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141.
142.
Molecular Diversity - Epidermal growth factor receptor (EGFR) has received widespread attention because it is an important target for anticancer drug design. Mutations in the EGFR, especially the... 相似文献
143.
Sheng De-Lei Shi Linfeng Li Danping Zhao Yanping 《Methodology and Computing in Applied Probability》2022,24(2):1119-1141
This paper considers a positive and increasing pension deficit of a certain pay-as-you-go (PAYG) pension system, and tries to make up for this deficit by using heterogeneous insurance. The positive pension deficit is formulated as a mathematical function in continuous time. The surplus of an appropriate heterogeneous insurance is described by diffusion approximation of a Cramér-Lundberg process. The system of extended Hamilton-Jacobi-Bellman equations under mean-variance criterion is established. The closed-form solution and optimal surplus-multiplier of heterogenous insurance are obtained. Some interpretations further explain the theoretical values of the results.
相似文献144.
145.
A pulsed time-of-flight (TOF) laser rangefinder with a pulsed laser diode and an avalanche photo diode (APD) receiver is constructed and tested. Trigged by an avalanche transistor, the laser diode can emit a periodic pulse with rise time of ~2 ns. A new structure with auto gain control (AGC) circuits both in the pre-amplifier and the post-amplifier is presented. Through this technology, not only the dynamic range of the receiver is extended, but also the walk error of timing discriminators is reduced. Large measurement range from 5 m to 500 m is achieved without any cooperative target. The single-shot precision is 3 cm for the weakest signal. Compared with previous laser rangefinders, the complexity of this system is greatly simplified. 相似文献
146.
Estephania Lira Jonas ?. Hansen Peipei Huo Ralf Bechstein Patrick Galliker Erik L?gsgaard Bj?rk Hammer Stefan Wendt Flemming Besenbacher 《Surface science》2010,604(21-22):1945-1960
High-resolution scanning tunneling microscopy (STM) and temperature-programmed desorption (TPD) were used to study the interaction of O2 with reduced TiO2(110)–(1 × 1) crystals. STM is the technique of choice to unravel the relation between vacancy and non-vacancy assisted O2 dissociation channels as a function of temperature. It is revealed that the vacancy-assisted, first O2 dissociation channel is preferred at low temperature (~ 120 K), whereas the non-vacancy assisted, second O2 dissociation channel operates at temperatures higher than 150 K–180 K. Based on the STM results on the two dissociative O2 interaction channels and the TPD data, a new comprehensive model of the O2 chemisorption on reduced TiO2(110) is proposed. The model explains the relations between the two dissociative and the molecular O2 interaction channels. The experimental data are interpreted by considering the available charge in the near-surface region of reduced TiO2(110) crystals, the kinetics of the two O2 dissociation channels as well as the kinetics of the diffusion and reaction of Ti interstitials. 相似文献
147.
Chunling Liu Yanping Yao Chunwu Wang Xin Gao Zhongliang Qiao Mei Li Yuxia Wang Baoxue Bo 《中国光学快报(英文版)》2008,6(3)
In order to improve the optical properties of the Ⅲ-Ⅴ laser diodes(LDs) by means of H2S plasma passivation technology,H2S plasma passivation treatment is performed on the GaAs(110) surface.The optimum passivation conditions obtained are 60-W radio frequency(RF)power and 20-min duration.So the laser cavity surfaces axe treated under the optimum passivation conditions.Consequently,compared with unpassivated lasers with only AR/HR-coatings,the catastrophic optical damage (COD) threshold value of the passivated lasers by H2S plasma treatment is increased by 33%,which is almost the same as that of (NH4)2Sx treatment.And the life-test experiment has demonstrated that this passivation method is more stable than(NH4)2Sx solution wet-passivated treatment. 相似文献
148.
单丁基磷酸酯的合成与表征 总被引:1,自引:0,他引:1
本文报道用三氯氧磷酯化、水解方法制备单丁基磷酸酯,用红外、核磁共振,质谱等方法对其结构进行了分析与表征。 相似文献
149.
提出一种采用Kohonen网络算法进行12电极电容CT系统的图像重建的方法.该网络由输入和输出两层神经元组成,输入为12电极电容CT系统测量所得的66个电容值,输出对应管道介质的空间分布模式.该网络采用竞争算法无监督学习,实验结果证明,该网络有较强的抗噪声能力,可重建出较精确的介质分布图像 相似文献
150.