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Hydrothermal treatment can facilitate hydrolysis of biomass wastes such as algae and livestock manures, by converting high-molecular weight carbohydrates and proteins to monosaccharides and amino acids. However, further decomposition and reciprocal reaction of monosaccharides and amino acids are usually accompanied with hydrothermal treatment, which have negative impacts on microbial fermentation performance. In this study, glucose and glycine were used as model substrates during hydrothermal treatment coupled with semi-continuous hydrogen and methane fermentation. The results showed that thermal decomposition of glucose was stronger than glycine, due to the binary interactions between carbonyl group and amino group. Acidic condition could suppress conversion of intermediate compounds to polymers, thereby improving 5-HMF concentration to 7.59 g/L. Hydrothermal by-products had adverse impacts on hydrogen fermentation stability, resulting in a wide fluctuation of hydrogen production rate of around 0.55 L/L/d. Adding sulfuric acid for treatment would increase the competition of sulphate reducing bacteria, and cause a stuck methane fermentation. Additionally, by-products degradation promoted the growth of hydrogenotrophic and mixotrophic methanogens.

Anode, usually with limited specific surface area, poor biocompatibility and high-cost materials, is still the key obstacle for conventional dual-chamber microbial fuel cell (MFC)’s wide application. To combat this challenge, graphene-like molybdenum disulfide (GL-MoS2) nanoflowers with a lateral size 200–300 nm are successfully synthesized via a simple one-step hydrothermal method and are used to modify MFC anodes. The experimental results show that GL-MoS2 nanoflowers modified carbon cloth (CC) and stainless-steel fiber felt (SSFF) anode obtains their maximum power density of 960.4 mW·m−2 and 713.6 mW·m−2 which are 1.7 and 3.6 times of their unmodified counterparts, respectively, which indicates that the modification not only can offer large specific surface area and good biocompatibility for biofilm growth, but also makes the anode surface more accessible for microbes’ colonization and substrate transfer and thus reduces polarization loss considerably. The graphene-like materials, especially those like GL-MoS2, are promising materials for excellent and cost-effective anode modification.

In this work, the electrical conductivity of nanocomposites filled with carbon black is simulated by the three-dimensional Monte Carlo method. First, three-dimensional model of the nanocomposites and carbon black is constructed and the conductive mechanism is studied. Then the calculation method of electrical conductivity of nanocomposites filled with carbon black is proposed according to the equivalent resistance of large-scale pure resistor network. Then the proposed electrical conductivity calculation method is verified by comparing with the simulation and experimental results. This result shows that it is feasible to directly obtain the conductivity of nanocomposites using the proposed conductivity calculation method. This study helps to estimate the electrical properties of nanocomposites filled with carbon black. And it also can help for studying nanocomposites filled with carbon nanotubes or graphene and the synergistic effect of hybrid fillers-filled nanocomposites.

Gradient-porous copper foam electrodes were applied to alleviate the adverse effects of the uneven current distribution of electrodes along the electrolyte flow direction in thermally regenerative ammonia-based batteries (TRABs). The results indicated that gradient-porous copper foam with a decreasing pore size (TRAB-LMS) provided the most uniform current distribution and generated the highest power density (15.5 W/m2), total charge (1800 C) and energy density (1224 W h/m3). With the increase in flow rate, the power density of the TRAB-LMS increased considerably within a certain range and then decreased slightly, with the optimal flowrate at 15 mL/min. Under the optimal flow rate, the performance of TRAB-LMS increased when the ammonia concentration rose from 0.5 to 2 M (1 M=1 mol L−1); however, it decreased slightly when the ammonia concentration further increased to 3 M. The slight decrease in the cathode potential suggested that the flow and ammonia concentration beyond the optional values facilitated not only the transfer of ammonia into the porous anode, but also the crossover of ammonia from the anode to the cathode.

Developing an oxygen evolution reaction electrocatalyst with low cost, abundant reserves and excellent performance is essential for the large scale application of renewable hydrogen energy. Herein, a selenium doped hierarchical Ni-based electrocatalyst was fabricated. Nickel nanosheet array (NNA) was firstly electrodeposited on stainless steel, and then selenium was doped in the NNA to form a hierarchical nanosheet structure via a hydrothermal process. The effect of hydrothermal temperature and duration on the OER performance were investigated. Results shown that after selenization at 140 °C for 12 h, the NNA electrodeposited for 30 min performed best OER performance with a current density of 50 mA cm−2 at overpotential of 365 mV and a small Tafel slope of about 34 mV dec−1. This work provides a valuable strategy to design high efficiency electrocatalysts and shows the universality of selenization for improving catalytic performance.

Scale-up is required in the practical application of microfluidic fuel cells. Using an array of electrodes is demonstrated as a promising way. However, the non-uniform current density distribution in array anodes will significantly limit the power output. In this study, current density distribution in air-breathing microfluidic fuel cells with an array of graphite rod anodes is tested under acidic and alkaline conditions. The array anode is divided into four layers according to their distance to cathode. Current density of each layer is recorded individually. The cell performance under alkaline media is better than that under acidic media and various current density distributions are found under different media. When the air-breathing microfluidic fuel cell is operated under acidic media, at current densities lower than 50 mA cm−3, current densities of two-layer anodes far from the cathode are higher than that of the other layers, while the reverse happens at current densities higher than 50 mA cm−3. This is mainly due to the enhanced fuel transport caused by CO2 bubbles and the lower ohmic resistance. Moreover, the generated CO2 bubbles lead to fluctuation of discharging densities especially at low voltages. However, for the air-breathing microfluidic fuel cell operated under alkaline media, two-layer anodes far from the cathode are main contributor to the total current density at all operation voltages.

In the past twenty years, membrane-less microfluidic fuel cells (M-MFCs) have undergone a rapid development as emerging chip-based power sources. They possess enormous advantages compared to congeneric membrane-separated micro fuel cells, including low costs, simple structures, superior flexibility, and the absence of membrane-related issues. As a promising micro power source, the technology has undergone significant progress towards providing an affordable solution for powering chip-based microsystems. This review provides a broad and balanced insight into the route towards performance enhancement, starting with a general description of the technology. We analyse the power-generation properties with respect to the thermodynamics and electrochemical kinetics, including fuel/oxidant type, acid–base properties, operating temperature, and electro-catalytic reactions. Moreover, we provide much needed insight into the charge and mass transport phenomena, examining the influence of electron and ion transport, reactant concentration, fuel/electrolyte flow rate, gas–liquid two-phase flow, and the cell design based on various electrode structures and a virtual membrane. Finally, we discuss the open challenges and briefly provide guidance for future industrial M-MFCs’ applications.

In the present study, we present a 3D oriented CuS/Cu2O/Cu nanowire photocathode grown on copper foam. This newly developed photocathode can effectively enhance the separation of electron–hole pairs and anti-photocorrosion as a result of the nanowire structure and bandgap gradient. In the meantime, it can provide more active sites and promote light utilization due to the vigorous porous structure and proper pore size. Experimental results confirmed the improved photoelectrochemical activity of the proposed photocathode as compared to the planar photocathode with CuS/Cu2O/Cu nanowires. The in-cell performance measurements of a dual-photoelectrode photocatalytic fuel cell with the proposed photocathode also demonstrated the enhancement of the cell performance by the proposed photocathode, presenting about 88% improvement in the maximum power density. The 3D oriented CuS/Cu2O/Cu nanowire photocathode represents a new route for the development of high-performance photocathodes, which can also be applied in other photoelectrochemical systems.

Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) is one of the most common aphid pests of winter cereals. To facilitate accurate gene expression analyses with qRT-PCR assays, the expression stability of candidate reference genes under specific experimental conditions must be verified before they can be used to normalize target gene expression levels. In this study, 10 candidate reference genes in M. dirhodum were analyzed by qRT-PCR under various experimental conditions. Their expression stability was evaluated with delta Ct, BestKeeper, geNorm, and NormFinder methods, and the final stability ranking was determined with RefFinder. The results indicate that the most appropriate sets of internal controls were SDHB and RPL8 across geographic population; RPL8, Actin, and GAPDH across developmental stage; SDHB and NADH across body part; RPL8 and Actin across wing dimorphism and temperature; RPL4 and EF1A across starvation stress; AK and RPL4 across insecticide treatments; RPL8 and NADH across antibiotic treatments; RPL8, RPL4, Actin, and NADH across all samples. The results of this study provide useful insights for establishing a standardized qRT-PCR procedure for M. dirhodum and may be relevant for identifying appropriate reference genes for molecular analyses of related insects.

Algal bloom biomass, sourced from a freshwater lake in Chongqing, was pre-treated by hydrothermal pre-treatments with or without acid/alkali catalysts, and subsequently used as a substrate for sustainable biohythane production via fermentation. Fourier transform infrared (FTIR) spectroscopy analyses suggested hydrothermal acid/alkali pre-treatments significantly changed peak intensities of chemical compositions in algal bloom biomass. Derivative thermogravimetric (DTG) analyses showed more macromolecular substances hydrolysed after hydrothermal acid/alkali pre-treatments. When bloom algae were pre-treated with 1% HCl at 140 °C for 10 min, an optimal specific hydrogen yield (SHY) of 39.4 mL/g volatile solid (VS) was obtained, which is 38.2% higher than raw biomass. However, a 34.4% decrease in SHY occurred under hydrothermal pre-treatment with 1% NaOH due to the enhancement of Maillard reaction. When using the effluents in methane fermentation, specific methane yields (SMYs) were 177.1–276.8 mL/g VS. Two-stage process effectively reduced the total fermentation time by 22.7% compared with single-stage fermentation.

Formic acid as a renewable fuel can be converted to clean electricity in fuel cells by high-efficient electrochemical oxidation. The conversion rate is fundamentally dictated by the synergy of interactive aspects: catalytic activity, accessibility to active sites, electron transfer, and anti-poisoning stability. For the first time, ordered mesoporous carbon (OMC) is used as the substrate for Pd–PdO catalyst for fuel cells. The unique ordered pore-channel network of OMC can enhance the spatial dispersion of Pd nanoparticles on the pore-channel wall, while the hollow pore-channel can facilitate reactant transport. Microwave and annealing treatments are found to enhance the chemical reduction and to strengthen the anchoring of Pd–PdO catalyst on OMC substrate, respectively. The OMC supported Pd–PdO catalyst (Pd–PdO/OMC) shows 1.7-fold and an order of magnitude higher mass activity and stability as compared to commercial Pd/C catalyst. For fuel cell testing, the Pd–PdO/OMC catalyst is applied to an air-breathing microfluidic fuel cell and achieves a maximum power density of 63.0 mW cm−2, at least one-fold higher than similar previous reports.

A direct formate microfluidic fuel cell with cotton thread-based electrodes is proposed. The palladium catalyst is directly coated on cotton threads by repeated dipping method to prepare electrodes, which integrates the flow channel and electrode together and provides exposed active sites for enhancing the mass transfer on the anode and cathode. The aqueous anolyte and catholyte transport through cotton threads by capillary force with aid of gravity, eliminating the use of any external pump and facilitating the integration and miniaturization of the whole system. In the experiment, a three-flow channel structure is employed. The fuel is sodium formate and the oxidant is hydrogen peroxide. 1 M Na2SO4 solution is introduced into the middle channel formed by cotton threads with no catalyst to alleviate the reactant crossover. Performance is evaluated under various catalyst loadings, fuel concentrations and differences in height between the inlet and outlet. Results show that the fuel cell produces an open circuit voltage (OCV) of 1.41 V. The maximum current density of 74.56 mA cm−2 and the peak power density of 24.75 mW cm−2 are yielded when the palladium loading is 1 mg cm−1 and the difference in height between the inlet and outlet is 7 cm, using 4 M HCOONa as fuel. Furthermore, the performance of the fuel cell increases first and then decreases with increasing the palladium loading. The same variation is observed with increasing the fuel concentration. However, the performance gradually increases with increasing the difference in height from 3 cm to 7 cm. The proposed microfluidic fuel cell with cotton thread-based electrodes shows enormous potential as a micro power source for portable devices.

Liquid absorption and solid adsorption technologies have been researched and reported widely for CO2 capture. Combining the advantages of these two capture materials, a novel anhydrous colloidal suspension was synthesized by dispersing amine-modified microporous silica nanospheres in 2-[2-(dimethylamino) ethoxy] ethanol. In this study, solid, hollow, and porous silica nanospheres with different internal pore structures were synthesized and characterized. The effects of the silica nanosphere microstructures on diethylenetriamine loading and CO2 absorption in anhydrous colloidal suspensions were studied. Due to a more developed pore structure, the hollow and porous silica-based absorbents possessed stronger amine loading capacities compared to solid silicon-based absorbent, and the best absorption performance was an absorption capacity of 1.2543 mmol/g at a pressure of 150 kPa and a temperature of 300 K. The results indicated that pore structure had a significant influence on the absorption property, and the porous silica-based absorbent was more favorable for CO2 absorption than solid and hollow silica-based absorbents. Moreover, the pseudo-second-order model was successful in predicting the CO2 absorption process in colloidal suspensions.

To investigate serum pituitary adenylate cyclase activating polypeptide (PACAP) levels in relation to disease progression in patients diagnosed with non-traumatic osteonecrosis of femoral head (ONFH). A total of 102 non-traumatic ONFH patients and 95 healthy controls were enrolled in this study. Serum PACAP levels were examined using enzyme-linked immunosorbent assay (ELISA). Radiographic progression of ONFH was detected using the Association Research Circulation Osseous (ARCO) classification system. Harris hip score (HSS) and visual analogue scale (VAS) were analyzed to understand clinical severity. Serum levels of the ONFH marker IL-33 and β‐CTX were also detected. ROC curve analysis was performed to investigate the potential diagnostic value of serum PACAP in the radiographic progression of ONFH. Serum PACAP levels were significantly decreased in non-traumatic ONFH patients when compared to healthy controls. ARCO stage 4 showed markedly lower serum PACAP levels than stage 3. ARCO stage 3 had significantly decreased serum PACAP levels compared to stage 1/2. Serum PACAP levels were negatively correlated with the ARCO classification. In addition, serum PACAP levels were positively associated with HSS score and negatively related to VAS score. Last, PACAP levels were negatively correlated with serum IL-33 and positively associated with β-CTX. ROC curve analysis indicated that PACAP may serve as an early indicator for the radiographic progression of ONFH. Reduced serum PACAP levels may reflect disease severity in non-traumatic ONFH patients.

The pyrolysis of methyl alkyl esters I to III and dithioesters IV to VI were theoretically calculated. All possible pyrolysis paths were considered. Both esters and dithioesters presented three potential paths via six-, four- and five-membered ring transition states, respectively. The calculation processes were calculated using MP2/6-31G(d) set. In-depth theoretical analyses were also presented, including NBO related analyses, synchronicities, and charge distributions, to reveal the detailed pyrolysis process.

In this study, nitrogen-rich biocarbon derived from carbonized Chlorella pyrenoidosa (CCP) was proposed to enhance the current generation from the anode of microbial fuel cells (MFCs). The results revealed that the carbon cloth decorated by CCP (CCP-CC) achieved the highest bioelectrocatalytic current density of 13.44 ± 0.34 A m−2 after the successful startup, which was 12% and 22% higher than those with carbon black (CB-CC) and the bare carbon cloth (CC), respectively. The results can be attributed to the advantages of CCP-CC over CB-CC and CC in terms of a higher active biomass content, a much smaller charge transfer resistance resulting from the facilitated direct electron transfer due to the presence of N-containing functional groups in CCP and the enhanced mediated electron transfer caused by the larger surface area of the CCP-CC anode for the flavin mediator adsorption.

Microbial electrosynthesis is an innovative technology capable of producing biofuels (particularly CH4) via CO2 reduction. Electron-uptaking from biocathode by microorganisms is the key step in the process of microbial electrosynthesis. However, the lack of understanding of electron transfer behaviors and their affecting factors largely limit the development of microbial electrosynthesis. Herein, we investigated the effects of initial startup cathode potentials (–0.7, –0.8, –0.9, –1.0 and –1.1 V vs. Ag/AgCl) on the electron transfer behaviors of biocathodes. The cyclic voltammetry (CV) showed typical sigmoidal catalytic currents corresponding to the CO2 reduction on the biocathodes started up at –0.7 and –0.8 V, but not on the other biocathodes. The CH4 production rate, Faradaic efficiency, scanning electron microscopy (SEM), and microbial community were also investigated. All the results indicated that the startup cathode potentials determine the electron transfer behaviors of biocathode: the biocathodes started up at –0.7 and –0.8 V mainly possessed a direct electron transfer manner, while the biocathodes started up at –0.9, –1.0 and –1.1 V mainly possessed an indirect electron transfer pathway. This study provides a guidance for the development of CH4-producing biocathodes with a desired electron transfer behavior.

Keyphrases provide core information for users to understand the document. Most previous works utilize machine learning based methods for keyphrases extraction and achieve promising performance. However, these methods focus on identify keyphrases from the input text, and can not extract keyphrases that do not appear in the text. In this paper, we present an encoder-decoder framework, which incorporating copying mechanism, to generate keyphrases for the given text. This framework (CopyNet) integrates the generation part and copying part. The generation part generates the keyphrase from the predefined vocabulary, and the copy part gets the keyphrases from the source text. Furthermore, we improve the CopyNet by using different probability of the two parts. To incorporate more related information for keyphrase generation, the automatically built keyphrase semantic web is merged into the dataset to participate in the training process of the neural network. Semantic similarity based and word co-occurrence based methods are used for keyphrase semantic web construction. We build a large-scale biomedical keyphrase dataset to evaluate the system performance. Experiments show that our improved CopyNet can achieve better performance with different portions of the generation and copying part, and the incorporation of the semantic web also effectively improves the keyphrase generation.

Localized fluid manipulation in microfluidic device is a key operation to various on-chip analytical/synthetic applications. In this work, we demonstrated the localized fluid actuation in microchannels by the infrared laser-induced evaporation–condensation-coalescence photothermal phase change process. Visualized experiments were carried out to investigate the dynamic phase change process and accompanying interfacial behaviors. Effects of laser power, spot speed, channel structure and actuation distance were investigated. Results indicate the actuation speed can be tuned by the output laser power, and the flow direction in microchannels can be selected by the control of laser spot trajectory. Long distance actuation performance suggests that the flow speed decreases due to the increase of fluid volume and flow resistance. The photothermally induced phase change process provides the means of simple and efficient localized fluid manipulation with remarkable dynamic response and the ability of agile maneuver in microfluidic channels, which could be further applied in different application scenarios.

Condensed deposition favors biochemical analysis, bioassays, and clinical diagnosis, but the existing strategies may suffer from low resolution, inaccurate control, cross-contamination, or miscellaneous apparatus. Herein, we propose a noncontact light strategy to enable the condensed deposition for droplet evaporative crystallization, in which the photothermal effect of a focused infrared laser is employed to induce intense evaporation. Due to the localized heating effect, not only can the droplet evaporative crystallization on the hydrophobic substrate be promoted, but also the resultant intensified Marangoni flow enables the movement of the early-formed crystals, preventing the pinning of the triple-phase contact line. Synergy of the Marangoni flow and nonuniform evaporation makes the solutes tend to accumulate near the focused light beam region, which facilitates the condensed deposition. More importantly, this light strategy not only enables condensed deposition on the hydrophobic surface with low hysteresis, but also works successfully on the hydrophilic substrate with high hysteresis via adjusting input laser power. It is demonstrated that the light strategy proposed in the present study has great potential for relevant applications.

The long startup time and low current density of biocathodes limit the application of microbial electrosynthesis systems for CO2 reduction to CH4. Herein, we reported an approach to accelerate the startup and enhance the current density of CH4-producing biocathodes through reversing the polarity during the startup period. A bioanode was first developed at −0.2 V vs. SHE with acetate as electron donor, and then worked as a biocathode by reversing the potential of electrode to −0.5 V vs. SHE. The results showed that the startup time of the biocathode reversed from the bioanode (∼18 days) was shortened by approximately 40% in contrast to that (>30 days) of the control biocathode started up with a constant potential of −0.5 V vs. SHE. In addition, the maximum CH4 production was increased by 1.2 ± 0.2 times than that of the control biocathode. The results suggested that the “reversed” biocathode possessed a thicker biofilm and higher biomass content than the control biocathode. Our results showed that polarity reversal was an efficient approach for the startup and performance enhancement of CH4-producing biocathodes in microbial electrosynthesis systems.

We demonstrated that the dimeric 1-tert-butyl-2,2,4,4,4-pentakis(dimethylamino)-2Λ5, 4Λ5-catenadi(phosphazene) supported on polystyrene (PS-t-BuP2) was an efficient and recyclable catalyst for the ring-opening polymerization (ROP) of δ-valerolactone (δ-VL). The heterogeneous catalyst PS-t-BuP2 could be recycled and reused for five consecutive cycles without significant decrease of catalytic activity. The monomer conversions maintained between 79% and 85% for five cycles. Using BnOH as initiator, the produced polyvalerolactones (PVLs) had controlled molecular weights (MWs) and narrow MW distributions (Đ), and the products were free of catalyst by simple filtration. The 1H NMR and MALDI-TOF characterizations of the obtained PVLs clearly indicated the presence of the initiator residue at the chain end.

In this work, a core-shell structured palladium catalyst layer in a gas-liquid-solid microreactor was proposed for the catalytic nitrobenzene hydrogenation through a facile and efficient approach. Via encapsulating the active palladium cores with the polydopamine shell, the proposed structure can construct barriers between the neighboring nanoparticles to not only inhibit the particle migration and aggregation during the hydrogen reduction and catalytic reaction processes but also protect the active palladium cores from being leaching. Because of these merits, the proposed core-shell structured palladium catalyst layer can significantly intensify the catalysis performance. Experimental results indicated that the developed catalyst layer showed good catalytic activity and operation durability. Compared to the conventional catalyst layer, the core-shell structure exhibited a 120% improvement in terms of the durability. Besides, the effect of the polydopamine encapsulating time on the structure and catalysis performance was also investigated. The best performance was achieved with the encapsulating time of 4 h in the present work. The obtained results reveal a facile and efficient avenue for designing the high-performance microreactors.

Water droplet freezing on the surface structures has a gigantic impact on the aircraft, power transmission lines and industrial facilities. Thereby, it is essential and meaningful to clearly understand the droplet impacting and icing behaviors on the supercooled superhydrophobic surface at an angle for the prevention of ice accretion. In the present research, the dynamic behaviors of a water droplet impacting on the superhydrophobic surface with different inclination and supercooling degree were visually studied by a high-speed camera. Moreover, the droplet dynamic behaviors were analyzed in terms of the contact time, freezing onset time, maximum spreading factor, rebounding energy, average sliding velocity and adhesion morphology on the surface. The results prove that the droplet rebounding process can be promoted by increasing the surface inclination. Moreover, with the gradually decreasing surface temperature the droplet successively undergoes full rebound, partial rebound and no rebound on the surface with an inclination of 30°, and the boundary temperatures of these three modes are −31.25 and −33.75 °C, respectively. Furthermore, the governing factor of the superhydrophobic surface anti-icing performance turns from the droplet rebounding energy into the average sliding velocity with an increase in the surface inclination, and the surface with an inclination of 30° has the best anti-icing performance. It is worth noting that reducing the surface de-icing difficulty rather than improving the anti-icing performance is more suitable for the extremely cold environment.

Continuous hydrothermal pretreatment in tubular reactors is a key process for the production of biofuel from microalgae biomass. Complex heat transfer characteristics of microalgae slurries, which consist of micron-sized cells suspended in water, are a challenge for the industrialization of hydrothermal pretreatment systems. In this study, the convective heat transfer characteristics of microalgae slurries flowing through a uniformly heated circular tube were experimentally investigated for the first time. The results revealed that the microalgae cell concentration and cell motion in the solid–liquid two-phase flow were the two main factors affecting the convective heat transfer characteristics of microalgae slurries in laminar tube flow. Considering the effects of the cell concentration, cell motion, viscosity variation with temperature and shear rate, and Peclet number, a novel correlation was proposed to predict the Nusselt number of microalgae slurries in laminar tube flow. In addition, a heat transfer deterioration phenomenon was observed under forced convection subcooled boiling conditions. This study provides guidance for the design and optimization of tubular heat exchangers in continuous hydrothermal pretreatment systems.

Carbon dioxide (CO2) as greenhouse gas is the primary cause of global warming. One of the ideal routes to remedy CO2 emission is to transform it to hydrocarbons by photocatalytic reduction of CO2. However, poor yield and product selectivity of photocatalytic reduction of CO2 pose significant challenges to its widespread applications. To address this critical issue, a coupled system that integrates photocatalytic reduction of CO2 with photocatalytic fuel cell (PFC) is developed for direct power generation using CO2. In this coupled system, the products by photocatalytic reduction of CO2 works as the fuels for the PFC to directly generate electricity. Direct power generation by this coupled system is demonstrated via only in the presence of CO2 as the input under illumination. A short circuit current density of 0.175 mA/cm2 and a maximum power output of 0.110 mW/cm2 are yielded for the case with the supply of CO2, which are much higher than those without CO2. Moreover, it is interesting to find that the fuel concentrations at the PFC outlet are even higher than those at the PFC inlet, implying that the coupled system proposed in this study can not only generate the electricity but also yield the solar fuels. This work opens a new avenue for the CO2 utilization toward direct power generation.

Microbial fuel cell is a unique energy technology where both wastewater treatment and electricity generation take place concurrently. However, the performance is typically rather limited due to the sluggish electron-transfer kinetics of oxygen reduction reaction at the cathode. Thus, development of high-performance cathode catalysts is of fundamental significance for the wide-spread application of microbial fuel cell. In this study, nanocomposites based on cobalt oxide nanoparticles supported on nitrogen-doped carbon nanotubes (Co/N-CNT) were synthesized by controlled pyrolysis of graphitic carbon nitride and cobalt acetate. Electrochemical tests indicated that the Co/N-CNT nanocomposites exhibited a high ORR electrocatalytic activity with a half-wave potential of +0.82 V and onset potential of +0.91 V vs. RHE, mostly via a four-electron reduction pathway. This was ascribed to the formation of high-efficiency Co N active sites that facilitated the ORR kinetics. A microbial fuel cell using the as-prepared Co/N-CNT as the cathode catalyst achieved a maximum power density of 1260 mW m−2, which was 16.6% higher than that based on state-of-art Pt/C catalyst (1080 mW m−2). The results suggest that Co/N-CNT nanocomposites may serve as viable cathode catalysts in microbial fuel cell application.

Porous Ni-Co-(WC)x ternary composite electrodes were fabricated by means of electrodeposition on a foam Ni substrate. The surface morphology and microstructure of the electrodes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrocatalytic properties of porous Ni-Co-(WC)x electrodes for hydrogen evolution reaction (HER) in 0.5 M H2SO4 solution at temperatures from 25 to 50 °C were conducted by means of cathodic polarization, electrochemical impedance spectroscopy (EIS), cyclic voltammetry and chronoamperometry (CA). These Ni-Co-WC electrodes are efficient electrocatalysts for HER. Compared with the porous Ni-Co electrode, the porous Ni-Co-(WC)x electrode exhibited a lower HER overpotential, a lower electrochemical impedance, a lower apparent activation energy and a higher exchange current density. The apparent exchange current density of porous Ni-Co-(WC)x (x = 10, 20, 30 and 40 g/l) is 2.01, 3.01, 7.8 and 19.91 times of porous Ni-Co electrode, respectively. With the increase of WC concentration and temperature, the apparent exchange current density of HER was enhanced. With the increase of WC concentration and potential, the HER resistance and the activation energy decreased. The Ni-Co-(WC)x electrode exhibited superior corrosion resistance and stability for HER.

In this work, the gas consumption characteristics were investigated by gas-liquid two-phase flow in a capillary microreactor using the catalytic hydrogenation of nitrobenzene as a reference gas-liquid reaction. Image processing technique was used to measure the gas consumption from the variation in the gas phase through the recorded images. The influence of the inlet nitrobenzene concentration and both the gas and liquid flow rates on the gas consumption and the microreactor performance was investigated. The experimental results showed that there existed a discrete hydrogen consumption process, i.e. the waiting stage and inburst stage. Hydrogen consumption was mainly attributed to the waiting stage in each bubble formation cycle. Minimal hydrogen was consumed in the inburst stage. In addition, there was a clear difference between the H2 consumption rates under each operating condition. As the gas flow rate and nitrobenzene concentration increased, the H2 consumption rate was gradually decreased with each successive formation cycle. Although the consumption rate was gradually reduced with each successive formation cycle with increasing liquid flow rate, the downward trend became increasingly gradual and clearly stabilized at 20 μL/min. The microreactor performances under different operating conditions were also investigated. The results showed that the nitrobenzene conversion was first increased and then gradually decreased with increasing the gas flow rate, whereas it was gradually decreased with increasing both the liquid flow rate and nitrobenzene concentration. The results obtained in this work are beneficial for not only understanding process intensification but also promoting the use of microreactor technology in additional industrial applications.

In this work, a solar responsive photocathode with the CuS/Cu2O/Cu cubic nanoparticles was developed to facilitate the separation of the electron/hole pairs so as to enhance the photoelectrochemical activity. The EIS and LSV results indicated the developed CuS/Cu2O/Cu photocathode showed better photoelectrochemical activity toward the oxygen reduction reaction than the Cu2O/Cu photocathode. Good stability of the developed CuS/Cu2O/Cu photocathode was confirmed by the photocurrent vs time measurement. Besides, the developed CuS/Cu2 O/Cu photocathode was also assessed by incorporating it into a photocatalytic fuel cell with the lateral design for simultaneous wastewater treatment and electricity generation. It was shown that higher cell performance was achieved than the Cu 2O/Cu photocathode. The performance of the photocatalytic fuel cell with the developed photocathode was then studied under various operating conditions. Experimental results indicated that increasing the light intensity and the Na2SO4 electrolyte concentration and decreasing the liquid flow rate in the testing range could improve the cell performance. This study provides a new photocathode design for the photocatalytic fuel cell applications and other photoelectrochemical systems.

In this work, the nitrogen-doped TiO2 photocatalyst is synthesized and applied in a microfluidic all-vanadium photoelectrochemical cell for enhancing the solar energy storage. The use of the nitrogen-doped TiO2 photoanode and the minimization design can ensure the visible-light response, increased specific surface area, vigorous pore structure and enhanced photon and mass transport as well as more uniform light distribution. Various characterizations are performed to evaluate the developed photocatalyst and microfluidic all-vanadium photoelectrochemical cell. The results confirm that the developed nitrogen-doped TiO2 photoanode can provide both the extended absorption spectrum and the small anatase crystal size as well as the obviously enlarged specific surface area with plentiful pore structure. Because of these merits, the microfluidic all-vanadium photoelectrochemical cell with the nitrogen-doped TiO2 photoanode yield the average photocurrent density of 0.103 mA/cm2 during the long-term operation, which is much higher than those with the un-doped TiO2 photoanode (0.086 mA/cm2) and commercial P25 TiO2 photoanode (0.073 mA/cm2), presenting 19.8% and 41% improvements, respectively. The results demonstrate not only the promotion of the vanadium reversible redox pairs conversion but also the inherently excellent stability by the nitrogen-doped TiO2 photoanode.

Membraneless microfluidic fuel cells are miniaturized and integratable power sources as compared with conventional fuel cells based on membrane electrode assembly. To elucidate the interaction of two-phase flow, mass transport and electrochemical reactions, a two-dimensional two-phase model is developed for the microfluidic fuel cell with a flow-through porous anode. The two-phase flow in the anode and the microchannel is formulated by the two-fluid model and mixture multiphase flow theory, respectively. The modelling results suggest that the retention of gas phase in the anode catalyst layer and microchannel can reduce the effective active area and impede the proton conduction to limit the cell performance. However, the commonly used single-phase assumption fails to capture these effects, resulting in overestimated performance. The fuel crossover shows an opposite trend as compared with that predicted by the previous single-phase model, and is found to correlate with the two-phase flow in the microchannel. The flow rates of fuel and electrolyte on the fuel transport and gas-phase removal are also discussed. The present work highlights the significance of two-phase effects in the modelling of microfluidic fuel cells, and provides insights into the two-phase flow and mass transfer for future development and operation.

Heterogeneous catalysts with a considerable active surface area are critically important to achieve the excellent catalytic activity. In this work, hence, a hierarchical Pd@Ni catalyst with a snow-like Ni nanostructure was prepared by combining the hydrothermal synthesis method with spontaneously galvanic replacement reaction. The snow-like Ni nanostructure on nickel foam not only effectively increased the specific surface area, but also ensured good dispersion of Pd nanocatalyst. Experimental results confirmed that the specific surface area of nickel foam was increased from 1 m2/g to 33 m2/g and the metallic active surface area was promoted from 0.34 m2/g to 1.31 m2/g. The catalytic activity and lifetime of the hierarchical Pd@Ni catalyst was also evaluated by nitrobenzene hydrogenation. It was demonstrated that, benefited from the higher catalytic surface area and the strong interaction between Pd and NiO, the hierarchical Pd@Ni catalyst could present both higher catalytic performance (TOF = 242 h−1) and lifetime than the conventional catalyst.

Coalescence and mixing of the complex chemical reagents on the droplet-based open microfluidics are considered to be critical steps for the sample processing and the follow-up reactions and chromogenic/fluorescence analyses. Recently, using the light to actuate the droplets coalescence has been demonstrated to be able to create the flexible, precise and high-throughput optical droplet-based reaction/analysis platforms. Particularly, the photothermal effect, which is one of the fluid-light interactions, is promising in the droplets coalescence by the light-induced phase change. In present study, a contact angle hypothesis traps (CAHTs)-assisted optical droplet-based reaction/analysis platform was developed. With the triple-phase contact line extension caused by the light-heating induced wetting transition, the coalescence of two neighboring droplets on the CAHTs was induced to facilitate the rapid mixing and detection. It was also confirmed that with the off-center light heating, the orientable extension of the irradiated droplet was realized, which could increase the critical CAHTs gap required for the occurrence of the droplets coalescence. With the developed platform, an ion detection by processing a chromogenic reaction was presented as a proof of concept. It is believed that this concept has the significant potential in many applications, including biomedicine, pharmacy, clinical diagnosis and chemosynthesis.

Bamboo charcoal tube (BCT) has been demonstrated to be the air-cathode for microbial fuel cells (MFCs). To enhance the performance of MFCs with BCT cathodes, we herein focus on optimizing BCT diameters and doping with nitrogen and phosphorus elements to improve the physical and chemical properties of BCT cathodes. Scanning electron microscope (SEM) analyses indicated that the cathode with 35 mm inner diameter had relatively ideal pore size distribution. Polarization curves, electrochemical impedance spectroscopy, and cyclic voltammetry results suggested that the cathode (35 mm inner diameter) delivered the highest power density of 7.5 ± 0.6 W m−3 among the cathodes with different diameters (27, 31, 35 and 39 mm). It was mainly because of its high oxygen reduction reaction performance, low cathode resistance, and beneficial effects on anode biofilm. In addition, rotating disk electrode (RDE) tests revealed that nitrogen and phosphorus doping could significantly improve the ORR catalytic activity of cathode by around 25% in the limiting current density.

In this study, we proposed a Pd–polyelectrolyte multilayer (PEM) hybrid film grafted on the polydopamine coated interior wall of a microreactor for nitrobenzene hydrogenation. Here, Pd nanoparticles were in situ synthesized in the PEMs consisting of poly(diallyldimethylammonium chloride) and poly(styrene sulfonate) via a two-stage ion-exchange and reduction process. The preparation process was monitored by UV-vis spectroscopy, which confirmed the formation of Pd in the PEM film. In addition, SEM and ICP-OES results indicated that the Pd content in the PEM film could be controlled by the number of the ion exchange and reduction cycles. Experimental results also showed that the prepared Pd–PEM hybrid film was active for the hydrogenation of nitrobenzene. The microreactor with the Pd–PEM hybrid film via multiple times had the increased catalyst loading, leading to a high yield of aniline and much better durability. In addition, it was also found that the NaCl concentration in the polyelectrolyte solution could affect the structure of the PEM film and therefore the Pd loading and catalytic performance.

Micranthanosides I and II (1–2), two diterpenoid glucosides featuring a new 1,10-secograyanane skeleton, thirteen new diterpenoid glycosides (3–15), and 21 known analogues were obtained from the ethanol extract of the leaves and twigs of Rhododendron micranthum. Micranthanoside XII (12) represent the first example of 3,5-epoxy-4,5-seco-ent-kaurane diterpenoid. The structures of these compounds were determined by spectroscopic data analysis and quantum chemical calculations. To clarify the chemical basis and provide reference for rational use of this medicinal plant, the antinociceptive and the anti-inflammatory activities of the compounds were tested. In the acetic acid-induced writhing test, compounds 17 and 19 showed significant antinociceptive activity at a dose of 3 mg kg−1 and compounds 2, 6 and 32 showed significant antinociceptive activity at a dose of 10 mg kg−1. Toxic reactions such as nausea and convulsion were observed when 17, 19, 29, and 31 at a dose of 10 mg kg−1 or 30 and 33 at a dose of 1 mg kg−1 were administered. The anti-inflammatory activities of the isolated compounds were evaluated by measuring the inhibitory effects of LPS-induced NO production in BV2 cells. At 10 μM, micranthanoside IX (9) and rhodomicranoside F (26) showed moderate anti-inflammatory activities with inhibition rates of 56.31% and 72.43%, respectively.

In this study, the pH-response of the zwitterionic polydopamine layer to the palladium deposition in a capillary microchannel and the resultant catalytic performance for the nitrobenzene hydrogenation were explored. Experimental results showed that the polydoapmine layer exhibited the switchable surface charge from positive to negative with increasing the pH value. Under low K2PdCl4 concentration, the intrinsic low pH not only allowed most palladium to be deposited at the inlet region of the microchannel, but also provided more accessible sites for the anion PdCl42− deposition. Such property resulted in less palladium deposited at the outlet region because of the limited supply of the precursor and poor mass transfer, while an excellent size distribution of the deposited palladium nanoparticles at both the inlet and outlet of the microreactor was obtained. With the increase of the K2PdCl4 concentration, the increased pH value of the precursor solution aggravated the dispersity of the deposited palladium species and led to large palladium particles at the upstream of the microreactor. The gradually lowered pH value of the precursor solution along the microchannel and the large concentration gradient could directly intensify the anion PdCl42− deposition. Thus, an inverse palladium distribution between the inlet and outlet regions was observed due to the shift of surface potential from negative to positive along the microchannel. Such feature influenced both the catalytic activity and the durability for the nitrobenzene hydrogenation. The obtained results in this work are beneficial for not only the controllable metal catalyst preparation but also the improvement in the economy utilization of catalyst.

The hydrodynamic characteristics of gas–liquid two-phase flow can significantly affect the performance of gas–liquid–solid microreactors. Using nitrobenzene hydrogenation as the reference heterogeneous catalytic reaction, the two-phase reacting flow behavior was visualized and characterized. Distinct differences in the length evolution, migration velocity and residence time of gas slugs were noticed for the reaction and non-reaction cases. The interface retraction of a gas slug was observed, which was mainly due to the hydrogen consumption at the gas pressure accumulation stage. Moreover, effects of the gas and liquid flow rates as well as the inlet nitrobenzene concentration on the two-phase flow behaviors and microreactor performance were also investigated. The results suggested that increasing the gas flow rate could enhance nitrobenzene conversion, but this effect was inhibited by the reduced residence time at high gas flow rates. Higher nitrobenzene concentration could enhance the interface retraction and extend the residence time, and together promote aniline production but in a trade-off with the conversion. This work reveals the intrinsic interaction between two-phase flow behaviors and catalytic reaction in microreactors, which can play a significant role in the development of microreactor technology.

Membraneless microfluidic fuel cells (MMFCs) outperform traditional membrane-based micro-fuel cells in membraneless architecture and high surface-to-volume ratio and facile integration, but still need substantial improvement in performance. The fundamental challenges are dictated by multiphysics regarding cell configurations: the interaction of fluid flow, mass transport and electrochemical reactions. We present a numerical research that investigates the effect of geometrical configurations (rod arrangement, cell length, rod diameter and spacer configuration) on the fuel transport and performance of an alkaline MMFC with cylinder anodes. Modeling results suggest that the staggered rod arrangement outperforms the in-line case by 10.1% at 50 μL min–1. Cell power output and power density vary nearly linearly with the cell length. In the case with 0.7 mm anodes and 0.3 mm spacers, the increased flow resistance at anode region drives the fuel to intrude into the spacer zone, leading to fuel transport limitation at downstream. The feasibility of non-spacer configuration is demonstrated, and the power density is 93.7% higher than the baseline due to reduced cell volume and enhanced fuel transport. In addition, horizontal extension of the anode array is found to be more favorable for scale-up, the maximum power density of 181.9 mW cm–3 is predicted. This study provides insight into the fundamental, and offers guidance to improve the cell design for promoting performance and facilitating system integration.

A woven thread-based microfluidic fuel cell based on graphite rod electrodes is proposed. Both inter-fiber gaps and inter-weave spaces could provide flow channels for the liquid transport through the woven cotton thread. Therefore, no external pumps are required to maintain the co-laminar flow, benefiting for the integration and miniaturization. In the experiment, sodium formate and hydrogen peroxide are used as fuel and oxidant, respectively. To improve the electrochemical reaction kinetics, KOH and H2SO4 serve as supporting electrolyte at the anode and cathode, respectively. Na2SO4 solution is used as the electrolyte to separate the cathode and anode in the middle flow channel and alleviate the reactant crossover. The open circuit potential of the fuel cell achieves 1.44 V and the maximum current density and power density are 56.6 mA cm−2 and 20.7 mW cm−2, respectively. Moreover, the cell performance reduces with increasing the electrode distance due to a high ohmic resistance. With an increase in the fuel concentration from 1 M to 4 M, the performance increases and it reduces with further increasing to 6 M owing to a correspondingly low flow rate. The highest fuel utilization rate reaches 10.9% at 4 M fuel concentration.

Flat-plate photobioreactor (PBR) with perforated inverted arc trough (PIAT) internals was proposed to promote CO2 bio-fixation by microalgae. The PIAT internals can enhance CO2 transfer from gas to culture medium by prolonging CO2 gas–liquid contact time and generate periodic aeration in the suspension upper side the PIAT providing suspension mixing. Experimental results showed gas–liquid contact time was prolonged from 0.448 s to 256 s and the CO2 partial pressure inside the PIAT internals was about 15.5 kPa during microalgae cultivation. Consequently, the dissolved CO2 concentration in the microalgae suspension of the proposed PBR was increased by 26.0% compared to that in the PBR without PIAT internals when 15% CO2 (v/v) was aerated at a rate of 15 mL min−1. The elevated CO2 transfer contributed to a 20.9% increment in biomass concentration (3.35 g L−1) and a 26.2% increment in CO2 fixation rate (36.6 mg L−1 h−1).

The miniaturization of membrane reactors aims to improve the mass transfer efficiency. A tube-in-tube hollow fiber catalytic membrane microreactor that contains dual characteristics of a catalytic membrane reactor and a microreactor was developed in this study. For a gas-liquid-solid (G-L-S) reactor, the immobilization of solid catalysts on a hollow fiber membrane (HFM) via layer-by-layer (LBL) self-assembly enables the model reaction of nitrobenzene hydrogenation to occur. The unique structure of the novel catalytic membrane microreactor separates the gas and liquid reactants and shortens the transfer distance. The experimental results showed that the nitrobenzene conversion was high during 30 h of continuous operation. The effects of the flow rates and inlet nitrobenzene concentration were also investigated. At a given gas flow rate, the nitrobenzene conversion and concentration of the product aniline decreased with increasing the liquid flow rate. Meanwhile, at a given liquid flow rate, an increase in the gas flow rate led to an increase in the pressure of the gas phase. Sufficient hydrogen promoted the reaction, increasing the nitrobenzene conversion and aniline concentration. In addition, the inlet nitrobenzene concentration affected the conversion. Higher concentration not only enhanced the reaction rate but also caused catalyst poisoning. Based on these results, the newly designed catalytic membrane microreactor is feasible to improve the performance towards multiphase reaction.

Aiming at ameliorating the poor hydrodynamic regimes and uneven light distribution in the conventional airlift flat-plate photobioreactor (AFP-PBR), a novel PBR with static airfoil-shaped deflectors (ASD-PBR) is proposed in this study to boost the microalgal biomass manipulation and hence the photo-biochemical conversion. The ASD module accelerated the circulation of microalgal suspension from the center to two sides with the help of bubbling so that the microalgal cells got more opportunities to access the light source. Compared with the control PBR, the solution velocity along the incident light direction increased by 114.8% in the newly-proposed ASD-PBR. Furthermore, the ASD module also served as a static mixer, which resulted in an increment of 11.5% in mass transfer coefficient and a decrement of 21.4% in mixing time. The amended hydrodynamic characteristics eventually contributed to an improvement of 18.3% and 10.9% in the maximum algal biomass yield and CO2 fixation rate, respectively.

Accurate and rapid blood typing plays a vital role in a variety of biomedical and forensic scenarios, but recognizing weak agglutination remains challenging. Herein, we demonstrated a flipping identification with a prompt error-discrimination (FLIPPED) platform for automatic blood group readouts. Bromocresol green dye was exploited as a characteristic chromatography indicator for the differentiation of plasma from whole blood by presenting a teal color against a brown color. After integrating these color changes into a quick-response (QR) code, prompt typing of ABO and Rhesus groups was automatically achieved and data could be uploaded wirelessly within 30 s using a commercially available smartphone to facilitate blood cross-matching. We further designed a color correction model and algorithm to remove potential errors from scanning angles and ambient light intensities, by which weak agglutination could be accurately recognized. With comparable accuracy and repeatability to classical column assay in grouping 450 blood samples, the proposed approach further demonstrates to be a versatile sample-to-result platform for clinical diagnostics, food safety, and environmental monitoring.

Xinjiang (XJ) and Ningxia (NX) provinces are important agricultural regions in western China. Aphids are one kind of the most devastating pests in both the provinces. Aphids are typical phloem-feeding insects distributed worldwide and can severely damage crops. In this study, two representative Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) populations were collected from the typical agricultural regions of XJ and NX, respectively for a high-throughput transcriptome sequencing analysis. A total of 5,265 differentially expressed genes (DEGs) were identified. The functional annotation of DEGs and the identification of enriched pathways indicated many of the DEGs are involved in processes related to energy metabolism, development, and insecticide resistance. Furthermore, an investigation of insecticide toxicity revealed the NX population is more resistant to insecticide treatments than the XJ population. Thus, the transcriptome data generated in present study can be used for functional gene characterization relevant to aphid development, metabolism, environmental adaptation, and insecticide resistance.

Carbonate reservoirs are the main reservoir types in China, which occupy the large ratio of reserves and production at present. The high-efficiency development of carbonate reservoirs is of great significance to assure the stability of national energy supply. The Lower Paleozoic reservoir in Jingbian gas field and the Sinian reservoir in Anyue gas field are two typical carbonate gas reservoirs, and their successful development experiences can provide significant references for other similar carbonate gas reservoirs. For Jingbian gas field, it is a lithological-stratigraphic reservoir developed in a westward monocline and multiple rows of nose-fold structures, and is a stable craton basin with simple palaeognomy distribution and stable connectivity, which has complex gas-water distribution. However, for Anyue gas field, it is a lithological-structural reservoir with multiple tectonic high points and multiple fault systems, and is biological dune beach facies under extensional setting with highly differentiated inside of the block in palaeognomy characteristics, which has limited connectivity and tectonic side water is in a local area. The difference of gas reservoir characteristics leads to the diverse development strategies. For these two gas reservoirs, although there are some similar aspects, such as the screen of enrichment areas, the application of irregular well pattern and reservoir stimulation techniques, the criteria of enrichment areas, the well types, and the means of reservoir stimulation are absolutely different. In addition, due to the differences of control reserves and production capacity for these two kinds of reservoirs, the mode of stable production is also different. The effective development of Jingbian gas field can give some references to the future exploitation on the Sinian gas reservoir. Firstly, the sedimentary characteristics should be studied comprehensively. Secondly, the distribution pattern and distribution characteristics of the palaeognomy should be found and determined. Thirdly, the distribution of fracture system in the reservoir should be depicted finely. Finally, dynamic monitoring on the production performance should be strengthened, and the management for this gas field should be improved further. The findings of this study can help for better understanding of the Karst weathering-crust carbonate gas reservoir formation characteristics and the optimal development technologies that should be taken in practice.

An NHC-catalyzed atroposelective reaction between ynals and urazoles is disclosed. The reaction establishes a chiral C-N axis via an atroposelective [3 + 2] annulation/desymmetrization process. Our reaction allows efficient access to axially chiral and heteroatom-rich urazole derivatives with potential applications in bioactive molecules and catalysis. Agency for Science, Technology and Research (A*STAR) Economic Development Board (EDB) Ministry of Education (MOE) Nanyang Technological University National Research Foundation (NRF) We acknowledge financial support from the National Natural Science Foundation of China (21772029, 21801051, 21961006, 22001173), The 10 Talent Plan (Shicengci) of Guizhou Province ([2016]5649), the Guizhou Province Returned Oversea Student Science and Technology Activity Program [(2014)-2], the Science and Technology Department of Guizhou Province ([2018]2802, [2019]1020, Qiankehejichu-ZK[2021]Key033), the Program of Introducing Talents of Discipline to Universities of China (111 Program, D20023) at Guizhou University, Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules, Department of Education, Guizhou Province [Qianjiaohe KY (2020)004], the Basic and Applied Research Foundation of Guangdong Province (2019A1515110906), the Guizhou Province FirstClass Disciplines Project [(Yiliu Xueke Jianshe Xiangmu)- GNYL(2017)008], Guizhou University of Traditional Chinese Medicine, and Guizhou University (China). Singapore National Research Foundation under its NRF Investigatorship (NRF-NRFI2016-06), the Ministry of Education, Singapore, under its MOE AcRF Tier 1 Award (RG108/16, RG5/19, RG1/18), MOE AcRF Tier 3 Award (MOE2018-T3-1-003), the Agency for Science, Technology and Research (A*STAR) under its A*STAR AME IRG Award (A1783c0008, A1783c0010), GSK-EDB Trust Fund, and Nanyang Research Award Grant, Nanyang Technological University.

Molecular mechanisms underlying wing evolution and development have been a point of scientific inquiry for decades. Phloem-feeding aphids are one of the most devastating global insect pests, where dispersal of winged morphs lead to annual movements, migrations, and range expansions. Aphids show a polyphenic wing dimorphism trait, and offer a model to study the role of environment in determining morphological plasticity of a single genotype. Despite recent progresses in the genetic understanding of wing polyphenism, the influence of environmental cues remains unclear. To investigate the involvement of miRNAs in wing development, we sequenced small RNA libraries of the English grain aphid, Sitobion avenae (F.), across six different developmental stages. As a result, we identified 113 conserved and 193 S. avenae-specific miRNAs. Gene Ontology and KEGG pathway analyses of putative target mRNAs for the six differentially expressed miRNAs are enriched for wing development processes. Dietary uptake of miR-263a, miR-316, and miR-184a agomirs and antagomirs led to significantly higher mortality (>70%) and a lower proportion of winged morphs (

Image enhancement is an essential processing for raw infrared images to improve contrast. In this paper, an infrared image enhancement method is proposed to solve the problem of over-enhancement on background in occurrence probability histogram based methods and the problem of uneven enhancement for targets in the saliency weight based method. First, the saliency histogram is constructed, where the bin values of target-related intensity levels are significantly larger than the bin values of background-related intensity levels. According to the value distribution of bins in saliency histogram, the intensity levels with several largest bin values, defined as the salient intensity levels, are segmented. Salient intensity levels are separated further away from non-salient levels to improve the contrast between targets and background. Second, salient intensity levels are divided into groups and each group is related to targets of a certain range of temperatures. Bin values of salient intensity levels are reallocated within each group to keep these intensity levels compact, for the purpose of performing equalized enhancement for targets. Experimental results demonstrate that the proposed method achieves better improvement on target-to-background contrast and better visual quality on targets by performing equalized enhancement for targets.