气相SiO_(2)复合水凝胶聚合物电解质用于近中性锌-空气电池

近中性锌-空气电池具有对锌负极良好的沉积/剥离相容性和对空气中二氧化碳的化学稳定性,在长循环方面展现出极高的应用前景。然而,液态电解质固有的水分挥发问题和可穿戴设备所需的柔性等需求,限制了这一体系的实际应用。本研究复合了具有高离子电导率和机械强度的聚丙烯酰胺聚合物骨架、具有丰富硅羟基的保水添加剂气相SiO_(2)和对二氧化碳稳定的近中性电解液,制备了气相SiO_(2)复合水凝胶聚合物电解质(SiO_(2)-HPE)。所合成的SiO_(2)-HPE聚合程度高,表面孔道丰富且元素分布均匀。SiO_(2)表面丰富的硅羟基通过改变HPE中的氢键网络,加强了对水分子的束缚,SiO_(2)-HPE因此展现出了良好的保水性、优异的机械性能和较高的离子电导率,是一种理想的柔性锌-空气电池电解质。基于SiO_(2)-HPE组装的近中性锌-空气电池,在相对湿度为30%的条件下,循环寿命可达200 h。此外,基于SiO_(2)-HPE的柔性近中性锌-空气电池器件在弯曲和剪切等特殊条件下都展现出优异的性能,并且可作为电源为不同的用电器供电,是一种极具潜力的下一代电化学储能器件。

Study on the coupling calculation method for the launch dynamics of a self-propelled artillery multibody system considering engraving process

The launch dynamics theory for multibody systems emerges as an innovative and efficacious approach for the study of launch dynamics,capable of addressing the challenges of complex modeling,diminished computational efficiency,and imprecise analyses of system dynamic responses found in the dynamics research of intricate multi-rigid-flexible body systems,such as self-propelled artillery.This advancement aims to enhance the firing accuracy and launch safety of self-propelled artillery.Recognizing the shortfall of overlooking the band engraving process in existing theories,this study introduces a novel coupling calculation methodology for the launch dynamics of a self-propelled artillery multibody system.This method leverages the ABAQUS subroutine interface VUAMP to compute the dynamic response of the projectile and barrel during the launch process of large-caliber self-propelled artillery.Additionally,it examines the changes in projectile resistance and band deformation in relation to projectile motion throughout the band engraving process.Comparative analysis of the computational outcomes with experimental data evidences that the proposed method offers a more precise depiction of the launch process of self-propelled artillery,thereby enhancing the accuracy of launch dynamics calculations for self-propelled artillery.

MiR-106a targets ATG7 to inhibit autophagy and angiogenesis after myocardial infarction

Background:Myocardial infarction(MI)is an acute condition in which the heart mus-cle dies due to the lack of blood supply.Previous research has suggested that au-tophagy and angiogenesis play vital roles in the prevention of heart failure after MI,and miR-106a is considered to be an important regulatory factor in MI.But the specific mechanism remains unknown.In this study,using cultured venous endothelial cells and a rat model of MI,we aimed to identify the potential target genes of miR-106a and discover the mechanisms of inhibiting autophagy and angiogenesis.Methods:We first explored the biological functions of miR-106a on autophagy and angiogenesis on endothelial cells.Then we identified ATG7,which was the down-stream target gene of miR-106a.The expression of miR-106a and ATG7 was investi-gated in the rat model of MI.Results:We found that miR-106a inhibits the proliferation,cell cycle,autophagy and angiogenesis,but promoted the apoptosis of vein endothelial cells.Moreover,ATG7 was identified as the target of miR-106a,and ATG7 rescued the inhibition of autophagy and angiogenesis by miR-106a.The expression of miR-106a in the rat model of MI was decreased but the expression of ATG7 was increased in the infarction areas.Conclusion:Our results indicate that miR-106a may inhibit autophagy and angiogenesis by targeting ATG7.This mechanism may be a potential therapeutic treatment for MI.

Learning to represent 2D human face with mathematical model

How to represent a human face pattern?While it is presented in a continuous way in human visual system,computers often store and process it in a discrete manner with 2D arrays of pixels.The authors attempt to learn a continuous surface representation for face image with explicit function.First,an explicit model(EmFace)for human face representation is pro-posed in the form of a finite sum of mathematical terms,where each term is an analytic function element.Further,to estimate the unknown parameters of EmFace,a novel neural network,EmNet,is designed with an encoder-decoder structure and trained from massive face images,where the encoder is defined by a deep convolutional neural network and the decoder is an explicit mathematical expression of EmFace.The authors demonstrate that our EmFace represents face image more accurate than the comparison method,with an average mean square error of 0.000888,0.000936,0.000953 on LFW,IARPA Janus Benchmark-B,and IJB-C datasets.Visualisation results show that,EmFace has a higher representation performance on faces with various expressions,postures,and other factors.Furthermore,EmFace achieves reasonable performance on several face image processing tasks,including face image restoration,denoising,and transformation.

Two-fold symmetry of the in-plane resistance in kagome superconductor Cs(V_(1-x)Ta_(x))_(3)Sb_(5) with enhanced superconductivity

The kagome superconductor CsV_(3)Sb_(5) has attracted widespread attention due to its rich correlated electron states including superconductivity, charge density wave(CDW), nematicity, and pair density wave. Notably, the modulation of the intertwined electronic orders by the chemical doping is significant to illuminate the cooperation/competition between multiple phases in kagome superconductors. In this study, we have synthesized a series of tantalum-substituted Cs(V_(1-x)Ta_(x))_(3)Sb_(5) by a modified self-flux method. Electrical transport measurements reveal that CDW is suppressed gradually and becomes undetectable as the doping content of x is over 0.07. Concurrently, the superconductivity is enhanced monotonically from T_(c) ~ 2.8 K at x = 0 to 5.2 K at x = 0.12. Intriguingly, in the absence of CDW, Cs(V_(1-x)Ta_(x))_(3)Sb_(5)(x = 0.12) crystals exhibit a pronounced two-fold symmetry of the in-plane angular-dependent magnetoresistance(AMR) in the superconducting state, indicating the anisotropic superconducting properties in the Cs(V_(1-x)Ta_(x))_(3)Sb_(5). Our findings demonstrate that Cs(V_(1-x)Ta_(x))_(3)Sb_(5) with the non-trivial band topology is an excellent platform to explore the superconductivity mechanism and intertwined electronic orders in quantum materials.

Ag nanoparticles deposited on oxygen-vacancy-containing BiVO_4 for enhanced near-infrared photocatalytic activity

This study investigates the photodegradation of the organic dye rhodamine B by Ag‐nanoparticlecontaining BiVO4catalysts under different irradiation conditions.The catalysts consist of Ag nanoparticles deposited on oxygen‐vacancy‐containing BiVO4.The morphology of the BiVO4is olive shaped,and it has a uniform size distribution.The BiVO4possesses a high oxygen vacancy density,and the resulting Ag nanoparticle‐BiVO4catalyst exhibits higher photocatalytic activity than BiVO4.The RhB degradation by the Ag nanoparticle‐BiVO4catalyst is99%after100min of simulated solar irradiation.BiVO4containing oxygen vacancies as a rationally designed support extends the catalyst response into the near‐infrared region,and facilitates the trapping and transfer of plasmonic hot electrons.The enhanced photocatalytic efficiency is attributed to charge transfer from the BiVO4to Ag nanoparticles,and surface plasmon resonance of the Ag nanoparticles.These insights into electron‐hole separation and charge transfer may arouse interest in solar‐driven wastewater treatment and water splitting.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Ultrafast Quasiparticle Dynamics and Electron-Phonon Coupling in(Li0.84Fe0.16)OHFe0.98Se

Distinctive superconducting behaviors between bulk and monolayer FeSe make it challenging to obtain a unified picture of all FeSe-based superconductors.We investigate the ultrafast quasiparticle(QP)dynamics of an intercalated superconductor(Li1-xFex)OHFe1-ySe,which is a bulk crystal but shares a similar electronic structure with single-layer FeSe on SrTiO3.We obtain the electron-phonon coupling(EPC)constant(0.22±0.04),which well bridges that of bulk FeSe crystal and single-layer FeSe on SrTiO3.Significantly,we find that such a positive correlation betweenλA1 g and superconducting Tc holds among all known FeSe-based superconductors,even in line with reported FeAs-based superconductors.Our observation indicates possible universal role of EPC in the superconductivity of all known categories of iron-based superconductors,which is a critical step towards achieving a unified superconducting mechanism for all iron-based superconductors.

In-package cold plasma treatment of braised chicken: voltage effect

This study investigated the effect of different dielectric barrier discharge cold plasma(DBD-CP) treatment voltages on the microbiological growth and quality characteristics of braised chicken during storage at(4 ± 1) ℃. Argon-packed samples were subjected to DBD-CP treatment for 3 min at voltages of 50, 60 and 70 k V. As a result, there was no significant(P > 0.05) difference in L*, a*, b* and p H of braised chicken between control and treatment groups at the same storage time. However, the development of lipid oxidation in DBD-CP treatment samples was slower than that in air-packed samples. Compared to air-packed samples, the reduction of total viable count, yeasts and molds, lactic acid bacteria and Pseudomonads spp. in 70 k V treated samples on day 15 were 3.21, 2.41, 2.44 and 1.96 lg(CFU/g), respectively. The results indicate that DBD-CP treatment could extend the shelf life of braised chicken without negative impacts on quality characteristics.

NaTiSi2O6复合材料用于锂离子电池负极材料

在本文中,我们首次报道了一种新型的硅酸盐负极材料NaTiSi2O6,由溶胶-凝胶法和固相烧结法合成而得。这种材料属于单斜晶系,空间群为C2/c。通过葡萄糖的高温裂解和碳化,NaTiSi2O6/C复合物被成功制备出来,其表面积为132 m^2·g^-1。在0.1 A·g^-1的电流密度下其首圈放电和充电的比容量分别为542.9 m Ah·g^-1和266.6 m Ah·g^-1,首圈库伦效率为49.1%。在经过100圈循环后,其充电比容量为224.1 m Ah·g^-1,容量保持率为84.1%。原位X射线衍射测试表明,其充放电机理为嵌入反应。这使得NaTiSi2O6成为硅酸盐负极材料家族中新的一员。

Effects of oxidation and precursors(lysine,glyoxal and Schiff base)on the formation of Nε-carboxymethyl-lysine in aged,stored and thermally treated chicken meat

Advanced glycation end products(AGEs)might pose health risks,and processing and storage could accelerate the generation of AGEs in meat.However,limited few reports indicated the changes of AGEs contents in meat during storage.In this study,the aim is to investigate the oxidation and precursors and their roles in the formation of N^(ε)-carboxymethyl-lysine(CML)in raw and cooked chicken meat after post-mortem ageing and storage.As post-mortem ageing and storage time increased,the CML content in cooked chicken breast significantly increased from 1.81 mg/kg to 2.00 mg/kg during 0-6 h,and then decreased from 2.00 mg/kg to 1.80 mg/kg during 6 h-1 day,finally increased again during 1-7 days,while the CML contents of raw and cooked leg significantly and continuously increased from 1.78 mg/kg to 2.08 mg/kg.Furthermore,CML was extremely positively correlated with fat oxidation(R^(2)=0.793,P<0.01),protein oxidation(R^(2)=0.917,P<0.01)and glyoxal(R^(2)=0.678,P<0.05),and was negatively correlated with lysine(R^(2)=0.536,P<0.05).No significant correlation was observed between the Schiff base and CML.

Formation of advanced glycation end products in raw and subsequently boiled broiler muscle:biological variation and effects of postmortem ageing and storage

The study aimed to investigate and compare the contents of carboxymethyllysine(CML)in two kinds of broilers during postmortem ageing and storage.The contents of CML in raw and boiled(100℃,30 min)broiler briskets and legs which were from white feather broilers(n=8)and yellow feather broilers(n=8)with ageing and storage at 4℃for 0-168 h were determined.Postmortem ageing and storage had a significant(P<0.05)effect on the color and A;in both boiled broilers meat.In addition,with the ageing and storage time increasing,CML content in raw white feather broiler brisket meat had no significant(P>0.05)change,while that in boiled brisket meat significantly(P<0.05)increased during 0-6 h,then decreased during 6-24 h,finally increased again.CML content in leg meat increased significantly(P<0.05)with the ageing and storage time prolonging.But postmortem ageing and storage had no significant(P>0.05)effect on the CML contents in raw/boiled yellow feather broilers.Meanwhile,CML contents in white feather broilers were much higher than that in yellow feather broilers.Thus,white feather broilers can be selected as the research object to study the mechanism of ageing and storage on CML content in the postmortem broiler in the future.

Quasi-Two-Dimensional Nature of High-Tc Superconductivity in Iron-Based(Li,Fe)OHFeSe

The intercalated iron selenide(Li,Fe)OHFeSe has a strongly layered structure analogous to the quasi-twodimensional(2D)bismuth cuprate superconductors,and exhibits both high-temperature(Tc)and topological superconductivity.However,the issue of its superconductivity dimensionality has not yet been fully investigated so far.Here we report that the quasi-2D superconductivity features,including the high anisotropyγ=151 and the associated quasi-2D vortices,are also revealed for(Li,Fe)OHFeSe,based on systematic experiments of the electrical transport and magnetization and model fittings.Thus,we establish a new vortex phase diagram for(Li,Fe)OHFeSe,which delineates an emergent quasi-2D vortex-liquid state,and a subsequent vortex-solid dimensional crossover from a pancake-like to a three-dimensional state with decreasing temperature and magnetic field.Furthermore,we find that all the quasi-2D characteristics revealed here for the high-Tciron selenide superconductor are very similar to those reported for high-Tcbismuth cuprate superconductors.

Unusual Normal and Superconducting State Properties Observed in Hydrothermal Fe_(1-δ)Se Flakes

The electronic and superconducting properties of Fe_(1-δ)Se single-crystal flakes grown hydrothermally are studied by the transport measurements under zero and high magnetic fields up to 38.5 T.The results contrast sharply with those previously reported for nematically ordered Fe Se by chemical-vapor-transport(CVT)growth.No signature of the electronic nematicity,but an evident metal-to-nonmetal crossover with increasing temperature,is detected in the normal state of the present hydrothermal samples.Interestingly,a higher superconducting critical temperature T_c of 13.2 K is observed compared to a suppressed T_c of 9 K in the presence of the nematicity in the CVT Fe Se.Moreover,the upper critical field in the zero-temperature limit is found to be isotropic with respect to the field direction and to reach a higher value of-42 T,which breaks the Pauli limit by a factor of 1.8.

Electronic Phase Separation in Iron Selenide(Li,Fe)OHFeSe Superconductor System

The phenomenon of phase separation into antiferromagnetic（AFM） and superconducting（SC） or normal-state regions has great implication for the origin of high-temperature（high-T_c） superconductivity. However, the occurrence of an intrinsic antiferromagnetism above the T_c of（Li,Fe）OHFe Se superconductor is questioned. Here we report a systematic study on a series of（Li,Fe）OHFe Se single crystal samples with T_c up to ～41 K. We observe an evident drop in the static magnetization at T_（afm） ～ 125 K, in some of the SC（T_c 38 K, cell parameter c■9.27 ？） and non-SC samples. We verify that this AFM signal is intrinsic to（Li,Fe）OHFe Se. Thus, our observations indicate mesoscopic-to-macroscopic coexistence of an AFM state with the normal（below T_（afm）） or SC（below T_c） state in（Li,Fe）OHFe Se. We explain such coexistence by electronic phase separation, similar to that in high-T_c cuprates and iron arsenides. However, such an AFM signal can be absent in some other samples of（Li,Fe）OHFe Se, particularly it is never observed in the SC samples of T_c 38 K, owing to a spatial scale of the phase separation too small for the macroscopic magnetic probe. For this case, we propose a microscopic electronic phase separation. The occurrence of two-dimensional AFM spin fluctuations below nearly the same temperature as T_（afm）, reported previously for a（Li,Fe）OHFe Se（T_c ～ 42 K） single crystal, suggests that the microscopic static phase separation reaches vanishing point in high T_c（Li,Fe）OHFe Se. A complete phase diagram is thus established. Our study provides key information of the underlying physics for high-T_c superconductivity.

Doping effects of transition metals on the superconductivity of (Li,Fe)OHFeSe films

The doping effects of transition metals(TMs = Mn, Co, Ni, and Cu) on the superconducting critical parameters are investigated in the films of iron selenide(Li,Fe)OHFe Se. The samples are grown via a matrix-assisted hydrothermal epitaxy method. Among the TMs, the elements of Mn and Co adjacent to Fe are observed to be incorporated into the crystal lattice more easily. It is suggested that the doped TMs mainly occupy the iron sites of the intercalated(Li,Fe)OH layers rather than those of the superconducting Fe Se layers. We find that the critical current density J_(c) can be enhanced much more strongly by the Mn dopant than the other TMs, while the critical temperature T_(c) is weakly affected by the TM doping.

Anisotropic Superconducting Properties of Kagome Metal CsV_3Sb_5

We systematically measure the superconducting(SC)and mixed state properties of high-quality CsV_3 Sb_5 single crystals with T_c-3.5 K.We find that the upper critical field H_(c2)(T)exhibits a large anisotropic ratio of H_(c2)^(ab)/H_(c2)^c^9 at zero temperature and fitting its temperature dependence requires a minimum two-band effective model.Moreover,the ratio of the lower critical field,H_(c1)^(ab)/H_(c1)^c,is also found to be larger than 1,which indicates that the in-plane energy dispersion is strongly renormalized near Fermi energy.Both H_(c1)(T)and SC diamagnetic signal are found to change little initially below T_c-3.5 K and then to increase abruptly upon cooling to a characteristic temperature of-2.8 K.Furthermore,we identify a two-fold anisotropy of in-plane angular-dependent magnetoresistance in the mixed state.Interestingly,we find that,below the same characteristic T-2.8 K,the orientation of this two-fold anisotropy displays a peculiar twist by an angle of 60°characteristic of the Kagome geometry.Our results suggest an intriguing superconducting state emerging in the complex environment of Kagome lattice,which,at least,is partially driven by electron-electron correlation.

Magnetic-Field-Induced Spin Nematicity in FeSe_(1-x)S_(x)and FeSe_(1-y)Te_(y)Superconductor Systems

The angular-dependent magnetoresistance(AMR)of the ab plane is measured on the single crystals of ironchalcogenide FeSe_(1-x)S_(x)(x=0,0.07,0.13 and 1)and FeSe_(1-y)Te_(y)(y=0.06,0.61 and 1)at various temperatures under fields up to 9 T.A pronounced twofold-anisotropic carrier-scattering effect is identified by AMR,and attributed to a magnetic-field-induced spin nematicity that emerges from the tetragonal normal-state regime below a characteristic temperature Tsn.This magnetically polarized spin nematicity is found to be ubiquitous in the isoelectronic FeSe_(1-x)S_(x)and FeSe_(1-y)Te_(y)systems,no matter whether the sample shows an electronic nematic order at T_(s)≤T_(sn),or an antiferromagnetic order at TN<T_(sn),or neither order.Importantly,we find that the induced spin nematicity shows a very different response to sulfur substitution from the spontaneous electronic nematicity:The spin-nematic T_(sn)is not suppressed but even enhanced by the substitution,whereas the electronicnematic T_(s)is rapidly suppressed,in the FeSe_(1-x)S_(x)system.Furthermore,we find that the superconductivity is significantly suppressed with the enhancement of the induced spin nematicity in both FeSe_(1-x)S_(x)and FeSe_(1-y)Te_(y)samples.

A density-wave-like transition in the polycrystalline V_(3)Sb_(2) sample with bilayer kagome lattice

Recently,transition-metal-based kagome metals have aroused much research interest as a novel platform to explore exotic topological quantum phenomena.Here we report on the synthesis,structure,and physical properties of a bilayer kagome lattice compound V_(3)Sb_(2).The polycrystalline V_(3)Sb_(2) samples were synthesized by conventional solid-state-reaction method in a sealed quartz tube at temperatures below 850℃.Measurements of magnetic susceptibility and resistivity revealed consistently a density-wave-like transition at Tdw≈160 K with a large thermal hysteresis,even though some sample-dependent behaviors were observed presumably due to the different preparation conditions.Upon cooling through Tdw,no strong anomaly in lattice parameters and no indication of symmetry lowering were detected in powder x-ray diffraction measurements.This transition can be suppressed completely by applying hydrostatic pressures of about 1.8 GPa,around which no sign of superconductivity was observed down to 1.5 K.Specific-heat measurements revealed a relatively large Sommerfeld coefficientγ=18.5 mJ·mol^(-1)·K^(-2),confirming the metallic ground state with moderate electronic correlations.Density functional theory calculations indicate that V_(3)Sb_(2) shows a non-trivial topological crystalline property.Thus,our study makes V_(3)Sb_(2) a new candidate of metallic kagome compound to study the interplay between density-wave-order,nontrivial band topology,and possible superconductivity.

Different behavior of upper critical field in Fe1-xSe single crystals

The temperature dependences of upper critical field(Hc2) for a series of iron-deficient Fe1-xSe single crystals are obtained from the measurements of in-plane resistivity in magnetic fields up to 9 T and perpendicular to the ab plane. For the samples with lower superconducting transition temperature Tc(< 7.2 K), the temperature dependence of Hc2 is appropriately described by an effective two-band model. For the samples with higher Tc( 7.2 K), the temperature dependence can also be fitted by a single-band Werthamer–Helfand–Hohenberg formula, besides the two-band model. Such a Tc-dependent change in Hc2(T) behavior is discussed in connection with recent related experimental results, showing an inherent link between the changes of intrinsic superconducting and normal state properties in the Fe Se system.

Hydrothermally Obtaining Superconductor Single Crystal of FeSe_(0.2)Te_(0.8)without Interstitial Fe

We report a hydrothermal route to remove interstitial excess Fe in non-superconducting iron chalcogenide Fe_(1+δ)Se_(1-x)Te_(x) single crystals.The extra-Fe-free(δ~0)FeSe_(0.2)Te_(0.8) single crystal thus obtained shows bulk superconductivity at T_c~13.8 K,which is about 2 K higher than the FeSe_(0.2)Te_(0.8) sample obtained by usual postannealing process.The upper critical fieldμ_0H_(c2) is estimated to be~42.5 T,similar to the annealed FeSe_(0.2)Te_(0.8).It is surprising to find that the hydrothermal FeSe_(0.2)Te_(0.8)exhibits a remarkably small isothermal magnetization hysteresis loop at T=3 K.This yields an extremely low critical current density J_(c)~1.1×10^(2)A·cm^(-2)(over 100times smaller than the annealed FeSe_(0.2)Te_(0.8)) and indicates more free vortices in the hydrothermal FeSe_(0.2)Te_(0.8).