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The micro-size flake silver powders were prepared through wet-chemical reduction method by using a micro-jet reactor. Herein ascorbic acid was used as a reducing agent, and sulfuric acid was used as a stabilizer. And the lauric acid was used as a dispersing agent to prevent particles’ agglomeration. The micro-jet reactor collides the two solutions together and uniformly mixes outside the reactor, to avoid the problem of clogging in the microchannel. The effects of dispersant addition and micro-jet flow rate on the morphology, particle size, and other parameters of silver powder is investigated in the present work. Interestingly, the addition of dispersant agent and stabilizer have a significant impact on the morphology and parameter of the silver particles. Under the conditions of micro-jet flow rate of 50 mL·min−1, sulfuric acid addition amount of 2%, and lauric acid addition amount of 0.8% by the weight of silver nitrate, a kind of flake silver powders with 4.40–4.70 μm can be prepared. The volume resistivity of the silver paste prepared from the obtained flake silver powders is in the range of 1.4–1.6 × 10−4 Ω·cm−1, which meets the application test requirements of conductive silver paste.

Efforts have been made to find a better therapeutic approach with fewer side effects in treating chronic obstructive pulmonary disease (COPD). This study investigated the effect of Buyuan decoction (BYD) on autophagy in COPD rats. An experimental model with Sprague-Dawley rats was established by lipopolysaccharide (LPS) injection and cigarette smoke exposure. Rats were randomly allocated into blank control (normal control), experimental model, low-dose BYD (8.0 g/kg/day), medium-dose BYD (16.0 g/kg/day), high-dose BYD (32.0 g/kg/day) and 3-MA (methyladenine) groups (6 rats/group). Cell and tissue morphology were observed using hematoxylin and eosin staining. Autophagic vesicles were examined with a transmission electron microscope. Protein expression of LC3-II/I, BNIP- 1, ATG7, p62, PI3K and p-PI3K in lung tissue was detected by Western blotting. Compared with the experimental model group, the inflammatory infiltrate in lung tissue was reduced, the nuclei of the pulmonary epithelial cells were restored to normal, and the expression of LC3, BNIP1, ATG7 and p-PI3K was significantly downregulated, while p62 expression was significantly upregulated after treatment with the BYD. The effect was most significant in the low-dose BYD group (P

Seismic method is a major approach for detecting the seismic geological features ahead of the tunnel, understanding the distribution of unfavorable geology, and ensuring the safety of tunnel construction. Observation system is the key for seismic detection, many studies have been conducted to optimize the observation system; however, most of them focused on the surface seismic investigation and numerical simulation rather than in tunnel field environment (limited aperture and full space environment). How to obtain better wavefield information with limited observation aperture is a great challenge. In this study numerical simulation and instrumental techniques (GPR, DC, etc.) were implemented to further check the result of seismic detection at the 1# tailrace tunnel at the Wudongde hydropower station. In the field case, observation detectors were arranged spatially in the tunnel and source points were placed in four ways: linearly along a single side, on the tunnel face, in front of the detectors, and behind the detectors. Then, after data acquisition, the data processing is conducted to carry out the migration results. The imaging results indicate that the observation system with sources and detectors in liner arrangement (with equal interval) helps to suppress artifacts, further supporting the advantages of spatial observation system with liner observation line (detectors). Moreover, the study provides suggestions for geological prospecting in similar tunnel projects.

The variable density method has become an effective method to solve the topology optimization problem of continuum structure due to its advantages such as few design variables and high efficiency. Aiming at the problem of the gray unit and sawtooth boundary in the optimization process of the variable density method, a post-processing method of variable density method for continuum topology optimization is proposed in this paper. The topology optimization model is binarized and the sawtooth shape boundary line is extracted, and the target discrete corner point set is obtained, used as the sample point for curve fitting to obtain the optimized structure with smooth boundary. Experimental results show that this method effectively avoids the zigzag boundary and intermediate density of the optimization result, and improves the manufacturability of the optimization result under the premise of ensuring that the structural performance is within the allowable range.

The MoS2-doped graphite/copper self-lubricating composites (Gr-MoS2/Cu) were synthesized by a rapid microwave sintering procedure. In this paper, the thermal properties and friction behaviors of Gr-MoS2/Cu composites at room temperature to 200 °C were studied. The doping of molybdenum disulfide solid lubricant into graphite could promote the formation of friction film in the friction process, and optimize the friction and wear properties of graphite/copper composites. Meanwhile, the thermal and frictional properties of the composites at 200 °C are better than those at room temperature. In addition, the influence of the heat dissipation on the friction property of composites was analyzed and studied. The excellent heat dissipation property of the composites effectively mitigated the damage of the friction film and improved the friction property of the composites in the friction process.

【Objective】 Hydraulic loss is a great concern in designing hydraulic apparatus and the objective of this paper is to investigate how to reduce it in the outlet conduit so as to improve the performance of shaft tubular pump. 【Method】 The analysis was based on the standard k-ε turbulent model, and water flow in the conduit was numerically simulated with the simulated results verified against experimental test. The validated model was then used to study the influence of outlet conduit parameters on the performance of the pump, from which we proposed three outlet conduits with different outlet widths. The simulated hydraulic loss and flow pattern in the conduits with different plane diffusion angles, elevation diffusion angles and transition section lengths were analyzed using the single factor method. 【Result】 With the increase in the plane diffusion angle, the hydraulic loss in the outlet decreased first followed by an increase after the angle was larger than 17o. For elevation diffusion angle less than 7°, the hydraulic loss remained almost unchanged, while when it was larger than 7o, the hydraulic loss increased steadily. With the increase in the diffusion section length, the hydraulic loss decreased first followed by an increase when the relative length of the transition section was more than 0.6~0.8. When the hydraulic design parameters were within the normal range, we did not find bad flow patterns in the conduit. 【Conclusion】 When the design parameters are selected appropriately, the hydraulic loss of the outlet conduit of the front shaft tubular pump system can be minimized, and the pump system efficiency will be improved.

Traditional machine learning relies on a centralized data pipeline for model training in various applications; however, data are inherently fragmented. Such a decentralized nature of databases presents the serious challenge for collaboration: sending all decentralized datasets to a central server raises serious privacy concerns. Although there has been a joint effort in tackling such a critical issue by proposing privacy-preserving machine learning frameworks, such as federated learning, most state-of-the-art frameworks are built still in a centralized way, in which a central client is needed for collecting and distributing model information (instead of data itself) from every other client, leading to high communication burden and high vulnerability when there exists a failure at or an attack on the central client. Here we propose a principled decentralized federated learning algorithm (DeceFL), which does not require a central client and relies only on local information transmission between clients and their neighbors, representing a fully decentralized learning framework. It has been further proven that every client reaches the global minimum with zero performance gap and achieves the same convergence rate $O(1/T)$ (where $T$ is the number of iterations in gradient descent) as centralized federated learning when the loss function is smooth and strongly convex. Finally, the proposed algorithm has been applied to a number of applications to illustrate its effectiveness for both convex and nonconvex loss functions, time-invariant and time-varying topologies, as well as IID and Non-IID of datasets, demonstrating its applicability to a wide range of real-world medical and industrial applications.

Regarding the issue of changes in the aerodynamic force of the bridge main beam under the action of wind-driven rain, this article explores the changes in air density caused by rainfall, the calculation theory of raindrop impact force and its simplified mass-weighted equivalent method (MWEM), and the calculation method of water accumulation thickness on the surface of the main beam. The calculation shows that the changes in air density caused by rainfall can be ignored, and the error of the MWEM increases with the increase in rainfall intensity; however, even at a rainfall intensity of 709 mm/h, the deviations in the MWEM value of the horizontal and vertical raindrop impact force is only about +5% and −4%, respectively. Then, based on the above analysis, a calculation model for the aerodynamic three-component forces of the main beam caused by rainfall under the action of wind-driven rain is provided. Finally, taking two typical main beam sections as an example, static three-component force tests are carried out on the main beam model under different rainfall intensities. The experimental results show that the drag coefficient variations obtained through the MWEM are in good agreement with experimental data, which proves the correctness of the theoretical model of the raindrop impact force. But for the lift and torque coefficient, the differences between theoretical and experimental values are much more significant than the drag coefficient, and it increases with the increase in rain intensity. It can be seen that the surface ponding model and influence of rainfall intensity need to be further explored. In summary, the theoretical calculation method for the additional aerodynamic force of wind-driven rain on the main beam proposed in this article is convenient and practical, and it can provide a certain reference for the rapid safety assessment of bridges under extreme meteorological conditions.

Graphene has become one of the most potential reinforcing materials because of the unique two-dimensional structure and the excellent thermal, electrical, and mechanical properties. In this paper, the preparation of the aluminum−graphene composites was reviewed. The influence factors on the mechanical properties and conductivity performances of the aluminum−graphene composites were introduced. Subsequently, the applications of the aluminum−graphene composites in the field of high strength and high conductivity materials were investigated. Challenges on the preparation of high quality graphene powders, the scale production of mixing powders, and the continuously processing method in the industrialization were discussed. The possible technological methods for the industrialization of aluminum−graphene composites and the potential research directions were proposed.

This paper extends frequency domain quantitative electroencephalography (qEEG) methods pursuing higher sensitivity to detect Brain Developmental Disorders. Prior qEEG work lacked integration of cross-spectral information omitting important functional connectivity descriptors. Lack of geographical diversity precluded accounting for site-specific variance, increasing qEEG nuisance variance. We ameliorate these weaknesses. (i) Create lifespan Riemannian multinational qEEG norms for cross-spectral tensors. These norms result from the HarMNqEEG project fostered by the Global Brain Consortium. We calculate the norms with data from 9 countries, 12 devices, and 14 studies, including 1564 subjects. Instead of raw data, only anonymized metadata and EEG cross-spectral tensors were shared. After visual and automatic quality control, developmental equations for the mean and standard deviation of qEEG traditional and Riemannian DPs were calculated using additive mixed-effects models. We demonstrate qEEG “batch effects” and provide methods to calculate harmonized z-scores. (ii) We also show that harmonized Riemannian norms produce z-scores with increased diagnostic accuracy predicting brain dysfunction produced by malnutrition in the first year of life and detecting COVID induced brain dysfunction. (iii) We offer open code and data to calculate different individual z-scores from the HarMNqEEG dataset. These results contribute to developing bias-free, low-cost neuroimaging technologies applicable in various health settings.

Abstract Dissolved oxygen evolving from aviation fuel leads to an increase in the oxygen concentration in an inert aircraft fuel tank ullage that may increase the flammability of the tank. Aviation fuel scrubbing with nitrogen-enriched air (NEA) can largely reduce the amount of dissolved oxygen and counteract the adverse effect of oxygen evolution. The gas–liquid mass transfer characteristics of aviation fuel scrubbing are investigated using the computational fluid dynamics method, which is verified experimentally. The effects of the NEA bubble diameter, NEA superficial velocity and fuel load on oxygen transfer between NEA and aviation fuel are discussed. Findings from this work indicate that the descent rate of the average dissolved oxygen concentration, gas holdup distribution and volumetric mass transfer coefficient increase with increasing NEA superficial velocity but decrease with increasing bubble diameter and fuel load. When the bubble diameter varies from 1 to 4 mm, the maximum change of descent rate of dissolved oxygen concentration is 18.46%, the gas holdup is 8.73%, the oxygen volumetric mass transfer coefficient is 81.45%. When the NEA superficial velocities varies from 0.04 to 0.10 m/s, the maximum change of descent rate of dissolved oxygen concentration is 146.77%, the gas holdup is 77.14%, the oxygen volumetric mass transfer coefficient is 175.38%. When the fuel load varies from 35 to 80%, the maximum change of descent rate of dissolved oxygen concentration is 21.15%, the gas holdup is 49.54%, the oxygen volumetric mass transfer coefficient is 44.57%. These results provide a better understanding of the gas and liquid mass transfer characteristics of aviation fuel scrubbing in aircraft fuel tanks and can promote the optimal design of fuel scrubbing inerting systems.

Sleep loss may lead to negative bias during social interaction. In the current study, we conducted a revised social evaluation task experiment to investigate how sleep deprivation influences the self-referential and cognitive processes of social feedback. The experiment consisted of a first impression task and a social feedback task. Seventy-eight participants completed the first impression task and were divided into normal and poor sleep groups. The results of an independent samples t-test showed that participants who slept worse were less likely to socialize with others but did not evaluate others as less attractive. Afterward, 22 of the participants from the first impression task were recruited to complete the social feedback task during functional magnetic resonance imaging (fMRI) on the mornings following two different sleep conditions at night: one night of normal sleep and one night of sleep deprivation. The results of this within-subject design study showed that participants who experienced the latter condition showed increased activation within the default mode network (i.e. superior parietal lobule, precuneus, inferior parietal lobule, inferior temporal gyrus, and medial frontal gyrus) and anterior cingulate cortex (ACC) and stronger negative insula functional connectivity (FC) with the precuneus to negative feedback than positive feedback. The altered activation and behavioral pattern may indicate a negative bias for social cues. However, stronger negative coupling may indicate stronger cognitive control, which may protect against potential damage to self-concept. Our study suggested that sleep impairs most social functions, but may protect against impairment of important ones, such as self-concept.

【Background】 Shaft tubular pump is a new pumping device with its generator installed in an open shaft, which is moisture-proof and has good ventilation. It has several advantages including easy operation and maintenance, low cost, and simple structure. It is generally used in low-lift and large-flow pumping stations. The development in shaft tubular pump has made it a favorable choice for ultra-low lift and large-flow pumping stations like Shenjiang Pumping Station for regional flood and drainage control. 【Objective】 The purpose of this paper is to test in situ hydraulic performance of shaft tubular pump in ultra-low lift and large-flow pumping station. 【Method】 We took Shenjiang Pumping Station as an example; the external characteristics of its shaft tubular pump were studied using the method of model test, from which we propose plans to improve it. 【Result】 When the blade angle was 0°, the pump was most efficient, reaching 77.57%, with the flow rate and lift being 220.5 L/s and 1.95 m respectively. In the range of the lifts we tested, the pumping station had sufficient cavitation margin and did not cause cavitation damage. When the blade angle was 0° and maximum lift was 2.93 m, the runaway speed was 1.80 times the rated speed. The flow in the original design was too slow while its associated runaway speed under maximum lift was too large, not ideal for safe operation of the pumping station. An optimization scheme for increasing the rated speed of the pump was proposed. Verification against experimental data showed that the energy and cavitation characteristics, runaway speed all met the requirements. 【Conclusion】 The shaft tubular pump has a good hydraulic performance and efficiency, and it is potential for use in ultra-low lift pump stations.

China's social and economic development is currently transitional. There is great incompatibility between the traditional construction land allocation model and the requirements of social and economic development, marked by a prominent contradiction between the supply and demand of construction land that has severely restricted the sustained and healthy development of China's social economy. Improving the efficiency of land resource allocation has become a new driving force for economic growth. With the limited driving power of this factor input for economic development, it is important to explore the occurrence and mechanism of rare construction land resource misallocation to secure the structural benefits of construction land allocation and sustainable economic development, as correcting construction land misallocation would greatly advance land supply-side reform and improve the efficiency of land resource allocation. To explain the mechanism of construction land misallocation, the article builds models for the measurement of both construction land misallocation and its mechanism, applying methods such as spatial autocorrelation model and the spatial Dubin model (SDM). Using these models, we focus on the space-time characteristics, driving factors, and spatial effects of construction land misallocation in China from 2001 to 2016. The sample data in this article come from 235 prefecture-level cities in China. The results show that the misallocation of construction land in China tends to decrease, followed by an increase, with a spatial distribution high in the West and low in the East. There were obvious spatial agglomeration and association features of construction land misallocation and its influencing factors in China, but the spatial correlation effect has weakened. Land financial dependence, industrial structure optimization, and market development have a significant negative impact on construction land misallocation, while government corruption and economic development have a significant positive impact and exert a space spillover effect. We find that the misallocation of construction land in our country is widespread and shows an upward trend. Changing the mode of economic development, increasing government governance, and improving market mechanisms and regional integration can effectively alleviate the misallocation of regional construction land. This paper is significant in discussing the driving factors of construction land misallocation from both theoretical and empirical perspectives, and in analyzing their spatial effect for the first time. It provides research directions and ideas for quantitatively exploring the problem of land resource misallocation, and indicates a feasible way to correct the misallocation of land resources.

Objective To detect the alterations of the transcriptome in host cells infected by enterovirus D68 (EV-D68) and look for the genes involved in its infection so as to lay a foundation for the preliminary exploration of the infection mechanism. Methods The virus was inoculated into human rhabdomyosarcoma (RD) cells at a multiplicity of infection (MOI) of 0.01. After 24 h, RNA was extracted from the infected RD cells and control cells for transcriptome sequencing. Differentially expressed genes (DEGs) were screened and analyzed by using Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Eight DEGs, EGR1, c-fos, ZNF625, ARRDC3, c-jun, ASNS, CHAC1 and ADM2 were validated by RT-qPCR. Results A total of 140 genes with at least 2-fold changes at expression level were identified from the sequencing results, of which 71 were up-regulated and 69 were down-regulated. The results of GO functional enrichment analysis mainly involved the regulation and response to ions while the results of KEGG enrichment analysis mainly related to parathyroid hormone synthesis, secretion and action, IL-17 and GnRH signaling pathway, Toll-like receptor signaling pathway, and MAPK signaling pathway and so on. The RT-qPCR results showed that the trend of fold change of expression in the selected 8 genes was basically consistent with the sequencing results, and the expression levels of c-fos and c-jun were increased with the increase of virus MOI and infection duration. Conclusion By validating and using the functional and enrichment analysis, we infer that the mechanism of EV-D68 exacerbating asthma may be related to the up-regulation of c-fos, and MAPK signaling pathway may play a pro-inflammatory and antiviral role during EV-D68 infection.

The transport of phosphate between cytoplasm and subcellular compartments is critical for plant metabolic regulation. We conducted bioinformatic analysis, heterologous expression in yeast, gene expression pattern and subcellular localization analysis to characterize the possible functions of OsPHT4 gene family in rice. Together with the PHT4 genes from higher plants, OsPHT4s can be classified into six distinct groups. OsPHT4;1–OsPHT4;4 are targeted to chloroplasts, and OsPHT4;6-1 and OsPHT4;6-2 are located to Golgi apparatus. OsPHT4 proteins can mediate inorganic phosphate (Pi) transport in yeast. In addition, dynamic transcriptional changes determined by qRT-PCR revealed different expression profiles of OsPHT4 genes in response to phosphate starvation, salicylic acid, abscisic acid and salt stress treatments. These results suggested that OsPHT4 proteins are involved in Pi distribution between the cytoplasm and chloroplast or Golgi apparatus and also involved in stress responses.

We put forward the multipolar model which captures the physics behind linear and nonlinear response driven by high-quality (high-Q) supercavity modes in subwavelength particles. We show that the formation of such trapped states associated with bound states in the continuum (quasi-BIC) can be understood through multipolar transformations of coupled leaky modes. The quasi-BIC state appears with increasing the order of the dominating multipole, where dipolar losses are completely suppressed. The efficient optical coupling to this state in the AlGaAs nanodisk is implemented via azimuthally polarized beam illumination matching its multipolar origin. We establish a one-to-one correspondence between the standard phenomenological non-Hermitian coupled-mode theory and multipolar models. The derived multipolar composition of the generated second-harmonic radiation from the AlGaAs nanodisk is then validated with full-wave numerical simulations. Back-action of the second-harmonic radiation onto the fundamental frequency is taken into account in the coupled nonlinear model with pump depletion. A hybrid metal-dielectric nanoantenna is proposed to augment the conversion efficiency up to tens of per cent due to increasing quality factors of the involved resonant states. Our findings delineate novel promising strategies in the design of functional elements for nonlinear nanophotonics applications.

Aiming at the current situation that ultrafiltration membrane is inefficient to remove the dissolved organic matters (DOM) in raw water and will meet serious membrane fouling after long-term operation, powdered activated carbon (PAC) was used as the coating material to form a cake layer on the surface of 100 kDa Polyvinylidene fluoride (PVDF) ultrafiltration membrane. In order to study its capability of removing macromolecular organic matters, particles and bacteria in micro-polluted water and the corresponding mechanism, contact angle (CA), fourier transform infrared spectrometer (FTIR) and scanning electron microscope (SEM) were systematically investigated to analyze the hydrophobicity, composition of the biofilm formed and morphology on the membrane surface. Results showed that the dynamic membrane can significantly improve the removal of organic matters through the adsorption of the powdered activated carbon. The removal rates of dissolved organic carbon (DOC), UV254 and proteinaceous substance are respectively 91.5%, 94.4% and 91.1%. Compared with the control PVDF ultrafiltration membrane, the dynamic membrane has better hydrophilicity. The loose cake layer formed by powdered activated carbon can also avoid the direct interaction between DOM and UF membrane, which slowed down the membrane fouling development.

Textile yarns are subjected to numerous types of forces during knitting, usually leading to yarn damages, such as decrease in tensile, bending, shearing, and surface properties, which are closely related to different yarn properties, knitted structures/actions, and machine settings. This article comprehensively evaluated yarn damages in the computerized flat knitting process. Five different commercially available and commonly used yarns including cotton, wool, polyester, acrylic, and viscose were selected as raw materials, and the tensile, bending, shear, and frictional properties were investigated and compared before knitting and after being unraveled from plain- and rib-knitted fabrics, respectively. The results show that knitting actions/structures exhibit different damage extents for all different raw materials. It has been observed that the modulus is declined by 3–30% for bending, 2–10% for tensile, and 8–80% for shearing due to flat knitting action, respectively. The frictional coefficient of yarns also increased from 6 to 23%. As compared to yarn before knitting, the yarns unroved from plain and rib structures have been damaged to a great extent as a result of the loss of mechanical properties. The results are completely in agreement with the statistical analysis that clearly represents the significant loss in yarn properties during the knitting process. The microscopic analysis of the yarns clearly illustrates the effect of knitting action on yarn surface and mechanical properties. For yarn’s cross-sectional shearing properties testing, this article self-designed an innovative “Yarn Shear Testing Device.” The methodology and results are of great importance for improving the quality of knitted products, evaluating knitting yarns’ knittability, and in the development of high-performance technical textiles.

Lithium-ion batteries (LIBs) are widely used in electric vehicles (EVs) due to their superior power performance over other batteries. However, when connected in series, overcharged cells of LIBs face the risk of explosion, and undercharged cells decrease the life cycle of the battery. Eventually, the inconsistency phenomenon between cells resulting from manufacturing tolerance and usage process reduces the overall charging capacity of the battery and increases the risk of explosion after long-time use. Research has focused on synthesizing active material to achieve higher energy density and extended life cycle for LIBs while neglecting a comparative analysis of equalization technology on the performance of battery packs. In this paper, a nondissipative equalization structure is proposed to reconcile the inconsistency of series-connected LIB cells. In this structure, a circuit uses high-level equalization units to enable direct energy transfer between any two individual cells, and dual interleaved inductors in each equalization unit increase the equalization speed of a single cell in one equalization cycle by a factor of two. The circuit is compared with the classical inductor equalization circuit (CIEC), dual interleaved equalization circuit (DIEC), and parallel architecture equalization circuit (PAEC) in the states of standing, charging, and discharging, respectively, to validate the advantages of the proposed scheme. Considering the diversity of imbalance states, the state of charge (SOC) and terminal voltage are both chosen as the equalization criterion. The second-order RC model of the LIB and the adaptive unscented Kalman filter (AUKF) algorithm are employed for SOC estimation. For effective equalization, the adaptive fuzzy neural network (AFNN) is utilized to further reduce energy consumption and equalization time. The experiment results show that the AFNN algorithm reduces the total equalization time by approximately 37.4% and improves equalization efficiency by about 4.89% in contrast with the conventional mean-difference algorithm. Particularly, the experiment results of the equalization circuit verification certify that the proposed equalization structure can greatly accelerate the equalization progress and reduce the equalization loss compared to the other three equalization circuits.

Health and financial uncertainties, as well as enforced social distancing, during the COVID-19 pandemic have adversely affected the mental health of people. These impacts are expected to continue even after the pandemic, particularly for those who lack support from family and friends. The salience network (SN), default mode network (DMN), and frontoparietal network (FPN) function in an interconnected manner to support information processing and emotional regulation processes in stressful contexts. In this study, we examined whether functional connectivity of the SN, DMN, and FPN, measured using resting-state functional magnetic resonance imaging before the pandemic, is a neurobiological marker of negative affect (NA) during the COVID-19 pandemic and after its peak in a large sample (N = 496, 360 females); the moderating role of social support in the brain-NA association was also investigated. We found that participants reported an increase in NA during the pandemic compared to before the pandemic, and the NA did not decrease, even after the peak period. People with higher connectivity within the SN and between the SN and the other two networks reported less NA during and after the COVID-19 outbreak peak, and the buffer effect was stronger if their social support was greater. These findings suggest that the functional networks that are responsible for affective processing and executive functioning, as well as the social support from family and friends, play an important role in protecting against NA under stressful and uncontrollable situations.

Background: The novel coronavirus (COVID-19) pandemic has affected humans worldwide and led to unprecedented stress and mortality. Detrimental effects of the pandemic on mental health, including risk of post-traumatic stress disorder (PTSD), have become an increasing concern. The identification of prospective neurobiological vulnerability markers for developing PTSD symptom during the pandemic is thus of high importance. Methods: Before the COVID-19 outbreak (September 20, 2019–January 11, 2020), some healthy participants underwent resting-state functional connectivity MRI (rs-fcMRI) acquisition. We assessed the PTSD symptomology of these individuals during the peak of COVID-19 pandemic (February 21, 2020–February 28, 2020) in China. This pseudo-prospective cohort design allowed us to test whether the pre-pandemic neural connectome status could predict the risk of developing PTSD symptom during the pandemic. Results: A total of 5.60% of participants (n = 42) were identified as being high-risk to develop PTSD symptom and 12.00% (n = 90) exhibited critical levels of PTSD symptoms during the COVID-19 pandemic. Pre-pandemic measures of functional connectivity (the neural connectome) prospectively classified those with heightened risk to develop PTSD symptom from matched controls (Accuracy = 76.19%, Sensitivity = 80.95%, Specificity = 71.43%). The trained classifier generalized to an independent sample. Continuous prediction models revealed that the same connectome could accurately predict the severity of PTSD symptoms within individuals (r2 = 0.31p

Atmospheric pollution can affect human production life and physical and mental health to a great extent. In this paper, the hourly pollutant monitoring data from five state-controlled automatic atmospheric monitoring stations in Daqing City from 2017 to 2021 are collected to analyze the temporal and spatial variation patterns of CO, SO2, NO2, PM2.5, PM10, O3. And to assess the health risks of atmospheric particulate matter. The HYSPLIT model is applied to analyze air pollutants' transport pathways and the potential source areas of atmospheric particulate matter with the PSCF model. The results show that the concentrations of SO2 and NO2 are higher in the north of Daqing and the concentrations of pollutants generally show a decreasing trend with time. The hazard quotient (HQ) for atmospheric particulate matter, which is slightly above the safe range set by the EPA, is higher in winter and spring. After principal component analysis, CO, NO2, and PM10 are the main factors affecting PM2.5. In the summer, the main urban area's air pollution is mostly influenced by the southwest pollution trajectory. In other seasons, the northwest route predominantly regulates the regional transfer of contaminants. The key regions that could be the sources of atmospheric particulate matter include North China, Inner Mongolia, Mongolia, and Russia.

Outdoor thermal comfort in urban environmental settings is often investigated at a small scale, e.g., in street canyons. Yet, pedestrian thermal comfort in a district is scarcely assessed, especially in terms of the comprehensive overhead environments such as sky openness, green coverage, and sun exposure. This study provides a systematic methodology to quantify the district-scale pedestrian thermal comfort performance considering overhead environments. Mobile transects were designed for data collection during peak hot hours within a medium-scale district. A portable weather station was used to measure outdoor thermal environments and a fisheye lens was to capture hemispherical images of overhead environments. A universal thermal comfort index, Physiological Equivalent Temperature (PET), was subsequently calculated with the collected thermal environment data. Meanwhile, hemispherical images were segmented into areas of visible sky, overhead greenery, and sun, which were further weighed into corresponding view factors. Eventually, a multiple regression model was developed between PET and view factors together with meteorological variables. The results showed that a decrease in the sky view factor of 0.17 or an increase in the green view factor of 0.21 could reduce PET by 0.5°C. The findings scientifically support resilient urban planning in greening and cooling urban dense spaces for comfortable and liveable environments.

High-risk societies are uncertain, ambiguous and unpredictable. Risk fluctuations are prone to the intertwining and overlapping of various accident hazards and safety risks. China is prone to the interweaving and overlapping of various accident hazards and safety risks, which leads to an increase in the number of factors affecting public safety as well [1]. Therefore, this paper will quantify specific ranking indicators in terms of frequency of hazards, degree of hazards and vulnerability to different hazards. The ranking is based on the quantified results in red, yellow and green and the hazard risk level is calculated according to the risk formula. This study will take the Chengdu-Chongqing region as an example and optimise the storage of materials in the emergency logistics base in order to maximise the precise and rapid supply of materials to the main demand points. The efficiency of emergency material deployment will be further improved and emergency materials will be well secured.

Two benzimidazole-based conjugated polyelectrolytes (+)-PPBIPV and (-)-PPBIPV which have opposite charges on their side chains were synthesized via Heck coupling reaction and characterized by 1H-NMR, UV-vis and PL spectroscopy. These two polyelectrolytes are both consisted of benzimidazole derivatives and phenylenevinylene units. The absorption and emission spectra reveal that the polymers both have solvent-dependency and concentration-dependency, and they exhibit aggregation effect in aqueous solution. In the respect of ion detection, the aqueous solution of (+)-PPBIPV has excellent selectivity and sensitivity for Fe3+. Moreover, Pd2+ can almost completely quench the fluorescence of (+)-PPBIPV in methanol solution, and its quenching constant KSV is 5.93×104 M-1. For (-)-PPBIPV, Sn2+ can double the fluorescence intensity of its aqueous solution, while (-)-PPBIPV has good identification for Fe3+ in methanol with a KSV = 3.44×105 M-1. Hence, two polyelectrolytes have considerable potential to become effective fluorescent sensing materials for some specific metal ions. All of the stoichiometric relationships between metal ions and conjugated polyelectrolytes were calculated using Benesi-Hildebrand equation.

This study developed a pair of lane changing (LC) model and car following (CF) model. They are used to investigate mutually adaptive maneuver of LC vehicle (LCV) and its immediate CF vehicle during the LCV's inserting process. The two models are developed based on a multianticipative CF model to simulate both of the LC and LC-adaptive CF maneuvers. A group of pairwise parameters are applied in the models to reflect the stimuli perceived by the two vehicle drivers simultaneously. Based on the united model framework, the features of the two vehicle maneuvers which are mutually and intensively influenced can be compared and analyzed. Vehicle trajectories collected on the urban arterial are applied to calibrating and validating the two models. Results show that the developed models can fit the trajectories in a higher accuracy than the previous models. The estimates of the model parameters revealed that dynamics of lateral moving vehicle influence the LC and CV maneuvers in different ways. It is found that the lateral influence has the heaviest influence on the vehicle maneuvers than other stimuli. The vehicles also adjust their maneuvers along with the change of traffic signal or LC target.

Automated pavement distress detection benefits road maintenance and operation by providing the condition and location of various distress rapidly. Existing work generally relies on manual labor or specific algorithms trained by dedicated datasets, which hinders the efficiency and applicable scenarios of methods. Street view map provides interactive panoramas of a large scale of urban roadway network, and is updated in a recurrent manner by the provider. This paper proposed a deep learning method based on a pre-trained neural network architecture to identify and locate different distress in real-time. About 20,000 street view images were collected and labeled as the training dataset using the Baidu e-map. Eight types of distress are notated using Yolov3 deep learning architecture. The scale-invariant feature transform (SIFT) descriptors combined with GPS and bounding boxes were applied to judge the deterioration of the distress. A decision tree was designed to evaluate the change of the distress over some time. A typical road in Shanghai was selected to verify the effectiveness of the proposed model. The images of the road from 2015 to 2017 were collected from the street view map. The results showed that the mean average precision of the proposed algorithm is 88.37%, demonstrating the vast potential of applying this method to detect pavement distress. 43 distress were newly generated, and 49 previous distress were patched in the two years. The proposed method can assist the authorities to schedule the maintenance activities more effectively.

Chromium carbide (Cr3C2) coatings on the diamond were fabricated using the mixtures of molten salt of NaCl and BaCl2, powders of metallic chromium and diamond as raw materials in the temperature range of 750–900 °C by the microwave-assisted molten-salt synthesis. The morphology, microstructure and phase composition of the surface layer were characterized by Scanning Electron Microscopy, Energy-dispersive Spectrometry and X-ray diffraction. The results show that the surface of the diamond particles could be coated with Cr, forming a uniform and continuous Cr3C2-coated layer. The coatings thickness on the diamond can be controlled by adjusting the heating temperature and time. The coating thickness expanded from 0.73 to 2.30 µm when the temperature was increased from 750 °C to 900 °C, and increasing rapidly during the temperature range of 800 °C–850 °C, the coating thickness expanded from 1.30 to 2.80 µm when the holding time was increased from 0.5 h to 4 h. The results illustrate that the microwave-assisted molten salt synthesis plays a positive role in chromium coatings on the diamond, offering a potent method for the surface metallization of diamond.

We present a rare case of spinal subdural hematoma induced by guidewire-based lumbar drainage in a subarachnoid hemorrhage patient with a ruptured intracranial aneurysm. Decreased muscle strength and muscle tension of bilateral lower limbs were noted, and an MRI confirmed the spinal subdural hematoma from the sacral to the thoracic segments. The spinal subdural hematoma evacuation and spinal canal decompression were performed by laminectomy. However, the patient did not benefit from the surgery and developed lower limb muscle atrophy. The complication of the spinal subdural hematoma after lumbar drainage is extremely rare; only limited approaches are available for the treatment of spinal hematoma to improve the outcome and avoid severe consequences. Thus, the present case might suggest refraining from use of a guidewire during lumbar drainage for the prevention of spinal subdural hematoma and close observation of the related symptoms and signs for the early detection of spinal hematoma after the procedure. In addition, full decompression can be performed by complete hematoma evacuation and laminectomy of related segments for the treatment of spinal subdural hematoma induced by lumbar drainage.