The nature-inspired preparation of porous films via the breath figure method (BF) is detailed. Topics include the formation mechanism for BFA films, the morphological control of BFA films, the ...chemical modification and functionalization of BFA films and applications of BFA films.
A breath figure (BF) is the water droplet array that forms when moisture comes in contact with a cold substrate. This water droplet array has been widely utilized in the past two decades as a ...versatile soft template for the fabrication of polymeric porous films. Accordingly, the ordered pores on the polymer films formed with such a method are named a breath figure array (BFA).The BF templating technique is undergoing rapid development. Several unconventional BF processes have been established to prepare porous films with unique morphologies or primary materials, and various newly developed functionalization techniques have significantly improved the performance of polymeric films with BFA, leading to novel applications, including templates, biosensors, and separation membranes. These recent achievements will be described in this Minireview.
Every breath you take: A breath figure (BF) is the water droplet array that forms when moisture comes in contact with a cold substrate. Several unconventional BF methods have been established to prepare BF array films with unique morphologies or primary materials, and various newly developed functionalization techniques have significantly improved the performance of BF array films, leading to some novel applications.
The adsorption capacity of intrinsic SnS2 to NH3, Cl2 and C2H2 is very weak. However, non-metallic elements B and N have strong chemical activity, which can significantly improve the conductivity and ...gas sensitivity of SnS2. Based on density functional theory, SnS2 was modified with B and N atoms to analyze its adsorption mechanism and gas sensitivity for NH3, Cl2 and C2H2 gases. The optimal structure, adsorption energy, state density and frontier molecular orbital theory are analyzed, and the results are in good agreement with the experimental results. The results show that the adsorption of gas molecules is exothermic and spontaneous. Only the adsorption of NH3 and Cl2 on B-SnS2 belongs to chemical adsorption, whereas other gas adsorption systems belong to physical adsorption. Moderate adsorption distance, large adsorption energy, charge transfer and frontier molecular orbital analysis show that gas adsorption leads to the change of the conductivity of the modified SnS2 system. The adsorption capacity of B-SnS2 to these gases is Cl2 > NH3 > C2H2. The adsorption capacity of N-SnS2 is NH3 > C2H2 > Cl2. Therefore, according to different conductivity changes, B-SnS2 and N-SnS2 materials can be developed for greenhouse gas detection of gas sensors.
A general challenge for preparing organic microporous polymers (MOPs) is to use cheap and sustainable building blocks while retaining the advanced functions. We demonstrate a strategy to massively ...prepare pitch-based MOPs, which are thermally and chemically stable. A maximum BET surface area of 758 m(2) g(-1) and high gas storage capacity were achieved.
Detecting the characteristic decomposition products (SO2, SOF2, and HF) of SF6 is an effective way to diagnose the electric discharge in SF6-insulated equipment. Based on first-principles ...calculations, Au, Ag, and Cu were chosen as the surface modification transition metal to improve the adsorption and gas-sensing properties of MoTe2 monolayer towards SO2, SOF2, and HF gases. The results show that Au, Ag, and Cu atoms tend to be trapped by TH sites on the MoTe2 monolayer, and the binding strength increases in the order of Ag < Au < Cu. In gas adsorption, the moderate adsorption energy provides the basis that the TM-MoTe2 monolayer can be used as gas-sensing material for SO2, SOF2, and HF. The conductivity of the adsorption system changes significantly. The conductivity decreases upon gases adsorption on TM-MoTe2 monolayer, except the conductivity of Ag-MoTe2 monolayer increases after interacting with SOF2 gas.
When the displacement of an object is evaluated using sensor data, its movement back to the starting point can be used to correct the measurement error of the sensor. In medicine, the movements of ...chest compressions also involve a reciprocating movement back to the starting point. The traditional method of evaluating the effects of chest compression depth (CCD) is to use an acceleration sensor or gyroscope to obtain chest compression movement data; from these data, the displacement value can be calculated and the CCD effect evaluated. However, this evaluation procedure suffers from sensor errors and environmental interference, limiting its applicability. Our objective is to reduce the auxiliary computing devices employed for CCD effectiveness evaluation and improve the accuracy of the evaluation results. To this end, we propose a one-dimensional convolutional neural network (1D-CNN) classification method. First, we use the chest compression evaluation criterion to classify the pre-collected sensor signal data, from which the proposed 1D-CNN model learns classification features. After training, the model is used to classify and evaluate sensor signal data instead of distance measurements; this effectively avoids the influence of pressure occlusion and electromagnetic waves. We collect and label 937 valid CCD results from an emergency care simulator. In addition, the proposed 1D-CNN structure is experimentally evaluated and compared against other CNN models and support vector machines. The results show that after sufficient training, the proposed 1D-CNN model can recognize the CCD results with an accuracy rate of more than 95%. The execution time suggests that the model balances accuracy and hardware requirements and can be embedded in portable devices.
To systematically explore the effects of the synthesis conditions on the porosity of hyper-cross-linked polymers (HCPs), a series of 9-phenylcarbazole (9-PCz) HCPs (P1–P11) has been made by changing ...the molar ratio of cross-linker to monomer, the reaction temperature T 1, the used amount of catalyst and the concentration of reactants. Fourier transform infrared spectroscopy was utilized to characterize the structure of the obtained polymers. The TG analysis of the HCPs showed good thermal stability. More importantly, a comparative study on the porosity revealed that: the molar ratio of cross-linker to monomer was the main influence factor of the BET specific surface area. Increasing the reaction temperature T 1 or changing the used amount of catalyst could improve the total pore volume greatly but sacrificed a part of the BET specific surface area. Fortunately changing the concentration of reactants could remedy this situation. Slightly changing the concentration of reactants could simultaneously obtain a high surface area and a high total pore volume. The BET specific surface areas of P3 was up to 769 m2 g−1 with narrow pore size distribution and the CO2 adsorption capacity of P11 was up to 52.4 cm3 g−1 (273 K/1.00 bar).
The aim of this study was to investigate the dissipation and residues of fluopyram in melon under field conditions and to assess its safe use. A liquid chromatography tandem mass spectrometry ...(LC-MS/MS) with QuEChERS for analysis of fluopyram and its metabolite M25 was established. Under the experimental condition of adding different levels of analytes (0.02 ~ 2 mg kg
−1
), the average residue recovery of fluopyram and M25 in melon was 96%~105% with a relative standard deviation of 2%~8%. The limit of quantitation of fluopyram and M25 in melon was 0.02 mg kg
−1
. Field trial results showed that the half-life of fluopyram in melon was 4.5-6.2 days, and the degradation was relatively fast. The residual of M25 in melon was lower than the LOQ. The terminal residues of fluopyram in melon sample were in the range of <0.02 ~ 0.095 mg kg
−1
, which was lower than the maximum residue limit for melon in EU (0.4 mg kg
−1
) and South Korea (0.6 mg kg
−1
). Dietary risk assessment indicated that the long-term intake risk quotient (rq
chronic
) and short-term intake risk quotient (rq
acute
) of fluopyram in people from different age groups were 0.000079 ~ 0.000671 and 0.002978 ~ 0.025268, respectively, which were significantly lower than 1. Therefore, the residues of fluopyram in melons would not affect the health of the general population in China.
Abstract
Background
The study aims were to analyze pregnancy outcomes after the use of emergency cerclage in patients with different BMIs.
Methods
A total of 76 singleton pregnant patients who ...underwent emergency cerclage at a tertiary comprehensive hospital in China between Jan 2017 and Dec 2021 were retrospectively divided into an obesity group of 37 patients with BMIs ≥ 28 kg/m
2
and a non-obesity group of 39 patients with BMIs < 28 kg/m
2
. The medical records of patients were reviewed and all relevant clinical data were further collected into an itemized data spreadsheet for various analyses.
Results
Emergent cerclage, along with amnioreduction if needed, could be safely performed on both obese and non-obese pregnant women with a dilated external cervix (> 1 cm), which effectively prolonged the gestational week up to ≥ 25 weeks. Obese gravidae had shorter suture-to-delivery intervals and mean pregnancy lengths but more spontaneous preterm births before 37 weeks, and a lower live birth rate (
P
< 0.05). Logistic regression analysis revealed that BMI, how many times cerclages have been performed during pregnancy (frequency of cerclage) and bacterial vaginosis, aerobic vaginitis and vulvovaginal candidiasis (vaginal microecology) were significantly correlated with fetal loss (
P
< 0.05), while rank correlation analysis established a negative correlation between BMI values and the suture-to-delivery interval (
P
= 0.031).
Conclusions
Pregnant cervical insufficiency patients with BMIs > 28 kg/m
2
may ill-serve the gestational outcomes and suture-to-delivery interval after their emergent cerclage. Additionally, BMI, frequency of cerclage and vaginal microecology accounted for higher fetal loss in patients who underwent emergency cerclage.
Industrialization has resulted in a large number of industrial waste slags being produced, which severely pollute the environment. This urgently needs resourceful treatment. The objective of this ...paper is to investigate the preparation, performance, and cementation mechanism of a novel geopolymer backfill paste for goaf. We reused diverse industrial waste slags based on low-calcium silica-alumina precursors (two fly ashes FAI, FAII, and red mud RM), high-calcium-based slags (carbide slag CS, soda residue SR, briquette residue slag BRS, and granulated blast furnace slag GBFS), and two additives (gypsum powder GP and lime powder LP). The hardening of backfill pastes was investigated by analyzing the effects of FAI, GBFS, RM, and LP on physical and chemical performance. The cementation mechanism of the prepared backfill paste was revealed through morphology, mineralogy, and chemical products through the use of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The results show that the prepared backfill paste incorporating various solid wastes (FAI, FAII, RM, CS, SR, GBFS, RBS, etc.) yields a 28-d compressive strength of 2.1 MPa (higher than the required value of 0.6 MPa) and a fluidity of 201 mm. Geopolymer gels (N,C)-A-S-H, calcium silicate hydrated C-S-H, and calcium aluminosilicate hydrated C-A-S-H gels serve as chemical cementers, whereas unreacted particles serve as physical filler skeletons. These findings provide an experimental and theoretical basis for the interchangeable use of various identical component solid wastes in backfill engineering materials.
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