Enhanced cycle performance of Li/S battery with the reduced graphene oxide/activated carbon functional interlayer

The high-energy lithium/sulfur(Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 m Ah/g. However, the polysulfide shuttle effect remains of great concern with a great number of publications dedicated to its mitigation. In this contribution, a three-dimensional(3D) reduced graphene oxide/activated carbon(RGO/AC) film, synthesized by a simple hydrothermal method and convenient mechanical pressing, is sandwiched between the separator and the sulfur-based cathode, acting as a functional interlayer to capture and trap polysulfide species. Consequently, the Li/S cell with this interlayer shows an impressive initial discharge capacity of 1078 m Ah/g and a reversible capacity of 655 m Ah/g even after 100 cycles. The RGO/AC interlayer impedes the movement of polysulfide while providing unimpeded channels for lithium ion mass transfer. Therefore, the RGO/AC interlayer with a well-designed structure represents strong potential for high-performance Li/S batteries.

Alkyl group functionalization-induced phonon thermal conductivity attenuation in graphene nanoribbons

We calculated the room-temperature phonon thermal conductivity and phonon spectrum of alkyl group-functionalized zigzag graphene nanoribbons(ZGNRs) with molecular dynamics simulations. The increase in both chain length and concentration of alkyl groups caused remarkable reduction of phonon thermal conductivity in functionalized ZGNRs. Phonon spectra analysis showed that functionalization of ZGNR with alkyl functional groups induced phonon–structural defect scattering, thus leading to the reduction of phonon thermal conductivity of ZGNR. Our study showed that surface functionalization is an effective routine to tune the phonon thermal conductivity of GNRs, which is useful in graphene thermal-related applications.

Lamin A/C Modulate Apoptosis of Rat Vascular Smooth Muscle Cells During Cyclic Stretch Application

Objective The apoptosis of vascular smooth muscle cells(VSMCs)influenced by abnormal cyclic stretch is crucial for vascular remodeling during hypertension.We explored that the causes of mechano-responsive lamin A/C changingin aonormai cyclic stretcn and its roles in VSMC apoptosis.Methods and results Our previous vascular proteomics study revealed that LaminA/C is mechano-sensitive molecule.When VSMCs are subjected to cyclic stretch,the expression of LaminA/C is significantly changed which participates dysfunctions of VSMCs during hypertension.However,the molecular mechanism involved in regulation of LaminA/C expression and the role of LaminA/C in the VSMC apoptosis during cyclic stretch application are still unclear.In the present study,VSMCs were subjected to different amplitudes of cyclic steetch in vitro:5%cyclic stretch(physiological strain)or 15%cyclic stretch(pathological strain).The expression of 2 different selective cleavage isomers of LaminA/C,i.e.LaminA and LaminC,and the apoptosis of VSMCs were detected.The results showed that compared with 5%group,15%cyclic stretch significantly decreased the expression of LaminA and LaminC,and promoted the apoptosis of VSMCs.Using specific small interfering RNA(siRNA)transfection which targets on LMNA the encoding gene of LaminA/C,the expression of LaminA and LaminC in VSMCs was significantly decreased,and the apoptosis was significantly increased.In order to study the molecular mechanism involved in cyclic stretch regulating the expression of LaminA/C,we focused on the microRNA(miR).Bioinformatics analysis showed that the 3’untranslated region(3’UTR)of LMNA has two potential binding sites to miR-124-3p.Double luciferase reported system revealed that both sites have binding abilities to miR-124-3p.Under static condition,miR-124-3p inhibitor significantly up-regulated the expression levels of LaminA and LaminC,while the miR-124-3p mimics significantly down-regulated them.RT-PCR results showed that 15%cyclic stretch significantly up-regulated the expression of miR-124-3p compared with 5%cyclic stretch.Furthermore,in order to study the role of changeed LaminA/C in VSMC apoptosis,LMNA-specific siRNA was transfected to repress the expression of LaminA/C in VSMCs,and Protein/DNA microarray was used to detecte the activity of transcription factors.The transcription factors whose activity were changed significantly(increase or decrease more than 2 times)were analyzed by cluster analysis and ingenurity pathway analysis(IPA).Six transcription factors associated with apoptosis were screened,in which TP53 was activated by the specific siRNA transfection and the other 5 were inavtived,including TP53,CREB1,MYC,STAT1/5/6 and JUN.Using abdominal aorta coarctation hypertensive model,the change of miR-124-3p in VSMCs was explored in vivo.A marked increase of miR-124-3p in thoracic aorta was revealed compared with the sham-operated controls,and in situ FISH revealed that this increase was mainly in the VSMCs.Conclusions The present study suggest that abnormally increased cyclic stretch(15%)up-regulates the expression of miR-124-3p in VSMCs,which subsequently targets on the 3’UTR of LMNA and decreases the expression of nuclear envelope protein LaminA/C;the repressed LaminA/C may play an important role in the apoptosis of VSMCs by regulating the activity of virious transcription factors,such as TP53,CREB1,MYC,STAT1/5/6 and JUN.The present study may provide a new insight into understanding the molecular mechanisms of vascular remodeling.

Bio-Inspired Optimal Dispatching of Wind Power Consumption Considering Multi-Time Scale Demand Response and High-Energy Load Participation

Bio-inspired computer modelling brings solutions fromthe living phenomena or biological systems to engineering domains.To overcome the obstruction problem of large-scale wind power consumption in Northwest China,this paper constructs a bio-inspired computer model.It is an optimal wind power consumption dispatching model of multi-time scale demand response that takes into account the involved high-energy load.First,the principle of wind power obstruction with the involvement of a high-energy load is examined in this work.In this step,highenergy load model with different regulation characteristics is established.Then,considering the multi-time scale characteristics of high-energy load and other demand-side resources response speed,a multi-time scale model of coordination optimization is built.An improved bio-inspired model incorporating particle swarm optimization is applied to minimize system operation and wind curtailment costs,as well as to find the most optimal energy configurationwithin the system.Lastly,we take an example of regional power grid in Gansu Province for simulation analysis.Results demonstrate that the suggested scheduling strategy can significantly enhance the wind power consumption level and minimize the system’s operational cost.

Effect of Initial Microstructure Prior to Extrusion on the Microstructure and Mechanical Properties of Extruded AZ80 Alloy with a Low Temperature and a Low Ratio

Magnesium(Mg)alloys are the lightest metal structural material for engineering applications and therefore have a wide market of applications.However,compared to steel and aluminum alloys,Mg alloys have lower mechanical properties,which greatly limits their application.Extrusion is one of the most important processing methods for Mg and its alloys.However,the effect of such a heterogeneous microstructure achieved at low temperatures on the mechanical properties is lacking investigation.In this work,commercial AZ80 alloys with different initial microstructures(as-cast and as-homogenized)were selected and extruded at a low extrusion temperature of 220℃and a low extrusion ratio of 4.The microstructure and mechanical properties of the two extruded AZ80 alloys were investigated.The results show that homogenized-extruded(HE)sample exhibits higher strength than the cast-extruded(CE)sample,which is mainly attributed to the high number density of fine dynamic precipitates and the high fraction of recrystallized ultrafine grains.Compared to the coarse compounds existing in CE sample,the fine dynamical precipitates of Mg17(Al,Zn)12form in the HE sample can effectively promote the dynamical recrystallization during extrusion,while they exhibit a similar effect on the size and orientation of the recrystallized grains.These results can facilitate the designing of high-strength wrought magnesium alloys by rational microstructure construction.

Shear properties of thawed natural permafrost by bender elements

Thawed permafrost could cause a serious stability problem for foundations and oil-wells in cold regions. A non-damage testing procedure, employing the Bender Element Method, was used for permafrost samples collected from a continuous frozen core obtained from the North Slope of Alaska, USA. The wave velocity and modulus of thawed permafrost were investigated on various isotropic confining pressure from 0 kPa to 400 kPa per 100 kPa. The received shear wave propagation was recorded, and the elastic wave theory was used to calculate shear modulus. Finally, the shear modulus affected by confining pressure, water content and dry density were analyzed and discussed, and a regression formulation of shear modulus based on the Janbu Model for thawed silty and sandy permafrost were proposed and validation.

Review and prospect of the effects of freeze-thaw on soil geotechnical properties

Freeze-thaw hazard is one of the main problems in cold regions engineering and artificial ground freezing engineering.To mitigate freeze-thaw hazards,it is essential to investigate the effects of freeze-thaw on soils engineering properties.This paper summarizes the effects of freeze-thaw on the physical and mechanical properties of soils reported in recent studies.The differences of freeze-thaw conditions between freezing shaft sinking and cold regions engineering are discussed.Based on the technological characteristics of freezing shaft sinking in deep alluvium,we further attempt to identify key research needs regarding the freeze-thaw effects on the engineering properties of deep soils.

Design and verification of a broadband highly-efficient plasmonic circulator

Circulators play a significant role in radar and microwave communication systems.This paper proposes a broadband and highly efficient plasmonic circulator,which consists of spoof surface plasmon polaritons(SSPPs)waveguides and ferrite disks to support non-reciprocal mode coupling.The simulated performance of symmetrically designed circulator shows that it has an insertion loss of roughly 0.5 dB while the isolation and return loss is more than 12 dB in the frequency range of 6.0 GHz–10.0 GHz(relative bandwidth of 50%).Equivalent circuit model has been proposed to explain the operating mechanism of the plasmonic circulator.The equivalent circuit model,numerical simulations,and experimental results are consistent with each other,which demonstrates the good performance of the proposed plasmonic circulator.

Dynamic change of agricultural energy efficiency and its influencing factors in China

In order to practice the concept of‘lucid waters and lush mountains are invaluable assets’and promote the green development of agriculture,it is necessary to improve the efficiency of agricultural energy utilization.Based on the panel data of 28 provinces from 1995 to 2018,this paper calculated China’s agricultural energy input from two categories of direct energy and indirect energy,and used EBM(Epsilon-based Measure)mixed distance function model to measure the energy efficiency of agriculture in China.The nuclear density function and spatial autocorrelation were used to analyze the dynamic evolution of agricultural energy efficiency,and the dynamic panel model was used to analyze the influencing factors of agricultural energy efficiency.The results showed that:①From 1995 to 2018,the total agricultural energy input had increased year by year in China,with an average annual growth rate of 2%.Energy input structure changed from indirect energy-based to direct energy-based.Agricultural energy efficiency showed an evolutionary trend of‘rising-stagnating-rising rapidly’in China.The agricultural energy efficiency was generally low in China,and there was a large space for improvement in agricultural energy efficiency.②From 1995 to 2018,the average annual growth rate of agricultural energy efficiency in the eastern,central and western regions was 2.7%,1.9%and 1.4%respectively.In 2018,the agricultural energy efficiency in the eastern,central and western regions was 0.81,0.71 and 0.59 respectively.The gap between regions was expanding rapidly,and the agricultural energy efficiency in the central and western regions needed to be improved.③From 1995 to 2018,the agricultural energy efficiency of each province was polarized and the absolute gap was widened.There was obvious improvement in agricultural energy efficiency in Guangdong,Shandong,Jiangxi,Jiangsu,Liaoning and Tianjin,while the agricultural energy efficiency of Xinjiang,Guizhou,Zhejiang,Shanghai,and Inner Mongolia deteriorated.④From 1995 to 2018,there was no global spatial correlation of China’s agricultural energy efficiency.However,local‘high-high’concentration gradually appeared in the eastern region since 2010.⑤The first lag of energy efficiency had a significant positive impact on agricultural energy efficiency,and agricultural energy efficiency improvement had a time lag.The level of human capital,per capita net income of farmers and the level of urbanizaton had a significant positive impact on agricultural energy efficiency.The disaster rate,the level of development of secondary and tertiary industries,and the level of opening up had a significant negative impact on agricultural energy efficiency.In the implementation of the strategy of rural revitalization,we should focus on the central and western regions,take the cultivation of professional farmers as the key,focus on improving agricultural production conditions,enhance the level of cooperation between regions,exert the leading role of the secondary and tertiary industries,and enhance the ability of agricultural disaster prevention and mitigation.

Global cold-chain related SARS-CoV-2 transmission identified by pandemic-scale phylogenomics

DEAR EDITOR,The COVID-19 pandemic caused by SARS-CoV-2 continues to pose a tremendous threat to human society. SARS-CoV-2is airborne and transmits primarily through social contact;however, whether cold chain-related transmission has occurred remains highly debated(Han & Liu, 2022;Lewis,2021;Ma et al., 2021;Mallapaty et al., 2021;Pang et al.,2020;Wu et al., 2021). Here, we present a novel method and identify two transmission routes based on lineage-specific reductions in the SARS-CoV-2 evolutionary rate.

Predicting DNA methylation status using word composition

Background: DNA methylation will influence the gene expression pattern and cause the changes of the genetic functions. Computational analysis of the methylation status for nucleotides can help to explore the underlying reasons for developing methylations. Results: We present a DNA sequence based method to analyze the methylation status of CpG dinucleotides using 5bp (5-mer) DNA fragments – named as the word composition encoding method. The prediction accuracy is 75.16% when all 5bp word compositions are used (totally 45 = 1024). Furthermore, 5-bp DNA fragments/words having the most impact on the methylation status are identified by mRMR (Maximum-Relevant-Minimum-Redundancy) feature selection method. As a result, 58 words are selected, and they are used to build a compact predictor, which achieves 77.45% prediction accuracy. When the word composition encoding method and the feature selection strategy are coupled together, the meaning of these words can be analyzed through their contribution towards the prediction. The biological evidence in the literature supports that the surrounding DNA sequence of the CpG dinucleotides will affect the methylation of the CpG dinucleotides. Conclusions: The main contribution of this paper is to find out and analyze the key DNA words taken from the neighbor-hood of the CpG dinucleotides that are inducing the DNA methylation.

Gene finding by integrating gene finders

Gene finding, the accurate annotation of genomic DNA, has become one of the central topics in biological research. Although various computational methods (gene finders) have been proposed and developed, they all have their own limitations in gene findings. In this paper, we introduce an integrating gene finder, which combines the results of several existing gene finders together, to improve the accuracy of gene finding. Four integration schemes, based on majority voting, are developed for the analysis of two datasets – the basic dataset and the testing dataset. The basic dataset consists of 1500 DNA sequences and the testing dataset consists of 103 DNA sequences. It is demonstrated that a simple integration (a simple voting for each nucleotide) can significantly improve the finding performance, and removing confusing gene finders, caused by poor performance or redundant results, is important for a further improvement of the integration. The best prediction results are obtained using weighted majority voting, aided by the mRMR (Minimum Redundancy Maximum Relevance) (Peng, 2005) method for the gene finder selection. The prediction accuracies are 84.16% and 90.06% for the basic dataset and testing dataset respectively, which are better than any individual gene finding software in our research.

Wheat morphological and biochemical responses to copper oxide nanoparticles in two soils

The widespread application of copper oxide nanoparticles(CuO NPs)in agricultural production has caused growing concerns about their impact on crops.In this study,wheat root elongation was used to evaluate the toxic effect concentrations of CuO NPs in two soils with differing properties,collected from farmlands in Guangdong(GD)and Shandong(SD)provinces,China.Plant morphological and biochemical properties were also assessed to explore the toxicity mechanism of CuO NPs on wheat seedlings.The root elongation results revealed lower toxic effect concentration values in the plants grown in GD soil than in SD soil.Furthermore,the treatment with CuO NPs at 200 mg Cu kg^(-1) significantly reduced wheat root and shoot biomass by 35.8%and 15.8%,respectively,in GD soil.Electron microscopy showed that CuO NPs deformed wheat roots and entered leaf cells,causing deformation and damaging the cell structure.The CuO NP treatments also decreased chlorophyll content,increased antioxidant enzyme activity,and increased membrane lipid peroxidation in wheat leaves.The addition of CuO NPs significantly reduced the Zn(by 17.3%)and Fe(by 26.9%)contents in the leaves of plants grown in GD and SD soils,respectively.However,the contents of Cu,Mg,and Mn were increased by 27.4%–52.5%in GD soil and by 17.9%–71.6%in SD soil.These results suggested that CuO NPs showed greater toxicity to wheat plants grown in acidic soil than in alkaline soil and that the adverse effects of CuO NP treatments on wheat seedlings were due to a combination of CuO NPs and released Cu^(2+).

研究生思政课堂参与类型及其生成机制——关系性存在理论视角

提升研究生思政课堂参与是实现立德树人根本任务的重要举措。本研究运用质性研究方法,基于关系性存在理论视角,探索研究生思政课堂参与类型及其生成机制。研究发现,知识共创和道德感召是研究生思政课堂参与的核心因素,以二者构筑起课堂参与类型划分的二维象限,研究生思政课堂参与可分为浸润型、情感型、工具型和封闭型四种类型。在课堂互动情境下,教师和学生通过联合行动将知识信息转换为意义符号,将情感符号转换为情感共鸣,在制度性评价体系的规约下共同完成研究生思政课堂情境下的关系协商。

南通市介入相关医务人员工作压力研究

目的了解介入相关医务人员工作压力现状,探索工作压力的影响因素,为提高介入相关医务人员社会心理健康及工作状态的干预措施相关研究提供参考。方法编制《介入相关医务人员工作压力现状调查问卷》,采用一般人口学资料调查表、工作压力源量表对南通市所有三级医院介入相关医务人员进行问卷调查,收集相关数据,并通过采用SPSS 24.0统计软件进行数据分析,包括独立样本t检验、方差分析以及回归分析等。结果采用Likert 5分计分法分非常同意、同意、无意见、不同意、非常不同意5个选项,分别赋予5至1分值,得分如下:南通市三级医院介入相关医务人员工作压力得分(3.78±0.806),处于偏高水平,排在前三位的是来自工作负荷得分(3.54±0.85),外部环境得分(3.45±0.87),组织管理得分(3.20±0.74),其他维度得分分别是职业前景得分(2.73±0.87),医患关系得分(2.71±0.83),工作兴趣得分(2.68±0.68),人际关系得分(2.04±0.85)。结论南通市介入相关医务人员工作压力较大,主要压力源来自工作负荷、外部环境和组织管理方面的压力。36~40岁的介入相关医务人员工作压力要高于其他年龄组,男性高于女性,减轻工作压力,提高心理健康水平,有助于减少介入相关医务人员的职业倦怠。

Fine-tuning of pore-space-partitioned metal-organic frameworks for efficient C_(2)H_(2)/C_(2)H_(4) and C_(2)H_(2)/CO_(2) separation

Acetylene (C_(2)H_(2)) and ethylene (C_(2)H_(4)) both are important chemical raw materials and energy fuel gasses.But the effective removement of trace C_(2)H_(2)from C_(2)H_(4)and the purification of C_(2)H_(2)from carbon dioxide(CO_(2)) are particularly challenging in the petrochemical industry.As a class of porous physical adsorbent,metal-organic frameworks (MOFs) have exhibited great success in separation and purification of light hydrocarbon gas.Herein,we rationally designed four novel MOFs by the strategy of pore space partition(PSP) via introducing triangular tri(pyridin-4-yl)-amine (TPA) into the 1D hexagonal channels of acs-type parent skeleton.By modulating the functional groups of linear dicarboxylate linkers for the parent skeleton,a series of isoreticular PSP-MOFs (SNNU-278-281) were successfully obtained.The synergistic effects of suitable pore size and Lewis basic functional groups make these MOFs ideal C_(2)H_(2)adsorbents.The gas adsorption experimental results show that all MOFs have excellent C_(2)H_(2)uptakes.Specially,SNNU-278demonstrates a high C_(2)H_(2)uptake of 149.7 cm3/g at 273 K and 1 atm.Meanwhile,SNNU-278-281 MOFs also show extremely great C_(2)H_(2)separation from CO_(2)and C_(2)H_(4).The optimized SNNU-281 with highdensity hydroxy groups exhibits extraordinary C_(2)H_(2)/CO_(2)and C_(2)H_(2)/C_(2)H_(4)dynamic breakthrough interval times up to 31 min/g and 17 min/g under 298 K and 1 bar.

Revisiting the false positive rate in detecting recent positive selection

There is increasing interest in studying the molecular mechanisms of recent adaptations caused by positive selection in the genomics era. Such endeavors to detect recent positive selection, however, have been severely handicapped by false positives due to the confounding impact of demography and the population structure. To reduce false positives, it is critical to conduct a functional analysis to identify the true candidate genes/mutations from those that are filtered through neutrality tests. However, the extremely high cost of such functional analysis may restrict studies within a small number of model species. In particular, when the false positive rate of neutrality tests is high, the efficiency of the functional analysis will also be very low. Therefore, although the recent improvements have been made in the （joint） inference of demography and selection, our ultimate goal, which is to understand the mechanism of adaptation generally in a wide variety of natural populations, may not be achieved using the currently available approaches. More attention should thus be spent on the development of more reliable tests that could not only free themselves from the confounding impact of demography and the population structure but also have reasonable power to detect selection.

Beyond our naked eyes

Transposable elements in bacteria are short segments of DNA-composed of hundreds to thousands of nucleotides that behave like small fairytale elfins who are always willing to relocate.Those small elements,having evolved for billions of years,are so successful that they occupy an extremely large proportion of genomes of living organisms,for example up to 50%of the human genome.