Axisymmetric photonic structures with PT-symmetry

Copyright 2016 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.PT-symmetric structures in photonic crystals, combining refractive index and gain-loss modulations is becoming a research field with increasing interest due to the light directionality induced by these particular potentials. Here, we consider PT-symmetric potentials with axial symmetry to direct light to the crystal central point obtaining a localization effect. The axial and PT-symmetric potential intrinsically generates an exceptional central point in the photonic crystal by the merge of both symmetries. This particular point in the crystal lattice causes field amplitude gradients with exponential slopes around the crystal center. The field localization strongly depends on the phase of the central point and on the complex amplitude of the PT-potential. The presented work analyzes in a first stage 1D linear PT-axisymmetric crystals and the role of the central point phase that determines the defect character, i.e. refractive index defect, gain-loss defect or a combination of both. The interplay of the directional light effect induced by the PT-symmetry and the light localization around the central point through the axial symmetry enhances localization and allows higher field concentration for certain phases. The linearity of the studied crystals introduces an exponential growth of the field that mainly depends on the complex amplitude of the potential. The work is completed by the analysis of 2D PT-axisymmetric potentials showing different spatial slopes and growth rates caused by symmetry reasons.Peer ReviewedPostprint (published version

Fabrication of ZnO based type-II core/shell nanowires for photovoltaic applications

近来，由于持续增长的能源危机和环境保护意识，光伏器件已成为一个热门的课题。许多研究都集中在如何提升这类使用氧化物半导体，如ZnO，TiO2，的太阳能电池和光电化学电池（PEC）的效率上。这些氧化物半导体有这大且固定的带隙，使得它们都不能有效地吸收太阳光的可见光区域，从而导致电池效率低下。一个可选的策略是在纳米线外包裹一层窄带隙半导体，例如ZnSe，CdSe，CdS，PbSe和ZnCdSe，应用这个方法已经把材料的吸收拓展至可见光区域。由于光俘获范围有限以及光激发电子注入效率低等原因，大部分的这种核壳结构的光电转化效率（PCE）都较低。相比起二元材料，通过控制组分，三元合金ZnCdSe具有带隙可...Recently, photovoltaic devices have been a subject of great interest due to the growing awareness of energy crisis and environmental protection. Many studies have been focused on increasing the efficiency of solar cells or photo-electrochemical (PEC) cells using oxide semiconductors, such as ZnO, TiO2. These oxide semiconductors have large and fixed bandgaps, which individually can’t efficiently a...学位：理学博士院系专业：物理与机电工程学院_凝聚态物理学号：1982011015419

Interconnection of Green Marketing and Green Human Resource Management Functions

Over the globe, we are moving to industrialization, which expands business creation, innovation, and different business exercises. This also expands human comfort, yet in addition, builds its way of life. In any case, on the opposite side, it likewise increments environmental danger that came about biological dangers to person. This article highlights the importance of green HRM practices for effective green marketing. The green human asset (the executives) has to make green mindfulness among the new ability and the current representative working for the association, energize their workers for helping the association to lessen the reasons for ecological debasement through green development, green projects and practices, hold the assets for the group of people yet to come. Based on extensive literature review, it is found that green HRM can create readiness, motivation and pledge to workers to contribute their endeavors and thoughts to the greening of their association for real reflection to the consumers in endeavors to cope with green skepticism and greenwash for effective green marketing and corporate social identity

Citrus: An Ancient Fruits of Promise for Health Benefits

Citrus is a group of fruit species, comprise an impressive list of additional vital nutrients, quite heterogeneous in many aspects and ancient times used to prevent and cure different diseases of the human body. It has a range of bioactive chemicals which is suitable for balanced diet and health. Citrus is one of the most important fruit in the world for health-related elements. Some species of the citrus act as a source of potential antioxidant showed prevention against heart diseases, anticancer, inflammation, antiviral, antibacterial and antifungal activity. Citrus fruit contained a higher level of flavonoids, terpenes, phytonutrients and range of phenolic compounds, vitamins C and carotenoids. These biochemicals are present in fruit rag, juice, seed and peel. The biocompounds present in citrus depend upon production, species to species. The aims and objectives of this chapter are to highlight the primary bioactive compounds in citrus and their role in controlling of diseases of a human

Self-collimation in 2D Complex P- and PT-symmetric systems

We predict the self-collimation phenomena (or equivalently, dynamical localization) in 2-dimensional P-symmetric and PT-symmetric complex potentials, with periodic modulations of both gain/loss and refractive index. Non diffractive propagation is analytically predicted and further confirmed by numerical integration of a paraxial model. The parameter space is explored to identify the self-collimation regime in crystals with different complex symmetries.Postprint (published version