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定点观测结果表明:海岸林带、农田林网对改善环境,促进农业生产效益十分显著;风力可降低39.2%—63.4%;蒸发量减少24.5%;相对湿度提高1%—2%;气温增高0.6—1.8℃;土壤含盐量从4.50000‰下降到0.43160‰—0.19000‰;早晚薯产量增加3.9%—16.4%,早晚稻产量增加3.3%—17.9%;特别是秋粮作物防护效益十分明显,出米率可提高3.5%—7.9%。 相似文献
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对南方某污水处理站运营过程中污染物去除率进行了系统的研究,结果表明在未进行酸碱调节的情况下总硬度的平均去除率为-6%;在加酸进行酸碱调节的情况下总硬度平均去除率为-7%;在加石灰进行酸碱调节的情况下总硬度的去除率为-27%;在加入75mg/l纯碱的情况下总硬度的平均去除率为14%;污水处理系统正常运营情况下铁含量的平均去除率为99.14%;最大去除率为99.76%;最小去除率为98.44%,在未加入PAM且沉淀效果差时, 铁含量的平均去除率为97.63%;最大去除率为98.98%;最小去除率为96.08%;污水处理系统在正常运营的情况下,油含量的平均去除率为94%;最大去除率为100%;最小去除率为72%,在未加入PAM沉淀效果差时,去除率为82%;最大去除率为87%;最小去除率为76%. 相似文献
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白蜡窄吉丁是我国重要的检疫性蛀干害虫,对白蜡属多个树种和美国流苏树危害较重。为了防控白蜡窄吉丁幼虫,选择不同药剂组合对绒毛白蜡进行树干喷洒和打孔注药防治。结果表明：树干喷洒7种药剂组合的防效顺序为40%氧乐果>1%甲维盐+25%溴氰菊酯>5%高氯·甲维盐>5%吡虫啉+20%氰戊菊酯>20%氰戊菊酯>1%甲维盐>25%溴氰菊酯;打孔注射8种药剂组合的防效顺序为40%氧乐果+1%有机硅>1%甲维盐>5%吡虫啉+1%有机硅>5%吡虫啉+20%氰戊菊酯+1%有机硅>1%甲维盐+25%溴氰菊酯+1%有机硅>5%高氯·甲维盐+1%有机硅>25%溴氰菊酯>20%氰戊菊酯。树干喷洒时,药剂的合理复配能够提高对白蜡窄吉丁幼虫的林间防效;在打孔注药中,药剂的复配使用并未提高对害虫的防效。在2种施药方法中40%氧乐果都具有最好的防效,而使用打孔注药方式防效更好。 相似文献
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利用3S技术处理遥感图像,分析了湘西自治州石漠化的现状和分布。结果表明,湘西州各县市石漠化面积比重表现为:凤凰县(53.41%)>花垣县(45.35%)>吉首市(44.91%)>永顺县(39.52%)>保靖县(39.45%)>龙山县(29.89%)>泸溪县(25.96%)>古丈县(24.57%);并针对存在的问题,提出了采用生物措施和工程措施相结合的水土保持措施,因地制宜,逐步改善湘西州石漠化现状。 相似文献
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20 0 1年在带岭林科所 4km落叶松种子园塑料大棚内进行了 10个树种、3个采条时期、3种插穗处理和 15种基质 135 0个组合的绿枝扦插试验。试验结果表明 :同一树种的不同采条时期、不同插穗处理、不同基质和不同树种的同一采条时期、同一插穗处理、同一基质的生根效果不同 ,并有明显的交互作用。统计结果得出树种最佳组合的生根率 :刺五加 80 % ;五味子 70 % ;紫椴 4 0 % ;花楸 30 % ;水曲柳 2 0 % ;黄菠萝 2 0 % ;山槐 2 0 % ;山梨 10 % ;春榆 10 % ;胡桃楸 0 %。 相似文献
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用增产菌分别处理火炬松、湿地松种子、苗木,种子比对照提早3～4天发芽,发芽率分别提高7.25%～8.73%、7%～10%;发芽势提高15.9%～59.2%;平均苗高与根茎粗分别增加4.7cm和0.26cm;I级苗增加11.71%～14.33%,苗木出圃率增加4.63%～15.26%;同时也促进了苗木根系的生长。 相似文献
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烟秆制备刨花板的力学性能研究 总被引：1，自引：0，他引：1
烟秆为烟草采摘烟口t-后的废弃物,为了更好的利用这种原料,利用不同含水率（9％、6％、3％、0％）和烟秆不同部位（上部、中部和下部）的刨花制成刨花板,测定刨花板的内结合强度、弹性模量和静曲强度,分析含水率和烟秆部位对刨花板力学性能的影响。结果表明,随着含水率从0增加至9％,刨花板的内结合强度从0．35MPa增加至0．58MPa,其弹性模量和静曲强度呈先增后减趋势,当含水率在6％时,烟秆刨花板的弹性模量和静曲强度最大。不同部位的烟秆刨花对刨花板的内结合强度、弹性模量、静曲强度有显著影响,其中,利用中部烟秆刨花制备的刨花板的内结合强度、弹性模量、静曲强度最小。利用烟秆刨花制备的刨花板其力学性能能达到国家标准的要求,因此利用烟秆制备刨花板是可行的。 相似文献
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采用造纸法对烟梗和烟末制烟草薄片纸基进行了实验研究,探讨了压榨对烟草薄片纸基性能的影响。结果表明,压榨压力从0 MPa上升至0.4 MPa,薄片纸基的抗张指数由17.27 N.m/g逐渐增加到23.69 N.m/g,撕裂指数由2.00 mN.m2/g下降至1.69 mN.m2/g,松厚度从2.43 cm3/g下降到1.80 cm3/g,紧度由0.41 g/cm3上升0.56 g/cm3,薄片纸基的透气度由1.20μm/(Pa.s)下降到0.04μm/(Pa.s),薄片纸基的填充值由7.23 cm3/g逐渐下降到6.08 cm3/g。随着压榨压力的增加,润湿性Max值(tW,max)和特征值(t95)呈相近变化规律,压榨压力为0 MPa时,tW,max值最小(0.097 s),t95值最小(0.442 s),烟草薄片纸基具有较好的渗透性能和较开放的表面结构。扫描电镜分析结果表明,在低压榨压力(<0.2 MPa)条件下,能够显著提高薄片纸基内部的孔隙率,有利于改善薄片纸基的填充值和透气度,并且可以提高薄片纸基的渗透性能。 相似文献
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Our previous paper showed tobacco stalks to posses the characteristics of a raw material for pulp and paper application. It contains the major biomass constituents and cell components common to wood species. In this study, preparation and characterization of tobacco stalk pulp by steam explosion (SE) pulping at two chemical pretreatments were attempted. Chemical pretreatment prior to SE pulping improved the brightness, yield, and strength properties of the resulting tobacco SE pulps in the order: 6% Na2SO3 + 1% NaOH > 6% Na2SO3 > control (untreated). The 6% Na2SO3 + 1% NaOH-impregnated tobacco stalks produced SE pulps of good fiber length distribution and considerable properties that compare well with pulps from other raw materials obtained from previous studies, and the nonimpregnated ones showed strength properties superior to those of their poplar counterpart. Prior to bleaching, pretreating the tobacco stalk SE pulps with two stages, 2% NaOH at 90°C, improved the initial pulp brightness by about 5 points. Two-stage 6% H2O2 bleaching gave a comparable effect with hypochlorite bleaching for both tobacco and poplar, giving a 29–34 brightness point increase for tobacco SE pulp and 61 for the poplar samples. The differences in the bleaching responses for untreated tobacco and poplar SE pulps were attributed to the differences in their lignin structure, as shown in the total yield of their respective nitrobenzene oxidation products and FT-IR spectra. Tobacco SE pulps contain more of the guaiacyl-type lignin and poplar the syringyl-type lignin.This paper was presented in part during the 1998 CORESTA (Cooperation Centre for Scientific Research Relative to Tobacco) Congress, Brighton, UK, October 1998 相似文献
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抗病毒剂VA诱导烟草对TMV的抗性与水杨酸含量的关系 总被引：1，自引：0，他引：1
为探明VA诱导烟草抗TMV机制中SA的作用 ,以烟草的 2个抗、感品种枯斑三生烟和三生烟为材料 ,抗病毒剂VA为诱导剂 ,用高效液相色谱法测定了VA对烟草体内SA含量的影响。结果发现 ,VA可以使烟草抗、感品种体内SA含量都增加 ,抗病品种枯斑三生烟SA含量增加更显著 ,且接种TMV后 ,SA含量在 4 8h出现一个峰值 ,表明SA在烟草抗TMV机制中起重要作用 ,且SA与过敏反应及PR蛋白 (病程相关蛋白 )的产生有关 相似文献
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间种对油茶幼林生长的影响及效益分析 总被引：1，自引：0，他引：1
选用黄豆、花生、红薯和烟叶4种农作物于油茶幼林内进行间作,研究不同间种模式对油茶幼树树体生长的影响,并对间种不同经济作物的油茶幼林林地经济效益进行分析。结果表明:间种可促进油茶幼林的生长,其中间种黄豆效果最好,树高增加了0.11 m,地径增加了0.04 cm,冠幅增加了0.21 m~2,花芽数增加了20个/枝。间种可增加油茶幼林的经济效益,其中间种烟叶效益最高,经济产出为48 960元/hm~2。综合来看,油茶幼林间种的经济作物宜选择较矮小、具根瘤固氮菌的花生、黄豆。 相似文献
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The 9-cis-epoxycarotenoid dioxygenase(NCED)gene is rate-limiting in abscisic acid(ABA) biosynthesis.In this study, an NCED gene, designated FvNCED3(KY008746), was cloned from velvet ash(Fraxinus velutina Torr.) with a RACE method. The full length c DNA of FvNCED3 encodes a 573-amino acid polypeptide.Sequencing analysis showed that the FvNCED3 protein was highly homologous to other NCED proteins. The expression patterns of FvNCED3 in different ash organs were analyzed by real-time PCR which revealed that FvNCED3 expression levels were highest in leaves and lowest in roots. The gene expression patterns of FvNCED3 under abiotic stress indicated that its expression increased under drought, salt and ABA stress and decreased due to high and low temperatures. There were no obvious changes under ultraviolet light. The 1094-bp upstream sequence 5' flank regulation region of the FvNCED3 gene was also cloned from ash using the Genome Walking method. To assess the activity of the FvNCED3 promoter, a p FvNCED3 p::GUS plant expression vector was constructed for tobacco transformation. GUS expression of the FvNCED3 GUS enzyme activity was detected in almost all transgenic tobacco tissues, especially in the young leaves,stigma, anther, ovule and ovary. After treating the transgenic tobacco with NaCl and placing it under drought stress, GUS staining of tobacco leaves increased compared with that under normal growth conditions. This result indicates that gene expression driven by the FvNCED3 promoter can be induced by salt and drought stress. 相似文献
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方文彬 《中南林业科技大学学报(自然科学版)》1991,(1)
应用最新的体视显微术方法,测定了烟草秆的组织比率。提出了合理计算全部位纤维长度的方法通过分析表明,烟皮纤维体积率为19.1%,烟骨纤维体积率为64.1%,全部位纤锥体积率为58.5%:全部位纤维长度为1102×10~(-6)m,长宽比为43,壁腔比小于1,柔性系数中等。适宜作造纸和纤维板的生产原料。是一种亟待加以开发利用的纤维植物资源。 相似文献
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A 3 125 bp cellulose synthase gene, PtoCesA1, which has a 98% identity to PtrCesA1 from Populus tremuloides, was cloned from cDNA prepared from secondary xylem of P tomentosa. Four anti-expression vectors with different fragments of PtoCesAl, named as pBIPF, pBICC1, pBIPR and pBIBR, were constructed. Some traits of transformed tobacco of pBICC1, pBIPR and pBIBR differed from wild types, such as small leaves, ＂dwarf＂ phenotype and thinner xylem and fiber cell walls than wild plants consistent with a loss of cellulose. It indicated that the growth of transgenic tobacco was restrained by the expression of anti-PtoCesA1. Transgenic tobacco was obtained and the contents of cellulose and lignin were analyzed as well as the width and length of fiber cells, and xylem thickness for both transgenic and control plants. Transformed tobacco showed a different phenotype from control plants and it implied that PtoCesA1 was essential for the cellulose biosynthesis in poplar stems. 相似文献