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.

Chloroacetate‐Promoted Selective Oxidation of Heterobenzylic Methylenes under Copper Catalysis

Abstract: The efficient selective oxidation and functionalization of C-H bonds with molecular oxygen and a copper catalyst to prepare the corresponding ketones was achieved with ethyl chloroacetate as a promoter. In this transformation, various substituted N-heterocyclic compounds were well tolerated. Preliminary mechanistic investigations indicated that organic radical species were involved in the overall process. The N-heterocyclic compounds and ethyl chloroacetate work synergistically to activate C-H bonds in the methylene group, which results in the easy generation of free radical intermediates, thus leading to the corresponding ketones in good yields.

Measurement of e+e−→π+π−ψ(3686) from 4.008 to 4.600 GeV and observation of a charged structure in the π±ψ(3686) mass spectrum

Abstract: We study the process e(+)e(-) -> p(+)p(-)psi(3686) using 5.1 fb(-1) of data collected at 16 center-of-mass energy (root s) points from 4.008 to 4.600 GeV by the BESIII detector operating at the BEPCII collider. The measured Born cross sections for e(+)e(-) -> p(+)p(-)psi(3686) are consistent with previous results, but with much improved precision. A fit to the cross section shows contributions from two structures: the first has M = 4209.5 +/- 7.4 +/- 1.4 MeV/c(2) and Gamma = 80.1 +/- 24.6 +/- 2.9 MeV, and the second has M = 4383.8 +/- 4.2 +/- 0.8 MeV/c(2) and Gamma = 84.2 +/- 12.5 +/- 2.1 MeV, where the first errors are statistical and the second systematic. The lower-mass resonance is observed in the process e(+)e(-) -> p(+)p(-)psi(3686) for the first time with a statistical significance of 5.8 sigma. A charged charmoniumlike structure is observed in the pi(+/-)psi(3686) invariant mass spectrum for data at root s = 4.416 GeV. A fit with an S-wave Breit-Wigner function yields a mass M = 4032.1 +/- 2.4 MeV/c(2), where the errors are statistical only. However, there are still unresolved discrepancies between the fit model and data. The width of the intermediate state varies in a wide range for different kinematic regions within the data set. Therefore, no simple interpretation of the data has been found, and a future data sample with larger statistics and more theoretical input will be required to better understand this issue.

Major factors affecting China's inter-regional research collaboration: Regional scientific productivity and geographical proximity

Abstract: On the basis of the measured frequency distribution of China"s inter-regional co-authored papers covered by the Chinese Science Citation Database, this paper shows the pattern of China"s inter-regional research collaboration (IRRC), and analyzes how the collaborative pattern was formed. A new method is used to calculate the expected value matrix based on an observed value matrix of IRRC, which is asymmetric and has no diagonal elements. The results fall into three groups. 1) Regional scientific productivity affects both the collaborative preference and ranking of authors" name; 2) geographical proximity is an important factor determining the pattern of IRRC; 3) when using Salton"s measure, regional mean collaborative strength increases as the regional productivity increases, and as the distance between two regions decreases.

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π -η′

Abstract: With a sample of (225.2 +/- 2.8) x 10(6) J/psi events registered in the BESIII detector, J/psi -> gamma pi(+)pi(-)eta' is studied using two eta' decay modes: eta' -> pi(+)pi(-)eta and eta' -> gamma rho(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20 sigma. In addition, in the pi(+)pi(-)eta' invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2 sigma and 6.4 sigma, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.