32,886 research outputs found
Public-Private Partnerships in the Electric Vehicle Charging Infrastructure in China: An Illustrative Case Study
© 2018 Kun Wang and Yongjian Ke. Effective supply of charging infrastructure is a necessary support for the development of electric vehicle and also an important strategic measure to promote energy consumption revolution and green development. The construction and operation of charging infrastructure in China is unfortunately not smooth, lagging behind the actual demand. Public-Private Partnerships (PPPs) may offer a promising way forward and accelerate the development of charging infrastructure by tapping the private sectors' financial resources and professional skills. However, PPP has not been commonly adopted in this sector yet. This paper hence studied an illustrative case of Anqing Project in China to demonstrate how governments structure a PPP deal in the electric vehicle charging infrastructures. A content analysis was conducted on the important project documents to investigate key elements including the planning, construction, risk sharing, profit distribution, and supervision during the execution stage. Based on the illustration, some key lessons and recommendations were provided to offer a reference for future charging infrastructure PPP projects in China
Immunization for complex network based on the effective degree of vertex
The basic idea of many effective immunization strategies is first to rank the
importance of vertices according to the degrees of vertices and then remove the
vertices from highest importance to lowest until the network becomes
disconnected. Here we define the effective degrees of vertex, i.e., the number
of its connections linking to un-immunized nodes in current network during the
immunization procedure, to rank the importance of vertex, and modify these
strategies by using the effective degrees of vertices. Simulations on both the
scale-free network models with various degree correlations and two real
networks have revealed that the immunization strategies based on the effective
degrees are often more effective than those based on the degrees in the initial
network.Comment: 16 pages, 5 figure
The Euler-Lagrange Cohomology and General Volume-Preserving Systems
We briefly introduce the conception on Euler-Lagrange cohomology groups on a
symplectic manifold and systematically present the
general form of volume-preserving equations on the manifold from the
cohomological point of view. It is shown that for every volume-preserving flow
generated by these equations there is an important 2-form that plays the analog
role with the Hamiltonian in the Hamilton mechanics. In addition, the ordinary
canonical equations with Hamiltonian are included as a special case with
the 2-form . It is studied the other volume preserving
systems on . It is also explored the relations between
our approach and Feng-Shang's volume-preserving systems as well as the Nambu
mechanics.Comment: Plain LaTeX, use packages amssymb and amscd, 15 pages, no figure
On Silicon Carbide Grains as the Carrier of the 21 Micron Emission Feature in Post-Asymptotic Giant Branch Stars
The mysterious 21mu emission feature seen in 12 proto-planetary nebulae
(PPNe) remains unidentified since its first detection in 1989. Over a dozen of
candidate materials have been proposed within the past decade, but none of them
has received general acceptance. Very recently, silicon carbide (SiC) grains
with impurities were suggested to be the carrier of this enigmatic feature,
based on recent laboratory data that doped SiC grains exhibit a resonance at
\~21mu. This proposal gains strength from the fact that SiC is a common dust
species in carbon-rich circumstellar envelopes. However, SiC dust has a strong
vibrational band at ~11.3mu. We show in this Letter that in order to be
consistent with the observed flux ratios of the 11.3mu feature to the 21mu
feature, the band strength of the 21mu resonance has to be very strong, too
strong to be consistent with current laboratory measurements. But this does not
yet readily rule out the SiC hypothesis since recent experimental results have
demonstrated that the 21mu resonance of doped SiC becomes stronger as the C
impurity increases. Further laboratory measurements of SiC dust with high
fractions of C impurity are urgently needed to test the hypothesis of SiC as
the carrier of the 21mu feature.Comment: 14 pages, 3 figures, accepted for publication in ApJ
Search for via the transition at LHCb and factory
It is interesting to study the characteristics of the whole family of
which contains two different heavy flavors. LHC and the proposed factory
provide an opportunity because a large database on the family will be
achieved. and its excited states can be identified via their decay modes.
As suggested by experimentalists, is not easy to be
clearly measured, instead, the trajectories of and occurring in
the decay of () can be unambiguously
identified, thus the measurement seems easier and more reliable, therefore this
mode is more favorable at early running stage of LHCb and the proposed
factory. In this work, we calculate the rate of
in terms of the QCD multipole-expansion and the numerical results indicate that
the experimental measurements with the luminosity of LHC and factory are
feasible.Comment: 12 pages, 1 figures and 4 tables, acceptted by SCIENCE CHINA Physics,
Mechanics & Astronomy (Science in China Series G
Organoaluminium complexes of ortho-, meta-, para-anisidines: synthesis, structural studies and ROP of ε-caprolactone (and rac-lactide)
Reaction of Me₃Al (two equivalents) with ortho-, meta- or para-anisidine, (OMe)(NH₂)C₆H₄, affords the complexes {[1,2-(OMe),NC₆H₄(μ-Me₂Al)](μ-Me₂Al)}₂ (1), [1,3-(Me₃AlOMe),NHC₆H₄(μ-Me₂Al)]2 (2) or [1,4-(Me₃AlOMe),NHC₆H₄(μ-Me₂Al)]₂ (3), respectively. The molecular structures of 1–3 have been determined and all three complexes were found to be highly active for the ring opening polymerization (ROP) of ε-caprolactone. 1 was found highly active either with or without benzyl alcohol present; at various temperatures, the activity order 1 > 2 ≈ 3 was observed. For the ROP of rac-lactide results for 1–3 were poor
Evidence for surprise minimization over value maximization in choice behavior
Classical economic models are predicated on the idea that the ultimate aim of choice is to maximize utility or reward. In contrast, an alternative perspective highlights the fact that adaptive behavior requires agents' to model their environment and minimize surprise about the states they frequent. We propose that choice behavior can be more accurately accounted for by surprise minimization compared to reward or utility maximization alone. Minimizing surprise makes a prediction at variance with expected utility models; namely, that in addition to attaining valuable states, agents attempt to maximize the entropy over outcomes and thus 'keep their options open'. We tested this prediction using a simple binary choice paradigm and show that human decision-making is better explained by surprise minimization compared to utility maximization. Furthermore, we replicated this entropy-seeking behavior in a control task with no explicit utilities. These findings highlight a limitation of purely economic motivations in explaining choice behavior and instead emphasize the importance of belief-based motivations
Устроєві засади громадського судочинства й народна правосвідомість на українських землях у складі Великого Князівства Литовського
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