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2, 6-diisopropylaniline (2, 6-DIPA) is a crucial non-intentionally organic additive that allows the assessment of the production processes, formulation qualities, and performance variations in biodegradable mulching film. Moreover, its release into the environment may have certain effects on human health. Hence, this study developed simultaneous heating hydrolysis–extraction and amine switchable hydrophilic solvent vortex-assisted homogeneous liquid–liquid microextraction for the gas chromatography–mass spectrometry analysis of the 2, 6-DIPA additive and its corresponding isocyanates in poly(butylene adipate-co-terephthalate) (PBAT) biodegradable agricultural mulching films. The heating hydrolysis–extraction conditions and factors influencing the efficiency of homogeneous liquid–liquid microextraction, such as the type and volume of amine, homogeneous-phase and phase separation transition pH, and extraction time were investigated and optimized. The optimum heating hydrolysis–extraction conditions were found to be a H2SO4 concentration of 2.5 M, heating temperature of 87.8 °C, and hydrolysis–extraction time of 3.0 h. As a switchable hydrophilic solvent, dipropylamine does not require a dispersant. Vortex assistance is helpful to speed up the extraction. Under the optimum experimental conditions, this method exhibits a better linearity (0.0144~7.200 μg mL−1 with R = 0.9986), low limit of detection and quantification (0.0033 μg g−1 and 0.0103 μg g−1), high extraction recovery (92.5~105.4%), desirable intra- and inter-day precision (relative standard deviation less than 4.1% and 4.7%), and high enrichment factor (90.9). Finally, this method was successfully applied to detect the content of the additive 2, 6-DIPA in PBAT biodegradable agricultural mulching films, thus facilitating production process monitoring or safety assessments.

Tobacco black shank caused by Phytophthora nicotianae is a devastating disease that causes huge losses to tobacco production across the world. Investigating the regulatory mechanism of tobacco resistance to P. nicotianae is of great importance for tobacco resistance breeding. The jasmonate (JA) signaling pathway plays a pivotal role in modulating plant pathogen resistance, but the mechanism underlying JA-mediated tobacco resistance to P. nicotianae remains largely unclear. This work explored the P. nicotianae responses of common tobacco cultivar TN90 using plants with RNAi-mediated silencing of NtCOI1 (encoding the perception protein of JA signal), and identified genes involved in this process by comparative transcriptome analyses. Interestingly, the majority of the differentially expressed bHLH transcription factor genes, whose homologs are correlated with JA-signaling, encode AtBPE-like regulators and were up-regulated in NtCOI1 -RI plants, implying a negative role in regulating tobacco response to P. nicotianae . A subsequent study on NtbHLH49, a member of this group, showed that it’s negatively regulated by JA treatment or P. nicotianae infection, and its protein was localized to the nucleus. Furthermore, overexpression of NtbHLH49 decreased tobacco resistance to P. nicotianae , while knockdown of its expression increased the resistance. Manipulation of NtbHLH49 expression also altered the expression of a set of pathogen resistance genes. This study identified a set of genes correlated with JA-mediated tobacco response to P. nicotianae , and revealed the function of AtBPE-like regulator NtbHLH49 in regulating tobacco resistance to this pathogen, providing insights into the JA-mediated tobacco responses to P. nicotianae .

Tobacco bacterial wilt has seriously affected tobacco production. Ethyl methanesulfonate (EMS) induced tobacco bacterial wilt resistant mutants are important for the control of tobacco bacterial wilt. High-throughput sequencing technology was used to study the rhizosphere bacterial community assemblages of bacterial wilt resistant mutant tobacco rhizosphere soil (namely KS), bacterial wilt susceptible tobacco rhizosphere soil (namely GS) and bulk soil (namely BS) in Xuancheng, Huanxi, Yibin and Luzhou. Alpha analysis showed that the bacterial community diversity and richness of KS and GS in the four regions were not significantly different. However, analysis of intergroup variation in the top 15 bacterial communities in terms of abundance showed that the bacterial communities of KS and GS were significantly different from BS, respectively. In addition, pH, alkali-hydrolysable nitrogen (AN) and soil organic carbon (SOC) were positively correlated with the bacterial community of KS and negatively correlated with GS in the other three regions except Huanxi. Network analysis showed that the three soils in the four regions did not show a consistent pattern of network complexity. PICRUSt functional prediction analysis showed that the COG functions were similar in all samples. All colonies were involved in RNA processing and modification, chromatin structure and dynamics, etc. In conclusion, our experiments showed that rhizosphere bacterial communities of tobacco in different regions have different compositional patterns, which are strongly related to soil factors.

Transcription factors (TFs) fused to the SRDX (a modified repressor domain at the C-terminal region of Arabidopsis SUPERMAN (SUPRD) with the sequence of LDLDLELRLGFA) motif repression domain at their C terminus, generating a chimeric repressor, could act as a dominant suppressor and overcome problems related to functional redundancy between TFs. Here, we demonstrate that transgenic Arabidopsis containing a chimeric AtERF4-SRDX construct display a variety of changes in plant growth and development, such as short primary roots and root hairs at early developmental stages, an increased number of rosette leaves with decreased leaf area, elongation of leaf petioles and inflorescence stems, prolonged growth period, reduced stem and leaf angle and a modified seed coat mucilage structure. The short primary root and the elongation of petioles and stems were due to reduced and enhanced lengthwise cell expansion respectively, while the redistribution of seed mucilage appeared to be the result of altered pectin methylesterase activity. Expression of AtERF4-SRDX also affected abiotic stress tolerance of transgenic plants, inducing enhanced resistance to drought but reduced tolerance to salinity and heat, which could be linked to abscisic acid signaling. Altogether, our findings provide new insights into the possible functions of AtERF4 in Arabidopsis growth and development, and in mediating plant responses to abiotic stresses.

This study applies ArcGIS to analyze the spatiotemporal distribution of cultural sites in the Ill River Valley in northwestern China. It explores relationships between the sites＇ spatiotemporal evolutionary characteristics, human history, and the natural environment. The results indicate that the numbers and proportions of the sites, and the frequency of their oc- currence, exhibited an inverted V-shaped change trend during six historical periods. The ＂high in the east and low in the west＂ spatial distribution pattern of the first three periods shifted to the one the ＂high in the west and low in the east＂ during the latter three periods, demonstrating a change in the spatial center of gravity of human activities. The sites were mainly distributed on slopes of grades 1-5, with their proportions increasing from 75% during the Spring and Autumn Period （770 BC-476 BC）-Qin Dynasty （221 BC-207 BC） to 93.75% during the Qing Dynasty-Modern period. The concentrated distribution of site elevations shifted from grades 4-8 during the Spring and Autumn Period-Qin Dynasty, and the Western Han （206 BC-8）-Southern and Northern Dynasties （420-589）, to grades 1-4 during the latter three periods. The number of sites showed a shifting trend from high-elevation mountains and hills to low-elevation plains, and from high slopes to low slopes. In particular, the sites exhibited a special ＂moist＂ evolutionary pattern of migration from middle and upstream areas to downstream areas, as opposed to the migration pattern of sites located in typical arid areas. The study also considered factors influencing the distribution and spatiotemporal evolution of cultural sites, notably, human factors and natural factors.

The innovation of organizational model of tobacco production is the key to realization of sustainable development of tobacco production in China. From the perspective of sustainable development, we analyze the necessity of innovation of organizational model of tobacco production, put forward the principles on innovation of organizational model of tobacco production, and offer corresponding recommendations for the ways of innovation of organizational model of tobacco production.

The new tussah varieties have been bred by selecting large, high quality and midterm based on the indexes of high cocoon shell rate and high stress re- sistance. In the meantime, whole cocoon weight, hatchabillty and other economic parameters were considered in new variety breeding. Through 14 generations of hybrid breeding for over 7 years, two new tussah varieties had been successfully obtained. The breeding results of DW were as follows ： the 1 000-cocoon weight was 11.57 kg; the whole cocoon weight was 12.06 g; the cocoon shell rate was 12.22% ; and the larval-pupal integrated survival rate was 95.87%. The breeding re- sults of GH were as follows： the 1 000-cocoon weight was 11.52 kg; the whole cocoon weight was 11.95 g; the cocoon shell rate was 12.66% ; and the larval-pupal integrated survival rate was 90.37%.

When compared to expensive lithium metal, the metal sodium resources on Earth are abundant and evenly distributed. Therefore, low-cost sodium-ion batteries are expected to replace lithium-ion batteries and become the most likely energy storage system for large-scale applications. Among the many anode materials for sodium-ion batteries, hard carbon has obvious advantages and great commercial potential. In this review, the adsorption behavior of sodium ions at the active sites on the surface of hard carbon, the process of entering the graphite lamellar, and their sequence in the discharge process are analyzed. The controversial storage mechanism of sodium ions is discussed, and four storage mechanisms for sodium ions are summarized. Not only is the storage mechanism of sodium ions (in hard carbon) analyzed in depth, but also the relationships between their morphology and structure regulation and between heteroatom doping and electrolyte optimization are further discussed, as well as the electrochemical performance of hard carbon anodes in sodium-ion batteries. It is expected that the sodium-ion batteries with hard carbon anodes will have excellent electrochemical performance, and lower costs will be required for large-scale energy storage systems.

Low Earth orbit (LEO) satellites offer a revolutionary potential for positioning, navigation, and timing (PNT) services due to their stronger signal power and rapid geometric changes compared to traditional global navigation satellite systems (GNSS). However, dedicated LEO navigation systems face high costs, so opportunity navigation based on LEO satellites is a potential solution. This paper presents an orthogonal frequency division multiplexing (OFDM)-based LEO navigation system and analyzes its navigation performance. We use 5G new radio (NR) as the satellite transmitting signal and introduce the NR signal components that can be used for navigation services. The LEO NR system and a novel zero-padding correlation (ZPC) are introduced. This ZPC receiver can eliminate cyclic prefix (CP) and inter-carrier interference, thereby improving tracking accuracy. The power spectral density (PSD) for the NR navigation signal is derived, followed by a comprehensive analysis of tracking accuracy under different NR configurations (bandwidth, spectral allocation, and signal components). An extended Kalman filter (EKF) is proposed to fuse pseudorange and pseudorange rate measurements for real-time positioning. The simulations demonstrate an 80% improvement in ranging precision (3.0–4.5 cm) and 88.3% enhancement in positioning accuracy (5.61 cm) compared to conventional receivers. The proposed ZPC receiver can achieve centimeter-level navigation accuracy. This work comprehensively analyzes the navigation performance of the LEO NR system and provides a reference for LEO PNT design.

As one of the most important chemicals and carbon‐free energy carriers, ammonia (NH3) has significant energy‐related applications in industry and agriculture. Ninety percent of NH3 is produced by the Haber–Bosch process using high‐purity N2 and H2 at high temperatures and pressures, which consumes about 1% of the total energy production and causes 1.4% of global CO2 emissions. The environmentally friendly electrochemical nitrogen reduction reaction (NRR) with low energy consumption is a promising alternative to the conventional Haber–Bosch process. However, the main issue is the low Faradaic efficiency and NH3 selectivity of electrochemical NRR, caused by inert nitrogen molecules and competitive hydrogen evolution reaction. As one of the cheapest and most abundant transition metals widely utilized in the Haber–Bosch process, the Fe element has presented the potential high performance for the electrochemical NRR. This article summarizes recent advances and research progress in non‐noble Fe‐based catalysts used for NH3 electrosynthesis. Various synthetic protocols, structure/morphology modification, performance improvement, and reaction mechanisms are comprehensively presented. Based on recent experimental and theoretical studies, we aim to illuminate the structure–property relationship and offer an excellent opportunity for engineering advanced Fe‐based catalysts for nitrogen fixation. The most critical challenges and opportunities for Fe‐based catalysts are also provided. This review would open up a promising avenue toward developing platinum‐group‐metal‐free catalysts for electrochemical NRR applications in the future. Emerging Fe‐based catalysts have been demonstrated to be promising substitutes for platinum‐group‐metal‐based catalysts for the electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions. However, breakthroughs in current Fe‐based catalyst improvement are needed to enable efficient ammonia (NH3) synthesis. This review focuses on the development of Fe‐based catalysts, with the tailored architecture and compositional design for the NRR discussed, focusing on the role of various active Fe sites in improving high Faradaic efficiency and NH3 yields. The key challenges and future opportunities in this exciting field are also highlighted.