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Whilst most bioorthogonal reactions focus on targeting binding-site cysteine residues, proximity-induced reactivity effect ensures that reaction also occurs at nucleophilic lysine residues. We report one example here that the propargylated-sulfonium center undergoes a nucleophilic reaction with lysine residue via proximity-induced conjugation. This propargylated-sulfonium tethered peptide resulting from a facile propargylation of thiolethers, enables amino-yne reaction at the selected lysine on MDM4 protein. This strategy represents a viable approach of lysine-targeted covalent inhibition in proximity.

The behavior of room temperature phosphorescence quenching and fluorescence enhancing of gadolinium labeled sinoporphyrin sodium (Gd-DVDMS) in the aqueous solution were studied. Gd-DVDMS was characterized by various techniques including mass spectra, Fourier transform infrared spectra and transmission electron microscopy. The optical behavior was monitored through UV–vis absorption spectra and photoluminescence spectra. The result shows that the phosphorescence intensity gradually quenches, almost disappears after dissolved 120 min, meanwhile the fluorescence intensity enhances 5 times. The above behavior is attributed to the decreased population of Gd-DVDMS as first excited triplet state (T1). Based on the time-invariant of both absorption spectra and phosphorescence decay curves at 710 nm of Gd-DVDMS in different dissolution time, the reason for the decreased population of Gd-DVDMS in T1 state is that the intersystem crossing from first excited state (S1) to T1 is prevented. In addition, the fluorescent decay curves of Gd-DVDMS initially dissolved in the aqueous solution and dissolved for 120 min were also measured for comparison. The big change in fluorescent lifetime further proves the conclusion that intersystem crossing is prevented, meanwhile, the increase in fluorescence intensity is demonstrated. In this work, the possibility of decomposition of Gd-DVDMS is excluded because the phosphorescence decay curve in Gd-DVDMS aqueous solution is sensible to DVDMS.

As a lead-free material, AgNbO3 has received a lot of attention for its potential application in the field of energy storage. Herein, AgxNbO2.5+x/2 ceramics were successfully synthesized via solid state reaction with the x ranged from 1 to 0.92. The effect of silver deficiency on structure, dielectric properties and energy storage performance was investigated. As x value decreased from 1 to 0.94, the unit volume of AgxNbO2.5+x/2 ceramics contracted. Meanwhile, all the compositions displayed double hysteresis loops with reduced Pmax, Pr and enhanced transformation fields (EF and EB) as functions of silver deficiency. Silver deficiency stabilized the antiferroelectric state in the FIE (-like) phase and improved the energy storage performance of AgNbO3 ceramics. Hence, an enhanced energy storage performance (Wrec = 3.1 J/cm3, η = 49%) were achieved in Ag0.94NbO2.97 ceramic.

The combustion characteristics of a hydrogen-fueled scramjet combustor were investigated experimentally and numerically. One nonreacting case (case 1), and two different equivalence ratio (ER) reacting cases (cases 2 and 3) were compared. The combustion process of each reacting case was divided into three phases. In the first phase, the monitor pressure in case 2 (ER = 0.1) reached a higher level due to the fuel injected before the hydrogen was ignited, whereas the change in case 3 (ER = 0.3) was the opposite, being less than that in the nonreacting flow. Almost all of the hydrogen in case 2 was in the front of the cavity, and that in case 3 was both throughout the whole cavity and near the top wall behind the cavity. In the second phase, the ignition times were about 0.010 s in case 2 and about 0.022 in case 3; a larger ER of hydrogen might be difficult to ignite. Finally, in the last phase, the hydrogen combustion was stable. The shock train in case 3 was pushed into the isolator, and the disturbing distance was about 0.08 m, in accordance with the wall pressure distribution. The higher static temperature in case 2 was mainly in the back of the cavity and that in case 3 was in the cavity shear layer, in line with the hydroxyl planner laser-induced fluorescence (OH-PLIF) results. The combustion mode in case 2 was supersonic combustion and that in case 3 was subsonic combustion.

Diversity preservation is a crucial technique in multiobjective evolutionary algorithms (MOEAs), which aims at evolving the population toward the Pareto front (PF) with a uniform distribution and a good extensity. In spite of many diversity preservation approaches in existing MOEAs, most of them encounter difficulties in tackling complex PFs. This article gives a detail introduction to existing diversity preservation approaches, as well as a revelation of the limitations of them. To address the limitations of existing diversity preservation approaches, this article proposes a multistage MOEA for better diversity performance. The proposed MOEA divides the optimization process into multiple stages according to the population in each generation, and updates the population by different steady-state selection schemes in different stages. According to the experimental results on 21 benchmark problems, the proposed MOEA exhibits better diversity performance than 11 existing MOEAs.

Herein, we report the high De-NOx performance of the A-site defective perovskite-based Pd/La0.5Sr0.3MnO3 catalyst. The formation of the defective perovskite structure can be proved by both the increased Mn4+/Mn3+ ratio and serious lattice contraction due to cationic nonstoichiometry. It promotes the Sr doping into perovskite lattice and reduces the formation of the SrCO3 phase. Our results demonstrate that below 300 °C the A-site defective perovskite can be more efficiently regenerated than the SrCO3 phase as NOx storage sites due to the latter's stronger basicity, and also exhibits the higher NO oxidation ability than the A-site stoichiometric and excessive catalysts. Both factors promote the low-temperature De-NOx activity of the Pd/La0.5Sr0.3MnO3 catalyst through improving its NOx trapping efficiency. Nevertheless, above 300 °C, the NOx reduction becomes the determinant of the De-NOx activity of the perovskite-based catalysts. A-site defects can weaken the interactions between perovskite and Pd, inducing activation of Pd sites by in-situ transformation from PdO to metallic Pd in the alternative lean-burn/fuel-rich atmospheric alternations, which boosts the De-NOx activity of the Pd/La0.5Sr0.3MnO3 catalyst. The Pd/La0.5Sr0.3MnO3 catalyst exhibits the high sulfur tolerance as well. These findings provide insight into optimizing the structural properties and catalytic activities of the perovskite-based catalysts via tuning formulation, and have potential to be applied for various related catalyst systems.

Incentive-based travel demand management (IBTDM) strategies utilize rewards to redistribute travel demand across space and time. Such congestion-alleviation solutions are usually managed by small private companies with constraint budgets. Aside from spending money on incentives, running promotional campaigns to achieve the gains in market share is essential for maintaining the financial health of IBTDM programs. Therefore, the budget allocation between the two counterparts—incentive and marketing expenditure—needs to be wisely determined. Based on the bottleneck model, this paper proposes an optimal budget allocation scheme considering the impact of a budget constraint and market penetration. It was found that the constraint budget should be prioritized to attract those with lower marketing costs in general. In situations with an insufficient budget and when marketing costs were lower for attracting lower-income individuals, IBTDM decision-makers should focus on those lower-income individuals at first. This mitigates inequity issues to some extent. Therefore, policy makers or planners should pay more attention to marketing cost when developing a marketing plan and try to reduce marketing cost to make full use of incentive budget.

A series of Ni3P and C@Ni3P catalyst were prepared by temperature programmed reduction method and characterized by XRD, TEM, N2 adsorption–desorption, H2-chemisorption, FT-IR, XPS and thermogravimetric analysis. Their catalytic performance in the hydrogenation of furfurnal was investigated. The 97% furfural conversion and 96.3% furfuryl alcohol selectivity were obtained over C@Ni3P-1 catalyst at 160 °C and 1.4 MPa H2 for 4 h. Furthermore, C@Ni3P-1 catalyst showed a high stability in reusing experiments and the satisfactory hydrogenation performance for other substrates.

At present, the study of upper-limb posture recognition is still in the primary stage; due to the diversity of the objective environment and the complexity of the human body posture, the upper-limb posture has no public dataset. In this paper, an upper extremity data acquisition system is designed, with a three-channel data acquisition mode, collect acceleration signal, and gyroscope signal as sample data. The datasets were preprocessed with deweighting, interpolation, and feature extraction. With the goal of recognizing human posture, experiments with KNN, logistic regression, and random gradient descent algorithms were conducted. In order to verify the superiority of each algorithm, the data window was adjusted to compare the recognition speed, computation time, and accuracy of each classifier. For the problem of improving the accuracy of human posture recognition, a neural network model based on full connectivity is developed. In addition, this paper proposes a finite state machine- (FSM-) based FES control model for controlling the upper limb to perform a range of functional tasks. In the process of constructing the network model, the effects of different hidden layers, activation functions, and optimizers on the recognition rate were experimental for the comparative analysis; the softplus activation function with better recognition performance and the adagrad optimizer are selected. Finally, by comparing the comprehensive recognition accuracy and time efficiency with other classification models, the fully connected neural network is verified in the human posture superiority in identification.

Through specific structural modification of a 4-phenylindoline precursor, new 4-arylindolines containing a thiazole moiety were developed and found to be promising modulators of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis. Compound A30 exhibited outstanding biochemical activity, with an IC50 of 11.2 nM in a homogeneous time-resolved fluorescence assay. In the cell-based assay, A30 significantly promoted IFN-γ secretion and rescued T-cell proliferation, which were inhibited by PD-1 activation. Furthermore, A30 showed favorable in vivo antitumor activity in a mouse 4T1 breast carcinoma model. Moreover, in mouse CT26 colon carcinoma models, A30 potently suppressed the growth of CT26/PD-L1 tumor but did not obviously affect the growth of CT26/vector tumor. The results of flow cytometry analysis indicated that A30 inhibited tumor growth by activating the immune microenvironment. We concluded that A30 is a new starting point for further development of PD-1/PD-L1 interaction inhibitors as antitumor agents.

With the increasing interest in exploring the deep-space environment, the problems of health and safety of astronauts' bone induced by microgravity warrants an investigation. Recent studies have discovered that several microRNAs (miRNAs) have played a vital role in osteoblast differentiation and bone formation under microgravity, whereas the in-depth signaling pathway mechanisms are not yet completely understood. Here, we performed the hind limb unloading (HLU) mice model and 3D clinostat-random position machine (RPM) to simulate the effects of microgravity on bone at animal and cellular level, respectively. Firstly, we screened the different expressed miRNAs under simulated microgravity by miRNA sequencing, we then identified the highest different expressed miRNA (miR-138–5p) that was up-regulated under simulated microgravity and inhibited osteoblast differentiation in MC3T3-E1 cells. Moreover, we analyzed miR-138's targets during osteogenic differentiation and we found that these targets regulated osteogenic differentiation through Wnt/β-catenin signaling, a key signaling pathway in controlling osteoblast differentiation. The association between miR-138–5p and β-catenin activity was determined by a luciferase reporter assay. Further experiments confirmed that miR-138–5p suppressed β-catenin expression and β-catenin activity. Moreover, β-catenin overexpression attenuated osteoblast differentiation reduction induced by increased miR-138–5p level in miR-138–5p overexpression osteoblastic cells. In addition, inhibition of miR-138–5p counteracted the negative effects of simulated microgravity on osteoblast differentiation and β-catenin expression in MC3T3-E1 cells. Our findings demonstrated that a signaling pathway mechanism of miR-138–5p in regulating osteoblast differentiation under simulated microgravity, which may reveal a novel mechanism for astronauts' bone loss induced by microgravity and provide a potential therapeutic target for disused osteoprosis.

DNA origami technology has proven to be an excellent tool for precisely manipulating molecules and colloidal elements in a three-dimensional manner. However, fabrication of single crystals with well-defined facets from highly programmable, complex DNA origami units is a great challenge. Here, we report the successful fabrication of DNA origami single crystals with Wulff shapes and high yield. By regulating the symmetries and binding modes of the DNA origami building blocks, the crystalline shapes can be designed and well-controlled. The single crystals are then used to induce precise growth of an ultrathin layer of silica on the edges, resulting in mechanically reinforced silica-DNA hybrid structures that preserve the details of the single crystals without distortion. The silica-infused microcrystals can be directly observed in the dry state, which allows meticulous analysis of the crystal facets and tomographic 3D reconstruction of the single crystals by high-resolution electron microscopy., DNA origami is a valuable tool for precise manipulation of molecules in a three dimensional manner, but the design and assembly of origami units into single crystals is challenging. Here, the authors report successful fabrication of DNA origami single crystals with Wulff shapes, and regulation of their shapes by changing the symmetry and binding modes of DNA origami building blocks.

Herein, we report the excellent De-NOx performance of La0.7Sr0.3MnO3 (LSM) perovskite-supported Pd catalysts (Pd-LSM) in alternating lean-burn/fuel-rich atmospheres using C3H6 as reductant and describe the in situ activation of the Pd catalysts via metal-support interaction (MSI) tuning. The NOx reduction conversion of the Pd-LSM catalyst increased significantly from 56.1% to 90.1% and the production of N2O was suppressed. Our results demonstrated that this behavior was mainly attributed to the in situ transformation of Pd2+ into Pd0 during the reaction. The generated Pd0 species could readily activate the C3H6 reductant and achieve an eight-fold higher turnover frequency than Pd2+ for the reduction of NOx. Moreover, excessive MSIs inhibited the in situ generation of Pd0, and thereby, lowered the De-NOx activity of the catalyst even at high Pd dispersion. In addition, the Pd-LSM catalysts exhibited much higher S tolerance than conventional Al2O3-supported catalysts. Our study provides a new approach for analyzing and designing highly active metal catalysts operated under dynamic alternating oxidizing/reducing atmospheric conditions.

Measuring environmental capacity of total nitrogen (TN) in marine water has become an effective indicator of how much TN is entering the ocean from various sources. However, the TN environmental capacity balance is affected not only by external input but also by removal of TN from water. This removal occurs by numerous mechanisms, among which sedimentation is one that should not be ignored. The influence of sedimentation rates on the environmental capacity of TN in the water body in the northern area of Bohai Bay was studied by investigating the total nitrogen contents of both water and sediments independently. The radioactivity of lead and cesium isotopes (i.e., 210Pb and 137Cs) that were present in columnar sediment samples was measured for time periods ranging from 48 to 72 h using a high-purity germanium detector. A constant rate of supply model (CRS) was used to calculate sedimentation rates. The results indicate that 5.81 × 106 t of sediment are removed from the water column annually through precipitation. Based on the concentration of TN in the studied sediment samples, we calculate that a total of 3.34 × 103 t of nitrogen are removed from the water via sedimentation every year. According to the target TN concentrations for the marine environment that were adopted for the study area for 2025 and 2030, the amount of TN removed from water by sedimentation could remove 62.08% and 64.85%, respectively, of the TN introduced to the marine environment by allowable amounts of anthropogenic discharge into the northern area of Bohai Bay in 2025 and 2030. The high sedimentation rate in Bohai Bay can be expected to remove half of all nitrogen currently entering the water in this area. This demonstrates that when the environmental capacity of TN in ocean water is used to determine the total amount of nitrogen that can be permissibly discharged from land sources, the capacity of the environment to “self-purify” via sedimentation should be considered.

The self-assembly of block copolymers in a confined space has been proven to be a facile and robust strategy for fabricating assembled structures with various potential applications. Herein, we employed a new pH-responsive polymer self-assembly method to regulate ion transport inside artificial nanochannels. The track-etched asymmetric nanochannels were functionalized with PS22k-b-P4VP17k/hPS4k blend polymers, and the ionic conductance and rectification properties of the proposed system were investigated. The pH-actuated changes in the surface charge and wettability resulted in the selective pH-gated ionic transport behavior. The designed system showed a good switching property to the pH stimulus and could recover during the repetitive experiments. The gating ability of the polymer-nanochannel system increased with increasing the weight of the homopolymer, and the proposed platform demonstrated robust stability and reusability. Numerical and the dissipative particle dynamics simulations were implemented to emulate the pH-dependent self-assembling behavior of diblock copolymers in a confined space, which were consistent with the experimental observations. As an example of the self-assembly of polymers in nanoconfinements, this work provides a facile and robust strategy for the regulation of ion transport in synthetic nanochannels. Meanwhile, this work can be further extended to design artificial smart nanogates for various applications such as mass delivery and energy harvesting.

Zero-dimensional lead-free organic-inorganic hybrid metal halides have drawn attention as a result of their local metal ion confinement structure and photoelectric properties. Herein, a lead-free compound of (Gua)3Cu2I5 (Gua = guanidine) with a different metal ion confinement has been discovered, which possesses a unique [Cu2I5]3- face-sharing tetrahedral dimer structure. First-principles calculation demonstrates the inherent nature of a direct band gap for (Gua)3Cu2I5, and its band gap of ∼2.98 eV was determined by experiments. Worthy of note is that (Gua)3Cu2I5 exhibits a highly efficient cool-white emission peaking at 481 nm, a full-width at half-maximum of 125 nm, a large Stokes shift, and a photoluminescence quantum efficiency of 96%, originating from self-trapped exciton emission. More importantly, (Gua)3Cu2I5 single crystals have a reversible thermoinduced luminescence characteristic due to a structural transition scaled by the electron-phonon coupling coefficients, which can be converted back and forth between cool-white and yellow color emission by heating or cooling treatment within a short time. In brief, as-synthesized (Gua)3Cu2I5 shows great potential for application both in single-component white solid-state lighting and sensitive temperature scaling.

Understanding the interplay between urban form, traffic volume, and air quality is significant for urban planning and environmental sustainability. However, limited progress has been made in bringing effective urban planning strategies to help control traffic demand and resulting air pollutants. Therefore, this study aims to investigate the interrelation between urban form, traffic volume, and air quality with a spatiotemporal stratified method. The method extracts and preprocesses traffic volume data in spatial (polluted and unpolluted zones) and temporal (periods in holidays and workdays) dimensions. Three decision tree models (random forest, random tree, M5 model tree) and two comparison models (multiple linear regression, artificial neural network) are used to examine the relationships. The final results show that the spatiotemporal stratification approach effectively reveals the interrelations, and the random forest model outperforms the other models. Specifically, highly aggregated roads and industrial areas are more associated with traffic volume in polluted zones. The dominance of waterway and vegetation shows a strong association with traffic volume in unpolluted zones. The degree of association also varies significantly between workdays and holidays. Our spatiotemporal stratified approach reveals heterogeneous relationships between urban form, traffic volume, and air quality and provides insightful references on sustainable urban development.

Enterovirus 71 (EV71) infection is more likely to cause hand, foot and mouth disease (HFMD) in children, which can lead to neurogenic complications and higher mortality. As a commonly used clinical medicine, Reduning injection (RDN) helps to shorten the symptoms of patients with HFMD and facilitate the early recovery of children. However, the regulatory mechanism of RDN on the HFMD immune system disorder caused by EV71 remains to be discussed. This study collected detailed treatment data of 56 children with HFMD who entered the affiliated Children's Hospital of Nanjing Medical University during 2019. Retrospective analysis of clinical data showed that the symptoms of the RDN treatment group were improved compared with the untreated group. To explore its mechanism, the relevant detection indicators were detected by flow cytometry, enzyme-linked immunosorbent assay and real-time quantitative PCR. It was found that the number and function of innate immune (ILCs) and adaptive immunity (Th1, Th2 and secreted cytokines) were reduced, suggesting that RDN plays a role by regulating cellular immunity. The in vitro differentiation inhibition test further confirmed that RDN affected Th1 differentiation by inhibiting the expression of transcription factors on the basis of Th1 cell differentiation in vitro.

The ability to manipulate liquids in a loss-free and refined manner has long been anticipated, with applications in fields such as analytical chemistry, medical diagnosis, and droplet-based manufacturing. The challenge derives from the liquid/solid contacts, which incur spontaneous spreading, strong pinning, and substantial retention. The retention-proof interfaces, including superhydrophobic surfaces, lubricant-infused surfaces, and liquid marbles, mitigate these issues by respectively introducing air, lubricant, and particulate layers to isolate liquids from underlying solids. Assisted by these interfaces, contrastive physical/chemical designs and engineering methods are leveraged to unlock unparalleled liquid-control methods that are otherwise inaccessible. In this review, we focus on the application of retention-proof interfaces in three facets of manipulation: the aliquoting, grip, and transport of fluids. We discuss the key features, strategies and implementations, highlighting the fundamental physics and operation principles. For aliquoting, the cooperation between diminutive geometries and interfaces in partition droplets are examined. For the grip, we discuss the impact of micro-/nanotextures on adhesion behavior and highlight the mechanisms of switching the adhesive forces. For the transport, we review various engineering and functionalizing forms through which subtle driving forces are dexterously imposed on mobile droplets. The performance of different techniques is evaluated, and potential directions are proposed.

The Asian summer monsoon (ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM. (1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr (thousand years) periodicity, while the cave oxygen-isotope (δ18O) records reveal periodicity in an almost pure precession band (~20 kyr periodicity)—the “Chinese 100 kyr problem”. (2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation (NHSI), whereas the Asian cave δ18O records follow NHSI without a significant lag—a discrepancy termed the “sea-land precession-phase paradox”. How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the “Chinese 100 kyr problem“ and “sea-land precession-phase paradox”.

To accurately assess the combustion fluctuation for a scramjet, a new method based on indium tin oxide (ITO) thin-film thermocouples (TFTCs) and time–frequency analysis (TFA) was developed in this study. ITO TFTCs were used to measure the transient wall-temperature change of the combustor, and the combustion fluctuation features were extracted from the temperature signal via TFA. The combustion fluctuation-resolving abilities of different TFA methods, including the short-time Fourier transform (STFT), continuous wavelet transform (CWT), and Hilbert–Huang transform (HHT), were investigated using a reconstruction signal. The results indicated that the CWT can provide an excellent global view and that the HHT is useful for localizing the frequency features in the time domain. Then, the effect of the equivalence ratio (ER) on the supersonic combustion fluctuation was researched. The total energy of the fluctuation was strongly correlated with the increase in the ER. Meanwhile, the frequency of main fluctuation was always concentrated at approximately 395 Hz, just like an intrinsic characteristic of the combustor. Additionally, the fuel type affected the energy of the combustion fluctuation, rather than the frequency.

Developing low-priced, yet effective and robust catalysts for the nitrogen reduction reaction (NRR) is of vital importance for scalable and renewable electrochemical NH3 synthesis. Herein, we provide the first demonstration of MoS3 as an efficient and durable NRR catalyst in neutral media. The prepared amorphous MoS3 naturally possessed enriched S vacancies and delivered an NH3 yield of 51.7 μg h−1 mg−1 and a Faradaic efficiency of 12.8% at −0.3 V (RHE) in 0.5 M LiClO4, considerably exceeding those of MoS2 and most reported NRR catalysts. Density functional theory calculations unraveled that S vacancies involved in MoS3 played a crucial role in activating the NRR via a consecutive mechanism with a low energetics barrier and simultaneously suppressing the hydrogen evolution reaction.

A graphene fragment is a benzenoid graph that its dualist graph is a unicyclic graph. In particular, when the dualist graph of a benzenoid graph is a circle, it is called cyclofusene. In this paper, we determine the Clar number of a cyclofusene graph, and prove a bound for the Clar number of the graphene fragment. Moreover, we construct the graphene fragment which can attain this bound. More precisely, it is shown that the Clar number of the graphene fragment with n hexagons is at most $$[\frac{2n}{3}]$$ .

A series of short intrinsically disordered polypeptide conjugated oligonucleotides (IDPOCs) were rationally developed and assembled into well-defined nanospheres. The nanospheres exhibited excellent reversible thermoresponsive regulation of their contraction and expansion. Furthermore, the nanospheres showed biocompatibility, drug encapsulation and effective cellular uptake.

As a promising cathode material for high performance lithium ion batteries, olivine LiMnxFe1−xPO4 (LMFP) combines the high safety of LiFePO4 and the high energy density of LiMnPO4. However, there are still obstacles to overcome for achieving higher rate performance, especially its inherent low electronic conductivity and Li+ diffusion coefficient. Here, the restricting factors for realizing high rate performance LMFP cathode materials are reviewed systematically. The bulk properties that affect the internal ion transport and electronic conduction are thoroughly expounded, particularly the phase transition mechanism, lattice distortion, point defects, element doping, Fe/Mn ratio and particle morphology. Moreover, the effect of utilizing a carbon-based/non-carbon material coating for improving the interface structure on rate performance is discussed comprehensively. A particular emphasis is placed on the design of LMFP-based batteries with high rate capability as well from the aspect of cell preparation technology, including the electrolyte selection and electrode design. Finally, on the basis of state-of-the-art understanding of bulk properties, the interface structure and cell preparation engineering, several technical challenges and research trends in improving the rate performance of LMFP cathode materials are proposed.

The electrochemical nitrogen reduction reaction (NRR) provides a promising route for energy-effective and sustainable ammonia synthesis, while developing high-efficiency NRR electrocatalysts is extremely desirable. Here we first exploited foordite SnNb2O6 nanosheets as an effective and durable NRR catalyst, which presented an NH3 yield of 53.1 μg h−1 mg−1 and a faradaic efficiency of 17.6% at −0.3 V (vs. reversible hydrogen electrode). Theoretical computations uncovered the dual-active-center mechanism of Nb3c (3c means three-fold coordinated bond) and Sn4c–Nb5c dimer on SnNb2O6 (311) to synergistically enhance the N2 adsorption and activation, consequently lowering the energy barrier for the rate-determining step and boosting the electrocatalytic NRR.

Due to the proposal and evolution of the DNA origami technique over the past decade, DNA molecules have been utilized as building blocks for the precise construction of nanoscale architectures. Benefiting from the superior programmability of DNA molecules, the sequence-dependent recognition mechanism and robust complementation among DNA strands make it possible to customize almost arbitrary structures. Such an assembly strategy bypasses some of the limits of conventional fabrication methods; the fabrication accuracy and complexity of the target product are unprecedentedly promoted as well. Furthermore, due to the spatial addressability of the final products, nanostructures assembled through the DNA origami technique can also serve as a versatile platform for the spatial positioning of functional elements, represented by colloidal nanoparticles (NPs). The subsequent fabrication of heterogeneous functional nanoarchitectures is realized via modifying colloidal NPs with DNA strands and manipulating them to anchor into DNA origami templates. This has given rise to investigations of their novel properties in nanophotonics and therapeutic effects towards some diseases. In this review, we survey the crucial progress in the development of DNA origami design, assembly and structural analysis and summarize available applications in nanophotonics and cancer therapy based on the object-dressed DNA origami complex. Moreover, we elucidate the development of this field and discuss the potential directions of this kind of application-oriented nanomanufacturing.

Laser-induced breakdown spectroscopy (LIBS) has been successfully applied for in situ detection in the sea, and the water pressure is found to be the main influence on the LIBS signal compared to temperature or salinity. In this study, we explored self-absorption to evaluate the pressure effects on LIBS detection. By using fast imaging and spectroscopic technique, it is proved that self-absorption (SA) was significantly enhanced with increased pressure, and the severe inhomogeneity of plasma distribution might be the reason. With this SA model, the LIBS intensity could be well-estimated according to the simulation results. Moreover, the self-absorption of LIBS underwater was more likely determined by the plasma temperature when the detection was carried out in a low-pressure regime. The obtained results would be helpful for the signal correction of LIBS in the deep sea.

This paper proposes a novel quadratic convex reformulation (QCR) for the nonconvex quadratic program with convex quadratic constraints. This new QCR is based on the technique of simultaneous diagon...

Assembly of distinct types of species, particularly possessing anisotropic configurations, is the premise to broaden structural diversity and explore materials' collective properties. However, it remains a great challenge to programmably cocrystallize manifold anisotropic nanoparticles with the desired assembly mode, because it requires not only the complementarity of both sizes and shapes but also the control over their directional interactions. Here, by introducing DNA origami technique into lattice engineering, we synthesize two types of DNA nano-objects with different symmetries and program the heterogeneous functional patches precisely on their surfaces with nanometer-level precision, which could guide further assembly of these nano-objects. We show that these anisotropic DNA nano-objects could be cocrystallized along specified modes via modulating the combination of surface patches. The highly ordered DNA crystals were thoroughly evidenced by techniques including small-angle X-ray scattering and electron microscopy after careful encapsulation of a thin layer of silica on these DNA nano-objects. Our strategy endows distinct shapes of organic DNA origami structures with regulation features to control the sophisticated modes of cocrystallization of these diverse components, laying a foundation for designing and fabricating customized three-dimensional structures with given optical and mechanical properties.

The paper presents the results of an experimental and numerical study on the combustion characteristics of a supersonic combustor operation enhanced by pilot hydrogen and air throttling, including ...

The subcycle interaction of light and electrons has been one of the key frontiers in free-electron lasers, attosecond science and dynamical investigation of matter. Capturing the underlying subcycle dynamics of electrons with an optical field promises fascinating vistas with unprecedented temporal resolution. Yet the rigorous synchronization requirement has kept its realization out of reach. Here, by direct spatial observation of periodic electron bunch fringes, we demonstrate a laser streaking concept for revealing the dynamics of free electrons emitted from a plasma mirror under sub-relativistic laser intensity. Field-induced electron beam deflection demonstrates subcycle charge dynamics with a streaking speed of ~60 μrad as−1. This provides us with an attosecond-resolution metrology to obtain more direct evidence about the light-field-induced electron dynamics in the plasma mirror. Our results offer unprecedented characterization of attosecond dynamics and open the way to extensive experimental investigations of the interaction of attosecond electrons with intense lasers. By focusing a sub-relativistic infrared laser pulse onto a silica target, a periodic deflection pattern of attosecond electron pulse trains is observed. It reveals these subcycle charge dynamics with a streaking speed of ~60 μrad as−1.

Droughts have caused many damages in many countries and might be aggravated around the world. Therefore, it is urgent to predict and monitor drought accurately. Soil moisture and its corresponding drought index (e.g., soil water deficit index, SWDI) are the key variables to define drought. However, in situ soil moisture observations are inaccessible in many areas. This study applies support vector machine (SVM) by using a new set of inputs to investigate the performance of in situ and remote sensing products (CMORPH-CRT, IMERG V05 and TRMM 3B42V7) for soil moisture and SWDI forecast over the Xiang River Basin. This study also assesses whether the addition of remote sensing soil moisture as input can improve the performance of SWDI prediction. The results are as follows: (1) the new set of inputs is suitable for drought prediction based on SVM; (2) using in situ precipitation as input to SVM shows the best performance for soil moisture prediction, which followed by TRMM 3B42V7, IMERG V05 and CMORPH-CRT; (3) in situ precipitation and IMERG V05 as input are more suitable for indirect SWDI prediction, while CMORPH-CRT and TRMM 3B42V7 are more suitable for direct SWDI prediction; (4) the addition of soil moisture with in situ precipitation or CMORPH-CRT both can improve the performance of direct SWDI prediction; (5) the lead time for drought prediction with SVM over the Xiang River Basin is about 2 weeks.

The tremendous growth of data traffic has spurred a rapid evolution of optical communications for a higher data transmission capacity. Next-generation fiber-optic communication systems will require dramatically increased complexity that cannot be obtained using discrete components. In this context, silicon photonics is quickly maturing. Capable of manipulating electrons and photons on the same platform, this disruptive technology promises to cram more complexity on a single chip, leading to orders-of-magnitude reduction of integrated photonic systems in size, energy, and cost. This paper provides a system perspective and reviews recent progress in silicon photonics probing all dimensions of light to scale the capacity of fiber-optic networks toward terabits-per-second per optical interface and petabits-per-second per transmission link. Firstly, we overview fundamentals and the evolving trends of silicon photonic fabrication process. Then, we focus on recent progress in silicon coherent optical transceivers. Further scaling the system capacity requires multiplexing techniques in all the dimensions of light: wavelength, polarization, and space, for which we have seen impressive demonstrations of on-chip functionalities such as polarization diversity circuits and wavelength- and space-division multiplexers. Despite these advances, large-scale silicon photonic integrated circuits incorporating a variety of active and passive functionalities still face considerable challenges, many of which will eventually be addressed as the technology continues evolving with the entire ecosystem at a fast pace.

The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards (STORM973) project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region (BMR) during the warm season from 2014 to 2018. The aim of the project was to understand how dynamical, microphysical and electrical processes interact in severe thunderstorms in the BMR, and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts. The platforms used in the field campaign included the Beijing Lightning Network (BLNET, consisting of 16 stations), 2 X-band dual linear polarimetric Doppler radars, and 4 laser raindrop spectrometers. The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region. Although diverse thunderstorm types were documented, it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area, influenced by the terrain and environmental conditions. The flash density maximums were found in eastern Changping District, central and eastern Shunyi District, and the central urban area of Beijing, suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing. In addition, the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions. The super (5% of the total), strong (35%), and weak (60%) thunderstorms contributed about 37%, 56%, and 7% to the total flashes in the BMR, respectively. Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms, the lightning flash rate can be used as an indicator of severe weather events, such as hail and short-duration heavy rainfall. Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale, through adjusting or correcting the thermodynamic and microphysical parameters of the model.

The dehydration of cellulose in polar aprotic solvents produces high-value anhydro-sugars, opening up a new avenue for the utilization of cellulose. However, there are still some problems that need to be solved. Herein, we selected some carbohydrates (e.g. cellulose, starch, cellobiose, maltose, methyl-β-D-glucopyranoside and methyl-α-D-glucopyranoside) to examine the influence of different glycosidic bonds and substituents on the preparation of levoglucosan (LGA). The results of LGA yields, reaction rate constants and activation energies from different saccharides show that β-glycosidic bond is more vulnerable to break, forming LGA more easily. The activation energies of the latter 4 carbohydrates are 89.9, 104.2, 93.3, 113.6 kJ/mol, respectively. The strength of acid affects the dehydration process of cellulose greatly. These acids whose pKa values are between − 3 and − 2, including p-toluenesulfonic acid, methanesulfonic acid, and sulfuric acid, can achieve the best yields of LGA and levoglucosenone (LGO). Accordingly, those acids with higher pKa value have no catalytic activity, whereas the rate of cellulose degradation using lower pKa valued acids as catalyst is too fast to be efficiently monitored and carbonization is severe. The side reaction of cellulose hydrolysis and the formation of byproducts including 5-hydroxymethylfurfural (HMF) and furfural (FF) could be suppressed effectively through the addition of phosphorus pentoxide as water absorbent into the reaction system. The molar concentration ratio of LGO and (HMF + FF + Glucose) reached 12.04, which is 105% higher than those without water absorbent. This ratio can reach 21.38 in LGA dehydration into LGO process when phosphorus pentoxide was added.

This study was conducted to understand the nature of the polar state in the morphotropic phase boundary composition 0.67BiFeO3–0.33BaTiO3 (0.67BF–0.33BT). Both the unpoled and poled specimens exhibit an average cubic structure. The poling induces a 0.14% increase in the lattice parameter. Macrodomains are absent both in the initial and polar state of 0.67BF–0.33BT. A typical relaxor-type dielectric anomaly was observed (Tf = ~ 627 K, TB = ~ 820 K). The remnant polarization (Pr), maximum value of electrostrain (Sm), and magnitude strain at Ec in the bipolar mode (Sneg) increase clearly during heating (Pr, ~ 40 µC/cm2; Sm, 0.191% under 40 kV/cm at 453 K). Unlike Bi0.5Na0.5TiO3-based nonergodic relaxors, the first-cycle bipolar electrostrain loops indicate that the minimum strain on the negative side of the bipolar strain curves is negative. Furthermore, the slopes of the relative permittivity versus log frequency plots in unpoled (− 21) and poled (− 23) specimens are similar. The transition between the relaxor state and ferroelectric-like state does not involve a clear dielectric anomaly even in the poled specimen.

The properties of Sn-Ce solid solution have a significant effect on the CO oxidation performance of the Pd/Sn1-xCexO2 catalyst. Herein, we compared the effects of Sn-rich and Ce-rich supports on the catalytic performance of the Pd/Sn1-xCexO2 catalysts. Our results show that the active oxygen species on the Ce-rich and Sn-rich supports are mainly the lattice oxygen species and the chemisorbed oxygen species, respectively. Although the active oxygen species on the Ce-rich supports have higher intrinsic activity, the active oxygen species on the Sn-rich supports have better mobility. It leads to an interesting phenomenon that the change trend of the activity of the Pd/Sn1-xCexO2 catalysts with temperature is consistent with that of their supports. Compared with the Ce-rich supports and the corresponding supported Pd catalysts, the catalytic activity of the Sn-rich supports and the corresponding supported Pd catalysts increased faster with the increase of temperature.

Herein, we synthesize the hydroxyl-enriched e-MnO2 catalyst (MnO2-AT) by simple acid washing. Acid washing destroys the sphere structure into fragments with abundant structure defects and maintains the crystal and pore structure of e-MnO2. MnO2-AT exhibits the high activity and selectivity for preferential oxidation of CO in the H2-rich stream, as well as the high activity for CO total oxidation. It can completely converts CO in preferential and total oxidation of CO at 170 °C and 90 °C, respectively, with a good stability. The acid washing treatment highly increases the surface hydroxyl groups on MnO2-AT. Our results demonstrate that with the aid of surface hydroxyl groups CO can easily form bicarbonate intermediates, which are more thermally unstable than carbonate intermediates. The faster CO2 desorption from bicarbonates than carbonates promotes the CO oxidation process.

In this paper, a novel multi-party quantum private comparison (MQPC) protocol with a semi-honest third party (TP) is proposed based on the entanglement swapping of d-level cat states and d-level Bell states. Here, TP is allowed to misbehave on his own but will not conspire with any party. In our protocol, n parties employ unitary operations to encode their private secrets and can compare the equality of their private secrets within one time execution of the protocol. Our protocol can withstand both the outside attacks and the participant attacks on the condition that none of the QKD methods is adopted to generate keys for security. One party cannot obtain other parties' secrets except for the case that their secrets are identical. The semi-honest TP cannot learn any information about these parties' secrets except the end comparison result on whether all private secrets from n parties are equal., Comment: 11 pages, 3 figures, 1 table

The design of an intelligent nanofluidic system for regulating the transport of substances such as ions and molecules is significant for applications in biological sensing, drug delivery, and energy harvesting. However, the existing nanofluidic system faces challenges in terms of an uncontrollable transport speed for molecules and ions and also a complex preparation processes, low durability, and slow response rate. Herein, we demonstrate the use of a bioinspired ferrofluid-based nanofluid that can facilitate multilevel ultrafast-responsive ion and molecule transport with speed control. Specifically, we reversibly deform bulk ferrofluids using a magnet and wet/dewet the outer surface of superhydrophilic nanochannels for building a smart transport system. By changing the direction and strength of the external magnetic field, a speed control, ultrafast-responsive molecular transport (

Understanding the urban form-air quality relationship is essential to mitigate intra-urban air pollution and to improve urban ecology. However, few studies considered urban form and meteorological factors integratively and analyzed their synthetic effects on air pollution. We investigate how to model the integrated effects on the spatiotemporal distribution of PM2.5 in the Atlanta metropolitan area to improve the understanding of the urban form-air quality relationship. Two groups of models are developed: one uses urban form only and the other uses wind-direct urban form. Relative humidity, wind speed, and temperature are included as control variables. Both linear (Multiple Linear Regression) and nonlinear models (Random Forest and Artificial Neural Network) are constructed and tested with both tenfold cross-validation and field PM2.5 data obtained from a portable device, AirBeam2. Random Forest overall outperforms other models suggesting that the urban form-air quality relationship is most likely to be nonlinear. Additionally, the group using wind-direct urban form outperforms the other group and the contribution of the same urban form metrics differs in different wind sections proving that meteorological factors and urban form have synthetic effects on PM2.5. Finally, the patch density, dominance, and aggregation of roads and vegetation, demonstrate higher attribute significance than other urban form metrics. Urban planners, practitioners, and policymakers need to carefully consider not only the spatial configuration of roads and vegetation but also the local climate patterns to minimize intra-urban air pollution effectively.

We exploit a high-performing resistive-type trace oxygen sensor based on 2D high-mobility semiconducting Bi2 O2 Se nanoplates. Scanning tunneling microscopy combined with first-principle calculations confirms an amorphous Se atomic layer formed on the surface of 2D Bi2 O2 Se exposed to oxygen, which contributes to larger specific surface area and abundant active adsorption sites. Such 2D Bi2 O2 Se oxygen sensors have remarkable oxygen-adsorption induced variations of carrier density/mobility, and exhibit an ultrahigh sensitivity featuring minimum detection limit of 0.25 ppm, long-term stability, high durativity, and wide-range response to concentration up to 400 ppm at room temperature. 2D Bi2 O2 Se arrayed sensors integrated in parallel form are found to possess an oxygen detection minimum of sub-0.25 ppm ascribed to an enhanced signal-to-noise ratio. These advanced sensor characteristics involving ease integration show 2D Bi2 O2 Se is an ideal candidate for trace oxygen detection.

So far, the synthesis of high-activity and low-cost photocatalysts remains a huge challenge. 3D flower-like MoS2/g-C3N4 hybrids were synthesized by a very simple method. All of them were characterized by various characterizations to determine the composition, morphology, and properties of the compounds. There are many sites with large specific surface area catalytic activity in this structure. These composites are all photocatalytic degradable organic dyes, and the photocatalytic properties of the flower-like 4% MoS2/g-C3N4 are the best. The stability and recyclability of the 4% MoS2/g-C3N4 photocatalyst are also excellent. The 4% MoS2/g-C3N4 can also have photocatalytic ability to produce hydrogen. 50 mg of 4% MoS2/g-C3N4 photocatalyst can produce about 156 umol of hydrogen with visible light irradiation for about 4 h. Rate of hydrogen production is about 780 µmol h − 1 g − 1. In view of the good photocatalytic performance of the catalyst, we have discussed the mechanism both photocatalytic degradation of organic harmful pollutants and photocatalytic hydrogen production.

Taking the previously reported compound BH-7d as the lead, we designed and synthesized a series of piperidinyl-substituted [1,2,4]triazolo[1,5-a]pyrimidines, and their anti-HIV activities as well as cytotoxicities were evaluated. Several compounds exhibited moderate anti-HIV (IIIB) potency, among which 2b was the most active one (EC50 = 4.29 μM). Structure-activity relationships derived from the antiretroviral results were analyzed. Additionally, most compounds demonstrated reduced cytotoxicity (CC50 > 200 μM) compared with those of BH-7d and etravirine. Molecular docking study further revealed the binding conformation of 2b in the binding pocket of HIV-1 reverse transcriptase. ispartof: CHEMICAL BIOLOGY & DRUG DESIGN vol:97 issue:1 pages:67-76 ispartof: location:England status: published

Flame stabilization in a kerosene-fueled scramjet combustor was investigated experimentally through Schlieren, flame luminosity, and wall pressure measurement, aiming to obtain better insight into combustion characteristics. Experiments were conducted in a direct-connected supersonic combustion facility with inflow conditions of Mach number 2.0, stagnation pressure 0.82 MPa, and temperature 950 K, simulating the flight condition of Mach number 4.0. Results revealed that kerosene was able to be ignited when the equivalence ratio of pilot hydrogen reached 0.080, but was unsuccessful when the equivalence ratio was 0.040. Once ignited, the intense combustion induced high back pressure forcing the flame to spread into the isolator. The pilot flame invariably appeared in the cavity shear layer and attached to the cavity ramp under different equivalence ratios of pilot hydrogen. With the mass flux of pilot hydrogen increased, the kerosene flame located near the cavity ramp was asymmetrical and unstable since it propagated upstream repeatedly. Therefore, the kerosene could be ignited by a suitable equivalence ratio of continuous pilot hydrogen, potentially accompanied with unstable combustion.

Ginkgolide B (GB) and Puerarin (Pue) are active pharmaceutical ingredients for the treatment of Parkinson’s disease (PD); however, both are poorly water-soluble, which limits their bioavailability. The present study used the niosome vesicle encapsulation technique to prepare a novel GB composite drug. The conditions for GB–Pue niosomal complex preparation were as follows: a hydration temperature of 60°C, a hydrophilic–lipophilic balance of 10.5, a drug–carrier mass ratio of 8:100, and a surfactant–cholesterol mass ratio of 1.5:1. The niosomal complex suspension was uniformly distributed and milky white in color, with no stratification over a duration of 1 month. It had an average particle size of 187.3 nm, a particle-size distribution of 0.237, a GB encapsulation efficiency (EE) of 68.2%, a GB drug-loading rate of 90.1%, a Pue EE of 40.5%, and a Pue drug-loading rate of 83.3%. The optimal storage temperature for the niosomal complex suspension was 4°C. Following an intravenous injection of the niosomal complex suspension into the rat tail, the area under the curve (AUC) from 0 to 4 h was 54.1 h µg mL−1, with a mean residence time (MRT) of 0.96 h, a distribution half-life (T1/2α) of 0.195 h, and a total clearance of 0.003 L h−1 kg−1. The AUC and MRT of the composite prescription were 1.1- and 1.4-times those of the commercial injection, respectively, showing significantly increased sustained release and bioavailability. Moreover, the distribution of GB in the brain tissue was 1.8-times that of the commercial injection. In conclusion, the novel GB niosomal composite drug, with excellent stability, improved pharmacokinetics, and brain tissue distribution, demonstrates great potential for the delivery of GB and Pue for PD therapeutics.

Electrochemical nitrogen fixation offers a promising route for sustainable NH3 production, while the rational design of effective and durable electrocatalysts is urgently required for an effective ...

In this work, we report the first observation of a structure-driven ferroelectric (FE) wake-up effect in polycrystalline AgNbO3-based antiferroelectric (AFE) materials, by which polarization gradua...

Silicon carbide (SiC) particles were utilized to improve the mechanical, thermal and anti-ablative properties of carbon/phenolic (C/Ph) composites. SiC–C/Ph composites were fabricated with different weight percentage of SiC by vacuum impregnation method. The mechanical and thermal properties were characterized by compression tests, thermal conductivity tests, and thermogravimetric analysis; meanwhile, ablation resistance was investigated using plasma wind tunnel tests and scanning electron microscopy. Experimental results showed that 5 wt% SiC modified C/Ph composites owned the optimum properties. Moreover, introducing SiC particles could result in an obvious decrease of compression strength, but an increase of thermal stability, thermal conductivity and anti-ablative performance. Notably, the ablation rate reached its the lowest point at 5% the SiC content in resin matrix composites.