Omnidirectional Single-negative Gap and in Fibonacci Sequences Composed of Single-negative Materials

The band structures of Fibonacci sequence composed of single-negative materials are studied with a transfer matrix method. A new type of omnidirectional single-negative gaps is found in the Fibonacci sequence. In contrast to the Bragg gaps, such an omnidirectional single-negative gap is insensitive to the incident angles and polarization, and is invariant upon the change of the ratio of the thicknesses of two media. It is found that omnidirectional single-negative gap exists in the other Fibonacci sequence, and it is rather stable and independence of the structure sequence.     

信息时代下提高应收账款风险控制、增强企业经济效益

应收账款是企业的一项资金投放,是企业为了增加销售和提高盈利而进行的投资。企业采取适当比例的应收账款可以减少存货,扩大产品销路,提高企业利润。但如果应收账款管理不足会造成应收账款余额过大从而导致企业资金短缺,周转困难;进而可能加大坏账损失率,恶化企业财务状况。因此,对于应收账款管理的好坏直接影响企业营运资金的周转和经营效益。本文研究监控应收账款的发生及收回,从而提高经济效益。     

Ni1−xCoxSe2?C/ZnIn2S4 Hybrid Nanocages with Strong 2D/2D Hetero-Interface Interaction Enable Efficient H2-Releasing Photocatalysis

Designing a semiconductor-based heterostructure photocatalyst for achieving the efficient separation of photogenerated electron-hole pairs is highly important for enhancing H₂ releasing photocatalysis. Here, a new class of Ni_1−xCo_xSe₂–C/ZnIn₂S₄ hierarchical nanocages with abundant and compact ZnIn₂S₄ nanosheets/Ni_1−xCo_xSe₂^ C nanosheets 2D/2D hetero–interfaces, is designed and synthesized. The constructed heterostructure photocatalyst exposes rich hetero-junctions, supplying the broad and short transfer paths for charge carriers. The close contacts of these two kinds of nanosheets induce a strong interaction between ZnIn₂S₄ and Ni_1−xCo_xSe₂ C, improving the separation and transfer of photo-generated electron-hole pairs. As a consequence, the distinctive Ni_1−xCo_xSe₂ C/ZnIn₂S₄ hierarchical nanocages without using additional noble-metal cocatalysts, display remarkable H₂-relaesing photocatalytic activity with a rate of 5.10 mmol g⁻¹ h⁻¹ under visible light irradiation, which is 6.2 and 30 times higher than those of fresh ZnIn₂S₄ nanosheets and bare Ni_1−xCo_xSe₂ C nanocages, respectively. Spectroscopic characterizations and theory calculations reveal that the strong interaction between ZnIn₂S₄ and Ni_1−xCo_xSe₂ C 2D/2D hetero-interfaces can powerfully promote the separation of photo-generated charge carriers and the electrons transfer from ZnIn₂S₄ to Ni_1−xCo_xSe₂ C.     

A Visible‐ and NIR‐Light Responsive Photothermal Therapy Agent by Chirality‐Dependent MoO3−x Nanoparticles

Chirality‐based semiconducting nanocrystals, as an emerging area, are envisioned to have great potential in chiral sensing, biomedicine, and chiroptical devices. Herein, chiral substoichiometric molybdenum oxide (l /d ‐Cys‐MoO_3?x) nanoparticles are synthesized via step‐by‐step reduction treatment with chiral cysteine molecules. The obtained nanoparticles are used as visible‐ and near‐infrared‐light dual responsive photothermal therapy agent for tumor cell ablation. Notably, the chiral nanoparticles show chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, l ‐Cys‐MoO_3?x is the most sensitive agent giving the highest mortality for HeLa cell ablation in vitro, and vice versa for right‐circularly polarized light with d ‐Cys‐MoO_3?x. In comparison to traditional photothermal therapy with near‐field light source, the investigations with chiral visible light at 532 nm indicate the possibility of chiral Cys‐MoO_3?x nanoparticles for visible light‐based phototherapy via metal–ligand charge transfer chirality, which provides insights for new methods in nanotechnology supported photothermal treatments.     

基于Widget的终端能力开放技术研究

终端能力开放是运营商在移动互联网飞速发展态势下,为提升自身竞争能力、构建全业务能力开放体系的一个重要方面。本文从终端能力的范围界定出发,分析和比较了现有的终端能力开放技术,并就Widget技术实现终端能力开放的技术架构和关键技术进行了研究。最后通过应用案例阐述了Widget的技术价值。     

对新形势下毕业设计管理工作的思考与实践

分析了目前高校毕业设计的状况、毕业生求职应聘活动以及就业形势对毕业设计造成的影响，提出了改革毕业设计管理制度的一些做法及思路，介绍了有关毕业设计教学实践的初步体会。     

增值业务助力电信运营商转型

分析了运营商当前面临的问题;提出通过开发新的业务满足人们通信、娱乐、学习、工作、生活的需要．改变人们的生活方式．即向综合信息服务提供商转变;探讨了如何从业务层面实现这一转变。     

树形分子键合剂在PET试片中的应用

在PET体系中加入0．4％的树形分子键合剂(DBA),分别考察了DBA对HMX、RDX、AP的键合效果,证实树形分子键合剂提高了PET试片、PET-DBP—HMX试片、PET—DBP—RDX试片和PET-DBP-AP试片的力学性能。     

自振荡半桥驱动器IR215X的可变频率驱动技术

在功率电路应用中,常常要求开关频率能连续变化。本文介绍了一种采用自振荡半桥驱动器ＩＲ２１５Ｘ实现的频率可变的驱动电路,并在高压钠灯电子镇流器上得到了应用。