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The position-dependent mode couplings between a semiconductor nanowire(NW) and a planar photonic crystal(PPC) nanocavity are studied. By scanning an NW across a PPC nanocavity along the hexagonal lattice's Γ– M and M – K directions, the variations of resonant wavelengths, quality factors, and mode volumes in both fundamental and second-order resonant modes are calculated, implying optimal configurations for strong mode-NW couplings and light-NW interactions. For the fundamental(second-order) resonant mode, scanning an NW along the M – K(Γ– M) direction is preferred, which supports stronger light-NW interactions with larger NW-position tolerances and higher quality factors simultaneously. The simulation results are confirmed experimentally with good agreements. 相似文献
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通过优化超声萃取时间、萃取次数、萃取溶剂类型等条件,建立了电子电气产品中六溴环十二烷(含α,β,γ3种同分异构体)的高效液相色谱-质谱(HPLC-MS)测定方法。经条件优化,采用甲苯超声萃取样品,重复萃取3次,每次15 min,离心取上清液,合并后经氮气吹干,用甲醇-水溶液重新溶解定容后进行检测。六溴环十二烷各同分异构体的线性范围为50~5 000μg/L,线性相关系数均大于0.999,方法检出限为1 mg/kg,样品加标回收率为88.3%~104.5%。该方法快速、简便、准确、稳定,用于实际样品的检测,阳性样品均为发泡聚苯乙烯材料。 相似文献
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根据Fourier级数的频域分析方法,并且运用快速Fourier变换的算法,在IBM-PC机上通过自编程序进行了不同磨粒几何外形参数的数值计算,利用这种计算方法,可以获得磨粒尖锐度、粗糙度和轮廓的角形特征等信息,是对不同磨粒外部几何形状进行比较判别的一种有效方法。 相似文献
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采用射频磁控溅射法在石英玻璃衬底上制备了ZnO:Mn薄膜, 结合N+ 注入获得Mn-N共掺ZnO薄膜, 进而研究了退火温度对其结构及室温铁磁性的影响. 结果表明, 退火后ZnO:(Mn, N) 薄膜中Mn2+和N3-均处于ZnO晶格位, 没有杂质相生成. 退火温度的升高 有助于修复N+注入引起的晶格损伤, 同时也会让N逸出薄膜, 导致受主(NO)浓度降低. 室温铁磁性存在于ZnO:(Mn, N)薄膜中, 其强弱受NO浓度的影响, 铁磁性起源可采用束缚磁极化子模型进行解释. 相似文献
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类钙钛矿新铌酸盐Ba5LaTi2Nb3O18的合成、结构与介电特性 总被引:2,自引:0,他引:2
为满足现代通信技术小型化、集成化与高可靠性的迫切要求,探索具有高介电常数、低介电损耗与低温度系数的微波介电材料引起了材料科学、化学、物理和电子科学等领域科学工作者的广泛关注,并已开发出复合钙钛矿结构的Ba(Mg1/3Ta2/3)O3、Ba(Zn1/3Ta2/3)O3和钨青铜结构的Ba6-3xLn8+2x·Ti18O54及Ba2Ti9O20等实用化的高性能材料[1~7].这类材料均由氧八面体共顶连接,而且氧八面体内(B位)、外(A位)阳离子比例等于或略大于1,由此,我们推测在B位与A位阳离子比例略小于1的类钙钛矿结构中也极有可能存在具有优良介电性能的新材料,因此对通式为AnBn-1O3n(n=5,6,7,8)的系列新化合物进行了系统的合成、结构与介电性能研究[8,9].本文报道在BaO-La2O3-TiO2-Nb2O5体系中合成的具有5层类钙钛矿结构的新铌酸盐Ba5LaTi2Nb3O18,发现该材料具有较好的介电性能. 相似文献
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钨青铜结构Ba6Zn0.67M9.33O30(M=Nb,Ta)的合成与介电特性 总被引:1,自引:0,他引:1
Two compounds Ba6Zn0.67M9.33O3 and Ba6Zn0.67M9.33O30 with tungsten bronze structure were synthesized in the BaO-ZnO-Nb2O5/Ta2O5 systems by the conventional high temperature solid-state reaction.The structure and dielectric properties of Ba6Zn0.67M9.33O3 and Ba6Zn0.67M9.33O30 were determined by X-ray powder diffraction,scanning electron microscope and dielectric measurements.The results show that Ba6Zn0.67M9.33O30 belongs to paraelectric phase of fully filled tetragonal tungsten bronze structure at room temperature with unit cell parameters a:1.26256(4) nm, c:0.39698(2) nm. The room temperature dielectric constant (ε) of Ba6Zn0.67M9.33O30 ceramic reached 108 combined with a low dielectric loss of 0.005 at 1 MHz. While Ba6Zn0.67M9.33O3 belongs to fully filled tetragonal tungsten bronze structure at room temperature with the unit cell parameters a:1.25940 (3) nm, c=0.40008(2) nm. Ba6Zn0.67M9.33O30 ceramic shows significant relaxor behaviors, and the phase transition from ferroelectric to paraelectric occurred at 55℃ (at 1 MHz). The room temperature dielectric constant (ε) of ceramic reached 570 at 1 MHz. 相似文献