黑白仰鼻猴（Rhinopithecus bieti）西藏种群栖息地变化研究

黑白仰鼻猴（Rhinopithecus bieti）目前分布在金沙江和澜沧江之间横断山脉的一个狭小的区域范围内（26o14’N-29o20’N，99o15’E-99o37’E），海拔2 600 m（南部） - 4 200 m（北部）之间；目前大约有15 群，数量估计约1700 个体。是我国特有的灵长类之一，为国家Ⅰ级保护动物，在IUCN（世界自然保护联盟）2007 受威胁物种红皮书中被列为濒危物种并处于小种群、高度片断化状态（ENC 2a）。西藏是黑白仰鼻猴分布的北端，约有300 个体。基于前人的野外调查和报道确认，暗针叶林和针阔叶混交林是其适宜栖息地，人们在低海拔和高海拔砍伐或者火烧暗针叶林和针阔叶混交林的产物－农田和夏季牧场正在逐渐侵蚀着其适宜栖息地。尽管当地藏族村民信奉佛教，禁止猎杀任何野生动物，但是近些年来，黑白仰鼻猴栖息地不断丧失，这与牧场和农田扩张、当地人们薪柴采集等活动有关。黑白仰鼻猴西藏种群主要在原始暗针叶林和和针阔叶混交林里活动。为了评估该物种的栖息地现状和变化情况，我们通过野外调查工作，应用GIS 和RS 技术，分别解译了1986 年、1992 年、1997 年、2001 年和2006 年的Landsat TM/ETM+ 冬季卫星影像，并对解译结果进行了计算和分析，得到了以下西藏种群栖息地的主要结果： 1）现有暗针叶林（包括原始针叶林和针阔混交林）面积是30 500 hm2 ，夏季牧场面积是13 100 hm2 ，农田面积是6 400 hm2 ；2）在过去20 年间（1986-2006 年），暗针叶林面积减少了14.6％（5 200 hm2 ），夏季牧场面积增加了47.2％（4 200 hm2 ），农田面积增加了14.3％（800 hm2 ）；3）在过去20 年间，暗针叶林的斑块数量增加了68.4％，平均斑块面积下降了49.3％（从1986 年的15.1 hm2 下降到2006 年的7.6 hm2 ），最大的斑块指数下降了54.9％；景观丰富度并没有变化，但Shannon 多样性指数和Shannon 均匀度指数分别增加了2.7％。这都表明栖息地丧失和破碎化程度越来越严重。在上述结果的基础上，我们进一步对栖息地变化的主要原因进行了初步分析和探讨。通过暗针叶林面积、夏季牧场面积和农田面积和当地各乡村的家庭户数、人口数量、平均家庭人口数和牲畜存栏数等统计数据的Spearman秩相关分析表明，暗针叶林面积变化分别与当地的人口数量、家庭户数和平均家庭人口数呈显著负相关，与牲畜存栏数呈负相关；而夏季牧场面积和农田面积都分别与人口数量、家庭户数和平均家庭人口数呈显著正相关，与牲畜存栏数呈正相关。这意味着在目前当地传统生产方式基本未发生改变的情况下，因人口数量增加所带来的生产等活动强度的增加是黑白仰鼻猴栖息地丧失与破碎化加剧的主要原因（R2 = 0.972）；当地人类经济活动的增加，如牧场和农田扩张，牲畜存栏数增加以及薪材采集和木质建筑等导致了栖息地丧失、退化和破碎化。但另一方面，当地一妻多夫的婚配制度（仅在西藏部分地区仍有保留）对黑白仰鼻猴的栖息地保护有积极的作用，因为大家庭（家庭人口数）的人均资源消耗，如薪柴需求、房屋数量、牧场和农田等，都比小家庭低。在过去20 年中（1983-2003 年），当地家庭户数的增加比人口数量增加要慢，这对黑白仰鼻猴的栖息地保护起到了一定的积极作用。因此，西藏种群作为单独的遗传亚种群，其保护工作任重而道远。

Syntheses, crystal structures, visible and near-IR luminescent properties of ternary lanthanide (Dy3+, Tm3+) complexes containing 4,4,4-trifluoro-1-phenyl-1,3-butanedione and 1,10-phenanthroline

The ligands 4,4,4-trifluoro-1-phenyl-1.3-butanedione (Hbfa) and 1,10-phenanthroline (phen) were used to prepare ternary lanthanide (Ln) complexes [Dy(bfa)(3)phen and Tm(bfa)(3)phen]. Crystal data: Dy(bfa)(3)phen C(42)H(26)FqN(2)O(6)Dy, triclinic, P (1) over bar, a= 9.9450(6) angstrom, b = 14.0944(9) angstrom, c = 14.6043(9) angstrom, alpha = 82.104(1)degrees, beta = 87.006(1)degrees, gamma = 76.490(1)degrees, V = 1971.1(2)angstrom(3), Z = 2; Tm(bfa)(3)phen C42H26F9N2O6Tm, triclinic, P (1) over bar, a = 9.898(5)angstrom, b = 13.918(5)angstrom, c = 14.753(5)angstrom, a = 83.517(5)degrees, alpha = 86.899(5)degrees, gamma = 76.818(5)degrees, V = 1965.3(14)angstrom(3), Z = 2. The coordination number of the central Ln(3+) (Ln = Dy, Tm) ion is eight, with six oxygen atoms from three Hbfa ligands and two nitrogen atoms from the phen ligand.

Synthesis and Luminescent Properties of LaAlO3:RE3+ (RE = Tm, Tb) Nanocrystalline Phosphors via a Sol-Gel Process

LaAlO3:Tm3+ and LaAlO3:Tb3+ phosphors were prepared through a Pechini-type sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photoluminescence, and cathodoluminescence (CL) spectra were utilized to characterize the synthesized phosphors. The XRD results reveal that the fully crystalline pure LaAlO3 Phase can be obtained at 800 degrees C. The FE-SEM image indicates that the phosphor samples are composed of aggregated spherical particles with sizes ranging from 40 to 80 nm. Under the excitation of ultraviolet light (230 nm) and low-voltage electron beams (1-3 kV), the LaAlO3:Tm3+ and LaAlO3:Tb3+ phosphors show the characteristic emissions of Tb3+ (D-1(2)-> H-3(6,4),F-3(4) transitions) and Tm3+ (D-5(3,4)-> F-7(6,5,4,3) transitions) respectively. The CL of the LaAlO3:Tm3+ phosphors have high color purity and comparable intensity to the Y2SiO5:Ce3+ commercial product, and the CL colors of Tb3+-doped LaAlO3 phosphors can be tuned from blue to green by changing the doping concentration of Tb3+ to some extent.

Self-assembled 3D flowerlike Lu2O3 and Lu2O3 : Ln(3+) (Ln = Eu, Tb, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures: Ethylene glycol-mediated hydrothermal synthesis and luminescent properties

Three-dimensional flowerlike Lu2O3 and Lu2O3:Ln(3+) (Ln = Eu, Th, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures have been successfully synthesized via ethylene glycol (EG)-mediated hydrothermal method followed by a subsequent heat treatment process. X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectra, thermogravimetric and differential thermal analysis, elemental analysis, inductively coupled plasma atomic absorption spectrometric analysis, ion chromatogram analysis, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, photoluminescence spectra as well kinetic decays, and cathodoluminescence spectra were used to characterize the samples. Hydrothermal temperature, EG, and CH3COONa play critical roles in the formation of the lutetium oxide precursor microflowers. The reaction mechanism and the self-assembly evolution process have been proposed. The as-formed lutetium oxide precursor could transform to Lu2O3 With their original flowerlike morphology and slight shrinkage in the size after postannealing process.

Four New Lanthanide-Nitronyl Nitroxide (Ln(III)=Pr-III, Sm-III, Eu-III, Tm-III) Complexes and a Tb-III Complex Exhibiting Single-Molecule Magnet Behavior

Five new complexes based on rare-earth-radical [Ln(hfac)(3)(NIT-5-Br-3py)](2) (Ln=Pr (1), Sm (2), Eu (3), Tb (4), Tm (5); hfac = hexafluoroacetylacetonate; NIT-5-Br-3py = 2-(4,4,5,5-tetramethyl-3-oxylimidazoline-1-oxide)-5-bromo-3-pyridine) have been synthesized and characterized by X-ray crystal diffraction. The single-crystal structures show that these complexes have similar structures, in which a NIT-5-Br-3py molecule acts as a bridging ligand linking two Ln(III) ions through the oxygen atom of the N-O group and nitrogen atom from the pyridine ring to form a four-spin system. Both static and dynamic magnetic properties were measured for complex 4, which exhibits single-molecule magnetism behavior.

Highly uniform and monodisperse beta-NaYF4 : Ln(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) hexagonal microprism crystals: Hydrothermal synthesis and luminescent properties

beta-NaYF4:Ln(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) hexagonal microprisms with remarkably uniform morphology and size have been synthesized via a facile hydrothermal route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. It is found that sodium citrate as a shape modifier introduced into the reaction system plays a critical role in the shape evolution of the final products. Furthermore, the shape and size of the products can be further manipulated by adjusting the molar ratio of citrate/RE3+ (RE represents the total amount of Y3+ and the doped rare earth elements such as Eu3+, Tb3+, Yb3+/Er3+, or Yb3+/Tm3+). Under the excitation of 397 nm ultraviolet light, NaYF4:xEu(3+) (x = 1.5, 5%) shows the emission lines of Eu3+ corresponding to D-5(0-3) -> F-7(J) (J = 0-4) transitions from 400 to 700 nm (whole visible spectral region) with different intensity, resulting in yellow and red down-conversion (DC) light emissions, respectively.

Thermoluminescence studies of LiBa2B5O10 : RE3+ (RE = Dy, Tb and Tm)

LiBa2B5O10:RE3+ (RE = Dy, Tb and Tm) was synthesized by the method of high-temperature solid-state reaction and the thermoluminescence (TL) properties of the samples under the irradiation of the gamma-ray were studied. The result showed that Dy3+ ion was the most efficient activator. When the concentration of Dy3+ was 2 mol%, LiBa2B5O10:Dy3+ exhibited a maximum TL output. The kinetic parameter of LiBa2B5O10:0.02Dy was estimated by the peak shape method, for which the average activation energy was 0.757 eV and the frequency factor was 1.50 x 10(7) s(-1). By the three-dimensional (3D) TL spectrum, the TL of the sample was contributed to the characteristic f-f transition of DY3+. The dose-response of LiBa2B5O10:0.02Dy to gamma-ray was linear in the range from 1 to 1000 mGy. In addition, the decay of the TL intensity of LiBa2B5O10:0.02Dy was also investigated.

Selective separation of yttrium by CA-100 in the presence of a complexing agent

The selective separation of Y from yttrium solution containing small heavy rare earth (HRE) impurities (Ho, Er, Tm, Yb, Lu) by liquid-liquid extraction using CA-100 in the presence of a water-soluble complexing agent of ethylenediaminetetraacetic acid (EDTA) was experimentally studied at 298K. Experiments were carried Out in two feeds, Feed-I: [RE](f) = 4.94 x 10(-3) M, Y = 98.5%, HRE (Ho, Er, Tm, Yb, Lu) = 1.5%; Feed-II: [RE](f) = 4.94 x 10(-3) M, Y = 99.9%, HRE (Ho, Er, Tm, Yb, Lu) = 0.1%, as a function of equilibrium pH (pH(eq)), the concentration ratio of [EDTA]:[HRE impurities]. It was shown that the extraction of HRE in the presence of EDTA was suppressed when compared to that of Y because of the masking effect, while the selective extraction of Y was enhanced and the separation factors increased to maximum at appropriate condition for Feed-I: Y/Ho = 1.53, Y/Er = 3.09, Y/Tm = 5.61, Y/Yb = 12.04, Y/Lu = 27.51 at pH 4.37 and [EDTA]:[HRE impurities] = 4: 1, for Feed-II: Y/Ho = 1.32, Y/Er = 1.91, Y/Tm = 2.00, Y/Yb = 3.05, Y/Lu = 3.33 at pH 4.42 and [EDTA]: [HRE impurities] = 8:1. The separation and purification of Y by this method was discussed.

新型化合物[Ni(en)_3]_2[Ni(en)_2(H_2O)_2]·[As_6V_(15)O_(42)]·4H_2O晶体的水热合成与表征

多金属氧酸盐因其在医药临床、工业催化、功能材料等方面的广泛应用而引起人们的关注 [1～ 6 ] ,其中 ,有关钒化学的研究一直很活跃 ,钒具有与钼、钨明显不同的结构特性 ,钒可以采取 VO4 ,VO5和VO6 方式配位 ,同时 ,钒的价态可以是 + 3,+ 4和 + 5价 .由于钒可采取多种配位方式及多种价态 ,与钼酸盐和钨酸盐相比 ,钒酸盐更具有结构柔顺性 ,同时易形成低价或混合价态物种 .在以往的文献中 ,有关 P- V- O体系多金属氧酸盐的水热合成的研究已有大量的报道 [7] ,在常规溶液合成中 ,人们已对As- V- O体系进行了相对深入的研究 ,而有关水热合成的研究报道却很少 ,已见报道的砷钒化合物有K6 [As6 V15O4 2 ( H2 O) ]· 6H2 O[8,9] ,[As8V14 O4 2 ( H2 O) 1/2 ]4 - [10 ] ,[As8V14 O4 2 ( X) ]6 - [11] ( X=SO2 - 3,SO2 - 4,H2 O) .为了探究水热条件下 As- V- O体系的反应特性 ,我们开展了这方面的研究工作 ,并取得了突破性进展 .本文采用中温水热技术合成了含有机基团...

Preparation of borates doped with divalent rare earth ions (RE2+) in air and spectroscopy of divalent rare earth ions (RE2+ = Sm, Eu, Tm, Yb)

The spectroscopic feature of divalent Sm2+, Eu2+, Tm2+ and Yb2+ is discussed in this paper. Especially the spectroscopic properties of some berates containing tetrahedral BO4 group such as SrB4O7, SrB6O10 and BaB8O13 doped with these divalent ions are reported. When the divalent alkaline earth ion in these berates is replaced partially by the above trivalent rare earth ion, the charge carried in the produced defects can be used as reductant to reduce the doped rare earth ion into divalent state at high temperature even in air. Therefore, a convenient and safe method is provided to prepared phosphors doped with these divalent rare earths.

在空气下制备掺二价稀土的硼酸盐及二价稀土离子(RE~(2+)=Sm,Eu,Tm,Yb)的光谱特征

本文讨论了Sm2 + 、Eu2 + 、Tm2 + 、Yb2 + 等二价稀土离子的光谱特征 ,特别是在一些含四面体硼酸根的硼酸盐如SrB4 O7、SrB6 O10 和BaB8O13中它们的光谱性质。当以三价稀土离子取代化合物中的二价碱土离子时 ,利用不等价取代而产生的缺陷所带的电荷 ,可在高温的空气下使上述的稀土离子还原成二价 ,不需加入化学还原剂 ,从而提出了一个简便、安全的制备含二价稀土离子发光材料的方法

Tb~(3+)在YAG中的发光及Tb~(3+)与Tm~(3 +)间的能量传递

采用溶胶 -凝胶方法合成了系列化合物 (Y1 -x- yTbxTmy) 3Al5O1 2 ,研究了Tb3+在该化合物中的发光及其浓度对发光性质的影响 ,以及Tb3+与Tm3+间的能量传递现象。

Calculation of chemical bond parameters in RBa2Cu4O8(R = Dy,Ho,Er,Tm,Yb) and Y2Ba4Cu7O14.3

Chemical bond parameters in RBa2Cu4O8(R = Dy, Ho, Er, Tm, Yb) and Y2Ba4Cu7O14.3 were calculated by using complex chemical bond theory. The results indicated that the bond covalency in CuO chain was larger than that in CuO2 plane. For metal atoms, the bond covalency of five coordinated case was larger than that of six coordinated case.