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Fine roots play key roles in belowground C cycling in terrestrial ecosystems. Based on their distinct functions, fine roots are either absorptive fine roots (AFRs) or transport fine roots (TFRs). However, the function-based fine root dynamics of trees and their responses to forest stand properties remain unclear. Here, we studied the dynamics of AFRs and TFRs and their responses to stand conditions and root density in a subtropical montane mixed forest based on a 2-a root window experiment. Mean (± SE) annual production, mortality, and turnover rate of AFRs were 7.87 ± 0.17 m m−2 a−1, 8.13 ± 0.20 m m−2 a−1and 2.96 ± 0.24 a−1, respectively, compared with 7.09 ± 0.17 m m−2 a−1, 4.59 ± 0.17 m m−2 a−1, and 2.01 ± 0.22 a−1, respectively, for TFRs. The production and mortality of fine roots were significantly higher in high root-density sites than in low-root density sites, whereas the turnover of fine roots was faster in the low root-density sites. Furthermore, root density had a larger positive effect than other environmental factors on TFR production but had no obvious impact on AFR production. Tree species diversity had an apparent positive effect on AFR production and was the crucial driver of AFR production, probably due to a complementary effect, but had no evident impact on TFR. Both tree density and tree species diversity were positively correlated with the mortality of AFRs and negatively related to the turnover of TFRs, suggesting that higher root density caused stronger competition for rooting space and that plants tend to reduce maintenance costs by decreasing TFR turnover. These findings illustrated the importance of root functional groups in understanding root dynamics and their responses to changes in environmental conditions.

Refereed/Peer-reviewed The textile industry uses a variety of synthetic dyes for dyeing and discharges a large amount of colored wastewater. It is difficult to achieve good decolorization effect for textile wastewater by conventional biological treatment methods, because it contains various synthetic dyes with complex structures. At present, coagulation is an economical and effective treatment method. However, in dye removal by coagulation research, the adaptability and mechanisms of coagulation removal of many dyes are still unknown due to the wide variety of dyes in use. In this study, ferric chloride (FeCl₃), aluminum chloride (AlCl₃) and magnesium chloride (MgCl₂) were selected as coagulants, and direct orange 26 (DO), direct yellow 11 (DY) and direct black 19 (DB) were used as the dye samples to conduct a series of coagulation experiments; in order to understand the coagulation adaptability and mechanism for high removal efficiency of direct dyes. In this system without particles, the direct dyes were dissolved directly in pure water and maintained in molecular state. The results showed that 1) AlCl₃, FeCl₃ and MgCl₂ exhibited superior coagulation efficiency on the three dyes. Direct dyes which contain more amino functional groups are more easily removed by coagulation. 2) The influence of hydraulic conditions on the residual turbidity was more significant compared with the color removal. 3) Zeta potential increased with the increase of the coagulant dosage, but the colloidal particles did not re-stabilize. This proved that charge neutralization is not the dominant mechanism of coagulation. The FT-IR and XRD patterns indicated that the direct dyes were removed by the chemical combination of the -SO₃H on the dye molecule and the hydrolysate of the coagulant.

Ionic liquids (ILs

Nowadays, polyhalogenated carbazoles (PHCZs) are a major pollutant that has recently sparked widespread concern. In this work, peroxymonosulfate (PMS) was activated by zero valent iron (Fe0) to remove 3,6-dichlorocarbazole (3,6-CCZ). First, the key parameters influencing 3,6-CCZ degradation (PMS dosage, Fe0 dosage, initial pH, temperature and co-existing ions) were determined. Under the determined optimum conditions, the removal rate of 3,6-CCZ reached 100% within 1.5 h. Sulfate radicals (SO4��-), hydroxyl radicals (OH��), and singlet oxygen (1O2) generated in the reaction were directly identified with 0.1 M 5,5-dimethyl-1-pyrrolidine N-oxide (DMPO) by in-situ electron paramagnetic resonance (EPR) and indirectly identified by radical quenching experiments. The main reactive oxygen species (ROS) were different from most reported hydroxyl radicals (OH��) and sulfate radicals (SO4��-). In this study, it was found that OH�� and 1O2 play a major role. Then, fresh and reacted Fe0 were characterized by XRD, SEM, and XPS. Iron corrosion products such as Fe2O3, Fe3O4, and FeOOH were generated. Finally, 3,6-CCZ degradation intermediates were identified by GC-MS and its degradation pathway was speculated. The intermediate pathway confirmed the combined action of (OH��) and (1O2) in 3,6-CCZ removal. This study provides new insight into the activation mechanism of Fe0-activated PMS and the removal mechanism of 3,6-CCZ. HighlightsFe0 is a long-lasting and efficient catalyst of PMS for the degradation of 3,6-CCZ.The key parameters influencing 3,6-CCZ degradation were determined.The degradation pathways of 3,6-CCZ were inferred.OH�� and 1O2 were the main ROS in Fe0-activated PMS system. Fe0 is a long-lasting and efficient catalyst of PMS for the degradation of 3,6-CCZ. The key parameters influencing 3,6-CCZ degradation were determined. The degradation pathways of 3,6-CCZ were inferred. OH�� and 1O2 were the main ROS in Fe0-activated PMS system.

Phenanthrene (PHE) is a typical compound biomagnified in the food chain which endangers human health and generally accumulates from marine life. It has been listed as one of the 16 priority PAHs evaluated in toxicology. In order to evaluate the changes of

Harmful algal blooms (HABs) destroy the balance of the aquatic ecosystem, causing huge economic losses and even further endangers human health. In addition to traditional methods of algae removal, photocatalytic inhibition of algae is drawing more and more interests with rich application scenarios and considerable potential. Simulated visible light sources are used to excite photocatalytic materials and optimize their performance. However, most of the light irradiation intensities used in the study exceeded 50 mW/cm

Aims To understand the response of alpine meadow to shrub encroachment, we analyzed alpine meadow plant community structure and function and soil properties at different shrub coverage sites in western Sichuan, P.R. China, further providing a reasonable scientific basis to better control or remove the effects of shrub encroachment on local meadow. Methods A site with an area of 200 × 200 m along the shrub line was selected as the study area (4300 m a.s.l.) in Yajiageng Valley, Hengduan Mountain, Southwest China. The study area was divided into four treatments. Control, low-, medium- and high -shrub- coverage plots were investigated for community composition, above- ground biomass and belowground biomass were harvested, and root functional traits and soil properties were measured in laboratory in the summer of 2020. Results There was no significant difference in the total aboveground biomass among all treatments, however, forb and legume biomass increased, and grass and sedge biomass decreased with increased shrub coverage; Species richness significantly decreased, but diversity and evenness index increased in the medium -shrub -coverage plots; Root biomass at the depth of both 0-10 cm and 10-20 cm significantly decreased in medium- and high -shrub -cover plots; The field capacity, soil total nitrogen (STN) and available nitrogen (AN) concentration were significantly decreased in the medium -shrub -coverage plots, and the total phosphorus (TP) concentration were significantly decreased among all treatments. Conclusion The process of shrub encroachment tends to limit the local dominant species and maintain the growth of nondominant species, which further increases the community diversity and maintains the stability of aboveground biomass. Shrub encroachment makes alpine meadow soil became drier and impoverishment and promoted the mineralization of organophosphorus and the dissolution of insoluble inorganic phosphorus, which strengthened the alpine ecosystem nitrogen (N) limit.

Nitrogen (N) deposition has complex effects on vegetation dynamics and nutrient cycling in terrestrial ecosystems. However, how N deposition alters fine root traits remains unclear in forest ecosystems. Here, we carried out a synthesis based on 890 paired observations of 14 fine root traits from 79 articles to assess the effects of N deposition on fine root traits. The results showed that N deposition mainly affected root nutrient content and stoichiometry. Specifically, N deposition increased the root N content, root carbon: phosphorus (C:P) and root nitrogen: phosphorus (N:P) ratio, but decreased the root P content and root C:N ratio. Moreover, N deposition increased fine root respiration, but had no significant effect on other root morphological and physiological traits. N deposition effects on fine root biomass, root tissue density and fungal colonization decreased with N deposition duration. Compared to fine root P content, N deposition effects on fine root C content and C:P ratio increased with N deposition level. Moreover, the interaction between N deposition level and duration significantly affected fine root biomass. N deposition effects on fine-root biomass decreased with greater N deposition duration, especially in high N deposition experiments. Moreover, the effect of N deposition on root diameter decreased with mean annual temperature and mean annual precipitation. N form, forest type and soil depth significantly affect the effect of N deposition on fine root C:P. Therefore, the effects of N deposition on fine root traits were not only determined by N deposition level, duration and their interactions, but also regulated by abiotic factors. These findings highlight the diverse responses of fine root traits to N deposition have strong implications for forest ecosystems soil carbon stocks in a world of increasing N deposition associated with decreased root-derived carbon inputs and increases in fine-root respiration.

Phenanthrene (PHE) is a typical food chain biomagnified compound which endangers human health and is generally accumulated from marine lives. Previous PHE-stressed Carp acute toxicity test showed that the safe concentration of PHE to carp was 1.12 mg/L. In this study, the carp was long-term exposed to PHE below safe concentration up to 25 days. The gene expression levels and cytochrome P450 (CYP1A/EROD (7-Ethoxylesorufin O-deethylase)) and glutathione S-transferase (GST) activities were determined in the carp liver and brain tissues. The results showed that both the CYP1A mRNA expression and EROD activity in the liver were continuously stimulated after induction with the increase in exposure time and exposure concentration. However, with the increase of PHE concentration, GST mRNA expression in the liver was firstly induced and then inhibited and the induction was significant in the treatment with 0.1 mg/L PHE in the 15th day (almost 2-fold). In the brain, after the 15th day, GST mRNA expression was suppressed, but GST activity was induced. Correlation analysis results showed that the CYP1A mRNA expression was significantly correlated with the activity of EROD in both tissues (liver, r = 0.602, P P GST mRNA expression and GST activity was poor (liver, r = 0.385, P P

Soil relative water concentration is one of the most important influences on crop growth and the diversity and composition of microorganisms in the crop rhizosphere. This study investigates the influences of soil relative water concentration on CO2 flux and rhizospheric microbial diversity in maize crops. Plots of maize were given different irrigation treatments; namely, control (natural precipitation) and low, medium, and high sprinkling irrigation quotas (achieving soil relative water contents of 55.0–65.0%, 65.0–75.0%, and 75.0–85.0%, respectively). Compared with controls, CO2 uptake increased with soil relative water concentration, mainly during the tasseling, pustulation, and mature growth stages. In addition, the richness and evenness of the bacterial and archaeal communities in the soil matrix increased with soil relative water concentration. However, the diversity of fungal communities had an inverse trend compared with that of bacterial and archaeal communities, which resulted from dry-wet cycling promoted the diversity of fungal diversity. The relative abundances of most dominant bacteria and fungi increased with soil relative water content and maize growth. These results demonstrate that modest water supplementation, especially during maize's tasseling, postulation, and mature stages, enhances its growth and increases the relative abundances of bacterial and fungal communities in the soil.

The development of oxygen reaction reduction (ORR) electrocatalysts that are low-cost, highly-active and have long-term stability for use in energy conversion and storage applications such as fuel cells and metal-air batteries is very important. In this paper, a facile one-step pyrolysis method was used to prepare bamboo-like N-doped carbon nanotubes (BNCNTs) as effective ORR electrocatalysts. Manganese and cobalt salts were used as the metal precursors, and urea was the C and N source. The resulting catalysts were characterized by the scanning electron microscopy, high resolution-transmission electron microscopy, X-ray photoelectron spectroscopy, Raman microscopy and X-ray power diffraction. The BNCNTs contained Mn and Co nanoparticles that were coated with graphitic carbon. The electrochemical performances of the catalysts in alkaline media were evaluated using cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The BNCNTs prepared with a Mn to Co molar ratio of 1:1 at 800 °C had the best catalytic activity. The reaction followed a quasi-4 electron reaction pathway with a smaller Tafel slope (57.5 mV dec-1) than that of the commercial Pt/C (72.8 mV dec-1). In addition, the limiting current density, durability and methanol crossover resistance were all superior to those of Pt/C. The above results indicate that Mn/Co-BNCNTs-800 is an active electrocatalyst with earth-abundant non-precious elements for ORR.

Cadmium sulfide, with its narrow band gap, can be used as a photocatalyst in the visible light region for the splitting of water, but its limited number of active sites and tendency to agglomerate are problematic for producing high yields of hydrogen. Therefore, an inverse emulsion polymerization method was used to fabricate polyacrylamide (PAM) microgels as a substrate to immobilize CdS nanoparticles (PAM-CdS). The PAM microgels not only immobilized the CdS nanoparticles, but also prevented aggregation. N Cd bonds in the PAM-CdS microgels facilitated electron transfer from the PAM to the CdS resulting in more electrons participating in the H2 production process. The electrostatic interactions between the PAM and CdS also hindered the recombination of electron-hole pairs. These PAM-CdS microgels exhibit admirable photocatalytic H2 production performance with a H2 production rate of up to 5.21 mmol h−1 g−1.

A fully electronic time reversal mirror (TRM) system, which can make signal time reversal transformation, is proposed in this paper. The high-order asymmetric all-pass equalizer (APE) is proposed to provide a prescribed group delay for the TRM system. Finally, two APEs are designed to be used in a demonstrated TRM, which has a time duration of 10 ns and a bandwidth of 1 GHz.

As an emerging class of organic contaminants, polyhalogenated carbazoles (PHCZs) have been increasingly detected all over the world since 1980s. Due to the environmental persistence, bioaccumulation, and dioxin-like toxicity, PHCZs have aroused widespread concerns in recent years. However, efficient approach for the degradation of PHCZs is quite limited so far. Therefore, in this study, an advanced oxidation process (AOP), sulfidated zero-valent iron/peroxymonosulfate (S-ZVI/PMS) system was used to degrade 3-chlorocarbazole (3-CCZ), which is one of the mostly detected PHCZs congeners. The degradation of 3-CCZ was systematically studied under different conditions by varying the molar ratio of S/Fe, the dosage of S-ZVI or PMS, pH and temperature. The results indicated that S-ZVI/PMS was an effective strategy for PHCZs treatment. The 20-min degradation efficiency of 3-CZZ was up to 96.6% with the pseudo-first-order rate constant of 0.168 min

Emulsions, usually oil-in-water emulsions, have been widely applied to the preparation of hydrophobic drug carriers. However, the synthesis of safe, biocompatible and high-performance carriers for water-soluble drugs remains a challenge. So polyacrylamide (PAM) microspheres stabilized by carbon dots (CDs) were fabricated via a water-in-oil Pickering emulsion without the use of any surfactant. The PAM/CD microspheres were spherical with an even distribution of the CDs on their surfaces. The size of the microspheres can be controlled by changing the amount of CDs, which also influenced the drug loading properties. The hydrophilic chemotherapy drug, 5-fluorouracil (5-FU), was successfully loaded into the PAM/CD microspheres through incubation. The encapsulation efficiencies ranged from 68 to 82% with a maximum drug loading of 48%. The 5-FU release profiles depended on the concentration of the drug incubation solution, the concentration of the CD solution and the pH of the drug release environment. The release of 5-FU was relatively steady for the first 12 h and followed non-Fickian diffusion kinetics. This synthetic approach could be extrapolated to loading of other water-soluble drugs into hydrophilic polymers.

Water eutrophication caused by harmful algal blooms (HABs) occurs worldwide. It causes huge economic losses and has serious and potentially life-threatening effects on human health. In this study, the bacterium Raoultella sp. S1 with high algicidal efficiency against the harmful algae Microcystis aeruginosa was isolated from eutrophic water. The results showed that Raoultella sp. S1 initially flocculated the algae, causing the cells to sediment within 180 min and then secreted soluble algicidal substances that killed the algal cells completely within 72 h. The algicidal activity was stable across the temperature range −85.0 to 85.0 °C and across the pH range 3.00–11.00. Scanning electron microscopy (SEM) revealed the crumpling and fragmentation of cells algal cells during the flocculation and lysis stages. The antioxidant system was activated under conditions of oxidative stress, causing the increased antioxidant enzymes activities. Meanwhile, the oxidative stress response triggered by the algicidal substances markedly increased the malondialdehyde (MDA) and glutathione (GSH) content. We investigated the content of Chl-a and the relative expression levels of genes related to photosynthesis, verifying that the algicidal compounds attack the photosynthetic system by degrading the photosynthetic pigment and inhibiting the expression of key genes. Also, the results of photosynthetic efficiency and relative electric transport rate confirmed that the photosynthetic system in algal cells was severely damaged within 24 h. The algicidal effect of Raoultella sp. S1 against Microcystis aeruginosa was evaluated by analyzing the physiological response and photosynthetic system impairment of the algal cells. The concentration of microcystin-LR (MC-LR) slightly increased during the process of algal cells ruptured, and then decreased below its initial level due to the biodegradation of Raoultella sp. S1. To further investigate the algicidal mechanism of Raoultella sp. S1, the main components in the cell-free supernatant was analyzed by UHPLC-TOF-MS. Several low-molecular-weight organic acids might be responsible for the algicidal activity of Raoultella sp. S1. It is concluded that Raoultella sp. S1 has the potential to control Microcystis aeruginosa blooms.

Ionic liquids (ILs1) which are called “green solvents”, are used widely in the textile industry as adjuvants due to their many advantages. However, their persistent residues may cause ecotoxicity. The aim of the study is to explore the toxicity of different anions on imidazole ILs and their toxicological mechanism. For the experiments 1-butyl-3-methylimidazole tetrafloroborate ([C4mim]BF4) and 1- butyl -3-methylimidazolium chloride ([C4mim]Cl) were selected to study their toxic effects on Isatis tinctoria. ILs may affect the germination rate. Fresh weight, dry weight and Hill reaction activity decreased continuously with increasing of IL concentrations, showing an effect-dose relationship. Transmission electron microscopy (TEM) revealed that cell walls were fuzzy, starch granules had accumulated and the chloroplast structure was damaged. These changes will affected the function and electron transport efficiency of photosystemⅡ. Superoxide anion accumulation stimulated the activity of antioxidant enzymes (SOD, POD, CAT) and caused lipid peroxidation as well as an increased malondialdehyde content. ILs also reduced indirubin and total flavonoids contents, which reduced the pharmacological efficacy of Isatis tinctoria. This is demonstrated by three-dimensional fluorescence chromatogram. [C4mim]Cl was more toxic than [C4mim]BF4. ILs caused toxic effects to Isatis tinctoria. The ecological toxicity of ILs should be considered when using them as additives in the textile industry.

Due to the limited resources of home-based elderly care monitoring equipment, how to accurately identify the elderly behavior is a hot issue concerned by many equipment manufacturers. A behavior recognition method suitable for embedded equipment is proposed. This method first introduces the TPN module in the SlowFast network to capture the visual action tempo of the elderly and uses Faster-CNN to detect the elderly and objects in the video frames. Then in the AIA module, the accuracy of the elderly indoor behavior recognition is improved by strengthening the correlation between the elderly and the objects. Experiments show that the improved network can run stably at 18FPS on Jetson Xavier NX. The indoor behavior recognition accuracy for the elderly reaches 90.61%, which is 8.25% higher than the original SlowFast network.

Due to the limited resources of the Internet of things terminal, the speed of image recognition is difficult to meet the application requirements. A design method of a fast image recognition accelerator based on a convolutional neural network (CNN) is proposed. A pipeline processing scheme combining software and hardware is designed. The operation strategy of the parallel image block, parallel input channel, and parallel output channel is adopted. Based on this strategy, a model of terminal resources and recognition time is established. By solving the model, the optimal number of image partition blocks and convolution parallel parameters are obtained. The experimental results show that the computational performance of the proposed accelerator is improved from 8.86 GOPs to 12.26 GOPs, which effectively improves the speed of image recognition.

Phenanthrene (PHE) is a typical compound biomagnified in the food chain which endangers human health and generally accumulates from marine life. It has been listed as one of the 16 priority PAHs evaluated in toxicology. In order to evaluate the changes of CYP1A GST mRNA expression and EROD GST enzyme activity in carp exposed to lower than safe concentrations of PHE. Long-term exposure of carp to PHE at lower than safe concentrations for up to 25 days. The mRNA expression level and cytochrome P450 (CYP1A/EROD (7-Ethoxylesorufin O-deethylase)) and glutathione S-transferase (GST) activity were measured in carp liver and brain tissue. The results showed that PHE stress induced low-concentration induction and high-concentration inhibition of CYP1A expression and EROD enzyme activity in the liver and brain of carp. In both two organs, GST enzyme activity was also induced. However, the expression of GST mRNA was first induced and then inhibited, after the 15th day. These results indicate that long-term exposure to PHE at lower than safe concentrations still poses a potential threat to carp’s oxidase system and gene expression.

Ionic liquids (ILs) are used as detoxication agents for fermentation of lignin into ethanol because of their good applicability. However, the residual ILs may be toxic to the yeast. In order to improve the use of ILs for fermentation and protected environment, the toxicity of ILs with different carbon chain length to Pichia stipitis was studied in this paper. Four kinds of common imidazolium chloride ILs ([C4mim]Cl, [C6mim]Cl, [C8mim]Cl and [C10mim]Cl) were selected. ILs can inhibit the proliferation of Pichia stipitis and increase their mortality. Oxidative stress reaction occurred in the cells, and the activities of antioxidant enzymes are affected. Comparing with the integrated biomarker response (IBR) index, it was found that the toxicity increases with increasing chain length. ILs may enter cells by damaging cell membranes and reduce ethanol production by damaging organelles such as mitochondria. ILs caused wrinkles and dents on the surface of cells up to cell deformation and even rupture. The toxicity sequence was as follows: [C10mim]Cl> [C8mim]Cl>[C6mim]Cl>[C4mim]Cl. Due to this toxicity to Pichia stipitis, these compounds should be used carefully in the fermentation process and also to avoid toxic effects on other organisms in the environment.

Nowadays, it is known that activated porous carbon materials behave high specific capacitance owing to their high specific surface area, microporous and mesoporous structures. Therefore, the carbon materials with low cost and good cycle stability become one of the most promising electrode materials in supercapacitors. In this paper, the carbon material prepared by the carbonization of wild rice stem and the alkali activation possesses high specific surface area up to 1228 m2/g, which makes it more hopeful application prospects in electrochemical field. The results indicate that activation temperature and alkali concentration play important roles in improving the performance of specific capacitance of the activated carbon. The activated porous carbon prepared at 800 °C with a KOH/wild rice stem mass ratio of 3 shows the best performance and displays a specific capacitance of 301 F/g at current density of 1 A/g in a three-electrode configuration. Furthermore, the assembled symmetric supercapacitor attains a high energy density of 13.05 Wh/kg at the power density of 250 W/kg in 6 M KOH electrolyte. So the activated porous carbon made from wild rice stem is a low-cost, eco-friendly and high performance material for supercapacitors.

An asymmetric reflection-type all-pass equalizer (APE) is proposed to realize arbitrarily prescribed group-delay responses. This letter provided its synthesis, including the low-pass prototype for the APE and a new optimization design method of the prototype APE. Finally, a four-order APE with the prescribed group-delay response is designed. Good agreement between the measurement result and the theory verifies the validity of the method.

A new technique of temporal imaging, called temporal synthetic aperture imaging (TSAI), is proposed to achieve higher time resolution of the imaging system for ultrafast optical processing. The proposed technique combines several of independent small-aperture systems together to get a higher time resolution and better image quality as a large-aperture system. It can solve the problem that an oversized aperture time lens is difficult to achieve in practice. In this paper, after analyzing the filtering effect, a novel implementation method of TSAI is presented. In order to verify the correctness, we demonstrate a decuple magnification of a signal with two 1ps width pulse separated 2ps, using a synthetic aperture by the system simulation.

A green approach for the preparation of a stable reduced graphene oxide (RGO) suspension from graphene oxide (GO) has been developed. This method uses l-serine (l-Ser) as the reductant and yellow dextrin (YD) as the stabilizing agent. X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction and thermogravimetric analyses showed that l-Ser can efficiently reduce GO at a comparatively low temperature, and that the YD adsorbed onto the RGO facilitating the formation of a stable RGO aqueous suspension. Since l-Ser and YD are natural environmentally friendly materials, this approach provides a green method to produce stable RGO from GO on a large scale. Sodium salicylate (SS) which has an aromatic structure was loaded onto the RGO through π-π interactions and a maximum loading capacity of 44.6mg/g was obtained. The release of the loaded SS can be controlled by adjusting the solution pH, and a 74.8% release was reached after 70h at pH 7.4. The release profile of SS could be further controlled by incorporating it into RGO Dispersed carboxylated chitosan films.

Nd 2 Zr 2 O 7 is being explored as an alternate thermal barrier coating (TBC) material for operating above 1300 °C, and great effort has been made to enlarge its thermal expansion coefficient (TEC) and improve its toughness. In this study, Sc 2 O 3 was doped to Nd 2 Zr 2 O 7 . The phase structure, TECs and toughness of (Nd 1- x Sc x ) 2 Zr 2 O 7 ( x = 0, 0.025, 0.05, 0.075, 0.1) compounds were investigated. (Nd 1- x Sc x ) 2 Zr 2 O 7 ( x = 0, 0.025, 0.05, 0.075) exhibited pyrochlore structure, while (Nd 0.9 Sc 0.1 ) 2 Zr 2 O 7 consisted of pyrochlore and fluorite phases. With the increase of the Sc 2 O 3 content, the ordering degree of the pyrochlore in the compounds decreased. In (Nd 1- x Sc x ) 2 Zr 2 O 7 series, (Nd 0.925 Sc 0.075 ) 2 Zr 2 O 7 exhibited the largest TEC, while the toughness of the compounds increased with increasing the Sc 2 O 3 content. The related mechanisms were discussed based on the crystal structure analysis. Considering the TEC and toughness, 10 mol% Sc 2 O 3 was suggested as the optimal doping content for Nd 2 Zr 2 O 7 ceramic.

We propose a new scheme to physically realize the short-time Fourier transform (STFT) of chirped optical pulse using time-lens array that enables us to get time-frequency representation without using FFT algorithm. The time-lens based upon the four-wave mixing is used to perform the process of temporal Fourier transformation. Pump pulse is used for both providing the quadratic phase and being the window function of STFT. The idea of STFT is physically realized in our scheme. Simulations have been done to investigate performance of the time-frequency representation scheme (TFRS) in comparison with STFT using FFT algorithm. Optimal measurement of resolution in time and frequency has been discussed.

Xie, Z.; Zhang, H.; Zhao, X.; Du, Z.; Xiang, L., and Wang, W., 2016. Assessment of heavy metal contamination and wetland management in a newly created coastal natural reserve, China. The investigation of the content and distribution of heavy metals in coastal soils is useful for improving our understanding of biogeochemical cycles and their potential feedback to global environmental change. The accumulation of heavy metals in the Yellow River Delta (YRD) was investigated using 43 sampling sites to determine the concentrations and vertical distribution of heavy metals. Factor analysis, contamination factors, and the geoaccumulation index were applied to evaluate the contamination condition. The contamination factors and geoaccumulation index clearly indicated that the coastal ecosystems are still in their pristine state with respect to metal pollution. Factor loadings reveal that the first principal component was strongly and positively related to arsenic, chromium, copper, nickel, lead, and zinc,...

A strain ZW-4 with remarkable ability to decolorize the Pigment Red 23 was isolated from aerobic sludge by the method of concentration gradient domestication. The strain was identified as Prototheca sp. according to its morphological characters and 16S rDNA sequence analysis. Experiments on the effect of decolorization conditions were carried out under aerobic conditions. The results showed that the best nutrient source was yeast powder, and the optimum conditions were 1% yeast powder, 5% inoculum, pH 7.5, temperature 35 °C, and salinity less than 4%. Under these conditions, the decolorization rate of Pigment Red 23 (initial concentration of 100 mg L−1) was more than 91% when the strain ZW-4 was cultivated for 18 h. The strain also showed better salt tolerance property, which ranged from 6 to 8%. Besides, spectrophotometric analysis demonstrated that the decolorization mechanism of Pigment Red 23 was mainly biological degradation. Furthermore, toxicity tests indicated that the toxicity of Pigment Red 23 a...

(RE 0.9 Sc 0.1 ) 2 Zr 2 O 7 and pure RE 2 Zr 2 O 7 (RE=La, Sm, Dy, Er) compounds were synthesized by a chemical-coprecipitation and calcination method, and their phase structure, thermal expansion behavior and fracture toughness were investigated. Compared with pure RE 2 Zr 2 O 7 , (La 0.9 Sc 0.1 ) 2 Zr 2 O 7 and (Sm 0.9 Sc 0.1 ) 2 Zr 2 O 7 exhibited larger lattice parameters mainly due to the presence of Sc 3+ interstitial ions, while (Dy 0.9 Sc 0.1 ) 2 Zr 2 O 7 and (Er 0.9 Sc 0.1 ) 2 Zr 2 O 7 had smaller lattice parameters, might attributable to the substitution of Sc 3+ for RE 3+ . With the addition of 10 mol% Sc 2 O 3 , the thermal expansion coefficients of La 2 Zr 2 O 7 and Sm 2 Zr 2 O 7 were obviously enhanced, while those of Dy 2 Zr 2 O 7 and Er 2 Zr 2 O 7 decreased, which was considered to have close relationship with the solid-solution mechanisms of Sc 2 O 3 in (RE 0.9 Sc 0.1 ) 2 Zr 2 O 7 . 10 mol% Sc 2 O 3 doping benefited the fracture toughness of (RE 0.9 Sc 0.1 ) 2 Zr 2 O 7 (RE=La, Sm, Dy, Er), which could be attributed to the increased cohesive energy due to the lattice distortion.

A new method of the high order all pass equalizer (APE) with impedance inverters is proposed. The values of the impedance inverters can be directly achieve with this method. A third order APE with center frequency at 6GHz is designed using the method. A good agreement between the simulation result and the theoretical derivation verify validity of the method.

Gd 2 Zr 2 O 7 has been considered as a promising thermal barrier coating candidate for operating above 1300 °C, but the relatively poor fracture toughness limits its application. In this study, effort was made to toughen Gd 2 Zr 2 O 7 with the addition of metastable tetragonal (t′) phase. For 3.5 mol% RE 2 O 3 (RE=Dy, Y, Er, Yb) stabilized ZrO 2 (RESZ) ceramics, the t′ phase stability increased with the decrease of RE 3+ ionic radius. Among these compounds, YbSZ exhibited the best phase stability and had excellent toughness, thus it was selected as the toughening agent for Gd 2 Zr 2 O 7 . The phase structure and mechanical properties of YbSZ doped Gd 2 Zr 2 O 7 were investigated. YbSZ first dissolved in Gd 2 Zr 2 O 7 lattice, then it presented as a second phase when its content reached to 15 mol%. With YbSZ content increasing, the fracture toughness of the compounds increased, and the related mechanisms were discussed.

(Gd 1− x Sc x ) 2 Zr 2 O 7 ( x =0, 0.025, 0.05, 0.075, 0.1, 0.2) ceramics were synthesized by chemical co-precipitation and calcination and their phase structure, thermal expansion behavior and mechanical properties were investigated. (Gd 1− x Sc x ) 2 Zr 2 O 7 ( x =0, 0.025, 0.05, 0.075) exhibited pyrochlore structure. The ordering degree decreased and the lattice parameter increased with increasing the Sc 2 O 3 content, but high Sc 2 O 3 doping led to a pyrochlore-fluorite phase transformation and to a decrease in the lattice parameter. Among the (Gd 1− x Sc x ) 2 Zr 2 O 7 ceramics investigated, (Gd 0.925 Sc 0.075 ) 2 Zr 2 O 7 yielded the largest thermal expansion coefficient (TEC). The structural disorder and lattice expansion could cause the initial increase in the TEC, and the decrease in the lattice parameter might contribute to the reduced TEC. Increasing Sc 2 O 3 content benefited the fracture toughness of (Gd 1− x Sc x ) 2 Zr 2 O 7 , which could be attributed to the increased cohesive energy due to the lattice distortion and structural disorder.

(Nd1−xScx)2Zr2O7 (x = 0, 0.1, 0.3, 0.5, 0.7) compounds were synthesized by solid state reaction at 1700 °C for 10 h, and characterized by XRD, Raman spectroscopy, SEM and high-temperature dilatometer. Nd2Zr2O7 exhibited pyrochlore phase, and its lattice parameter increased after Sc2O3 doping, which could be attributed to the presence of Sc3+ interstitial ions in pyrochlore lattice. Fluorite phase formed in the doped Nd2Zr2O7, and (Nd0.3Sc0.7)2Zr2O7 exhibited pure fluorite phase. The thermal expansion coefficient (TEC) of Nd2Zr2O7 was significantly enhanced by 10 mol% Sc2O3 doping, but higher Sc2O3 doping decreased the TEC. The reduced crystal energy due to the presence of Sc3+ interstitial ions could cause the initial increase in the TEC, and the formation of fluorite phase might contribute to the reduced TEC. Considering the alleviation of the thermal expansion mismatch stress for the high-temperature applications of Nd2Zr2O7, Sc2O3 was an excellent dopant and there existed an optimal Sc2O3 content for the optimization design of compound compositions. Keywords: Pyrochlore, Doping, Phase constitution, Thermal expansion coefficient

This study reports novel kinds of high tensile strength alkaline anion-exchange membranes composed of imidazolium-functionalized anion exchange polymer electrolytes. The membranes were prepared by a combined thermal and chemical cross-linking of poly (vinyl alcohol) and poly (3-methyl-1-vinylimidazolium chloride)-co-(1-vinylpyrrolidone) (PMVIC-co-VP). Characterizations by AC impedance technique, mechanical property, FTIR spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), along with the water uptake, alkaline resistance and oxidation stability were carried out on the membranes consisting of different PVA/PVA-PMVIC-co-VP mass ratios to evaluate their applicability in alkaline fuel cells. The membrane in a mass ratio of 1:0.4 exhibited high tensile stress at break in the range of 59.3∼76.6 MPa, and the elongation at break around 9.2∼14.9%, depending on the annealing temperature from 130∼190 °C. The OH− conductivity of the membranes was found to be increased with increasing annealing temperature and mass ratio, and reached high up to 1.7 × 10−2 S cm−1. Besides, the membranes showed perfect oxidation stability in 30% H2O2 for 250 hours with no obvious weight loss was observed. XPS analysis indicated that some degradation occurred when the membrane was exposed to 8 M KOH at 85 °C for 312 h, but no lessened OH− conductivity was detected. SEM pictures revealed an ordered microvoid structure with pore size ca. 100∼150 nm uniformly dispersed on the membrane surface, which imparted the PVA/PVA-PMVIC-co-VP membrane with good OH− conductivity.

Feather is a kind of waste and hardly to be degraded in the environment. Thermoplastic film was made from feather by mechanical method with enhancing the temperature and pressure to 160°C, 5 MPa, respectively. Glycerol was added as plasticizer in various amounts in mass ratio of 10, 20, 40, 60, and 80%, respectively. During film preparation, influence glycerol content on film’s mechanical property was studied, and 40% was chosen as the best ratio. Film with the best mechanical property was used to adsorb Cr(VI) in aqueous solution. Effects of temperature, adsorbent dosage, initial concentration, and pH on adsorption were studied. The adsorption was endothermic and fitted to both Langmuir and Freundlich models, and the process contained both physical and chemical adsorptions. The biggest removal rate was 99.1%, and the best absorption capacity was 75.45 mg/g at 60°C. After adsorption, there appeared many particles on the surface of the film that can be seen in SEM. FT-IR was used to study the chemi...

Most known allergenic proteins in rice ( Oryza sativa ) seed belong to the Tryp_alpha_amyl family (PF00234), but the sequence characterization and the evolution of the allergenic Tryp_alpha_amyl family members in plants have not been fully investigated. In this study, two specific motifs were found besides the common alpha-amylase inhibitors (AAI) domain from the allergenic Tryp_alpha_amyl family members in rice seeds (trRSAs). To understand the evolution and functional importance of the Tryp_alpha_amy1 family and the specific motifs for the allergenic one, a BLAST search identified 75 homologous proteins of trRSAs (trHAs) from 22 plant species including main crops such as rice, maize ( Zea mays ), wheat ( Triticum aestivum ), and sorghum ( Sorghum bicolor ) from all available sequences in the public databases. Statistical analysis showed that the allergenicity of trHAs is closely associated with these two motifs with high number of cysteine residues (p value = 0.00026), and the trHAs with and without the two motifs were clustered into separate clades, respectively. Furthermore, significant difference was observed on the secondary and tertiary structures of allergenic and nonallergenic trHAs. In addition, expression analysis showed that trHA-encoding genes of purple false brome ( Brachypodium distachyon ), barrel medic ( Medicago truncatula ), rice, and sorghum are dominantly expressed in seeds. This work provides insight into the understanding of the properties of allergens in the Tryp_alpha_amyl family and is helpful for allergy therapy.