Synthesis and application on parallel image storage of bisfurylfulgide

A bisfurylfulgide, E, E-3,4-bis[1-(2,5-dimethyl-3-furyl)ethylidene]-3,4-dihydrofuran-2,5-dione, is synthesized by Stobbe condensation reaction. The molecular structure of target compound is confirmed by single crystal X-ray crystallography analysis. It shows that the distances between two possible reaction sites of molecule are 0.3394 and 0.3406 nm respectively, which is favorable to photocyclization. The photochromic properties of this compound in different solvents are investigated, and the result shows that the compound exhibits excellent photochromic behavior. The primary result of applied research on parallel image storage is also presented.

Effect of cryoprotectants on hatching rate of red seabream (Pagrus major) embryos

The objectives were to investigate the effect of cryoprotectants on the hatching rate of red seabream embryos. Heart-beat embryos were immersed in: five permeable cryoprotectants, dimethyl sulfoxide (DMSO), glycerol (Gly), methanol (MeOH), 1,2-propylene glycol (PG), and ethylene glycol (EG). in concentrations of 5-30% for 10, 30, or 60 min; and two non-permeable cryoprotectants: polyvinylpyrrolidone (PVP), and sucrose (in concentrations of 5-20% for 10 or 30 min). The embryos were then washed and incubated in filtered seawater until hatching occurred. The hatching rate of the embryos treated with permeable cryoprotectants decreased (P < 0.05) with increased concentration and duration of exposure. In addition, PG was the least toxic permeable cryoprotectant, followed by DMSO and EG, whereas Gly and MeOH were the most toxic. At a concentration of 15% and 30 min exposure, the hatching rate of the embryos immersed in PG was 93.3 +/- 7.0% (mean +/- S.D.), however. in DMSO. EG, Gly. and MeOH, it was 82.7 +/- 10.4, 22.0 +/- 5.7, 0.0 +/- 0.0, and 0.0 +/- 0.0%, respectively. Hatching rate of embryos treated with PVP decreased (P < 0.05) with the increase of concentration and exposure time, whereas for embryos treated with sucrose, there was no significant decrease in comparison with the control at the concentrations used. (C) 2008 Elsevier Inc. All rights reserved.

杉木人工林土壤中毒性化感物质的鉴定与来源

针对杉木化感物质种类的争论，我们以生测活性做导向，对杉木人工林土壤中毒性化感物质进行了分离，并通过质谱、核磁共振等仪器对化感物质的化学结构进行了鉴定，然后研究了其活性和来源，同时从土壤养分和化感作用两个方面对杉木火力楠混交林解决杉木连栽障碍的作用机制进行了研究。结果表明： (1) 虽然不同连栽代数土壤养分与杉木幼苗苗高存在正相关关系，即随着杉木连栽代数的增加，土壤养分含量逐渐降低，土壤处理的杉木幼苗苗高也逐渐降低，但是同一林分中，距杉木根系不同距离的土壤养分含量与杉木幼苗根长存在负相关关系。在一代和二代杉木林中，与杉木林地土相比，杉木根际土能够显著地抑制杉木幼苗根生长。单用土壤养分匮缺来解释连栽杉木生产力下降是不充分的，杉木化感作用也是连栽障碍的重要原因之一。 (2) 从杉木人工林土壤中检测到8种酚酸类物质：对羟基苯甲酸、香草酸、阿魏酸、苯甲酸、肉桂酸、香草醛、异香草醛和香豆素。自然浓度的酚类物质没有抑制杉木幼苗的生长，反而促进了杉木幼苗的生长。从连栽杉木林土壤分离到一种新环二肽(6-hydroxy-1,3-dimethyl-8-nonadecyl-[1,4]-diazocane-2,5-diketone)，它在自然浓度条件下能够显著地抑制杉木幼苗的生长。而且当浓度达到40nmol•ml-1时，环二肽对杉木幼苗根生长的抑制率接近50%，显示其具有较高的化感活性。因此，引起连栽杉木生产力下降的化感物质不是对羟基苯甲酸等酚酸类物质，而是从杉木林土壤中分离得到的环二肽。 (3) 杉木各组织中环二肽含量最多的为叶凋落物，而且用杉木叶凋落物处理的土壤中环二肽含量显著增加，这说明杉木叶凋落物是环二肽的重要来源之一。杉木根系分泌物中含有环二肽，而且随着连栽代数的增加，杉木根系分泌环二肽的速率也增加，这说明杉木根系分泌物也是环二肽的重要来源之一。杉木成熟林每年每公顷凋落的叶凋落物中含有约0.173~0.418 mol的环二肽，而每年每公顷杉木根系分泌的环二肽可达1.289~1.362 mol，显著高于前者。因此，杉木根系分泌物是杉木化感物质环二肽最重要的来源。 (4) 杉木火力楠混交林能够提高土壤有机质、全氮等养分含量，增加土壤微生物数量及土壤蔗糖酶、脲酶和磷酸酶等土壤酶活性，从而提高了混交林土壤熟化程度，加速了土壤有机质的转化速率，增强了土壤养分的供应能力，改善了土壤养分匮缺的状况。与二代杉木林相比，杉木火力楠混交林中杉木根系分泌环二肽的速率降低了33.2%，杉木火力楠混交林能减少环二肽的释放量，从而降低土壤中化感物质的含量，减弱林地土壤对杉木幼苗生长的抑制作用，缓解了连栽杉木自毒作用。因此，杉木火力楠混交林是一种高生产力和生态协调的造林模式。

典型污染海湾河口沉积物中砷的形态分布研究

锦州湾是我国较大的浅水海湾之一，该湾西南五里河沿岸汇集数家工厂排污直接人海， 形成该湾口处的最大污染源。其西南部潮滩地段已成为我国海域污染最严重的区域之一。 本文对葫芦岛3条河流、五里河口和锦州湾水体、沉积物中As的含量、分布、形态及行为进行了系统研究。结果表明，葫芦岛的连山河和五里河未受到明显的As污染，沉积物总As含量一般低于10 mg•kg-1，河水As含量一般低于10 μg•L-1，茨山河下游紧邻葫芦岛锌厂，受到了严重的As污染，沉积物As含量达75.2 mg•kg-1。五里河口区As污染非常严重，锌厂在该区排污口处沉积物As含量高达3176.1 mg•kg-1，超过国家沉积物As标准158倍。受锌厂排污的影响锦州湾As污染也很严重，沉积物中As最高含量达到569.5 mg•kg-1。沉积物和孔隙水As含量在剖面上具有相似的变化趋势，表明孔隙水As含量主要受沉积物As含量影响。锦州湾沉积物中As主要以可交换态存在，残渣态次之，盐酸提取态最少，表明锦州湾沉积物中As的活性很强，有大量的可交换态As随时会进入上覆水体，是重要的As释放源，沉积物中大量As的释放可能会对葫芦岛和锦州湾地区生态系统造成严重的威胁。 以盐度和酸碱度作为环境影响因子进行的释放模拟实验，结果显示：不同盐度条件下，沉积物中的As均在48h左右达到最大释放量。此时，盐度为0‰的水体中As的释放量最大，而其他两种盐度的水体中As的释放量较小且二者相差不大。另外，在室温条件下，随着pH值的升高，沉积物中As的释放量逐渐增加。 通过对不同形态的单一含砷矿物的As提取效果研究得出：对于分级提取方法中吸附态砷的最佳提取条件应为1M KH2PO4 (pH5) 24h, 无定型铁氧化物上结合的砷0.2M oxalic/oxalate (pH3)避光 6h, 硫化亚铁上结合的砷，0.2M oxalic/oxalate (pH3)避光 1h。