双奇核~(172)Re高自旋态转动带结构实验研究

利用重离子熔合蒸发反应 14 9Sm (2 7Al,4nγ) 172 Re布居了形变双奇核 172 Re的高自旋态 ,用 12套带有BGO反康普顿抑制的高纯锗探测器阵列进行了在束γ实验测量 ,首次建立了形变双奇核172 Re由 3个转动带构成的高自旋态能级纲图 .研究和讨论了 3个转动带的结构特征 ,基于已有的高自旋态核结构知识并通过系统学比较和分析指出它们的准粒子组态分别为πh11 2 νi13 2 ,πh9 2 νi13 2 和π1 2 -[5 41] ν1 2 -[5 2 1].发现前两个转动带在自旋小于 18.5时其转动能级呈现反常的旋称劈裂 .

不同方法计算湿地松林生物量的比较

利用实测值建模法、估计值建模法和平均标准木法计算中国科学院千烟洲试验站湿地松(Pi-nus elliotii)人工林各器官生物量和总地上生物量,并与利用文献中的湿地松相对生长方程计算的结果进行比较。结果表明,枝条基径与该枝条叶生物量及总生物量之间存在显著的相关关系;不同方法计算的总地上生物量存在一定的差别,其中实测值建模法和估计值建模法的计算结果最接近,分别为7.9×104和8.0×104kg.hm-2,利用平均标准木法得到的生物量偏低,为7.41×104kg.hm-2;3种方法得到的各器官生物量差别较大,尤其是叶生物量,利用实测值建模法的计算结果为8450 kg.hm-2,估计值建模法和平均标准木法的计算结果分别为6 580和1.0×104kg.hm-2,其中平均标准木法的计算结果因取样的不同而有所差异;直接利用他人建立的相对生长方程计算的生物量与以上3种方法计算结果相比差异较大,使用时须谨慎。计算总地上生物量时,实测值建模法是最可靠的方法,估计值建模法在一定程度上可以代替实测值建模法。

短期菲胁迫对大豆幼苗超氧化物歧化酶活性及丙二醛含量的影响

研究了不同浓度 ( 0～ 2 0 0 μg·g-1)菲胁迫和恢复培养后大豆幼苗生长、超氧化物歧化酶 (SOD)活性及丙二醛 (MDA)含量的变化 .结果表明 ,2 0 0 μg·g-1菲处理 5d后大豆幼苗生长受到抑制 ,但幼苗恢复培养后经短暂停滞期后仍可恢复生长 .菲污染对大豆幼苗SOD活性变化的剂量 效应关系的作用形式比较复杂 ,胁迫 2d时为线性关系 ,胁迫 5d和 8d时为抛物线型 .在菲处理前期 ( 2d) ,幼苗SOD活性被 10 0和2 0 0 μg·g-1菲显著诱导 [分别为对照的 1.15倍 (P <0 .0 5 )和 1.2 6倍 (P <0 .0 1) ].菲暴露 8d时 ,SOD活性显著降低 ,2 0 0 μg·g-1菲处理组SOD活性为对照的 88% (P <0 .0 5 ) .菲处理 5d后恢复培养 2d和 4d ,5 0和10 0 μg·g-1菲处理组幼苗SOD活性得到恢复 ,而 2 0 0 μg·g-1菲处理组幼苗SOD活性仍明显高于对照 (P <0 .0 5 ) .试验亦反映出 ,10 0和 2 0 0 μg·g-1菲处理 5d和 8d ,幼苗MDA含量均比对照显著增加 (P <0 .0 5和P <0 .0 1) .可以认为 ,SOD活性可作为大豆幼苗遭受短期菲胁迫的生物标记物 .

Heat capacities and thermodynamic functions of p-chlorobenzoic acid

The heat capacities of p-chlorobenzoic acid were measured in the temperature range from 80 to 580 K by means of an automatic adiabatic calorimeter equipped with a small sample cell of internal volume of 7.4cm(3). The construction and procedures of the calorimetric system were described in detail. The performance of this calorimetric apparatus was evaluated by heat capacity measurements on alpha-Al2O3. The deviations of experimental heat capacities from the corresponding smoothed values lie within +/-0.28 per cent, while the inaccuracy is within +/-0.40 per cent, compared with the recommended reference data in the whole experimental temperature range. A fusion transition at T = 512.280 K was found from the C-p-T curve of p-chlorobenzoic acid. The enthalpy and entropy of the phase transition, as well as the thermodynamic functions {G((T)) - G((298.15))}, {H-(T) - H-(298.15)} and {S-(T) - S-298.15}, were derived from the heat capacity data. The mass fraction purity of p-chlorobenzoic acid sample used in the present calorimetric study was determined to be 0.99935 by fraction melting approach. (C) 2002 Elsevier Science Ltd. All rights reserved.

抗HER2-hTNF-α新型免疫毒素的制备及功能研究

HER2/neu基因在肿瘤中的过度表达使其成为许多肿瘤的标志分子.为了增加过度表达HER2/neu的肿瘤细胞对肿瘤坏死因子(TNF)的敏感性和提高HER2/neu抗体的肿瘤杀伤效应,将抗HER2/neu单链抗体C6.5与人肿瘤坏死因子hTNF-α融合,构建了scFvC6.5-hTNF-α融合蛋白,完成了重组蛋白在大肠杆菌中的表达,产率为400μg/L菌液.经过亲和层析和柱复性,融合蛋白的纯度达95%以上.ELISA试验表明,scFvC6.5-hTNF-α能够特异结合HER2/neu阳性卵巢癌细胞SKOV-3和乳腺癌细胞MCF-7,而不结合HER2/neu阴性的黑色素瘤细胞A375.MTT试验表明,scFvC6.5-hTNF-α能够选择性地杀伤SKOV-3和MCF-7细胞,而不影响A375细胞的生长.这种肿瘤细胞特异性杀伤作用提示该免疫毒素具有肿瘤靶向治疗的潜在应用价值.

神府东胜煤田复垦区土壤入渗特性的试验研究

土壤入渗性能是最基本的土壤物理特性之一。复垦区土壤的结构组成复杂,入渗特性有别于非矿区土壤。本文以神府东胜煤田马家塔复垦区为研究对象,利用圆盘入渗仪分别测定了复垦区乔木、林地、荒地、灌木林地和草地的土壤入渗特性,用经典统计学方法对复垦区土壤入渗性能的空间变异性进行了分析。实测结果表明,不同土地利用方式下的土壤入渗特性有较大的差异;在测定范围内,乔木林地、荒地、草地和灌木林地的稳定入渗率均表现出0 cm>—3 cm>—15 cm的规律性,其中草地稳定入渗率随吸力的变化更明显。研究表明:乔木林地稳定入渗率和累积入渗量的变异系数分别为0.58和0.49.属于中等变异。

辽宁省土地退化与景观生态建设

利用 1997～ 1998年 1∶2 5万辽宁省TM遥感影像及相应的GIS获取的数据 ,调查分析了辽宁省土壤侵蚀、土地沙化和盐渍化 3种类型土地退化程度、面积和分布 .结果表明 ,全省 92 .5 2 %的土地面积遭受不同程度的侵蚀 ,3.39%的土地为沙化土地 ,2 .2 2 %土地为盐渍化土地 .在此基础上 ,以新的角度进行全省土地退化分区 :现代侵蚀退化区、地质侵蚀退化区和沙化盐渍化退化区 ,分析不同区域内不同类型的退化特点和原因 ,依据区域自身特点和景观生态学原理 ,提出相应的景观生态建设恢复治理模式 .

应用GUS基因研究弗氏中华根瘤菌的结瘤及效果

应用GUS(葡萄糖苷酶 )基因标记技术将标记基因GUS导入受体菌S .fredii8855,标记菌株形成的根瘤可被GUS染色缓冲液染成蓝色 ,而土著菌形成的根瘤不能着色 .由此即可十分简便地确定土著菌的影响程度 .盆栽试验表明 ,S .fredii 8855的结瘤抗酸碱能力高于土著菌 ,能在土壤中较大范围内迁移 .当它的根瘤占有率不小于 43%时 ,接种能显著提高大豆产量 ,大豆产量与根瘤占有率呈正相关 (r=0 .98) ,而与总瘤数关系不大 (r=0 .1 3) .土壤N素显著抑制其结瘤 ,补加P能缓解这种抑制作用 .

樱桃砧木根癌病敏感性评价方法

建立了樱桃砧木对农杆菌敏感性的评价方法,在5种樱桃砧木,对樱桃(Prunus.pseudocerasus)、CAB(P.cerasus)、Gisela5、Gisela6(P.cerasus×P.canescens)、colt(P.avium×P.pseudocerasus)的组培苗茎上接种野生型农杆菌(C58),40d后调查结瘤百分率和瘤重,基于结瘤百分率和病情指数评价了供试材料的敏感性,结果表明:该方法能反映不同砧木的抗性水平,可作为樱桃砧木根癌病敏感性评价、筛选抗性种质的一种有效的方法。

Charge carrier transporting, photoluminescent, and electroluminescent properties of zinc(II)-2-(2-hydroxyphenyl)benzothiazolate complex

Zinc(II)-2-(2-hydroxyphenyl)benzothiazolate complex is an excellent white-light-emitting material. Despite some studies devoted to this complex, no information on the real origin of the unusually broad electroluminescent (EL) emission is available. Therefore, we investigate photoluminescent and EL properties of the zinc complex. Orange phosphorescent emission at 580 nm was observed for the complex in thin film at 77 K, whereas only fluorescent emission was obtained at room temperature. Molecular orbitals, excitation energy, and emission energy of the complex were investigated using quantum chemical calculations. We fabricated the device with a structure of ITO/F16CuPc(5.5 nm)/Zn-complex/Al, where F16CuPc is hexadecafluoro copper phthalocyanine. The EL spectra varied strongly with the thickness of the emissive layer. We observed a significant change in the emission spectra with the viewing angles. Optical interference effects and light emission originating both from fluorescence and from phosphorescence can explain all of the observed phenomena, resulting in the broad light emission for the devices based on the Zn complex. We calculated the charge transfer integral and the reorganization energy to explain why the Zn complex is a better electron transporter than a hole transporter.

A novel white light emitting long-lasting phosphor

A novel white light emitting long-lasting phosphor Cd1-xDyxSiO3 is reported in this letter. The Dy3+ doped CdSiO3 phosphor emits white light. The phosphorescence can be seen with the naked eye in the dark clearly even after the 254 nm UV irradiation have been removed for about 30 min. In the emission spectrum of 5% Dy3+ doped CdSiO3 phosphor, there are two emission peaks of Dy3+, 580 mn (F-4(9/2)-->H-6(13/2)) and 486 nm (F-4(9/2)-->H-6(15/2)), as well as a broad band emission located at about 410 nm. All the three emissions form a white light with CIE chromaticity coordinates x=0.3874, y=0.3760 and the color temperature is 4000 K under 254 mn excitation. It indicated that this phosphor is a promising new luminescent material for practice application.