排序方式: 共有62条查询结果,搜索用时 15 毫秒
51.
采用一锅水热还原路径制备得到均匀单分散、具有分级结构的MoO2微球。用XRD、FESEM、TEM及紫外-可见吸收光谱对产品进行了表征。结果表明MoO2微球的尺寸大小为1.5~3.5μm,由微小的纳米片或纳米粒子组装而成。对比实验表明,一些反应参数如还原剂柠檬酸C6H8O7和矿化剂Na2CO3的用量极大地影响了MoO2微球的生长。基于MoO2微球生长时间演变的对比实验,提出了取向聚集-奥斯瓦尔德熟化生长机制。光催化评价结果表明,钨灯辐照时,在H2O2辅助下,MoO2微球对降解罗丹明B具有较高的催化活性。 相似文献
52.
简正波群速度广泛应用于海底参数反演,海深不确定性对反演结果有较大影响。为了减小海深测量误差对反演结果的影响,本文通过理论分析和仿真计算对Pekeris声波导情况下正则简正波群速度随海深和海底声速的变化规律进行研究,结果表明当所选取的频率处于某号简正波的Airy频率附近时,该号简正波的群速度对海深变化不敏感,而比同频率的低号简正波的群速度受海底声速的影响更大。将这一变化规律应用于由简正波群速度反演海底声速,仿真与实验结果表明,应用Airy频率附近的简正波的群速度反演海底声速,能有效克服海深不确定性对反演结果的影响。 相似文献
53.
Imaging properties of a two-dimensional photonic crystal (PC) slab consisting of a triangular lattice of metallic cylinders immersed in a dielectric background are investigated by the finite-difference time-domain technique. With the calculated field patterns of a point source placed in the vicinity of the PC slab and the corresponding equifrequency-surface contours, we find that a high-quality image ca.n form in the opposite side of the slab in the lowest TM-polarized photonic band, and this near-field image is formed mainly by the self-collimation effect. 相似文献
54.
給出几个二次根式的一个多項式,例如3~(1/3)-2~(1/2)+(1/7)5~(1/5)+(4/3)13~(1/13)-6(11~(1/11+9))在中学教材里,认为它已不能进一步簡化。但我們可以問:为什么不能再行簡化?比方說,是否存在有理数a及自然数k使上式变为k~(1/a)?对于这个問題,在中学教材里,还不能予以简单地肯定或否定,为此我們来研究二次最簡根式的綫性关系,順便也指明二次最簡根式的另一种性貭。值 相似文献
55.
采用一锅水热还原路径制备得到均匀单分散、具有分级结构的MoO2微球。用XRD、FESEM、TEM及紫外-可见吸收光谱对产品进行了表征。结果表明MoO2微球的尺寸大小为1.5~3.5μm,由微小的纳米片或纳米粒子组装而成。对比实验表明,一些反应参数如还原剂柠檬酸C6H8O7和矿化剂Na2CO3的用量极大地影响了MoO2微球的生长。基于MoO2微球生长时间演变的对比实验,提出了取向聚集-奥斯瓦尔德熟化生长机制。光催化评价结果表明,钨灯辐照时,在H2O2辅助下,MoO2微球对降解罗丹明B具有较高的催化活性。 相似文献
56.
57.
高分子辅助水热制备单晶碲纳米管 总被引:1,自引:0,他引:1
Te single-crystal nanotubes were synthesized using Na2TeO3 and (NH2)2CS as starting materials and pol-yacrymide (PAM) as morphology-director under hydrothermal conditions. The obtained products were characteri-zed by XRD, FESEM, SEM and TEM techniques. The results show that Te nanotubes grow along c axial with the inner diameters of 100~500 nm, wall thickness of 80~160 nm and lengths of 5~10 μm. A possible mechanism for the growth of Te nanotubes was discussed. 相似文献
58.
59.
The extraordinary light transmission through a 200-nm thick gold
film when passing through different subwavelength hole arrays is
observed experimentally. The sample is fabricated by electron beam
lithography and reactive ion etching system. A comparison between
light transmissions shows that the hole shape changing from
rectangular to diamond strongly affects the transmission intensity
although both structures possess the same lattice constant of
600,nm. Moreover, the position of the transmission maximum
undergoes a spectral red-shift of about 63,nm. Numerical
simulations by using a transfer matrix method reproduce the observed
transmission spectrum quite well. 相似文献
60.
基于欧拉Gamma函数的奇特性质,利用函数的单调性理论以及一些简单函数的积分表达式与级数展开式证明了函数f_α(x),α∈R和函数s(x)的对数完全单调性,并利用该性质得出了一个比原有结论更精确的不等式以及一个双边不等式. 相似文献