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.

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。

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.

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。

MT集成式扩束光纤连接器插入损耗研究

简要介绍了MT集成式扩束光纤连接器的工作原理。通过Zemax软件仿真,分别计算了1.0透镜MT集成式扩束产品和0.5透镜MT集成式扩束产品理论上耦合损耗均能够满足要求。并且分析了接触件对接径向偏移、角度偏移、轴向偏移对1.0透镜和0.5透镜MT集成式扩束连接器的影响,分析出选择的自聚焦透镜直径越大,其扩术后插入损耗对角度偏差越敏感,选择的自聚焦透镜直径越小,其扩术后插入损耗对径向偏差越敏感。

MT集成式扩束连接器发展探析

随着光传输技术在军用领域的发展与完善,接触式的光纤连接器已经大量应用于航天、航空、船舶、电子等极端领域中,同时也出现了传输不稳定,端面容易损伤以及易污染等问题。而扩束光纤连接器可以有效地解决这些问题,目前陶瓷插针式扩束接触件衍生的连接器应用范围较广,其均是由1.0外径的透镜或更大直径的透镜为基础制作的扩束光路。光链路中集成度较高的MT集成式扩束连接器应用较少。基于此,将针对现有不同结构的MT扩束连接器进行对比分析,并对MT集成式扩束光纤连接器的工作原理及优点进行分析,从而对其未来发展进行阐述。

MT5500B交流电动轮卡车控制原理与控制功能

伴随着科学技术的快速发展与社会的进步,卡车已经在现代物流与运输领域中发挥着举足轻重的作用。为提高卡车运行效率,减少能源消耗,加强安全性与驾驶舒适性等,车辆控制系统日趋复杂与智能化。其中MT5500B卡车控制系统这一先进技术的应用给卡车行业带了一场革命。MT5500B卡车控制系统因其卓越的性能和强大的功能而受到赞誉,它是一种高度智能化的系统,集成了先进的传感器、电子控制单元(ECU)和执行器。本论文将对MT5500B卡车控制系统原理及控制功能进行深入探究,目的是为了给读者对于该技术有一个深刻的认识。通过对它的原理进行解剖,将展示它是怎样通过对车辆各方面进行实时监测与精确控制,从而达到更加有效,更加安全,更加连续地进行运输。

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.

基于大地测量和MT技术分析吉林龙岗火山区现今地壳运动特征及其机理

位于吉林长白山西麓龙岗山脉中段的龙岗火山群是中国近代主要火山活动区之一.通过对火山区2010—2020年多期GNSS(Global Navigation Satallite System)观测资料及1970—2010年多个时段的一、二等水准资料进行解算,获取现今三维地壳运动速度场.GNSS获取的水平运动速率从西向东增大,东部主要以拉张运动为主,连续面应变率场结果反映火山区位于膨胀区;一等水准路线长抚线和丹抚线资料显示火山区以垂直上升运动为主,主要速率为0.55~1.83 mm/a,其中抚松—仙人桥—老山队一带为主要隆升区,速率多大于1.0 mm/a;该区域分布丰富的地热资源,也是地震多发地区.邻近区域的二等水准路线梅通线速率相对较小,为0.23~0.77 mm/a.结合对99个测点大地电磁数据三维反演得到的火山区深部电性结构:与隆升区对应的中下地壳赋存相对较浅的岩浆系统,电性边界带推测的浑江断裂北向延伸.断裂附近的低阻体规模最大,向下延伸至地幔尺度.最浅的低阻体位于最年轻的金龙顶子火山大约10 km以下位置,以上的高阻结构认为是岩浆溢流结束后的后撤和固结.综合分析认为现今火山区地壳的膨胀隆升、地震活动与幔源物质的上涌、间断性的运移引起断层活动有关.

求解无人驾驶车辆路径规划问题的QPC-MT-RRT算法

针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算法。该算法根据无人驾驶车辆路径规划的相关理论,建立无人驾驶车辆路径规划问题的车辆运动学模型,为规划无人驾驶车辆最优、最高效、最安全路径提供理论依据。将上述算法在MATLAB上仿真,并在平均路径长度、平均路径规划时间、平均采样节点个数及节点利用率4个方面与基本RRT算法及MT-RRT算法进行了对比。仿真结果表明:5次多项式曲线与MT-RRT算法的融合算法具有最高的性能,可以规划出最优路径。

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.

“MT+CAT+PE”翻译模式下科技英语文本的翻译研究

全球化和数字化下的翻译服务正在飞速发展,“MT+CAT+PE”翻译模式在科技文本的翻译活动中切实可行。本文在“信达切”翻译原则的指导下,研究“MT+CAT+PE”翻译模式下的科技英语文本翻译,描述MT、CAT出现的误译和计算机辅助翻译的应用方法,并提出译后编辑的方法,以期为译员提高翻译活动的质量和效率提供借鉴。

基于FPGA和B61580S3的1553B总线RT/MT功能的设计与验证

1553B总线协议因具有优越的实时性、高度的数据可靠性以及可同时挂载多个终端等优势,在国内航空航天领域的电子交互网络中得到广泛使用。文中基于B61580S3协议芯片内置的16位缓冲模式实现了MIL-STD-1553B总线功能。采用VHDL硬件描述语言为FPGA设计了总线接口控制电路,通过FPGA对协议芯片的控制以及协议芯片内部数据自动解析和强大的中断机制,实现了RT/MT功能;通过测试台上位机软件对设计的1553B总线接口的测试与验证,结果表明接口设计可靠,传输误码率低,有较高的应用价值。

应用于MTS的多点测温系统设计

针对调制转移光谱稳频(MTS)系统中,温度波动会影响激光频率稳定性的问题,设计出多点测温系统。该系统以FPGA为核心,通过基准电压源激励电桥电路,将三线制PT1000温度变化转换为电压变化,利用同步采样ADC对转换电压进行采集,最后在LabVIEW中将采集电压转换为温度实时显示和存储。信号调理电路中的抗射频干扰滤波和FPGA中的均值滤波,可降低噪声干扰,提高测温精度。实验结果表明:该系统具备线性度好、精度高、重复性好的优点,可对10~80℃的温度进行监测和存储,采用分段线性拟合后,其测温误差不超过0.02℃,可以满足实验需求。

MT法在鄂尔多斯盆地北部地热资源勘查中的应用

鄂尔多斯盆地北部地热资源埋藏深、温度高、储量大、开发潜力大,合理地选择物探方法可以很好地确定靶区,圈定热储构造,更精准地为钻探提供依据.由于MT法探测深度的优势,其反演电阻率特征能很清晰地反映出地热田导水导热构造的分布、产状等特征.本研究利用前期ER01、ER02地热井测井成果,重新标定ER03地热井物探解释参数,划分出4000 m深度范围内的热储层在水平和纵向上的分布规律,圈定地热异常范围和空间分布特点,确定地下热水的富水部位及有利的勘探井位,提出下一步工作的建议.