Effect of the core-shell latex polymer content on the compatibility, morphology and mechanical properties of PC/PBA-cs-PMMA blends

The toughening effect of the content of a core-shell poly(butyl acrylate)/poly(methyl methacrylate) latex polymer (PBA-cs-PMMA) on the mechanical properties, morphology and compatibility of its blends with polycarbonate(PC), i.e., PC/PBA-cs-PMMa, was studied. The mechanical properties of the blends are strongly affected by varying the content of PBA-cs-PMMA in the blend. When the PBA-cs-PMMA content is only 5 wt.-%, the impact strength of PC/PBA-cs-PMMA is almost 19 times as high as that of pure PC, indicating that PBA-cs-PMMA is a very good impact modifier for PC. With increasing interphacial layer thickness and decreasing interphacial tension, the interphacial activity becomes more and more effective and, at the same time, miscibility increases too.

含核－壳聚合物共混体系PC／PBA－cs－PMMA的研究

将聚碳酸酯（ＰＣ）和聚丙烯酸丁酯－聚甲基丙烯酸甲酯核－壳聚合物（ＰＢＡ－ｃｓ－ＰＭＭＡ），采用密炼机以不同条件机械混合。经力学性能测试、形态结构观察和转变行为表征表明，ＰＣ与ＰＭＭＡ具有一定的相容性，ＰＢＡ－ｃｓ－ＰＭＭＡ能很好地分散在ＰＣ中，当其含量超过１０％，共混物的冲击强度值为ＰＣ的１０余倍，是ＰＣ的良好增韧剂。增韧机理属银纹和剪切屈服共存。

稀土离子与红细胞作用的~(133)Cs NMR研究

随着稀土资源的不断开发利用,它们不可避免地通过多种途径进入生物体内,因而从分子和细胞水平上研究稀土的生物效应具有非常重要的理论和实际意义.关于稀土与细胞作用的研究已有诸多报道,本文报道用~(133)Cs NMR方法研究La~(3+)对Cs~+跨膜进入红细胞的影响.对于物质跨膜传输的研究,首先需要合适的手段将被传输物质在膜两侧的分布区分开.在碱金属离子中,仅~(133)Cs~+在不引入顺磁位移试剂情况下,细胞内外NMR信号能确切区分,并且在体系中无K~+时,Cs~+有类似于K~+的功能,故~(133)Cs是研究稀土离子与细胞作用

固体ASm_2I_5的d-f跃迁荧光和反射光谱(A=K,Rb,Cs,T1)

本文系统地研究了化合物ASm_2I_5(A=K,Rb,Cs,T1)固体粉末的荧光光谱和反射光谱.讨论了Sm~(2+)在立方晶体场中的分裂能随着碱金属离子半径的增大而减小和f-d激发能随着A-I(A=Rb,T1)键的共价性增加而明显降低的现象.并从晶场效应和化学键性质两个方面解释了ASm_2I_5(A=K,Rb,Cs)和ASm_2I_5(A=Rb,T1)中的Sm~(2+)荧光光谱分别发生蓝移和红移的现象.

Lg尾波衰减成像研究——北京及邻区衰减成像

With the development of the technology of earthquake observation, more and more researchers work at many fields' of seismicity using seismic kinetic property, as the result, the study of attenuation has also made great progress, especially in the mechanism of the attenuation and the physical process. Aki put forward single back scattering theory to explain the forming of the seismic coda wave in 1969. Then, researchers started to develop the study in seismic scattering and attenuation. My thesis is also based on that theory. We assume that the Lg wave is a superposition fo high-mode surface waves, the coda of Lg is caused by scattering. Sato proposed Single Isotropic Scattering model (SIS model) to interpreted the scatter property, and he also formulated the geometrical spreading term. Then Xie (1988) developed the single spectral-ratio (SSR) method to obtain the Lg coda Q and the frequency dependent factor n. Later, he get to lateral images in the area of scatter ellipse. SSR method is explored and used in the study of Lg coda waves of regional earthquakes in my thesis. Choosing the earthquakes records with high ratio of signal-noise ,which were recorded at the stations from 1989 to 1999, we obtain the single trace Lg coda Q and its frequency dependent factor n. The results proved that SIS model is the reasonable model to explain the Lg coda wave, and SSR method also can be used to process Lg coda of regional earthquakes to get to the satisfied Lg coda Q. Based on the Lg coda Q we obtained using the former method, we explore the programs to inverse the regional Lg coda Q independently, and then make use of them to inverse the Lg coda Q of Beijing and adjacent area. The inversion result is satisfied. We conclude that the distribution of Qo (Q in lHz) is marked by the inhomogeneity, which is related to the tectonic structure: The value of Qo in uplift area, for example, Yanshan uplift, Taihang uplift, Luxi Uplift, is higher than the depression area, for example, Jizhong depression, Huanghua depression, and Jiyang depression, and the border between the higher Q area and lower Q area is very clear; Lg coda Q is also related to the velocity structure, higher velocity area is also with higher Q, lower velocity area is with lower Q; and higher heat-flow area is companied with lower Q. All in all, the value of Q reflects the difference of characteristics of lithofaces, porosity, the liquid content between the pores and heat flow. So, the Q value difference between uplift area and depression area reveals the difference of tectonic structure, lithology and physical character of the rock. So, the study of Lg coda Q is help to understand the earthquakes propagation mechanism through the inhomogenous medium, the cause of the coda, attenuation mechanism of the coda. Making use of the lateral images of Q, with velocity images, heat flow results, and other experimental result, we will be promoted to understand the complex structure of the crust, its inhomogenous character, and so on.

红枫湖沉积物~(137)Cs扩散迁移性研究员

保存在湖泊沉积物~(137)Cs剖面中的环境信息记录，可能因~(137)Cs沉积后的再迁移作用而失真。~(137)Cs吸附动力学及离子交换实验表明红枫湖沉积物中的~(137)Cs绝大部分处于固定态，少量处于交换态和造反性吸附态。同时Cs~（+）浓度很低时，高Cs~(+)浓度下在各吸附态与粘土矿物表面的特定吸附部位之间，通常比较明确的对应关系变得有些模糊。本文以界面过程的数学模型为核心，通过模式分析，重建了红枫湖地区历年的~(137)Cs大气沉降通量值，获得了红枫湖集水区 ~(137)Cs流域侵蚀寄宿时间，约为550年。 ~(137)Cs的扩散和其它沉积后再迁移作用。虽然导致~(137)Cs剖面发生了一些变化，但通过适当的数据处理，仍可从中提取出有价值环境信息。

Using oxidized carbon nanotubes as matrix for analysis of small molecules by MALDI-TOF MS

Oxidized carbon nanotubes are tested as a matrix for analysis of small molecules by matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). Compared with nonoxidized carbon nanotubes, oxidized carbon nanotubes facilitate sample preparation because of their higher solubility in water. The matrix layer of oxidized carbon nanotubes is much more homogeneous and compact than that of nonoxidized carbon nanotubes. The efficiency of desorption/ionization for analytes and the reproducibility of peak intensities within and between sample spots are greatly enhanced on the surface of oxidized carbon nanotubes. The advantage of the oxidized carbon nanotubes in comparison with alpha-cyano-4-hydroxycinnamic acid (CCA) and carbon nanotubes is demonstrated by MALDI-TOF-MS analysis of an amino acid mixture. The matrix is successfully used for analysis of synthetic hydroxypropyl P-cyclodextrin, suggesting a great potential for monitoring reactions and for product quality control. Reliable quantitative analysis of jatrorrhizine and palmatine with a wide linear range (1-100 ng/mL) and good reproducibility of relative peak areas (RSD less than 10 %) is achieved using this matrix. Concentrations of jatrorrhizine (8.65 mg/mL) and palmatine (10.4 mg/mL) in an extract of Coptis chinensis Franch are determined simultaneously using the matrix and a standard addition method. (c) 2005 American Society for Mass Spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with a matrix of carbon nanotubes for the analysis of low-mass compounds in environmental samples

The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for environmental analysis has been mainly focused on qualitative analysis of high-mass molecules, such as toxins, humic acid, and microorganisms. Herein,we describe a novel MALDI-TOF-MS method with a matrix of oxidized carbon nanotubes for analysis of low-mass compounds in environmental samples. A number of chemicals in the environment were qualitatively analyzed by the present method, and it was found that most of them, especially the highly polar chemicals, were measurable with high sensitivity. With the intrinsic ability to measure high-mass chemicals, this method can compensate for the current shortage of methods for environmental analysis for the measurement of highly polar or high-mass chemicals. For sample analysis, arsenic speciation in Chinese traditional medicines was qualified and diphenylolpropane in water samples was quantified. With the relatively high tolerance of the method to interfering molecules, a simple pretreatment or even no pretreatment could be employed before MS detection. Furthermore, this method can be employed in a high-throughput format.

CS 30322--023: An Ultra Metal-Poor TP-AGB Star?

info:eu-repo/semantics/published