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The Earth Summit Mission-2022:Successful ozone soundings contribute to source identification in the north Mt.Qomolangma region 被引量:3
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作者 Jinqiang Zhang Chunxiang Ye +11 位作者 Yuejian Xuan Zhixuan Bai Weili Lin Dan Li Lingkun Ran Baofeng Jiao YaomingMa Weiqiang Ma Nan Yao Yunshu Zeng Daren Lv Tong Zhu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第2期412-421,共10页
As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde... As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite. 展开更多
关键词 Ozone soundings mt.qomolangma Vertical ozone structure Ozone source Satellite data
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VEGETATION CHANGE IN THE MT.QOMOLANGMA NATURAL RESERVE FROM 1981 TO 2001 被引量:1
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作者 ZHANG YILI & ZHANG WEI Dr.Zhang Yili is a researcher of Institute of Tibetan Plateau Research(ITP),the Chinese Academy of Sciences(CAS.) Dr.Zhang Wei comes from the Institute of Geographical Sciences and Natural Resources Research(IGSNRR),CAS.. 《China's Tibet》 2007年第4期8-19,共12页
1 Introduction On 18 May 1989,the Mt.Qomolangma (Everest)Natural Reserve(abbr.MQNR)in Tibet Autonomous Region formally came into existence and it was listed as World Network of Biosphere Reserves(WNBR)in May 2005.The ... 1 Introduction On 18 May 1989,the Mt.Qomolangma (Everest)Natural Reserve(abbr.MQNR)in Tibet Autonomous Region formally came into existence and it was listed as World Network of Biosphere Reserves(WNBR)in May 2005.The MQNR is a comprehensive reserve,which mainly protects alpine ecosystems,plateau natural landscapes,geological remains and Tibetan historical and cultural heritages. 展开更多
关键词 VEGETATION CHANGE IN THE mt.qomolangma NATURAL RESERVE FROM 1981 TO 2001 MT
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The Mountain Summit Auspicious Clouds and Dreams—Recapping the Moment of the Olympic Torch Relay Leg at the Mt.Qomolangma
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作者 Zhang Xianqun 《China's Tibet》 2008年第4期4-9,共6页
The Beijing leg of the 2008 Olympic torch relay be-gan in spring.Along with the citizens in other cities,we were longing for a distinctive and stun-ning torch relay in terms of the route and the many colorful cer-emon... The Beijing leg of the 2008 Olympic torch relay be-gan in spring.Along with the citizens in other cities,we were longing for a distinctive and stun-ning torch relay in terms of the route and the many colorful cer-emonial activities. The unprecedented plan to ex-tend the torch relay to Mt. Qomolangma will surely attract at-tention from all over the world. 展开更多
关键词 Recapping the Moment of the Olympic Torch Relay Leg at the mt.qomolangma The Mountain Summit Auspicious Clouds and Dreams
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Meteorological Features at 6523 m of Mt.Qomolangma(Everest)between 1 May and 22 July 2005 被引量:4
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作者 XIE Aihong REN Jiawen QIN Xiang JIANG Youyan 《Journal of Mountain Science》 SCIE CSCD 2006年第3期181-190,共10页
Mt. Qomolangma (Everest), the highest mountain peak in the world, has little been studied extensively from a meteorological perspective, mostly because of the remoteness of the region and the resultant lack of meteo... Mt. Qomolangma (Everest), the highest mountain peak in the world, has little been studied extensively from a meteorological perspective, mostly because of the remoteness of the region and the resultant lack of meteorological data. An automatic weather station (AWS), the highest in the world, was set up on 27 April 2005 at the Ruopula Pass (6523 m asl) on the northern slope of Mt. Qomolangma by the team of integrated scientific expedition to Mt. Qomolangma. Here its meteorological characteristics were analyzed according to the lo-minute-averaged and 24-hour records of air temperature, relative humidity, air pressure and wind from 1 May to 22 July 2005. It is shown that at 6523 m of Mt. Qomolangma, these meteorological elements display very obvious diurnal variations, and the character of averaged diurnal variation is one-peak-and-one-vale for air temperature, one-vale for relative humidity, two-peak-and-two-vale for air pressure, and one-peak with day-night asymmetry for wind speed. In the 83 days, all the air temperature, relative humidity and air pressure increased with some different fluctuations, while wind speed decreased gradually and wind direction turned from north to south. The variations of relative humidity had great fluctuations and obvious local differences. Then the paper discusses the reason for the characters of diurnal and daily variations. Compared with the corresponding records in May 1960, 5-day-averaged maximums, minimums and diurnal variations of air temperature in May 2005 were apparently lower. 展开更多
关键词 Mt. Qomolangma (Everest) RADIATION air temperature relative humidity pressure
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Seasonal variations in heavy metals concentrations in Mt.Qomolangma Region snow 被引量:3
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作者 段建平 王丽丽 +2 位作者 任贾文 李论 韩军青 《Journal of Geographical Sciences》 SCIE CSCD 2009年第2期249-256,共8页
The concentrations of heavy metals Ba, Pb, Cu, Zn and Co in snow pit collected in September, 2005 from the accumulation area of the East Rongbuk Glacier (6523 m a.s.l.), which lies on the northern slope of Mt. Qomol... The concentrations of heavy metals Ba, Pb, Cu, Zn and Co in snow pit collected in September, 2005 from the accumulation area of the East Rongbuk Glacier (6523 m a.s.l.), which lies on the northern slope of Mt. Qomolangma, were determined by inductively coupled plasma mass spectrometry (ICP-MS). Concentrations (pg/ml) of heavy metals are Ba2-227, Co2.8-15.7, Cu10-120, Zn29-4948 and Pb14-142, respectively. The 5180 was determined by MAT-252. The time period of the snow pit spans from autumn 2005 to summer 2004. Seasonal variations of the concentrations and δ^18O are observed, of which Pb, Cu, Zn and Co are much lower in summer monsoon season than that in non summer monsoon season, suggesting that different sources of heavy metals contributed to the site. EFc (crustal enrichment factors) is Co3.6, Cu27, Pb33 and Zn180, respectively. Higher EFo values of Pb, Cu and Zn suggest that Pb, Cu especially Zn are mainly contributed by anthropogenic sources. 展开更多
关键词 heavy metals seasonal variations Mt. Qomolangma Region
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Hydrological Characteristics of the Rongbuk Glacier Catchment in Mt.Qomolangma Region in the Central Himalayas,China 被引量:2
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作者 LIU Weigang REN Jiawen +4 位作者 QIN Xiang LIU Jingshi LIU Qiang CUI Xiaoqing WANG Yetang 《Journal of Mountain Science》 SCIE CSCD 2010年第2期146-156,共11页
From 8 April to 11 October in 2005, hydrological observation of the Rongbuk Glacier catchment was carried out in the Mr. Qomolangma (Everest) region in the central Himalayas, China. The results demonstrated that due... From 8 April to 11 October in 2005, hydrological observation of the Rongbuk Glacier catchment was carried out in the Mr. Qomolangma (Everest) region in the central Himalayas, China. The results demonstrated that due to its large area with glacier lakes at the tongue of the Rongbuk Glacier, a large amount of stream flow was found at night, which indicates the strong storage characteristic of the Rongbuk Glacier catchment. There was a time lag ranging from 8 to 14 hours between daily discharge peaks and maximum melting (maximum temperature). As melting went on the time lag got shorter. A high correlation was found between the hydrological process and daily temperature during the ablation period. The runoff from April to October was about 80% of the total in the observation period. Compared with the discharge data in 1959, the runoff in 2005 was much more, and the runoff in June, July and August increased by 69%, 35% and 14%, respectively. The rising of temperature is a major factor causing the increase in runoff. The discharges from precipitation and snow and ice melting are separated. The discharge induced by precipitation accounts for about 20% of the total runoff, while snow and ice melting for about 80%. 展开更多
关键词 Central Himalayas Mt. Qomolangma Rongbuk Glacier Hydrological characteristics
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Spatial-temporal dynamics of alpine grassland coverage and its response to climate warming in Mt.Qomolangma Nature Preserve during 2000-2019 被引量:2
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作者 MA Fei PENG Pei-hao 《Journal of Mountain Science》 SCIE CSCD 2022年第8期2297-2311,共15页
The Qinghai-Tibet Plateau(QTP)has the largest and highest alpine grassland ecosystem in the world,which is considered to be the most sensitive and vulnerable ecosystem to climate change.Its dynamic changes and driving... The Qinghai-Tibet Plateau(QTP)has the largest and highest alpine grassland ecosystem in the world,which is considered to be the most sensitive and vulnerable ecosystem to climate change.Its dynamic changes and driving mechanism have always been widely researched.The Qomolangma National Nature Preserve(QNNP),with the largest altitude difference in the world,was selected as the study area to analyse the spatial-temporal dynamics of grassland coverage and the different characteristics of elevation gradients at the southern slope(SS)and northern slope(NS)with MODIS MOD13Q1 NDVI and MOD11A2 land surface temperature data from 2000to 2019 using the Mann-Kendall trend test and Theil-Sen slope methods.Further,the response mechanism of grassland coverage to climate warming is discussed.The results revealed that from 2000 to 2019,the grassland coverage change in the study area is mainly stable.The increased area proportion of grassland coverage on the southern slope is significantly higher than that on the northern slope,and the decreased area proportion of grassland coverage on the northern slope is significantly greater than that on the southern slope.The change characteristics of grassland coverage in the QNNP exhibit an obvious elevation gradient;the higher the elevation,the greater the increased area proportion of grassland coverage,particularly on the SS.The land surface temperature can be used as a proxy for analysing the temporal and spatial variation trends of air temperature in the QNNP.With the increase of the altitude,the land surface temperature rise rate on both the southern slope and northern slope exhibited an increasing trend,and the sensitivity of grassland coverage to temperature rise was higher on the northern slope.The water condition was the decisive factor for the horizontal and vertical spatial heterogeneity of the dynamic change of grassland coverage,and the melting of glaciers and thawing of permafrost were important sources of water for grassland growth in the QNNP.Climate warming promotes the growth of grassland in areas with a sufficient water supply,but adversely affects the growth of grassland in areas with insufficient water supplies,which will be further intensified by human activities. 展开更多
关键词 Alpine grassland Global warming Vegetation dynamic Elevation gradient Qomolangma
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5G Reaches Mt.Qomolangma
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作者 MA LI 《China Today》 2020年第7期52-54,共3页
ON the afternoon of April 30,a 5G base station jointly built by China Mobile and Huawei started operating at the 6,500-meter-high advanced camp of Mt.Qomolangma,becoming the highest of its kind in the world.“China Mo... ON the afternoon of April 30,a 5G base station jointly built by China Mobile and Huawei started operating at the 6,500-meter-high advanced camp of Mt.Qomolangma,becoming the highest of its kind in the world.“China Mobile and Huawei built a 5G base station on Mt.Qomolangma at an altitude of 6,500 meters within a short period of time and under extremely harsh circumstances.This accomplishment testifies to the maturity of China’s 5G industrial chain,”said Wang Bo,a manager of Huawei’s Lhasa branch. 展开更多
关键词 jointly Mt. BECOMING
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PHENTOK’S LIFE OF CLIMBING:THE FIRST WOMAN ON THE SUMMIT OF MT.QOMOLANGMA
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作者 Huang Xing Xu Wanhu 《China's Tibet》 2014年第5期65-70,共6页
On March 31,2014,Phentok,the first woman mountaineer in the world to reach the summit of Mt.Qomolangma from the north side,passed away because of complications from diabetes,aged75.From her humble upbringing as a serf... On March 31,2014,Phentok,the first woman mountaineer in the world to reach the summit of Mt.Qomolangma from the north side,passed away because of complications from diabetes,aged75.From her humble upbringing as a serf to the first Chinese woman on Mt.Qomolangma,she left behind 展开更多
关键词 珠穆朗玛峰 MT 女人 生活 糖尿病并发症
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职工基本医疗保险再分配效应的理论模型和实证分析
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作者 褚福灵 纪文芳 《中央财经大学学报》 北大核心 2026年第1期45-60,共16页
职工基本医疗保险有利于推动收入再分配和实现共同富裕。本文从制度层面构建再分配理论模型,通过对比参保者获得医保报销前工资性收入的基尼系数与获得医保报销后工资性收入的基尼系数,分析两类基尼系数的差距,评估职工基本医保的再分... 职工基本医疗保险有利于推动收入再分配和实现共同富裕。本文从制度层面构建再分配理论模型,通过对比参保者获得医保报销前工资性收入的基尼系数与获得医保报销后工资性收入的基尼系数,分析两类基尼系数的差距,评估职工基本医保的再分配效果。如果医保报销医疗费用后的工资性收入差距变小,表明再分配为正效应,反之为负效应。研究发现住院费用低于起付线时,再分配未发挥作用;超过起付线后,医保报销能正向调节收入差距,且费用支出档次越高,效果越强。基于2019年中国家庭金融调查(CHFS)数据实证测算,发现职工医保在全国及各地区均能缩小收入差距,中部地区效果最佳,东北地区最弱。分档测算显示,职工医保在各医疗费档次下均为正向调节收入,且住院报销效果优于非住院报销。制度仍存在缴费机制不合理、地区待遇差距大、基金统筹层次低等问题。为此,本文提出按实际收入调整缴费标准、推进医保区域制度一体化、加强基金统筹管理等建议。 展开更多
关键词 职工基本医疗保险 再分配效应 基尼系数 MT指数
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水稻金属硫蛋白基因家族鉴定及OsMT1.3A和OsMT1.4A功能分析 被引量:1
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作者 苗渝青 张超 +5 位作者 韩子静 翟雨航 张文祺 金锐 张振华 陈海飞 《生物工程学报》 北大核心 2026年第1期288-302,共15页
金属硫蛋白(metallothionein,MT)是一类低分子量蛋白。目前,已有大量关于植物吸收和调控重金属Cd积累的分子机制的研究,然而研究结果相对来说不够系统,主要集中于部分转运蛋白的研究。为系统揭示金属硫蛋白在水稻调控网络中的潜在功能,... 金属硫蛋白(metallothionein,MT)是一类低分子量蛋白。目前,已有大量关于植物吸收和调控重金属Cd积累的分子机制的研究,然而研究结果相对来说不够系统,主要集中于部分转运蛋白的研究。为系统揭示金属硫蛋白在水稻调控网络中的潜在功能,并弥补现有研究在基因家族层面系统性的不足的缺口,本研究通过生物信息学分析,共鉴定到14个水稻金属硫蛋白基因家族成员,水稻金属硫蛋白基因家族成员的motif有较大差异,蛋白序列的进化树分析将其分为4类亚家族,其中OsMT1.4A、OsMT1.4B、OsMT1.4C、OsMT1.1C、OsMT1.1G串联成簇分布在12号染色体上。预测的顺式元件与植物激素、生长、环境、光响应相关。大部分的金属硫蛋白受各类激素诱导表达,镉胁迫诱导其中10个成员的表达量上调。OsMT1.3A、OsMT1.3B保守结构域与其他OsMTs差异较大,表达模式与其他家族基因截然不同。异源表达OsMT1.3A、OsMT1.4A显著提高了细菌和酵母对Cd的耐受性,水稻中过表达OsMT1.4A显著增加了有效穗数和产量。本研究为通过生物技术的手段培育Cd耐受并具有修复Cd污染潜力的农作物提供了优异的基因资源。 展开更多
关键词 水稻 微生物 镉胁迫 金属硫蛋白基因家族 表达模式
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血浆瓜氨酸浓度降低是MT‑ATP6基因相关线粒体病新生儿疾病筛查生化标志:2例病例报道并文献复习
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作者 鄢慧明 全颖 +4 位作者 周莹 蒋罗 张靓玉 万正卿 席惠 《中国当代儿科杂志》 北大核心 2026年第2期250-256,共7页
该文报道血浆瓜氨酸(plasma citrulline,pCit)浓度降低对于MT‑ATP6基因相关线粒体病早期识别的价值。病例1,3月龄急性起病,迅速进展为代谢危象、多器官功能衰竭及中枢性呼吸衰竭而夭折。病例2,6月龄发病,逐步出现发育落后,影像学显示双... 该文报道血浆瓜氨酸(plasma citrulline,pCit)浓度降低对于MT‑ATP6基因相关线粒体病早期识别的价值。病例1,3月龄急性起病,迅速进展为代谢危象、多器官功能衰竭及中枢性呼吸衰竭而夭折。病例2,6月龄发病,逐步出现发育落后,影像学显示双侧基底节对称性病变,诊断为Leigh综合征,在补充瓜氨酸及综合干预后,智能发育和代谢指标均得到改善。2例患儿均存在MT‑ATP6基因m.8993T>G(p.L156R)变异,确诊为MTATP6基因相关线粒体病。该病例系列提示,新生儿疾病筛查pCit浓度降低应警惕线粒体MT‑ATP6基因相关线粒体病可能,早期诊断和代谢干预有利于改善预后。 展开更多
关键词 线粒体病 MT‑ATP6 m.8993T>G 低瓜氨酸血症 新生儿疾病筛查
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地层和电阻率约束反演在神居山地区地热资源勘查中的应用研究
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作者 李琳 季克其 +1 位作者 王军成 高士银 《地下水》 2026年第1期184-188,215,共6页
目前地热资源的勘探主要集中在中深部、深部,而地球物理方法在分辨率和探测深度上存在一定的相悖性,特别是在覆盖层较厚、热储埋深较大的地区,地热资源的勘探难度也进一步增大。不同的物探方法在勘探精度、勘探深度、生产成本等方面均... 目前地热资源的勘探主要集中在中深部、深部,而地球物理方法在分辨率和探测深度上存在一定的相悖性,特别是在覆盖层较厚、热储埋深较大的地区,地热资源的勘探难度也进一步增大。不同的物探方法在勘探精度、勘探深度、生产成本等方面均存在一定的优势,加之物探成果往往具有多解性,这就要求地热资源勘探要通过多种勘探技术和反演方法综合分析来提高勘探的精度。以神居山地热资源勘查为例,建立以微动分层为基础、以大地电磁和音频大地电磁电阻率为填充的地电模型,并代入实测的CSAMT法和WFEM法实测数据进行反演,提高了反演精度和近场数据的利用率,在一定程度上优化了勘探数据,减少了反演的多解性,提高了勘探成果的可靠性;最终建立了一套适用于中深部和深部的约束反演流程体系,为地热资源勘探提供了可靠的科学依据。 展开更多
关键词 地层约束 电阻率约束 地电模型 约束反演 CSAMT法 AMT法 MT法 MSM法 WFEM法
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基于大语言模型的世界鱼类拉汉对偶翻译
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作者 钱建硕 丁刘勇 +3 位作者 李雁羽 陈晋南 王环珊 何德奎 《湖泊科学》 北大核心 2026年第1期425-434,I0054-I0059,共16页
物种名是生物分类学的核心概念,是认识和描述生物多样性的前提。拉丁种名的命名具有语言独立性、规范性和唯一性,不受地域和语言差异影响,确保跨语言、跨学科交流的准确性;但物种地方名(俗名)缺少命名规则,融合了历史与文化传统,往往存... 物种名是生物分类学的核心概念,是认识和描述生物多样性的前提。拉丁种名的命名具有语言独立性、规范性和唯一性,不受地域和语言差异影响,确保跨语言、跨学科交流的准确性;但物种地方名(俗名)缺少命名规则,融合了历史与文化传统,往往存在误用、混乱甚至是缺失的情况,特别是在鱼类中,约20%的物种缺少中文名,严重制约了生物多样性认知、跨语言交流、科学传播和数据共享与利用等。为应对这一问题,本研究整合《拉汉世界鱼类系统名典》等多个权威数据源,构建了60564条高质量拉丁学名与中文名双语平行语料库。基于多语言大模型mT5(multilingual text-to-text transfer transformer,包含small、base、large三种参数规模),引入对偶学习框架与命名规则约束,实现鱼类中文名的自动生成与校正。结果显示,微调后的mT5-large模型在独立测试集上获得的BLEURT和COMET的对偶译质评分分别为0.90和0.93,较DeepSeek-R1等通用大语言模型提升38%~159%,并将低频属名与新描述种名的翻译错误率降低25%~80%。所有生成的鱼类中文名均由分类学专家逐条审定,以确保命名的科学性和规范性。本研究首次系统性地补全了全球鱼类的中文名系统,打通了物种学名与俗名之间的信息壁垒;并开发配套微信小程序面向所有用户开放,实时更新种名信息和分类变动。研究方法为其他生物类群的多语言俗名翻译提供了可复制、可推广的技术范式,助力全球生物多样性与文化多样性保护实践。 展开更多
关键词 双命名法 鱼类命名编目 对偶学习 mT5大语言模型
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MT双螺套机械连接配合630 MPa高强钢筋在预制混凝土构件中的研究与应用
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作者 邹翾 胡晓依 +1 位作者 赵宝军 储宏道 《建筑施工》 2026年第1期54-58,67,共6页
预制混凝土构件受力钢筋连接方法是装配式建筑的关键技术之一。为分析MT双螺套机械连接的可靠性,通过多种直径的630 MPa钢筋机械接头型式检验,得出MT双螺套筒能满足一级接头的标准;同时,对多个预制装配式工程应用结果进行分析,得出MT双... 预制混凝土构件受力钢筋连接方法是装配式建筑的关键技术之一。为分析MT双螺套机械连接的可靠性,通过多种直径的630 MPa钢筋机械接头型式检验,得出MT双螺套筒能满足一级接头的标准;同时,对多个预制装配式工程应用结果进行分析,得出MT双螺套机械连接配合使用高强钢筋具有较好的施工优势和经济性,可促进装配式建筑的可持续发展。 展开更多
关键词 装配式建筑 预制混凝土构件 高强钢筋 MT双螺套连接
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30 mT梁运输与跨墩龙门吊提升施工工艺
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作者 周少成 《交通世界》 2026年第4期228-230,共3页
为应对T梁运输过程中易倾覆、吊装作业期间可能出现摆动等问题,以袁河特大桥工程项目为例,分析了30 mT梁运输和跨墩龙门吊提升的关键技术要点,包括龙门吊拼装及调试、T梁装运及提升作业、T梁及特殊梁跨架设作业等,并提出了地面运输与架... 为应对T梁运输过程中易倾覆、吊装作业期间可能出现摆动等问题,以袁河特大桥工程项目为例,分析了30 mT梁运输和跨墩龙门吊提升的关键技术要点,包括龙门吊拼装及调试、T梁装运及提升作业、T梁及特殊梁跨架设作业等,并提出了地面运输与架梁作业中的相关注意事项,可为T梁吊装工程提供参考。 展开更多
关键词 30 mT梁 吊装作业 龙门吊 提升施工
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矿用卡车RP接触器改造
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作者 朱健伟 王世龙 +2 位作者 白水 任会斌 刘庆成 《设备管理与维修》 2026年第1期98-100,共3页
MT4400AC型矿用卡车主要承担露天煤矿原煤运输任务,现场工作环境恶劣,随着采煤区变动,运输坡度加大,导致电制动频繁投入,进而导致RP接触器经常烧蚀,增加维修成本,降低生产效率。对矿用卡车电控制动系统进行分析,提出矿用卡车RP接触器改... MT4400AC型矿用卡车主要承担露天煤矿原煤运输任务,现场工作环境恶劣,随着采煤区变动,运输坡度加大,导致电制动频繁投入,进而导致RP接触器经常烧蚀,增加维修成本,降低生产效率。对矿用卡车电控制动系统进行分析,提出矿用卡车RP接触器改造方案。实践证明,该方案能够有效降低矿用卡车故障率及维修成本,为矿区生产提供保障。 展开更多
关键词 MT4400AC矿用卡车 RP接触器 故障率
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Organochlorine pesticides in fresh-fallen snow on East Rongbuk Glacier of Mt.Qomolangma (Everest) 被引量:6
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作者 WANG Feng ZHU Tong +1 位作者 XU BaiQing KANG ShiChang 《Science China Earth Sciences》 SCIE EI CAS 2007年第7期1097-1102,共6页
During a field campaign in April 2005,fresh-fallen snow samples were collected on the East Rongbuk Glacier of the Mt. Qomolangma at four altitudes (6500 m,6300 m,6100 m and 5900 m),to study the role of Mt. Qomolangma ... During a field campaign in April 2005,fresh-fallen snow samples were collected on the East Rongbuk Glacier of the Mt. Qomolangma at four altitudes (6500 m,6300 m,6100 m and 5900 m),to study the role of Mt. Qomolangma as "cold-traps" for Persistent Organic Pollutants. From these snow samples col-lected at the highest-altitude,organochlorine pesticides (OCPs):HCB,p,p′-DDT and p,p′-DDD were detected,with the concentrations in the ranges of 44―72 pg/L,401―1560 pg/L,and 20―80 pg/L,re-spectively. The concentration of o,p′-DDT was around the method detection limit. Analysis of backward trajectories showed that the detected compounds came from the north of India,suggesting that DDTs detected in the snow were possibly originated from new emissions in this area. Relationships between the concentrations of OCPs in snow samples and the sampling altitudes were discussed. The altitudes had no obvious effect on HCB concentrations in the fresh-fallen snow,while increases in the concen-trations of p,p′-DDT and p,p′-DDD with increasing altitude were found,which was reversed compared to the trends observed in North America. Three factors likely resulted in this trend: (1) the properties of the target compounds; (2) the low temperatures at high altitudes; and (3) the location of the mountain sampling sites relative to their sources. 展开更多
关键词 Mt. Qomolangma (Everest) Tibet ORGANOCHLORINE PESTICIDES SNOW LONG-RANGE transport
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作为IEEE802网桥的5G LAN系统架构
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作者 李涵宇 《邮电设计技术》 2026年第1期87-92,共6页
为了实现5G网络对局域网业务的支持,解决现有5G局域网技术推广问题,提出了作为IEEE802网桥的5G局域网系统架构。首先说明了5G局域网技术的应用场景和现状,并阐述了现有5G局域网技术的方案及其局限性。然后进行针对性的改进,把3GPP标准... 为了实现5G网络对局域网业务的支持,解决现有5G局域网技术推广问题,提出了作为IEEE802网桥的5G局域网系统架构。首先说明了5G局域网技术的应用场景和现状,并阐述了现有5G局域网技术的方案及其局限性。然后进行针对性的改进,把3GPP标准终端解耦为终端设备和移动终端,把移动终端改进为IEEE802标准端口,与核心网、接入网和承载网组合成为IEEE802标准网桥。实现了IEEE802局域网与5G无线通信网络的融合,在融入IEEE802技术的基础上推动5G局域网技术的应用。最后对该架构的应用前景进行了展望。 展开更多
关键词 5G局域网 终端 终端设备 移动终端 IEEE802网桥 端口 MAC中继实体
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On crustal movement in Mt.Qomolangma area 被引量:1
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作者 陈俊勇 王泽民 +2 位作者 庞尚益 张骥 张全德 《Science China Earth Sciences》 SCIE EI CAS 2002年第3期233-240,共8页
Mt. Qomolangma lies in the collision zone between the fringe of Eurasia plate and Indian plate. The crustal movement there is still very active so far. In the past three decades China carried out five geodetic campaig... Mt. Qomolangma lies in the collision zone between the fringe of Eurasia plate and Indian plate. The crustal movement there is still very active so far. In the past three decades China carried out five geodetic campaigns in Mt. Qomolangma and its north vicinal area, independently or cooperatively with other countries, including triangulation, leveling, GPS positioning, atmospheric, astronomical and gravity measurements. On the basis of the observation results achieved in the campaigns the crustal movements in the area were studied and explored. A non-stationary phenomenon both in time and space of the crustal vertical movement in the area is found. There seems to be some relevance between the phenomenon of non-stationary in time and seismic episode in China. The phenomenon of non-stationary in space is possibly relevant to the no-homo- geneity of crustal medium and non-uniform absorption of terrestrial stress. The horizontal crustal movement in the area is in the direction of NEE at a speed of 6—7 cm per year, and the trend of strike slip movement is manifested evidently in the collision fringe of Indian plate and Qinghai-Xizang block. 展开更多
关键词 Mt. Qomolangma CRUSTAL movement geodynamics.
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