Catalase (CAT) Gene Family in Rapeseed (Brassica napus L.): Genome-Wide Analysis,Identification, and Expression Pattern in Response to Multiple Hormones and Abiotic Stress Conditions

Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all aerobic organisms. Environmental stresses induce the generation of reactive oxygen species (ROS) that eventually hinder plant growth and development. The CAT enzyme translates the hydrogen peroxide (H₂O₂) to water (H₂O) and reduce the ROS levels to shelter the cells’ death. So far, the CAT gene family has not been reported in rapeseed (Brassica napus L.). Therefore, a genome-wide comprehensive analysis was conducted to classify the CAT genes in the rapeseed genome. The current study identified 14 BnCAT genes in the rapeseed genome. Based on phylogenetic and synteny analysis, the BnCATs belong to four groups (Groups I–IV). A gene structure and conserved motif analysis showed that Group I, Group II, and Group IV possess almost the same intron/exon pattern, and an equal number of motifs, while Group III contains diverse structures and contain 15 motifs. By analyzing the cis-elements in the promoters, we identified five hormone-correlated responsive elements and four stress-related responsive elements. Further, six putative bna-miRNAs were also identified, targeting three genes (BnCAT4, BnCAT6, and BnCAT8). Gene ontology (GO) enrichment analysis showed that the BnCAT genes were largely related to cellular organelles, ROS response, stimulus response, stress response, and antioxidant enzymes. Almost 10 BnCAT genes showed higher expression levels in different tissues, i.e., root, leaf, stem, and silique. The expression analysis showed that BnCAT1–BnCAT3 and BnCAT11–BnCAT13 were significantly upregulated by cold, salinity, abscisic acid (ABA), and gibberellic acid (GA) treatment, but not by drought and methyl jasmonate (MeJA). Notably, most of the genes were upregulated by waterlogging stress, except BnCAT6, BnCAT9, and BnCAT10. Our results opened new windows for future investigations and provided insights into the CAT family genes in rapeseed.     

Formation of Proto-Kranz in C3 Rice Induced by Spike-Stalk Injection Method

Introduction of C4 photosynthetic traits into C3 crops is an important strategy for improving photosynthetic capacity and productivity. Here, we report the research results of a variant line of sorghum–rice (SR) plant with big panicle and high spikelet density by introducing sorghum genome DNA into rice by spike-stalk injection. The whole-genome resequencing showed that a few sorghum genes could be integrated into the rice genome. Gene expression was confirmed for two C4 photosynthetic enzymes containing pyruvate, orthophosphate dikinase and phosphoenolpyruvate carboxykinase. Exogenous sorghum DNA integration induced a series of key traits associated with the C4 pathway called “proto-Kranz” anatomy, including leaf thickness, bundle sheath number and size, and chloroplast size in bundle sheath cells. Significantly, transgenic plants exhibited enhanced photosynthetic capacity resulting from both photosynthetic CO₂-concentrating effect and improved energy balance, which led to an increase in carbohydrate levels and productivity. Furthermore, such rice plant exhibited delayed leaf senescence. In summary, this study provides a proof for the feasibility of inducing the transition from C3 leaf anatomy to proto-Kranz by spike-stalk injection to achieve efficient photosynthesis and increase productivity.     

Low Dielectric Polyimide/Fluorinated Ethylene Propylene (PI/FEP) Nanocomposite Film for High-Frequency Flexible Circuit Board Application

The low dielectric polymer films have drawn great attention to the application as the dielectric insulating materials in high-frequency circuit boards, while the weak adhesion to the copper foils and the poor processability resulted from the fluorinated or rigid structures limited their high-frequency application. In this work, the low dielectric and high adhesive polyimide/fluorinated ethylene propylene (PI/FEP) nanocomposite film for high-frequency flexible circuit board application is developed. It is indicated that the fluorocarbon surfactants can significantly improve the dispersion of FEP in PI substrate, and thus, the PI/FEP nanocomposite film exhibits excellent mechanical properties, including the tensile strength increases to 46.6 MPa and the elongation at the break increases to 13.7%. Importantly, at the high-frequency of 10 GHz, the 60 wt% FEP filled PI nanocomposite film displays an ultralow dielectric loss (0.006) and a reduced dielectric constant (2.69). In addition, the high-frequency flexible circuit board with the PI/FEP film as the dielectric insulating layer has a high peel strength of 0.75 N mm⁻¹, indicating this PI/FEP nanocomposite film can meet the requirements of the high-frequency flexible circuit board application.     

Bioderived Bilayer Shell Modification β-FeOOH Nanorods via Self-Assembly Technique as Sustainable Flame Retardants for Enhancing Flame Retardancy of Epoxy Resin

The design and application of bioderived flame retardants have been widely conducted to meet the concept of green and sustainable development. Here, self-assembly technique is used to prepare core–shell bioderived additives by using β-FeOOH as the core and polydopamine (PDA)/tannic acid (TA) bilayer as the shell, following adsorption of nickel ions to enhance the thermal stability, flame retardancy, and mechanical properties of epoxy resin (EP). The molecular structure of biobased resources is rich in hydroxyl groups and carbon content, which can be dehydrated and carbonized during combustion and promote the formation of robust protective char layer. With the addition of 5 wt% β-FeOOH@PTNi, the EP composites can pass V-0 rating in the UL-94 test. The peak heat release rate and total heat release decrease by 28.4% and 17.4% compared with pure EP. The bioderived nanorods can capture the oxygen free radicals, contributing to flame retarding in gaseous phase. Thus, the release of high-toxic CO and flammable gaseous is significantly suppressed. Besides, the storage modulus of EP composites increases by 16.0% with the addition of 5% β-FeOOH@PTNi compared with pure EP. This work provides a sustainable methodology for the design of bioderived flame retardants for EP.     

3D Printing Conductive Composites with Poly(ionic liquid) as a Noncovalent Intermedia to Fabricate Carbon Circuits

In this study, a kind of imidazole type poly(ionic liquid) ([PEP-MIM]Cl) is synthesized, which can disperse carbon effectively. [PEP-MIM]Cl is used as an intermediate to coat carbon on the poly(acrylic acid)(PAA-co-MBA) via ion exchange to obtain conductive polymer composite (CPC). A series of characterizations are performed. Experiments show that carbon can be coated on the PAA-co-MBA uniformly, and compared with using carbon as filler, this method requires less carbon to achieve good conductive performance. The carbon layer on the polymer's surface is enriched via the swelling-shrinking properties of PAA-co-MBA according to the SEM images. Furthermore, in combination with 3D printing technology, PAA-co-MBA can be designed into different shapes to achieve various functions such as pressure-sensing element. Finally, a new type of CPC named carbon clad polymeric laminate (CCPL) is prepared by using the carbon coating method and 3D printing technology. It has the potential to replace copper clad laminate (CCL) and printed circuit board (PCB), to a certain extent. This technology expands the preparation method and application of the CPC such as flexible and wearable conductive fabrics.     

粉煤灰高附加值利用研究进展

粉煤灰是火电厂燃煤过程中产生的固体残渣, 其成分复杂, 具有毒性, 若处理不当会对环境造成危害。因此, 粉煤灰的高附加值利用迫在眉睫。然而, 粉煤灰的品质是制约其高附加值利用的主要因素。目前, 中国粉煤灰品质参差不齐, 缺少完善的品质评价体系, 由此造成粉煤灰利用领域的局限性。针对上述问题, 首先分析了中国粉煤灰的资源化特性, 总结了粉煤灰的品质评价方法, 并重点阐述了适用于粉煤灰高附加值利用的品质评价方法;其次, 详细介绍了粉煤灰高附加值利用技术（高附加值提取技术、高附加值材料制备技术）;最后, 对粉煤灰高附加值利用的发展趋势做出了展望。     

岩溶区石灰石矿山溶洞探测分析

江西南城南方水泥有限公司蒋源矿区矿山开采过程中发现了溶洞,并利用空洞仪（一种物探设备）对溶洞探测并采集数据以及使用RTK对溶洞分布情况进行坐标数据采集。经过对空洞仪成像分析,结合现场采集的数据制作出溶洞空间分布图,精确掌握溶洞发育的规模、空间状态,对制定岩溶发育区域矿山开采、爆破施工方案、应急预案,以及确保施工安全起到了非常重要的作用。     

Effects of Ultrasonic Vibration on Material Flow and Thermal Cycles in Friction Stir Welding of Dissimilar Al/Mg Alloys

Comparative experiments are performed in friction stir welding (FSW) of dissimilar Al/Mg alloys with and without assistance of ultrasonic vibration. Metallographic characterization of the welds at transverse cross sections reveals that ultrasonic vibration induces differences in plastic material flow in two conditions. In FSW, the plastic material in the peripheral area of shoulder-affected zone (SAZ) tends to flow downward because of the weakening of the driving force of the shoulder, and a plastic material insulation layer is formed at the SAZ edge. When ultrasonic vibration is exerted, the stirred zone is divided into the inner and outer shear layers, the downward material flow trend of the inner shear layer disappears and tends to flow upward, and the onion-ring structure caused by the swirl motion is avoided in the pin-affected zone. By improving the flow behavior of plastic materials in the stirred zone, ultrasonic vibration reduces the heat generation, accelerates the heat dissipation in nugget zone and changes the thermal cycles, thus inhibiting the formation of intermetallic compound layers.

     

Preparation of ceramic coatings on inner surface of steel tubes using a combined technique of hot-dipping and plasma electrolytic oxidation

A new method for inner surface modification of steel tubes, named a combined technique of hot-dipping and plasma electrolytic oxidation (PEO) was proposed and demonstrated in this paper. In this work, metallurgically bonded ceramic coatings on inner surface of steel tubes were obtained using this method. In the combined process, aluminum coatings on steel were firstly prepared by the hot-dip process and then metallurgically bonded ceramic coatings were obtained on the aluminum coatings by PEO. The element distribution, phase composition and morphology of the aluminide layer and the ceramic coatings were characterized by SEM/EDX and XRD. The corrosion resistance of the ceramic coatings were also studied. The results show that, after hot-dip treatment, the coating layers consist of two layers, where Al, Fe_xAl _(1−x) were detected from external topcoat to the aluminide/steel substrate. Then after PEO process, uniform Al₂O₃ ceramic coatings have been deposited on inner surface of steel tubes. The ceramic coatings are mainly composed of -Al₂O₃ and γ-Al₂O₃ phase. The compound coatings show favorable corrosion resistance property. The investigations indicate that the combination of hot-dipping and plasma electrolytic oxidation proves a promising technique for inner surface modification of steel tubes for protective purposes.     

Run(n=2～7)金属团簇与氧反应的DFT研究

采用密度泛函理论的广义梯度近似(DFT／GGA)，对Run簇(n=2～7)与氧相互作用的几何结构与电子结构及吸附能之间的关系进行讨论。对氧原子及氧分子在Run金属簇上的吸附研究表明：电荷主要是从Ru的5s、4d轨道向O的2p轨道迁移，并使得金属．金属之间的键减弱。比较特殊的是当氧分子在桥位吸附时，Ru与吸附的O2会发生化学反应，并且由于Ru金属轨道的电子向O2的反键πg轨道转移，导致Ru-O之间的键的生成以及O-O之间的键发生断裂。同时，作者也观察到Ru．Ru之间的化学键发生断裂，形成具有原子活性的自由Ru原子，这可以部分解释一旦氧化物种形成，经过一诱导期后，氧化反应会加速进行的实验事实。