Sterilization of Cotton Fabrics Using Plasma Treatment

Microbial contamination induces surface deformations and strength degradation of cotton fabrics by invading deeply into the fibers. In this study, the sterilization effects of low pressure plasmas on bacteria-inoculated cotton fabrics were investigated. Oxygen plasma treatment completely sterilized the cotton fabrics inoculated with various concentrations of staphylococcus aureus. Also, the influence of plasma treatment on physical properties of fabrics was examined. It was found that the plasma treatment did not affect ultimate tensile strength and surface morphology of the fabrics because it took advantage of relatively low plasma temperature.

Water Holding Characteristics of Coarse Woody Debris of Abies fabri Forest on the East Slope of Tibet Sygera Mountain

Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD in subalpine forest of southeast Tibet,CWD reserve of primitive A. fabri forest in Sygera Mountain was investigated by sample plot method,and water absorption and storage capacity of CWD was studied by using soaking method. The results showed that decay grade was positively related to water storage potential,that is to say,the higher the decay grade,the larger the water storage potential. Saturated water holding capacity,saturated water holding rate,effective water holding capacity and effective water holding rate of A. fabri CWD all rose with decay grade increased,and the order was Ⅴ>Ⅳ>Ⅲ>Ⅱ>Ⅰ. CWD reserve was 51.555 t/hm^2,and the maximum water storage capacity was 71.601 t/hm^2,while effective water storage capacity was 60.861 t/hm2,which was equivalent to 6.086 mm of rainfall.

Streamwater chemistry and flow dynamics along vegetation-soil gradient in a subalpine Abies fabri forest watershed, China

Streamwater chemistry and spatial flow dynamics from a subalpine Abies fabri forest in an experimental watershed located in the east slope of Gongga Mountain were analyzed to gain insights into the gradient effect of primary community succession on the stream biogeochemical process. Results showed that high sand content(exceeding 80%) and porosity in the soil(exceeding 20% in A horizon and 35% in B horizon), as well as a thick humus layer on the soil surface, made the water exchange quickly in the Huangbengliu(HBL) watershed. Consequently, no surface runoff was observed, and the stream discharge changed rapidly with the daily precipitation. The flow trends of base ions in the stream water were influenced by the Abies fabri succession gradient. Ca 2+ , HCO - 3 and SO 2- 4 were the dominant anions in the streamwater in this region. A significant difference of Ca 2+ , HCO - 3 and SO 2- 4 concentration exported between the succession stages in the watershed can be found. But they had the similar temporal change in the stream flow. Ca 2+ , HCO - 3 and SO 2- 4 showed significantly negative correlations with the daily precipitation and the stream discharge. \;Concentrations of Cl -, Na +, K +, and Mg 2+ were low in all streamwaters monitored and we observed no differences along the Abies fabri succession gradient. Low ratios of Na:(Na+Ca) (range from 0.1 to 0.2) implied cations were from bedrock weathering(internal source process in the soil system) in this region. But, a variance analysis showed there were almost no differences between rainwater and streamwaters for Mg 2+ , Na +, K +, and Cl - concentrations. This indicated that they might be come from rainfall inputs(external source). The highly mobile capacity, rapid water exchange between precipitation and discharge, and long-term export lead to this observed pattern were suggested.

APPLICATION OF COMPOSITE FIBRE TO HIGH ELASTIC KNITTED FABRIC

The knitting condition and technology for PBT/PET composite fibre on loop wheel machine as well as the effect of knitted fabric structure and stitch parameter are discussed in this paper. The properties of high elastic plain knitted fabrics are also discussed.

Effect of Fallen Wood of Abies fabri Forest on Seedling Recruitment in Tibet Sygera Mountain

The impact on seedling recruitment by fallen wood of A. fabri forest in Tibet Sygera Mountain was studied. The results showed that regenerated seedlings on fallen wood roughly showed normal distribution,and there were more regenerated seedlings in the middle of fallen wood,while regenerated seedlings were fewer at two ends. Fallen wood at level IV had the most regenerated seedlings,followed by level-III fallen wood,and regenerated seedlings were the fewest on fallen wood at level V. The number and species of regenerated seedling on and around fallen wood on the west slope were more than that on the east slope. With the improvement of decomposition level,regenerated seedling per unit area firstly increased and then decreased,but the number of regenerated seedling on and around fallen wood was far more than that in woodland.

Medium and Long Term Decomposition Process of Litter in Abies Fabri Forest

Litter is an important part of forest ecosystem and its decomposition process is the key link of nutrient cycling in forest ecosystem.Accurate determination of litter decomposition dynamics is very important to study the pattern and process of forest ecosystem.This paper selected The Gongga Mountain Alpine Ecosystem Observation and Experiment Station at an altitude of 3000 m to observe and determine litter decomposition process of the Abies fabri forest over a long period of time.The results showed that:①The decomposition rate of litter was broadleaf>needles>dead branches,and the time required to decompose half of broadleaf,needles and dead branches was 6.8 years,10.5 years and 14.5 years respectively;the time of decompose 95%of them was 29.3 years,45.6 years and 63.1 years,respectively;②Regardless of broadleaf,needles or dead branches,the organic carbon content of them decreased with time,while the decomposition rate of organic carbon increased with time;By using the exponential decay model the decomposition coefficient of litter organic carbon calculated was broadleaf>needle>dead branches;③The organic carbon released by the annual decomposition of broadleaf,needles and dead branches in Abies fabri forest was 52.18,4.32 and 0.67 kg/hm^2,respectively.The total amount of organic carbon released by various litter was 61.13 kg/hm^2 per year,accounting for 6.58%of the total organic carbon of litter.

Fabrication and sensing characteristics of intrinsic Fabry–Perot interferometers in fiber tapers

This Letter presents intrinsic Fabry–Perot interferometers in the fiber tapers fabricated by the femtosecond laser micromachining technique. The sensing of temperatures as high as 1000°C based on the fiber device is characterized, with a sensitivity of 15.28 pm∕°C. A nearly linear refractive index sensing is also obtained by using the fringe visibility to characterize, with a sensitivity of 73.05 dB∕RIU. These intrinsic Fabry–Perot interferometers in fiber tapers may be useful in applications of high-temperature and linear refractive index sensing.

RBCC引射模态主火箭射流对Fabri壅塞影响研究

引射模态发动机性能偏低限制了RBCC发动机的应用,为了提高引射抽吸能力和发动机性能,针对地面零速起飞状态,采用包含飞行器前后体的全流道一体化数值模拟方法,研究了主次流总压比对Fabri壅塞和引射抽吸能力的影响。结果表明:当主次流总压比低于25,提高主次流总压比可提高主火箭射流马赫数,引射空气流量可提高56. 4%;当主次流总压比高于33,提高主次流总压比增大了射流欠膨胀程度,挤压引射空气流道,导致引射抽吸能力降低,引射比可降低53. 1%;主次流总压比高于134可产生Fabri壅塞,火箭射流将引射空气流道堵塞,引射空气流量降为零。

Jrendy Fabries

Designer: LI YING Gold Prize The prize-winning women’s line featured golden patterns on black silks and brocades. Shown here is a tropical match of a sleeve less blouse with a long narrow skirt.

Temperature variability since A.D.1837 inferred from tree-ring maximum density of Abies fabri on Gongga Mountain,China

Two tree-ring MXD (maximum latewood density) chronologies of Abies fabri were developed from the eastern slopes of Gongga Mountain, and a regional chronology (RC) was established based on the two MXD chronologies. There were significant positive correlations between the three MXD chronologies and August-September temperature, and the RC had the highest correlation (r=0.733, n=48, P<0.001) with mean August-September temperature. Based on growth-climate analyses, we reconstructed mean August-September temperature during the past 171 years for the study area. The reconstruction explained 53.5% of the instrumental temperature variance during the period 1960-2007 (F=52.8, R2adj =52.4%). In the past 171 years, there were 22 very warm years and 23 very cold years, four cold periods (1837-1842, 1884-1891, 1899-1905 and 1984-1989) and three warm periods (1966-1973, 1916-1924 and 1876-1881). Our reconstruction was validated by other tree ring-based temperature reconstructions from the surrounding area and documented climate disaster events.

超声心动图监测45例法布雷病患者心脏早期受累的特征分析

【目的】分析45例临床确诊的法布雷病(AFD)患者的临床特征,同时应用超声心动图二维斑点追踪技术(2D-STE)评估法布雷病患者应变图像,以期探索法布雷患者心脏早期受累在超声心动图(UCG)上的表现。【方法】本研究为观察性研究。共纳入确诊为AFD的患者45例,根据UCG测量左室壁有无肥厚,分为左室壁肥厚组(17例,室间隔或左室后壁厚度≥12 mm)和无左室壁肥厚组(28例)。收集患者基线资料,并对所有患者进行常规UCG检查及二维斑点追踪超声心动图分析。应用TomTec工作站分析超声心动图图像,比较两组的临床基线资料、UCG常规参数及心肌应变特征。【结果】本研究共纳入45例AFD患者,年龄(32.33±16.11)岁,其中男性27例(60.00%)。左室壁肥厚组17例(37.78%),无左室壁肥厚组28例(62.22%)。45例患者的左室射血分数(LVEF)均正常(>50%)。与无左室壁肥厚组相比,左室壁肥厚组患者的靶器官受累比例明显增加。与无左室壁肥厚组相比,左室壁肥厚组患者的E/A,平均E/E'明显升高(P<0.05);左室壁肥厚组的整体、心肌层、心内膜以及各节段的纵向应变(LS),周向应变(CS)及径向应变(RS)的差异均无统计学意义(P值均>0.05)。AFD患者心肌层的整体和各节段LS、CS的绝对值均低于心内膜的对应值(P值均<0.05)。AFD患者的中间段的LS、RS绝对值较基底段和心尖段高(P值均<0.05)。【结论】早期收缩功能障碍与左室壁厚度无明显关系。2D-STE心肌应变可以早期监测AFD室壁肌层受累较心内膜严重,而中间段受累较心尖段和基底段轻。

光纤激光传感器结构发展综述

光纤激光传感技术是光纤传感技术中的重要组成部分。首先介绍了光纤激光传感技术的原理,然后分析了基于单一结构和双结构的10种光纤激光传感器的原理和特性,并对比了2种传感结构的应用情况和温度灵敏度,最后从解调方式、多参量测量以及提升检测范围等3个方面对光纤激光传感技术进行了总结和展望。

塞曼效应实验中固体F-P标准具的应用与教学

塞曼效应实验是高校近代物理实验课程中的重要内容,学校大多采用空气隙法布里-珀罗(F-P)标准具作为分光元件,本文介绍了固体F-P标准具在塞曼效应实验中的教学与应用、干涉分光的基本原理与特征以及干涉图样的分布规律.结合相关现象与分析,给出了塞曼效应实验的光路调节、谱线观测等过程.该实验教学过程可以加深学生对F-P标准具原理的理解.

基于FBG和F-P的温度和折射率双参量传感器

提出了一种由单模布拉格光栅和多模Fabry-Perot腔级联而成的温度和折射率双参量传感器。对多模光纤的末端采用氢氟酸进行腐蚀,在腐蚀后形成的凹陷处填充紫外胶,从而形成Fabry-Perot腔。Fabry-Perot腔和单模光纤布拉格光栅级联后,构成最终的传感结构。Fabry-Perot腔对温度和折射率敏感,而光纤布拉格光栅对温度敏感而对折射率不敏感。利用上述特性,采用灵敏度矩阵法可实现对温度和折射率的同时测量。实验结果表明,传感器的温度和折射率灵敏度分别为-0.4832nm/℃和-508.64pm/RIU。该传感器具有制作工艺简单、结构紧凑、成本低、灵敏度高的优点,有很好的应用前景。

基于QEPAS技术的痕量气体高灵敏度检测系统研究

搭建了一种用于乙炔痕量气体高灵敏度探测的全光式石英音叉增强型光声光谱系统。为了提高系统探测灵敏度,采用光功率放大技术提高激励光源功率,采用直角棱镜使激光束穿过两个共振管,采用光纤珐珀传感技术测量音叉叉股面外单向振动代替面内对称振动;同时利用自稳定技术提高系统的稳定性。采用有限元分析方法对传统商用石英音叉的振动进行了模拟和分析。在对激光调制深度、微共振管结构尺寸和激光输出功率等参数优化基础上,得到了2.9 ppb的系统检测极限,归一化等效噪声系数为2.4×10^(-9)cm^(-1)·W·Hz^(-1/2);二次谐波信号幅值与C_(2)H_(2)浓度呈现良好的线性关系,其线性相关系数达到0.999。最后经过1小时的连续实验验证了通过自稳定技术可以有效提高系统的稳定性。

单晶氧化镁高温光纤传感技术应用方法研究

提出采用氧化镁制作方形法珀腔的压力敏感单元,利用微机电系统技术实现其热应力匹配一体化、批量化加工,集成光纤实现高温压力检测。对氧化镁压力敏感单元进行全温区和动态仿真以及高温压力测试平台实验验证,结果表明采用氧化镁作为敏感材料的传感器在室温、15 MPa的压力范围内腔长呈近似线性变化,非线性误差为0.75%FS,且在室温~800℃范围内均能稳定工作。该材料在传感领域的应用为航空发动机内外部高温狭小空间或受关注位置的原位压力测试提供了一种新的思路。

医学领域微小力值传感测量技术的研究进展

针对医学领域科学研究、临床疾病的诊断与手术等对微小力值测量的迫切需求,对医学领域微小力值传感测量研究方向、进展及其应用情况进行了综述。首先,从医学领域微小力值测量的需求出发,分析了测量的特点与要求,介绍了电容式、电阻应变式和压电式等传统电学式微小力传感测量技术的国内外研究成果,分析了电学式测量方法的技术特点与不足;然后,系统地介绍了目前微小力值测量中广泛采用的光学式一维及多维传感测量技术,对基于光学相干层析成像(OCT)、法布里-珀罗干涉仪(FPI)、光纤布拉格光栅(FBG)、强度调制型光纤传感等的光学式微小力值传感测量原理、方法、技术特点进行了分析;最后,对国内外最新研究成果、发展水平及在医学领域的应用情况进行了分类整理和归纳评述,对不同测量原理与方法的技术特性、优缺点、适用测量范围与应用场景进行了系统性的对比分析。研究结果表明:当前医学领域微小力值传感测量存在的主要问题包括微小力值无法溯源、高精度宽量程测量需求无法满足,并且在多种参数的并行监测和同步测量、复合传感测量、集成光路式传感技术等方面有待进一步研究和探索。该综述可为后续医学领域微小力值传感测量研究方向与思路提供参考。

基于等离激元法布里-珀罗腔折射率测量的实验设计

利用自下而上的纳米加工工艺,制备了一种由银纳米线对和金膜构成的等离激元法布里珀罗(F-P)腔。暗场散射光谱和数值模拟表明,金膜表面传输的表面等离激元经银纳米线对的多次反射下,会在腔内形成驻波现象,并在散射光谱中呈现出多光束干涉调制的光谱线型。利用这一原理设计一个折射率测量实验,通过测量不同浓度甘油溶液的折射率,得到了F-P腔共振波长随溶液折射率增大的线性红移规律。进而通过调谐F-P腔的长度,得到该F-P腔最高的探测灵敏度为555 nm/RIU。

基于光纤传感的带式输送机张力检测技术

针对目前带式输送机张力检测存在易损坏及准确性和可靠性差的问题,提出了一种基于光纤传感的带式输送机的张力检测方法。将法珀腔传感头置于带式输送机张紧装置的液压回路中,液压回路的压力使法珀腔传感头的硅膜片产生形变,引起法珀腔传感头反射光变化;光电解调器光路接收法珀腔传感头的反射光后,经光路解调后得到反射光谱,通过光电解调器电路的光电转换、处理、分析后,得到反射光光谱的自由光谱范围,再根据油缸内部面积计算出带式输送机张力,实现了带式输送机张力检测。根据双干涉效应原理设计了法珀腔传感头,采用Jetson Nano嵌入式系统开发板设计了光电解调器硬件,采用Python语言设计了光电解调器软件,并进行了实验研究。实验结果表明:该方法能够实现带式输送机张力检测,压力测量范围为0~25 MPa,灵敏度为0.148 nm/MPa,测量精度为0.1%,不易损坏,抗干扰性好,准确性和可靠性高。

基于混合干涉结构的光纤温盐深传感器设计

提出了一种基于法布里-珀罗干涉仪(FPI)级联马赫-曾德干涉仪(MZI)的混合干涉型光纤温盐深传感器。利用两段单模光纤与二氧化硅(SiO_(2))毛细管制作了28μm的FPI微腔。FPI导出单模光纤依次与大芯径多模光纤、细芯光纤对准熔接,并在细芯光纤后错位熔接单模光纤,FPI导出单模-多模-细芯-错位熔接单模构成MZI。对传感器的温度、折射率及深度响应特性进行了理论分析和实验研究,通过监测反射谱和透射谱,选取不同的特征波长。实验结果表明:FPI对折射率变化不敏感,温度和深度灵敏度为0.578 nm/℃和1.297 2 nm/cm, MZI两个特征波谷对温度灵敏度分别为0.052 4 nm/℃和0.055 2 nm/℃,折射率灵敏度分别为-35.157 nm/RIU和-27.581 nm/RIU,对深度变化不敏感。该传感器具有制作简单、成本低廉等优点。