A numerical simulation of kinetic constraint on evaporation of ammonium nitrate in diffusion denuder

A numerical simulation model has been developed to investigate the diffusion and reaction in diffusion denuder for reactive gases and aerosols. The analytical equation for equilibrium and kinetic equations of NH 4NO 3, NH 3 and HNO 3 system were presented. The model results of sampling efficiencies were agree with those calculated by Gormley Kennedy equation and other models. The evaporation of NH 4NO 3 aerosol has a kinetic constraint. The kinetic constant can be estimated from evaporation data. The model results showed that an annular denuder can separate reactive gases and aerosols.

Application of KCl-denuder for measuring gas-phase mercuric species(Hg^(2+))in atmosphere

KCl denuder technique was meployed in the measurement of Hg(II) species in atmosphere firstly. Intensive lab tests indicate that Hg 0 can pass through KCl denuder freely, while Hg 2+ can be trapped in it very efficiently. The efficiencies for adsorbing inorganic Hg 2+ averaged between 95% to 100% with a gross mean of 98%, and those for absorption of organic Hg 2+ were around 94%. Mass balance calculation shows that mercury trapped in denuder can be quantitatively extracted by 1 mol/L HCl (super grade) and analysed by the method of SnCl 2 reduction CVAFS determination, thus, demonstrated the feasibility of KCl denuder in measurement of Hg(II) in atmosphere. Preliminary application at two sites Gteborg, Sweden and one site in Ireland, found 0 04—0 15 ng/m 3 of Hg(II) species, contributing to 2%—10% of the total mercury.

Investigation on sampling artifacts of particle associated PAHs using ozone denuder systems

Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.

Migration of paleo-uplift in southwestern Tarim Basin and its implications for orogenesis and reservoir development, NW China

Based on well horizon calibration,the typical seismic profiles in southwestern Tarim Basin were interpreted systematically,regional geological sections were established,and the regional denudation thickness of each tectonic period was restored.On this basis,the plane morphology maps of ancient structures of the Cambrian pre-salt dolomites in different periods were compiled,and the spatial distribution,development,evolution and migration of paleo-uplift in the late Early Paleozoic were analyzed.In the late Early Paleozoic,there existed a unified regional paleo-uplift widely distributed in southwestern Tarim Basin,which is called the southwestern Tarim plaeo-uplift.The“Tarim SW paleo-uplift”and“Hetian paleo-uplift”proposed in previous literatures are not independent,but the result of the spatio-temporal migration and evolution of the southwestern Tarim paleo-uplift identified in this paper.The southwestern Tarim paleo-uplift emerged at the end of Middle Ordovician,and took its initial shape with increased amplitude in the Late Ordovician.During the Silurian,the southwestern Tarim paleo-uplift rose steadily and expanded rapidly to the east,incorporating Pishan-Hetian and other areas,with the structural high locating in the Pishan-Hetian area.During the Devonian,the southwestern Tarim paleo-uplift began to shrink gradually,to a limited range in the Pishan-Hetian area in the southern part of the basin.During the Carboniferous,the southwestern Tarim paleo-uplift became an underwater uplift,that is,the paleo-uplift gradually died out.The southwestern Tarim paleo-uplift belongs to the forebulge of the southwestern Tarim foreland basin in the late Early Paleozoic,and its formation and evolution are related to the early Paleozoic orogeny of the West Kunlun orogenic belt in the south of the Tarim Basin.The migration of the southwestern Tarim paleo-uplift from the northwestern part of the southwestern Tarim Basin to the Pishan-Hetian area indicates the early Paleozoic orogenic process of the West Kunlun orogenic belt,which started in the western section at the end of Middle Ordovician and extended from west to east in a“scissor”style.The migration and evolution of the southwestern Tarim paleo-uplift controlled the development of unconformities at the end of Middle Ordovician,the end of Late Ordovician,and the end of Middle Devonian,and the spatial distribution of dissolved fracture-cave reservoirs in weathered crust below the unconformities in the southwest of Tarim Basin.The migration of the structural high of the southwestern Tarim paleo-uplift also played an important role in controlling the development of dissolved fracture-cave reservoirs in weathered crust.

青岛海岸大气中氨和有机胺的特征、来源及气粒分配研究

本研究聚焦2019年8—10月、11—12月在青岛近海岸地区在线离子色谱观测数据,并以8—10月Denuder采样器同步测定的气态和颗粒态氨和有机胺为辅助,分析了氨和有机胺的浓度变化、气体来源以及气粒分配。结果显示,观测期间氨气和气态有机胺分别受海洋源和陆地源的影响。在8—10月观测时段,来自陆地源的氨和有机胺浓度水平要明显高于海洋源。NH_(3)和DMA_(gas)通常在每天的6:00—8:00、10:00—12:00出现较高值。NH^(+)_(4)、DMAH^(+)、NO^(-)_(3)通常在每天的3:00—6:00出现较高值。在11—12月观测时段,来自陆地源的浓度水平与海洋源相当,在此基础上,利用E-AIM-Ⅱ热力学平衡模型研究了氨和有机胺的气粒分配,模拟结果显示:在8—10月观测期间,气粒分配浓度与相对湿度具有一定的关系,而11—12月并非如此。

Effect of Nickel Contamination on Formation of Denuded Zone in Czochralski Silicon

The effect of nickel contamination under rapid thermal processing （RTP） on the magic denuded zone （MDZ） in Czochralski silicon is investigated. It is found that the bulk defects can effectively getter nickel atoms once the MDZ forms. However,if the silicon sample is initially contaminated with nickel, the MDZ cannot form during the subsequent RTP,and a high density of precipitates occurs near the surface. In conventional IG processes,the DZ can form regardless of the nickel contamination sequence. Based on the facts,we propose that the formation of nickel silicide （Ni3Si） at the surface keeps the concentration of vacancies in the near-surface zone still higher than the critical concentration for oxygen precipitation under the subsequent RTP, which prevents MDZ formation.

Effect of Rapid Thermal Annealing Ambient on Gettering Efficiency and Surface Microstructure in 300mm CZ Silicon Wafers

The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demonstrated that a high density of oxygen precipitates and thin denuded zone are obtained in N2/NH3 ambient,while a relatively lower density of oxygen precipitates and thicker denuded zone are observed in N2 ambient. As the RTA duration times increased, the oxygen precipitate density increased and the denuded zone depth decreased. X-ray photoelectron spectroscopy （XPS） data and atomic force microscope （AFM） results show that there RTA process,which can explain the different effect of RTA was a surface nitriding reaction during the N2/NH3 ambient ambient.

Improvement of in vitro Cytoplasmic Maturation of Denuded Porcine Oocytes by Coculture with Follicular Mural Granulosa Cells

[Objective] This study aimed to improve the in vitro maturation quality of denuded porcine oocytes and provide scientific basis for establishing a stable and efficient denuded oocyte culture system. [Method] The first polar body extrusion rate, oocyte glutathione （GSH） content, positive rate of brilliant cresyl blue （BCB） staining and development potential of activated oocytes or fertilized oocytes were employed as main indicators to investigate the effects of follicular mural granulosa cell （MGC） coculture on cytoplasmic maturation of cumulus cell-removal oocytes （Denuded Oocyte, DO）. [Result] According to in vitro maturation results, compared with DO group, the first polar body extrusion rate of porcine oocytes in DO＋MGC group was not significantly different, but the nuclear maturation process was improved and was more similar to that in COC （cumulus-oocyte complex） group. Detection of GSH content in mature oocytes showed that there was no significant difference between DO＋ MGC group （optical density of 1 053.67） and COC group （optical density of 1 426.00） or between DO＋MGC group and COC＋GC group （optical density of 1 541.00）, however, GSH content in mature oocytes of DO group （optical density of 724.67） was significantly lower than that of COC group and COC＋GC group （P0.05）. Detection of glucose-6-phosphate dehydrogenase （G6PDH） activity showed that there was no significant difference in BCB positive oocyte rate between DO ＋MGC group （88.26% ） and COC group （92.75%） or between DO＋MGC group and DO group （82.86% ）, however, BCB positive oocyte rate of DO group was significantly lower than that of COC group （P0.05）. Furthermore, the cleavage rate and blastocyst rate of activated mature oocytes derived from DO ＋MGC group （94.98% and 43.67% , respectively） were significantly higher than those from DO group （52.54% and 8.97%, respectively） （P0.05）, and were not significantly different compared with those from COC group （97.11% and 38.30%, respectively）. In addition, the cleavage rate of fertilized oocytes derived from DO＋MGC group （72.65%） showed no significant difference compared with that from DO group （63.59%）, but the blastocyst rate of DO＋MGC group was significantly higher than that of DO group （9.88%） （P0.05）. [Conclusion] MGC coculture can significantly improve the in vitro cytoplasmic maturation quality of denuded porcine oocytes, thereby enhancing the subsequent developmental potential.

Establishment of an untransfected human corneal epithelial cell line and its biocompatibility with denuded amniotic membrane

AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM). METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors, yielding an HCEP cell line which was its growth performance, chromosome morphology, tumorigenicity and expression of marker proteins analyzed. In addition, the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light, electron and slit-lamp microscopies. RESULTS: HCEP cells proliferated to confluence in 3 weeks, which have been subcultured to passage 160. A continuous untransfected HCEP cell line, designated as utHCEPC01, was established with a population doubling time of 45.42 hours as was determined at passage 100. The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3. They, with no tumorigenicity, formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture, maintained expression of marker proteins including keratin 3 and integrin p 1 and attached tightly to dAMs. The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original. CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study. The cells maintained expression of marker proteins. The cell line was biocompatible with dAM. It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP, promising for the treatment of diseases caused by corneal epithelial disorders.

Tectono–sedimentary Evolution of the Late Triassic Xujiahe Formation in the Sichuan Basin

The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although the Late Triassic Xujiahe Formation is assumed to represent the commencement of continental deposition in the Sichuan Basin,little research is available on the details of this particular stratum.Sequence stratigraphic analysis reveals that the Xujiahe Formation comprises four third-order depositional sequences.Moreover,two tectono-sedimentary evolution stages,deposition and denudation,have been identified.Typical wedge-shaped geometry revealed in a cross section of the southern Sichuan Basin normal to the Longmen Shan fold-thrust belt is displayed for the entire Xujiahe Formation.The depositional extent did not cover the Luzhou paleohigh during the LST1 to LST2 （LST,TST and HST mean Iowstand,transgressive and highstand systems tracts,1,2,3 and 4 represent depositional sequence 1,2,3 and 4）,deltaic and fluvial systems fed sediments from the Longmen Shan belt,Luzhou paleohigh,Hannan dome,and Daba Shan paleohigh into a foreland basin with a centrally located lake.The forebulge of the western Sichuan foreland basin was located southeast of the Luzhou paleohigh after LST2.According to the principle of nonmarine sequence stratigraphy and the lithology of the Xujiahe Formation,four thrusting events in the Longmen Shan fold-thrust belt were distinguished,corresponding to the basal boundaries of sequences 1,2,3,and 4.The northern Sichuan Basin was tilted after the deposition of sequence 3,inducing intensive erosion of sequences 3 and 4,and formation of wedge-shaped deposition geometry in sequence 4 from south to north.The tilting probably resulted from small-scale subduction and exhumation of the western South China block during the South and North China block collision.

A Compilation of New and Existing Thermochronology Data Concerning the Lhasa Terrane Combined with a Geological Synthesis of the Area

The history and geodynamic mechanisms of Cenozoic exhumation and denudation of the Lhasa terrane(LT),southern Tibetan Plateau, remain poorly constrained. Most previous studies investigating the exhumation of the LT have relied on extrapolating interpretations based on a few well-studied but small areas, which inevitably introduce bias. Here,our compilation of new and published thermochronologic ages are plotted against latitude, longitude, and elevation, to illustrate the distribution of cooling ages across broad regions of the LT. Primary results reveal that(1) the north LT experienced significant exhumation during 80–40 Ma;(2) compared with north LT, exhumation and erosion in the south LT continued after ~40 Ma;and(3) N–S striking rifting, E–W striking river incision, and thrusts led to continued local denudation of the south LT between 20–5 Ma.

Metamorphic Core Complexes and Its Significance in the Continental Crustal Evolution

Metamorphic core complexes are a basic structural pattern related to extensional tectonics. Several characteristics of different scales of metamorphic core complexes in the Fangshan and Yunmengshan (Beijing) , Zhongtiaoshan (Shanxi) , and Dengfong (Henan) are examined. A three-layer model for metam orphic core complexes is suggested . The conclusion is that metam orphic core complexes are the result of multiphase intracontinental crustal extensions and are an important tectonic pattern. which exposes the basement metam orphic rocks to the ground surface in the intracontinental cover .

Recovery of the Erosion Thickness and Characterization of the Paleogeomorphology in the Southern Lishui Sag, East China Sea Shelf Basin

The restoration of the denudation thickness is the basis for quantitatively analyzing the basin burial history,thermal evolution history and hydrocarbon accumulation conditions.The well data is not sufficient to do this in the southern Lishui Sag with only 5 wells,so the new,high-quality three-dimensional(3D)seismic data is essential.The methods employed to determine the eroded thicknesses of key unconformities in the study area are the mudstone acoustic time difference(AC)method,vitrinite reflectance(Ro%)method and stratigraphic trend comparison method.On the basis of the structural evolution,the restoration of the paleogeomorphology is carried out.The results show that the Wenzhou formation(E2 w)in the entire study area has been all denuded.The denudation thickness is in the range of 0–550 m,and decreases gradually from west,thicker than 200 m,to east.The erosion of the upper Lingfeng formation(E1l)are mainly occurred in the N-P-1 structural trap(N-P-1),the N-P-2 structural trap(N-P-2)and the N-P-3 structural trap(N-P-3).Among them,the eroded area in N-P-1(near well S-1)and N-P-2 is 200–230 km^2,and the denudation thickness is 0–600 m,which increases from south to north,even up to 200–400 m in the region around well S-1.In N-P-3,the extent of denudation is 30–50 km^2,and the denudation thickness is 0–400 m.In the early stage of the upper E1 l,one north-south strike slip fault began to develop in the southern study area.Affected by this fault,the southern Lingfeng bulge was offset,forming a gorge,and the eastern and western sides of the concave belt connected to each other.On the basis of the paleo-geomorphological characteristics,it is shown that the sedimentary center of the west subsag began to migrate to the south.

Study on soils under shifting cultivation and other land use categories in Chittagong Hill Tracts, Bangladesh

Soil samples were collected and analyzed from 25 sites of three hilly regions （Rangamati, Banderban and Khagrachari） for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts, Bangladesh. There were natural forests, bushy land, slashed sites, slashed and burnt sites, and the sites prepared for shifting cultivation, one year after shifting cultivation and two years after shifting cultivation. The soils were generally yellowish brown to reddish brown, sandy to sandy clay loam, strongly acid, and well to excessively drained on steep slopes with considerable variation among the sites and land use categories. Bulk density was the highest in sites of one year after shifting cultivation （1.52 g·cm^-3） and the lowest in forested sites （1.38 g·cm^-3）. Water holding capacities were, however, statistically similar in all sites. Organic carbon varied from 0.54% （slashed and burnt sites） to 1.55% （forested sites） and total N ranged from 0.05% （shifting cultivation for one year） to 0.13% （forested sites）. Available phosphorus （Bray ＆ Kurtz-2 P） was the maximum in forested sites （12.32 mg·kg^-l）, and it did not differ significantly in other sites. Contents of available Ca, Mg and K were also higher in the bushy lands and forested sites than cleared and shifting cultivated sites.

Transplantation of tissue-engineered human corneal epithelium in limbal stem cell deficiency rabbit models

AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed with DiI-labeled untransfected HCEP cells and denuded amniotic membrane (dAM) in air-liquid interface culture, and their morphology and structure were characterized by hematoxylin-eosin (HE) staining of paraffin-sections, immunohistochemistry and electron microscopy. LSCD models were established by mechanical and alcohol treatment of the left eyes of New Zealand white rabbits, and their eyes were transplanted with TE-HCEPs with dAM surface outside by lamellar keratoplasty (LKP). Corneal transparency, neovascularization, thickness, and epithelial integrality of both traumatic and post transplantation eyes were checked once a week by slit-lamp corneal microscopy, a corneal pachymeter, and periodic acid-Schiff (PAS) staining. At day 120 post surgery, the rabbits in each group were sacrificed and their corneas were examined by DiI label observation, HE staining, immunohistochemistry and electron microscopy. RESULTS: After cultured for 5 days on dAM, HCEP cells, maintaining keratin 3 expression, reconstructed a 6-7 layer TE-HCEP with normal morphology and structure. The traumatic rabbit corneas, entirely opaque, conjunctivalized and with invaded blood vessels, were used as LSCD models for TE-HCEP transplantation. After transplantation, obvious edema was not found in TE-HCEP-transplanted corneas which became more and more transparent, the invaded blood vessels reduced gradually throughout the monitoring period. The corneas decreased to normal thickness on day 25, while those of dAM eyes were over 575 mu m in thickness during the monitoring period. A 45 layer of epithelium consisting of TE-HCEP originated cells attached tightly to the anterior surface of stroma was reconstructed 120 days after TE-HCEP transplantation, which was similar to the normal control eye in morphology and structure. In contrast, intense corneal edema, turbid, invaded blood vessels were found in dAM eyes, and no multilayer epithelium was found but only a few scattered conjunctiva-like cells appeared. CONCLUSION: The TE-HCEP, with similar morphology and structure to those of innate HCEP, could reconstruct a multilayer corneal epithelium with normal functions in restoring corneal transparency and thickness of LSCD rabbits after transplantation. It may be a promising HCEP equivalent for clinical therapy of corneal epithelial disorders.

In vitro reconstruction and characterization of tissue-engineered human corneal epithelium with seeder cells from an untransfected human corneal epithelial cell line

AIM: To demonstrate the morphology and structure of in vitro reconstructed tissue-engineered human corneal epithelium (TE-HCEP) with seeder cells from an untransfected HCEP cell line. METHODS: The TE-HCEPs were reconstructed in vitro with seeder cells from an untransfected HCEP cell line, and scaffold carriers of denuded amniotic membrane (dAM) in air-liquid interface culture for 3, 5, 7 and 9 days, respectively. The specimens were examined with hematoxylin-eosin (HE) staining of paraffin-section, immunocytochemical staining, scanning and transmission electron microscopy. RESULTS: During in vitro reconstruction of TE-HCEP, HCEP cells formed a 3-4, 6-7 and 8-10 layers of an HCEP-like structure on dAMs in air-liquid interface culture for 3, 5 and 7 days, respectively. But the cells deceased to 5-6 layers and the structure of straified epithelium became loose at day 9. And the cells maintained positive expression of marker proteins (keratin 3 and keratin 12), cell-junction proteins (zonula occludens-1, E-cadherin, connexin 43 and integrin beta 1) and membrane transport protein of Na+-K+ ATPase. The HCEP cells in TE-HCEP were rich in microvilli on apical surface and established numerous cell-cell and cell-dAM junctions at day 5. CONCLUSION: The morphology and structure of the reconstructed TE-HCEP were similar to those of HCEP in vivo. The HCEP cells in the reconstructed TE-HCEP maintained the properties of HCEP cells, including abilities of forming intercellular and cell-extracellular matrix junctions and abilities of performing membrane transportation. The untransfected HCEP cells and dAMs could promisingly be used in reconstruction HCEP equivalent for clinical corneal epithelium transplantation.

Planation Surfaces on the Tibet Plateau,China

A planation hypothesis is proposed to explain landform evolution of the Tibet Plateau. A denudation threshold （T）, the maximum potential denudation rate for a certain type of rock, is introduced to explain the combined effects of lithology and tectonics on landform evolution. If the tectonic uplifting rate （U） is equal to or less than the threshold rate （U ≤ T）, the tectonic uplifting and terrain denudation are in dynamic equilibrium, and landforms are in a steady state. The end product should be planation surfaces whether the original landforms are flat plains or deeply dissected mountains. If U 〉 T, uplift and denudation are not able to reach a dynamic equilibrium state. The plateau surface is mostly underlain by soft rocks, such as the Mesozoic epimetamorphic argillites and Tertiary sedimentary rocks, while the mountain ranges comprise hard rocks, such as granite, gneiss and limestone. In soft rock regions, hills are low with a relative relief of mostly less than 100 m and the slopes are gentle at a gradient of 〈200. In contrast, hills can maintain steep slopes in hard rock regions. The Tibet Plateau has been under an equilibrium condition between tectonic uplifting and denudation except for the mountain ranges. The plateau might have reached the present altitudes before the Quaternary.

UPLIFT AND DENUDATION AT SOUTHEAST MARGIN OF TIBET PLATEAU IN QUATERNARY

The southeast margin of Tibet plateau mainly consists of the Western Yunnan plateau (WYP). The uplift and denudation at the southeast margin of Tibet plateau can be represented by that of the WYP. Based on the uplift of ancient plantain surface, river terrace and sedimentary response in peripheral basins of the WYP, suggest that the WYP experienced a rapid uplift and denudation in Quaternary. The WYP have been uplifted about 610～700m, and eroded away about 1095～1600m since Quaternary, average denudation rate reach 0 68～0 94mm/a. Uplift rates in different time interval were calculated according to river terrace. Relations between WYP and Tibetan plateau are discussed further..The Yinggehai basin located at the south termination of the Red River fault, it is the younger (mainly Neogene) pull\|apart basin, which developed at releasing bend of the Red River right\|lateral wrench fault. Since the Neogene, the subsidence center of the Yinggehai basin shifted southward and, connected with the Southeast Hainan basin. Both basins collected large amounts of the Holocene and Quaternary deposits of marine origin. They are peripheral marine basin of the WYP.. Silicate clastic sediments in both basins have been large supported from the WYP into both basins through the Red River system. The total volumes derived from the WYP in the Neogene and Quaternary is 2 8004×10 14 t(1 and 5 1206×10 14 t. The sedimentation rate in Yinggehai basin rose from 0 52mm/a in the Neogene to 1 39mm/a in the Quaternary. The facts that accumulation volume and sedimentation rate rose greatly after the Neogene, suggested a rapid uplift in the WYP. The rapid uplift was responsible for the unconformity between the Neogene and Quaternary. Elevation of ancient planation surface,and river terrace supported the rapid uplift of the WYP also. The ancient planation surface was elevated from 2500～2600m to 3000～3200m during Quaternary, seven terraces in Tue can be traced through the field area in elevation from 20 5m to 612m above the modern river surface in the Lancang River. The Jinsha River also incised into bed rocks about 700m in Shigu. All the facts suggest that southeast margin of Tibet plateau rose rapidly; the plateau was elevated about 610～700m in the Quaternary.

CENOZOIC BASIN EVOLUTION, STRUCTURAL STYLES OF THE QAIDAM AND AN ESTIMATE OF DENUDATION IN ADJACENT MOUNTAIN SYSTEMS, NORTHEAST QINGHAI—TIBETAN PLATEAU

Qaidam basin is located at northeast Qinghai—Xizang (Tibet) plateau, and surrounded by east Kunlun, south Qilian and Altun mountain systems. The purpose of this paper is to study the Cenozoic basin evolutionary stages, structural styles of the Qaidam, and the denudation in adjacent mountain systems through seismic profile interpretation and complemented by field observation. The Qaidam basin has experienced two tectonic stages of Paleogene—early Miocene (65～12Ma) and late Miocene—present (12～0Ma). The former is characterized by differential uplift of the mountains and subsidence of the basin, and the latter by intense compression, wrench, thrusting and folding. The compressional structural styles are mainly distributed in the Circle Hero—Range Depression of southwest Qaidam, such as Nanyishan, Youquanzi, Younan, Youshashan anticline belts and thrust faults. The wrench structural styles of the northern Qaidam include en echelon uplifts (fault—block outcrops) such as Seshitengshan, Luliangshan, Xitieshan and Eimnikshan, which are mainly composed of pre\|Sinian and Paleozoic rocks; en echelon anticlines such as Lenghu—Nanbaxian belts; and en echelon depressions such as Kunteyi, Senan and Yibei depressions, which are mainly composed of Mesozoic and Cenozoic rocks.

New approach to resolve the amount of Quaternary uplift and associated denudation of the mountain ranges in the Japanese Islands

Low-temperature thermochronology is a widely used tool for revealing denudation histories of mountain ranges. Although this technique has been applied mainly to continental orogens, such as the European Alps, Himalayas, and Andes, recent technological development of low-temperature thermochronology has made it applicable to a wider variety of mountain ranges with various sizes and tectonic histories. The Japanese Islands comprise young and active island arcs, where an early stage of mountain range formation is observed. Numerous attempts have been made to constrain the uplift and denudation histories of the mountains in the Japanese Islands using geologic, geomorphologic, or geodetic methods. However, the number of thermochronometric attempts has been limited primarily due to the small amount of total denudation since the initiation of the uplift. In this review paper, we introduce the tectonic and geomorphic settings of the mountain ranges in the Japanese Islands, and discuss previous attempts to estimate uplift or denudation of the Japanese mountains using methods other than ther- mochronology. Furthermore, we discuss problems of the thermochronometric applications in revealing denudation histories of the Japanese mountains. Finally, we present a case study of the Kiso Range in central Japan and discuss the current effectiveness and applicability of low-temperature thermochronology to the Japanese mountainous areas.