棉花老化种子活力与生理性状的相关性研究

为探讨老化种子活力与其生理性状的相关性，以5个人工老化的棉花品种为材料进行发芽试验，分别测定其种子发芽指数、发芽势、发芽率和幼苗的电导率、MDA（丙二醛）含量、CAT（过氧化氢酶）及POD（过氧化物酶）活性．结果表明：不同棉花品种老化种子的活力指标存在一定的差异；相关性分析显示，棉花老化种子活力指标与MDA、电导率呈一定的负相关，与CAT、POD呈正相关，其中发芽势和发芽率与POD为显著正相关．     

B/C65/3519 tex竹棉混纺纱的工艺研究

对在棉型纺织设备上加工竹纤维并与其他多种纤维进行混纺的技术的研究,一直是国内纺织界竞相开展的前沿性应用技术研究新课题,根据竹纤维的纤维结构特性,通过制定合理的竹纤维混纺纱工艺配置及工艺参数,可以实现竹纤维混纺纱在棉型纺织设备上加工的目的,为竹纤维的纱线加工开辟了一条有效途径.     

Layer‐by‐layer deposition of antimicrobial polymers on cellulosic fibers: a new strategy to develop bioactive textiles

In recent years, there has been an increase of infectious diseases caused by different microorganisms and the development of antibiotic resistance. In this way, the search for new and efficient antibacterial materials is imperative. The main polysaccharides currently used in the biomedical and pharmaceutical domains are chitin and its derivative chitosan (CH) and alginates (ALG). In this study, a simple technique of Layer by Layer (LbL) of applying polycation CH and polyanion ALG was used to prepare CH/ALG multilayers on cotton samples via the electrostatic assembly with success. The CH/ALG cotton samples (functionalized) were investigated for their antibacterial properties towards Staphylococcus aureus and Klebsiella pneumonia using the international standard method JIS L 1902:2002. The antibacterial activity of the functionalized samples was tested in terms of bacteriostatic and bactericidal activity, and results showed that the samples exhibited a bacteriostatic effect on the two bacteria tested, as expected. In addition, samples with five layers (CH/ALG/CH/ALG/CH) were more effective in inhibiting bacterial growth. This new coating for cellulosic fibers is a new strategy and may open new avenues for the development of antimicrobial polymers with potential application in health‐care field. Copyright © 2013 John Wiley & Sons, Ltd.     

Driving Mechanism of Cotton Comber's Detaching Roller Based on Time-Sharing Unidirectional Drive

The high-speed reciprocating motion of a detaching roller limits the velocity of a cotton comber and affects the quality of comber slivers. The article has proposed a controllable time-sharing unidirectional hybrid drive mechanism after analyzing detaching roller＇s current numerical control drive method. The analysis focuses on the detaching roller motion required according to cotton comber＇s velocity and process. The double-servo motors of the mechanism consists of differential gear trains. The mechanism addresses the problem of increased servo motor power,and failure of promptly responded to the positive inversion process of mechanism driven by servo motors. A velocity calculation model of the detaching roller controllable drive mechanism will be generated by using superposition method and design of differential gear trains. The accuracy of the model will be verified using the test platform. This study has presented a reliable and practical high-speed drive mechanism and can be a reference to future studies on high-speed reciprocating motion drive.     

Surface hydrophobization of cotton via laccase-mediated polydopamine deposition and dodecyl gallate grafting

Natural fibers containing components with phenolic hydroxyl groups, such as jute, wool, and silk, can be directly modified by laccase-catalyzed grafting. However, cellulosic fibers like cotton cannot be functionalized in this manner. In this work, we developed a facile two-step method to graft polymers on cotton fabric via laccase catalysis. First, polydopamine (PDA) coating was deposited on the surface of the cotton fabrics via catalysis of laccase/2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) system. Then, the newly formed PDA coating acted as the secondary reaction platform for subsequent laccase-mediated grafting of hydrophobic monomer dodecyl gallate (DG). The oxidation of dopamine (DA) catalyzed with the laccase/TEMPO system was investigated using UV–visible (UV–vis) spectroscopy. The scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) results verified that the PDA was coated on the surface of cotton fibers. Fourier transform infrared (FTIR) spectra indicated that the PDA-coated cotton was successfully grafted with DG (DG-PDA-cotton). According to the weighting method, the grafting percentage was about 1.06%. The hydrophobicity of the DG-PDA-cotton fabrics was greatly improved with a contact angle of 133°. Also, the grafted cotton fabrics show repellency of water-soluble stains like coffee, milk, and tea. This study provides a new strategy for surface modification of cotton by laccase-mediated grafting, which offers the references for the green fabrication of cotton fabrics with improved functionalization.     

分子生物学手段检测转Bt基因棉花中Cry杀虫蛋白的定性和定量方法

建立了转Bt基因棉花中Cry杀虫蛋白的提取、样品前处理以及酶联免疫(ELISA)定量分析方法,并使用凝胶电泳、普通聚合酶链式反应(PCR)和实时荧光定量PCR等分子生物学手段对转基因棉花中的Bt基因进行定性和定量检测.所建立的苏云金芽孢杆菌杀虫晶体蛋白(Cry1Ab蛋白和Cry1Ac蛋白)标准曲线线性关系良好,相关系数r2均大于0.999,相对标准偏差RSD均小于2.0%.方法简单、快速、重现性和精密度好,可为农业食品行业和环境领域科研人员提供一种简便快速地从转基因棉花中检测Bt毒蛋白的分析方法.     

The Identification of Cotton Fibers Dyed with Reactive Dyes for Forensic Purposes

Some of the most common microtraces that are currently collected at crime scenes are fragments of single fibers. The perpetrator leaves them at a crime scene or takes them away, for example, on their clothing or body. In turn, the microscopic dimensions of such traces mean that the perpetrator does not notice them and therefore usually does not take action to remove them. Cotton and polyester fibers dyed by reactive and dispersion dyes, respectively, are very popular within clothing products, and they are hidden among microtraces at the scene of a crime. In our recently published review paper, we summarized the possibilities for the identification of disperse dyes of polyester fibers for forensic purposes. In this review, we are concerned with cotton fibers dyed with reactive dyes. Cotton fibers are natural ones that cannot easily be distinguished on the basis of morphological features. Consequently, their color and consequently the dye composition are often their only characteristics. The presented methods for the identification of reactive dyes could be very interesting not only for forensic laboratories, but also for scientists working in food, cosmetics or pharmaceutical/medical sciences.     

用近红外光谱分析转基因抗虫棉根际全氮和有机质含量

随着转基因植物的普及推广,人们越来越关心其生态安全性。以转基因棉花及其对照为实验材料,借助于近红外光谱仪对转基因棉花及其对照根际土壤和非根际土壤中的全氮和有机质进行了分析测定,扫描区间为12 000～4 000 cm-1,分辨率为4 cm-1,扫描次数为64次;同时用标准方法进行对比测定。结果显示近红外检测样品的结果与标准方法结果无明显差别,说明通过扫描光谱加上数学和计算机软件分析,非常准确、方便地测定了转基因作物根际土壤中的全氮和有机质。结果显示,转基因棉花根际土壤中的全氮和有机质含量显著高于对照中的含量,分析原因主要可能与转基因抗虫棉向根际土壤分泌毒蛋白所致,毒蛋白会结合在土壤颗粒上,降解较慢,增加了全氮和有机质的含量,有机质又会增加土壤微生物的繁殖,进一步增加了土壤有机质含量。     

河北省棉花生育期连阴雨气候变化特征分析

利用河北省65个气象观测站自1954年(或建站)至2000年的气象资料,分析了河北省棉花四个生育期的连阴雨气候变化特征.结果表明:河北省棉区大部棉花播种出苗期、蕾期、花铃期和吐絮期连阴雨分别为1～2年一遇、1～3年一遇、1～2年一遇和2～6年一遇.不同时期重连阴雨所占比率分别为25%、65%、49%和45%.近50年来,除播种出苗期连阴雨历年出现次数具有增多趋势外,其它各个时期的连阴雨、重连阴雨以及播种出苗期重连阴雨均具有减少趋势,但各时期减少幅度有所不同.     

含杀菌、吸附双功能基棉纤维的制备与性能

化学改性;吸附剂;杀菌剂;含杀菌、吸附双功能基棉纤维的制备与性能