Unveiling of Terahertz Emission from Ultrafast Demagnetization and the Anomalous Hall Effect in a Single Ferromagnetic Film

Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond timescale.We demonstrate that THz radiation changes its polarity with reversal of the magnetization applied by the external magnetic field.In addition,it is found that the sign of THz polarity excited from different sides is defined by the thickness of the Fe layer and Fe/dielectric interface.Based on the thickness and symmetry dependences of THz emission,we experimentally distinguish between the two major contributions:ultrafast demagnetization and the anomalous Hall effect.Our experimental results not only enrich understanding of THz electromagnetic generation induced by femtosecond laser pulses but also provide a practical way to access laser-induced ultrafast spin dynamics in magnetic structures.

Degree of shade tolerance shapes seasonality of chlorophyll, nitrogen and phosphorus levels of trees and herbs in a temperate deciduous forest

Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf traits.However,leaf structural and chemical traits variation among co-existing species,and plant functional types within the canopy are poorly quantified.In this study,the seasonality of leaf chlorophyll,nitrogen(N),and phosphorus(P)were quantified vertically along the canopy of four major tree species and two types of herbs in a temperate deciduous forest.The role of shade tolerance in shaping the seasonal variation and vertical differentiation was examined.During the entire season,chlorophyll content showed a distinct asymmetric unimodal pattern for all species,with greater chlorophyll levels in autumn than in spring,and the timing of peak chlorophyll per leaf area gradually decreased as shade tolerance increased.Chlorophyll a:b ratios gradually decreased with increasing shade tolerance.Leaf N and P contents sharply declined during leaf expansion,remained steady in the mature stage and decreased again during leaf senescence.Over the seasons,the lower canopy layer had significantly higher chlorophyll per leaf mass but not chlorophyll per leaf area than the upper canopy layer regardless of degree of shade tolerance.However,N and P per leaf area of intermediate shade-tolerant and fully shade-tolerant tree species were significantly higher in the upper canopy than in the lower.Seasonal variations in N:P ratios suggest changes in N or P limitation.These findings indicate that shade tolerance is a key feature shaping inter-specific differences in leaf chlorophyll,N,and P contents as well as their seasonality in temperate deciduous forests,which have significant implications for modeling leaf photosynthesis and ecosystem production.

Molecular investigation into the transformation of recalcitrant dissolved organic sulfur in refinery sour water during stripping process

Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD)and organic sulfur contents.Even after the recovery of H_(2)S from the sour water by the stripping process,the effluent still contains a high concentration of dissolved organic sulfur(DOS),which can have a huge bad influence.While chemical composition of dissolved organic matter(DOM)in refinery wastewater has been extensively studied,the investigation of recalcitrant DOS from sour waters remains unclear.In the present study,chemical composition of sour water DOMs(especially DOS)was investigated using fluorescence spectroscopy(excitation-emission matrix,EEM)and mass spectrometry,including gas chromatography-mass spectrometry(GC-MS)and high-resolution Orbitrap MS.The GC-MS and EEM results showed that volatile and low-aromaticity compounds were effectively removed during the stripping process,while compounds with high hydrophilicity and humification degree were found to be more recalcitrant.The Orbitrap MS results showed that weak-polar oxygenated sulfur compounds were easier to be removed than oxygenated compounds.However,the effluent still contained significant amounts of sulfur-containing compounds with multiple sulfur atoms,particularly in the form of highly unsaturated and aromatic compounds.The Orbitrap MS/MS results of CHOS-containing compounds from the effluent indicate that the sulfur atoms may exist as sulfonates,disulfide bonds,thioethers.Understanding the composition and structure of sour water DOS is crucial for the development of effective treatment processes that can target polysulfide compounds and minimize their impact on the environment.

Synergistic effects of planting density and nitrogen fertilization on chlorophyll degradation and leaf senescence after silking in maize

Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.

TPI缺乏症斑马鱼模型的构建及分析

磷酸丙糖异构酶缺乏症(triosephosphate isomerase deficiency,TPI DF)是一种严重的多系统退行性疾病,通常表现为溶血性贫血、神经肌肉功能障碍和易感染,患者多于起病5年内死亡。目前尚不清楚TPI DF的具体发病机制,缺乏有效的临床治疗方法。本研究选取TPI DF患者中最常见的突变位点TPI1^(E105D),构建了表达人源性TPI1^(E105D)(hTPI1^(E105D))的转基因斑马鱼(Danio rerio)模型[Tg(Ubi:TPI1^(E105D)-eGFP)]。功能分析表明,过表达TPI1^(E105D)影响红系及髓系细胞发育、导致神经以及肌肉发育异常。综上所述,本研究构建了磷酸丙糖异构酶缺乏症的斑马鱼疾病模型,并能够复现TPI DF患者的大部分临床表型,该模型为后续研究TPI DF的发病机制及药物筛选提供了新的实验动物模型。

Nano-Ni-Induced Electronic Modulation of MoS_(2) Nanosheets Enables Energy-Saving H_(2) Production and Sulfide Degradation

Electrocatalytic hydrogen evolution and sulfion(S^(2-))recycling are promising strategies for boosting H_(2)production and removing environmental pollutants.Here,a nano-Ni-functionalized molybdenum disulfide(MoS_(2))nanosheet was assembled on steel mesh(Ni-MoS_(2)/SM)for use in sulfide oxidation reaction-assisted,energy-saving H_(2)production.Experimental and theoretical calculation results revealed that anchoring nano-Ni on high-surface-area slack MoS_(2)nanosheets not only optimized catalyst adsorption of polysulfides but also played an important role in promoting hydrogen evolution reaction kinetics by absorbing OH_(ad),thereby greatly enhancing the catalytic performance toward sulfide oxidation reaction and hydrogen evolution reaction.Meanwhile,the Ni/MoS^(2-)based hydrogen evolution reaction+sulfide oxidation reaction system achieved nearly 100%hydrogen production efficiency and only consumed 61%less power per kWh than the oxygen evolution reaction+hydrogen evolution reaction system,which suggested our proposed Ni-MoS_(2)and novel hydrogen production system are promising for sustainable energy production.

古生代psammichnitids(砂迹类)的行为习性演化及其生物古地理迁移

Psammichnites和Dictyodora为古生代海相环境典型的弯曲带状遗迹,是由具有虹吸器官的生物所形成的遗迹化石,一般被归入到psammichnitids。通过文献资料调研和样品分析,对古生代Psammichnites和Dictyodora的形态功能对比和时空分布特征进行研究。结果表明:(1)Psammichnites通常具有短、浅的凹槽;随着时间的推移,Dictyodora的壁高却逐渐增大。(2)Psammichnites主要分布于正常浅海环境;Dictyodora大都分布于深海环境,也有个别类型分布于浅海环境。(3)Psammichnites的种级多样性在石炭纪浅海环境呈快速增加,属于晚期辐射类型,但Psammichnites gigas广泛分布于寒武纪早期,具有很好的地层指示意义;Dictyodora的种级多样性在奥陶纪快速增加,属于早期辐射类型。(4)寒武纪—奥陶纪,Psammichnites和Dictyodora主要分布于南半球中高纬度的Iapetus和Rheic大洋,其中Laurussia大陆的形成以及Iapetus和Rheic大洋的闭合对其古地理分布具有显著影响;自石炭纪开始,Psammichnites和Dictyodora均向新的空白生态位进行迁移,反映出造迹生物对于新生态位的适应和迁移均受环境变迁的强烈影响;二叠纪之后,Psammichnites和Dictyodora在地层中没有发现,可能暗示它们的造迹生物均在二叠纪末生物大灭绝事件中遭受了毁灭性打击。上述对Psammichnites和Dictyodora行为习性演化特征及其生物古地理迁移特征的系统总结和归纳,可为从精细和精深角度深入解读遗迹化石所反映的遗迹类群的演化生态学和生物古地理迁移特征提供新资料和新认识。

基于Ka波段云雷达观测的中国西天山降雨云宏微观物理特征研究

利用Ka毫米波云雷达与自动气象站降雨资料,研究了西天山地区2019年和2020年5~8月的降雨云宏微观特性。结果表明:(1)降雨主要发生在夜间,累积降雨量集中在21:00(北京时间,下同)至次日07:00,降雨频次和累积降雨量相关系数为0.71。大雨强频次虽最少,但对总累积降雨量贡献较显著。(2)小雨强、中雨强、大雨强平均反射率因子最大值分别为30 dBZ、35.8 dBZ和39.5 dBZ,最大平均液态水含量分别为1.5 g m^(-3)、4.2 g m^(-3)和7.3 g m^(-3)。(3)不同降雨强度对应的反射率因子都有两个集中区域,2.0~4.4 km反射率因子集中在15~26 dBZ,地面附近的小雨强、中雨强、大雨强对应的反射率因子分别集中在24~32 dBZ、29~38 dBZ和31~42 dBZ。1.75 km以下中雨强和大雨强液态含水量小于1gm^(-3)的频率明显少于小雨强,降雨强度的越大降雨粒子径向速度越集中。

过敏性鼻炎患者用药依从性的相关影响因素分析

目的:探讨影响过敏性鼻炎(AR)患者用药依从性的相关因素。方法:以整群抽样方式选择2020年1月-2021年10月就诊于宜春市人民医院的96例AR患者为研究对象。收集、整理患者资料,分析影响AR患者用药依从性相关因素。结果:96例AR患者中用药依从性好47例(48.96%),用药依从性差49例(51.04%);单因素分析显示,用药依从性差组年龄≥50岁、居住地农村、文化程度初中及以下、病程≥3年、药品数量≥3种比例均高于用药依从性好组(P<0.05);两组性别、医疗费用支付方式、工作状况、个人收入、病情严重程度、家族史比较,差异均无统计学意义(P>0.05);多因素分析显示,年龄≥50岁[β=1.145,OR=3.142,95%CI(1.306,7.562)]、居住地农村[β=1.021,OR=2.776,95%CI(1.129,6.825)]、文化程度初中及以下[β=1.019,OR=2.770,95%CI(1.018,7.543)]、病程≥3年[β=1.153,OR=3.168,95%CI(1.261,7.958)]、药品数量≥3种[β=0.844,OR=2.326,95%CI(1.025,5.277)]是影响AR患者用药依从性的高危因素(P<0.05)。结论:AR患者用药依从性有待提高,其受年龄、居住地、文化程度、病程、药品数量影响。

Glass-compatible and self-powered temperature alarm system by temperature-responsive organic manganese halides via backward energy transfer process

A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which has a unique temperature-dependent backward energy transfer process from selftrapped state to^(4)T_(1)energy level of Mn,is used for triggering the temperature alarm.The LSC with redemitted CsPbI_(3)perovskite-polymer composite films on the glass substrate is used for power supply.The spectrally separated nature between the green-emitted OMHs for temperature alarm and red-emitted CsPbI3in LSC for power supply allows for probing the signal light of temperature-responsive OMHs without the interference of LSCs,making it possible to calibrate the temperature visually just by a self-powered brightness detection circuit with LED indicators.Taking advantage of LSC without hot spot effects plaguing the solar cells,as-prepared temperature alarm system can operate well on both sunny and cloudy day.

Machine learning-based stiffness optimization of digital composite metamaterials with desired positive or negative Poisson's ratio

Mechanical metamaterials such as auxetic materials have attracted great interest due to their unusual properties that are dictated by their architectures.However,these architected materials usually have low stiffness because of the bending or rotation deformation mechanisms in the microstructures.In this work,a convolutional neural network(CNN)based self-learning multi-objective optimization is performed to design digital composite materials.The CNN models have undergone rigorous training using randomly generated two-phase digital composite materials,along with their corresponding Poisson's ratios and stiffness values.Then the CNN models are used for designing composite material structures with the minimum Poisson's ratio at a given volume fraction constraint.Furthermore,we have designed composite materials with optimized stiffness while exhibiting a desired Poisson's ratio(negative,zero,or positive).The optimized designs have been successfully and efficiently obtained,and their validity has been confirmed through finite element analysis results.This self-learning multi-objective optimization model offers a promising approach for achieving comprehensive multi-objective optimization.

Integrated Sensing and Communication for Future Wireless Networks

Integrated sensing and communication(ISAC)is anticipated to play a pivotal role in realizing the ability to sense,control,and optimize wireless environments,as well as providing ubiquitous connectivity with ultra-high throughput and reliability,and ultra-low latency for future wireless networks.Therefore,it can meet the requirements of mass data transmission,centimeter-level localization,and highly fine-grained environmental sensing for new applications,such as extended reality,holographic communication,autonomous driving,smart healthcare,and intelligent industry.The technology of ISAC deviates from traditional pattern of isolated design for communication and sensing.It can efficiently utilize wireless resources and potentially achieve mutual benefits by combining sensing and communication systems.The ultimate goal of the ISAC system has two aspects.On the one hand,the wireless communication system gains new functions。

Single exposure passive three-dimensional information reconstruction based on an ordinary imaging system

Existing three-dimensional(3D) imaging technologies have issues such as requiring active illumination, multiple exposures, or coding modulation. We propose a passive single 3D imaging method based on an ordinary imaging system.Using the point spread function of the imaging system to realize the non-coding measurement on the target, the full-focus images and depth information of the 3D target can be extracted from a single two-dimensional(2D) image through the compressed sensing algorithm. Simulation and experiments show that this approach can complete passive 3D imaging based on an ordinary imaging system without any coding operations. This method can achieve millimeter-level vertical resolution under single exposure conditions and has the potential for real-time dynamic 3D imaging. It improves the efficiency of 3D information detection, reduces the complexity of the imaging system, and may be of considerable value to the field of computer vision and other related applications.

Perovskite solar cells with NiO_(x) hole-transport layer

Inverted perovskite solar cells(PSCs)have attracted interest due to their simple fabrication,long-term stability,and small hysteresis[1-3].It is noteworthy that the quality of the hole-transport layer(HTL)largely determines the device performance.Nickel oxide(NiO_(x))has been paid great attention as a hole-transport material in PSCs because of its natural p-type property,low cost,good stability,and high transmittance[4,5].

硫辛酸对糖尿病肾病Ⅲ期患者PCX和VEGF的影响

目的探讨糖尿病肾病(DN)Ⅲ期患者尿足细胞标志蛋白(PCX)及血管内皮生长因子(VEGF)水平的变化及α-硫辛酸(ALA)对其的影响。方法 122例2型糖尿病患者根据24 h尿白蛋白排泄率分为单纯糖尿病组(SDM组)62例、DNⅢ期组(NA组)60例。NA组随机分为ALA治疗组(NAⅠ组30例)和常规治疗组(NAⅡ30例),另选正常对照者(NC组)60例。比较ALA治疗前及治疗2周后丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)、尿PCX及血VEGF的变化。结果 NAⅠ组经ALA治疗后MDA、UAER、PCX及VEGF较治疗前下降(P<0.05),SOD及GSH-px较治疗前上升(P<0.05)。结论 ALA可通过抗氧化应激保护DNⅢ期患者肾小球足细胞。

东天山哈密地区典型暴雨事件对流触发机制对比分析

本文选取2018年7月31日(简称“7.31”暴雨)和2016年8月8日(简称“8.8”暴雨)两次东天山哈密地区强降水天气过程,利用NCEP/NCAR的FNL资料(0.25°×0.25°)、中国地面卫星雷达三源融合逐小时降水产品、新疆地区常规观测资料、FY-2G卫星产品,通过对暴雨期间锋生函数计算诊断,证实了两次强降水过程中尺度对流系统触发因子差异,取得如下主要结果:(1)“7.31”暴雨期间,500 hPa西太平洋副热带高压位置异常偏北,700 hPa暖舌沿副高南侧偏东急流向西北伸展,低层增暖增湿,暴雨区上空形成不稳定大气层结,多个中尺度对流系统在700 hPa低空急流前生成,向东北方向移动和发展。“8.8”暴雨期间,500 hPa西太平洋副热带高压位置异常偏西,对流云团在对流层低层西南急流前生成向东北方向移动。(2)对流层低层暴雨区暖锋锋生是“7.31”暴雨中尺度对流云团的触发因子,云团初生阶段对流触发主要是锋生水平散度项和由垂直运动发展引起的倾斜项决定,成熟阶段暖锋锋生主要由锋生形变项和倾斜项所致。低空东南急流的维持加强利于锋面次级环流发展,是造成中尺度对流系统长时间维持的主要原因。(3)“8.8”暴雨对流云团由对流层低层弱冷锋触发。对流云团发展初始阶段,对流层低层冷锋锋生主要由水平辐散项决定;对流云团成熟阶段,对流层低层冷锋锋生主要由倾斜项决定。低层切变线长时间维持和加强利于低层冷锋进一步锋生,是造成中尺度对流系统长时间维持的主要原因。

新冠肺炎疫情期间武汉市水务集团应急保障措施及思考(排水篇)

新冠肺炎(COVID-19)发生,武汉市水务集团有限公司(简称武水集团)紧急启动战时应急保障机制,采取多种应急措施,保障了所辖城市污水处理厂、污水泵站和管网的安全、稳定运行。同时发现了污水处理厂药剂种类过多、储备困难、自动化程度有待提高、在线仪表安装不足等问题,尤其是污水处理厂建设时留下的"硬伤"给应急保障带来的影响。提出了下一步研究和改进的方向,为提升污水处理行业应对类似突发公共卫生事件的应急保障能力提供借鉴。

移动支付环境下用户转换意图影响要素研究

移动支付作为重要的支付方式,如何有效推广对服务提供方尤为重要。针对当前网上支付依然占据主导地位的现状,研究探讨了有效吸引消费者转换至移动支付方式的方法,以期为逐渐增多的移动支付提供主体提高服务水平提供借鉴和参考。基于人口迁徙理论中PPM模型的'推—拉—调节'视角,结合过往研究构建移动支付转换意图影响要素模型,并通过问卷调研和结构方程模型进行实证分析。研究表明,原支付系统质量不满度、替代技术优势与亲友舆论密度对移动支付转换意图具有正向影响,转换成本对转换意图无显著影响;转换成本对替代技术优势和亲友舆论密度对转换意图间的正向作用均产生负向调节作用,而对原支付系统质量不满度与转换意图间无影响。

中国汉族人群脸部特征相关SNP位点研究

脸部形态是人类重要的生物特征之一,了解脸部形态特征的遗传基础在群体遗传学、发育生物学和法庭科学中具有重要意义。本研究针对中国汉族成年男性人群1177名个体,在高分辨率三维人脸图像的17个脸部特征点中提取出136组欧几里德距离(Euclidean distance)表型。结合3×低深度测序数据,用线性回归分析了125个已报道的与脸部形态显著相关的SNP位点和136组脸部表型之间的相关性。结果表明,在经过多重校正后,来自10个不同基因区域的12个SNP位点与一个或多个脸部特征显著相关(显著性阈值P<1.35×10^–3),解释了年龄和BMI指数校正后3.89%脸部表型差异。相关SNP位点包括TEX41 rs17479393,PAX3 rs974448、RAB7A/ACAD9 rs2977562、DCHS2 rs9995821、DCHS2 rs2045323、C5orf50 rs6555969、SUPT3H/RUNX2 rs1852985、MSRA rs11782517、EYA1 rs10504499、GSC rs2224309、DICER1 rs7161418和DHX35 rs2206437。本研究结果对揭示中国汉族人群脸部形态的遗传机制和脸部特征的遗传推断提供了参考数据。

焦虑对大学生生活满意度的影响

目的探究大学生焦虑、网络社会支持寻求、社交网络(SNS)成瘾和生活满意度之间的潜在关系和作用机制,为大学生缓解焦虑情绪和提高生活满意度提供理论参考。方法采用焦虑子量表、网络社会支持寻求量表、社交网络成瘾量表和生活满意度量表对286名大学生进行调查,通过Smart PLS 3.0构建结构方程模型对数据进行分析。结果焦虑感显著正向预测网络社会支持寻求(β=0.475)和SNS成瘾(β=0.406),网络社会支持寻求显著正向预测SNS成瘾(β=0.228),焦虑(β=-0.159)、网络社会支持寻求(β=-0.150)和SNS成瘾(β=-0.227)均显著负向预测生活满意度。此外,网络社会支持寻求和社交网络成瘾在焦虑和生活满意度之间存在链式中介作用,中介效应值为-0.025。结论大学生心理焦虑水平与其社交网络使用行为密切相关,但网络社会支持寻求和社交网络成瘾行为都不利于大学生生活满意度的提升。