Fully open-flavor tetraquark states bcqˉsˉbc\bar{q}\bar{s} and scqˉbˉsc\bar{q}\bar{b} with JP=0+,1+J^{P}=0^{+},1^{+}

We have studied the masses for fully open-flavor tetraquark states $bc\bar{q}\bar{s}$ and $sc\bar{q}\bar{b}$ with quantum numbers $J^{P}=0^{+},1^{+}$. We systematically construct all diquark-antiquark interpolating currents and calculate the two-point correlation functions and spectral densities in the framework of QCD sum rule method. Our calculations show that the masses are about $7.1-7.2$ GeV for the $bc\bar{q}\bar{s}$ tetraquark states and $7.0-7.1$ GeV for the $sc\bar{q}\bar{b}$ tetraquarks. The masses of $bc\bar{q}\bar{s}$ tetraquarks are below the thresholds of $\bar{B}_{s}D$ and $\bar{B}_{s}^{*}D$ final states for the scalar and axial-vector channels respectively. The $sc\bar{q}\bar{b}$ tetraquark states with $J^{P}=1^{+}$ lie below the $B_{c}^{+}K^{*}$ and $B_{s}^{*}D$ thresholds. Such low masses for these possible tetraquark states indicate that they can only decay via weak interaction and thus are very narrow and stable.Comment: 17 pages, 4 figure

External Social Capital, Inter-Organizational Knowledge Trading and Enterprise Innovation Performance in Supply Chain: Evidence from Manufacturing Enterprises in China

Based on perspective of cooperative innovation in supply chain, a conceptual model for the effect of external social capital, inter-organizational knowledge trading on enterprise innovation performance is proposed and empirically tested using the data collected from 256 enterprises in supply chain through the structural equation modeling. The external social capital consists of external cognitive capital, external relationship capital, external structure capital and external position capital in this paper. Inter-organizational knowledge trading is divided into explicit knowledge trading and tacit knowledge trading. The results show that external structure capital and external position capital have significant positive impact on explicit knowledge trading, tacit knowledge trading and enterprise innovation performance. External cognitive capital has significant positive impact on explicit knowledge trading and tacit knowledge trading, it does not impact enterprise innovation performance significantly. Although external relationship capital has significant positive impact on tacit knowledge trading, it does not impact explicit knowledge trading and enterprise innovation performance significantly. Finally, we also find that explicit knowledge trading and tacit knowledge trading have significant positive impact on enterprise innovation performance

Lithic Technological Variability of the Middle Pleistocene in the Eastern Nihewan Basin, Northern China

Previous studies have generalized the technological character of the Lower Paleolithic of China with reference to its non-Acheulean features, but regional perspectives on technological variability were largely overlooked. This study examines two lithic assemblages from Middle Pleistocene sites in the Nihewan Basin in northern China: Cenjiawan and Maliang. Through applications of refitting analysis, technological analysis, and use-wear examinations, technological variability within these assemblages is assessed. The results reveal some aspects of lithic technology that were largely undocumented in Lower Paleolithic industries, such as intentional selection of high-quality raw materials, continuously rotating core reduction, and evidence for butchering/meat-processing tool use, suggesting that the Cenjiawan and Maliang lithic assemblages might represent regional and/or temporal variations of Lower Paleolithic industries in northern China. The data are compared to other Lower Paleolithic industries such as Xiaochangliang, Dongguotou, and Zhoukoudian (Localities 1 and 15). KEYWORDS: Lower Paleolithic, lithic technology, core reduction, refitting, use-wear