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Marine biofouling which interferes with normal marine operation and also causes huge economic loss has become a worldwide problem. With the development of society, there is an urgent need to develop non-toxic and efficient anti-fouling strategies. Capsaicin is an environmentally friendly antifouling agent, but controlling the stable release of capsaicin from the coating is still a challenge to be solved. To achieve long-lasting antifouling property, in this work, we incorporate a derivative of capsaicin

Solar-induced chlorophyll fluorescence (SIF) has been used to estimate leaf-level net CO assimilation by a mechanistic light reaction (MLR-SIF) equation. However, the application of this model would be limited by the challenging measurement and estimation of input parameters (e.g. fraction of open PSII reaction centres, q). We modified the MLR-SIF model by replacing q by the easily obtained parameters (non-photochemical quenching [NPQ]) to facilitate its application. We employed synchronous measurements of gas exchanges, ChlF parameters and SIF for Leymus chinensis, Populus tomentosa Carrières and Ulmus pumila var. sabulosa under the soil–water deficit and rehydration process to test the robustness of the modified MLR-SIF model. Our results demonstrated that for L. chinensis the net photosynthesis rate dynamics under severe soil–water stress and saturated water condition were effectively captured by the modified MLR-SIF model ( R = 0.75–0.92, RMSE = 1.11–3.56) . For P. tomentosa Carrières and U. pumila var. sabulosa, the net photosynthesis rates were predicted by the modified MLR-SIF model with good accuracy ( R = 0.86, RMSE = 9.44; R = 0.88, RMSE = 4.16) across the water deficit and rehydration condition . However, the electron transport rate estimated by the modified MLR-SIF model uncoupled with the photosynthetic capacity ( r = -0.13) and lowered the net photosynthesis rate simulation precision ( R = 0.35, RMSE = 3.41) for L. chinensis under mild drought stress and saturated light intensities. The electron transport rate estimated by the modified MLR-SIF model downregulated the photosynthetic capacity for P. tomentosa Carrières ( r = 0.32) and U. pumila var. sabulosa ( r = 0.22) under mild drought stress. The shift of the Rubisco and RUBP limited state cross-points, the dynamic photosynthesis parameters across the plant species and the alternative electron sinks under soil–water deficit and rehydration process influenced the simulation precision of the modified MLR-SIF model. Our modified MLR-SIF model provided a basis for understanding and inferring the photosynthetic rate by SIF and NPQ under water stress.

With the development of science and technology and the ever-increasing focus of the environmental protection, waterborne acrylic resin based coating has been commonly used in a wide range of applications due to its high flexibility and good UV resistance. Continuous attempts have been extensively carried out to improve its corrosion resistance and mechanical properties through doping of different nanomaterials. In this study, Functionalized Graphene Oxide (FGO) nanosheets covalently bonded to hydroxylated acrylic resin was introduced into the Hydroxyacrylic Acid Dispersion (HAD) matrix to enhance the performance. To study the effect of grafted hydroxylated acrylic resin on morphology and properties of GO nanosheets, the GO and FGO nanosheets have been systematically characterized with various testing methods, such as FTIR, field emission-scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), Raman spectroscopy, X-ray diffraction (XRD) analysis, UV–vis analysis, and thermogravimetric analysis (TGA). The morphology, physical–mechanical, and anti-corrosion properties of the HAD coatings doped with GO and FGO nanosheets have been compared. The results confirmed that FGO’s dispersion behavior in the HAD matrix has been improved after modifification with the hydroxylated acrylic resin, and the interfacial bonds between the HAD-FGO nanosheets have been significantly enhanced.

Protective coatings with the lotus effect enable high water repellency and self-cleaning abilities. These properties have been vital research areas for many years geared towards understanding coatings for improvement. In this article, a superhydrophobic coating of epoxy/fluorescent SiO2 nanoparticles/PDMS resin composite with a sandwich structure was prepared and studied using fluorescence (FL) optical studies. Briefly, the pristine SiO2 nanoparticles were first chemically modified with the aggregation-induced emission luminogen (AIEgen) molecules, whose FL behaviors are known to be strongly dictated by the way their molecular rotors are restricted. According to this principle, one can facilely track and understand the nano, micro, and macro interaction of the polymers and the SiO2 nanoparticles in the superhydrophobic coatings under various environments and during use. The current findings show that such emissive superhydrophobic composite coatings can be prepared and characterized easily with a fast, contactless, and nondestructive FL spectroscopic technique. The method does not require the traditional complex and expensive professional sample preparation steps.

Self-stratifying coatings are excellent replacements for traditional coatings, which need primers and sealers during their application on substrates. In this work, we introduced aggregation-induced emission (AIE) luminogens (AIEgens) during the synthesis of self-stratifying coating to study and trace the mechanism and reactions between the individual components of the coating resin, its film-forming properties, and response to the environment in real time. The AIEgens introduced into the coating materials were a backbone to these studies. They can emit light (under excitation) with different properties depending on how their molecular rotors are restricted or free to move. More still, the reported fluorescent AIE-based self-stratifying coatings demonstrated reliable hydrophobicity and self-cleaning properties (contact angle above 130°), good thermal tolerance (above 350°), excellent toughness, chemical, and corrosion resistance. Such coatings can find use in various home and industrial applications.

Organic polymers with ordered nanostructures templated from lyotropic liquid crystals (LLC) have many potential applications in areas such as membranes, tissue engineering, and drug delivery. However, after removing the LLC templates, the high surface tension during vacuum or air drying will deform the structure to a great extent. This study investigates the structure retention in cross-linked poly(ethylene glycol) diacrylate polymer through reinforcement of a silica network and using a volatile solvent with low surface tension. The LLC templates were formed from non-ionic surfactant, Brij 56/water system. Silica network was obtained through a sol–gel method using TEOS as a silica precursor and hydrochloric acid as a catalyst. The LLC templates were removed and the samples were dried from this solvent using a mixed solvent n-hexane and ethanol (H–E solvent) with lower surface tension. Samples dried from H–E solvent preserved the structure template from LLC even with low TEOS loading due to the presence of a non-polar solvent that has little effect on silica reverse hydrolysis and lower surface tension. This indicates that drying the sample from a volatile solvent with low surface tension combining with the silica network reinforcement facilities the structure retention.

Since the 1970s, a substantial area of arable farmland in a semi-humid area of northeast China has been planted as deciduous forests (Populus tomentosa Carr.). This study investigates the effects of afforestation on soil organic carbon (SOC) content and the chemical composition of the soil. Soil samples (Calcic chernozem) were collected from the upper 10 cm of paired arable land and secondary forests established 5 and 25 years previously. Carbon isotope analysis and pyrolysis–gas chromatography/mass spectrometry were used to determine SOC composition. The results show that (i) compared to the arable land, five years of afforestation caused a decrease in SOC and N concentration, while 25 years of afforestation resulted in an increase in SOC content; (ii) stable isotope δ13C analyses of the forest soils show gradual loss of crop-derived C and an accumulation of forest-derived C; and (iii) afforestation increased lignin abundance and decreased decompositional activity in the 25-year-old forest topsoi...

The alignment of nanostructures in materials such as lyotropic liquid crystals (LLCs) templated materials has the potential to signicantly improve their performances. However, accurately characterising and quantifying the alignement of such fine structures remains very challenging. In situ small angle X-ray scattering (SAXS) and molecular dynamics were employed for the first time to understand the hexagonal LLC alignment process with magnetic nanoparticles under a magnetic field. The enhanced alignment has been illustrated from the distribution of azimuthal intensity in the samples exposed to magnetic field. Molecular dynamics simulations reveal the relationship between the imposed force of the magenetic nanoparticles under magnetic field and the force transferred to the LLC cylinders which leads to the LLC alignment. The combinational study with experimental measurement and computational simulation will enable the development and control of nanostructures in novel materials for various applications.

In an effort to optimize soil management practices that can help mitigate terrestrial carbon emissions, biochar has been applied to a wide range of soil environments to examine its effect on soil greenhouse gas emissions. Such studies have shown that the soil methane (CH4) flux response can vary widely leading to both increase and decrease in CH4 flux upon biochar amendment. To address this discrepancy, multiple meta-analysis studies have been performed in recent years to determine the key factors that may control the direction of CH4 flux upon biochar treatment. However, even comparing across conclusions from meta-analyses reveals disagreement upon which factors ultimately determine the change in direction and magnitude of CH4 flux due to biochar addition. Furthermore, using multiple observations from a single study can lead to misinterpretation of the influence of a factor within a meta-analysis due to non-independence. In this study, we use a multivariate meta-regression approach that allows factor interactions to investigate which biochar, soil, and management practice factors in combination or individually best explain the CH4 flux response in past biochar amendment studies. Our results show that the interaction of multiple soil factors (i.e., water saturation, soil texture, and soil organic carbon content) best explains the soil CH4 flux response to biochar addition (minimum deviance information criterion (DIC) value along with lowest heterogeneity) as compared to all models utilizing individual factors alone. These findings provide insight into the specific soil factors that should be taken into account simultaneously when optimizing the CH4 flux response to biochar amendments and building empirical models to quantitatively predict soil CH4 flux.

The alignment of nanostructures in materials such as lyotropic liquid crystal (LLC) templated materials has the potential to significantly improve their performances. However, accurately characterising and quantifying the alignment of such fine structures remains very challenging. In situ small angle X-ray scattering (SAXS) and molecular dynamics were employed for the first time to understand the hexagonal LLC alignment process with magnetic nanoparticles under a magnetic field. The enhanced alignment has been illustrated from the distribution of azimuthal intensity in the samples exposed to magnetic field. Molecular dynamics simulations reveal the relationship between the imposed force of the magnetic nanoparticles under magnetic field and the force transferred to the LLC cylinders which leads to the LLC alignment. The combinational study with experimental measurement and computational simulation will enable the development and control of nanostructures in novel materials for various applications.

Addition of biochar to soils has been shown to increase crop yield and aid in mitigating greenhouse gas emissions by decreasing the extent of soil methane (CH4) flux. Previous studies utilizing metaanalysis to better understand the impact of environmental and management factors on CH4 flux from biochar treated soil systems have provided contrasting results, ranging from significant increase, decrease, to no change in methane flux after amendment. We hypothesized that these discrepancies could be explained by separating studies into two major land use categories, upland and paddy, prior to analysis so that the overall redox conditions are more comparable across studies upon which statistical comparisons are made. Furthermore, past studies did not consider potentially critical soil properties including soil organic carbon, total nitrogen, C/N, and soil texture; a number of biochar properties including biochar pH and C/N; and five additional management and experimental factors. In this study, Hedge's d metric was calculated and Wilcoxon analyses were used in a meta-analysis to determine the impact of these additional factors on methane flux from biochar-amended upland versus paddy soils. We demonstrate that variations in soil characteristics including SOC, C/N, and pH significantly influences the methane flux from biochar treated soils, while biochar characteristics and management practices have less to no effect as determined by the magnitude of the Hedge's d metric. Soils with low SOC, total nitrogen, C/N, acidic or alkaline pH exhibited lowest CH4 emission rates/highest CH4 uptake rates, whereas soils with higher SOC content, C/N, and circumneutral pH exhibited higher CH4 emission with biochar addition. Several possible mechanisms are suggested to explain the role of these variables in CH4 cycling. Results from this study will be used to evaluate the input parameters for building a linear additive model to quantitatively predict soil methane flux in response to biochar additions. Ultimately, implementation of the linear additive model can be extremely valuable for advising agricultural practices toward minimize methane emissions or maximizing methane sink strength. We suggest that additional field and controlled experiments be performed to better define the reaction network that controls methane flux from biochar treated soils, with particular attention to paddy soils where studies are still lacking.

Afforestation is a prevalent practice carried out for soil recovery and carbon sequestration. Improved understanding of the effects of afforestation on soil organic carbon (SOC) content and dynamics is necessary to identify the particular processes of soil organic matter (SOM) formation and/or decomposition that result from afforestation. To elucidate these mechanisms, we have used a sequential density fractionation technique to identify the transfer mechanisms of forest derived C to soil fractions and investigate the impact of afforestation on SOC sequestration. Surface soil samples from continuous maize crop land (C4) and forest land (C3), which had been established 5, 12 and 25 yr, respectively, on the Northeast China Plain were separated into five density fractions. SOC, nitrogen (N) concentration and δ13C data from the three forests and adjacent cropland were compared. Afforestation decreased SOC concentration in the < 2.5 g cm-3 fractions from 5 yr forest sites, but increased SOC content in the < 2.0 g cm-3 fractions from 25 yr forest sites. Afforestation did not affect soil mass distribution, SOC and N proportional weight distributions across the density fractions. The < 1.8 g cm-3 fractions from 12 and 25 yr forests showed higher C/N and lower δ13C as compared to other fractions. Incorporation of forest litter-derived C occurred from low density (< 1.8 g cm-3) fractions to aggregates of higher density (1.8-2.5 g cm-3) through aggregate recombination and C transport in the pore system of the aggregates. Some forest litter-derived C could transfer from the light fractions or directly diffuse and adsorb onto mineral particles. Results from this study indicate that microaggregate protection and association between organic material and minerals provide major contribution to the SOC sequestration in the afforested soil system.

Cross-linked poly(ethylene glycol) diacrylate (PEGDA) hydrogels with uniformly controlled nanoporous structures templated from hexagonal lyotropic liquid crystals (LLC) represent separation membrane materials with potentially high permeability and selectivity due to their high pore density and narrow pore size distribution. However, retaining LLC templated nanostructures is a challenge as the polymer gels are not strong enough to sustain the surface tension during the drying process. In the current study, cross-linked PEGDA gels were reinforced with a silica network synthesized via an in situ sol-gel method, which assists in the retention of the hexagonal LLC structure. The silica precursor does not obstruct the formation of hexagonal phases. After surfactant removal and drying, these hexagonal structures in samples with a certain amount of tetraethoxysilane (TEOS) loading are well retained while the nanostructures are collapsed in samples without silica reinforcement, leading to the hypothesis that the reinforcement provided by the silica network stabilizes the LLC structure. The study examines the conditions necessary for a sufficient and well dispersed silica network in PEGDA gels that contributes to the retention of original LLC structures, which potentially enables broad applications of these gels as biomedical and membrane materials.