207Rn高自旋态能级结构研究

本论文首先介绍了原子核高自旋态研究的一般概况以及其物理解释的基本理论，然后介绍了在束γ谱学及其实验技术。在此基础上分析和讨论了~(207)Rn核的高自旋态实验研究。利用能量为85Mev到95Mev的~(16)O束流，通过~(196)Pt（~(16)O,5n）~(207)Rn反应布居了~(207)Rn的高自旋态。用十台BGO（AC）HPGe探测器进行了下射线的激发函数、γ-γ-t符合及γ射线的单谱等的测量。基于上述测量，本工作建立了包括17条γ跃迁和18个能级的~(207)Rn的高自旋能级纲图，并且基于实验测量的DCO系数建议了各能级的自旋值。为了从物理上讨论207Rn的核结构，本文利用经验壳模型对它的部分能级组态进行了计算。用一个f_5/2)价中子空穴与208助核芯祸合定性地解释了~(207)Rn的低位激发态。用一个i_(13/2)价中子空穴与~(208)Rn核芯藕合定性地解释了~(207)Rn的高位激发态。

SLEUTH城市扩展模型的应用与准确性评估

基于多时相TM遥感影像,利用SLEUTH模型对沈阳市1988~2004年间的城市扩展过程进行了模拟。采用ROC曲线、多分辨率误差估算和景观指数3种方法对SLEUTH模型在总体预测能力、城市扩展数量、空间位置和空间格局上的模拟准确性给予全面定量评估。结果表明,SLEUTH模型具有可信精度,对城市扩展总体趋势拟合较好,但是对城市扩展空间位置的预测和城市空间格局的表达还有待于提高。

生态场理论在沙地云杉种群更新中的应用

生态场理论是物理生态学的基本理论，它基于植物分布格局、植物生长模型、植物竞争以及资源利用的研究。研究森林草原过渡带上沙地云杉种群在更新中产生的生态场的特性，结果表明：沙地云杉种群生态场是半椭圆形特殊的非均匀场；生态场强度随着与母树距离的增大而变化，开始时迅速增大，３～５ｍ处场强达到最大，然后逐渐下降；由于生态场的重叠而使叠加部分的场强明显增大；生态场的作用范围与坡度、坡长等地形因子及树高、冠半径等测树因子都有密切的关系。长轴半径（Ｒ）与坡度（Ｘ）、坡长（Ｌ）和树高（Ｈ）存在下列多元线性关系：Ｒ＝０．９２３Ｈ＋０．３１６Ｘ＋０．０１５Ｌ－４．３１４（ｒ＝０．８２５）

文冠果化学成分预试与综合利用的研究

文冠果干种仁含粗脂肪60％、粗蛋白26％．粗纤维0．34％，淀粉0．9％．总糖2．6％．文冠果皂甙0．5％，17种氨基酸．18种微量元素：文冠果叶含12种微量元素．19．8％的粗蛋白和16种氨基酸。对种壳、果皮、果柄等部位的化学组分也做了分析．指出了综合利用的前景。

Facile synthesis of poly(o-phenylenediamine) microfibrils using cupric sulfate as the oxidant

A rapid, templateless, surfactantless approach is proposed to prepare microfibrils by simply mixing of aqueous cupric sulfate and o-phenylenediamine (oPD) solutions at room temperature. The as-prepared poly(o-phenylenediamine) (PoPD) microfibrils have been characterized by optical microscope, transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis) and X-ray diffraction (XRD).

La-2(Zr0.7Ce0.3)(2)O-7 - A new oxide ceramic material with high sintering-resistance

Oxide ceramics with high sintering-resistance above 1473 K have very important applications in thermal barrier coatings (TBCs), catalytic combustion and high-temperature structural materials. Lanthanum zirconate (La2Zr2O7, LZ) is an attractive TBC material which has higher sintering-resistance than yttria stabilized zirconia (YSZ), and this property could be further improved by the proper addition of ceria.

Sonochemical synthesis of monodispersed KY3F10 : Eu3+ nanospheres with bimodal size distribution

Monodispersed KY3F10:Eu3+ nanospheres with bimodal size distribution have been successfully synthesized via a facile and efficient sonochemical method in a surfactant-free system. Rare-earth nitrate (Y, Eu)(NO3)(3) and potassium fluoborate (KBF4) were used as precursors. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and photoluminescence (PL) spectra were used to characterize the samples.

聚电解质溶液浓度区域的划分

按照DeGennes[1] 提出的标度概念 ,柔性高分子溶液可以划分为稀溶液 ,亚浓溶液和浓溶液 3个区域 ,它们之间分别以接触浓度c 和交叠浓度c 为分界线 .钱人元等[2 ] 根据聚苯乙烯溶液激基荧光强度浓度依赖性的实验结果 ,提出稀溶液区还应细分为极稀溶液和稀溶液两个区域 ,它的分界浓度称为动态接触浓度cs.中性高分子溶液存在这一分界浓度 ,已经得到体积排除色谱[3 ] 、高分子溶液的物理凝胶化[4] 、以及动态光散射[5] 等研究结果的证实 .本文作者之一 (程 )从中性高分子在溶液中由于范德华分子间吸引力的存在容易自缔合而形成团族的概念出发 ,导出了溶液粘度与cs 之间的理论关系[6,7] .聚电解质由于在溶液中可以离解为聚离子和对离子的特性 ,关于它的溶液浓度区域的划分问题 ,已经引发了一些理论的[8～ 11] 和许多实验的研究 ,其中包括光散射[12～ 14 ] 、小角X射线散射[15] 、小角中子散射[16] 、准弹性中子散射[17] 、溶液电导[18] 和溶液粘度[19]等 .这些研究中的绝大多数 ,仍然将溶液划分为稀溶液 ,亚浓溶液和浓溶液 3个区域.

Seed-mediated synthesis of branched gold nanoparticles with the assistance of citrate and their surface-enhanced Raman scattering properties

We report an easy synthesis of highly branched gold particles through a seed-mediated growth approach in the presence of citrate. The addition of citrate in the growth solution is found to be crucial for the formation of these branched gold particles. Their size can be varied from 47 to 185 nm. The length of the thumb-like branch is estimated to be between about 5 and 20 nm, and changes slightly as the particle size increases. Owing to these obtuse and short branches, their surface plasmon resonance displays a marked red-shift with respect to the normal spherical particles. These branched gold particles exhibit stronger SERS activity than the non-branched ones, which is most likely related to these unique branching features.

Synthesis of highly faceted multiply twinned gold nanocrystals stabilized by polyoxometalates

A novel and facile chemical synthesis of highly faceted multiply twinned gold nanocrystals is reported. The gold nanocrystals are hexagonal in transmission electron microscopy and icosahedral in scanning electron microscopy. Phosphotungstic acid (PTA), which was previously reduced, serves as a reductant and stabilizer for the synthesis of gold nanocrystals. The PTA-gold nanocomposites are quite stable in aqueous solutions, and electrochemically active towards the hydrogen evolution reaction.

Hydrothermal synthesis and structure of [Ni(en)(2)V6O14](n)

A new complex [Ni (en)(2)V6O14](n) was hydrothermally synthesized and characterized by 2-dimensional vanadium oxide framework pillared by Ni(en)(2)group. Single crystal X-ray analysis indicates that this compound crystallizes in monoclinic system, space group P2(1)/c with a=0. 892 17(18) nm, b = 1. 711 1(3) nm, c=0. 662 73(13) nm, beta=111. 58(3)degrees, V=0.940 8(3) nm(3), Z=2, D-c=2.501 g/cm(3), R=0. 042 3, omegaR=0. 060 9, S=1. 006.