Construction of strong built-in electric field in binary metal sulfide heterojunction to propel high-loading lithium-sulfur batteries

The practical application of lithium-sulfur(Li-S)batteries is greatly hindered by soluble polysulfides shuttling and sluggish sulfur redox kinetics.Rational design of multifunctional hybrid materials with superior electronic conductivity and high electrocatalytic activity,e.g.,heterostructures,is a promising strategy to solve the above obstacles.Herein,a binary metal sulfide MnS-MoS_(2) heterojunction electrocatalyst is first designed for the construction of high-sulfur-loaded and durable Li-S batteries.The MnS-MoS_(2) p-n heterojunction shows a unique structure of MoS_(2) nanosheets decorated with ample MnS nanodots,which contributes to the formation of a strong built-in electric field at the two-phase interface.The MnS-MoS_(2) hybrid host shows strong soluble polysulfide affinity,enhanced electronic conductivity,and exceptional catalytic effect on sulfur reduction.Benefiting from the synergistic effect,the as-derived S/MnS-MoS_(2) cathode delivers a superb rate capability(643 m A h g^(-1)at 6 C)and a durable cyclability(0.048%decay per cycle over 1000 cycles).More impressively,an areal capacity of 9.9 m A h cm^(-2)can be achieved even under an extremely high sulfur loading of 14.7 mg cm^(-2)and a low electrolyte to sulfur ratio of 2.9μL mg^(-1).This work provides an in-depth understanding of the interfacial catalytic effect of binary metal compound heterojunctions on sulfur reaction kinetics.

Mixing of miscible shear-thinning fluids in a lid-driven cavity

The concentration and velocity fields of two refractive index matched miscible shear-thinning fluids in a lid-driven cavity were investigated by using planar laser-induced fluorescence and particle image velocimetry,as well by computational fluid dynamics.Quantitative analyses show that the results obtained by flow simulations with the species transport model are in good agreement with the experimental results.The effects of different parameters were studied by using the intensity of segregation.For two fluids with the same rheological parameters,the relative amounts of liquids H_(1)/H and the power-law index n dominate the mixing process while the Reynolds number Re plays a marginal role.As for two fluids with density difference,buoyancy has significant influence on the mixing process.The dimensionless group Ar/Re(redefined such as to include shear thinning behavior)is proposed for assessing the effect of buoyancy and rheological properties on the mixing of miscible shear-thinning fluids.

Comparison in structure and predicted function of epiphytic bacteria on Neopyropia yezoensis and Neopyropia katadae

The economic alga Neopyropia,which holds significant value in China for its edibility and economic potential,harbors diverse epiphytic bacteria on its surface.The epiphytic bacteria on Neopyropia yezoensis and Neopyropia katadae,two nori species of Neopyropia living at the same tidal level but with distinct physiological states and living habits,were investigated to understand the differences between them and the effects of epiphytic bacteria on their differential characteristics.Analysis of 16S rRNA gene sequences and real-time quantitative PCR(qPCR)of thalli and seawater samples(n=24)revealed notable differences in microbial diversity and community structure between the two species.Bacteroidetes dominated the bacterial communities in association with N.yezoensis,whereas Proteobacteria were predominant in N.katadae.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt2)analysis revealed enriched genes that related to the ABC transport system,iron complex outer membrane receptor proteins,and proliferation in N.yezoensis,whereas N.katadae exhibited enrichment of genes that related to energy supply as well as cell wall and cell membrane production.The results of qPCR indicate a higher abundance of epiphytic bacteria on surface of N.yezoensis than those on surface of N.katadae.The findings indicate that differences in the living environments of N.yezoensis and N.katadae may result in distinct structural composition and abundance of epiphytic bacteria on their surfaces,thereby conferring specific biological functionalities to each microbial community,and the epiphytic bacteria may shape the living habits of hosts to some extents.This study provided a basis for understanding the close association between surface microorganisms and algal bodies,and the physiological and ecological characteristics of nori species.

Tracking gassing behavior in pouch cell by operando on-line electrochemical mass spectrometry

As the rapid development of more powerful and safer lithiumion batteries, the mechanism study of gases evolution is attacking more and more attention in recent years. Especially under overcharge/discharge and/or high-temperature working condition.

乡村振兴背景下农村剩余劳动力就业问题研究——以新川村代加工作坊为例

乡村振兴背景下解决农村剩余劳动力再就业问题有利于带动农村产业发展,对于推动乡村振兴有着积极意义。本文结合国家提出的乡村振兴战略,以乡村代加工作坊为例,以实践的角度研究农村剩余劳动力再就业问题,分析其作为拓宽农村剩余劳动力转移渠道存在哪些障碍,并在此基础上提出相关对策建议。

A Magentoelectric Coefficient Measurement System with a Free-Stress Sample Holder

With less extra stress on the testing sample, a free-stress sample holder was designed to place the sample horizontally. With the free-stress sample holder, a magnetoelectric (ME) coefficient measurement system was developed based on dynamic method. This measurement system has the hardware part and the software part, integrated by the DC magnetic field generation module, the AC magnetic field generation module, the induced ME voltage detecting module and PC software module. Then, a sample of Terfenol-D/PZT/Terfenol-D trilayer was designed and fabricated, and the relationships of its ME coefficient influenced by the DC magnetic field and the frequency of the AC magnetic field were tested using the measurement system. And the results showed that the free-stress sample holder was proven to improve the accuracy of the measurement system by less stress interference.

印记基因Igf2r和RB-1在代谢综合征不孕患者子宫内膜表达水平的研究

目的:研究印记基因Igf2r和RB-1在代谢综合征(MS)不孕患者子宫内膜的表达。方法:选择2011年7月至2011年12月因不孕症来我院生殖中心就诊的MS患者11例作为实验组,代谢正常女性15例作为对照组,收集分泌期的子宫内膜组织,采用实时定量聚合酶链反应方法(RT-PCR)测定子宫内膜组织Igf2r和RB-1的表达水平。结果:Igf2r和RB-1在MS患者和代谢正常妇女子宫内膜中均有表达,与正常女性相比较,MS患者子宫内膜Igf2r表达水平下降(P = 0.0051),RB-1表达水平升高(P = 0.0364),具有显著性差异。结论:MS不孕患者子宫内膜组织印记基因Igf2r表达水平明显下降,RB-1表达水平明显升高,两者可能影响MS患者的子宫内膜容受性。

聚硼硅氧烷基复合材料的阻尼与自修复性能

以硼酸和羟基硅油为原料制备了聚硼硅氧烷凝胶(PBS-Gel),并将PBS-Gel与聚甲基乙烯基硅橡胶(VMQ)复合,制备了一种具有自修复特性的高阻尼弹性材料。采用傅里叶变换反射红外光谱分析仪、旋转流变仪、动态力学热分析仪研究了PBS-Gel的合成温度对其阻尼性能的影响和VMQ含量对PBS-Gel/VMQ复合材料阻尼性能的影响。结果表明,PBSGel合成温度越高其阻尼性能越差,当合成温度为120℃时凝胶阻尼性能最好,最高损耗因子达2. 97,有效阻尼温域(tanδ> 0. 3)宽110℃;并将120℃合成的PBS-Gel与VMQ复合,发现当VMQ质量分数为25%时,复合材料自愈合性能与阻尼性能最好,最高损耗因子为1. 38,有效阻尼温域(tanδ> 0. 3)宽156℃,在自修复1 d后拉伸强度可恢复至72%,断裂面经喷水处理后的样品恢复率可达95%。针对复合材料的高阻尼与自修复特性,在现有研究的基础上提出了一种"次价键"断裂再愈合的新机理。

Research on Coal Seam Floor Water Inrush Monitoring Based on Perception of IoT Coupled with GIS

To the complication and uncertainty in coal seam floor water-inrush monitoring, Internet of Things (IoT) perception is applied to the monitoring and controlling of coal seam floor water inrush with major impacting factors analyzed, and an open distribution information processing platform is constructed based on IoT-GIS coupling perception. Then using the platform to comprehensively perceive various floor water inrush impacting parameters, an AHP model is established. At this stage, by means of weight reasoning algorithm based on dynamic Bayesian network, the AHP weight can be worked out using the two-way probability transfer and chain rules. Then the multiple factors are spatially fused by GIS to form a non-linear mathematical model for the calculation of the water inrush relative probability index. After that, the discrimination threshold of the comb graph for the floor water inrush relative probability index is used to further identify the floor water inrush mode. The experiments in 10# Coal Seam of Suntuan Mine show that, the accuracy perceived the floor water inrush is above 92%, and the platform of IoT-GIS coupling perception has the obvious technical advantage than traditional monitoring technology. Therefore, it has has demonstrated strong systematic robustness, important theoretical and application significance.

On microbial community of Pyropia haitanensis by metagenomic analysis

Microorganisms plays an important role in the growth of Pyropia haitanensis.To understand the structural and functional diversity of the microorganism community of P.haitanensis(PH40),the associated metabolic pathway network in cluster of orthologous groups(COG)and Kyoto Encyclopedia of Genes and Genomes(KEGG),and carbohydrate-active enzymes(CAZymes)were explored in metagenomic analysis.DNA extraction from gametophytes of P.haitanensis was performed first,followed by library construction,sequencing,preprocessing of sequencing data,taxonomy assignment,gene prediction,and functional annotation.The results show that the predominant microorganisms of P.haitanensis were bacteria(98.98%),and the phylum with the highest abundance was Proteobacteria(54.64%),followed by Bacteroidetes(37.92%).Erythrobacter(3.98%)and Hyunsoonleella jejuensis(1.56%)were the genera and species with the highest abundance of bacteria,respectively.The COG annotation demonstrated that genes associated with microbial metabolism was the predominant category.The results of metabolic pathway annotation show that the ABC transport system and two-component system were the main pathways in the microbial community.Plant growth hormone biosynthesis pathway and multi-vitamin biosynthesis functional units(modules)were the other important pathways.The CAZyme annotation revealed that the starch might be an important carbon source for microorganisms.Glycosyl transferase family 2(GT2)and glycosyl transferase family 3(GT3)were the highly abundant families in glucoside transferase superfamily.Six metagenome-assembled genomes containing enzymes involved in the biosynthesis of cobalamin(vitamin B 12)and indole-3-acetic acid were obtained by binning method.They were confirmed to belong to Rhodobacterales and Rhizobiales,respectively.Our findings provide comprehensive insights into the microorganism community of Pyropia.

Development of organelle single nucleotide polymorphism (SNP) markers and their application for the identification of cytoplasmic inheritance patterns in Pyropia yezoensis (Bangiales,Rhodophyta)

The genus Pyropia contains several important cultivated species.Genetic research in nori species has mainly focused on the cell nucleus,with few studies on organelles(chloroplast and mitochondria).Due to the high copy numbers of organelles in cells,which influence the development and traits of algae,it is necessary to study their genetic mechanism.In this study,the marine red alga Pyropia yezoensis,an important economic macroalga,was selected as the study object.To investigate organelle(chloroplast and mitochondria)inheritance in P.yezoensis,the wild type RZ(maternal strain)was crossed with the red mutant HT(paternal strain)and 30 color-sectors from 11 F1 gametophytic blades were examined.The complete chloroplast and mitochondrial genomes of the red mutant(HT)were assembled for the first time.One reliable and stable single nucleotide polymorphism(SNP)loci filtrated by bioinformatics analysis was used as a molecular marker for chloroplast and mitochondrial DNA,respectively,in subsequent experiments.PCR amplification and sequence analysis showed that the haplotypes of color-sectors detected were consistent with those of the maternal parent,confirming that both chloroplast and mitochondrial genomes were inherited maternally in P.yezoensis.The inheritance pattern of organelles in P.yezoensis can be used to guide the hybridization and breeding of nori.Additionally,the organelle SNP markers developed in this study can be applied in subsequent genetic research.

Construction of high-density genetic linkage map of Pyropia yezoensis(Bangiales,Rhodophyta)and identifi cation of red color trait QTLs in the thalli

Pyropia yezoensis is an important macroalga because of its extensive global distribution and economic importance.Color is an important trait in the thalli of P.yezoensis,it is also an effective marker to identify the hybridization in genetic breeding.In this study,a high-density genetic linkage map was constructed based on high-throughput single nucleotide polymorphism(SNP)markers,and used for analyzing the quantitative trait loci(QTLs)of red color trait in the thalli of P.yezoensis.The conchospore undergoes meiosis to develop into an ordered tetrad,and each cell has a haploid phenotype and can grow into a single individual.Based on this theory,F1 haploid population was used as the mapping population.The map included 531 SNP markers,394.57 cM long on average distance of 0.74 cM.Collinear analysis of the genetic linkage map and the physical map indicated that the coverage between the two maps was 79.42%.Furthermore,QTL mapping identified six QTLs for the chromosomal regions associated with the red color trait of the thalli.The value of phenotypic variance explained(PVE)by an individual QTL ranged from 4.71%-63.11%.And QTL qRed-1-1,with a PVE of 63.11%,was considered the major QTL.Thus,these data may provide a platform for gene and QTL fine mapping,and marker-assisted breeding in P.yezoensis in the future.

Water Changes and Sources of Siling Co Using Landsat and GRACE Data since 1972

The inland lakes on the Tibetan Plateau(TP)are undergoing significant changes due to their sensitivity to climate.The largest lake in Tibet,Siling Co,has expanded most dramatically during recent decades.Using Landsat,GRACE and meteorological data,the expansion of Siling Co was detailed in four stages and the process was further explained.The results show that the lake area increased from 1647.30 km^(2)in 1972 to 2438.99 km^(2)in 2020.It experienced a slow growth at a rate 6.03 km^(2)/yr from 1972 to 1988,while fluctuating at 1.44 km^(2)/yr during 1989–1997,then accelerated at 60.28 km^(2)/yr between 1998 and 2005,and expanded slowly again at 11.40 km^(2)/yr since 2006.The continued expansion led to its merger with nearby Yagain Co in 2003.Terrestrial water storage(TWS)increase was also observed from GRACE(0.65 cm/yr),with about 0.75 coefficient of determination between the TWS and lake area during 2002–2020.The long-term expansion of Siling Co is related to the increasing trends of temperature and precipitation,but their contributions vary with time span.Specifically,the accelerated stage between 1998 and 2005 can be explained by the increased temperature and precipitation accompanied by a drop in evaporation,while the slow expansion since 2006 was due to the decrease in precipitation and temperature and the rise in evaporation.There is no obvious mass loss of glaciers revealed by GRACE during 2002–2020,which may be related to the negative trend of the temperature.Furthermore,the precipitation may still make a major contribution in this phase,as its average is about 93.9 mm higher than that in 1988–1997.

In situ reduction strategy towards high conductivity,anti-freezing and super-stretchable rGO based hydrogel for diverse flexible electronics

Hydrogels electrolytes with flexibility and high conductivity have been widely used in kinds of flexible electronics.However,hydrogels always suffer from the inevitable freezing of water at subzero temperatures,which results in the sacrificing of their electrical properties.Herein,an anti-freezing,flexible hydrogel based on in situ reduction of graphene oxide(GO)and laponite has been developed as electrolyte for high performance supercapacitor and sensitive sensors.The crosslinked GO and laponite in polyacrylamide(PAM)resulted in an enhanced mechanical property,while the in-situ reduction of GO in the hydrogel enhanced the conductivity and diminishes the aggregated of GO.These features guarantee a reliable electro signal as sensor and a high performance of the supercapacitor.Besides,in the process of preparation of reduced graphene oxide(rGO)hydrogel,the addition of ethylene glycol(EG)and KOH,endows the hydrogel antifreeze properties.This anti-freezing electrolyte can be stretched to a strain of 1600%and maintained a specific capacitance of 37.38 F·g^(-1) at-20℃.In addition,the photothermal conversion character of rGO in the hydrogel,endows it’s the potential application in wound healing.The overall merits of the hydrogel will open up a new avenue for sensitive sensor and energy storage device in practical applications.

高分子单晶:从结晶策略到功能化应用

现代高分子科学诞生一百年以来,高分子化学、高分子物理与高分子加工发展迅速,形成了较为完整的学科体系。作为高分子物理的重要构成部分,高分子结晶学聚焦于微观结晶过程,揭示高分子链独特的运动行为。高分子晶体依据其独立结构数目分为单晶和多晶,其中高分子单晶中分子链紧密排列,形貌表现出完美的几何对称性,具备优异的力学和光电性能。但由于分子链运动的复杂性,高分子单晶的培养仍然存在很大的困难。几十年来,大量科学家致力于高分子单晶的研究,获得了丰硕成果。在本文中,我们着眼于高分子单晶研究的历史与进展,细致论述了高分子单晶的结晶策略及其功能化应用,希望能对相关研究者提供有效的帮助。

聚合物膜离子选择性电极传感新方法研究进展

传统的离子选择性电极属于电位型传感器,其检测原理基于电极敏感膜的电位响应与分析物离子的活度关系符合能斯特方程.近年来,以聚合物膜为敏感元件的离子选择性电极蓬勃发展,其换能方式已经从传统的零电流电位检测法发展到计时电位法、库仑法、安培法、离子迁移伏安法、光学法等多种传感新方法.这些新型信号输出方式的采用,提高了聚合物膜离子选择性电极的检测性能、扩大了电极的应用范围.本文综述了近年来发展的聚合物膜离子选择性电极传感新方法,重点介绍了各类分析信号的输出原理与应用,并对该领域未来的发展做出了展望.

Translation landscape of SARS-CoV-2 noncanonical subgenomic RNAs

The ongoing COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with a positive-stranded RNA genome. Current proteomic studies of SARS-CoV-2 mainly focus on the proteins encoded by its genomic RNA(gRNA) or canonical subgenomic RNAs(sgRNAs). Here, we systematically investigated the translation landscape of SARS-CoV-2, especially its noncanonical sgRNAs. We first constructed a strict pipeline, named vipep, for identifying reliable peptides derived from RNA viruses using RNA-seq and mass spectrometry data. We applied vipep to analyze 24 sets of mass spectrometry data related to SARS-CoV-2infection. In addition to known canonical proteins, we identified many noncanonical sgRNA-derived peptides,which stably increase after viral infection. Furthermore, we explored the potential functions of those proteins encoded by noncanonical sgRNAs and found that they can bind to viral RNAs and may have immunogenic activity. The generalized vipep pipeline is applicable to any RNA viruses and these results have expanded the SARSCoV-2 translation map, providing new insights for understanding the functions of SARS-CoV-2 sgRNAs.

Discrepancy in photosynthetic responses of the red alga Pyropia yezoensis to dehydration stresses under exposure to desiccation,high salinity,and high mannitol concentration

Macroalgae that inhabit intertidal zones are exposed to the air for several hours during low tide and must endure desiccation and high variations in temperature, light intensity, and salinity. Pyropia yezoensis (Rhodophyta, Bangiales), a typical intertidal red macroalga that is commercially cultivated in the northwestern Pacific Ocean, was investigated under different dehydration stresses of desiccation, high salinity, and high mannitol concentration. Using chlorophyll fluorescence imaging, photosynthetic activities of P. yezoensis thalli were analyzed using six parameters derived from quenching curves and rapid light curves. A distinct discrepancy was revealed in photosynthetic responses to different dehydration stresses. Dehydration caused by exposure to air resulted in rapid decreases in photosynthetic activities, which were always lower than two other stresses at the same water loss (WL) level. High salinity only reduced photosynthesis significantly at its maximum WL of 40% but maintained a relatively stable maximum quantum yield of photosystem II (PSII) (Fv/Fm). High mannitol concentration induced maximum WL of 20% for a longer time (60 min) than the other two treatments and caused no adverse influences on the six parameters at different WL except for a significant decrease in non-photochemical quenching (NPQ) at 20% WL. Illustrated by chlorophyll fluorescence images, severe spatial heterogeneities were induced by desiccation with lower values in the upper parts than the middle or basal parts of the thalli. The NPQ and rETRmax (maximum relative electron transport rate) demonstrated clear distinctions for evaluating photosynthetic responses, indicating their sensitivity and applicability. The findings of this study indicated that the natural dehydration of exposure to air results in stronger and more heterogeneous effects than those of high salinity or high mannitol concentration.

Remaining Useful Life Prediction for a Multi-stack Solid Oxide Fuel Cell System with Degradation Interactions

Due to the constraints of manufacturing and materials,high-power plants cannot rely on only one solid oxide fuel cell stack.A multi-stack system is a solution for a highpower system,which consists of multiple fuel cell stacks.A short lifetime is one of the main challenges for the fuel cell before largescale commercial applications,and prognostic is an important method to improve the reliability of fuel cells.Different from the traditional prognostic approaches applied to single-stack fuel cell systems,the key problem in multi-stack prediction is how to solve the correlation of multi-stack degradation,which can directly affect the accuracy of prediction.In response to this difficulty,a standard Brownian motion is added to the traditional Wiener process to model the degradation of each stack,and then the probability density function of the remaining useful life(RUL)of each stack is calculated.Furthermore,a Copula function is adopted to reflect the dependence between life distributions,so as to obtain the remaining useful life for the whole multi-stack system.1 The simulation results show that compared with the traditional prediction model,the proposed approach has a higher prediction accuracy for multi-stack fuel cell systems.

Effects of decontamination treatment combined with natural chemicals and/or ultra-high pressure on the quality and safety of ready-to-eat wine-pickled mud snails(Bullacta exarata)

Ready-to-eat wine-pickled mud snails(Bullacta exarata)typically host a large number of microorganisms and are frequently contaminated with pathogenic bacteria during processing,resulting in a higher risk for foodborne illness with consumption.In this study,the decontamination effects of different treatment methods,including the use of ultrasonic cleaning(USC),natural chemicals,and ultra-high pressure(UHP),on the quality and safety of pickled mud snails were investigated by assessing the total viable count(TVC),total volatile base nitrogen(TVB-N)content,thiobarbituric acid-reactive substance(TBARS),and pH value of the products after 12 months of storage at-20℃.Treatment with 200 W USC for 5 min was the most effective approach for reducing TVC in raw mud snails,with a minimal change in food quality.Natural chemical treatment or UHP treatment significantly inhibited the increase inTVC,pH,and TBARS and TVB-N accumulation compared with the control group;however,their combined treatment had no synergistic effect.In contrast,the combined chemical treatment was more effective in inhibiting changes in the above indices in pickled mud snails than UHP treatment alone or combined chemicals+UHP treatment.In addition,the bacterial diversity of pickled mud snails before and after 12 months of storage at-20℃was determined using lllumina MiSeq sequencing.Our results indicated that USC combined with natural chemicals can be utilized commercially to maintain the quality and safety of pickled mud snails during storage at-20℃.