水稻中的纳米硅及其紫外吸收

为了了解水稻中硅的亚显微结构及其紫外吸收特性,根据强酸不会腐蚀SiO₂玻璃的事实,选择湿消化方法分离水稻中的硅体。以浓硫酸和硝酸混合液分别处理水稻叶片和稻壳,经多级沉降分离出其中的硅体。X射线光电子能谱结果表明硅体距离表面10 nm以内碳相对质量为35.05%,远高于硅体表面(5.88%),说明硅质壁能够阻止强酸进入硅体内部,避免硅体内氧化,保持硅体结构完整和相对独立的理化性质。电镜显示硅体SiO₂结构致密,由1～2 nm的SiO₂凝胶粒子粘聚而成,纳米颗粒相互融合组成排列方向一致的纳米棒,内部还有微米尺度(≤1μm)和纳米尺度(≤1～2 nm)的隙孔。颖壳硅体最大吸收位于285 nm;叶片纳米硅对紫外辐射的吸收极其有限,表明水稻颖壳和叶片硅体对紫外辐射具有不同的抵抗机制。     

Fluorometric determination of water in organic solvents using europium ion-based luminescent nanospheres

Microchimica Acta - Luminescent nanospheres with strong red fluorescence were prepared from a europium(III) mixed complex with 2-thenoyltrifluoroacetone and 1,10-phenanthroline, and characterized...     

基于Mathematica软件下等效电子光谱项的推求

基于Mathematica计算软件,借助组合数学方法,编写了推求任意等效电子组态光谱项的计算程序,系统地给出了fn(n=1～14)及gn(n=1～18)组态的光谱项.     

Jefferson国家实验室（JLab）简介

简要介绍了JLab的一般情况、JLab高性能加速器CEBAF（Continue Electron Beam Accelerator Facility）和3个实验大厅的主要实验设备。着重介绍了CEBAF的连续束流与实验大厅的高密靶及高精度谱仪结合所得到的高精度实验结果，介绍了JLab实验室要解决的根本问题、相应的物理课题以及中国组正在参与数据分析和正在做的实验。最后简要介绍了CEBAF升级至12 GeV及其带来新的研究机会和新的物理课题，以及中国组与JLab的合作情况。The general situation of JLab is briefly introduced. The accelerator CEBAF with high quality and the equipments in the three Halls are described. The experimental results with high accuracies, which were obtained by using continue beam with high energy resolution, and high density target and high resolution spectrometers in the halls, are presented with two examples. The basic physics problems which JLab intends to solve, and the programs which JLab completed and is going to do, are stated. The programs which China group is cooperating with other groups are emphasized. The energy escalation for CEBAF will bring new opportunities for scientific researches.     

微波消解-原子吸收光谱法测定茶树菇子实体中的6种金属元素

建立了原子吸收光谱法测定茶树菇子实体中金属元素(Ca,Mg,Zn,Cu,Mn和Fe)的方法。对茶树菇子实体采用微波消解处理,然后采用原子吸收光谱法测定茶树菇子实体中金属元素含量。该方法的平均回收率为98.0%—103.2%,相对标准偏差(RSD)不大于4.84%。研究表明,该法适用于茶树菇子实体中金属元素的测定。方法简便、快速、准确,为茶树菇子实体的营养价值提供了参考数据。     

Community detection using global and local structural information

Community detection is of considerable importance for understanding both the structure and function of complex networks. In this paper, we introduced the general procedure of the community detection algorithms using global and local structural information, where the edge betweenness and the local similarity measures respectively based on local random walk dynamics and local cyclic structures were used. The algorithms were tested on artificial and real-world networks. The results clearly show that all the algorithms have excellent performance in the tests and the local similarity measure based on local random walk dynamics is superior to that based on local cyclic structures.     

无向超环面网$C(3,3,\ldots,3)$的$(n,2n)$控制数

$(d,k)$控制数是用来刻画容错网络中资源共享可靠性的一个新参数. 本文证明：$n\, (n\geq 3)$维无向超环面网$C(3,3,\ldots,3)$的$(n,2n)$控制数为 $3$.     

A novel nonenzymatic fluorescent sensor for glucose based on silica nanoparticles doped with europium coordination compound

Amino-functionalized luminescent silica nanoparticles (LSNPs) doped with the europium(III) mixed complex, Eu(TTA)₃phen with 2-thenoyltrifluoroacetone (TTA) and 1,10-phenanthroline(phen) were synthesized successfully using an revised Stöber method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR), and fluorescence spectroscopy were performed for characterizing the synthesized nanoparticles. In the presence of glucose, the fluorescence intensity of the amino-functionalized LSNPs was enhanced due to the enhanced fluorescence resonance energy transfer. Based on fluorescence-enhancing effect, a simple and sensitive method for the determination of glucose was proposed. Under the optimized experimental conditions, the enhanced fluorescence intensity ratio (ΔF/F₀) was linear with the concentration of glucose (c) in the range of 0.0-180 μg ml⁻¹ with a detection limit of 0.8 μg ml⁻¹ (S/N = 3). The R.S.D. values were 0.33% and 0.37% at the levels of 22.5 and 100 μg ml⁻¹, respectively. The proposed method was applied to the determination of glucose in synthetic samples with satisfactory results. The proposed method was also performed to the analysis of blood glucose in human serum samples and the results were in good agreement with clinical data provided by the hospital, which indicates that the method presented here is not only simple, sensitive, but also reliable and suitable for practical applications.     

人血,唾液及尿中锂的原子吸收法测定

本文研究了人血、唾液及尿中锂的测定.对人血灰化条件作了探讨,采用灰化辅助剂硫酸以提高锂的回收率,并对直接测定法与标准加入法作了比较,本文C.V。小于3.2%,标准加入回收率在98.2～105%之间,适用于精神病治疗中锂的临床分析。