Hazard evaluation of forest combustibles based on the correlation between pyrolysis products and combustion parameters.

Persistent organic pollutants (POPs) sourced by the forest fire release are emerging as significant contributors. Despite their increasing importance, the impact of forest fires on POPs remains inadequately explored and an unclear understanding. Herein, the research, choosing four typical forest combustibles, focuses on the relationship between typical POPs and wildfire parameters by assessing the predominant compounds and their concentration in POPs emissions from such fuels through molecular-level analysis. Experiments reveal forest combustibles thermally degrade to release products, releasing a variety of products, including acids (>7.94 %), aldehydes (>2.32 %), ketones (>3.40 %), alcohols (>7.70 %), esters (>2.33 %), ethers (>4.44 %), hydrocarbons (>6.36 %), aromatic compounds (>21.40 %), and nitrogen-bearing compounds (>11.83 %); notably, aromatic compounds, containing substantial concentrations, are also recognized as POPs. By delving into the pyrolysis (20 °C·ms-1) and burning processes (25, 35 and 50 kW/m2) of forest combustibles, we can gain a comprehensive understanding of the origin of POPs in wildfires. Moreover, Pearson correlation analysis is employed to establish connections between emitting volatiles and forest fire risk, further unveiling a significant correlation between fire hazards of forest combustibles and the presence of aromatic compounds (Correlation over 0.8). These findings are crucial for comprehending the POPs in forests and evaluating forest fire hazards at the molecular level.

First Report of Root Rot on Hydroponically Grown Romaine Lettuce Caused by Pythium dissotocum in Korea.

The romaine lettuce (Lactuca sativa L.) is one of the most frequently consumed vegetables in Korea. In January 2023, the romaine lettuce cultured within an indoor hydroponic farm in South Korea displayed severe disease, with an incidence of approximately 13.7% of 300 plants. The diseased plants showed symptoms of stunted growth, lower leaf yellowing, and brown or black-colored soft and mushy root rot, in which the outer layer of root was sloughed off, leaving a thread-like appearance. These symptoms were similar to those of Pythium root rot previously reported to occur on lettuce (McGehee et al., 2018; Stanghellini and Kronland, 1986). Samples of romaine lettuce with rot symptoms were collected from the hydroponic farm. The infected roots were rinsed three times with sterilized distilled water (SDW), dried on sterilized filter paper, and sliced into segments (about 0.5 cm in length), which were placed into Petri dishes (9 cm in diameter) containing V8 juice agar (V8A: 8% V8 juice and 1.5% agar powder) and cultured at 25°C for 2 days. The emerging hyphae were transferred to new Petri dishes containing V8A. After four rounds of sub-culturing, a total of 11 strains were isolated and all of them exhibited the same morphology. Strain KNU2301TP was purified via isolation of a single zoospore and stored at -80°C. The mycelia were non-pigmented. The hyphae obtained from a three-day-old culture grown in V8A were aseptate and the diameter of major hyphae was up to 7 µm. The filamentous sporangia were not to slightly inflated and formed dendroid-like branches. Vesicles containing zoospores were formed on the filamentous sporangia. The encysted zoospores were spherical with a diameter of 8.1 to10 µm (average 8.9 ± 0.6 µm; n = 50). These morphological characteristics of KNU2301TP were similar to those of a previously reported oomycete, Pythium dissotocum (Van der Plaats-Niterink 1981). The genomic DNA was extracted from mycelia cultured on V8A by a previously described extraction method (Chi et al. 2009). Sequences of internal transcribed spacer (ITS) region and cytochrome c oxidase subunit II (cox2) gene were amplified with paired primers ITS1/ITS4 and cox2_F/R, respectively (Callaghan et al., 2022; Hudspeth et al. 2000; White et al. 1990). The resulting sequences were deposited in GenBank (GenBank Accession Nos.; ITS: OQ683867; cox2: OQ700848). The sequences of ITS and cox2 gene of strain KNU2301TP were 99.61% and 100% identical to the sequences of ITS (MG719858) and cox2 gene (MG719859) of P. dissotocum strain YNP-3, respectively. Based on the result of the morphological characterization and sequence analysis, the strain KNU2301TP was identified as P. dissotocum. For Koch's postulates, 15 lettuce seedlings (eighteen-day-old) were inoculated by immersing the roots in a spore suspension (1 × 105 zoospores/ mL) and incubated at 25°C under 16/8 h light/dark cycles for 8 days. Fifteen plants of same age were treated with SDW in the same manner as a control The symptoms resembling those originally found at the farm were developed on the inoculated plants, but not on controls. The strain reisolated from the inoculated plants by same method mentioned above was confirmed as strain KNU2301TP by analysis of morphology and ITS and cox2 sequences. To our knowledge, this is the first report of root rot on hydroponically grown lettuce caused by P. dissotocum in Korea. Root rot on lettuce caused by P. dissotocum has been previously reported in USA, Canada, and Finland (McGehee et al. 2018; Stanghellini and Rasmussen 1994). Since lettuce is an important and popular leafy vegetable around the world, further work would focus on developing efficient strategies to manage this Pythium root rot disease.

The Cell Wall Integrity MAP Kinase Signaling Pathway Is Required for Development, Pathogenicity, and Stress Adaption of the Pepper Anthracnose Fungus Colletotrichum scovillei.

The cell wall integrity (CWI) signaling pathway plays important roles in the dissemination and infection of several plant pathogenic fungi. However, its roles in the pepper fruit anthracnose fungus Colletotrichum scovillei remain uninvestigated. In this study, the major components of the CWI signaling pathway-CsMCK1 (MAPKKK), CsMKK1 (MAPKK), and CsMPS1 (MAPK)-were functionally characterized in C. scovillei via homology-dependent gene replacement. The ΔCsmck1, ΔCsmkk1, and ΔCsmps1 mutants showed impairments in fungal growth, conidiation, and tolerance to CWI and salt stresses. Moreover, ΔCsmck1, ΔCsmkk1, and ΔCsmps1 failed to develop anthracnose disease on pepper fruits due to defects in appressorium formation and invasive hyphae growth. These results suggest that CsMCK1, CsMKK1, and CsMPS1 play important roles in mycelial growth, conidiation, appressorium formation, plant infection, and stress adaption of C. scovillei. These findings will contribute to a better understanding of the roles of the CWI signaling pathway in the development of pepper fruit anthracnose disease.

Sophisticated yet Convenient Information Encryption/Decryption Based on Synergistically Time-/Temperature-Resolved Photonic Inks.

Exploring high-safety but convenient encryption and decryption technologies to combat threats of information leakage is urgently needed but remains a great challenge. Here, a synergistically time- and temperature-resolved information coding/decoding solution based on functional photonic inks is demonstrated. Encrypted messages can be stored into multiple channels with dynamic-color patterns, and information decryption is only enabled at appointed temperature and time points. Notably, the ink can be easily processed into quick-response codes and multipixel plates. With high transparency and responsive color variations controlled by ink compositions and ambient temperatures, advanced 3D stacking multichannel coding and Morse coding techniques can be applied for multi-information storage, complex anticounterfeiting, and information interference. This study paves an avenue for the design and development of dynamic photonic inks and complex encryption technologies for high-end anticounterfeiting applications.

Role of the cAMP signaling pathway in the dissemination and development on pepper fruit anthracnose disease caused by Colletotrichum scovillei.

The ascomycete fungus Colletotrichum scovillei causes severe anthracnose disease on the fruit of sweet pepper and chili pepper (Capsicum annuum L.) worldwide. Understanding the biology of C. scovillei would improve the management of fruit anthracnose diseases. The cyclic adenosine monophosphate (cAMP) signaling pathway regulates diverse cellular and physiological processes in several foliar fungal pathogens. We investigated the roles of the cAMP signaling pathway in C. scovillei using pharmaceutical and genetic approaches. Exogenous cAMP was found to increase conidiation, appressorium formation, and anthracnose disease development in C. scovillei. CsAc1, CsCap1, and CsPdeH, which regulate the intracellular cAMP level, were deleted by homology-dependent gene replacement. Expectedly, the intracellular cAMP level was significantly decreased in ΔCsac1 and ΔCscap1 but increased in ΔCspdeh. All three deletion mutants exhibited serious defects in multiple fungal developments and pathogenicity, suggesting regulation of the intracellular cAMP level is important for C. scovillei. Notably, exogenous cAMP recovered the defect of ΔCsac1 in appressorium development, but not penetration, which was further recovered by adding CaCl2. This result suggests that CsAc1 is associated with both the cAMP and Ca2+ signaling pathways in C. scovillei. ΔCscap1 produced morphologically abnormal conidia with reduced tolerance to thermal stress. ΔCspdeh was completely defective in conidiation in C. scovillei, unlike other foliar pathogens. Taken together, these results demonstrate the importance of cAMP signaling in anthracnose disease caused by C. scovillei.

Highly Flame-Retardant and Low Heat/Smoke-Release Wood Materials: Fabrication and Properties.

Wood is an important renewable material exhibiting excellent physical and mechanical properties, environmental friendliness, and sustainability, and has been widely applied in daily life. However, its inherent flammability and susceptibility to fungal attack greatly limit its application in many areas. Use of fire-retardant coatings and preservatives has endowed wood with improved safety performance; importantly, the cooperative effect of dual treatments on the burning behavior and flame retardancy of wood needs to be better understood. Here, a two-step treatment for wood is proposed, with a copper-boron preservative (CBP) and a fire-retardant coating. The thermal degradation and burning behavior of treated wood were investigated. The CBP formed a physical barrier on the wood surface, facilitating a charring process at high temperatures and thus suppressing the release of heat and smoke. Notably, the dual-treated wood exhibited lower heat release and reduced smoke emission compared with the mono-treated wood, indicating a cooperative effect between CBP and fire-retardant coatings, beneficial to the improvement of fire safety. This experimental work improved fire retardance and suppressed smoke release in flammable materials, and offers a new design for developing fire-retardant coatings.

NADPH Oxidases Are Required for Appressorium-Mediated Penetration in Colletotrichum scovillei-Pepper Fruit Pathosystem.

NADPH oxidase (Nox) complexes are known to play essential roles in differentiation and proliferation of many filamentous fungi. However, the functions of Noxs have not been elucidated in Colletotrichum species. Therefore, we set out to characterize the roles of Nox enzymes and their regulators in Colletotrichum scovillei, which causes serious anthracnose disease on pepper fruits in temperate and subtropical and temperate region. In this study, we generated targeted deletion mutants for CsNox1, CsNox2, CsNoxR, and CsNoxD via homologous recombination. All deletion mutants were normal in mycelial growth, conidiation, conidial germination, and appressorium formation, suggesting that CsNox1, CsNox2, CsNoxR, and CsNoxD are not involved in those developmental processes. Notably, conidia of ΔCsnox2 and ΔCsnoxr, other than ΔCsnox1 and ΔCsnoxd, failed to cause anthracnose on intact pepper fruits. However, they still caused normal disease on wounded pepper fruits, suggesting that Csnox2 and CsnoxR are essential for penetration-related morphogenesis in C. scovillei. Further observation proved that ΔCsnox2 and ΔCsnoxr were unable to form penetration peg, while they fully developed appressoria, revealing that defect of anthracnose development by ΔCsnox2 and ΔCsnoxr resulted from failure in penetration peg formation. Our results suggest that CsNox2 and CsNoxR are critical for appressorium- mediated penetration in C. scovillei-pepper fruit pathosystem, which provides insight into understanding roles of Nox genes in anthracnose disease development.

Model of Markov-Based Piano Note Recognition Algorithm and Piano Teaching Model Construction.

Piano note recognition is a process that converts music audio files into digital music files automatically, which is critical for piano assistant training and automatic recording of musical pieces. The Merle spectral coefficients, for example, have been used to implement the majority of the existing examples. The piano is one of the most popular forms of student education in today's world. Piano teachers should be aware of the implications. We can only truly adapt piano teaching to the educational purposes of higher education institutions if we implement a systematic, progressive, practical, and innovative philosophy of piano teaching. The Markov model is a statistical model that is widely used in speech signal processing. This thesis develops a set of mathematical models for piano speech recognition based on the Markov model, learns them systematically and scientifically, and achieves a better teaching effect. It is demonstrated that the Markov method detects the corresponding endpoints with an accuracy of 72.83 percent, which is 16.42 percent better than the a priori method. In terms of amplitude and phase, the Markov model shows a significant improvement. The findings of this study can be used to improve piano playing techniques taught to students in accordance with their favourite popular music, depending on the theme.

A sponge heated by electromagnetic induction and solar energy for quick, efficient, and safe cleanup of high-viscosity crude oil spills.

Frequent oil spills have caused severe environmental and ecological damage. Effective cleanup has become a complex challenge owing to the poor flowability of viscous crude oils. The current method of solar heating to reduce the viscosity of heavy oil is only suitable during sunny days, while the use of Joule heating is limited by the risk of direct exposure to high-voltage electricity. Herein, we demonstrate a noncontact electromagnetic induction and solar dual-heating sponge for the quick, safe, and energy-saving cleanup of ultrahigh-viscosity heavy oil. The resulting sponge with magnetic, conductive, and hydrophobic properties can be rapidly heated to absorb heavy oil under alternating magnetic fields, solar irradiation, or both of these conditions. By constructing theoretical models and fitting the actual data, an in-depth analysis of induction and solar heating processes is carried out. The sponge has excellent resilience and stability, indicating its reusability, fast and continuous adsorption (16.17 g in 10 s), and large capacity (75-81 g/g, the highest value ever) for soft asphalt (a highly viscous crude oil). This work provides a new noncontact dual-heating strategy for heavy oil cleanup, in which absorbents use induction heating during an emergency and then switch to partial or full solar heating to save energy in sunny conditions. ENVIRONMENTAL IMPLICATION: Heavy oils stranded on the beach or floating on water can kill underwater plants by blocking sunlight, or trap water birds and other animals. Heavy oil also contains aromatic substances that are toxic to aquatic organisms. Although oil spills near shallow water cannot be cleaned up by fences or other machinery, an oil adsorbent can deal with this problem. However, common adsorbents cannot effectively absorb high-viscosity oils, such as heavy oil. In this paper, an induction and solar dual-heating sponge is developed for the effective cleanup of high-viscosity oil.

CsPOM1, a DYRK Family Kinase, Plays Diverse Roles in Fungal Development, Virulence, and Stress Tolerance in the Anthracnose Pathogen Colletotrichum scovillei.

Colletotrichum scovillei is the major anthracnose fungus of sweet pepper and chili pepper (Capsicum annuum L.), causing significant losses in the yield and quality of the pepper fruits. Molecular mechanisms governing development and pathogenicity have been widely studied in many foliar fungal pathogens, but the information on fruit diseases is still limited. In this study, we determined the functional roles of the dual-specificity tyrosine phosphorylation-regulated kinase CsPOM1 in C. scovillei. Knockout mutant for CsPOM1 gene was obtained via homology-dependent gene replacement. The ΔCspom1 mutant exhibited a reduction in vegetative growth on osmotic stress, surface hydrophobicity, and conidiation compared with wild-type. Conidia of the ΔCspom1 mutant were already two-celled before inoculation on an induction surface, indicating that CsPOM1 negatively regulates conidial cell division. The ΔCspom1 mutant, similar to wild-type, formed appressoria on the plant surface, but was significantly reduced on hydrophobic coverslips, probably due to a defect in the recognition of surface hydrophobicity. Treatment of conidia with cutin monomers restored appressorium formation on hydrophobic coverslips in the ΔCspom1 mutant. On pepper fruits, the ΔCspom1 mutant exhibited delayed penetration and invasive growth, leading to significantly reduced virulence. Collectively, the results showed that CsPOM1 is important for stress tolerance, conidiation, surface hydrophobicity, appressorium formation, and virulence in C. scovillei.

Mitogen-Activated Protein Kinase CsPMK1 Is Essential for Pepper Fruit Anthracnose by Colletotrichum scovillei.

The phytopathogenic fungus Colletotrichum scovillei, belonging to the Colletotrichum acutatum species complex, causes severe anthracnose disease on several fruits, including chili pepper (Capsicum annuum). However, the molecular mechanisms underlying the development and pathogenicity of Colletotrichum scovillei are unclear. The conserved Fus3/Kss1-related MAPK regulates fungal development and pathogenicity. Here, the role of CsPMK1, orthologous to Fus3/Kss1, was characterized by phenotypic comparison of a target deletion mutant (ΔCspmk1). The mycelial growth and conidiation of ΔCspmk1 were normal compared to that of the wild type. ΔCspmk1 produced morphologically abnormal conidia, which were delayed in conidial germination. Germinated conidia of ΔCspmk1 failed to develop appressoria on inductive surfaces of hydrophobic coverslips and host plants. ΔCspmk1 was completely defective in infectious growth, which may result from failure to suppress host immunity. Furthermore, ΔCspmk1 was impaired in nuclear division and lipid mobilization during appressorium formation, in response to a hydrophobic surface. CsPMK1 was found to interact with CsHOX7, a homeobox transcription factor essential for appressorium formation, via a yeast two-hybridization analysis. Taken together, these findings suggest that CsPMK1 is required for fungal development, stress adaptation, and pathogenicity of C. scovillei.

The Autophagy Protein CsATG8 is Involved in Asexual Development and Virulence in the Pepper Anthracnose Fungus Colletotrichum scovillei.

Autophagy serves as a survival mechanism and plays important role in nutrient recycling under conditions of starvation, nutrient storage, ad differentiation of plant pathogenic fungi. However, autophagy-related genes have not been investigated in Colletotrichum scovillei, a causal agent of pepper fruit anthracnose disease. ATG8 is involved in autophagosome formation and is considered a marker of autophagy. Therefore, we generated an ATG8 deletion mutant, ΔCsatg8, via homologous recombination to determine the functional roles of CsATG8 in the development and virulence of C. scovillei. Compared with the wild-type, the deletion mutant ΔCsatg8 exhibited a severe reduction in conidiation. Conidia produced by ΔCsatg8 were defective in survival, conidial germination, and appressorium formation. Moreover, conidia of ΔCsatg8 showed reduced lipid amount and PTS1 selectivity. A virulence assay showed that anthracnose development on pepper fruits was reduced in ΔCsatg8. Taken together, our results suggest that CsATG8 plays various roles in conidium production and associated development, and virulence in C. scovillei.

The Small GTPase CsRAC1 Is Important for Fungal Development and Pepper Anthracnose in Colletotrichum scovillei.

The pepper anthracnose fungus, Colletotrichum scovillei, causes severe losses of pepper fruit production in the tropical and temperate zones. RAC1 is a highly conserved small GTP-binding protein in the Rho GTPase family. This protein has been demonstrated to play a role in fungal development, and pathogenicity in several plant pathogenic fungi. However, the functional roles of RAC1 are not characterized in C. scovillei causing anthracnose on pepper fruits. Here, we generated a deletion mutant (ΔCsrac1) via homologous recombination to investigate the functional roles of CsRAC1. The ΔCsrac1 showed pleiotropic defects in fungal growth and developments, including vegetative growth, conidiogenesis, conidial germination and appressorium formation, compared to wild-type. Although ΔCsrac1 was able to develop appressoria, it failed to differentiate appressorium pegs. However, ΔCsrac1 still caused anthracnose disease with significantly reduced rate on wounded pepper fruits. Further analyses revealed that ΔCsrac1 was defective in tolerance to oxidative stress and suppression of host-defense genes. Taken together, our results suggest that CsRAC1 plays essential roles in fungal development and pathogenicity in C. scovillei-pepper fruit pathosystem.

Ultralight Biomass Aerogels with Multifunctionality and Superelasticity Under Extreme Conditions.

Biomass aerogels are highly attractive candidates in various applications due to their intrinsic merits of high strength, high porosity, biodegradability, and renewability. However, under low-temperature harsh conditions, biomass aerogels suffer from weakened mechanical properties, become extremely brittle, and lose functionality. Herein, we report a multifunctional biomass aerogel with lamella nanostructures (∼1 µm) fabricated from cellulose nanofibers (∼200 nm) and gelatin, showing outstanding elasticity from room temperature to ultralow temperatures (repeatedly bent, twisted, or compressed in liquid nitrogen). The resultant aerogel exhibits excellent organic solvent absorption, thermal infrared stealth, and thermal insulation performance in both normal and extreme environments. Even at dry ice temperature (-78 °C), the aerogel can selectively and repeatedly absorb organic solvents in the same way as room temperature with high capacities (90-177 g/g). Excellent heat insulation and infrared stealth performances are achieved in a wide temperature range of -196 to 80 °C. Further, this aerogel combines with the advantages of ultralow density (∼6 mg/cm3), biodegradability, flame retardancy, and performance stability, making it a perfect candidate for multifunctional applications under harsh conditions. This work greatly broadens application temperature windows of biomass aerogels and sheds light on the development of mechanically robust biomass aerogels for various applications under extreme conditions.

Pex7 selectively imports PTS2 target proteins to peroxisomes and is required for anthracnose disease development in Colletotrichum scovillei.

Pex7 is a shuttling receptor that imports matrix proteins with a type 2 peroxisomal targeting signal (PTS2) to peroxisomes. The Pex7-mediated PTS2 protein import contributes to crucial metabolic processes such as the fatty acid ß-oxidation and glucose metabolism in a number of fungi, but cellular roles of Pex7 between the import of PTS2 target proteins and metabolic processes have not been fully understood. In this study, we investigated the functional roles of CsPex7, a homolog of the yeast Pex7, by targeted gene deletion in the pepper anthracnose fungus Colletotrichum scovillei. CsPex7 was required for carbon source utilization, scavenging of reactive oxygen species, conidial production, and disease development in C. scovillei. The expression of fluorescently tagged PTS2 signal of hexokinases and 3-ketoacyl-CoA thiolases showed that peroxisomal localization of the hexokinase CsGlk1 PTS2 is dependent on CsPex7, but those of the 3-ketoacyl-CoA thiolases are independent on CsPex7. In addition, GFP-tagged CsPex7 proteins were intensely localized to the peroxisomes on glucose-containing media, indicating a role of CsPex7 in glucose utilization. Collectively, these findings indicate that CsPex7 selectively recognizes specific PTS2 signal for import of PTS2-containing proteins to peroxisomes, thereby mediating peroxisomal targeting efficiency of PTS2-containing proteins in C. scovillei. On pepper fruits, the ΔCspex7 mutant exhibited significantly reduced virulence, in which excessive accumulation of hydrogen peroxide was observed in the pepper cells. We think the reduced virulence results from the abnormality in hydrogen peroxide metabolism of the ΔCspex7 mutant. Our findings provide insight into the cellular roles of CsPex7 in PTS2 protein import system.

Homeobox Transcription Factors Are Required for Fungal Development and the Suppression of Host Defense Mechanisms in the Colletotrichum scovillei-Pepper Pathosystem.

Colletotrichum scovillei, an ascomycete phytopathogenic fungus, is the main causal agent of serious yield losses of economic crops worldwide. The fungus causes anthracnose disease on several fruits, including peppers. However, little is known regarding the underlying molecular mechanisms involved in the development of anthracnose caused by this fungus. In an initial step toward understanding the development of anthracnose on pepper fruits, we retrieved 624 transcription factors (TFs) from the whole genome of C. scovillei and comparatively analyzed the entire repertoire of TFs among phytopathogenic fungi. Evolution and proliferation of members of the homeobox-like superfamily, including homeobox (HOX) TFs that regulate the development of eukaryotic organisms, were demonstrated in the genus Colletotrichum. C. scovillei was found to contain 10 HOX TF genes (CsHOX1 to CsHOX10), which were functionally characterized using deletion mutants of each CsHOX gene. Notably, CsHOX1 was identified as a pathogenicity factor required for the suppression of host defense mechanisms, which represents a new role for HOX TFs in pathogenic fungi. CsHOX2 and CsHOX7 were found to play essential roles in conidiation and appressorium development, respectively, in a stage-specific manner in C. scovillei. Our study provides a molecular basis for understanding the mechanisms associated with the development of anthracnose on fruits caused by C. scovillei, which will aid in the development of novel approaches for disease management. IMPORTANCE The ascomycete phytopathogenic fungus, Colletotrichum scovillei, causes serious yield loss on peppers. However, little is known about molecular mechanisms involved in the development of anthracnose caused by this fungus. We analyzed whole-genome sequences of C. scovillei and isolated 624 putative TFs, revealing the existence of 10 homeobox (HOX) transcription factor (TF) genes. We found that CsHOX1 is a pathogenicity factor required for the suppression of host defense mechanism, which represents a new role for HOX TFs in pathogenic fungi. We also found that CsHOX2 and CsHOX7 play essential roles in conidiation and appressorium development, respectively, in a stage-specific manner in C. scovillei. Our study contributes to understanding the mechanisms associated with the development of anthracnose on fruits caused by C. scovillei, which will aid for initiating novel approaches for disease management.

Flame-responsive aryl ether nitrile structure towards multiple fire hazards suppression of thermoplastic polyester.

Multiple fire hazards (heat, smoke, dripping) caused by thermoplastic polymers pose integrated risks. Halogen or phosphorus flame-retardants tend to increase toxic, smoke or dripping hazards due to their flame-retardant mechanism. The physical blending flame-retardants into matrixes also presents a migration dilemma with causing potential environmental threats. Herein, we propose a novel multi-hazards inhibition strategy by chemical-incorporating aryl ether nitrile structures into poly(ethylene terephthalate)(PET), which is a typical thermoplastic polymer and a major contributor of multiple fire hazards. Through flame-responsive cyclotrimerization and aliphatic fragment capture, the flammability risks and multi-hazards (heat, smoke, toxicity, dripping) are significantly suppressed. The limiting oxygen index of the modified PET increases from 21.0 to 31.0. The peak of heat release, total smoke release, and carbon monoxide production decrease by 49.0 %, 31.1 %, and 52.6 %, respectively. The dripping hazards are eliminated, and the UL-94 rating reaches to V-0 level with no dripping production. Hence, this state-of-art strategy supplies a new approach for the fire hazards suppression of thermoplastic polymers.

Optical inspection path planning for large liquid crystal glass substrate detection instrument.

A large liquid crystal glass substrate detection instrument usually uses the air flotation platform to support a glass substrate. The glass substrate will be deformed by air pressure on the air flotation platform, which will affect the accuracy of detection. In this paper, combined with the characteristics of the detection method of the detection instrument, an optimal detection scanning path with the minimum deflection variation range of the glass substrate is planned so as to minimize the influence of glass substrate deformation on the detection accuracy. In theory, the calculation model of the deflection variation ranges of different paths on the glass substrate is established, the numerical method is used to solve it, and finally, the optimal scanning path for the optical inspection is obtained. The experimental results verify the correctness of the model.

A theoretical design method for the nozzle pitch of air-flotation system to reduce large liquid crystal display glass substrate's deformation.

The deformation of large glass substrate in air-flotation system affects detection accuracy of inspection instrument. According to the gas lubrication theory, Timoshenko's thin film theory and the simulation figure of the pressure distribution of the air film flow field, the air load distribution model of the air film is established, and the deformation expression of the large liquid crystal glass substrate in air-flotation system is given. On this basis, a theoretical design method for designing nozzle pitch of orifice throttling air-flotation system was proposed. Combined with examples, the results of theories and simulation are compared. An experiment on the deformation of the glass substrate was carried out on an experimental prototype. The difference between the experimental results and the theoretical results does not exceed 10%.

In situ phthalocyanine synthesis chemistry in flames towards molecular fireproof engineering.

The boundaries between phthalocyanine synthesis and combustion chemistry were broken through to achieve molecular fireproofing via in situ phthalocyanine (Pcs) synthesis during combustion. Furthermore in situ Pcs chemistry achieves a flame-retarding organic thermoplastic polymer, showing state-of-the-art fire-safety performance and an ultra-low fire hazard.