Response of Zhadang Glacier runoff in Nam Co Basin,Tibet, to changes in air temperature and precipitation form

This paper describes 2007/2008 inter-annual changes in runoff from the Zhadang Glacier located on the northern slope of Nyainqêntanglha Range, Tibet, and analyzes their causes. Precipitation increased by 17.9% in summer months of 2008 compared with the same period in 2007, drainage basin runoff decreased by 33.3%, and glacial meltwater decreased by 53.8%. Change in positive accumulated air temperature explained approximately half of the inter-annual difference in glacial meltwater using a de-gree-day model. This suggests that the glacier is extremely sensitive to changes in air temperature. Energy balance analysis showed that change in glacier surface albedo, considered to be caused by difference in precipitation form, resulted in the large inter-annual difference in glacial meltwater. It was shown statistically that precipitation form in the summer months of 2007 was mainly rainfall which comprised 71.5% of total precipitation, while during the same period in 2008 rainfall accounted for 30.7%, with the majority of precipitation falling as snow. Precipitation form should be considered an independent factor when analyzing glacier sensitivity to climate change or forecasting the runoff from certain glaciers.     

低温高效催化分解过氧化氢的Co-SiO_2催化剂

H2O2常在工业和实验室过程中用作绿色氧化剂,但其残留量需要分解处理,否则会对环境造成一定的污染.采用溶胶凝胶法合成M-SiO2(M=Ni、Zn、Fe、Bi、Cu、Al、Cd、Co)催化剂.考察了催化剂在低温条件下(5~20℃)对H2O2的催化分解性能,结果表明Co-SiO2催化剂对H2O2表现出优异的催化分解作用.当Co质量分数为8.0%时,Co-SiO2催化效果达到最佳.在5~20℃范围内,0.05 g 8.0%Co-SiO2催化剂对H2O2均表现出优异的催化分解性能.5℃下反应40 min时,10 mL 1.0 mol/L H2O2分解率为71.7%,20℃下分解率几乎达到100%.并以XRD对代表性的Co-SiO2催化剂进行表征,结果表明Co在SiO2中可能处于高分散状态.     

椭圆钴纳米环磁化动力学研究

利用Monte-Carlo方法模拟了不同偏心率、不同厚度的椭圆钴纳米环的磁特性.模拟结果表明:当系统的偏心率较小时,厚度越大的椭圆钴纳米环的涡旋态（“vortex”态）越稳定,此系统的磁滞回线保持圆形纳米环的主要特征;系统的偏心率较大时,系统的磁特性与圆形纳米环有较大差别,涡旋态的稳定性与厚度并无明显关联;对椭圆钴纳米环的自旋组态分析发现,椭圆系统在极化态（“onion”态）与涡旋态之间出现了更多的亚稳态     

Phase-field simulation on microstructure evolution of D0_(19) phase in γ/γ′structure of Co–Al–W superalloys

The morphological evolution and precipitation kinetics of γ′ and D0_(19)(Co_3 W) phase in Co–Al–W alloys at 900 °C have been studied by applying Phase-field method and experiment in order to understand the transformation process of γ′ phase and D0_(19) phase. The growth processes of D0_(19) phase and precipitation of γ′ phase under elastic fields were simulated through coupling with thermodynamics and dynamics databases. The simulation results indicate that the misfit δ≥ 0.53% has a greater impact on γ′ particle morphology in γ/γ′ structure.Co–Al–W alloy with low Al and high W is one of the factors to promote the precipitation of D0_(19) phase. Three stages during aging, namely the γ′ phase incubation stage, the γ′ phase fast nucleation and growth stage, and the transformation from γ′ phase to D0_(19) phase stage can be observed with the non-constant coarsening rate that varying with the decrease of γ′ phase. The particle size distribution(PSD) during the precipitation of D0_(19) phase is more in line with MLSW theory than LSW theory. This simulation results are in good agreement with the experiment results to help analyze microstructure evolution of Co–Al–W alloy.     

3-吡啶4-苯甲酸构筑的-维链状钴（Ⅱ）配合物

以3-吡啶-4-苯甲酸（HL）和Co（NO3）2·6H2O为原料,利用水热法合成了一雏链状钴配合物{[Co（L）2（HL）（H2O）]·H2O}n（1）。通过x-射线单晶衍射技术测定其晶体结构,并利用元素分析、热重分析等技术对其进行了表征。晶体结构分析表明：配合物1属三斜晶系,空间群P-1,晶胞参数为：a=1．1362（2）nm,b=1．1688（2）nm,c=1．4104（3）nm,α=93．93（3）°,β=104．25（3）°,γ=116．81（3）°,Z=2,V=1．593（3）nm3,Mr=690．56,Dc=1．658／g·cm-3,μ=0．745mm-1,最终偏离因子R1=0．0969,wR2=0．1616。配合物1呈现出一维分子钩双链结构,相邻链间通过O—H…O氢键相互作用组装成二维超分子结构。     

二甲基亚砜中Co2+电化学行为的研究

研究了二甲基亚砜中Co2+在Pt电极上的电化学行为.293 K时,在0.01 mol·L-1CoCl2-0.1mol·L-1LiClO4-DMSO体系中利用循环伏安法、计时电流法、计时电量法测定Co2+的扩散系数D0和传递系数a分别为1.66×10-6cm2·8-1和0.12;并通过塔菲尔曲线求出交换电流密度i0=3.36×10-8A/cm2.     

催化荧光光度法测定痕量铜

荧光素（HFin）可发射强而稳定的荧光,Cu^2＋能氧化HFin而导致HFin的荧光信号猝灭．Cu（Bipy）^2＋（Bipy为α,a’-联吡啶）与4．0-D-Cu（4．0-D为4代聚酰胺-胺树枝状分子）能催化Cu^2＋氧化HFin的反应,使HFin荧光信号剧烈猝灭,且Cu^2＋的含量与AF值呈线性关系．基此实验事实,建立了Cu（Bipy）2＋和4．0-D—Cu（4．0代树枝状铜配合物）催化HFin荧光光度法测定痕量铜的新方法．该方法的线性范围为0．040～28（Pg mL^-1）,工作曲线的回归方程AF=209．5＋14．39Ccu^2＋（Pg mL^-1）,n=7,相关系数r=0．9991,检出限为1．0×10^-14g mL^-1．分别对0．040和28（Pg mL^-1）Cu^2＋重复测定8次,RSD依次为3．1％和4．2％．本方法快速、准确、灵敏、重现性好,并成功用于人发与茶叶中痕量铜的测定．同时探讨了Cu（Bipy）^2＋和4．0-D—Cu催化荧光光度法测定痕量铜的反应机理．     

强磁场下蒸镀法制备Co_3O_4薄膜

为了研究强磁场对蒸镀法制备Co3O4薄膜结构影响,以提高该材料的取向性,改善Co3O4薄膜的磁学性能,该文以99.99%的Co为原料,分别在无磁场和强磁场条件下低真空热蒸镀Co3O4薄膜,采用扫描电子显微镜、X射线衍射和振动样品磁强计研究了以Si(111)为基底的Co3O4薄膜晶粒尺寸、取向和磁性能。结果表明:随着磁场强度增加至4T,晶粒尺寸由200 nm减至20 nm,晶体由杂乱取向排列转为平行于磁场方向取向生长,薄膜的矫顽力减小,矩磁比增大至0.81。结果表明:强磁场对蒸镀法制备Co3O4薄膜晶粒的大小和取向有显著影响,能显著提高材料的矩磁比。     

海水中Co2+对中国对虾仔虾生长及体内AKP和ATPase活性的影响

在去除重金属离子的海水中添不同浓度的Co2+进行养殖实验.结果表明:中国对虾(Penaeuschinensis)仔虾对Co2+最佳需要量为μg/L.低浓度的Co2+对AKP和ATPase都有激活作用,高浓度的Co2+对AKP和ATPase有抑制作用.由于AKP和ATPase活性的高低与中国对虾仔虾生长状况相一致,因此AKP和ATPase活性可作为检测水中Co2+浓度是否适合中国对虾仔虾存活和生长的指标.     

1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5(HPMBP)合钴(II)配合物的合成及晶体结构

合成了 1 -苯基 - 3-甲基 - 4 -苯甲酰基 -吡唑啉酮 - 5 (HPMBP)合钴 (II)化合物 ,并进行了元素分析和红外光谱表征 ,用 X射线衍射方法测定了其晶体结构 .晶体属单斜晶系 ,空间群P2 1 / c,a=1 1 .2 5 9(4) ,b=1 4.784(5 ) ,c=1 1 .6 0 7(4) ,β=1 0 7.1 5 7(7) ,V=30 39.43 3,Z=2 ,Dc=0 .76 9g·cm- 3,F(0 0 0 ) =1 384,最终偏离因子 R=0 .0 993,金属 Co(II)原子与PMBP- 及乙醇中的氧原子配位形成八面体构型 .