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In this paper, we empirically examine how unfair (i.e. negatively assortive) matching between colleges and students affects the medium-run allocative efficiency of the college admissions system, as measured by total wage levels among college graduates. Using data from China College Student Survey, we find that unfair matching tends to increase the total wage level. The implication is that student ability and school quality tend to substitute for, rather than complement each other. We also find evidence that unfair matching leads to higher total human capital investment in English skills, leadership ability, and double majors, but not to higher GPAs. We interpret this finding as an indication that unfair matching, by increasing the inequality of ability within a college, encourages diversified human capital investment instead of monotonic competition. These findings also indicate possible channels of improvement in allocative efficiency.

We define a vertex weighted Bartholdi zeta function of a graph G, and give a determinant expression of it. Furthermore, we define a vertex weighted Bartholdi L-function of a graph. As a corollary, we show that the vertex weighted Bartholdi zeta function of a regular covering of G is a product of vertex weighted Bartholdi L-functions of G.

In this work, we investigate the SU(3) flavor symmetry, heavy quark spin symmetry and their breaking effects in the di-meson systems. We prove the existence of the [ D ‾ s ∗ D s ∗ ] 0 + + , [ D ‾ s ∗ D s / D ‾ s D s ∗ ] 1 + - , and [ D ‾ s ∗ D s ∗ ] 1 + - bound states as the consequence of two prerequisites in the SU(3) flavor symmetry and heavy quark spin symmetry. The first prerequisite, the X ( 3872 ) as the weakly D ‾ ∗ D / D ‾ D ∗ bound state is supported by its mass and decay branching ratios. The second prerequisite, the existence of the [ D ‾ s D s ] 0 + + bound state is supported by the lattice QCD calculation and the observation of χ c 0 ( 3930 ) by the LHCb Collaboration. We hope the future experimental analyses can search for these bound states in the B → D ( s ) ( * ) D ‾ ( s ) ( * ) h processes (h denotes the light hadrons). The [ D ‾ s ∗ D s ∗ ] 0 + + bound state is also expected to be reconstructed in the J / ψ ϕ final state in the B → J / ψ ϕ K decay.

Inflammation is a defense mechanism associated with a wide range of diseases. Celastrol is a small molecule isolated from traditional Chinese medicine with potent anti-inflammation activity. In this study, we established an integrated quantitative proteomics strategy to investigate the acute response to celastrol treatment in a rat macrophage cell line challenged with lipopolysaccharide (LPS). Both stable-isotopic based non-targeted quantitative profiling and PRM-based targeted quantitation methods were employed. Dimethyl-labeling based non-targeted profiling revealed 28 and 52 proteins that significantly up- and down-regulated by celastrol. Bioinformatics analysis pinpoint key signaling pathways affected. Seven proteins were selected for examining their time-dependent regulatory pattern in response to celastrol using targeted PRM quantitation. The abundance of mRNA at multiple time-points of selected proteins was also examined. Celastrol induced an acute response of selected key transcriptional factors in terms of mRNA or protein abundance within one hour. Interestingly, regulatory trend of mRNA and protein abundance suggested a novel dual mechanism of celastrol in the terms of acute anti-inflammation. The integrated quantitative proteomic strategy established in this study constitutes an efficient workflow to characterize key components and their time-dependent regulatory pattern for monitoring drug response.

Aerobic glycolysis, also known as the Warburg effect, is a hallmark of cancer and essential for metabolism in malignancies, but its regulation and modulation in cancer cells remain poorly understood. Here, using large-scale functional screening, we identified a tumor-associated and broadly expressed oncogenic long noncoding RNA LINC00973. Notably, knocking down LINC00973 significantly inhibits the proliferation of multiple types of cancer cells and reduces tumor growth in vivo. Mechanistically, LINC00973 directly binds to lactate dehydrogenase A (LDHA), an essential glycolytic enzyme, and enhances its enzymatic activity, thereby promoting glycolysis. Clinically, high expression of LINC00973 is significantly associated with poor prognosis in many types of human cancers. This work demonstrates that LINC00973 modulates cancer-specific regulation of the Warburg effect, and may represent a potential target for broad-acting anti-cancer therapies.

Hydrolytic dehydrogenation of Ammonia-borane (NH3BH3, abbreviation AB) has attracted much attention due to its high hydrogen content and stability. Therefore, the design and construction of low cost and high performance catalysts for AB hydrolysis are of great significance. In this work, a series of RhCu/CoOx alloy catalysts were prepared by a in-situ reduction method. The catalytic activity of hydrolytic dehydrogenation of AB was optimized by regulating the molar ratio of Rh to Cu in the RhCu/CoOx catalysts. The results verify that Rh1Cu2/CoOx has the best catalytic activity for hydrolytic dehydrogenation of AB, and the corresponding hydrolysis reaction type was first order. The turnover frequency (TOF) reached 670.95 mol H 2 mol cat − 1 min−1, and the apparent activation energy (Ea) was 28.86 kJ mol−1, showing excellent catalytic performance for hydrolytic dehydrogenation of AB.

Heterogeneity significantly effects the accuracy of flow and contaminant transport prediction in subsurface formations. The spatial correlation structure of hydraulic conductivity (K) is a crucial factor to characterize the heterogeneous architecture. In presented study, the relationship between the spatial correlation structure of K and plume dispersion is analyzed through the integration of experimental and numerical simulation approaches. A detailed description on the sedimentary facies types in a column experiment is obtained to ensure the accuracy of the heterogeneous characterization. The spatial correlation structure of K is analyzed with the components of ln(K) covariance and facies transition probability structures. Lagrangian-based models are developed to estimate solute dispersion in nonreactive tracer injection experiments. The results show that the model can predict plume spreading accurately when the spatial correlation structure is well defined. The dispersivities calculated by the Lagrangian-based model are slightly higher than those obtained from the solute transport experiments. Further, the upscaled dispersivity derived from the transition probability is dominated by the cross-transition probability structure, while the contribution of the auto-transition terms is quite small. The numerical modeling results confirm that the upscaled dispersivity can reproduce the solute breakthrough in the heterogeneous sediment well. The scale dependence of dispersion is strengthened when the flow direction is perpendicular to the bedding plane where the conductivity dramatically changes along the flow path in a layered bedding sediment.

Resonance interaction between a molecular transition and a confined electromagnetic field can lead to weak or strong light-matter coupling. Considering the substantial exciton–phonon coupling in thermally activated delayed fluorescence (TADF) materials, it is thus interesting to explore whether weak light-matter coupling can be used to redistribute optical density of states and to change the rate of radiative decay. Here, we demonstrate that the emission distribution of TADF emitters can be reshaped and narrowed in a top-emitting organic light-emitting device (OLED) with a weakly coupled microcavity. The Purcell effect of weak microcavity is found to be different for TADF emitters with different molecular orientations. We demonstrate that radiative rates of the TADF emitters with vertical orientation can be substantial increased in weakly coupled organic microcavity. These observations can enhance external quantum efficiencies, reduce efficiency roll-off, and improve color-purities of TADF OLEDs, especially for emitters without highly horizontal orientation., This work not only presents photophysical processes of thermally activated delayed fluorescent emitters in a weak Fabry-Pérot cavity, but also establishes a connection between emitter orientation and Purcell effect.

Pyrrolizidine alkaloids (PAs) and PA N-oxides are common phytotoxins produced by over 6000 plant species. Humans are frequently exposed to PAs via ingestion of PA-containing herbal products or PA-contaminated foods. PAs require metabolic activation to form pyrrole-protein adducts and pyrrole-DNA adducts which lead to cytotoxicity and genotoxicity. Individual PAs differ in their metabolic activation patterns, which may cause significant difference in toxic potency of different PAs. This review discusses the current knowledge and recent advances of metabolic pathways of different PAs, especially the metabolic activation and metabolism-mediated cytotoxicity and genotoxicity, and the risk evaluation methods of PA exposure. In addition, this review provides perspectives of precision toxicity assessment strategies and biomarker development for the risk control and translational investigations of human intoxication by PAs.

Conversion from CO2 to C2H4 is important for the development of energy and the environment, but the high energy barrier of hydrogenation of the *CO intermediate and C-C coupling step tend to result in C1 compounds as the main product and thus restrict the generation of C2H4. Here, we report a metal-organic framework (denoted as PcCu-Cu-O), composed of 2,3,9,10,16,17,23,24-octahydroxyphthalo-cyaninato)copper(II) (PcCu-(OH)8) ligands and the square-planar CuO4 nodes, as the electrocatalyst for CO2 to C2H4. Compared with the discrete molecular copper-phthalocyanine (Faradaic efficiency (FE) of C2H4 = 25%), PcCu-Cu-O exhibits much higher performance for electrocatalytic reduction of CO2 to C2H4 with a FE of 50(1)% and a current density of 7.3 mA cm-2 at the potential of -1.2 V vs RHE in 0.1 M KHCO3 solution, representing the best performance reported to date. In-situ infrared spectroscopy and control experiments suggested that the enhanced electrochemical performance may be ascribed to the synergistic effect between the CuPc unit and the CuO4 unit, namely the CO on the CO-producing site (CuO4 site) can efficiently migrate and dimerize with the *CO intermediate adsorbed on the C2H4-producing site (CuPc), giving a lower C-C dimerization energy barrier.

Antibiotic resistance genes (ARGs) as emergence contaminations have spread widely in the water environment. Wild fish may be recipients and communicators of ARGs in the water environment, however, the distribution and transmission of ARGs in the wild fish and relevant water environment were rarely reported. Here, we have profiled ARGs and bacterial communities in wild freshwater fish and relevant water in a peri-urban river using high-throughput qPCR and 16S rRNA gene sequence. A total of 80 and 220 unique ARG subtypes were identified in fish and water samples. Fish and water both showed significant ARG seasonal variations (P0.05). The highest absolute abundance of ARGs in fish and water occurred in summer (1.32 × 10

To determine the trace amount of four benzoic acid esters in cosmetics, ionic dispersive liquid–liquid microextraction (DLLME) and magnetic solid-phase extraction were combined and optimized. After solvent optimization, 1-octyl-3-methylimidazolium hexafluorophosphate was selected as the extraction solvent to form hydrophobic droplets in the process of ionic DLLME, followed by removal of ions from the sample solution containing Fe3O4@GO nano-materials. The magnetic nano-materials were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. Some parameters affecting the efficiency of extraction were optimized using Box-Behnken design. Under optimized conditions, the limit of detection for all the preservatives was less than 0.135 mg/L and the accuracy ranged from 88.5% to 101%. This technology could determine the trace amount of preservatives in cosmetics with comparatively higher accuracy and sensitivity.

This paper concerned the thermal conversion characteristics, kinetics, thermodynamics, and incineration operation parameters and gas emissions of petrochemical wastewater (PW) and its sludge (PWS). The combustion properties of PWS were evaluated via thermogravimetric analysis, and the results showed that the combustion process of PWS had four stages, and the combustion pathway was typical “thermal degradation with char formation + char combustion”. With heating rates increasing, thermal curves shifted toward lower temperatures, and the ignition, burnout, and comprehensive combustibility improved significantly. The kinetic parameters were determined by Coats–Redfern approach, and the results confirmed the existence of kinetic compensation effect. The thermodynamic parameters (ΔH, ΔG, ΔS) from PWS combustion at maximum degradation rate temperatures were estimated by the activated complex theory. To make the research practical, operation parameters and gas emissions from a petrochemical wastewater incinerator were tested. The results showed that, except HCl, and CO at 4.50 t h–1 PW injection, the gas pollutants in the flue gas after the PW incineration did not exceed the discharge limits in China. The parameters of combustion efficiency of the incineration plant at different PW injections were very high, and met the requirement in GB 18484-2001.

Prostate-specific membrane antigen (PSMA)-targeted radioligands have played an increasing role in the diagnosis of prostate cancer. [68Ga]Ga-P16-093 is a PSMA-targeting agent for positron emission tomography imaging, currently under a Phase 2 clinical trial. In the present study, P16-093 was labeled with 18F via [18F]AlF2+ complex formation, and the biological properties of [18F]AlF-P16-093 were evaluated. Optimization of radiolabeling efficiency was performed by testing a series of parameters, including the amount of free ligand; the amount of Al3+; and the influence of solvent, pH, temperature, reaction time, and reaction volume. Optimal labeling results were achieved at pH 5 by reacting at 60 °C for 15 min in a vial containing 74-370 MBq of [18F]fluoride, 46 nmol of P16-093, 40 nmol of AlCl3·6 H2O, and 50% EtOH. [18F]AlF-P16-093 was prepared with a non-decay-corrected radiochemical yield of 54.4 ± 4.4% (n = 9) within 30 min (final radiochemical purity ≥95%). In vitro, [18F]AlF-P16-093 showed PSMA-specific high uptakes in PIP-PC3 cells. The binding affinity of [18F]AlF-P16-093 to PSMA was determined as Kd of 12.4 ± 2.0 nM. The tumor uptake in mice with a xenografted PSMA-expressing PIP-PC3 tumor was high (18.8 ± 5.14% ID/g at 1 h postinjection) and retained without washout for 2 h. In addition, tumor uptake was almost completely blocked by coinjecting a PSMA inhibitor, 2-PMPA. The bone activity at 1 h post injection was higher with [18F]AlF-P16-093 (2.83 ± 0.49% ID/g) in comparison to that of [68Ga]Ga-P16-093 (0.26 ± 0.07% ID/g). In summary, an efficient and simple radiosynthesis of [18F]AlF-P16-093 was achieved. [18F]AlF-P16-093 showed desirable in vivo pharmacokinetics and excellent PSMA-targeting properties for imaging PSMA expression in prostate cancer.

Electrochemical CO2 reduction into high-value-added carbon-based fuels is a promising strategy to achieve the global carbon balance. Developing cost and effective electrocatalysts for conversion CO2 to CO is critical to the application. Herein, we have successfully prepared highly dispersed cobalt (II) phthalocyanine (CoPc) on N-doped carbon nanoparticles (N-C-CoPc) with a simple synthetic route. Both characterization and electrochemical analysis demonstrated that the cobalt (II) atoms derived from the phthalocyanine are well dispersed with a single atomically state. As a result, the prepared N-C-CoPc catalyst exhibits an outstanding catalytic CO2 to CO with ultralow overpotential of 170 mV, Faradaic efficiency of CO (FECO) achieving about 90% in the region of −0.58 V to −0.78 V vs RHE, and an exceptional turnover frequency with 3.89 s−1. This work provides a promising approach for preparing N-C carrier under mild conditions.

Amyloid β peptide (Aβ) plays a crucial role in the pathogenesis of Alzheimer's disease (AD). Currently, decreasing Aβ production and preventing Aβ aggregation are thought to be important strategies in anti-AD therapy. However, inhibiting Aβ production or aggregation in isolation is not sufficient to reverse the neurodegenerative process of AD patients in clinical testing. Here, a self-assembly molecular chaperone (SAMC) consisting of γ-secretase inhibitor DAPT and mixed-shell polymeric micelles is devised, serving as a bifunctional suppressor of AD. This two-in-one combinational system can simultaneously inhibit Aβ production and aggregation, which would contribute to enhancing the therapeutic effect by decreasing Aβ levels. Decorating a neuron-specific RVG29 peptide onto the surface, the DAPT-incorporated SAMC can specifically target neuronal cells and, thus, will relieve the strong side effect of DAPT on normal cells. Therefore, this combination strategy holds great potential to open up an avenue for AD treatment.

A general and metal-free visible-light-induced decarboxylative arylation procedure at room temperature was described for the construction of acylated heterocyclic derivatives, such as benzimidazo/indolo[2,1-a]isoquinolin-6(5H)-ones, aroylazaspiro[4.5]trienones, thioflavones, and so on. This practical arylation procedure was conducted by using 2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN) as a photocatalyst under mild conditions, which avoided the use of an additional base, traditional heating, and metal reagents.

Ceramic capacitors require promising energy storage properties to meet the demands of electronic industry which can be tailored by ferroelectric polarization and electrical breakdown strength. Electrical breakdown exhibits close relation to leakage current in advanced dielectric materials when stimulated by high levels of electric field. The suppression of leakage can be an effective strategy to elevate dielectric breakdown. In this work, Zr ions were employed to replace Ti ions in Ba0.3Sr0.7TiO3 ceramics to achieve the improvement of dielectric breakdown and then increase energy storage ability. Zr doping can obviously reduce the leakage current more than an order of magnitude by blocking the path between two adjacent Ti ions and increasing the distance of electron hopping. A promising energy storage density can be obtained with good fatigue endurance upto cycles of 105. This indicates that the strategy of suppressing leakage by trace amount of Zr doping is an effective approach to tailor energy storage behavior of dielectric ceramics.

Abuse of antibiotics in aquaculture have been alarming and might aggravate spread of resistance genes in the environment. Holistic ARGs proliferation checks require deeper analyses of coupled absolute abundances in 16S rRNA bacteria communities at the phylum level to detect biomarkers. Sulfanilamide (sul) and copper II sulfate (CuSO4 II) were, therefore, designed and added as separate or combined treatments in 9 replicate engineered goldfish tanks comprising 3 individual sul, 3 CuSO4 II, 3 (sul + CuSO4 II) combinations, and 3 controls within 180 days. The DNA from water and fish guts was sequenced under qPCR to determine 16S rRNA bacteria biomarkers co-occurring with the correspondent ARGs. Combined chemical addition at 0.8–1.5 mg sul + 0.5–1.0 mg CuSO4 II/3 L of tank waters reduced sequenced 16S rRNA bacteria absolute abundances in fish gut and water samples while portraying the biomarkers. Absolute abundances of the entire 16S rRNA bacteria was higher in fish guts (3.4 × 1014–4.9 × 108 copies/g) than water samples (1.5 × 109–2.6 × 1015 copies/L), respectively. Much as sul 1(log) were dominant over intl 1(log) genes, and their fundamental profiles were also higher in the fish guts than water samples; the Spearman’s correlation analyses revealed positive relationship (p Proteobacteria (10–50:15–65%) > Planktomycetes (10–52:8–25%) featured prominently based on LEfSe use as the hot-spotted biomarkers, hence justifying its higher prospects towards innovative environmental microbiological and biotechnological studies.

The present work deals with the microstructure evolution during creep of P91 steel. In particular, the changes of prior austenite grain (PAG) and low-angle grain boundary (LAGB) during creep were s...

The pristine transition metals (TMs) offer limited choices for high-performance heterogeneous catalysts because they are usually restricted in less optimal regions on the reactivity volcano map. Us...

Joining of SiC ceramics was successfully achieved at a relatively low temperature of 1500 °C without any pressure using pure polycarbosilane (PCS) as the joining material, which was distributed homogenously on the surface of SiC monolith through a screen printing method. The XRD pattern shows that the pyrolysis product of PCS is single-phase SiC. The interlayer thickness of the SiC joint is approximately 2 μm. This ultra-thin interlayer with lower possibility of the existence of defects contributes to the average shear strength of 105.8 ± 10.4 MPa, higher than that of other works using other preceramic polymers to the best of our knowledge. Due to the simplicity, low cost and high joining strength, the screen printing method using PCS as the joining material has good practicality in SiC ceramics joining.

Hyperspectral remote sensing can get spatially and spectrally continuous data simultaneously. However, the imaging equipment is usually expensive and complex, along with the low spatial resolution. In recent years, reconstruction of hyperspectral image by deep learning from the widely used low-cost, high spatial resolution RGB camera, has attracted extensive attention in many fields. However, most research is limited to three bands in the range of 400–700 nm, which greatly restrains its application in remote sensing. In this study, a more suitable for remote sensing multispectral to hyperspectral network (M2H-Net) is proposed, which can take many bands as input and output hyperspectral images with any number of bands within a wider spectral range (380–2500 nm). Its characteristics include adding residual connection on U-Net to reduce vanishing gradients; adding convolution combinations with different kernel sizes (1 × 1 and 3 × 3) to balance the spectral and spatial relationships. It is applied on images from different platforms (UAVs and Satellites), different imaging modes (frame and pushbroom) and different spectral response functions (narrow and wide bandwidth), and the results show that: 1) it has a very high accuracy of hyperspectral image reconstruction. The mean relative absolute error (MRAE) and root mean squared error (RMSE) are between 0.039 and 0.074 and 0.010–0.016, respectively, which are 69.2% and 41.2% lower than those of U-Net; 2) it has high efficiency with fast convergence (about 40 epochs) and stable performance. Compared with many algorithms won in the new trends in image restoration and enhancement (NTIRE) competition, M2H-Net ranked 7th in accuracy, but took less time (0.44 s); 3) it has strong generalization ability. Using the pre-trained M2H-Nets to reconstruct Cubert S185 and GF-5 hyperspectral images in different locations, different times and complex scenes, high accuracy (MRAE = 0.072, RMSE = 0.011) can still be obtained. This method is more suitable for remote sensing to meet the needs of multiple bands, spectrum width and complex scenes, thus provides the possibility to generate the global coverage hyperspectral imagery by using the massive in-orbit or historical archived multispectral images, which will not only greatly save the R&D and investment on hyperspectral imaging equipment, but also conduct data collection with higher efficiency and lower complexity. Due to the ability to reconstruct hyperspectral images in specified bands on demand, M2H-Net is also of great value in hyperspectral image processing, such as data compression, storage and transmission, etc.

Background Short Tandem repeats (STRs) existed as popular elements in both eukaryotic and prokaryotic genomes. Results In this study, we analyzed the characteristics, distributions, and motif features of STRs within whole-genomes of 140 plant species. The results showed that STR density was negatively correlated with the genome size. Hexanucleotide repeat was the most abundant type of STRs. The distribution of algae shows a preference different from that of other plants. By analyzing GC contents of STRs and genome, it was concluded that STR motif was influenced by GC contents. Analysis of the long STRs in genome (length ≥ 1000 bp) found that dicots have the more long STRs. For STR types, di- and tri-nucleotide accounted for the highest proportion. Analyzing and designing long STRs in CDS (length ≥ 500 bp) was to verify the role of long STRs in Gossypium hirsutum TM-1 and Solanum tuberosum. By comparing the long STRs found in Fragaria x ananassa with other species, some evolutionary characteristics of the long STRs were obtained. Conclusions We got the characteristics, distribution, and motif features of STRs in the whole genome of 140 plants and obtained some evolutionary characteristics of long STRs. The study provides useful insights into STR preference, characteristics, and distribution in plants. How to cite: Zhu L, Wu H, Li H, et al., Short Tandem Repeats in plants: genomic distribution and function prediction. Electron J Biotechnol 2021;50. https://doi.org/10.1016/j.ejbt.2020.12.003

Triclosan (TCS) is a ubiquitous antimicrobial used in many daily consumer products. It has been reported to induce endocrine disrupting effects at low doses in mammals, disturbing sex hormone function and thyroid function. The hypothalamus plays a crucial role in the maintenance of neuroendocrine function and energy homeostasis. We speculated that the adverse effects of TCS might be related to the disturbance of metabolic processes in hypothalamus. The present study aimed at investigating the effects of TCS exposure on the protein and metabolite profiles in hypothalamus of mice. Male C57BL/6 mice were orally exposed to TCS at the dosage of 10 mg/kg/d for 13 weeks. The hypothalamus was isolated and processed for mass spectrometry (MS)-based proteomics and metabolomics analyses. The results showed that a 10.6% decrease (P = 0.066) in body weight gain was observed in the TCS exposure group compared with vehicle control group. Differential analysis defined 52 proteins and 57 metabolites that delineated TCS exposed mice from vehicle controls. Among the differential features, multiple proteins and metabolites were found to play vital roles in neuronal signaling and function. Bioinformatics analysis revealed that these differentially expressed proteins and metabolites were involved in four major biological processes, including glucose metabolism, purine metabolism, neurotransmitter release, and neural plasticity, suggesting the disturbance of homeostasis in energy metabolism, mitochondria function, neurotransmitter system, and neuronal function. Our results may provide insights into the neurotoxicity of TCS and extend our understanding of the biological effects induced by TCS exposure.

The majority of tissue-specific environmental quality standards (EQSs) considering metal tolerance are prior to the chemical-specific EQSs in aquatic organisms. However, metal baseline levels in marine organisms were very scarce. We explored the correlation between Hg, Cd, Pb, Cu, and Zn concentrations in water or sediments and those metal concentrations in marine organisms (crustacean, mollusc, and fish) by generalized additive models (GAMs) and executed a meta-analysis of Hg, Cd, Pb, Cu, and Zn contents in those three organisms by implementing cumulative frequency distribution analysis of individual metal distribution in a heavy metal-contaminated semi-enclosed Bay, China. Results showed that the average contents of Hg, Cd, Pb, Cu, and Zn were 0.042±0.01, 0.38±0.22, 1.72±0.65, 3.61±1.01, and 16.08±6.33 μg/L in water; 0.064±0.02, 0.42±0.04, 20.54±7.76, 28.97±3.90, and 96.74±35.11 μg/g dw in sediment; and 0.0049±0.0028, 0.52±0.28, 0.24±0.15, 11.05±6.95, and 21.12±4.47 μg/g dw in crustacean, 0.015±0.0087, 0.24±0.17, 0.08±0.02, 0.37±0.35, and 10.62±6.79 μg/g dw in mollusc; and 0.0038±0.0028, 0.065±0.05, 0.32±0.19, 2.01±0.59, and 16.04±4.97 μg/g dw in fish. The mercury content in mollusc presented a negative correlation with mercury content in sediment, while the content of other metals (Cd, Pb, Cu, and Zn) in organisms showed positive correlations with the content of those metals in water or sediment. We further obtained tissue-baseline-C5% in crustacean, mollusc, and fish which were 1.191, 3.341, and 0.014 μg/g dw for Cu; 0.013, 0.072, and 0.033 μg/g dw for Cd, 0.015, 0.027, and 0.052 μg/g dw for Pb; 9.515, 14.422, and 0.056 μg/g dw for Zn; and 0.0009, 0.004, and 0.0035 μg/g dw for Hg, respectively. However, there were no obvious relationships of the 4d-NOEC in laboratory toxicity tests with C5%, as well as C50% and 4d-LC50 or tolerance index a for Cu, Cd, Pb, Zn, and Hg in organisms. Our results pointed out the controversy of laboratory sensitive species toxicity results for deriving chemical-specific EQSs with field studies. We advocated to set up the metal concentration baselines in aquatic organisms and further served the tissue-specific EQSs, which are essential basis for geochemical recordings, bio-monitoring, and semi-enclosed bay management in the world.

This paper presents a hybrid metaheuristic optimizer called CHDJ to identify accurate and reliable values for the model parameters of solid oxide fuel cells (SOFC). CHDJ is a hybridizer of differential evolution (DE) and Jaya algorithm. The core of CHDJ lies in a developed competitive hybrid operation. In this operation, three vectors including the DE mutant vector, the Jaya mutant vector, and the crossover vector that constituted by the foregoing two mutant vectors form a tri-competitive mechanism together. This mechanism can contribute to exploring the global space extensively and exploiting the local region meticulously to generate promising candidate solutions. To verify the performance of CHDJ, two SOFC models including a cylindrical cell and a tubular stack operating at different pressures and temperatures are employed. Experimental results demonstrate that these three vectors interact and cooperate organically. They make CHDJ take full advantages of the exploration of DE and the exploitation of Jaya effectively. The optimal values of the mean square error (MSE) between the measured voltage and the calculated voltage obtained by CHDJ on the cylindrical cell at 1073K, 1173K, 1213K, and 1273K are 2.9215E-06, 1.4610E-06, 1.9093E-06, and 2.4682E-06, respectively. On the tubular stack, for the operating conditions of 3atm constant pressure at 873K, 923K, 973K, 1023K, and 1073K, the optimal MSE values are 2.7489E-05, 1.6169E-04, 6.9207E-04, 1.4833E-03, and 1.5876E-03, respectively. For the operating conditions of 1073K constant temperature under 1atm, 2atm, 3atm, 4atm, and 5atm, the results are 1.5293E-03, 1.6289E-03, 1.5876E-03, 1.5868E-03, and 1.5870E-03, respectively. Comparisons with other algorithms show that CHDJ achieves better overall performance. It can skip local optima and find optimal solutions, and thus can serve as a hopeful candidate method for parameter identification of SOFC models.

Due to its high strength, high density, high hardness and good penetration capabilities, Depleted uranium alloys have already shined in armor-piercing projectiles. There should also be a lot of room for improvement in the application of fragment killing elements. Therefore, regarding the performance of the depleted uranium alloy to penetrate the target plate, further investigation is needed to analyze its advantages and disadvantages compared to tungsten alloy. To study the difference in penetration performance between depleted uranium alloy and tungsten alloy fragments, firstly, a theoretical analysis of the adiabatic shear sensitivity of DU and tungsten alloys was given from the perspective of material constitutive model. Then, taking the cylindrical fragment penetration target as the research object, the penetration process and velocity characteristics of the steel target plates penetrated by DU alloy fragment and tungsten alloy fragment were compared and analyzed, by using finite element software ANSYS/LS-DYNA and Lagrange algorithm. Lastly, the influence of different postures when impacting target and different fragment shapes on the penetration results is carried out in the research. The results show that in the penetration process of the DU and tungsten alloy fragments, the self-sharpening properties of the DU alloy can make the fragment head sharper and the penetrating ability enhance. Under the same conditions, the penetration capability of cylindrical fragment impacting target in vertical posture is better than that in horizontal posture, and the penetration capability of the spherical fragment is slightly better than that of cylindrical fragment.

Infectious diseases caused by pathogenic microorganisms such as viruses and bacteria pose a great threat to human health. Although a significant progress has been obtained in the diagnosis and prevention of infectious diseases, it still remains challenging to develop rapid and cost-effective detection approaches and overcome the side effects of therapeutic agents and pathogen resistance. Functional nucleic acids (FNAs), especially the most widely used aptamers and DNAzymes, hold the advantages of high stability and flexible design, which make them ideal molecular recognition tools for bacteria and viruses, as well as potential therapeutic drugs for infectious diseases. This review summarizes important advances in the selection and detection of bacterial- and virus-associated FNAs, along with their potential prevention ability of infectious disease in recent years. Finally, the challenges and future development directions are concluded.

Gd and Si co-doped HfO2 gate dielectric thin films were prepared by atomic layer deposition (ALD), while Gd[N(SiMe3)2]3, Hf[NEtMe]4, and H2O are chosen to be precursors. The Gd and Si were successfully co-doped into HfO2 films using only one doping precursor Gd[N(SiMe3)2]3. The doping concentration can be facilely tuned by controlling ALD recipe. The atomic percentages of Si/(Si + Gd + Hf) and Gd/(Si + Gd + Hf) increase from 11.5 to 28.9% and from 6.8 to 28.4% when changing the ALD cycle ratio of GdxSiyO to HfO2 from 1:9 to 1:1. The band gap and band alignment were investigated by X-ray photoelectron spectroscopy. The results imply that the band gap of Gd/Si co-doped HfO2 films has a positive relation with doping concentration. Moreover, the valence band offset decreases with doping concentration first but then increases, while the change of conduction band offset is opposite. The (1:6)-HfxGdySizO films with 11.6 at.% Gd/(Gd + Hf) exhibit the maximum accumulation capacitance and dielectric constant, which are only slightly smaller than those of the HfO2 films. Compared to HfO2 films, the leakage current density of (1:6)-HfxGdySizO films is decreased by at least one order of magnitude. Therefore, Gd and Si co-doping can improve the electrical properties of HfO2 films.

Spaceborne synthetic aperture radar (SAR) is considered one of the most powerful sensors for tropical cyclone assessment. In this study, 14 tropical cyclone (TC) events captured by the Sentinel-1A/...

Solar-driven water evaporation is an effective approach for using solar energy to purify seawater and wastewater. However, the high energy requirements of bulk water evaporation fundamentally restrict the practicality of solar freshwater production. Herein, we demonstrate an efficient hierarchical solar evaporator by combining polydopamine (PDA) and Ti3C2Tx MXene (MX) with a cellulose network skeleton of delignified wood (DW). By integrating activated water in a hydrated cellulose network and the synergistic photothermal effect between PDA and MX, the obtained PDMX@DW evaporator achieved a high evaporation rate of 2.08 kg m−2 h−1 and energy efficiency of 93.6% under 1 sun illumination. Differential scanning calorimetry and dark evaporation experiments indicated that the water in PDMX@DW exhibited a lower vaporization enthalpy (1915 J g−1) than bulk water (2440 J g−1). Raman spectral analysis and density functional theory calculations were used to investigate the structure of water molecules in the cellulose network, and it turns out that high contents of weakly hydrogen-bonded intermediate water were the most likely origin of the reduced vaporization enthalpy. More importantly, due to the interactive cellulose network structure and increased water supply rate, PDMX@DW exhibited excellent salt resistance and long-term stability in high-concentration brine. This work provides an effective method for breaking the evaporation limitation of the traditional wood-based evaporator and improving its salt resistance.

Dense pressure-sintered reaction-bonded Si3N4 (PSRBSN) ceramics were obtained by a hot-press sintering method. Precursor Si powders were prepared with Eu2O3–MgO–Y2O3 sintering additive. The addition of Eu2O3–MgO–Y2O3 was shown to promote full nitridation of the Si powder. The nitrided Si3N4 particles had an equiaxial morphology, without whisker formation, after the Si powders doped with Eu2O3–MgO–Y2O3 were nitrided at 1400 °C for 2 h. After hot pressing, the relative density, Vickers hardness, flexural strength, and fracture toughness of the PSRBSN ceramics, with 5 wt% Eu2O3 doping, were 98.3 ± 0.2%, 17.8 ± 0.8 GPa, 697.0 ± 67.0 MPa, and 7.3 ± 0.3 MPa m1/2, respectively. The thermal conductivity was 73.6 ± 0.2 W m−1 K−1, significantly higher than the counterpart without Eu2O3 doping, or with ZrO2 doping by conventional methods.

The ultraviolet to terahertz band forms the main focus of optoelectronics research, while light detection in different bands generally requires the use of different materials and processing methods. However, researchers are aiming to realize multi-band detection simultaneously in the same device in certain specific application scenarios and ultra-wideband photoelectric detectors can also realize multi-function and multi-system integration. Therefore, the research and development work on ultra-wideband photoelectric detectors has important practical application value. Here, we produced self-powered suspended Pd-reduced graphene oxide-Ti (Pd-rGO-Ti) photodetectors. We varied the properties of the rGO films by using different annealing temperatures and achieved p-doping and n-doping of the films by evaporating palladium films and titanium films, respectively, thus enabling preparation of photothermoelectric (PTE) photodetectors based on rGO films. The resulting detectors have excellent photoelectric responses over a wideband illumination wavelength range from 375 nm to 118.8 μm (2.52 THz). At the same time, we determined the best experimental conditions and device structure by varying the channel width, the laser spot irradiation position and the experimental atmospheric pressure. The maximum responsivity obtained from our detectors is 142.08 mV W−1, the response time is approximately 100–200 ms and the devices have high detection sensitivity. Based on this work, we assumed in the subsequent experiments that detectors with higher performance can be obtained by reducing the channel width and atmospheric pressure. With advantages that include simple fabrication, low cost, large-scale production potential and ultra-wideband responses, these Pd-rGO-Ti photodetectors have broad application prospects in high-performance integrated optoelectronics.

The joining of liquid-phase sintered SiC (LPS-SiC) ceramics was conducted using spark plasma sintering (SPS), through solid state diffusion bonding, with Ti-metal foil as a joining interlayer. Samples were joined at 1400 °C, under applied pressures of either 10 or 30 MPa, and with different atmospheres (argon, Ar, vs. vacuum). It was demonstrated that the shear strength of the joints increased with an increase in the applied joining pressure. The joining atmosphere also affected on both the microstructure and shear strength of the SiC joints. The composition and microstructure of the interlayer were examined to understand the mechanism. As a result, a SiC-SiC joining with a good mechanical performance could be achieved under an Ar environment, which in turn could provide a cost-effective approach and greatly widen the applications of SiC ceramic components with complex shape.

Sodium-ion batteries (SIBs) have been attracting great attention as the most promising alternative to lithium-ion batteries (LIBs) for large-scale energy storage. However, the absence of suitable anode materials is the main bottleneck for the commercial application of SIBs. Herein, the adsorption and diffusion behaviors of Na on graphether are predicted by first-principles density functional calculations. Our results show that Na atoms can be adsorbed on graphether forming a uniform and stable coverage on both sides. Even at low intercalated Na concentrations, the semiconducting graphether can be changed to a metallic state, ensuring good electrical conductivity. Due to the structural anisotropy of graphether, the Na+ ions show a remarkable one-dimensional diffusion with an ultralow energy barrier of 0.04 eV, suggesting ultrafast charge/discharge characteristics. The graphether monolayer has a high theoretical specific capacity of 670 mA h g-1, which is much higher than commercial graphite anode materials. Furthermore, the average voltage is 1.58 V, comparable with that of commercial TiO2 anode materials for LIBs (1.5 V). During the charge/discharge process, graphether could mostly preserve the structural integrity upon the adsorption of Na even at the maximum concentration, suggesting its good reversibility. All these results show that graphether is a promising anode material for high-performance SIBs.

The influence of TiO2 amount on the microstructure and relevant properties of SiO2-Al2O3-B2O3-Na2O-Li2O-BaO vitrified bond and vitrified bond CBN composites were systematically studied via SEM, EDS, FTIR, and XPS. Results indicated that adding TiO2 could regulate the quantity of β-quartz solid solution and rutile crystals in the vitrified bond and considerably affect the thermal properties and mechanical strength of this bond. Under sintering temperature, the dense B2O3 oxide layer on the CBN surface diffused into vitrified bond and reacted with Ti4+ enriched at the interface to form a strong chemical Ti-B bond. This reaction extensively improved the interfacial wettability between the CBN and the vitrified bond. When the TiO2 amount was 6wt.%, the interfacial wettability significantly improved, and the wetting angle decreased from 68° to 43°. The flexure strength and hardness of the composites were 116.18 MPa and 128 HRB, which were 48.49% and 34.74% higher than those of the basic-formula composites, respectively.

Two mononuclear Dy(III) compounds and one heteronuclear Dy(III)–K(I) compound, [Dy(tmpd)3(4,4′-dmpy)] (1), [KDy2(tmpd)8]·C5H6N (2) and [Dy(tmpd)3(dppz)] (3) (4,4′-dmpy = 4,4′-dimethyl-2,2′-bipyridyl, tmpd = 4,4,4-trifluoro-1-(4-methylphenyl)butane-1,3-dione, and dppz = dipyrido[3,2-a:2′,3′-c]phenazine), were synthesized by changing the organic bases and auxiliary ligands. The coordination environments of compounds 1 and 3 are different DyN2O6 configurations resulting from steric effects of different auxiliary ligands, while 2 has KF6O6 and DyO8 coordination environments because of the introduction of an organic base (CH3OK). The Dy(III) ions in compounds 1 and 2 have a triangular dodecahedral (D2d) configuration and square antiprismatic (D4d) configuration, respectively. Compound 3 contains two crystallographically equivalent Dy(III) ions of which the eight-coordinated geometries uniformly behave as distorted square antiprismatic (D4d) configurations. Compound 2 affords a novel Dy(III)–K(I) compound with unusually coordinated fluorine atoms of trifluoromethyl groups of β-diketone ligands. 2 is a centrosymmetric structure in which the central K(I) ion is located at the middle of two Dy(III) ions, resulting in an icosahedral (Ih) configuration. Magnetic investigations demonstrate that 1 and 3 display slow magnetic relaxation behaviors. The effective barriers are 94.91 K in 1 and 82.44 K in 3. The M versus H data exhibit weak butterfly-shaped hysteresis loops at 2 K for 1 and 3. The uniaxial magnetic anisotropies, magnetostructural correlations and relaxation mechanism were investigated both experimentally and theoretically. The experimental and theoretical studies indicate that compound 1 exhibits the best magnetic properties among compounds 1–3. The theoretical predictions of quantum tunneling of magnetization time and effective barriers are consistent with the corresponding experimental values. Our results indicate that the different organic bases and substituted groups of auxiliary ligands play an important role in synthetic processes, finally affording distinct structures and magnetic properties.

Foreground detection is one of the key steps in computer vision applications. Many foreground and background models have been proposed and achieved promising performance in static scenes. However, due to challenges such as dynamic background, irregular movement, and noise, most algorithms degrade sharply in complex scenes. To address the problem, we propose a motion-aware structured matrix factorization approach (MSMF), which integrates the structural and spatiotemporal motion information into a unified sparse-low-rank matrix factorization framework. Technologically, it has three main contributions: First, a variant of structured sparsity-inducing norm is proposed to constrain both structure and sparsity of foreground. The model is robust to the statistical variability of the underlying foreground pixels in complex scenes. Second, to capture the ambiguous pixels, a spatiotemporal cube-based motion trajectory is extracted for assisting matrix factorization. Finally, to solve the optimization problem of structured matrix factorization, we develop an augmented Lagrange multiplier method with the alternating direction strategy and Douglas-Rachford monotone operator splitting algorithm. Experiments demonstrate that the proposed approach achieves impressive performance in separating irregular moving foreground while suppressing the dynamic background and the noise, and outperforms some state-of-the-art algorithms.

Nanocomposite metal oxides have been attracted great attention in the electrode material of supercapacitor. Herein, a novel Ag/Ni hetero-metallic complex with the hamburger-like structure was prepared, which was then calcined to form Ag/NiO nanocomposite via in-situ preparation. The in-situ formed Ag/NiO exhibits a very high capacitance of 1480 F g −1 at a current density of 0.6 A g−1 in 1 M KOH solution, and the cycling stability was retained about 85% after 3000 cycles with the current of 5 A g−1. The results showed that the in-situ formed Ag/NiO derived from hetero-metallic MOF possess high specific capacitance, which could provide a new effective strategy to improve the conductivity of metal oxides nanocomposite.

Efficient and stable deep-blue emission from perovskite light-emitting diodes (LEDs) is required for their application in lighting and displays. However, this is difficult to achieve due to the phase segregation issue of mixed halide perovskites and the challenge of synthesizing high-quality single-halide deep-blue perovskite nanocrystals through a traditional method. Here, we show that an antisolvent treatment can facilitate the in situ formation of perovskite nanocrystals using a facile spin-coating method. We find that the dropping time of the antisolvent can significantly affect the constitution of nanocrystal perovskite films. With a delay in the start time of the antisolvent treatment, small single-halide perovskite nanocrystals can be achieved, exhibiting efficient deep-blue emission. The LED device shows a stable electroluminescence (EL) peak at 465 nm, with a peak external quantum efficiency and a peak current efficiency of 2.4% and 2.5 cd A-1, respectively. This work provides a facile approach to changing the size of perovskite nanocrystals, thus effectively tuning their EL emission spectra.

Pyrrolizidine alkaloids (PAs) are naturally occurring hepatotoxins widely present in hundreds of plant species and also known to contaminate many foodstuffs, such as grain, honey, and tea. The formation of pyrrole–protein adducts via metabolic activation of PAs has been suggested as a primary trigger initiating hepatotoxicity. The present study for the first time tested the suitability of pyrrole–hemoglobin adducts as a novel and specific biomarker of PA exposure in humans. The level and elimination kinetics of pyrrole–hemoglobin adducts were systematically investigated in the blood samples of 43 PA-induced liver injury (PA-ILI) patients. The results revealed significantly higher concentrations (84.50 ± 78.38 nM) and longer persistence (~ 4 months) of pyrrole–hemoglobin adducts than that (concentration: 9.53 ± 10.72 nM; persistence: ~ 2 months) of pyrrole–plasma protein adducts, our previously developed PA exposure biomarker. Our findings confirmed that pyrrole–hemoglobin adducts with higher level and longer persistence should serve as a more applicable PA exposure biomarker for future clinical diagnosis of PA-ILI in drug/herb-induced liver injury patients.

The conservation and management of rain and water in a city environment are a crucial aspect of sustainability. Sponge cities are a solution for the remediation of excessive water consumption, high pollution, and rainstorm waterlogging in urban areas. Perennial ryegrass (Lolium perenne L.) is a common species and promising bioremediation plant for the construction of sponge cities. It could be useful to purify high nitrogen and phosphorus content in wastewater runoff, but its response to high total nitrogen (TN) and total phosphorus (TP) levels has not been studied. The present study aimed to evaluate the effects of high TN + TP level on seed germination, plant growth, antioxidant response, and assimilation rate of N and P in perennial ryegrass. Compared with the control, treatments with 20 mg/L N + 4 mg/L P (20N4P) significantly decreased germination potential at day 3, but the germination rate at day 10 was similar between all treatments and the control, suggesting that a high TN + TP concentration might delay germination, but not prevent it. Treatment with 20N4P also induced significant withering and decreased shoot length, root length, and dry shoot weight of ryegrass seedlings, compared with the control. Treatments with 80N16P significantly decreased levels of chlorophyll a (Chl-a) and chlorophyll b (Chl-b), demonstrating inhibition of photosynthesis. Compared with the control, treatment with 40N8P increased the carotenoid (Car), malondialdehyde (MDA), and glutathione (GSH) content, which might alleviate oxidative stress induced by high TN + TP concentration. Moreover, high levels of TN + TP (160N32P and 320N64P) significantly reduced the removal capacity of N and P by plants. Overall, the present results provide a theoretical foundation for the development of ryegrass for bioremediation of wastewater during construction of sponge cities.

The Cadmium (Cd)-polluted soils are is an increasing concern worldwide. Phytoextraction of Cd pollutants by high biomass plants, such as sweet sorghum, is considered an environmentally-friendly, cost-effective and sustainable strategy for remediating this problem. Nitrogen (N) is a macronutrient essential for plant growth, development and stress resistance. Nevertheless, how nitrate, as an important form of N, affects Cd uptake, translocation and accumulation in sweet sorghum is still unclear. In the present study, a series of nitrate levels (N1, 0.5 mm; N2, 2 mm; N3, 4 mm; N4, 8 mm and N5, 16 mm) with or without added 5 μm CdCl2 treatment in sweet sorghum was investigated hydroponically. The results indicate that Cd accumulation in the aboveground parts of sweet sorghum was enhanced by optimum nitrate supply, resulting from both increased dry weight and Cd concentration. Although root-to-shoot Cd translocation was not enhanced by increased nitrate, some Cd was transferred from cell walls to vacuoles in leaves. Intriguingly, expression levels of Cd uptake and transport genes, SbNramp1, SbNramp5 and SbHMA3, were not closely related to increased Cd as affected by nitrate supply. The expression of SbNRT1.1B in relation to nitrate transport showed an inverted 'U' shape with increasing nitrate levels under Cd stress, which was in agreement with trends in Cd concentration changes in aboveground tissues. Based on the aforementioned results, nitrate might regulate Cd uptake and accumulation through expression of SbNRT1.1B rather than SbNramp1, SbNramp5 or SbHMA3, the well-documented genes related to Cd uptake and transport in sweet sorghum.

Graphene has excellent electrical, optical, thermal, and mechanical properties that make it an ideal optoelectronic material. However, it still has some problems, such as a very low light absorption rate, which means it cannot meet the application requirements of high-performance optoelectronic devices. Here, we produce a high-responsivity photodetector based on a monolayer graphene/RbAg4I5 composite nanostructure. With the aid of poly(methyl methacrylate), we suspend the monolayer graphene on a hollow carving groove with a width of 100 μm. A RbAg4I5 film evaporated on the back of the graphene causes the composite nanostructure to generate a large photocurrent under periodic illumination. Experimental results show that the dissociation and recombination of ion-electron bound states (IEBSs) are responsible for the excellent photoresponse. The device has very high (>1 A W-1) responsivity in wide-band illumination wavelength from 375 nm to 808 nm, especially at 375 nm, where it shows a responsivity of up to ∼5000 A W-1. We designed the dimensions of the carving groove to allow the light spot to cover the entire groove, and we cut the graphene sheet to match the length of the carving groove. With the structural optimizations, the energy of light can be used more efficiently to dissociate the IEBSs, which greatly improves the photoresponse of optoelectronic devices based on the proposed monolayer graphene/RbAg4I5 composite nanostructure.

In this paper zinc oxide (ZnO) doped carbon nanofiber (CNF) was synthesized and used for electrode modification with hemoglobin (Hb) immobilized on the surface of carbon ionic liquid electrode (CILE). Ultraviolet–visible (UV–Vis) and Fourier transform infrared spectroscopic studies showed that Hb maintained its native structure in the composite film without denaturation, indicating that the modified materials had good biocompatibility. On the modified electrode (Nafion/Hb/ZnO-CNF/CILE), direct electron transfer of Hb was achieved with well-shaped and enhanced redox waves, and electrochemical behaviors of Hb were investigated in detail. Nafion/Hb/ZnO-CNF/CILE exhibited excellent electrochemical catalytic ability to the reduction of trichloroacetic acid (TCA) and NaNO2, as indicated by a linear relationship between peak current and concentration of analytes. The biosensor was applied to the quantitative analysis of TCA in various samples with good recovery. Experimental results demonstrated the potential applications of ZnO-CNF nanocomposite as a new generation of electrochemical biosensors.

The main objective of this work is to investigate the syngas production from petrochemical sludge (PS) and sawdust (SD) co-pyrolysis. In this study, the pyrolysis experiments of PS, SD and their blends were carried out in TG-MS analyzer and fixed bed reactor. The effects of pyrolysis temperature and interactions between PS and SD on gas evolution behavior, products distribution and gas compositions were investigated. The PS pyrolysis result showed high temperature favored the gas production and there was a distinct increase in gas yield when temperature exceeded 700 °C. The Fe3O4 in solid was reduced by carbon with the generation of CO and CO2, leading to the increase of gas yield. During the co-pyrolysis process, significant interactions between PS and SD were observed. SD addition promoted the increase of gas yield, as well as the generation of H2 and CO. In addition, the activation energy during co-pyrolysis process was reduced due to the interaction. The strongest accelerative effect on gas yield appeared at 60 wt% SD, under which the gas yield was 39.59 wt%, H2+CO content was 61.34 vol%, LHV was 13.39 MJ/Nm3. It was concluded that SD addition was conductive to syngas production from PS pyrolysis.

Silicon nitride (Si3N4) ceramic cutting tool with excellent cutting performance was successfully achieved through the control of phase composition and microstructure. The hardness of the tool with 49.7 wt% and 4.9 wt% α-Si3N4 is ∼20.1 GPa and ∼17.5 GPa, respectively. In continuous cutting of cast iron, the tool life significantly increases from ∼1200 m to ∼2400 m when α-Si3N4 content increases from 4.9 wt% to 49.7 wt%, respectively. The longer tool life is attributed to a better abrasive and adhesive wear resistance of α-Si3N4 phase. In addition, the chemical reaction between Si3N4 ceramic tool and cast iron would lead to the formation of an amorphous oxide layer on wear surface. It was noted that the higher α-Si3N4 content would lead to greater probability of chipping due to lower fracture toughness. Therefore, high-performance Si3N4 ceramic tool could be achieved using an α-Si3N4 matrix ceramic reinforced with elongated β-Si3N4 phase.

Multivariate metal-organic frameworks (MTV-MOFs) have drawn much attention in recent years for their promising applications in many fields of chemistry and materials. Constructing functional MOFs from multiple components for electrochemical water is crucial to high performance renewable energy storage and conversion devices. In this work, a series of bitmetallic-, trimetallic-, and tetrametallic-MOF-74/NFs were grown in situ on nickel foam (NF) by a facile solvothermal route. Specifically, the optimized FeCoMnNi-MOF-74/NF with a multilevel and hollow nanostructure was successfully fabricated and used as highly efficient bifunctional electrocatalysts for water splitting. It exhibited an ultralow overpotential of 250 and 108 mV to achieve the current density of 50 and 10 mA cm-2, along with the relatively small Tafel slope of 41.28 and 72.89 mV dec-1 for OER and HER in 1 M KOH, respectively. It is superior to other multimetallic-MOF-74 composites at the same condition and also surpasses the benchmark of commercial noble-metal catalysts as well. As a result, a low cell voltage of ca. 1.62 V was obtained at a current density of 10 mA cm-2, when tetrametallic FeCoMnNi-MOF-74/NF is employed as both anode and cathode electrodes for the real water splitting. The present work potentially provides a new insight into prospecting and designing multivariate MOFs as a promising material for efficient electrocatalysis in the practical application.

Three reactors chemical looping (TRCL) is a promising hydrogen production process without needing H2 purification and capturing CO2 directly. Based on the deficient research on the energy conversion mechanism in TRCL and the role of external heat sources in the TRCL process, this paper studied the thermodynamic characteristics of energy conversion in methane-TRCL and syngas-TRCL and water-gas shift (WGS) systems, and established the mathematical model of the related parameters through the concept of energy grade. Meanwhile, in this system the energy grade effects of input heat, heat quantity, hydrogen concentration in syngas and steam quantity on the thermodynamic performance are studied. The results show that the TRCL system of methane and syngas has the highest exergy efficiency with 89% and 88.3% respectively, while the energy grade of external input heat is 0.694. Under mentioned above, methane-TRCL is suitable for the case where the heat input value is greater than 310.52 kJ/mol, and the syngas-TRCL system is more efficient than WGS system with 4.8%.