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At present, gradient‐structure alloys with strong properties can be machined by strong surface plastic deformation. This kind of alloy also has high strength, excellent plastic toughness, and work hardening properties. Herein, nanometer polycrystalline nickel–cobalt alloys with grain gradient are studied. The change of mechanical properties and evolution mechanism of internal defects of graded polycrystalline nickel–cobalt alloys under shear loading are emphatically revealed, and the unusual strengthening mechanism brought about by gradient structure is revealed. The results show that grain gradient microstructure can improve the strength and maintain the toughness of the alloy to a certain extent. The uneven grain boundary distribution due to the gradient structure brings different hindering effects to the dislocation movement. Therefore, the mechanical properties exhibited are different from those of uniform microstructure. [ABSTRACT FROM AUTHOR]

Gradient nanostructured metals have become one of the research hotspots in the field of materials science due to their excellent mechanical properties and unique deformation behavior. In our contributions, the nanotwin gradient was introduced into the nanocrystalline Ni–Co alloy, and the influence of the gradient structure on the shear properties and microscopic deformation behavior was studied in order to reveal the strengthening mechanism. The gradient nanotwin Ni–Co alloy has elastic deformation and work hardening at the initial shear stage. The stress decreases after reaching the stress limit, and the uniform plastic deformation is maintained at the later stage. The excellent stability of fine twin layer and its effective hindrance to dislocation nucleation and movement can improve the strength of the material. In addition, the yield and work hardening of nanotwin gradient Ni–Co alloy are easy to occur at low temperature, and the stress–strain curve fluctuates obviously. At high temperature, the alloy is prone to plastic deformation, and the strength is reduced macroscopically. The higher the temperature is, the more difficult it is to yield. The results provide a solid theoretical basis for the design of Ni‐based alloys. [ABSTRACT FROM AUTHOR]

Plant architecture is one of the key factors affecting maize yield formation and can be divided into secondary traits, such as plant height (PH), ear height (EH), and leaf number (LN). It is a viable approach for exploiting genetic resources to improve plant density. In this study, one natural panel of 226 inbred lines and 150 family lines derived from the offspring of T32 crossed with Qi319 were genotyped by using the MaizeSNP50 chip and the genotyping by sequence (GBS) method and phenotyped under three different environments. Based on the results, a genome-wide association study (GWAS) and linkage mapping were analyzed by using the MLM and ICIM models, respectively. The results showed that 120 QTNs (quantitative trait nucleotides) and 32 QTL (quantitative trait loci) related to plant architecture were identified, including four QTL and 40 QTNs of PH, eight QTL and 41 QTNs of EH, and 20 QTL and 39 QTNs of LN. One dominant QTL, qLN7-2, was identified in the Zhangye environment. Six QTNs were commonly identified to be related to PH, EH, and LN in different environments. The candidate gene analysis revealed that Zm00001d021574 was involved in regulating plant architecture traits through the autophagy pathway, and Zm00001d044730 was predicted to interact with the male sterility-related gene ms26. These results provide abundant genetic resources for improving maize plant architecture traits by using approaches to biological breeding. [ABSTRACT FROM AUTHOR]

Using first principles calculations, we have confirmed the electronic and optical properties of 2D kagomes graphene doped with IVA elements (Si, Ge, Sn, Pb). The results show that Si-doped system has higher structural stability. The doping system increases the band gap of single-layer kagomes graphene, with Sn doping system being the most pronounced, and therefore can be considered as an attractive material for optoelectronic devices. The difference charge density and bonding population verify that the covalence of doping atoms and C atoms decreases, and that the degree of covalence diminution increases with increasing atomic number. The undoped kagomes graphene exhibits a strong light absorption capacity in the ultraviolet region, and the absorption peaks value decreases after doping, indicating that the element doping has a great weakening effect on the light absorption capacity, which has a certain potential significance for this material to be used as the antireflection film and wave permeable material of solar cells. In addition, the Pb and Sn-doped models possess the highest and lowest static dielectric constants, respectively. The peak value of electron energy loss is lower in the range of ultraviolet and visible wavelengths. These characteristics demonstrate that kagomes graphene offers substantial potential in the areas of optoelectronic and microelectronic devices. [ABSTRACT FROM AUTHOR]

Carbon paper is one of the most widely used gas diffusion layer substrate materials due to its stable performance, relatively low cost, and easy for subsequent processing. Water-soluble phenolic resin, which is more ecologically friendly than alcohol-soluble phenolic resin, was used to prepare carbon paper as the precursor of the carbon matrix. And the effect of different resin solution concentrations on the properties of carbon paper was explored. The results showed that the graphitization, electrical conductivity and mechanical properties of carbon paper increased with the increase of resin solution concentration. When the concentration of resin solution was 20 wt%, the performance of carbon paper was relatively optimal. The graphitization of the carbon paper reached 65.45%, the porosity reached 80.74%, the resistance value at 1 MPa pressure was only 7.61 mΩ cm2, the tensile strength was 1.57 MPa, and the elastic modulus was 1210.98 MPa. [ABSTRACT FROM AUTHOR]

Nanotwinned exist in crystals as coherent interfaces with low interfacial energy, which can not only improve the strength of metal materials, but also increase the ductility. In this manuscript, we have performed molecular dynamics simulations of the mechanical properties of a nano-columnar crystalline Cu-Ni alloy with different twin boundary spacing. It is found that the model without twin has a stacking fault tetrahedron composed of stair-rod dislocations, which results in a small change in dislocation density at the later stage of deformation, and the average stress after yielding is lower than that of the model with twin. During the deformation process, with the increase of Other atoms, the dislocation slip barrier is enhanced, the tensile strength is increased, and the yield phenomenon is delayed, which is more obvious with the decrease of twin boundary spacing. The dislocation density decreases with the decrease of the spacing of the twin boundary, and the dislocation segments become shorter. When the twin boundary spacing is 0.625 nm, the tensile strength is increased by about 71% compared with the model without twin structure. [ABSTRACT FROM AUTHOR]

Dendrobium officinale polysaccharide (DOP) has shown various biological activities. However, the ability of DOP to participate in immune regulation during anti-gastric cancer treatment has remained unclear. In this study, the in vitro results showed that DOP has the potential to polarize THP-1 macrophages from the M2 to the M1 phenotype, downregulate the STAT6/PPAR-r signaling pathway and the protein expression of their down-targeted ARG1 and TGM2, and further decrease the main protein and mRNA expression in the JAGGED1/NOTCH1 signaling pathway. DOP suppressed the migration of gastric cancer cells by decreasing the protein expression of N-cadherin and Vimentin and increasing E-cadherin. In addition, CM-DOP promoted the apoptosis of gastric cancer cells by upregulating Caspase-3 and increasing the ratio of Bax/Bcl-2. In vivo, DOP effectively inhibited the growth of tumors and the expression of Ki-67. In summary, these findings demonstrated that DOP converted the polarization of M2 subtype macrophages into M1 subtypes via the STAT6/PPAR-r and JAGGED1/NOTCH1 signaling pathways in order to reduce apoptosis and prevent migration, thus indicating the potential of DOP as an adjuvant tumor therapy in preclinical and clinical trials. [ABSTRACT FROM AUTHOR]

Grain boundary engineering is an effective and feasible metal strengthening strategy to enhance the properties of nanopolycrystalline alloys by changing the number, configuration, and connectivity of different types of grain boundaries, especially for the twin boundaries. In the present contribution, the effect of twin spacing and loading mode on the deformation behavior and mechanism of NiCoAl columnar polycrystalline alloy is investigated. The results show that the nanotwins can not only increase the bearing capacity of dislocations but also emit many dislocations, resulting in the coupling effect of dislocation strengthening and twin strengthening. When the twin spacing is large, intrinsic stacking faults occur and gradually transform into deformation twins. In this stage, Shockley partial dislocation controls plastic deformation. When the twin spacing is small, the high‐density twin layers and stacking faults are more likely to interweave, showing a combination action of Shockley partial dislocation and stair‐rod dislocation. With the loading changing to Z axis, the yield strength decreases due to reduced resistance to the dislocation and a weakened number of Shockley partial dislocations of the emission, leading to less strengthening of the twins. The insights provide a solid theoretical foundation for the further application of NiCoAl in industrial production. [ABSTRACT FROM AUTHOR]

Ni–Co alloy has high temperature resistance, corrosion resistance, excellent magnetic and catalytic capabilities, and is widely used in energy development, chemical industry, electronics, aviation and aerospace, such as combustion chamber hot end parts, aircraft engine working blades and hydrogen evolution catalysts. It is well known that the properties of materials depend on the structure and morphology, which depend on the preparation method. At present, the main methods for preparing nano-Ni–Co alloy are electrodeposition, sol–gel method and solution reduction method. The parameters in these preparation methods affect the morphology and properties of nano-Ni–Co alloy, so it is particularly important to study the influence of various parameters on the properties of Ni–Co alloy. In this work, the preparation methods and research progress of nano-Ni–Co alloy in recent decades are summarized, hoping to provide valuable information for the development of Ni–Co alloy. [ABSTRACT FROM AUTHOR]

Molecular dynamics was used to study the uniaxial tensile process of Ni–Co alloy with gradient nanotwin structure, and the microstructure and deformation mechanism of mechanical properties of gradient nanotwin Ni–Co alloy were studied from the micro perspectives of dislocation, twin layer and grain boundary movement. The results show that when the twin structure Ni–Co alloy is uniaxial stretched along the gradient direction and perpendicular to the gradient direction, the twin layer has different strengthening effects on the structure and strengthening mechanism, the stretching in different directions has greater influence on the dislocation movement and stacking fault nucleation of the nanogradient twin structure. The yield strength of Ni–Co alloy is 11.3 Gpa and 5.5 Gpa, respectively, after stretching along gradient and vertical gradient directions, Young's modulus reaches 221.16 Gpa and 127.90 Gpa. It is found that the gradient twin structure stretched along gradient direction has greater strength and the twin layer breaks into fragments and distributes in the system during the process of strain increase. At different temperatures, it was found that the strength and plasticity of the material decreased sharply with the increase of temperature, the dislocation density in the system also decreased with the increase of temperature, resulting in poor performance of the material. [ABSTRACT FROM AUTHOR]

In this contribution, molecular dynamics method is used to accurately add quantitative Co atoms in the grain boundary (GB) region of nano-polycrystalline Ni to study the effect of solute atoms on the GB and the deformation mechanism of the material. It was found that adding an appropriate amount of Co atoms at the GBs can improve the tensile strength of the material to a certain extent through solid solution strengthening. However, excessive introduction of solute atom will increase the activity of GB atoms, destroy the stability of GBs, and accelerate the appearance of material yielding. At the same time, the Co atoms at the GB gradually detached from the GB region and diffused into the grains. In addition, the dislocations are distributed in a grid at the GBs, and with the increase in strain, the number and length of dislocations gradually increase, forming a large number of entanglements. Moreover, the Shockley dislocation interacts with other dislocations to form a more stable dislocation structure by hindering the generation and movement of other dislocations, which greatly enhances the strength of the system. [ABSTRACT FROM AUTHOR]

Herein, the effects of different Co content and temperature factors on the shear mechanical properties of nano‐polycrystalline nickel–cobalt alloy are analyzed by molecular dynamics (MD) simulations. It is found in the work that the highest shear modulus of 63.03 GPa is obtained when the Co content is 10%, attributed to the lattice distortion caused by the difference in the lattice parameters between two elements. During the shearing process, the multilevel twins are present with intensification of the deformation process, resulting in excellent dynamic shear performance. Shockley dislocations will drive the stacking faults and other partial dislocations to constitute a tetrahedral edge, and finally forms a tetrahedral structure. In addition, as the temperature of the shear environment increases, the highest strain and stress decrease. The grain boundary atoms increase significantly, and the atoms inside the grains decrease accordingly. As the degree of atomic disorder increases, the grain boundaries will melt gradually. The decrease of partial dislocation density can weaken the entanglement effect caused by dislocations. The previous conclusions promote the product development and application of nano‐polycrystalline alloys in the future, and provide important guidance significant for the engineering application of nickel–cobalt alloys. [ABSTRACT FROM AUTHOR]

Exploring the next generation of invincible energy materials with fascinating properties is vital in the challenge of energy crisis. In this paper, we extract T-carbon as a potential candidate and have an insight into the electronic and optical properties by means of first principles. It is found that S1 position doping system is relatively more stable with the formation energy of 0.323 eV, and has the smallest bandgap value of 1.228 eV. Charge density difference maps show that the electron loss is obvious near the S atom and the covalent bond is weakened. The population analysis shows that the S atom will obtain electrons through competition, while the Se atom will lose electrons. Additionally, the peak values of 2 in the doped systems decrease significantly, especially for S2 doping system, indicating that S2 doping can effectively improve the service life in related devices. Compared with the instinct system, the absorption coefficient is lower in the UV region and greater in the visible region. The peak of energy loss spectrum reduces after doping, especially for Se1 doping. The results provide a theoretical basis for the industrial application of T-carbon in the energy microdevice fields. [ABSTRACT FROM AUTHOR]

The article discusses the use of a flexible auxiliary single-arm transluminal endoscopic robot (FASTER) to assist in endoscopic submucosal dissection (ESD) of early gastric angle cancer. The robot allows for precise manipulation of grasping forceps to exert controlled pulling forces in multiple directions away from the gastric wall. The authors successfully completed a gastric angle ESD using FASTER, achieving complete removal of the lesion without complications. They believe that FASTER offers advantages such as flexibility, enabling an antegrade, tangential approach, and effectively coping with difficult gastric angle lesions. Further cases and longer follow-up are needed to validate the technique's advantages. [Extracted from the article]

The intrinsic point defect influence data for β –Si3N4 by far are incomplete and experimental clarification is not easy. In this contribution, the effects of vacancy ( V 2c , V 6h and V Si ) and interstitial ( I N and I Si ) defects on the electronic properties of H-passivated β –Si3N4 (0001) surface are explored based on density functional theory (DFT) calculation. The results show that it is easier to form N 6h vacancy defects in the surface layer under Si-rich conditions. The existence of N vacancies makes the bottom of conduction bands shift downwards, and the top of valance band is away from Fermi level. The presence of V Si makes the system have the characteristics of p-type semiconductor, and the closer to the inner layer, the narrower the range of additional energy bands and the greater the degree of localization of electrons. The closer the Si atom vacancy is to the surface, the smaller the photon energy corresponding to the maximum absorption coefficient is. Compared with the N vacancy system, the Si vacancy system has higher reflection ability in the low energy region. For the interstitial defect systems, I N is easy to form on the surface layer, and I Si is easy to produce in the inner layer. The I N system has a new additional energy level at the Fermi level, and as the I N is closer to the inner layer, the energy range of the additional energy level is also narrower. In the I Si system, the new additional energy levels appear at the Fermi level and the intermediate band. The results have positive significance for the design of this advanced structural and functional integrated ceramics. The absorption coefficient and reflection coefficient of I Si - 3 system are much higher than those of other systems when the energy is greater than 2.5 eV. [ABSTRACT FROM AUTHOR]

Ni–Co alloy has great advantages in the fields of micro-electromechanical systems and aerospace, however, the lack of micro-deformation mechanism restricts its industrial application. Herein, the deformation mechanism and microstructure evolution of Ni–Co alloy nanoplate under shear loading are investigated by MD. The yield strength increases gradually with the increase of the velocity, and the highest shear modulus is 111.43 GPa. The stress concentration leads to the nucleation and expansion of the dislocation, and the stacking fault expands with the dislocation motion, swallowing most of the disordered atoms. By Dislocation Extraction Algorithm (DXA), it is found that Shockley and Perfect dislocations make a major role, and the interactions between dislocations are responsible for the high mechanical properties. As the temperature increases, the yield strength decreases significantly, the stress fluctuations in the plastic phase at 100 K and 200 K are greater compared to other temperatures. Meanwhile, the coherence of the dislocations motion decreases, and the atoms in the stacking faults are scattered, leading to the decreasing of area. The above results are helpful for the design and control of nanoelectronic facilities and provide a significant guide for the industrial applications of Ni–Co alloy nanoplate. [ABSTRACT FROM AUTHOR]

In this paper, the microscopic electronic structure and related optical properties of the 4H-SiC (111) surface doped with B, Al, Ga elements are explored by first principles calculation methods. Compared with Al- and Ga-doped systems, the formation energy of B-doped system is found to be very small, showing excellent stability. The bandgaps of doped system decrease obviously, and an indirect bandgap is observed in all the systems. Charge density difference maps show that the covalency is increased after B doping and the iconicity is increased after Al and Ga doping. Moreover, due to the sharp increase in static dielectric constant and dielectric loss, the B-doped system can be used as the candidate for absorbing materials. In addition, the increase in the peak value of the absorption and reflectivity makes the doped systems more promising in the development of solar cells. [ABSTRACT FROM AUTHOR]

An insight into electronic structure and optical feature of S-adsorbed 3C–SiC (111) surface is carried out employing first-principles calculation. It is found that the T o and B position systems with adsorption energies of 3.880 and 3.895, respectively, are relatively stable compared to the T w and C systems. Impurity energy levels are present near Fermi level in C and T w position adsorption systems and the band-gap decreases obviously in the two systems. A raindrop-like electron cloud of S atom can be observed in T w adsorption system and the order of the chemical bond strength in the adsorption system is (B , T o ) > T w > C. The B and T o adsorption systems have good light permeability in the visible and infrared regions, while the C and T w adsorption systems are relatively suitable as dielectric materials and have high service life when they as devices in the ultraviolet region. [ABSTRACT FROM AUTHOR]

Along with extensive research on the 3D printing and microwave absorption ceramics, 3D printing technology provides a great possibility for microwave absorption ceramics with arbitrary shapes in a faster, cheaper and more flexible way. This review focuses on the latest evolution in the raw materials, the structure design and the advanced additive manufacturing technologies of 3D printing microwave absorption ceramics. Firstly, the representative raw materials are divided into three categories, including ceramic powder, cermet powder and precursor resin. In addition, additives give rise to improvement of microwave absorption properties of ceramics. Secondly, based on two attenuation theories, structure design makes further efforts to enhance the microwave absorption performance of ceramics. Finally, comparisons are made between diversified manufacturing technologies to facilitate the selection of the best ones for different application in practical use. This study presents a summary of research that has been conducted to produce microwave absorption ceramics by additive manufacturing. [ABSTRACT FROM AUTHOR]

Study Question: Is there an association between peak serum estradiol (E2) level during controlled ovarian stimulation (COS) and neonatal birthweight in freeze-all cycles?Summary Answer: Peak serum E2 level during ovarian stimulation is not associated with neonatal birthweight in freeze-all cycles.What Is Known Already: Supraphysiologic E2 levels during COS have been demonstrated to generate a suboptimal peri-implantation endometrial environment and thus lead to adverse neonatal outcomes in fresh embryo transfer cycles. Previous experimental studies also suggested a potential influence of superovulation on oocyte epigenetic programming, but whether it translates into altered phenotypes of fetal growth and development remains unclear in clinical practice. By segmenting the process of COS and embryo transfer, the freeze-all policy provides a novel model to investigate the sole impact of ovarian stimulation on oocytes after ruling out the effects of hyperestrogenic milieu on endometrium in fresh cycles.Study Design, Size, Duration: A retrospective cohort study of 8501 patients who underwent their first COS cycles with a freeze-all strategy and delivered live-born singletons in subsequent frozen-thawed embryo transfer cycles from January 2007 to December 2016 at a tertiary-care academic medical center.Participants/materials, Setting, Methods: Patients were categorized into six groups according to E2 level on trigger day in regular increments of 1000 pg/mL: <1000, 1000-1999, 2000-2999, 3000-3999, 4000-4999 and ≥5000 pg/mL. Univariable and multivariable linear regression and logistic regression analysis were performed to assess the independent association between peak E2 level and measures of neonatal birthweight including absolute birthweight, Z-score, low birthweight (LBW) and small-for-gestational age (SGA).Main Results and the Role Of Chance: The six groups did not differ significantly in birthweight, Z-score or the incidence of LBW and SGA. Compared with the E2 <1000 pg/mL group, the adjusted mean difference (95% confidence interval [CI]) of stratified higher E2 groups was 17.2 (-31.0-65.5), 12.3 (-35.9-60.5), -4.1 (-51.9-43.7), -0.6 (-48.9-47.8) and -3.6 (-50.0-42.8) g for birthweight, and 0 (-0.11-0.10), 0.02 (-0.08-0.12), 0.04 (-0.06-0.14), -0.01 (-0.11-0.10) and -0.04 (-0.14-0.06) for Z-score, respectively. Regarding the outcomes of LBW and SGA, no increased risks were observed in each E2 category, with the adjusted odds ratio (95% CI) being 1.21 (0.68-2.16), 1.0 (0.58-1.90), 0.90 (0.50-1.63), 0.93 (0.51-1.69) and 1.08 (0.61-1.90) for LBW, and 0.97 (0.58-1.64), 1.06 (0.63-1.77), 0.77 (0.46-1.31), 0.71 (0.41-1.22) and 1.00 (0.60-1.65) for SGA, respectively.Limitations, Reasons For Caution: The study was retrospective in design, and other unknown confounding factors may not be included for adjustment. Furthermore, the generalization of the study finding could be limited to some extent by the majority of double cleavage-stage embryo transfer and difference in birthweight reference percentiles between Chinese and other populations.Wider Implications Of the Findings: Our observations suggest that the hyperestrogenic milieu during COS does not seem to pose adverse effects on neonatal birthweight after frozen-thawed embryo transfer, which provides reassuring information for high ovarian responders in freeze-all cycles concerning their offspring's health.Study Funding/competing Interest(s): This study was funded by the National Key Research and Development Program of China (SQ2018YFC100163) and National Natural Science Foundation of China (81571397, 81771533). The authors declare no conflict of interest. [ABSTRACT FROM AUTHOR]

We use a first-principles calculation to explore the effects of vacancies on structural, electronic and optical properties of β - Si 3 N 4 based on density functional theory (DFT). The results show that after optimization, the Si vacancy system of β - Si 3 N 4 is more difficult to produce than N vacancy system under the same thermodynamic conditions. The band gaps including N vacancy and Si vacancy systems are smaller than that of the perfect crystal. The charge density difference and population analysis show that the bonding near Si vacancy has stronger covalent property, whereas those near nitrogen vacancy have stronger ionic property. For Si vacancy system, the materials have much higher values of the imaginary part of the dielectric constant than those of N vacancies and perfect β - Si 3 N 4 . The maximum value of the Si vacancy system in absorption and reflection spectra is lower than those in different nitrogen vacancy systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • PdO NPs are successfully confined within ZSM-5 by a one-pot hydrothermal method. • Pd(en) 2 2+ is sandwiched in small piece zeolite with high dispersion during crystallization. • Pd@Z5 keeps stable toluene adsorption efficiency in fluctuation toluene atmosphere. • Pd@Z5 is stable when the reaction temperature fluctuated from 200 ∼ 800 °C. • Pd@Z5 shows enhanced SO 2 resistance for toluene oxidation at 210 °C. Herein, 1 wt% PdO nanoparticles were in situ confinement within HZSM-5 by one-pot hydrothermal method. Characterizations confirmed that Pd(en) 2 2+ were first loaded on small pieces HZSM-5, after small HZSM-5 self-assembly aggregated into larger pieces, Pd active sites were sandwiched in the HZSM-5 crystal with small particle size and high dispersion. The sample was thermal-stable after calcination or utilization at 800 °C, which guaranteed Pd@Z5 a robust bi-functional adsorbent/catalyst for VOCs elimination. The adsorption capacity reached 58.5 mg/g in 100 ppm toluene/humid air, and the adsorption efficiency was not affected by 100 ∼ 500 ppm toluene. Pd@Z5 was stable for toluene oxidation in switching temperatures, PdO size was almost unchanged under 800 °C. Conversely, PdO impregnated directly on ZSM-5 suffered significant sintering after calcination at 800 °C, leading PdO nanoparticles decomposed and aggregated into larger nanoparticles. The adsorption capacity of Pd/Z5-800 declined by 40% and its T 90 increased by 26 °C compared to Pd/Z5. Furthermore, Pd@Z5 showed better resistance to SO 2 than Pd/Z5, demonstrating the sample had great potential for practical application. [ABSTRACT FROM AUTHOR]

As a novel two-dimensional nanomaterial, MXene is one of the most promising alternative electrode materials due to its large specific surface area, good electrical conductivity, excellent mechanical properties and tunable structure. This paper investigates the electrochemical performance of the MXene materials Zr 2 N and Zr 2 NS 2 as anode materials for lithium and sodium ion batteries. The results showed that on the Zr 2 N monolayer, lithium and sodium ions tended to adsorb at the C site, while on the Zr 2 NS 2 monolayer, lithium and sodium ions tended to adsorb at the B and A sites, respectively. The results of the Charge difference density diagram and Mulliken population analysis show that there is a significant electron transfer between the adsorbed metal ions and the material surface. This indicates that lithium and sodium ions form chemisorption on the Zr 2 N and Zr 2 NS 2 surfaces. The high theoretical specific capacity and low migration barrier suggest that Zr 2 N and Zr 2 NS 2 are promising anode materials for lithium and sodium ion batteries. • The electrochemical properties of Zr 2 N and Zr 2 NS 2 as anode materials for lithium and sodium ion batteries are analyzed and discussed. • The high theoretical specific capacity and low migration barrier suggest that Zr 2 N and Zr 2 NS 2 are promising anode materials for lithium and sodium ion batteries. • It provides positive theoretical guidance for the experiment. [ABSTRACT FROM AUTHOR]

Structural stability along with the electronic and the optical properties of intrinsic 3C-SiC, Si 3 1 C 3 2 Na and Si 3 0 C 3 2 Na 2 are studied by the first-principles calculations. Si 3 1 C 3 2 Na system possesses the most considerate stability with lowest binding energy (E B) and formation energy (E f) compared to Si 3 0 C 3 2 Na 2 . It is observed that the non-filled impurity energy levels in the vicinity of the Fermi level can subsequently give rise to an enhancement of electrical conductivity of 3C-SiC. Through the analysis of charge difference density maps, it is found that covalence of bonds between the Na atom and nearby C atom reduces in varying degrees. In different concentrations of Na doping systems, especially for the supercell of Si 3 0 C 3 2 Na 2 , the real and imaginary parts of the dielectric constant are visibly added in the energy range of 0–0.5 eV, demonstrating that the dielectric loss property of the 3C-SiC is improved evidently. These features confirm that the Na-doped 3C-SiC semiconductor is propitious to the wide application of 3C-SiC in the field of absorbing materials. [ABSTRACT FROM AUTHOR]

Leaf senescence plays an important role in the improvement of maize kernel yields. However, the underlying regulatory mechanisms of leaf senescence in maize are largely unknown. We isolated ZmVQ52 and studied the function of ZmVQ52 which encoded, a VQ family transcription factor. ZmVQ52 is constitutively expressed in maize tissues, and mainly expressed in the leaf; it is located in the nucleus of maize protoplasts. Four WRKY family proteins—ZmWRKY20, ZmWRKY36, ZmWRKY50, and ZmWRKY71—were identified as interacting with ZmVQ52. The overexpression of ZmVQ52 in Arabidopsis accelerated premature leaf senescence. The leaf of the ZmVQ52-overexpression line showed a lower chlorophyll content and higher senescence rate than the WT. A number of leaf senescence regulating genes were up-regulated in the ZmVQ52-overexpression line. Additionally, hormone treatments revealed that the leaf of the ZmVQ52-overexpressed line was more sensitive to salicylic acid (SA) and jasmonic acid (JA), and had an enhanced tolerance to abscisic acid (ABA). Moreover, a transcriptome analysis of the ZmVQ52-overexpression line revealed that ZmVQ52 is mainly involved in the circadian pathway and photosynthetic pathways. [ABSTRACT FROM AUTHOR]

This work utilizes in situ transmission electron microscopy–based nanopillar compression to investigate the effect of electrochemical cycling on the mechanical properties of LiCoO2. The ultimate strength of LiCoO2 in the pristine state, and after 1 and 11 cycles are 5.62 ± 0.22 GPa, 3.91 ± 1.22 GPa, and 2.27 ± 1.07 GPa, respectively. The reduced average yield strengths and the large standard deviations of cycled samples, relative to the pristine powder, are hypothesized to result from nonuniform accumulation of Li+ site‐point defects during cycling; either H+ or Li+ vacancies. Density functional theory calculations support our hypothesized link between a nonuniform Li site‐point defect distribution in the cathode and reduction in the materials cohesive strength. Cycling lithium cobalt oxide reduces its strength as a result of point defect accumulation. [ABSTRACT FROM AUTHOR]

• The deformation mechanism of nanotwins under Hall-Petch enhancement effect was studied via MD simulation. • Excessive volume fraction of nano twins causes Hall-Petch effect breakdown. • Critical volume fraction nanotwins effectively inhibit grain rotation and stabilize grain boundaries. • Nanotwin layer inhibits dislocation nucleation and leads to deformation mechanism transformation. Grain boundary plasticity dominates the mechanical behavior of materials, and the introduction of intragranular nanotwins can achieve coordination between strength and ductility in metals and alloys. In this effort, nanotwins with different volume contents are introduced in NiCoAl alloys to explore the strengthening mechanism under the Hall-Petch effect from perspectives such as grain boundary energy, grain rotation angle, and grain coarsening. The results indicate that the introduction of nanotwins with critical volume fraction effectively inhibits grain boundary migration and grain combination, and improves the strength of the alloy by reducing grain boundary energy and hindering grain rotation. Meanwhile, it leads to a change in the strengthening mechanism from the combined effects of dislocation movement, grain boundary migration and deformation twinning to the dual strengthening of local movement of dislocations within the grain and Lomer-Cottrell locks. The latter hinders the slip of local dislocations within the grain and improves the mechanical property. In addition, based on the average grain size and atomic mean square displacement after high-temperature annealing, the stability mechanism of nanotwins in the alloy can obtain an insight from the aspect of atomic motion. This article explains the Hall-Petch strengthening mechanism from a more detailed and interesting point and provides insights into the strengthening mechanism of nanotwins under the Hall-Petch effect. [Display omitted] [ABSTRACT FROM AUTHOR]

Electronic structures and optical properties of IV A elements (Ge, Sn and Pb)-doped 3C-SiC are investigated by means of the first-principles calculation. The results reveal that the structure of Ge-doped system is more stable with a lower formation energy of 1.249 eV compared with those of Sn- and Pb-doped 3C-SiC systems of 3.360 eV and 5.476 eV, respectively. Doping of the IV A elements can increase the band gap, and there is an obvious transition from an indirect band gap to a direct band gap. Furthermore, charge difference density analysis proves that the covalent order of bonding between the doping atoms and the C atoms is Ge–C > Sn–C > Pb–C, which is fully verified by population values. Due to the lower static dielectric constant, the service life of 3C-SiC dramatically improved in production practice. Moreover, the lower reflectivity and absorption peak in the visible region, implying its wide application foreground in photoelectric devices. [ABSTRACT FROM AUTHOR]

Abstract: A stable cyclopenta‐fused tetraphenanthrenylene macrocycle, CPTP‐M, was synthesized, and the structure was confirmed by X‐ray crystallographic analysis. It exhibits a large radical character (number of unpaired electron, NU=3.52) and a small singlet–triplet energy gap (ΔES‐T=−2.8 kcal mol−1 by SQUID). Its backbone contains 60 ([4n]) conjugated π electrons and is globally antiaromatic. NMR measurements and theoretical calculations revealed that its dication/dianion is globally aromatic owing to the existence of [4n−2]/[4n+2] π‐conjugated electrons. Remarkably, the ring‐current map of the tetraanion shows a unique ring‐in‐ring structure, with a diamagnetic outer ring and a paramagnetic inner ring. Accordingly, both the inner‐rim and outer‐rim protons are deshielded in its 1H NMR spectrum. The tetraanion can be regarded as an isoelectronic structure of the known octulene, which shows similar electronic properties. [ABSTRACT FROM AUTHOR]

Abstract: A stable cyclopenta‐fused tetraphenanthrenylene macrocycle, CPTP‐M, was synthesized, and the structure was confirmed by X‐ray crystallographic analysis. It exhibits a large radical character (number of unpaired electron, NU=3.52) and a small singlet–triplet energy gap (ΔES‐T=−2.8 kcal mol−1 by SQUID). Its backbone contains 60 ([4n]) conjugated π electrons and is globally antiaromatic. NMR measurements and theoretical calculations revealed that its dication/dianion is globally aromatic owing to the existence of [4n−2]/[4n+2] π‐conjugated electrons. Remarkably, the ring‐current map of the tetraanion shows a unique ring‐in‐ring structure, with a diamagnetic outer ring and a paramagnetic inner ring. Accordingly, both the inner‐rim and outer‐rim protons are deshielded in its 1H NMR spectrum. The tetraanion can be regarded as an isoelectronic structure of the known octulene, which shows similar electronic properties. [ABSTRACT FROM AUTHOR]

Based on first‐principles with the generalized gradient approximation (GGA) of the Perdew–Burke–Ernzerhof (PBE) form, the authors carry out systematic investigations regarding the electronic structures and optical properties of zinc‐blende (ZB) ZnS doped with six types of transition metals. The Cd‐doped system has greater structural stability with a lower formation energy of 0.526 eV compared to other systems. Additionally, the band structures of systems are employed to show the superior semiconductor capacity of Mo‐ and Pt‐doped systems with decreased band gaps (EG) of 0.978 eV and 0.843 eV, which are smaller than those of the pure system and others. Moreover, charge difference density maps show that the covalent properties of MoS and PtS bonds are enhanced by exposing the electron‐deficient region. Meantime, optical properties, including absorption and reflectivity spectra, dielectric constant, and loss function, are introduced to reveal that the absorption spectra curves reach the lowest absorption peak of 2.375 × 105 cm−1 at 7.227 eV for the Mo‐doped system, in which the system exhibits a relatively negative reflectivity spectrum and dielectric loss that is expected in the solar cell industry, predicting its broad scope of application prospects in the photoelectric and microelectronic device fields. [ABSTRACT FROM AUTHOR]

Highlights • First principles is adopted to study the new properties of the counter electrodes. • The electronic structure of tin doped CuS are simulated by first princples. • The new optical properties of tin doped CuS are simulated by first princples. Abstract In order to study whether tin doped CuS could be used as counter electrodes for dye-sensitized solar cells, first-principles were used to calculate the electronic structure and optical properties of it. The calculated results show that tin ions can substitute two different kinds of copper ions in the supercell of CuS, and they demonstrate different properties. The calculated results of electronic structure indicate that the introduction of tin ions change the conductive properties of CuS counter electrode. The calculated results of optical properties indicate that the introduction of tin ions change the optical properties of CuS counter electrode, and tin doped CuS could be excellent counter electrodes for dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

We use first-principles calculations in this contribution to study electronic structures and optical properties, especially absorption and reflectivity spectra, dielectric constant and loss function of Li, Na, K, Be, Mg, Ca and Al adsorption behaviors on (2 0 0) surface of hexagonal silicon nitride (β-Si 3 N 4 ). The lower adsorption energy of −3.931 eV for Ca-adsorbed surface indicates that it has more excellent structural stability. The seven kinds of adsorptions are all featured by chemisorption with commonly negative value of adsorption energy, implying relatively abated capacity of defending the chemical corrosion formed by metals mentioned above. Band gaps of surfaces with different adsorptions are 0.113 eV, 0.099 eV, 0.113 eV, 0.147 eV, 0.154 eV, 0.151 eV and 0.111 eV for Li-, Na-, K-, Be-, Mg-, Ca- and Al-adsorbed surface structure, respectively, along with 0.143 eV for clean surface of β-Si 3 N 4 , which leads more efficient measures of potential for obtaining outstanding semiconductor properties for materials. Moreover, absorption spectra curve of surface drops to a lower peak value of 5.46 × 10 4  cm −1 , 4.94 × 10 4  cm −1 and 3.53 × 10 4  cm −1 for Na-, Mg- and Ca-adsorption, decreasing by 10.0%, 18.6% and 41.8% in contrast to clean surface, 6.07 × 10 4  cm −1 , respectively, in which the surface carries decreased reflectivity spectra and dielectric loss that are greatly valued and expected in solar cell industry, indicating its broader application potential in photoelectric and microelectronics devices fields. [ABSTRACT FROM AUTHOR]

Electronic structures and optical properties of zinc-blende aluminum nitride doped with transition metals are investigated. Lu-doped system possesses the most considerate stability with the lowest formation energy of −9.033 eV compared to others. Band structures of systems are introduced to investigate a more excellent semiconductor capacity for Re-doped system with a band gap (EG) of 0.689 eV, with others having band gaps of 2.120, 2.159, 1.806, 1.837 and 0.879 eV, respectively, much smaller than that of pristine one, 3.113 eV. Moreover, absorption spectra curve reaches the lowest peak of 2.558×105cm−1 for Os-doped system; simultaneously, the system exhibits a relatively negative reflectivity spectra and dielectric loss of 5.620 eV that are extensively expected in solar cell industry, predicting its broad scope of application prospects in photoelectric and microelectronic devices. [ABSTRACT FROM AUTHOR]

In the present research, we use a first principles calculation to investigate the electronic structure and optical properties of Mo-, Pt- and Rh-doped rutile TiO2. The results indicate that the band gap of the Mo-, Pt-, and Rh-doped systems decreases to 1.758, 0.906, and 0.971 eV, respectively, compared with the 1.968 eV band gap of intrinsic TiO2, which is due to the hybridization of the doped atom d and O p orbital electrons, resulting in the formation of an impurity level and enhanced conductivity. The charge-difference density maps show that the covalence is enhanced in the region around Ti atoms for Mo- and Pt-doped systems, whereas Rh doping has little effect on the covalence. Based on these results, the bond population is 0.42, 0.28, and 0.27 for Mo–O, Pt–O, and Rh–O bonds, respectively. In the absorption spectrum, the peaks of the doped systems decrease significantly and redshift. Compared with the Mo-doped system, the Rh- and Pt-doped systems have lower static dielectric constant and dielectric loss in the low-energy region, which is promising for fascinating applications in microelectronic components. [ABSTRACT FROM AUTHOR]

Bandgap tailoring of β-Si3N4 is performed by single and co-doping by using density functional theory (DFT) of PBE functional and plane-wave pseudopotential method. The results reveal that a direct bandgap transfers into an indirect one when single-doped with As element. Also, a considerate decrease of bandgap to 0.221 eV and 0.315 eV is present for Al–P and As–P co-doped systems, respectively, exhibiting a representative semiconductor property that is characteristic for a narrower bandgap. Compared with other doped systems, Al-doped system with formation energy of 2.67 eV is present for a more stable structure. From charge density difference (CDD) maps, it is found that the blue area between co-doped atoms increases, illustrating an enhancement of covalent property for Al–P and Al–As bonds. Moreover, a slightly obvious “Blue shift” phenomenon can be obtained in Al, Al–P and Al–As doped systems, indicating an enhanced capacity of responses to light, which contributes to the insight for broader applications with regard to photoelectric devices. [ABSTRACT FROM AUTHOR]

Improving oxygen electrochemistry through nanoscopic confinement has recently been highlighted as a promising strategy. In-depth understanding the role of confinement is therefore required. In this study, we simulate the oxygen evolution reaction (OER) on iron oxide nanoclusters under confinement of (7,7) and (8,8) armchair carbon nanotubes (CNTs). The free energies of the four proton coupled electron transfer (PCET) steps and the OER overpotentials are calculated. The Fe 4 O 6 nanocluster confined in (7,7) CNT is found to be the most active for OER among the systems considered in this work. This leads to an increase in catalytic efficiency of OER compared to the hematite (110) surface, which was reported recently as an active surface towards OER. The calculated results show that the OER overpotential depends strongly on the magnetic properties of the iron oxide nanocluster. These findings are helpful for experimental design of efficient catalyst for water splitting applications. [ABSTRACT FROM AUTHOR]

Based on first-principles simulations with the generalized gradient approximation (GGA) of the Perdew-Burke-Ernzerhof (PBE) functional, we studied the electronic structures and optical properties of hexagonal silicon nitride (β-Si3N4) doped with IV A elements, C, Ge, Sn and Pb. It was found that the Ge-doped system is characterized by a more stable structure with a lower formation energy of 2.584 eV compared with those of the C-, Sn- and Pb-doped systems of 3.877 eV, 5.249 eV and 7.672 eV, respectively. The band gap (EG) of the Pb-doped system was the lowest at 1.6 eV, displaying semiconducting characteristics. Additionally, there was a transition from a direct band gap to an indirect band gap in the C-doped system. Charge difference density analysis showed that the covalent property of the C-N bonds was enhanced by expansion of the electron-free region and the larger Mulliken population values of 0.71 and 0.86. Furthermore, lower absorption and reflectivity peaks at 11.30 eV were observed for the C-doped system, demonstrating its broader potential for application in photoelectric and microelectronic devices. [ABSTRACT FROM AUTHOR]

Photosynthetic biomanufacturing provides a promising solution for sustainable production of biofuels and biochemicals. Cyanobacteria are among the most promising microbial platforms for the construction of photosynthetic cell factories. Metabolic engineering of cyanobacteria has enabled effective photosynthetic synthesis of diverse natural or non-natural metabolites, while commercialization of photosynthetic biomanufacturing is usually restricted by process and economic feasibilities. In actual outdoor conditions, active cell growth and product synthesis is restricted to narrow light exposure windows of the day-night cycles and is threatened by diverse physical, chemical, and biological environmental stresses. For biomass harvesting and bioproduct recovery, energy and cost consuming processing and equipment is required, which further decreases the economic and environmental competitiveness of the entire process. To facilitate scaled photosynthetic biomanufacturing, lots of efforts have been made to engineer cyanobacterial cell properties required by robust & continual cultivation and convenient & efficient recovery. In this review, we specifically summarized recently reported engineering strategies on optimizing industrial properties of cyanobacterial cells. Through systematically re-editing the metabolism, morphology, mutualism interaction of cyanobacterial chassis cells, the adaptabilities and compatibilities of the cyanobacterial cell factories to the industrial process could be significantly improved. Cell growth and product synthesis of the tailored cyanobacterial cells could be expanded and maintained at night and in stressful environments, while convenient biomass harvesting could also be expected. For developing more feasible cyanobacterial photosynthetic biomanufacturing in large scale, we here propose the importance of tailoring industrial properties of cyanobacteria and outline the directions that should be exploited in the future. [ABSTRACT FROM AUTHOR]

Using DFT-GGA-PW91 calculations we investigate the electronic structures and optical properties of doped GaP. It is found that the lattice constants and volume increase slightly for Al, In, As and Sb doped systems and E G distinctly decrease after doping. The formation energies are 0.587 and 0.273 eV for As and Sb doped systems, respectively, and lower remarkably than those in other systems, indicating that the stability of the two systems is higher. The direct band gap transition occurs when doped with In, As and Sb elements. The charge density difference images reveal that electron loss near Al atom is observed accompanying the enhancement of covalent bond feature, and then electron enrichment is present around N atom demonstrating that the ionic bond characteristic is obvious. The Sb-doped system has the higher static dielectric constant illustrating the applications in semiconductor devices. The absorption peak value is located at 194.7 nm for Al-doped system and this shows that the system can absorb a large amount of light and displays “Barrier-type” characteristics in UV region. In the visible region, the doped systems have lower reflectivity coefficient, indicating that the systems all have “clear-type” properties. This is conducive to fundamentally insights to a tunable band gap semiconductor with enormous potential in device fields. [ABSTRACT FROM AUTHOR]

This paper reports the experiment and theory simulation results of silver substituting cadmium in CdS quantum dots (QDs). The experiment results show that the average particle size of as-prepared samples is about 6.0 nm, and the phase structure is hexagonal wurtzite. Compared with that of pure CdS QDs, the peak of photoluminescence spectrum of CdS QDs the cadmium of which are substituted by silver are red shift from 533 nm to 567 nm, which leads to the luminous colours change from green to yellow. The theoretical simulation results show that the optical property changes of CdS QDs are due to the silver substituting cadmium changing the energy level spacing, the conductivity and the way of electronic transition of CdS crystals. [ABSTRACT FROM AUTHOR]

Objective: To identify the risk factors for suboptimal response to GnRH agonist (GnRH-a) trigger and evaluate the effect of hCG on the outcome of patients with suboptimal response to GnRH-a.Design: A retrospective data analysis.Setting: A tertiary-care academic medical center.Patient(s): A total of 8,092 women undergoing 8,970 IVF/intracytoplasmic sperm injection (ICSI) treatment cycles.Intervention(s): All women underwent hMG + medroxyprogesterone acetate (MPA)/P treatment cycles during IVF/ICSI, which were triggered using a GnRH-a alone or in combination with hCG (1,000, 2,000, or 5,000 IU). Viable embryos were cryopreserved for later transfer.Main Outcome Measure(s): The rates of oocyte retrieval, mature oocytes, fertilization, and the number of oocytes retrieved, mature oocytes, and embryos frozen.Result(s): In total, 2.71% (243/8,970) of patients exhibited a suboptimal response to GnRH-a. The suboptimal responders (LH ≤15 mIU/mL) had a significantly lower oocyte retrieval rate (48.16% vs. 68.26%), fewer mature oocytes (4.10 vs. 8.29), and fewer frozen embryos (2.32 vs. 3.54) than the appropriate responders. Basal LH levels served as the single most valuable marker for differentiating suboptimal responders with the areas under the receiver operating curve of 0.805. Administering dual trigger (GnRH-a and hCG 1,000, 2,000, 5,000 IU) significantly increased oocyte retrieval rates (60.04% vs. 48.16%; 68.13% vs. 48.16%; and 65.76% vs. 48.16%, respectively) in patients with a suboptimal response.Conclusion(s): Basal LH level was useful predictor of the suboptimal response to GnRH-a trigger. Administrating dual trigger including 1,000 IU hCG for final oocyte maturation could improve the oocytes retrieval rate of GnRH-a suboptimal responder. [ABSTRACT FROM AUTHOR]

The electronic structure and optical property of wurtzite AgInS 2 with vacancy defects and tin doping have been investigated by the first principle based on density functional theory. The results show that the intrinsic silver and indium vacancy may lead to the narrowing of bandgap. It shows metal characteristic after a silver atom and an indium atom are respectively replaced by tin atoms in the supercell of wurtzite AgInS 2 . The optical property study indicates that the absorption curves and reflectivity curves of AgInS 2 are blue shift and weakened owing to the existence of vacancy defects and tin doping. [ABSTRACT FROM AUTHOR]

The electronic structure and optical property of wurtzite AgInS 2 with vacancy defects and doped by zinc have been investigated by the first principle to study the luminescence mechanism. The results show that the intrinsic silver vacancy and zinc vacancy may lead to the narrowing of bandgap, and it shows metallic characteristics after a indium atom is replaced by a zinc atom in the supercell of wurtzite AgInS 2 . The dielectric property study indicates that the main peaks of imaginary part are red shift after the silver atom and the indium atom of wurtzite AgInS 2 are replaced respectively by zinc atoms. The optical property study indicates that the reflectivity and absorbility of AgInS 2 are improved after the silver atom and the indium atom are replaced respectively by the zinc atoms. [ABSTRACT FROM AUTHOR]

Two series of regioisomeric luminophores that contained a dithieno[2,3- a:3′,2′- c]phenazine (DTP) unit as an electron acceptor have been designed and synthesized. To investigate the effect of substitution pattern on the optoelectronic properties of these luminophores, electron donors ( N, N-dihexylaniline or N, N-dihexyl-4-vinylaniline) were incorporated at the 2,5-, 8,11-, and 9,10-positions of the DTP unit. We found that the optoelectronic properties of the regioisomeric luminophores were greatly affected by the substitution pattern: functionalization at the 8,11-positions of the DTP unit was superior to the other two substitution patterns in extending the effective π-conjugation and strengthening the intramolecular charge-transfer interactions. Moreover, the insertion of vinyl groups between the DTP and N, N-dihexylaniline units narrowed the energy band-gap for isomers 4 and 5. However, hypsochromically shifted absorption and photoluminescence maxima were observed for isomeric luminophore 6, in which electron donors were substituted at the 2,5-positions of the DTP unit. These results should facilitate greater understanding of the structure-property relationships in regioisomeric semiconductors and present a new way to design optoelectronic materials with effective substitution patterns. [ABSTRACT FROM AUTHOR]

• The graphene/GaP heterostructure is dominated by vdW interaction. • The equilibrium interlayer spacing is 3.40 Å and the binding energy is −39.35 meV. • A tiny bandgap of 20 meV has opened at the Dirac point. • The interlayer distance and biaxial strain may change the contact mode. • A conversion from p-type Schottky to p-type Ohmic contact is present. Establishing the desired heterostructures by assembling suitable semiconductor materials has shown significant potential for applications in next-generation micro-nano electronic devices. In this present contribution, we demonstrate the geometric structure and electronic properties of graphene/GaP heterostructure by first-principles calculations. It is found that the heterostructure is characterized by weak interlayer coupling accompanying the stable layer spacing of 3.40 Å and binding energy of −39.35 meV, meaning that the interlayer is dominated by van der Waals (vdW) force. The electronic band structure of free-standing graphene and GaP monolayers are preserved well. Meanwhile, a tiny bandgap of approximatively 20 meV at the Dirac point of graphene is opened, which is attributed to the breakdown of sublattice symmetry. In the ground state, the Schottky contact of p -type is present with the n -type and p -type SBH of 1.71 eV and 0.10 eV, respectively, which can be effectively induced by imposing interlayer coupling as well as in-plane strains. Especially, the transition of p -Schottky contact to p -Ohmic contact occurs when the layer spacing decreases to 3.20 Å or the strain increases to +2 %. These theoretical results may offer potential guiding principle in future electronic devices. [ABSTRACT FROM AUTHOR]

The electronic structure and photocatalytic properties of two-dimensional GaSe/MoS 2 heterostructure are systematically studied by first-principles calculation. It is found that it could be used as a potential visible light catalyst to decompose water into H 2 and O 2. The lattice mismatch rate is 3.55%, and the binding energy was −0.446 eV, indicating that it has a stable configuration. An indirect band gap of 2.255 eV with hybrid HSE06 functional is observed, which falls into a wide range of visible light absorption. It exhibits II-type band alignment and this can promote the spatial separation of photogenerated carriers. In addition, the band edge spans the redox potential of water, indicating that heterostructure can produce hydrogen by photocatalytic decomposition H 2 O. The electrons transfer from GaSe to MoS 2 layer, while the holes do the opposite, thus improving the photocatalytic efficiency. Therefore, GaSe/MoS 2 heterostructure has broad application prospects in photocatalysis. • The GaSe/MoS 2 heterostructure is a very promising photocatalyst. • Work function of a material plays a momentous role in the band alignments. • The density of state can show the mechanism behind the orbital reconfiguration. • Semiconductor photocatalysis is considered as an ideal way to convert solar energy into chemical energy. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are performed to clarify the shear mechanical property of β -Si 3 N 4 nano-thin layer in the basal plane with different extreme strain rates and loading temperatures. The thin layer displays nonlinear and linear response stress–strain relationships, and fracture stresses and strains increase gradually with increasing the strain rates, which is attributed to the appearance of a great quantity of single nitrogen atom and “turtle-like” hexagon defects. With increasing loading temperature, there is a noticeable drop in both fracture stress and fracture strain. In the higher loading temperature range, the lower fracture stresses are obtained owing to the disappearance of defects mentioned above, which can be also elaborated by a combination of factors such as the appeared N 6h –Si bond breaking alone in configuration evolution and the accompanied lower total energy. [ABSTRACT FROM AUTHOR]

Objective: To determine the effect of aspirin and low-molecular-weight heparin (LMWH) for women affected by recurrent spontaneous abortion (RSA).Methods: The present prospective observational study included women with RSA (≥ 2 previous spontaneous abortions) and those without a history of RSA attending Ren Ji Hospital, Shanghai, China, between March 2011 and March 2014. D-dimer levels, auto-antibodies, and platelet aggregation in response to arachidonic acid (AA) and adenosine diphosphate (ADP) were monitored before pregnancy. Women with unexplained RSA and increased platelet aggregation received low-dose aspirin, and those with elevated D-dimer levels (> 0.75 μg/mL) received LMWH. Platelet aggregation in response to AA and ADP, and D-dimer levels were monitored during pregnancy.Results: Among 517 participants with RSA, 325 had unexplained RSA. Compared with 63 control patients, those with unexplained RSA and two, three, four, or at least five previous spontaneous abortions had increased platelet aggregation in response to AA (P < 0.05 for all comparisons) but not to ADP. Among 37 women with unexplained RSA who became pregnant, aspirin reduced platelet aggregation in response to AA (P < 0.001). LMWH reduced D-dimer levels during pregnancy (P < 0.001). Among 37 women with unexplained RSA who became pregnant and completed the study, 33 (89.2%) had a live birth.Conclusion: Aspirin and LMWH maintained a lower thrombotic state and led to a high live birth rate among patients with unexplained RSA. [ABSTRACT FROM AUTHOR]

This article first examines the reasons behind the initial emergence of the securities market in post-Mao China. It then provides a narrative of the rapid development of the market, which is followed by an examination of the features of Chinese securities and futures regulation. The aim of analysis here is to highlight some specific features of the Chinese securities market and its regulation and thus, to shed light on the potential for corruption in the present system as a result of the dual-system scheme - capitalist practice within a socialist setting without an effective regulatory framework that also incorporates checks and balances. [ABSTRACT FROM AUTHOR]