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Combining the anomalies and environmental monitoring data of the early stage Beidou satellites, the space radiation environment spatial/temporal distribution and space radiation effect risk characteristics are analyzed, and the dynamic characteristics of space environmental factors, such as hot plasma, high-energy electron and solar proton are summarized. The systematic joint monitoring for surface charging, internal charging, single event effect and total dose effect with corresponding space environment factors is proposed. The detector types, measurement parameters range and engineering constraints are allocated, and the engineering application and scientific research of detection data are prospected.

Background Public health measures, such as social isolation, are vital to control the spread of the coronavirus disease 2019 (COVID-19), but such measures may increase the risk of depression. Thus, this study examines the influencing and moderating factors of depressive symptoms among individuals subjected to mandatory social isolation. Methods An online cross-sectional survey was conducted to collect data from people under mandatory home or centralized social isolation in Shenzhen, China, from February 28 to March 6, 2020. The perceived risk of infection with COVID-19, perceived tone of media coverage, perceived quality of people-oriented public health services, and their depressive symptoms were assessed. Three rounds of stepwise multiple regression were performed to examine the moderating effects after controlling various variables, such as demographics, duration and venue of mandatory social isolation, infection and isolation status of family, time spent on COVID-related news, and online social support. Results Among the 340 participants, 57.6% were men, the average age was 35.5 years old (SD = 8.37), and 55.6% held a bachelor’s degree or above. Individuals subjected to mandatory social isolation generally reported low levels of depressive symptoms. Perceived susceptibility to infection was relatively low, whereas perceived tone of media coverage was mainly positive. In terms of perceived quality of public health services, 12 (3.5%), 103 (30.3%), and 225 (66.2%) participants reported low, medium, and high quality of people-oriented services, respectively. Perceived susceptibility was positively associated with depression, whereas perceived tone of media coverage was negatively associated. The quality of people-centered public health services moderated the association between perceived risk and depressive symptoms and between perceived tone of media coverage and depressive symptoms. Conclusions This study revealed the depressive symptoms among individuals subjected to mandatory social isolation during the COVID-19 pandemic and highlighted that frontline public health workers play a critical role in protecting public mental health.

In this study, we report a novel ratiometric fluorescent probe with a blue shift of 180 nm based on a D-π-A-A structure. The probe composed of a hydroxyl moiety as a donor, a naphthyl ring as a π bridge, and benzothiazole/hemicyanine as an acceptor has good selectivity and high sensitivity to bisulfite (HSO

Background Coronavirus disease 2019 (COVID-19) caused by a new Betacoronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently a global pandemic. Gathered clinicopathological evidence in COVID-19 patients shows that alveoli injuries and interstitial changes are the major mechanisms of impaired O2/CO2 exchange. Few rehabilitation exercises concerning COVID-19 patients were reported. Here, we present a modified version of rehabilitation exercises based on the underlying mechanism of the disease to mild cases of COVID-19. These exercises aimed to improve the pulmonary function of patients and ease the expectoration process. Additionally, an essential branch of Traditional Chinese Medicine (TCM) named acupressure was integrated into the exercises to facilitate the recovery and maintenance of pulmonary function. Methods From March 4, 2020 to May 5, 2020, a total of 60 COVID-19 patients who completed the full course of MRE were enrolled in this observational study. The diagnostic and classification criteria were based on the 7th edition of Diagnosis and Treatment Guideline of COVID-19 published by the National Health Commission of the People's Republic of China. We prospectively gathered patients' reported outcomes concerning respiration-related symptoms at four different time points, including: (I) at admission; (II) at the time of hospital discharge; (III) two weeks after discharge; (IV) four weeks after discharge. The reported respiratory symptoms included dry cough, productive cough, difficulty in expectoration, and dyspnea. Results In total, 60 confirmed mild COVID-19 cases were enrolled with a median age of 54 years old. The baseline prevalence for dry cough, productive cough, difficulty in expectoration, and dyspnea were 41.7%, 43.3%, 35.0%, and 50.0%, respectively. The pronounced decline in symptom prevalence was recorded over time. Interestingly, four weeks after discharge, we noticed a lower remission rate in productive cough and difficulty in expectoration. Conclusions The modified rehabilitation exercises were retrieved from the Eight-Section Brocade, and are specifically designed for rehabilitation of COVID-19 patients at home or health facilities. Based on current findings on pronouncedly improved remission rate in respiratory symptoms, we recommend the MRE as suitable rehabilitation exercise to smooth respiration and ease the expectoration process in mild COVID-19 cases.

Topography is tightly coupled with soil organic carbon (SOC) cycling in sloping landscapes. However, we know little about the spatial variation of SOC accumulation and persistence along a topographic gradient and the controlling processes. Here, we assessed the spatial variation of SOC and its composition along a topographic gradient in a humid mountain forest. The variables associated with environmental factors, topographical traits, carbon input from plants, and soil physico-chemical properties were analyzed to assess their contributions. Results showed that both SOC and mineral-bound organic carbon (MOC) contents were comparable among the topographic positions (ridge, middle slope, lower slope and valley). However, particulate organic carbon (POC) content decreased significantly from ridge to valley. Our measured environmental variables explained 67%, 74% and 77% of the variations in SOC contents for 0–10 cm, 10–20 cm and 20–40 cm soils, respectively. Soil physico-chemical properties (including pH and soil reactive Fe/Al oxides) were the main driver on SOC and MOC variations. In contrast, the variation in POC was more explained by topographical traits and carbon input. We also observed significantly lower SOC stability for ridge soil than valley soil. The significant topographic patterns for SOC fraction and SOC stability suggested that the soil carbon cycling processes were dependent on landscape positions. Future carbon budget and carbon dynamic researches in the humid sloping landscapes should take into account the topographic effects, especially for the free and light carbon fractions.

DNA-modified lanthanide-doped upconversion nanoparticles (DNA-UCNPs) that combine the functions of DNA and the optical features of UCNPs have shown great promise in a wide range of fields. However, challenges remain in precisely tethering and orienting the DNA strands on the UCNP surface. Herein, we systematically investigate the sequence dependence of DNAs in their interactions with UCNPs, and reveal that poly-cytosine (poly-C) has high affinity for the UCNP surface. A general approach to synthesize monodispersed DNA-UCNP conjugates is developed using poly-C-containing diblock DNA strands. The poly-C segment of the DNA strand binds to the surfaces of UCNPs and the second segment is oriented perpendicularly on the UCNP surface, making the DNA-UCNPs highly stable and monodispersed in aqueous solution. The dense layer of DNA on the UCNP surface enables the programmable assembly of UCNPs with other DNA-functionalized nanoparticles or DNA origamis through hybridization, resulting in the formation of well-organized complex structures.

The low room temperature ionic conductivity (RTσ) of polyethylene oxide (PEO)-based solid-state polymer electrolyte (SPE) severely restricts its application for lithium batteries. Herein, acrylamide (AM) has been introduced into the poly(ethylene glycol) methyl ether methacrylate-poly(ethylene glycol) diacrylate (P-P). The multiple hydrogen bonds of AM expand the original single lithium environment (Li···O-C) to three types (Li···O-C, Li···N-H, and Li···O═C), which accelerates the conduction of lithium ions. In addition, the double bond modification of nanosilica (═SiO

Background This study aimed to characterize a cohort of patients with a refractory course of COVID-19, and to investigate factors associated with the duration of viral clearance (DoVC). Materials & Methods A total of 65 patients with refractory COVID-19 were retrospectively enrolled from Huoshenshan Hospital. Univariate analysis and multivariate analysis were performed to examine the potential association between clinicopathologic characteristics and the DoVC. Results The median DoVC in the overall study cohort was 48 days (ranged from 21 to 104 days). Multivariate analysis indicated that fever at illness onset (Hazard ratio (HR) = 4.897, 95% CI [1.809–13.260], p = 0.002), serum level of aspartate aminotransferase (AST) > 21.8 IU/L (HR = 3.010, 95% CI [1.195–7.578], p = 0.019), and titer of SARS-CoV-2 IgG > 142.09 AU/ml (HR = 3.061, 95% CI [1.263–7.415], p = 0.013) were the three independent risk factors associated with delayed viral clearance. Conclusion The current study suggested that clinical characteristics such as fever at illness onset, a high serum level of AST or SARS-CoV-2 IgG were associated with delayed viral clearance. Patients with these characteristics might need a more individualized treatment strategy to accelerate their recovery from the refractory COVID-19.

Knowledge of the spatial and temporal variabilities of soil respiration is important in estimating the soil carbon budget and in understanding how soils may respond to global changes. In areas with complex terrain, the topography can modify the hydrological conditions and other biophysical variables, which complicates the spatial and temporal heterogeneity of soil respiration. Herein, we investigated soil respiration along topographic transects with ridge, middle slope, lower slope and valley positions in a humid subtropical mountain forest in China to assess the driving factors of the variations in soil respiration. Our results showed that there were substantial temporal and spatial variations in soil respiration. The temporal variation of soil respiration could be well explained by the dynamics of soil temperature and moisture. Soil respiration rates also showed clear topographic pattern and decreased significantly from the ridge to valley soils, with the mean rates equaled 3.43 ± 0.13, 2.64 ± 0.30, 2.13 ± 0.26 and 1.88 ± 0.24 μmol m−2 s−1 at the ridge, middle slope, lower slope, and valley, respectively. Correlation analyses revealed that the spatial variation of soil respiration could be explained by multiple variables (e.g., soil temperature, basal area of the trees, thickness of the forest floor, root biomass and stock of soil dissolved carbon, soil C/N and soil bulk density). Results from partial least squares path modeling suggested that the topography modified the fine root distribution and the lateral losses of light and dissolved organic materials that created areas of high carbon sources for soil respiration at the ridge. The topographically regulated processes further resulted in a high soil C/N at the ridge that favored SOC decomposition. The higher respiration rate for the ridge soil and its higher sensitivity to soil temperature and moisture changes suggested that the ridge position was a potential hot spot for future environmental changes. Future studies and management practices regarding the soil carbon efflux in forest ecosystems with topographical variations should take into account the topographic effects.

Despite being a crucial component of nutrient cycling and soil carbon (C) dynamics in forest ecosystems, there is too little information from past studies to discern whether dissolved organic carbon (DOC) exchanges with soil organic carbon or passes unaltered through soils. In this study, we added 13C-labelled litter-derived DOC into different depth soil columns in a 180-day incubation experiment to determine the fate of DOC in soils, and to monitor the changes in DOC composition when it percolates through the soil. The results showed that δ13C values increased in soil microbes, which indicated that some litter-derived DOC was immobilized by soil microbial communities. Approximately 76% of litter-derived DOC was retained in the soil (60% in topsoil and 16% in midsoil). Meanwhile, 18%, 4%, and 3% of litter-derived DOC were mineralized into CO2 in topsoil, midsoil and subsoil respectively. Only 0.04% of litter-derived DOC leached from the soil column (0–60 cm). These results indicated that DOC was mainly retained on soil, and a small portion was mineralized by microorganisms, with minimal leaching. The composition of water soluble soil organic carbon (WSOC) and leachate DOC (LDOC) were similar between the control and treatment. This indicated that the composition of WSOC and LDOC was more similar to soil C than the added DOC, which supports the previously hypothesized dynamic exchange model. These findings provide new insight by showing that most litter-derived DOC is sequestered in forest soils.

Preparing few-layer black phosphorus flakes, in a scalable, fast, and benign way, is a key step to promote both the fundamental research and practical applications of black phosphorus. Although the...

BACKGROUND The present study was designed to reveal the trajectory of self-reported somatic symptom burden and sleep quality over time in patients with COVID-19 and to identify prognostic factors for greater somatic symptom burden and sleep disturbance. MATERIAL AND METHODS Seventy-four patients with COVID-19 were prospectively followed for longitudinal assessment of somatic symptom burden and sleep quality. We used the 8-item Somatic Symptom Scale (SSS-8) and the modified Medical Research Council (mMRC) scale for somatic symptom burden and the Pittsburgh Sleep Quality Index for sleep quality investigation. Univariate and multivariate analyses were performed to identify independent factors associated with somatic symptom burden and sleep quality. RESULTS Although the degree of physical discomfort and sleep quality issues tended to decline during self-quarantine, patients still experienced these problems to a certain degree. Univariate and multivariate analyses showed that SSS-8 scores at admission (relative risk [RR] 1.234, 95% CI 1.075-1.417, P=0.003) and mMRC scores at discharge (RR 2.420, 95% CI 1.251-4.682, P=0.009) were 2 independent prognostic indicators of somatic symptom burden. In addition, muscle pain as a chief complaint (RR 4.682, 95% CI 1.247-17.580, P

The root-knot nematode is one of the most damaging plant-parasitic nematodes worldwide, and the ecofriendly alternative approach of biological control has been used to suppress nematode populations. Here the nematicidal activity of Aspergillus japonicus ZW1 fermentation filtrate against Meloidogyne incognita was evaluated in vitro and in greenhouse, and the effects of A. japonicus ZW1 fermentation filtrate on seed germination and the active compound of A. japonicus ZW1 fermentation filtrate were determined. The 2-week fermentation filtrate (2-WF) of A. japonicus ZW1 exhibited markedly inhibitory effects on egg hatching, and 5% 2-WF showed potential nematicidal activities on second-stage juveniles (J2s); the mortality of J2s was 100% after 24 h exposure. The internal contents of nematodes were degraded and remarkable protruded wrinkles were present on the body surface of J2s. The nematicidal activity of the fermentation was stable after boiling and was not affected by storage time. A germination assay revealed that 2-WF did not have a negative effect on the viability and germination of corn, wheat, rice, cowpeas, cucumbers, soybeans, or tomato seeds. The pot-grown study confirmed that a 20% fermentation broth solution significantly reduced root galls and egg numbers on tomatoes, and decreased galls and eggs by 47.3% and 51.8% respectively, over Czapek medium and water controls. The active compound from the A. japonicus ZW1 fermentation filtrate was isolated and identified as 1,5-Dimethyl Citrate hydrochloride ester on the basis of nuclear magnetic resonance (NMR) and LC-MS (liquid chromatograph-mass spectrometer) techniques. Thus, fermentation of A. japonicus ZW1 could be considered a potential new biological nematicide for the control of M. incognita.

Background:Public health measures including social isolationare essential forCOVID-19 control,but also increase the risk of depression. This study examined the influencing and moderating factors on socially isolated people’s depressive symptoms. Methods: Data were collected from people in mandatory home or centralizedsocial isolation in Shenzhen, China from February 28 to March 6 in 2020. We assessed their perceived COVID-19risk, perceived tone of media coverage, perceived quality of people-oriented public health services, and depressive symptoms.Three stepwise multiple regressions were performed to examine the moderating effects controlling age, gender, education, monthly income, socially isolated venue,time spent on COVID-related news, and online social support.Results:We examined data from 340 people. 57.6% men, averaged age at 35.5 years old (SD = 8.37), 55.6% held bachelor’s degree or above.Overall, people in social isolation reported a moderate level ofdepressive symptoms (M =1.24, SD = 0.4). The perceived susceptibility of being infected was relatively low (M = 1.36, SD = 0.54), and the perceived tone of media coverage was mainly positive (M = 1.97, SD = 1.05). In terms of perceived quality of public health services, 3.2% (n = 11) participants reported low-level, 49.1% (n = 167) medium-level, and 47.6 (n =162) high-level quality ofpeople-oriented services. Perceived riskwas significantly associated with depression (β= .12, p< 0.01), and perceived tone of media coverage was negatively associated with depression (β= -.05, p< 0.01).The quality of people-centered public health service moderated the association between perceived riskand depressive symptoms(β= -.15, p< 0.05), and the relationship between perceived tone of media coverage and depressive symptoms(β= .01, p< 0.01).Conclusions:This studyfound thatpeople-oriented public health servicesreduced the effect of risk perception and media tone on depressive symptoms among COVID-19 socially isolated people, suggesting a critical role for frontline public health workers in protecting public mental health.

Climate change has been observed to significantly influence forest growth, community composition, and species distribution ranges. These influences in turn will impose continuous impacts on forest production and carbon (C) storage potential. Forests in the subtropical China that are experiencing rapid regeneration and recovery may suffer multiple threats in the face of future climate change. Understanding how climate change may affect forest C sequestration and species dynamics over time will help formulate better management strategies for maintaining forest productivity and biodiversity. Here, we used a forest landscape model (LANDIS‐II) to evaluate the long‐term effects of current business‐as‐usual (BAU) management and climate projections (current, RCP4.5, and RCP8.5 climate scenarios; IPCC representative concentration pathways [RCPs] scenarios) on above‐ and belowground forest C storage and tree species dynamics in the Sangzhi County in the subtropical China. Our simulations showed a fast‐growing period of forest total C in the first 70 yr, regardless of climate regime. Moderate climate change (RCP4.5 climate scenario) increased soil organic carbon (SOC) (12%) and detrital C (16%) but reduced live C (5%), contributing to a slight augment of 3% in forest C storage compared to the control climate, while severe climate change (RCP8.5 climate scenario) decreased SOC (16%), detrital C (27%), and live C (12%), resulting in a dramatic reduction of 14% in forest C storage, primarily because severe warming‐induced water stress restrained species establishment and regeneration in temperature‐sensitive areas like the lower elevations. Meanwhile, nature reserves in the higher elevations could act as “safe islands” by providing suitable conditions for most tree species, but the logging ban caused higher canopy closure, which in turn inhibit the growth and establishment of shade‐intolerant species. The results also highlighted the positive responses of native “warm species” to climate warming and suggest that using them to replace some conventional coniferous plantation tree species would better mitigate the future climate change. Poor performance of the current BAU management in maintaining forest productivity and diversity suggests that new climate‐adapted management strategies should be designed accordingly.

A parallel two-degree-of-freedom (two-DOF) setback arming mechanism was designed in this study according to acceleration signal characteristics of weak launch and service conditions. A model of an inertia switch with a low g-feature was designed to be used in the electromechanical fuze of the proposed mechanism. Simulations were conducted to analyze the motion characteristics of the inertia switch that was based on the parallel two-DOF spring-mass system under the launch overload and the service dropping overload. The reliability and safety of the inertia switch were validated.

Large-scale distributed space surveillance radar is a very important ground-based equipment to maintain a complete catalogue for Low Earth Orbit (LEO) space debris. However, due to the thousands of kilometers distance between each sites of the distributed radar system, how to optimally implement the Transmitting/Receiving (T/R) beams alignment in a great space using the narrow beam, which proposed a special and considerable technical challenge in the space surveillance area. According to the common coordinate transformation model and the radar beam space model, we presented a two dimensional projection algorithm for T/R beam using the direction angles, which could visually describe and assess the beam alignment performance. Subsequently, the optimal mathematical models for the orientation angle of the antenna array, the site location and the T/R beam coverage are constructed, and also the beam alignment parameters are precisely solved. At last, we conducted the optimal beam alignment experiments base on the site parameters of Air Force Space Surveillance System (AFSSS). The simulation results demonstrate the correctness and effectiveness of our novel method, which can significantly stimulate the construction for the LEO space debris surveillance equipment.

The emerging wearable and foldable electronic devices drive the development of flexible lithium ion batteries (LIBs). Carbon materials are considered as one of the most promising electrode materials for LIBs due to their light weight, low cost and good structural stability against repeated deformations. However, the specific capacity, rate capability and long-term cycling performance still need to be improved for their applications in next-generation LIBs. Herein, we report a facile approach for immobilizing phosphorus into a large-area carbon nanosheets/nanofibers interwoven free-standing paper for LIBs. As an anode material for LIBs, it shows high reversible capacity of 1100 mAh g−1 at a current density of 200 mA g−1, excellent rate capabilities (e.g., 200 mAh g−1 at 20,000 mA g−1). Even at a high current density of 1000 mA g−1, it still maintains a superior specific capacity of 607 mAh g−1 without obvious decay.

In this study we investigated the effect of multi-pass rolling and post-rolling heat treatment upon the microstructure at interface and mechanical properties of the explosive welding Mg/Al composite plates. The thin explosive welding Mg/Al composite plates with 2.14 mm in thickness and good surface quality were obtained by 5 passes hot rolling (30% reduction, 400 °C). To meet the requirement of subsequent forming, annealing process was performed. The results indicate that the thickness of interfacial diffusion layer increases with the increase of annealing temperature and holding time. The mechanical properties of composite plates increase first and then decrease with the increase of annealing temperature and holding time. The tensile strength and elongation of the composite plates under 200 °C/2 h annealing condition reach the maximum, which are 285 MPa and 24.5% respectively. Fracture surface morphology indicates that the post-rolling or annealed composite plates all exhibit mixed-mode of ductile and brittle fractures.

In preclinical and clinical research, to destroy cancers, particularly those located in deep tissues, is still a great challenge. Photodynamic therapy and photothermal therapy are promising alternative approaches for tissue cancer curing. Black phosphorus (BP)-based nanomaterials, with broad UV–vis near-infrared absorbance and excellent photothermal effect, have shown great potential in biomedical applications. Herein, a biocompatible therapeutic platform, chlorin e6 (Ce6)-decorated BP nanosheets (NSs), has been developed for fluorescence and thermal imaging-guided photothermal and photodynamic synergistic cancer treatment. Taking advantage of the relatively high surface area of exfoliated BP NSs, the PEG-NH2-modified BP NSs (BP@PEG) are loaded with a Ce6 photosensitizer. The resulted BP@PEG/Ce6 NSs not only have good biocompatibility, physiological stability, and tumor-targeting property but also exhibit enhanced photothermal conversion efficiency (43.6%) compared with BP@PEG NSs (28.7%). In addition, BP...

Deep soil stores a large amount of organic carbon (C) and nitrogen (N). However, little is known regarding the interactions between soil C and net N mineralization in deep soil, which complicates the prediction of ecosystem C and N dynamics. In this study, a 150-day laboratory soil incubation experiment was performed under 20 °C and 25 °C to investigate the influence of soil depth and warming on C and net N mineralization and their relationship. Soils were collected from a Hapludalfs profile in a subtropical forest with three depth intervals: 0–10 (topsoil), 10–30 (midsoil), and 30–60 cm (subsoil). Soil microbial community-level physiological profiling (CLPP) was conducted to investigate the role of the microbial community in C and N mineralization. The results demonstrated that both C and net N mineralization rates in subsoil were significantly lower than in topsoil. Compared to topsoil, subsoil had lower temperature sensitivity of C mineralization and relatively higher temperature sensitivity of net N mineralization. Cumulative soil C and net N mineralized were positively correlated in topsoil with the mineralized N per mineralized C showed as 0.19 and 0.31 at 20 °C and 25 °C, respectively. However, there was no significant correlation between cumulative soil C and net N mineralized in subsoil due to the low amount of net N mineralization. The lack of labile C source and degradable organic N were believed to limit the net N mineralization in subsoil. The microbial community in topsoil used relatively more easily decomposable carbohydrates and carboxylic acids, which favored C mineralization. In contrast, the microbial community in subsoil had relatively high utilization of amino acids (N-containing substrates), which indicated there was N limitation. This distinguished substrate utilization patterns of microbial communities could explain the observed C and N mineralization rates among the soil depths, and suggests that the microbial community played an important role in soil C and N mineralization. The decoupled relationships between soil C and net N mineralization in deep soil and their differentiated responses to warmer temperatures among soil depths indicated that deep soil should be considered separately from topsoil for ecosystem C and N cycling, especially for ecosystem C dynamic models.

Cylindrical resonators are commonly used in Coriolis vibratory gyroscopes (CVGs), which measure angular velocity through the precession of solid waves. Quality factor and its homogeneity are critical indicators of the resonator. In this paper, we present the observation and analysis of the Q factor variation behavior around the resonator’s axis of symmetry. We measured the resonator’s Q factor by the amplitude frequency response (AFR), with an acoustic source for excitation and a laser Doppler vibrometer (LDV) for detection. We then theoretically analyzed the Q variation behavior based on the two-dimensional mass-spring model. The experimental results were consistent with the theoretical calculation. By comparing experimental results with numerical calculations, we showed that the nature of this Q variation was due to the fact that when the excitation direction is misaligned with principle axes, for each detection point, the vibration is the superposition of two eigen-modes, and fitting with a one-dimensional oscillator would result in repetitive errors. This work is significant for understanding the mechanism of resonator’s Q factor variation behavior, as well as improving CVG’s performances.

The influence of hot rolling on the evolution of the interface microstructure as well as mechanical properties of the Mg/Al explosive welding composite plates was investigated. The hardening phenomenon induced by explosive welding could be eliminated effectively through preheating treatment. An intermetallic compound layer consisting of Al3Mg2 and Mg17Al12 was observed at the Mg/Al interface after annealing at 400 °C. The composite plate then was hot rolled at 400 °C with different reduction ratios. The composite plates presented different degrees of warp and edge cracks with increasing the reduction ratio. At the reduction ratio of 30%, the coordination deformation ability of the constituent Mg and Al alloys is consistent with the composite plate. The results showed that the tensile strength and the elongation of the composite plates increased significantly after hot rolling owing to the dynamic recrystallization and the intermetallic compounds thickness decrease during hot rolling.

Clustering is one of the important tasks of machine learning. Gene Expression Programming (GEP) is used to solve clustering problems because of its strong global searching ability. In order to solve the limitation of lower rate of convergence and easy falling into optimal local solution in the traditional GEP clustering process, this paper proposes a parallel GEP clustering algorithm based on the producer-consumer model (PGEPC/PCM), which parallelizes the time-consuming operations such as fitness calculation, recombination, and mutation in GEP clustering analysis to speed up, improves the calculation method of fitness function to enable it to cluster automatically. This algorithm can fast calculate accurate clustering center points in parallel. Extensive experiments on four widely used benchmark Iris, Wine, Soybean and Seeds from the UCI machine learning data sets are conducted to investigate the influence of algorithmic component and results are compared with traditional GEP clustering algorithm. These comparisons demonstrate the competitive efficiency of the proposed algorithm.

Traveling Salesman Problem is one of the most valuable combination optimization NP-hard in mathematics and computer science. Simulated Annealing Algorithm is one of the better algorithms to solve the TSP problem. However, with the increasing scale of the TSP problem, this algorithm also shows some limitations. That is, the solution performance is poor, and the efficiency is low. This paper proposes a new Nested Simulated Annealing Algorithm (NSA), which divides the megacity group into small and medium-sized urban groups through recursive diffusion and setting the threshold method. In this way, the large-scale TSP problem can be transformed into small and medium-sized TSP problem at first. And then optimize the small and medium-sized TSP problem by using the Simulated Annealing Algorithm. Finally, synthesize a whole to achieve the final optimization effect. In this paper, we use three large-scale TSP problems in the TSPLIB database to test the proposed algorithm and compare it with the traditional Simulated Annealing Algorithm. The results show that the Nested Simulated Annealing Algorithm proposed in this paper has better efficiency and effect than the original algorithm in solving large-scale TSP problems.

Dissolved organic matter is important in the vertical and lateral translocation of nutrients in forest ecosystems. However, little is known about the changes in dissolved organic matter concentration and chemical components in ecosystem sources in humid mountain forests. Here, we measured the concentration and chemical components of dissolved organic matter at throughfall, stemflow, litter leachate, runoff, and soil pore water (at depths of 10 cm, 30 cm, and 60 cm) in a subtropical humid mountain forest during two growing seasons. The concentration of dissolved organic carbon and dissolved nitrogen showed a clear monthly trend. The dissolved organic carbon concentration and the proportion of hydrophobic organic acid in the surficial water were higher than those in the soil pore water, and this difference was accompanied by a decrease in the hydrophobic organic acid concentration from the surficial water to the soil pore water. We also found that dissolved organic matter properties in surficial water were related to canopy cover, tree species, litter carbon content, and slope, whereas dissolved organic matter in soil pore water was associated with soil C, N, and P content and pH. In addition, the rainfall pattern is important to the dissolved organic matter concentration and partitioning within the seven sources. These findings showed that the dissolved organic carbon movement from surficial water into soil pore water is a significant component of carbon cycling in forest ecosystems, and this is important in estimating the carbon budget in forest ecosystems.

Lithium-sulfur batteries show great potential in the field of energy storage because of their high-energy density, but the shuttle effect of lithium polysulfide has seriously hindered their practical process. Quasi-solid-state electrolyte (QPE) is considered to be a promising alternative to traditional liquid electrolyte, which can improve the safety and cycling performance of lithium-sulfur batteries. Herein, a novel poly(vinyl carbonate-co-butyl acrylate) QPE with 3D crosslinked network (PEGDA-P(VCA-co-BA)) is designed to capture lithium polysulfide through a chemical adsorption of abundant ester groups. The PEGDA-P(VCA-co-BA) QPE exhibits high ionic conductivity of 2.9 mS cm−1. In order to synergize the beneficial effect of the PEGDA-P(VCA-co-BA) QPE, the nitrogen-doped carbon nanotube film-supported sulfur/Li cells are assembled with the QPE. As-assembled lithium-sulfur batteries show high initial capacity of 1080 mAh g−1 at 0.1 C, long cycle life (capacity retention of 715 mAh g−1 after 500 cycles) and superior rate performance.