China’s internationalized higher education during Covid-19: Collective student autoethnography

This is an accepted manuscript of an article published by Springer in Postdigital Science and Education on 08/05/2020, available online: https://doi.org/10.1007/s42438-020-00128-1 The accepted version of the publication may differ from the final published version.This article presents 15 autoethnographical texts detailing student experiences at Beijing Normal University in the midst of the Covid-19 pandemic. Contributions have been collected over 6 weeks between 15 February and 1 April 2020, edited by Hejia Wang (assisted by Moses Oladele Ogunniran and Yingying Huang), and supervised by Michael Peters. Through shared in-depth empirical feelings and representations from a wide variety of cultural, historical, and social contexts, the article outlines an answer to the question: How do students, connected virtually but separated physically in an internationalized university, deal with disruption brought about by the Covid-19 pandemic? Student testimonies offer reflections on Covid-19 and Chinese international education, experiences of online teaching and learning, reflections on university coping mechanisms, an account of realities and feelings related to changes in academic life, and discussions on coping strategies in Chinese international higher education. Contributors expose their individual feelings, effects, benefits, challenges, and risk management strategies. Collected at the peak of the Covid-19 pandemic, these testimonies are unable to offer systemic answers to challenges facing the whole world. However, these experiences and feelings will provide important inputs to global discussions about the future of the world, after Covid-19.Published onlin

Edge states in a two-dimensional honeycomb lattice of massive magnetic skyrmions

We study the collective dynamics of a two-dimensional honeycomb lattice of magnetic skyrmions. By performing large-scale micromagnetic simulations, we find multiple chiral and non-chiral edge modes of skyrmion oscillations in the lattice. The non-chiral edge states are due to the Tamm-Shockley mechanism, while the chiral ones are topologically protected against structure defects and hold different handednesses depending on the mode frequency. To interpret the emerging multiband nature of the chiral edge states, we generalize the massless Thiele's equation by including a second-order inertial term of skyrmion mass as well as a third-order non-Newtonian gyroscopic term, which allows us to model the band structure of skrymion oscillations. Theoretical results compare well with numerical simulations. Our findings uncover the importance of high order effects in strongly coupled skyrmions and are helpful for designing novel topological devices.Comment: 6 pages,4 figures,accepted by Physical Review B as a Rapid Communicatio

Mobility and home: Shifting constructions of gender, race, and nationality in Chinese diasporic literature

Mobility and home are often assumed to be antithetical concepts. Visions of mobility and home are especially mediated through ideological mappings of gender, in which women are relegated to the local and the domestic as extensions of ideas of home, and men are assigned to the public terrain, the outer world. The dissertation not only seeks to problematize gendered ideologies of mobility and home but also investigates the ways in which home is redefined or reconfigured through different tropes of mobility. Through analysis of three novels, Bone by Fae Myenne Ng, Mulberry and Peach by Hualing Nieh and The Moon of Vancouver by Xiulan Du, I examine many implications of home that are fixated in binaries of domestic and public, male and female, East and West, and Asia and America. My study explores particularly the ways in which different tropes of mobility as conducted or imagined by the novelistic characters not only challenge the dichotomized understandings of home embedded in hegemonic structures of patriarchy, Orientalism, nationalism, imperialism and capitalism, but also redefine home in its relation with mobility. Chapter One discusses gendered ideologies of home and mobility in both Chinese and Western cultures and outlines the major theoretical strands of my study. It also introduces the thematic connections of the three novels. Chapter Two explores the ways in which Ngs characters use different modes of mobility to re-map and re-imagine different homes and re-articulate their positions in them. Chapter Three analyzes how the constant mobility of Nieh\u27s female protagonist reveals home as the locus of two conflicting desires and re-defines feeling at home as a perpetual state of reformation and negotiation. Chapter Four examines how capitalism on both a global and local scale affects transnational migration and the plans of settlement of Du’s characters

Parameter Optimization of Droop Controllers for Microgrids in Islanded Mode by the SQP Method with Gradient Sampling

For enhancing the stability of the microgrid operation, this paper proposes an optimization model considering the small-signal stability constraint. Due to the nonsmooth property of the spectral abscissa function, the droop controller parameters’ optimization is a nonsmooth optimization problem. The Sequential Quadratic Programming with Gradient Sampling (SQP-GS) is implemented to optimize the droop controller parameters for solving the nonsmooth problem. The SQP-GS method can guarantee the solution of the optimization problem globally and efficiently converges to stationary points with probability of one. In the current iteration, the gradient of the nonsmooth function can be evaluated on a set of randomly generated nearby points by computing closed-form sensitivities. A test on the microgrid system shows that the optimality and the efficiency of the SQP-GS are better than those of the heuristic algorithms

Improved L1/2 Threshold Iterative High Resolution SAR Imaging Algorithm

An improved Synthetic Aperture Radar (SAR) imaging algorithm is proposed to address the issues of low azimuth resolution and noise interference in the sparse sampling condition. Based on the existing L1/2 regularization theory and iterative threshold algorithm, the gradient operator is modified, which can improve the solution accuracy of the reconstructed image and reduce the load of calculation. Then, under full sampling and under-sampling conditions, the original and improved L1/2 iterative threshold algorithm are combined with the approximate observation model to image SAR echo signals and compare their imaging performance. The experimental findings demonstrate that the improved algorithm improves the azimuth resolution of SAR images and has higher convergence performance

Response of hydrological ecosystem services to land-use change and risk assessment in Jiangxi Province, China

Water bodies provide humans with important hydrological ecosystem services (HESs), directly or indirectly. Water yield, water conservation, and soil conservation are essential to HESs. Since China's reform and opening up, and with its rapid socio-economic development, land use in Jiangxi Province has undergone drastic change, resulting in threats to the ecological environment. This paper evaluates three HESs, water yield, water conservation, and soil conservation, in Jiangxi Province based on land use and rainfall data, quantifies the impacts of different land classes on each ecosystem, predicts future land use using the patch-generating land use simulation (PLUS) model, and finally, discusses the ecological risks in the study area. The following results were obtained: (1) The HESs in the basin increased and then decreased from 2000 to 2020, and the spatial distribution of water yield and water conservation was greatly influenced by rainfall. Soil conservation was mostly consistent with the elevation distribution. (2) Over time, the overall aggregation of HESs in the study area increased. There were small differences in the effects of various land uses on water yield and water conservation, and large differences in the effects on soil conservation. (3) The distribution of ecological risks was not affected by different land use strategies, with the lower ecological risk level 1 dominating. Most risk areas were present in Ganzhou, Ji'an, Shangrao, and Jiujiang. The ecological risk from urban sprawl (US) accounted for the most significant proportion, and that from the ecological protection (EP) strategy accounted for the lowest proportion. This study provides reference for sustainable land use development and ecological risk prevention in the study area

Research Progress in Rat Models of Intrauterine Adhesion

Intact endometrium and proper endometrial thickness are the necessary conditions for normal uterine reproductive function. Intrauterine adhesion (IUA) can cause recurrent abortion and infertility, which seriously affects the normal reproductive function of patients. At present, the treatment methods for IUA include surgery elimination and use of estrogen, but there are problems such as poor effectiveness, high rate of recurrence, and still with low pregnancy rate. The specific pathogenesis and developmental mechanism of IUA and the repair mechanism of damaged endometrium are still unclear. Establishing an appropriate animal model is conducive to the research of human IUA in all aspects. Here, we introduced the common rat models of IUA in recent years, including physical and mechanical damage method, chemical damage method, biological damage method and combined damage method, and described its application from the aspects of modeling rate, stability, and pathogenesis of IUA, and discussed the observation indexes to evaluate the success of modeling, in order to provide useful reference for selecting appropriate modeling methods. Generally, the combined model of repeated endometrial damage and infection of pregnant rats may be more suitable for the clinical IUA caused by multiple abortions and infections after curettage

The Microstructure of Nanocrystalline TiB2 Films Prepared by Chemical Vapor Deposition

Nanocrystalline titanium diboride (TiB2) ceramics films were prepared on a high purity graphite substrate via chemical vapor deposition (CVD). The substrate was synthesized by a gas mixture of TiCl4, BCl3, and H2 under 1000 °C and 10 Pa. Properties and microstructures of TiB2 films were also examined. The as-deposited TiB2 films had a nano-sized grain structure and the grain size was around 60 nm, which was determined by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Further research found that a gas flow ratio of TiCl4/BCl3 had an influence on the film properties and microstructures. The analyzed results illustrated that the grain size of the TiB2 film obtained with a TiCl4/BCl3 gas flow ratio of 1, was larger than the grain size of the as-prepared TiB2 film prepared with a stoichiometric TiCl4/BCl3 gas flow ratio of 0.5. In addition, the films deposited faster at excessive TiCl4. However, under the condition of different TiCl4/BCl3 gas flow ratios, all of the as-prepared TiB2 films have a preferential orientation growth in the (100) direction