352 research outputs found
Optimization of the Beijing Economy-Energy-Emissions System 2021â2035:A Scenario Simulation Analysis Based on a System Dynamics Model
Analysis and Introduction of Effective Permeability with Additional Air-Gaps on Wireless Power Transfer Coils for Electric Vehicle based on SAE J2954 Recommended Practice
The wireless power transfer (WPT) method for electric vehicles (EVs) is becoming more popular, and to ensure the interoperability of WPT systems, the Society of Automotive Engineers (SAE) established the J2954 recommended practice (RP). It includes powering frequency, electrical parameters, specifications, testing procedures, and other contents for EV WPT. Specifically, it describes the ranges of self-inductances of the transmitting coil, the receiving coil, and coupling coefficient (k), as well as the impedance matching values of the WPT system. Following the electrical parameters listed in SAE J2954 RP is crucial to ensure the EV wireless charging system is interoperable. This paper introduces a method for adjusting the effective permeability of the ferrite blocks in the standard model, to tune the self-inductance of the coils as well as the coupling coefficient. To guarantee the given values of the self-inductance of the coil and coupling coefficient matched those in the standard, we slightly modified the air-gap between the ferrite tiles in a specific region. Based on this method, it was possible to successfully tune the self-inductance of the transmitting coil and receiving coil as well as the coupling coefficient. The proposed method was verified by simulation and experimental measurements
Preparation and characterization of \u3ba-carrageenase immobilized onto magnetic iron oxide nanoparticles
Background: Carboxyl-functionalized magnetic nanoparticles were
synthesized via chemical co-precipitation method and modified with
oleic acid which was oxidized by potassium permanganate, and
\u3ba-carrageenase from Pseudoalteromonas sp. ASY5 was subsequently
immobilized onto them. The immobilization conditions were further
optimized, and the characterizations of the immobilized
\u3ba-carrageenase were investigated. Results: The
\u3ba-carrageenase was immobilized onto magnetic iron oxide
nanoparticles, and the bonding was verified by Fourier transform
infrared spectroscopy. The optimal conditions for \u3ba-carrageenase
immobilization were 2.5% (w/v) glutaraldehyde, 13.9 U
\u3ba-carrageenase for 20 mg of magnetic nanoparticles, a 2-h
cross-linking time, and a 2-h immobilization time at 25\ub0C. Under
these conditions, the activity of the immobilized enzyme and the enzyme
recovery rate were 326.0 U \ub7 g-1 carriers and 46.9%, respectively.
The properties of the immobilized \u3ba-carrageenase were compared
with those of the free enzyme. The optimum temperatures of the free and
immobilized \u3ba-carrageenase were 60 and 55\ub0C, respectively,
and the optimum pH of \u3ba-carrageenase did not change before and
after immobilization (pH 7.5). After immobilization,
\u3ba-carrageenase exhibited lower thermal stability and improved pH
stability, as well as better storage stability. The immobilized
\u3ba-carrageenase maintained 43.5% of the original activity after
being used 4 times. The kinetic constant value (Km) of
\u3ba-carrageenase indicates that the immobilized enzyme had a lower
binding affinity for the substrate. Conclusions: Under optimal
conditions, the activity of the immobilized enzyme and enzyme recovery
rate were 326.0 U \ub7 g-1\ub7\u3ba-carrageenase-CMNPs and 46.9%,
respectively. The thermal, pH, and storage stabilities of
\u3ba-carrageenase-CMNPs were relatively higher than those of free
\u3ba-carrageenase
Efficient immobilization of agarase using carboxyl-functionalized magnetic nanoparticles as support
Background: A simple and efficient strategy for agarase immobilization
was developed with carboxyl-functionalized magnetic nanoparticles
(CMNPs) as support. The CMNPs and immobilized agarase (agarase-CMNPs)
were characterized by transmission electron microscopy, dynamic light
scattering, vibrating sample magnetometry, scanning electron
microscopy, X-ray diffraction, thermogravimetric analysis, and
zeta-potential analysis. The hydrolyzed products were separated and
detected by ESI-TOF-MS. Results: The agarase-CMNPs exhibited a regular
spherical shape with a mean diameter of 12 nm, whereas their average
size in the aqueous solution was 43.7 nm as measured by dynamic light
scattering. These results indicated that agarase-CMNPs had water
swelling properties. Saturation magnetizations were 44 and 29 emu/g for
the carriers and agarase-CMNPs, respectively. Thus, the particles had
superparamagnetic characteristics, and agarase was successfully
immobilized onto the supports. Agaro-oligosaccharides were prepared
with agar as substrate using agarase-CMNPs as biocatalyst. The
catalytic activity of agarase-CMNPs was unchanged after six reuses. The
ESI-TOF mass spectrogram showed that the major products hydrolyzed by
agarase-CMNPs after six recycle uses were neoagarotetraose,
neoagarohexaose, and neoagarooctaose. Meanwhile, the end-products after
90 min of enzymatic treatment by agarase-CMNPs were neoagarobiose and
neoagarotetraose. Conclusions: The enhanced agarase properties upon
immobilization suggested that CMNPs can be effective carriers for
agarase immobilization. Agarase-CMNPs can be remarkably used in
developing systems for repeated batch production of agar-derived
oligosaccharides
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
A Global Value Chain Analysis of Chinas Virtual Water Footprint Through Agricultural Trade
The use of the global value chain (GVC) method has been gaining traction in recent research on resource use for production and trade. China has become one of the largest centers for forward- and backward-linkages for trade in inputs for agricultural and food products. Traditional methods of virtual water (VW) trade show the overestimation of Chinaâs use of foreign VW. Here, we use global value chain analysis based on the GTAP database to get the embodied trade of VW for China in the major agricultural sectors and agro-based industries. We find that China is a net importer of blue VW through its trade in primary and net exporter of blue VW through the processed agricultural commodities. It is a net importer of green VW through primary and processed agricultural commodities. The GVC method reveals that China is partially responsible for the imports of blue water, while the rest of the imports are caused by other countries through their imports of blue VW from China. We conclude that the sustainability of global water resources can be achieved through better estimates on VW trade and sharing the responsibility by the end-users
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