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一种面向配网设备的在线红外测温系统设计

电工技术 2024年第3期 139-142,146页

作者：张光儒张家午赵军马振祺陈杰国网甘肃省电力公司电力科学研究院甘肃兰州730070 国网甘肃省电力公司甘肃兰州730000

设计了一种面向配网设备的在线红外测温系统,阐述了该系统的设计思路及工作原理,介绍了系统工作流程;利用该系统对一台标准热源进行温度测量,验证其测量重复性;同时,与目前电力系统现场设备红外测温领域广泛应用的红外测温仪进行对比分... 详细信息

设计了一种面向配网设备的在线红外测温系统,阐述了该系统的设计思路及工作原理,介绍了系统工作流程;利用该系统对一台标准热源进行温度测量,验证其测量重复性;同时,与目前电力系统现场设备红外测温领域广泛应用的红外测温仪进行对比分析,验证该红外测温系统的测量有效性及优势,为系统后续深化应用提供参考。

关键词：配网设备红外测温系统重复性验证

Palaeovegetational and palaeoenvironmental changes since the last deglacial in Gonghe Basin, northeast Tibetan Plateau

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Journal of Geographical Sciences 2013年第1期23卷 136-146页

作者： CHENG Bo CHEN Fahu zhang jiawu College of Urban and Environmental Sciences Central China Normal University Wuhan 430079 China Key Laboratory of Western China's Environmental Systems (Ministry of Education) Lanzhou UniversityLanzhou 730000 China

Paleoenvironmental history in the monsoonal margin in the northeast Tibetan Pla- teau provides important clue to the regional climate. Previous researches have been limited by either poor chronology or low resolution. Here we present a high-resolution pollen record from a 40.92-m-long sediment core （DLH） taken from Dalianhai, a terminal lake situated in the Gonghe Basin, the northeast Tibetan Plateau for reconstructing the vegetation and climate history since the last deglacial on the basis of a chronology controlled by 10 AMS 14C dates on plant remains preserved in the core sediments. The pollen assemblages in DLH core can be partitioned into 6 pollen zones and each zone is mainly characterized by the growth and decline of tree or herb pollen percentage. During the periods of 14.8-12.9 ka and 9.4-3.9 ka, the subalpine arboreal and local herbaceous pollen increased, indicating the subalpine forest developed in the surrounding mountains and a desert steppe or typical steppe developed in Gonghe Basin under a relatively moister climate. During the periods of 15.8-14.8 ka, 12.9-9.4 ka and 3.9-1.4 ka, the forest shrank or disappeared according to different degrees of aridity, and the desert steppe degraded to a more arid steppe desert in the basin, indicating a dry climate. After 1.4 ka, vegetation type around Dalianhai was mainly dominated by steppe suggested by increased Artemisia. Our results suggested the climate history in this region was dry from 15.8-14.8 ka, humid from 14.8-12.9 ka and dry from 12.9-9.4 ka, after which the climate was humid during 9.4-3.9 ka, followed by dry conditions during 3.9-1.4 ka and humid conditions in the last 1.4 ka. The change of pollen percentage and the evolution of palaeovegetation in Dalianhai since the last deglacial were similar to those recorded in Qinghai Lake. The forest expanded in the mountains around Dalianhai during the Bol- ling-Aller^d period, shrank during the Younger Dryas and the early Holocene, then it devel- oped an

关键词： pollen record Dalianhai last deglacial Holocene palaeovegetation

Paleohydrological Changes in the Western Tibetan Plateau over the Past 16,000 years Based on Sedimentary Records of n-Alkanes and Grain Size

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Acta Geologica Sinica(English Edition) 2020年第3期94卷 707-716页

作者： WANG Mingda YANG Yaping zhang jiawu HOU Juzhi Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Western China’s Environmental System(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China

Both monsoons and westerlies have exerted influence on climate dynamics over the Tibetan Plateau(TP) since the last deglaciation, producing complex patterns of paleohydroclimatic conditions. Diverse proxy records are essential to forge a robust understanding of the climate system on the TP. Currently, there is a general lack of understanding of the response of inland lakes over the TP to climate change, especially glacier-fed lakes. Paleohydrological reconstructions of such lakes could deepen our understanding of the history of lake systems and their relationship to regional climate variability. Here we use records of n-alkanes and grain size from the sediments of Bangong Co in the western TP to reconstruct paleohydrological changes over the past 16,000 years. The Paq record(the ratio of non-emergent aquatic macrophytes versus emergent aquatic macrophytes and terrestrial plants) is generally consistent with the variations in summer temperature and precipitation isotopes. The changes in grain-size distributions show a similar trend to Paq but with less pronounced fluctuations in the early-middle Holocene. The new data combined with previous results from the site demonstrate that: 1) Bangong Co experienced relatively large water-level fluctuations during the last deglaciation, with a steadily high lake-level during the early-middle Holocene and a decreasing lake-level in the late Holocene;2) The lake level fluctuations were driven by both high summer temperatures via the melting water and monsoon precipitation. However, the dominant factor controlling lake level changed over time. The lake-level history at Bangong Co deduced from the n-alkanes and grain-size records reveals the past hydrological changes in the catchment area, and stimulates more discussion about the future of glacier-fed lakes under the conditions of unprecedented warming in the region.

关键词： lake level n-alkane Paq grain size Bangong Co Tibetan Plateau

Different climatic controls of soil δ^(13)C_(org) in three mid-latitude regions of the Northern Hemisphere since the Last Glacial period

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Chinese Science Bulletin 2007年第2期52卷 259-266页

作者： RAO ZhiGuo ZHU ZhaoYu zhang jiawu Key Laboratory of Marginal Sea Geology Guangzhou Institute of Geochemistry Chinese 510640 China Center for Arid Environment and Paleoclimate Research (CAEP) Key Laboratory of Westem China's Environmental System ofo Ministry of Education Lanzhou University Lanzhou 730000 China Graduate University of Chinese Academy of Sciences Beijing 100039 China

Paleoecological records of soil δ13Corg from three regions in the middle latitudes of the Northern Hemisphere, including the Chinese Loess Plateau (CLP), the Great Plains and adjacent areas of North America and northwestern Europe, showed different variations since the Last Glacial period. An at-tempt was made to evaluate the causes for the difference in δ13Corg on the basis of the modern climatic data collected in these regions and of the modern C3 and C4 plant distributions. The analysis indicates that temperature, especially the growing season temperature, has a dominant control on the growth of C4 plants. When the mean annual or growing season temperatures are below the "threshold value" , the growth of C4 plants is limited. When the temperature is above the "threshold value" , C4 plants can grow under a wide range of precipitation. However, when the precipitation is high enough to favor the growth of trees, the proportions of C4 plants in local biomass will decline. The implicit control factor recovered by sedimentary records is consistent with the control factor on modern C3/C4 distribution. Pure C3 plants have been dominating the local biomass since the Last Glacial period in European loess region, mainly owing to the low local temperature. The increases in C4 plants from the late Pleistocene to the Holocene in the Chinese Loess Plateau, the Great Plains and adjacent areas, mainly reflect the influ-ence of increasing temperature.

关键词：冰河时代大气污染二氧化碳温度气候变化

The discovery of annually laminated sediments (varves) from shallow Sugan Lake in inland arid China and their paleoclimatic significance

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Science China Earth Sciences 2007年第8期50卷 1218-1224页

作者： ZHOU AiFeng CHEN FaHu QIANG MingRui YANG MeiLin zhang jiawu CAEP Key Laboratory of West China’s Environmental System(Ministry of Education)Lanzhou UniversityLanzhou 730000China

Detailed examination of sedimentary cores retrieved from Sugan Lake in the northern Qaidam Basin of northwest China’s Tibetan Plateau reveal that fine laminated beddings form in the sediments where water depth exceeds 3 m. Seasonal surface sediments trapped at the bottom of the lake suggest that sediments deposited during summer and autumn are mainly light colored monohydrocalcites, while those deposited in winter are dark organic matter, indicating that varve layers form under modern limnological conditions. Continuous varve sediments comprising four types have accumulated in the upper 5.5 m of Core SG03I from the center of the lake. All types exhibit clear seasonality indicative of annual deposition. Varve counts correspondence with 210Pb dates on recent sediments in the upper core suggest the continuous varves of the upper 5.5 m of the core formed in the late Holocene (2670 a BP). The Sugan Lake varve sequence is the first demonstration of annually laminated sediments re-ported in arid western China.

关键词： Sugan Lake varve Tibetan Plateau arid China

Effects of climate change and human activity on lake shrinkage in Gonghe Basin of northeastern Tibetan Plateau during the past 60 years

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Journal of Arid Land 2016年第4期8卷 479-491页

作者： WU Duo CHEN Fahu LI Kai XIE Yaowen zhang jiawu ZHOU Aifeng College of Earth and Environmental Sciences MOE Key Laboratory of Western China's Environmental SystemsLanzhou University

Changes in the status of freshwater resources are a topic of major global, regional and local concern. This is especially so in the arid and semi-arid regions of China, where shortage of water resources plays a crucial role in limiting sustainable socioeconomic development, as well as in sustaining natural ecosystems. Recent climate change, as well as the effects of localized human activity, such as the use of water for irrigation agriculture, may have significant effects on the status of the water resources in the region. Here, we report the results of a study of changes in the areas of lakes in Gonghe Basin, northeastern Tibetan Plateau of China, over the last 60 years. The data were acquired from optical satellite images and demonstrate that the total water area of lakes in Gonghe Basin decreased significantly from the 1950s to 1980s. The cause is ascribed mainly to human activity including exploitation of farmland, against a background of increasing population; in addition, climatic data for the region demonstrate a minor drying trend during this period as the temperature increased slightly. After the construction of several reservoirs, significant amounts of water were redistributed to promote irrigation agriculture and we conclude that this caused a significant shrinkage of the natural lakes. However, both the area of farmland and the population size remained approximately constant after 1990. We conclude that the variation of the total area of lakes during the second period was mainly controlled by climatic factors （precipitation and temperature）. As the regional temperature reached a new high, the area of some of the lakes decreased sharply before finally maintaining a relatively steady state. We emphasize that anthropogenic climate change and human activity have both significantly influenced the status of water resources in the arid and semi-arid regions of China.

关键词： Gonghe Basin lake shrinkage climate change human activity

Cav3.2 channel regulates cerebral ischemia/reperfusion injury:a promising target for intervention

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Neural Regeneration Research 2024年第11期19卷 2480-2487页

作者： Feibiao Dai Chengyun Hu Xue Li Zhetao zhang Hongtao Wang Wanjun Zhou jiawu Wang Qingtian Geng Yongfei Dong Chaoliang Tang Graduate School Wannan Medical CollegeWuhuAnhui ProvinceChina Department of Anesthesiology The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina Core Facility Center for Medical Sciences The First Affiliated Hospital of USTC(Anhui Provincial Hospital)HefeiAnhui ProvinceChina Department of Pharmacy The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina Department of Neurosurgery The First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina

Calcium influx into neurons triggers neuronal death during cerebral ischemia/reperfusion *** calcium channels are involved in cerebral ischemia/reperfusion ***3.2 channel is a main subtype of T-type calcium channels.T-type calcium channel blockers,such as pimozide and mibefradil,have been shown to prevent cerebral ischemia/reperfusion injury-induced brain ***,the role of Cav3.2 channels in cerebral ischemia/reperfusion injury remains ***,in vitro and in vivo models of cerebral ischemia/reperfusion injury were established using middle cerebral artery occlusion in mice and high glucose hypoxia/reoxygenation exposure in primary hippocampal *** results showed that Cav3.2 expression was significantly upregulated in injured hippocampal tissue and primary hippocampal *** further established a Cav3.2 gene-knockout mouse model of cerebral ischemia/reperfusion ***3.2 knockout markedly reduced infarct volume and brain water content,and alleviated neurological dysfunction after cerebral ischemia/reperfusion ***,Cav3.2 knockout attenuated cerebral ischemia/reperfusion injury-induced oxidative stress,inflammatory response,and neuronal *** the hippocampus of Cav3.2-knockout mice,calcineurin overexpression offset the beneficial effect of Cav3.2 knockout after cerebral ischemia/reperfusion *** findings suggest that the neuroprotective function of Cav3.2 knockout is mediated by calcineurin/nuclear factor of activated T cells 3 *** from this study suggest that Cav3.2 could be a promising target for treatment of cerebral ischemia/reperfusion injury.

关键词： calcineurin Cav3.2 channel cerebral ischemia/reperfusion hippocampus hypoxia/reoxygenation inflammatory response nuclear factor of activated T cells 3 oxidative stress primary hippocampal neurons stroke

Extension of drylands in northern China around 250 kaBP linked with the uplift of the southeast margin of Tibetan Plateau

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Chinese Science Bulletin 2002年第20期47卷 1739-1745页

作者： WU Haibin GUO Zhengtang FANG Xiaomin zhang jiawu CHEN Fahu Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China Department of Geography Lanzhou UniversityLanzhou 730000China Institute of Earth Environment Chinese Academy of SciencesXi'an 710075China

Study on two loess sections, one located at Wu-wei near the Tengger Desert in northwestern China, another located near Ganzi at the southeast margin of the Tibetan Plateau in southwest China, reveals a coeval drying step occurred at -250 kaBP. It is expressed by the increase in eolian grain-size at Wuwei, and by a drastic extension of C4 plants and a decrease of loess chemical weathering intensity at Ganzi. Examination of the available eolian data indicates that the event has also been clearly documented in the loess sections near the deserts in northern China, and in the eolian records from the North Pacific. On the contrary, the signal is rather weak for the central and southern Loess Plateau regions as well as for Central Asia, where the climates are influenced by the southeast Asian monsoon and the westerlies, respectively. Since the climate at Ganzi is under strong control of the southwest Asian monsoon, we interpret this drying step as a result of decreased influence of the southwest summer

关键词： aridification loess-paleosol sequences organic carbon isotope chemical weathering intensity Tibetan Plateau.

Comparison of the carbon isotope composition of total organic carbon and long-chain n-alkanes from surface soils in eastern China and their significance

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Chinese Science Bulletin 2008年第24期53卷 3921-3927页

作者： RAO ZhiGuo JIA GuoDong ZHU ZhaoYu WU Yi zhang jiawu State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Key Laboratory of Marginal Sea Geology Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Key Laboratory of Western China's Environment Systems Ministry of Education Lanzhou University Lanzhou 730000 China

Surface soil samples collected over a high spatial resolution in eastern China were analyzed for carbon isotope composition(δ 13C) of total organic carbon(TOC) and higher plant-derived long-chain n-alkanes,with the latter reported as weighted mean *** two sets of δ 13C values are significantly correlated and show similar trends in spatial *** spatial distribution of δ 13C shows less negative values in the mid-latitudes between 31°N and 40°N and more negative ones at higher and lower *** is consistent with previously reported carbon isotope data from surface soil phytoliths in the same region and suggests that the mid-latitude area provides relatively favorable growing conditions for C4 ***,δ 13C values of both TOC and long-chain n-alkanes from 12 surface soil samples collected from a small grassland in north China displayed similar carbon isotope values and the difference between paired δ 13C of a soil samples remains relatively *** data demonstrate that in eastern China,soil δ 13C composition of both TOC and long-chain n-alkanes is effective indicators of C3/C4 ratios of the prevailing *** work suggests that -22‰ and -32‰ are good estimated end members for the weighted mean δ 13C values of long-chain n-alkanes(C27,C29 and C31 n-alkanes) from soils under dominant C4 or C3 vegetation,allowing us to reconstruct paleovegetation trends.

关键词：植物总有机碳碳同位素表面土壤