43 research outputs found

    ENERGY FOR MIXED FOREST OF CUNNINGHAMIA LANCEOLATA AND TSOONGIODENDRON ODORUM

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    对杉木观光木混交林群落能量的研究结果表明 :混交林中观光木地上部分灰分含量以皮最高 ,而杉木则以叶最高 ,两者GCV(干重热值 )和AFCV(去灰分热值 )均以叶为最高 ;观光木、杉木地下各部分的灰分含量均随径级的减小而增加 ,GCV均以粗根最高 ,细根最低 ;观光木的平均灰分含量高于杉木 ,但GCV和AFCV均低于杉木 ;从乔木层、灌木层到草本层 ,灰分含量依次增加 ,GCV和AFCV则依次降低 .混交林群落的能量现存量、年净增量、归还量和净固定量分别是纯林的 1.2 6倍、1.15倍、1.0 2倍和 1.0 9倍 ,其中以乔木层的占大部分 ,林下植被虽然能量现存量仅占群落的很小一部分 ,而其能量年净增量、归还量和净固定量却占有一定比重 .混交林群落的太阳能转化率为 1.5 7% ,而纯林为 1.44 % .表明杉观混交林是一种能量生产力较高和维持地力能力较强的杉阔混交类型 .同时 ,混交林的能量累积比大于纯林 ,能量流动速率则低于纯林 ;乔木层的能量累积比高于林下植被 ,能量流动速率则低于林下植被 .从能量的角度看 ,构建合理的群落结构必须选择高能量累积比的乔木层树种 ,同时须促进能量流动速率快的林下植被的发育以维持和提高地力 .表 4参 2 2Based on the measurement of biomass and productivity, the caloric value of plant samples, the standing crop of energy, net energy production and energy conversing efficiency of mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum were determined. Among the aboveground fractions, ash content was highest in barks of Tsoongiodendron odorum and in leaves of Cunninghamia lanceolata , and GCV and AFCV were both highest in leaves of the two species. For underground fractions, ash content increased with the increase of root diameter size, and GCV was highest in coarse roots and lowest in fine roots. The mean ash content was higher, and the mean of GCV and AFCV of Tsoongiodendron odorum were lower than those of Cunninghamia lanceolata . The mean ash content increased in an order from tree layer, shrub layer to herb layer, while those of GCV and AFCV decreased. The standing crop, net accumulation, production and returning of energy of mixed forest were 1.26, 1.15, 1.09 and 1.02 times as much as that of pure forest, respectively. The undergrowth played an important role in energy process, though it accounted for only a slight proportion in community. The energy conversing efficiency was 1.57% for mixed forest and 1.44% for pure forest. The ratio of energy accumulation was higher, and the rate of energy flow was lower in mixed forest than in pure forest. The tree layer had a higher ratio of energy accumulation and a lower rate of energy flow than undergrowth did. In view of energy efficiency, trees with high accumulated rate of energy should be introduced and growth of undergrowth should be promoted in a managed forest community. Tab 4, Ref 22中国博士后科研基金;; 福建省科委重大基础研究项目 (2 0 0 0 F 0 4 );; 高等学校骨干教师资助计划资

    影响根癌农杆菌介导的香蕉遗传转化因素研究

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    以香蕉 (Musa spp.)的横切薄层切片 (transverse thin cell layer,t TCL)外植体作为转化受体 ,通过对外植体 GUS基因瞬时表达率的研究以及受体材料对抗生素的敏感性实验 ,找出了较适合的外植体转化条件和培养条件。研究表明 :用低代香蕉无菌苗为材料 ,横切薄层切片芽再生率高 ,有较高的 GUS基因瞬时表达率 ;香蕉对头孢霉素 (Cefotaxime)和羧苄霉素 (Carbenicillin)不敏感 ,而对潮霉素(Hygromycin)很敏感 ;菌液的预处理是影响香蕉转化的主要因子 ,重悬液中的蔗糖浓度也是影响转化的因素之一 ,对遗传转化有明显的促进作

    香蕉农杆菌介导高效转化体系

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    以香蕉 (Musaspp .)的横切薄层切片 (tTCL)外植体作为转化受体 ,研究影响根癌农杆菌转化香蕉的因素。研究表明 ,菌液的预处理和重悬液的pH值是影响香蕉转化的主要因子 ,而乙酰丁香酮 (AS)是香蕉遗传转化中必需的酚类物质 ,80 μmol/L是较理想的浓度 ;感染时间以 8~ 15min ,共培养的时间和温度分别以 4~ 5d及 2 6℃为最佳的条

    Optimization of degrease process during extracting collagen from sea-fish scales

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    研究了鱼鳞胶原蛋白提取过程中的脱脂工艺条件。采用l9(33)正交实验,考察了碱浓度、温度、时间等因素对鱼鳞脱脂工艺的影响,并使用离子色谱检测了脱脂溶液中羟脯氨酸的含量,以考察各种条件对鱼鳞胶原蛋白在脱脂工艺过程中溶出的影响。确定了鱼鳞胶原蛋白提取过程中的脱脂优化工艺,即温度18℃,碱浓度0.5MOl/l,时间8H。放大实验至原料2kg,得脱脂率为92%,适合规模化生产。Degreasation process during collagen extraction from sea-fish scales was explored.The effect of base concentration,temperature and time on degreasing were investigated with the orthogonal method.Ion chromatography was applied to observe the effects of factors on the dissolution of collagen from scales while degreasing.The optimum parameters were:temperature 18℃,base concentration 0.5mol/L and degreasing time 8h.The process was carried out at large scale well with degrease rate at 92%,which indicated that the process could be performed for plant-scale production.国家海洋局第三海洋研究所科研基本业务费(海三科2009006);国家科技支撑计划(2007BAB26B03

    不同形貌氧化铟八面体的可控合成与发光性质

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    FORMS OF SOIL PHOSPHORUS AND P ADSORPTION IN SOILS UNDER

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    通过对黄土旱塬地区长期定位施肥(26a)条件下的不同轮作系统的土壤磷素形态和吸持参数的测定,研究了轮作和施肥对土壤磷素吸持特性和磷素形态的影响,以及土壤磷素吸持参数与磷素形态之间的关系。结果表明,长期轮作与施肥均可以减低土壤磷素的最大吸附量(Qm),相对于其他轮作和连作,在氮磷(NP)施肥下,小麦-玉米-豌豆轮作可以减低土壤的Qm,在氮磷有机肥(NPM)施肥下,小麦-玉米轮作可以减低土壤的Qm。在施肥相同的条件下,小麦-玉米轮作和小麦-豌豆轮作可以显著增加土壤中各形态无机磷的含量,长期轮作较连作可以增加土壤中的有效磷养分,尤其对Ca2-P的提高效果更为显著。相关分析表明,Qm和磷吸持指数(PSI)与全磷(T-P)、Olsen-P、CaCl2-P、Ca2-P、Ca8-P、Fe-P、Ca10-P和有机磷呈极显著负相关(p&lt;0.01),与闭蓄态磷(O-P)呈显著负相关(p&lt;0.05),与Al-P关系不显著。土壤有机质(SOM)与Qm、PSI和磷最大缓冲能力(MBC)之间存在极显著负相关关系,与磷吸持饱和度(DPSS)存在显著正相关。通径系数和逐步回归分析表明,在石灰性黑垆土土壤的</span

    5种植物对铀的积累特征差异研究

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    采用盆栽试验,研究不同铀浓度(0、1、5、20 mg/kg)胁迫下,苜蓿、黑麦草、高丹草、苏丹草和印度芥菜的光合色素、可溶性蛋白质和丙二醛(MDA)含量的变化,以及植物地上部分和根部对铀的富集量。结果表明,低浓度铀可刺激植物光合色素和可溶性蛋白质含量的增加,但随着铀浓度的增加,植物光合色素和可溶性蛋白质含量逐渐下降。铀胁迫诱导植物体内MDA含量呈明显升高的趋势
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