Search

Owing to the high electron delocalization in 2D ultrathin regions derived from π-d conjugations, electrically conductive metal-organic frameworks (MOFs) are widely used in electronic applications but mostly for rigid devices. The interaction mechanism between conductive 2D MOFs and flexible substrates remains unclear, which cannot meet the increasing demand for next-generation wearable electronics. Herein, conductive copper-benzenehexathiol (Cu-BHT) layers are developed and the underlying mechanisms responsible for the conductivity difference on different representative substrates are explored. It is found that not only the molecular movement inside the polymer but also the fusion between polymer and Cu-MOFs affects the intrinsic conductivity and long-term stability. Therefore, the potential guiding criteria for selecting flexible substrates for conductive 2D MOFs are established. As a demonstration, the Cu-BHT/polymer layer is considered the flexible electrode of triboelectric nanogenerators to harvest energy from water droplets and human motions, verifying the significant role of conductive 2D MOFs in flexible and wearable applications. This study reveals the insights to the potential interaction effect on the conductivity stability of Cu-BHT and advances the development of 2D conductive MOFs in flexible and wearable electronics., Nano Energy, 111, ISSN:2211-2855

Two-dimensional conductive metal-organic frameworks (2D conductive MOFs) with π-d conjugations exhibit high electrical conductivity and diverse coordination structures, making them constitute a desirable platform for new electronic devices. Defects are inevitable in the self-assembly process of 2D conductive MOFs. Arguably, defect engineering that deliberately manipulates defects demonstrates great potential to enhance the electrocatalytic activity of this family of novel materials. Herein, a facile and universal defect engineering strategy is proposed and demonstrated for metal vacancy regulation of metal benzenehexathiolato (BHT) coordination polymer films. Controllable metal vacancies can be produced by simply tuning the proton concentration during the confined self-assembly process at the liquid-liquid interface. This facile but universal defect design strategy has been proven to be effective in a class of materials including Cu-BHT, Ni-BHT, and Ag-BHT for physicochemical regulation. To further demonstrate the feasibility and practicality in electrochemical applications, the elaborately fabricated Cu-BHT films with abundant Cu vacancies deliver competitive performance in electrocatalytic sensing of H

The recent use of cryoprotectant replacement method for solving the easy drying problem of hydrogels has attracted increasing research interest. However, the conductivity decrease of organohydrogels due to the induced insulating solvent limited their electronic applications. Herein, we introduce the Hofmeister effect and electrostatic interaction to generate hydrogen and sodium bonds in the hydrogel. Combined with its double network, an effective charge channel that will not be affected by the solvent replacement, is therefore built. The developed organohydrogel-based single-electrode triboelectric nanogenerator (OHS-TENG) shows low conductivity decrease (one order) and high output (1.02-1.81 W/m2), which is much better than reported OHS-TENGs (2-3 orders, 41.2-710 mW/m2). Moreover, replacing water with glycerol in the hydrogel enables the device to exhibit excellent long-term stability (four months) and temperature tolerance (-50-100 °C). The presented strategy and mechanism can be extended to common organohydrogel systems aiming at high performance in electronic applications.

Quartz and clay are substituted gradually by fly ash using a triaxial ceramic formulation under simulated industrial conditions and the effects of fly ash substitution on the macroscopic properties and microstructures of the sintered ceramics are evaluated systematically. With the substitution of 35 wt% (1250 °C), the ceramic sample exhibited optimal properties, including linear shrinkage of 15.61%, bulk density of 2.39 g cm-3, water absorption of 0.62% and flexural strength of 41.70 MPa, due to the accelerated densification and fly ash-spurred needle-shaped mullite. The microstructure analysis shows that the sintered matrix consists of three types of particles, quartz-, clay- and feldspar-like particles showing sintering behavior with respect to filling the glassy matrix with preserved morphology, precipitating mullite crystals, and fusing with the surrounding glassy matrix, respectively. The strength of the fly ash - containing ceramics is analyzed by the dispersion-strengthening mechanism and porosity and the results indicate that the fly ash particles affect the mechanical strength due to Griffith flaws when the total porosity is less than 25% and pores at higher total porosity. This study provides a viable strategy to recycle industrial fly ash in the production of architectural ceramics.

To discover and develop novel active molecules, in this study, a series of novel pyrethrin derivatives containing 1,3,4-oxadiazole and thioether moieties were designed and synthesized. Bioassay results revealed that some of the target compounds possessed good insecticidal activities against Plutella xylostella (P. xylostella), Vegetable aphids (V. aphids), and Empoasca vitis (E. vitis), respectively, which were even better than those of the commercial insecticidal agents chlorpyrifos, beta cypermethrin, spinosad, and azadirachtin. The results favored our rational design intention and provide a new class of small-molecule inhibitors available for the development of active insecticidal agents targeting P. xylostella, V. aphids, and E. vitis.

Incorporation of additives into silicon carbide (SiC) ceramics in low temperature, atmospheric pressure sintering is challenging because uniform mixing of additives and raw SiC powders is quite difficult. Herein, an impregnation coating process in which a precise amount of Al 2 O 3 is introduced to raw SiC granules on the nanoscale is described and high-performance SiC ceramics can be processed by atmospheric pressure sintering. The uniform coating promotes densification of SiC via enhanced liquid mass transfer and inhibits grain growth and recombination during sintering. The effects of the doping content on the ceramic structure and mechanical properties are studied. Coating a single layer of Al 2 O 3 nano-particles on SiC particles yield the best interfacial activity, sintering density, and mechanical properties. The SiC sample with 7.5 wt% Al 2 O 3 possesses the best properties such as a relative density of 97.98%, flexural strength of 434.40 MPa, fracture toughness of 5.23 MPa·m 1/2 , and Vickers hardness of 28.21 GPa. The sintering kinetics analyzed by the isothermal sintering method fits the Singh model with an apparent activation energy of 574.64 kJ/mol. The sintering rate is governed by both the interface reaction and diffusion and the model and experimental results provide insights with respect to materials design and commercial batch production.

LiNi0.8Co0.1Mn0.1O2 (NCM811) has a high potential for using as the cathode material for lithium–ion batteries (LIBs) for electric vehicles owing to its high energy density and low cost. However, its poor rate capability and cycling performance have significantly hindered its application. In this study, we successfully design a uniform magnesium oxide (MgO) coating on NCM811 via a wet-chemical coating followed by heat treatment using magnesium ethoxide [Mg (OEt)2] dissolved in ethanol as the Mg source. The effects of MgO coating on the surface states, crystal structure, and electrochemical performances of NCM811 cathode material are studied in detail. After 100 cycles, the capacity retention of MgO-coated NCM811 is 90.1% at room temperature at 1 C, whereas the pristine NCM811 is only 74.5%. Besides, the MgO-coated NCM811 delivers a better rate property than pristine NCM811. Prominent improvements in electrochemical performances are attributed to the fact that the formation of MgO coating layer helps to suppress deleterious side reactions, lower the overpotential on the surface, and facilitate lithium–ion diffusion.

Healthcare-associated infections (HAIs) not only bring additional medical cost to the patients but also prolong the length of stay (LOS). 2119 HAI case-patients and 2119 matched control-patients were identified in 68 hospitals in 14 primary sampling provinces of 7 major regions of China. The HAI caused an increase in stay of 10.4 days. The LOS due to HAI increased from 9.7 to 10.9 days in different levels of hospitals. There was no statistically significant difference in the increased LOS between different hospital levels. The increased LOS due to HAI in different regions was 8.2 to 12.6 days. Comparing between regions, we found that the increased LOS due to HAI in South China is longer than other regions except the Northeast. The gastrointestinal infection (GI) caused the shortest extra LOS of 6.7 days while the BSI caused the longest extra LOS of 12.8 days. The increased LOS for GI was significantly shorter than that of other sites. Among 2119 case-patients, the non-multidrug-resistant pathogens were detected in 365 cases. The average increased LOS due to these bacterial infections was 12.2 days. E. coli infection caused significantly shorter LOS. The studied MDROs, namely, MRSA, VRE, ESBLs-E. coli, ESBLs-KP, CR-E. coli, CR-KP, CR-AB, and CR-PA were detected in 381 cases (18.0%). The average increased LOS due to these MDRO infections was 14 days. Comparing between different MDRO infections, we found that the increased LOS due to HAI caused by CR-PA (26.5 days) is longer than other MDRO infections (shorter than 19.8 days).

Flexible lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3-0.2 mol%Y nanofibers (BCTZY NFs) were synthesized by electrospinning and their corresponding nanogenerators (NGs) with vertical alignments were fabricated. The low-temperature sintering properties of BCTZY NFs were investigated, to optimize their synthesis path and minimize the thermal energy consumption during the sintering process. The continuity, flexibility, and stability of the BCTZ-based NFs were improved by adding Y3+. Moreover, the temperature-evolved Raman spectra displayed a high Curie temperature of 280 °C for BCTZY NFs, which was far higher than that of about 90 °C for BCTZ-based ceramic bulks, owing to the discontinuous physical property of NFs. The dielectric, ferroelectric, and piezoelectric properties of the vertically aligned BCTZY NFs/PDMS were estimated and compared with those of BCTZ NFs/PDMS composites, to verify the advantages of vertical alignments and the donor doping effect of Y3+. Vertically aligned BCTZY NF-based NGs showed an average VOC of 3.0 V and ISC of 85 nA by finger tapping, suggesting their potential applications in tiny energy harvesting.

Using coal fly ash (CFA) as the raw materials in ceramic production is an effective means to realize large-quantity and high-value utilization. An eco-friendly and cleaner process to prepare architectural ceramics from CFA is described in this paper. CFA first undergoes mechanochemical activation and then used to prepare porcelain ceramic tiles with outstanding mechanical properties. The solution after activation is the sole raw materials to produce foamed ceramics with novel thermal insulation properties. The mechanochemical activation mechanism is investigated systematically. During activation, some of the octahedrally coordinated Al3+ ions are converted into tetrahedrally coordinated Al3+, which can substitute for Si4+ in the tetrahedral rendering the silicate structure in activated CFA unstable. Moreover, the preparation mechanism of the foamed ceramics is studied. On the micro-level, solidification of the foamed ceramics can be interpreted as Si-O-Si structural transformation from two-dimensional layers to a three-dimensional network during sintering. The two final products are characterized and the good mechanical properties of as-obtained porcelain ceramic tiles are attributed to the needle-shape mullite derived from activated CFA. The low thermal conductivity of 0.0453 W/m·K of the as-obtained foamed ceramics arises from the unique cavity construction. Finally, the substance flow, gas emission, and heavy metal leaching behavior of the final products are discussed and the results indicate that there is almost no hazardous waste emission in the process. This study provides insights into more efficient and cleaner utilization of CFA as ceramic materials.

Background Feeding jejunostomy is widely used for enteral nutrition (EN) after esophagectomy; however, its risks and benefits are still controversial. We aimed to evaluate the short-term and long-term outcomes of feeding jejunal tube (FJT) in patients undergoing esophagectomy for esophageal squamous cell carcinoma (ESCC) who were deemed high-risk for anastomotic leakage. Methods We retrospectively analyzed 716 patients who underwent esophagectomy with (FJT group, n=68) or without (control group, n=648) intraoperative placement of FJT. Propensity score matching (PSM) was used for the adjustment of confounding factors. Risk level for anastomotic leakage was determined for every patient after PSM. Results Patients in the FJT group were at higher risk of anastomotic leakage (14.9% vs. 11.3%), and had a statistically non-significant increase of postoperative complications [31.3% vs. 21.8%, odds ratio (OR) =1.139, 95% confidence interval (CI), 0.947-1.370, P=0.141] after PSM. Medical expenditure, length of postoperative hospital stay, and short-term mortality were similar between the FJT and control groups. Placement of FJT appeared to accelerate the recovery of anastomotic leakage (27.2 vs. 37.4 d, P=0.073). Patients in FJT group achieved comparable overall survival (OS) both before [hazard ratio (HR) =0.850, P=0.390] and after (HR =0.797, P=0.292) PSM. Conclusions FJT showed acceptable safety profile along with potential benefits for ESCC patients with a high presumed risk of anastomotic leakage. While FJT does not impact OS, placement of FJT should be considered in esophagectomy patients and tailored to individual patients based on their leak-risk profile.

Calcium silicate hydrate is proposed as a potential silicate fertilizer. It is the main phase of the by-product of a mild hydrochemical process used to extract alumina from coal fly ash. Its preparation by decomposing sodium calcium silicate hydrate, the residue after extracting alumina from coal fly ash, was investigated. The results revealed that the intermediate of the sodium calcium silicate hydrate was easily decomposed into calcium silicate hydrate in a dilute alkaline solution and an available silica content of 28.57% was obtained under the decomposition conditions of a 30 g/L Na2O solution, a liquid-volume to solid-mass ratio of 25, a reaction temperature of 150 °C and a reaction time of 4 h, with a stirring speed of 600 rpm. Subsequently, Si uptake experiments were conducted on wheat seedlings by hydroponics to test Si’s effects on their growth. The results proved that the Si concentration in the wheat seedling shoots was greatly enhanced from 1.213 mg/g to 3.983 mg/g when 0.02 g of calcium silicate hydrate was distributed in the pot in which 3.87 g of seeds were cultivated.

The advancement of wearable electronics and environmental awareness requires a wearable triboelectric nanogenerator (TENG) to feature the concepts of sustainability and environmental suitability. While most wearable TENGs are developed based on complex surface modification approaches to avoid the necessity of a physical spacer, herein a nanogap TENG is fabricated based on surface self-modified sustainable polymer films. Compared with poly(lactic acid) (PLA)-based and polycaprolactone (PCL)-based TENGs, the polybutylene succinate (PBS)-based TENG shows the highest output performance, representing up to 3.5-fold that of the reported TENGs based on biodegradable materials with a 0-4 mm spacer, due to the higher content of the ester group and surface roughness resulting from the surface self-modification. The nanogap device is demonstrated as a pressure/angle sensor with acceptable sensitivity for use in health monitoring. More importantly, the environmental suitability of the triboelectric films in air, water, and phosphate buffered saline systems indicates their stability in natural water and saline environments. Moreover, the antibacterial property of the triboelectric films indicates future applications in wearable and implantable electronics. This work demonstrates the potential applications of a biocompatible and environmentally stable TENG in wearable electronics and biomedical systems.

The development of earth-abundant transition-metal-based electrocatalysts with bifunctional properties (oxygen evolution reaction (OER) and hydrogen evolution reaction (HER)) is crucial to commercial hydrogen production. In this work, layered double hydroxide (LDH)-zinc oxide (ZnO) heterostructures and oxygen vacancies are constructed synchronously by plasma magnetron sputtering of NiFe-LDH. Using the optimal conditions, ZnO nanoparticles are uniformly distributed on the NiFe-LDH nanoflowers, which are prepared uniformly on the three-dimensional porous Ni foam. In the LDH-ZnO heterostructures and oxygen vacancies, electrons are depleted at the Ni cations on the NiFe-LDH surface and the active sites change from Fe cations to Ni cations during OER. Our theoretical assessment confirms the change of active sites after the deposition of ZnO and reveals the charge-transfer mechanism. Owing to the significant improvement in the OER dynamics, overall water splitting can be achieved at only 1.603 V in 1 M KOH when the Ni/LDH-ZnO and Ni/LDH are used as the anode and cathode, respectively. The work reveals a novel design of self-supported catalytic electrodes for efficient water splitting and also provides insights into the surface modification of catalytic materials.

The shrinking unreacted core model has been one of the most widely used models for the uncatalyzed reaction kinetics between the liquid/gas and the solid phases. However, the classical shrinking unreacted core model (CSUC model) is only applicable to spherical particles. Currently, the CSUC model has been used in many studies regardless of its applicable conditions. For example, Wang et al. (2016) investigated the decomposition kinetics of a rod-like residue and deduced the rate-controlling step using the CSUC model. The purpose of this comment is to propose a modified shrinking unreacted core model (shrinking cylinder model) suitable for materials with a high aspect ratio. The authors hope that this work will be helpful for kinetic analysis of rod-shaped and fiber-shaped materials in the uncatalyzed liquid/gas-solid reactions.

With the rapid development of wearable electronics, flexible and sensitive energy harvesters have recently attracted considerable attention. Herein, a novel piezo-triboelectric nanogenerator (PTNG) based on BCZT/PVDF-HFP composite nanofibers (BP-based NFs) is fabricated using silicone rubber as the negative triboelectric counterpart. The introduction of BCZT nanoparticles markedly improves both the piezoelectric and triboelectric properties of the BP-SG PTNG, where the output voltage and current density are 2.5–3 fold higher than those of pure PVDF-HFP PTNG. Owing to the uniform distribution of BCZT particles on the fiber surface via electrospinning, the maximum power density of the device reaches 161.7 mW m−2, representing 5.5-fold improvement compared to that of BaTiO3/PVDF-based composite PTNG. The device shows stable output for 1200 cycles and after three month storage and exhibits high sensitivity to minute body movements as proved by the output response in both two-electrode and single-electrode modes. This study demonstrates a novel approach to fabricate flexible PTNGs with simple structure and high sensitivity for use in self-powered wearable electronics.

Terahertz (THz) refers to electromagnetic waves with frequency from 0.1 to 10 THz, which lies between millimeter waves and infrared light. This paper proposes an ultra-thin metasurface absorber which is perfectly suited to be the signal coupling part of terahertz focal plane array (FPA) detector. The absorptance of the proposed metasurface is higher than 80% from 4.46 to 5.76 THz (25.4%) while the thickness is merely 1.12 µm (0.018 λ). Since the metasurface absorber will be applied to terahertz FPA detector which requires planar array formation, it is divided into meta-atoms. Each meta-atom consists of the same unit cell layout, and air gaps are introduced between adjacent meta-atoms to enhance the thermal isolation, which is crucial for FPA detector to obtain desired imaging results. Due to the symmetrical layout of meta-atoms, absorptance keeps stable for different polarized waves, moreover, good absorptance could also be achieved for incidence angles range of ± 30 °. Spectral measurements show good agreement with the simulation. As a result, features of ultra-thin thickness, polarization insensitivity, and high absorptance make the proposed metasurface absorber well suited to highly efficient coupling of terahertz signals in FPA detector.

BCZT-CuY/rGO/PDMS composites with excellent elasticity and flexibility, and their nanogenerators (NGs) with favorable electrical properties, were fabricated. The impact of rGO on the dispersion of BCZT-CuY, the mechanical properties of BCZT-CuY/rGO/PDMS, and electrical performance of BCZT-CuY/rGO-based NGs were systematically investigated. The results indicated that the distribution of BCZT-CuY in PDMS with added rGO was much more uniform than that without rGO. Moreover, its elastic modulus and elongation at the break increased to 4.6 MPa and 250%, respectively, with the introduction of rGO. Apart from a high d33 at the percolation threshold, the average VOC (1.36 V) and ISC (35nA) achieved by finger tapping BCZT-CuY/rGO-based NGs suggested their considerable potential in harvesting tiny energy.

Lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3-xwt%CuOywt%Y2O3 (BCZT-CuxYy) ceramics with high piezoelectricity were synthesized by the conventional solid-state reaction method. The role of Cu and Y (Cu/Y) in sintering, phase transition, and electrical properties of such ceramics was systematically studied. The results indicated that the sintering temperatures of BCZT-CuxYy decreased by at least 100 °C due to the low melting point of CuO. The promotion effect of Cu/Y on phase transition lied in the improvement of TC by 5–15 °C and the coexistence of O+T phase near room temperature. The contribution of Cu/Y to electrical properties was mainly ascribed to the grains growth, the formed oxygen vacancies and lattice distortions, and the donor doping effect of Y3+. Adding 0.10 wt% Cu2+ and 0.06 wt% Y3+ into BCZT dramatically improved the electrical properties as following: d33 = 552 pC/N, em = 10175, er = 4546, tanδ = 0.016, TC = 100 °C, kp = 0.475, Qm = 157.2, Pr = 10.82 μC/cm2 and EC = 2.33 kV/cm. A plausible mechanism was obtained to explain the reaction process and the favorable performances of BCZT-CuxYy. Co-doping Cu2+ and Y3+ into BCZT could be a promising method to improve and balance the sintering, phase transition, and electrical properties for potential practical applications of lead-free piezoceramics.

Surgical site infections (SSIs) are the leading cause of hospital-acquired infections and are associated with substantial healthcare costs, with increased morbidity and mortality. To investigate the effects of the antibiotic stewardship program on prevention and control of SSI during clean surgery, we investigated this situation in our institution.We performed a quasi-experimental study to compare the effect before and after the antibiotic stewardship program intervention. During the pre-intervention stage (January 1, 2010 through December 31, 2011), comprehensive surveillance was performed to determine the SSI baseline data. In the second stage (January 1, 2012 through December 31, 2016), an infectious diseases physician and an infection control practitioner identified the surgical patients daily and followed up on the duration of antimicrobial prophylaxis.From January 1, 2010 to December 31, 2016, 41,426 patients underwent clean surgeries in a grade III, class A hospital. The rate of prophylactic antibiotic use in the 41,426 clean surgeries was reduced from 82.9% to 28.0% after the interventions. The rate of antibiotic agents administered within 120 minutes of the first incision increased from 20.8% to 85.1%. The rate at which prophylactic antimicrobial agents were discontinued in the first 24 hours after surgery increased from 22.1% to 60.4%. Appropriate antibiotic selection increased from 37.0% to 93.6%. Prophylactic antibiotic re-dosing increased from 3.8% to 64.8%. The SSI rate decreased from 0.7% to 0.5% (p 0.05). The pathogen detection rate increased from 16.7% up to 41.8% after intervention. The intensity of antibiotic consumption reduced from 74.9 defined daily doses (DDDs) per 100 bed-days to 34.2 DDDs per 100 bed-days after the interventions.Long-term and continuous antibiotic stewardship programs have important effects on the prevention and control of SSI during clean surgery.

Mn-Based catalysts with a Mn loading of 4 wt% were prepared using an impregnation method. Their Hg0 removal efficiencies were in the following order: 4% Mn/MK10 (montmorillonite K 10) > 4% Mn/SiO2 > 4% Mn/TiO2 > 4% Mn/Al2O3. Results from various characterization techniques, such as BET, XRD, STEM, H2-TPR, Hg0-TPD and XPS, suggested that the species, morphologies, and distributions of MnOx led to the different performances in Hg0 removal. The support effect on Hg0 adsorption and oxidation was studied. For 4% Mn/Al2O3 and 4% Mn/SiO2, physical adsorption dominates Hg0 removal at low temperature (150 °C), while chemical adsorption is more important at high temperature (350 °C). At both low and high temperatures, chemical adsorption and oxidation play leading roles in 4% Mn/TiO2 and 4% Mn/MK10, respectively. The effect of MnOx species and their morphologies on Hg0 oxidation was investigated. Amorphous MnO2 benefits Hg0 oxidation at both low and high temperatures, while amorphous Mn2O3 only facilitates Hg0 oxidation at high temperature. Hg0 oxidation on Mn-based catalysts follows a Mars–Maessen mechanism where the lattice oxygen of MnOx reacts with the absorbed Hg0.

Owing to its potential to maximize the power output, hybrid energy harvesting technology has attracted more research interest. Boosting merits such as renewable energy sources and high output, hybrid photovoltaic-triboelectric nanogenerator (HPTNG) is considered as one of the promising power sources for next-generation smart electronics. To date, there is still a lack of a comprehensive review of the latest development and challenges of HPTNGs. Herein, we systematically summarize the recent advances of the hybrid photovoltaic-triboelectric energy-harvesting system. In particular, the structural flexibility and simplification of the hybridized device is described, followed by the detailed discussion from perspectives of the input mechanical energy sources, the output interaction between triboelectric nanogenerators and solar cells, as well as the functions and applications of the HPTNGs. Finally, the main challenges and perspective for the future development of HPTNGs are discussed.

The automotive industry consumes a large amount of fossil fuels consequently exacerbating the global environmental and energy crisis and fuel cell electric vehicles (FCEVs) are promising alternatives in the continuous transition to clean energy. This paper summarizes the recent development of fuel cell technologies from the perspectives of the automobile industry and discusses current bottlenecks hindering commercialization of FCEVs. Current status of the fuel cell technology, policies and market prospect of FCEVs, as well as recent progress of FCEVs are reviewed. Polymer electrolyte membrane fuel cells constitute the mainstream and most mature fuel cell technology for automobile applications. Hybridization with an auxiliary battery system will greatly boost the dynamic response of FCEVs. Hydrogen FCEVs have entered the preliminary commercialization stage since 2015 and the market share of FCEVs is expected to grow at a high rate. Challenges encountered by commercialization of FCEVs and future outlook are also discussed. Future efforts are expected to focus on solving problems such as the high cost of fuel cell stack production and maintenance, insufficient hydrogen supply facilities, insufficient reliability, slow cold start, safety concerns, and immature energy management systems of FCEVs. This review serves as a reference and guide for future technological development and commercialization of FCEVs.

Iron and steel production is one of the most significant anthropogenic sources of atmospheric mercury emission. However, there is little information about this source in China. In this study, we focused on three typical Chinese sintering furnace processes. Mercury in flue gas was sampled using the EPA Method 30B and Ontario Hydro Method, and solid samples were also analyzed. We found that 1.12–4.66% of mercury input in sintering furnace processes was emitted into the atmosphere. The total mercury concentrations in the sintering furnace flue gas were 17.773, 31.765 and 18.275 μg/m 3 ; the major mercury species was oxidized form, which accounted for 73.4– 94.7% of the total mercury. The mercury concentrations in the stack flue gas were 0.373, 0.533 and 0.465 μg/m 3 , while its removal efficiencies by air pollution control devices (APCDs) were 97.5%, 81.1% and 96.8%, and its emission factors were 2.49, 2.71 and 1.28 mg/t sinter. The main mercury inputs were iron ore, coal, coke and lime, where the iron ore input was 74.84– 92.22% of the total mercury quantity. Moreover, mercury was distributed in fly ash (19.22– 81.54%), gypsum (13.29– 46.00%), iron ore sinter (0– 11.45%), and flue gas (1.12– 4.66%). An approximate mercury mass balance could be obtained from various samples in this study.

Although HBr promotes Hg0 oxidation over the V2O5-WO3/TiO2 catalyst, it possibly influences the catalyst DeNOx activity. NH3-SCR experiments were conducted over a commercial V2O5-WO3/TiO2 catalyst in the presence of HBr. NO conversion obviously decreases in the low temperature range (i.e.

The rapid economic development in China places a large demand for energy, and as a result, thermal power plants in China are producing an enormous amount of coal fly ash (CFA) which causes severe environmental pollution. This paper briefly describes the current production and utilization status of CFA in China and identifies the challenges confronting sustainable CFA utilization as the Chinese economy is being transformed. These issues include a regional imbalance in supply and demand, reducing demand in the real estate industry as well as stricter laws for environmental protection. Viable directions for future CFA utilization are proposed, for example, production of CFA-based ceramic tiles, recovery of elemental resources, agricultural melioration, treatment of wastewater and flue gas, and production of high-volume CFA concretes. This paper has some guiding significance for sustainable and cleaner utilization of CFA in China and even worldwide. Graphical abstract.

Chlorpyrifos is a widely used organophosphorus pesticide that efficiently protects crops against pests. However, recent studies suggest that severe exposure to chlorpyrifos may present adverse health effects in human. To analyze the exposure level and metabolic characteristics of chlorpyrifos pesticide in urban adults and farmers with/without occupation pesticide contact, the occurrence of urinary chlorpyrifos and methyl chlorpyrifos (CP-me), as well as their metabolite, 3,5,6-trichloro-2-pyridinol (TCPy), was determined in farmers of an agricultural village in China, and in urban adults of a nearby town. The geometric mean (GM) concentrations of TCPy, which is the major marker of chlorpyrifos exposure, were 4.29 and 7.57μg/g-creatinine in urban adults and farmers before pesticide application, respectively. Chlorpyrifos spraying significantly increased the concentrations of urinary TCPy. In the first day after spraying, a GM concentration of 43.7μg/g-creatinine was detected in the urine specimens from farmers, which decreased to 38.1 and 22.8μg/g-creatinine in the second and third day after chlorpyrifos spraying. The ratio of TCPy and its parent compounds, i.e. chlorpyrifos and CP-me, was positively associated with the sum concentration of urinary chlorpyrifos, CP-me, and TCPy, suggesting the increasing metabolic efficiency of chlorpyrifos to TCPy at higher chlorpyrifos exposure levels. To estimate the farmers' occupational exposure to chlorpyrifos pesticide, a new model based on the fitted first-order elimination kinetics of TCPy was established. Occupational chlorpyrifos exposure in a farmer was estimated to be 3.70μg/kg-bw/day (GM), which is an exposure level that is higher than the recommended guideline levels. Significant increase of urinary 8-hydroxydeoxyguanosine (8-OHdG) was observed on the first day after chlorpyrifos spraying, which indicates a potential oxidative damage in farmers. However, urinary 8-OHdG returned to its baseline level within two days.