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71.
Frost R. L. Weier M. L. Erickson Kristy L. 《Journal of Thermal Analysis and Calorimetry》2004,76(3):1025-1033
Struvite (NH4MgPO4·6H2O) is a mineral often found in urinary tracts and kidneys. Thermal decomposition using slow low heating shows that the 'kidney'
stone can be decomposed at temperatures below 40°C. At this temperature both ammonia and water are evolved. If more rapid
heating is employed the decomposition occurs at around 80°C. The implication of this work rests with the use of low slow heat
for the decomposition of the kidney stones.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
72.
用分子动力学模拟方法 (MD)研究了 3 0 0K时钙钛矿型CaSiO3 ,从高压到负压的解压缩过程 .MD模拟获得的P V关系与实验数据相近 ,与已报道的MD模拟数据基本一致 ,所得体积模量也在实验数据分布范围内 .减压缩和重压缩的MD模拟数据与实验结果相似 .钙钛矿型CaSiO3 解压缩成非晶态时 ,存在两个结构破坏阶段 :破坏硅氧八面体和破坏钙氧二十面体 .当钙氧二十面体被破坏后 ,重压缩不能得到钙钛矿型结构 .只要钙氧二十面体未被破坏 ,重压缩可恢复钙钛矿型结构 .本研究得到的结果尚未见相关报道 .由MD模拟数据计算了CaSiO3 系统的红外光谱 ,分析这些数据可知钙钛矿型CaSiO3 解压缩非晶化是一个二阶软模相变 .研究表明钙钛矿型CaSiO3 结构存在一个等容的亚稳极限 ,其解压缩非晶化是一个受动力学控制的亚稳状态 . 相似文献
73.
Jun Shen Tianhe Yang Qinyuan Zhang Jue Wang Qinyao Zhang 《Journal of Sol-Gel Science and Technology》2003,26(1-3):1029-1032
In GaAs based infrared detectors, a considerable part of the incident light will be reflected at the surface, thus it decreases the detectors sensitivity considerably. In this paper, a TiO2 nanoporous coating was prepared successfully on the GaAs substrate by sol-gel method. The optical parameters of the coating were also controlled successfully. It was proved that the coating could greatly improve the transmittance of the incident light, which agrees with the theoretical results quite well. In the 2.5–6.0 m waveband, the maximum transmittance of GaAs substrate is 56%, while the transmittance of the GaAs substrate coated with a nanostructured TiO2 coating is about 94%. 相似文献
74.
提出一种新的目标转化因子分析,其初始向量的构造基于实际最大差异光谱,无需分离即可从红外混合体系中解析出纯组份光谱。该算法简单易懂,不必迭代,运算量小,应用于模拟及实际体系,结果令人满意。 相似文献
75.
本文报道用Nicolet 170 SXFT-IR红外光谱仪观测磁疗手术胆结石、磁疗破碎排出胆结石及服中草药破碎胆结石的红外光谱,分析并比较了它们的光谱特征。 相似文献
76.
The Fourier transform far infrared spectra of oxalate hydrates of whole rare-earth series except Pm and Sc are investigated in the range of 100-400 cm~(-1). The assignment of vibrational frequencies is made on the basis of normal coordinate analysis using our NORVIB program. The model used for the hghter elements of the lanthanide series (La to Eu) is based on the crystal structure of Nd_2(C_2O_4)_3. 10H_2O, in which each lanthanide ion is surrounded by nine O atoms, six from three oxalate ions and three from Water molecules.The model adopted for the heavier elements of the lanthanide series (Gd to Lu) and Ytterbium is based on the crystal structure of Yb_2(C_2O_4)_3· 6H_2O, in which each ion is surrounded by eight atoms, six from three oxalate ions and two from water molecules. The variation of the metal-ligand frequencies and force constants with the atomic numbers of lanthanides is plotted and discussed. 相似文献
77.
重整汽油近红外光谱的稳健偏最小二乘解析 总被引:1,自引:0,他引:1
近红外光谱(NIR)光谱复杂,组分间光谱重叠严重,目前,多元线性回归(MultipleLinearRe gression,MLR)和偏最小二乘法(PartialLeast squares,PLS)是近红外光谱分析中使用最多和效果较好的方法[1]。稳健偏最小二乘(RobustPartialLeast Squares,RPLS)是由稳健统计学构造的具有稳健性能的多元校正方法。当化学测量中引入随机异常点或误差的内在分布偏离正态分布时,它仍能给予接近最优性能的校正,确保分析结果的准确性,是消除奇异点的非常有效的方法[2-4],… 相似文献
78.
Hg1-xMnxTe semiconducting semimagnetic alloy has been examined in the context of its possible applications in infrared detectors.
For analysis of detector properties the intrinsic carrier concentration has been calculated as a function of temperature and
crystal composition. The starting material was In-doped Hg1-xMnxTe grown by the modified Bridgman method. The as-grown crystals with manganese content of 12-19% were p-type with carrier
concentration
and mobility of 100 cm2/ Vs at 77 K. An-type layer was formed on the surface by the annealing process in saturated Hg-vapour at 270-320° for 2 hrs. Capacitance-voltage
curves have C-3 dependence on applied voltage indicating that the junction is linearly graded. From standard electrical measurements and
spectral characteristics the main detector parameters were determined and compared to those of Hg1-xCdxTe devices. The influence of material properties on detector parameters was analyzed. In order to estimate the carrier transport
mechanisms, differential resistivities and current-voltage curves were measured over a wide range of temperaturesi.e. 25 to 300 K. From the temperature dependence of the R0A product, it was established that at high temperatures (150-300 K) the carrier transport is dominated by a recombination-generation
mechanism. In low temperature region the excess current at forward bias is probably attributed to carrier tunneling via energy
states distributed randomly within the forbidden gap. At reverse bias the leakage surface or volume currents dominate in the
carrier transport. 相似文献
79.
G. R. Sudhakaran R. L. Bhattacharjee J. C. Sarker L. H. Johnston 《International Journal of Infrared and Millimeter Waves》1986,7(12):1903-1911
A submillimeter laser Stark spectrum has been observed for fully deuterated Methyl Chloride (CD3Cl) with the 337 m line of the HCN laser up to Stark fields of about 54000 V/cm. The spectra were taken for both Parallel and Perpendicular Polarizations and the multiplet transitions were identified as JK=42K41K in the ground vibrational state. Three families with K=12, 13 and 14 have been identified and their zero field frequencies have been given with improved accuracy over those calculated from available molecular constants. 相似文献
80.
Applications of chalcogenide glass optical fibers 总被引:2,自引:0,他引:2
Chalcogenide-glass fibers based on sulfide, selenide, telluride and their rare-earth-doped compositions are being actively pursued worldwide. Great strides have been made in reducing optical losses using improved chemical purification techniques, but further improvements are needed in both purification and fiberization technology to attain the theoretical optical losses. Despite this, chalcogenide-glass fibers are enabling numerous applications that include laser power delivery, chemical sensing, and imaging, scanning near field microscopy/spectroscopy, IR sources/lasers, amplifiers and optical switches. 相似文献