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71.
实验光谱学和理论计算都发现,“重原子”能隔离分子中的某些振动能景,如SiH_4中Si—H振动泛频的“局域模”.Roger 等在研究F 原子与M(CH_2CH=CH_2)_4(M=Sn,Ge)的反应中,发现了Sn,Ge 对过剩能量转移到其它部分有强烈的阻碍作用(在中间态的寿命时间内).最近,在研究O(~1D)+M(CH_3)_4生成OH(v)反应中,观测到类似的现象.M=C 时,Lutz 用激光诱导荧光方法检测OH 的振动分布,振动是冷的,v=1与v=0的布居比为0.05, 相似文献
72.
Hu Yang Weisi Yin Xuxin Kong Min Xu Yefeng Yao Qun Chen Rongshi Cheng 《Colloid and polymer science》2006,284(8):935-940
The compact single-chain (SC) particulates of Poly(N-isopropylacrylamide) (PNIPAM), which have been formed above its lower critical solution temperature in an aqueous solution containing the surfactant of sodium n-dodecyl sulfate (SDS), were recovered from the solution by freeze-drying. Under scanning electron microscopy, the compact particulate appears as a spherical or elliptical particulate individually dispersed in SDS, which acts as a solid solvent to prevent agglomeration. The conformation of the compact SC particulates of PNIPAM dispersed in SDS had been studied by the solid-state high-resolution 13C NMR spectroscopy. The 13C spin-lattice relaxation time T
1 of the SC sample was determined in comparison with that of the original one. It was found that the T
1 of the methyl carbon in the isopropyl group of the SC sample was about 45% higher than that in the original multichain sample, which revealed the differences in the motion of the methyl group in the different condensed states and illuminated the characteristic conformation of the compact SC globular particulates of PNIPAM. 相似文献
73.
用计算机多元分析研究冠心病微量元素谱,识别冠心病患者与健康者;非线性映射法判别率男性86.6%,女性96.2%;SIMCA差别法正确回判率男性85.0%,女性88.3%。 相似文献
74.
Jin Ling CHAI Yan Hong GAO Kong Shuang ZHAO Gan Zuo LI Gao Yong ZHANG 《中国化学快报》2005,16(9):1263-1266
The dielectric relaxation spectroscopy (DRS) of Winsor I -Ⅲ microemulsions for nonionic surfactant octyl polyglucoside CsG1.46/1-butanol/cyclohexanedwater system was studied. The experiment shows that the permittivity decreases with the increase in the frequency and clear dielectric relaxation phenomena were observed. Permittivity obviously decreases with the change of the microstructure of the microemulsion, W/O, B.C. and O/W can be distinguished by the permittivity. 相似文献
75.
本实验采用金属有机化学方法成功地将富勒烯分子引入到PNVC侧链形成CBP(CharmBraceletPolymer)型共聚功能材料,研究了其UV-VIs谱行为。结果表明,C_(60)或C_(60)/C_(70)混合物化学修饰的产物其紫外可见谱明显向长波方向移动,谱峰范围由280nm扩展至870nm。C_(60)含量增加,红移程度增大,在可见区域的吸收程度亦增加。产物主要存在5个特征峰,分别位于215nm、265nm、298nm、335nm、345nm处,其中215nm峰为C_(60)仅存的特征峰。最后讨论了不同合成条件与产物硝化处理对其UV-VIS谱行为的影响。 相似文献
76.
An efficient solution-processable route employing Pb(Ac)2 as lead source and anti-solvent treatment to achieve fully covered and homogenous perovskite films is reported. 相似文献
77.
The electrocatalytic properties of the SiC particle‐modified glassy carbon electrode (MGC) for adrenaline oxidation were studied by cyclic voltammetry (CV), double‐potential step chronocoulometry (DPSCC), and electrochemical impedance spectroscopy (EIS) techniques in McIlvaine buffer solution. It was shown that the electrode modified with SiC particles markedly displayed an electrocatalytic effect on the process of the electrochemical reaction of adrenaline, i.e., the activity and the reversibility of the MGC electrode has been significantly improved. This was attributed to the adsorption effect of the electroactive adrenaline molecules on the MGC electrode surface. 相似文献
78.
用时间分辨-傅立叶变换红外发射光谱法研究了OH自由基与CO的反应.OH自由基由248 nm的激光光解硝酸得到.在实验中首次观测到了产物CO2的非对称伸缩振动(ν3)的激发态.对CO2发射光谱的拟合结果显示,其振动态的布居在量子数v=2时最大 ,而最高振动量子数达到v=6.由实验得到的CO2振动布居与Schatz等人用全量子化计算该反应的中间物HOCO解离动力学得到的CO2布居结果能很好地吻合. 相似文献
79.
Jingjing Xu Yidong Lu Baohong Liu Chunhe Xu Jilie Kong 《Journal of Solid State Electrochemistry》2007,11(12):1689-1695
An ultrathin, ordered, and packed protein film, consisting of the 2-mercaptoacetic acid (MAA), polydimethyldiallylammonium
chloride (PDDA), and wild-type (WT) photosynthetic reaction center (RC; termed as WT-RC) or its pheophytin (Phe)-replaced
counterpart (termed as Phe-RC), was fabricated by self-assembling technique onto gold electrode for facilitating the electron
transfer (ET) between RC and the electrode surface. Near-infrared (NIR)-visible (Vis) absorption and fluorescence (FL) emission
spectra revealed the influence of pigment substitution on the cofactors arrangement and excitation relaxation of the proteins,
respectively. Square wave voltammetry (SWV) and photoelectric tests were employed to systematically address the differences
between the WT-RC films and mutant ones on the direct and photo-induced ET. The electrochemical results demonstrated that
ET initiated by the oxidation of the primary donor (P) was obviously slowed down, and the formed P+ had more population as well as more positive redox potential in the Phe-RC films compared with those in the WT ones. The
photoelectrochemical results displayed the dramatically enhanced photoelectric performances of the mutant ones, further suggesting
the slow-down formation of final charge-separated state in Phe-RC. The functionalized protein films introduced in this paper
provided an efficient approach to sensitively probe the redox cofactors and ET differences resulting from only minor changes
in pigment arrangement in the pigment–protein complex. The favored ET process observed for the membrane proteins RC was potentially
valuable for a deep understanding of the multi-step biological ET process and development of versatile bioelectronic devices. 相似文献
80.
The effects of atomic multipole moments obtained by the potential-derived method on hydrogen bonding
A potential-derived atomic multipole method called the cumulative potential-derived atomic multipole method is developed, with which electrostatic atomic multipole moments are derived by fitting the molecular electric potential in a cumulative way. It is applied to the hydrides of N , O , F , S , Cl , and methanol and the hydrogen-bonded dimers formed between them. The relationship between atomic multipole moments and molecular charge distributions is found. The structures calculated with Buckingham's electrostatic model are in good agreement with experiments. The phenomena of nonlinear structures of most H -bonded complexes—the deviations of symmetry axes of electron donors from H bonds—and correct distinguishing between two alternative structures are attributed to atomic dipole and quadrupole moments. Compared with other methods, this method has a quantitative and qualitative advantage and simple algorithm. The main conclusion is that the atomic multipole moments play a substantial role, although a potential-derived charge model was deemed sufficient previously. © 1993 John Wiley & Sons, Inc. 相似文献