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In this paper, 3D-SiC network skeleton with different structures was successfully constructed by regulating the microstructure of SiC foam ceramic struts via polyurethane replication technology combined with reactive infiltration of Si and solid-state sintering. Then, SiC/Al composites with 3D-interpenetrated network structure (3D-SiC/Al) were fabricated via vacuum pressure infiltration of Al alloy into the 3D-SiC skeleton, for application as electronic packaging. The effects of different skeleton structures on the thermal conductivity (TC), coefficient of thermal expansion (CTE), and flexural strength of the composites were investigated in detail. Furthermore, representative volume element (RVE) models of the 3D-SiC/Al composites were developed and their heat transfer properties and dimensional stability were also comparatively analyzed by finite element (FE) simulations. The results showed that the 3D-SiC/Al composites exhibited high TC of 196 W/m·K, low CTE of 8.03 × 10−6 K−1, and excellent flexural strength of 272 MPa. Low thermal deformation parameter (TDP) and Ashby map demonstrated that the synergistic effect of a complete 3D network skeleton and a clean well-bonded interface in the 3D-SiC/Al composites facilitated the integration of low CTE and high TC even at a low SiC content of 30 vol%. The FE results revealed a 63.5 % reduction in thermal stress and nearly an order of magnitude increase in heat flux for the RVE model of 3D-SiC (30 vol%)/Al composite compared to the RVE model of SiCP (60 vol%)/Al composite. This work provides a novel and scalable method for designing and synthesizing various composites for electronic packaging.

A highly permeable porous SiC ceramic membrane with multilayered unidirectional gradient pore microstructure was prepared by one-step freeze-casting process. The multilayer microstructures, mechanical properties and filtering performances of freeze-casting SiC ceramic membranes were controlled by optimizing the preparation process. It was found that with the increase of solid content from 30 vol% to 40 vol%, the directional pore channels gradually narrowed by about 50% and the mechanical properties increased from 0.47 MPa to 5.44 MPa. In addition, the increase of coarse particle content not only thickened the separation layer and the transition layer, but also widened the directional pore channel, which is beneficial to improve the permeability efficiency. When the coarse particle content of SiC ceramic membranes was 90%, the average pore size of separation layer, transition layer and lamellar structure was 5.52 μm, 7.63 μm and 36.09 μm, respectively. The maximum water permeability of S35C90 ceramic membrane reached up to 5.67 × 105 L/m2 h bar, and the rejection rate for ground calcium carbonate was 96.1%, confirming the superior perviousness and separation efficiency of freeze-casting ceramic membranes in the field of filtration.

CuO/ZnO/CeO2/ZrO2 nanoflowers catalyst was grown on an Al2O3 foam ceramic by a one-step hydrothermal process, while a naked Al2O3 foam ceramic and an Al2O3 foam ceramic grown with ZnO nanorods that directly impregnated into the catalyst precursor solution were also fabricated simultaneously. The morphology, composition, redox property and specific surface area of catalysts on the three ceramics were investigated in detail. The catalyst-loaded ceramics were used as catalyst supports in a microreactor to study the catalytic performance for methanol steam reforming. Results showed that the microreactor with Al2O3 support grown with nanoflowers catalyst achieved 99.8% methanol conversion rate, 0.16 mol/h H2 flow rate at 310 °C, and an inlet methanol flow rate of 0.048 mol/h. Moreover, the microreactor exhibited 92% methanol conversion rate after 30 h continuous reaction.

Microbial electrolysis cell (MEC) has been existing problems such as poor applicability to real wastewater and lack of cost-effective electrode materials in the practical application of refractory wastewater. A hydrolysis-acidification combined MEC system (HAR-MECs) with four inexpensive stainless-steel and conventional carbon cloth cathodes for the treatment of real textile-dyeing wastewater, which was fully evaluated the technical feasibility in terms of parameter optimization, spectral analysis, succession and cooperative/competition effect of microbial. Results showed that the optimum performance was achieved with a 12 h hydraulic retention time (HRT) and an applied voltage of 0.7 V in the HAR-MEC system with a 100 μm aperture stainless-steel mesh cathode (SSM-100 μm), and the associated optimum BOD

Nutrients and heavy metals (HM) in the sediment have an impact on microbial diversity and community structure. In this study, the distribution characteristics of nutrients, HM, and microbial community in the sediments along the Longsha River, a tributary of the Pearl River (or Zhu Jiang), China were investigated by analyzing samples from 11 sites. On the basis of the HM-contamination level, the 11 sampling sites were divided into three groups to explore the changes in microbial communities at different ecological risk levels. Results indicated that nutrient concentrations were higher near farmlands and residential lands, while the ecological risk of HM at the 11 sampling sites was from high to low as S10 S2 S9 S6 S11 S7 S5 S8 S3 S4 S1. Among these HM, Cu, Cr, and Ni had intense ecological risks. In addition, the results of Variance Partitioning Analysis (VPA) revealed a higher contribution of HM (35.93%) to microbial community variation than nutrients (12.08%) and pH (4.08%). Furthermore, the HM-tolerant microbial taxa (Clostridium_sensu_stricto_1, Romboutsia, norank_o__Gaiellales, and etc.) were the dominant genera, and they were more dynamic around industrial lands, while microbes involved in the C, N, and S cycles (e.g., Smithella, Thiobacillus, Dechloromonas, Bacter oidetes_vadinHA17, and Syntrophorhabdus) were inhibited by HM, while their abundance was lower near industrial lands and highway but higher around residential lands. A three-unit monitoring program of land-use types, pollutants, and microbial communities was proposed. These results provide a new perspective on the control of riparian land-use types based on contaminants and microbes, and different microbial community response patterns may provide a reference for contaminant control in sediments with intensive industrial activities.

Increasing applications of engineered nanomaterials lead to the release of nanoparticles into various environmental media, especially soil. However, the environmental behavior of nano ZnO in soil and the toxic mechanism to terrestrial invertebrates were not fully understood. In this study, the concentrations of nano ZnO in earthworms (Eisenia fetida) were measured to assess its bioaccumulation. The ratio of nano ZnO in earthworms to soil in 250 mg/kg treatment group was lower than that in 10 mg/kg treatment group as the earthworms would not take up too much nano ZnO to protect themselves from the damage. Combination of in-vivo and in-vitro tests was adapted to investigate the toxic mechanism of nano ZnO to earthworms. In in-vivo test, biomarkers including ROS, SOD, and MDA suggested that the toxic effects of nano ZnO to earthworms were caused by the oxidative stress. To further elucidate its toxic mechanism, in-vitro toxicity test was carried out by employing earthworm coelomocytes. The biomarkers, intracellular ROS, extracellular LDH, and cell viability showed concentration-dependent manner with nano ZnO in the culture media, demonstrating that in-vitro toxicity test could be utilized to reveal the toxic mechanism of nano ZnO to earthworms or other organisms.

Alkyl-diamondoid fuels are attractive for aerospace vehicles due to their high energy density and supreme low-temperature performance. Here we reported a facile route to synthesize alkyl-diamondoids via solvent-free rearrangement of tetrahydrotricyclopentadiene simply catalyzed by acid. The reaction conditions including catalysts, temperature, catalyst dosage, and solvent were optimized. Notably, under the optimal conditions (10.7 wt% cat., 180 °C, 20 h) an extremely high content of alkyl-diamondoids (85.6%) was found in liquid phase, with high carbon yield of alkyl-diamondoids (60.0%) was obtained. The reaction kinetics of rearrangement has been investigated, and the reaction rate constants and apparent activation energies were calculated based on the experimental kinetic data. The resultant diamondoid-based product shows excellent low-temperature performance and a higher energy content than reported diamondoids and widely used JP-10 fuel, thus is superior as a high-energy-density fuel.

Intrahepatic cholangiocarcinoma (ICC) is cancer that originates from the liver's secondary ductal epithelium or branch. Due to the lack of early-stage clinical symptoms and very high mortality, the 5-year postoperative survival rate is only about 35%. A critical step to improve patients' survival is accurately predicting their survival status and giving appropriate treatment. The tumor microenvironment of ICC is the immediate environment on which the tumor cell growth depends. The differentiation of tumor glands, the stroma status, and the tumor-infiltrating lymphocytes in such environments are strictly related to the tumor progress. It is crucial to develop a computerized system for characterizing the tumor environment. This work aims to develop the quantitative histomorphological features that describe lymphocyte density distribution at the cell level and the different components at the tumor's tissue level in HE-stained whole slide images (WSIs). The goal is to explore whether these features could stratify patients' survival. This study comprised of 127 patients diagnosed with ICC after surgery, where 78 cases were randomly chosen as the modeling set, and the rest of the 49 cases were testing set. Deep learning-based models were developed for tissue segmentation and lymphocyte detection in the WSIs. A total of 107-dimensional features, including different type of graph features on the WSIs were extracted by exploring the histomorphological patterns of these identified tumor tissue and lymphocytes. The top 3 discriminative features were chosen with the mRMR algorithm via 5-fold cross-validation to predict the patient's survival. The model's performance was evaluated on the independent testing set, which achieved an AUC of 0.6818 and the log-rank test p-value of 0.03. The Cox multivariable test was used to control the TNM staging, γ-Glutamytransferase, and the Peritumoral Glisson's Sheath Invasion. It showed that our model could independently predict survival risk with a p-value of 0.048 and HR (95% confidence interval) of 2.90 (1.01-8.32). These results indicated that the composition in tissue-level and global arrangement of lymphocytes in the cell-level could distinguish ICC patients' survival risk.

A process via Diels-Alder reaction of lignocellulose-derived 2-methylfuran and petroleum-derived dicyclopentadiene following by hydrodeoxygenation was proposed to synthesize a new kind high-density liquid fuel. The results show that the catalysts, temperature and reactant ratio can affect the product distribution of Diels-Alder reaction greatly. Among the investigated catalysts, HY zeolite exhibited the best catalytic activity and showed good recycling ability. Over HY zeolite, high conversion of reactants along with acceptable selectivity of the target products was obtained, under the reaction temperature of 150 °C and 2-MF/DCPD ratio of 2:1. After hydrodeoxygenation, the as-obtained fuel has a density of 0.984 g/mL, much higher than that of widely used JP-10 fuel (0.94 g/mL), a low freezing point of −58 °C and a volumetric neat heat of combustion of 41.96 MJ/L. Furthermore, a blended fuel with 25% JP-10 exhibits high density and excellent cryogenic properties, which is very promising to serve as high-density fuel for advanced propulsion application.

Bicyclic and multi-cyclic hydrocarbons usually have high density over 0.87 g/cm3, which is very popular to synthesize from biomass-derived renewable chemicals, but their cryogenic properties need to be further improved for practical applications. In this work, we synthesized ethyl-substituted bicyclic high-performance hydrocarbons with improved cryogenic properties from the biomass-derived 4-ethylphenol and phenylmethaol. For the alkylation reaction between 4-ethylphenol with phenylmethanol, the reaction conditions were optimized, under which the conversion of phenylmethanol can achieve 100% with monoalkylated products (2-benzyl-4-ethylphenol and 3-benzyl-4-ethylphenol) selectivity of 71%. After hydrodeoxygenation catalyzed by a mixture catalyst of Pd/C and HZSM-5, the alkylation products were mainly converted to the ethyl-substituted dicyclohexylmethane. The obtained fuel shows a high density of 0.873 g/cm3 (20 °C), gravimetric net heat of combustion of 42.7 MJ/kg, and the freezing point of −42 °C, which is promising to serve as a blend component for jet fuel application.

Long-term stress effects of varying concentrations of organic matter on nitrogen removal, physiochemical characteristics and microbial community of anammox granular sludge were evaluated in UASB (Up-flow Anaerobic Sludge Bed/Blanket) reactors. With increase of COD (Chemical Oxygen Demand) concentration (made by glucose) from 0 mg L−1 to 200 mg L−1, ammonium removal efficiency decreased sequentially from 97.71% to 46.52%, while the nitrite removal efficiency was maintained at 96.78–98.62%. The TN removal efficiency reached the highest (98.00%) at 50 mg L−1 of COD. However, 150 and 200 mg L−1 of COD caused the disintegration of anammox granular sludge, while also reducing extracellular polymeric substances (EPS) content, mechanical strength and sedimentation performance, respectively. The main bacteria at the phylum level had shifted from Chloroflexi to Proteobacteria, according to high-throughput Miseq sequencing analyses. Candidatus Brocadia became the dominant anammox genus under long-term organic matter stress, which correlated positively with ammonium and TN removal efficiency, instability coefficient (IC), protein/polysaccharide (PN/PS) and particle size, but negatively with COD concentration and EPS, respectively.

Multi-cyclic hydrocarbons from biomass are sustainable alternative for jet fuel. Here we report an unexpected hydrogenated intramolecular cyclization of diphenylmethane derivatives synthesized by alkylation of bio-derived compounds. With the presence of commonly used zeolite-Pd/C dual catalyst, conventional hydrodeoxygenation (HDO) occurs to produce dicyclohexylmethane. However, when only hydrogenation catalysts like Pd/C or Ni is used, novel intramolecular cyclization takes place to produce perhydrofluorene with the selectivity as high as 96.0%. The two pathways were illustrated by step-by-step controlled reactions in detail and a mechanism was proposed to explain the reason for perhydrofluorene formation. Moreover, this intramolecular cyclization is versatile for diphenylmethane with OCH3 or OH group at any position. The synthesized perhydrofluorene shows density of 0.96 g/mL, much higher than any biofuels reported and even higher than the widely used high-density fuel JP-10 derived from petroleum. It is believed that this biofuel can be excellent additive to improve the density of other jet fuels.

Design and choice of fuels continue to be improved for aviation propulsion, and alkyl adamantanes have attracted great attention due to their high density, good low-temperature properties and potential characteristics. Herein, we reported a facile route to synthesize mono-substituted alkyl adamantanes via modified Grignard coupling (followed with one-step hydrodeoxygenation), including 1-ethyl-adamantane, 2-ethyl-adamantane, and 1-n-propyl-adamantane with high yields (> 75%). The process was modified via concentrating the Grignard reagents and altering the solvent, and one-step hydrodeoxygenation catalyzed by commercial Pd/C and zeolites was developed. Subsequently, comprehensive characteristics of alkyl diamondoid series, such as oxidation stability and combustion properties, were evaluated using pressure differential scanning calorimetry, rapid small-scale oxidation test, and hot-plate ignition test. Also, the specific impulse of alkyl diamondoids were revealed by theoretical calculation. The high-density alkyl diamondoids present adequate oxidation stability and possess better combustion characteristics over JP-10, thus can be considered as potential high-energy-density fuel for aerospace propulsion.

Using conventional anaerobic digestion to treat refractory wastewater has several drawbacks such as long start-up period, temperature sensitivity, volatile fatty acids (VFAs) accumulation and so on. The coupling of the bioelectrochemical systems with anaerobic digestion (BES-AD) has been proposed to enhance the degradation of refractory pollutants. In this review, the mechanism of BES-AD is firstly discussed. Then, the performance of BES-AD is evaluated with respect to different types of wastewater, anaerobic reactors, electrode materials and microbial communities associated with different systems. The embedding of BES addresses the accumulation of VFA and accelerates the start-up period, thus, allows for the growth of various microbial communities in the system. Novel electrodes with high biocompatibility and large specific surface area can be fabricated by the bioelectrodes-based modification and used for synergistic reinforcement of the system by combining macroscopic effects with microscopic biological mechanisms. However, the modification of BES electrodes is deemed to be the key for further improving BES performance.

Thermal oxidation stability is a key issue for jet fuel when serving as a coolant in aircraft. However, the deposition propensity and mechanism of hydrocarbons with different molecule structures remain ambiguous. In this study, the oxidation stability and deposition propensity of C10 hydrocarbon fuels, i.e., tetralin, cis-/trans-decalin, exo-tetrahydrodicyclopentadiene (exo-THDCPD), and n-decane, were determined. The oxidation stability of hydrocarbons follows the order of n-decane > exo-THDCPD > trans-decalin > cis-decalin > tetralin, which is highly associated with the molecular-structure-dependent C–H bond dissociation enthalpy. Differently, the deposition propensity follows the order of trans-decalin > exo-THDCPD > n-decane > cis-decalin > tetralin, which can be associated with the stability of oxidation intermediates, especially the hydroperoxides. The more stable the intermediates are, the fewer deposits will be produced. These results demonstrate the relationship between thermal oxidation stability and hydrocarbon molecular structure, which is helpful for a better understanding of jet fuel deposition mechanism.

Constructing junctions between semiconductors is an effective way to promote charge separation and thus to improve the photoelectrochemical and photocatalytic H 2 generation, and specifically, p-n homojunction is considered as a very promising structure. Herein, we fabricate TiO 2 p-n homojunction by in-situ decorating n-type oxygen-defected TiO 2 QDs on p-type titanium-defected TiO 2 surface. The composite structure and O-/Ti-vacancies are testified by TEM, XRD, XPS, EPR and UV–vis DRS characterizations. The “V-shaped” Mott-Schottky plot and anodic shift of onset potential in I-V curves verify the characteristics of p-n homojunction. PL and EIS analyses indicate p-n homojunction is much more efficient in charge separation and transfer than p-type, n-type and n-n type-II homojunction, subsequently leading to the significantly high photoactivity. Compared with p-TiO 2 , p-n homojunction TiO 2 possesses 5-fold and 1.7-fold higher performances in photoelectrochemical and photocatalytic hydrogen generation, respectively. This work provides new opportunities to design and fabricate highly efficient TiO 2 photocathodes for hydrogen generation.

Highly thermal-stable jet fuel plays an important role in the advanced supersonic aircrafts, but its oxidation to the insoluble deposits is a serious problem when serving as a coolant. However, there are few reports as to the deep insights of insoluble deposits formation. Here we apply the PetroOxy device to investigate the thermal oxidation and deposition behaviors of highly thermal-stable jet fuel, using decalin as the model jet fuel, in order to explore the formation mechanism of insoluble deposits. All oxidation products (gas, liquid and solid) of fuel at different oxidation stages were separated and carefully characterized. The initial oxidation of fuel produces hydroperoxides, which then decompose rapidly to produce gas products (H2, CO or CO2) as well as large amounts of polar species (soluble oxidized products, e.g., alcohols, ketones, and molecular growth products). Meanwhile, these polar monomer species condense to produce soluble macromolecular oxidatively reactive species (SMORS) and insoluble deposits. The SMORS amount increases during the overall oxidation process, but the amount of insoluble deposits increases only in the presence of oxygen. The characterizations of liquid chromatography/electrospray ionization mass spectrometry and solution-state 2D heteronuclear single quantum coherence NMR confirm that the concentration of highly polar macromolecular species in insoluble deposits is much higher than that in SMORS, which causes the precipitation of the insoluble deposits from the bulk fuel. We further propose the detailed formation process and chemical structures of the insoluble deposits during the autoxidation of highly thermal-stable jet fuel, which would be helpful for a better understanding of the deposition mechanism of jet fuel and the improvement of its thermal stability.

The discreteness of fatigue test results of inorganic bonded stabilized materials is very voluminous. In this study, the fatigue crack checking process of cement stabilized macadam is analyzed by using measurement uncertainty and interval analysis theory in order to improve the efficiency of fatigue test data. Firstly, the measurement uncertainty of the bending strength and fatigue life of cement stabilized macadam is evaluated based on the measurement uncertainty theory. Secondly, the regression analysis of the fatigue life interval of different stress ratio conditions is realized, following which the regression model of the fatigue life interval of cement stabilized macadam is derived. Finally, the calculation model of fatigue cracking life interval is deduced, and the fatigue cracking life interval of cement stabilized macadam is then obtained by interval algorithm. Meanwhile an evaluation method of interval comparison results is proposed in order to undertake a comparative analysis of the fatigue cracking life interval of cement stabilized macadam. According to the findings, the non-uniformity of the specimen is determined as the root cause of the large discreteness of fatigue test results. A fatigue interval model with 95% guarantee rate can be obtained based on the regression analysis method of fatigue life interval, which is proved to be effective in improving the efficiency of fatigue test data. There is a case of interval expansion in calculating the equation of fatigue cracking life interval. It is verified that the extended interval result has engineering applicability. Therefore, it can be surmised that the interval result comparison method proposed in this paper can achieve both quantitative and qualitative evaluation, which is particularly suitable for the engineering field of interval analysis.

Alkyl-adamantane fuels are appealing for aerospace vehicles due to their high density, good low-temperature performance and thermal stability. Here we reported a facile route to synthesize dimethyl-adamantane fuels via solvent-free rearrangement. The thermodynamic preference of six products (dimethyl-adamantane isomers) was revealed by Density Functional Theory (DFT) calculation and experiment, and the reaction pathway was further discussed. The reaction conditions including catalyst, catalyst dosage, temperature, and solvent were optimized, with the dimethyl-adamantane yield of 88.7%. We synthesized two typical dimethyl-adamantane fuels (with different compositions of isomers) by adjusting the reaction conditions and then evaluated their properties. It is found the two fuels show different fuel properties (e.g., density, heating value, thermal stability) due to the difference in methyl substitution position, although both with high density and good low-temperature fluidity. Specifically, the dimethyl-adamantane with methyl on the tertiary carbon shows better thermal stability than JP-10 and decalin. This work presents dimethyl-adamantanes as good high-density and high-thermal-stability fuels, and suggests the position of methyl substitution on adamantane has considerable effect on their properties.