热水法提取香菇多糖和茶树菇多糖研究

真菌多糖具有降血糖、抗肿瘤、抗氧化、抗病毒和免疫调节等多种生理功能,且对机体毒副作用小,具有广阔的开发前景。以营养价值和药用价值均较高的香菇(Lentinus edodes)、茶树菇(Agrocybe aegirit)为原料,用热水提取法在90℃、料液比1∶20(g∶m L)、提取1次、4 h的条件下,提取两种真菌多糖。结果表明,热水法提取香菇多糖的得率为9.70%,茶树菇多糖的得率为13.10%,说明茶树菇中的多糖含量高于香菇。该研究可为后续开发利用真菌多糖提供重要依据。     

丘陵山地区耕地水约束状态研究——以黎香溪流域为例

建立一种土壤水循环机理与地形特征结合的层次评价模型,以长江一级支流——黎香溪流域为研究区,以土壤的蓄水量、土壤地形湿度、蒸散发量和灌溉用水条件作为评价因子,采用层次分析法对流域耕地水约束状态进行综合分析,将水约束状态分为轻度、一般、较重、重度、极重5个等级。通过对300个样本的抽样调查,分析结果总体正确率为78%。灌溉条件的影响力随着约束等级的降低而增加,正确率随着约束等级的降低而降低,从极重到轻度正确率分别为85.00%、81.67%、78.33%、75.00%和68.33%。流域内耕地受用水较重及以上程度约束占总面积的55%。模型对流域内部耕地用水状态的相对差异模拟精度较高,灌溉水平的差异是误差的主要来源。     

Old and New Cultivars of Soya Bean (Glycine max L.) Subjected to Soil Drying Differ in Abscisic Acid Accumulation,Water Relations Characteristics and Yield

Two old (Huangsedadou and Longxixiaohuangpi (LX)) and two new (Jindou 19 (JD) and Zhonghuang 30 (ZH)) soya bean (Glycine max (L.) Merr.) cultivars were used to investigate the influence of soil drying on the abscisic acid (ABA) accumulation in leaves, stomatal conductance (g_s), leaf water relations, osmotic adjustment (OA), leaf desiccation tolerance, yield and yield components. The greater ABA accumulation was induced by soil drying, which also inducing g_s decreased at higher soil water contents (SWC) and leaf relative water content (RWC) significantly decreased at lower SWC in the new soya bean cultivars than in the old soya bean cultivars. The soil water threshold between the value at which stomata began to close and the RWC began to decrease was significantly broader in the new cultivars than in the old cultivars. The new cultivars had significantly higher OA and lower lethal leaf water potential than old cultivars when the soil dried. The old cultivars had greater biomass, but lower grain yield than the new cultivars in well‐watered, moderate stress and severe stress conditions. Thus with soil drying, the new soya bean cultivars demonstrated greater adaptation to drought by inducing greater ABA accumulation, stomatal closure at higher SWC, enhanced OA and better water relations, associated with increased leaf desiccation tolerance, greater water use efficiency and higher yield.     

混合絮凝剂处理中纤板厂木片水洗废水的研究

对中密度纤维板厂木片水洗废水处理方案进行研究:混合絮凝剂的成分和最佳投放量经研究确定为15 g/m3聚合氯化铝和1 g/m3聚丙烯酰胺,对木片质量也不会有较大损害;确定最佳处理水量占总水量的比例为15%,既能使废水水质得到改善,而且处理成本为最小,达到资源回收利用的目的。     

日粮钙水平对泌乳水牛生产性能的影响

为了探讨日粮钙水平对泌乳水牛生产性能的影响,本试验选用12头胎次、泌乳时间、泌乳量相近的水牛,随机分成4组,每组3头水牛。采用4×4拉丁方试验方法,4组水牛基础日粮中钙含量分别占基础日粮干物质的0.47%、0.62%、0.78%、0.93%,其他营养成分均相同,其中磷占采食干物质比例为0.50%;共4期试验,每一试验期21 d,其中预饲期7 d,正饲期14 d。试验结果表明:1、不同钙水平日粮对泌乳水牛的产奶性能影响不显著(P>0.05),但0.78%钙水平日粮组水牛的产奶量分别比其他3组提高5.4%、5.5%、3.9%,不同钙水平对水牛奶营养成分影响不显著(P>0.05)。2、不同钙水平日粮对水牛血浆中钙含量影响差异显著(P<0.05);随着日粮钙水平的上升,水牛血液甲状旁腺素和1,25二羟基维生素D呈显著下降趋势(P<0.05)。综合各指标,日粮钙占采食干物质的比例为0.78%能进一步提高泌乳水牛产奶量。     

惠州市基塘系统三种典型养殖模式的水质调查与分析

介绍了惠州市基塘系统三种典型的水产养殖模式，并对旱季和雨季时三种养殖模式塘的一些常规污染指标进行了监测与分析，结果表明：猪鱼模式塘中的COD、NH3-N和TN呈现升高的趋势，猪粪水对其贡献率最大，旱季时猪鱼模式塘和单投饲料塘的NH，-N和TN污染严重；各模式塘受到重金属不同程度的污染，其中铜污染尤为严重。最后给出了改善水产养殖用水的措施。     

水处理设备的单片微机控制器

介绍了用 89C2 0 51单片机系统对水处理设备工作的控制 ,使水处理设备能全面、可靠、无人值守地工作 ,达到智能的档次 .文中描述了水处理设备控制器的软件设计和硬件设计     

Contamination of shallow groundwater system and soil-plant transfer of trace metals under amended irrigated fields

This study focuses on experimental pilot assessment of contamination of shallow groundwater systems and soil-plant transfer of trace metals under amended irrigated fields. The study approach involved a pilot experimental (greenhouse) set-up of organo-mineral amended test plots/troughs (40 cm × 47 cm × 46 cm) planted with two common vegetable crops (Amaranthus hybridus and Abelmoschus esculentus) and irrigated with wastewater. In addition to the geochemical analyses of the primary un-amended and amended soils before planting as well as residual soils after harvesting, measurements of the physico-chemical parameters and chemical analyses of trace metals concentrations in irrigation leachates and harvested vegetable tissues were also undertaken following appropriate standard sample preparation and analytical methods.The results of the geochemical analyses carried out on irrigation leachate samples collected during the sprouting stage revealed that most of the analyzed trace metals in the collected leachates exhibited 2-10 folds depletion (except for Cu and Co with enrichment of about 1.5-3 folds) compared to the initial wastewater used for irrigation. A situation attributed to uptake/bioaccumulation of these metals and selective enrichment in the residual soils as well as to leaching by infiltrating irrigation water. Nonetheless, the observed higher trace elements concentrations in the second sets of leachates collected during harvesting stage compared to the first sets of leachates collected during the sprouting/vegetative stage is an indication of higher plant uptake during sprouting/vegetative stage or initial sorption/complexation of biosolids amendment before later vertical re-mobilization by infiltrating irrigation water.Although, virtually all of the analyzed metals exhibited elevated concentrations (2-173 ppm) in both A. hybridus and A. esculentus, a closer evaluation revealed 1.2-8.2 folds enrichment of Cr, Co, Ni, Cd, Cu, and Pb in A. esculentus compared to that of A. hybridus, an indication of the fact that phyto-accumulation of trace metal is plant-specific and dependent on physiological set-up. The overall evaluation had clearly demonstrated the potential danger of bioaccumulation of toxic trace metals under biosolid amended soils as well as impacts of irrigation-induced leaching on the shallow groundwater quality, while the need to evolve a sustainable agricultural practices is also highlighted.

Capsule

Organo-mineral amendment can lead to trace metal bioaccumulation (in plants) and irrigation-induced leaching to shallow groundwater system.     

利用随机网络模型和CT数字图像预测近饱和土壤水分特征曲线

通过对连续土壤切片CT图像的分析,定量获取了土壤孔隙的大小分布情况。在此基础上建立了基于土壤孔隙形态学特征的随机网络模型,在孔隙尺度模拟了土壤中的水分运动过程,并预测了近饱和土壤水分特征曲线。结果表明,通过选取合适的模型参数,基于土壤孔隙形态学特征建立的随机网络模型可以模拟出与土壤样本实测值非常接近的水分特征曲线,可以作为一种快速测量的方法。