3,958 research outputs found
Closed-loop supply chain coordination based on recyclers\u27 competition model
In a closed-loop supply chain led by manufacturing enterprises, there are often two or more recyclers that are very competitive among each other. The manufacturer may also provide many recycling contracts in order to identify recyclers’ private information. This paper examines a closed-loop supply chain consisting of a manufacturer at the core of the supply chain and two competing recyclers. In order to strike a balance between its own interest and overall interest manufacturer provides two different recycling contracts: price contract and quantity contract. Two
situations have been analyzed in this paper: the first in which only advantage recycler adopts quantity contract and the second in which both recyclers adopt quantity contract. A numerical simulation has been carried out according to some current data of an enterprise. In case in which the advantage recycler adopts quantity contract and the inferior recycler adopts price contract, the closed-loop supply chain has reached its equilibrium and the interests of all parties have been balanced
Study on the essential management system of the coal mines
AbstractSerious accidents occur continuously in China's coal mines in recent years, which have brought about huge economic losses and negative society impact. The signs have emerged before the happening of the coal accidents. The accidents occur mainly because of the management negligence. The essential safety management system is built for coal safety management in China in allusion to the safety management problem of coal mines. The system is composed of six sections, risk management, establishing the management standard and management measure, managing and controlling the human unsafe behaviors, safeguard management, evaluation system and information system
Development of docetaxel and alendronate-loaded chitosan-conjugated polylactide-co-glycolide nanoparticles: In vitro characterization in osteosarcoma cells
Purpose: To develop docetaxel (DTX)- and alendronate (ALN)-loaded, chitosan (CS)-conjugated polylactide- co-glycolide (PLGA) nanoparticles (NPs) to increase therapeutic efficacy in osteosarcoma cells.Methods: Drug-loaded PLGA NPs were prepared by nanoprecipitation and chemically conjugated by the carboxylic group of PLGA to the amine-bearing CS polymer. The nanocarrier was characterized by dynamic light scattering, transmission electron microscopy, scanning electron microscopy, and differential scanning calorimetry as well as by in vitro drug release and cell culture studies.Results: NP size was within the tumour targeting range (~200 nm) with an effective positive charge (20 mV), thus increasing cellular uptake efficiency. Morphological analysis revealed clear spherical particles with uniform dispersion. The NPs exhibited identical sustained release kinetics for both DTX and ALN. CS-conjugated PLGA with dual-drug-loaded (DTX and AL) NPs showed typical time-dependent cellular uptake and also displayed superior cytotoxicity in MG-63 cells compared with blank NPs, which were safe and biocompatible.Conclusion: Combined loading of DTX and ALN in NPs increased the therapeutic efficacy of the formulation for osteosarcoma treatment, thus indicating the potential benefit of a combinatorial drug regimen using nanocarriers for effective treatment of osteosarcoma.Keywords: Chitosan, Docetaxel, Alendronate, Nanocarriers, Sustained-release kinetics, Polylactide-coglycolide, Osteosarcoma, Cellular uptak
Hadronic Rapidity Spectra in Heavy Ion Collisions at SPS and AGS energies in a Quark Combination Model
The quark combination mechanism of hadron production is applied to
nucleus-nucleus collisions at the CERN Super Proton Synchrotron (SPS) and BNL
Alternating Gradient Synchrotron (AGS). The rapidity spectra of identified
hadrons and their spectrum widths are studied. The data of ,
, , , , , and
at 80 and 40 AGeV, in particular at 30 and 20 AGeV where the onset of
deconfinement is suggested to happen, are consistently described by the quark
combination model. However at AGS 11.6 AGeV below the onset the spectra of
, and can not be simultaneously explained,
indicating the disappearance of intrinsic correlation of their production in
the constituent quark level. The collision-energy dependence of the rapidity
spectrum widths of constituent quarks and the strangeness of the hot and dense
quark matter produced in heavy ion collisions are obtained and discussed.Comment: 7 pages, 5 figure
The two-loop supersymmetric corrections to lepton anomalous magnetic and electric dipole moments
Using the effective Lagrangian method, we analyze the electroweak corrections
to the anomalous dipole moments of lepton from some special two-loop
topological diagrams which are composed of neutralino (chargino) - slepton
(sneutrino) in the minimal supersymmetric extension of the standard model
(MSSM). Considering the translational invariance of the inner loop momenta and
the electromagnetic gauge invariance, we get all dimension 6 operators and
derive their coefficients. After applying equations of motion to the external
leptons, the anomalous dipole moments of lepton are obtained. The numerical
results imply that there is a parameter space where the two-loop supersymmetric
corrections to the muon anomalous dipole moments may be significant.Comment: Revtex, 45 pages, including 8 fig
Quantum electric-dipole liquid on a triangular lattice
Geometric frustrations and quantum mechanical fluctuations may prohibit the
formation of long-range ordering even at the lowest temperature, and therefore
liquid-like ground states could be expected. A good example is the quantum spin
liquid in frustrated magnets that represents an exotic phase of matter and is
attracting enormous interests. Geometric frustrations and quantum fluctuations
can happen beyond magnetic systems. Here we propose that quantum
electric-dipole liquids, analogs to quantum spin liquids, could emerge in
frustrated dielectrics where antiferroelectrically coupled small electric
dipoles reside on a triangular lattice. The quantum paraelectric hexaferrite
BaFe12O19, in which small electric dipoles originated from the off-center
displacement of Fe3+ in the FeO5 bipyramids constitute a two-dimensional
triangular lattice, represents a promising candidate to generate the
anticipated electric-dipole liquid. We present a series of experimental
evidences, including dielectric permittivity, heat capacity, and thermal
conductivity measured down to 66 mK, to reveal the existence of a nontrivial
ground state in BaFe12O19, characterized by itinerant low-energy excitations
with a small gap, to which we interpret as an exotic liquid-like quantum phase.
The quantum electric-dipole liquids in frustrated dielectrics open up a fresh
playground for fundamental physics and may find applications in quantum
information and computation as well.Comment: 13 pages, 6 figure
A Scalable Test Problem Generator for Sequential Transfer Optimization
Sequential transfer optimization (STO), which aims to improve optimization
performance by exploiting knowledge captured from previously-solved
optimization tasks stored in a database, has been gaining increasing research
attention in recent years. However, despite significant advancements in
algorithm design, the test problems in STO are not well designed. Oftentimes,
they are either randomly assembled by other benchmark functions that have
identical optima or are generated from practical problems that exhibit limited
variations. The relationships between the optimal solutions of source and
target tasks in these problems are manually configured and thus monotonous,
limiting their ability to represent the diverse relationships of real-world
problems. Consequently, the promising results achieved by many algorithms on
these problems are highly biased and difficult to be generalized to other
problems. In light of this, we first introduce a few rudimentary concepts for
characterizing STO problems (STOPs) and present an important problem feature
overlooked in previous studies, namely similarity distribution, which
quantitatively delineates the relationship between the optima of source and
target tasks. Then, we propose general design guidelines and a problem
generator with superior extendibility. Specifically, the similarity
distribution of a problem can be systematically customized by modifying a
parameterized density function, enabling a broad spectrum of representation for
the diverse similarity relationships of real-world problems. Lastly, a
benchmark suite with 12 individual STOPs is developed using the proposed
generator, which can serve as an arena for comparing different STO algorithms.
The source code of the benchmark suite is available at
https://github.com/XmingHsueh/STOP
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