Sulfur dioxide is a colorless gas with strong pungent odor, and prolonged inhalation can damage the respiratory system and heart. Precise measurement of sulfur dioxide is very important for the human ...health. While the current sulfur dioxide sensor works at a high temperature and is easily interfered by humidity. Therefore, in this work, we used solution method to coat perovskite nanocrystals Cs 3 Cu 2 I 5 with metal oxides Fe 2 O 3 , and obtained the room-temperature sulfur dioxide gas-sensitive materials Cs 3 Cu 2 I 5 @Fe 2 O 3 nanocrystals. Meanwhile, combined with machine learning, the sensor has the ability of self-calibrating under different humidity environment, realizing the high precision and anti-interference measurement of sulfur dioxide. In addition, in this structure, the coating Fe 2 O 3 not only helps to improve water stability, but also transfer the interaction of sulfur dioxide to the inner Cs 3 Cu 2 I 5 , and lower the gas-sensitive temperature to room temperature. The response/recovery time of the sulfur dioxide sensor based on Cs 3 Cu 2 I 5 @Fe 2 O 3 is 31/816 s, and the sensitivity is 0.19 at 10 ppm. Then, intelligent classification algorithm was used for recognition, and the accurate recognition rate was up to 95.0%. Furthermore, density functional theory was implemented to reveal the gas-sensitive mechanism that sulfur dioxide was adsorbed by Cs 3 Cu 2 I 5 @Fe 2 O 3 nanocrystals, the good response was attributed to the band structure changes significantly, and the hybridization of electron orbitals was appeared between gas and nanocrystals. We believe that the sensor will have potential in sulfur dioxide, and the idea of using machine learning to intelligent eliminate humidity interference can also be extended to other gas sensor.
The application of poly(lactic acid) (PLA) in the packaging area is frequently dwarfed by the inadequate gas/water barrier properties, low heat resistance and high UV transmittance. Herein, an ...environmentally friendly and high-efficiency microwave-assisted functionalization (MAF) approach was proposed to aqueous grafting waste bamboo fibers with the bridging agent. It permitted significant promotion of interfacial interactions between the MAF bamboo fibers (MAFBs) and neighboring PLA chains, contributing to uniform dispersion and intimate interphase. Featuring the morphological features, the MAFB-reinforced (5, 10 and 20 wt%) PLA biocomposites achieved an unexpected combination of high mechanical properties, exceptional resistance to heat deflection and UV irradiation, and excellent water barrier performance. Upon addition of only 5 wt% MAFBs, the tensile strength and toughness of PLA composite films were increased to 46.5 MPa and 0.6 MJ/m3, increasing over 52 % and nearly 107 % compared to those of the counterpart loaded pristine bamboo fibers (PBFs), respectively. This was favorably accompanied by the remarkably reduced water vapor permeability, falling down to the lowest value of 3.5 × 10−11 g∙m/Pa∙s∙m2 for PLA/MAFB (80/20) with a decrease of nearly 79 % compared to the counterpart. It is of interest to note the MAFB-enabled nearly 100 % UV-blocking ratio for PLA loaded 10 and 20 wt% fibers, as well as excellent resistance to heat deflection even at high temperatures like 120 °C. This effort paves the way to multifunctional natural fibers with high affinity to PLA for elegant implementation of high-heat and UV-resistant packaging materials in an ecofriendly manner.
The microwave-assisted functionalization (MAF) approach was proposed to construct intimate interphase for bamboo fiber-reinforced PLA biocomposites, contributing to improvements in water vapor barrier, heat resistance and UV-blocking properties in need for green packaging. Display omitted
•An aqueous microwave-assisted functionalization (MAF) approach was established.•MAF enabled ecofriendly and high-efficiency synthesis of functionalized bamboo fibers (MAFBs).•The MAFBs exhibited intimate affinity to poly(lactic acid) (PLA).•MAFBs endowed PLA with high resistance to heat deflection and nearly 100 % UV-blocking performance.
Using superlubricants to reduce friction and wear can dramatically reduce energy consumption and economic losses in industrial production. In this paper, we report a natural and environmentally ...friendly lubricant based on phytic acid solution (PA-0) that can achieve robust macroscale liquid superlubrication between PDMS and glass interfaces, and the superlubrication state can be maintained for at least 13 h. Significantly, its superlubrication can also be extended to other friction pair materials, reflecting its robustness and universality as a superlubricant. The calculation of the lubricating film thickness reveals that the superlubrication realized by the PA-0 solution belongs to the mixed lubrication state that comprises boundary lubrication and hydrodynamic lubrication. These findings may advance the practical application of liquid superlubrication.
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•Phytic acid (PA) is widely found in plant seeds and has the advantages of natural abundance, non-toxicity and low cost.•The superlubricating state achieved by PA-0 lubricant can be maintained for up to 13 h.•The superlubrication of the obtained PA-0 lubricating material can be realized between PDMS and various friction pairs.
The past decades have witnessed the archetypal shift from petroleum-based to bioplastics including poly(lactic acid) (PLA) for multifunctional packaging. Here we disclose a microwave-assisted ...functionalization (MAF) approach to functionalize wood fibers (FWFs) at minute level and high yields (approaching 99 %), conferring high affinity to PLA matrix and significant promotion of mechanical properties. By incorporating of 10 wt% FWFs, the tensile strength and toughness of PLA composite films were elevated to 54.5 MPa and 1.6 MJ/m3, increasing nearly 28 % and over 45 % compared to those of the counterpart loaded pristine wood fibers (PWFs), respectively. It is of significance to note the FWF-enabled unique optical properties for PLA, as exemplified by approximately 100 % UV-blocking ratio (UVR) in the whole UV region with the addition of 20 wt% FWFs. By contrast, the UVR values of PWF-filled PLA (5 %–20 %) gradually decreased as the fiber contents increased, mainly ascribed to the UV reflection at the poorly bonded interfaces and relatively inferior functionality of PWFs. This distinction allowed us to fabricate UV-barrier packaging for preservation of fresh fruits, which were perishable under the UV light of sunshine. The impressive mechanical robustness and high UVR, may prompt affordable and ecofriendly PLA/FWF composites appropriate for packaging.
Synopsis: The concept of microwave-assisted functionalization was conceived to functionalize natural fibers, which enabled a combination of mechanical strength, UV barrier and transparency for the poly(lactic acid) composite films. Display omitted
•Poly(lactic acid) (PLA) biocomposites were developed for multifunctional packaging.•An aqueous microwave-assisted functionalization (MAF) approach was established.•MAF enabled ecofriendly and high-efficiency synthesis of functionalized wood fibers (FWFs).•FWF endowed PLA with excellent UV shielding and high transmission to visible light.
The association between low-level crystalline silica (silica) exposure and mortality risk is not well understood. We investigated a cohort of 44,807 Chinese workers who had worked in metal mines or ...pottery factories for at least 1 year from January 1, 1960, to December 31, 1974, and were followed through 2003. Low-level silica exposure was defined as having a lifetime highest annual mean silica exposure at or under a permissible exposure limit (PEL). We considered 3 widely used PELs, including 0.05 mg/m3, 0.10 mg/m3, and 0.35 mg/m3. Cumulative silica exposure was estimated by linking a job exposure matrix with each participant's work history. For the 0.10-mg/m3 exposure level, Cox proportional hazards models showed significantly increased risk of mortality from all diseases (for each 1-ln mg/m3-years increase in logged cumulative silica exposure, hazard ratio (HR) = 1.05, 95% confidence interval (CI): 1.03, 1.07), malignant neoplasms (HR = 1.06, 95% CI: 1.03, 1.09), lung cancer (HR = 1.08, 95% CI: 1.02, 1.14), ischemic heart disease (HR = 1.09, 95% CI: 1.02, 1.16), pulmonary heart disease (HR = 1.08, 95% CI: 1.00, 1.16), and respiratory disease (HR = 1.20, 95% CI: 1.14, 1.26). The 0.05-mg/m3 and 0.35-mg/m3 exposure levels yielded similar associations. Long-term exposure to low levels (PELs ≤0.05 mg/m3, ≤0.10 mg/m3, or ≤0.35 mg/m3) of silica is associated with increased total and certain cause-specific mortality risk. Control of ambient silica levels and use of personal protective equipment should be emphasized in practice.
The concept of bio-inspired gradient hierarchies, in which the well-defined MOF nanocrystals serve as active nanodielectrics to create electroactive shell at poly(lactic acid) (PLA) nanofibers, is ...introduced to promote the surface activity and electroactivity of PLA nanofibrous membranes (NFMs). The strategy enabled significant refinement of PLA nanofibers during coaxial electrospinning (∼40 % decline of fiber diameter), accompanied by remarkable increase of specific surface area (nearly 1.5 m2/g), porosity (approximately 85 %) and dielectric constants for the bio-inspired gradient PLA (BG-PLA) NFMs. It largely boosted initial electret properties and electrostatic adsorption capability of BG-PLA NFMs, as well as charge regeneration by TENG mechanisms even under high-humidity environment. The BG-PLA NFMs thus featured exceptionally high PM0.3 filtration efficiencies with well-controlled air resistance (94.3 %, 163.4 Pa, 85 L/min), in contrast to the relatively low efficiency of only 80.0 % for normal PLA. During the application evaluation of outdoor air purification, excellent long-term filtering performance was demonstrated for the BG-PLA for up to 4 h (nearly 98.0 %, 53 Pa), whereas normal PLA exhibited a gradually declined filtration efficiency and an increased pressure drop. Moreover, the BG-PLA NFMs of increased electroactivity were ready to generate tribo-output currents as driven by respiratory vibrations, which enabled real-time monitoring of electrophysiological signals. This bio-inspired gradient strategy opens up promising pathways to engender biodegradable nanofibers of high surface activity and electroactivity, which has significant implications for intelligent protective membranes.
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•A bio-inspired strategy was unraveled to engender hierarchically gradient poly(lactic acid) (PLA) nanofibers.•The bio-inspired gradient PLA nanofibers exhibited high surface activity and enhanced electret mechanisms.•An impressive combination of efficient PM0.3 filtration and favorable breathability were demonstrated for the PLA NFMs.•The NFMs enabled real-time respiratory monitoring and self-powered wireless signal transmission.
Early embryonic development is a finely orchestrated process that requires precise regulation of gene expression coordinated with morphogenetic events. TATA-box binding protein-associated factors ...(TAFs), integral components of transcription initiation coactivators like TFIID and SAGA, play a crucial role in this intricate process. Here we show that disruptions in TAF5, TAF12 and TAF13 individually lead to embryonic lethality in the mouse, resulting in overlapping yet distinct phenotypes. Taf5 and Taf12 mutant embryos exhibited a failure to implant post-blastocyst formation, and Taf5 mutants have aberrant lineage specification within the inner cell mass. In contrast, Taf13 mutant embryos successfully implant and form egg-cylinder stages but fail to initiate gastrulation. Strikingly, we observed a depletion of pluripotency factors in TAF13-deficient embryos, including OCT4, NANOG and SOX2, highlighting an indispensable role of TAF13 in maintaining pluripotency. Transcriptomic analysis revealed distinct gene targets affected by the loss of TAF5, TAF12 and TAF13. Thus, we propose that TAF5, TAF12 and TAF13 convey locus specificity to the TFIID complex throughout the mouse genome.
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•Taf5 and Taf12 mutant embryos form blastocysts but fail to implant.•Taf5 mutants exhibit aberrant lineage specification within the inner cell mass.•Taf13 mutant embryos fail to initiate gastrulation.•Taf13 mutant embryos are missing pluripotency factors OCT4, NANOG and SOX2.•Transcriptomes suggest each TAF (−5, −12, −13) confers unique locus specificity.
•The microstructure of the PPy aerogel could be tuned by precisely adjusting the molar ratio of methyl orange to pyrrole and the concentration of the pyrrole monomer.•A ultralong nanotubes aerogels ...with excellent structure-driven elasticity, adjustable flexibility, and high solar evaporation performance.•A salt-rejecting solar evaporator for long-term and stable evaporation under highly saline water.•Provides a strategy to design and develop new polymer-based nanotubular aerogels for efficient solar steam generation.
Solar interface evaporation is considered to be a sustainable and environmentally friendly technology for obtaining fresh water from seawater. However, the preparation of photothermal conversion materials with excellent evaporation performance, good mechanical properties, and simple method for the solar interface evaporation still faces challenge.
Herein, we report the fabrication of ultralong polypyrrole nanotubes aerogel-based solar steam generator through one-pot oxidative self-polymerization of pyrrole monomer using methyl orange as template and ferric chloride as oxidant.
The as-prepared aerogel shows excellent elasticity, which can be compressed by 30% and recover to its original shape within a few seconds. In combination with abundant porosity (92.3%), low thermal conductivity (0.077 W m−1 K−1), super hydrophilic wettability and high light absorption (94%), the as-prepared aerogel shows a high solar-to-vapor efficiency above 74.5% even in high concentration saline (20%). This work provides new opportunities for effective design of conductive polymer-based photothermal monolithic materials with tunable porosity, adjustable morphology, required mechanical properties and high evaporation performance.
Precisely controlled preparation of ultra-long polypyrrole nanotube aerogels for solar steam generation. Display omitted
Traditional inhibitors have such disadvantages as unstable inhibitory effects and short active lifetimes. Sodium bicarbonate, stable in nature, is expected to absorb heat and lower the temperature ...upon heated and decomposition, enabling its decomposition product to be effective for preventing coal oxidation and spontaneous combustion. Accordingly, the present study investigates the characteristics of sodium bicarbonate and proposes a novel method for preventing the spontaneous combustion of coal using sodium bicarbonate. By establishing a programmed temperature experimental system of coal spontaneous combustion in the laboratory, the researchers added sodium bicarbonate (0.5–3 g) to the coal samples, and analyzed changes in CO and O2 concentration. The results out of the present experimental conditions, compared with those of coal samples treated with magnesium and calcium chlorides, show that adding different amounts of sodium bicarbonate can inhibit coal oxidation with an optimal addition amount of 3 g. When the amount of sodium bicarbonate added was larger than 2 g and the temperature above 130 °C, its inhibitory effect is more significant than that of existing inhibiting agents.
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•In this paper, heat control inhibitor is used to inhibit coal spontaneous combustion.•The loss of water weakens the effect of the inhibitor.•When the amount of sodium bicarbonate was more than 2 g, the inhibitory effect was already desirable.
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