Correlating the fineness and residual gum content of degummed hemp fibres

It is well known residual gum exists in degummed or retted hemp fibres. Gum removal results in improvement in fibre fineness and the properties of the resultant hemp yarns. However, it is not known what correlation if any exists between the residual gum content in retted hemp fibres and the fibre fineness, described in terms of fibre width in this paper. This study examined the mean width and coefficient of variation (CV) of fibre width of seventeen chemically retted hemp samples with reference to residual gum content. The mean and CV of fibre width were obtained from an Optical fibre diameter analyser (OFDA 100). The linear regression analysis results show that the mean fibre width is directly proportional to the residual gum content. A slightly weaker linear correlation also exists between the coefficient of variation of fibre width and the residual gum content. The strong linear co-relation between the mean of fibre width and the residual gum content is a significant outcome, since testing for fibre width using the OFDA is a much simpler and quicker process than testing the residual gum content. Scanning Electron Microscopy (SEM) reinforces the OFDA findings. SEM micrographs show a flat ribbon like fibre cross-section hence the term “fibre width” is used instead of fibre diameter. Spectral differences in the untreated dry decorticated skin samples and chemically treated and subsequently carded samples indicate delignification. The peaks at 1370 cm⁻¹, 1325 cm⁻¹, 1733 cm⁻¹, and 1600 cm⁻¹ attributed to lignin in the untreated samples are missing from the spectra of the treated samples. The spectra of the treated samples are more amine-dominated with some of the OH character lost.     

苎麻主要品质性状相互关系的研究

苎麻纤维细度、细度均匀度、断裂强力、强度、伸长率及结晶度等品质性状是影响苎麻品质及其可纺性的几项主要因素。本文对30个苎麻品种的主要品质性状进行了研究,并利用断裂强力与纤维直径之间的极显著相关性,建立断裂强力依直径的回归方程：y=-1．887＋1．756x。     

A joint influence of the distributions of fiber length and fineness on the strength efficiency of the fibers in yarn

The length and fineness of fibers are critical to the strength of yarns. Much research has been conducted on the issue in the past decades. Zeidman and Sawhney introduced a new parameter called strength efficiency (SE) of fibers in a yarn using an elaborate probabilistic method. Their final formula, a non-dimensional measure, describes the influence of the fiber length distribution on the strength of yarn. The result, however, is based on the assumption that the fibers are identical in all respects including their cross-sectional area. The influence of fiber fineness can not be seen in their formula. In fact the joint influence of fiber length and fineness is rarely studied. We derive a new strength efficiency of the joint influence of fiber length and fineness on the basis of Zeidman’s result. The conclusion is helpful to the understanding of the comprehensive influence of fiber length and fineness on the strength of yarn. Furthermore, we give a plausible method to estimate the critical length defined by Zeidman. The result can be applied to the research of the properties between fibers and yarns.     

日粮不同精粗比与中草药添加剂对滩羊增重、肉理化性能、血液生化和免疫指标的影响

试验探讨在不同精粗比日粮中添加中草药对滩羊增重、肉理化性能、血液生化及免疫指标的影响。试验1组日粮精粗比为1.59,不添加中草药添加剂;试验2、3、4组日粮精粗比分别为1.59、2.31、0.98,且添加0.65%中草药添加剂。结果表明:各试验组间增重、日增重差异不显著(P>0.05)。试验3组增重和日增重高于试验2组和试验4组;饲喂中草药添加剂的试验2、3、4组IgA、IgG、IgM、WBC、LYM指标均高于不添加中草药添加剂的试验1组,且试验4组IgA、IgG、IgM、WBC、LYM均高于其他各组。试验90 d,试验4组与试验3组之间白细胞差异显著(P<0.05),试验30 d与试验90 d,试验3组淋巴细胞差异显著(P<0.05),试验4组淋巴细胞差异显著(P<0.05),中草药添加剂与合适的精粗比日粮可显著提高滩羊的血液生化指标和免疫水平;试验4组与试验3组间熟肉率差异显著(P<0.05),试验3组与其他各组pH值差异显著(P<0.05),且在各组中最高。说明滩羊育肥期日粮中添加0.65%中草药添加剂精粗比为0.98对其增重、肉理化性能、血液...     

凉山半细毛羊羊毛生产性能的研究

凉山半细毛羊被毛为辫型毛丛结构，主体经度48－50支，毛丛长度16－18.5cm(公羊）和15－17cm（母羊）。成年公羊剪毛量6.42kg，母羊4.58kg，净毛率67％。羊毛含氨基酸17种，其中含硫氨基酸占8.03%。     

贵州高原人工草地上的绵羊放牧越冬试验

本文研究了绵羊在贵州高原人工草地上的放牧越冬情况,试验结果表明,杂种绵羊冬春季节在足够的优质豆科、禾本科混播人工草地上,进行纯放牧,其体重、羊毛细度均未发生明显变化,证明在这种条件下可以安全越冬;亦说明大力发展人工草地是发展养羊业的重要措施。     

山东山羊绒理化特性及超微结构研究

本研究通过理化方法和电镜观察，对山东３个绒山羊品种的５７个绒样进行了系统分析和综合评价。结果表明其主要质量指标均达到出口标准和符合深加工要求，原绒含绒率平均为５６．１６％，绒细度１４．８３μｍ，绒伸直长度为４．３８ｃｍ，工业手排长度２．４７ｃｍ，强度４．０５ｇ，伸度３７．２２％，绒纤维鳞片以环形为主，密度达７２２．８０层／ｃｍ。青、紫、白３个绒种相比，以紫绒最好。但山东山羊绒具色泽多样、手排时易断     

非编码RNA调节羊绒细度候选基因的研究进展

羊绒细度是评价羊绒品质和衡量羊绒价格的关键数量性状,近年来,随着羊绒细度功能标记基因的深入研究,通过高通量数据解析及全基因组关联分析,逐步筛选出羊绒细度性状的候选基因,但是羊绒细度关键调控基因、表达量及分子调节机制尚未明了。基因表达受多种调节因子调控,其中非编码RNA的调节作用比较活跃,主要包括microRNA、lncRNA和circRNA等。经高通量测序和生物信息分析发现,非编码RNA在绒山羊品种间和品种内的不同羊绒细度个体皮肤、次级毛囊及次级毛囊周期性生长发育中差异表达并调节羊绒细度相关靶基因,但多种非编码RNA共同调节同一靶基因的信号通路甚少。目前通过对羊绒细度差异基因进行SNP标记辅助选择、转录组筛选、高通量解析非编码RNA调节及全基因组关联分析等相关研究发现,两两通路聚焦相同的羊绒细度靶基因较多,两条通路以上共同聚焦到某个或某几个羊绒细度的关键靶基因较少。作者主要讨论了羊绒细度候选基因及转录水平上microRNA、lncRNA和circRNA对羊绒细度相关靶基因分子调控机制的研究进展。     

陆地棉纤维细度相关性状的遗传及相关性分析

 利用主基因与多基因混合遗传模型的P₁、P₂、F₁、F₂四世代联合分析方法,研究了棉花纤维细度相关性状的遗传,进一步明确了主基因存在的普遍性。同时,对麦克隆值密切相关的纤维线密度及成熟度比率进行了F₂、F_2:3家系的主基因 多基因单世代分析,初步判定线密度也存在一对主基因。性状间的遗传相关分析表明,麦克隆值及成熟度比率与整齐度分别呈极显著正相关和不相关,该两个性状与其它性状的相关性两个世代表现不一致;线密度与整齐度呈正相关,与伸长率呈极显著负相关,与长度、强度及衣分不相关。线密度与各性状的相关性要比麦克隆值和成熟度比率稳定,受环境影响小,有必要加强线密度的选择及深入研究。     

镉胁迫下不同细度品种苎麻耐性比较研究

旨在了解不同细度品种对重金属Cd耐性的差异性。试验选择长势一致苎麻扦插苗(苗龄60天)进行移栽,土壤Cd胁迫处理分别为0、25、75、150 mg/kg共4个处理,进行为期一整年的Cd耐性试验调查。结果表明:12个不同细度品种苎麻在25 mg/kg土壤Cd胁迫处理下的综合耐性指数在0.80~1.18区间,耐性最好的是中细度品种‘中苎一号’,最差的是低细度品种‘大竹黄白麻’;在75 mg/kg胁迫处理下的综合耐性指数在0.09~0.77之间,表现最好的是中细度品种‘湘苎3号’,最差的是低细度品种‘大竹黄白麻’。在150 mg/kg土壤Cd胁迫处理下的耐性指数在0.32~0.54之间,最好的是高细度品种‘厚皮种一号’,最差的是低细度品种‘大竹黄白麻’。由此可知,苎麻对重金属Cd具有很好的耐受能力,且呈现出中、高细度品种的Cd耐性大于低细度品种。75 mg/kg Cd胁迫浓度是待测品种‘大竹黄白麻’、‘宁乡冲天炮’、‘浏阳大叶青’、‘邻水青顶家麻’、‘川苎八号’、‘中苎一号’、‘武岗红皮麻’、‘湘饲纤兼用一号’苎麻的耐Cd阈值。150 mg/kg Cd胁迫浓度是待测品种‘湘苎三号’、‘多倍体一号’、‘资兴麻’、‘厚皮种一号’的耐Cd阈值。