HPLC测定西宁市鱼产品中的孔雀石绿与结晶紫

探索了西宁市鱼类产品中孔雀石绿与结晶紫的高效液相色谱荧光检测方法,方法在0.1ng/g-700ng/g范围内具有很好的线性关系,相关系数r为0.9998,定量限为0.5μg/kg.采用不同的鱼类产品进行验证,孔雀石绿的回收率在88％-94％之间,相对标准偏差(RSD)为3.15％-4.87％.结晶紫的回收率在94％-108％,相对标准偏差(RSD)为2.54％-4.05％.本法提取快捷、简便,适用于大批量的抽样检测,可检测出鱼类样品中痕量的孔雀石绿,为水产养殖提供可行的监测手段,为鱼类中孔雀石绿的检测标准的制定提供依据.     

Synthesis of propylene carbonate from urea and 1,2-propylene glycol over ZnO/NaY catalyst

Propylene carbonate (PC) was produced from 1,2-propylene glycol (1,2-PG) and urea in a continuous-flow fixed bed reactor over heterogeneous ZnO catalyst supported on NaY. Among different ZnO loadings of ZnO/NaY catalysts, 5 wt% ZnO loadings of ZnO/NaY showed the highest activity. Characterization and reaction results indicated that the catalysts with a balanced strength of acid and base sites performed well for the synthesis of propylene carbonate from urea and 1,2-PG.     

硅桥调控的聚茂钒体系电子结构和输运性质

利用密度泛函理论和非平衡格林函数的方法对硅桥调控后的聚茂钒体系（[V（Cp）₂（SiH₂）_n]_m（n=1（a）,n=2（b）,n=3（c）;m=∞;Cp=环戊二烯基））的电子结构和输运性质进行了研究。研究结果表明：随着硅桥的增长,V-V的铁磁性耦合变弱而反铁磁性耦合增强。a和b证实为铁磁性基态,而c更倾向为反铁磁性基态。a和b的铁磁性基态中的每个钒原子的磁距为3.0μ_B,超过钒-苯络合物或者纯聚茂钒体系的3倍。a-c的输运性质同它们的电子结构相一致,导电性变化规律为c > b > a。对于a和b,自旋向下状态的导电性略强于自旋向上状态。a和c都发生了明显的负微分电阻效应而b却没有,这主要是由于两个二茂钒的排列取向不同：a和c（SiH₂为奇数）中二茂钒呈V-型取向排列,进而导致了类似于离子键的量子点耦合,而b（SiH₂是偶数）中二茂钒是平行-型取向排列,从而导致了类似于共价键的量子点耦合。此外,由于散射区和两个电极之间的不对称耦合,a-c的导电性对电压施加方向较敏感。     

Neutron dose measurement in carbon ion radiation therapy at HIRFL (IMP)

For radiation protection purposes, the neutron dose in carbon ion radiation therapy at the HIRFL (Heavy Ion Research Facility in Lanzhou) was investigated. The neutron dose from primary 12C ions with a specific energy of 100 MeV/u delivered from SSC was roughly measured with a standard Anderson-Broun rem-meter using a polyethylene target at various distances. The result shows that a maximum neutron dose contribution of 19 mSv in a typically surface tumor treatment was obtained, which is less than 1% of the planed heavy ion dose and is in reasonable agreement with other reports. Also the γ-ray dose was measured in this experiment using a thermo luminescent detector.     

锂离子电池正极材料Li2FeSiO4/C的改性研究

采用改进的溶胶-凝胶法合成了Li2Fe1-xMnxSiO4/C(x=0, 1/4, 1/3, 1/2)复合材料. 用X射线衍射(XRD)、拉曼光谱和扫描电子显微镜(SEM)对材料的结构和形貌进行了表征. 通过恒流充放电对材料的电化学性能进行了测试. 结果表明, 在室温、1.5~4.8 V电压范围内, 于C/16倍率下进行充放电测试时, Li2Fe3/4Mn1/4SiO4/C具有较高的首次放电比容量(201.0 mA·h/g), 具有良好的电化学性能.     

Effect of Density and Surface Roughness on Optical Properties of Silicon Carbide Optical Components

The effect of density and surface roughness on the optical properties of silicon carbide optical components is investigated. The density is the major factor of the total reflectance while the surface roughness is the major factor of the diffuse reflectance. The specular reflectance of silicon carbide optical components can be improved by increasing the density and decreasing the surface roughness, in the form of reducing bulk absorption and surface-related scattering, respectively. The contribution of the surface roughness to the specular reflectance is much greater than that of the density. When the rms surface roughness decreases to 2.228nm, the specular reflectance decreases to less than 0. 7% accordingly.     

Pseudogap and Superconducting Gap in SmFeAs（O1-xFx） Superconductor from Photoemission Spectroscopy

High resolution photoemission measurements are carried out on non-superconducting SmOFeAs paxent compound and superconducting SmFeAs（O1-xFx） （x = 0.12, and 0.15） compounds. The momentum-integrated spectra exhibit a clear Fermi cutoff that shows little leading-edge shift in the superconducting state. A robust feature at 13 meV is identified in all these samples. Spectral weight suppression near IF, F with decreasing temperature is observed in both undoped and doped samples that points to a possible existence of a pseudogap in these Fe-based compounds.     

Determination of Nucleic Acids by the Columinescence Effect of Tb-Gd-Nucleic Acid System

Because rare earth ions have some characteristics such as narrow spectral width,long fluorescence life, large stokes shift and strongly binding with biological molecules, therefore they are usually as fluorescence probes to study nucleic acids, However the sensitivity is low. It is found that the fluorescence of Tb-nucleic acids (fish sperm DNA and yeast RNA) can increased by Sc³⁺,Y³⁺,La³⁺, Gd³⁺ and Lu³⁺, among which Gd³⁺ and Lu³⁺ have the greatest enhancement. This is a newly found co-luminescence effect.     

铁(Ⅱ,Ⅲ)对邻苯二甲酸铕(Ⅲ)荧光性能的猝灭研究

在液相中合成了掺杂不同浓度Fe2 ,Fe3 的邻苯二甲酸铕系列配合物,测定了该系列配合物的荧光光谱和红外光谱.实验结果表明,微量Fe2 ,Fe3 的存在对邻苯二甲酸铕荧光产生了猝灭作用.这可能是由于配合物在发光过程中Fe2 捕获了基态的空穴或者Fe3 捕获了激发态的电子所引起的.     

Synthesis of functionalized 2H-1-benzopyrans by DBU-catalyzed reactions of salicylic aldehydes with allenic ketones and esters

[reaction: see text] DBU-catalyzed reactions of salicylic aldehydes with 3-methylpenta-3,4-dien-2-one, 3-benzylpenta-3,4-dien-2-one, or ethyl 2-methylbuta-2,3-dienoate gave the corresponding functionalized 2H-1-chromenes in good to excellent yields and good diastereoselectivities in some cases in DMSO, respectively.