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61.
当γ,μ满足一定条件时,六次函数V(R,γ)=C[R6+2γR4+(γ2+μ)R2]的图像是双势阱,可用来描述质子转移,且其相应的Schrodinger方程有解析解.用此势函数结合一维双势阱模型及变分法,并用B3P86密度泛函方法在6-311G水平下计算了该分子的平衡态和过渡态的构型及能量,研究了9-羟基苯嵌萘酮的基态能级劈裂,与其它理论值相比,所得计算结果[ΔH(0)=86.13cm-1]与实验值符合得较好. 相似文献
62.
This paper reports that a novel type of suspended ZnO nanowire field-effect
transistors (FETs) were successfully fabricated using a
photolithography process, and their electrical properties were
characterized by I--V measurements. Single-crystalline ZnO
nanowires were synthesized by a hydrothermal method, they were used
as a suspended ZnO nanowire channel of back-gate field-effect
transistors (FET). The fabricated suspended nanowire FETs showed a
p-channel depletion mode, exhibited high on--off current ratio of
~105. When VDS=2.5 V, the peak transconductances
of the suspended FETs were 0.396 μS, the oxide capacitance was
found to be 1.547 fF, the pinch-off voltage VTH was about
0.6 V, the electron mobility was on average 50.17 cm2/Vs. The
resistivity of the ZnO nanowire channel was estimated to be
0.96× 102Ω cm at VGS = 0 V. These
characteristics revealed that the suspended nanowire FET fabricated
by the photolithography process had excellent performance. Better
contacts between the ZnO nanowire and metal electrodes could be
improved through annealing and metal deposition using a focused ion
beam. 相似文献
63.
Device research on GaAs-based InAlAs/InGaAs metamorphic high electron mobility transistors grown by metal organic chemical vapour deposition
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This paper applies a novel quad-layer resist and e-beam
lithography technique to fabricate a GaAs-based InAlAs/InGaAs
metamorphic high electron mobility transistor (HEMT) grown by metal
organic chemical vapour deposition (MOCVD). The gate length of
the metamorphic HEMT was 150~nm, the maximum current density was
330~mA/mm, the maximum transconductance was 470~mS/mm, the threshold
voltage was -0.6~V, and the maximum current gain cut-off frequency
and maximum oscillation frequency were 102~GHz and 450~GHz,
respectively. This is the first report on tri-termination devices
whose frequency value is above 400~GHz in China. The excellent
frequency performances promise the possibility of metamorphic HEMTs
grown by MOCVD for millimetre-wave applications, and more
outstanding device performances would be obtained after optimizing
the material structure, the elaborate T-gate and other device
processes further. 相似文献
64.
65.
66.
Kong Wei-Shong Lv Na Luo Dian Ling Jun Gao Qian Liu Chun-Bo Li Yin-Ke Liu Xin Xiang Hai-Ying Mi Qi-Li Li Gan-Peng Yang Guang-Yu Hu Qiu-Fen Li Xue-Mei 《Chemistry of Natural Compounds》2021,57(2):260-264
Chemistry of Natural Compounds - Two new chromone derivatives (1 and 2), together with four known (3–6) ones, were isolated from the stems of a local sun cured tobacco (Fenghuang tobacco,... 相似文献
67.
Li Xue-Mei Mi Qi-Li Gao Qian Li Jing Song Chun-Man Zeng Wan-Li Xiang Hai-Ying Liu Xin Chen Jian-Hua Zhang Cheng-Ming Yang Guang-Yu Hu Qiu-Fen Chen Zhang-Yu 《Chemistry of Natural Compounds》2021,57(2):293-296
Chemistry of Natural Compounds - Two new naphthalene derivatives, 1-(3-hydroxy-1-(hydroxymethyl)-2-methoxy-6-methylnaphthalen-7-yl) propan-2-one (1) and... 相似文献
68.
The aberrations for anterior corneal surface, posterior corneal surface and complete eyes are measured and calculated. The aberrations for the crystalline lens are obtained by subtracting the aberrations in cornea from that in complete eyes. It is shown that the combination between the crystalline lens and the cornea can be either a compensatory or an additive process. The combination between the anterior and the posterior corneal surfaces on the aberrations is complicated, compensatory or additive. The anterior corneal surface contributes mainly lower-order aberrations (astigmatism) of images, while the posterior corneal surface and the crystalline lens contribute mainly higher-order aberrations. 相似文献
69.
70.
BAI Yin-Juan GAN Hai-Ying LU Jun SHI Zhen 《有机化学》2003,23(Z1):286-287
Since ferrocene was synthesized, derivatives of ferrocene have attracted the attention of chemists, and recently solvent-free organic reaction has been an important new dimension in preparative organic chemistry. [1] Solventless synthesis without the use of supporting reagents which can avoid the risk of high pressure development and volatile toxic solvent employment is very amaizing and eco-friendly. 相似文献