Journals
2026 EN
Wang Wenxuan · Dou Xiankang · Gu ShengYang
+4 more
Abstract A strong westward zonal wavenumber‐2 quasi‐4‐day wave (Q4DW) during the 2018/2019 Northern Hemisphere sudden stratospheric warming (SSW) is both captured by Aura Microwave Limb Sounder (MLS) observations and our new whole neutral atmosphere data assimilation system. The Q4DW during this SSW is characterized by a double‐peak altitudinal structure in temperature, geopotential height, and neutral winds ranging from ∼40 km up to the lower thermosphere. The Eliassen‐Palm flux diagnostics show that the wave source at ∼55 km over 45°N–75°N, the excitation, propagation, and amplification of which are controlled by the critical layer and atmospheric barotropic/baroclinic instability in the polar stratosphere related to SSW. The first Hough‐mode decomposition analysis of Q4DW indicates that the enhancement of the Rossby (2, −3) normal mode is mainly responsible for the amplification of Q4DW, the latitudinal structure of which is distorted by the anomalous background winds during this SSW. In the ionosphere, a simultaneous quasi‐4‐day oscillation (Q4DO) is found in the Wuhan University total electron content (TEC) product near 10:00–12:00 LT at magnetic latitudes of ∼+15° and ∼−25° with maximum amplitudes of ∼1.1 TECU and 1.2 TECU, respectively. Besides, the Q4DO also displays significant interhemispheric asymmetry and longitudinal variations. Interestingly, the secondary wave components ( s = 4, T = 10.7 hr and s = 0, T = 13.7 hr) in neutral winds from the nonlinear interactions between the Q4DW and the migrating semidiurnal tide are detected in the dynamo region, which may play a dominant role in generating Q4DO in the F‐region ionosphere.
Journals
2026 EN
Jiang Dou
This study quantitatively examines the role of utility-generating government spending in achieving economic (in)determinacy within a two-sector framework. In the model, the government allocates expenditures to two types of commodities: consumption and investment goods. It is assumed that government spending on both goods generates externalities in preferences. The key findings are as follows. When private consumption and public spending are complements in the utility function, the results diverge from those of the one-sector model counterpart: stronger external effects of government spending reduce the likelihood of indeterminacy. Conversely, when private consumption and public spending are Edgeworth substitutes, the economy becomes more susceptible to belief-driven fluctuations. Furthermore, the artificial sunspot-driven business cycles generated by the model align with most of the U.S. stylized facts.
Journals
2026 EN
Huang Jingru · Lan Hui · Wang Yan
+1 more
Computer simulations are commonly used to mimic, understand, and predict true physical phenomena in many applications. Calibration aims to adjust the computer model parameters, called calibration parameters, so that the computer outputs match the physical observations as closely as possible. The orthogonal Gaussian Process calibration (OGP calibration) [J Am Stat Assoc. 112(519) (2017) 1274-1285] offers a fast convergence rate, high estimation accuracy, and convenient uncertainty quantification for the parameter estimates. However, the OGP calibration suffers from high computational complexity and is prone to local optima. It is extremely difficult for the OGP calibration to identify the optimal set of calibration parameters. In this work, we propose a gradient-free local variational inference framework for the OGP calibration to address these two issues simultaneously. Specifically, to reduce the computational complexity, an efficient algorithm is proposed to evaluate the variational density of the calibration parameters and the discrepancy between the true physical process and the calibrated computer simulation model. To prevent the estimator from falling into a local optimum, the least-squares estimate of the calibration parameters is introduced as the prior information in the variational inference framework. Results of a numerical simulation and a real-world case study demonstrate that, compared to the OGP calibration, the complexity of the proposed algorithm is greatly reduced without sacrificing too much accuracy.
Journals
2026 EN
Zhang Xiuxia · Dou Aixia · Deng Lingzhi
+5 more
Cropland abandonment poses a significant threat to global food security, especially in ecologically fragile arid regions, where it compromises both agricultural sustainability and ecosystem integrity. Despite its importance, the spatial distribution of abandoned croplands across large geographic areas remains poorly understood. This study focuses on the Hexi Corridor, a representative oasis agricultural zone in northwestern China. Combining multi-dimensional Sentinel-2 features (phenological, spectral, textural, and physiographic) with feature optimisation, we employed a Random Forest-based post-classification change detection approach to map abandoned croplands from 2021 to 2023, achieving high accuracy (overall accuracy: 92.08%; Kappa: 0.84). (1) Landscape pattern indices and kernel density analysis revealed key spatial trends: abandonment rates declined from 7.05% in 2022 to 5.38% in 2023, while persistent abandonment covered 11,170 ha and recultivation reached 34,403 ha. (2) Spatial heterogeneity was pronounced, with core abandonment zones concentrated in Jiuquan (Yumen, Guazhou) and Zhangye (Shandan County), whereas Jinchang (Yongchang County) and Wuwei (Minqin County) underwent significant rehabilitation. (3) Abandoned croplands exhibited increased fragmentation, driven by a 21% rise in patch density, whereas recultivation was characterized by smaller, scattered plots (patch density > 109), indicating a shift from contiguous to fragmented cultivation. Kernel density analysis revealed an ‘oasis-edge aggregation’ pattern in abandonment, characterized by high-density clusters in Shandan County following remediation efforts and a distinct recultivation hotspot in Yongchang County. Our multi-feature RF approach establishes a robust framework for large-scale abandonment monitoring and delivers critical insights to support sustainable land management in arid regions.
Journals
2026 EN
Yu Pengfei · Zeng Shaoliang · Zhu Haoran
+5 more
A micro-rheological integration experiment was conducted on model oils without asphaltene and with 0.05 wt% asphaltene. The study examined the viscosity-temperature characteristics of both model oils under different cooling rates and shear rates. Significant changes were observed in the viscosity-temperature curve of the asphaltene-containing model oil. At low shear rates, a distinct wavelet peak was identified in the temperature range of 37-30 °C, where viscosity initially increased, then decreased, and subsequently increased again. This wavelet peak diminished with the increasing shear rate, eventually forming a “buffer platform”. The underlying mechanism was attributed to asphaltene altering the wax crystal behavior from “uniform precipitation network structure formation” to “formation of unstable large aggregates - dissociation into multiple small stable aggregates - growth into larger stable aggregates.” In addition, the wax precipitation rate remained constant in the model oil without asphaltene, while in the asphaltene-containing model oil, the rate significantly accelerated between 34.5 °C and 32.5 °C. And the asphaltenes promoted the formation of small wax crystal particles but inhibited the growth of wax crystal particles.
Journals
2026 EN
Zhang Canran · Dou Jianping · Wang Shuai
+1 more
To solve simple assembly line balancing problems (SALBPs) with NP-hard essence, many metaheuristic algorithms are used. However, few studies fully exploit the characteristics of a typical SALBP type I (SALBP-I) to select or design algorithms. This study explores characteristics of SALBP-I instances by analysing fitness landscapes and explaining performance differences of three particle swarm optimization (PSO) algorithms. Three fitness landscape analysis (FLA) metrics are selected to comprehensively explore the landscapes. Then, effects of structural parameters (cycle time, order strength and objective function) for experimental instances on landscapes are investigated by FLA, and a set of instances based on the three parameters is designed. Finally, three PSO algorithms are compared based on instances to investigate their ability to explore and exploit landscapes. The computational results show that FLA can be used to analyse differences in SALBP landscapes, and provide effective guidelines for the selection of PSO updating mechanisms for solving SALBP-I.
Journals
2026 EN
Meng Zhaojun · Dou Wen · Wang HaoJie
+6 more
Emamectin benzoate (EB) is frequently used against various pests in Allium tuberosum Rottler and Dendrobium officinale , but its residue levels and safety to public health are still unclear after field application. This study conducted field residue trials of EB in Allium tuberosum Rottler and Dendrobium officinale and assessed the long-term and short-term dietary risks of EB through a dietary risk assessment model. Based on LC-MS/MS, an enhanced residue analytical method of EB was established with excellent linearity (R 2 > 0.9990), accuracy (recoveries ranging from 99% to 107%) and precision (standard deviations from 1.4% to 4.7%). After EB applications, the residues in Allium tuberosum Rottler leaves were less than 0.01 mg/kg (the limit of quantification) at 5 d, while in fresh and dried stems of Dendrobium officinale , they were 0.001–0.13 mg/kg at 14 d. The long-term RQ is 79.1%, and the short-term RQ ranges from 0.0365% to 0.1248%, ensuring accuracy, indicating highly unlikely to pose significant public health concerns. The results of this study can provide a reference for the safe application of EB in Allium tuberosum Rottler and Dendrobium officinale .
Journals
2026 EN
Liu Yiting · Huang Tao · Li Zhizhong
+2 more
Anxiety and depressive symptoms are prevalent among adolescents. Social jetlag has been recognized as a potential risk factor for mental health issues. However, the mechanisms underlying social jetlag and mental health remain unclear. This study aims to investigate the associations of social jetlag with anxiety and depressive symptoms in adolescents. The mediating effects of sleep quality and self-control on these associations were also examined. A cross-sectional study was conducted. In total, 633 adolescents completed an online survey. Social jetlag, sleep quality, self-control, anxiety, and depressive symptoms were assessed using the Munich Chronotype Questionnaire, Pittsburgh Sleep Quality Index, Dual-Mode of Self-Control Scale, Self-rating Anxiety Scale, and Center for Epidemiological Studies Depression Scale, respectively. Multiple linear regression and mediation analyses were performed. The results show that female adolescents experienced higher levels of social jetlag, poorer sleep quality, lower self-control, more severe anxiety and depressive symptoms than male adolescents. Social jetlag was a significant predictor of sleep quality, self-control, anxiety, and depressive symptoms. Notably, sleep quality and self-control had a chain-mediating effect on the associations of social jetlag with anxiety and depressive symptoms in Chinese adolescents. These findings provide evidence for the development of targeted interventions to improve the mental health of adolescents. Reducing social jetlag and improving sleep quality and self-control may be relevant for mitigating anxiety and depressive symptoms.
Journals
2026 EN
Nagajothi Nagashreyaa · Dou Pengyue · Felter Elizabeth
+2 more
Objective: This study investigated factors influencing Fall 2023 COVID vaccine uptake in graduate and undergraduate public health students. Participants: 107 public health students at a large public university. Methods: We distributed a Qualtrics survey assessing student status, Fall 2023 COVID-19 vaccine uptake, and factors influencing vaccination. We analyzed quantitative data with descriptive statistics and Chi-square tests and used thematic analysis to analyze open-ended responses. Results: Graduate students ( n = 46, 43% of participants) were significantly more likely to have received their vaccine than undergraduates ( p = 0.008). For respondents that did not plan to vaccinate ( n = 27), the most common reasons were “COVID-19 is not a concern” ( n = 14, 50%) and “It is too inconvenient to receive a vaccine” ( n = 11, 39.2%). Most respondents denied the influence of social media on their vaccination decisions. Conclusions: Our results emphasize the importance of prioritizing convenience and accessibility when implementing vaccination programs for public health students.
Journals
2026 EN
Wang Lian · Qiao Jia · Wei Zhenhai
+3 more
The purpose was to investigate the effects of respiratory-swallow coordination training with bimodal signal biofeedback on swallowing function in patients with post-stroke dysphagia. Post-stroke dysphagia Patients were randomly assigned to either the control group or the experimental group. The control group received conventional rehabilitation, while the experimental group underwent additional respiratory-swallow coordination training based on biofeedback. The training protocol consisted of three phases, conducted at an intensity of 30 min/day, 6 days/week, for two consecutive weeks. Outcome measures included the Functional Oral Intake Scale (FOIS) score, the Rosenbek Penetration-Aspiration Scale (PAS) score, respiratory-swallow coordination, and videofluoroscopic swallowing study temporal and kinematic parameter. Assessments were conducted at baseline, post-treatment, and at a one-month follow-up. Thirty patients were enrolled. Both groups showed significant improvement in FOIS scores from baseline to both two-week post-treatment and one-month follow-up ( p < 0.001). Compared to the controls, the experimental group demonstrated significantly greater FOIS scoreimprovement at both post-treatment and follow-up ( p < 0.001). The proportion of patients with a ≥ 2-point increase in FOIS scores was significantly higher in the experimental group than in the control group at both post-treatment ( p < 0.01) and one-month follow-up ( p < 0.01). After two weeks of treatment, the percentage of PAS scores ≥6 was significantly lower in the experimental group than in the control group ( p < 0.001). Additionally, the percentage of optimal respiratory-swallow pattern was significantly higher in the experimental group than in the control group ( p < 0.001). Bimodal signal biofeedback-based respiratory-swallow coordination training can effectively improve respiratory-swallow coordination and swallowing function in patients with post-stroke dysphagia.