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Fucoxanthin, a dietary carotenoid, is predominantly found in edible brown algae and is commonly consumed worldwide. Fucoxanthin has been shown to possess beneficial health activities such as antidiabetic, anti-inflammatory, antimutagenic, and antiobesity; however, the effects of fucoxanthin on VEGF-mediated angiogenesis and its possible binding with VEGF are unknown. Here, different lines of evidence supported the suppressive roles of fucoxanthin in VEGF-mediated angiogenesis. In human umbilical vein endothelial cells, fucoxanthin remarkedly suppressed VEGF-mediated cell proliferative, migration, and invasive abilities, as well as tube formation, without cytotoxicity. In addition, fucoxanthin inhibited the subintestinal vessel formation of zebrafish in vivo. In signaling cascades, fucoxanthin was proposed to interact with VEGF, thus attenuating VEGF’s functions in activating the VEGF receptor and its related downstream signaling, i.e., phosphorylations of MEK and Erk. Fucoxanthin also significantly blocked VEGF-triggered ROS formation. Furthermore, the outcomes of applying fucoxanthin in cancer cells were identified, which included (i) inhibiting VEGF-mediated cell proliferation and migration and (ii) inhibiting NF-κB translocation vialimiting MMP2 expression. These lines of investigations supported the antiangiogenic roles of fucoxanthin, as well as reviewing its signaling mechanisms, in blocking the VEGF-triggered responses. The results would benefit the potential development of fucoxanthin for the prevention and treatment of angiogenesis-related diseases.

In this study, a microwave slot-antenna loaded with complementary split ring resonator (CSRR) for wireless temperature-pressure detection in high-temperature environments was presented. To achieve the design of a miniaturized high-temperature sensor with multiple parameters, it is proposed to use an S11 to simultaneously monitor temperature and pressure parameters. Using resonant amplitude to monitor changes in environmental temperature and using resonant frequency to characterize changes in pressure, the sensitivity mechanisms for the temperature and pressure sensing are described in detail. The working principle of the temperature-pressure sensor is elaborated via circuit analysis and simulation optimization of high-frequency structure simulator (HFSS). The sensor was customized and fabricated on the high-temperature cofired ceramics (HTCC) using the 3-D co-firing and screen-printing technology. The as-prepared sensor can stably work at the ambient environment of $20~^{\circ }$ C– $800~^{\circ }$ C and 100–300 kPa, with a temperature sensitivity of 0.0133 dB/°C and a pressure sensitivity of 235 kHz/kPa at $800~^{\circ }$ C. The temperature compensation algorithm is proposed to achieve accurate acquisition of pressure signals in a high-temperature environment. The sensor has the potential for utilization in simultaneous temperature and pressure monitoring in harsh environments.

Oxide inclusions significantly impeded the mechanical properties of the Wire and Arc Additive Manufacturing (WAAM) made high nitrogen Cr–Mn austenite stainless steels (HNSs). This paper focused on the inclusions' component, crystallization characteristics and formation mechanism. Results revealed that there are two types of inclusions: the round-shape nano-size inclusion (Type-I) and the micron-size island-shape inclusion (Type-II). The Type-I inclusion usually consists of the MnO particle or the combination of the MnO, Si-oxides and precipitations (MnS or Cr2N). Most of the Type-I oxide inclusion is located in the range between 300 nm and 700 nm,the number of Type-I oxide inclusion takes the main part of 69.7%.With higher content, smaller size and more even distributions, the isolated Type-I oxide inclusions would be beneficial to the mechanical properties owing to the Orowan strengthening mechanism. The Type-II inclusion is mostly composed of the MnO matrix and the coherent chromite spinel (MnCr2O4). In general, the larger the size, the more serious the negative impact on mechanical properties. And there was a strong negative correlation between the size and quantity of type II oxide inclusions. After heat treatment, abundant phase transformations occurred in the Type-II inclusions and some harmful phases (Sigma, MnS et cl.) were often found in or around the inclusions with specific orientation relationships. During deposition, the unstable droplet transformation and the trapped residual slag were the main causes for the inclusions in the molten pool.

Lewis acid-catalyzed cycloaddition between bicyclo[1.1.0]butanes (BCBs) and unsaturated substrates has recently been demonstrated to be a powerful strategy for synthesizing bicyclo[2.1.1]hexanes. However, their reaction mechanisms remain elusive. This computational work explored the recently developed TMSOTf-catalyzed cycloaddition of BCB ketone to ketene and determined the rate-determining step as the activation of BCB ketone. Contrary to the previous proposal of BCB enolate as the active species, this work instead identified the catalytically active species to be a partially Lewis acid-activated BCB cation, which shows a greater electrophilicity and larger orbital interactions with ketene compared to those of the pristine BCB. The most favorable reaction pathway uniquely utilizes this activated BCB species as an electrophile to react with ketene as a nucleophile, while the previously proposed enolate is relatively inactive. Moreover, the in situ-generated TfO anion is revealed to be non-innocent, and its coordination mode and orientation could affect the reaction kinetics.

Chirality transformation is a basic, attractive, and important strategy for obtaining enantioenriched products with desired chiral elements. The reported chirality conversion reaction often involves the process from one type of chirality to another one. To better utilize the chirality transformation strategy for obtaining two or more products with different chiral elements in a single reaction, a new method of kinetic resolution accompanied by a chirality transformation protocol is proposed and successfully realized in this study. This process is used for the asymmetric oxidation of phenol compounds along with the kinetic resolution of oxaziridines. A wide scope of products, including axially chiral phenols, oxaziridines, and α-hydroxyl cyclic ketones were smoothly obtained in high levels of yields and enantioselectivities in the developed method. These products can be readily used for the synthesis of various types of chiral ligands, which are potential choices for other catalytic asymmetric reactions.

Poly(N-isopropylacrylamide) (PNIPAM) is capable of improving the reversibility and responsiveness of flexible electronics. However, its phase transition-induced volume variation and poor adhesiveness remain limitations for expending its applications. Herein, a pressure-sensitive adhesive (PSA), which is a type of mesh scaffold, is constructed inside the network of PNIPAM, providing the hydrogel with a constant volume in response to different temperatures, in situtunable mechanical properties, and superior adhesiveness. The reversible density of the mesh scaffold adjusts the aggregation state of the hydrogel chains, whereupon it is capable of changing its mechanical modulus from 6.7 kPa to 45.3 kPa. This mechanical mechanism contributes to hydrogel-based flexible devices for multiple applications, especially in pressure-related sensors. The mesh scaffold restricts the phase-transition-induced volume variation, which allows the hydrogel sensor to stably monitor the external pressure at various temperatures. The high adhesion enables the effective interfacial interaction with the skin, avoiding the loss of sensing signals during the detection of human body movements. When it is assembled into an electronic device, it can transmit information and recognize sign language viaMorse code. Thus, herein, we report a hydrogel sensor that is promising for pressure detection in temperature-unstable environments, especially for managing the health of patients who require emergency medical care through sign language recognition.

High-reliability and low-latency communication is essential for timely information exchange in vehicle platooning. As a key enabler of this, the cellular vehicular-to-everything (C-V2X) network uses a sensing-based semi-persistent scheduling (SPS) protocol, where radio resources are reserved for a number of transmissions with reduced resource re-allocation and control overhead. However, consecutive access collisions may be caused by reservation conflict, which leads to long delay and threatens platoon’s stability and safety. In this paper, a coordinating resource reservation (CRR) protocol is proposed for vehicle platooning. By implementing error detection with coordination among platoon vehicles, the resource reservation is improved for reduced collisions and delay. Specifically, packet reception/loss information is sent out by platoon vehicles through their own packets. Such information is shared with transmitters and guides them to reserve new resources when access collision occurs. As a result, long delay is avoided while no extra feedback packet is introduced. Furthermore, Markov analysis is presented to evaluate the performance of SPS and the proposed CRR for vehicle platooning, providing the quantified performance gains. Finally, simulation results demonstrate the superiority of the proposed CRR in reducing packet loss and latency, compared with the legacy SPS and other state-of-the-art solutions.

This paper aims to address the problem of multi-UAV cooperative search for multiple targets in a mountainous environment, considering the constraints of UAV dynamics and prior environmental information. Firstly, using the target probability distribution map, two strategies of information fusion and information diffusion are employed to solve the problem of environmental information inconsistency caused by different UAVs searching different areas, thereby improving the coordination of UAV groups. Secondly, the task region is decomposed into several high-value sub-regions by using data clustering method. Based on this, a hierarchical search strategy is proposed, which allows precise or rough search in different probability areas by adjusting the altitude of the aircraft, thereby improving the search efficiency. Third, the Elite Dung Beetle Optimization Algorithm (EDBOA) is proposed based on bionics by accurately simulating the social behavior of dung beetles to plan paths that satisfy the UAV dynamics constraints and adapt to the mountainous terrain, where the mountain is considered as an obstacle to be avoided. Finally, the objective function for path optimization is formulated by considering factors such as coverage within the task region, smoothness of the search path, and path length. The effectiveness and superiority of the proposed schemes are verified by the simulation.

The deformation behavior of Ti-55511 alloy was investigated by hot compression tests conducted at deformation temperatures of 993∼1113 K and strain rates of 0.001–1 s−1. To eliminate the effects of friction and adiabatic temperature rise on the flow stresses, the flow curves were corrected. Subsequently, a strain compensated Arrhenius (SCA) model was developed and further modified using the back propagation artificial neural network (BPANN) method. The modified model exhibits significant improvements compared to the SCA model. The average absolute relative error (AARE) decreases from 4.895 % to 0.756 %, while the relative error (δ) range decreases from −14.75 %–17.99 % to −4.78 %–8.01 %. Moreover, cross-validation also confirms the modified model has higher generalization ability and prediction accuracy than the SCA model. Microstructural characterization reveals dynamic recrystallization (DRX) of the α phase and dynamic recovery (DRV) of the β phase are the main mechanisms responsible for softening, and their volume fractions increase with decreasing strain rate and increasing deformation temperature. The equiaxed α phase undergoes elongation first, followed by gradual migration and transformation of grain boundaries. Finally, the β phase wedges into the α phase until the α phase separates. The continuous dynamic recrystallization (CDRX) of β phase accompanies its DRV, which is mainly characterised by progressive sub-grain rotation. The α grains aggregated by dislocations promote CDRX of the β phase.

The multi-pass fillet welds of casing pipe were welded onto the in-service pipeline, which is widely used in pipeline repairs. However, the influence of welding heat input of B-type sleeve circumferential fillet weld on the temperature and stress field at the pipe circumferential weld is still unclear. In this paper, a double ellipsoid heat source model is developed to investigate the weld temperature field, residual stress field, and deformation field of the repair welding in service. The results show that the increase of weld heat input can effectively increase the size of the weld pool and the size of the high-temperature zone of the B-type sleeve circumferential fillet weld. And the peak temperature of the inner wall of the pipe girth weld increases with the increase of welding heat input of the sleeve circumferential fillet weld. The axial stress peak of the inner wall of the pipe girth weld reduces with the increase of welding heat input of sleeve circumferential fillet weld, and the axial deformation peak of the inner wall of the pipe girth weld increases first and then decreases with the increase of welding heat input of sleeve circumferential fillet weld.

Conductive hydrogels, exhibiting wide applications in electronic skins and soft wearable sensors, often require maturely regulating of the hydrogel mechanical properties to meet specific demands and work for a long-term or under extreme environment. However, in situregulation of the mechanical properties of hydrogels is still a challenge, and regular conductive hydrogels will inevitably freeze at subzero temperature and easily dehydrate, which leads to a short service life. Herein, a novel adhesive hydrogel (PAA-Dopa-Zr4+) capable of strain sensing is proposed with antifreezing, nondrying, strong surface adhesion, and tunable mechanical properties. 3,4-Dihydroxyphenyl-l-alanine (l-Dopa)-grafted poly(acrylic acid) (PAA) and Zr4+ion are introduced into the hydrogel, which broadly alters the mechanical properties via tuning the in situaggregation state of polymer chains by ions based on the complexation effect. The catechol groups of l-Dopa and viscous glucose endow the hydrogel with high adhesiveness for skin and device interface (including humid and dry environments) and exhibit an outstanding temperature tolerance under extreme wide temperature spectrum (−35 to 65 °C) or long-lasting moisture retention (60 days). Furthermore, this PAA-Dopa-Zr4+can be assembled as a flexible strain-sensitive sensor to detect human motions based on specific mechanical properties requirements. This work, enabling superior adhesive and temperature tolerance performance and broad mechanical tenability, presents a new paradigm for numerous applications to wearable sensing and personalized healthcare monitoring.

K418 alloy was prepared by selective laser melting (SLM) at different laser powers (160∼240 W) in this paper. The influence of laser power on the densification behavior, microstructure, microhardness, and tensile properties was studied systematically. The results showed that the densities of the material increased rapidly first and then decreased slowly with the increase of laser power. When the laser power increased from 160 W to 240 W, the surface defects of the specimen decreased, the microstructure changed from columnar dendrites to cellular, and the grains grew in the <001> direction preferentially. When the laser power is 200 W, the grain size is the smallest, the content of small-angle grain boundaries is more, the Schmidt factor is less, and then the best mechanical properties are achieved, at which the microhardness reaches 362.89 ± 5.01 HV, the tensile strength reaches 1244.35 ± 70.1 MPa, the yield strength reaches 863.89 ± 23.1 MPa, and the elongation of the material reaches a maximum of 12.53 ± 0.71 %. In addition, the fracture mode of the material is a mixed tough-brittle fracture mechanism.

The 17-4 precipitation-hardened (PH) stainless steel was prepared by laser-powder bed fusion (L-PBF), and the effects of different aging temperatures on the microstructures and properties of 17-4PH stainless steel were systematically studied. The results show that the 17-4PH stainless steel prepared by laser powder bed fusion requires a solid solution treatment in order to obtain the lath martensite structure, and then the niobium carbides and ε-Cu phase nanoparticles were precipitated by aging treatment to improve the strength of 17-4PH stainless steel. When the aging heat treatment parameter is 450 °C/5 h, the mechanical properties of the 17-4PH stainless steel are better, and the ultimate tensile strength (UTS) and elongation (El) are 1387 MPa and 7.3%, respectively. Compared with the as-printed 17-4PH stainless steel, the ultimate tensile strength of aging heat treatment exhibits an increase of 25.2%, and then, as the increase of aging temperature, the niobium carbides and ε-Cu precipitation phase become coarser, resulting in a decrease in the strength of 17-4PH stainless steel and an increase in plasticity.

A multistate energy decomposition analysis (MS-EDA) method is described to dissect the energy components in molecular complexes in excited states. In MS-EDA, the total binding energy of an excimer or an exciplex is partitioned into a ground-state term, called local interaction energy, and excited-state contributions that include exciton excitation energy, superexchange stabilization, and orbital and configuration-state delocalization. An important feature of MS-EDA is that key intermediate states associated with different energy terms can be variationally optimized, providing quantitative insights into widely used physical concepts such as exciton delocalization and superexchange charge-transfer effects in excited states. By introducing structure-weighted adiabatic excitation energy as the minimum photoexcitation energy needed to produce an excited-state complex, the binding energy of an exciplex and excimer can be defined. On the basis of the nature of intermolecular forces through MS-EDA analysis, it was found that molecular complexes in the excited states can be classified into three main categories, including (1) encounter excited-state complex, (2) charge-transfer exciplex, and (3) intimate excimer or exciplex. The illustrative examples in this Perspective highlight the interplay of local excitation polarization, exciton resonance, and superexchange effects in molecular excited states. It is hoped that MS-EDA can be a useful tool for understanding photochemical and photobiological processes.

The dynamic tensile mechanical properties of 18Ni350 maraging steel (M350) fabricated by wire arc additive manufacturing (WAAM) was investigated by the split Hopkinson tensile bar (SHTB) and microstructural analysis. The results show that the yield stress (YS) of M350 samples, both in as-built and heat-treated state, increases firstly and then decreases with increasing strain rate. The YS of the as-built sample reaches the maximum value of 2195 MPa at 1230s−1, and that increases to 3395 MPa after heat treatment, due to the precipitation of intermetallic. Compared with the sample in the horizonal direction, the sample in the vertical direction exhibits a higher dynamic strength, due to the preferred growth of columnar crystal along the vertical direction during WAAM process. Under dynamic load, the retained austenite transformed into martensite and the oxide inclusions are cracked, resulting in a heterogeneous fracture morphology. Based on those results the hardening model and the anisotropic model of the strain rate sensitive material fabricated by WAAM were established. The results can provide a guidance for the reliability evaluation of maraging steel fabricated by WAAM under dynamic load conditions.

The welding parameters optimization of TC4 titanium alloys/304 stainless steel (TC4/304 SS) by friction stir lap welding (FSLW) based on orthogonal test was researched. The results show that when the rotating speed was constant, the area of the high temperature zone and the peak temperature decreased with the increase of the traversing speed; when the traversing speed was constant, the area of the high temperature zone and the peak temperature increased with the increasing rotating speed. Among them, under the condition of low heat input, the interface temperature was about 912 °C, the material at the interface cannot fully react, and there was no formation of a large amount of brittle and hard intermetallic compounds; under the condition of medium heat input, the interface temperature was about 930 °C, this temperature caused a large amount of brittle and hard intermetallic compounds at the interface; under high heat input, the interface temperature was about 975 °C, a large number of intermetallic compounds were not formed at the interface.

A flexible self-consistent field method, called target state optimization (TSO), is presented for exploring electronic excited configurations and localized diabatic states. The key idea is to partition molecular orbitals into different subspaces according to the excitation or localization pattern for a target state. Because of the orbital-subspace constraint, orbitals belonging to different subspaces do not mix. Furthermore, the determinant wave function for such excited or diabatic configurations can be variationally optimized as a ground state procedure, unlike conventional ΔSCF methods, without the possibility of collapsing back to the ground state or other lower-energy configurations. The TSO method can be applied both in Hartree–Fock theory and in Kohn–Sham density functional theory (DFT). The density projection procedure and the working equations for implementing the TSO method are described along with several illustrative applications. For valence excited states of organic compounds, it was found that the computed excitation energies from TSO–DFT and time-dependent density functional theory (TD-DFT) are of similar quality with average errors of 0.5 and 0.4 eV, respectively. For core excitation, doubly excited states and charge-transfer states, the performance of TSO-DFT is clearly superior to that from conventional TD-DFT calculations. It is shown that variationally optimized charge-localized diabatic states can be defined using TSO-DFT in energy decomposition analysis to gain both qualitative and quantitative insights on intermolecular interactions. Alternatively, the variational diabatic states may be used in molecular dynamics simulation of charge transfer processes. The TSO method can also be used to define basis states in multistate density functional theory for excited states through nonorthogonal state interaction calculations. The software implementing TSO-DFT can be accessed from the authors.

To provide a pathway to improve the tensile properties of wire arc additive manufactured Ti6Al4V, the microstructures and properties of Ti6Al4V-0.1Si produced by the wire arc additive manufacturing were investigated in this study. It was demonstrated that the tensile strength of Ti6Al4V-0.1Si improved more than 100 MPa compared with traditional WAAM Ti6Al4V. The microstructures of WAAM Ti6Al4V and Ti6Al4V-0.1Si mainly consists of basket-weave structures but the width of the α-phase lamellae of Ti6Al4V-0.1Si is significantly lower.

It is challenging to diagnose drowning in autopsy even with the help of post-mortem multi-slice computed tomography (MSCT) due to the complex pathophysiology and the shortage of forensic specialists equipped with radiology knowledge. Therefore, a computer-aided diagnosis (CAD) system was developed to help with diagnosis. Most deep learning-based CAD systems only utilize 2D information, which is proper for 2D data such as chest X-ray images. However, 3D information should also be considered for 3D data like CT. Conventional 3D methods require a huge amount of data and computational cost when using 3D methods. In this article, we proposed a 2.5D method that converts 3D data into 2D images to train 2D deep learning models for drowning diagnosis. The key point of this 2.5D method is that it uses a subset to represent the whole case, covering this case as much as possible while avoiding other repetitive information. To evaluate the effectiveness of the proposed method, conventional 2D, previous 2.5D, and 3D deep learning-based methods were tested using an MSCT dataset obtained from Tohoku university. Then, to provide explainable diagnosis results, a visualization method called Gradient-weighted Class Activation Mapping was employed to visualize features relevant to drowning in CT images. Results on drowning diagnosis showed that our proposed method achieved the best performance compared to other 2D, 2.5D, and 3D methods. The visual assessment also demonstrated that our method could find the saliency regions corresponding to drowning.

The instability of arc morphology and severe spatters caused by the droplet burst leads to a great challenge in cold metal transfer (CMT) welding with high nitrogen steels (HNSs). During this process, the effusion of evaporative Mn will intensify the loss of nitrogen and change the solidification models. This paper focuses on the influence of droplet transition on arc morphology, Mn evaporation and the additive seam characteristics under various parameters. The results show that four typical stages of the droplet were found as the growth, parking, expansion and bursting stages. A stable arc and droplet transition process can be achieved by using a lower peak current (140 ∼ 240 A) along with less peak-current duration (3–5 ms) which also avoids the spatter accumulation zone at the weld toe area. The welding fume is mainly composed of the MnO and Mn3O4oxides and varies with the peak current. The loss of Mn was more sensitive to the peak current than the peak current durations (≤7 ms); and a maximum value of 1.83 wt% was found at a peak current of 300 A. Once the loss of Mn was higher than 1 %, the loss of nitrogen will exceed 20 % resulting in an austenite-ferrite dual-phase microstructure.

For periodical beacon broadcasting in cellular vehicle-to-everything (C-V2X) networks, a distributed reservation media access control (MAC) protocol, the sensing-based semi-persistent scheduling (SPS), is adopted. However, how to quantify the communication reliability and latency is an open issue, which is critical for low-latency and high-reliability services. In this paper, an analytical model for SPS is presented, based on which the impacts of beacon rate, range settings and system configuration on access collision probability and delay outage probability are quantified. The analytical model provides important insights and guideline to adapt and optimize protocol parameters including the sensing range, transmit power and resource reservation. The enhanced MAC protocol can maintain high-reliability and low-latency services with a wide range of vehicle density. Simulations are conducted to validate the analysis and the results demonstrate that the proposed MAC enhancement solution can reduce collision probability while ensuring the delay outage probability based on service requirements.

The multi-pass fillet welds of casing pipe were welded onto the in-service pipeline, which is widely used in pipeline repairs. However, the residual stress of repairing welded joints is larger, and it is easy to cause cracks in the heat-affected zone. In this paper, the local heat treatment was used to adjust the residual stress of the repaired welded joint of the in-service pipeline. The results show that the local heat treatment is very useful for reducing the residual stress of the repair welding joint of the in-service pipeline.

Freezing and dehydration together with interfacial failure are capable of causing the functional reduction of hydrogels for sensing applications. Herein, we develop a multifunctional bilayer that consists of a mussel-inspired adhesive layer and a functionally ionic layer that is composed of sodium p-styrene sulfonate (SSS) and an ionic liquid of [BMIM]Cl. The adhesive layer enables the strong adhesion of the bilayer to the surface of the skin. The introduction of ionic elements of SSS-[BMIM]Cl not only provides the bilayer with sensing adaptability in a wide temperature range of −25 to 75 °C, but also endows it with elastic, stretchable, self-healing, and conductive features. These mechanical properties are utilized to assemble a wearable sensor that has unprecedented sensitivity and reusability in monitoring human motions, including stretching, pulsing, frowning, and speaking. It is thus expected that the concept in this work would provide a promising route to design soft sensing devices that can work in a wide temperature range.

Low-dimensional halide perovskites with quantum-well structures are promising materials for electronics and optoelectronics because of their excellent optoelectronic properties. This work concerns two novel, lead-free, one-dimensional organic–inorganic hybrid perovskite-like Cu(I) halides, (MV)Cu2X4(MV = methyl viologen; X = Br, I), for optoelectronic applications. Both Cu(I) halides exhibited good stability under ambient conditions. The optical bandgaps of (MV)Cu2Br4and (MV)Cu2I4are 1.4 and 1.5 eV, respectively, which are in the ideal bandgap range for solar cells. (MV)Cu2Br4possessed a characteristic quantum-well structure in which [CuBr4]n3n–chains with a nanowire-like structure were rolled up and isolated by tightly packed organic cations. Thanks to quantum confinement in the unique structure, the optical bandgap of (MV)Cu2Br4fell in the ideal bandgap range for solar cells and was superior to that of (MV)Cu2I4. The good photoresponse properties of these Cu(I) halides suggest their great potential for application as light-harvesting materials in solar cells.

The complicated thermal history of wire + arc additive manufacturing (WAAM) will affect the microstructure variation and mechanical properties of the as-deposited material. Numerial models of Inconel 718 in WAAM deposition were established and the location-related thermal history and temperature distribution were analyzed. A hybrid method of WAAM and cold rolling was investigated and its effect on the microstructure distribution and texture was investigated compared to that in as-deposited condition. The results show that WAAM deposition features repeated thermal cycles, high heating rate and low cooling rate. The trough values of the thermal cycles first increases and then decreases, while the peak temperature always decreases with the proceeding of the deposition process. The as-deposited samples show columnar dendrites and its average dendrite arm spacing increases with the increased build height due to the location-related heat accumulation. The strongly textured columnar dendrites with preferred <001> orientation transform to equiaxed grains with random orientation in heat-affected zone after cold rolling process, and its average size decreases with the increased rolling force. The as-deposited samples show the strongest intensity of 7.609 for the {100} family of grains oriented along the transverse direction; while it decreases to 3.629 and 2.057 for the cold rolled conditions with the force of 50 kN and 75 kN, respectively. The relationship between thermal history and the microstructure distribution was discussed. The mechanism of hybrid WAAM and cold rolling method consisted of spatially and temporally heterogeneous work hardening and recrystallization.

Homogeneous catalysis and biocatalysis have been widely applied in synthetic, medicinal, and energy chemistry as well as synthetic biology. Driven by developments of new computational chemistry methods and better computer hardware, computational chemistry has become an essentially indispensable mechanistic “instrument” to help understand structures and decipher reaction mechanisms in catalysis. In addition, synergy between computational and experimental chemistry deepens our mechanistic understanding, which further promotes the rational design of new catalysts. In this Account, we summarize new or deeper mechanistic insights (including isotope, dispersion, and dynamical effects) into several complex homogeneous reactions from our systematic computational studies along with subsequent experimental studies by different groups. Apart from uncovering new mechanisms in some reactions, a few computational predictions (such as excited-state heavy-atom tunneling, steric-controlled enantioswitching, and a new geminal addition mechanism) based on our mechanistic insights were further verified by ensuing experiments.

Flexible thermoelectric materials and devices show great potential to solve the energy crisis but still face great challenges of high cost, complex fabrication, and tedious postprocessing. Searching for abnormal thermoelectric materials with rapid and scale-up production can significantly accelerate their applications. Here, we develop superlarge 25 × 20 cm2commercial graphite-produced composite films in batches, achieved by a standard 10 min industrial process. The high cost effectiveness (S2σ/cost) of 7250 μW g m–1K–2$–1is absolutely ahead of that of the existing thermoelectric materials. The optimized composite film shows a high power factor of 94 μW m–1K–2at 150 °C, representing the optimal value of normal carbon materials so far. Furthermore, we design two types of flexible thermoelectric devices fabricated based on such a novel composite, which achieve an output open-circuit voltage of 3.70 mV using the human wrist as the heat source and 1.33 mV soaking in river water as the cold source. Our study provides distinguished inspiration to enrich flexible and cost-effective thermoelectric materials with industrial production.

A palladium-catalyzed reaction of N-propargyl oxazolidines with alkenes for the synthesis of indolizidines has been developed. Through a sequential 6-exo-dig cyclization/proton transfer/[3+2] cycloaddition/cycloreversion/aromatization process, a series of fused polycyclic indolizines are obtained in moderate to good yields with high functional group tolerance. Experimental and theoretical studies suggest that the [3+2] cycloaddition/cycloreversion of the oxazolidine ring probably involves C–C and C–O bond cleavage, providing a new ring restructuring approach for the synthesis of heterocycles.

Sandy gravel foundations exhibit non-linear dynamic behavior when subjected to strong ground motions, which can have amplification effects on superstructures and can reveal insufficient lateral resistance of foundations. Grouting methods can be used to improve the seismic performance of natural sandy gravel foundations. The strength and stiffness of grouted sandy gravel foundations are different from those of natural foundations, which have unknown earthquake resistance. Few studies have investigated the seismic behavior of sandy gravel foundations before and after grouting. In this study, two shaking table tests were performed to evaluate the effect of grouting reinforcement on seismic performance. The natural frequency, acceleration amplification effect, lateral displacement, and vertical settlement of the non-grouted and grouted sandy gravel foundations were measured and compared. Additionally, the dynamic stress-strain relationships of the two foundations were obtained by a linear inversion method to evaluate the seismic energy dissipation. The test results indicated that the acceleration amplification, lateral displacement amplitude, and vertical settlement of the grouted sandy gravel foundation were lower than that of the non-grouted foundation under low-intensity earthquakes. However, a contrasting result was observed under high-intensity earthquakes. This demonstrated that different grouting reinforcement strategies are required for different sandy gravel foundations. In addition, the dynamic stress-strain relationship of the two foundations exhibited two different energy dissipation mechanisms. The results provide insights relating to the development of foundations for relevant engineering sites and to the dynamic behavior of grouted foundations prior to investigating soil-structure interaction problems.