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131.
Huixue Lao 《The Ramanujan Journal》2009,19(3):339-350
Let λ
f
(n) be the Fourier coefficient of a Hecke primitive eigencuspform f(z) of even integral weight k for the full modular group. In this paper we study the cancelation of the function λ
f
(n) over some special sequences.
This work is supported by the National Natural Science Foundation of China (Grant No. 10701048). 相似文献
132.
用磷钼酸与咪唑合成了一种新的杂多酸-有机电荷转移盐(C3H5N2H)3[PMo12O40]。通过元素分析、红外光谱、固体漫反射光谱、电子自旋共振及热分析等测试技术对其进行了表征,用单扫描法(Achar法和Coats-Redfern法)对合成化合物的TG分析结果进行了非等温热分解动力学研究。推断结果表明,合成化合物的第1步热分解为球对称的三维扩散机理(n=2),其动力学方程为dα/dt=1.58×108[1-(1-α)1/3]-1(1-α)2/3exp(-40931.0/T),求得分解反应的表观活化能E=340.30kJ/mol,指前因子A=1.05×108s-1。标题化合物对紫外光具有光致变色性质,用固体漫反射光谱研究了其光致变色反应动力学。结果显示,其光致变色反应表现为一级或准一级动力学,速率常数k=9.80×10-5s-1。 相似文献
133.
Jiayi Chen Peixin Cui Guoqiang Zhao Kun Rui Mengmeng Lao Yaping Chen Xusheng Zheng Yinzhu Jiang Hongge Pan Shi Xue Dou Wenping Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(36):12670-12674
Highly active and durable electrocatalysts for the oxygen evolution reaction (OER) is greatly desired. Iridium oxide/graphitic carbon nitride (IrO2/GCN) heterostructures are designed with low‐coordinate IrO2 nanoparticles (NPs) confined on superhydrophilic highly stable GCN nanosheets for efficient acidic OER. The GCN nanosheets not only ensure the homogeneous distribution and confinement of IrO2 NPs but also endows the heterostructured catalyst system with a superhydrophilic surface, which can maximize the exposure of active sites and promotes mass diffusion. The coordination number of Ir atoms is decreased owing to the strong interaction between IrO2 and GCN, leading to lattice strain and increment of electron density around Ir sites and hence modulating the attachment between the catalyst and reaction intermediates. The optimized IrO2/GCN heterostructure delivers not only by far the highest mass activity among the reported IrO2‐based catalysts but also decent durability. 相似文献
134.
设计并研制了室温连续工作的单模13 μm垂直腔面发射激光器(VCSEL),阈值电流为051 mA,最高连续工作温度达到82℃,斜率效率为029 W/A.采用InAsP/InGaAsP应变补偿多量子阱作为有源增益区,由晶片直接键合技术融合InP基谐振腔和GaAs基GaAs/Al(Ga)As分布布拉格下反射腔镜,并由电子束蒸发法沉积SiO2/TiO2介质薄膜上反射腔镜形成13 μm VCSEL结构.讨论并分析了谐振腔模式与量子阱增益峰相对位置对器件性能的影响.
关键词:
垂直腔面发射激光器
晶片直接键合
应变补偿多量子阱 相似文献
135.
136.
In this paper, it is proved that the problem of composite beams jointed by bolts can be solved in terms of certain equivalent continuous beams. The equivalent beam is specified as follows: 1) It consists of supports of the original beam and equivalent supports situated at the points where bolts are used. 2) It is loaded by the given load on the original beam.Then the reactions at the bolts in the original composite beam are equal to a constant C times the reactions at various supports of the equivalent continuous beam. The constant is equal to C=(E′J′-k(EJ+E′J′))/(EJ+E′J′), where EJ and E′J′ are flexaral rigidities of the first and second parts of the composite beam respectively, and k is the distributing ratio of load on the second part.The solution of the problem is then greatly simplified.This method can be generalized for composite beams consisting of more than two parts, on which the given load is not proportionately distributed. 相似文献
137.
For juices, the microprocedure has proved to be simple, convenient, accurate, and there is no sample preparation. It has the advantages over conventional wet digestion methods which require time, attention, acid handling, hood space, and possible lead loss due to multiple extraction.These data indicate some infants may be ingesting double the estimate permissible maximum daily intake of 300 μg of lead, above which (3) the entire amount of lead cannot be excreted and accumulation in the body begins. 相似文献
138.
ZnO nanowalls 总被引:1,自引:0,他引:1
J.Y.?Lao J.Y.?Huang D.Z.?Wang Z.F.?RenEmail author D.?Steeves B.?Kimball W.?Porter 《Applied Physics A: Materials Science & Processing》2004,78(4):539-542
Wurtzite ZnO nanowall structures have been synthesized on a (110) Al2O3 substrate by a thermal evaporation and condensation method. The nanowalls are connected to each other and have a thickness of about 20–100 nm. An excellent epitaxial relationship with the substrate has been observed by X-ray diffraction. Edge-dislocation dipoles were observed by transmission electron microscopy. Photoluminescence measurements show strong UV emission at 390 nm for the white-gray nanowalls grown at high temperature, and very weak UV emission for the reddish nanowalls grown at low temperature. PACS 78.55.-m; 81.05.Je; 81.10.Bk; 81.15.Ef 相似文献
139.
“水波纹”绿松石是一种在外观上呈现水波纹状花纹图案的天然绿松石,产量稀少却深受消费者喜爱,前人对绿松石的研究较丰富,但对“水波纹”绿松石的研究较少。对一块基底呈浅蓝白色,条纹呈蓝绿色的“水波纹”绿松石样品用显微激光拉曼光谱仪、显微红外光谱仪、微区X射线衍射、激光剥蚀电感耦合等离子体质谱仪、扫描电镜、显微紫外-可见-近红外光谱仪等测试其各种性能。结果表明,条纹区与非条纹区的主要矿物均为绿松石;红外光谱和拉曼光谱均显示绿松石的光谱;条纹区与非条纹区的化学成分不同,条纹区Al2O3,SiO2,MgO,V,Co,Ni,U及Y,Mo,Cd的含量较非条纹区含量高,而非条纹区P2O5,CuO,K2O及Na2O的含量较条纹区含量高;扫描电镜微形貌显示,条带区的晶体多为厚板状、晶体颗粒大、排列紧密,几乎不可见孔隙,非条带区的晶体多为大小不一的柱状、碎片状,杂乱排列,可见孔隙;微区X射线衍射表明条带区的结晶度较非条带区的结晶度高;显微紫外-可见-近红外光谱表明条带区与非条带区的致色离子相同,均在426和660 nm处有可见吸收峰,致色离子均为Fe3+和Cu2+。“水波纹”绿松石样品的谱学特征表明,条纹处与非条纹处的颜色差异与致色离子没有明显关系,而颜色及透明度差异与绿松石的结晶程度、致密程度有主要关系,“水波纹”绿松石中绿松石结晶度的变化表明了绿松石形成环境的不稳定性,结晶度的周期性变化表明了形成绿松石的外界环境具有周期性变化的规律,为研究绿松石的颜色成因及绿松石的成矿环境提供数据支撑。 相似文献
140.
Let Λ(n) be the von Mangoldt function, x real and y small compared with x. This paper gives a non-trivial estimate on the exponential sum over primes in short intervals
for all α ∈ [0,1] whenever
. This result is as good as what was previously derived from the Generalized Riemann Hypothesis. 相似文献