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Magnetic characteristics of dustfall in urban area of north china and its environmental significance

science china Earth sciences 2007年第11期50卷 1724-1732页

作者： XIA Dunsheng1,2, YANG LiPing2, MA JianYing1, YU Ye1, WANG Guan2 & CHEN FaHu2 1 key laboratory of Desert and Desertification, Institute of Cold and Arid Regions environmental and Engineering, Chinese Academy of sciences, lanzhou 730000, china 2 caep, key laboratory of west china’s environmental system (Ministry of Education), lanzhou university, lanzhou 730000, china key laboratory of Desert and Desertification Institute of Cold and Arid Regions Environmental and Engineering Chinese Academy of Sciences Lanzhou China caep Key Laboratory of West China’s Environmental System (Ministry of Education) Lanzhou University Lanzhou China

Urban particulate pollutants not only affect urban air quality but also directly threaten public health. lanzhou has been one of the most seriously polluted cities in the world due to its special geophysical location and weather conditions, which makes it an ideal place for urban particulate pollution study. In this study a set of environmental magnetic parameters (χ_(1f),χ_(fd)%, χ_(ARM), sIRM, HIRM, sOFT and back field IRM) were measured and analyzed for the dustfall samples collected monthly during 1997.4—2000.5 and 2004.11—2005.10 at lanzhou university campus (KLD and CCs) and at a clear site of Gaolanxian (GLX). Results demonstrate that the main magnetic minerals in the dustfall are magnetite, with some maghaemite and haematite. Cross plots of M_(rs)/M_s vs. B_(cr)/B_c and χ_(fd)% vs. χ_(ARM)/sIRM indicate that the main magnetic grain sizes are pseudo-single-domain (PsD). The high concentration of magnetic minerals in the dustfall indicates that lanzhou is seriously polluted. The main pollution sources are anthropogenic activities and nature dust, with the former posing a great threat during the whole year, which is different from the general view that the natural dust is the main contributor in summer. With great efforts of the government and local authority in the past decades, the air quality in lanzhou has been improved in winter, but it is not so obvious in summer. This study also reveals that as a simple, rapid and accurate technology, environmental magnetism could be a valuable tool for urban pollution study.

关键词： environmental magnetism,dustfall,air pollution,lanzhou

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Dating and genesis of the upper Weihe River terraces in Longxi basin,china

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Progress in Natural science:Materials International 2007年第11期17卷 1334-1340页

作者： Pan Baotian, Liu Xiaofeng, Gao Hongshan, Wang Yong and Li Jijun(key laboratory of western china’s environmental system, Ministry of Education, lanzhou university, lanzhou 730000, china) key laboratory of western china's environmental system Lanzhou University Lanzhou 730000 China

seven terraces along the Weihe River in Longxi basin have been investigated. These terraces all consist of archetypal duality in structure, namely the floodplain deposits and the layer of gravels overlaid by varying thickness of the loess. By resorting to various dating approaches such as palaeomagnetic, optically stimulated luminescenece (OsL), 14C and loess-paleosol sequence, we provide preliminary timing of these seven terraces along upper Weihe River. Analysis on sedimentation characteristics and dating of these terraces showed that seven terraces may be jointly generated by tectonic uplifts and climatic changes. Tectonic uplifts may accommodate initial river incision, and climatic change may be responsible for processes of subsequent channel widening and aggradation. Aggradation normally occurs during glacial periods, in contrast to down-cuttings during transitions from glacial to interglacial period. Moreover, on the basis of the timings and heights of these terraces, we infer that the long-term rate of river incision was determined to be 0.2 m/kyr during the last 870 kyr, which differs from other river incision rates. This discrepancy may reflect spatio-temporal differentiation of tectonic activities in the Qinling orogenic belt during the Pleistocene.

关键词： loess stratigraphy river terraces climate change Upper Weihe River

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The environmental signal of an early Holocene pollen record from the shiyang River basin lake sediments, NW china

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Chinese science Bulletin 2002年第4期47卷 267-273页

作者： ZHU Yan, CHEN Fahu & Madsen DavidCollege of geography and Environment, Northwest Normal university, lanzhou 730070, china National key laboratory of west environmental system, lanzhou university, lanzhou 730000, china Utah Geological surv College of geography and Environment Northwest Normal University Lanzhou China National key laboratory of west environmental system Lanzhou University Lanzhou China Utah Geological survey Utah USA

Pollen analyses of 85 samples from the san-jiaocheng section well along the margin of a palaeolake at the end of the shiyang River, NW china, show that Picea and sabina dominate the pollen assemblage. Together they reach as high as 40%-60%, with the percentage of Picea varying inversely with that of sabina. similar results were obtained from another section in the shiyang River drainage. Using modern ecological habitat relationship analogues, pol-len transport characteristics, and the overall pollen assem-blage, we propose that both Picea and sabina pollen were transported by the river from the mountains at the upper reaches of the shiyang River, and that the assemblage is more indicative of changes in upland vegetation than of local conditions near the section. This interpretation is supported by pollen data derived from surface samples, water samples, and riverbed samples. Using a moisture indicator (the Picea to sabina ratio) and calculated pollen concentrations, we identify a series of

关键词： NW china The environmental signal of an early Holocene pollen record from the shiyang River basin lake sediments

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Holocene climate variation denoted by Barkol Lake sediments in northeastern Xinjiang and its possible linkage to the high and low latitude climates

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science china Earth sciences 2011年第4期54卷 603-614页

作者： XUE JiBin & ZHONG Wei 1 school of Geography,south china Normal university,Guangzhou 510631,china 2 key laboratory of Oasis Ecology(Ministry of Education) ,Xinjiang university,Urumqi 830046,china 3 key laboratory of western china's environmental systems(Ministry of Education) ,lanzhou university,lanzhou 730000,china school of Geography South China Normal University Guangzhou China key laboratory of Oasis Ecology (Ministry of Education) Xinjiang University Urumqi China key laboratory of western china’s environmental systems (Ministry of Education) Lanzhou University Lanzhou China

The climate over the closed inland Barkol Lake,which is located in northeastern Xinjiang Uygur Autonomous Region,is significantly influenced by westerly winds *** improve our understanding of past climate processes in westerly wind influenced regions in northwestern china,a 250-cm sediment section was retrieved from this *** taking the carbon reservoir effect into consideration,the chronological sequence of this section was reconstructed based on seven conventional radiocarbon dates of bulk samples,and the bottom age of this section was determined to be about 9400 cal a ***-proxy datasets,includingδ18O car,δ13C car of authigenic carbonate,and total organic carbon were examined using wavelet analysis and singular spectrum analysis *** show that the Holocene in the Barkol Lake region can be divided into four stages:(1) a cold and dry early stage before～8000 cal a BP;(2) a moderately warm and wet middle stage between～8000 and 6000 cal a BP;(3) a warm and dry stage,along with a cooling-wetting tendency from 6000 to 2700 cal a BP;and(4) a fluctuating cooling and wet stage between 2700-800 cal a BP,and a drier stage since 800 cal a *** general trend of Holocene climatic changes revealed by Barkol Lake sediments was in agreement with that of adjacent *** infer that climatic changes during the Holocene in the Barkol Lake region were influenced not only by high latitudes,especially the North Atlantic region climate,but also tropical low-latitude processes,such as the El Nio/La Nia-southern *** study demonstrates that the enhanced activities of ENsO may have played an important role in climatic changes in northeastern Xinjiang during the *** results also suggest that climatic patterns may be temporally different in the northern Xinjiang area in response to the changing predominant control of either the westerly or the Asian summer monsoon,depending on the contrast of their relative strengths.

关键词： Barkol Lake Holocene climate change tropical processes northern high-latitude climate

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Characteristics and origins of primary fluids and noble gases in mantle-derived minerals from the Yishu area,shandong Province,china

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science china Earth sciences 2006年第1期49卷 77-87页

作者： MA Jinlong1,2, TAO Mingxin2,3 & YE Xianren2 1. Resources and environmental school, lanzhou university, lanzhou 730000, china 2. key laboratory of Gas Geochemistry, Institute of Geology and Geophysics, Chinese Academy of sciences, lanzhou 730000, china 3. College of Resources science & Technology, Beijing Normal university, Beijing 100875, china Resources and environmental school Lanzhou University Lanzhou China key laboratory of Gas Geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou China College of Resources science & Technology Beijing Normal University Beijing China

Fluids and noble gases of mantle-derived materials are important tracers forthe mantle information. Compositions of primary fluids and noble gases in mantle-derived mineralsfrom the Yishu area, shandong Province, china, were tested by the methods of heat-bursting andheat-melting respectively. The fluids are mainly composed of CO_2, CO and H_2, which account forabout 90% of the total, and are similar to the mantle-derived rocks from other areas of easternchina; ratios of ~3He/~4He in almost all samples range from 0.82 Ra to 2.74 Ra, whereas^(40)Ar/^(36)Ar from 299.5 to 758.8. Both ranges are much lower than those of the typical oceanmantle-derived samples (such as MORB) and primarily reflect the influences of the atmosphericcomponents and the radiogenic isotopes. Ratios of C/~3He range from 27.6 x 10~9 to 1050 x 10~9,N_2/Ar from 927 to 56612, and N_2/~3He from 2.5 x 10~9 to 27 x 10~9, similar to those in westernUnited states and New Zealand which belong to the tectonic plate collision regions. The ratios fallin the intersect of mantle-crust-atmosphere in the comprehensive tracer-charts, reflecting theinfluences of the atmosphere and the crusts with organic components. Our results suggest that thecomposition of the primary fluids and the isotopic ratios of the noble gases may either reflect theevolution process of mantle-derived rocks connected with the rise and eruption of magma, or theinfluence of the ancient subduction-plate on the continental mantle of this region.

关键词： noble gases, primary fluids, mantle-derived minerals, Yishu area.

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Vicissitude of sogo Nur and environmental-climatic change during last 1500 years

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science china Earth sciences 2004年第Z1期47卷 61-70页

作者： JIN Heling, XIAO Honglang, sUN Liangying, ZHANG Hong, sUN Zhong & LI Xiaozekey laboratory of Desert and Desertification, Cold and Arid Regions environmental and Engineering Research Institute, Chinese Academy of sciences, lanzhou 730000, china school of Resources and Environment, lanzhou university, lanzhou 730000, china key laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China school of Resources and Environment Lanzhou University Lanzhou China

Lakes in arid zone are sensitive to climatic changes. The lacustrine sediment sequence in sogo Nur has well and truly recorded climatic events such as the sui-Tang Dynasty Warm Period, the song-Liao Dynasty Cold Period, the Medieval Warm Period, the Little Ice Age and the 20th Century Warm Period. Commonly, the climate in warm Periods was relatively humid,accordingly the lake area extended and water level rose, and vice versa. Apart from climatic change, human activity is also an important factor of influencing lake vicissitude, and they played the dominant role alternatively during different periods; the factor of climatic change predominated in historical period, while since the beginning of the 20th century the utilization of water resources by human has became decisive.

关键词： granularity, soluble salt, lake vicissitude, climatic change, sogo Nur.

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Terrace dating as an archive of the run-through of the sanmen Gorges

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Progress in Natural science:Materials International 2005年第12期15卷 1096-1103页

作者： PAN Baotian,WANG Junping,GAO Hongshan,CHEN Yingying,LI Jijun and LIU Xiaofeng key laboratory of western china’s environmental systems,Ministry of Education,and Department of Geography,lanzhou university,lanzhou 730000,china key laboratory of western china's environmental systems of Ministry of Education Department of Geography Lanzhou University Lanzhou 730000 China

Analysis of morphological properties in the sanmen Gorges region of the Yellow River shows that four river terraces have been developed at the entrance to the ***,thick aeolian loess-paleosol sequence was deposited on the terraces,which makes it easy to date the *** dating of paleomagnetic,loess-paleosol sequence matching and thermoluminescence show that terraces T2,T3 and T4 were formed 0.129 Ma,0.625 Ma and 0.865 Ma ago,*** formation of these terraces in this region indicates that the Yellow River has experienced four intensive downcutting events during the last 0.9 *** Yellow River cut through the sanmen Gorges and inpoured into the East china sea no later than 0.865 Ma.

关键词： river terrace paleomagnetic dating Yellow River loess

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Discovery of a 1.0 Ma Yellow River terrace and redating of the fourth Yellow River terrace in lanzhou area

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Progress in Natural science:Materials International 2007年第2期17卷 197-205页

作者： PAN Baotian , sU Huai, HU Chunsheng, HU Xiaofei, ZHOU Tian and LI Jijun (key laboratory of western china’s environmental systems, Ministry of Education, and Department of Geography, lanzhou university, lanzhou 730000, china) key laboratory of western china's environmental system MOE Department of Geography Lanzhou University Lanzhou 730000 China

Based on the aeolian loess sequence-stratigraphic division and paleomagnetic datings on terraces, we found that an undiscovered terrace with the age of 1.0 Ma BP lies between the Dunwashan terrace and Wuyishan terrace. This terrace recorded an intensive Yellow River incision event during that period. Results of paleomagnetic dating and optically stimulated luminescence (OsL) dating of the Wuyishan loess section and Zaoshugou loess section on the fourth Yellow River terrace (T4) show that the age of the fourth Yellow River terrace in lanzhou area is 0.86 Ma BP rather than the previously believed 0. 6 Ma BP. This result answers a long-term question in the ge-omorphology community of whether there exists a 0. 8 Ma terrace in lanzhou area. The discovery of the 1. 0 Ma Yellow River terrace and redating of the age of 0.6 Ma terrace in lanzhou area provide new insights into further research on the evolution of Yellow River.

关键词： lanzhou area Yellow River terrace dating.

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Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors

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science china(Technological sciences) 2010年第7期53卷 1957-1966页

作者： DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil Engineering, lanzhou university of Technology, lanzhou 730050, china 2 state key laboratory of Frozen soil Engineering, Cold and Arid Regions environmental and Engineering Research Institute, Chinese Academy of sciences, lanzhou 730000, china College of Civil Engineering Lanzhou University of Technology Lanzhou China state key laboratory of Frozen soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China

A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3D nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.

关键词： frame supporting structure with prestressed anchor slope dynamic calculation model seismic performance seismic design

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Cardiovascular Risk Factors in china

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Journal of Geriatric Cardiology 2024年第2期21卷 153-199页

作者： sheng-shou HU the Writing Committee of the Report on Cardiovascular Health and Diseases in china Fuwai Hospital National Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina 不详

The Annual Report on Cardiovascular Health and Diseases in china(2022) intricate landscape of cardiovascular health in china. This section dissects cardiovascular risk factors in china which including hypertension, dyslipidemia, diabetes mellitus, chronic kidney disease, metabolic syndrome and air pollution. Hypertension prevalence has steadily increased in china,with efforts to control it facing challenges in achieving optimal rates, especially in rural areas. Interventions like salt substitutes and intensive blood pressure control show promise but need improvement. Abnormal lipid levels, indicative of dyslipidemia,have risen significantly, posing a risk for cardiovascular diseases. Despite efforts, many patients struggle to achieve target lipid levels, necessitating improved treatment strategies. Both type 1 and type 2 diabetes mellitus affect millions of adults in china,with long-term complications adding to the disease burden. Early intervention and effective management are crucial to mitigate its impact. Prevalent among older adults, chronic kidney disease is associated with diabetes mellitus, hypertension, and cardiovascular diseases, necessitating comprehensive management approaches. The prevalence of metabolic syndrome, characterized by a cluster of risk factors, has increased in both adults and adolescents, calling for lifestyle modifications and public health interventions. Ambient and household air pollution remain significant environmental risk factors, despite some improvements in air quality. Continued efforts to reduce emissions are essential for mitigating associated health risks. Addressing these risk factors requires a multifaceted approach, including public health initiatives, policy interventions, and individual-level strategies to promote healthy lifestyles and reduce environmental exposures. surveillance and research efforts are crucial for monitoring trends and developing effective strategies to lessen the burden of cardiovascular diseases in

关键词： landscape adding spite

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