Henan Normal University

About: Henan Normal University is a education organization based out in Xinxiang, China. It is known for research contribution in the topics: Catalysis & Ionic liquid. The organization has 10863 authors who have published 11077 publications receiving 166773 citations.

Probing natural SUSY from stop pair production at the LHC

Abstract: We consider the natural supersymmetry scenario in the framework of the R-parity conserving minimal supersymmetric standard model (called natural MSSM) and examine the observability of stop pair production at the LHC. We first scan the parameters of this scenario under various experimental constraints, including the SM-like Higgs boson mass, the indirect limits from precision electroweak data and B-decays. Then in the allowed parameter space we study the stop pair production at the LHC followed by the stop decay into a top quark plus a lightest neutralino or into a bottom quark plus a chargino. From detailed Monte Carlo simulations of the signals and backgrounds, we find the two decay modes are complementary to each other in probing the stop pair production, and the LHC with root s = 14 TeV and 100 fb(-1) luminosity is capable of discovering the stop predicted in natural MSSM up to 450 GeV. If no excess events were observed at the LHC, the 95% C.L. exclusion limits of the stop masses can reach around 537 GeV.

Formation and catalytic activity of Pt supported on oxidized graphene for the CO oxidation reaction.

Abstract: The geometries, stabilities, electronic properties and catalytic capability of the platinum catalyst supported on oxidized graphene (Pt/OG) are investigated using the first-principles density-functional theory. Compared with the oxygen adatom, the hydroxyl molecule adsorbs weakly and aggregates easily on graphene, while the single oxygen adatom will form the epoxy group (EG) on pristine graphene or the oxygen dopant (OD) in defective graphene. The formation of EG and OD are used to model oxidized graphene (OG). The OD at the vacancy site forms the most stable configuration with a small formation energy and large diffusion barrier, indicating that an OD is easier to incorporate into the graphene sheet. The OD sheet as a substrate can effectively enhance the stability of the Pt catalyst as compared with pristine graphene or the graphene sheet with EG. Moreover, the complete CO oxidation reactions on the Pt/OD system include a two-step process with the Langmuir–Hinshelwood (LH) reaction as a starting step followed by the Eley–Rideal (ER) reaction. The results suggest that the OD sheet can be used as the reactive support to control the stability and reactivity of catalysts, which opens up a new avenue for fabrication of low cost and highly efficient graphene-based catalysts.

Composition-tunable 2D SnSe2(1−x)S2x alloys towards efficient bandgap engineering and high performance (opto)electronics

Abstract: Efficient bandgap engineering is a significant strategy for the utilization of widely concerned two-dimensional (2D) layered materials in versatile devices such as nanoelectronics, optoelectronics, and photonics. Alloying transition-metal dichalcogenides (TMDs) with different components has been proved as a very effective way to get 2D nanostructured semiconductors with artificially designed tunable bandgaps. Here we report a systematically study of chemical vapor transport (CVT) grown SnSe2(1−x)S2x alloys with continuously bandgaps ranging from 1.37 eV (SnSe2) to 2.27 eV (SnS2). The carrier mobility of 2D SnSe2(1−x)S2x nanosheets can be tuned from 2.34 cm2 V−1 s−1 (SnS2) to 71.30 cm2 V−1 s−1 (SnSe2) by controlling the S composition in the alloy. Furthermore, the carrier mobility of SnSeS increase from 10.34 to 12.16 cm2 V−1 s−1 under illumination, showing excellent optoelectronic properties. Our study suggests that SnSe2(1−x)S2x nanosheets is a highly qualified 2D materials for next-generation nanoelectronics and optoelectronics application.

Observation of a Neutral Charmoniumlike State Z(c)(4025)(0) in e(+)e(-) -> (D*(D)over-bar*)(0)pi(0)

Abstract: We report a study of the process e(+)e(-) -> (D*(D) over bar*)(0)pi(0) using e(+)e(-) collision data samples with integrated luminosities of 1092 pb(-1) at root s = 4.23 GeV and 826 pb(-1) at root s = 4.26 GeV collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the (D*(D) over bar*)(0) mass threshold in the pi(0) recoil mass spectrum, which we denote as Z(c)(4025)(0). Assuming a Breit-Wigner line shape, its pole mass and pole width are determined to be (4025.5(-4.7)(+2.0) +/- 3.1) MeV/c(2) and (23.0 +/- 6.0 +/- 1.0) MeV, respectively. The Born cross sections of e(+)e(-) -> Z(c)(4025)(0)pi(0) -> (D*(D) over bar*)(0)pi(0) are measured to be (61.6 +/- 8.2 +/- 9.0) pb at root s = 4.23 GeV and (43.4 +/- 8.0 +/- 5.4) pb at root s = 4.26 GeV. The first uncertainties are statistical and the second are systematic.