Short Growth Cycle Research Articles

An organic-inorganic dual network built in fast-growing wood veneers to improve the flame retardant and mechanical properties of plywood

Fast-growing wood is widely used in plywood production due to its short growth cycle and low cost. However, its loose fiber structure, inferior material quality, and high flammability significantly limit the application range of plywood products and hinder high-value utilization. This paper reports a simple method for modifying fast-growing wood veneers. We modified phenolic resin with Mg(OH)₂@nano-silica composite particles and impregnated it into the veneers, constructing an organic-inorganic hybrid dual-network structure on both the surface and interior of the veneers. The plywood prepared from the modified veneers exhibited a bending strength of 115.6 MPa, a modulus of elasticity of 9.7 GPa, and a wet shear strength of 2.1 MPa, representing increases of 86.1%, 47.0%, and 90.9%, respectively, compared to plywood made from unmodified veneers. Additionally, the peak heat release rate decreased by 15.3%, and the ignition time was extended to 26 seconds. The uniformly distributed inorganic network effectively mitigated stress concentration and, together with the phenolic resin, formed an efficient thermal insulation layer, enhancing the flame retardancy of the material. This study offers a simple and effective treatment method for reinforcing fast-growing wood veneers, promoting the use of fast-growing wood in high-performance applications.

Bamboo powders effectively reinforcing the modulus of PBAT composites and creep resistance

AbstractBamboo has a short growth cycle and exists in large quantities in nature. This paper uses bamboo powders (BP) to reinforce polybutylene adipate/terephthalate (PBAT) modulus and creep resistance. The BP was surface modified by γ‐(2,3‐epoxypropoxy)propyltrimethoxysilane (KH560), and compounded with PBAT in a twin‐screw extruder. The results showed that the specific surface area and micropores of BP were considerably higher than that of common wood powders and cellulose and contributes significantly to the modulus and the creep resistance of composites. Compared with pristine PBAT, the tensile modulus, flexural modulus of K‐BP/PBAT composites increased by 225%, 608%, respectively, at a filler content of 25 wt%. In addition, the creep resistance of K‐BP25 was improved by a factor of 3.25 compared to PBAT. The enhancement mechanism of K‐BP was discussed, the large specific surface area and micropores of K‐BP provided more anchoring sites, which effectively increased the interfacial binding force between K‐BP and PBAT, and enhanced the nucleation ability of PBAT, thus improving the modulus and creep resistance of the composites. The results of this paper broadened the scope of application of PBAT.Highlights The bamboo powders effectively reinforcing the modulus of PBAT. The bamboo powders effectively reinforcing the creep resistance of PBAT. The special feature of K‐BP can provide more anchoring sites for PBAT. The K‐BP improves the nucleation ability of PBAT.

Evaluation of forage quality in various soybean varieties and high-yield cultivation techniques

ContextThe rising demand for animal protein has intensified forage shortages and restricted pasture availability, underscoring the critical need for effective dual-purpose animal feeds. ObjectiveThis study aims to evaluate the potential of vegetative soybeans as animal feed by assessing their nutritional value and productivity. Specifically, it explores the feasibility of using late-maturing soybean varieties, adapted to low latitudes, as forage in high-latitude regions and examines the impact of different planting dates on their growth and effectiveness during limited growing seasons. MethodsTo achieve these objectives, a series of field and controlled experiments were conducted. The first experiment assessed 418 mid-maturing soybean varieties from the Huang-Huai-Hai Basin in China for their nutritional value as forage during 2020 and 2021. The second experiment tested late-maturing and photoperiod-sensitive soybean varieties, including "ZGDD" and the methionine-enhanced material "Ox-CGS," under tropical conditions with extended daylight. The third experiment evaluated forage soybeans sown on June 19th, July 14th, and August 8th, 2022, to determine their yield and protein content. ResultsResults showed that the first experiment yielded an average protein content of 24.7 %, ether extract content of 1.9 %, neutral detergent fiber content of 41.9 %, and acid detergent fiber content of 27.3 %, with a relative feeding value of 153, surpassing local standards for high-quality leguminous forage. The second experiment demonstrated that extended daylight increased crude protein yield by 3.7 times compared to Chinese soybean seed yields, and "Ox-CGS" showed a 24.2 % increase in methionine content. The third experiment revealed that forage soybeans achieved a crude protein yield of 0.95 t/ha within 60 days, exceeding the 2022 average of 0.68 t/ha for seed soybeans in China. ConclusionsThe findings indicate that photoperiod-sensitive soybeans can be effectively used as forage over extended periods, utilizing artificial lighting or cultivation in higher latitudes, and that short growth cycles enhance crude protein accumulation. Implications or significanceThis research highlights the potential of soybeans to alleviate forage shortages, improve land use efficiency, and contribute to food security and agricultural development, especially on marginal lands and in regions with limited growing seasons.

Effect of Polyethylene Glycol with Different Molecular Weights on the Properties of Mytilaria laosensis Timber

Mytilaria laosensis, a common fast-growing tree species in southern China, boasts excellent growth speed and attractive color and texture. However, due to its short growth cycle and high proportion of juvenile wood, it typically exhibits poor dimensional stability and low strength, which significantly limits its practical applications. This study uses vacuum impregnation to modify M. laosensis wood with polyethylene glycol (PEG), focusing on the effects and mechanisms of PEG with different molecular weights on wood properties. The results indicate that PEG enters the wood cell walls through capillary action and diffusion, forming hydrogen bonds with the free hydroxyl groups on cellulose and hemicellulose, which keeps the cell walls swollen and enhances dimensional stability. Post modification, the dimensional stability of M. laosensis wood improved, with an anti-swelling efficiency ranging from 61.43% to 71.22%, showing an initial increase followed by a decrease with increasing PEG molecular weight. The optimal PEG molecular weight for anti-swelling efficiency was 1500 Da, achieving 71.22%. The flexural modulus of elasticity and flexural strength of the treated wood also first decreased and then increased with increasing PEG molecular weight. Among them, the PEG1000-treated material showed the best performance, with the flexural modulus of elasticity increased by about 29% and the flexural strength increased by about 5% compared to untreated wood. Additionally, PEG, having a higher pyrolysis temperature than wood, raised the initial pyrolysis temperature and maximum pyrolysis rate temperature of M. laosensis wood, thus improving its thermal stability. These findings provide scientific evidence and technical support for the efficient utilization and industrialization of M. laosensis wood, promoting its widespread application and industrial development.

Lindernia dubia (L.) Pennel as an Alien Weed in Central Spain: A Case Study.

Lindernia dubia (L.) Pennell is a species with invasive behavior outside of its native range of distribution (America), linked mainly to aquatic habitats. This annual species has been acknowledged as a weed in rice paddies in Europe and Asia. Due to the impacts of this invasive plant, some authors have even listed this species as a global invader. The present work focused on spontaneous plant species occurring in seedlings of Typha domingensis Pers. grown in central Spain for the establishment of constructed wetlands. Weed inventory revealed the presence of L. dubia as a dominant spontaneous species in this crop environment. A suite of mesocosm experiments were designed to study the population density of L. dubia versus that of the other dominant plant species, and to determine traits associated with its weedy potential. The results showed that L. dubia presents competitive attributes such as morphological variability, early flowering, long seeding time, short growth cycle, small and light seeds and a high seed production and germination rate (25 °C), meaning a high reproductive capacity in a cycle of about three months for plant growth in non-limiting conditions. The data obtained from this work provide a basis for understanding the weedy potential of L. dubia, and for management decisions of a potentially invasive species, which has been little investigated in Europe.

Walnut shell oil-bath torrefaction coupled with fast pyrolysis: Effect of torrefaction heating modes

Lignocellulosic biomass, renewable with short growth cycle and diverse sources, can be substituted fossil fuel. However, low effective hydrogen-to-carbon ratio (H/Ceff) limits its applications. Torrefaction and co-pyrolysis with high H/Ceff feedstocks are promising technology. This paper investigated the effect of heating modes on oil-bath torrefaction of walnut shells, followed by fast co-pyrolysis. Six heating modes during oil-bath torrefaction were evaluated. Com1 (Microwave 67 %, Lightwave 33 %) yielded the lowest residual yield 84 wt%, while the highest gas production 495.47 mL/g which mainly composed of CO and CO2. Torrefied feedstock under Com1 had the highest H/Ceff. Decarboxylation and decarbonylation reactions dominated among oil-bath torrefaction. Com1 produced the most hydrocarbons and least oxygen-containing compounds. As microwave ratio decreased, the content of olefins, acids and phenols decreased, monocyclic aromatic hydrocarbons and alcohols was showed opposite tend. This study offers new ideas for microwave and lightwave torrefaction and promoting hydrocarbon production from lignocellulosic biomass.

Cloning, Expression, Purification, and Characterization of Lactate Dehydrogenase from Plasmodium knowlesi: A Zoonotic Malaria Parasite.

Plasmodium knowlesi is the only Plasmodium that causes zoonotic disease among the Plasmodium that cause infection in humans. It is fatal due to its short asexual growth cycle within 24 h. Lactate dehydrogenase (LDH), an enzyme that catalyzes the final step of glycolysis, is a biomarker for diagnosing infection by Plasmodium spp. parasite. Therefore, this study aimed to efficiently produce the soluble form of P. knowlesi LDH (PkLDH) using a bacterial expression system for studying malaria caused by P. knowlesi. Recombinant pET-21a(+)-PkLDH plasmid was constructed by inserting the PkLDH gene into a pET-21a(+) expression vector. Subsequently, the recombinant plasmid was inserted into the protein-expressing Escherichia coli Rosetta(DE3) strain, and the optimal conditions for overexpression of the PkLDH protein were established using this strain. We obtained a yield of 52.0 mg/L PkLDH from the Rosetta(DE3) strain and confirmed an activity of 483.9 U/mg through experiments. This methodology for high-efficiency PkLDH production can be utilized for the development of diagnostic methods and drug candidates for distinguishing malaria caused by P. knowlesi.

Tissue culture and Agrobacterium-mediated genetic transformation of the oil crop sunflower

Sunflower is one of the four major oil crops in the world. ‘Zaoaidatou’ (ZADT), the main variety of oil sunflower in the northwest of China, has a short growth cycle, high yield, and high resistance to abiotic stress. However, the ability to tolerate adervesity is limited. Therefore, in this study, we used the retention line of backbone parent ZADT as material to establish its tissue culture and genetic transformation system for new variety cultivating to enhance resistance and yields by molecular breeding. The combination of 0.05 mg/L IAA and 2 mg/L KT in MS was more suitable for direct induction of adventitious buds with cotyledon nodes and the addition of 0.9 mg/L IBA to MS was for adventitious rooting. On this basis, an efficient Agrobacterium tumefaciens-mediated genetic transformation system for ZADT was developed by the screening of kanamycin and optimization of transformation conditions. The rate of positive seedlings reached 8.0%, as determined by polymerase chain reaction (PCR), under the condition of 45 mg/L kanamycin, bacterial density of OD600 0.8, infection time of 30 min, and co-cultivation of three days. These efficient regeneration and genetic transformation platforms are very useful for accelerating the molecular breeding process on sunflower.

Assessing Seasonal Effects on Identification of Cultivation Methods of Short-Growth Cycle Brassica chinensis L. Using IRMS and NIRS.

Seasonal (temporal) variations can influence the δ13C, δ2H, δ18O, and δ15N values and nutrient composition of organic (ORG), green (GRE), and conventional (CON) vegetables with a short growth cycle. Stable isotope ratio mass spectrometry (IRMS) and near-infrared spectroscopy (NIRS) combined with the partial least squares-discriminant analysis (PLS-DA) method were used to investigate seasonal effects on the identification of ORG, GRE, and CON Brassica chinensis L. samples (BCs). The results showed that δ15N values had significant differences among the three cultivation methods and that δ13C, δ2H, and δ18O values were significantly higher in winter and spring and lower in summer. The NIR spectra were relatively clustered across seasons. Neither IRMS-PLS-DA nor NIRS-PLS-DA could effectively identify all BC cultivation methods due to seasonal effects, while IRMS-NIRS-PLS-DA combined with Norris smoothing and derivative pretreatment had better predictive abilities, with an 89.80% accuracy for ORG and BCs, 88.89% for ORG and GRE BCs, and 75.00% for GRE and CON BCs. The IRMS-NIRS-PLS-DA provided an effective and robust method to identify BC cultivation methods, integrating multi-seasonal differences.

Research progress on bamboo fiber reinforced polymeric composites: Processes, properties, and future directions

AbstractCharacterized by rapid maturation, short growth cycles, and high strength and toughness, bamboo can be compounded with polymers to produce bamboofiber reinforced polymeric composites (BFRPCs). These composites exhibit corrosion resistance comparable to traditional materials such as glass fiber and carbon fiber composites. Additionally, they possess features like low density, high strength, degradability, and environmental friendliness, with low production costs and strong industrial applicability. This paper reviews the accomplishments in BFRPCs and provides an overview of the production processes for BFRPCs. Furthermore, it summarizes the research status of mechanical properties, moisture absorption characteristics, interface performance, and flame retardancy of these composites. The current issues with BFRPCs were analyzed. Finally, the paper explores future research directions and potential applications of BFRPCs.Highlights The performance studies on BFRPCs are comprehensively presented. Composite processing of BFPRCs is reviewed. Pros and cons of various types of BFRPCs are analyzed. Overview of the applications of BFRPCs in various domains is presented. Future trends and challenges of BFRPCs are introduced.

Testing biowaste materials as peat replacement in organo-mineral fertilizers

Organo-mineral fertilizers (OMFs) can have higher efficiency than mineral fertilizers. In Europe, peat is commonly used as an organic matrix in OMFs, as it is a highly stable organic material. However, peat extraction releases long-term stored organic C. Stabilized biowaste materials could replace peat in OMFs. Thus, this study aimed to understand how the variety of chemical properties in biowastes can influence OMF-soil interactions and nutrient availability to plants. Peat, green compost (GC), municipal solid waste compost (MSWC), and vermicompost (VC) were used as the organic matrix of OMFs with a C-N-P2O5 content of 7.5, 10, and 5%, respectively. OMFs were tested first in a ten-day plant-free incubation to measure Hedley P fractionation, nitrate, ammonium, total N in the soil, and CO2 and NH3 emissions. Further, a 30-day greenhouse trial measured maize yield and N and P use efficiencies. Controls included no fertilization (N0P0) and mineral N and P fertilization (MFNP). No differences were found in the incubation experiment for mineral N fractions in the soil. Fertilization significantly increased CO2 emissions, which were slightly higher in OMFs over MFNP, whereas OMFs significantly increased ammonia volatilization compared to MFNP. Available P had consistent results in the incubation and the greenhouse trials. Peat and MFNP had the highest water-and bicarbonate-P pools in the first experiment and higher yield and P use efficiency by maize. Therefore, OMFs from biowaste materials exhibited limited suitability for short growth cycles due to lower P use efficiency and higher ammonia volatilization.

Water resistant, biodegradable and flexible corn starch/carboxymethyl cellulose composite film for slow-release fertilizer coating materials

The inherent limitations of Cornstarch (CS) and Carboxymethyl Cellulose (CMC) membranes, such as brittleness, fragility, and water solubility, limit their use in controlled-release fertilizers. This study reports on the synthesis of crosslinked CMC/CS-20-E composite membranes using the casting technique, with epichlorohydrin (ECH) as the crosslinking agent in an acidic environment to crosslink CS and CMC. The synthesized composite film demonstrates remarkable water resistance, as evidenced by the insignificant alteration in its morphology and structure post 72 h of water immersion. Its flexibility is reflected in its capacity to endure knotting and bending, with an elongation at break reaching 78.1 %. Moreover, the degradation rate surpasses 90 % within a span of seven days. The CMC/CS-20-E-x-urea controlled-release fertilizer was subsequently produced using a layer-by-layer self-assembly technique, where urea particles were incorporated into the crosslinked composite solution. This CMC/CS-20-E-x-urea controlled-release fertilizer displayed superior controlled-release performance over a duration of seven days when juxtaposed with pure urea. In particular, the CMC/CS-20-E-3 %-urea controlled-release fertilizer showed a cumulative release rate of 84 % by the seventh day. The controlled-release fertilizers developed in this study offer a promising strategy for creating eco-friendly options that are crucial for fertilizing crops with short growth cycles.

A Novel Flame-Retardant, Smoke-Suppressing, and Superhydrophobic Transparent Bamboo.

Silica glass, known for its brittleness, weight, and non-biodegradable nature, faces challenges in finding suitable alternatives. Transparent wood, made by infusing polymers into wood, shows promise but is hindered by limited availability of wood in China and fire risks associated with its use. This study explores the potential of utilizing bamboo, which has a shorter growth cycle, as a valuable resource for developing flame-retardant, smoke-suppressing, and superhydrophobic transparent bamboo. A 3-layered flame-retardant barrier, composed of a top silane layer, an intermediate layer of SiO2 formed through hydrolysis-condensation of Na2SiO3 on the surface, and an inner layer of Na2SiO3, has been confirmed to be effective in reducing heat release, slowing flame spread, and inhibiting the release of combustible volatiles, toxic smoke, and CO. Compared to natural bamboo and other congeneric transparent products, the transparent bamboo displays remarkable superiority, with the majority of parameters being notably lower by an entire order of magnitude. It achieves a long ignition time of 116 s, low total heat release (0.7 MJ/m2), low total smoke production (0.063 m2), and low peak CO concentration (0.008 kg/kg). Moreover, when used as a substrate for perovskite solar cells, the transparent bamboo displays the potential to act as a light management layer, leading to a marked efficiency enhancement of 15.29%. The excellent features of transparent bamboo make it an enticing choice for future advancements in flame-retardant glasses and optical devices.

Kelp Nanofiber‐Based Composite Membranes for Highly Efficient Osmotic Energy Conversion

AbstractThe blue osmotic energy harvesting based on the nanofiber‐based layered membranes has received tremendous attention. However, the most nanofiber‐based ion‐selective membranes are suffering from uneconomical, environmentally unfriendly characteristics and a long growth cycle, as well as insufficient power density. In this work, kelp cellulose nanofibers (KCNFs) from green and inexpensive kelp with short growth cycle are compounded with hydrophilic MXene nanosheets to prepare KCNF/MXene nanofluidic membranes. Notably, the KCNF/MXene‐40 (40 is the mass fraction of KCNF) membrane with an aligned nacre‐like nanostructure achieves 3.03‐fold increase in mechanical strength compared to the pure MXene membrane. The ingenious combination of the surface charge of the MXene nanosheets and the space charge formed by negatively charged KCNFs endows the KCNF/MXene‐40 membrane with enhanced cation selectivity (≈0.85), high energy conversion efficiency of 24.04% and high power density of 66.23 W m−2 in a 500‐fold concentration gradient, which has exceeded most reported state‐of‐the‐art 2D nanofluidic membranes. More importantly, the membrane exhibits the exceptional long‐term stability with relatively unchanged power density within 6000 s. Under the conditions of the natural seawater and simulated river water, the KCNF/MXene‐based generator deliveries an output power density of ≈10.56 W m−2.

Rearing Axenic Delia antiqua with Half-Fermented Sterile Diets.

Axenic insects are obtained from sterile artificial rearing systems using sterile media. These insects, characterized by their small size, short growth cycle, and low feed requirements, are ideal for studying the relationship between microorganisms and hosts. The gut microbiota significantly influences the physiological characteristics of insect hosts, and introducing specific strains into axenic insects provides a method for verifying gut microbial functions. Delia antiqua, a threatening pest in the order Diptera, family Anthomyiidae, and genus Delia, primarily feeds on onions, garlic, leeks, and other vegetables of the family Liliaceae. Its larvae feed on the bulbs, causing rotting, wilting, and even death of entire plants. By rearing axenic larvae, follow-up studies can be conducted to observe the effects of intestinal microflora on the growth and development of D. antiqua. Unlike the method involving antibiotic elimination of associated microbes, this article presents a low-cost and high-efficiency approach to raising axenic D. antiqua. After surface sterilization of D. antiqua eggs, half-fermented sterile diets were used to raise larvae, and the axenic state of D. antiqua was verified through culture-dependent and culture-independent assays. In conclusion, the combination of insect egg sterilization and the preparation of sterile diets for larval culture has enabled the development of an efficient and simple method for obtaining axenic D. antiqua. This method provides a powerful approach to studying insect-microflora interactions.

Assessing the risk and morphological characteristics of weedy rice outbreak in Thap Muoi district, Dong Thap province, Vietnam

The Thap Muoi district in Dong Thap province, Vietnam, is renowned as the largest rice producer, cultivating 112,762 hectares and specialising in three rice crops per year, with some areas achieving 3.5 annual crops. However, changing farming practices, low-quality rice seeds, and mechanisation have led to the emergence and spread of weedy rice (Oryza spp.) in Thap Muoi and the broader Mekong delta. This comprehensive assessment of weedy rice outbreak risks in Thap Muoi provides a vital foundation for effective management strategies to prevent its spread in the Mekong delta. Sixty questionnaires were collected from rice-farming households. Approximately 80% of farmers reported the appearance of weedy rice approximately five years ago. Alarmingly, 95% of surveyed farmers (57 individuals) reported weedy rice infestations, with 40% of them encountering infection levels ranging from 11 to 20 plants/m2. To distinguish weedy rice from cultivated varieties, seven distinct types were identified based on various morphological characteristics, including growth time, leaf blade structure, plant height, leaf/stem colour and shape, grain beard/tail, seed/husk colour, grain length, ripening time, and seed dispersal potential. However, all seven weedy rice varieties exhibited short growth cycles and the capacity to produce seeds, posing significant challenges to rice production management in Thap Muoi. This research underscores the critical importance of assessing weedy rice outbreak risks in Thap Muoi and understanding its morphology and prevalence. This understanding is essential for developing effective preventive measures to mitigate the threat of weedy rice outbreaks across the entire Mekong delta in Vietnam.

Design value of tensile strength of raw bamboo

Bamboo has the advantages of a short growth cycle, good mechanical properties, energy savings, and environmental protection. It is regarded as a new building material with great development potential and application prospects. However, current research on the design values of raw bamboo materials is lacking. In this study, the design value of tensile strength of raw bamboo material was determined by a tensile test of the raw bamboo material, and the statistical values of the tensile strength and elastic modulus of the raw bamboo material were obtained. The standard value and resistance uncertainty statistical parameters of the tensile strength of the raw bamboo material were determined. Considering different load combinations and load effect ratios, the relationship between the reliability index and the resistance component coefficient and the optimal resistance partial coefficient under different load combinations were obtained, and the design value of the tensile strength of the raw bamboo material was obtained.

Turning Waste into Treasure: The Full Technological Process and Product Performance Characterization of Flushable Wet Wipes Prepared from Corn Stalk.

As a daily consumable, wet wipes are mostly synthetic fibers, which are incinerated or landfilled after use. The nanoplastics generated during this process will lead to environmental pollution. The application of flushable wet wipes, which are dispersible and fully degradable, is of great significance. The main raw material for flushable wipes is wood pulp, which has a long growth cycle and high cost. Corn is widely planted and has a short growth cycle. Currently most corn stalk is treated by incineration, which produces a lot of smoke that pollutes the environment. Therefore, using corn stalk as the raw material for flushable wet wipes, replacing wood pulp, is both cost-effective and environmentally friendly. In this study, aiming at industrial production, we explored the full process of producing flushable wet wipes from corn stalk to pulp board, then to the final wipes. The corn stalk was treated using alkali and a bleaching agent to obtain corn stalk pulp, which was then made into pulp board through the nonwoven wet-laid process. The optimal parameters for the alkali treatment and bleaching were obtained. The properties of the corn stalk pulp board were compared with the commercial wood pulp board. Further, we mixed the corn stalk pulp with Lyocell fiber to prepare wet-laid webs, which were then bonded using a chemical binder poloxamer. Then, the evenness of the web, mechanical properties, absorption, and dispersibility of the flushable wipes were characterized. Results showed that the pulp obtained using the optimal treatment process has a high yield and better whiteness. The properties of the corn stalk pulp board are comparable with the commercial wood pulp board, which can therefore potentially be replaced by the corn stalk board prepared in our study. The prepared flushable wet wipes had good evenness and their water absorption rate was more than 600%. The mechanical strength in dry and wet states achieved 595.94 N/m and 179.00 N/m, respectively. Most importantly, the wet wipes can completely disperse under the standardized testing method. A good balance of dispersibility and wet strength of the wet wipes was achieved.

Strong, tough, anisotropic, flexible, and transparent bamboo films

Bamboo has higher strength, better toughness, and a shorter growth cycle than wood. It is of great significance to use top-down nanotechnology to construct high-performance bamboo film (BF) instead of petroleum-based plastic film. However, bamboo lacks lateral cell tissues, and its structure is prone to disintegration when the components are removed. Herein, slice bamboo veneers (SBV) were used as building blocks, and a sequential process of alkali pretreatment-crosslinking-delignification-compression densification was conducted to fabricate the high-performance BF. The oriented arrangement of nanofibers, highly dense microstructure, and a large number of hydrogen bonds between cellulose microfibrils endowed BF with anisotropic and excellent mechanical and optical properties. The longitudinal tensile strength and toughness of the prepared BF were 656.6 MPa and 33.7 MJ m−3, respectively, and its light transmittance and haze were 70.2% and 88.1%, respectively. In addition, BF has good thermal insulation with a thermal conductivity of 0.0857 W m−1 K−1. The combined characteristics of BF, including high strength, high toughness, flexibility, anisotropy, high optical transmittance, and thermal insulation, make them suitable to be applied as optoelectronic substrates, insulating building materials, and green packaging materials.

Effects of Exogenous Plant Hormone Spraying on the Phytoremediation by Bidens pilosa L. in Cadmium-contaminated Soil

To explore the effect of exogenous plant hormone spraying on the absorption of heavy metals by hyperaccumulated plants, Bidens pilosa L. was selected as the tested plant owing to the large biomass, short growth cycle, and high accumulation efficiency. Here, the effect of foliar spraying 6-benzylaminopurine (6-BA), salicylic acid (SA), and 24-epi-brassinosteroid (24-EBR) on the remediation of cadmium (Cd)-contaminated soil by B. pilosa L. was examined. The results showed:① the efficiency of the remediation in Cd-contaminated soil by B. pilosa L. was effectively enhanced after the spraying of all three kinds of exogenous plant hormones with appropriate concentrations. The spraying of the three exogenous plant hormones could promote the cadmium concentration in the leaves of B. pilosa L. to increase by 4.21%, 31.79%, and 14.89%; promote the translocation factor (TF) to increase by 9.67%, 18.83%, and 17.85%; promote the phytoextraction rates (PR) to increase by 15.36%, 32.33%, and 64.38%, respectively. ② The growth of B. pilosa L. was significantly promoted after the spraying of the three kinds of exogenous plant hormones with appropriate concentrations. The spraying of the three exogenous plant hormones could promote plant growth under cadmium stress, and the dry weight of the plant root, stem, and leaf was increased by 37.53%, 74.50%, and 104.02%, respectively. ③ The photosynthesis of B. pilosa L. was significantly enhanced after the spraying of the three kinds of exogenous plant hormones with appropriate concentrations. The chlorophyll concentration of the plant was significantly increased after foliar spraying with plant hormones, and the concentration of chlorophyll a was increased by 79.31%, 92.27%, and 51.12%; the photochemical quenching coefficient (qP) was increased by 11.32%, 89.16%, and 78.43%; and the non-photochemical quenching coefficient (NPQ) was increased by 51.71%, 241.12%, and 27.85%, respectively, after foliar spraying with appropriate concentrations of 6-BA, SA, and 24-EBR. ④ The antioxidant capacity of B. pilosa L. was significantly strengthened after the spraying of the three kinds of exogenous plant hormones with appropriate concentrations. The malondialdehyde (MDA) concentration of the plant was reduced by 62.41%, 68.67%, and 46.76% after the application of 6-BA, SA, and 24-EBR, respectively. Meanwhile, superoxide dismutase (SOD) was increased by 68.33%, 10.28%, and 6.17%, and catalase (CAT) was increased by 31.43%, 37.87%, and 37.31%, respectively. Generally, the spraying of exogenous 6-BA, SA, and 24-EBR with the appropriate concentration under Cd stress could significantly increase the biomass of B. pilosa L. and promote the accumulation of heavy metals in the plant, improve the photosynthetic ability of the plant, reduce the oxidative damage of the plant under heavy metal stress, enhance the antioxidant capacity, and improve the absorption and tolerance of plants to Cd. It also could promote the transfer of Cd from roots to shoots, improve the phytoextraction rates of Cd from the plant, and effectively strengthen the phytoremediation efficiency. Among them, 30 mg·L-1 SA foliar spraying had the best effect.