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91.
92.
大尺度光学列阵的成像特性 总被引:2,自引:1,他引:1
本文由光线光学理论出发,分析了无单元像差的光学元件大尺度列阵的成像特性,得到了较傍轴近似更普适的成像特性变换矩阵,其结果包含了列阵的傍轴近似成像理论.并进一步证明了大尺度平面列阵的成像特性只具有近似的准相位共轭特性,且只有在傍轴近似下才是较完善的准相位共轭成像.该结论与以往理论相比更接近实际,且能更好地解释迄今为止所观察到的实验结果及本文的实验结果. 相似文献
93.
设a,b是不同的正整数,本文证明了当max(a,b)>10126时,Pell方程组x2-ay2=1和z2-by2=1至多有2组正整数解(x,y,z). 相似文献
94.
To clarify the mechanism of reduced volume expansion-related cryoprotection changes in solution volume during freezing using several types of cryoprotectant were investigated. The effect of each cryoprotectant solution on the survival of asparagus nodal segments cooled slowly (0.5 degrees C/min) to -40 degrees C was also examined. The ratio of the volume at -40 degrees C to the volume at +20 degrees C was used as an index for expansion, calculated as a ratio of the density at +20 degrees C to the density at -40 degrees C. Distilled, deionized water showed the largest volume change at a ratio of 1.094. The ratio gradually decreased with an increase in the molar concentration of cryoprotectant, with the magnitude of the change dependent on the nature of the cryoprotectant. Raffinose was the most effective in reducing volume expansion when compared with other cryoprotectants at a same concentration. Raffinose exhibited greatest cryoprotection in asparagus tissue at 0.6 M where the solution became saturated. Dimethyl sulfoxide (Me2SO) at 1.69 M had the largest effect on cryoprotecting asparagus tissue. Furthermore, Me2SO was also the most effective in reducing volume expansion among the group of cryoprotectants permeable to the plasma membrane. It is concluded that cryoprotection in tissues was closely related to reduced volume expansion especially at low concentration (< or = 1.0 M). Cryoprotectants of impermeable sugar group lost their cryoprotective effect at > 1.0 M, which may due to severe dehydration and cell damage occurred in hypertonic solution. Useful cryoprotectants should be furnished with high ability of reducing volume expansion during freezing as well as low toxicity and high permeability for cells. 相似文献
95.
WANG Yue BI Xiao-Jun CUI Shu-Wang DING Lin-Kai DAN Zeng-Luo-Bu DING Xiao-Hong FAN Chao FENG Cun-Feng FENG Zhao-Yang FENG Zhen-Yong GAO Xiao-Yu GENG Qing-Xi GUO Hong-Wei HE Hui-Hai HE Mao HU Hai-Bing HU Hong-Bo HUANG Qing JIA Huan-Yu LA Ba-Ci-Ren LE Gui-Ming LI Ai-Feng LI Jin-Yu LOU Yu-Qing LU Hong LU Sui-Ling MENG Xian-Ru MU Jun REN Jing-Ru TAN You-Heng WANG Bo WANG Hui WANG Yong-Gang WU Han-Rong XUE Liang YANG Xian-Chu YE Zong-Hai YU Guang-Ce YUAN Ai-Fang ZHANG Hui-Min ZHANG Ji-Long ZHANG Nai-Jian ZHANG Xue-Yao ZHANG Yong ZHANG Yi ZHA Xi-Sang-Zhu ZHOU Xun-Xiu YUAN Qiang 《中国物理C(英文版)》2008,32(11)
Using the data taken from Tibet Ⅱ High Density (HD) Array (1997 February--1999 September) and Tibet-Ⅲ array (1999 November--2005 November), our previous northern sky survey for TeV γ-ray point sources has now been updated by a factor of 2.8 improved statistics. From 0.0° to 60.0° in declination (Dec) range, no new TeV γ-ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV T-ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level (C.L.), the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits. 相似文献
96.
In order to investigate the consequences on the distribution of cell recovery through a cross-section of articular cartilage, the pathway for ice nucleation and diffusion of water and solutes in porcine osteochondral tissue was altered by drilling a 2mm diameter hole through the subchondral bone to the base of the cartilage. Samples equilibrated with 1M dimethyl sulfoxide were cooled at 1 C/min to -30 degrees C then stored in liquid nitrogen. A significant increase in chondrocyte recovery was documented when compared to samples cryopreserved without holes (48.3 percent vs 28.6 percent, P=0.003). The most significant change due to bone base modification was an increase in recovery in the middle section of the cartilage. These results provide insight into mechanisms of cryoinjury in tissue systems. 相似文献
97.
血管输入阻抗的拟合方法与初值选取 总被引:1,自引:0,他引:1
研究了模拟动脉系统的集中参数模型的数据拟合问题,分析了用修正的Noordeergraaf五单元模型计算血管输入阻抗的有关问题,对参数拟合问题中被广泛运用的Newton迭代法与正交试验法作了评述,就其中至关重要的初值选取问题建议了一些简单实用的方法,讨论了参数选取的范围与参考值,并将数值计算结果与实测结果作了比较,所建议方法的有效性得到了证实。 相似文献
98.
中药掺伪的二维相关红外光谱法分析 总被引:8,自引:3,他引:5
旨在建立基于二维相关红外光谱(2D IR spectra)的分析技术,以进行中药中是否掺杂化学药物的判别。以减肥药盐酸芬氟拉明(fenfluramine hydrochloride, FH)、盐酸西布曲明(sibutramine hydrochloride, SH)为待检化合物,确定二者同步相关谱中的特征相关峰。首先通过比较掺杂中药与盐酸芬氟拉明的同步谱中特征相关峰的相似性,初步对掺杂化合物盐酸芬氟拉明进行判定,而后利用掺杂中药异步谱能确认相关峰来源的特性,进一步确证盐酸芬氟拉明的存在;此外,根据掺杂中药同步谱中未出现与盐酸西布曲明同步谱相似的特征相关峰,可以直接判别其中未掺杂盐酸西布曲明。实验所建立的方法无需样品分离,速度快,成本低,为快速简便地进行复杂体系中是否存在化学药物的判别提供了一种新的可能的方法。 相似文献
99.
S. D. Forder P. A. Bingham O. J. McGann M. C. Stennett N. C. Hyatt 《Hyperfine Interactions》2013,217(1-3):83-90
The necessity to immobilise waste safely requires the development of stable materials. Mössbauer spectroscopy has been used to help understand and obtain desirable properties in alkali borosilicate glasses, phosphate glasses and vitrified sewage sludge ash. Phosphate glasses suitable for waste immobilisation have been microwaved and conventionally melted and differences reported. The environment of Fe in promising ceramics has also been studied. Mössbauer studies of irradiated vitrified wasteforms show their resistance to radiation damage. 相似文献
100.
We construct general structures of one and two variable interpolation function,without depending on the existence of divided difference or inverse differences,and we also discuss the block based oscula... 相似文献