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1.
以籼粳杂交(沈农265/R99)F1及其亲本为试验材料,对低温预处理、不同基本培养基、基因型、不同激素配比等影响花药培养效果的因素进行了研究。结果表明:(1)不同低温处理时间沈农265/R99 F1的愈伤诱导率、绿苗分化率和花药培养力差异达到极显著水平,低温预处理7 d的花药培养效果最好。(2)3个基因型的愈伤诱导率、绿苗分化率以及花药培养力差异很大,沈农265/R99适合在SK3培养基上培养,沈农265适合在改良N6培养基上培养,R99适合在M8培养基上培养,培养基与基因型存在互作效应。(3)沈农265/R99F1花药诱导愈伤的最佳的激素配比为2,4-D(2 mg.L-1)、NAA(1mg.L-1)、KT(0.5 mg.L-1)。  相似文献   

2.
甘薯茎尖培养的适宜培养基筛选   总被引:2,自引:2,他引:0  
黄华康  袁照年 《杂粮作物》2002,22(3):141-143
利用已报道的8种不同的甘薯茎尖培养基,对6个甘薯栽培品种的茎尖分生组织进行培养,结果表明,不同甘薯品种茎尖培养成功率差异较大,6-BA1.0mg/L+NAA0.24mg/L+MS为相对广谱的培养基。6个品种培养的平均成苗率达65.4%。金山1255、金山57、湘75-55较易培养,其平均成苗率达68.2%。而新种花、夏引一号平均成苗率较低,说明甘薯茎尖培养基具有基因型选择性。  相似文献   

3.
Far-infrared polyethylene terephthalate (FPET) fibers have been commonly used in clothing in order to attain heat retention, and the combination of three-dimensional crimped hollow polyethylene terephthalate (TPET) fibers makes the clothing to be fluffy and air permeable, and thereby improves the wearing comfort. This study aims to make thermally insulating nonwoven composites by using recycled far infrared fibers. The composites are used to cover the heat transfer lines and prevent the heat emissivity. A specified amount of low-melting-point polyethylene terephthalate (LPET) fibers and FPET and TPET fibers at different ratios are blended, followed by being needle punched at 100-300 needles/min, and then hot pressed at 120 °C, in order to form thirty nonwoven composite types. These nonwoven composites are measured for their porosity, thickness, and air permeability, and are tested for thermal insulation and temperature-rise slope under a constant ambient temperature.  相似文献   

4.
Poly(p-phenylene terephthalamide) fibers prepared by dry-jet wet spinning processes have a notable response to very brief heat treatment (seconds) under tension. The modulus of the as-spun fiber can be greatly affected by the heat treatment conditions (temperature, tension and duration). The crystallite orientation and the fiber modulus will increase by this short-term heating under tension. The present research reports the heat treatment techniques, devices and its process conditions. It reports in details the structural relationships between the fiber properties which are influenced by the heat treatment process. In particular, focuses deeply on the effect of the crystal orientation changes of the fibers, on the mechanical properties and, also, investigates the thermal degradation steps & behaviours of the heat treated fibers. The heat treated PPTA fibers have a molecular orientation higher than that for the as-spun one.  相似文献   

5.
The effect of boron phosphate (BPO4) nanoparticles on the mechanical, thermal, and flame retardant properties of polypropylene (PP) and polyamide 6 (PA-6) fibers are investigated by tensile testing, thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and micro combustion calorimeter (MCC). The addition of BPO4 reduces the mechanical properties of the both PP and PA-6 fibers. According to the TGA results, the addition of BPO4 does not change the thermal behavior of PP fiber and slightly reduces the thermal stability of PA-6 fiber by about 30 °C. According to MCC results, the addition of BPO4 does not change the effective total heat evolution and heat release rate (HRR) peak for PP fibers. Although the inclusion of BPO4 does not change the total heat evolution of PA-6 fiber, it reduces the HRR peaks due to increase in barrier effect of char.  相似文献   

6.
The study employs limiting oxygen index (LOI) measurements, cone calorimetry (CONE) and thermogravimetric analysis (TGA) to examine the catalytic effect of zinc ion content on the flame retardance and thermal degradation of alginate fibers. LOI results show that all zinc alginate fibers are intrinsically flame retardant, with LOI values of over 27.0, as compared with about 24.5 for alginic acid fiber. The heat release rate (HRR) and total heat release values of zinc alginate fibers (obtained from CONE) are significantly less than those of alginic acid fiber, and decrease with increasing zinc ion content. TGA indicates that char formation increases and maximum thermal weight-loss rate is reduced when zinc content in the fibers is increased. The residues of zinc alginate fibers keep their shapes better than those of the alginic acid fiber. Further discussion of the combustion process and flame retardant mechanism is presented.  相似文献   

7.
为了进一步提高小麦花药培养效率,以8个小麦杂交F1代为供试材料,通过在培养基中添加不同浓度的噻重氮苯基脲(thidiazuron,TDZ)探讨其对小麦花药培养的作用。结果表明,TDZ的作用与添加剂量及小麦基因型密切相关。在诱导培养基中添加TDZ对基因型中麦875/郑豫麦043具有负向调控作用,但对兰考198/黄明118、郑麦7698/西农979以及天禾7号/0836H-3则具有正向促进作用。TDZ的最佳添加剂量为0.05mg·L-1,可显著提高3个基因型的胚性愈伤组织诱导率和绿苗产率,其中兰考198/黄明118胚性愈伤组织诱导率和绿苗产率最高,分别达到25.1%和8.7%。同样,在分化培养基中添加一定剂量的TDZ,对4个基因型的愈伤组织分化均表现正向促进作用,TDZ的适宜浓度范围为0.5~1.0mg·L-1,以添加0.5mg·L-1的处理表现最优,能够显著提高绿苗分化率和绿苗/白苗比率;基因型兰考198/黄明118的绿苗分化率和绿苗/白苗比率最高,分别达50%和1.87。研究还表明,在诱导培养基或分化培养基中添加TDZ还能够促进绿苗增殖,提高单倍体自然加倍效率。本研究结果将有助于小麦花药培养技术的优化,进而提高花培育种效率。  相似文献   

8.
为了给小麦花培育种提供参考,以3个高花药培养力的小麦材料为母本、4个农艺性状较好的小麦品种为父本,按不完全双列杂交方法配制了12个组合,对12个组合F1的愈伤组织诱导率、绿苗分化率和绿苗产率3个性状进行了检测,并进行了亲本及组合的一般配合力和特殊配合力效应分析。结果表明,3个高花药培养力小麦材料的愈伤组织诱导率、绿苗分化率和绿苗产率3个性状一般配合力效应的表现不尽相同。3个高培养力小麦材料中H6123和H60148的绿苗产率一般配合力表现正效应,其中H6123绿苗产率的一般配合力相对效应值最高,达到18.61,是一个优良的花培亲本。12个组合中有7个组合的绿苗产率特殊配合力表现正效应,且其中的5个组合中都含有1个绿苗产率一般配合力相对效应值较高的亲本,说明高配合力的亲本材料在组合配制中具有重要的作用。  相似文献   

9.
为给耐热性小麦品种的选育和推广提供依据,以黄淮北片小麦全身落黄型品种邯6172和邯麦13及灰白落黄型品种石4185和早衰落黄型品种鲁麦14为供试材料,研究了灌浆期热胁迫对小麦植株含水量、干物质转运量和籽粒灌浆特性的影响,并通过千粒重热感指数评价了不同类型品种的耐热性。结果表明,高温加快了小麦叶片黄化衰老,不同品种衰老快慢不同,邯6172和邯麦13的旗叶、倒2叶、倒3叶分别于热胁迫后19、16、10d开始黄化,叶片黄化速度慢,分别比鲁麦14、石4185晚3~6d。热胁迫使穗、茎、叶含水量下降,不同品种下降速率不同,灌浆后期差异更为显著,其中花后31d鲁麦14、石4185、邯6172和邯麦13穗部含水量分别比对照下降28.7%、30.3%、12.1%和17.4%,叶片含水量分别下降53.8%、44.4%、18.7%和21.5%;鲁麦14、石4185茎秆含水量始终低于邯6172和邯麦13,失水失绿早。热胁迫下全身落黄小麦叶片衰老速度慢,绿叶数目、绿叶面积均较高,穗茎叶含水量相对较高,充分延缓了叶片等光合器官的衰老,保证了正常的生理代谢功能,营养器官干物质转运量和籽粒灌浆速率下降幅度较小,千粒重降低不明显,产量和千粒重热感指数小于1,耐热性好。  相似文献   

10.
The ultrafine composite fibers consisting of lauric acid (LA) and polyamide 6 (PA6) as form-stable phase change materials (PCMs), were prepared successfully by electrospinning. The effect of carbon nanotubes (CNTs) on the structural morphology, phase change behaviors, thermal stability, flammability and thermal conductivity properties of electrospun LA/PA6 composite fibers was investigated by field-emission scanning electron microscopy (FE-SEM), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), microscale combustion calorimeter (MCC) and melting/freezing times measurements, respectively. SEM observations indicated that the LA/PA6 and LA/PA6/CNTs composite fibers possessed flat and ribbon-shaped morphologies, but the neat PA6 fibers had cylindrical shape with smooth surface; and the average fiber diameters for LA/PA6 composite fibers decreased generally with the addition of CNTs. DSC measurements indicated that the heat enthalpies of the composite fibers were lower that that of neat LA powders, while the amounts of CNTs had no appreciable effect on the phase change temperatures and heat enthalpies of the composite fibers. TGA results showed that the addition of CNTs increased the onset thermal degradation temperature, maximum weight loss temperature and charred residue at 700 °C of the composite fibers, attributed to the improved thermal stability properties. It could be found from MCC tests that there were two-step combustion processes for composite fibers, and corresponded respectively to combustion of LA and polymer chains (PA6) in composite fibers. The addition of CNTs reduced the peak of heat release rate (PHRR) of electrospun composite fibers, contributing to the decreased flammability properties. The improved thermal conductivity performances of LA/PA6/CNTs composite fibers was also confirmed by comparing the melting/freezing times of LA/PA6 composite fibers with that of neat LA powders. The results from the SEM observation showed that the composite fibers had no appreciable variations in shape and diameter after heating/cooling processes.  相似文献   

11.
A water and dye-free heat treatment method was used to color wool fibers. The heat effect changed wool fibers to different colors from white in a nitrogen atmosphere. The influences of heating temperature and time on the colors of wool were investigated and the mechanical property of colored wool fibers was evaluated. The color strength of wool fibers increased as heat treatment temperature and time increased. The tensile strength retention rate of wool fiber was relatively high (≥90 %) when the heat temperature was below 200 °C. The surface morphologies of wool fibers scarcely changed during the heat treatment. The carbon content of fibers was found to reduce by heat treatment, indicating oxidization of components in the wool fibers in the process of coloration. Heat treatment may provide a water and dye-free approach to color wool and other textile fibers, albeit within a limited color range.  相似文献   

12.
为了建立高效的小麦花药离体培养体系,对6个小麦品种(系)的5个花药离体培养性状进行了鉴定,并利用6种不同时间的低温预处理对两个小麦品种幼穗进行了处理效果的探讨。结果表明,6个品种(系)的出愈及绿苗分化能力均较强,愈伤组织诱导率、绿苗分化率和绿苗产率分别达到116.48%、5.79%和10.25%以上,初步建立了小麦花药液体漂浮离体培养体系,其培养效果好于固体培养方式。6种不同时间的低温预处理培养结果表明,幼穗经4 ℃低温预处理后,愈伤组织诱导率、绿苗分化率及绿苗产率与对照相比均表现下降的趋势,白苗分化率及白苗产率具有增加的趋势,说明未进行低温预处理的适期幼穗培养效果更好。  相似文献   

13.
Kenaf (Hibiscus cannabinus) grown in northern Mississippi and elsewhere often is injured by early frost and killed before harvest. Frost kill often is associated with fungal growth or rot, so its effect on fiber quality is a major concern. Fiber processing also affects the quality and chemical composition of fibers. Therefore, this study was aimed at determining the effects of frost kill on processing, fiber quality and chemical composition of kenaf fibers. Frost-damaged kenaf with fungal growth was decorticated by hand and divided into six sections (26.88 cm/each) from the base to tip of the stem and then retted chemically or bacterially in the laboratory. Fiber characteristics were compared between the two processes and the six locations on the plant. Ash, cellulose, hemicellulose, and lignin contents of the resultant fibers were measured. Bacterially retted (BR) fibers were stronger (11.8 g/tex) than the chemically retted fibers (CR), 7.5 g/tex, at all locations. The BR fibers from decorticated green ribbons were stronger than those from frost-killed ribbons. However, no significant differences occurred between the CR fibers from decorticated and frost-killed ribbons. Residual gum content was higher for the BR fibers (23.3%) than for the CR fibers (8.1%). The stretch properties were not affected significantly by the frost kill or fungus. The base of the stem had the weakest fibers in both processes, which may have been due to greater fungal disease. The CR process extracted more fiber than the BR process, with a consistent higher yield of clean fibers. In the BR process, the fiber extracted was higher at the tip than at the base of the stem. This may have been related to the presence of fungus, which inhibits the BR process. Analysis of chemical composition of the processed fibers indicated that CR is efficient in reducing hemicellulose and lignin contents. These results indicate that frost kill may not be the appropriate method for harvesting kenaf for quality fibers. However, fibers extracted by chemical retting were unaffected by the presence of fungus as a result of frost kill.  相似文献   

14.
Dyeing is a state-of-the-art realm of textile engineering, however, the emphasis on petroleum-based products is now shifting towards green fibers, particularly, green manufacturing processes. In the present work, a natural mordant, sumac, was extracted and used alone and in combination with alum (a mineral mordant) in silk fibers dyeing with madder and Reseda green dye to make the green production of Iranian carpet possible. The FT-IR ATR spectra of the washed, mordanted, and mordanted dyed silk fibers revealed bonding between silk fibers and green materials. The color of the silk fibers dyed with madder and Reseda extraction was quantified in terms of CIELab (L*, a*, and b*) and K/S values. The effects of different treatments on fastness properties including light, wash, and rubbing fastness were assessed by ISO standard test method.  相似文献   

15.
以冬瓜子叶节为试材,探讨培养条件、不同基因型及诱导、伸长和生根培养基不同激素类型与配比情况,初步建立了冬瓜组培再生体系。结果表明:种子剥皮消毒后,在纸桥培养基暗培养发芽率较高,且节约成本;以暗培养5 d、见光培养1 d刚转为淡绿色的闭合子叶,其不定芽诱导率最高,约75%;以13个不同基因型冬瓜子叶节为外植体,接种至不同激素浓度组合的培养基上,筛选出分化率较高的品种B214,其不定芽再生率可达到79.2%,诱导分化培养基为MS+4.0 mg/L 6-BA+0.4 mg/L NAA,伸长培养基为MS+1.0  相似文献   

16.
Biocomposites derived from polymeric resin and lignocellulosic fibers may be processed at temperatures ranging from 100 °C to 230 °C for durations of up to 30 min. These processing parameters normally lead to the degradation of the fiber's mechanical properties such as Young's modulus (E), ultimate tensile strength (UTS) and percentage elongation at break (%EB). In this study, the effect of processing temperature and duration of heating on the mechanical properties of coir fibers were examined by heating the fibers in an oven at 150 °C and 200 °C for 10, 20 and 30 min to simulate processing conditions. Degradation of mechanical properties was evaluated based on the tensile properties. It was observed that the UTS and %EB of heat treated fibers decreased by 1.17-44.00% and 15.28-81.93%, respectively, compared to untreated fibers. However, the stiffness or E of the fibers increased by 6.3-25.0%. Infra red spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to elucidate further the influence of chemical, thermal and microstructural degradation on the resulting tensile properties of the fibers. The main chemical changes observed at 2922, 2851, 1733, 1651, 1460, 1421 and1370 cm−1 absorption bands were attributed to oxidation, dehydration and depolymerization as well as volatization of the fiber components. These phenomena were also attributed to in the TGA, and in addition the TGA showed increased thermal stability of the heat treated coir fibers with reference to the untreated counterparts which was most probably due to increased recrystallization and cross linking. The microstructural features including microcracks, micropores, collapsed microfibrils and sort of cooled molten liquid observed on the surface of heat treated coir fibers from the scanning electron microscope (SEM) could not directly be linked to the effect of temperature and durations of heating although such features may have largely account for the lower tensile properties of heat treated coir fibers with reference to untreated ones.  相似文献   

17.
亚麻屑和红麻芯用于仙客来栽培基质的研究初报   总被引:3,自引:0,他引:3  
为提高亚麻屑和红麻芯的附加值,促进生物资源的综合利用,分别用25%、50%、75%与100%的亚麻屑和红麻芯替代普通泥炭作为仙客来栽培基质。结果表明:用25%的亚麻屑或50%的红麻芯替代普通泥炭均有利于仙客来的生长与开花,其各项指标均优于常规基质。  相似文献   

18.
The phase, luminescence spectrum, chromaticity and afterglow properties of rare-earth strontium aluminate luminescent fibers, which appear the primary colors of red, yellow and blue in the sun, were measured by XRD, fluorescence spectrometer, spectral scanning-meter and illuminometer. With the analysis, the experiment results indicated that the emission peak of yellow and blue luminescent fibers were located at 520 nm, which were caused by transition of Eu2+. The crystal phase structure of red luminescent fiber was destructed, the yellow light emission being created at 580 nm. This may be the transition of Dy3+ of rare-earth strontium aluminate. The three kinds of chromatic light of fiber are yellow, yellow-green and green light successively (The illumination strength is declining with the order of rare-earth strontium aluminate, yellow, blue and red). Comparing to rare-earth strontium aluminate, the afterglow duration of luminescent fibers were extended.  相似文献   

19.
Nowadays, automotive, packaging and sport equipment industries are using natural fibre based composite materials as they are cheap, abundantly available and having a lot of ecological advantages. The main objective of this paper is to introduce a new concept of fibre twisting and to investigate the effect of twisting and the fibre orientation on the mechanical properties of bio degradable green composites. Here, the composites are fabricated by vacuum assisted compression molding technique in which the problems of hand lay process are eliminated. Here, two fibers namely twisted neem and twisted kenaf are sandwiched between layers of glass fibres to enhance the stiffness and strength of the laminates. Initially, the fibers are alkalized to increase the mechanical properties. The result shows that there is a significant improvement in mechanical properties of composites due to the presence of twisted fibers. It also shows the influence of fiber orientation on mechanical properties.  相似文献   

20.
We studied the influence of silica and glass fibers on the properties of polyester non-woven padding, fixing interesting changes in thermoinsulation, thickness and stiffness of obtained composites. It was found that the combination of inorganic and polyester fibers allowed for obtaining improved thermoinsulating property, compared to non-woven materials based on individual fibers. The improvement is attributed to the enhanced reflectance and the decreased air permeability, which can reduce the heat lost through radiation and convection. The application of inorganic fibers also made the development of non-woven materials with small thickness, keeping thermoinsulating property similar or better, compared to the commonly used polyester non-woven padding. Furthermore, the designed non-woven composites in real models of winter jackets were evaluated in a climate chamber at -10 °C by infrared thermal camera. The results showed that the addition of inorganic fibers allowed the surface temperature of winter jackets more than 5 °C lower than that of winter jacket with pure polyester padding. They significantly enhanced the protection from cold and reduced heat loss from the human body.  相似文献   

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