Synthesis and antiviral activities of amide derivatives containing the alpha-aminophosphonate moiety

Starting from (substituted-)benzaldehydes, the title compounds 6 were synthesized through five step reactions. Benzaldehydes were treated with ammonium hydroxide, followed by dialkyl phosphite, to give dialkyl N-(arylmethylene)-1-amino-1-aryl methylphosphonates ( 3). Phosphonates 3 were then easily hydrolyzed to give dialkyl 1-amino-1-aryl-methylphosphonates 5. Target compounds 6 were then obtained by the reaction of 5 and substituted benzoic or cinnamic acid. Their structures were clearly verified by spectroscopic data (IR, 1H, 13C, and 31P NMR, and elemental analysis). These compounds were shown to be antivirally active in the bioassay. It was found that title compounds 6g, 6l, and 6n had the same inactivation effect of TMV (EC 50 = 54.8, 60.0, and 65.2 microg/mL, respectively) as commercial product Ningnanmycin (EC50 = 55.6 microg/mL). To the best of our knowledge, this is the first report on the synthesis and antiviral activity of amide derivatives containing an alpha-aminophosphonate moiety.     

Carbon exchange in a freshwater marsh in the Sanjiang Plain, northeastern China

Northern wetlands are critically important to global change because of their role in modulating atmospheric concentrations of greenhouse gases, especially CO₂ and CH₄. At present, continuous observations for CO₂ and CH₄ fluxes from northern wetlands in Asia are still very limited. In this paper, two growing season measurements for CO₂ flux by eddy covariance technique and CH₄ flux by static chamber technique were conducted in 2004 and 2005, at a permanently inundated marsh in the Sanjiang Plain, northeastern China. The seasonal variations of CO₂ exchange and CH₄ flux and the environmental controls on them were investigated. During the growing seasons, large variations in net ecosystem CO₂ exchange (NEE) and gross ecosystem productivity (GEP) were observed with the range of −4.0 to 2.2 (where negative exchange is a gain of carbon from the atmosphere) and 0-7.6 g C m⁻² d⁻¹, respectively. Ecosystem respiration (RE) displayed relatively smooth seasonal pattern with the range of 0.8-4.2 g C m⁻² d⁻¹. More than 70% of the total GEP was consumed by respiration, which resulted in a net CO₂ uptake of 143 ± 9.8 and 100 ± 9.2 g C m⁻² for the marsh over the growing seasons of 2004 and 2005, respectively. A significant portion of the accumulated NEE-C was lost by CH₄ emission during the growing seasons, indicating the great potential of CH₄ emission from the inundated marsh. Air temperature and leaf area index jointly affected the seasonal variation of GEP and the seasonal dynamic of RE was mainly controlled by soil temperature and leaf area index. Soil temperature also exerted the dominant influence over variation of CH₄ flux while no significant relationship was found between CH₄ emission and water table level. The close relationships between carbon fluxes and temperature can provide insights into the response of marsh carbon exchange to a changing climate. Future long term flux measurements over the freshwater marsh ecosystems are undoubtedly necessary.     

Studies of O,O-dimethyl α-(2,4-dichlorophenoxyacetoxy)ethylphosphonate (HW02) as a new herbicide. 1. Synthesis and herbicidal activity of HW02 and analogues as novel inhibitors of pyruvate dehydrogenase complex

On the basis of the previous work for optimization of O,O-diethyl α-(substituted phenoxyacetoxy)alkylphosphonates, further extensive synthetic modifications were made to the substituents in alkylphosphonate and phenoxy moieties of the title compounds. New O,O-dimethyl α-(substituted phenoxyacetoxy)alkylphosphonates were synthesized as potential inhibitors of pyruvate dehydorogenase complex (PDHc). Their herbicidal activity and efficacy in vitro against PDHc were examined. Some of these compounds exhibited significant herbicidal activity and were demonstrated to be effective inhibitors of PDHc from three different plants. The structure-activity relationships of these compounds including previously reported analogous compounds were studied by examining their herbicidal activities. Both inhibitory potency against PDHc and herbicidal activity of title compounds could be increased greatly by optimizing substituent groups of the title compounds. O,O-Dimethyl α-(2,4-dichlorophenoxyacetoxy)ethylphosphonate (I-5), which acted as a competitive inhibitor of PDHc with much higher inhibitory potency against PDHc from Pisum sativum and Phaseolus radiatus than from Oryza sativa , was found to be the most effective compound against broadleaf weeds and showed potential utility as herbicide.     

牵引式山地果园运输机驱动绳轮摩擦磨损

为探究牵引式山地果园运输机驱动绳轮系统的摩擦磨损机理,该研究首先利用Adams软件建立绳轮系统模型,在各因素水平允许范围内进行单因素试验,再进行台架试验分析不同因素对绳轮接触处摩擦磨损的影响。仿真模型计算结果表明,从连接负载端开始,各完整缠绕圈所在槽道受到的摩擦力沿钢丝绳方向呈现逐渐减小趋势,与多槽轮的磨损形貌分析结果一致,且槽道上容易发生的失效形式为塑性变形和微动磨损。单因素试验结果显示,圈数从2/3增加到4/5,受力最大处摩擦力减小48.66 %,各槽道受力标准差由102.97 N减小到46.53 N,受力更加均衡;多槽轮中心距越小或轮径越大,各完整缠绕圈的槽道受力越均衡;同一多槽轮上的槽距和槽壁角度对摩擦的影响很小。台架正交试验的多槽轮磨损率分析结果表明,较大的中心距,较小的预紧力,较多的圈数可以缓解磨损。研究结果可为后续对驱动绳轮系统的优化提供参考。     

一种茶树促生菌固化剂的研制及其施用效果

为了提高茶园土壤有效养分含量和促生菌的定殖效率,以茶园土壤和茶树生长特性为条件,筛选耐酸铝和养分转化效率较高的菌株,再通过固定化技术,获得固定化促生菌剂,以游离态菌液为对照,通过田间试验比较菌株的土壤定殖、土壤微生物区系和土壤养分状况。试验筛选出一株红酵母菌属的菌株(Rhodotorula sp.)命名为WYS2。通过固化技术(0.25%活性炭吸附2%菌体后,用1%海藻酸钠+2%琼脂包埋)制作的促生菌固化菌剂,在与有机肥施用40 d后促生菌WYS2在土壤定殖效率较游离态菌悬液提高293倍。同时在0～20 cm土层中,与不施用菌株WYS2处理和施用游离态WYS2菌悬液处理相比,固定化WYS2菌剂处理的土壤碱解氮含量增加了23.4%～39.8%,速效钾含量增加了18.1%～25.1%,铵态氮含量增加了36.4%～45.1%。因此,认为利用筛选出的促生红酵母菌WYS2结合固定化技术使用后可有效提高其土壤定殖效率,同时促进茶园土壤碱解氮、速效钾和铵态氮等速效养分含量的增加。     

短序与阔叶十大功劳化学组分及小檗碱含量的FTIR比较研究

为快速评价短序与阔叶十大功劳不同部位化学成分差异,本研究运用FTIR采集短序和阔叶十大功劳不同部位的红外光谱并比较短序与阔叶十大功劳不同部位盐酸小檗碱含量差异。研究结果显示,生物碱、黄酮和丁香酯等化学成分,短序十大功劳根、茎及叶片中均较阔叶十大功劳丰富,但是,多糖和苷类含量在两种十大功劳根中相当,在茎和叶片中均以阔叶十大功劳含量高,尤其是叶片中这种差异更明显。最后,与盐酸小檗碱标准品比较发现,2种十大功劳中盐酸小檗碱含量均以茎中最高,叶片中含量最低;2种十大功劳比较各部位盐酸小檗碱含量均以短序十大功劳中高。故运用FTIR技术可以快速找出2种十大功劳化学成分的差异,本研究结果将为十大功劳属植物资源合理开发利用及良种选育提供参考。     

生物渗滤床处理养殖废水的技术经济性研究

该试验研究了生物渗滤床对养殖废水的处理效果，同时对生物渗滤床与常规好氧生物方法处理养殖废水的技术经济参数进行对比分析。结果显示，生物渗滤床对养殖废水具有很好的处理效果，出水COD平均浓度120mg／L，明显优于畜禽养殖业污染物排放标准的指标要求(COD≤400mg／L)；可实现全自动控制、基建投资费用可节省45％、运行能耗可节省86％，吨水处理费用仅为0.22元。技术经济分析结果表明，生物渗滤床是一种高效、稳定、低成本的养殖废水处理新技术，完全能够取代常规好氧生物处理方法。     

基于AHP的武汉地区樟科植物园林应用价值评价

对武汉植物园引种成功的樟科植物进行了调查和统计,在此基础上,运用层次分析法(AHP)对武汉植物园樟科物种进行了园林应用价值评价。确立了三个约束层(观赏性C1、适应性C2、资源数量C3)、14个标准层的评价模型,并制定了标准层所有14个指标的5级评价标准,通过数据统计,从中筛选出24种具有园林应用前景的种类,为武汉地区的樟科植物园林应用提供了科学的决策依据。     

钙质钝化材料对四川盆地6种主要旱作土壤Cd的钝化效应

为针对性、定量化地利用钝化处理实现不同类型Cd污染土壤的安全利用,以四川盆地6种主要旱作土壤为研究对象,采用室内培养试验和土培试验探讨了6个剂量水平下,钙质钝化材料对土壤pH、CEC、有效Cd含量、Cd形态、小白菜生物量和Cd含量的影响。结果表明:(1)钙质钝化材料可提升6种土壤的pH和CEC,土壤CEC随用量的增加而持续增加,而土壤pH在提升至微碱性水平后,不再随用量的增加而增加;(2)6种土壤有效Cd含量随钝化材料用量的增加先显著降低,后趋于平稳,用量＞2.5%后均无显著变化。该添加量下,有效Cd含量降幅为典型黄壤(63.32%)＞酸性紫色土(46.65%)＞漂洗黄壤(38.51%)＞中性紫色土(34.97%)＞石灰性紫色土(18.03%)＞灰潮土(16.60%);土壤中可交换态Cd主要向碳酸盐结合态、铁锰氧化物结合态和残渣态形态转化;(3)除石灰性紫色土外,钙质钝化材料可显著提升其余5种污染土壤中小白菜的生物量并显著降低其可食部位Cd含量。用量为2.5%时,典型黄壤、漂洗黄壤和酸性紫色土中小白菜Cd含量降幅高达84.28%,79.90%,69.87%,显著优于中性紫色土、灰潮土和石灰性紫色土(5%用量时降幅仅为40.27%,31.13%,17.98%)。该研究揭示钙质钝化材料对6种Cd污染旱作土壤的剂量-效应差异,并在典型黄壤、漂洗黄壤和酸性紫色土中钝化效率较优,为不同土壤条件下钙质钝化材料的合理使用提供科学依据。     

Effects of earthworms and plant growth–promoting rhizobacteria (PGPR) on availability of nitrogen,phosphorus, and potassium in soil

Both earthworms and plant growth–promoting rhizobacteria (PGPR) are ubiquitous and important for promoting circulation of plant macronutrients. Two series of laboratory experiments were conducted to investigate the effects of earthworm casts and activities on the growth of PGPR, and the inoculation of earthworms and PGPR on the availability of N, P, and K in soils, respectively. During a short incubation period (0–34 h), the extracts of earthworm (Pheretima guillelmi)‐worked soil significantly (p < 0.05) increased the abundance of the three species of PGPR, including N‐fixing bacteria (NFB) (Azotobacter chroococcum HKN‐5), phosphate‐solubilizing bacteria (PSB) (Bacillus megaterium HKP‐1), and K‐solubilizing bacteria (KSB) (B. mucilaginous HKK‐1), in Luria‐Bertani (LB) broth. There were synergistic effects of dual inoculation of earthworms and PGPR on increasing the concentrations of NH$ _4^+ $ ‐N, (NO$ _3^- $ + NO$ _2^- $ )‐N, NaHCO₃‐extractable P, and NH₄OAc‐extractable K in the corresponding soils. Bioavailable N (the sum of NH$ _4^+ $ ‐N and [NO$ _3^- $ + NO$ _2^- $ ]‐N) in the dual inoculation was 4 to 24 times those inoculated with earthworms or NFB alone, respectively. The significantly higher concentrations of bioavailable N and P in the dual inoculation of earthworms and NFB or PSB may be due to the higher abundance of PGPR and/or higher activities of urease and acid phosphatase than those of single inoculation of NFB or PSB, respectively. Dual inoculation of earthworms and PGPR would be most effective in reducing the need for chemical fertilizers in agriculture.