6,848 research outputs found
Research and Practice on Equilibrium Theory of Road Capacity
AbstractThe main problems of traffic at present are low design and over design, and this paper puts forward equilibrium theory of road capacity based on the main problems and then puts forward corresponding model based on equilibrium theory for the purpose of guiding and improving the design of road, The paper takes Zhouzhuang Road in Wuhan as example, and conducts capacity equilibrium test based on different traffic organization optimization scheme. Meanwhile, the paper will evaluate the model with VISSIN, and then demonstrates the feasibility and effectiveness of capacity equilibrium model
A New Two-Dimensional Functional Material with Desirable Bandgap and Ultrahigh Carrier Mobility
Two-dimensional (2D) semiconductors with direct and modest bandgap and
ultrahigh carrier mobility are highly desired functional materials for
nanoelectronic applications. Herein, we predict that monolayer CaP3 is a new 2D
functional material that possesses not only a direct bandgap of 1.15 eV (based
on HSE06 computation), and also a very high electron mobility up to 19930 cm2
V-1 s-1, comparable to that of monolayer phosphorene. More remarkably, contrary
to the bilayer phosphorene which possesses dramatically reduced carrier
mobility compared to its monolayer counterpart, CaP3 bilayer possesses even
higher electron mobility (22380 cm2 V-1 s-1) than its monolayer counterpart.
The bandgap of 2D CaP3 can be tuned over a wide range from 1.15 to 0.37 eV
(HSE06 values) through controlling the number of stacked CaP3 layers. Besides
novel electronic properties, 2D CaP3 also exhibits optical absorption over the
entire visible-light range. The combined novel electronic, charge mobility, and
optical properties render 2D CaP3 an exciting functional material for future
nanoelectronic and optoelectronic applications
康复专科护士的发展现状与展望
Through access to a lot of relevant information on the role of the rehabilitation nurse specialist functions, explore how rehabilitation specialist nurse qualifications provides a basis for our rehabilitation specialist nurse cultivating and development.本文通过查阅大量相关资料,对康复专科护士的角色、功能等进行综述,探索康复专科护士的资格认证方式为我国康复专科护士的培养及使用提供依据
Exact calculations of vertex and in the unitary gauge
In this paper, we present the exact calculations for the vertex
and in the unitary gauge. We found that (a) the
divergent- and -dependent terms are left in the effective vertex function
for transition even after we sum up
the contributions from four related Feynman diagrams; (b) for an on-shell
photon, such terms do not contribute et al; (c) for off-shell photon, these
terms will be canceled when the contributions from both vertex and are taken into account simultaneously, and therefore the
finite and gauge independent function , which
governs the semi-leptonic decay , is derived in the unitary
gauge.Comment: 13 pages, 2 figures, Revte
Far-Field Tunable Nano-focusing Based on Metallic Slits Surrounded with Nonlinear-Variant Widths and Linear-Variant Depths of Circular Dielectric Grating
In this work, we design a new tunable nanofocusing lens by the linear-variant
depths and nonlinear-variant widths of circular grating for far field practical
applications. The constructively interference of cylindrical surface plasmon
launched by the subwavelength metallic structure can form a
subdiffraction-limited focus, and the focal length of the this structures can
be adjusted if the each groove depth and width of circular grating are arranged
in traced profile. According to the numerical calculation, the range of
focusing points shift is much more than other plasmonic lens, and the relative
phase of emitting light scattered by surface plasmon coupling circular grating
can be modulated by the nonlinear-variant width and linear-variant depth. The
simulation result indicates that the different relative phase of emitting light
lead to variant focal length. We firstly show a unique phenomenon for the
linear-variant depths and nonlinear-variant widths of circular grating that the
positive change and negative change of the depths and widths of grooves can
result in different of variation trend between relative phases and focal
lengths. These results paved the road for utilizing the plasmonic lens in
high-density optical storage, nanolithography, superresolution optical
microscopic imaging, optical trapping, and sensing.Comment: 14pages,9figure
Phonon and Raman scattering of two-dimensional transition metal dichalcogenides from monolayer, multilayer to bulk material
Two-dimensional (2D) transition metal dichalcogenide (TMD) nanosheets exhibit
remarkable electronic and optical properties. The 2D features, sizable
bandgaps, and recent advances in the synthesis, characterization, and device
fabrication of the representative MoS, WS, WSe, and MoSe TMDs
make TMDs very attractive in nanoelectronics and optoelectronics. Similar to
graphite and graphene, the atoms within each layer in 2D TMDs are joined
together by covalent bonds, while van der Waals interactions keep the layers
together. This makes the physical and chemical properties of 2D TMDs layer
dependent. In this review, we discuss the basic lattice vibrations of
monolayer, multilayer, and bulk TMDs, including high-frequency optical phonons,
interlayer shear and layer breathing phonons, the Raman selection rule,
layer-number evolution of phonons, multiple phonon replica, and phonons at the
edge of the Brillouin zone. The extensive capabilities of Raman spectroscopy in
investigating the properties of TMDs are discussed, such as interlayer
coupling, spin--orbit splitting, and external perturbations. The interlayer
vibrational modes are used in rapid and substrate-free characterization of the
layer number of multilayer TMDs and in probing interface coupling in TMD
heterostructures. The success of Raman spectroscopy in investigating TMD
nanosheets paves the way for experiments on other 2D crystals and related van
der Waals heterostructures.Comment: 30 pages, 23 figure
Analysis of the children's dynamic and static stereopsis of intermittent exotropia
AIM: To compare and analyze the stereopsis of intermittent exotropia children under the different backgrounds of dynamic stimuli and static stimuli.<p>METHODS: We collected 56 children(male 26, female 30 with intermittent exotropia at the age from 5y to 12y and examined their stereopsis under the different backgrounds of dynamic stimuli and static stimuli using a multidimensional sense perception training software. The differences between the dynamic stereopsis and static stereopsis were compared.<p>RESULTS: Totally 17 cases(30%)had both dynamicstereopsis and static stereopsis, 39 cases(70%)had either dynamic or static stereopsis deficit, only 10 cases(26%)had dynamic stereopsis, 25 cases(64%)static stereopsis left and 4 cases(10%)were without any form of stereopsis. The positive rate of dynamic stereopsis was better than the positive rate of static stereopsis, with statistical significance(<i>P</i><0.05).<p>CONCLUSION: Dynamicstereopsis is better than the static stereopsis to intermittent exotropia children
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