Since the LHCb collaboration announced the observation of the doubly charmed baryon
Ξ
cc
+
+
, a series of studies of doubly heavy baryons have been presented. In this work, I analyse the ...non-leptonic weak decays of doubly heavy baryons
Ξ
bc
and
Ω
bc
under the flavor
SU
(3) symmetry. I mainly focus on the
W
-exchange diagrams, which will contribute to the decay channels with final states are light meson and light baryon. These channels would be helpful for searching for
Ξ
bc
and
Ω
bc
at LHC. And these channels and relations of corresponding decay widths could be examined by the future experimental facilities such as LHC, Belle II and CEPC.
We perform an analysis of angular distributions in semileptonic decays of charmed baryons
B
1
(
′
)
→
B
2
(
′
)
(
→
B
3
(
′
)
B
4
(
′
)
)
ℓ
+
ν
ℓ
, where the
B
1
=
(
Λ
c
+
,
Ξ
c
(
0
,
+
)
)
are the ...SU(3)-antitriplet baryons and
B
1
′
=
Ω
c
-
is an SU(3) sextet. We will firstly derive analytic expressions for angular distributions using the helicity amplitude technique. Based on the lattice quantum chromodynamics (QCD) results for
Λ
c
+
→
Λ
and
Ξ
c
0
→
Ξ
-
form factors and model calculation of the
Ω
c
0
→
Ω
-
transition, we predict the branching fractions:
B
(
Λ
c
+
→
Λ
(
→
p
π
-
)
e
+
ν
e
)
=
2.48
(
15
)
%
,
B
(
Λ
c
+
→
Λ
(
→
p
π
-
)
μ
+
ν
μ
)
=
2.50
(
14
)
%
,
B
(
Ξ
c
0
→
Ξ
-
(
→
Λ
π
-
)
e
+
ν
e
)
=
2.40
(
30
)
%
,
B
(
Ξ
c
0
→
Ξ
-
(
→
Λ
π
-
)
μ
+
ν
ν
)
=
2.41
(
30
)
%
,
B
(
Ω
c
0
→
Ω
-
(
→
Λ
K
-
)
e
+
ν
e
)
=
0.362
(
14
)
%
,
B
(
Ω
c
0
→
Ω
-
(
→
Λ
K
-
)
μ
+
ν
ν
)
=
0.350
(
14
)
%
. We also predict the
q
2
dependence and angular distributions of these processes, in particular the coefficients for the
cos
n
θ
ℓ
(
cos
n
θ
h
,
cos
n
ϕ
)
(
n
=
0
,
1
,
2
,
…
)
terms. This work can provide a theoretical basis for the ongoing experiments at BESIII, LHCb, and BELLE-II.
To explore population aging and the epidemic trend of pulmonary tuberculosis (PTB) in the elderly, and provide a basis for the prevention and control of pulmonary tuberculosis among the elderly.
We ...collected clinical information of 239,707 newly active PTB patients in Shandong Province from 2005 to 2017. We analyzed and compared the clinical characteristics, reported incidence and temporal trend of PTB among the elderly group (≥60 years) and the non-elderly group (< 60 years) through logistic model and Join-point regression model.
Among the total PTB cases, 77,192(32.2%) were elderly. Compared with non-elderly patients, newly active elderly PTB patients account for a greater proportion of male cases (OR 1.688, 95% CI 1.656-1.722), rural population cases (OR 3.411, 95% CI 3.320-3.505) and bacteriologically confirmed PTB cases (OR 1.213, 95%CI 1.193-1.234). The annual reported incidence of total, elderly, pulmonary bacteriologically confirmed cases were 35.21, 68.84, 35.63 (per 100,000), respectively. The annual reported incidence of PTB in the whole population, the elderly group and the non-elderly group has shown a slow downward trend since 2008. The joinpoint regression model showed that the overall reported incidence of PTB in the elderly significantly decreased from 2007 to 2017 (APC = -5.3, P < 0.05). The reported incidence of bacteriologically confirmed PTB among elderly patients declined rapidly from 2005 to 2014(2005-2010 APC = -7.2%, P < 0.05; 2010-2014 APC = -22.6%, P < 0.05; 2014-2017 APC = -9.0%, P = 0.1). The reported incidence of clinically diagnosed PTB among elderly patients from 2005 to 2017 (11.48-38.42/100,000) increased by about 235%. It rose significantly from 2007 to 2014 (APC = 9.4, P<0.05).
Compared with the non-elderly population, the reported incidence of PTB in the elderly population is higher. The main burden of PTB will shift to the elderly, men, rural population, and clinically diagnosed patients. With the intensification of aging, more researches on elderly PTB prevention and treatment will facilitate the realization of the global tuberculosis (TB) control targets.
To realize the research on the establishment method of the coupled-resonator acoustic waveguides (CRAWs) and the adjustable method of the transmission frequency, a new model of the acoustic waveguide ...of the resonance body is proposed, and the continuous adjustment of the transmission frequency is realized. Defects are created by rotating the scatterer and changing Young's modulus of the shape-memory alloy (SMA), and the coupling between the defect resonance bodies forms a waveguide path. We calculated the dispersion relationship and transmission characteristics of the model studied the physical mechanism behind the method of establishing the coupled resonance body and the formation principle of guided modes, and analyzed the control range of the transmission frequency. The results show that the relationship of the coupling effect is strongly related to the distance between the defect resonance bodies. Compared with the linear defect waveguide, CRAWs have the advantages of low energy transmission loss and no interference of guided modes. The research on the method of establishing the waveguide of the coupled resonance body is realized, and the improvement of energy transmission, the improvement of the guided mode, and the flexible and arbitrary construction of the waveguide path can be realized.
Large-scale sports events have become a good opportunity for major enterprises to promote due to their high social attention; however, they also force enterprises to confront the risks of uncertainty ...and extreme loss. During the 2018 Russia World Cup, Vatti Co., Ltd.'s promotion activity "If France Wins, Get a Full Refund" suffered double losses economically and reputationally due to France's victory and the company's failure to fulfill its promise. This paper uses option hedging theory, and the risk management tools to construct a risk management model. Case analysis and program improvement were carried out. The research results show that using the winning odds can effectively control the risks. Companies should determine their promotion plan based on sale returns and the maximum implicit income generated by promotional activities. The research paper opens a new field using derivative financial instruments to control corporate promotion risks.
Microbial remediation of heavy metal polluted environment is ecofriendly and cost effective. Therefore, in the present study, Shewanella putrefaciens stain 4H was previously isolated by our group ...from the activated sludge of secondary sedimentation tank in a dyeing wastewater treatment plant. The bacterium was able to reduce chromate effectively. The strains showed significant ability to reduce Cr(VI) in the pH range of 8.0 to 10.0 (optimum pH 9.0) and 25-42 ℃ (optimum 30 ℃) and were able to reduce 300 mg/L of Cr(VI) in 72 h under parthenogenetic anaerobic conditions. In this paper, the complete genome sequence was obtained by Nanopore sequencing technology and analyzed chromium metabolism-related genes by comparative genomics The genomic sequence of S. putrefaciens 4H has a length of 4,631,110 bp with a G + C content of 44.66% and contains 4015 protein-coding genes and 3223, 2414, 2343 genes were correspondingly annotated into the COG, KEGG, and GO databases. The qRT-PCR analysis showed that the expression of chrA, mtrC, and undA genes was up-regulated under Cr(VI) stress. This study explores the Chromium Metabolism-Related Genes of S. putrefaciens 4H and will help to deepen our understanding of the mechanisms of Cr(VI) tolerance and reduction in this strain, thus contributing to the better application of S. putrefaciens 4H in the field of remediation of chromium-contaminated environments.
Aqueous all‐iron redox flow batteries (RFBs) are promising competitors for next‐generation grid‐scale energy storage applications. However, the high‐performance operation of all‐iron RFBs in a wider ...temperature range is greatly hindered by inferior iron plating/stripping reaction and low solid–liquid transition temperature at Fe anode. Herein, a universal electrolyte additive design strategy for all‐iron RFBs is reported, which realizes a highly reversible and dendrite‐free Fe anode at low temperatures. Quantum chemistry calculations first screen several organic molecules with oxygen‐containing functional groups and identify N,N‐Dimethylacetmide (DMAc) as a potential candidate with low cost, high solubility, and strong interactions with Fe2+ and H2O. Combined experimental characterizations and theoretical calculations subsequently demonstrate that adding DMAc into the FeCl2 solution effectively reshapes the primary solvation shell of Fe2+ via the Fe2+‐O (DMAc) bond and breaks hydrogen‐bonding network of water through intensified H‐bond interaction between DMAc and H2O, thereby affording the Fe anode with enhanced Fe/Fe2+ reversibility and lower freezing point. Consequently, the assembled all‐iron RFB achieves an excellent combination of high power density (25 mW cm−2), long charge‐discharge cycling stability (95.59% capacity retention in 103 h), and preeminent battery efficiency at −20 °C (95% coulombic efficiency), which promise a future for wider temperature range operation of all‐iron RFBs.
A universal additive design strategy is proposed for all‐iron flow batteries at low‐temperature operation. By reshaping the solvation structure and breaking hydrogen‐bonding network of water, N,N‐Dimethylacetmide (DMAc) proves to realize both enhanced Fe/Fe2+ reversibility and lower freezing point, which enables the all‐iron flow cell an excellent combination of high power density, long cycling stability and preeminent battery efficiency at −20 °C.
We investigate the leading twist light-cone distribution amplitudes (LCDAs) of vector meson in the framework of large momentum effective theory. We derive the matching equation for the LCDAs and ...quasidistribution amplitudes. The matching coefficients are determined to one loop accuracy, both in the ultraviolet cutoff and dimensional regularization schemes. This calculation provides the possibility of studying the full x behavior of LCDAs and extracting LCDAs of vector mesons from lattice simulations.
Radar-absorbing materials are used in stealth technologies for concealment of an object from radar detection. Resistive and/or magnetic composite materials are used to reduce the backscattered ...microwave signals. However, nontunable characteristics or the required complex structure hampered the application of these materials. Here, multilayer graphene-based frequency selective surfaces (MLGFSS), which reach a size of 150 mm <inline-formula> <tex-math notation="LaTeX">\times </tex-math></inline-formula> 150 mm, are designed and fabricated. By properly changing the growth temperature of MLG using the chemical vapor deposition approach and designing the pattern of graphene layer, the impedance matching condition can be satisfied at different frequencies. As a result, two kinds of absorbers with different working bandwidths are realized. The performances of the proposed absorbers are analyzed using full-wave simulation and are also tested with experimental results. Our method of fabricating large-area MLGFSS avoids the direct contact between the stencil mask and graphene, and guarantees the integrity and quality of patterned graphene structure. A good agreement between simulation and measurement results demonstrates that such ultrathin MLGFSS is very useful in the design of graphene-based functional devices at microwave frequencies.
In this article, to reduce the operating frequency and the size of the spoof surface plasmon polariton (SSPP) attenuator and introduce the filtering function into the graphene attenuator, we propose ...a tunable graphene filtering attenuator, namely the graphene-based effective SSPP (ESSPP) attenuator. It consists of an ESSPP waveguide and a graphene sandwich structure (GSS). The effect of GSS on the attenuation and dimensions of the ESSPP waveguide on the passband are analyzed in detail, and the closed form of the attenuation is proposed. Finally, five prototypes of the graphene filtering attenuator are fabricated and measured. The experimental results show that not only the attenuation of this attenuator can be tuned but also that the upper and lower cutoff frequencies can be adjusted independently, which means that this filtering attenuator demonstrates expected filtering and attenuation performance.
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