（S-MIL-53）and prepared MMHFMs.Moreover,the effect of MOFs loading was systematically investigated first;then gas separation performance of MMHFMs for pure and mixed gas was evaluated under different pressures.MMHFMs containing post-functionalized S-MIL-53 achieved remarkable gas permeation properties which was better than model predictions.Compared to pure HFMs,CO2permeance of MMHFM loaded with 15%S-MIL-53 increased by 157%accompanying with 40%increase for CO2/N2selectivity,which outperformed the MMHFM filled with naked MIL-53.The pure and mixed gas permeation measurements with elevated feed pressure indicated that incorporation of S-MIL-53 also increased the resistance against CO2plasticization.This work reveals that post-modified MOFs embedded in MMHFMs facilitate the improvement of gas separation performance and suppression of membrane plasticization.

STUDY ON FUNCTIONAL GROUPS OF CARBON FIBER SURFACE

Rayon-based carbon fibers were anodically oxidized in the presence of a variety of electrolytes. The functional groups produced on carbon fiber surface were characterized by Fourier Transform Infrared Spectroscopy (FTIR). Both K Br pellet spectra and ATR difference spectra indicate that carboxyl and phenolic and carbonyl groups were produced. The acidic groups, carboxyl and phenol, were measured by potentiometrie titration with standard solutions of acid and alkali. The results show that the amount of acidic groups is related to the electrolyte used.

Fiber-Loop Ringdown Multi-Function Sensors

We demonstrate a fiber-loop ring down multi-function sensors system, which can be used to measure refractive index and curvature simultaneously. Good agreement has been found between theoretical analyses and experimental results. It has great potential for sensor applications.

基于分子动力学的芳纶/功能化碳纳米管复合材料体系热力学性能模拟

对位芳纶绝缘纸以其优异的介电性能、力学性能在电气绝缘领域得到广泛应用。为探究不同功能化碳纳米管与对位芳纶共掺的复合材料热力学性能,该文通过分子动力学模拟方法建立了对位芳纶分子体系模型、未功能化碳纳米管以及分别接枝羟基、羧基和氨基官能团的芳纶/功能化碳纳米管复合体系模型。在Materials Studio和LAMMPS中计算了复合材料热导率、玻璃化转变温度、力学性能、结构参数及相对介电常数。结果表明,芳纶复合材料体系各项性能均有不同幅度提升。芳纶/羧基化碳纳米管(PPTA/CNT—COOH)的热导率较掺杂前提升了75.4%,玻璃化转变温度提升了43.29 K。芳纶/羟基化碳纳米管(PPTA/CNT—OH)和芳纶/氨基化碳纳米管(PPTA/CNT—NH2)的热导率依次提升70.2%和63.2%。在力学性能上,复合材料比掺杂前的弹性模量平均增强30%以上,剪切模量增强15%以上。通过计算体系结构参数,从均方位移、自由体积占比、氢键数量与结合强度等分子层面阐释了材料性能增强的内在机理,最终发现PPTA/CNT—COOH在热力学性能上较其他掺杂体系提升最为明显,且碳纳米管的掺入未对材料介电常数引起较大改变,所得结果可为对位芳纶复合绝缘材料的掺杂设计、性能调控提供理论支持。

菠萝果渣中不溶性膳食纤维提取工艺优化及其功能特性研究

以菠萝果渣为原料,采用碱处理法提取菠萝不溶性膳食纤维(PIDF)。以PIDF得率为指标,在单因素试验基础上通过响应面法优化提取工艺,并探究PIDF的结构和功能特性。结果表明:最优工艺参数为液料比26∶1(mL/g)、NaOH体积分数6%、提取温度40℃、提取时间75 min,在此条件下PIDF得率为48.81%;PIDF具有疏松的孔洞结构,其持水性、持油性和膨胀性分别为(5.16±0.21)g/g、(3.86±0.11)g/g和(5.49±0.09)mL/g,表明PIDF具有较好的结构及功能特性。

先驱体转化SiBCN陶瓷的制备、性能与应用

先驱体转化法是制备高性能陶瓷材料的重要方法,尤其在连续纤维及其复合材料(FRCMC)的制备、元素组成与微结构调控等方面具有显著优势。先驱体转化SiBCN陶瓷具有多元素含量可调、化学键合结构可控的特点,构建了不同结构特征和特殊性能的陶瓷材料。近几年,先驱体转化SiBCN陶瓷发展呈现出新的特点,结构功能一体化设计与制备技术受到了国内外的广泛关注。本文主要梳理了2016年至今先驱体转化SiBCN陶瓷的国内外研究进展,首先简要介绍先驱体转化SiBCN陶瓷的主要特点,然后以先驱体转化陶瓷产物的典型特点为分类依据,分别从SiBCN陶瓷先驱体及其陶瓷产物、连续SiBCN陶瓷纤维、SiBCN基复合材料和功能化SiBCN陶瓷4个方面综述了主要研究进展,提出了未来发展趋势和重点任务,期望为SiBCN陶瓷研制与应用研究提供参考,促进我国先进陶瓷材料的发展进步。

DSI Studio软件结合DTI在脑功能区肿瘤术后运动功能评估中的应用

目的研究DSI Studio结合弥散张量成像(diffusion tensor imaging,DTI)应用于脑功能区肿瘤患者术后运动功能预后评估的价值。方法选择2018年1月~2022年8月于郑州大学第二附属医院行手术治疗且病理确诊的41例脑功能区肿瘤患者纳入研究。所有患者均完成3.0T磁共振成像常规序列及DTI检查,分别测量患侧及健侧内囊后肢皮质脊髓束(corticospinal tract,CST)投射区DTI参数,分析与患者MRC肌力评分及CST分级的相关性。结果患侧FA值明显低于健侧FA值(P<0.001),患侧ADC值明显高于健侧ADC值(P<0.001);患侧FA值、偏侧rFA值与CST分级呈负相关(P<0.01);ADC值、rADC值与CST分级呈正相关性(P<0.01);患侧FA值、偏侧rFA值与手术前后肌力评分程度呈正相关(P<0.01);ADC值、rADC值与CST分级呈负相关性(P<0.01);患者术前CST分级与对侧肌力呈负相关;患侧FA值,rFA值、ADC值、rADC值和CST分级受试者工作特征曲线下的面积分别是0.820(P<0.01)、0.796(P<0.01)、0.698(P<0.05)、0.638(P>0.05)、0.708(P<0.05)。结论DTI参数与肌力评分及CST分级对脑功能区肿瘤患者的术后运动功能预后的评估具有一定价值。

聚酯纤维的负离子释放功能化改性及表征

以聚酯纤维为研究对象,对其进行了表面电气石负载改性整理,以增加聚酯纤维的远红外辐射率和负离子释放等功能。采用单因素分析法分别探讨了时间、硅烷偶联剂用量及温度对聚酯纤维改性整理效果的影响。结果表明:聚酯纤维最佳改性整理工艺条件为1g聚酯短纤维浸泡在含有电气石的硅烷偶联剂酸性溶液中,于50℃烘箱中静置反应6h时,电气石负载率可达1.71%。对所得改性整理纤维进行表征及性能测试,电气石粉体成功引入到了聚酯纤维表面,其远红外辐射率达0.7,负离子释放量为950ions/cm^(3)。

驱蚊莱赛尔纤维的研制

以香茅油和辛癸酸甘油酯为芯材,异佛尔酮二异氰酸酯(IPDI)为壁材,乙二醇为致孔剂,通过界面聚合法制备香茅醛纳米胶囊。制备的香茅醛纳米胶囊平均粒径约为220.5 nm,驱蚊率达到90%以上,对大肠埃希菌和金黄葡萄球菌的抑菌率均达到99.99%。通过原液共混的湿法纺丝工艺制备了驱蚊功能莱赛尔纤维,驱蚊效果达到B级,对金黄葡萄球菌有良好的抑制作用。

功能性蚕丝纤维研究新进展

蚕丝纤维因其优异的穿着舒适性,出色的力学性能、生物相容性、生物可降解性及其对人体无毒无炎症的特点,逐渐在多学科交叉融合应用方面表现出巨大的潜力,但同时也因其存在光致发黄、老化、细菌引起的变形甚至降解、不能机洗、难打理等缺陷,急需实现技术创新,开发具有更广阔应用场景的高性能/多功能蚕丝纤维。本文系统总结了高性能/多功能蚕丝纤维制备新技术,包括基因编辑法、添食法、物理改性法、化学改性法,并指出其所存在的问题和面临的挑战。在此基础上,进一步探讨了高性能/多功能蚕丝纤维的未来发展方向,以期为我国桑蚕产业的转型升级提供理论支撑。