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Ferroelectric polarizationhas been considered to be an key factor to tune the structural and photoelectric properties of perovskites and their heterostructures. While there has been growing researches made in the novel phenomena originating from interface formed between oxide perovskites, the effects of ferroelectric polarization on the electronic properties of halide perovskites and their heterostructures are rarely studied. Herein, by using first-principles calculations, all-inorganic halide perovskite heterostructure composed of 3D perovskite tetragonal CsPbBr3 and 2D Ruddlesden-Popper (RP) perovskite Cs2PbI2Cl2 is constructed for disclosing the relationship between the intrinsic polarization of tetragonal CsPbBr3 and electronic band structure of heterostructure. Cs atoms and Pb atoms of tetragonal CsPbBr3 in heterostructure are artificially moved away from the equivalent centers to simulate increased polarization. Our results show that with the spontaneous polarization of tetragonal CsPbBr3 increasing, the bandgap of heterostructure decreases, and the band alignment switches from staggered type-II to broken-gap type-III. Moreover, large cation-anion displacements along z-direction in tetragonal CsPbBr3 can be observed when tensile strains (≥5%) are applied, indicating a increased ferroelectric polarization, which also facilitates the decreasing of bandgap in heterostructure and the type-II-type-III transition of band alignment. Our study suggests that control over the polarization of ferroelectric materials is of great importance to tune the photoelectric properties of perovskite-based devices.

The forest tree family Aceraceae is widespread in the northern hemisphere and it has ecological and economic importance. However, the phylogenetic relationships and classifications within the family are still controversial due to transitional intraspecific morphological characteristics and introgression hybridization among species. In this study, we determined the evolutionary relationships and molecular evolution of Aceraceae based on plastid phylogenomics and two nuclear gene variations. Phylogenetic analysis based on the plastid genomes suggested that Aceraceae species can be divided into two larger sub-clades corresponding to the two genera Acer and Dipteronia. Conjoint analysis of the plastid and nuclear gene sequences supported the classification with two genera in the family. Molecular dating showed that the two genera diverged 60.2 million years ago, which is generally consistently with previously reported results. Divergence hotspots and positively selected genes identified in the plastid genomes could be useful genetic resources in Aceraceae.

In general, two-dimensional semiconductor-based van der Waals heterostructures (vdWHs) can be modulated to achieve the transition of band alignments (type-I, type-II, and type-III), which can be applied in different applications. However, it is rare in three-dimensional perovskite-based vdWHs, and it is challenging to achieve the tunable band alignments for a single perovskite-based heterostructure. Here, we systematically investigate the electronic and optical properties of all-inorganic perovskite vdWHs CsSnBr3/WS2(1-x)Se2x based on density functional theory (DFT) calculation. The calculated results show that the transitions of band alignment from type-II to type-I and type-III to type-II are achieved by modulating the doping ratio of the Se atom in the WS2(1-x)Se2x monolayer for SnBr2/WS2(1-x)Se2x and CsBr/WS2(1-x)Se2x heterostructures, respectively, in which the CsBr and SnBr2 represent two different terminated surfaces of CsSnBr3. The change of band alignments can be attributed to the conduction band minimum (CBM) transforming from the W 5d to Sn 5p orbital in SnBr2/WS2(1-x)Se2x vdWHs, and the valence band maximum (VBM) and CBM change from an overlapped state to a separated one in CsBr/WS2(1-x)Se2x vdWHs. This work can provide a theoretical basis for the dynamic modulation of band alignments in perovskite-based vdWHs.

Growth and environment literature has gained much attention in recent times. However, the emphasis was laid on the conventional economic growth or gross domestic product at the expense of the category of growth that is evenly shared and whose social benefits are far reaching than just an increase in the overall economic pie. It is on this note that the present paper looks at the type of relationship between growth and environment with particular emphasis on growth that is all inclusive. Data are sourced from World Governance and Development Indicators (WGI and WDI) and an index of inclusive growth constructed using principal component analysis (PCA). The findings indicate that institutional quality plays a major role in enhancing growth-environmental sustainability. The results further find a new phenomenon called environmental inclusive-growth Kuznets curve (EIKC) and added to the EKC debate. That is, at the early phase of inclusive growth, environmental degradation rises as well but environmental quality improves with the rise in inclusive growth at a higher phase of the relationship. The study recommends that policymakers should encourage the economies of sub-Saharan Africa to pursue inclusive growth and not compromise it for sustainability since sustainability comes later. Institutional quality which serves as a transmission mechanism in the study can as well be used as a robust and efficient structure to avoid adverse environmental externalities of inclusive growth.

Aims: Pinus yunnanesis is commercially, culturally and economically important, but there is a lack of ecological data on its role in stand dynamics. Our aims are to clarify the structure, composition, regeneration and growth trends of primary mature P. yunnanensis forests. Study area: The Tianchi National Nature Reserve in the Xuepan Mountains, Yunlong County, northwestern Yunnan, China. Methods: We investigated forests containing P. yunnanensis, measured tree ages and analyzed the data. Results: Six forest types were identified: (1) coniferous forest: Pinus yunnanensis (Type 1); (2) mixed coniferous and evergreen broad-leaved forest: P. yunnanensis-Lithocarpus variolosus (Type 2); (3) mixed coniferous and deciduous broad-leaved forest: P. yunnanensis-Quercus griffithii (Type 3); (4) mixed evergreen broad-leaved and coniferous forest: Castanopsis orthacantha-P. yunnanensis-Schima argentea (Type 4); (5) mixed coniferous, evergreen and deciduous broad-leaved forest: Pinus yunnanensis-Schima argentea-Quercus griffithii (Type 5); (6) mixed coniferous and evergreen broad-leaved forest: Pinus armandii-Quercus rehderiana-Pinus yunnanensis (Type 6). The size- and age-structure and regeneration patterns of P. yunnanensis were highly variable within these six forest types. P. yunnanensis regeneration was well balanced in forest Type 1 as compared to the other five types. All six forest types were identified as rare and old-growth with P. yunnaensis trees reaching ages of more than 105 years (a maximum age of 165 years with a diameter 116 cm at breast height) except for the Type 4 forest (a 90-year-old stand). Growth rates of P. yunnanensis, based upon ring width measurements, were high for the first 10 years, then declined after the 10th year. In contrast, basal area increment (BAI) increased for the first 25 years, plateaued, and only declined as trees became older. Trees in the older age classes grew more quickly than younger trees at the same age, a consequence of either site quality or competitive differences. The BAI of P. yunnanensis in all age classes in the Tianchi National Nature Reserve was much higher than those of the secondary and degraded natural P. yunnanensis forests of other areas. Conclusions: The P. yunnanensis forests of the Tianchi area appear to be some of the last remnants of primeval and old-growth forests of this species. These forests are structurally diverse and contain a rich diversity of overstory, mid-story, and understory species. Taxonomic reference: Editorial Committee of Flora Republicae Popularis Sinicae (1959–2004) for vascular plants. Abbreviations: BA = basal area; BAI = basal area increment; DBH = diameter at breast height; H = height; RBA = relative basal area.

Background Schima genus of Theaceae is confined to subtropics and tropics of South, East and Southeast Asia. Thirteen species of Schima are distributed in subtropical China. Many of them appear as dominant canopy species in the subtropical forests. To date, Schima species richness distribution patterns of China have remained unknown. Meanwhile, there has been a longtime debate as to whether forests dominated by Schima species are early or late successional forests. We aim to clarify Schima species richness patterns and these species’ roles in the forest succession and regeneration dynamics of the subtropical ecosystem in Yunnan Province, China. Method We mapped Schima species richness distribution patterns in China. Based on 71 vegetation plots, we analyzed forest characteristics, population structure, and regeneration dynamics of Schima species in Yunnan. Results Yunnan was found to harbor the greatest richness and the highest rarity-weighted richness of Schima species in the subtropical regions of China. We classified five primary and six secondary forest types containing Schima species as one of dominants. Yunnan had the high floristic diversity and varying stand structure of forests containing Schima species. The Schima species studied generally had a sporadic regeneration type and a long life-span. Four species (Schima argentea, Schima villosa, Schima sinensis, Schima sericans) were shade-intolerant. But three species (Schima noronhae, Schima khasiana and Schima wallichii) were considered as bi-modal type species having shade-intolerant and shade-tolerant traits. Schima noronhae was seen to be a top dominant in late successional forests, while S. wallichii was found as a top-dominant in early or middle or late successional forests. S. khasiana, Schima villosa, Schima sinensis usually appeared as a top dominant in early or middle successional secondary forests, though they also presented as a second dominant in late-successional forests. Schima argentea and Schima sericans dominated only in the early or middle/seral successional forests. Schima species’ regeneration establishment depended mainly on forest canopy gap formation through moderate human and natural disturbances. Conclusions Yunnan has high species richness and rarity-weighted richness of Schima. Both moderate human and natural disturbances have provided regeneration niches for Schima species. Some of the Schima species studied as a second dominant (rare as the top-dominant) present in the late-successional forests. Some of them are more often as the top-dominant in early or middle successional forests, where as time goes by the dominance of Schima species would be replaced by their associated dominant taxa such as Castanopsis species.

The structure stabilities, elastic properties, and electronic structures of L12-and D022-TiAl3 under different pressures have been investigated by the first-principles. The formation energy shows that both L12-TiAl3 and D022-TiAl3 were stable at pressure up to 40 GPa. There would be a phase transition from D022 phase to L12 phase when pressure is about 25 GPa D022-TiAl3 and L12-TiAl3 satisfy the mechanical property stability, and both the stiffness and plasticity increase with the increase of pressure. The elastic anisotropy of D022 structure is larger than the L12 structure. The bonding situation and electronic properties of TiAl3 (L12 and D022) were analyzed by differential charge density and density of states (DOS) curve.

The Chinese water pine Glyptostrobus pensilis is the sole surviving species of the genus Glyptostrobus. It is endemic to southern China, central Vietnam, and eastern Laos, and today it is nearly extinct in the wild. Forest community characteristics and population structure of G. pensilis in China have remained unknown up to now. We investigated six swamp forest stands and analyzed their forest community characteristics (i.e. vertical stratification, species composition, and diversity) and population structure, including the frequency distribution of DBH (diameter at breast height) and age-classes as found in Fujian Province, southeastern China.The vertical stratifications of all the forest stands were rather simple. The remaining wild specimens ranged from roughly 15 to some 357 years for an average of ca. 85 years, with only a few individuals less than 20 years old. Compared with the stands and populations of G. pensilis in Vietnam, the taxonomic compositions of the stands in the two regions were different, except for the dominant species-G. pensilis. The Shannon–Wiener index showed the overstory of each stand had much lower diversity (0.26 on average) in Fujian Province than that (1.97 on average) in Vietnam, whereas the diversity indices were about the same (around 2.41) for the understories in the two regions. Furthermore, we discovered 18 G. pensilis seedlings at the study sites in Fujian Province. This discovery demonstrates that G. pensilis regeneration is extremely poor and its populations are declining, although these populations are relatively healthier than those in Vietnam. Keywords: Age-class, Fujian Province, Glyptostrobus, Regeneration, Relict plant, Vietnam

We present a comparative study on the ferromagnetic and antiferromagnetic chiral domain walls under non-gradient spin torques by collective coordinates method. Based on the steady solutions, the stable chiral walls are picked out by linear stability analysis. We find that the spin torques drive the antiferromagnetic wall more quickly and stable than the ferromagnetic one. For the antiferromagnetic wall, the velocity is proportional to the exchange interaction, while Dzyaloshinskii-Moriya interaction for the ferromagnetic wall. Due to the strongness of exchange interaction, the antiferromagnetic wall propagates much faster than the ferromagnetic one. In addition, the antiferromagnetic wall remains the Neel type, while the ferromagnetic wall switches to a Bloch type with the current increasing. Finally, Dzyaloshinskii-Moriya interaction influences the motion direction of antiferromagnetic wall, but has no effect on the magnitude of velocity. For ferromagnetic walls, it determines the magnitude of velocity.

High transaction costs caused by dispersed and fragmented tracts, insecure tenure and incomplete information in rural land market has become a common issue in the transition economies. Horizontal integration may economize on transaction costs but aggrandize governance inputs. Therefore trade-off between integration and governance is one of the biggest challenges in land commercialization and rural restructuring worldwide. Resorting to a field survey in Nanhai District, Guangdong Province, this work estimates how the transaction costs of rural collective construction land are influenced by the horizontal integration degree and the level of self-organization governance of collectives. Four Tobit models are constructed based on the scale of collectives and the results show that: (1) There is an almost U-shaped relationship between the horizontal integration degree of the collectives and the transaction costs. The horizontal integration among shareholders can not only centralize the fragmented land assets from individual farmers and reduce the transaction costs of rural construction land, but also result in organization costs. The transaction costs are not decreasing as the horizontal integration increases until the transaction costs saved are equal to resultant organization costs. (2) The more collective leaders, the higher organization costs and the more opportunism behaviors, which will give rise to the transaction costs. This suggests that the Chinese authorities should strengthen the ongoing efforts to reduce the transaction costs of market and improve the efficiency through a more transparent and accessible market and optimal scale of horizontal integration of the collective. Our work sheds some light on the mechanisms at play in the reform and innovation of rural grass-root governance and it contributes to a better understanding of land-based shareholding cooperation system and nature of ongoing rural construction land market in China and transitional economies.

AlCrSiN coatings with splendid mechanical and thermal properties have attracted wide attention as excellent alternatives for advanced machining applications. Here, Ni-alloyed AlCrSiN coatings were deposited by cathodic arc evaporation and elaborated with respect to mechanical, tribological and anti-oxidation properties. With the increase of Ni content, multiphase composite structured AlCrSiN-Ni coatings show a sustained decline in hardness, elastic modulus and the ratio of hardness to modulus, which causes the decrease of wear resistance at room temperature and 600 °C. Nevertheless, the addition of Ni effectively enhances the toughness and reduces the friction, especially, at 600 °C, where AlCrSiN, AlCrSiN_Ni5, and AlCrSiN_Ni20 obtained a average friction coefficient of ~0.93, 0.86 and 0.66, respectively. Oxidation kinetics studies at 800 – 1000 °C indicate that Ni-containing coatings have relatively lower activation energies, 173.8 kJ/mol of AlCrSiN_Ni5 and 156.6 kJ/mol of AlCrSiN_Ni20, than 176.5 kJ/mol of AlCrSiN. The faster outward diffusion of Cr in Ni-containing coatings forms a Cr2O3/NiAl2O4 two-layer oxide scale with less protection effect and poor adhesion, leading to inferior oxidation resistance.

In recent years, two-dimensional (2D) organic–inorganic perovskites have been attracting considerable attention because of their unique performance and enhanced stability for photovoltaic solar cells or photoluminescent devices. However, how the two-dimensionality affects the photoelectric properties of all-inorganic perovskites remains unclear. In this work, the electronic and optical properties including band structures, carrier mobility, optical absorption spectra and exciton-binding energies for the all-inorganic perovskite Cs2PbI4 with a Ruddlesden–Popper (RP) structure are investigated systemically by using density functional theory with a spin orbit coupling (SOC) effect. The calculated results demonstrate the thickness-dependence of electronic properties in the all-inorganic 2D RP perovskite Cs2PbI4 and its carrier mobility which is comparable to that of CsPbI3 thin films. The exciton-binding energies of perovskite Cs2PbI4 with a RP structure increase with the decrease of the number of layers. Besides, the value of exciton-binding energy for monolayers (181.70 meV) is more than 3 times larger than that of CsPbI3 (59.12 meV). Moreover, the calculated results show that two dimensional layered Ruddlesden–Popper perovskite Cs2PbI4 may not be a good material for photovoltaic applications due to its low carrier mobility and poor visible light absorption, but may be a good material for light-emission applications due to its larger thickness-dependent exciton binding energy. Our work would provide a theoretical basis for other ultrathin two-dimensional perovskite materials with potential application for photoluminescent devices or solar absorbers.

Today East Asia harbors many “relict” plant species whose ranges were much larger during the Paleogene-Neogene and earlier. The ecological and climatic conditions suitable for these relict species have not been identified. Here, we map the abundance and distribution patterns of relict species, showing high abundance in the humid subtropical/warm-temperate forest regions. We further use Ecological Niche Modeling to show that these patterns align with maps of climate refugia, and we predict species’ chances of persistence given the future climatic changes expected for East Asia. By 2070, potentially suitable areas with high richness of relict species will decrease, although the areas as a whole will probably expand. We identify areas in southwestern China and northern Vietnam as long-term climatically stable refugia likely to preserve ancient lineages, highlighting areas that could be prioritized for conservation of such species., We acknowledge funding by the Global Environmental Research (S-14) of the Ministry of the Environment (Japan), the Proyecto Intramural Especial, PIE (grant no. 201630I024) from the CSIC, Spain, the Natural Science Foundation Project of CQ CSTC (cstc2016jcyjA0379) (China), and the Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University (Thailand).

A domain-wall configuration and a current-injection scheme are proposed which ensure the satisfaction of the boundary condition of the dynamic Walker wall driven by the spin-orbit torques (SOTs). The analytic solutions of the wall are obtained in the whole region of current by the traveling-wave method. In the steady regime, the initial velocity mainly depends on the Slonczewski SOT. Meanwhile, the final steady velocity largely relies on the fieldlike one. The critical behavior of velocity is closely linked to the ratio of the fieldlike SOT parameter $\ensuremath{\beta}$ to the Gilbert damping constant $\ensuremath{\alpha}$. Reducing the difference between $\ensuremath{\beta}$ and $\ensuremath{\alpha}$, the Walker breakdown is postponed and the Walker velocity is enhanced. Additionally, by adjusting an applied magnetic field, $\ensuremath{\beta}$ can be measured by halting the wall. In the periodic regime, the wall propagates back and forth with an average velocity increasing almost linearly for high currents.

Dipentodon sinicus Dunn. (Dipentodonaceae) is a rare and threatened relict plant species usually found co-dominating with other relict plants in subtropical forest patches in highly fragmented habitats of southwestern China, northern Vietnam and northeastern Myanmar of East Asia. To date, its management and conservation strategies in the light of climate change have not been explored. We evaluated effects of climate change on the distribution of climatically suitable areas of D. sinicus as found prevailing during the last glacial maximum (LGM), the mid-Holocene and the present time, and predicted the distribution of climatically suitable habitats in 2070 throughout East Asia. The results as derived from ecological niche modeling (ENM) show the current distribution to be limited to the prehistoric (the mid-Holocene and LGM) refugia, and to indicate decreasing probability of presence and a reducing range of distribution for 2070. In addition, the suitable areas predicted with high probability (0.5–1) only account for on average 9.8% of the total area of potential habitats (threshold‒1) among the models for the year 2070, thereby indicating that D. sinicus is highly vulnerable. Under all the future scenarios for the year 2070, 69–74.2% of potential habitats in China would be outside protected areas. We assess and propose priorities for protected areas, and provide suggestions for conservation management strategies., This study received financial support from Science and Technology Department of Yunnan University, China (2019YNU002), the Ministry of Science and Technology of China (2015FY210200-15), Ajuts a Grups de Recerca Consolidats” (grants nos. 2014-SGR514-GREB and 2017-SGR1116) from the Generalitat de Catalunya (Spain), Applied Basic Research Foundation of Yunnan Province, China (Grant No. 2019FB058), the Environment Research and Technology Development Fund (JPMEERF15S11407) of the Environmental Restoration and Conservation Agency of Japan, and the Kakenhi Grant Number 15H02833., Highlights Abstract Keywords 1. Introduction 2. Material and methods 2.1. Species 2.2. Occurrence data and ecological niche modeling 3. Results 3.1. Model performance and present potential distribution 3.2. Projected distribution during the mid-Holocene (ca. 6000 yr BP) and LGM (ca. 21,000 yr BP) 3.3. Projected distribution under future climate (2070) 4. Discussion 4.1. Effects of climate change on spatial distribution patterns of D. sinicus 5. Recommendations for future conservation efforts and management Declaration of competing interest Acknowledgements Appendix A. Supplementary data References

Recently, all-inorganic two-dimensional (2D) Ruddlesden-Popper (RP) halide perovskites have drawn much attention due to their excellent stability in ambient air. However, their electronic and optical performance resulting from a wide bandgap and low carrier mobility have hindered their use in photodetectors. To overcome these limitations, in this work, taking advantage of hexagonal indium selenide ($\mathrm{In}\mathrm{Se}$) with a high electron mobility, we construct an atomically thin heterostructure. Density-functional-theory (DFT) calculations of the electronic and optical properties are performed for these heterostructures. The results demonstrate that the photodetection response spectrum of the heterostructures is significantly broadened as the bandgap decreases from 2.17 to 0.40 eV for the $\mathrm{In}\mathrm{Se}$/${\mathrm{Cs}}_{2}{\mathrm{Sn}\mathrm{I}}_{2}{\mathrm{Cl}}_{2}$ heterostructure. Moreover, the electron effective mass, ${m}_{e}^{\ensuremath{\ast}}$, is reduced from 1.13 ${m}_{0}$ to 0.41 ${m}_{0}$ for the $\mathrm{In}\mathrm{Se}$/${\mathrm{Cs}}_{2}{\mathrm{Ge}\mathrm{I}}_{2}{\mathrm{Cl}}_{2}$ heterostructure. The significant reductions in both the band gap and effective mass are determined to be related to the type-II band alignment, which favors the carrier separation at the interface. The physical mechanisms related to the usage of this material in photodetectors are also discussed. The proposed III--VI semiconductor InSe and all-inorganic 2D RP perovskite ${\mathrm{Cs}}_{2}X{\mathrm{I}}_{2}{\mathrm{Cl}}_{2}$ (X = $\mathrm{Pb}$, $\mathrm{Sn}$, and $\mathrm{Ge}$) heterostructures provide challenges and opportunities for designing high-performance photodetectors.

Pathogenic enterotoxigenic Escherichia coli (ETEC) has been considered a major cause of diarrhea which is a serious public health problem in humans and animals. This study was aimed at examining the effect of γ-aminobutyric acid (GABA) supplementation on intestinal secretory immunoglobulin A (SIgA) secretion and gut microbiota profile in healthy and ETEC-infected weaning piglets. A total of thirty-seven weaning piglets were randomly distributed into two groups fed with the basal diet or supplemented with 40 mg·kg−1 of GABA for three weeks, and some piglets were infected with ETEC at the last week. According to whether ETEC was inoculated or not, the experiment was divided into two stages (referred as CON1 and CON2 and GABA1 and GABA2). The growth performance, organ indices, amino acid levels, and biochemical parameters of serum, intestinal SIgA concentration, gut microbiota composition, and intestinal metabolites were analyzed at the end of each stage. We found that, in both the normal and ETEC-infected piglets, jejunal SIgA secretion and expression of some cytokines, such as IL-4, IL-13, and IL-17, were increased by GABA supplementation. Meanwhile, we observed that some low-abundance microbes, like Enterococcus and Bacteroidetes, were markedly increased in GABA-supplemented groups. KEGG enrichment analysis revealed that the nitrogen metabolism, sphingolipid signaling pathway, sphingolipid metabolism, and microbial metabolism in diverse environments were enriched in the GABA1 group. Further analysis revealed that alterations in microbial metabolism were closely correlated to changes in the abundances of Enterococcus and Bacteroidetes. In conclusion, GABA supplementation can enhance intestinal mucosal immunity by promoting jejunal SIgA secretion, which might be related with the T-cell-dependent pathway and altered gut microbiota structure and metabolism.

The feasibility of using Feammox coupled with nitrate-dependent Fe(II) oxidizing (NAFO) to cause the simultaneous conversion of NH4+ and NO3− was explored by inoculation with Feammox sludge and the use Fe cycling as catalyst. After 61 days operation, the simultaneous conversion of NO3− and NH4+ occurred with the presence of interconversion between Fe(III) and Fe(II). The conversion ratio of NH4+ to NO3− stabilized at 0.9–1. The results of isotopic tracing and microbial diversity analysis indicated that NH4+ was first oxidized to NO2− by Fe(III), then NO3− was reduced to NO2− and N2 by the Fe(II) produced in Feammox process, and finally, the NO2− produced in NAFO process underwent an Anammox process with the remaining NH4+ to yield N2. The results showed the simultaneous continuous conversion process of NO3− and NH4+ with limited Fe as a catalyst was a coupled process of Feammox, Anammox, and NAFO under the anaerobic conditions.

We theoretically investigate the Dzyaloshinskii–Moriya solitons driven by the magnetic field and spin-polarized current in anisotropic ferromagnetic nanowires. The external field and Dzyaloshinskii–Moriya interaction determine the formation region of soliton solution and the corresponding phase diagram is given for different types of solitons. The Dzyaloshinskii–Moriya interaction affects the internal structure distortion of solitons which determines the soliton energy. Also, we obtain the critical value of Dzyaloshinskii–Moriya interaction for soliton formation. The roles of Dzyaloshinskii–Moriya interaction effect on the soliton energy are completely opposite for the solitons of type I and type II in ferromagnetic nanowires.

The dynamics of domain wall driven by the spin-orbit torques is theoretically studied in the heavy metal/ferromagnet bilayer with Dzyaloshinskii-Moriya interaction (DMI) and in-plane magnetic anisotropy. Based on the Walker profile, we infer that DMI has a selectivity for the chirality of head-to-head (tail-to-tail) static wall. By analyzing the dynamic equations obtained from the collective coordinates methods, we find that there exists a switching or a hysteresis of the polarity of wall in the low-current regime. In the presence of DMI, the wall can keep sustained propagation which velocity saturates for high current and is proportional to the strength of DMI. Furthermore, the DMI makes the adjacent walls possess the same chirality and move in the same direction.

A simple hydrothermal method was used to synthesize a series of seven polymetallic Li-MOFs (Metal organic frameworks) with the molecular formula Li2(H2O)2M2(H2O)2(BHC) [BHC: benzene-1,2,3,4,5,6-hexacarboxylate; M: Mn, Co, Ni], which are named as MnLi, CoLi, NiLi, MnCoLi, MnNiLi, CoNiLi and MnCoNiLi, respectively. Single crystal X-ray diffractometer (SXRD), powder X-ray diffractometer (PXRD), Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the structures, phases, morphologies and elemental oxidation states. The seven Li-MOFs have identical structure, all of which belong to monoclinic system, P21/c space group with the similar unit cell parameters. The transition metal ions and lithium ions are coordinated with the carboxyl groups of BHC to form a unique three-dimensional framework. When used as anode materials for lithium ion batteries, MnCoLi exhibited the best electrochemical performance among others with the discharge capacity of 799.4 mAh g−1 after 100 cycles at a current density of 100 mA g−1. The superior electrochemical performance of Li-MOFs shows potential application prospects in the field of electrode materials.

Lead iodide perovskite has long been considered to be promising for photovoltaic applications due to the high power conversion efficiency. However, the toxicity and instability of lead iodide perovskite limit its widespread use. Recently, germanium iodide perovskite CH3NH3GeI3 has attracted much attention due to the lead-free and high distorted structure. In this study, we exhibited a detailed theoretical investigation to predict total ferroelectric polarization of about 13.8 μC cm−2 and disentangle the contributions of MA cation (MA = CH3NH3), the center charge of MA cation and Ge2+ ion relative to the inorganic framework. Based on the electronic structure, optical absorption as well as carrier mobility of the system are further calculated, which exhibit strong anisotropy along the same direction. Further regulating atomic structure to strengthen or weaken the polarization, variable optical absorption spectra and hence tunable efficiencies are obtained. By analyzing the electronic structure with applied increased polarization, we conclude that polarization driven optical absorption can be attributed to an increased p–p orbital transition from I to Ge. In the case of CH3NH3GeI3, we discuss the relationship between ferroelectricity and photovoltaic performance, reveal the potential of utilizing polar material for higher solar conversion, and speculate that it is a general rule to raise the efficiency by enhancing the polarization.

Plant plastomes play crucial roles in species evolution and phylogenetic reconstruction studies due to being maternally inherited and due to the moderate evolutionary rate of genomes. However, patterns of sequence divergence and molecular evolution of the plastid genomes in the horticulturally- and economically-important Lonicera L. species are poorly understood. In this study, we collected the complete plastomes of seven Lonicera species and determined the various repeat sequence variations and protein sequence evolution by comparative genomic analysis. A total of 498 repeats were identified in plastid genomes, which included tandem (130), dispersed (277), and palindromic (91) types of repeat variations. Simple sequence repeat (SSR) elements analysis indicated the enriched SSRs in seven genomes to be mononucleotides, followed by tetra-nucleotides, dinucleotides, tri-nucleotides, hex-nucleotides, and penta-nucleotides. We identified 18 divergence hotspot regions (rps15, rps16, rps18, rpl23, psaJ, infA, ycf1, trnN-GUU-ndhF, rpoC2-rpoC1, rbcL-psaI, trnI-CAU-ycf2, psbZ-trnG-UCC, trnK-UUU-rps16, infA-rps8, rpl14-rpl16, trnV-GAC-rrn16, trnL-UAA intron, and rps12-clpP) that could be used as the potential molecular genetic markers for the further study of population genetics and phylogenetic evolution of Lonicera species. We found that a large number of repeat sequences were distributed in the divergence hotspots of plastid genomes. Interestingly, 16 genes were determined under positive selection, which included four genes for the subunits of ribosome proteins (rps7, rpl2, rpl16, and rpl22), three genes for the subunits of photosystem proteins (psaJ, psbC, and ycf4), three NADH oxidoreductase genes (ndhB, ndhH, and ndhK), two subunits of ATP genes (atpA and atpB), and four other genes (infA, rbcL, ycf1, and ycf2). Phylogenetic analysis based on the whole plastome demonstrated that the seven Lonicera species form a highly-supported monophyletic clade. The availability of these plastid genomes provides important genetic information for further species identification and biological research on Lonicera.

In this study, based on density functional theory, the formation enthalpy, density of states, elastic properties and elastic anisotropy of Al3M (M = Ti, Ta, V, Nb, Hf) compounds were calculated. The calculation results of enthalpy formation indicate that Al3M (M = Ti, Ta, V, Nb, Hf) compounds are formed. State density analysis of Al3M (M = Ti, Ta, V, Nb, Hf) compounds at the Fermi level is non-zero, showing metal properties. The density of states show that Al3Ta has the highest structural stability. The calculation results of mechanical properties show that Al3Ta has greater resistance to bulk deformation and shear deformation. By calculating the anisotropic indexes, the sequence of anisotropy in elastic modulus is Al3Hf > Al3Ti > Al3V > Al3Nb > Al3Ta.

We theoretically investigate the effect of Dzyaloshinskii-Moriya interaction (DMI) on magnetic solitons in anisotropic ferromagnetic wires driven by the adiabatic spin-transfer torque. The DMI changes the formation region of soliton solution and the corresponding phase diagram is given for different types of soliton solutions. Also, it affects the processional frequency and the internal structure distortion of solitons. We show that the DMI decreases the energy for symmetric soliton while increases the energy for antisymmetric one. It implies that the DMI favours the more steady state of magnetization for the case of strong easy-axis anisotropy.

The solar cell based on hybrid organic-inorganic halide perovskite has received considerable attention. One of the most important issues in the pursuit of further developments in this area is to obtain both a high carrier mobility and an excellent ability of light adsorption. In this paper, we investigate the electronic structure and electronic effective masses of the new non-toxic material CH3NH3GeCl3 by first-principle calculations. The results show that the absorption efficiency of CH3NH3GeCl3 is more superior to that of CH3NH3PbI3 in short wavelength region. We trace this result to the ferroelectricity caused by the more serious octahedral GeCl6− distortion. We also discover a new relationship between the carrier effective masses anisotropy and the anisotropy of electronic density of states along three principal directions. Moreover, while applied the isotropic compressive pressure, the absorption efficiency and carrier mobility of CH3NH3GeCl3 in orthorhombic phase are improved greatly due to changes of electronic structure. We speculate that these are general results of tuning of the carrier mobility by controlling the band gap and the electronic occupation along different directions, to obtain both a high carrier mobility and an excellent ability of light adsorption.

We investigated the anharmonic effects on the dynamics and measurement accuracy of a multimode cold atomic interferometer driven by two Kapitza–Dirac pulses. The first Kapitza–Dirac pulse creates several spatially addressable modes from the ground state of an anharmonic trap and the external field. These modes evolve along different paths and coherently recombine under the anharmonic potential. The second Kapitza–Dirac pulse separates these mixed modes again. The anharmonic effect causes the asymmetry of the density distribution function of the cold atoms and it is observed at the measurement time. The expected sensitivity is calculated by the Fisher information and the Cramer–Rao lower bound. As the anharmonic effect is enhanced, the measurement accuracy of the current atomic interferometer is slightly reduced relative to the measurement accuracy Δ g ∕ g ≈ 1 0 − 9 in the case of a harmonic trap.

Coordination polymers (CPs) have shown promising potential as electrode materials for lithium ion batteries (LIBs). However, their practical applications are plagued by poor cyclability and unsatisfactory rate performance. Herein, a composite, combining a novel Ce-Co bimetallic coordination polymer with cerium dioxide and graphene nanoplatelets (Ce-Co-CP/CeO2/G), is synthesized and applied as anode materials for LIBs. It is found that the addition of graphene can significantly enhance the conductivity of electrode material. Furthermore, the graphene nanoplatelets can act as a template for the formation of a lamellar morphology of Ce-Co-CP/CeO2/G, which is beneficial to shorten the pathway for Li+-ion migration and thus improves the electrochemical performance. Consequently, the charge capacity of the sample reaches 454.3 mAh/g after 100 cycles at a current of 100 mA/g. Even at a high current density of 1000 mA/g, it can still deliver a capacity of 196.2 mAh/g after 1000 cycles. This work shows a development potential of bimetallic CP materials as a candidate for electrode materials for the next-generation LIBs.

A new Mn(II) complex with the formula [Mn2(H2O)(phen)4(seb)2]·4.5H2O (phen: 1,10-phenanthroline; H2seb: sebacic acid), (complex 1), was synthesized using a mild hydrothermal method. The structure of complex 1 was studied using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), single crystal X-ray diffraction (SXRD) analysis, thermogravimetric analysis (TGA), and Fourier infrared spectroscopy (FTIR). Mn2O3 was obtained by calcination of complex 1 at 850 °C in air and its pure phase was confirmed by PXRD analysis. The electrochemical performance of Mn2O3 as a material for the negative electrode used in lithium ion batteries (Lib) shows a specific charge and discharge capacity of 377.7 and 798.6 mAh/g, as was observed at the first cycle. The charge and discharge capacity were approximately 168.1 and 168.4 mAh/g after 100 cycles. The above capacities are repeatable and demonstrate the good structural stability of Mn2O3 under applied electric power.

There has been great interest inhow to boost the performance of perovskite solar cells effectively. Building heterostructures between layered two-dimensional materials and perovskites is a common way to achieve the goal. In this work, the electronic and optical properties of the MoS2/CsPbBr3 heterostructure are studied systematically by density functional theory calculations. The calculated results show that the heterostructure can effectively retain some of the excellent properties of individual MoS2 and CsPbBr3. Furthermore, the optical performance of the two kinds of interfaces—CsBr/MoS2 contact and PbBr2/MoS2 contact—is better than that of the individual perovskite layers. We attribute the increased light absorption to the type II electronic band alignment of the heterostructure, interfacial charge transfer, and electron-hole separation. This work may be beneficial for improving the properties of perovskite solar cells and may open a way for the theoretical exploration of inorganic perovskite–based heterostructures.

Electroluminescence devices based all-inorganic halide perovskite material with the excellent luminescence performance have been studied extensively in recent years . However, the important role for the electrodes of electroluminescence devices is payed few attention by theoretical and experimental studies. Appropriate electrodes can reduce the Schottky barrier height to decrease the energy loss, and prevent the metal impurities from diffusing into the perovskite material to generate deep impurity levels, which improves the luminous efficiency and lifetime of devices. In this paper, not only the interface effects between CsPbBr3 and common metal electrode (Ag, Au, Ni, Cu and Pt) are studied by first-principle calculations, but also the diffusion effects of metal electrode atom into the CsPbBr3 layer are also explored by nudged elastic band calculations. The calculated results show the metal Ag is more suitable for the cathode for CsPbBr3 electroluminescence devices, while the metal Pt is more applicable for the anode. Based on the overall consideration about the interface effects and diffusion effects of the CsPbBr3-metal electrode junctions, the essential principle is analyzed. The work provides theoretical guidance for how to select the right electrode for the electroluminescence performance of all-inorganic halide perovskite. The critical factor of Schottky barrier height between the electrode and the light-emitting semiconductor, and transition level generated by metal impurities also provide a valuable reference how to select the suitable electrodes for other electroluminescence devices.

AlCrSiN coatings with exceptional oxidation resistance are promising protective layers for cutting tools. Due to the inferior tribological properties at elevated temperatures, recently, tailoring of AlCrSiN by alloying has attracted widespread attention. The addition of Ni is a practical method to reduce friction and increase toughness. Whereas, the lower hardness of Ni-containing AlCrSiN coatings leads to poor wear resistance. Here, to optimize the phase structure of monolithic AlCrSiN–Ni for synergistic improvement of mechanical and tribological properties, the AlCrSiN–Ni/AlCrN multilayer was deposited by cathodic arc evaporation and investigated by combing X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, nanoindentation, and ball-on-disc tribometer. Without the formation of wurtzite AlN, epitaxially grown AlCrSiN–Ni/AlCrN coatings obtain coherent interlayer interfaces and dual-phase cubic structure involving nitride and metallic Ni. Correspondingly, the hardness increases from 21.6 ± 0.8 GPa of AlCrSiN–Ni to 31.1 ± 0.7 GPa of AlCrSiN–Ni/AlCrN. Also, significant enhancement of scratch toughness was achieved by the multilayer. For wear tests at 600 °C, the multilayer exhibits an average friction coefficient of ∼0.81, which is between ∼0.95 of AlCrSiN and ∼0.61 of AlCrSiN–Ni. Furthermore, the superior mechanical properties upgrade the wear resistance of the coating. The wear rate at 600 °C for the multilayer is 3.9 × 10−6 mm3/N·m, while other monolithic coatings have a wear rate higher than 2.0 × 10−5 mm3/N·m.

Acer tsinglingense is an ecologically and economically important tree species in China. In this study, we characterized its whole plastid genome sequence using the Illumina sequencing platform. The complete plastid genome size of A. tsinglingense is 156,039 bp in length, including a large single-copy [LSC] region of 85,760 bp, a small single-copy [SSC] region of 18,139 bp, and a pair of inverted repeats [IRs] of 26,070 bp. The genome contains 137 genes, including 89 protein-coding genes, 40 tRNA genes, and 8 rRNA genes. The GC contents in chloroplast genome, LSC region, SSC region, and IR region were 38.0%, 36.2%, 32.4%, and 42.9%, respectively. The phylogenetic analysis based on the plastid genomes showed that A. tsinglingense was more closely related with the congeneric A. laevigatum, A. palmatum, A. wilsonii, and A. buergerianum, these species were clustered into a monophyletic clade with high bootstrap support.

The complete chloroplast genome from Cardiocrinum cathayanum (Liliaceae), an important herbaceous perennial species of the Liliaceae, is determined in this study. We characterized its whole plastid...

Psathyrostachys huashanica Keng belongs to the genus Psathyrostachys within the Gramineae family, is a rare and endangered herb plant endemic to China. In the current work, we first developed its w...

Pinus pumila is a rare and endangered conifer plant in the family Pinaceae. Here, we determined the complete chloroplast (cp) genome sequence of P. pumila. The cpDNA was 117,398 bp in lengt...

In terms of Darboux transformation we investigate the dynamic process of spin wave passing through a magnetic soliton. It causes nonlinear excitations, such as Akhmediev breathers solution and Kuznetsov-Ma soliton. The former case demonstrates a spatial periodic process of a magnetic soliton forming the petal with four pieces. The spatial separation of adjacent magnetic petals increases rapidly, while one valley splits into two and the amplitude of valley increases gradually with the increasing amplitude of spin wave. The other case shows a localized process of the spin-wave background. In the limit case, we get rogue waves and clarify its formation mechanism.

In this paper, small diameter InP nanowires with high crystal quality were synthesized through a chemical vapor deposition method. Benefitting from the high crystallinity and large specific surface area of InP nanowires, the simply constructed photodetector demonstrates a high responsivity of up to 1170 AW−1 and an external quantum efficiency of 2.8×105% with a fast rise time of 110 ms and a fall time of 130 ms, even at low bias of 0.1 V. The effect of back-gate voltage on photoresponse of the device was systematically investigated, confirming that the photocurrent dominates over thermionic and tunneling currents in the whole operation. A mechanism based on energy band theory at the junction between metal and semiconductor was proposed to explain the back-gate voltage dependent performance of the photodetectors. These convincing results indicate that fine InP nanowires will have a brilliant future in smart optoelectronics.

We theoretically investigate the steady magnetic domain wall driven by spin-orbit torques in the heavy-metal/magnet bilayers with perpendicular anisotropy. Based on collective coordinates method and stability analysis, we analyze the effects of tilted current and Dzyaloshinskii-Moriya interaction on the wall. We find that the wall acquires a sustained motion in the high-current regime by deviating the current from the wall track. Also, a persistent motion can be supported by the competition between spin-orbit torques and Dzyaloshinskii-Moriya interaction in transforming wall type. In the low-current regime, there exist a switching of wall chirality and a reversal of wall motion.

In terms of Darboux transformation, we have exactly solved the higher-order nonlinear Schrodinger equation that describes the propagation of ultrashort optical pulses in optical fibers. We discuss the modulation instability (MI) process in detail and find that the higher-order term has no effect on the MI condition. Under different conditions, we obtain Kuznetsov–Ma soliton and Akhmediev breather solutions of higher-order nonlinear Schrodinger equation. The former describes the propagation of a bright pulse on a continuous wave background in the presence of higher-order effects and the soliton's peak position is shifted owing to the presence of a nonvanishing background, while the latter implies the modulation instability process that can be used in practice to produce a train of ultrashort optical soliton pulses.