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41.
以光子晶体光纤环为研究对象,利用白光干涉仪测试了不同温度下保偏光子晶体光纤环和普通保偏光纤环内部的偏振交叉耦合强度分布,分析了光纤环中固定耦合点不同温度下的偏振耦合强度变化。结果表明,在-40℃~50℃的温度条件下,保偏光子晶体光纤环偏振耦合强度最大变化率为0.97%;普通保偏光纤环偏振耦合强度的变化率为4.71%,约为保偏光子晶体光纤环的5倍。实验研究证明,光子晶体光纤环的偏振交叉耦合强度温度稳定性高于普通保偏光纤环的偏振交叉耦合强度的温度稳定性。 相似文献
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Low dislocation density Ge wafers grown by a vertical gradient freeze (VGF) method used for the fabrication of multi-junction photovoltaic cells (MJC) have been studied by a whole wafer scale measurement of the lattice parameter, X-ray rocking curves, etch pit density (EPD), impurities concentration, minority carrier lifetime and residual stress. Impurity content in the VGF-Ge wafers, including that of B, is quite low although B2O3 encapsulation is used in the growth process. An obvious difference exists across the whole wafer regarding the distribution of etch pit density, lattice parameter, full width at half maximum (FWHM) of the X-ray rocking curve and residual stress measured by Raman spectra. These are in contrast to a reference Ge substrate wafer grown by the Cz method. The influence of the VGF-Ge substrate on the performance of the MJC is analyzed and evaluated by a comparison of the statistical results of cell parameters. 相似文献
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针对合流制管网系统在雨天溢流污染严重,造成城市水体黑臭现象的问题,以银川市某高密度城区合流制管网系统为例,基于SWMM模型,在短历时设计降雨和长历时设计降雨两种条件下,模拟分析了合流制溢流(CSO)调蓄池、雨污管道混错接改造、绿化带海绵化改造等“灰绿”协同措施对CSO污染的影响。结果表明:CSO调蓄池、雨污管道混错接改造、绿化带海绵化改造及“灰绿”措施结合4种方案在短历时、长历时设计降雨条件下,随着降水量的增加,溢流水量及溢流污染物负荷均增加,溢流削减率均逐渐减小,其中“灰绿”措施结合方案对溢流污染的削减效果最为显著;重现期小于5 a时,溢流水量削减率与溢流污染物负荷削减率基本达到80%;降雨条件为中雨时,污染物负荷削减率基本达到75%;重现期为20 a时,溢流水量削减率及TSS、COD、TP、NH^(+)_(4)-N负荷削减率分别达到64%、70%、70%、70%、70%;降雨条件为大雨时,溢流水量削减率及TSS、COD、TP、NH^(+)_(4)-N负荷削减率分别达到28%、32%、26%、31%、33%。 相似文献
46.
Congming Zhang Xiaochun Wei Chongwei Chen Kun Cao Yongping Li Qiang Jiao Juan Ding Jingming Zhou Braden C. Fleming Qian Chen Xianwen Shang Lei Wei 《International journal of molecular sciences》2014,15(5):7250-7265
To determine whether there is a correlation between the concentration of Indian hedgehog (Ihh) in synovial fluid (SF) and the severity of cartilage damage in the human knee joints, the knee cartilages from patients were classified using the Outer-bridge scoring system and graded using the Modified Mankin score. Expression of Ihh in cartilage and SF samples were analyzed with immunohistochemistry (IHC), western blot, and enzyme-linked immunosorbent assay (ELISA). Furthermore, we detected and compared Ihh protein levels in rat and mice cartilages between normal control and surgery-induced osteoarthritis (OA) group by IHC and fluorescence molecular tomography in vivo respectively. Ihh expression was increased 5.2-fold in OA cartilage, 3.1-fold in relative normal OA cartilage, and 1.71-fold in OA SF compared to normal control samples. The concentrations of Ihh in cartilage and SF samples was significantly increased in early-stage OA samples when compared to normal samples (r = 0.556; p < 0.001); however, there were no significant differences between normal samples and late-stage OA samples. Up-regulation of Ihh protein was also an early event in the surgery-induced OA models. Increased Ihh is associated with the severity of OA cartilage damage. Elevated Ihh content in human knee joint synovial fluid correlates with early cartilage lesions. 相似文献
47.
Chenglong Zhang Jingming Fei Lei Guo Jianxing Yu Binbin Zhang Zheng Yan Fuxing Ye 《Ceramics International》2018,44(8):8818-8826
LaPO4 powders were produced by a chemical co-precipitation and calcination method. The ceramic exhibited a monazite structure, kept phase stability at 1400?°C for 100?h, and had low thermal conductivity (~ 1.41?W/m?K, 1000?°C). LaPO4/Y2O3 partially stabilized ZrO2 (LaPO4/YSZ) double-ceramic-layer (DCL) thermal barrier coatings (TBCs) were fabricated by air plasma spray. The LaPO4 coating contained many nanozones. Thermal cycling tests indicated that the spallation of LaPO4/YSZ DCL TBCs initially occurred in the LaPO4 coating. The failure mode was similar to those of many newly developed TBCs, probably due to the low toughness of the ceramics. LaPO4/YSZ DCL TBCs were highly resistant to V2O5 corrosion. Exposed to V2O5 at 700–900?°C for 4?h, La(P,V)O4 formed as the corrosion product, which had little detrimental effect on the coating microstructure. At 1000?°C for 4?h, a minor amount of LaVO4 was generated. 相似文献
48.
秦镜明 《哈尔滨工业大学学报》1988,(5)
在微波近场测试中,为减少测试误差,可以在喇叭天线的口面处加一个微波透镜。本文以光学原理为基础,推导了微波透镜的计算公式。通过实验比较,使用微波透镜后测试结果明显改善,天线增益明显提高,使近场测试的结果更接近于远场测试的结果。 相似文献
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围绕施工阶段对通风和空调工程的监理工作,以国家相关规范为指导,结合工作实践,从理论和实务上对如何有效地做好本分部工程监理工作进行有效的探讨。 相似文献