岷江干旱河谷甜樱桃发展优势及栽培技术研究

岷江上游干旱河谷特有的生态环境条件适宜发展优质特色水果.甜樱桃作为该区域新兴特色水果之一,近5年来发展面积已超过了400hm2.甜樱桃的引种和规模化栽培表明,岷江上游干旱河谷区发展优质、高产甜樱桃具有独特的优势.总结了岷江干旱河谷栽培甜樱桃的成熟技术和管理措施,探讨了发展甜樱桃的巨大潜力,同时对存在的问题进行了分析,以期为汶川地震灾害农业产业的恢复重建和结构调整提出新的思路.     

不同土地利用方式及开垦时间对岩溶山区土壤养分空间分布的影响

采集贵州普定典型岩溶山区7种土地利用方式和3个不同开垦时间(27 a、39 a、48 a)的0～10 cm、10～20 cm、20～40 cm土壤样品,进行室内理化分析.结果显示,林地土壤有机质、全氮、碱解氮累积量较多,玉米黄豆地含量最少.林地土壤0～10 cm层有机质、全氮、碱解氮分别比玉米黄豆地高271.0%、317.7%、246.1%.林地和撂荒地对土壤养分循环较为有利.林地开垦为农业用地后,土壤有机质、全氮、碱解氮含量明显下降,全磷、有效磷、全钾含量没有明显变化,有效钾含量增多.开垦39 a的0～10 cm层土壤有机质、全氮、全磷、有效磷、有效钾含量高于开垦27 a和48 a土壤的含量,碱解氮低于开垦27 a和48 a土壤的含量;开垦27 a的土壤全钾含量高于开垦39 a和48 a土壤的含量.开垦时间长或短对土壤养分含量的影响未表现特殊规律性,可能受到其他因素的影响.     

三丁基锡对中国近海常见海洋微藻的毒性效应

研究三丁基氯化锡（TBT）对中国近海常见5种硅藻和甲藻（硅藻中丹麦细柱藻（Leptocylindrus danicus）、派格棍形藻（Bacilaria paxillifera）、聚生角毛藻（Chaetoceros socialis）,甲藻中微型原甲藻（Prorocentrum minimum）、简裸甲藻（Gymnodinium simplex））的毒性效应,考察了有机锡对浮游藻光合活性（Fv/Fm）、粒径、生长的影响。结果表明：派格棍形藻、聚生角毛藻、简裸甲藻的光合活性（Fv/Fm）受TBT影响较显著;微型原甲藻、丹麦细柱藻的光合活性受TBT影响较小。高质量浓度TBT胁迫下海洋微藻峰值粒径显著减小,低质量浓度TBT对峰值粒径影响不显著。低质量浓度TBT对派格棍形藻、聚生角毛藻、简裸甲藻、微型原甲藻均有较强的毒性作用,非检测毒性浓度（NDEC）分别为1.17、1.07、0.23、3.73μg.L-1,丹麦细柱藻对TBT具有很强耐受性,NDEC为112.62μg.L-1。     

Isolation and characterization of a thermophilic Bacillus shackletonii K5 from a biotrickling filter for the production of polyhydroxybutyrate

Polyhydroxyalkanoates（PHAs） are aliphatic polyesters accumulated intracellularly by both Gram-negative and Gram-positive bacteria. However, compared to the PHAs of Gramnegative bacteria, few endotoxins（lipopolysaccharides, LPS）, which would be co-purified with PHAs and cause immunogenic reactions, are found in the PHAs produced by Gram-positive bacteria. A thermophilic Gram-positive bacterium K5, which exhibited good growth and polyhydroxybutyrate（PHB）-accumulating ability, has been isolated and characterized from a biotrickling filter designed for the removal of NOx from flue gas in a coal-fired power plant in China. Based on the biochemical characterization and 16 S rRNA gene sequence（Genbank accession no. JX437933）, the strain K5 has been identified as Bacillus shackletonii, which has rarely been reported in the literature, and this report is the first time that B. shackletonii has been found to accumulate PHB. The strain K5 was able to utilize glucose as carbon source to synthesize PHB at a broad range of temperatures（from 35 to 50 °C）, and the ideal temperature was 45 °C. The strain K5 could effectively yield PHB of up to 69.9% of its cell dry weight（CDW）（2.28 g/L） in flask experiments employing glucose as carbon source at 45 °C, followed by 56.8% and 52.3% of its CDW when using sodium succinate and glycerol as carbon source, respectively. For batch cultivation, the strain K5 was able to produce PHB of up to 72.6% of its cell dry weight（9.76 g/L） employing glucose as carbon source at 45 °C and pH 7.0.     

荒漠蓝藻抗逆性及应用研究进展

蓝藻是荒漠藻类中的主要类群,它能抵御荒漠生境中高低温、干旱、高盐碱、高紫外辐射等极端环境的胁迫,蓝藻胞外多糖及胞内的伪枝藻素、MAAs等在抵抗逆境胁迫过程中起了重要的作用.主要介绍了荒漠蓝藻抗逆性及其培养条件的研究进展,并概述了荒漠蓝藻的应用研究.     

连续流态下以实际低基质生活污水培养好氧颗粒污泥及其脱氮性能

研究了连续流系统污泥颗粒化过程中COD、氨氮和TN的去除效果以及成熟好氧颗粒污泥的物理性质和脱氮动力学.结果表明40 d内连续流系统内能形成好氧颗粒污泥.随着颗粒化程度的提高,系统脱氮除碳性能有所增加;第41~60 d稳定运行期间,系统对COD、氨氮和TN的平均去除率分别到达到85.54%、95.5%和65.56%,且反应过程中硝酸盐氮和亚硝酸盐氮的积累不高.成熟颗粒污泥有较多的空隙结构,含有大量的胞外聚合物,相比于接种絮状污泥,其含水率、湿密度、沉降速度、机械强度、SVI值等都体现出了明显的优势.成熟好氧颗粒污泥同步硝化反硝化效率为81.69%,硝化速率(以NH+4-N计)和反硝化速率(以NO-x-N计)分别为5.78 mg·(L·h)-1和4.90 mg·(L·h)-1.     

The Dual Model for Tourism Resource Productivity Improvement

Abstract

For natural resource science, resource productivity studying is an important subject. But researches on tourism resource productivity are limited. The most significant influencing factor on tourism resource productivity is the potential market scale of tourist locations, and second most important influencing factor is the resource endowment. Regional urban population is significantly correlated with region tourist numbers, being the decisive factor of region potential tour market scale. In tourism development, the dual model should be adopted: on one hand to enhance tour spot attractiveness, on the other hand to cultivate the potential market by improving urbanization level and other means. In the situation of tourism development fever spreading, the dual model for improving tourism productivity helps to avoid the “Great Leap Forward” which means that too rapid tourism construction divorces from actual market demand.