Phys. Rev. B 98, 241104 (2018) Topological crystalline insulators (TCI) are insulating electronic phases of
matter with nontrivial topology originating from crystalline symmetries. Recent
theoretical ...advances have provided powerful guidelines to search for TCIs in
real materials. Using density functional theory, we identify a class of new TCI
states in the tetragonal lattice of the Ca$_2$As material family. On both top
and side surfaces, we observe topological surface states protected
independently by rotational and mirror symmetries. We show that a particular
lattice distortion can single out the newly proposed topological protection by
the rotational symmetry. As a result, the Dirac points of the topological
surface states are moved to generic locations in momentum space away from any
high symmetry lines. Such topological surface states have not been seen before.
Moreover, the other family members, including Ca$_2$Sb, Ca$_2$Bi and Sr$_2$Sb,
feature different topological surface states due to their distinct topological
invariants. We thus further propose topological phase transitions in the
pseudo-binary systems such as (Ca$_{1-x}$Sr$_x$)$_2$As and
Ca$_2$As$_x$Sb$_{1-x}$. Our work reveals rich and exotic TCI physics across the
Ca$_2$As family of materials, and suggests the feasibility of materials
database search methods to discover new TCIs.
To evaluate the safety, efficacy and tolerability of China-made sildenafil citrate (Jinge) in the treatment of ED.
We conducted a multi-center, randomized, double-blind and placebo-controlled ...clinical trial among 222 ED patients in five urological or andrological clinics of China. The patients were randomly assigned to receive sildenafil citrate (SC, n = 111) or placebo (n = 111) for 8 weeks. We obtained and analyzed the demographic and clinical characteristics of the patients, the scores of International Index of Erectile Function (IIEF), the success rate of sexual intercourse, and the incidence of adverse events.
No statistically significant differences were found between the patients of the SC and those of the placebo group in the mean age (［47.2±11.32］ yr vs ［46.67±13.08］ yr, P>0.05), psychological etiology (27.93% vs 23.42%, P>0.05), organic etiology (21.62% vs 29.73%, P>0.05) or mixed etiology (50.45% vs 46.85%, P>0.05), nor in height, weight, nationality, or history of smoking, drinking or allergy. Com
Commun.Theor.Phys. 63, 215 (2015) We investigate the two-body reaction $\pi^- p \to K^{0} \Lambda$ within the
effective Lagrangian approach and the isobar model. In addition to the
"background" ...contributions from $t$-channel $K^*$ exchange, $u$-channel
$\Sigma(1192)$ and $\Sigma^*(1385)$ exchanges, and $s$-channel nucleon pole
terms, the contributions from the nucleon resonances $N^*(1535)$, $N^*(1650)$,
and $N^*(1720)$ are investigated. It is shown that the inclusion of these
nucleon resonances contributions leads to a good description of the
experimental total and differential cross sections data at low energy region.
The $s$-channel $N^*(1535)$, $N^*(1650)$, and $N^*(1720)$ resonances and the
$t$-channel $K^*$ exchange give the dominant contributions below $W = 1.76$
GeV, while the $u$-channel $\Sigma(1192)$ and $\Sigma^*(1385)$ exchanges give
the minor contributions.
We report the application of the resistive anode readout method on a two
dimensional imaging GEM detector. The resistive anode consists of $6\times6$
cells with the cell size ...$6~\mathrm{mm}\times6~\mathrm{mm}$. New electronics
and DAQ system are used to process the signals from the 49 readout channels.
The detector has been tested by using the X-ray tube (8~keV). The spatial
resolution of the detector is about $103.46~\mathrm{{\mu}m}$ with the detector
response part about $66.41~\mathrm{{\mu}m}$. The nonlinearity of the detector
is less than $1.5\%$. A quite good two dimensional imaging capability is
achieved as well. The performances of the detector show the prospect of the
resistive anode readout method for the large readout area imaging detectors.
To investigate the effectiveness of testicular sperm cryopreservation in male fertility preservation by evaluating the clinical outcome of ICSI cycles with frozen-thawed testicular sperm for ...azoospermia patients.
We retrospectively analyzed 96 samples of cryopreserved testicular sperm obtained by testicular biopsy, vasovasostomy (V-V), vasoepididymostomy (V-E) , of which 55 were subjected to 60 ICSI cycles with frozen-thawed testicular sperm. We evaluated the rates of sperm recovery, fertilization, cleavage, transferable and good-quality embryos, clinical pregnancy, pregnancy outcome, and health of the newborns.
All the frozen testicular sperm samples were recovered successfully. The rates of fertilization, 2PN fertilization, cleavage, available embryos and good-quality embryos were 77.6, 69.4, 99.4, 84.5 and 40.8%, respectively. There were transferable embryos in all cycles. Fresh embryos were transferred in 52 of the 60 cycles, with the clinical pregnancy rate of 57.7% (30/52), including 19 singletons and 1
This paper presents a prognosis algorithm for the tension on ice-coated AC transmission lines. Firstly, the difference time sequences are built with the collected tension data on ice-coated AC ...transmission lines. Then the autoregressive model is applied on the obtained difference sequences and the model parameters are estimated through the Yule-Walk method. Finally, we can predict the tension on ice-coated transmission lines in the future 8 hours. The developed prognosis algorithm is verified through the tension data of Dazheng 73# ice-coated AC transmission line in Zhaotong area, Yunnan Province, China.
We investigate the \(\gamma p \to \phi K^+ \Lambda\) reaction near threshold within an effective Lagrangian approach and the isobar model. Various nucleon resonances caused by the \(\pi\) and ...\(\eta\) meson exchanges and background contributions are considered. It is shown that the contribution from the \(N^*(1535)\) resonance caused by the \(\eta\) meson exchange plays the predominant role. Hence, this reaction provides a good new platform to study the \(N^*(1535)\) resonance. The predicted total cross section and specific features of angular distributions can be tested by future experiments.
We investigate the $a_2(1320)$ meson photon production in the $\gamma p \to n
a^+_2(1320)$ and $\gamma p \to n \rho^0 \pi^+$ reactions within the effective
Lagrangian method. For $\gamma p \to n ...a^+_2(1320)$ reaction, by considering
the contributions only from the $t-$channel $\pi^+$ exchange, we get a fairly
good description of the current experimental total cross section data. We also
studied the $\gamma p \to n \rho^0 \pi^+$ reaction, which mainly contribute to
the $\gamma p \to n \pi^+ \pi^+ \pi^-$ reaction. The latter reaction has
measured by the CLAS Collaboration. The total cross sections, invariant mass
distribution, and the Dalitz Plot of $\gamma p \to n \rho^0 \pi^+$ reaction are
shown, which can be tested by future experiments.
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