PVA固定化污泥反应器启动特性的研究

比较了ＰＶＡ固定化污泥反应器和游离污泥反应器在启动过程中的特性差异。结果表明，ＰＶＡ固定化污泥反应器能在高浓度ＣＯＤ下稳定启动，能抗高容积有机负荷和水质不稳定的冲击，ＣＯＤ绝对去除量高２～３倍，出水ＳＳ和Ｏ．Ｄ值明显较低，ＶＦＡ浓度较低而总碱度（ＴＡ）较高，污泥产酸活性和产甲烷活性也较高。游离污泥反应器的性能相对较差，这种差异的微生物学原因在于污泥经ＰＶＡ固定后建立了良好的产酸化和产甲烷化的互营体系，而游离污泥反应器形成这种互营体系则需要较长的时间。     

Assessment of microbial activity and bacterial community composition in the rhizosphere of a copper accumulator and a non-accumulator

Soil microorganisms may play an important role in the uptake of heavy metals from soils. However, assessments of bacterial activity and community composition in the rhizosphere of accumulators have been largely ignored. We studied potential effects of a copper (Cu)-accumulator, Elsholtzia splendens, and a non-Cu-accumulator plant, Trifolium repens, on soil microbial activity and community composition with increasing Cu addition. The results showed that concentrations of Cu in the shoots of E. splendens were 2.1, 2.2 and 2.4 times those of T. repens under the treatment of different Cu concentrations. Soil microbial biomass and phosphatase activity in the rhizosphere of E. splendens were higher than those of T.repens. PCR-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprint analysis revealed that addition of Cu decreased the number of bands in bare soil and soil with T. repens. However, there was a significant increase in the number of bands in soil with E. splendens incorporated with either 200 or 500 mg kg⁻¹ Cu. The abundances of five phylogenetic groups related most closely to -, β-, γ-proteobacteria, Gram-positive bacteria and CFB group, respectively, were determined in the rhizosphere of plants. Some specific clone such as E13 (metal-contaminated soil clone K20-64) was found in the rhizosphere of E. splendens. Results indicated that E. splendens, as a Cu-accumulator, played an important role in governing soil microbial activity and bacterial community composition in the rhizosphere in response to Cu stress.     

Biomass and Cu and Zn Uptake of Two Turfgrass Species Grown in Sludge Compost–soil Mixtures

Two kinds of common turfgrass, fescue and ryegrass, were grown in soils amended with 20?×?80% sludge compost (SC) in this research. The effects of SC on two kinds of soil and response of fescue and ryegrass to the SC amendment were studied. The results showed that urease activity, extractable content of Cu and Zn and Electrical conductivity of both soils increased while pH decreased with the increase of SC amendment. However, the change of these parameters also depended strongly on soil characteristics. Sludge compost at the ≤40 and ≤60% levels can improve growth of fescue and ryegrass, respectively. The biomass of fescue grown in substrate with 40% SC increased 27% in a red soil and 44% in a yellow loamy soil compared to the control. The biomass of ryegrass grown in substrate with 60% SC increased 120% in the red soil and 86% in the yellow loamy soil. Sludge compost amendment at these levels did not significantly affect soluble salt contents of soil or Cu and Zn in plant tissue. Therefore, rational use of sludge compost can take advantage of its beneficial effect as a nutrient source for plant production while avoiding the potential deleterious effects on soil and plant.     

红茶色素的形成与降解作用的初步研究

在红茶制造中,用铜酶抑制剂二乙基二硫代氨基甲酸钠能抑制多酚氧化酶活性24%左右,从而部分的抑制了茶叶发酵,特别是茶黄素的形成受到了抑制。采用茶叶匀浆发酵法,结果表明,非酶性氧化产物中茶黄素约为酶促氧化形成量的6.8%,茶红素约为20.6%。用茶黄素单没食子酯在纯过氧化物酶作用下,研究其降解作用,其产物用双向纸层析和紫外光谱进行分析鉴定,结果鉴别出3,4-二羟苯甲酸、咖啡酸、没食子酸和邻苯二酚等4种成分。     

侧柏人工幼林年生长动态及其与水热关系研究初报

侧柏人工幼林年生长动态及其与水热关系研究初报薄颖生韩恩贤罗伟祥（陕西省林业科学研究所杨陵７１２１００）关键词侧柏,人工幼林,生长动态,水分,热量,回归分析侧柏是黄土高原造林的优良树种之一［１～３］。过去由于对该树种的生物学、生态学及造林学特性等方面...     

有机肥和无机肥对水稻土产甲烷的影响

在盆栽条件下,研究了二种有机肥和五种无机肥对淹水稻上产甲烷细菌数量和甲烷释放量的影响。结果表明有机肥对产甲烷菌数量和甲烷释放量均有较大的促进作用,其中以绿肥最为显著。无机肥料的施用处理中,NH4HCO3、（NH4）2SO4、CO（NH2）2和NH4Cl对水稻土产甲烷细菌数量的增加和甲烷释放量均略有促进作用,而施NaNO3处理的对甲烷释放总量有较明显的抑制作用。     

龙泉市兰花资源调查报告

163 个样地调查以及线路和补充调查表明, 龙泉市兰花共计7 种2 变种,其中1 种为浙江新记录。兰花的生长分布与地形、气候、土壤和植物等生境因子关系密切。海拔高度变化能影响并限制兰花种类和数量的分布;西坡、中上坡和陡急坡兰花分布多;兰花喜荫, 但需要一定光照强度, 对空气湿度要求较高;兰花最适生长于壤质、团粒、酸性或强酸性、有机质含量高、排水良好的土壤中;兰花与上层乔木树种关系不大, 而与杜鹃、木等酸性灌木树种有一定相关。通过推算, 龙泉市兰花资源蕴藏总量为2592.8 万束。文中对龙泉市兰花资源状况作了分析, 概要地提出了保护意见。     

寄主作物对美洲斑潜蝇蛀食和发育的影响

美洲斑潜蝇在寄主作物上的虫道呈蛇形,且主要分布在叶片正面,明显有别于豌豆彩潜蝇、番茄斑潜蝇。幼虫在不同寄主作物上蛀食能力差异明显,在丝瓜、茄子和豇豆上单个潜道面积分别为53.34、51.76、34.55 m m 2 。不同龄期幼虫蛀食量差异较大,其中以3 龄幼虫为最大,约占蛀食量59.30% ～70.68% 。在25℃下,卵历期2.3～2.8 d, 寄主作物对卵的发育影响不明显,对幼虫历期有一定的影响。     

小麦节水高产优质栽培研究进展

水资源短缺已成为全球的第一生态问题．我国水资源不但总量不足,而且地域和季节分布不均衡,尤以北方地区水资源缺乏更为严重．因此,在总结前人研究成果的基础上,从小麦生理生化方面详细论述了水分和氮素在小麦生长、产量和品质中的作用,并着重分析了水分和氮素互作对小麦生长的影响。     

凸轮-六杆式导苗机构设计及仿真

为了提高导苗管式移栽机作业质量,简化核心部件结构,通过AHP-模糊综合评价法优化提出了凸轮-六杆式导苗机构,根据导苗管式移栽机作业农艺要求,并结合导苗机构作业时序设计规定,确定了导苗机构的关键结构与运动参数。当株距δ=225mm、作业效率ξ=80株/(min·行)时,ωc=8.3 8 rad/s,υm=0.3 0 m/s,φc 0∈(-15°,72°),φg 0=3 5 0°,l1=2 4 mm,l2=6 0 mm,l3∈(285,295)mm,l4=1 8 0 mm,l5=1 0 5 mm,l6=4 5 mm,l7=3 5 5 mm,l9=2 9 0 mm。在该设计参数下,对凸轮-六杆式导苗机构进行了虚拟样机分析,结果表明:钵苗从导苗管滑道斜抛落入开沟器底部能够保持直立姿态,验证了结构分析和设计的正确性。