129 research outputs found
Research on Evaluation of Regional Logistics Capability under Big Data Background
Over the past few years, the emerging information technology has greatly promoted the development of e-commerce, and then the level of the logistics industry’s ability to put forward higher requirements. At this stage, the development of regional logistics is not balanced, the problems of each region are not the same. In this paper, the regional logistics capability evaluation system is established by analytic hierarchy process (AHP). The paper analyzes and evaluates the regional logistics development in six typical provinces, and puts forward suggestions to promote the regional logistics capability, so as to promote the sound development of regional logistics
Sorting photons by radial quantum number
The Laguerre-Gaussian (LG) modes constitute a complete basis set for
representing the transverse structure of a {paraxial} photon field in free
space. Earlier workers have shown how to construct a device for sorting a
photon according to its azimuthal LG mode index, which describes the orbital
angular momentum (OAM) carried by the field. In this paper we propose and
demonstrate a mode sorter based on the fractional Fourier transform (FRFT) to
efficiently decompose the optical field according to its radial profile. We
experimentally characterize the performance of our implementation by separating
individual radial modes as well as superposition states. The reported scheme
can, in principle, achieve unit efficiency and thus can be suitable for
applications that involve quantum states of light. This approach can be readily
combined with existing OAM mode sorters to provide a complete characterization
of the transverse profile of the optical field
Using all transverse degrees of freedom in quantum communications based on a generic mode sorter
The dimension of the state space for information encoding offered by the
transverse structure of light is usually limited by the finite size of
apertures. The widely used orbital angular momentum (OAM) number of
Laguerre-Gaussian (LG) modes in free-space communications cannot achieve the
theoretical maximum transmission capacity unless the radial degree of freedom
is multiplexed into the protocol. While the methodology to sort the radial
quantum number has been developed, the application of radial modes in quantum
communications requires an additional ability to efficiently measure the
superposition of LG modes in the mutually unbiased basis. Here we develop and
implement a generic mode sorter that is capable of sorting the superposition of
LG modes through the use of a mode converter. As a consequence, we demonstrate
an 8-dimensional quantum key distribution experiment involving all three
transverse degrees of freedom: spin, azimuthal, and radial quantum numbers of
photons. Our protocol presents an important step towards the goal of reaching
the capacity limit of a free-space link and can be useful to other applications
that involve spatial modes of photons
Selection of Ovine Oocytes by Brilliant Cresyl Blue Staining
Sheep oocytes derived from the ovaries collected from the slaughterhouse are often used for research on in vitro embryo production, animal cloning, transgenesis, embryonic stem cells, and other embryo biotechnology aspects. Improving the in vitro culture efficiency of oocytes can provide more materials for similar studies. Generally, determination of oocyte quality is mostly based on the layers of cumulus cells and cytoplasm or cytoplasm uniformity and colors. This requires considerable experience to better identify oocyte quality because of the intense subjectivity involved (Gordon (2003), Madison et al. (1992) and De Loos et al. (1992)). BCB staining is a function of glucose-6-phosphate dehydrogenase (G6PD) activity, an enzyme synthesized in developing oocytes, which decreases in activity with maturation. Therefore, unstained oocytes (BCB−) are high in G6PD activity, while the less mature oocytes stains are deep blue (BCB+) due to insuffcient G6PD activity to decolorize the BCB dye
High-dimensional quantum key distribution based on mutually partially unbiased bases
We propose a practical high-dimensional quantum key distribution protocol based on mutually partially unbiased bases utilizing transverse modes of light. In contrast to conventional protocols using mutually unbiased bases, our protocol uses Laguerre-Gaussian and Hermite-Gaussian modes of the same mode order as two mutually partially unbiased bases for encoding, which leads to a scheme free from mode-dependent diffraction in long-distance channels. Since only linear and passive optical elements are needed, our experimental implementation significantly simplifies qudit generation and state measurement. Since this protocol differs from conventional protocols using mutually unbiased bases, we provide a security analysis of our protocol
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