非偏振光法测定浆料纤维粗度

主要探讨利用非偏振光原理进行造纸浆料纤维粗度测定的方法。本研究确定的测定浆料纤维粗度的方法中以μg/m为单位,非偏振光法采用的是直接成像技术,能够真实地反映纤维的形态。     

偏振光显微镜定性分析PET和PTT纤维

传统的纤维成分定性分析测试方法如FZ/T 01057.2-4-2007虽然可以区分芳香族聚酯和其他纤维材料,但无法进一步鉴别PET和PTT.正是由于大多数纤维都具有各向异性的特性,其在偏振光下会发生双折射的现象,产生各种纤维独有干涉条纹,可以利用偏振光显微镜(PLM)对纤维进行区分.该检验方法操作简单、快捷,操作过程中不产生任何污染,能有效地区分PET和PTT纤维,值得推广应用.     

偏振光显微镜鉴别纤维、印染、矿石材料的方法

关于偏振光检验纤维成熟度和双折射率的方法，作者已在《偏振光检验纤维成熟度和双折射率》〔１〕一书中作了较为详细的介绍。现根据美国康乃尔大学（CornellUniversity）的教课书《偏振光显微镜方法》〔２〕，介绍书中一张彩色图的应用。该图可依据某一材料试样的厚度，以及试样在偏振光显微镜下观察的干涉色，在图上查得该试样的双折射率和材料的名称。如左页彩图所示：顶端横坐标为试样厚度。左侧纵坐标为试样在偏振光显微镜下观察的干涉色，分为第一级干涉色、第二级干涉色和第三级干涉色。第一级干涉色的光程差在０～６００nm，干涉色…     

二维偏振光的干涉

针对一维偏振光的干涉问题,从更为广泛的二维偏振光干涉模型入手进行分析,推 导出了近轴条件下二维偏振光干涉场强的分布表达式.分析表明：干涉条纹不仅与三光束空 间位置有关,而且与光场的偏振方向有关.对一维偏振光干涉,只要两偏振片的偏振化方向 之间的夹角＜45°就可看到清晰的干涉条纹.     

纤维素类纤维定性鉴别方法

显微镜法是鉴别各种纤维素纤维的简便、快速而有效的方法。观察未染色纤维素类纤维的形态特征(纵横向截面)，可区分大多数的纤维素类纤维；利用纤维的皮芯结构对染色和褪色的“各向异性差异”，可区分Lyoeell、Modal、粘胶等类似结构的纤维。     

减少浮选法脱墨过程中的纤维流失

减少浮选脱墨中的纤维流失对节约资源和降低使用二次纤维造纸的成本来说都很重要。该文研究了这个问题的2个方面:在浆渣流中的纤维浓度和气泡(或是湿流)的去除比率。浮选试验使用尼龙和木纤维在圆筒状浮选槽中进行。实验表明:提高气泡稳定性将使浮选过程中排出的纤维浓度减少;然而,却提高了湿部废料的排除率;因此,总的纤维损失随气泡稳定性的提高而增加。实验同时表明,通过减少气泡发生器的使用和气泡的排除是减少浮选脱墨中纤维流失的有效途径。     

偏振光反射在涂层结构研究中的应用

偏振光反射计是一种用于获取纸张涂层结构、粗糙度和光学性能等方面信息的一种有用的非接触式的测试仪器。这种反射计可测试包括折射率、微观粗糙度(表面粗糙度比光的波长小)、宏观粗糙度(表面粗糙度比光的波长大)及各种光泽度和反射率等基本数据。该文应用偏振光反射计和其他辅助技术分析了取自中试车间和工厂的涂布纸,对有效折射率与通常习惯测定的涂层孔隙率的关系进行了研究;研究发现,折射率与由水银渗透孔隙测定仪测定的孔隙直径有很好的关联性;同时探讨了关于涂层结构的研究方法,研究表明,由反射计测得的数据能够提供关于涂层结构有价值的观点,允许涂层颜料和原纸粗糙度有所差别,并帮助量化纸页光泽度的物理起源。     

偏振光显微镜在纤维检测中的应用

一、化学纤维的双折射率与光程差 化学纤维双折射率的测定方法很多,如浸没法、光程差法、折射仪法、象差显微镜法等,应用最普遍的是浸没法与光程差法,此两方法均可在偏振光显微镜上实施。 (1)利用浸没法可以测定形状不规则截面纤维,反映的是纤维表面双折射率。本法缺点为测试时间长,不易选择适宜折射率的浸油,如涤纶n_(11)=1.725,n_⊥=1.527 ⊿n=0.198,测定涤纶⊿n时需要选择涤纶n_(11)与n_⊥附近范围内的浸油,如果浸油本身的n_(11),n_⊥与涤纶n_(11) n_⊥相差太远就无法测定。     

神经妥乐平联合红外偏振光治疗带状疱疹后遗痛疗效观察

目的探讨神经妥乐平联合红外偏振光治疗带状疱疹后遗神经痛(postherpetic neuralgia,PHN)的疗效。方法将80例PHN患者随机分为治疗组和对照组,治疗组40例采用0.9%氯化钠100 mL+神经妥乐平7.2 U,一日1次静脉滴注,疗程15 d,红外偏振光照射治疗,一日2次,每次15 min,共治疗30次;对照组:红外偏振光照射治疗,一日2次,每次15min,共治疗30次。15 d后比较两组患者治疗前后疼痛缓解情况,疼痛评价采用视觉模拟评分法(visual analogue scale,VAS)。结果两组治疗后VAS评分均较治疗前下降,治疗组下降程度大于对照组。治疗组治愈15例,显效18例,有效率82.5%,治愈率37.5%;对照组治愈7例,显效15例,有效率55.0%,治愈率17.5%,两组患者均未出现明显不良反应。治疗组有效率明显高于对照组(P0.01),治愈率也高于对照组(P0.05)。结论神经妥乐平联合红外偏振光治疗是一种安全有效的治疗带状疱疹后遗神经痛的方法。     

市售仿水貂毛皮的鉴别方法

水貂毛皮具有很高的经济价值,市售毛皮产品中经常出现以黄狼(黄鼠狼)、河狸(海狸)、麝鼠(青根貂)毛皮来仿冒水貂毛皮的现象,令普通消费者甚至专业人士很难通过感官区分。本文借助现代分析仪器,利用扫描电镜法(SEM)观察水貂、黄狼、河狸、麝鼠毛皮绒毛的鳞片层特征;利用纤维细度仪法(FFI)观察这四种动物毛皮绒毛的内部超微结构。结果表明:通过扫描电镜分析可以有效区分水貂与河狸、水貂与麝鼠的毛皮,但由于黄狼和水貂均属于食肉目鼬科,其绒毛的鳞片形态基本一致,无法被有效区分;通过纤维细度仪分析可以有效区分水貂与黄狼、水貂与河狸的毛皮,但水貂和麝鼠绒毛有部分形态一致,也无法被有效区分。因此,在实际鉴别过程中,使用两种方法互为佐证,可作为水貂毛皮材质鉴定依据。     

Quantification of gaping, bruising, and blood spots in salmon fillets using image analysis

Abstract: An image analysis method was developed to quantify the gaping, bruising, and blood spots of red salmon (Oncorhynchus nerka) fillets. Images of 15 fillets with various levels of gaping were taken either with a dSLR camera, or with a video camera. Also, the same fillets were recorded using the same camera both under regular illumination, and under polarized illumination. In either case, light at an angle was used to highlight the gapes in the flesh. An image analysis method was developed that can adaptively apply an L*_threshold value to the image depending on the average color of the fillet, and quantify the resulting percent of the fillet area that has an L* value less than or equal to L*_threshold. Polarized lighting changed the color by eliminating artifacts resulting from reflections. It is recommended to use polarized light for this purpose. Both cameras could be used adequately to quantify defects. The proper setting of the L*_threshold value depended on the camera and on the polarized light. No correlation could be found between the average L* value of the fillets and the L*_threshold value. It was possible to quantify the gaping, bruising, and blood spots on the salmon fillets using this method, which can be the first step toward the automation of this operation. Practical Application: Gaping, bruising, and blood spots can be recognized and quantified by analyzing images of salmon fillets. Polarized light is recommended to eliminate color artifacts caused by reflected light. This can be used to automate the detection of these defects.     

Applying ultrasound-assisted processing to obtain cellulose fibres from rice straw to be used as reinforcing agents

Rice straw (RS) is one of the most globally abundant agro-industrial residues. For its valorisation, a green combined ultrasound-reflux heating method was applied to obtain cellulose fibres (CF) from RS. The new method produced CF with a higher yield (37%) than the alkaline process (29%), more hydrophilic, and with a lower tendency to aggregate. Despite the slightly different degree of purification detected by the chemical and FTIR analysis, both fibres exhibited similar crystallinity, thermal behaviour, morphogeometric characteristics, and aspect ratio distributions (20–60). Both CF showed similar reinforcing capabilities in methylcellulose/gum Arabic films, enhancing the film stretchability and resistance to break by about 33% and 20%. Non-noticeable changes in water vapour permeability and the light internal transmission were observed, indicating good compatibility CF-polymer matrix. Therefore, using the ultrasound-heating method to obtain CF is an eco-friendlier process than the alkaline treatment, supplying suitable fibres as industrial reinforcing agents.Industrial relevanceUltrasound, an emerging technology in food processing, combined with reflux heating, can be a green alternative for obtaining cellulose microfibres for industrial applications. The new combined method was faster than the alkaline process (1.5 h vs. 6 h) and was more environmentally-friendly since it does not require a strong alkaline solution. Besides, both cellulose microfibres exhibited similar performances when incorporated into a polymer matrix. These results boost knowledge in the food packaging field, as well as the valorisation of agro-industrial wastes for industrial applications.     

Color Change of the Snapper (Pagrus auratus) and Gurnard (Chelidonichthys kumu) Skin and Eyes during Storage: Effect of Light Polarization and Contact with Ice

Ten gurnard and 10 snapper were stored on ice. One side always contacted the ice; the other side was always exposed to air. At different intervals for up to 12 d, the fish were placed in a light box, and the images of both sides were taken using polarized and nonpolarized illumination. Image analysis resulted in average L*, a*, and b* values of skin, and average L* values of the eyes. The skin L* value of gurnard changed significantly over time while that of snapper was substantially constant. The a* and b* values of both fish decreased over time. The L* values of eyes were significantly lower for polarized images, and significantly lower for the side of fish exposed to air only. This may be a concern in quality evaluation methods such as QIM. The difference of colors between the polarized and nonpolarized images was calculated to quantify the reflection off the surface of fish. For accurate measurement of surface color and eye color, use of polarized light is recommended.     

丙烯酸树脂复鞣剂在革内渗透情况的研究

复鞣剂在革内的渗透分布情况与成革质量关系很大 ,长期以来只能靠眼看手摸来评价复鞣效果。利用IHA染色法在媒染剂 A作用下使透入到革内的丙烯酸复鞣剂上色 ,而其余部分不上色 ,由此判断丙烯酸树脂复鞣剂的渗透情况。研究了羊皮使用不同品种的丙烯酸树脂复鞣剂 (ART- II,DM)复鞣后 ,复鞣剂在不同部位随复鞣时间变化的渗透情况。研究结果表明 :由于肉面的胶原纤维编织较疏松 ,而粒面层胶原纤维编织紧密 ,故丙烯酸树脂首先从肉面开始透入 ,且从肉面透入革内的深度大于从粒面透入的深度 ,而不是像有人认为的复鞣剂主要是渗透并填充到乳头层和网状层 2层交界处。同时利用扫描电镜对复鞣后的革样进行了电镜观察 ,结果与光镜一致     

Studies of factors affecting light scattering by individual human hair fibres

An automated goniophotometer has been built to investigate the scattering of light by different types of singly mounted human hair fibres using white light and laser illumination. The effects that varying hair colour and treatment (gold coating, ultraviolet irradiation and dyeing) have on the specular reflectance and on the half-peak-height width (ω) have been studied. The polarization of light has been used to discriminate between light reflected from the front surface and light scattered internally by the hair. It has been found that the analysis of results from individual hair fibres has been useful in understanding the light scattering mechanisms which occur in human hair.     

Chemical characterisation of vegetable and arable crop residue materials: a comparison of methods

Although it is widely recognised that chemical composition controls the patterns of decomposition and N mineralisation of crop residue materials, there has been little agreement as to the nature of the most important chemical fractions. We investigated whether this could be attributed to differences in methodologies employed for chemical characterisation of the lignin and cellulose fractions of plant materials. The cellulose and lignin contents of cauliflower, potato, red beet, Brussels sprouts and wheat crop residues were analysed by a number of contrasting methods. These were forage fibre and forest products analyses, which utilise KMnO₄ and H₂SO₄ respectively to separate the two fractions, and a third method, which employs NaClO₂. For all the materials, the forage fibre method gave substantially lower amounts of both lignin and cellulose than the other methods. There was correlation between lignin determined by the different methods. Low recovery of lignin by the forage fibre method was found to arise partly from incomplete delignification by KMnO₄. The cellulose contents given by the different methods were highly correlated. However, it was apparent that the forage fibre method underestimated cellulose, since only alpha-cellulose was measured. The characteristics of crop residues grown on two sites with different N fertiliser treatments were determined by forest products analysis. The materials were shown to span a range with respect to both lignin (12–26%) and cellulose (17–71%) contents. The chemical characteristics of the materials were not significantly affected by the amount of nitrogen used to produce the crop. © 1999 Society of Chemical Industry     

多孔性纳米纤维素膜的制备及应用综述

首先简述了纳米纤维素膜的孔结构及其表征方法;然后以制备工艺为主线,详细论述了纳米纤维素制备、悬浮液配制,纳米纤维素膜制备对纳米纤维素膜多孔结构的影响;最后综述了多孔性纳米纤维素膜在导电储能材料、分离材料、吸附材料领域的应用。为了拓宽其应用领域,满足应用要求,采用单一的调孔方式具有一定局限性,将多种方式相结合制备特定孔结构的纳米纤维素膜,并复合其他材料制备功能性的多孔性纳米纤维素膜是未来的发展方向。     

纺织新材料及染整加工特性(上)

介绍近年来国内外开发的纺织新材料：新型天然纤维、再生纤维素纤维、再生蛋白质纤维、新型和功能性合成纤维等的基本特性;并对部分纺织新材料,如聚乳酸纤维（PLA）、竹纤维、大豆蛋白纤维和聚对苯二甲酸丙二醇酯（PTT）纤维的前处理、染色、热定形、后整理等关键技术作了综述分析。     

Chemical composition of alkaline-pretreated sugarcane bagasse and its effects on the physicochemical characteristics of fat-replaced sausage

The potential of cellulose from sugarcane bagasse used for pork sausage was investigated. The purity level of cellulose fibre from sugarcane bagasse and the functional characteristics in pork sausage were studied. The differences in the sugarcane fibre and sausage characteristics were strongly related to the cellulose/lignin content of the extracted cellulose under different amounts of bleaching. Bleached sugarcane fibres showed better water (3.55) and oil (2.34) holding capacity in comparison with untreated fibre (2.92 and 2.38, respectively). The sugarcane fibres in each treatment stage showed different effects on sausage properties. Sausages with 1% cellulose fibres added had an improved texture profile, but the addition of 3% cellulose fibres to sausages resulted in a higher cooking yield. Consumers considered the sensory characteristics of all sausages as acceptable. These results indicated that low levels of cellulose extracted from sugarcane bagasse could be added and maintain the inherent characteristics of meat products.