Comparison of the lethal effect of CO2 and acidification on red sea bream (Pagrus major) during the early developmental stages

To compare the acute toxicity of CO(2)- and HCl-acidified seawater, eggs and larvae of a marine fish, Pagrus major, were exposed to seawater equilibrated with CO(2)-enriched gas mixtures (CO(2)=5% or 10%, O(2)=20.95% balanced with N(2)) or seawater acidified with 1 N HCl at two pH levels (pH 6.2 (=5% CO(2)) and 5.9 (=10% CO(2))) for 6 h (eggs) or 24 h (larvae). Mortalities of eggs were 85.8% (CO(2)) and 3.6% (HCl) at pH 6.2, and 97.4% (CO(2)) and 0.9% (HCl) at pH 5.9, while those of larvae were 61.2% (CO(2)) and 1.6% (HCl) at pH 6.2, and 100% (CO(2)) and 5.0% (HCl) at pH 5.9. Thus, previous research on the effects of acidified seawater on marine organisms, as a substitute for CO(2), has largely underestimated the toxic effects of CO(2).     

CT淋巴管成像对原发性乳糜尿患者诊断及分级的应用价值初探

目的：探讨CT淋巴管成像（CTL）对于原发性乳糜尿患者诊断及分级的应用价值。方法：回顾性收集确诊为原发性乳糜尿的79例患者的临床及CTL影像学资料,CTL指标主要包括：(1)肾脏受累侧别及肾内淋巴管分布范围：单肾、双肾、肾窦、肾实质及肾门上区、肾门下区;(2)腹膜后异常淋巴管分布情况：包括腹膜后、腰干区域、肾血管周、肾周脂肪囊、肾上腺区域等;(3)腹盆部及胸部扩张淋巴管分布及淋巴反流情况;(4)其他异常表现：包括腹盆部、胸部及骨骼等部位的淋巴管相关异常改变;(5)影像学分级：按照腹膜后累及区域范围进行影像学分级,将腹膜后区域分为左侧和右侧肾门上区、肾门下区、腰干区、肾血管旁区、肾周区等10个区域,累及5个及以内区域为轻度,累及6个及以上区域为重度。根据乳糜尿临床分级标准进行临床分级,对于原发性乳糜尿患者临床特点及CTL征象采用分类变量资料中的构成比进行统计描述,利用一致性Kappa检验评估原发性乳糜尿患者影像分级及临床分级的一致性。结果：79例CTL示肾内异常碘油沉积74例（93.7%）,单肾55例（69.6%）,双肾19例（24.1%）,肾窦74例（93.7%）,肾实质37例（46....     

囊腔型肺癌的临床病理与CT表现分析

目的：囊腔型肺癌是一种少见的、具有特殊形态学表现的肺癌,在影像学上尚未被充分认识,本研究通过分析其CT特征及临床病理,以提高对该类特殊类型肺癌的认识及诊断能力。方法：回顾性总结分析本院2015年1月至2021年6月期间确诊的囊腔型肺癌患者的临床信息、病理类型及CT图像特征。结果：病理类型：腺癌44例（86.27%）,其中微浸润性腺癌7例（1 3.7 3%）,浸润性腺癌3 5例（6 8.6 3%）（组织学类型：贴壁为主型1 1例（21.57%）、乳头状为主型8例（15.69%）、腺泡为主型15例（29.41%）且其中2例（3.92%）含微乳头成分占比大于20%,1例（1.96%）未分型）,1例（1.96%）化疗后手术病理提示腺癌,1例（1.96%）淋巴结穿刺活检提示肺转移性腺癌;鳞癌5例（9.80%）,其中角化性鳞状细胞癌3例（5.89%）,非角化性鳞状细胞癌2例（3.92%）;大细胞癌1例（1.96%）,高级别粘液表皮样癌1例（1.96%）。病灶以外周分布为主40例（80.30%）;平均直径为（4.7±2.7）cm,主体成分：囊腔伴磨玻璃成分20例（39.22%）、囊腔伴实性成分22例...     

Geochemical significance of tricyclic and tetracyclic terpanes in source rock extracts from the Offshore Niger Delta Basin,Nigeria

Tricyclic and tetracyclic terpanes are important constituents of crude oil and source rock extracts.However,they have not been reported in the Offshore Niger Delta Basin,Nigeria.Thus,the present study investigated the geochemical significance of tricyclic and tetracyclic terpanes in source rock extracts from the Offshore Niger Delta Bain,Nigeria with gas chromatography-mass spectrometry(GC-MS).The total relative abundances of tricyclic terpanes,C_(19)TT-C_(21)TT,and C23 TT in the rock samples ranged from 82.50 to 96.37%,50.08 to 74.17%,and 25.83 to 49.92%,respectively.These values showed the source rocks were formed from a mixed origin(terrestrial and marine).Among the tricyclic and tetracyclic terpanes identified in the rock extracts,the conventional(C_(20)TT,C_(23)TT,C_(24)TT,C_(24)TeT) and recent(Y1,X1,Z1)were more prominent than all others,indicating mixed input of terrigenous and marine organic matter.The C_(24)TT/C_(23)TT,C_(24)TeT/(C_(24)TeT+C_(26)TT),C_(19)TT/C_(23)TT,C_(20)TT/C_(23)TT,C_(25)TT/C_(24)TeT,C_(25)TT/C_(26)TT,C_(19)TT/C_(20)TT,C_(24)TeT/C_(26)TT,Z1/(Z1+C_(24)TT),and Y1/(Y1+C~(24)TT)in the rock samples range from 0.33 to 1.30,0.76 to 0.90,0.18 to 0.73,0.34 to 1.05,0.33 to 1.74,0.30 to 1.39,0.31 to0.89,1.66 to 4.33,0.36 to 0.83,and 0.34 to 0.79,respectively.These values further showed that the rock samples were formed from mixed input of terrigenous and marine organic matter and deposited under oxic to suboxic conditions in lacustrine-fluvial/deltaic environments.Also,the C_(24)TeT/C_(20-26)TT,C_(24)TeT/C_(30)HOP,and C_(23)TT/C_(30)HOP ranged from 0.16 to 0.45,0.02 to 0.42,and 0.01 to 0.48,respectively.This range of values suggests that source rocks were within immature to early mature stage.Thus,this study showed that tricyclic and tetracyclic terpanes were effective in determining the origin,depositional environments,and thermal maturity of source rocks in the Niger Delta Basin,Nigeria.     

1950～1990年中国地磁剩余场冠谐分析

根据中国1950、1960、1970、1980年和1990年地磁三分量绝对测量资料，使用球冠谐和分析方法，分别计算1950～1990年各个年代中国地磁剩余场冠谐模型. 球冠极点位于36°N和104°E，球冠半角为30°，冠谐模型的截断阶数为8. 地磁剩余场冠谐模型的均方偏差分别为：对于X分量，1950年为93.1 nT，1960年为128.9 nT，1970年为107.2 nT，1980年为107.6 nT，1990年为95.2 nT；对于Y分量，1950～1990年依次为74.8 nT，98.1 nT，89.2 nT，89.9 nT和84.0 nT；对于Z分量，分别为122.2 nT(1950年)，135.0 nT(1960年)，137.7 nT(1970年)，110.1 nT(1980年)和107.5 nT(1990年). 根据中国地磁剩余场冠谐模型和全球地磁场DGRF模型，得到中国地磁场的冠谐模型，并对冠谐模型的边界效应进行了分析和讨论.     

Multivariate statistical methods and GIS based evaluation of the health risk potential and water quality due to arsenic pollution in the Kızılırmak River

The K?z?l?rmak River is Turkey's longest (1,355 km) river and it is important since it constitutes the drinking and irrigation water source of the Central Anatolia Region. In the current study, the spatial distribution, effect on irrigation water quality, environmental pollution status, ecotoxicological and health risks as well as possible sources of 12 potential toxic elements' (PTEs) (manganese (Mn), aluminum (Al), arsenic (As), chromium (Cr), zinc (Zn), iron (Fe), nickel (Ni), cadmium (Cd), cobalt (Co), copper (Cu), mercury (Hg), and lead (Pb)) concentrations from surface water samples in the K?z?l?rmak River were analyzed by using geographical information systems (GIS) software, ecotoxicological indices, and multivariate statistical analysis. As a result of the current study, it was determined that the As concentration is above the World Health Organization (WHO) limit values, and, in terms of the 12 PTEs, there is slight heavy metal contamination in the river according to the Heavy Metal Pollution Index (HPI) and Heavy Metal Evaluation Index (HEI) values and there is a low level of pollution. The Hazard Quotient for ingestion (HQ_ingestion) and Hazard Index (HI) values indicate that non-carcinogenic effects may occur. Exposure to river water is likely to result in a low level of carcinogenic risk (CR) in adults, mainly due to the As concentration. The water at Sampling Station S3 (131.79) cannot be used for drinking and is not suitable for consumption. According to the sodium percentage (Na%), Sodium Absorption Ratio (SAR), and Magnesium Hazard (MH) index results, river water is suitable for agricultural use.     

Stable isotope-guided analysis of biomagnification profiles of arsenic species in a tropical mangrove ecosystem

We performed stable carbon and nitrogen-guided analyses of biomagnification profiles of arsenic (As) species, including total As, lipid-soluble As, eight water-soluble As compounds (arsenobetaine (AB), arsenocholine (AC), tetramethylarsonium ion (TETRA), trimethylarsine oxide (TMAO), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenate (As[V]), and arsenite (As[III])), and non-extracted As in a tropical mangrove ecosystem in the Ba Ria Vung Tau, South Vietnam. Arsenobetaine was the predominant As species (65-96% of water-soluble As). Simple linear regression slopes of log-transformed concentrations of total As, As fractions or individual As compounds on stable nitrogen isotopic ratio (δ15N) values are regarded as indices of biomagnification. In this ecosystem, lipid-soluble As (slope, 0.130) and AB (slope, 0.108) were significantly biomagnified through the food web; total As and other water-soluble As compounds were not. To our knowledge, this is one of the first reports on biomagnification profiles of As compounds from a tropical mangrove ecosystem.     

Competitive Sorption of Antimony with Zinc,Nickel, and Aluminum in a Seaweed Based Fixed‐bed Sorption Column

The removal of heavy metals such as Ni(II), Zn(II), Al(III), and Sb(III) from aqueous metal solutions was investigated using novel, cost effective, seaweed derived sorbents. Studies with a laboratory scale fixed‐bed sorption column, using a seaweed waste material (referred to as waste Ascophyllum product (WAP)) from the processing of Ascophyllum nodosum as biosorbent, demonstrated high removal efficiencies (RE) for a variety of heavy metals including Ni(II), Zn(II) and Al(III), with 90, 90 and 74% RE achieved from initial 10 mg/L metal solutions, respectively. The presence of Sb(III) in multi component metal solutions suppressed the removal of Ni(II), Zn(II) and Al(III), reducing the RE to 28, 17 and 24%, respectively. The use of Polysiphonia lanosa as a biosorbent showed a 67% RE for Sb(III), both alone and in combination with other metals. Potentiometric and conductometric titrations, X‐ray photoelectron and mid‐infrared spectroscopic analysis demonstrated that carboxyl, alcohol, sulfonate and ether groups were heavily involved in Sb(III) binding by P. lanosa. Only carboxyl and sulfonate groups were involved in Sb(III) binding by WAP. Furthermore, a greater amount of weak acidic groups (mainly carboxylic functions) were involved in Sb(III) binding by P. lanosa, compared to WAP which involved a greater concentration of strong acidic groups (mainly sulfonates).     

Selective Separation and Preconcentration of Fe(III) and Zn(II) Ions by Solvent Extraction Using a New Triketone Reagent

A simple, rapid, and accurate method was developed for separation and preconcentration of trace levels of iron(III) and zinc(II) ions in environmental samples. Methyl‐2‐(4‐methoxy‐benzoyl)‐3‐(4‐methoxyphenyl)‐3‐oxopropanoylcarbamate (MMPC) has been proposed as a new complexing agent for Fe(III) and Zn(II) ions using solvent extraction prior to their determination by flame atomic absorption spectrometry (FAAS). Fe(III) and Zn(II) ions can be selectively separated from Fe(II), Pb(II), Co(II), Cu(II), Mn(II), Cr(III), Ni(II), Cd(II), Ag(I), Au(III), Pd(II), Cr(VI), and Al(III) ions in the solution by using the MMPC reagent. The analytical parameters such as pH, sample volume, shaking time, amount of MMPC reagent, volume of methyl isobutyl ketone (MIBK), effect of ionic strength, and type of back extractant were investigated. The recovery values for Fe(III) and Zn(II) ions were greater than 95% and the detection limits for Fe(III) and Zn(II) ions were 0.26 and 0.32 µg L^?1, respectively. The precision of the method as the relative standard deviation changed between 1.8 and 2.1%. Calibration curves have a determination coefficient (r²) of at least 0.997 or higher. The preconcentration factor was found to be 100. Accuracy of the method was checked by analyzing of a certified reference material and spiked samples. The developed method was applied to several matrices such as water, hair, and food samples.     

Content and distribution of trace metals in surface sediments from the northern Bering Sea, Chukchi Sea and adjacent Arctic areas

Concentrations of trace metals (Zn, Cr, Cu, V, Cd and Pb), total organic carbon (TOC), black carbon (BC) and their granulometry were examined in 25 surface sediment samples from the northern Bering Sea, Chukchi Sea and adjacent areas. Trace metal concentrations in the sediments varied from 21.06-168.21 mg kg(-1) for Zn, 8.91-46.94 mg kg(-1) for Cr, 2.69-49.39 mg kg(-1) for Cu, 32.46-185.54 mg kg(-1) for V, 0.09-0.92 mg kg(-1) for Cd, and 0.95-15.25 mg kg(-1) for Pb. The geoaccumulation index (Igeo) indicated that trace metal contamination (Zn and Cd) existed in some stations of the study area. The distribution of grain size plays an important role in influencing the distribution of trace metals (Zn, Cr, Cu, V, and Pb) in sediments from the Chukchi Sea and adjacent areas.     

Distribution and seasonal variation in the partial pressure of CO2 during autumn and winter in Jiaozhou Bay, a region of high urbanization

We investigated the partial pressure of carbon dioxide (pCO(2)) in Jiaozhou Bay (JZB), which is surrounded by the economically developed city of Qingdao, during two cruises undertaken in November, 2007 (autumn) and February, 2008 (winter). Results indicated that sea surface pCO(2) in autumn varied between 315 and 720 μatm, with an average level of 418 μatm. In winter the sea surface pCO(2) ranged from 145 to 315 μatm with an average of 249 μatm, which is below atmospheric pCO(2). Despite seasonal temperature variation between autumn and winter, it was noted that biological process (production and respiration) were responsible for both spatial and seasonal variation during these seasons. We found that Jiaozhou Bay served as a net atmospheric CO(2) source in autumn (November) (2.87 mmol m(-2)d(-1)), while in winter (February) it served as a net sink (-16.22 mmol m(-2)d(-1)).     

A nutrient loading budget for Biscayne Bay, Florida

The water quality in Biscayne Bay has been significantly affected by past and continuing coastal and watershed development. The nutrient concentrations in the Bay have been dramatically changed by the conversion of natural creeks and sheet flow freshwater inputs to rapid and episodic canal inputs from the large and rapidly expanding Miami metropolitan area. This study is an evaluation of nutrient loadings to Biscayne Bay for 1994-2002 from canal, atmospheric, and groundwater sources. Dissolved inorganic nitrogen (DIN, as nitrate, nitrite, and ammonium) and total phosphorus (TP) loadings by the canals were influenced by their geographic locations relative to discharge amount, watershed land use, stormwater runoff, and proximity to landfills. Annual budgets showed that canals contributed the bulk of N loading to the bay as 1687.2 metric ton N yr(-1) (88% total load). Direct atmospheric DIN load for Biscayne Bay was only 231.7 ton N yr(-1), based on surface area. Of the canal DIN load, nitrate+nitrite (NO(x)(-)) loading (1294.5 ton N yr(-1)) made up a much greater proportion than that of ammonium (NH(4)(+), 392.6 ton N yr(-1)). In the urbanized north and central Bay, canal DIN load was evenly split between NO(x)(-) and NH(4)(+). However, in the south, 95% of the DIN load was in the form of NO(x)(-), reflecting the more agricultural land use. Contrary to N, canals contributed the only 66% of P load to the bay (27.5 ton P yr(-1)). Atmospheric TP load was 14 ton Pyr(-1). In the north, canal P load dominated the budget while in the south, atmospheric load was almost double canal load. Groundwater inputs, estimated only for the south Bay, represented an important source of N and P in this zone. Groundwater input of N (141 ton N yr(-1)) was about equal to atmospheric load, while P load (5.9 ton P yr(-1)) was about equal to canal load.     

Geoaccumulation and distribution of heavy metals in the urban river sediment

Current study presents the application of chemometric techniques to comprehend the interrelations among sediment variables whilst identifying the possible pollution source at Langat River,Malaysia.Surface sediment samples（0-10 cm）were collected at 22 sampling stations and analyzed for total metals（~（48）Cd,~（29）Cu,~（30）Zn,~（82）Pb）,pH,redox potential（Eh）,salinity,electrical conductivity（EC）,loss on ignition（LOI）and cation exchange capacity（CEC）.The principal component analysis（PCA）scrutinized the origin of environmental pollution by various anthropogenic and natural activities：four principal components were obtained with 86.34%（5 cm）and88.34%（10 cm）.Standard,forward and backward stepwise discriminant analysis effectively discriminate 2variables（84.06%）indicating high variation of heavy metals accumulation at both depth.The cluster analysis accounted for high input of Zn and Pb at LA8,LA 10,LA 11 and LA 12 that mergers three（5 cm）and four（10cm）into clusters.This is consistent with the contamination factor（C_1）that shows high Cd（LA 1）and Pb（LA 7,LA 8,LA 10,LA 11 and LA 12）contaminations at 5cm.These indicate that Pb and Zn are the most bioavailable metals in the sediment with significant positive linear relationship at both sediment depths.Therefore,this approach is a good indication of environmental pollution status that transfers new findings on the assessment of heavy metals by interpreting large complex datasets and predicting the fate of heavy metals in the sediment.     

210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose

In recent years, there has been increasing interest in the significance of natural radionuclides, particularly (210)Po, in the marine environment. (210)Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for (210)Po and (210)Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their (210)Po and (210)Pb content. The (210)Po and (210)Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg(-1) dry weight (dw) and from 1.0 ± 0.3 Bq kg(-1) to 35 ± 4.0 Bq kg(-1) (dw), respectively. There were no significant differences in the activity concentrations of (210)Po and (210)Pb in fish samples between seasons (ANOVA, P>0.05). The highest dose contribution of (210)Po to humans was calculated to be 10,530 μSv year(-1).     

Carbon and nitrogen cycling in the Zhubi coral reef lagoon of the South China Sea as revealed by 210Po and 210Pb

The radionuclides (210)Po and (210)Pb were examined to trace the cycling of particulate organic carbon (POC) and particulate organic nitrogen (PON) in the Zhubi coral reef lagoon. The net export flux of POC to the open sea is 14 mg Cm(-2) d(-1). However, the net exchange of PON has not yet been observed. On average, the vertical export fluxes in the lagoon of POC and PON, as derived from (210)Po/(210)Pb disequilibria, are 43 mg Cm(-2) d(-1) and 13.8 mg Nm(-2) d(-1), respectively. The deficit of (210)Po relative to (210)Pb in particulate matter provides evidence for the degradation of particulate organic matter. According to the mass balance budgets, 310 mg Cm(-2) d(-1) and 121 mg Nm(-2) d(-1) were recycled into dissolved fractions. Based on a first-order kinetics model, the degradation rate constants of POC and PON are 0.28 and 0.30 m(-1), respectively. Thus, (210)Po and (210)Pb can quantify the cycling of carbon and nitrogen in this coral lagoon.     

Evaluation of weather forecast systems for storm surge modeling in the Chesapeake Bay

Accurate forecast of sea-level heights in coastal areas depends, among other factors, upon a reliable coupling of a meteorological forecast system to a hydrodynamic and wave system. This study evaluates the predictive skills of the coupled circulation and wind-wave model system (ADCIRC+SWAN) for simulating storm tides in the Chesapeake Bay, forced by six different products: (1) Global Forecast System (GFS), (2) Climate Forecast System (CFS) version 2, (3) North American Mesoscale Forecast System (NAM), (4) Rapid Refresh (RAP), (5) European Center for Medium-Range Weather Forecasts (ECMWF), and (6) the Atlantic hurricane database (HURDAT2). This evaluation is based on the hindcasting of four events: Irene (2011), Sandy (2012), Joaquin (2015), and Jonas (2016). By comparing the simulated water levels to observations at 13 monitoring stations, we have found that the ADCIR+SWAN System forced by the following: (1) the HURDAT2-based system exhibited the weakest statistical skills owing to a noteworthy overprediction of the simulated wind speed; (2) the ECMWF, RAP, and NAM products captured the moment of the peak and moderately its magnitude during all storms, with a correlation coefficient ranging between 0.98 and 0.77; (3) the CFS system exhibited the worst averaged root-mean-square difference (excepting HURDAT2); (4) the GFS system (the lowest horizontal resolution product tested) resulted in a clear underprediction of the maximum water elevation. Overall, the simulations forced by NAM and ECMWF systems induced the most accurate results best accuracy to support water level forecasting in the Chesapeake Bay during both tropical and extra-tropical storms.     

Evaluation of groundwater quality using pollution index of groundwater(PIG) and non-carcinogenic health risk assessment in part of the Gangetic Basin

The aim of this study was to evaluate groundwater fitness for domestic and irrigational use in Unnao district of Uttar Pradesh,India.For this study,block wise(n=16) groundwater samples were collected,and measured parameters were analyzed using the pollution index of groundwater(PIG),various irrigational indices,and graphical techniques.The results of this study suggested that most of the parameters were within the prescribed limits of WHO and BIS,excluding F~-(0.4 to 2.6 mg L~(-1))and Fe~(2+)(0.1 to 1.7 mg L~(-1)).Concentrations of total dissolved solids(TDS) were exceeded the desirable limit( 500 mg L~(-1)) in 43.75% of samples at some sites.The Gibbs plot revealed that groundwater chemistry was governed by rock-water interaction in the region,especially silicate weathering.The Piper plot suggested that Ca~(2+)-HCO_3~-is dominant hydrochemical facies in the area followed by mixed Ca~(2+)-Na~+-HCO_3~-type,Na~+-Cl~-type,and Na~+-HCO_3~-type.PIG evaluation revealed that the contribution of F~-and Fe~(2+) in groundwater degradation is high in comparison to other elements in the region,about 18.75% samples showed low pollution,while about 6.25% samples shows moderate pollution,and 6.25%samples reflected high pollution.The human health risk(HHR) assessment finding suggested that children(mean:1.36) are more vulnerable than adults(mean:1.01).Sodium absorption ration(SAR),Residual sodium carbonate(RSC),and Permeability index(PI) indicated that most of the groundwater was suitable for irrigation,whereas,Magnesium hazard ration(MHR) and Potential salinity(PS) indices suggested that only 37.5% and 56.25%of the samples were suitable for irrigational use,respectively.This regional study would help in decision making for stakeholders and relevant authorities in the execution of groundwater management and remediation plans in the area.     

Methane and nitrous oxide fluxes in the polluted Adyar River and estuary, SE India

We measured dissolved N(2)O, CH(4), O(2), NH(4)(+), NO(3)(-) and NO(2)(-) on 7 transects along the polluted Adyar River-estuary, SE India and estimated N(2)O and CH(4) emissions using a gas exchange relation and a floating chamber. High NO(2)(-) implied some nitrification of a large anthropogenic NH(4)(+) pool. In the lower catchment CH(4) was maximal (6.3+/-4.3 x 10(4)nM), exceeding the ebullition threshold, whereas strong undersaturation of N(2)O and O(2) implied intense denitrification. Emissions fluxes for the whole Adyar system approximately 2.5 x 10(8) g CH(4)yr(-1) and approximately 2.4 x 10(6)gN(2)O yr(-1) estimated with a gas exchange relation and approximately 2 x 10(9) g CH(4)yr(-1) derived with a floating chamber illustrate the importance of CH(4) ebullition. An equivalent CO(2) flux approximately 1-10 x 10(10)gy r(-1) derived using global warming potentials is equivalent to total Chennai motor vehicle CO(2) emissions in one month. Studies such as this may inform more effective waste management and future compliance with international emissions agreements.     

In situ cosmogenic ~(10)Be,~(26)Al,and ~(21)Ne dating in sediments from the Guizhou Plateau,southwest China

Landscape evolution is modulated by the regional tectonic uplift,climate change,and river dynamics.However,how to distinguish these mechanisms through the research of surface exhumation and fluvial incision remains controversial.In this study,cosmogenic~(10)Be,~(26)Al,and~(21)Ne concentrations in quartz from cave deposits,modern river sediments,and bedrocks were measured to constrain the applicability of cosmogenic~(21)Ne and discuss Quaternary landscape evolution history in the Guizhou Plateau,southeast China.Using the~(26)Al-~(10)Be and~(21)Ne-~(10)Be pairs to distinguish the cosmogenic~(21)Ne concentration from the excess~(21)Ne,we found that the nucleogenic~(21)Ne produced by the U and Th decay in quartz is significant in the samples although there is the possibility of inherited cosmogenic~(21)Ne.Combining with previous studies,we suggest that the precise approach for applying the cosmogenic~(21)Ne could be reached by (1) estimating the contribution from nucleogenic~(21)Ne,(2) avoiding samples with complex burial histories to exclude inherited cosmogenic~(21)Ne,and (3) combining the~(10)Be-~(26)Al-~(21)Ne nuclides method for the Quaternary samples.In addition,both pre-burial basin denudation rates and burial ages derived from the~(26)Al-~(10)Be pair were used to determine the different timescale surface denudation rate and fluvial incision rate in relation to previous work.The consistency of the different timescales pre-burial basin denudation rate,~(36)Cl surface denudation rate,and modern basin denudation rate indicates that the landscape-scale surface denudation has been likely stabilized since the Quaternary in the Guizhou Plateau area.The slightly higher river incision rates than the local surface denudation rate show that the river dynamics may not have reached a steady-state due to the regional tectonic uplift in the Guizhou Plateau.     

Earthquake behavior of variable rupture-scale on active faults and application of the cascade-rupturing model

IntroductionThe earlier concept of the characteristic earthquakes means those earthquakes recurring along the same portion of active fault zones, and having nearly the same size, displacement and rupture scale (Schwartz, Coppersmith, 1984). However, more and more evidences have suggested that the rupture(s scale of earthquakes recurred on an individual fault portion has variability (Thatcher, 1990). For instance, the rupture of the 1906 San Francisco, California, earthquake with magnitude 8.…