Time Ring Data: Definition and Application in Spatio-Temporal Analysis of Urban Expansion and Forest Loss

Remote sensing can provide spatio-temporal continuous Earth observation data and is becoming the main data source for spatial and temporal analysis. Remote sensing data have been widely used in applications such as meteorological monitoring, forest investigation, environmental health, urban planning, and water conservancy. While long-time-series remote sensing data are used for spatio-temporal analysis, this analysis is usually limited because of the large data volumes and complex models used. This study intends to develop an innovative and simple approach to reveal the spatio-temporal characteristics of geographic features from the perspective of remote sensing data themselves. We defined an efficient remote sensing data structure, namely time ring (TR) data, to depict the spatio-temporal dynamics of two common geographic features. One is spatially expansive features. Taking nighttime light (NTL) as an example, we generated a NTL TR map to exhibit urban expansion with spatial and temporal information. The speed and acceleration maps of NTL TR data indicated extraordinary expansion in the last 10 years, especially in coastal cities and provincial capitals. Beijing, Tianjin, Hebei Province, Shandong Province, and Jiangsu Province exhibited fast acceleration of urbanization. The other is spatially contractive features. We took forest loss in the Amazon basin as an example and produced a forest cover TR map. The speed and acceleration were mapped in two 10-year periods (2000–2010 and 2010–2020) in order to observe the changes in Amazon forest cover. Then, combining cropland TR data, we determined the consistency of the spatio-temporal variations and used a linear regression model to detect the association between the acceleration of cropland and forest. The forest TR map showed that, spatially, there was an apparent phenomenon of forest loss occurring in the southern and eastern Amazon basin. Temporally, the speed of forest loss was more drastic between 2000 and 2010 than that in 2010–2020. In addition, the acceleration of forest loss showed a dispersed distribution, except for in Bolivia, which demonstrated a concentrated regional acceleration. The R-squared value of the linear regression between forest and cropland acceleration reached 0.75, indicating that forest loss was closely linked to the expansion of cropland. The TR data defined in this study not only optimized the use of remote sensing data, but also facilitated their application in spatio-temporal integrative analysis. More importantly, multi-field TR data could be jointly applied to explore the driving force at spatial and temporal scales

Research on Stacked Piezoelectric Cymbal Vibrator

As demand for haptic feedback increases, piezoelectric materials have become one of the best candidate materials due to their small size, high electromechanical coupling coefficient, and fast response. A stacked piezoelectric cymbal vibrator is proposed based on the common cymbal-type transducer, which is composed of a piezoelectric stack to drive and a cymbal disk to amplify displacement. A coupling theoretical model between the piezoelectric stack and the cymbal-type structure is established. The longitudinal and radial displacements of the stacked piezoelectric cymbal vibrator are calculated in the low frequency range (<1000 Hz) by the theoretical model and the finite element method. The theoretical and numerical results are in good agreement. The results show that the radial displacement can be converted into longitudinal displacement and then effectively amplified by the cymbal disk with an amplification ratio of 30. The feature is conducive to its widespread application in the field of consumer electronics

The Influences of Tai Chi on Balance Function and Exercise Capacity among Stroke Patients: A Meta-Analysis

Objective. This study aims to explore the influences of Tai Chi on the balance function and exercise capacity among stroke patients. Methods. Databases including PubMed, Embase, WOS (Web of Science), the Cochrane Library, CNKI (China National Knowledge Infrastructure), Wanfang Data, VIP (VIP database), and CBM (China Biology Medicine disc) were retrieved to gather the figures of randomized controlled trials on the balance function and exercise capacity among stroke patients. Then relevant data were input and analyzed in Review Manager 5.3. Results. Nineteen papers were included and analyzed in this study. According to the combined effect size, the balance function of stroke patients improved significantly: the Berg Balance Function Scale score [MD = 7.67, 95% CI (3.44, 11.90)]; standing and walking test scores [MD = 3.42, 95% CI (4.22, −2.63)]; gravity swing area [MD = 0.79, 95% CI (1.48, 0.10)]; and gravity swing speed [MD = −5.43, 95% CI (−7.79, 3.08)]. In addition, the exercise capacity improved significantly as well: the FMA (Fugl-Meyer Assessment Scale) scale score [MD = 4.15, 95% CI (1.68, 6.63)]. There are no significant influences or changes of other related results. Conclusions. Stroke patients are able to improve their balance functions and exercise capacities prominently when they do Tai Chi exercise once or twice a week and ≥5 times/week and >30 ≤ 60 min/time

Preparation and characterization of an ultrathin carbon shell coating a silver core for shell-isolated nanoparticle-enhanced Raman spectroscopy

A well-designed type of ultrathin carbon shell coating a silver core was prepared for the first time through an alternate adsorption and carbonization method. The obtained ultrathin carbon shell shows prominent advantages, including sufficient uniformity, better chemical stability than silica or alumina, biocompatibility, being free of pin-holes and low cost

Tribological Properties of Alkylphenyl Diphosphates as High-Performance Antiwear Additive in Lithium Complex Grease and Polyurea Grease for Steel/Steel Contacts at Elevated Temperature

The alkylphenyl diphosphates pentaerythritol tetrakis­(diphenyl phosphate) (PDP) and trimethylolpropane tris­(diphenyl phosphate) (TDP) were evaluated as the antiwear additives in lithium complex grease and polyurea grease at 200 °C. The results indicated that both additives may effectively reduce the sliding friction and wear as compared to the base greases. The tribological performances were generally better than the normally used molybdenum disulfide (MoS₂)-based additive package in lithium complex grease and also in polyurea grease. Boundary lubrication films composed of Fe­(OH)­O, Fe₃O₄, FePO₄, and compounds containing the P–O bonds were formed on the worn surface, which resulted in excellent friction reduction and antiwear performance

Using the Eco-Erosion Index to assess regional ecological stress due to urbanization – a case study in the Yangtze river delta urban agglomeration

Urban agglomeration (the spread of cities into large agglomerations) has become the main form of urbanization in China, and natural ecosystems surrounding the urban areas are becoming degraded and fragmented as a result. Although ecological indicators have been widely used to assess the regional ecological stress resulting from urbanization, few of them consider spatial adjacency relationships between urban and natural landscapes. From this perspective a novel ecological indicator, the Eco-Erosion Index (EEI), was developed and applied to assess the regional ecological stress caused by urban agglomeration development across 26 cities in the Yangtze River Delta, China (YRD). We analyzed: i) temporal change in land use and land cover (LULC) and ecosystem services value (ESV) in YRD from 1990 to 2010, ii) spatiotemporal dynamics of EEI of YRD at different scales: provincial, municipal, and 5 km-grid, iii) inter-relationships between EEI and LULC and ESV to explore its effectiveness as an indicator. The results showed that urban agglomeration in YRD has led to increasing regional ecological stress from 1990 to 2010. EEI values increased from 0.197 in 1990 to 0.321 in 2010. The closer to Shanghai City, the greater the EEI values of the cities become. EEI is highly related with LULC and ESV but integrates these two variables as it represents both the spatial occupation and landscape adjacency effects. The EEI values demonstrate some scale effects, and EEI at fine scale provides useful information to guide sustainable urban landscape management

High prevalence of NTDs in Shanxi province: a combined epidemiological approach

BACKGROUND: Shanxi Province has historically reported a high prevalence of NTDs. In order to establish baseline rates for NTDs and discuss the risk factors associated with sociodemographic, maternal characteristics, and geographic factors, we performed the present study using an approach combining population and hospital-based methodologies. METHODS: We used v 2 and Fisher&apos;s exact tests to evaluate variation in the prevalence by selected covariates and computed crude ORs and 95% CIs. Adjusted odds ratios (AORs) were performed using logistic regression with all the covariates included in the model. RESULTS: The overall NTD prevalence during the 3 year study period was 199.38 per 10,000 births, with a higher NTD prevalence clustered in 46 villages within this geographic area. However, no statistical significance was found between NTD prevalence and the elevation of the villages or their distance from coal plants. AORs revealed women aged 20 and above had a lower risk of NTDs compared to those younger than 20 (AOR range 0.4-0.5). A higher risk of NTDs was observed among female infants (AOR 1.50; 95% CI: 1.04-2.17), women with four or more previous births (AOR 2.80; 95% CI: 1.20-6.52), and a previous history of birth defects (AOR 3.23; 95% CI: 1.46-7.12)