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Stigmaria asiatica Jongmans et Gothan is a common species from the Permo-Carboniferous of East Asia. It is characterized by a relatively slender rhizomorph and represents the underground rooting system of lowland arborescent lycopsids. This species from the Wuda Coalfield (Asselian, lower Permian) represents the recovery taxon dominating the subsequent peat-forming vegetation after a volcanic eruption destroyed the previous flora, termed the Wuda Tuff Flora (Chinese “vegetational Pompeii”). It is characterized by novel downward axes, probably for access to deeper groundwater. Here, the anatomy of S. asiatica, including that of the axes and rootlets, is reported in detail for the first time. The axis contains stelar tissues, including pith, primary and secondary xylem, and phloem, and both primary and secondary cortical tissues. The primary cortex is tripartite and is divided into inner, middle, and outer zones. Secondary cortex is produced in the interior of the outer cortex splitting the outer cortex into inner and outer portions. The homogeneous pith and mesarch primary xylem maturation of S. asiatica are different from previously recorded species of Stigmaria Brongniart. Rootlets are composed of a central monarch vascular bundle surrounded by inner cortex and a ring of outer cortex. A vacant region is present between the inner and outer cortices. In some cases, connectives between the inner and outer cortices are present. According to the presented statistical analysis, it is proposed that rootlets of S. asiatica were highly branched, with at least for 7 bifurcations. Rootlets, together with the downward penetrating rhizomorph, helped to both anchor the plant and search for and absorb deep groundwater.

Despite the known hazards to wildlife, plastic waste to waterways and oceans continues to increase at alarming rates every year. Nanoplastics are a breakdown product of plastic debris in the environment (0.1–100 nm). Their small size renders them bioavailable, and they are likely to accumulate/adsorb persistent organic pollutants, which could increase their toxicity. In this study, we evaluated the effects of nanoplastics and phenanthrene on the early life stages of zebrafish. Zebrafish embryos were exposed to fluorescent nanoparticles and observed with fluorescence microscopy. Polystyrene nanoplastics (80 nm) attached to the embryonic chorionic membrane and were ingested when zebrafish reached 144 h after fertilization, the point at which they first open their mouth, as observed by the fluorescence in their intestines. Exposure alone or in combination with phenanthrene resulted in zebrafish pericardial edema, spinal curvature, increased embryonic heart rate, shortened body length, and increased mortality. Co-exposure to 5 mg/L nanoplastics and 0.1 mg/L phenanthrene caused more negative effects on length, teratogenicity and mortality of zebrafish embryos than the corresponding concentrations of single exposure. This study provides clear evidence that nanoplastics can be ingested by zebrafish larvae, thus future work to assess the toxicological effects is important to marine wildlife management.

The objective of this study was to assess the effectiveness and practicability of an activity index combining acceleration and location data for automated estrus detection in dairy cows. By using a wearable neck tag, measurements of acceleration and location were gathered from 22 multiparous cows monitored incessantly for 6 days to derive activity records of each cow. The maximum-minimum distance clustering (MMDC) method was used to divide hourly activity data into low, medium, high, and intensity level groups. The weighted sum of the proportions of the low, medium, high, and intensity activities in an hour constituted the activity level. The activity index was defined as the ratio of the variation in hourly activity level compared to the same time period during the previous three days. Furthermore, whether the cow was in estrus was judged above a set threshold. The study showed that the power consumption and communication effects of the neck tags were acceptable for indoor-housing conditions. For the two consecutive time periods, the activity-index-based detection algorithm achieved 90.91% for accuracy, 100% for precision, 100% for specificity, 83.33% for recall, 90.91% for F1 score, and 0.82 for Kappa coefficient. On the basis of these results, it can be concluded that the combination of acceleration and location in the activity index can promote estrus detection in dairy cows.

The evolution of the Mozambique Ocean spans the Rodinia and Gondwana supercontinent cycles playing a key role in Earth history. Integrated petrological, geochronological, geochemical, and isotopic data on the Neoproterozoic units from the Lhasa terrane, Tibet, constrain the magmatic and metamorphic evolution of the ocean. Our results reveal two magmatic (ca. 695 Ma and ca. 671 Ma) and two metamorphic (ca. 700 Ma and ca. 650 Ma) pulses. Gabbros define the first magmatic suite. They have within-plate affinities and experienced crustal contamination. Their positive zircon eHf(t) (+1.6 to +9.6) and whole-rock eNd(t) (+2.7 to +6.1) values are indicative of a depleted mantle source. Gabbros from the second magmatic event belong to the tholeiitic series, lack evidence for crustal contamination, and are geochemically similar to E-MORB. They have negative to positive zircon eHf(t) (−3.2 to +1.5) and low positive whole-rock eNd(t) (+1.4 to +2.0) values, and were probably derived from an E-MORB-type enriched mantle source, slightly modified by subduction components. Evidence for the metamorphic events (ca. 700 and ca. 650 Ma) was obtained from U Pb dating of zircon rims of marbles and gabbros, which are characterized by low Th/U ratios (0.01–0.07) indicative of a metamorphic origin. Integrating previous studies with the data presented in this contribution, we suggest that the history of the Lhasa terrane was linked to the evolution of the Mozambique Ocean. The older mafic magmatism (ca. 695 Ma) and metamorphism (ca. 700 Ma) formed during terrane accretion processes along an active continental margin to the ocean. The relatively younger mafic magmatism (ca. 671 Ma) provides a record from an oceanic fragment that was metamorphosed (ca. 650 Ma) during closure of the Mozambique Ocean.

The microstructure and mechanical properties of as-cast and isothermally annealed CxHf0.25NbTaW0.5 (x=0, 0.05, 0.15, 0.25) refractory high-entropy alloys (RHEAs) were studied. Both the as-cast and annealed RHEAs consisted of disordered body-centered cubic solid solution phase and metal carbide (MC) phase with a face-centered cubic crystal structure (Fm-3m space group). The primary carbides were enriched with Hf and C elements and tended to form lamellar eutectic-like microstructure in the interdendrites. The lamellar eutectic-like structure in the interdendrites would be formed from the decomposition of sub-carbide M2C under the influence of Hf element. After isothermal annealing, slatted carbides were precipitated on the matrix, and the distribution became more uniform with high C content. The formation of carbides strongly influenced the mechanical properties both at room and high temperatures. The yield strength values of C0.25Hf0.25NbTaW0.5 RHEA at 1473 and 1673 K were 792 and 749 MPa, respectively. The result had exceeded the high temperature mechanical properties of currently known RHEAs. Moreover, this RHEA exhibited high-temperature performance stability and excellent plasticity, exceeding 30 and 50% at room and elevated temperatures (above 1273 K), respectively. During thermal deformation, carbon-containing RHEAs obtained more severe work hardening than that of ACH0 RHEAs, and required greater dynamic recrystallization to achieve the dynamic equilibrium.

While there have been multiple recent reports in the literature focusing on the effects of magnetic field on the phase transformation behaviors, the research conducted with an ultra-high magnetic field greater than 20 T is still preliminary. In the current study, the structure evolution of Co-B alloys are experimentally studied with undercooling. The effects of a 25 T magnetic field on the solidification behavior and the subsequent solid-state phase transformation behavior have been investigated. The 25 T magnetic field is confirmed to have little effect on the homogeneous nucleation, but have some influence on the heterogeneous nucleation of Co3B and Co23B6 phases by modifying the wetting angle θ. The decomposition of Co23B6 phase in the subsequent cooling process can be effectively suppressed by applying the 25 T magnetic field. The present work might be helpful for not only theoretically understanding the influence of ultra-high magnetic field on the phase transformation behaviors but a potential technology of field-manipulation of magnetic materials.

Recent technological advancements and developments have led to a dramatic increase in the amount of high-dimensional data and thus have increased the demand for proper and efficient multivariate regression methods. Numerous traditional multivariate approaches such as principal component analysis have been used broadly in various research areas, including investment analysis, image identification, and population genetic structure analysis. However, these common approaches have the limitations of ignoring the correlations between responses and a low variable selection efficiency. Therefore, in this article, we introduce the reduced rank regression method and its extensions, sparse reduced rank regression and subspace assisted regression with row sparsity, which hold potential to meet the above demands and thus improve the interpretability of regression models. We conducted a simulation study to evaluate their performance and compared them with several other variable selection methods. For different application scenarios, we also provide selection suggestions based on predictive ability and variable selection accuracy. Finally, to demonstrate the practical value of these methods in the field of microbiome research, we applied our chosen method to real population-level microbiome data, the results of which validated our method. Our method extensions provide valuable guidelines for future omics research, especially with respect to multivariate regression, and could pave the way for novel discoveries in microbiome and related research fields.

H2O2 has been widely applied in the fields of chemical synthesis, medical sterilization, pollutant removal, et al., due to its strong oxidizing property and the avoidable secondary pollution. Despite of the enhanced performance for H2O2 generation over g-C3N4 semiconductors through promoting the separation of photo-generated charge carriers, the effect of migration orientation of charge carriers is still ambiguous. For this emotion, surface modification of g-C3N4 was employed to adjust the migration orientation of charge carriers, in order to investigate systematically its effect on the performance of H2O2 generation. It was found that ultrathin g-C3N4 (UCN) modified by boron nitride (BN), as an effective hole-attract agent, demonstrated a significantly enhanced performance. Particularly, for the optimum UCN/BN-40% catalyst, 4.0-fold higher yield of H2O2 was obtained in comparison with the pristine UCN. As comparison, UCN modified by carbon dust demonstrated a completely opposite tendency. The remarkably improved performance over UCN/BN was ascribed to the fact that more photo-generated electrons were remained inside of triazine structure of g-C3N4, leading to the formation of larger amount of 1,4-endoxide. It is anticipated that our work could provide new insights for the design of photocatalyst with significantly improved performance for H2O2 generation.

The 6th generation (6G) communication envisions a highly integrated network where aerial vehicles connect satellites and terrestrial systems. As low altitude vehicle, unmanned aerial vehicle (UAV) is able to quickly establish wireless networks without resorting to terrestrial infrastructure. Due to strong invulnerability, synergistic cooperation and flexible scheduling, the multi-UAV communication system can significantly improve system performance through collaboratively designing multi-UAV trajectory and radio resource scheduling. This article proposes a multi-UAV wireless powered communication (WPC) system for 6G-enabled Internet of Things (IoT). Specifically, each time slot is split into uplink and downlink subslot. In the downlink subslot, multiple UAVs dispatched as aerial communication platforms transfer energy to multiple IoT users. In the uplink subslot, the association between UAVs and users is designed, and then the scheduled user uploads data to the specific UAV by using the harvested energy. According to the proposed system, we propose a collaborative scheme of multi-UAV trajectory optimization and resource scheduling. By synergistically optimizing UAV-user association, subslot duration, user transmit power, and multi-UAV trajectory, we maximize the minimum average achievable rate among all users. Particularly, the nonconvex optimization problem can be efficiently figured out by an alternative iteration algorithm proposed in this article. Finally, numerical results show that our design can not only optimize multi-UAV flight path, but also achieve higher objective value than benchmark schemes.

The precision fabrication of ceramic moulds for the mass-production of micro/meso-structural arrays places a tremendous challenge to the manufacturing industry. This work aims to reveal the physics behind the processes so as to address this technological challenge. A new method for texturing the diamond grinding wheel surface with a micro-abrasive waterjet is proposed for highly efficient form-grinding of ceramic moulds into the required micro/meso-structural surfaces. It shows that this technology provides some unique advantages in improving the sharpness and geometrical accuracy of the grinding wheels. The mechanisms about material removal and texture formation in grinding wheel truing are investigated to enable the precise control of micro/meso-structure generation on the grinding wheel. A theoretical model is established to study the effect of grinding wheel surface micro/meso-textures and grain trajectory on the quality of the ground mould surface and reveal the reflection mechanism of the ground marks on the mould surface. Furthermore, an integrated rough-fine grinding strategy is proposed which is shown to significantly increase the grinding efficiency by 15–24 times. It is found that ductile domain grinding of ceramic moulds to achieve the required contour profile of 6.7 μm PV accuracy and a surface roughness Ra of less than 40 nm can be achieved.

Rational design of carbon materials for electrochemical devices has attracted great attentions over the past decades. Doping carbon with heteroatoms has been widely proven to be an effective way to improve the physical and electrochemical properties of carbon. The selective types and doping level of heteroatoms, as well as simple and green doping routes, are keys to the development of heteroatoms doped carbon. Due to a strong synergistic effect generated by the co-doping of boron (B) and nitrogen (N), B, N co-doped carbon materials have been demonstrated to be promising catalysts for multiple electrochemical devices. Herein, we report an eco-friendly and one-step approach to synthesis of B, N co-doped graphene (B, N-G) using BN as B and N doping resources. The decomposition of BN under a controlled flow of water steam at high temperature not only enables a high-level B and N co-doping into carbon but also facilitates the formation of highly active catalytic sites. Benefiting from high co-doping level of heteroatoms and highly active catalytic sites (e.g., BC2O), the B, N-G as cathode for rechargeable lithium oxygen batteries displays outstanding lithium storage properties with an ultrahigh specific capacity of 18222 mAh g−1 at 100 mA g−1 and good cycling stability with a limited specific capacity of 1000 mAh g−1 over 120 cycles at 1 A g−1.

Al matrix composites have attracted significant attention of researchers in recent years due to their lightweight, excellent mechanical and tribological properties. In this study, an Al2024 matrix hybrid composite (AMHC) reinforced with both TiC nanoparticles and graphene nanoplatelets (GNPs) was produced via a route of powder metallurgy. And its microstructure, microhardness and tribological properties are compared with those of unreinforced Al2024 alloy matrix and Al2024 matrix composites reinforced with either only TiC or GNPs. It was found that the distribution of Al2Cu, TiC nanoparticles and GNPs in the matrix and the wear resistance are significantly improved when introducing both TiC nanoparticles and the GNPs. The wear mechanisms change from the adhesion-dominant wear for Al2024 and the other singly reinforced composites into abrasive-dominant wear for the hybrid composite. The significantly improved wear resistance of the AMHC is attributed to the synergistic effects of reinforcing and self-lubricating of the TiC and GNPs.

Flexible thermoelectric materials are presented with potential applications in electronic devices and energy conversion due to their convenient preparation, good flexibility, and various forms. However, as ductility is rarely observed in inorganic semiconductors and ceramic insulators, reports on applications of inorganic oxide materials in flexible thermoelectric materials are sparse. Here, we report a new method for the synthesis of a flexible Na1.4Co2O4 thermoelectric material based on Na1.4Co2O4 bulk materials, which are prepared by a self-flux method and painted on print paper. Seebeck coefficient and power factor of the obtained thermoelectric material are 78–102 μVK-1 and 159–223 μWm-1K-2, respectively, in a temperature range of 303–522 K, which are superior to those values of other conductive polymers and their compounds. More interestingly, the n-type Na1.4Co2O4 flexible material is obtained in the painting process at higher pressure with Seebeck coefficients of –109 to –183 μVK-1 in a temperature range of 303–522 K. The convenient preparation method of these novel flexible thermoelectric materials may be expanded to the synthesis of other flexible thermoelectric materials, which will be the focus of future work.

The strip formation process on a glass surface in 3D printing of viscous droplets is presented with the relevant strip characteristics modelled. PEDOT:PSS polymer inks at different viscosities are used. It is found that unlike the symmetric circulation flow developed by a single droplet deposition, strip-printing by multiple droplets is achieved by the coalescence of droplets spreading unequally in different directions. Whereas the liquid viscous cohesion retards the flow in the direction aligning with the centre line of the coalesced droplets, the side spreading driven by liquid surface tension fills up the space on the target surface along the bridge between two coalesced droplets. When the deposition distance or space of two consecutive droplets is set at greater than a critical value, this flow inequality results in strips of scallop shape. With a deposition distance below the critical value, the strips formed tend to have parallel edges and the strip width increases with a decrease in the deposition distance. However, if the distance is set below a saturate level at which the liquid surface tension cannot withstand the deposited liquid volume, bulges are detrimentally formed randomly along the printed strips. Because of the viscous retardation to the spreading of drop liquid, the strips printed using a higher viscosity ink is narrower than that of a lower viscosity. Based on the strip formation process, the relevant characteristics of the printed strips are mathematically modelled using dimensional analysis. The developed models are found in good agreement with the experimental data and can be used to guide the selection of the operating parameters for strips with desired characteristics.

Nickel diselenide (NiSe2) is a promising low-cost catalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), due to its suitable d-electron configuration and high electrical conductivity. Several representative elements, e.g., Co, Fe and P, have been utilized as cation or anion to promote the electrocatalytic activity of NiSe2 by modulating the interaction with Se element, whilst the catalyst stability is less concerned. In this work, the catalytic Ni nanoparticles were in-situ encapsulated in carbon nanotubes grown on three-dimensional conducting carbon framework. Subsequent phosphorization and selenization yield dispersed P-doped NiSe2 nanoparticles protected by carbon shell with highly exposed yet stable active sides, resulting in significantly promoted HER and OER activities as well as accelerated kinetics. In detail, the P-NiSe2@N-CNTs/NC hybrid catalyst deliver low overpotentials of 95 and 306 mV at 10 mA cm−2 for HER and OER in alkaline media, respectively. DFT calculations reveal that P doping reduces the electron density surrounding Ni atoms while accumulates the charges to Se, respectively, which in turn reduces the energy barriers for both water dissociation and intermediates adsorption for both HER and OER. As a concept of proof, a cell assembled by P-NiSe2@N-CNTs/NC hybrid catalyst-based anode and cathode performs a low applied voltage of 1.609 V to reach 10 mA cm−2, and outstanding long-term stability.

Background Lycopene, one of the carotenoids, was increasingly attractive thanks to the significant nutritional and pharmaceutical value, causing the numerous demands of non-chemically synthesized lycopene. However, the insufficient lycopene production led to the high price. One potential way to ameliorate the situation was to elevate the extraction efficiency of lycopene by emerging technologies such as ultrasound-assisted extraction, microwave-assisted extraction. However, there is no comprehensive evaluation of these technologies. Therefore, this review is to comprehensively evaluate these technologies. Scope and approach The market investigations indicated the huge demands of lycopene. Rising challenges spawned many new assisted technologies to weaken the hindrances in lycopene extraction. This review mainly discussed the emerging technologies for natural lycopene extraction. In addition, the evaluation of various technologies was performed, including the influences on isomerization and degradation, economic analysis and sustainability analysis. Key findings and conclusions Hindrances of lycopene extraction from cells were illustrated. Besides, almost all the treatments could elevate the efficiency to different extents, which offered various ideas and pathways for lycopene extraction. And the summarization of advantages and disadvantages indicated the promising application potential. Many technologies could affect the isomerization and degradation of lycopene, indicating the necessity to control the extraction conditions. Statistical analysis presented comprehensive comparisons of key indicators (temperature, time, L/S and yield), and supported further evaluation. The economic analysis and sustainability analysis indicated that the cost and environmental effects varied with methods. In the future, methods with low cost, high efficiency and environment-friendly effects will be preferred.

Several fossil woods from Early Cretaceous sediments in Yumen City in northwestern North China Block, China, have been described. They belong to two fossil wood taxa, Piceoxylon yumeniense Zhou, Peng, Deng, Zhang and Yang n. sp. and Protophyllocladoxylon chijinense Zhou, Peng, Deng, Zhang and Yang n. sp. The well-preserved specimens yield secondary xylem with distinct growth rings. Piceoxylon yumeniense exhibits cross-field with taxodioid pits as well as two distinct xylem ray types. The bi- to triseriate rays are characterised by one or two horizontal resin canals with unequal uniseriate ends. Protophyllocladoxylon chijinense Zhou, Peng, Deng, Zhang and Yang n. sp. shows window-like cross-field pits, which are occasionally cupressoid and have uniseriate xylem rays. These fossil wood records improve our understanding of the fossil diversity, floral composition and palaeoclimate of the Xiagou Formation. Palaeoclimatic analysis of the palaeoxylogical assemblage indicates that the northwestern Gansu region predominantly exhibited a warm and wet climate condition, while a brief cooling event may have occurred in the region during the Early Cretaceous.

FCC, BCC and B2 phases, the most common phases in high-entropy alloys (HEAs), are widely investigated to tailor their mechanical and magnetic performances. The detailed investigation of FCC to BCC/B2 phase transformation of AlCoCrFeNi HEA in this paper reveals its evolution and structure-properties relations in terms of both temperature and holding duration. With increasing heat treatment temperature and duration, such transition will progress simultaneously at both the dendric core (DC) region and inter-dendric (ID) region and the volume of phase transformation from FCC to BCC phases is greater than FCC to B2 phases, resulting in increased yield strength and saturation magnetization. The obvious phase transition of the AlCoCrFeNi HEA at 1200 °C can enhance its yield strength and saturation magnetization as a sacrifice of its fracture strain. However, an excellent combination of mechanical-magnetic properties was achieved when heat-treated at 1100 °C for 50 h by optimizing both the transformation and the size of B2 phases. Our present study could pave ways to design the HEAs or other alloys with an optimum combination of mechanical and magnetic properties for application-oriented viewpoints.

BACKGROUND: Blueberry is among the fastest growing fruit crops in the world, which is beneficial to human health and attracts extensive interests. In contrast to its rapid development and utilization, availability of molecular and genetic resources for blueberries are still scarce. OBJECTIVE: In present report, transcriptomic profiling of four widely cultivated varieties of Rabbiteye and Southern Highbush blueberries were characterized to assist the breeding programs. METHODS: Both de novo and reference-based assembly were conducted to generate the genetic resources that can be used in the further functional and breeding studies. RESULTS: De novo and reference-based assembly found average 136,350 and 158,123 non-redundant transcripts, respectively. Average 57,668 de novo assembled transcripts can be functionally annotated by homology search with different databases. We further detected 6,268 polymorphic simple sequence repeats, 566,913 high-quality single nucleotide polymorphisms and 88,662 insertion and deletions among the four varieties with comparison to a recently released reference genome of blueberry. Differentially expressed genes analysis showed that varieties of same species show less differences within species but larger differences between species. CONCLUSIONS: These comprehensive and high-quality genetic resources will contribute to a wide range of genetics and molecular breeding studies in blueberries.

Formamidinatoantimony(I/III) complexes have been successfully synthesized as monomers or dimers in the solid state featuring a variety of coordination geometries and have also been comprehensively characterized. The antimony(I) formamidinate complex bis[μ-N,N′-bis(2,6-diisopropylphenyl)formamidinato]diantimony(I)(2 Sb—Sb) tetrahydrofuran heptasolvate, [Sb2(C25H35N2)2]·7C4H8O or [Sb2(DippForm)2]·7THF, (1), was obtained by a metathesis reaction between sodium bis(trimethylsilyl)amide [NaN(SiMe3)2] and N,N′-bis(2,6-diisopropylphenyl)formamidine (DippFormH), followed by SbCl3. A range of trivalent haloformamidinatoantimony(III) complexes, namely, bis[N,N′-bis(2,6-diisopropylphenyl)formamidinato]chloridoantimony(III), [Sb(C25H35N2)2Cl] or [Sb(DippForm)2Cl], (2), bis[N,N′-bis(2,6-diisopropylphenyl)formamidinato]bromidoantimony(III), [SbBr(C25H35N2)2] or [SbBr(DippForm)2], (3), bis[N,N′-bis(2,6-diisopropylphenyl)formamidinato]iodidoantimony(III), [Sb(C25H35N2)2I] or [Sb(DippForm)2I], (4), [N,N′-bis(2,6-diisopropylphenyl)formamidinato]dibromidoantimony(III), [SbBr2(C25H35N2)] or [SbBr2(DippForm)], (5), and [N,N′-bis(2,6-diisopropylphenyl)formamidinato]diiodidoantimony(III), [Sb(C25H35N2)I2] or [Sb(DippForm)I2], (6), were also synthesized by adding DippFormH and MN(SiMe3)2 (M = Li or Na) to the corresponding antimony halides SbX 3 (X = Cl, Br or I) in differing ratios. The complexes were all stable to rearrangement.

The accurate determination of the interface shear strength is essential in the design of geosynthetic-reinforced soil structures. The particle geometries of three types of soil materials and a spherical granular medium are imaged and quantified using binary image-based methods and described in terms of regularity. Cyclic direct shear tests are conducted to investigate the effects of particle regularity on the interface shear strength, stress–displacement relationship, shear stiffness, and damping ratio. The results reveal that the interface shear strength and deformation strongly depend on particle regularity. The vertical displacement ratio is found to increase with particle regularity under the same cycle number. The interface stiffness is observed to increase with the cycle number for particle regularities of 0.453, 0.565, and 0.672 but decreases with the cycle number for a particle regularity of 0.971. For a given regularity, the trend of damping ratio with the increasing cycle number is contrary to the that of shear stiffness. Finally, it is observed that the cyclic friction angle decreases with increasing particle regularity, the relationship of which is determined using linear regression. Thus, the systematic quantification of particle shape characteristics can lead to a better understanding of soil–geogrid interface behaviour.

At the post-transcriptional level, microRNAs (miRNAs) play an important role in the regulation of gene expression, thereby influencing the outcome of many biological processes in insects, such as development, reproduction, metamorphosis, immunity, and insecticide resistance. The alteration of miRNA expression by mimic/agomir or inhibitor/antagomir via injection/feeding can lead to pest developmental abnormalities, death, or reduced pesticide resistance, indicating that miRNAs are potential targets for pest control. This review provides an overview of recent advances in understanding the regulatory roles of miRNA in agricultural and public health insect pest, and further highlights the potential of miRNAs as prospective targets in pest control.

To investigate the effect of ultra-high permittivity ceramic (UHPC) on water freezing, a UHPC-based high voltage electric field-assisted freezing system (UHPC-HVEFF) and a low permittivity acrylic-based high voltage electric field-assisted freezing system (LPA-HVEFF) were developed. The freezing behaviours of water under UHPC-HVEFF and LPA-HVEFF at 0, 3, 6, 9 kV were comparatively studied. Hierarchical cluster analysis (HCA) was used to visualize the difference between UHPC-HVEFF and LPA-HVEFF. COMSOL was used to simulate the distribution of electric field strength in the water sample under HVEF. It was found that the decreasing percentage of the supercooling degree of the water reached 34.9%, 89.2% and 90.3% under UHPC-HVEFF at 3, 6 and 9 kV, respectively, whereas those were only 2.40%, 10.4% and 24.6% under LPA-HVEFF at 3, 6 and 9 kV, respectively. Results from the simulation indicated that the electric field strength in the water under UHPC-HVEFF was on average 11.7-7.5 times that of LPA-HVEFF, thus contributing to the high freezing efficiency of UHPC-HVEFF. This study indicated that UHPC possessed great potential to increase the sample-treating capacity of HVEF-assisted freezing system.

This study provides a 16.2-kyr record of mercury (Hg) deposition derived from a lacustrine sedimentary sequence in Dahu Swamp, eastern Nanling Mountains. Results indicate that changes in climatic conditions had a significant effect on Hg concentrations (Hg–C) and accumulation rates (Hg-AR). Multi-proxy records including dry density, grain size, geochemical elements, organic matter and pollen indicators were compared with Hg accumulation. The results revealed that the contributions of detrital input and atmospheric deposition were minor, and Hg accumulation in the sediments was closely related to changes in climatic conditions: relatively drier and colder climate would result in shrinkage of the lake water body thus favoring increased formation of organic-rich peat or gyttja and leading to enhanced absorption of Hg by organic matter and result in increases of Hg–C and Hg-AR in sediments, and vice versa. Our results indicate that variations of Hg accumulation in Dahu Swamp were greatly impacted by climate under the influences of solar insolation changes and shrinkage or expansion of ice sheets in high latitudes to the north. The results of this study provide an insight into the response of Hg accumulation to low latitude climate processes in the East Asian summer monsoon region.

This study proposes new approaches for the dissipative analysis issue of high-speed train systems. First, an improved boundary circulatory functional approach is introduced for constructing a weak Lyapunov-Krasovskii functional, which can fully excavate some intrinsic relationships between sampling interval and time delay. Based on the looped-functional tactics and recombinant technology, the constraint conditions are further relaxed for obtaining new theoretical results. Second, by using resultful integral inequalities and correlation analysis approaches, several relaxed criteria are established with respect to the asymptotical stable of the considered sampled-data systems. Third, a new reliable memory sampling controller is designed under the desired dissipative performance. Finally, numerical experiments on high-speed trains on the Shinkansen in Japan illustrate the importance of theoretical results.

In this paper, we study steady two-dimensional periodic equatorial water waves of small amplitude which propagate over a flat bed and with a specified fixed mean-depth. In particular, we focus on irrotational flows and develop an equivalent formulation using flow force functions. The analysis is based on the local bifurcation theory due to Crandall-Rabinowitz.

This paper considers a class of 3-dimensional real analytic nonlinear quasi-periodic systems with a small perturbation parameter, whose unperturbed part has a degenerate equilibrium point. Based on the Leray-Schauder Continuation Theorem [18] , [20] and using technique of outer parameter, we prove that the system has a small response solution for many sufficiently small parameters.

The synthesis of high-quality ultrathin overlayers is critically dependent on the surface structure of substrates, especially involving the overlayer-substrate interaction. By using in situ surface measurements, we demonstrate that the overlayer-substrate interaction can be tuned by doping near-surface Ar nanobubbles. The interfacial coupling strength significantly decreases with near-surface Ar nanobubbles, accompanying by an “anisotropic to isotropic” growth transformation. On the substrate containing near-surface Ar, the growth front crosses entire surface atomic steps in both uphill and downhill directions with no difference, and thus, the morphology of the two-dimensional (2D) overlayer exhibits a round-shape. Especially, the round-shaped 2D overlayers coalesce seamlessly with a growth acceleration in the approaching direction, which is barely observed in the synthesis of 2D materials. This can be attributed to the immigration lifetime and diffusion rate of growth species, which depends on the overlayer-substrate interaction and the surface catalysis. Furthermore, the “round to hexagon” morphological transition is achieved by etching-regrowth, revealing the inherent growth kinetics under quasi-freestanding conditions. These findings provide a novel promising way to modulate the growth, coalescence, and etching dynamics of 2D materials on solid surfaces by adjusting the strength of overlayer-substrate interaction, which contributes to optimization of large-scale production of 2D material crystals.

Channeling carbon dioxide The separation of gas molecules with physisorbents can be challenging because there is often a tradeoff between capacity and selectivity. Zhou et al. report a template-free hydrothermal synthesis of the one-dimensional channel zeolite mordenite, in which some silicon was replaced by iron. Rather than forming a powder that requires further shaping, this mechanically stable material self-assembled into monoliths. Iron atoms bound in tetrahedral zeolite sites narrowed the channels and enabled the size-exclusion separation of carbon dioxide (CO 2 ) over nitrogen (N 2 ) and methane. High CO 2 uptake and highly efficient CO 2 –N 2 separation was demonstrated for both dry and humid conditions. Science , aax5776, this issue p. 315

Sensory systems are attractive evolutionary models to address how organisms adapt to local environments that can cause ecological speciation. However, tests of these evolutionary models have focused on visual, auditory, and olfactory senses. Here, we show local adaptation of bitter taste receptor genes in two neighboring populations of a wild mammal—the blind mole rat Spalax galili—that show ecological speciation in divergent soil environments. We found that basalt-type bitter receptors showed higher response intensity and sensitivity compared with chalk-type ones using both genetic and cell-based functional analyses. Such functional changes could help animals adapted to basalt soil select plants with less bitterness from diverse local foods, whereas a weaker reception to bitter taste may allow consumption of a greater range of plants for animals inhabiting chalk soil with a scarcity of food supply. Our study shows divergent selection on food resources through local adaptation of bitter receptors, and suggests that taste plays an important yet underappreciated role in speciation.

The addition of glycerin reduced the dielectric constant of the aqueous alumina suspension, increased the zeta potential of the alumina powder, thickened the electric double layer, and improved the dispersibility of an alumina suspension for aqueous gel-casting. The glycerin-added suspension can effectively avoid the agglomeration, so that the green body had a more uniform microstructure and a higher relative density. The simultaneous addition of magnesium nitrate, EDTA and glycerol in aqueous-based alumina slurry can effectively promote the homogeneity of green microstructure and hence obtaining the sintered sample with relative sintered density of 99.7% and the mean grain size and distribution of 1.20 ± 0.44 μm. The (pressure-less sintered) sample Mg + EDTA + Gly exhibited superior Vickers hardness comparable to the samples prepared using HP, HIP, and SPS due to the small grain size (1.2 μm) and high sintered density (99.7%).

With the proliferation of smartphone-based ridesharing apps around the world, traffic assignment with ridesharing is drawing increasing attention in recent years. A number of ridesharing user equilibrium (RUE) models have been proposed, but most of them are formulated as path-based mixed complementarity problems based on presumed ridesharing price and inconvenience functions, thus are inconvenient to implement in reality. In this study, by redefining the set of feasible driver trajectories and the market equilibrium conditions for ridesharing, we propose an alternative approach to modeling the RUE when the driver- and rider-demand for each OD pair are fixed and given. We show that the resulting RUE conditions can be equivalently transformed into a convex programming problem, and the existence and uniqueness of RUE link flows are guaranteed under mild conditions. The structure of the model is similar to the classic Beckmann’s formulation, except for the additional ridesharing demand-supply constraints. So a dual subgradient algorithm with averaging is proposed to solve the problem, and the dual sub-problem can be solved by the Frank-Wolfe method. The algorithm effectively avoids path enumeration, therefore is implementable on large networks. The impact of problem size on the computational efficiency of the algorithm is theoretically analyzed and numerically demonstrated.

2D transition metal dichalcogenides (TMDs) have been considered as promising non-precious electrocatalysts for the hydrogen evolution reaction (HER). However, their limited active sites and poor electric conductivity pose a significant hurdle to their HER performance, resulting in a large overpotential. Here, we report the defect engineering in ultrathin tungsten telluride (WTe2) nanosheets with semimetal nature to improve hydrogen evolution effectively. We find that the oxygen plasma etching imposes a cutting effect on WTe2 nanosheets, resulting in a large number of tungsten vacancies. Particularly, the sample after plasma treatment for 10 min shows a feather-like structure with an overpotential of 251 mV at 10 mA/cm2 and a Tafel slope of 94 mV/dec, which is 4 times lower than the Tafel slope of pristine nanosheets. Further first-principles calculations shed light on the evolution of defect-rich WTe2 nanosheets and offer rational explanation to their superiority in efficient hydrogen evolution.

The activity and hydrothermal stability of the Rh/CexZr1-xO2 (x = 0, 0.05, 0.3, 0.5) model three-way catalysts for gasoline vehicle emissions control were investigated in this work. Among the Rh/CexZr1-xO2 samples with different Ce/Zr ratios, the Rh/ZrO2 sample exhibits a significantly better activity and hydrothermal stability than the rest of the samples. The impacts of having more Ce components in the Rh/CexZr1-xO2 catalysts are associated with the strong Rh–O–Ce interaction that tends to over stabilize the rhodium species. A significant amount of such rhodium atoms can be found in the bulk of the support oxides after a hydrothermal aging at 1050 °C with 10% H2O in air for 12 h. Differently, the sintering of rhodium on the surface of Rh/ZrO2 catalysts is the main reason for the catalyst deactivation during the hydrothermal aging. These findings provide an example where high dispersion of supported metal induced by strong metal-support interactions does not necessarily lead to high catalytic activity.

The mechanical properties and microstructure of the A356-T6 wheel hub based on low pressure die casting-hot flow forming process were analyzed by means of optical microscopy (OM), scanning electron microscopy (SEM) and tensile tests. Results showed that the size of the eutectic region and the morphology of the Si phase were the main factors affecting the mechanical properties and fracture morphology of the wheel hub. There was a uniform distribution of eutectic area and fine Si phase morphology in the microstructure of the upper rim and lower rim, moreover, the ultimate tensile strength and yield strength of the upper rim reached 282.4MPa and 185.1MPa, respectively. The fractures were mainly composed of fine quasi-cleavage platform and dimple. The microstructure of the rim showed a long strip along the deformation direction and the eutectic structure and Si particles were uniformly distributed. Irregular polygonal eutectic regions and coarse rod-like Si particles were accumulating in the spoke, causing a serious decrease in mechanical properties, especially in the spoke center and spoke R angle.

A series of novel methylated (–)-epigallocatechin-3-gallate-4β-triazolopodophyllotoxin derivatives is synthesized by utilizing the click reaction. Evaluation of their cytotoxicity against a panel of five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480) using the MTT assay shows that most of these compounds exhibit weak cytotoxicity. It is observed that compound 12 shows the highest activity against A-549 cells with an IC50 value of 10.27 ± 0.90 μM. Molecular docking results suggested that this compound 12 has a higher binding affinity for epidermal growth factor receptor than for tubulin. Our findings support the utility of compound 12 as a novel compound for the further development of anticancer agents.

The conceptual hydrologic model has been widely used for flood forecasting, while long short-term memory (LSTM) neural network has been demonstrated a powerful ability to tackle time-series predictions. This study proposed a novel hybrid model by combining the Xinanjiang (XAJ) conceptual model and LSTM model (XAJ-LSTM) to achieve precise multi-step-ahead flood forecasts. The hybrid model takes flood forecasts of the XAJ model as the input variables of the LSTM model to enhance the physical mechanism of hydrological modeling. Using the XAJ and the LSTM models as benchmark models for comparison purposes, the hybrid model was applied to the Lushui reservoir catchment in China. The results demonstrated that three models could offer reasonable multi-step-ahead flood forecasts and the XAJ-LSTM model not only could effectively simulate the long-term dependence between precipitation and flood datasets, but also could create more accurate forecasts than the XAJ and the LSTM models. The hybrid model maintained similar forecast performance after feeding with simulated flood values of the XAJ model during horizons to . The study concludes that the XAJ-LSTM model that integrates the conceptual model and machine learning can raise the accuracy of multi-step-ahead flood forecasts while improving the interpretability of data-driven model internals. HIGHLIGHTS Proposed a novel hybrid XAJ-LSTM model that combines XAJ model with LSTM neural network.; Compared XAJ-LSTM model with XAJ model and LSTM neural network for multi-step-ahead flood forecasting.; Employed MIV algorithm to analyze the relative importance of the input variables.

Lactam cyclic peptides are a class of interesting and pharmaceutically active molecules, but their previous syntheses have required the use of heavy metals and/or forcing conditions. Here, we describe the efficient application of the previously reported tert-butyl disulfide-protected amino acids and their use in the efficient, solid-phase synthesis of a series of lactam cyclic peptides under mild, metal-free conditions.

This paper proposes a new microwave non-destructive testing (NDT) method based on liquid flow controlled spoof surface plasmon polaritons (SSPPs) to detect defects in non-metallic composites. The sensor based on this method is composed of SSPPs structure and liquid flow controller. The liquid flow controller can be used to control the sensing area of the sensor. The detection is based on the change of the transmission coefficient at the cut-off frequency of SSPPs sensor, which is caused by defects. Since liquid movement has continuity, the sensor’s field distribution is also continuous change. So in a certain detection range, the liquid flow scanning method can avoid the problem of defect missing detection. Taking FR4 as an example, both the simulation and experiment results reveal that this liquid flow controlled SSPPs sensor can effectively realize defects detection with a radius of 1mm in non-metallic composites. The sensor has the advantages of simple structure, easy operation, fast detection speed and convenient detection of curved MUT.

Selective elimination of sulfur dioxide is significant in flue gas desulfurization and natural gas purification, yet developing adsorbents with high capture capacity especially at low partial pressure as well as excellent cycling stability remains a challenge. Herein, a family of isostructural gallate-based MOFs with abundant hydrogen bond donors decorating the pore channel was reported for selective recognition and dense packing of sulfur dioxide via multiple hydrogen bonding interactions. Multiple O···H-O hydrogen bonds and O···H-C hydrogen bonds guarantee SO2 molecules are firmly grasped within the framework, and appropriate pore apertures afford dense packing of SO2 with high uptake and density up to 1.86 g cm-3, which is evidenced by dispersion-corrected density functional theory calculations and X-ray diffraction resolution of a SO2-loaded single crystal. Ultrahigh adsorption uptake of SO2 at extremely low pressure (0.002 bar) was achieved on Co-gallate (6.13 mmol cm-3), outperforming all reported state-of-the-art MOFs. Record-high IAST selectivity of SO2/CO2 (325 for Mg-gallate) and ultrahigh selectivity of SO2/N2 (>1.0 × 104) and SO2/CH4 (>1.0 × 104) were also realized. Breakthrough experiments further demonstrate the excellent removal performance of trace amounts of SO2 in a deep desulfurization process. More importantly, M-gallate shows almost unchanged breakthrough performance after five cycles, indicating the robust cycling stability of these MOFs.

Purpose The purpose of this study is to fabricate high-aspect-ratio grooves with high surface quality by femtosecond laser (FS) to improve the machinability of silicon carbide (SiC) and optimize the process parameters in micromechanical applications. Design/methodology/approach Four contrast experiments are reported to characterize the FS laser grooving process for SiC with polarization direction, crystal orientation, multi-pass scanning and z layer feed, respectively. The effects of different experimental conditions on the groove characteristics, material removal rate (MRR), aspect ratio, heat affected zone (HAZ) and surface roughness Ra are analyzed. Findings The influence of increasing laser fluence and multi-scanning pass on the groove depth is greater than on the groove width. The MRR, aspect ratio, HAZ and Ra increased with the increase of laser fluence and multi-scanning pass. The direction of laser polarization affects the direction of hot electron injection but has little effect on the material characteristics. FS laser ablation is an isotropic process and there is no obvious change in different crystal orientations. The z-layer feed can significantly increase the groove width and depth and reduce HAZ and Ra. The maximum aspect ratio of 82.67% was fabricated. Originality/value The results contribute to the understanding of the removal mechanism and reduce the friction of the microfluidic device and improve the flowability in the FS laser ablation of SiC. This paper provides suggestions for the selection of suitable process parameters and provides a wider possibility for the application of micro-texture on SiC.

A new 2-dimensional (2D) zinc(II) coordination polymer based on a flexible bis(imidazole) ligand, namely, [Zn2(BIBP)(BPDC)2·DMF] n (1) BIBP is 1,4-bis(4-(imidazole-1-yl)benzyl)piperazine and H2BPDC is benzophenone-2,4′-dicarboxylic acid), has been synthesized and characterized through single-crystal X-ray diffraction, infrared (IR) spectroscopy, and elemental and thermal gravimetric analysis. Complex 1 exhibits a 2D framework oriented parallel to [0 2 1] based on [Zn(BPDC)] n chains. The fluorescence and catalytic properties of complex 1 for the photodegradation of methylene blue were investigated.

Granular soil is commonly encountered during underground constructions in and around urban areas. Due to the lack of cohesion in the granular soil, tunneling through it can easily induce excessive ground settlement and/or even collapse. This study primarily focuses on the tunnel/ground stability during the construction phase before introducing the tunnel lining. The influence of relative tunnel depth and the density of granular soil on the stability and collapse mechanisms of shallow tunnels are investigated using discrete element method (DEM). The tunneling process is numerically realized by an air bag model, which is developed to pressure/depressurize the tunnel. The pressurized air bag in the DEM is calibrated and verified against physical tests. The unloading of the tunnels is realized by reducing the pressure of the fully pressurized air bag stepwise. The soil displacement, soil volume loss as well as the evolution of soil stress are recorded and compared with predictions based on previous experimental studies. Our results show that the tunnel stability and failure mechanisms are significantly influenced by the soil density and relative tunnel depth. The tunnel stability is less dependent on the relative tunnel depth with the increment of the soil density. The soil density is shown to have a notable effect on tunnel stability, especially for relatively deep tunnels. The width of surface settlement trough does not appear to change before the tunnel collapse. However, it decreases dramatically at collapse and keeps decreasing thereafter. The tunnel stability number of different test cases in granular soil is found to be smaller than that in clayed soil but larger than that in saturated sandy soil.

A series of 8,9-substituted Luotonin A analogs were designed, synthesized, and evaluated for antiproliferative activity against four cancer cell lines. The structure–activity relationship study revealed that the in vitro anticancer activity of Luotonin A was significantly improved by the introduction of 8-piperazine group and the 5-deaza modification. Two promising compounds 6a and 7a displayed potent topoisomerase I inhibitory activity. And a rational binding mode of 7a with topoisomerase I–DNA complex was proposed based on the molecular docking study.

Antibody-drug conjugates (ADCs) have attracted great attention in recent years in the wake of an accelerated FDA approval rate and several large-scale acquisitions. To date, there are ten ADC drugs on the market and more than 70 in various stages of clinical trials. Yet, due to the complicated nature of ADC molecules, considerations need to cover many aspects for the success of ADCs, including target specificity, linker-payload stability, tumor permeability, and clearance rate. This topical review summarizes and discusses current methods used to increase stability and homogeneity of ADCs of cysteine conjugation. We believe that they will lead to improvement of efficacy and pharmacokinetics (PK) of ADC drugs.

Harvesting solar energy for photothermal conversion in an efficient manner for steam-electricity cogeneration is particularly opportune in the context of comprehensive solar utilization to address the challenge of a global shortage of fresh water. However, the fragile solar thermal devices and the single-energy utilization pattern greatly hinder extensive solar energy exploitation and practical application. Herein, a flexible carbon cloth nanocomposite with a biomimetic pelargonium hortorum-petal-like surface that embraces all desirable chemical and physical properties, that is, enhanced light acquisition, excellent photothermal property, and operational durability, for high-performance solar-driven interfacial water evaporation distillation is reported. Combined with the two-dimensional water channel, the solar evaporator shows a solar-to-steam conversion efficiency of 93% under the simulated solar illumination of 1 kW m-2. More strikingly, the solar steam generation-induced electricity based on the practical consideration toward more infusive solar thermal application is proposed. Such integrative steam-electricity generators presented here provide an attractive method to produce on-site electricity and fresh water in an individualized mode in various resource-constrained areas.

The enterovirus genus of the picornavirus family contains many important human pathogens. EV-D68 primarily infects children, and the disease manifestations range from respiratory illnesses to neurological complications such as acute flaccid myelitis (AFM). EV-A71 is a major pathogen for the hand, foot, and mouth disease (HFMD) in children and can also lead to AFM and death in severe cases. CVB3 infection can cause cardiac arrhythmias, acute heart failure, as well as type 1 diabetes. There is currently no FDA-approved antiviral for any of these enteroviruses. In this study, we report our discovery and development of pyrazolopyridine-containing small molecules with potent and broad-spectrum antiviral activity against multiple strains of EV-D68, EV-A71, and CVB3. Serial viral passage experiments, coupled with reverse genetics and thermal shift binding assays, suggested that these molecules target the viral protein 2C. Overall, the pyrazolopyridine inhibitors represent a promising class of candidates for the urgently needed non-polio enterovirus antivirals.

A new family of N2O-type hydrazine-containing bipyrrole boron complexes has been developed via a one-pot condensation of formylisoindole, hydrazine, and various organoboronic acids. Because of the conformation-restricted coplanar structure and the axial-substituted aryl groups, these novel dyes show deep-red absorption, bright near-infrared (NIR) fluorescence in both solution and solid states, and good solubility in organic solvents. The derivative with pyridinium ions also has been synthesized as an NIR mitochondrially targetable fluorescent probe.