螺旋藻品系Z中不同形态藻丝体的生长速率和光合色素比较

The line-shaped filaments Sp-Z(L) were isolated and cultured from Spirulina platensis Sp-Z. The growth rate of Sp-Z(L) was only 64% as much as that of SP-Z when the light intensity was 4000 Lux. The contentS (×10-3 g / g dry weight) of chlorophylls, carotenoids and phycobilins of Sp-Z(L) and Sp-Z were 20.6, 0.343, 5.00 and 24.1 0.297, 4.46, respectively. Moreover, as to the absorption spectra of the three photopigments of SP-Z(L), red shifts were observed. Therefore, after the spiral Sp-Z breeded or changed…     

变温对昆虫发育速率影响的分析方法研究

温度是影响昆虫发育快慢的主要生态因子。昆虫自然种群一般都生活在不断变动的温度条件下,因此,有关变温对昆虫发育速率的影响,一直受到昆虫学者的注意。本文就有关的统计方法进行评述,并提出一种计算简便、效率高的新方法。     

碘乙酸抑制SeGSHPx对RBC膜脂质过氧化速率的影响及硒甲硫氨酸和V_E的保护作用

 本文用碘乙酸抑制SeGSHPx观察其对RBC膜的脂质过氧化速率的影响以及硒甲硫氨酸和V_E的保护作用。结果说明,同一V_E含量的RBC随着SeGSHPx抑制程度的增加脂质过氧化速率增加;同一SeGSHPx抑制状态的RBC随着V_E含量的降低脂质过氧化速率增加,反映了V_E和SeGSHPx在协同地保护细胞免受脂质过氧化损伤,当细胞的抗氧化保护系统处于低能状态时,不论是由于V_E含量降低或SeGSHPx活性降低或二者兼有,补充V_E和应用能提高SeGSHPx活性的含硒制剂,都能有一定的保护作用。     

Forest net primary productivity dynamics and driving forces in Jiangxi Province,China

Aims Subtropical forest ecosystem has great carbon sequestration capacity. Net primary productivity (NPP) plays a critical role in forest carbon cycle and is affected by a number of factors, including climate change, atmospheric composition, forest disturbance intensity and frequency, and forest age, etc. However, the contribution of these factors to the temporal-spatial dynamics of NPP is still not clear. Quantifying the main driving forces on the temporal-spatial dynamics of NPP for subtropical forest ecosystems is a critical foundation for understanding their carbon cycle.
Methods We utilized multi-sources dataset, including observed meteorological data, inversed annual maximum leaf area index (LAI), referenced NPP (simulated by Boreal Ecosystem Productivity Simulator (BEPS) model), forest age and forest types, land cover, digital elevation model (DEM), soil texture, CO₂ concentration and nitrogen deposition. We used the InTEC (integrated terrestrial ecosystem carbon-budget) model to simulate the NPP dynamics for forest ecosystems in Jiangxi Province during the period of 1901-2010. The effects of climate change, forest age, CO₂ concentration and nitrogen (N) deposition on forest NPP from 1970 to 2010 were discussed through designed scenarios.
Important findings (1) Validations by flux measurements and forest inventory data indicated that the InTEC model was able to capture the interannual and spatial variations of forest NPP. (2) The average forest NPP was 47.7 Tg C·a^-1 (± 4.2 Tg C·a^-1) during 1901-2010. The NPP in the 1970s, 1980s, 1990s and 2000s was 50.7, 48.8, 45.4, and 55.2 Tg C·a^-1, respectively. As forest regrows, NPP significantly increased for forests in Jiangxi Province in the 2000s, and exceed that in the 1970s for more than 60% of the forest area. (3) During 1970-2010, under the scenarios of disturbance and non-disturbance, the forest NPP were underestimated by 7.3 Tg C·a^-1 (14.5%) and overestimated by 3.6 Tg C·a^-1 (7.1%) compared to the scenarios of all disturbance and non-disturbance factors, respectively. Compared to the average NPP during 1970-2010, climate change decreased NPP by -2.0 Tg C·a^-1 (-4.7%), N deposition increased NPP by 4.5 Tg C·a^-1 (10.4%), CO₂ concentration change, and the integrated fertilization of CO₂ and N deposition increased NPP by 4.4 Tg C·a^-1 (10.3%) and 9.4 Tg C·a^-1 (21.8%), respectively.     

后置反硝化生物滤池脱氮效果研究

采用生活污水处理厂的二级出水为原水,以醋酸钠和硝酸钾为外碳源和氮源,挂膜15天后分析进、出水COD、TN和NO3--N。试验表明,挂膜成功后COD去除率稳定在72%～83%,出水COD平均浓度为11.71mg/L,低于污水厂二级出水值;反硝化细菌不断增值,到第8天达到最佳状态,TN和NO3--N的最高去除率分别为66.33%和65.34%,出水浓度分别为11.28mg/L和9.54mg/L,可以达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准。     

一种Zalerion arboricola发酵产物的分离、纯化和结构鉴定

抗真菌药物卡泊芬净是以丝状真菌Zalerion arboricola的菌体代谢产物纽莫康定B0为中间体经化学合成得到。该菌在代谢产纽莫康定B0的同时还会产生多种具有相似结构的代谢物。为了从这些结构类似物中寻找潜在的抗真菌药物中间体,对Zalerion arboricola菌株HCCB30111的代谢产物进行了分离纯化和结构鉴定。本实验成功的从该菌株的发酵液中分离到一个化合物,经结构鉴定证明其为纽莫康定B0的结构类似物。该发现为进一步质量研究,结构修饰和抗真菌活性物质的筛选工作奠定了基础。     

贝壳砂改良土壤中反硝化细菌的分析

【目的】通过对一处经过长期使用贝壳砂进行改良的土壤中的反硝化细菌的多样性和细菌分离分析,研究该土壤中反硝化细菌的组成特征。【方法】采用454焦磷酸测序的方法分析了土壤样品中微生物群落的组成,选用Giltay培养基培养、鉴定从土壤中挑选的分离物的反硝化能力,并对具有反硝化能力的微生物进行了16S rRNA基因鉴定。【结果】该土壤样品中占据优势地位的为Proteobacteria、Acidobacteria、Bacteroidetes、Chloroflexi等门的微生物,属的水平上则有近70%尚未确立分类地位。所分离的细菌中,共得到12株厌氧条件下具有较高硝酸盐去除效率的微生物,分属Pseudomonas、Aeromonas、Serratia和Acinetobacter,均为γ变形菌纲的微生物。【结论】该土壤中具有较高的微生物多样性,包括很多未知类型的微生物和众多类型的反硝化细菌;分离到了11株具有反硝化能力的菌株,可用于该土壤的反硝化过程的进一步研究。     

引黄灌区土壤有机碳密度剖面特征及固碳速率

为揭示灌溉耕作对土壤有机碳密度剖面(0—100 cm)分布产生的影响,通过在宁夏引黄灌区进行实地调查与采样,以无灌溉耕作的自然土壤作为对照,研究不同灌溉耕作时间序列下灌区土壤有机碳密度的剖面分布特征,并估算其平均固碳速率。结果表明:灌区土壤有机碳含量具有随土层深度增加而下降的剖面分布特征,灌溉耕作对增加表层土壤有机碳含量作用最明显;灌区土壤剖面碳密度与灌溉耕作时间和土壤类型均显著相关(P0.01),相关系数分别为0.63和0.74,且因灌溉耕作时间和土壤类型的不同,土壤有机碳密度差异性显著(P0.05);灌溉耕作影响的土层深度及剖面土壤有机碳密度的增加量因灌溉耕作时间长短的不同而异;引黄灌区5类土壤的平均固碳速率为0.53 MgC·hm-2·a-1。引黄灌溉耕作在增加农田土壤固碳中发挥着重要作用。     

荔枝树干液流速率与气象因子的关系

采用热扩散茎流仪于2011—2012年连续监测‘桂味’荔枝树干液流速率,将所得数据和果园内自动气象站观测数据一起进行对比分析,建立了液流速率与气象因子的关系模型。实验结果表明:(1)树干液流速率日变化呈现"昼高夜低"的规律。季节变化有呈现"先高后低"的趋势,整体上以果实发育期和成熟期(5—7月)液流速率较高。2011年年平均液流速率明显大于2012年;(2)树干液流速率日变化在晴天时多呈单峰曲线,且振幅较大;在雨天呈多峰曲线,且振幅较小。总体上,晴天平均液流速率约是雨天的两倍;(3)回归分析表明,在一定范围内,树干液流速率与太阳辐射强度、空气温度呈正相关,与空气湿度呈负相关。影响液流速率最重要的气象因子在晴天是空气温度,在雨天是太阳辐射。