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排序方式: 共有498条查询结果,搜索用时 31 毫秒
31.
利用溶液聚合和成酰胺反应合成了多功能梳状两亲性共聚物,聚(甲基丙烯酸-co-甲基丙烯酸十八酯)-(乙醇胺-乙二胺叶酸)(PSM-EE-FA).用红外光谱(FTIR),核磁共振(1H-NMR)及凝胶渗透色谱(GPC)表征了该聚合物的结构及分子量分布.实验结果证明合成了该聚合物,其数均分子量(Mn)为28600,多分散性为1.375.用该两亲梳状聚合物包覆油溶性CdSe/ZnS量子点,通过相转移作用,得到水溶性靶向量子点(PSM-EE-FA-QDs).该水溶性量子点溶液具有较好的稳定性.通过紫外-可见(UV-Vis)及荧光发射光谱分析对该量子点的光学性质进行研究.结果表明,PSM-EE-FA-QDs的紫外-可见光谱及荧光发射光谱峰形与原量子点基本一致.由于量子点表面聚合物层的形成,峰位发生少量红移.该量子点水溶液的荧光强度是原量子点氯仿溶液的98%,荧光产率是原量子点氯仿溶液的95%.动态光散射(DLS)及透射电镜(TEM)测试结果表明水溶性量子点分布均匀.合成的水溶性量子点不但光学性能稳定,而且聚合物及水溶性量子点的合成方法较为简便. 相似文献
32.
THE EVIDENCE OF DECONFINEMENT PHASE TRANSITION OF SU(2) LATTICE GAUGE MODEL BY MONTE CARLO METHOD 下载免费PDF全文
In this paper,we have calculated the SU(2) lattice gauge by the Monte Carlo method.For the finite temperature problem 83×4 lattice is used and for the zero temperature problem 84 lattice.From the calculations of the energy density,heat capacity and entropy density,the results indicate that there is a deconfinement phase transition when T/ΛL=40—50. 相似文献
33.
Ponomarenko S. P. Dul'nev P. G. Borovikov Yu. Ya. Sivachek T. E. Vovk D. N. 《Russian Journal of General Chemistry》2002,72(11):1743-1749
Complexes (1 : 2) of iron trichloride with N-oxides of pyridine, picolines, and 2,6-lutidine were studied by optical spectroscopy, dielectrometry, and conductometry. In solid complexes, three crystalline phases are in equilibrium; the nuclei of each of these phases can be detected in the oily state. The enthalpies of the coordination bonds are different in different phases. One of the phases of the 3-picoline N-oxide complex shows a strong orientation disorder; disappearance of the short-range order causes weakening of the coordination bonds by 1.6 kcal. The thermal motion of free base molecules in two phases of the 2,6-lutidine N-oxide complex is gaslike. In the solid phase of this complex, there is a strong distribution of the relaxation frequencies; the mean relaxation frequency is close to 220 Hz. Upon irradiation of the complexes with solar or UV light, specific coloration centers can form. Weak alternating electric fields initiate in some compounds reversible chemical reactions. The intermolecular and charge equilibria in the compounds are very labile; the energy of generation of the low-temperature electrical conductivity in them is close to 0.9 eV. 相似文献
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35.
O. V. Nestroinaya I. G. Ryl’tsova O. E. Lebedeva B. M. Uralbekov O. I. Ponomarenko 《Russian Journal of General Chemistry》2017,87(2):163-167
A series of multi-component layered double hydroxides with hydrotalcite structure containing doubly charged magnesium and cobalt cations and triply charged aluminum and iron cations in the brucite-like layers have been synthesized by co-precipitation at variable pH. Formation of the hydrotalcite structure has been confirmed by X-ray diffraction analysis. Thermal behavior of the synthesized samples has been studied by IR spectroscopy, thermogravimetry, and differential thermal analysis. 相似文献
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37.
V. M. Orlovskii É. A. Sosnin V. F. Tarasenko A. G. Ponomarenko Yu. I. Khapov 《Technical Physics》1999,44(1):69-73
Results are presented from a study of HF lasers pumped by non-chain chemical reactions initiated by a radially convergent
and by a planar electron beam. The main channels of formation of vibrationally excited HF molecules are analyzed. The distribution
of the energy density of the radiation in the output beam of a wide-aperture laser is measured. In 30 liters of a mixture
of SF6:H2=8:1 at a pressure of 1.1 atm an output energy of ∼200 J is obtained at an ∼11% efficiency with respect to the energy deposition.
It is shown that the admixture of a buffer gas of neon or argon improves the uniformity of the radiation energy distribution
in the output beam of an HF laser pumped by a non-chain chemical reaction and initiated by an electron beam, and it also increases
the output energy.
Zh. Tekh. Fiz. 69, 76–81 (January 1999) 相似文献
38.
39.
Polychloroprene/organoclay nanocomposites (ENC) were characterized by X-ray scattering, DSC and stretching calorimetry techniques.The infinite cluster of highly anisometric organoclay particles was likely to set on at filler volume fraction as low as ? ? 0.04. Quantitative analysis of thermoelastic behavior over the entire range of relative elongations provided additional support for the concept of strain-dependent strain amplification factor as the major parameter controlling the thermomechanical properties of the ENC. Low values of the fitting parameter C in the modified equation for the total heats of stretching were regarded as evidence for the reduced exothermal effects of external friction between organoclay nanoparticles coated with the boundary interphase. Stress relaxation behavior of the ENC was qualitatively consistent with the original assumption that after initial stretching to the highest elongation (λlim) the pre-existing infinite clusters of filler particles were broken into isolated clusters which remained structurally similar, whatever the subsequent stretching to λf < λlim. 相似文献
40.
以LCD为目标的自动定焦判据选择 总被引:2,自引:0,他引:2
在光学综合自动测量中 ,使用液晶显示屏作为分划板可以大大简化结构 ,提高效率 ,真正地实现自动测量。由于液晶显示具有对比度低、噪声大等特点 ,所以根据液晶的这些特点以及图像处理和CCD信号接收的特点选择两种适用的判据进行了分析和试验比较 ,并给出了结果。结果表明 ,这两种判别函数都适用于以液晶显示屏为目标和用图像处理方法进行光学参数测量的系统 ,其中锐度判别函数更优于信息熵判别函数 ,前者具有更好的抗干扰性和稳定性 ,而且其判定结果更接近目视清晰度判别 相似文献