95 resultados para rischio, idrocarburi, ADIOS2, Po

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文合成了聚(环氧乙烷-环氧丙烷-烯丙基缩水甘油醚,三元共聚物,P(EO-PO-AGE)。扭辨分析、DSC、X-射线衍射结果表明,三元共聚物的玻璃化转变温度较低(T_g=-74℃),无定形结构含量~98%,并确定了与LiClO_4组成为Li/O(mole)=0.25的结晶络合物存在。络合物电导行为的研究发现,络合物电导与盐浓度有关,在Li/O(mole)=0.05时具有较大值,室温下电导可达5×10~-5)scm~(-1)。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文研究了二甲氧基聚乙二醇(PEGDME)对聚合物电解质膜的影响。结果表明,PEGDME增塑的(环氧乙烷-环氧丙烷-烯丙基缩水甘油醚)三元共聚物-LiClO_4络合物具有较低的玻璃化转变温度,室温导电率≥10~(-4)Scm~(-1),热稳定性及力学性能良好,在100℃下无相分离,室温下在干燥器中放置一年无蠕变。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

It is to investigate molecule interactions between antigen and antibody with ellipsometric imaging technique and demonstrate some features and possibilities offered by applications of the technique. Molecule interaction is an important interest for molecule biologist and immunologist. They have used some established methods such as immufluorcence, radioimmunoassay and surface plasma resonance, etc, to study the molecule interaction. At the same time, experimentalists hope to use some updated technique with more direct visual results. Ellipsometric imaging is non-destructive and exhibits a high sensitivity to phase transitions with thin layers. It is capable of imaging local variations in the optical properties such as thickness due to the presence of different surface concentration of molecule or different deposited molecules. If a molecular mono-layer (such as antigen) with bio-activity were deposited on a surface to form a sensing surface and then incubated in a solution with other molecules (such as antibody), a variation of the layer thickness when the molecules on the sensing surface reacted with the others in the solution could be observed with ellipsometric imaging. Every point on the surface was measured at the same time with a high sensitivity to distinguish the variation between mono-layer and molecular complexes. Ellipsometric imaging is based on conventional ellipsometry with charge coupled device (CCD) as detector and images are caught with computer with image processing technique. It has advantages of high sensitivity to thickness variation (resolution in the order of angstrom), big field of view (in square centimeter), high sampling speed (a picture taken within one second), and high lateral resolution (in the order of micrometer). Here it has just shown one application in study of antigen-antibody interaction, and it is possible to observe molecule interaction process with an in-situ technique.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

固体表面的性质对蛋白质的吸附具有很大的影响作用,蛋白质在固体表面的吸附可分为共价吸附和非共价吸附.非共价吸附主要包括氢键、疏水力和静电力三种相互作用.其中静电相互作用对蛋白质吸附的影响仍未有一致的看法.该文将椭偏显微成像系统与电化学方法联用来研究静电相互作用在蛋白质吸附中的影响.在0.1MKH<,2>PO<,4>-Na<,2>HPO<,4>(pH=7.80)溶液中,金膜表面零电荷电势(PZC)在-0.60V(vs.SCE)左右.开路电位为+0.10V(vs.SCE),大于零电荷电势(PZC),说明金膜表面带正电荷.假设蛋白质在金表面表面吸附后,没有蛋白质吸附区域的单位面积的电容与吸附前时的单位面积的电容相同.计算出在FIB吸附达到饱和后实际蛋白质真正占据的比表面仅为36.7%.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

ABSTRACT Recently, people are confused with two opposite variations of elastic modulus with decreasing size of nano scale sample: elastic modulus either decreases or increases with decreas- ing sample size. In this paper, based on intermolecular potentials and a one dimensional model, we provide a unified understanding of the two opposite size effects. Firstly, we analyzed the mi- crostructural variation near the surface of an fcc nanofilm based on the Lennard-Jones potential. It is found that the atomic lattice near the surface becomes looser in comparison with the bulk, indicating that atoms in the bulk are located at the balance of repulsive forces, resulting in the decrease of the elastic moduli with the decreasing thickness of the film accordingly. In addition, the decrease in moduli should be attributed to both the looser surface layer and smaller coor- dination number of surface atoms. Furthermore, it is found that both looser and tighter lattice near the surface can appear for a general pair potential and the governing mechanism should be attributed to the surplus of the nearest force to all other long range interactions in the pair po- tential. Surprisingly, the surplus can be simply expressed by a sum of the long range interactions and the sum being positive or negative determines the looser or tighter lattice near surface re- spectively. To justify this concept, we examined ZnO in terms of Buckingham potential with long range Coulomb interactions. It is found that compared to its bulk lattice, the ZnO lattice near the surface becomes tighter, indicating the atoms in the bulk located at the balance of attractive forces, owing to the long range Coulomb interaction. Correspondingly, the elastic modulus of one- dimensional ZnO chain increases with decreasing size. Finally, a kind of many-body potential for Cu was examined. In this case, the surface layer becomes tighter than the bulk and the modulus increases with deceasing size, owing to the long range repulsive pair interaction, as well as the cohesive many-body interaction caused by the electron redistribution.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The dot matrix hologram (DMH) has been widely used in anti-counterfeiting label. With the same technology and cell array configuration, we can encode to the incidence beam. These codes can be some image matrix grating with different grating gap and different grating orientation. When the multi-level phase diffractive grating is etched, the incidence beam on the cell appears as an encoding image. When the encoded grating and DMH are used in the same label synchronously, the technology of multi-encoded grating array enhances the anti-counterfeit ability.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

采用提拉法生长了质量优异的Yb:Ca5(PO4)2F(Yb:FAP)晶体。运用化学腐蚀,光学显微镜、扫描电子显微镜以及能量散射光谱仪观察了该晶体中的生长条纹和包裹物等宏观缺陷,以及晶体的位错腐蚀形貌、位错密度及其分布情况,同时观察了晶体中亚晶界的形态。由晶体中位错的径向变化以及生长条纹可知:晶体在生长过程中为微凸界面生长。高温下CaF2的挥发造成了在晶体生长后期熔体中组分偏离化学计量比,出现组分过冷,形成包裹物。且位错密度显著增加。Yb:FAP晶体的各向异性使得晶体在(10 10)面的位错蚀坑形状、大小以

Relevância:

10.00% 10.00%

Publicador:

Resumo:

以简并引物,利用RT -PCR,克隆了普通小麦和黑麦根系的PO 43-转运子( Trans-porter)基因长约1.2kb的部分cDNA序列。对其与GenBank中的已知序列进行同源性比较,结果表明:(1)小麦与拟南芥、番茄等高等植物的氨基酸水平的同源性为60%~78%; (2)与酵母较低为40%左右,而与丝状真菌和细菌的同源性则<27%; (3)小麦与黑麦的同源性为75%。对其表达特性的研究表明:(1)该基因在根系和茎叶组织中均有表达,但在根系组织中转录产物的累积量显著高于茎叶;(2)磷饥饿条件下,茎叶和根系组织中该基因的表达均增强,但根系组织中增强幅度较大,由此认为该基因产物的功能不只是根系从生长环境中吸收PO 43-,而与PO 43-在植物体内的转运密切相关;(3)磷饥饿5天 后的植株重新供给充足的PO 43-,则该基因的表达在24小时内即显著减弱;(4)分根试验中同株的部分根系生长于磷饥饿(OuM)环境中,而另一部分根系生长于PO 43-充足(250uM)的环境中,这两部分根系中该基因转录产物的积累水平并无显著差异。因此认为植物感受磷饥饿胁迫的信号可能来自植物体内部POi-库的耗竭。此外,用磷讥饿条件下的普通小麦根系mRNA构建了cDNA文库,以克隆的部分序列为探针,从cDNA文库中分离了全长序列。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

对山葡萄(Vitis amurensis)杂交的F1、F2、F3杂种后代中,果实搪、酸含量不同的实生苗叶片,进行了Vc、VB1Vpp的分析测定,并对这些植株的叶片、卷须、一年生技条扦插芽和种子播出的幼苗分别进行了过氧化物酶同功酶的聚丙烯酰胺(PO-lyacrylamide)垂直平板电泳分析。实脸结果表明:在三代的实生苗中,Vc、VB1、Vpp的含量与含糖量均呈正相关,Vc和Vpp与含酸量负相关,VB1与含酸量呈正相关,Vc与Vpp呈正相关.Vc含量低的实生苗易受冻而导致萌芽推迟,Vc在果实潜色期间呈动态变化,着色期早的Vc含量降低,正处在着色期的Vc含量最低,着色晚的Vc含量就高。叶片中Vc、Vpp含量可作为实生苗含量筛选的参考指标。 而且发现,在实生苗幼龄阶段,通过过氧化物酶同功酶能够从品质上进行单株分离与筛选。一年生枝条的扦插芽以及生长季节的卷须和叶片为材料的分离筛选效果相对稍差。F1实生苗中,抗寒、含糖量高的单株表达出双亲的酶带;F2品贡优良的单株从表达出亲本中含糖童截的酶潜并且酶带数目相对少些的单株中产生;F3品质优良的单株则从酶谱复杂、杂种谱带较多的单株产生;品质性状较劣,同功酶表现出相反的结果。这为育种工作中果实品质性状的童期鉴定提供了参考依据。在实际鉴定工作上,最好有几种方法,几种酶的功酶联合使用。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We investigated the distribution of Y-chromosome haplotype using 19 Y-SNPs in Han Chinese populations from 22 provinces of China. Our data indicate distinctive patterns of Y chromosome between southern and northern Han Chinese populations. The southern po

Relevância:

10.00% 10.00%

Publicador:

Resumo:

 目的 研究2 型糖尿病患者中线粒体tRNAL eu (UUR) 基因3243AöG 突变和NADH 脱氢酶亚 单位1 基因( ND1 ) 基因3316GöA 突变的发生频率及其与2 型糖尿病的相关性。方法 应用聚合酶链反 应及限制性片段长度多态性技术检测225 例中国云南2 型糖尿病患者和195 名无糖尿病家族史的健康对 照者有无3243AöG 突变和3316GöA 突变, 并经DNA 直接测序确证。结果 2 型糖尿病患者中3316GöA 突变者5 例(2. 22% ) , 195 例对照者中突变者2 例(1. 03% ) , 突变发生率在两组间差异无统计学意义(P = 0. 4576) ; 两组中无线粒体3243AöG 突变。结论 线粒体tRNAL eu (UUR) 基因3243AöG 突变在中国云南2 型 糖尿病人群中发生频率低, 可能不是云南人群中2 型糖尿病的常见病因。线粒体ND1 基因3316GöA 突变 可能仅为人群中线粒体基因组的正常多态。其他的遗传、环境及子宫内因素需要进一步研究。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Enfuvirtide (ENF) is currently the only FDA approved HIV fusion inhibitor in clinical use. Searching for more drugs in this category with higher efficacy and lower toxicity seems to be a logical next step. In line with this objective, a synthetic peptide

Relevância:

10.00% 10.00%

Publicador:

Resumo:

采用不连续垂直板聚丙烯酰胺凝胶电泳技术,对河曲藏獒、青海藏獒、青海藏狮犬和青海土种犬共4个群体103只犬的9个血液蛋白基因座(Tf、Po、Es-1、Es-2、Sα_2:、Hb、Alb、Pr、Amy)的多态性进行了检测,分析了两个藏獒群体的群体内和群体间的遗传变异,并以Nei氏标准遗传距离(D)为基础用UPGMA法探讨了不同犬群之间的遗传关系.结果表明,在4个被测犬群中,Tf、Po、Es-1、Es-2和Sα_2 5个基因座上存在多态性,其中Tf、Es-1和Po分别由3个等住基因所控制,Es-2和Sα_2,分别由2个等位基因所控制,而Hb、Alb、Pr和Amy基因座均呈现单态;河曲藏獒群体内遗传变异较青海藏獒丰富,而两个藏獒群体间的遗传分化程度很低(G_(ST)=0.0187);以Nei氏标准遗传距离(D)为基础的UPGMA法聚类结果表明.青海藏獒与青海藏狮犬和青海土种犬的遗传关系近于河曲藏獒.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

采用不连续垂直板聚丙烯酰胺凝胶电泳技术,对河曲藏獒和青海藏獒2个群体86只犬的9个结构基因座(Tf、Po、Es-1、Es-2、Sα2、Hb、Alb、Pr、Amy)的遗传变异情况进行了检测,探讨了2个藏獒群体的遗传结构和遗传分化。结果表明,河曲藏獒群体内遗传变异较青海藏獒丰富,而2个藏獒群体间的遗传分化程度很低(GST=0.018 7);较大的基因流(Nm=14.543 7)是2个藏獒不同地理群体间遗传分化水平低的主要原因。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A genome-wide view of sequence mutability in mice is still limited, although biologists usually assume the same scenario for mice as for humans. In this study, we examined the sequence context in the local environment of 482,528 mouse single nucleotide po