TeO2-ZnCl2-BaO-NaF玻璃系统的结构及中红外透过特性的研究

制备了一种新型的氧卤碲酸盐玻璃：（80-x）TeO2—15ZnCl2-xBaO-5NaF（x=30、20、10、0mol％），对玻璃的机械强度、热稳定性、拉曼光谱、紫外吸收光谱、红外透过光谱等特性进行了研究．通过拉曼光谱分析研究了玻璃组分含量的变化对玻璃结构和红外透过性能的影响．结果表明，随着BaO含量的增加，玻璃在红外波段透过率显著增加，并且红外透过截止波长向长波方向移动，本文对这一实验结果进行了机理性的研究探讨．同时，通过在熔制过程中通入高纯O2，以及引入适量的卤化物有效地除去玻璃中的[OH]基团，使

SURFACE TENSION AND DENSITY OF NaCl-NaF-RE2O8 MELTS

Surface tension and density of NaCl-NaF-RE2O, melts have been measured by means of maximum buble pressure and Archimedes methods. The results are expressed by two mathematic models. Mass fraction of RE2O5 in the melts from 0.0 to 0.6% and that of NaF/NaCl, 50-90%. This investigation shows that there might be com plexes in the melts. The information obtained can be used as a reference in the preparation of Al-RE alloys.

NaCl-NaF-RE_2O_3体系的表面张力和密度

以NaCl-NaF体系为还原介质,以RE_2O_3,REOCl,或RE_2(CO_3)_3为原料,以铝为还原剂,在铝熔融过程中直接制备Al-RE应用合金已获得了应用.结果表明,这一方法使用简单,操作方便,不需额外设备,容易为工厂采用.本工作是为这一工艺开展的基础研究工作. 资料对LaCl_3-碱金属氯化物,碱土金属氯化物的表面张力和密度进行了专门总结,对NaCl-NaF-RE_2O_3体系未见报导。

花岗岩-LiF-NaF-H_2O体系液相不混溶的实验研究

Liquid segregation phenomena have been found and explained in the F(Li)-rich granites in south China by Wang Linakui et al. (1979; 1983). A number of experimental investigations into the liquid immiscibilities in the granites systems have been carried out (Anfilogov et al., 1983; Glyuk et al., 1971; Glyuk et al., 1973a; 1973b; kovalenko, 1978; Wang Liangkui et al., 1987). Nevertheless, the detailed scenarios of the liquid immiscibilities in the granitic magmas are much less understood. This experimental study is amide to get access to this problem. Starting materials are biotite granite +LiF(3-10%)+NaF(3-10%)+H_2O(30%). The experimental results have shown that the liquid immiscibilities of melts of different compositions occur at 1 kbar and 840 ℃ when 5wt% (LiF + NaF) are added to the granite samples. three kinds of glasses indicating of three types of coexisting immiscible melts have been observed: light blue matrix glass, melanocratic glass balls and leucocratic glass balls. It is interesting that we have observed various kinds of textures as follows: spherulitic texture, droplets, flow bands, swirls. All these textures can be comparable to those in the natural granitic bodies. Electron microprobe data suggest that these different kinds of glasses are of different chemical compositions respectively; matrix glasses are F-poor silicate melts; melanocratic balls correspond to F-rich silicate melts; and leucocratic balls are the melts consisting mainly of fluorides. Raman spectrometric data have indicated that different glasses have different melt structures. TFM Diagrams at 1000 * 10~5 Pa have been plotted, in which two miscible gaps are found. One of the two gaps corresponds to the immiscibility between F - poor silicate melt and F-rich silicate melt, another to that between the silicate melt and fluoride melt. The experiments at different pressures have suggested that the decreases in pressures are favorable to the liquid immiscibility. Several reversal experiments have indicated that the equilibria in different runs have been achieved. We have applied the experimental results to explain the field evidence of immiscibilities in some of granites associated with W-Sn-Nb-Ta mineralization. These field phenomena include flow structure, globular structures,mineralized globular patche and glass inclusions in topaz. We believe that the liquid immiscibility (liquid segregation) is a possible way of generation of F(Li)-rich granites. During the evolution of the granitic magmas, the contents of Li, F, H_2O and ore-forming elements in the magmas become higher and higher. The granites formed in the extensional tectonic settings commonly bear higher abundences of the above-mentioned elements. the pressures of the granitic magmas are relatively lower during the processes of their emplacements and cooling. The late-staged magmas will produce liquid immiscibilities, leading to the production of several coexisting immiscible melts with different chemical compositions. The flow of immiscible consisting magmas will produce F(Li)-rich granites. It is also considered that liquid immiscibilities are of great significance in the production of rare metal granites. The ore-forming processes and magmatic crystallization and metasomatic processes can be occur at the same time. The mineralisations of rare metals are related to both magmatic and hydrothermal processes.

Microscopic Model Of Nano-Scale Particles Removal In High Pressure Co2-Based Solvents

A physical model is presented to describe the kinds of static forces responsible for adhesion of nano-scale copper metal particles to silicon surface with a fluid layer. To demonstrate the extent of particle cleaning, Received in revised form equilibrium separation distance (ESD) and net adhesion force (NAF) of a regulated metal particle with different radii (10-300 nm) on the silicon surface in CO2-based cleaning systems under different pressures were simulated. Generally, increasing the pressure of the cleaning system decreased the net adhesion force between spherical copper particle and silicon surface entrapped with medium. For CO2 + isopropanol cleaning system, the equilibrium separation distance exhibited a maximum at temperature 313.15 K in the Equilibrium separation distance regions of pressure space (1.84-8.02 MPa). When the dimension of copper particle was given, for example, High pressure 50 nm radius particles, the net adhesion force decreased and equilibrium separation distance increased with increased pressure in the CO2 + H2O cleaning system at temperature 348.15 K under 2.50-12.67 MPa pressure range. However, the net adhesion force and equilibrium separation distance both decreased with an increase in surfactant concentration at given pressure (27.6 or 27.5 MPa) and temperature (318 or 298 K) for CO2 + H2O with surfactant PFPE COO-NH4+ or DiF(8)-PO4-Na+. (C) 2008 Elsevier B.V. All rights reserved.

Spectroscopic properties of Er3+/Yb3+ codoped fluorophosphate glasses

Er3+/Yb3+ cocloped fluorophosphate glasses were prepared and their thermal stabilities, Raman spectra, absorption spectra, and fluorescence spectra were measured. It is found that proper content of NaF or PbF2 is helpful for the increase of stability against crystallization. The variation of AI(PO3)3 or NaF content in the composition affects not the maximum phonon energy but the phonon density. The introduction of PbF2 decreases the phonon energy slightly. Intense green and red upconversion luminescence was observed for the fluorophosphate glass with low phosphate content. A glass matrix for upconversion luminescence requiring neither expensive raw material nor special atmospheric conditioned preparation is provided. Infrared luminescence around 1530 nm was researched. Fluorophosphate glasses with bandwidth properties and stimulated-emission cross sections better than tellurite, germanate and silicate glasses are obtained. Through the introduction of NaF, the bandwidth properties are decreased. Through the introduction of PbF2 the gain properties are increased. On the whole, it is difficult to obtain a material with the best gain properties and bandwidth properties simultaneously. There should be a compromise between them according to the demand. (C) 2006 Elsevier B.V. All rights reserved.

抗边信道攻击的快速并行标量乘法

在椭圆曲线密码体制里面。标量乘法是一个非常重要的运算。它的性能对整个密码体制的效率有着举足轻重的作用。论文首先提出一个快速窗口算法用以实现标量乘法，此算法利用了NAF表示的窗口算法和边信道原子块（side channel atomicity）方法。所以算法有效。快速而且可以边信道攻击。在此基础上提出了一个并行算法，它对于边信道攻击是安全的，高效的。

稀土氟化物和钨酸盐纳米/微米材料的合成和发光性质研究

在现代化学和材料科学中，纳米/微米材料的尺寸和形貌控制引起了学术界的广泛关注，如何合理控制材料的定向生长，调节其组成、形貌、尺寸以及维度，进而更好的理解晶体生长的复杂现象、揭示其潜在的基本理论和原理并最终实现按照人们的设计合成功能材料具有十分重要的意义。本论文在稀土氟化物和钨酸盐纳米/微米材料的设计合成、形貌控制、形成机制以及发光性质等方面进行了一些探索性的研究。 发展了一种简单、整体、没有模板、环境友好的水热方法合成系列稀土氟化物。用有机添加剂柠檬酸钠(Na3C6H5O7•2H2O)作为配位剂和形貌控制剂，通过改变氟源(NaF, NH4F或NaBF4)和最初溶液的pH值，得到了具有不同成分、晶体结构、尺寸和形貌的稀土氟化物，包括二元氟化物LnF3 (Ln = La-Lu)和三元氟化物NaREF4 (RE = Y, Yb, Lu)；首次研究了具有各种晶体结构和形貌的含镱(Yb)和镥(Lu)的二元和三元氟化物的可控合成；对各种产物可能的形成机理进行了合理、系统的讨论；并对各种基质中Eu3+, Tb3+掺杂的下转换和Yb3+/Er3+, Yb3+/Ym3+共掺杂的上转换发光性质进行了详细的研究。由于具有优良的荧光性质和可控的形貌和尺寸，这些发光材料可能在光显示、光发射二级管(LEDs)、固体激光器等领域有着潜在的应用价值。这些研究结论不仅丰富了稀土氟化物化学的内容，而且探索了纳米/微米材料的晶体生长规律和形成机理。 采用超声化学途径合成了CaWO4, CaWO4:Eu3+和CaWO4:Tb3+亚微米尺寸的球形荧光粒子，详细讨论了合成材料的结构、形成机理、光致发光、阴极射线发光性质以及能量传递现象，为其它钨酸盐的合成提供了新的思路。

超声化学法合成稀土纳米材料

稀土纳米材料因其独特的光、电、磁和催化等性能，在纳米器件和功能材料等诸多领域具有重要的应用价值。大量研究表明，纳米材料的物理和化学性质与其尺寸、成分、形貌和晶型密切相关。稀土纳米材料的合成方法有许多，然而，要真正实现这类材料的简单可控合成仍然是个艰难的课题。超声化学法由于具有操作简单、合成周期短、反应温度低、成本低廉并且产物均匀、粒径分布窄和纯度高等突出优点，已经在无机纳米材料制备领域中显示出独特的魅力。因此，本论文的工作是运用超声化学法合成有广泛应用前景的稀土纳米材料，对产物的形貌和粒径进行有效的调控，研究和分析其形成机理，并进一步考察其形貌、结构与性能之间的相互关系。 在本论文中，我们研究的体系集中在稀土磷酸盐、稀土氟化物和稀土钒酸盐三类纳米材料。 采用超声化学法得到的CePO4:Tb和CePO4:Tb/LaPO4(核/壳)纳米棒结晶完好，具有CePO4体材料的六方相结构。CePO4:Tb纳米棒直径为10-30 nm，长度为200 nm，CePO4:Tb/LaPO4(核/壳)纳米棒的LaPO4壳的厚度为2-10 nm。CePO4:Tb和CePO4:Tb/LaPO4(核/壳)纳米棒均具有Ce3+ (5d - 4f)和Tb3+ 5D4-7FJ(J = 6-3)的特征发射。与CePO4:Tb纳米棒核相比，CePO4:Tb/LaPO4(核/壳)纳米棒的光谱强度及荧光寿命均有较大的提高，这是由于形成核/壳结构后发光中心镧系金属离子与表面淬灭中心的距离增大，减少了能量传递过程中非辐射复合的路径，使能量淬灭受到抑制。 采用简单、快速、无模板辅助的超声化学法合成了稀土氟化物，并对产物的形貌和粒径进行了有效的调控。通过应用不同氟源(KBF4、NaF和NH4F)选择性合成了具有不同形貌的CeF3纳米材料，如片状、棒状和颗粒状。对具有不同形貌的CeF3样品进行了UV-Vis吸收光谱和荧光光谱测试和比较。研究结果表明不同形貌的样品，它们的光学性质存在很大差异，这说明纳米材料的光学性质与其形貌、粒径、晶体结构等因素有密切的关系。得到的EuF3单晶纳米材料具有三维花状形貌。这些纳米花的外形为球状，平均直径为0.9 μm-1.0 μm，每个花瓣的厚度约为0.14 μm。在其他实验条件不变的情况下，采用搅拌法而不经过超声辐射的对比实验只能得到二维纳米片，这表明超声辐射对花状EuF3的形成起到了至关重要的作用。基于不同反应时间的实验结果，我们提出了这种三维花状EuF3纳米材料可能的形成机理。 采用超声化学法选择性地合成了介孔及棒状CeVO4和纺锤状的YVO4:Eu3+ 纳米材料。CeVO4纳米棒的平均直径为5 nm，长度为150 nm。介孔CeVO4材料的比表面积较高(122 m2•g-1)，孔径分布窄，其催化性能有望得到提高。纺锤状的YVO4:Eu3+ 纳米粒子具有四方相锆石结构，其直径为90-150 nm，长度为250-300 nm。超声辐射对样品的形貌起着关键作用，在其他反应条件不变，未采用超声辐射的情况下只能得到团聚严重的纳米颗粒。荧光测试表明，纺锤状YVO4:Eu样品表现为Eu3+ 5D0-7FJ(J = 1- 4)的特征跃迁，以5D0-7F2电偶极跃迁(614nm)为最强峰，属于红光发射。

熔盐电解制备铝-钕母合金的研究

本文是以液态铝为阴极，在稍高于铝-钕合金低共晶点的温度下，熔盐电解制备铝-钕母合金。工作内容分两部分：I、在较低温度(660-700℃)下电解NdCl_3-KCl·NaCl熔体及氟化物添加剂对电解的影响，II、NdCl_3-KCl·NaCl-NaF及NdCl_3-KCl·NaCl-CaF_2熔体部分熔度图。本文第一部分，在30重量%NaCl_3-70重量%KCl·NaCl熔体中，首次于700℃下较系统地研究电解制备铝-钕母合金，电流效率达到78%，加机械搅拌时可达90%，大大超过熔盐电解制备金属钕的电流效率（50%）。但是，实验中看出纯氯化物熔体存在着下列缺点：1、造渣较多，2、当阴极电流密度高于0.75安培/厘米~2时，阴极上生成枝状物沉积；虽然机械搅拌能避免枝状物生成，但操作不便，搅拌棒材料不易解决。本工作的重点是通过添加氟化物改善熔体性能，提高电流效率。实验得出：何氯化物熔体添加氟化物，不仅能改善金属在熔体中的凝聚性能；还能增加熔体流动性、减少造渣、提高熔体稳定性，便于电解质的连续使用；特别是能促进Nd~(3+)离子被铝热还原，使Nd~(3+)离子被电化学还原的同时，伴随的化学还原作用加剧了，提高了钕的沉积效率。本工作还确定，多种氟化物均可作为添加剂，添加量为1%左右，便可得到满意的结果，而无需机械搅拌。实验证实，在熔盐电解制备铝-钕合金时，温度是一个重要因素。除电解质的温度外，阴极合金的温度也有影响，二者的温度愈低，愈有利于提高电流效率。当阴极合金温度不高于675 ℃时，电流效率最高。为配合熔盐电解制取铝-钕母合金，还研究了熔盐的部分物理化学性质。Nd~(3+)离子的析出电势测量结果表明，无论在纯氯化物熔体，还是加有少量氟化物的熔体中，钕在液态铝阴极上的析出电势都比在固态钼阴极上的低1伏左右；不论在液态或固态阴极上，也不论于纯氯化物或加有少量氟化物的电解质中，Nd~(3+)离子的析出电势均随其浓度的增加而下降；但氟化钠的加入使钕的析出电势升高了90毫伏。表面张力测量结果表明，氟化钠使熔体表面张力增大。第二部分，绘制了NdCl_3-KCl·NaCl-NaF及NdCl_3-KCl·NaCl-CaF_2两个熔体的部分熔度图。在实际电解所采用的浓度范围，即NdCl_3含量为10～30重量%时，向熔体添加NaF和CaF_2，对体系初晶点有不同的影响：加1%左右的NaF，体系初晶温度即达到最低点，而加CaF_2，需8%左右才能达到最低点。所得熔度图表明，往溶有10～30重量% NdCl_3的KCl·NaCl熔体添加1%左右的NaF或CaF_2，其初晶点均低于645 ℃，均适于作为在较低温度下电解制备铝-钕母合金的电解质。此外，在附录中还综述了熔盐电解铝-钕母合金的有关研究概况和主要研究方向。

冠醚修饰电极及其在分析化学中的应用

本论文较系统地研究了Naf:on聚合物薄膜冠醚修饰电极阳极溶出伏安法在分析中的应用。首次将Naf:on薄膜冠醚类化合物修饰电极应用于铊、银和铅三种离子的测定，得到了高灵敏度的分析方法亦用于实际样品测定。用涂层法制备了Naf:on聚合物薄膜冠醚（二环已基18－冠－6）化学修饰电极，用这种修饰电极测定金属离子的高灵敏度来源于将Naf:on对大阳离子的强离子交换能力、冠醚类化合物络合金属阳离子形成大阳离子的能力与溶出伏安法的高灵敏度三者的结合，冠醚化合物中性分子可与金属阳离子络合形成大络阳离子：M~(n+)＋qC=(MC_q)~(n+) Naf:on膜由于其具有的对大阳离子的强交换能力而将冠醚与和金属离子形成的大阳离子络合并吸附于电极表面，在溶出伏安法的富集过程中，电位置于是以令（MCq）~(n+)还原的位置以使（MCq）~(n+)还原：（MCq）~(n+)＋ne=M＋qC 析出的零价态的金属可在Naf:on膜内固定，同时又放出冠醚分子成为新的未被占据的络合吸附中心，继续捕获溶液中的阳离子从而起到富集作用。由于使用溶出伏安法排除电极表面络合吸附饱和的问题，从而使本方法灵敏度大大高于一般的使用化学修饰电极进行预富集的分析测定方法。提出了Naf:on薄膜冠醚修饰电极阳极溶出伏安法测定水溶液中Te(I)的方法，在电位为－1.30 Vvs.Ag/Ag ce处0.1高氯酸锂溶液中，用该修饰电极富集30分钟，检测下限可低至2×10~(-12)M（0.4 ppt）。溶液中Te(I)浓度在5×10(-12)M～1×10(-8)M范围内与溶出峰电流成良好的线性关系且通过原点，可以用标准加入法测定。常见共存元素Zn（II），Su（II），Cu（II），Fe（II），Co（II），Ni（II），In（III）等无干扰。Pb（II）与Cd（II）共存时对Te（I）有干扰，同1×10~(-3)M EDTA掩蔽可有消除干扰。测定了合成样品中的Te（I）含量，平行测定七组样品相对标准偏差4.2％。本文法是目前Te（I）的分析中最灵敏的电化学方法之一。提出了Naf:on薄膜冠醚修饰电极阳极溶出伏安法测定水溶液中Ag（I）的方法。在0.01MHNO_3 4～7×10~(-3)M Cl混合溶液中，检测电位在－0.30Vvs.SCE富集30分钟，检出下限可低至2×10~(-12)M，是迄今所见Ag（I）的分析中灵敏度最高的电分析方法。Ag（I）浓度在2×10~(-11)M～1×10~(-8)M范围内与溶出峰电流成良好的线性关系且通过原点。五到十倍量的Hg（II）和Au（II）有干扰。用本法测定了分析纯硝酸铵中的银含量为0.000048％，平行测定七组样品相对标准偏差为3.7％。提出用Naf:on薄膜冠醚修饰电极阳极溶出伏安法测定水样中铅的方法。在0.lMLiNO_3底液中，电位在－1.10Vvs.SCE富庥3分钟检测限达5×10~(-10)M，方法快速灵敏。Pb（II）浓度在1×10~(-9)～1×10~(-7)M范围内与溶出峰电流呈线性关系。1×10~(-6)以上Cu（II）存在使Pb（II）的峰电流时显增加。用本方法测定了自来水样中的铅含量，平行测定七组样品相对标准偏差8.0％。该修饰电极在K~+浓度为1×10~(-5)～1×10~(-7)M范围内对K~+有能斯特响应。本工作为铊、铅、银的痕量分析提供了高灵敏度的方法，为溶出伏安法摆脱汞污染的问题做出了贡献，为化学修饰电极用于分析化学领域提供了新的途径。

富钇稀土-铝合金制取的研究Study on Preparation of Yttrium-Rich RE-Al Alloys

我国江西龙南稀土矿是目前世界上储量最大的富钇稀土矿、研制具有多种用途的钇（Y）-铝（Al）或富钇混合稀土（Ymm）-铝中间合金，对于开拓我国龙南稀土矿的应用领域扩大稀土合金出口具有重要意义。基于这一背景并针对目前氟化物体系制取Ymm-Al合金时存在着电解温度高，腐蚀现象严重，电效偏低等缺点，本文系统开展了在氯化物熔盐体系中电解制取Ymm-Al合金的研究工作。本工作由三部分组成：在第一部分工作中，开展了熔盐电解所需要基本原料-无水稀土氯化物制取的工艺研究。利用化学分析和结构分析手段，弄清了干法氯化过程中YmmCl_3水解的机理，提出了减弱水解的措施，即YmmCl_3先在850-900 ℃灼烧1.5 + 0.2hr，脱掉吸附水并将碱式碳酸盐转化为氧化物，增加稀土氧化物的比表面。通过条件试验得到最佳工艺条件为：采用NH_4 Cl:Ymm_2 O_3 = 14:1（摩尔比）的配料比，每次投入氯化装置的原料量为0.26 - 0.36 kg, 在400-450 ℃氯化反应激烈开始后迅速降温至400 ℃以下，待物料粘结现象消失后，再行升温氯化。出料及后期控制温在475 ± 25 ℃。经过3.8 ± 0.2hr氯化，可制得水不溶物小于1%并符合熔盐电解要求的YmmCl_3原料。此新工艺与原有干法工艺相比，流程短，装置简单，不需密闭抽真空，成本低，适于制取任何量的优质熔盐电解所需氯化稀土原料。在第二部分工作中，利用上述YmmCl_3原料，以液态铝为阴极，在氯化物体系中进行熔盐电解，通过试验得出在小型试验规模制取Ymm-Al合金的最隹工艺条件为：电解质组成（重量比）40%YmmCl_3-1%NaF-59%等摩尔的NaCl-KCl；电解温度为790 ± 5 ℃；阴极电流密为0.7 - 0.02A/cm~2；电解电量为333 ± 5库仑/克铝，制得钇铝合金中Ymm含量为10 ± 2%。添加1%的NaF可消除阴极表面生成枝状物，减少合金中夹渣和熔盐中沉渣。在电解工作中，将方差分析应用于试验数据处理，方差分析结果表明，各种试验因素对电效有明显影响，试验数据可靠，试验误差在允许范围以内。在第三部分工作中，利用线性扫描伏安法测定了在最隹电解工艺条件下Y~（3+）和Ymm在液态铝及钼电极上的析出电位。测定结果表明：Y~（3+）和Ymm~（3+）在液态铝阴极上的析出电位比在钼阴极上偏正0.2 ～ 0.8伏，氟离子的加入要比不加氟时析出电位不有同程度的负移，但考虑到氟离了具有消渣作用，加入少量氟比物添加剂对提高电效有利。

簇毛麦（ Dasypyrum villosum）矮秆突变体的研究

株高是农作物的重要农艺性状之一，适度矮化有利于农作物的耐肥、抗倒、高产等。20世纪50年代，以日本的赤小麦为矮源的半矮秆小麦的培育和推广，使得世界粮食产量显著增长，被誉为“绿色革命”。迄今为止，已报到的麦类矮秆、半矮秆基因已达70多个，但由于某些矮源极度矮化或者矮化的同时伴随不利的农艺性状，使得真正运用于育种实践的矮源较少。因此，发掘和鉴定新的控制麦类作物株高的基因，开展株高基因定位、克隆及作用机理等方面的研究，对实现麦类作物株高的定向改良，具有重要的理论意义和应用价值。簇毛麦(Dasypyrum villosum，2n＝14，VV)是禾本科簇毛麦属一年生二倍体异花授粉植物，为栽培小麦的近缘属。本课题组在不同来源的簇毛麦杂交后代中发现了一株自然突变产生的矮秆突变体。观察分析了该突变体的生物学特性，对矮秆性状进行了遗传分析，对茎节细胞长度、花粉的活力进行了细胞学观察，考察了该突变体内源赤霉素含量及不同浓度外施赤霉素对突变体的作用，分析了赤霉素生物合成途径中的内根贝壳杉烯氧化酶（KO）和赤霉素20氧化酶(GA20ox)的转录水平，对赤霉素20氧化酶和赤霉素3-β羟化酶(GA3ox)进行了克隆和序列分析，并对GA20ox进行了原核表达和表达的组织特异性研究。主要研究结果如下：1. 该突变体与对照植株在苗期无差异，在拔节后期才表现出植株矮小，相对对照植株，节间伸长明显受到抑制，叶鞘长度基本不变。在成熟期，对照植株的平均株高为110cm，而突变株的平均株高为32cm，仅为对照植株的1/3 左右。除了株高变矮以外，在成熟后期，突变株还表现一定程度的早衰和雄性不育。I2-KI染色法观察花粉活力结果表明，对照植株花粉90%以上都是有活力的，而突变植株的花粉仅20%左右有活力。2. 突变株与对照植株的杂交F1代均表现正常株高，表明该突变性状为隐性突变。F1代植株相互授粉得到的168株F2代植株中，株高出现分离，正常株高（株高高于80cm）与矮秆植株（株高矮于40cm）的株数比为130：38，经卡方检验，其分离比符合3：1的分离比，因此推测该突变体属于单基因的隐性突变。3. 用ELISA方法检测突变株和对照植株的幼嫩种子中内源性生物活性赤霉素（GA1＋3）含量，结果表明突变株的赤霉素含量为36 ng/ml，而对照植株的赤霉素含量为900 ng/ml。对突变株外施赤霉素，发现矮秆突变株的株高和花粉育性均可得到恢复。这些结果表明该突变株为赤霉素缺陷型突变。4. 用荧光定量PCR方法比较突变株与对照植株中内根贝壳杉烯氧化酶和赤霉素20氧化酶的转录水平，结果表明突变株的KO转录水平比对照植株分别提高了6倍（苗期）和16倍（成熟期），突变株的GA20ox转录水平与对照植株在苗期无明显差异，在成熟期突变株较对照植株则提高了10倍左右。这些结果表明该矮秆突变体与赤霉素的生物合成途径密切相关，而且极有可能在赤霉素的生物合成途径早期就发生了改变。5. 以簇毛麦总基因组为模板，同源克隆了GenBank登录号为EU142950，RT-PCR分离克隆了簇毛麦的GA3ox基因cDNA全长序列，分析结果表明该cDNA全长1206bp，含完整编码区1104bp，推测该序列编码蛋白含368个氨基酸残基，分子量为40.063KD，等电点为6.27。预测的氨基酸序列含有双加氧酶的活性结构，在酶活性中心2个Fe离子结合的氨基酸残基非常保守。该序列与小麦、大麦和水稻的GA3ox基因一致性分别为98%、96%、86%。基因组序列与cDNA序列在外显子部分一致，在478-715bp和879-1019bp处分别含238bp和140bp的内含子。6. 通过RT-PCR技术克隆了簇毛麦的GA20ox基因全长，命名为DvGA20ox，GenBank登录号为EU142949。该基因全长1080个碱基，编码359个氨基酸，具有典型的植物GA20ox基因结构。该基因编码的蛋白质与小麦、大麦、黑麦草等GA20ox蛋白的同源性分别为98%，97% 和91%。该序列重组到原核表达载体pET-32a(+)上，将获得的重组子pET-32a(+)-DvGA20ox转化大肠杆菌BL21pLysS后用IPTG进行诱导表达。SDS-PAGE分析表明，DvGA20ox基因在大肠杆菌中获得了高效表达，融合蛋白分子量为55kDa。定量PCR分析表明，该基因在簇毛麦不同器官中的表达差异明显：叶片中表达水平最高，根部表达水平次之，茎部和穗中表达较弱。在外施赤霉素后，该基因的表达水平在两小时以后急剧下降，表明该基因的表达受自身的反馈调节。本研究结果认为，(1)该簇毛麦矮秆突变体为单基因的隐性突变；(2)该矮秆突变体为赤霉素敏感突变，内源赤霉素含量检测表明突变体的内源性赤霉素含量仅为对照植株的1/30；(3)荧光定量PCR结果表明突变株的赤霉素生物合成途径的关键酶基因表达水平比对照植株高，而且突变植株的赤霉素生物合成改变很可能发生在赤霉素生物合成途径的早期；(4)GA20ox有表达的组织特异性，且受到自身产物的反馈调节。 Plant height is an impotrant agronomic trait of triticeae crops.Semi-dwarf cropcultivars, including those of wheat, maize and rice, have significantly increased grainproduction that has been known as “green revolution”. The new dwarf varieties couldraise the harvest Index at the expense of straw biomass, and, at the sametime, improvelodging resistance and responsiveness to nitrogen fertilizer. Moreover, dwarf traits ofplant are crucial for elucidating mechanisms for plant growth and development aswell. In many plant species, various dwarf mutants have been isolated and theirmodles of inheritance and physiology also have been widely investigated.The causesfor their dwarf phenotypes were found to be associated with plant hormones,especially, gibberellins GAs.Dasypyrum villosum Candargy (syn.Haynaldia villosa) is a cross-pollinating,diploid (2n = 2x = 14) annual species that belongs to the tribe Triticeae. It is native toSouthern Europe and West Asia, especially the Caucasuses, and grows underconditions unfavorable to most cultivated crops. The genome of D. villosum,designated V by Sears, is considered an important donor of genes to wheat for improving powdery mildew resistance, take-all, eyespot, and plant and seed storageprotein content. A spontaneous dwarf mutant was found in D. villosum populations.The biological character and modles of inheritance of this dwarf mutant are studied.The cell length of stem cell is observed. The influence of extraneous gibberellin tothe dwarf mutant is also examined; the transcript level of key enzyme of gibberellinbiosynthesis pathway in mutant and control plants is compared. GA3ox and GA20oxare cloned and its expression pattern is researched.1. The dwarf mutant showed no difference with control plants at seedlingstage.At mature stage, the average height of control plants were 110cm and the dwarfplants were 33cm. The height of the mutant plant was only one third of the normalplants due to the shortened internodes. Cytology observation showed that theelongation of stem epidermal and the parenchyma cells were reduced. The dwarfmutant also shows partly male sterile. Pollen viability test indicates that more than80% of the pollen of the mutant is not viable.2. The inheritance modle of this dwarf mutant is studied. All The F1 plantsshowed normal phenotype indicating that the dwarfism is controlled by recessivealleles. Among the 168 F2 plants, there are 130 normal plants and 30 dwarf plants, thesegregation proportion accord with Mendel’s 3:1 segregation. We therefore proposethat this dwarf phenotype is controlled by a single recessive gene.3. Quantitative analyses of endogenous GA1+3 in the young seeds indicated thatthe content of GA1+3 was 36ng/ml in mutant plants and 900ng/ml in normal plants.The endogenous bioactive GA1+3 in mutant plants are only about 1/30 of that innormal plants. In addition, exogenously supplied GA3 could considerably restore themutant plant to normal phenotype. These results showed that this mutant wasdefective in the GA biosynthesis.4. More than ten enzymes are involved in GA biosynthesis. KO catalyzes thefirst cytochrome P450-mediated step in the gibberellin biosynthetic pathway and themutant of KO lead to a gibberellin-responsive dwarf mutant. GA20ox catalyze therate-limited steps so that their transcript level will influence the endogenous GAbiosynthesis and modifies plant architecture. The relative expression levels of genesencoding KO and GA20ox were quantified by real time PCR to assess whether thechanges in GA content correlated with the expression of GA metabolism genes andwhere the mutant occurred during the GA biosynthesis pathway. In mutant plants,the transcript levels of KO increased about 6-fold and 16-fold at the seedling stage and elongating stage respectively comparing with the normal plants. For theseedlings, there was no notable difference in the expression of GA20ox betweenmutant and normal plants. At the elongating stage, GA20ox transcript increased 10times in mutant plants, suggesting that the GA biosynthesis pathway in mutant plantshad changed from the early steps rather than the late steps.5. A full length cDNA of D. villosum gibberellin 3β-hydroxylase homology(designated as DvGA3ox) was isolated and consisted of 1206bp containing an openreading frame of 1104bp encoding 368 predicted amino acid residues. Identityanalysis showed that the gibberellin 3β-hydroxylase nucleotide sequence shared 98%,96% and 86% homology with that of wheat, barley and rice. The predicted peptidecontained the active-site Fe of known gibberellin 3β-hydroxylase and the regionhomologous to wheat, barley and Arabidopsis. The genomic clone of gibberellin3β-hydroxylase has two introns.6. The full-length cDNA of D. villosum gibberellin 20 oxidase (designated asDvGA20ox) was isolated and consisted of 1080-bp and encoded 359 amino acidresidues with a calculated mol wt of 42.46 KD. Comparative and bio-informaticsanalyses revealed that DvGA20ox had close similarity with GA20ox from otherspecies and contained a conserved LPWKET and NYYPXCQKP regions. Tissueexpression pattern analysis revealed DvGA20ox expressed in all the tissues that wereexamined and the highest expression of DvGA20ox in expanding leaves followed byroots. Heterologous expression of this cDNA clone in Escherichia coli gave a fusionprotein that about 55KD. Transcript levels of DvGA20ox dramatically reduced twohours after application of biologically active GA3, suggesting that the biosynthesis ofthis enzymes might be under feedback control.

beta-NaYF4 and beta-NaYF4:Eu3+ Microstructures: Morphology Control and Tunable Luminescence Properties

beta-NaYF4 hexagonal microprisms and microrods with different aspect ratios have been prepared via a simple hydrothermal route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. The influences of reaction temperature and the molar ratio of NaF to y(3+) on the crystal phases and shapes of final products have been studied in detail. The aspect ratios of products increase gradually with the increase of reaction temperature and NaF/Y3+ molar ratio. The growth mechanisms of crystals prepared under the different conditions are presented systematically. More importantly, the systematical investigation on the luminescence properties of beta-NaYF4:xEu(3+) (x = 0.5, 1, 2, 3, 5, and 10 mol %) with hexagonally microprismatic morphology shows the characteristic emissions of Eu3+ (D-5(J)-F-7(J'), J, J' = 0, 1, 2, 3). Under the excitation of single wavelength light of 397 nm, the luminescence colors of the corresponding products can be tuned feasibly from bluish white to yellow to red by changing the doping concentration of Eu3+.

Morphological control and luminescent properties of CeF3 nanocrystals

The nanocrystals of CeF3 with the hexagonal structure and different morphologies such as the disk, the rod, and the dot have been successfully synthesized via a mild ultrasound assisted route from an aqueous solution of cerium nitrate and different fluorine sources (KBF4, NaF, NH4F). The use of different fluorine sources has a remarkable effect on the morphology of the final product. The luminescence and UV-vis absorption properties of CeF3 nanocrystals with different morphologies have been investigated. Compared with other shape nanocrystals, the luminescence intensity of the disklike nanocrystals is obviously enhanced. It is suggested that the function-improved materials could be obtained by tailoring the shape of the CeF3 nanocrystals.