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Ammonia is a promising carbon-free alternative fuel for use in combustion systems. The main associated challenges are its relatively low reactivity and high NOx emissions compared to conventional fuels. Therefore, the combustion behaviour of ammonia and ammonia blends still needs to be better understood over a wide range of conditions. To this end, a comprehensive chemical kinetic mechanism C3MechV3.4, which is an update of C3MechV3.3, has been developed for improved predictions of the combustion of ammonia and ammonia blends. C3MechV3.4 has been validated using a wide range of experimental results for pure ammonia and ammonia/hydrogen, ammonia/methanol and ammonia/n-heptane blends. These validations target different data sets including ignition delay times, species profiles measured as a function of time, and/or temperature and laminar flame speeds over a wide range of conditions. The updated developed mechanism gives good predictions for pure ammonia and its blends with hydrogen, methanol and n-heptane. The most important reactions affecting predictions in different regimes for the various ammonia mixtures are discussed.

Heterogeneous metals and alloys are a new class of materials with superior mechanical properties. In this paper, we engineered sandwich-structured pure aluminum laminates composed of middle coarse-grained layer and outer fine-grained layer via extrusion, rolling and annealing. By controlling the post-annealing regimes, a larger degree of microstructure heterogeneities such as boundary spacing, misorientation and texture across the hetero-interface were obtained, which resulted in obvious mechanical differences. Tensile tests indicated that the 300 °C/30 min annealed laminates enabled a relatively high tensile ductility while simultaneously retaining a high strength, which was better than prediction by the rule-of-mixture. To explain the reasons behind it, the evolution of geometrically necessary dislocations and strain gradient at the hetero-interface zone were detected using in-situ tension and microscopic digital image correlation technique. It was found that with the increasing applied strain, a significant strain gradient was developed near the interface, which was accommodated by geometrically necessary dislocations, thereby contributing to higher hetero-deformation induced (HDI) strengthening and hardening.

The equilibrium relationship between the charge transfer and gas evolution capacities of reasonable size Al-STO nanoparticles induces the balance point of HER and OER half-reactions.

Surface state of ZnIn2S4 is regulated with γ-ray radiation, achieving over 10 times enhanced photocatalytic H2-evolution performance, which provides reasonable inspiration to regulate the surface vacancies of photocatalysts for enhanced activity.

A quasi three-dimensional Sb2S3/rGO/MXene composite exhibits high adsorption energy of Na+, excellent rate capability and stable cycling performance.

The reasonable design of a highly efficient photocatalyst to improve its hydrogen production performance has attracted extensive attention.

The traditional two-wheeled self-balancing robot can travel quickly in a flat road environment, and it is easy to destabilize andcapsize when passing through a bumpy road. To improve the passing ability of a two-wheeled robot, a new wheel-leggedtwo-wheeled robot is developed. A seven-link leg structure is proposed through the comprehensive design of mechanismconfiguration, which decouples the balanced motion and leg motion of the robot. Based on the Euler-Lagrange method, thedynamic model of the system is obtained by applying the nonholonomic dynamic Routh equation in the generalized coordinatesystem. The robot’s state space is divided according to the robot’s height, and the Riccati equation is solved in real-time by thelinear quadratic regulator(LQR) method to complete the balance and motion control of the robot. The robot leg motion controlis achieved based on the Active Disturbance Rejection Control(ADRC) way. A robot simulation model is built on Recurdyn toverify the algorithm’s feasibility, and then an experimental prototype is built to demonstrate the algorithm’s effectiveness. Theexperimental results show that the control method based on LQR and ADRC can make the robot pass through the bumpy road.

A high-resolution (∼500 m) numerical model was used to study the reef and atoll wakes in the Xisha Archipelago (XA) during 2009. Statistical analyses of simulation data indicated strong cyclonic dominance in the mixing layer (above ∼35 m) and weak anticyclonic dominance in the subsurface layer (35∼160 m) for both eddies and filaments in the XA. The intrinsic dynamical properties of the flow, such as the vertical stratification and velocity magnitude, and the terrain of reefs and atolls had a significant effect on the asymmetry. Without considering the existence of reefs and atolls, the “background cyclonic dominance” generated under local planetary rotation (f≈4.1×10−5 s−1) and vertical stratification (with mean Brunt–Väisälä frequency N = 0.02 s−1 at 75 m) was stronger for filaments than eddies in the upper layer from 0∼200 m, and the larger vorticity amplitude in the cyclonic filaments could greatly enhance the cyclonic wake eddies. Furthermore, inertial–centrifugal instability induced selective destabilization of anticyclonic wake eddies in different water layers. As the Rossby number (Ro) and core vorticity (Burger number, Bu) decreased (increased) with the water depth, a more stable state was achieved for the anticyclonic wake eddies in the deeper layer. The stratification and slipping reefs and atolls also led to vertical decoupled shedding, which intensified the asymmetry.

In continuous-variable quantum key distribution (CV-QKD), the key information are encoded on quadratures of the optical field, which are measured via balanced homodyne detector (BHD). The bandwidth of the BHD is one of key parameters for precise characterization of quantum states. We establish a theoretical model to analyze the impact of the BHD bandwidth and signal modulation patterns on the channel parameters estimation of CV-QKD systems. Based on the proposed model, the secure key rate of a practical CV-QKD system under different BHD bandwidths and signal modulation patterns are investigated. Our results show that insufficient BHD bandwidth will result in wrong estimate of the transmission loss and excess noise, which significantly affects the performance of CV-QKD systems. Given the BHD bandwidth, there exists an optimal signal repetition rate that maximizes the secure key rate. The BHD bandwidth requirement of the QKD system increases with the transmission distance for large duty cycle pulse. Furthermore, the root raised-cosine pulse signal modulation performs better than the square pulse signal modulation in general.

We synthesized Pd particles in reversible ionic liquid formed by carbon dioxide induction of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1-hexanol solution. Transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) were used to characterize their morphology and size. The particles have smaller size and more uniform size distribution compared with those synthesized in the mixed solution without carbon dioxide. The particles size obtained by TEM is obviously larger than that obtained by SAXS, which indicates the aggregation of the Pd particles in the separation and washing processes of TEM characterization. Then we studied the catalytic performance of Pd nanoparticles in p -nitrotoluene and 2-nitrobenzaldehyde hydrogenation reaction. The results showed that the nanoparticles have high catalytic activity and selectivity for nitro group with aldehyde group unchanged.

The term M-phase supershift denotes the phosphorylation-dependent substantial increase in the apparent molecular weight of numerous proteins of varied biological functions during M-phase induction. Although the M-phase supershift of multiple key mitotic regulators has been attributed to the multisite phosphorylation catalyzed by the Cdk1/cyclin B/Cks complex, this view is challenged by multiple lines of paradoxical observations. To solve this problem, we reconstituted the M-phase supershift of Xenopus Cdc25C, Myt1, Wee1A, APC3, and Greatwall in Xenopus egg extracts and characterized the supershift-producing phosphorylations. Our results demonstrate that their M-phase supershifts are each due to simultaneous phosphorylation of a considerable portion of S/T/Y residues in a long intrinsically disordered region that is enriched in both S/T residues and S/TP motifs. Although the major mitotic kinases in Xenopus egg extracts, Cdk1, MAPK, Plx1, and RSK2, are able to phosphorylate the five mitotic regulators, they are neither sufficient nor required to produce the M-phase supershift. Accordingly, inhibition of the four major mitotic kinase activities in Xenopus oocytes did not inhibit the M-phase supershift in okadaic acid-induced oocyte maturation. These findings indicate that the M-phase supershift is produced by a previously unrecognized category of mitotic phosphorylation that likely plays important roles in M-phase induction.

This study aimed to evaluate the effects of dietary protein level on the production performance, slaughter performance, meat quality, and flavor of finishing pigs. Twenty-seven Duroc♂ × Bamei♀ binary cross-bred pigs (60.86 ± 2.52 kg body weight) were randomly assigned to three groups, each group has three replicates, and each replicate has three pigs. Three groups of finishing pigs were fed 16.0, 14.0, and 12.0% crude protein levels diets, and these low-protein diets were supplemented with four limiting amino acids (lysine, methionine, threonine and tryptophan). The results showed that the pigs fed low-protein diets increased (P < 0.05) loin eye muscle area, and reduced (P < 0.05) heart weight, lung weight. The feed-weight ratio of the 14.0% protein group was reduced (P > 0.05); Dietary protein levels significantly affected the luminance (L24h), yellowness (b45min and b24h) (P < 0.05), reduced shear stress, muscle water loss, drip loss, the levels of crude fat (P < 0.05), and increased marbling score (P < 0.05) in the muscle of finishing pigs; The low-protein diets improved PUFA/TFA, PUFA/SFA (P > 0.05), and increased hexanal, E-2-heptenal, 1-octen-3-ol, EAA/TAA in the muscle of finishing pigs (P < 0.05); The results indicated that reduced the crude protein levels of dietary by 2.0–4.0%, and supplementation with four balanced limiting amino acids had no significant effects on the production performance and slaughter performance of finishing pigs, and could effectively improve meat quality and flavor.

The objective of clustering ensemble is to fuse multiple base partitions (BPs) to find the underlying data structure. It has been observed that sample can change its neighbors in different BPs and different samples have different relationship stability of sample. This difference shows that samples may have different contributions to the detection of underlying data structure. In addition, clustering ensemble aims to integrate the inconsistent parts of BPs by initially extracting the consistent parts. However, the existing clustering ensemble methods treat all samples equally. They neither consider sample relationship stability nor whether sample belongs to the consistent result or the inconsistent result in BPs. To tackle these deficiencies, we introduce the certainty of a sample to qualify its neighbor relationship stability and propose a formula to calculate this certainty. Then, we develop a clustering ensemble algorithm based on the sample’s certainty. It is based on the following idea: the neighbor relationship of cluster core in BPs is more stable, and different cluster cores usually do not form neighbor relationships in BPs. This idea forms the basis of the clustering ensemble process. According to the sample’s certainty, this algorithm divides a dataset into two subsets: cluster core samples and cluster halo samples. Then, the proposed algorithm discovers a clear core structure using cluster core samples and gradually assigns cluster halo samples to the core structure. The experiments on six synthetic datasets illustrate how our algorithm works. This algorithm has excellent performance and outperforms twelve state-of-the-art clustering ensemble algorithms on twelve real datasets.

The joint control strategy of four-wheel steering and electronic differential on account of pavement parameter identification is proposed in the manuscript. On account of fuzzy control theory, the four-wheel steering and the electronic differential controllers are designed. By controlling the rear wheel rotation angle and reasonable distributing the driving torque, makes the vehicle actual values of parameters follow the ideal values. This strategy is verified by the joint simulation experiment of Carsim and Matlab/Simulink. The results show that the joint control strategy can ensure the stability of the vehicle.

A trend towards the increasing use of Adaptive Mesh Refinement (AMR) algorithms to simulate combustion processes is observed in the recent literature. AMR is attractive as it enables the physical phenomena of interest to be tracked by the numerical mesh, reducing the computational cost drastically. It is particularly efficient for combustion as small computational cells are needed very locally to resolve the flame structure. However, the questions arising from the coupling between AMR and the turbulent flame propagation have rarely been investigated so far. Indeed, the incomplete cascading of turbulent structures from a relatively coarse mesh used to solve the flow to a finer mesh solving the flame has implications on the turbulent combustion model which must be considered. In the present paper, a strategy for coupling AMR with the Thickened Flame Model (TFM) is proposed. It is shown that, under conditions relevant to industrial cases, the standard TFM model strongly under-estimates the turbulent flame propagation when the effects of AMR is not taken into account. A new model, AMR-E, is introduced to take this effect into account. The behavior of the model is first analyzed on an a priori 1D-study and is consequently validated on a 3-D turbulent flame propagation in Homogeneous Isotropic Turbulence (HIT). In particular, it is shown that the presented model has a similar behavior for different AMR refinement levels in the flame front.

Non-alcoholic fatty liver disease (NAFLD) has a high prevalence worldwide, with a significant proportion of patients progressing into non-alcoholic steatohepatitis (NASH) and further into cirrhosis and hepatocellular carcinoma (HCC). Most of the current animal models of NASH have limitations, such as incompatibility with human pathogenesis characteristics or long induction periods, which severely limit the development of new drugs and preclinical studies for NASH. We investigated the progression of NASH and fibrosis, as well as metabolic indicators, at different time points in aged mice induced by the Gubra Amylin NASH (GAN) diet, a high-fat, high-sugar, high-cholesterol diet, and attempted to establish a rapid and useful mouse model of NASH. Young and aged C57BL/6 mice were induced on a normal chow or GAN diet for 12 and 21 weeks, respectively. After 12 weeks of induction, aged mice developed NASH, including hepatic steatosis, lobular inflammation and hepatic ballooning, and the phenotype was more severe compared with young mice. After 21 weeks of induction, aged mice developed hepatic fibrosis, which greatly shortened the induction time compared with young mice. Furthermore, analysis of immune cell infiltration in the liver by flow cytometry elucidated the changes of multiple immune cells during the pathogenesis of NASH. These findings suggest that aged mice may develop NASH and fibrosis more rapidly under GAN diet induction, which may significantly shorten the period for preclinical studies of NASH.

We experimentally demonstrate a high-rate discretely modulated continuous-variable quantum key distribution over 80-km standard single-mode fiber with a 2.5 Gbaud, 16-symbol, two-ring constellation. With the help of well-designed digital signal processing algorithms, the excess noise of the system can be effectively suppressed. The achieved secret key rates are 49.02 Mbits/s, 11.86 Mbits/s, and 2.11 Mbits/s over 25-km, 50-km, and 80-km optical fiber, respectively, and achieve 67.4%, 70.0%, and 66.5% of the secret key rate performance of a Gaussian-modulated protocol. Our work shows that it is feasible to build a high-performance, long-distance continuous-variable quantum key distribution system with only a small constellation size.

To improve the seismic performance of a staggered truss steel framing system, the basic force unit in the truss system is replaced by a friction energy dissipation truss. The difference between a friction energy dissipation truss and an ordinary truss is that the upper chord is a friction energy dissipation composite chord. In this paper, we investigate the effects of the number of bolts and the friction surface on the energy dissipation capacity of the chord by a quasi-static test on six composite chord specimens at a scale of 1:2. The results show that the hysteresis curves of friction energy dissipation composite chords are ideal rectangles, and the energy dissipation capacity is excellent. The more bolts there are in the specimen, the slower the energy dissipation capacity of the chord decreases. Among the different friction surface specimens, the energy dissipation capacity of the aluminum friction plate specimen decays the fastest, while the energy dissipation capacity of the shot-blasted treated specimen decays substantially after the first cycle. Friction plates can improve the stability of the hysteresis properties. Based on the test results, this paper proposes a calculation method for the ultimate bearing capacity of the composite chord, which provides a basis for the design of a friction energy dissipation truss. In addition, we studied the effects of different bolt clamping forces and slotted bolt hole lengths on the energy dissipation capacity of composite chords by establishing a finite element analysis. It was shown that as the clamping force of the bolt increases, the energy dissipation capacity of the specimen becomes stronger but the stability decreases. The energy dissipation capacity of the chord is close to a linear relationship with the slotted bolt hole lengths; thus, increasing the slotted bolt hole lengths within the allowable range of inter-story drifts can enhance the energy dissipation capacity of the chord. Finally, we propose the design method of the angle steel by analyzing the force of the chord.

Octogenarians with esophageal cancer typically have a poor physical condition, reduced physiological reserves, and high postoperative mortality (POM). Extensive lymph node dissection increases surgical trauma and postoperative complications. The purpose of this study was to examine the associations between the number of dissected lymph nodes and short-term and long-term postoperative outcomes in octogenarians with thoracic esophageal cancer.We examined the data of patients from the Surveillance, Epidemiology, and End Results database. We divided the patients into two groups in accordance with the number of lymph nodes dissected: patients with15 examined lymph nodes (eLNs) and patients with ≥15 eLNs. Mortality was quantified at 30, 60, and 90 d after surgery. Univariable and multivariable logistic regression analyses were performed to identify predictors of 90-day mortality. Kaplan-Meier analysis and the log-rank test were used to analyze the overall survival and cause-specific survival of the patients.A total of 208 octogenarians with thoracic esophageal cancer were included in the analysis. The 30-day POM rates were 10.3% and 6.9%, the 60-day POM rates were 16.9% and 13.9%, and the 90-day POM rates were 21.3% and 19.4% for patients with15 eLNs and ≥15 eLNs, respectively. However, the differences in POM between the two groups were statistically nonsignificant (all P 0.05). In accordance with the multivariable logistic regression analysis, age and marital status were significantly associated with 90-day POM. Furthermore, no significant difference was found between the groups in terms of long-term survival. The 5-year overall survival rates were 29% and 26.8% (P = 0.719) and the 5-year cause-specific survival rates were 43.2% and 34.1% (P = 0.446) in patients with15 eLNs and ≥15 eLNs, respectively.We have demonstrated that octogenarians undergoing esophagectomy are associated with an unacceptably high POM, and less extensive lymph node resection does not decrease POM. Octogenarians may not benefit from esophagectomy with lymphadenectomy. Additional studies need to be conducted to further guide clinicians performing highly selective esophagectomy.

Seahorses have a circum-global distribution in tropical to temperate coastal waters. Yet, seahorses show many adaptations for a sedentary, cryptic lifestyle: they require specific habitats, such as seagrass, kelp or coral reefs, lack pelvic and caudal fins, and give birth to directly developed offspring without pronounced pelagic larval stage, rendering long-range dispersal by conventional means inefficient. Here we investigate seahorses’ worldwide dispersal and biogeographic patterns based on a de novo genome assembly of Hippocampus erectus as well as 358 re-sequenced genomes from 21 species. Seahorses evolved in the late Oligocene and subsequent circum-global colonization routes are identified and linked to changing dynamics in ocean currents and paleo-temporal seaway openings. Furthermore, the genetic basis of the recurring “bony spines” adaptive phenotype is linked to independent substitutions in a key developmental gene. Analyses thus suggest that rafting via ocean currents compensates for poor dispersal and rapid adaptation facilitates colonizing new habitats., A new seahorse genome and the re-sequenced genomes of 21 other species shed new light on the evolutionary origin and global dispersal routes of seahorses, and show that bony spines—a key adaptation against predation—probably evolved multiple times via independent substitutions in the bmp3 gene.

In terms of CO2 capture and storage (CCS), it is highly desired to substitute of high efficiency process for the applied one which is far from the ideal one. Physical processes cannot capture CO2 effectively, meanwhile CO2 desorption is energy-intensive in chemical processes. Herein, a depth-suitable and water-stable trap for CO2 capture was discovered. Carboxylates can react with polybasic acid roots by forming united hydrogen bonds. Carboxylate ionic liquid (IL) aqueous solutions can absorb one equimolar CO2 chemically under ambient pressure, and its CO2 desorption is easy, similar to that in physical absorption/desorption processes. When used as aqueous solutions, carboxylate ILs can replace alkanolamines directly in the applied CCS process, and the efficiency is enhanced significantly due to the low regenerating temperature. CO2 (or polybasic acids) can be used as a polarity switch for ILs and surfactants. A new method for producing carboxylate ILs is also proposed.

Heteroaromatic units are commonly used as π-spacers for sensitizers in dye-sensitized solar cells (DSSCs). Here, we investigated the influence of the π-spacer on the photophysical properties, electrochemical properties and photovoltaic performance of carbazol-phenyl functionalized phenothiazine donor based organic dyes, i.e., CPPC-No (without a π-spacer), CPPC-Th (thiophene as the π-spacer), CPPC-Fu (furane as the π-spacer), CPPC-Ph (phenyl as the π-spacer) and CPPC-Py (pyridine as the π-spacer). The solar to electric power conversion efficiency (PCE) achieved with these dyes strongly depends on the type of π-spacer, increasing in the order of CPPC-Ph < No < Py < Th < Fu. The width of the absorption band and the photocurrent density increased with the electron richness of the π-spacer. Theoretical calculations indicated that the planar molecular configuration of CPPC-Fu promotes the intramolecular charge transfer process. As a result, the CPPC-Fu based device showed a PCE of 7.4% under one sunlight illumination. The dyes using thiophene and pyridine as π-spacers showed slightly lower performance, however, still significantly higher than the PCE achieved with the control compound lacking a π-spacer. By contrast, introducing a phenyl group as the π-spacer led to a decrease in device efficiency. These results give deeper insight into the effect of different π-spacers on DSSC performance, showing the importance of molecular engineering in developing high efficiency organic dyes.

Hydrogen economy is crucial for our society, and the efficient storage of hydrogen is a key step. Formic acid is a relatively ideal medium for hydrogen storage. The hydrogenation of CO2 to formic acid is a thermodynamically limited reaction; thus, the continuous production of formic acid from CO2 effectively is very interesting. Herein, we report a method of continuous-flow formic acid production via the hydrogenation of carbon dioxide using water as the solvent without any base, and the concentration of formic acid by electrodialysis offline and online was tested. The TON of the reaction could reach 35 000, and 2.5 mol L−1 formic acid aqueous solution was obtained after concentrating by electrodialysis.

Summary C(OH)–C bonds are widely distributed in naturally renewable biomass, such as carbohydrates, lignin, and their platform molecules. Selective cleavage and functionalization of C(OH)–C bonds is an attractive strategy in terms of producing value-added chemicals from biomass. However, effective transformation of alcohols into esters by activation of C(OH)–C bonds has not been achieved so far. Herein, for the first time, we report selective cleavage and esterification of C(OH)–C bonds, catalyzed by inexpensive copper salts, using environmentally benign oxygen as the oxidant, to afford methyl esters in excellent yields. A diverse range of phenylethanol derivatives that contain C(OH)–C bonds were effectively converted into methyl benzoates. Detailed analysis revealed that the high efficiency and selectivity resulted mainly from the fact that, in addition to the major esterification reaction, the side products (e.g., olefins and acids) were also transformed in situ into esters in the reaction system.

In the process of vehicles changing lanes, ice and snow pavement is a very common special working condition, and the research on automatic lane change is usually based on medium and high adhesion coefficient roads. Aiming at the special situation of low adhesion coefficient of ice and snow pavement, this paper studies the process of automatic lane change of vehicles on low adhesion roads driven by the front drive automobile driven by in-wheel motor. First, a dynamic model of a front drive automobile driven by in-wheel motor is established. Then, the trajectory planning is performed based on the fifth-degree polynomial method; the lateral acceleration threshold to ensure the safety of the lane change is deduced; the optimization function of the lane change time and the longitudinal driving displacement is established; and the optimal trajectory to ensure the safety and the lane change efficiency is obtained. Finally, the controller is established based on the fuzzy adaptive PID control algorithm, and the driving torque of the hub motor is distributed through the torque distribution strategy to perform the trajectory tracking control of the vehicle. Simulation results show that the vehicle can safely and smoothly change lanes along the planned trajectory.

Idiopathic pulmonary fibrosis (IPF) is a fatal and progressive lung disease with limited therapies, while transforming growth factor-β1 (TGF-β1) plays a central role in the pathogenesis of IPF. Here, we aim to investigate the chemical constituents and biological activities of Inula japonica Thunb. on the TGF-β1/Smad3 signaling pathway to determine the principal compounds of anti-pulmonary fibrosis drugs. Extracts of Inula japonica Thunb. were separated by silica gel column chromatography, ODS medium pressure liquid chromatography and HPLC. The purities and structures were established by NMR, MS and circular dichroism. These extracts’ cytotoxicity and proliferation inhibition of fibroblasts were determined by MTT assay. The lung fibroblasts stably transformed with TGF-β1/Smad3-luciferase reporter gene were used to screen for active ingredients that exert an inhibitory effect on the TGF-β1/Smad3 signaling pathway. Real-time PCR assays were used to detect whether the selected compounds could interfere with the activation of fibroblasts. Among the nineteen compounds extracted from Inula japonica Thunb., 15 and 17 have shown significant inhibitory activity of the TGF-β1/Smad3 pathway in fibroblasts. Additionally, mRNA levels of α-SMA and collagen 1 in myofibroblasts after TGF-β1 stimulation were suppressed by 15 and 17. In conclusion, chemical components of the extract from Inula japonica Thunb. might be potential agents for the treatment of IPF.

The discovery of graphene has intrigued the significant interest in exploring and developing the two-dimensional layered materials (2DLMs) for the photonics application in recent years. Unlike the isotropic graphene, a number of 2DLMs possess the in-plane anisotropic crystal structure with low symmetry, enabling a new degree of freedom for achieving the novel polarization-dependent and versatile ultrafast photonic devices. In this review article, we focus on the typical anisotropic 2DLMs including BP, ReS2, ReSe2, SnS, and SnSe and summarize the recent development of these anisotropic 2DLMs in the pulsed laser and the optical switch applications. First, we introduce the fabrication methods as well as the material characterization of the anisotropic 2DLMs by analyzing the polarized Raman configuration. Second, we discuss the anisotropic nonlinear optical properties of the anisotropic 2DLMs and concentrate on the anisotropic nonlinear absorption response. Next, we sum up state of the art of the anisotropic 2DLMs in the application of pulse lasers and optical switches. This review ends with perspectives on the challenge and outlook of the anisotropic 2DLMs for ultrafast photonics applications.

The electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a highly attractive strategy to generate valuable biomass-based oxygenated chemicals. Robust, stable and inexpensive electrocatalysts are crucial for this interesting reaction. In this work, we found that the electrocatalytic performance of cobalt oxide (CoO) could be significantly improved by introducing oxygen vacancies via Se doping. The resulting CoO-CoSe2 with a CoO/CoSe2 molar ratio of 23 : 1 showed excellent performance and stability for the electro-oxidation of HMF to FDCA, and a FDCA yield of 99% could be achieved with a faradaic efficiency of 97.9% at a potential of 1.43 V vs. RHE. A systematic study indicates that the introduction of rich oxygen vacancies could enhance the catalytic activity and the selectivity to FDCA by increasing the electrochemical surface area and reducing charge transfer resistance. As far as we know, this is the first work to develop a highly stable metal oxide as the active component for this reaction.

Cu(OH)2/CuO nanocomposite-derived Cu2O/Cu was highly efficient for CO2 electroreduction to C2 products. The highest faradaic efficiency and current density could reach 64.5% and 26.2 mA cm−2, respectively. By changing the calcination time, moderate grain boundary density and the Cu+/Cu0 ratio in catalysts can be controlled, leading to a large number of active sites and low interfacial charge transfer resistance.