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161.
树突状细胞(DC)是目前所知机体内功能最强的专职抗原提呈细胞,可在体内外向T细胞提呈抗原并诱发CTL反应,在抗肿瘤免疫中发挥重要作用.近年采用DC疫苗进行抗肿瘤治疗已成为当今肿瘤生物治疗领域备受关注的焦点之一.针对DC抗肿瘤机制、妇科肿瘤的免疫逃逸及在妇科肿瘤上的应用进行了研究. 相似文献
162.
利用水热法在直流磁控溅射制备的掺铝氧化锌 (AZO) 种子层上制备了不同形貌和光学性能的掺银ZnO纳米棒, 并采用XRD、扫描电镜、透射谱、光发射谱和EDS谱详细研究了Ag离子与Zn离子的摩尔百分比 (RAg/Zn) 及AZO种子层对掺银ZnO纳米棒的结构和光学性质的影响. 随着RAg/Zn的增加, 掺银ZnO 纳米棒的微结构和光学性质的变化与银掺杂诱导的纳米棒的端面尺寸变化有关. 平均端面尺寸的变化归结于种子层颗粒大小和颗粒数密度不同导致掺入的Ag离子的相对比例不同. 溅射15 min的AZO种子层上生长的ZnO纳米棒由于缺陷增多导致在可见光区的发光峰明显强于溅射10 min 的AZO种子层上、相同RAg/Zn 条件下生长的ZnO纳米棒. Ag掺杂产生的点缺陷增多导致可见光区PL波包较宽. 纯ZnO纳米棒的微结构与种子层厚度导致的结晶度和颗粒大小有关.
关键词:
ZnO纳米棒
水热法
Ag掺杂
直流磁控溅射 相似文献
163.
用脉冲直流放电产生Ar原子亚稳态3p54s[3/2]2和3p54s′[1/2]0.在单光子32500~35600 cm-1能量范围内, 结合飞行时间质谱技术获得Ar原子共振增强激发光谱.光谱分析表明,所有谱线来源于Ar原子3p54s[3/2]2和3p54s′[1/2]0两个亚稳态吸收单个光子向偶宇称np′、nf′自电离Rydberg态序列的跃迁.实验观测到许多新的自电离能级,并获得更精确和系统的能级位置和量子亏损值数据. 相似文献
164.
Glasses with composition xBi2O3 ·(0.30 - x)BaO · 0.70B2O3 have been prepared in the range (0.00 ≤ x ≤ 0.15) containing 2.0 mol% of V2O5. Electron paramagnetic resonance (EPR), optical transmission and absorption spectra and DC conductivity of these glasses have been studied. The spin Hamiltonian parameters (SHP) of VO2+ ions, dipolar hyperfine coupling parameter P, Fermi contact interaction parameter K, and molecular orbital coefficients (α2 and γ2) have been calculated. The SHP arc related with the theoretical optical basicity. Ath. The position of the absorption edge and the values of the optical band gap have also been reported. The effect of addition of Bi2O3 on the DC conductivity has also been studied. 相似文献
165.
Abstract Measurements of electron paramagnetic resonance, infrared and electrical properties were carried out for the K2SO4—Na2SO4 mixed system before and after γ-irradiation. EPR measurements revealed the presence of a quartet of lines characterized by an isotropic g-value of 2.0034. These lines are mainly attributed to the formation of a SO? 3 center which results from the interaction of γ-rays with the sulfate ion. A decrease in the absorption intensity of the Infrared radiation was observed after γ-irradiation due to radiation damage in the sulfate group. The electrical conductivity, σ, was measured for the K2SO4—Na2SO4 system before and after γ-irradiation in the temperature range from 30 up to 430°C. A considerable decrease in the conductivity value accompanied by an increase in the activation energy was observed after γ-irradiation. The energy of formation of Frenkel defects was estimated to be 2.94eV. The current-voltage characteristics were measured at different temperatures in order to estimate the type of conduction in the samples. Isothermal annealing kinetics was investigated at different temperatures before and after γ-irradiation. The electrical conductivity decreases with increasing time of annealing and the annealing process is dominated by a unique rate process. 相似文献
166.
We study Lagrange duality theorems for canonical DC programming problems. We show two types Lagrange duality results by using a decomposition method to infinite convex programming problems and by using a previous result by Lemaire (1998) [6]. Also we observe these constraint qualifications for the duality theorems. 相似文献
167.
Gilberto Gonzalez Avalos Rene Galindo Orozco 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(1):38-57
A procedure is proposed to obtain the linearization of a class of non-linear physical systems using bond graphs. Also, a junction structure of a non-linear bond graph considering linearly dependent and independent state variables is described. From the junction structure of the non-linear bond graph a procedure to build a linearized bond graph is presented. Finally, an example of a Programmable Universal Manipulation Arm (PUMA) manipulator is given. 相似文献
168.
The DC electrical resistivity (p) was studied for Co substituted SbNi ferrites as a function of temperature and composition. The experimental results showed that DC resistivity, Curie temperature and activation energies for electrical conduction increase as Co-ion substitution decreases. The DC electrical conductivity increases as temperature increases. The real part of dielectric constant (e') was found to be inversely proportional to the root mean square value of the electrical resistivity. 相似文献
169.
M. A. El Hiti 《Phase Transitions》2013,86(2):117-122
The DC electrical conductivity was studied as a function of both composition and temperature for the ferrite system NixMg1–xFe2O4 prepared by the usual ceramic technique. The experimental results proved that, the DC electrical conductivity increases as the temperature increases and as the nickel ion content and porosity decrease. The Curie temperature and the activation energies for electrical conduction increase as the nickel ion content increases. 相似文献
170.