生态稳定化污泥农用研究

污泥中的有机质及各项营养成分在农业生产中可起到重要的肥效作用,但未稳定的污泥在农用过程中会引起作物的不良反应,从而影响作物的产量.试验中以人工湿地积存污泥为肥料,与当地土壤按不同配比掺合,同时,以水稻草焚烧后的余灰作为补充钾源,混匀制成栽培基质进行小麦的盆栽试验.通过植株的生长状况及产量较直观地探寻此类污泥农用的稳定性.

7-Amino actinomycin D bound to single-stranded hairpin DNA enhanced by loop sequence-dependent luminescent Eu3+ and Tb3+ binding

Lanthanide Eu3+ and Tb3+ ions have been widely used in luminescent resonance energy transfer (LRET) for bioassays to study metal binding microenvironments. We report here that Eu3+ or Tb3+ can increase the binding affinity of antitumor antibiotic drug agent, 7-amino actinomycin D (7AACTD), binding to 5'-GT/TG-5' or 5'-GA/AG-5' mismatched stem region of the single-stranded hairpin DNA. Further studies indicate that the effect of Eu3+ or Tb3+ on 7AACTD binding is related to DNA loop sequence. Our results will provide new insights into how metal ions can enhance antitumor agents binding to their targets.

2,5-二(2-菲基)-[3,2-b]并二噻吩的合成、表征及在有机薄膜晶体管中的应用

近年来,有机薄膜晶体管(OTFTs)因其成本低、加工简便,特别适用于制备大面积柔性器件而引起人们的广泛关注[1].并苯类化合物和噻吩衍生物是目前最重要的两类高迁移率OTFT材料.由并五苯制备的多晶OTFTs器件迁移率可达到5cm2/(V·s)[2];烷基修饰齐聚噻吩的场致迁移率也可达到非晶硅[0·1~1cm2/(V·s)]的水平[3].但是,这两类材料具有较窄的能隙和较高的最高被占分子轨道(HOMO)能级,容易与空气中的氧气和水发生作用,所制备的器件在空气中衰减较快,并且并苯类化合物对光也非常敏感,限制了其应用范围[4~6].因此,制备稳定的高迁移率有机半导体材料是有机光电子研究领域的重要课题之一.制备稳定的高迁移率有机半导体材料的途径包括用较稳定的芳香基团对噻吩齐聚物进行封端,以增大能隙和降低HOMO能级[7].菲类化合物是并苯类化合物的异构体,具有较好的光稳定性[8].[3,2-b]并二噻吩是一种平面稠环分子,与2,2′-二噻吩相比,HOMO能级相对降低,因而具有相对好的稳定性[9].本文合成了2,5-二(2-菲基)-[3,2-b]并二噻吩(PhTT),表征了其基本的物理和化学性质,制备了相应的有机薄膜晶...

Determination of ultra-trace concentrations of elements in high purity tellurium by inductively coupled plasma mass spectrometry after Fe(OH)(3) coprecipitation

In this work, a method was established for the determination of impurities in high purity tellurium by inductively coupled plasma mass spectrometry (ICP-MS) after Fe(OH)(3) coprecipitation. After comparison of coprecipitation ability and separation efficiency between Fe(OH), and Al(OH)(3), Fe(OH)(3) was chosen as the precipitate. A separation factor of 160 for 200 mg tellurium was obtained under conditions of pH 9 and 2 mg of Fe3(+). The 13 elements, such as Bi, Sn, Pb, In, Tl, Cd, Cu, Co, Ni, Zn, Ti, Be and Zr, could be almost completely coprecipitated under these conditions. In addition, Te memory effect imposed on the ICP-MS instrument was assessed, as well as Te matrix effect that caused the low recovery of Ga, As, Sb and V in real sample was discussed. Finally, the method was evaluated through recovery test and was applied to practical sample analysis, with detection limits of most of the elements being below 0.15 mug g(-1) and R.S.D. below or at approximately 10%, which indicated that this method could fully satisfy the requirements for analysis of 99.999% similar to 99.9999% high purity Te.

The influence of nucleating agent on crystallization behavior and properties of polypropylene and its copolymer with ethylene

The influences of nucleating agent EDBS on crystallization behavior and properties of polypropylene UP) and its copolymer with a small amount (4. 48 %, molar fraction) of ethylene (CPP) were studied. DSC results indicated that the crystallization temperature of iPP and CPP samples with 0.5 % (mass fraction) EDBS obviously increased and the degree of crystallinity of these samples became higher. In addition, adding small amount of EDBS enhanced the crystallization of the low isotacticity and low molecular weight segments of the CPP. PLM results showed that their spherulite size decreased markedly, and as a result, the transmittance and haze of the films were all improved.

Syntheses and crystal structures of mononuclear rhodium hydrido complexes from the reactions of [Rh(H)(2)(PPh3)(2)(EtOH)(2)]ClO4 with various nitrogen ligands

Reactions of the Rh hydrido complex [Rh(H)(2)(PPh3)(2)(EtOH)(2)]ClO4 (1) With nitrogen ligands such as 2-(4-thiazolyl)benzimidazole (tbz). pyridazine (pdz), imidazole (im) and pyrimidine (pmd) in CH,Cl, afforded Various mononuclear Rh hydrido complexes, [Rh(H)(2)(PPh3)(2)(tbz)]CIO4 (2), [Rh(H)(2)(PPh3)(2)(pdZ)(2)]ClO(4)(.)2CH(2)Cl(2) (3). [Rh(H)Cl(PPh3)(2)(pdz)(2)](ClO4CH2Cl2)-C-. (4). [Rh(H)(2)(PPh3)(2)(im)(2)]ClO(4)(.)2CH(2)Cl(2) (5). [Rh(H)Cl(PPh3)(2)(im)(2)](ClO4CH2Cl2)-C-. (6). [Rh(H)(2)(PPh3)(2)(pmd)(2)](ClO4CH2Cl2)-C-. (7) and the Rh non-hydrido complex [RhCl2(pmd)(4)]ClO4 (8). The Rh complexes 2. 3, 5 and 6 were crystallographically characterized. The formation process was monitored by H-1 NMR and UV-Vis spectra. In all the Rh hydrido complexes, the Rh atom is coordinated by two PPh3. ligands in trans-positions and two nitrogen ligands in the cis-positions. The remaining sites Lire occupied by one or two hydride atoms to form a saturated 18-electron framework in a slightly distorted octahedral geometry. For complex 2 an appreciable inter-molecular pi interaction is observed between planes of tbz and PPh3 ligands, while an intra-molecular hydrogen bonding interaction between C-H and Cl atoms is found in complex 6.

成核剂对聚丙烯及其共聚物的结晶行为和性能的影响

研究了成核剂 1 ,3∶ 2 ,4-对二乙基苄叉山梨醇 (EDBS)对聚丙烯及其乙烯共聚物的结晶行为和结晶形态的影响 ,并对其薄膜进行了光学性能的表征 .结果表明 ,添加少量 (质量分数 0 .5 % )的成核剂 ,使聚丙烯样品的结晶温度大大提高 ,结晶度明显增加 .而对于乙烯共聚聚丙烯样品 ,添加少量 (质量分数 0 .5 % )成核剂 ,不仅使其整体结晶温度大大提高 ,结晶度增加 ,而且明显强化了低有序部分的结晶 .少量成核剂的加入 ,使聚丙烯及其共聚物的球晶尺寸明显缩小 ,薄膜的透光性和雾度显著改善

Monte Carlo simulation for the modification of polymer via grafting

Monte Carlo method has been applied to investigate the kinetic of grafting reaction in free radical copolymerization. The simulation is quits in agreement with that of theoretical and experimental results. It proves that the Monte Carlo simulation is an effective method for investigating the grafting reaction of free radical copolymerization. (C) 2000 Elsevier Science Ltd. All rights reserved.

未来十年全球无人无缆自主式潜水器的发展趋势

本文阐述了全球无人无缆自主式潜水器（ＡＵＶ）应用背景和重要性，以及它的开发和应用，同时也阐述了中国的开发现状。最后展望未来十年全球无人无缆自主式潜水器（ＡＵＶ）的发展趋势。

空间机器人运动学和动力学控制

本文介绍空间机器人运动学和动力学控制.空间机器人是由操作手和卫星本体组成,在微小重力场工作(漂浮在空中),其运动学和动力学控制要比地面机器人复杂且有其特点,本文则主要综述它与地面机器人的不同之处及其研究成果,指出了当前的研究方向.

桂中旱片的成因机制及早片综合区划

桂中地区降水不少,但由于自然及人为等因素,旱情严重,成为广西著名的旱片之一。对其成因机制的探讨是桂中环境治理和区域开发的科学基础。在概述地质地理特征的基础上,进行了桂中旱区的干旱时空分析,重点揭示了桂中旱片的成因机制;然后,根据干旱类型、旱灾脆弱度及从便于地下水利用出发,进行了桂中旱片的综合区划;最后,遵循生态环境治理、综合抗旱与脱贫致富相结合的原则,提出了治理对策措施。

金矿废弃物中氰化物的环境地球化学行为

目前大多数黄金企业都是采用氰化法提金工艺,用于从矿石中提取黄金的氰化钠溶液浓度一般为0.05%～0.1%,使金矿成为环境氰化物污染的主要来源之一.尽管已有许多比较成熟的氰化物处理技术,但由于种种原因,中国大多数金矿排放的废弃物中仍含有相当浓度的氰化物.氰化物对人类和许多生物是一种剧毒物质,水体中CN-含量达0.3～0.5 mg/L即可使鱼致死,对人的致死量按HCN计为0.05～0.1 g.黄金企业大量累积的金矿废弃物成为威胁地区生态环境安全的化学定时炸弹.近年来国内外不时发生因尾矿坝垮塌造成的氰化物排放事故,国际上最为严重的一次是2000年初罗马尼亚的两座金矿,由于积雪融化和连续下雨,发生尾矿坝决口事件,使蒂萨河、多瑙河近800 km的河段遭受不同程度的污染,致使该流域内大量的生物死亡;我国也曾发生过不同程度的金矿尾矿坝垮塌污染环境事故.因此,研究氰化物在不同气候条件下的金矿尾矿、河流和污染土壤中的环境地球化学行为显得非常重要.