Operations capability, productivity and business performance: the moderating effect of environmental dynamism

Purpose – The purpose of this study is to investigate the relationships between operations capability, productivity and business performance in the context of environmental dynamism. Design/methodology/approach – A proposed conceptual framework grounded in the resourcebased view (RBV) and dynamic capability view (DCV) is analysed using archival data from 193 automakers in the UK. Findings – The results show that operations capability, as an important dynamic capability, has a significant positive effect on productivity, which in turn leads to improved business performance. The results also suggest that productivity fully mediates the relationship between operations capability and business performance, and that environmental dynamism significantly moderates the relationship between operations capability and productivity. Practical implications – The research findings provide practical insights that will help managers develop operations capability to gain greater productivity and business performance in a dynamic environment

Global well-posedness for a fifth-order shallow water equation in Sobolev spaces

AbstractThe Cauchy problem of a fifth-order shallow water equation∂tu−∂x2∂tu+∂x3u+3u∂xu−2∂xu∂x2u−u∂x3u−∂x5u=0 is shown to be globally well-posed in Sobolev spaces Hs(R) for s>(610−17)/4. The proof relies on the I-method developed by Colliander, Keel, Staffilani, Takaoka and Tao. For this equation lacks scaling invariance, we reconsider the local result and pay special attention to the relationship between the lifespan of the local solution and the initial data. We prove the almost conservation law, and combine it with the local result to obtain the global well-posedness

Global well-posedness for a fifth-order shallow water equation in Sobolev spaces

AbstractThe Cauchy problem of a fifth-order shallow water equation∂tu−∂x2∂tu+∂x3u+3u∂xu−2∂xu∂x2u−u∂x3u−∂x5u=0 is shown to be globally well-posed in Sobolev spaces Hs(R) for s>(610−17)/4. The proof relies on the I-method developed by Colliander, Keel, Staffilani, Takaoka and Tao. For this equation lacks scaling invariance, we reconsider the local result and pay special attention to the relationship between the lifespan of the local solution and the initial data. We prove the almost conservation law, and combine it with the local result to obtain the global well-posedness

Migration Experiences and Reported Sexual Behavior Among Young, Unmarried Female Migrants in Changzhou, China.

BackgroundChina has a large migrant population, including many young unmarried women. Little is known about their sexual behavior, contraceptive use, and risk of unintended pregnancy.Methods475 unmarried female migrants aged 15-24, working in 1 of 6 factories in 2 districts of Changzhou city, completed an anonymous self-administered questionnaire in May 2012 on demographic characteristics, work and living situation, and health. We examined demographic and migration experience predictors of sexual and contraceptive behavior using bivariate and multivariate regressions.Results30.1% of the respondents were sexually experienced, with the average age at first sex of 19 years (standard deviation=3). 37.8% reported using contraception at first sex, 58.0% reported using consistent contraception during the past year, and 28.0% reported having at least 1 unintended pregnancy with all unintended pregnancies resulting in abortion. Those who had had at least 1 abortion reported having on average 1.6 abortions [SD=1] in total. Migrating with a boyfriend and changing jobs fewer times were associated with being sexually experienced. Younger age, less education, and changing jobs more times were associated with inconsistent contraceptive use.ConclusionThese findings demonstrate there is an unmet need for reproductive health education and services where these women work as well as in their hometown communities. This education must begin early to reach young women before they migrate

Euler--Chern Correspondence via Topological Superconductivity

The Fermi sea topology is characterized by the Euler characteristics $\chi_F$. In this paper, we examine how $\chi_F$ of the metallic state is inhereted by the topological invariant of the superconducting state. We establish a correspondence between the Euler characteristic and the Chern number $C$ of $p$-wave topological superconductors without time-reversal symmetry in two dimensions. By rewriting the pairing potential $\Delta_{\bf k}=\Delta_1-i\Delta_2$ as a vector field ${\bf u}=(\Delta_1,\Delta_2)$, we found that $\chi_F=C$ when ${\bf u}$ and fermion velocity ${\bf v}$ can be smoothly deformed to be parallel or antiparallel on each Fermi surface. We also discuss a similar correspondence between Euler characteristic and 3D winding number of time-reversal-invariant $p$-wave topological superconductors in three dimensions.Comment: 6 pages, 3 figur

Non-Adiabatic Effect in Topological and Interacting Charge Pumping

Topological charge pumping occurs in the adiabatic limit, and the non-adiabatic effect due to finite ramping velocity reduces the pumping efficiency and leads to deviation from quantized charge pumping. In this work, we discuss the relation between this deviation from quantized charge pumping and the entanglement generation after a pumping circle. In this simplest setting, we show that purity $\mathcal{P}$ of the half system reduced density matrix equals to $\mathcal{R}$ defined as $(1-\kappa)^2+\kappa^2$, where $\kappa$ denotes the pumping efficiency. In generic situations, we argue $\mathcal{P}<\mathcal{R}$ and the pumping efficiency can provide an upper bound for purity and, therefore, a lower bound for generated entanglement. To support this conjecture, we propose a solvable pumping scheme in the Rice--Mele--Hubbard model, which can be represented as brick-wall type quantum circuit model. With this pumping scheme, numerical calculation of charge pumping only needs to include at most six sites, and therefore, the interaction and the finite temperature effects can be both included reliably in the exact diagonalization calculation. The numerical results using the solvable pumping circle identify two regimes where the pumping efficiency is sensitive to ramping velocity and support the conjecture $\mathcal{P}<\mathcal{R}$ when both interaction and finite temperature effects are present.Comment: 5 pages, 3 figure

Analysis of Urban Ecological Vulnerability and prospects under the Impact of Urban Expansion

Currently, urban expansion has been an important means of urban economic development, but the coercive impact of its rapid expansion on the ecological vulnerability of the region has become an increasingly important issue that restricts sustainable urban development. This paper uses a SWOT analysis method to analyze this phenomenon, and then proposes solutions based on the problem in order to better grasp the future and lead the development of a new type of city that is low-carbon and ecological

The mechanism of the irradiation synergistic effect of Silicon bipolar junction transistors explained by multiscale simulations of Monte Carlo and excited-state first-principle calculations

Neutron and $\gamma$-ray irradiation damages to transistors are found to be non-additive, and this is denoted as the irradiation synergistic effect (ISE). Its mechanism is not well-understood. The recent defect-based model [ACS Appl. Electron. Mater. 2, 3783 (2020)] for Silicon bipolar junction transistors (BJT) achieve quantitative agreement with experiments, but its assumptions on the defect reactions are unverified. Going beyond the model requires directly representing the effect of $\gamma$-ray irradiation in first-principles calculations, which is not feasible previously. In this work, we examine the defect-based model of the ISE by developing a multiscale method for the simulation of the $\gamma$-ray irradiation, where the $\gamma$-ray-induced electronic excitations are treated explicitly in excited-state first-principles calculations. We find the calculations agree with experiments, and the effect of the $\gamma$-ray-induced excitation is significantly different from the effects of defect charge state and temperature. We propose a diffusion-based qualitative explanation of the mechanism of positive/negative ISE in NPN/PNP BJTs in the end.Comment: 11 pages, 7 figures. Accepted by J. Chem. Phy