FLNet: Landmark Driven Fetching and Learning Network for Faithful Talking Facial Animation Synthesis

Talking face synthesis has been widely studied in either appearance-based or warping-based methods. Previous works mostly utilize single face image as a source, and generate novel facial animations by merging other person's facial features. However, some facial regions like eyes or teeth, which may be hidden in the source image, can not be synthesized faithfully and stably. In this paper, We present a landmark driven two-stream network to generate faithful talking facial animation, in which more facial details are created, preserved and transferred from multiple source images instead of a single one. Specifically, we propose a network consisting of a learning and fetching stream. The fetching sub-net directly learns to attentively warp and merge facial regions from five source images of distinctive landmarks, while the learning pipeline renders facial organs from the training face space to compensate. Compared to baseline algorithms, extensive experiments demonstrate that the proposed method achieves a higher performance both quantitatively and qualitatively. Codes are at https://github.com/kgu3/FLNet_AAAI2020.Comment: Accepted by AAAI 202

Electron irradiation-induced defects for reliability improvement in monolayer MoS2-based conductive-point memory devices

Monolayer molybdenum disulfide has been previously discovered to exhibit non-volatile resistive switching behavior in a vertical metal-insulator-metal structure, featuring ultra-thin sub-nanometer active layer thickness. However, the reliability of these nascent 2D-based memory devices was not previously investigated for practical applications. Here, we employ an electron irradiation treatment on monolayer MoS2 film to modify the defect properties. Raman, photoluminescence, and X-ray photoelectron spectroscopy measurements have been performed to confirm the increasing amount of sulfur vacancies introduced by the e-beam irradiation process. The statistical electrical studies reveal the reliability can be improved by up to 1.5× for yield and 11× for average DC cycling endurance in the devices with a moderate radiation dose compared to unirradiated devices. Based on our previously proposed virtual conductive-point model with the metal ion substitution into sulfur vacancy, Monte Carlo simulations have been performed to illustrate the irradiation effect on device reliability, elucidating a clustering failure mechanism. This work provides an approach by electron irradiation to enhance the reliability of 2D memory devices and inspires further research in defect engineering to precisely control the switching properties for a wide range of applications from memory computing to radio- frequency switches.This work was supported in part by the National Science Foundation (NSF) grant #1809017, and an NSF MRSEC under Cooperative Agreement No. DMR-1720595. The authors acknowledge use of Texas Nanofabrication Facilities supported by the NSF NNCI award #1542159. D.A. acknowledges the Presidential Early Career Award for Scientists and Engineers (PECASE) through the Army Research Office (W911NF-16-1- 0277).Center for Dynamics and Control of Material

Light-driven C-H bond activation mediated by 2D transition metal dichalcogenides

C-H bond activation enables the facile synthesis of new chemicals. While C-H activation in short-chain alkanes has been widely investigated, it remains largely unexplored for long-chain organic molecules. Here, we report light-driven C-H activation in complex organic materials mediated by 2D transition metal dichalcogenides (TMDCs) and the resultant solid-state synthesis of luminescent carbon dots in a spatially-resolved fashion. We unravel the efficient H adsorption and a lowered energy barrier of C-C coupling mediated by 2D TMDCs to promote C-H activation. Our results shed light on 2D materials for C-H activation in organic compounds for applications in organic chemistry, environmental remediation, and photonic materials

Sulfurization Engineering of One-Step Low-Temperature MoS2 and WS2 Thin Films for Memristor Device Applications

2D materials have been of considerable interest as new materials for device applications. Non-volatile resistive switching applications of MoS2 and WS2 have been previously demonstrated; however, these applications are dramatically limited by high temperatures and extended times needed for the large-area synthesis of 2D materials on crystalline substrates. The experimental results demonstrate a one-step sulfurization method to synthesize MoS2 and WS2 at 550 °C in 15 min on sapphire wafers. Furthermore, a large area transfer of the synthesized thin films to SiO2/Si substrates is achieved. Following this, MoS2 and WS2 memristors are fabricated that exhibit stable non-volatile switching and a satisfactory large on/off current ratio (103–105) with good uniformity. Tuning the sulfurization parameters (temperature and metal precursor thickness) is found to be a straightforward and effective strategy to improve the performance of the memristors. The demonstration of large-scale MoS2 and WS2 memristors with a one-step low-temperature sulfurization method with simple strategy to tuning can lead to potential applications such as flexible memory and neuromorphic computing.This research was primarily supported by the National Science Foundation through the Center for Dynamics and Control of Materials: an NSF MRSEC under Cooperative Agreement No. DMR-1720595. The work was partly done at the Texas Nanofabrication Facility supported by NSF grant NNCI-2025227. This work was performed in part at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy’s NNSA, under contract 89233218CNA000001.Center for Dynamics and Control of Material

Risk factors for overweight and obesity, and changes in body mass index of Chinese adults in Shanghai

<p>Abstract</p> <p>Background</p> <p>Over the past two decades, the prevalence of overweight or obesity has increased in China. The aims of this study were to firstly assess the baseline prevelences and the risk factors for overweight and obesity, and secondly to detect the changes of body mass index (BMI) over a follow-up period in Chinese adults in Shanghai.</p> <p>Methods</p> <p>The data set of a population-based longitudinal study was analyzed. Anthropometric and biochemical data were collected for 5364 subjects (aged 25–95 years) during a period of 1998–2001. Among those individuals, 3032 subjects were interviewed and reexamined at the second survey from 2003 to 2004. Then the standardized prevalences for overweight and obesity were calculated using baseline data; the possible contributing factors of overweight and obesity were detected using binary logistic regression analysis; and the changes of BMI were evaluated after an average of 3.6-year follow-up period.</p> <p>Results</p> <p>(1) According to the WHO standard and the Chinese standard, the sex- and age-standardized prevalences were 27.5% and 32.4% for overweight, and 3.7% and 9.1% for obesity, respectively. (2) The risks of overweight and obesity differed among different age groups. Family history of obesity increased the risk of overweight and obesity by about 1.2-fold for both genders. Current male smokers had a lower risk of overweight and obesity (OR = 0.76, <it>p </it>< 0.05) than nonsmokers. In contrast, current male drinkers had a higher risk of overweight and obesity (OR = 1.42, <it>p </it>< 0.05) than nondrinkers. Compared with low-educated women, medium- and high- educated women were at lower risk of overweight and obesity, and the corresponding ORs (95% CIs) were 0.64 (0.52–0.79) and 0.50(0.36–0.68), respectively. (3) The annual changes of BMI means ranged from an increase of 0.1 kg/m²to a decrease of 0.2 kg/m²(by genders and age groups). Meanwhile, the BMI increase was statistically significant in the 35–44 years age group, and the BMI decrease was significant above 65 years for both genders.</p> <p>Conclusion</p> <p>This study showed high prevalence of overweight and obesity in Shanghai metropolis populations. The risk factors of overweight and obesity were multifactorial and gender specific. After 3.6 years, BMI means changed slightly, BMI increased mainly in middle-aged individuals and decreased in old individuals.</p

Precision Higgs physics at the CEPC

The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics. The Higgs boson will be the subject of extensive studies of the ongoing LHC program. At the same time, lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC, with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson. The Circular Electron Positron Collider~(CEPC) is one of such proposed Higgs factories. The CEPC is an $e^+e^-$ circular collider proposed by and to be hosted in China. Located in a tunnel of approximately 100~km in circumference, it will operate at a center-of-mass energy of 240~GeV as the Higgs factory. In this paper, we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.Comment: 46 pages, 37 figure

Growth and defect engineering of two-dimensional materials for memristor improvement

The non-volatile resistive switching phenomenon has been widely observed recently in the Two-dimensional (2D) materials down to monolayer, with promising memristor applications. However, many fundamental challenges for 2D memristors remain towards industrialization, including large-scale growth of 2D thin films and device reliability. This dissertation presents a feasible method for wafer-scale synthesis of MoS₂ and WS₂ films and multiple strategies to improve the reliability of 2D memristor. In Chapter 2, a significant improvement in yield and endurance has been demonstrated with defect engineering. The E-beam irradiation effect on MoS₂ is detailed studied with material characterization and Montre Carlo simulations. Chapter 3 presents a simple one-step low-temperature sulfurization process to synthesize wafer-scale few-layer MoS₂ and WS₂. The sulfurized film-based memristors show stable non-volatile switching and a satisfactory on/off current ratio. The impact of sulfurization parameters on film quality has been systematically studied to guide device optimization. The performance of memristors based on MoS₂ grown with sulfurization parameters is evaluated and compared. A qualitative model is proposed to provide more insight on reliability improvement with sulfurization parameters adjustment. In Chapter 5, MoS₂ memristors under fabrication configurations are comprehensively compared. Considerable reliability (yield and endurance) improvements are achieved by reducing top electrode deposition rate and increasing MoS₂ thickness. The statistical analysis further reveals an intriguing convergence of switching metrics, despite the reliability difference. The reliability improvements and independence switching metrics can be understood with a proposed general-purpose “active layer” model. Monte Carlo simulations have been performed to provide a more intuitive understanding of endurance failure mode associated with the formation of clusters in the active layer.Electrical and Computer Engineerin

Preparation of sucrose-based microporous carbons and their application as electrode materials for supercapacitors

Microporous carbon materials were prepared by carbonization of sulfuric acid-pretreated sucrose. The pore size and specific surface area of the samples were measured to be in the ranges of 0.7-1.2 nm and 178-603 m /g, respectively. The pore parameters were found to depend strongly on the carbonization temperature. Raman spectra showed that the intensity of the G band was stronger than that of the D band for the samples obtained with carbonization temperatures above 800 °C. It was also found that the sample carbonized at 800 °C displayed the highest specific surface area with a main pore size of about 0.75 nm. This sample exhibited the highest specific capacitance (232 F/g) at a current density of 0.1 A/g and lowest electrical resistance based on the results of cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). All samples displayed a good cycle performance behavior evaluated using both three-electrode and two-electrode cells. Based on the experimental results, the formation mechanism of the carbon materials as well as the relationship between the pore structure and their electrochemical properties were analyzed and discussed

Hub Gene Identification and Heat-Stress-Related Transcriptional Regulation Mechanism in Cabbage (<i>Brassica oleracea</i> L.)

Cabbage is a heat-stress-sensitive cool-season crop. When exposed to high temperatures, cabbage plants can experience reduced growth, wilting, leaf yellowing, and premature bolting (the formation of a flowering stem). The regulatory mechanism controlling heat stress is poorly understood in cabbage. To investigate this mechanism, physiological changes and transcriptional profiling for different heat treatment times were analyzed in this study. The results showed that superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities were enhanced under heat stress. In particular, the increase in SOD and POD activities after 12 h of heat treatment was greater than that after 4 h of heat treatment. With increasing heat treatment duration, the leaf CAT activity and H2O2 content decreased after the initial increase. The electrolyte leakage and malondialdehyde (MDA) content dropped significantly, while the proline content increased. Alongside that, 7007 and 5537 upregulated genes were identified in the experimental group treated with heat stress for the 4 h and 12 h treatments, respectively. We found that 10,479 DEGs were shared in the heat stress treatment, of which 1241 were associated with the heat treatment time. By integrating the expression patterns and functional annotations of genes related to heat stress, we identified 15 hub genes that respond to heat stress in cabbage. Meanwhile, we had constructed a physiological to molecular model of cabbage response to long-term heat stress. These findings provide new insights for the comprehensive analysis of cabbage response to heat stress and genetic resources for breeding new varieties of cabbage with heat tolerance via genetic engineering