草鱼干扰素的分离纯化及某些理化和生物学特性

通过ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ阴离子交换层析、Ｓｅｐｈａｃｒｙｌ Ｓ－２００凝胶层析、高效液相层析和梯度聚丙烯酰张胶电泳等技术,对病毒诱生的草鱼血清干扰素进行了分离纯化。纯化的草鱼干扰素在ＳＤＳ－聚丙烯酰胺凝胶电泳中呈现单一组份,分子量为３８ｋＤ,等电点为５．２５,过碘酸－Ｓｃｈｉｆｆ试剂反应表现为典型的糖蛋白染色特征。理化和生物学特性研究表明,草鱼干扰素具有１０００００ｇ（２ｈ）离心不沉降、耐     

植物诱导抗病技术的发展现状

对植物诱导抗病技术进行了综述;针对生物诱导因子、物理诱导因子和化学诱导因子,分析了各种诱导因子的特征和应用;指出了植物诱导抗病性研究的现状和问题;并对诱导抗病性的应用和发展方向做作了概括.     

某化肥项目余热利用分析

该工程为利用某化肥项目生产过程中产生的余热进行发电。通过对化肥项目生产流程产生的废气与余热蒸汽总量分析,提出余热利用发电的装机方案,对该规模项目余热利用的方式与规模进行探讨。     

化学打顶对阿拉尔垦区主栽品种光合冠层的影响

化学打顶是指利用植物生长调节剂来打破作物顶端优势,进而保障作物的正常生长和生产。本文为探究化学打顶对作物的影响,利用摇钱素和棉花打顶剂处理新陆中70和新陆中82不同品种,同时测定不同化学打顶剂处理条件下,棉花的净光合速率、气孔导度、蒸腾速率、胞间CO₂浓度及棉花冠层叶面积指数指标。研究发现：不同化学打顶处理条件下,与人工打顶相比化学打顶的棉花的五种指标变化均不明显,但新陆中70和新陆中82品种的净光合速率平均值与对照相比分别高出3 μmol/(m2.s)和2 μmol/(m2.s),且冠层叶面积指数值比人工打顶的略高。试验结果表明化学打顶处理后没有造成棉花疯长,提高了光能利用率,进而增加作物群体的光合作用。     

广东陈香茶后发酵过程中主要微生物种群和酶类活性变化的研究

以岭头单丛茶树品种晒青毛茶为材料进行后发酵加工陈香茶,重点跟踪研究后发酵过程不同阶段的微生物种群、主要生化成分及主导酶类的变化并进行鉴定和分析。结果表明,在陈香茶后发酵过程中,微生物以产黄青霉和黑曲霉为主。茶多酚、茶黄素、茶红素、游离氨基酸等茶叶品质成分含量均呈下降趋势,而茶褐素逐步增加;果胶酶、纤维素酶等促进茶叶品质形成的酶类在后发酵一翻（4 d）时活力到达最高峰,多酚氧化酶在整个过程中活性较低。     

Response of soil properties and yam yield to Chromolaena odorata (Asteraceae) and Tithonia diversifolia (Asteraceae) mulches

Plant materials differ in their chemical composition, rate of decomposition and suitability as mulch materials. Experiments were conducted during 2006–2007 and 2007–2008 cropping seasons for early yam cultivation at Owo in the forest–savanna transition zone of southwest Nigeria to study the effect of Chromolaena odorata and Tithonia diversifolia mulches applied at 0.0, 5.0, 7.5, 10.0 and 12.5 t ha^?1 on soil chemical properties, leaf nutrient composition, growth and tuber yield of white yam (Dioscorea rotundata Poir). Both C. odorata and T. diversifolia mulches reduced soil bulk density and temperature; increased concentrations of soil organic matter (SOM), total N, available P, exchangeable K, Ca and Mg, leaf N, P, K, Ca and Mg; enhanced growth and yield of yam compared with control. The values of SOM, total N and available P and leaf N and P concentrations increased with increasing mulch rate. C. odorata mulch and T. diversifolia mulch applied at 10.0 and 7.5 t ha^?1, respectively, was found to be suitable for yam production. T. diversifolia mulch compared with C. odorata mulch produced higher values of soil chemical properties, leaf nutrient concentrations, growth and yield of yam. T. diversifolia mulch produced 19% and 18% higher tuber yield compared with C. odorata mulch during 2006–2007 and 2007–2008 cropping seasons, respectively.     

Minimizing ammonia volatilization from urea,improving lowland rice (cv. MR219) seed germination,plant growth variables,nutrient uptake,and nutrient recovery using clinoptilolite zeolite

The anionic nature and high cation exchange capacity (CEC) of clinoptilolite zeolite can be exploited to reduce ammonia (NH₃) loss from urea and to improve soil chemical properties to increase nutrient utilization efficiency in lowland rice cultivation. A closed-dynamic airflow system was used to determine NH₃ loss from treatments (20, 40, and 60 g clinoptilolite zeolite pot^?1). Seed germination study was conducted to evaluate the effects of clinoptilolite zeolite on rice seed germination. A pot study was conducted to determine the effects of clinoptilolite zeolite on rice plant growth variables, nutrient uptake, nutrient recovery, and soil chemical properties. Standard procedures were used to determine NH₃ loss, rice plant height, number of leaves, number of tillers, dry matter production, nutrient uptake, nutrient recovery, and soil chemical properties. Application of clinoptilolite zeolite (15%) increased shoot elongation of seedlings and significantly reduced NH₃ loss (up to 26% with 60 g zeolite pot^?1), and increased number of leaves, total dry matter, nutrient uptake, nutrient recovery, soil pH, CEC, and exchangeable Na⁺. Amending acid soils with clinoptilolite zeolite can significantly minimize NH₃ loss and improve rice plant growth variables, nutrient uptake, nutrient recovery, and soil chemical properties. These findings are being validated in our ongoing field trials.     

氧化节杆菌生物降解苯并芘

A pot experiment was conducted with multi-metal (Pb, Cd, Cu, and Zn) contaminated acidic soil to investigate changes in available metal burden resulting from the application of industrial wastes (fly ash and steel slag). The efficiency of amendments-induced metal stabilization was evaluated by diffusive gradients in thin films (DGT), sequential extraction, and plant uptake. The stability of remediation was assessed by an acidification test and by chemical equilibrium modeling. Addition of fly ash (20 g kg-1 ) and steel slag (3 g kg-1 ) resulted in similar increase in soil pH. Both amendments significantly decreased the concentrations of metals measured with DGT (C DGT) and the metal uptake by Oryza sativa L. Significant correlations were found between C DGT and the concentration of a combination of metal fractions (exchangeable, bound to carbonates, and bound to Fe/Mn oxides), unraveling the labile species that participate in the flux of metal resupply. The capability of metal resupply, as reflected by the R (ratio of C DGT to pore water metal concentration) values, significantly decreased in the amended soils. The C DGT correlated well with the plant uptake, suggesting that DGT is a good indicator for bioavailability. Acidification raised the extractable metal concentration in amended soil but the concentration did not return to the pre-amendment level. Equilibrium modeling indicated that the soil amendments induced the precipitation of several Fe, Al and Ca minerals, which may play a positive role in metal stabilization. Chemical stabilization with alkaline amendments could be an effective and stable soil remediation strategy for attenuating metal bioavailability and reducing plant metal uptake.     

Landscape and Land‐Use Effects on the Spatial Variation of Soil Chemical Properties

The current study addressed the spatial variation of soil organic matter (SOM), total nitrogen (TN), extractable phosphorus (EP), and extractable potassium (EK) in agricultural soils of a representative region, northeast China. Soil cation exchange capacity (CEC) and the effects of landscape attributes and land use were also investigated. The techniques used included conventional statistics, geostatistics, and geographic information systems (GIS). Our study demonstrated that EP had the greatest coefficient of variation (CV), and CEC had the least CV. The experimental semivariograms of the five soil chemical properties included in this study were all fitted with exponential models. The five soil variables all showed moderate spatial dependence. The SOM, EK, and CEC decreased with increasing altitude. Significant negative relationships were found between the slope gradient and EP, EK, and CEC. Relatively steeper slopes might result in greater soil erosion, which leads to a decline in soil nutrients. Soil types had significant impacts on all soil chemical properties, which reflect the effect of the parent soil material. In general, the mean values of soil variables for vegetable land were statistically greater than those for upland and paddy fields. After being divided into two parts along the Yinma River, soil samples of the western part have statistically greater SOM, EP, EK, and CEC values than those collected from the eastern part.     

马尾松纯林改造成针阔混交林后土壤化学性质的变化

在25 a生的马尾松林下分别套种火力楠、闽粤栲、苦槠、格氏栲、青栲和拉氏栲等阔叶树种的1 a生幼苗,16年后形成郁闭的针阔混交异龄林。土壤化学分析结果显示,在马尾松林下套种阔叶树(除青栲外)明显增加了林下表层土壤(0~20 cm)的有机质含量。各林分下土壤全K、全M g、全C a、全N和全P的平均含量分别为11.41,6.64,4.33,1.45,0.46 g/kg,表明土壤K、M g、C a的含量比较丰富,而N和P则相对缺乏,营造混交林在一定程度上增加了土壤N、P含量。所有混交林深层土壤(20~60 cm)的有效N、P含量均大于马尾松纯林,而有效K的含量则相反。混交林下0~20 cm,20~40 cm和40~60 cm土壤的平均pH值分别为4.40,4.61和4.68,而马尾松纯林下各土层的pH值则依次为4.39,4.41及4.42,说明在马尾松林下套种阔叶树在一定程度上降低了20 cm以下土层的活性酸度。套种阔叶树(除苦槠外)后由于降低了土壤交换性酸度,增加了土壤盐基离子浓度,从而明显提高了土壤盐基饱和度。