Changes of the Hailuogou Glacier,Mt. Gongga,China,against the Background of Global Warming in the Last Several Decades

Great change, associated with global warming, has occurred at the Hailuogou （海螺沟） glacier, Mt. Gongga （贡嘎）, China, since the early 20th century. Various data indicate that the glacier has retreated 1 822 m in the past 106 years, with an annual mean retreat of 17.2 m, and the front elevation has risen by 300 m since 1823. Comparison of glacier variations and temperature fluctuations in China and the Northern Hemisphere, over the last 100 years, indicates that glacier retreat stages occurred during the warm phase, and vice versa. Mass balance records during 1959/60-2003/04 have shown that the glacier has suffered a constant mass loss of snow and ice. The accumulated mass balance, -10.83 m water equivalent, indicates an annual mean value of -0.24 m water equivalent. The correlation between the mass balance and temperature is significant, which also indicates that climate warming is the crucial cause of glacier loss. Local hydrological and climatic data demonstrate that runoff from the glacier has been increasing both seasonally and annually. The correlation analysis and trend analysis indicate that ice and snow melted water is the main cause of an increase in the runoff. As the climate has become warmer, changes in the glacier surface morphology have obviously occurred. These include a decrease in glacier thickness, enlargement of glacial caves, and reduction of the size of clefts on the glacier surface. The ablation period has lengthened and the ablation area has expanded. A variety of factors thus provide evidence that the Hailuogou glacier has suffered a rapid loss of snow and ice as a result of climatic warming.

The carbon accumulation and dissipation features of sub-alpine woodland in Mt.Gongga

Based on biomass investigations, soil respiration an d plant photosynthesis measurement of dominant trees in Hailuogou valley o f Mt. Gongga, Southwest China, the carbon (C) storage, absorption and release for several typical woodlands in sub-alpine zones have been di scussed. For Abies fabri forest of 3,000 m above sea level, the C stor age amount is 177.4 t/ha for above-ground biomass and 143.2 t/ha for s oil below-ground biomass. The annual gross C fixed by vegetation photo synthesis is 20-24 t/ha. The C release by canopy respiration is 3.0-5.5 t/ha for arbors and 10-19 t/ha for surface soil and roots. The annual net C f ixed of forest ecosystem is about 6.0-7.1 t/ha. At lower elevations, t he amount of C released by woodlands is higher than that of woods a t higher elevations. The C fixed capacity of renewed forest with middle-aged t rees is higher than that of mature forest. Before becoming over-matured forest, woodland is an important sink of C whereas bareland in woods is the source of atmospheric C.

1-MCP与MT联合处理对芒果保鲜效果的影响

为探究1-甲基环丙烯(1-MCP)与褪黑素(MT)联合处理对芒果保鲜效果的影响,该研究用0.1 mg/L 1-MCP和0.2 mmol/L MT联合处理芒果后,于25℃贮藏10 d,每2 d取样测定相关指标。结果显示:1-MCP和MT联合处理可以延缓芒果果皮叶绿素降解和类胡萝卜素含量升高,在贮藏第10天,处理组的果皮叶绿素为0.078 mg/g,是对照组的5.27倍;延缓了果肉L*值的下降和a*、b*值的升高,抑制原果胶降解和可溶性果胶含量的升高,贮藏第6天处理组的原果胶含量比对照高2.53倍,而可溶性果胶含量比对照低44.04%,同时在贮藏前期显著抑制了多聚半乳糖醛酸酶(PG)和纤维素酶(Cx)活性,降低了β-半乳糖苷酶(β-Gal)活性,并且维持了果肉更完整的细胞结构,但果肉类黄酮含量在贮藏中期显著低于对照。综上,1-MCP和MT联合处理保持了芒果良好的外观品质,延缓了细胞壁物质的降解,提高了货架期品质。

Elevational patterns of bird species richness on the eastern slope of Mt.Gongga,Sichuan Province,China

Background:In biological systems,biological diversity often displays a rapid turn-over across elevations.This defining feature has made mountains classic systems for studying the spatial variation in diversity.Because patterns of elevational diversity can vary among lineages and mountain systems it remains difficult to extrapolate findings from one montane region to another,or among lineages.In this study,we assessed patterns and drivers of avian diversity along an elevational gradient on the eastern slope of Mt.Gongga,the highest peak in the Hengduan Mountain Range in central China,and a mountain where comprehensive studies of avian diversity are still lacking.Methods:We surveyed bird species in eight 400-m elevational bands from 1200 to 4400 m a.s.l.between 2012 and 2017.To test the relationship between bird species richness and environmental factors,we examined the relative importance of seven ecological variables on breeding season distribution patterns:land area(LA),mean daily temperature(MDT),seasonal temperature range(STR),the mid-domain effect(MDE),seasonal precipitation(SP),invertebrate biomass(IB) and enhanced vegetation index(EVI).Climate data were obtained from five local meteorological stations and three temperature/relative humidity smart sensors in 2016.Results:A total of 219 bird species were recorded in the field,of which 204 were recorded during the breeding season(April–August).Species richness curves(calculated separately for total species,large-ranged species,and smallranged species) were all hump-shaped.Large-ranged species contributed more to the total species richness pattern than small-ranged species.EVI and IB were positively correlated with total species richness and small-ranged species richness.LA and MDT were positively correlated with small-ranged species richness,while STR and SP were negatively correlated with small-ranged species richness.MDE was positively correlated with large-ranged species richness.When we considered the combination of candidate factors using multiple regression models and model-averaging,total species richness and large-ranged species richness were correlated with STR(negative) and MDE(positive),while small-ranged species richness was correlated with STR(negative) and IB(positive).Conclusions:Although no single key factor or suite of factors could explain patterns of diversity,we found that MDE,IB and STR play important but varying roles in shaping the elevational richness patterns of different bird species categories.Model-averaging indicates that small-ranged species appear to be mostly influenced by IB,as opposed to large-ranged species,which exhibit patterns more consistent with the MDE model.Our data also indicate that the species richness varied between seasons,offering a promising direction for future work.

产教融合背景下基于MTS理论的金融知识学习及教学模式研究

在产教融合背景下,金融类课程的教学模式正向问题导向型转变。金融知识学习及教学通过产学协同,并匹配不同学生的学习特征和所要传授的知识特征,实现人才培养质量的提升。产教融合的模式中,混合型师资队伍建设是核心环节,通过案例研究,基于多团队系统理论,探讨产教融合背景下如何构建由校内教师、行业专家和学生组成的多元化教学团队,并分析其运行机制和效果;同时,基于学习模型的教学支持与模式创新,结合学生学习特征,对主要教学方法进行体系化梳理,并优化教学方法,形成教学方案。

Altitudinal migration behavior patterns of birds on the eastern slope of Mt.Gongga,China

Many bird species in montane regions exhibit altitudinal migration behavior;however,altitudinal migration of birds is still understudied,especially in Asia.Mt.Gongga(7556 m) is the highest peak of the Hengduan Mountains in Southwest China.The steep elevation gradient and the high bird diversity make the eastern slope of Mt.Gongga(Hailuo Valley) an ideal place for studying the altitudinal migration behavior patterns of birds.We synchronously recorded the local bird diversity,temperature and humidity at two sites(1800 and 3000 m a.s.l.) during three migration seasons from September 2020 to June 2021 to identify birds exhibiting altitudinal migration behavior.During our surveys,we recorded 146 bird species in total and 20 passerine bird species were altitudinal migrants according to our altitudinal migration formula.Among those 20 altitudinal migrant species,eight bird species displayed a typical altitudinal migration pattern(upward migration during the breeding season and downward migration during the non-breeding season).Moreover,temperature was correlated with the daily number of individuals(DNI) at each study site.Therefore,increasing temperatures possibly caused upward migration of birds(DNI decreased at 1800 m and increased at 3000 m) and vice versa.To further elaborate,the Rufousgorgeted Flycatcher(Ficedula strophiata),the species with the most prominent altitudinal migration behavior,initiated upward migration at a temperature of 11-12℃ at 1800 m and initiated downward migration at a temperature of 12-13℃ at 3000 m.Besides,humidity was positively correlated with the DNI.Therefore,increasing humidity(equals to increasing rainfall or snow) possibly caused downward migration of birds(DNI increased) and vice versa.Furthermore,bird species exhibiting a typical altitudinal migration behavior pattern are feeding on insects.Thus,the spatial and temporal changes of the invertebrate biomass might be an important ecological driver for the altitudinal migration of invertivorous(birds eating invertebrates) birds.This study provides fundamental data for the altitudinal migration of birds in the Hengduan Mountains and shows how altitudinal migration is seasonally dynamic across an elevational gradient in a subtropical mountain region.

基于VTI介质海洋CSEM和MT数据联合反演的黄海海相残留盆地深部结构研究

黄海海相残留盆地因其地层结构和深部地质构造的复杂性,一直是我国海洋地球科学的一项研究重点,虽然针对该研究区已开展了一系列的地球物理调查,但由于高速碳酸盐岩层对地震波存在着一定的屏蔽作用,致使该海域深部地震资料品质受到较大影响.海洋电磁法不受高速屏蔽层影响,有利于获得高速屏蔽层内部及其下方的深部结构信息.海洋可控源电磁法(Controlled source electromagnetic method,CSEM)和海洋大地电磁测深(Magnetotelleric,MT)能够提供海底电性结构的互补信息,较于单一的电磁方法,二者联合可获得更为准确的海底电性分布.本文提出了基于乘积目标函数的层状垂直各向异性(Vertical anisotropic,VTI)介质海洋可控源电磁和大地电磁资料联合反演方法,该方法在迭代过程中根据数据的拟合情况自适应调整CSEM和MT数据的权重和正则化因子的权重,反演参数包括海底介质的横向电阻率、垂向电阻率和地层厚度.以南黄海地质地球物理资料为例,建立浅水环境地电模型,并结合浅水环境的高噪声背景特点进行合成数据模型测试及分析.将本文所提出算法应用于理论模型合成数据和南黄海实测资料反演,结果表明,较于单独的海洋CSEM和MT反演,联合反演方法能够较准确地重构海底地层的电性分布,提高对海底地层各向异性电阻率的分辨能力.

基于调车工况的MT-2缓冲器容量需求仿真分析

为了分析MT-2缓冲器在调车连挂作业时的容量需求问题,基于摩擦式缓冲器非线性力学特性及车辆调车冲击受力特点,建立了铁道货车纵向冲击动力学模型,对调车过程中不同车辆质量、不同速度、不同编组方式及不同车体刚度等工况下MT-2缓冲器容量需求进行了分析。研究结果表明:缓冲器做功与车辆质量和连挂速度的平方成正比,冲击车和被冲击车数量都大于2辆时冲击面缓冲器的容量需求将与车辆数量无关。对同时考虑质量、速度、编组方式、车体刚度的缓冲器容量需求值进行了函数拟合,完成了比例系数κ、μ和λ的求解;不同车辆数量之间冲击时,不同车钩号的缓冲器做功值大小不一,在冲击面车钩号的缓冲器做功值均为最大,沿着冲击面前、后的车钩号逐渐递减,调车冲击时计算容量需求值时应不考虑车体刚度,以重车冲击重车模式时冲击面的缓冲器容量需求为准。

基于MT-CNN的矿井带式输送机输煤量检测技术

为实现矿井带式输送机输煤量检测的信息化、智能化,提出基于MT-CNN的矿井带式输送机输煤量检测技术。为了全面提升输煤量检测技术,从而提高矿井效益,选取了多任务卷积神经网络(MT-CNN)对检测目标进行多核心识别检测,优化了图像直线信息和边缘信息的提取效率,构建了良好的网络层次结构,优化了信息连接通道,从而全面提高图像识别分析和数据检测处理的效果。通过MT-CNN技术对输煤量的轮廓形态和荷载状态进行分析运算,经过图像样本数据训练获取矿井带式输送机输煤量的相关数据。研究结果表明,该技术能够有效提高输煤量图像识别的真实性,而检测时间缩短49%,计算结果准确率提高到98%,有效提高了输煤量检测的效率和准确度,具有较好的应用性能和良好的使用效果。加强矿井带式输送机的输煤量检测,可以为后续研究提供依据,很大程度上推动了相关技术发展,实现矿井信息化、智能化、现代化发展。

5G集约化VoLTE短信网关MT成功率提升方案研究

导致集约化VoLTE短信网关上线后MT成功率较割接前下降的三种主要原因,包括VoLTE网关对短信中心长会话保持参数识别错误、多业务处理机之间缺乏有效的协同机制、对MT短信ENUMDNS查询量过大。实施针对性改进措施后,成功率得到了显著提升。

基于MT7620A的智慧监控网关设计

针对网络摄像机不具备远程监控能力的问题,基于MT7620A设计了一种支持远程监控的智慧网关。网关使用MT7620A作为主控芯片,搭载OpenWrt系统。通过创建ONVIF客户端与同一局域网中支持ONVIF协议的监控设备进行通信,实现设备发现、信息获取、云台控制和视频流读取等功能;网关与云平台通过MQTT协议实现信令交互,云平台可以向网关发送设备管理、云台控制和视频流读取等命令;网关通过数据处理模块对命令进行解析和协议转换,实现对设备的管理,以及对监控设备云台的控制和视频流读取。网关在使用FFMPEG接口获取视频流之后,通过Socket TCP与云平台建立连接并发送视频流,保证视频流远程传输的稳定可靠。网关配有4G通信模块,避免了接入互联网受到有线网络通信的限制,双重通信方式更加有效地保障了网络传输。测试结果表明,所设计的网关能够支持云平台实现对设备的远程监控和控制。

CSAMT、MT等电磁法在矿山地质勘探中技术参数研究

目前,在矿山地质勘探中广泛采用CSAMT、MT等电磁法,但该类电磁法均存在电磁干扰影响因素,都存在其所对应地质条件的最佳工作技术参数,为了降低野外数据采集工作过程中电磁干扰并达到最佳工作目标任务要求,本文通过作者十几年来积累的关于CSAMT、MT在各种不同矿山地质条件下的工作经验及试验结论,总结得出该类电磁法在一定地质条件下的最佳工作技术参数,将为今后在不同矿山、不同地质条件下开展该相关方法提供参考示范。

抗肿瘤肽Mt5对人肝癌细胞增殖和凋亡的影响及机制

目的探讨抗肿瘤肽Mt5通过磷脂酰肌醇-3激酶(PI3K)/蛋白激酶B(AKT)信号通路对人肝癌细胞增殖与凋亡的影响。方法采用pymol构建Mt5的三维可视化结构示意图,Prot Param分析Mt5的正电荷和疏水性,NPS分析Mt5的α-螺旋所占比例;运用实时无标记细胞分析(RTCA)技术检测不同浓度Mt5(50 mg/L、100mg/L、200 mg/L、400 mg/L)作用后的HepG2细胞活力;通过实时荧光定量PCR法(qRT-PCR)法检测不同浓度Mt5(25 mg/L、50 mg/L、100 mg/L)作用后HepG2细胞中PI3K、AKT信使RNA(mRNA)表达;以Western blot法检测不同浓度Mt5(25 mg/L、50 mg/L、100 mg/L)作用后凋亡相关蛋白B细胞淋巴瘤-2蛋白(Bcl-2)、Bcl-2相关X蛋白(bax)和PI3K、AKT蛋白表达。结果生物学信息结果表明,Mt5的正电荷为+8,疏水性为0.588,α-螺旋度为84.62%;RTCA结果显示Mt5不同浓度处理组作用后,HepG2细胞指数随着Mt5浓度的增大和时间的延长逐渐降低至0以下;qPCR结果显示,Mt5组HepG2细胞中PI3K和AKT mRNA较阴性对照组表达降低(P<0.05),bax蛋白表达较阴性对照组升高(P<0.05),且呈浓度依赖性;Western blot结果显示,Mt5组HepG2细胞中Bcl-2、PI3K及AKT蛋白表达较阴性对照组降低(P<0.05),且呈浓度依赖性。结论Mt5可抑制人肝癌细胞增殖及诱导细胞凋亡,其机制可能与抑制PI3K/AKT信号通路有关。

ZNT1 Involves Cuproptosis through Regulating MTF1-conduced Expression of MT1X under Copper Overload

Industrial activities such as smelting emissions,mineral combustion and industrial wastewater discharge might lead to copper pollution in the environment.This kind of copper pollution has harmful effects on aquatic o rganisms,plants and animals through direct or indirect exposure.However,the current understanding of the toxicity of copper is rather limited.Copper overload can perturb intracellular homeostasis and induce oxidative stress and e ven cell death.Recently,cuproptosis has been identified as a copper-dependent form of cell death induced by o xidative stress in mitochondria.We uncover here that zinc transporter 1(ZNT1)is an important regulator involved in cuproptosis.Firstly,we established the copper overload-induced cell death model with the overexpression of copper importer SLC31A1 in HeLa cells.Using this model,we conducted unbiased genome-wide CRISPR-Cas9 screens in cells treated with copper.Our results revealed a significant enrichment of ZNT1 gene in both library A and library B plasmids.Knocking out of ZNT1 in HeLa cells notably prevented cuproptosis.Subsequent knockout of metal transcription factor 1(MTF1)in ZNT1-deficient cells nearly abolished their ability to resist copper-induced cell death.However,overexpression of metallothionein 1X(MT1X)in the double-knockout cells could p artially restored the resistance to cuproptosis by loss of MTF1.Mechanistically,knockout of ZNT1 could promote MT1X expression by activating MTF1.As a consequence,the interaction between MT1X and copper was e nhanced,reducing the flow of copper into mitochondria and eliminating mitochondria damage.Taken together,this study reveals the important role of ZNT1 in cuproptosis and shows MTF1-MT1X axis mediated resistance to c uproptosis.Moreover,our study will help to understand the regulatory mechanism of cellular and systemic copper homeostasis under copper overload,and present insights into novel treatments for damages caused by both genetic copper overload diseases and environmental copper contamination.

养殖水域Cu^(2+)胁迫对虹鳟MT2基因表达模式的影响

为了探究水体中铜离子胁迫对虹鳟(Oncorhynchus mykiss)MT2基因表达模式的影响,开发Metallothioneins作为检测水域生态中重金属铜污染的分子标志,该研究利用TA克隆法获得了虹鳟MT2基因的CDS序列,检测了MT2基因在虹鳟不同组织中的表达模式,以及Cu^(2+)胁迫(Cu^(2+)浓度75、150和300μg/L)后1、2、3和4 d和胁迫恢复1、2 d时间点的MT2基因表达动态。结果表明,虹鳟MT2基因CDS区长186 bp,编码62个氨基酸,具有典型的半胱氨酸(Cys)-X(1~3个)-半胱氨酸结构,属不稳定亲水性蛋白。虹鳟MT2基因序列与大西洋鲑的同源性最高且在肝脏中表达量最高,其次是脑和肠道。胁迫试验结果显示,MT2基因在肝脏和鳃中呈现先升高后降低的趋势,在头肾、脾脏和脑中呈现逐渐升高的趋势,且呈现一定的剂量依赖性,肠道MT2基因在胁迫2、3和4 d被显著抑制。胁迫恢复后,处理组肝脏、头肾、鳃、脑MT2基因表达量仍显著升高。综上,虹鳟MT2基因能在不同组织中被Cu^(2+)诱导表达,推测MT2基因在虹鳟抗重金属毒性中可能发挥着重要作用,且MT2基因表达量与铜离子的浓度相关,可以作为分子生物标志检测水域生态中的重金属铜污染。

Assessment of sediment connectivity using modelling and field-based approaches in the Slavíč River catchment(MoravskoslezskéBeskydy Mts,Czech Republic)

Mountain streams act as conveyors of sediments within the river continuum,where the physical transport of sediments between river reaches through the catchment or between individual parts(e.g.,between hillslopes and channels)of the catchment is assumed.This study focused on sediment connectivity analysis in the SlavíčRiver catchment in the MoravskoslezskéBeskydy Mts in the eastern part of the Czech Republic.The connectivity index and connectivity index target modelling were combined with an analysis of anthropogenic interventions.Additionally,field mapping,grain size of bed sediments and stream power analysis were used to obtain information about connectivity in the catchment.Based on the analysis and obtained results,terrain topography is the current main driving factor affecting the connectivity of sediment movement in the SlavíčRiver catchment.However,the modelling provided valuable information about high sediment connectivity despite different recent land use conditions(highly forested area of the catchment)than those in historical times from the 16th to 19th centuries when the SlavíčRiver catchment was highly deforested and sediment connectivity was probably higher.The analysis of anthropogenic interventions,field mapping,grain size of bed sediments and stream power analysis revealed more deceleration of sediment movement through the catchment,decreased sediment connectivity with bed erosion,and gradual river channel process transformation in some reaches.Field mapping has identified various natural formations and human-induced changes impacting the longitudinal and lateral connectivity in the SlavíčRiver.For instance,embankments along 48%of the river's length,both on the right and left banks,significantly hinder lateral sediment supply to the channel.Stream power index analysis indicates increased energy levels in the flowing water in the river's upper reaches(up to 404.8 W m^(-2)).This high energy is also observed in certain downstream sections(up to 337.6 W m^(-2)),where it is influenced by human activities.These conditions lead to intensified erosion processes,playing a crucial role in sediment connectivity.Similar observations were described in recent studies that pointed out the long-term human interventions on many streams draining European mountains,where a decrease in sediment connectivity in these streams is linked with sediment deficits and the transformation of processes forming channels.

MT-1207对小鼠血糖、血脂和动脉粥样硬化的作用

目的研究MT-1207对小鼠血糖、血脂和动脉粥样硬化的作用。方法载脂蛋白E(ApoE)基因敲除(ApoE^(-/-))小鼠分别给予普通饲料、氯沙坦含药饲料和MT-1207含药饲料,给药剂量为30 mg/kg,测定小鼠的体质量、血糖和血脂指标,并评价动脉粥样硬化的斑块面积。对8周龄的雄性C57小鼠给予高脂饲料,每天以30mg/kg的剂量灌胃MT-1207和氯沙坦,考察小鼠的体质量、血糖和血脂的水平,进一步评价MT-1207对血糖、血脂的作用。结果长期MT-1207饲料给药和氯沙坦饲料给药的ApoE^(-/-)小鼠体质量增长更快,但血糖和血脂的水平没有显著改善,动脉粥样硬化的斑块面积也无明显变化。MT-1207和氯沙坦对高脂饮食的C57小鼠血糖、血脂均无明显改善作用。结论MT-1207和氯沙坦对血糖、血脂以及动脉粥样硬化没有改善作用,不会加重动脉粥样硬化。

矿用卡车MT5500电动轮典型故障分析及检修工艺优化

介绍了MT5500矿用卡车电动轮装配工艺的改进和密封设计的优化,旨在解决牵引电机压盖螺栓断裂和漏油故障问题;通过调整装配工艺和改进密封设计,提高了电动轮的使用寿命,降低了配件更换频率和检修工时。应用表明:新工艺的应用不仅提高了卡车的出动率,还降低了维修的劳动强度。

“CAT+MT+PE”模式下的商务英语文本翻译

随着人工智能技术发展的日渐成熟与翻译需求的多样化,计算机辅助翻译在商务英语文本翻译中占据的地位越来越重要。与此同时,人们也在探索更加高效高质的翻译模式。本文将聚焦“CAT+MT+PE”翻译模式在商务英语文本翻译中的应用,深刻论述这种翻译模式相比传统翻译模式效率和质量都有大幅提高。

单轮抱死的故障原因及分析——以MT5500卡车为例

卡车在运行中出现单轮抱死故障,不仅会降低卡车的行驶速度和操控性能,还会增加安全隐患。本文以MT5500卡车为例,针对其在运行中出现的单轮抱死故障进行分析,发现故障的原因主要是制动系统的问题,如制动盘和制动片的磨损、制动液的压力不足等。针对这些问题,本文提出了具体的解决方案,通过实施这些方案,能够有效地解决单轮抱死的故障,提高卡车的运行效率和安全性。