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131.
Amplified luminescence quenching has been demonstrated in metal-organic frameworks (MOFs) composed of Ru(II)-bpy building blocks with long-lived, largely triplet metal-to-ligand charge-transfer excited states. Strong non-covalent interactions between the MOF surface and cationic quencher molecules coupled with rapid energy transfer through the MOF microcrystal facilitates amplified quenching with a 7000-fold enhancement of the Stern-V?lmer quenching constant for methylene blue compared to a model complex. 相似文献
132.
133.
Rounova Olga Demin Peter Korotkov Mikhail Malkova Victoriya Ustinnikova Olga 《Analytical and bioanalytical chemistry》2018,410(26):6935-6942
Analytical and Bioanalytical Chemistry - In the study presented, a simple analytical method for the direct determination of glycine in immunoglobulins by hydrophilic interaction liquid... 相似文献
134.
天然微晶纤维素晶须补强天然橡胶的研究 总被引:7,自引:0,他引:7
采用硫酸酸解天然微晶纤维素(microcrystalline cellulose,简称MCC)制备纳米微晶纤维素晶须(cellulosewhisker,简称CW),加入天然橡胶胶乳共沉后混炼硫化.结果表明,CW对天然橡胶具有明显的补强作用,经间苯二酚(R)与六亚甲基四胺(H)改性后,NR/RH-CW复合材料的模量、断裂伸长率和撕裂强度都进一步改善.热空气(100℃,72 h)老化后,NR/RH-CW复合材料的力学性能明显优于纯NR,其拉伸强度由28.54 MPa下降至21.78 MPa,变化率缩小至23.7%;断裂伸长率由594%下降至493%,变化率缩小至17.0%,而纯NR的拉伸强度由22.0 MPa下降至2.4 MPa,变化率为89.1%;断裂伸长率由579%下降至168%,变化率为71.0%.扫描电镜分析表明,RH-CW与NR基体的界面相容性较CW改善.热重分析表明,CW的加入使NR的5%失重温度降低,但残重增加,微分曲线在520℃处出现了一个小峰,RH-CW的加入,使该峰变大,残重进一步增加. 相似文献
135.
聚并苯导电高分子材料的ESR研究 总被引:4,自引:0,他引:4
本文对由热固性酚醛树脂通过高温裂解制备的聚并苯导电高分子本征材料的ESR进行了研究。结果表明在各种裂解温度下制备的样品由于其结构不同,表现在ESR线宽、自旋浓度、线型的峰高比等差异很大,并给予了解释。 相似文献
136.
本文研究了带有阻尼项的定常Stokes方程,证明了弱解的存在唯一性得到了有限元逼近问题适定性,给出了有限元逼近误差,并提出了求解逼近解的迭代算法.数值算例表明算法是正确的和有效的. 相似文献
137.
V. A. Kul’bachinskii V. G. Kytin R. A. Lunin A. V. Golikov A. V. Demin A. S. Bugaev A. P. Senichkin A. De Visser R. T. F. Van Schaijk 《Journal of Experimental and Theoretical Physics》1999,89(6):1154-1159
The effect of illumination with various wavelengths λ (770 nm<λ<1120 nm) on the conductivity of GaAs structures with tin δ-doping of the vicinal faces was investigated in the temperature range 4.2–300 K. Negative persistent photoconductivity was
found in strongly doped samples. It was shown on the basis of the results of investigations of the Hall and Shubnikov-de Haas
effects that the negative photoconductivity is due to a large decrease in the electron mobility with increasing electron density.
The decrease of electron mobility is explained by ionization of DX centers, which destroys the spatial correlation in the
distribution of positively charged donors and negatively charged DX centers.
Zh. éksp. Teor. Fiz. 116, 2130–2139 (December 1999) 相似文献
138.
Noncentrality of large impurity atoms—Pb and Sn atoms—substituting for Ge atoms in a GeTe lattice has been discovered by means
of EXAFS investigations in Ge0.9Pb0.1Te and Ge0.85Sn0.15Te samples. The transition of impurity atoms into a noncentral position under conditions of a strong local stress is explained
by the participation of an unshared electron pair from the impurity atoms in the formation of the chemical bond.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 8, 600–603 (25 April 1996) 相似文献
139.
R. V. Demin O. Yu. Gorbenko A. R. Kaul L. I. Koroleva O. V. Mel’nikov A. Z. Muminov R. Szymczak M. Baran 《Physics of the Solid State》2005,47(12):2287-2291
The first thin La1?xAgyMnO3 epitaxial films (y ≤ x) were grown on SrTiO3 (110) substrates with silver present in the ionized state (Ag+) only. The Curie temperatures TC of the compositions with x = y = 0.05, x = y = 0.1, and x = 0.3 and y = 0.27 crystallizing in the hexagonal structure \(R\bar 3c\) above or close to room temperature. The temperature dependences of electrical resistivity ρ and of magnetoresistance ¦Δρ/ρ/¦ = ¦(ρH ? ρ H = 0)/ρH=0¦ pass through maxima near TC, with the magnetoresistance being negative and reaching colossal values of ~7–20% in a magnetic field H = 8.2 kOe not only at TC but also at room temperature. The magnetic moment per formula unit as derived from the saturation magnetization at T = 5 K is substantially smaller than expected for complete ferromagnetic ordering. The magnetization in fields of up to 6 kOe depends on the actual sample cooling conditions, and the hysteresis loop of a field-cooled sample is displaced along the H axis by ΔH. The above properties can be accounted for by the fact that the films are in a two-phase magnetic (ferromagnetic-antiferromagnetic) state induced by strong s-d exchange. The maximum value of Δ H was used to calculate the energy of exchange coupling between the ferromagnetic and antiferromagnetic parts of a sample. 相似文献