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This paper is concerned with the resilient consensus control problem of the linear multi-agent system under the false data injection attacks, where each agent may receive the injected false data by attackers from its neighbours through communication links. Due to the existence of the false data, the desired consensus of multi-agent can not be reached by the general distributed consensus algorithms. By constructing an extended state observer to estimate the state and the injected false data towards each agent, a distributed resilient consensus control algorithm is designed to offset the negative effect of the attacks. Firstly, a sufficient condition is derived for the undirected multi-agent system under a bounded and decaying false data injection. Secondly, a sufficient and necessary condition is provided for the directed multi-agent system under the false data injection with decaying rate. Finally, the simulation results illustrate the effectiveness of the proposed consensus algorithms against the false data attacks. [ABSTRACT FROM AUTHOR]

In order to extract polyester (PET) and microcrystalline cellulose (MCC) from waste polyester-cotton blended fabrics (WPBFs), a deep eutectic solvent (DES) synthesized from choline chloride (ChCl) and p-toluenesulfonic acid (TsOH) was developed as the treatment solvent. The orthogonal experiment method was designed to explore the optimal conditions for the separation process (75 vol.% DES, 110 °C, 10 min). The PET component was easily separated after the degradation of the cotton component from WPBFs. Recycled and untreated products were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), and tensile tests. The results showed that the yields of recycled PET (R-PET) and MCC were 99.20, and 69.46%, respectively. Furthermore, glucose was also obtained with a yield of 38.91%. In particular, there was no significant deterioration in the properties of R-PET. MCC was obtained with crystallinity of 86.46%, which can be applied as the raw material of MCC in various industries. Moreover, the lifetime of the recyclable DES (ChCl/TsOH) showed that its treatment efficiency can still meet the requirement after the fifth recycling. [ABSTRACT FROM AUTHOR]

In this work, a metal–glass joint between Ti and K9 glass was obtained by vacuum diffusion bonding after Ti was pre-oxidized at different temperatures to explore the effect of the pre-oxidation procedure on the properties of diffusion bonding joints. For the oxide layer, X-ray diffraction revealed that the oxide film consisted of TiO2 and some low-valence Ti–O compounds such as Ti6O, Ti3O, TiO, etc. The x/y ratio of TixOy decreased as oxidation temperature increased. Scanning and transmission electron microscopy showed that the morphology of the oxide layer gradually changed from dense to loose and porous, and the oxidized particle size gradually increased and distributed in layers from inside to outside, with the increase in temperature. From the results of diffusion bonding at 700 °C for 2 h, good Ti-K9 joints without cracks and pores can be obtained when the pre-oxidation temperature attained 900 °C. A transition layer appeared at the Ti-K9 interface with the diffusion of elements Ti, Si, and O, etc. Shear strength tests showed that the structure of the oxide layer at different conditions can directly affect the strength of the joint between Ti and glass. The joint to Ti pre-oxidized at 900 °C exhibited the highest shear strength, producing an average failure strength of 20.6 ± 1.2 MPa. An appropriate amount of oxide layer can improve the quality of the Ti-K9 joint. The feasibility of diffusion bonding added to process versatility for the use of Ti-K9 joint on practical application. [ABSTRACT FROM AUTHOR]

The preparation of value-added products is an effective way to reuse waste cotton fabrics (WCFs). Seven kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) were rapidly formed and characterized. Performances of these ChCl-based DESs were evaluated in terms of degradation of WCFs to 5-hydroxymethylfurfural (5-HMF) without any additional catalyst. The degradation was characterized by high-performance liquid chromatography (HPLC) and scanning electron microscopy (SEM) method. The results showed that the DESs formed by ChCl and p-toluene sulfonic acid (p-TSA) had the best effect in converting WCFs. Moreover, the stability of 5-HMF in the as-obtained DESs was also investigated. The highest 5-HMF yield was 10.20 % at 100 °C, with a reaction time of 90 min, and the molar ratio of hydrogen bond acceptor (HBA) to hydrogen bond donor (HBD) was 1:1.3 in ChCl/p-TSA DESs system without a catalyst. The investigated DESs system offers a good alternative compared to the available WCFs degradation methods, considering its cost-efficiency, environmental, and operability aspects. Therefore, the green and environmentally friendly synthesis of 5-HMF from cellulose materials (WCFs) could be an effective method to realize the high-value utilization of waste textiles, having an important theoretical significance and practical value. [ABSTRACT FROM AUTHOR]

We investigated the effect of increased spring (April–May) dust aerosol over the Arabian Peninsula (AP) on the subseasonal-to-seasonal (S2S) variability of the Asian summer monsoon (ASM) using MERRA-2 re-analysis data (1980–2018). Result shows that abundant AP spring dust leads to more dust covering the AP and Pakistan northwestern India (PNWI) during May–June, causing a cooler land surface and a warmer lower and middle atmosphere with enhanced local atmospheric stability. However, the warmer atmosphere increases the meridional temperature gradient, boosting moisture transport from the Arabian Sea to PNWI, causing increased convective potential energy in PNWI region. As season advances, the accumulated convection potential energy eventually breaks through the local stability, via the elevated heat pump (EHP) effect, increasing precipitation over PNWI. In July and August, cloud radiation-circulation feedback further enhances the warming of the upper troposphere, strengthening precipitation in PNWI. Dynamical adjustments of large-scale circulations induced by the feedback strongly modulate ASM precipitation. Over southern and central China, precipitation is reduced, in conjunction with a contraction of South Asian High, and the development of an anomalous east-to-west oriented upper-level wavetrain in July. In August, the upper level wavetrain undergoes strong wave-mean flow interaction, culminating in the development of an anticyclonic center with drought conditions over northeast China, Korea and Japan. Over the Indian subcontinent, increased precipitation in PNWI plays an important role in initiating the EHP feedback leading to increased precipitation over the Indian subcontinent, and in modulating the jetstream-wave interaction in downstream East Asian regions in July–August. [ABSTRACT FROM AUTHOR]

We investigated the intraseasonal relationship between the atmospheric heat source over Tibetan Plateau (TP) and summer rainfall in eastern China. A quasi-biweekly oscillation (QBWO) is the common dominant periodicity over both the TP and eastern China. Crucially, the TP heat source QBWO leads rainfall QBWO over its downstream region by 2–8 days. The QBWO over the TP shows a significant eastward propagation. Phase composite further identified the specific propagation pathway: TP QBWO first propagates eastward to central China, southward to southern China, and then northeastward to the lower reaches of the Yangtze River with a zigzag propagating pathway. Mechanistically, the eastward propagation of the upper level divergence caused by the movement of the 200 hPa jet core and south Asian high contributes to the eastward propagation of the rainfall QBWO. Simultaneously, the eastward (westward) shift in the western north Pacific subtropical high causes deepening (flattening) of the monsoon trough and the occurrence of an anomalous cyclone (anticyclone) over the western north Pacific. An anomalous anticyclonic (cyclonic) circulation around the TP appears with the wet-to-dry (dry-to-wet) phase transition of the TP QBWO. Together, they play a crucial part in the southward (northeastward) movement of the QBWO. Further dynamic analysis indicates that the horizontal moisture advection acts on the whole eastward-propagating process of the QBWO, whereas the horizontal vorticity advection is only significant when QBWO is over the TP. This study shows that the fluctuations in TP heat source are important indicators in extended forecasts of summer rainfall in eastern China. [ABSTRACT FROM AUTHOR]

The isothermal wetting and spreading behaviors of Sn-Ti/ZrO2 systems were investigated by the sessile drop method, and the interfacial microstructures were characterized by XRD and TEM. The wettability improved significantly with the increase in Ti content or with the increase in temperature as a result of the interfacial phenomena. For example, for tests at 1000 °C, we found that: (1) XTi = 0 to XTi = 2.0%, the final contact angle decreased from 144° to 42° along with the increase in the coverage of ZrO2 by a Ti2O3 interfacial layer; (2) XTi = 2.0% to XTi = 4.0%, the contact angle decreased to 22° because of the replacement of Ti2O3 by a more metallic layer; (3) XTi = 4.0% to XTi = 8.0%, no further decrease in the angle was observed as the interfacial layer remains Ti11.31Sn3O10. For XTi = 4.0%, the temperature increase from 900 to 1000 °C led to a decrease in contact angle from 47° to 22°, respectively, due to the interfacial layer shifting from Ti2O3 to Ti11.31Sn3O10. For all the systems, the Ti enhanced the loss of oxygen from zirconia leading to the formation of black ZrO2-x. Spreading kinetics of Sn-Ti/ZrO2 systems was controlled by the reaction-limited dynamics. The diffusion of released oxygen changed the spreading rate in the rapid-spreading stage. [ABSTRACT FROM AUTHOR]

The propagation and underlying mechanisms of the boreal summer quasi-biweekly oscillation (QBWO) over the entire Asian monsoon region are investigated, based on ECMWF Interim reanalysis (ERA-Interim) data, GPCP precipitation data, and an atmospheric general circulation model (AGCM). Statistical analyses indicate that the QBWO over the Asian monsoon region derives its main origin from the equatorial western Pacific and moves northwestward to the Bay of Bengal and northern India, and then northward to the Tibetan Plateau (TP) area, with a baroclinic vertical structure. Northward propagation of the QBWO is promoted by three main mechanisms: barotropic vorticity, boundary moisture advection, and surface sensible heating (SSH). It is dominated by the barotropic vorticity effect when the QBWO signals are situated to the south of 20°N. During the propagation taking place farther north toward the TP, the boundary moisture advection and SSH are the leading mechanisms. We use an AGCM to verify the importance of SSH on the northward propagation of the QBWO. Numerical simulations confirm the diagnostic conclusion that the equatorial western Pacific is the source of the QBWO. Importantly, the model can accurately simulate the propagation pathway of the QBWO signals over the Asian monsoon region. Simultaneously, sensitivity experiments demonstrate that the SSH over northern India and the southern slope of the TP greatly contributes to the northward propagation of the QBWO as far as the TP area. [ABSTRACT FROM AUTHOR]

In horizontal position welding process, the key problem is the poor weld formation and weld defects induced by the downward motion of the molten metal. Base on the research results of welding process, droplet transfer, molten pool behavior, temperature field, reasons, and solutions of the typical weld appearance defects in rotating arc narrow gap horizontal GMAW are studied. The causes and mechanisms of the defects of sagging surface, under cut, and convex surface are explored. The relationship of the defects and the welding parameters is established. The main causes of the appearance defects can be classified into three categories. The first one is the excessive heat input of the welding process, the second one is unstable welding process, and the third one is the mismatch between the fusion area of base metal and filling metal. Finally, the optimum welding parameters of rotating arc narrow gap horizontal welding are determined. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to explore the effects of patient education and progressive muscle relaxation (PMR) alone or combined on adherence to continuous positive airway pressure (CPAP) treatment in obstructive sleep apnea (OSA) patients. Methods: One hundred and fifty-two Han Chinese OSA patients were randomly assigned to a control group (C), an education group (E), a PMR group (P), and an education + PMR group (E + P), with 38 patients each group. The adherence to CPAP was defined as 4 or more hours of CPAP usage per night and at least 9 of each 14 nights of ventilator use. The CPAP adherence rates, cumulative patient dropout rates, CPAP usage, and scores of daytime sleepiness, sleep quality, anxiety, and depression were compared among the groups at 4, 8, and 12 weeks of intervention. Results: All study groups were comparable in baseline characteristics. Group E + P showed significant improvement in CPAP adherence, daytime sleepiness, and sleep quality compared with group C at 4, 8, and 12 weeks of intervention. Compared with group C, group E only showed significant improvement in CPAP adherence, daytime sleepiness, and sleep quality at 4 weeks of intervention, while group P showed no significant improvement over time. Scores of anxiety and depression were significantly improved in group E + P compared with group C at 12 weeks of intervention. Conclusions: Combined intervention with patient education and PMR can significantly improve CPAP adherence in OSA patients for at least 12 weeks. The intervention paradigm may serve as an important reference for future studies on CPAP adherence. [ABSTRACT FROM AUTHOR]

The trend in the atmospheric heat source over the central and eastern Tibetan Plateau (CE-TP) is quantitatively estimated using historical observations at 71 meteorological stations, three reanalysis datasets from 1980-2008, and two satellite radiation datasets from 1984-2007. Results show that a weakening of sensible heat (SH) flux over the CE-TP continues. The most significant trend occurs in spring, induced mainly by decelerated surface wind speeds. The ground-air temperature difference shows a notable increasing trend over the last 5 years. Trends in net radiation flux of the atmospheric column over the CE-TP, evaluated by two satellite radiation datasets, are clearly different. Trends in the atmospheric heat source calculated by the three reanalysis datasets are not completely consistent, and even show opposite signals. Results from the two datasets both show a weakening of the heat source but the magnitude of one is significantly stronger, whereas an increase is indicated by the other data. Therefore, it is challenging to accurately calculate the trend in the atmospheric heat source over the CE-TP, particularly from the estimates of the reanalysis datasets. [ABSTRACT FROM AUTHOR]

According to the Kukhtarev equations and a simplified model based on the photovoltaic charge carriers transport mechanism, the distributions of the index changes (DICs) in LiNbO3:Fe crystals induced by sheet beams with various intensity profiles are theoretically analyzed. The numerically simulated results coincide with the analytic expressions deduced from the simplified model. The DICs in a LiNbO3:Fe crystal induced by sheet beams with rectangular, Gaussian and square law profiles are measured by using the interferometric method. By employing the analytic expressions, the experimental data points are well fitted. By utilizing the angular spectrum theory and the ray equation, the uniformities of the intensity profiles of the writing beams along the propagation directions and the influences of the self-defocusing effect of the crystal are numerically simulated, respectively. The results show that the experimental results are reliable. The numerically simulated method and the analytic expressions can be both employed to predict the DICs induced by sheet beams with various light intensity profiles. Furthermore, utilizing writing beams with proper intensity profiles, any desired index distributions could be obtained. [ABSTRACT FROM AUTHOR]