Wearable pressure sensor for athletes’ full-range motion signal monitoring

In order to real-time grasp of various physiological signals of athletes during sports, a high-performance flexible pressure sensor that can monitor various physiological signals and human motion was designed. Porous polydimethylsiloxane (PDMS) foam prepared by the sacrificial template method and graphene as raw materials were used to prepare a flexible pressure sensor with wide working range (0–100 kPa), ultra-high sensitivity (the average sensitivity in the range of 0–30 kPa is 17.9 kPa ^−1 , the sensitivity in the range of 30–100 kPa reaches 79 kPa ^−1 ), fast response ability (response time is 20 ms) and long-term work stability (more than 10 000 cycles). The excellent performance of this pressure sensor depends on the use of PDMS foam with a high elastic modulus and the graphene loading level is controlled to an appropriate ratio. Finally, we used the conductive porous PDMS foam based flexible pressure sensor to demonstrate accurate and real-time monitoring of athletes’ tiny physiological signals (including pulse and electrocardiograph signals), vocalization and facial emotions, as well as violent joint and limb movements (including joint bending, walking, squats, jogging, and jumping), showing the potential in coaching athletes

A Method for Evaluating the Maximum Capacity of Grid-Connected Wind Farms Considering Multiple Stability Constraints

Boosting the capacity of grid-connected wind farms will greatly contribute to increasing the share of sustainable energy in the global generation mix. It is imperative to study the way to quantitatively assess the maximum capacity of grid-connected wind farms in combination with power system stability characteristics. In this work, a method to evaluate the maximum capacity of grid-connected wind farms considering the joint constraints of frequency and voltage stability is proposed based on the global intrinsic property of frequency stability and the local characteristic of voltage stability. Firstly, the maximum capacity of grid-connected wind farms in the power grid with high wind power penetration is assessed globally based on the frequency stability constraints, and then locally considering the voltage stability constraints of each local power grid. Further on, a quantitative method to evaluate the capacity of grid-connected wind farms is proposed based on the correlation between the local static voltage stability margin and the local capacity of grid-connected wind farms, as well as the global constraint of the maximum capacity of grid-connected wind farms. Finally, the effectiveness of the proposed method is verified by the simulation results of an actual regional power grid

Mechanical Properties and Microscopic Mechanism of Coral Sand-Cement Mortar

The workability and mechanical performance of coral sand-cement mortar (coral mortar, for short) and the modification effects of mineral admixtures on the coral mortar were studied in this paper. The results showed that the strength of coral mortar was lower than that of standard mortar, but the strength of coral mortar was improved by compositing with the mineral admixture, which can be attributed to the improvement of the microstructure and interface transition area. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to explore the microscopic mechanism involved in the mechanical properties, volume stability, and hydration of mortar. The analyses revealed that the internal curing effect of coral sand improved the mechanical properties of mortar and its ability to resist shrinkage. The uneven surface of coral sand formed a meshing state of close combination with the hardened cement mortar, which helped to improve the volume stability of mortar. The Ca2+ and Mg2+ ions from coral sand participated in the hydration reaction of cement, which contributed to generating more hydration products. Moreover, the microaggregate filling and pozzolanic effects of fly ash and slag improved the mechanical properties of coral mortar and resistance to chloride ion diffusion

Factors associated with favourable outcome in large hemispheric infarctions

Abstract Background Large hemispheric infarction (LHI) is a devastating condition with high mortality and poor functional outcome in most conservatively treated patients. The purpose of this study was to explore factors associated with favorable outcome in patients with LHI. Methods We prospectively enrolled consecutive patients with LHI. Favorable outcome was defined as a modified Rankin Scale (mRS) score of 0 to 3 at 90 days. Multivariate logistic regression analysis was employed to identify the independent factors associated with favorable outcome. Results Two hundred fifty-six cases with LHI were identified: 41 (16.0%) died during hospitalization, 94 (36.7%) died at 3 month, and 113 (44.1%) survived with favorable outcome at day 90. Compared with patients with unfavorable outcome, the favorable cases were younger (55.8 ± 14.7 vs. 66.2 ± 14.1), had less history of hypertension (38.9% vs. 59.3%), lower baseline NIHSS score (median NIHSS score 11 vs. 17), lower blood pressure on admission (systolic 134.7 ± 24.9 vs. 145.1 ± 26.1 mmHg; diastolic 80.2 ± 14.9 vs. 86.9 ± 16.2 mmHg; respectively), lower level of baseline serum glucose (7.2 ± 3.3 vs. 8.2 ± 3.3 mmol/L), a lower frequency of stroke-related complications (55.8% vs. 91.4%), more use of antiplatelets (93.8% vs. 57.1%) and statins (46.9% vs. 25.7%) in the acute phase of stroke, but less use of osmotic agents (69.9% vs. 89.3%), mechanical ventilation (1.8% vs. 20.0%) or decompressive hemicraniectomy (1.8% vs. 15.7%). Multivariable analysis identified the following factors associated with favorable outcome: age (odds ratio, OR 0.95, 95% confidence interval [CI] 0.92–0.98, p < 0.001), baseline NIHSS score (OR 0.90, 95% CI 0.84–0.96, p = 0.002), statins used in acute phase (OR 2.49, 95% CI 1.10–5.65, p = 0.029), brain edema (OR 0.05, 95% CI 0.01–0.21, p < 0.001) and pneumonia (OR 0.42, 95% CI 0.19–0.93, p = 0.032). Conclusion More than one third of patients with LHI have relatively favorable clinical outcomes at 90 days. Younger age, lower baseline NIHSS score, absence of brain edema and pneumonia, and statins used in the acute phase were associated with favorable outcome of patients with LHI at 90 days

Preparation of sustainable ultra-high performance concrete (UHPC) with ultra-fine glass powder as multi-dimensional substitute material

High cost and CO2 emissions are the issues that need to be addressed in the widespread application of UHPC. The application of mineral admixtures in UHPC has become a new development direction. Ultra-fine glass powders with median diameter d50 of 316 nm (named as nGP) and 5.33 μm (named as mGP) were fabricated to replace silica fume and blast furnace slag, respectively, to prepare eco-friendly UHPC. The outcomes of the study revealed that both nGP and mGP can significantly promote the hydration of UHPC pastes. The incorporation of ultra-fine GP increased the hydration products and improved the microstructure of UHPC due to its pore filling effect, nucleation effect and pozzolanic activity. The compressive strength of UHPC containing ultra-fine glass powders was larger than the reference ones and the optimal substitution rates of silica fume by nGP and blast furnace slag by mGP were 60% and 50%, respectively. Ultra-fine GP is feasible to be employed as multi-dimensional substitute material to produce low cost eco-friendly UHPC.Web of Science401art. no. 13285

A Simulation Study on Optimization of Sowing Time of Maize (<i>Zea mays</i> L.) for Maximization of Growth and Yield in the Present Context of Climate Change under the North China Plain

Adjusting the sowing dates of crops is an effective measure for adapting them to climate change, but very few studies have explained how the optimum sowing dates can be determined. In this study, we used the sowing date field data from 2018 to 2021 from Hebei Gucheng Agricultural Meteorology National Observation and Research Station to analyze the effects of the sowing date on growth, development, and yield of maize, and to quantify the impact of light-temperature potential productivity on different stages of the yield formation. The results showed that delayed sowing decreased the vegetative growth period (VGP) and increased the reproductive growth period (RGP) of maize. The light-temperature potential productivity of the whole growth (WG) period had an exponential relationship with the theoretical yield. At least 14,614.95 kg ha−1 of light-temperature potential productivity was needed to produce grain yield. The maximum theoretical yield was approximately 18,052.56 kg ha−1, as indicated by the curve simulation results. The influence of light-temperature potential productivity on theoretical yield was as follows: VGP > RGP > vegetative and reproductive period (VRP). Accordingly, a method for determining the sowing time window based on VGP was established, and the optimal sowing dates were estimated for 1995–2021 and the SSP2-4.5 scenario in CMIP6 in the middle of this century (2030–2060). The simulation results showed that the optimum sowing date of maize “Lianyu 1” at the study site was 20–25 May in 1995–2021. In the middle of this century, the optimal sowing time of maize was ahead of schedule and the suitable sowing window was increased slightly. We conclude that advancing the sowing date of maize is a practical strategy for enhancing yield in the context of climate warming, and this strategy will provide a meaningful reference for scientific optimization of sowing dates to adapt maize to climate change

A Simulation Study on Optimization of Sowing Time of Maize (Zea mays L.) for Maximization of Growth and Yield in the Present Context of Climate Change under the North China Plain

Adjusting the sowing dates of crops is an effective measure for adapting them to climate change, but very few studies have explained how the optimum sowing dates can be determined. In this study, we used the sowing date field data from 2018 to 2021 from Hebei Gucheng Agricultural Meteorology National Observation and Research Station to analyze the effects of the sowing date on growth, development, and yield of maize, and to quantify the impact of light-temperature potential productivity on different stages of the yield formation. The results showed that delayed sowing decreased the vegetative growth period (VGP) and increased the reproductive growth period (RGP) of maize. The light-temperature potential productivity of the whole growth (WG) period had an exponential relationship with the theoretical yield. At least 14,614.95 kg ha&minus;1 of light-temperature potential productivity was needed to produce grain yield. The maximum theoretical yield was approximately 18,052.56 kg ha&minus;1, as indicated by the curve simulation results. The influence of light-temperature potential productivity on theoretical yield was as follows: VGP &gt; RGP &gt; vegetative and reproductive period (VRP). Accordingly, a method for determining the sowing time window based on VGP was established, and the optimal sowing dates were estimated for 1995&ndash;2021 and the SSP2-4.5 scenario in CMIP6 in the middle of this century (2030&ndash;2060). The simulation results showed that the optimum sowing date of maize &ldquo;Lianyu 1&rdquo; at the study site was 20&ndash;25 May in 1995&ndash;2021. In the middle of this century, the optimal sowing time of maize was ahead of schedule and the suitable sowing window was increased slightly. We conclude that advancing the sowing date of maize is a practical strategy for enhancing yield in the context of climate warming, and this strategy will provide a meaningful reference for scientific optimization of sowing dates to adapt maize to climate change

Achieving superior anti-corrosion properties of vinyl ester resin coatings via compositing with 3-methacryloxy propyl trimethoxysilane functionalized MXene nanosheets

Exposure of steel to harsh marine environment can cause serious corrosion, which significantly affects its durability. In this study, a novel two-dimensional MXene nanosheets were functionalized with 3-methacryloxy propyl trimethoxysilane (γ-MPS@MXene) followed by introducing into the vinyl ester resin (VER) through solution blending method to enhance the anti-corrosion properties of the coatings. The effects of γ-MPS@MXene incorporation on the mechanical properties, thermal stability, dynamic thermo-mechanical properties, UV aging resistance, anti-corrosion properties of the VER nanocomposites were systematically investigated. The optimum tensile strength, elastic modulus, hardness, thermal stability and UV aging resistance of γ-MPS@MXene VER nanocomposites can be achieved when composited with 0.08 wt% γ-MPS@MXene. The electrochemical impedance spectroscopy(EIS) results demonstrate the introduction of γ-MPS@MXene nanosheets into the VER enhanced the anti-corrosion properties of the composites coating remarkablely and the anti-corrosion mechanism was also revealed. The favourable interfacial interaction between γ-MPS@MXene and VER matrix through covalent cross-linking diminished interfacial defects of the composite coating and was also beneficial to enhancement of the compatibility, the well-dispersed γ-MPS@MXene in VER created a “labyrinth effect”, which prolonged the diffusion path of corrosive medium to the carbon steel substrate. This research provides a promising strategy for the fabrication of heavy anti-corrosion nanocomposite resin coatings, which can realize long-term corrosion protection of metal substrates