Response to the Letter to the Editor

Journal of Nanoparticle Research -     

Melting from one to two to three dimensions

The transformation of a crystalline solid into a liquid, seeming to have no precursor and no intermediate states, has challenged scientists for over a century. The search for the fundamental mechanism stimulated the development of quantum mechanics, concepts of the roles of dimensionality and topological order in condensed matter, and experimental techniques to test the theories. We now understand that the transition begins at lower temperatures than the melting point of the bulk. It starts at the edges of crystal planes, progresses across the surface, evolves into the successive melting of atomic layers, and ends in bulk phase coexistence. The memory of the process remains within a few molecular distances at the crystal-melt interface.     

The need to certify products to CDRH Regulations

Laser products that are sold in the United States are required to comply with the regulations published by the Center for Devices and Radiological Health (CDRH) within the US Food and Drug Administration [1]. The need to certify products is straightforward in most instances, however, the applicability of the regulations is not as clear for: lasers sold only to Original Equipment Manufacturers (OEMs) as components for incorporation into end-use products, end-use products that contain lasers which have already been certified by their manufacturers, and end-use products that are being imported into the US and that already comply with international laser safety standards. This article will discuss these applications in an attempt to clarify the need for certification by laser product manufacturers and importers. The discussion applies equally for lasers and laser systems.     

Corrections to deuterium hyperfine structure due to deuteron excitations

We consider the corrections to the deuterium hyperfine structure originating from the two-photon exchange between an electron and deuteron, with deuteron excitations in the intermediate states. In particular, the motion of the two intermediate nucleons as a whole is taken into account. The problem is solved in the zero-range approximation. The result is in good agreement with the experimental value of deuterium hyperfine splitting.     

Metropolitan Optical Networks: When to Change to DWDM

In this article we propose a new methodology to estimate the change in the bandwidth demand in time, mainly in residential areas. The bandwidth demand forecast is a basic aspect to decide the evolution of metropolitan optical networks. The word evolution refers to the necessity of making changes in networks, either by upgrading or replacing different elements that are part of the network. This analysis, along with a technological alternatives analysis, provides the operator the needed information to achieve the appropriate network planning and to make investment decisions.     

Attempt to generalize fractional-order electric elements to complex-order ones

The complex derivative D~(α±jβ), with α, β∈ R+ is a generalization of the concept of integer derivative, where α = 1,β = 0. Fractional-order electric elements and circuits are becoming more and more attractive. In this paper, the complexorder electric elements concept is proposed for the first time, and the complex-order elements are modeled and analyzed.Some interesting phenomena are found that the real part of the order affects the phase of output signal, and the imaginary part affects the amplitude for both the complex-order capacitor and complex-order memristor. More interesting is that the complex-order capacitor can do well at the time of fitting electrochemistry impedance spectra. The complex-order memristor is also analyzed. The area inside the hysteresis loops increases with the increasing of the imaginary part of the order and decreases with the increasing of the real part. Some complex case of complex-order memristors hysteresis loops are analyzed at last, whose loop has touching points beyond the origin of the coordinate system.     

Metropolitan Optical Networks: When to Change to DWDM

In this article we propose a new methodology to estimate the change in the bandwidth demand in time, mainly in residential areas. The bandwidth demand forecast is a basic aspect to decide the evolution of metropolitan optical networks. The word evolution refers to the necessity of making changes in networks, either by upgrading or replacing different elements that are part of the network. This analysis, along with a technological alternatives analysis, provides the operator the needed information to achieve the appropriate network planning and to make investment decisions.     

创设认知冲突培养学生提出问题的能力--以牛顿第一定律的教学为例

提出问题与批判性思维密切相关,对社会民主体系顺畅构建与学生个体的长远发展都很重要.在教学中培养学生提出问题的能力,是义务教育物理新课标的要求,是提升学生学科素养和表达能力的重要途径.认知冲突有较高的教学价值,利用学生学习中的矛盾,创设认知冲突,不仅可以激发学生学习的兴趣和动力,更可以从多个维度培养学生提出问题的能力.