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Lignin/tannin/ZnONP composite coatings were designed for paper-based green packaging. Multiple functions, such as high strength, moisture resistance, low air permeance, heat endurance, UV aging resistance, and antibacterial/mold properties, were successfully integrated into one biobased coating. Prepolymerization improved the physical properties of coatings at high lignin contents. The best ingredient ratio was: 40% lignin, 15% tannin, and 10% ZnONPs (based on tannin weight), and the as-prepared biocoating was labeled LTZn-10. After coated with LTZn-10, the tensile strength and bursting strength of the packaging were efficiently enhanced by more than 3 times and were dramatically increased by 51.6 and 5.6 times at the wet state, respectively, which reveals that the packaging has favorable moisture resistance and it can be used in high humidity environments. Scanning electron microscopy (SEM) proved that most of the pores on the paper were blocked by the coatings, which helped to decrease the air permeance by 10.3 times. Meanwhile, ZnONPs were evenly spread on the coatings, which endowed the packaging with excellent antibacterial/mold performance. No colony or mycelium was found in the test against Gram-negative/positive bacteria and eight common molds. Besides, antibacterial activity is only available while the bacteria come in contact with the coating and no active substances were released into the culture medium, which is a good property that can keep the cargo from contamination of antibacterial agents. In addition, the coated paper presented an improved Tg and thermal degradation temperature, indicating that the coated package has favorable thermostability and can maintain its outstanding physical properties in a wider temperature range. Lignin and tannin promoted the UV stability and service life of the coated paper, as a rare physical decrease was observed after UV aging for 72 h. The function-integrated biobased coating with favorable sustainability is a good candidate to be widely used in paper-based green packaging fields.

In underwater drilling and blasting engineering, the blasting vibration signal is mixed with a mass of noises due to the complexity of monitoring environment, the error of monitoring sensors and the reflection of propagation medium. In order to accurately obtain the characteristics of vibration signal, a novel denoising model is established. The complete ensemble empirical mode decomposition with adaptive noise is used to decompose the original signal, and the objective function of the filtering algorithm is used to obtain the optimal denoising signal. The results indicate that the model can not only successfully remove the high-frequency noise but also has no effect on the low-frequency signal components, which verifies the reliability and validity of the denoising model.

Dynamic tensile failure is one of the main failure modes of layered rock masses during the excavation of underground engineering. This study investigates the influence of loading rate and layered inclination angle on the mechanical properties and failure mechanisms of layered slate using a split-Hopkinson pressure bar system and high-speed cameras. The results show that, overall, the dynamic elastic modulus E, postpeak stress reduction rate K, and failure load of the discs with the 7 tested bedding angles increase with the increasing loading rate. A nonlinear formula is proposed to describe the relationship between loading rate and failure load for the 7 tested inclination angles. As the inclination angle of the bedding planes increases from 0° to 90°, both the static and dynamic failure loads of the slate increased. However, with increasing loading rate, the anisotropic influence coefficient N ranges from 3.25 under the static load to 1.35 under the dynamic load, and the bedding effect gradually decreases. From the dynamic Brazilian splitting tests, the failure of the discs is mainly observed along the bedding planes when the inclination angle is less than or equal to 45°. Failure of the discs mainly occurs along the centre of the disc and previously intact planes when the inclination angle is greater than 60°. This study provides significant data to evaluate the mechanical properties and failure mechanisms of layered rock and the safety and stability of layered rock under dynamic loading.

Atrazine has been widely used as a synthetic herbicide in many countries. Due to its persistence and mobility, atrazine is difficult to eliminate by conventional treatment processes or biodegradation and may cause varying degrees of harm to untargeted organisms and threaten environmental sustainability. In recent years, microbubble ozonation has been reported to accelerate the removal of persistent organic pollutants, but there has been little research on the removal of atrazine using this approach. In this study, microbubble ozonation was shown to enhance the degradation of atrazine under a variety of pH conditions compared to macrobubble ozonation using the same concentration of aqueous ozone. The microbubble surface is usually negatively charged and hydroxyl ions accumulating at the gas–liquid interface can promote the self-decomposition of ozone and the formation of hydroxyl radicals. This promotion of ozone decomposition by microbubbles, together with the effect of microbubble collapse, were the major reasons for the enhanced degradation of atrazine. Common background components in water include organic humic acids, metal ions and inorganic ions. When low concentrations of humic acid or ferrous iron at concentrations similar to residual levels from coagulation processes were added into a pure water system, they exerted a positive effect on removal of atrazine, while the presence of bicarbonate in natural water may inhibit the degradation of atrazine in water treatment plants.

Rapid industrialization and urbanization have contributed to eutrophication of urban landscape water in China. As an important part of aquatic ecosystems, macrophytes have many advantages in controlling eutrophication and algal blooms. In recent years, micro-nanobubble (MNB) aeration has increasingly been used for restoring natural waters suffering from eutrophication, which may affect the growth of macrophytes and thereby affect ecological restoration, but the effect of MNBs on macrophytes has not drawn great attention. In this study, three common species of macrophytes (Echinodorus amazonicus or EA, Echinodorus quadricostatus or EQ and Microsorum pteropus or MP) were grown for 60 days in water aerated with MNBs and their growth was compared to that of the same plants grown with standard macrobubble aeration. The growth of EA and EQ was significantly inhibited by MNB aeration, and was accompanied by various symptoms of senescence (yellowing and chlorophyll degradation, the decrease of photosynthesis rate, carbon fixation and plant growth, and the decline of respiration rate). However, the growth of MP plants was not significantly affected under the same conditions. The final fresh weights (FFWs) of EA, EQ and MP in the presence of high MNB levels were 0.75, 0.83 and 1.05 times those in the macrobubble aeration system; we designate this parameter ratioFFW. We found the initial total antioxidant capacity (T-AOC) of EA and EQ to be 48.00 and 64.67 U mL−1, respectively, markedly lower than that of MP (617.33 U mL−1). The ratioFFW values and other growth indexes of the three plant species were positively correlated with their T-AOC. Macrophytes use their antioxidant defense mechanisms to prevent oxidative damage by ROS, while still allowing exogenous ROS to function as signalling molecules to regulate plant growth and senescence. Premature senescence is a protective mechanism employed when plants are stressed and their growth is consequently inhibited. Our results suggest that instead of positively promoting the growth of dense macrophytes, the MNBs potentially induce damage to water ecosystem.

Algal blooms and wastewater effluents can introduce algal organic matter (AOM) and effluent organic matter (EfOM) into surface waters, respectively. In this study, the impact of bromide and iodide on the formation of halogenated disinfection byproducts (DBPs) during chlorination and chloramination from various types of dissolved organic matter (DOM, e.g., natural organic matter (NOM), AOM, and EfOM) were investigated based on the data collected from literature. In general, higher formation of trihalomethanes (THMs) and haloacetic acids (HAAs) was observed in NOM than AOM and EfOM, indicating high reactivities of phenolic moieties with both chlorine and monochloramine. The formation of haloacetaldehydes (HALs), haloacetonitriles (HANs) and haloacetamides (HAMs) was much lower than THMs and HAAs. Increasing initial bromide concentrations increased the formation of THMs, HAAs, HANs, and HAMs, but not HALs. Bromine substitution factor (BSF) values of DBPs formed in chlorination decreased as specific ultraviolet absorbance (SUVA) increased. AOM favored the formation of iodinated THMs (I-THMs) during chloramination using preformed chloramines and chlorination-chloramination processes. Increasing prechlorination time can reduce the I-THM concentrations because of the conversion of iodide to iodate, but this increased the formation of chlorinated and brominated DBPs. In an analogous way, iodine substitution factor (ISF) values of I-THMs formed in chloramination decreased as SUVA values of DOM increased. Compared to chlorination, the formation of noniodinated DBPs is low in chloramination.

Rationale Rhapontigenin, a stilbene compound isolated from the medicinal plant of rhubarb rhizomes, has shown a variety of biological activities. The purpose of this study was to identify and characterize the metabolites of rhapontigenin in rat liver microsomes, hepatocytes, urine, and human liver microsomes and hepatocytes. Methods The samples were analyzed by ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole/orbitrap high-resolution mass spectrometry (UPLC-Q/Orbitrap-HRMS). The structures of the metabolites were interpreted by MS, MS/MS data, and elemental compositions. Results A total of 11 metabolites were detected and tentatively identified. M1, identified as piceatannol, was unambiguously identified using reference standard. Our results suggested that rhapontigenin was metabolized through the following pathways: (a) demethylation to produce piceatannol (M1), which further underwent oxidation to form ortho-quinone intermediate. This intermediate was reactive and conjugated with GSH (M10 and M11), which were further converted into N-acetyl-cysteine and excreted in urine. M1 also underwent sulfation (M8) and glucuronidation (M5); (b) direct sulfation, forming M6 and M7; and (c) direct glucuronidation to form M2, M3, and M4. Glucuronidation was a major metabolic pathway in hepatocytes and urine. Conclusions The current study provides an overview of the metabolism of rhapontigenin, which is of great importance for us to understand the disposition of this compound.

A lignin-based PU coating was prepared for paper-based green packaging. Two representative diisocyanate were used to prepare the coatings. Due to the rigid aromatic, the physical properties of the TDI system reached the maximum below the lignin content of 40%. The HDI that contains flexible aliphatic chains alleviated the brittleness of coating, and it showed physical advantages when the lignin content was more than 50%. Owing to the high lignin content, the coating presented enhanced thermal stability. After coated with the lignin-based PU coatings, the dry tensile strength of coated paper was improved by 126%. Amazingly, the wet strength was increased from 0.31 to 12.6 MPa with an improvement nearly 40 times. Based on the coordination of lignin, Ag+ was introduced into the PU matrix, which imparted the coating with excellent antibacterial ability. The colony forming units of E. coli and S. aureus were both less than 1. However, no inhibition halo was observed, which indicated that the Ag was firmly anchored on the coating and the antibacterial ability is only available when the bacterial contact the coating surface. The lignin-based PU coating with favorable sustainability and properties shows great potential in paper-based green packaging fields.

A series of triaxial repetitive impact tests were conducted on a 50-mm-diameter split Hopkinson pressure bar testing device to reveal the characteristics of dynamic stress–strain of sandstone under confining pressure, and the confining pressure in this study was set as 5 and 10 MPa. The results showed that sandstone is very sensitive to confining pressure and strain rate. As the confining pressure and strain rate increases, the dynamic strength, critical strain and absorbed energy also increases, however with the increases in number of impacts, they decrease. With impact numbers increases, the stress–strain curve of sandstone gradually transits from a Class I to a Class II. The dynamic statistical damage constitutive model used in the paper can describe the dynamic response of sandstone under confining pressure with repetitive impact. Various influencing factors, such as material characteristics, confining pressure, strain rate and damage on the dynamic mechanical behavior of sandstone are also fully considered in the model. The damage curve changes from concave to convex as the $${F \mathord{\left/ {\vphantom {F {F_{0} }}} \right. \kern-\nulldelimiterspace} {F_{0} }}$$ increase. When the $${F \mathord{\left/ {\vphantom {F {F_{0} }}} \right. \kern-\nulldelimiterspace} {F_{0} }}$$ exceed 0.5, the damage curve appears convex, and the damage is obvious. By comparing with the variation of the reflected wave waveform with the impact numbers, it is found that damage evolution law of the rock under confining pressure with the impact numbers is similar to that of the reflected wave waveform with the impact numbers, can reflect the damage degree of the rock specimen without other auxiliary equipment, which has been verified.

Seismic wave induced by blasting excavation of tunnel may exert adverse effects to the surrounding rock. To study the different characteristics and attenuation of blast-induced vibration in the blasting tunnel and adjacent tunnel, field blasting tests are carried out to record velocity–time histories during blasting in Wanhua Underground Gas Storage. The characteristics and attenuation of vibration velocity and energy are presented based on the field data. And the dynamic finite-element model is established to further study the vibration attenuation law. Results demonstrate that PPV and vibration energy of the adjacent tunnel is greater than that in the blasting tunnel and attenuates more readily when monitoring points are near the blasting area. The dominant frequencies of the adjacent tunnel are higher than that in the blasting tunnel at three orthogonal directions. Adopting vibration energy as the evaluation index of seismic intensity, the fitting formula has favorable prediction accuracy, which will provide more accurate guidance for controlling the adverse effects of tunnel blasting.

Nanobubble technology, as an emerging and sustainable approach, has been used for remediation of eutrophication. However, the influence of nanobubbles on the restoration of aquatic vegetation and the mechanisms are unclear. In this study, the effect of nanobubbles at different concentrations on the growth of Iris pseudacorus (Iris) and Echinodorus amazonicus (Echinodorus) was investigated. The results demonstrated that nanobubbles can enhance the delivery of oxygen to plants, while appropriate nanobubble levels will promote plant growth, excess nanobubbles could inhibit plant growth and photosynthesis. The nanobubble concentration thresholds for this switch from growth promotion to growth inhibition were 3.45 × 107 and 1.23 × 107 particles/mL for Iris and Echinodorus, respectively. Below the threshold, an increase in nanobubble concentration enhanced plant aerobic respiration and ROS generations in plants, resulting in superior plant growth. However, above the threshold, high nanobubble concentrations induced hyperoxia stress, particularly in submergent plants, which result in collapse of the antioxidant system and the inhibition of plant physiological activity. The expression of genes involved in modulating redox potential and the oxidative stress response, as well as the generation of relevant hormones, were also altered. Overall, this study provides an evidence-based strategy to guide the future application of nanobubble technology for sustainable management of natural waters.

In underground engineering practice, the surrounding rocks are subjected to a nonuniform stress field with various radial gradients. In this study, a series of conventional triaxial repetitive impact tests using hollow cylindrical sandstone (HOS) specimens were conducted to reveal the impact waveform features and failure properties of rocks under nonuniform stress conditions. The tests were conducted using a modified large diameter split Hopkinson pressure bar testing system. The confining pressure was set as 5, 10 and 12 MPa. The data of specimens under equilibrium stress states were chosen and analyzed, and the results showed that more applied numbers of cyclic impact loads were needed to break rocks with the increase of confining pressure. Three types of cracks, i.e., ring-shaped cracks around the hole in the center of specimens, axial cracks located in the outer cylindrical surface, and lateral cracks fracturing rock fragments into small pieces appeared in HOS specimens. The failure degrees of HOS specimens could be judged by the waveform features of the reflected wave, and the waveform features of reflected wave are similar in the same failure mode, regardless of the impact velocity and the number of impacts, which only affect the failure degree.

Due to the functional integration potential and the excellent design freedom, molded interconnect devices (MID) are becoming more and more attractive for several fields, such as consumer electronics, automotive and lighting technologies. In this context, the need for better reliability, especially for the solid state lighting, has significantly increased recently. Thermal management impacts not only the efficiency but also the reliability and the color stability of LED arrays, where LEDs are subjected to mutual interferences. Thus, the use of highly filled and thermally conductive thermoplastics appears very appealing.In light of this fact, an experimental and computational study, with focus on the influence of the substrate material and heat dissipation concepts on the thermal management of low- and high-power LEDs on MID, is presented in this paper. The accuracy of the implemented Finite Elements Analysis (FEA) is also examined in this work and used to forecast the reliability of a 3D-MID lighting module.

Research on the dynamic compressive characteristics of sandstone under radial gradient stress and confining pressure is conducive to understanding the characteristics of the surrounding rock, especially in an excavation operation for an underground mine roadway and tunnel. The present work aimed at studying the effects of radial gradient stress and confining pressure on the impact of compression of sandstone using a large-diameter split Hopkinson pressure bar. The results showed that the dynamic strength of sandstone under radial gradient stress increased with strain rate following a power function, and the dynamic strength of the sandstone under radial gradient stress was lower and more sensitive to strain rate. The increase in strain at peak stress (peak strain) was linearly correlated with the strain rate under different confining pressures. The sensitivity of the peak strain to confining pressure was lower for the sandstone with a hole, while the values of the elastic modulus were decreased. However, further increasing the stain rate would lead to an increase in the elastic modulus. Also, the ductility of the sandstone with a hole tested in this study was found to improve more significantly. Finally, with an increase in the incident energy, the absorbed energy per unit volume would increase, but would not be affected obviously by the radial gradient stress.