In this paper, silver-loaded TiO
2 photocatalyst was prepared by photochemical impregnation method and characterized by transmission electron microscopy (TEM), diffuse reflectance spectra (DRS), ...photooxidation of phenol and photoreduction of Cr(VI). Electron paramagnetic resonance (EPR) was used to detect photoproduced paramagnetic radicals. The correlation of photocatalytic activity and photogenerated reactive species was discussed, and the mechanism of silver-loaded TiO
2 for enhancement of photocatalytic activity was elucidated. The results show that deposited silver on TiO
2 surface acts as a site where electrons accumulate. The better separation between electrons and holes on the modified TiO
2 surface allowed more efficiency for the oxidation and reduction reactions. The enhanced photocatalytic activity was mainly attributed to the increased amounts of O
2
−
reactive species and surface Ti
3+ reactive center on silver-loaded TiO
2 photocatalyst.
A
bstract
Using 2.93 fb
−
1
of
e
+
e
−
collision data collected with the BESIII detector at the center-of-mass energy 3.773 GeV, we perform the first amplitude analysis of the decay
D
+
→
K
S
0
π
+
π
...0
π
0
and determine the relative magnitudes and phases of different intermediate processes. The absolute branching fraction of
D
+
→
K
S
0
π
+
π
0
π
0
is measured to be (2.888
±
0.058
stat
.
±
0.069
syst
.
)%. The dominant intermediate processes are
D
+
→
K
S
0
a
1
(1260)
+
(
→ ρ
+
π
0
) and
D
+
→
K
¯
*0
ρ
+
, with branching fractions of (8.66
±
1.04
stat
.
±
1.39
syst
.
)
×
10
−
3
and (9.70
±
0.81
stat
.
±
0.53
syst
.
)
×
10
−
3
, respectively.
A
bstract
Based on
e
+
e
−
collision samples corresponding to an integrated luminosity of 4.4 fb
−
1
collected with the BESIII detector at center-of-mass energies between 4
.
6 GeV and 4
.
7 GeV, a ...partial wave analysis of the charmed baryon hadronic decay
Λ
c
+
→
Λ
π
+
π
0
is performed, and the decays
Λ
c
+
→
Λ
ρ
(770)
+
and
Λ
c
+
→
Σ(1385)
π
are studied for the first time. Making use of the world-average branching fraction
B
Λ
c
+
→
Λ
π
+
π
0
, their branching fractions are determined to be
B
Λ
c
+
→
Λ
ρ
770
+
=
4.06
±
0.30
±
0.35
±
0.23
×
10
−
2
,
B
Λ
c
+
→
Σ
1385
+
π
0
=
5.86
±
0.49
±
0.52
±
0.35
×
10
−
3
,
B
Λ
c
+
→
Σ
1385
0
π
+
=
6.47
±
0.59
±
0.66
±
0.38
×
10
−
3
,
where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions
B
Λ
c
+
→
Λ
π
+
π
0
and
B
Σ
1385
→
Λ
π
. In addition, the decay asymmetry parameters are measured to be
α
Λ
ρ
(770)+
= − 0.763 ± 0.053 ± 0.045,
α
Σ
1385
+
π
0
=
−
0.917
±
0.069
±
0.056
, and
α
Σ
1385
0
π
+
=
−
0.789
±
0.098
±
0.056
.
A
bstract
Using data samples with an integrated luminosity of 6
.
4 fb
−
1
collected by the BESIII detector operating at the BEPCII storage ring, the process of
e
+
e
−
→
γϕJ/ψ
is studied. The ...processes of
e
+
e
−
→
ϕχ
c
1
,
c
2
,
χ
c
1
,
c
2
→
γJ/ψ
are observed with a significance of more than 10
σ
. The
s
-dependent cross section of
e
+
e
−
→
ϕχ
c
1
,
c
2
is measured between 4.600 and 4.951 GeV, and evidence of a resonance structure is found for the first time in the
ϕχ
c
2
process. We also search for the processes of
e
+
e
−
→
γX
(4140),
γX
(4274) and
γX
(4500) via the
γϕJ/ψ
final state, but no obvious structures are found. The upper limits on the production cross section times the branching fraction for these processes at the 90% confidence level are reported.
To evaluate the possible role of the autonomic (sympathetic) nervous system function among the patients with primary premature ejaculation (PPE) and determine whether there is an etiological basis ...for this condition. We performed sympathetic skin response located in the penis (PSSR) in 52 patients with PPE and 46 normally potent men. The latencies and amplitudes of PSSR were measured. The PSSR waveforms were classified into P type and N type according to the waveform characteristics. The waveform distribution in the PPE patients was not statistically different from that in the control group (P=0.609). Mean latency of the PSSR was significantly shorter in the patients than that in the normally potent men (P<0.001). Mean amplitude of the PSSR was significantly greater in patients than that in the normal men (P<0.001). Patients with PPE have hyperactivity of the sympathetic nervous system, which may be another factor involved in the pathological mechanisms of PPE, and the PSSR is an objective test to evaluate patients with PPE.
We describe here the aging characteristics and strengthening behavior of a low-carbon medium-Mn Cu precipitation-strengthened steel. Atom probe tomography (APT) was employed to characterize the ...evolution of Cu-rich precipitates in terms of mean radius, number density and volume fraction. Aging at 500 °C and 550 °C for 1 h resulted in substantial coherent body-centered cubic (bcc) Cu-rich precipitates with mean radius of 1.35 and 2.59 nm, respectively. The precipitation strengthening mechanism for these two aging conditions was shearing mechanism and the corresponding strengthening contribution was ~ 266 and ~ 312 MPa, respectively. Here, coherency strengthening and modulus strengthening played a major role, while the contribution of chemical strengthening was relatively small. With increased aging temperature to 600 °C, the precipitates grew and coarsened to elongated shape with incoherent face-centered cubic (fcc) structure, and the strengthening mechanism was Orowan mechanism with a contribution of ~ 232 MPa. Increasing the aging temperature also facilitated the formation of retained austenite, which was of great benefit to plasticity without pronounced deterioration on precipitation strengthening. Ultra-high yield strength of 1020 MPa with superior total elongation of 25.8% was obtained in the sample aged at 600 °C for 1 h. The excellent mechanical properties derived from the combination of precipitation strengthening by Cu-rich precipitates and plasticity effect of retained austenite can be considered as a design principle to simultaneously optimize strength and ductility.
Observation of e+e−→ π0π0ψ2(3823) Bai, X. H.; Balossino, I.; Bettoni, D. ...
The journal of high energy physics,
16/2, Letnik:
2023, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A
bstract
Using a data sample corresponding to an integrated luminosity of 11.3 fb
−
1
collected at center-of-mass energies from 4.23 to 4.70 GeV with the BESIII detector, we observe the process
e
+
...e
−
→ π
0
π
0
ψ
2
(3823) for the first time with a statistical significance of 6
.
0 standard deviations. The ratio of average cross sections for
e
+
e
−
→ π
0
π
0
ψ
2
(3823) and
π
+
π
−
ψ
2
(3823) is determined to be
R
=
σ
e
+
e
−
→
π
0
π
0
ψ
2
3823
σ
e
+
e
−
→
π
+
π
−
ψ
2
3823
=
0.57
±
0.14
±
0.05
, which is consistent with expectations from isospin symmetry. Here and below, the first uncertainties are statistical and the second are systematic. The mass of the
ψ
2
(3823) is measured to be
M
ψ
2
(3823) = 3824
.
5
±
2
.
4
±
1
.
0 MeV/
c
2
. Due to the limited data sample, an upper limit of 18.8 MeV at 90% confidence level is set on the intrinsic width of
ψ
2
(3823).
In this study, dynamics of dissolved organic matter (DOM) and mineralization of soil organic C and N in subtropical China were investigated. Paddy and upland soils were derived from Tertiary ...sandstone, Quaternary red clay and river alluvium with low, middle, and high levels of soil fertility. Dissolved organic carbon contents (DOC) varied from 3.8 to 68.7
mg/kg and dissolved organic nitrogen contents (DON) ranged from 2.9 to 18.3
mg/kg, respectively, during the experimental period. Both DOC and DON increased with increasing soil fertility. The content of DOM was characterized by strong seasonal fluctuation in soils, and seasonal patterns showed the maximum value in Nov and the minimum in July. The contribution of DOM to mineralization of C and N was significantly affected by soil types and seasons. DOM removal significantly decreased the cumulative organic C mineralization in soils derived from Tertiary sandstone and River alluvium (by 1.6%–20.3% with an average of 7.1%), while it did not significantly change those in soils derived from Quaternary red clay. Similarly, the cumulative mineralization of N in paddy soils after DOM removal decreased by 6.7%–27.3% over seasons. In this study, DOM played an important role in soil C and N mineralization in subtropical China. It appears that contribution of DOM to minerilization of C and N in paddy soils was possibly related to DOM content and composition.
A
bstract
The singly Cabibbo-suppressed decay
D
s
+
→
K
+
π
+
π
−
π
0
is observed by using a data set corresponding to an integrated luminosity of 6.32 fb
−
1
recorded by the BESIII detector at the ...centre-of-mass energies between 4.178 and 4.226 GeV. The first amplitude analysis of
D
s
+
→
K
+
π
+
π
−
π
0
reveals the sub-structures in this decay and determines the fractions and relative phases of different intermediate processes. The dominant intermediate process is
D
s
+
→
K
*0
ρ
+
, with a fit fraction of (40
.
5 ± 2
.
8
stat
.
± 1
.
5
syst
.
)%. With the detection efficiency based on our amplitude analysis, the absolute branching fraction for
D
s
+
→
K
+
π
+
π
−
π
0
is measured to be (9
.
75
±
0
.
54
stat
.
±
0
.
17
syst
.
)
×
10
−
3
.
A novel catalyst, polyoxometallate-stabilized platinum–ruthenium alloy nanoparticles supported on multiwalled carbon nanotubes (Pt–Ru–PMo
12-MWNTs), was synthesized by a microwave-assisted polyol ...process. The effects of microwave reaction time, microwave reaction power, and pH value of the reaction solution on the electrocatalytic properties of Pt–Ru–PMo
12-MWNTs catalysts were also investigated. The polyoxometallate (PMo
12) formed a self-assembled monolayer on the surface of the Pt/Ru nanoparticles and MWNTs, which effectively prevented the agglomeration of Pt, Ru nanoparticles and MWNTs, due to the electrostatic repulsive interactions between the negatively charged PMo
12 monolayers. Energy dispersive spectroscopy examination and electrochemical measurements showed that the loading content of Pt/Ru and their electrochemical activity vary with the synthesis conditions, such as pH, reaction time, and microwave power. It was found that the a Pt–Ru–PMo
12-MWNTs electrocatalyst with high Pt loading content, small crystallite size, and good electrocatalytic activity could be synthesized using a long reaction time, intermediate microwave power, and a pH value of 7. The electrocatalysts obtained were characterized using X-ray diffraction, and scanning and transmission electron microscopy. Their electrocatalytic properties were also investigated by using the cyclic voltammetry technique.
