HAN基单组元推进剂热分解过程的分子动力学模拟

为揭示非催化点火方式的硝酸羟胺(HAN)基单组元液体火箭发动机内推进剂的反应机理,采用分子动力学模拟方法,在ReaxFF/lg力场下对HAN基推进剂热分解机理及配方影响作用机制开展研究。计算结果表明:推进剂热分解过程存在两个阶段。第一个阶段为吸热阶段,推进剂内硝酸羟胺和硝酸肼氢键断裂,分解生成羟胺、肼和硝酸,吸热阶段主要受推进剂内氢键个数影响;第二个阶段为推进剂分解反应阶段,由硝酸和羟胺的分解所引发,生成NH_(2)、NO_(2)和OH。OH为主要的氧化性物质,与肼、甲醇反应,生成大量的水。肼在推进剂中的分解主要依靠与OH反应脱氢,生成N_(2)H_(3),并最终分解形成N_(2)和H_(2)。推进剂配方仅对与OH的反应有显著影响。降低甲醇的含量,能够显著提升燃料的反应速率,同时促进肼分子的反应脱氢,提高推进剂初始分解速率;提高硝酸羟胺的含量能够促进甲醇的分解,但受肼分解反应速率较低的影响,推进剂整体分解速率降低。

Haplotype and Genetic Analysis of 41 Y-STR Loci in the Wuwei Han Population from Gansu Province,China

Objective Y-Chromosomal short tandem repeat polymorphism(Y-STR)analysis plays an indispensable role in the identification of male individuals,population genetics,and biogeographic research.While profiles of many populations based on Y-STR markers in human genomes are ample,haplotype data for the Wuwei Han are still scarce.Methods In this study,2180 unrelated Wuwei Han male individuals residing in Gansu Province,China were collected and genotyped using the novel Microreader™40Y Plus ID system.Phylogenetic relationship reconstructions,multidimensional scaling(MDS),and heatmap analysis were performed based on the genetic distance(Rst)values between our studied population and other populations of the Ymax module in the Y-STR Haplotype Reference Database(YHRD).Results A total of 2129 unique haplotypes were obtained,and the haplotype diversity(HD)and discrimination capacity(DC)for the Wuwei Han were 0.9999 and 0.9931,respectively.Conclusion Our results demonstrate that the Wuwei Han population had intimate genetic relationships with East Asians,especially the geographically close Han populations.Overall,this Y-Chromosomal assay gives valuable information about paternal lineages in male individual tracking and genealogical database construction.

Comparative study of type 2 diabetes mellitus-associated gut microbiota between the Dai and Han populations

BACKGROUND The global prevalence of type 2 diabetes mellitus(T2DM)is increasing.T2DM is associated with alterations of the gut microbiota,which can be affected by age,illness,and genetics.Previous studies revealed that there are discriminating microbiota compositions between the Dai and the Han populations.However,the specific gut microbiota differences between the two populations have not been elucidated.AIM To compare the gut microbiota differences in subjects with and without T2DM in the Dai and Han populations.METHODS A total of 35 subjects of the Han population(including 15 healthy children,8 adult healthy controls,and 12 adult T2DM patients)and 32 subjects of the Dai population(including 10 healthy children,10 adult healthy controls,and 12 adult T2DM patients)were enrolled in this study.Fasting venous blood samples were collected from all the subjects for biochemical analysis.Fecal samples were collected from all the subjects for DNA extraction and 16S rRNA sequencing,which was followed by analyses of the gut microbiota composition.RESULTS No significant difference in alpha diversity was observed between healthy children and adults.The diversity of gut microbiota was decreased in T2DM patients compared to the healthy adults in both the Dai and Han populations. There was a significant difference in gut microbiota between healthy children and healthy adults in the Hanpopulation with an increased abundance of Bacteroidetes and decreased Firmicutes in children. However, thisdifference was less in the Dai population. Significant increases in Bacteroidetes in the Han population and Proteobacteriain the Dai population and decreases in Firmicutes in both the Han and Dai population were observed inT2DM patients compared to healthy adults. Linear discriminant analysis Effect Size analysis also showed that thegut microbiota was different between the Han and Dai populations in heathy children, adults, and T2DM patients.Four bacteria were consistently increased and two consistently decreased in the Han population compared to theDai population.CONCLUSION Differences in gut microbiota were found between the Han and Dai populations. A significant increase inBacteroidetes was related to the occurrence of T2DM in the Han population, while a significant increase in Proteobacteriawas related to the occurrence of T2DM in the Dai population.

HAN基电控固体推进剂电化学性能对燃烧性能的影响

硝酸羟胺(HAN)基电控固体推进剂是一种以HAN为主要氧化剂的新型智能推进剂,通过外加电源控制其燃烧速率与启停。为探索电化学性能与燃烧性能间的关系,在研究推进剂的离子迁移率、过电位的变化规律的基础上,将其与推进剂的点火电压、点火延迟进行关联。研究发现,推进剂在外加低电压(1.6~2.8 V)刺激下,离子迁移率与电压大小正相关,推进剂基体的改良在提高离子迁移率方面的效果大于离子掺杂。在燃烧性能方面,离子迁移率影响点火电压,过电位决定点火延迟;离子迁移率越高,点火时,推进剂的电流密度与反应活性越高;当迁移率由0.09 mm^(2)·s^(-1)·V^(-1)升高至0.16 mm^(2)·s^(-1)·V^(-1)时,点火电压由210 V降至70 V,有利于拓宽电控固体推进剂的应用范围;点火电压一定时,推进剂过电位越小,电分解速率越大,点火延迟越小,当过电位由0.67 V降至0.51 V时,点火延迟由1.68 s降至0.31 s,有利于推进剂满足快速响应的战略需求。

Serum Esterase Polymorphisms and Their Associations with Prolificacy in Small Tail Han Sheep

[ Objective] The aim of this research was to provide a theoretical basis for the.breeding and identification of multiparous Small Tail Han sheep. [ Method] The polymorphisms of serum esterase （Es） locus in Small Tail Han sheep were detected by vertical discontinuous polyacrylamide gel electrophoresis （PAGE）. According to the statistical analysis of different genotypes and their litter size, the correlation between Es polymor- phisms and litter size was analyzed. [ Result] There were three genotypes in Es locus, and Es^＋- was the dominate genotype. The differences of ewe litter size in the 1 ,t parity among these three genotypes were nonsignificant （ P 〉 0.05）, As far as the 2^nd and 3rd parity was considered, the litter size of genotype Es＋＋ was significantly （P〈0.05） higher than that of Es-- and Es^＋- ; the average litter size of Es＋＋ was extremely significant （ P 〈 0.01 ） higher than that of Es - - and Es ＋ - while there was no significant difference （ P 〉 0.05） between the latter two. [ Conclusion] The Es lo- cus could be regarded as a genetic marker locus for early selection of high-yielding ewes and Es ＋＋ is the high-yielding genotype of Small Tail Han sheep.

On Chinese-English Translation of Disease and Syndrome Terms in Shang Han Lun from the Perspective of Functional Equivalence Theory

Shang Han Lun is one of the most famous and important traditional medical books in China,so many translation versions of it have emerged.Based on the comparison of examples taken from two of these translation versions,Young Jie De ' s Shang Han Lun Explained and Huang Hai s Introduction to Treatise on Exogenous Febrile Disease,the paper points out that Nida s Functional Equivalence Theory provides a new idea for the translation of Disease and Syndrome Terms in TCM that literal translation,liberal translation and transliteration can be adopted appropriately to make readers of translation versions understand TCM accurately and easily.

Relationship between the -455G/A and -148C/T polymorphisms in the beta-fibrinogen gene and cerebral infarction in the Xinjiang Uygur and Han Chinese populations

We sought to investigate the correlation between the -455G/A and -148C/T polymorphisms of the β-fibrinogen gene and plasma fibrinogen levels in patients with cerebral infarction and in healthy subjects among the Xinjiang Uygur and Han Chinese populations, by using polymerase chain reaction-restriction enzyme digestion analysis. Results showed that there were no statistically significant differences in the distributions of the -455G/A genotype and allele frequency between the Uygurs and the Han. Plasma fibrinogen levels in cerebral infarction patients among the Uygurs and the Han were higher than those among healthy subjects. In particular, the frequencies of the -455G/A AA and -148C/T TT genotypes were significantly higher than in healthy subjects. Individuals carrying the A or T allele had a higher incidence of cerebral infarction compared with those carrying the G or C allele. Our experimental findings indicate that the -148C/T and -455G/A polymorphisms are associated with cerebral infarction in Xinjiang Uygur and Han Chinese subjects. The susceptibility- conferring alleles are -148T and -455A, and the susceptibility-conferring genotype is -455G/A ＋ AA.

E670G polymorphism of PCSK9 gene of patients with coronary heart disease among Han population in Hainan and three provinces in the northeast of China

Objective: To investigate the correlation between E670 G polymorphism of proprotein convertase subtilisin/kexin type 9(PCSK9) gene and coronary heart disease(CHD), and contrastively study the regional differences of E670 G polymorphism of PCSK9 gene between patients with CHD among the Han population in Hainan and three provinces in the northeast of China(TPNC), providing scientific basis for prevention and treatment of patients with CHD in different regions. Methods: A total of 233 cases of patients with CHD were selected from the Han population in Hainan and TPNC as the experimental group(118 cases from Hainan, 115 cases from TPNC), and 239 cases with non-CHD were selected among the Han population also in the two regions as control group(125 cases from Hainan, 114 cases from TPNC). The triglyceride(TG), total cholesterol(TC), high density lipoprotein cholesterol and low density lipoprotein cholesterol(LDL-C) levels of plasma were tested and PCR-RFLP method was used to test the E670 G polymorphism of PCSK9 gene. The statistical software package SPSS 21.0 was used for the statistical analysis and P<0.05 was considered as statistically significant. Results: The levels of systolic pressure, diastolic blood pressure, fasting blood sugar, TC, TG, and LDL-C of patients in CHD group were significantly higher than those in non-CHD group, while the high density lipoprotein cholesterol level was lower than that in non-CHD group(P<0.05). In CHD group, the frequencies of AG, GG genotypes of PCSK9 gene and G allele were higher than those in non-CHD group(P<0.05), and in CHD group, the frequencies of AG, GG genotypes and G allele of patients both in Hainan and TPNC were higher than those in control group(P<0.05). Among the patients with CHD, the frequencies of GG genotype and G allele of patients in Hainan were lower than those in TPNC(P<0.05), and in CHD group, the levels of TG, TC and LDL-C of GG genotype were higher than those of AA genotype(P<0.05). While in non-CHD group, there were no significant differences between the frequencies of GG genotype and G allele of patients in Hainan and TPNC(P>0.05). Conclusions: There was a close correlation between the E670 G polymorphism of PCSK9 gene and CHD with serum lipid level. Among Han population in Hainan and TPNC, the E670 G polymorphism of PCSK9 gene of patients with CHD exhibited regional differences.

新型HAN基液体推进剂EMP⁃01液滴电点火特性

为探究新型硝酸羟胺(HAN)基液体推进剂EMP‑01液滴点火特性,搭建了通过将液滴静置在半球形凹槽内并插入电极的液滴电点火实验平台,在液滴直径6.5 mm、电极间距0.5 mm、电压加载速率为86.31 V∙s-1的工况下,研究了EMP‑01液滴的电点火燃烧特性,确定了着火延迟时间;同时,不改变液滴直径以及电极间距,研究了电压加载速率为34.20~246.37 V∙s^(-1)时液滴着火延迟时间与燃烧过程的变化规律。结果表明,电点火燃烧中,EMP‑01液滴分依次经历为加热、热分解、燃烧3个阶段,并且在热分解阶段会产生周期性的膨胀收缩。电压加载速率为34.20 V∙s^(-1)时,EMP‑01液滴无法成功点火;电压加载速率为49.49~246.37 V∙s^(-1)时,随着电压加载速率增加,EMP‑01液滴着火延迟时间不断减小,且减小速率逐渐变缓。

Association between PPARG genetic polymorphisms and ischemic stroke risk in a northern Chinese Han population: a case-control study

Two common polymorphisms of the peroxisome proliferator-activated receptor gamma(PPARG) gene, rs1801282 and rs3856806, may be important candidate gene loci affecting the susceptibility to ischemic stroke. This case-control study sought to identify the relationship between these two single-nucleotide polymorphisms and ischemic stroke risk in a northern Chinese Han population. A total of 910 ischemic stroke participants were recruited from the First Hospital of China Medical University, Shenyang, China as a case group, of whom 895 completed the study. The 883 healthy controls were recruited from the Health Check Center of the First Hospital of China Medical University, Shenyang, China. All participants or family members provided informed consent. The study protocol was approved by the Ethics Committee of the First Hospital of China Medical University, China on February 20, 2012(approval No. 2012-38-1). The protocol was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR-COC-17013559). Plasma genomic DNA was extracted from all participants and analyzed for rs1801282 and rs3856806 single nucleotide polymorphisms using a SNaPshot Multiplex sequencing assay. Odds ratios(ORs) and 95% confidence intervals(CIs) were calculated using unconditional logistic regression to estimate the association between ischemic stroke and a particular genotype. Results demonstrated that the G allele frequency of the PPARG gene rs1801282 locus was significantly higher in the case group than in the control group(P < 0.001). Individuals carrying the G allele had a 1.844 fold increased risk of ischemic stroke(OR = 1.844, 95% CI: 1.286–2.645, P < 0.001). Individuals carrying the rs3856806 T allele had a 1.366 fold increased risk of ischemic stroke(OR = 1.366, 95% CI: 1.077–1.733, P = 0.010). The distribution frequencies of the PPARG gene haplotypes rs1801282-rs3856806 in the control and case groups were determined. The frequency of distribution in the G-T haplotype case group was significantly higher than that in the control group. The risk of ischemic stroke increased to 2.953 times in individuals carrying the G-T haplotype(OR = 2.953, 95% CI: 2.082–4.190, P < 0.001). The rs1801282 G allele and rs3856806 T allele had a multiplicative interaction(OR = 3.404, 95% CI: 1.631–7.102, P < 0.001) and additive interaction(RERI = 41.705, 95% CI: 14.586–68.824, AP = 0.860;95% CI: 0.779–0.940;S = 8.170, 95% CI: 3.772–17.697) on ischemic stroke risk, showing a synergistic effect. Of all ischemic stroke cases, 86% were attributed to the interaction of the G allele of rs1801282 and the T allele of rs3856806. The effect of the PPARG rs1801282 G allele on ischemic stroke risk was enhanced in the presence of the rs3856806 T allele(OR = 8.001 vs. 1.844). The effect of the rs3856806 T allele on ischemic stroke risk was also enhanced in the presence of the rs1801282 G allele(OR = 2.546 vs. 1.366). Our results confirmed that the G allele of the PPARG gene rs1801282 locus and the T allele of the rs3856806 locus may be independent risk factors for ischemic stroke in the Han population of northern China, with a synergistic effect between the two alleles.

The association analysis polymorphism of CDKAL1 and diabetic retinopathy in Chinese Han population

AIM： To identify the contribution of CDKAL1 to the development of diabetic retinopathy（DR） in Chinese population.·METHODS： A case-control study was performed to investigate the genetic association between DR and polymorphic variants of CDKAL1 in Chinese Han population with type 2 diabetes mellitus（T2DM）. A welldefined population with T2 DM, consisting of 475 controls and 105 DR patients, was recruited. All subjects were genotyped for the genetic variant（rs10946398） of CDKAL1. Genotyping was performed by i PLEX technology. The association between rs10946398 and T2 DM was assessed by univariate and multivariate logistic regression（MLR） analysis.· RESULTS： There were significant differences in C allele frequencies of rs10946398（CDKAL1） between control and DR groups（45.06% versus 55.00%, P 〈0.05）.The rs10946398 of CDKAL1 was found to be associated with the increased risk of DR among patients with diabetes.·CONCLUSION： Our findings suggest that rs10946398 of CDKAL1 is independently associated with DR in a Chinese Han population.

Association of single nucleotide polymorphism of vitamin D receptor gene start codon and the suscepbility to prostate cancer in Han nationality in Hubei, China

Aim: To investigate the single nucleotide polymorphism of vitamin D receptor (VDR) gene start codon in the Han nationality in Hubei and its relationship to the susceptibility to prostate cancel (PCa). Methods: The VDR genotypes were determined by poly-merase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 80 patients with PCa and 96 normal male controls from the Han nationality in Hubei, using endonuclease Fok. Direct sequencing was done in part of the PCR products. Results: The frequency distribution of Fok I alleles in this cohort all followed the Hardy-Weinberg equilibrium. The distribution of genotypes and alleles had no significant difference between PCa patients and the controls (P>0.05). Conclusion: There was no significant relationship between Fok I polymorphism of VDR gene start codon and PCa in the Han nationality in Hubei.

MAPT as a predisposing gene for sporadic amyotrophic lateral sclerosis in the Chinese Han population

A previous study of European Caucasian patients with sporadic amyotrophic lateral sclerosis demonstrated that a polymorphism in the microtubule-associated protein Tau （MAPT） gene was significantly associated with sporadic amyotrophic lateral sclerosis pathogenesis. Here, we tested this association in 107 sporadic amyotrophic lateral sclerosis patients and 100 healthy controls from the Chinese Han population. We screened the mutation-susceptible regions of MAPT- the 3＇ and 5＇ untranslated regions as well as introns 9, 10, 11, and 12 - by direct sequencing, and identified 33 genetic variations. Two of these, 105788 A 〉 G in intron 9 and 123972 T 〉 A in intron 11, were not present in the control group. The age of onset in patients with the 105788 A 〉 G and/or the 123972 T 〉 A variant was younger than that in patients without either genetic variation. Moreover, the pa- tients with a genetic variation were more prone to bulbar palsy and breathing difficulties than those with the wild-type genotype. This led to a shorter survival period in patients with a MAPT genetic variant. Our study suggests that the MAPT gene is a potential risk gene for sporadic amyotrophic lateral sclerosis in the Chinese Han population.

Study on FSHR and LHR mRNA Levels of Different BMPRIB Genotypes of Small Tail Han Sheep During the Oestrum

The relationship between different BMPRIB genotypes of Small Tail Han sheep and FSHR and LHR mRNA levels during the oestrum was studied using semiquantitative PCR. The results indicated that FSHR mRNA extracted from the right ovary of BB （1.14±0.11） ewes showed higher levels compared with AA （0.44±0.11） and AB （0.36±0.08） ewes （P〈0.01）, and LHR mRNA extracted from the right ovary of BB （0.42±0.02） ewes showed significantly higher levels compared with AA （0.23±0.02） and AB （0.25±0.04） ewes （P〈0.01）; however, the mRNA extracted from the left ovary showed no significant difference in levels among the genotypes during the oestrum. It indicated that the fecundity induced by a mutation of BMPRIB in Small Tail Han sheep may be related to the changes of the mRNA expression of LHR and FSHR in ovary.

Associations between thromboxane A synthase 1 gene polymorphisms and the risk of ischemic stroke in a Chinese Han population

Thromboxane A synthase 1 （TBXAS1） catalyses the synthesis of thromboxane A2 （TXA2）, which plays an important role in the pathogenesis of ischemic stroke. Thus, the TBXAS1 gene was investigated as a candidate gene involved in the formation of atherosclerosis. This case-control study collected peripheral blood specimens and clinical data of 370 ischemic stroke patients and 340 healthy controls in the Northern Chinese Han population from October 2010 to May 2011. Two TBXAS1 single-nucleotide polymorphisms, rs2267682 and rs10487667, were analyzed using a SNaPshot Multiplex sequencing assay to explore the relationships between the single-nucleotide polymorphisms in TBXAS1 and ischemic stroke. The TT genotype frequency and T allele frequency of rs2267682 in the patients with ischemic stroke were significantly higher than those in the controls （P 〈 0.01 and P = 0.02）. Furthermore, compared with the GG ＋ GT genotype, the TT rs2267682 genotype was associated with increased risk of ischemic stroke （odds ratio （OR） = 1.80, 95% confidence interval （CI）： 1.16–2.79, P 〈 0.01）. Multivariate logistic analysis with adjustments for confounding factors revealed that rs2267682 was still associated with ischemic stroke （OR = 1.94,95% CI ： 1.13–3.33, P = 0.02）. The frequency of the T-G haplotype in the patients was significantly higher than that in the controls according haplotype analysis （OR = 1.49, 95% CI： 1.10–2.00, P 〈 0.01）. These data reveal that the rs2267682 TBXAS1 polymorphism is associated with ischemic stroke. The TT genotype of TBXAS1 and T allele of rs2267682 increase susceptibility to ischemic stroke in this Northern Chinese Han population. The protocol has been registered with the Chinese Clinical Trial Registry （registration number： ChiCTR-COC-17013559）.

Estimation of Water Environmental Capacity Considering Hydraulic Project Operation in the Xiangyang Reach of the Han River, Central China

Using the Xiangyang Reach of the Han River as an example, this paper evaluates the changes of water environmental capacity after the implementation of Cuijiaying Hydro-junction project. The allowable pollutant loads entering the Xiangyang Reach were estimated using two-dimensional steady state water quality model with different data sets. The water environmental capacity has declined in the reservoir area of the Cuijiaying Hydro-junction project during the low-flow period;it is appearing to increase slightly in the upper and lower stream of this reservoir. However, the state of flow may turn into the state of reservoirs flow in the reservoir area, and the changes of hydrological regime may cause the water flow and the nutrient contents suitable for the occurrence of ecological environment problems.

The Levels of Genetic Differentiation of Small-Tailed Han Sheep and Tan Sheep Populations Using Structural Loci

Using the method of ＂random sampling in typical colonies of the central area of the habitat＂ and several electrophoresis techniques, the variations of 17 structural loci encoding blood proteins in 60 Small-Tailed Han sheep and 73 Tan sheep were examined and compared with those of 14 other sheep populations in China and other countries to investigate their levels of genetic differentiation. The average heterozygosities of Small-Tailed Han sheep and Tan sheep were 0.2360 and 0.2587, respectively. The average polymorphic information content values were 0.1974 and 0.2102, respectively. The average effective numbers of alleles were 1.5723 and 1.5751, respectively. The coefficients of gene differentiation in the four groups （including 4, 6, 13, and 16 sheep populations, respectively） were 0.049323, 0.059987, 0.1728, and 0.201256, respectively, indicating that the degree of gene differentiation at the structural loci was the least in Hu sheep, Tong sheep, Small-Tailed Hart sheep, and Tan sheep; followed by the above-mentioned four sheep populations and two Mongolian sheep populations; and was the highest in sheep populations belonging to the Mongolian sheep group, South Asian sheep, and European sheep. The earlier researchers＇ conclusions that both Small-Tailed Han sheep and Tan sheep evolved from Mongolian sheep were further verified by the results of this study. Hu sheep, Tong sheep, Small-Tailed Han sheep, and Tan sheep were decreasingly affected by the bloodline of Mongolian sheep to different degrees. The relationships among sheep populations were not closely related to the geographical distances among sheep populations.

Glimpse of the Han Dynasty from Han Stone Relief——Take the Han stone relief in Tengzhou For Example

Han stone relief is a kind of unique burial art in China and has a far-reaching influence in the whole history of art.Han stone relief is discovered in quite a few districts in China.Tengzhou is one of the districts that discovers Han stone relief at the earliest and has relatively abundant remains.The article takes Han stone relief that is in Tengzhou Shandong as an example,analyzes the subjects and contents of it,as well as its values,and explores the mainstream ideology which is reflected by these stone portraits at that time.

The Integration of Farmers and Nomads: Archaeological Evidence for the Human Subsistence Strategy in Northwestern China during the Han Dynasty

The integration of farmers and nomads in northwestern China during the Han Dynasty(206 BCE ~ 220 CE) provides a crucial opportunity to reconstruct the material exchanges, formation and development of the Silk Road in antiquity. The subsistence strategy is arguably an effective proxy for the integration of various groups of people(e.g. farmers and nomads). In this paper, we have reported new stable isotope data from the Huangwan tombs dated to the Han dynasty in middle Gansu, which was the key juncture between the Han and Xiongnu empire, in order to fill the gap and further understand the substance strategies employed by the local people. According to the results of plant remains and stable isotopic data, millet farming, the typical agricultural activities for the Han Chinese in the Central Plains, was also the primary lifestyle for the Huangwan people in the mid Gansu. More importantly, this shows fundamentally remarkable difference from the agricultural practices in the Bronze Age Gansu Corridor, which were based on a variety of crops, including wheat, barley and millet. This major shift in the subsistence production at Huangwan can be correlated to a wider historical background in which the Han empire showed increasing political and military presence in the Gansu Corridor, indicating that local indigenous nomads followed the lifestyle of Han Chinese(e.g., millet farming), and/or the Han immigrates maintained millet farming.

Occurrence and distribution of hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system, South Korea

We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.