粗枝云杉( Picea asperata Mast.)天然群体的遗传变异

西南地区在我国的经济发展和生态环境建设中占重要地位，但也是我国生态环境最脆弱的地区之一，生态系统退化，生态功能减弱，严重制约着西南林业的可持续经营与发展。本项目采用DNA 分子标记SSR 研究不同生境条件下粗枝云杉群体的遗传变异及其时空分布格局，考察遗传变异与复杂的山地生态环境间的潜在联系，系统地揭示粗枝云杉天然群体与环境系统相互作用的生态适应与分子进化机制。粗枝云杉适应性强，生长迅速，在植树造林和工业用材方面占有重要地位，研究成果可为中国西南部亚高山天然林的可持续经营及退化生态系统的恢复与重建提供理论依据和科学指导。主要研究结果如下： 1. SSR 位点变异丰富，等位基因频率的分布格局多样。7 个SSR 标记全是多态位点，每位点的等位基因数变化范围为13~24，平均为19.9 个。SSR 位点的等位基因片段长度范围变化较大。73.1%的等位基因变异遵循逐步突变模型(SSM)而发生1 个重复基元的变化，22.3%和4.6%的变异分别按两阶段突变模型(TMP)发生1 个重复基元以上的变化和在SSR 位点侧翼区发生1 个碱基变化的插入-删除事件。 2. 粗枝云杉拥有中等偏高水平的遗传多样性和相对大的群体间遗传分化。通过分析代表10 个群体的250 个个体在7 个SSR位点的变化，调查了源自中国西南山区的粗枝云杉的微卫星变异。相当高的遗传多样性和强烈的群体分化发生在粗枝云杉中， 其群体平均Nei's 期望杂合度为0.707 ， 群体间遗传距离为0.121~0.224(FST)和0.100~0.537(RST)。然而，群体间遗传距离与地理距离之间无相关性，从而排除了简单的距离分离模式并暗示迁移不是影响粗枝云杉遗传变异格局的主要因素。事实上，使用私有等位基因估算的基因流数量非常低，仅等于0.753。等位基因置换检验(Allele permutation tests)揭示逐步突变及遗传漂变都对群体间分化有贡献。另外，在多数位点检测到显著的群体间遗传差异，这个结果说明自然选择，假设通过环境压力，是引起粗枝云杉微地理分化的主要因素之一。根据SSR基因型，250 个粗枝云杉个体的70%被正确地归类入其各自的来源群体，结果表明微卫星(SSR)对区分来自中国不同生态地理位点的粗枝云杉基因型是有效的。 3. 在SSR、RAPD 和AFLP 位点，显著的群体间遗传结构被发现的，但三种标记间遗传分化程度和群体遗传关系有差异。利用来自10 个群体的247 个个体，我们报告了关于样本粗枝云杉群体间遗传关系的总体看法。根据各自对评价遗传关系的信息能力和适用性，SSR、RAPD 和AFLP 标记被选用，三种技术非常有效地区别这些基因型。使用的SSR、RAPD 和AFLP 标记分别估计平均Dice 相似性系数。Mantel 检验产生显著但相对低的共表型适合度(RAPD = 0.63£AFLP = 0.60和SSR = 0.75)。比较三种标记系统，RAPD 和AFLP 共表型指数相对高地相关(r =0.59)，而RAPD 和SSR 及SSR 和AFLP 之间的相关系数分别是0.53 和0.35。所有系统树，包括不同标记资料结合获得的系统树，反映了多数群体依据它们的地理条件而成某种特定关系。结果暗示单个或结合标记系统能用来深入洞察粗枝云杉遗传研究，并且不同标记系统合并资料能提供更可靠的信息。 Southwestern region plays an important role in economic developmentand ecological construction in China. Yet, it is also one of the weak regionsof ecological environment in China with degraded ecosystem and imperfectfunction, which restricts the sustaining management and development ofsouthwestern forestry. The genetic variation and spatial distribution patternof P. asperata populations originating from different habitats wereinvestigated using SSR molecular markers in this study. The correlationsbetween genetic variation and ecological and environmental conditionswere detected, and the interaction between P. asperata populations andenvironmental system and the mechanism of ecological adaption -molecular evolution were revealed. Given the significant ecological andeconomic roles of the fast-growing and wide-adaptive species in reforestation and production of pulp wood and timber, the study couldprovide a strong theoretical evidence and scientific direction for thesustaining management of subalpine natural forest, and the afforestationand rehabilitation of degraded ecosystem. The results are as follows: 1. The genetic variation at SSR loci was abundant and the distributionof allelic frequencies was uneven. All seven loci were polymorphic, and thenumber of alleles per locus varied from 13 to 24 with a mean valueequaling 19.9. The allele sizes at SSR loci were found to vary widely.73.1% of allelic variation followed stepwise mutation model (SSM) whichresults increase or decrease by one repeat type, and 22.3% and 4.6% wereresulted from two-phase mutation model (TMP) with allele size varying bymore than one repeat type and from insertion-deletion events in theflanking regions at SSR loci with a single basepair changing, respectively. 2. P. asperata possessed a moderate to high level of genetic diversityand considerable genetic differentiation. Microsatellite variation of P.asperata. originating from the mountains of southwestern China wasinvestigated by analyzing variation at seven SSR loci in 250 individualsrepresenting ten populations. A fair degree of genetic diversity and strongpopulation subdivision occurred with the mean gene diversity (H) of 0.707,and genetic distances among populations varying between 0.121 and 0.224(FST) and between 0.100 and 0.537 (RST). However, inter-populationgenetic distances showed no correlation with geographic distances between the population sites. This ruled out a simple isolation by distance modeland suggested that migration does not have a great impact. In fact, theamount of gene flow, detected using private alleles, was very low, equalingonly 0.753. Allele permutation tests revealed that stepwise-like mutations,coupled with genetic drift, could contribute to population differentiation.Moreover, significant genetic differences between populations weredetected at most loci. The results indicate that natural selection, presumablythrough environmental stress, may be one of the main factors causingmicro-geographical differentiation in the genetic structure of P. asperata.Based on SSR genotypes, 70% of the 250 individuals were correctlyclassified into their sites of origin. This suggests that microsatellites (SSRs) are effective in distinguishing genotypes of P. asperata originating fromdiverse eco-geographical sites in China. 3. Using a set of 247 individuals from ten P. asperata populations wereport an overview on the genetic relationship among the sampled P.asperata populations. RAPD, AFLP and SSR were used in terms of theirinformativeness and applicability for evaluate relationship and all threetechniques discriminated the genotypes very effectively. Mean Dicesimilarities coefficient were estimated using RAPD, AFLP and SSR,respectively. The Mantel test resulted in a significant but relatively low fit(RAPD = 0.63, AFLP = 0.60 and SSR = 0.75) of cophenetic values.Comparing the three marker systems to each other, RAPD and AFLP cophenetic indices were highly correlated (r = 0.59), while correlationcoefficient between RAPD and SSR was r = 0.53 and between SSR andAFLP was r = 0.35. For all markers a relatively high similarity indendrogram topologies was obtained although some differences wereobserved. All the dendrograms, including that obtained by the combineduse of all the marker data, reflect some relationships for most of thepopulations according to their geographic conditions. The results indicatethat single or combined marker system could be used to insight into geneticstudy in P. asperata and the combined data of different marker systems canprovide more reliable information.

卧龙自然保护区不同海拔的中国沙棘(Hippophae rhamnoides subsp. sinensis)天然群体的遗传多样性分析

中国沙棘是一种雌雄异株、风媒传粉的灌木或乔木，在中国西南的卧龙自然保护区有广泛的分布。本研究以采集于四川卧龙自然保护区5 个海拔(1800 m、2200 m、2600 m、3000 m、3400 m)梯度的中国沙棘天然群体为材料，以ISSR 和AFLP 标记技术研究其遗传多样性水平及其遗传结构，旨在了解卧龙地区中国沙棘天然群体的遗传多样性水平以及遗传多样性在群体间、群体内以及雌雄亚群体间的分布和特征，为中国沙棘树种的遗传改良及种质资源保存提供遗传研究背景与实验依据。同时探讨ISSR、AFLP 和RAPD三种标记对中国沙棘天然群体的遗传变异水平和群体间遗传结构的评估能力和各自的优缺点。研究得出以下主要结论： 1. ISSR和AFLP分析都表明卧龙自然保护区的中国沙棘群体拥有较高的遗传变异水平(h = 0.249，HT = 0.305)。出现这种结果的主要原因可能与卧龙自然保护区多变的气候条件和生境的异质度大有关。 2. ISSR 和AFLP 都揭示出卧龙自然保护区中国沙棘群体的遗传多样性随着海拔的增加发生显著的变化，表现为中海拔群体(2200 m 和2600 m)比高海拔群体(3000 m 和3400 m)和低海拔群体(1800 m)有更高的遗传多样性的趋势。出现这种趋势的可能解释是低海拔群体处在相对高温和相对干旱的环境，高海拔群体受到低温和紫外线胁迫，而中海拔群体存在中国沙棘生长的适宜环境。 3. ISSR 和AFLP 分析都表明：卧龙自然保护区中国沙棘的遗传结构遵循分布范围广、交配系统以异交为主的木本植物的通常模式，即大多数的遗传变异存在于群体内，只有少部分的遗传变异存在于群体间。 4. 经Mantel 检测表明，卧龙自然保护区中国沙棘群体间的海拔距离和对应遗传距离之间存在显著的正相关关系，即随着垂直海拔距离的增加，群体间的遗传距离也随之增加。Mantel 检测结果以及聚类分析将卧龙自然保护区5 个不同海拔的中国沙棘群体分为低、中、高海拔群体三组的研究结果都表明，海拔很可能是限制群体间基因交流的主要因素。 5. ISSR 分析发现同一海拔的雌雄亚群体首先聚类的研究结果表明，同一海拔的雌雄亚群体在遗传上最相似。方差分析结果表明只有3.8%的总遗传变异存在于雌雄亚群体间，这可能与雌雄植株间的交配和遗传物质的混合有关。 6. ISSR、AFLP 和RAPD 分析都表明卧龙自然保护区不同海拔的中国沙棘天然群体的遗传多样性水平较高。它们的分析结果估算得到的Nei's 平均基因多样度(h)分别为0.249、0.214 和0.170。从该结果可以看出ISSR 和AFLP 比RAPD 检测到更多的遗传多态性,这很可能是不同标记检测的基因组的位点不同所致。 7. 依据对不同标记系统的比较分析，认为ISSR、AFLP 和RAPD 三种分子标记系统都能成功地用于调查卧龙自然保护区不同海拔的中国沙棘群体的遗传变异水平及遗传变异结构，提供关于中国沙棘天然群体多态性水平和遗传变异分布的有用信息。在三者中，AFLP 具有最高效能指数和标记指数，在确定种间分类关系或鉴别个体方面是一种比较理想的标记。 Hippophae rhamnoides subsp. sinensis, a dioecious and deciduous shrub species,occupies a wide range of habitats in the Wolong Nature Reserve, Southwest China. Ourpresent study investigated the pattern of genetic variation and differentiation among fivenatural populations of H. rhamnoides subsp. sinensis, occurring along an altitudinal gradientthat varied from 1,800 to 3,400 m above sea level in the Wolong Natural Reserve, by usingISSR and AFLP markers to guide its genetic improvement and germplasm conservation. And,comparative study of ISSR, AFLP and RAPD was performed to detect their capacity toestimating the level and pattern of genetic variation occurring among the five elevationpopulations of H. rhamnoides subsp. sinensis, and to discuss their application to the study onplant genetics. The results were list following: 1. The ISSR and AFLP analysis conducted for the H. rhamnoides subsp. sinensispopulations located in the Wolong Natural Reserve of China revealed the presence of highlevels of genetic variation (h = 0.249, HT = 0.305). Besides such features as relatively widedistribution, dominantly outcrossing mating system, and effective seed dispersal by small animals and birds, it is sometimes argued that hard climatic conditions and heterogeneous habitats may also contribute to high levels of diversity. 2. Genetic diversity of H. rhamnoides subsp. sinensis populations was found to varysignificantly with changing elevation, showing a trend that mid-elevation populations (2,200m and 2,600 m) were genetically more diverse than both low-elevation (1,800 m) andhigh-elevation populations (3,000 m and 3,400 m). H. rhamnoides subsp. sinensis is thoughtto be stressed by drought and high temperature at low elevations, and by low temperature athigh elevations. The high genetic variability present in the mid-elevation populations of H.rhamnoides subsp. sinensis is assumed to be related to a greater plant density in the middlealtitudinal zone, where favorable ecological conditions permit its continuous distributioncovering the zone from 2,200 m to 2,600 m above sea level. 3. The genetic structure of H. rhamnoides subsp. sinensis revealed by ISSRs andAFLPs followed the general pattern detected in woody species with widespread distributionsand outcrossing mating systems. Such plants possess more genetic diversity withinpopulations and less variation among populations than species with other combinations oftraits. 4. In the present study, Mantel tests showed positive correlations between altitudinaldistances and genetic distances among populations or subpopulations. The observedrelationship between altitude and genetic distances, and the result of the cluster analysisincluding populations or male subpopulations and classifying the groups into three altitudeclusters suggest that altitude is a major factor that restricts gene flow between populationsand subpopulations. 5. The analysis of molecular variance showed that only 3.8% of the variability residedbetween female and male subpopulations. Such a very restricted proportion of the totalmolecular variance between female and male subpopulations is due to common sexuality andmixing of genetic material between females and males. 6. The analysis based on ISSRs, AFLPs and RAPDs all revealed relatively high levelsof genetic variation among different altitudinal populations of H. rhamnoides subsp. sinensisin Wolong Natural Reserve of China. Their estimates of mean Nei’s gene diversity is equal to0.249, 0.214 and 0.170 respectively, suggesting the higher capacity of detecting geneticvariation of ISSR and AFLP than RAPD. It might be ascribed to their distinct sensitivity todifferent type of genetic variation. 7. Based on the coparative study on ISSR, AFLP and RAPD, we drew a conclusion thatthey all successfully reveal some useful information concerning the level and pattern ofgenetic vatiation occurring among different elevation populations of H. rhamnoides subsp.sinensis. AFLP is a ideal tool to taxonomic study and individual identification for theirhighest efficiency index and marker index among the three marker systems.

中国沙棘(Hippophae rhamnoides subsp. sinensis)天然群体的遗传变异分析

近十年，植物群体遗传学的研究飞速发展，然而与海拔相关的植物群体遗传结构和遗传变异研究却相对较少。到目前为止，还不清楚遗传变异与海拔之间是否有一个通用的格局。在山区，各种生态因子，如温度、降水、降雪、紫外线辐射强度以及土壤成分都随海拔梯度急剧变化，造成了即使在一个小的空间区域，植被类型变化显著，这种高山环境的异质性和复杂性为我们研究植物群体遗传结构和分化提供了方便。沙棘(Hippophea)属于胡颓子科(Elaeagnaceae)为多年生落叶灌木或乔木，雌雄异株，天然种群分布极为广泛。中国沙棘(H. rhamnoides subsp. sinensis)是沙棘属植物中分布较广的一个亚种，种内形态变异非常丰富，加之其具有独特的繁育系统和广泛的生态地理分布，是研究沙棘属植物遗传变异和系统分化的理想材料。本文从1,800 m 到3,400 m 分5 个海拔梯度进行取样，用RAPD 和cpSSR 分子标记研究了卧龙自然保护区中国沙棘天然群体的遗传结构和遗传变异。5 个取样群体依次标记为A、B、C、D 和E，它们分别代表分布在海拔1,800，2,200，2,600，3,000 和3,400 m 的5 个天然群体。RAPD实验用11 条寡核苷酸引物，扩增得到151 个重复性好的位点，其中143 个多态位点，多态率达94.7%。在5 个沙棘群体中，总遗传多样性值(HT)为0.289，B群体内的遗传多样性值为0.315，这完全符合沙棘这种多年生、远交的木本植物具有高遗传变异的特性。5 个群体内遗传多样性随海拔升高呈低－高－低变异趋势，在2,200 m海拔处的B群体遗传多样性达最大值0.315，3,400 m海拔处的E群体则表现最小仅0.098。5 个群体间的遗传分化值GST＝0.406，也即是说有40.6%的遗传变异存在于群体间，1,800 m海拔处的A群体与其它群体的明显分离是造成群体间遗传分化大的原因。UPGMA聚类图和PCoA散点图进一步确证了5 个群体间的关系和所有个体间的关系。最后，经过Mantel检测，遗传距离与海拔表现了明显的相关性(r = 0.646, P = 0.011)。cpSSR 实验中，经过对24 对cpSSR 通用引物筛选，11 对引物能扩增出特异性条带，只有2 对引物(ccmp2 和ARCP4)呈现多态性。4 个等位基因共组合出4 种单倍型，单倍型Ⅰ出现在A 群体的所有个体和B 群体的8 个个体中，C、D、E 三个群体均不含有，而单倍型Ⅱ出现在C、D、E 三个群体的所有个体及B 群体的18 个个体中，A 群体不含有。另外两种单倍型Ⅲ和Ⅳ为稀有类型，仅B 群体中的4 个个体拥有。这种单倍型分布模式和TFPGA 群体聚类图揭示了，C、D、E 群体可能来源于同一祖先种，而A 群体却是由另一祖先种发展起来的，B 群体则兼具了这两种起源种的信息，这可能是因为在历史上的某一时期，在中国沙棘群体高山分化的过程中，B 群体处某个或者某些个体发生了基因突变，具备了适应高海拔环境的能力，产生了高海拔沙棘群体的祖先种。 In recent ten years, studies about population genetics of plants developed rapidly,whereas their genetic structure and genetic variation along altitudinal gradients have beenstudied relatively little. So far, it is uncleared whether there is a common pattern betweengenetic variation and altitudinal gradients. In the mountain environments, importantecological factors, e.g., temperature, rainfall, snowfall, ultraviolet radiation and soil substratesetc., change rapidly with altitudes, which cause the vegetation distribution varying typically,even on a small spatial scale. The mountain environments, which are heterogeneous andcomplex, facilitate and offer a good opportunity to characterize population genetic structureand population differentiation.The species of the genus Hippophae L. (Elaeagnaceae) are perennial deciduous shrubs ortrees, which are dioecious, wind-pollinated pioneer plants. The natural genus has a widedistribution extending from Northern Europe through Central Europe and Central Asia toChina. According to the latest taxonomy, the genus Hippophae is divided into six species and12 subspecies. The subspecies H. rhamnoides ssp. sinensis shows significant morphologicalvariations, large geographic range and dominantly outcrossing mating system. Thesecharacteristics of the subspecies are favourable to elucidate genetic variation and systemevolution. To estimate genetic variation and genetic structure of H. rhamnoides ssp. sinensisat different altitudes, we surveyed five natural populations in the Wolong Natural Reserve at altitudes ranging from 1,800 to 3,400 m above sea level (a.s.l.) using random amplifiedpolymorphic DNA markers (RAPDs) and cpSSR molecular methods. The five populations A,B, C, D, and E correspond to the altitudes 1,800, 2,200, 2,600, 3,000 and 3,400 m,respectively.Based on 11 decamer primers, a total of 151 reproducible DNA loci were yielded, ofwhich 143 were polymorphic and the percentage of polymorphic loci equaled 94.7%. Amongthe five populations investigated, the total gene diversity (HT) and gene diversity within population B equaled 0.289 and 0.315, respectively, which are modest for a subspecies of H.rhamnoides, which is an outcrossing, long-lived, woody plant. The amount of geneticvariation within populations varied from 0.098 within population E (3,400 m a.s.l.) to 0.315within population B (2,200 m a.s.l.). The coefficient of gene differentiation (GST) amongpopulations equaled 0.406 and revealed that 40.6% of the genetic variance existed amongpopulations and 59.4% within populations. The population A (1,800 m a.s.l.) differed greatlyfrom the other four populations, which contributes to high genetic differentiation. A UPGMAcluster analysis and principal coordinate analyses based on Nei's genetic distances furthercorroborated the relationships among the five populations and all the sampling individuals,respectively. Mantel tests detected a significant correlation between genetic distances andaltitudinal gradients (r = 0.646, P = 0.011).Eleven of the original 24 cpSSR primer pairs tested produced good PCR products, onlytwo (ccmp2 and ARCP4) of which were polymorphic. Four total length variants (alleles) werecombined resulting in 4 haplotypes. The haplotype was present in all individuals of Ⅰpopulation A and 8 individuals of populations B, the other three populations (C, D and Epopulations) did not share. The haplotype was present in all individuals of populations C, D Ⅱand E and 18 individuals of populations B, population A did not share. The other twohaplotypes and were rare haplotypes, which were only shared in 4 individuals of Ⅲ Ⅳpopulation B. The distribution of haplotypes and TFPGA population clustering map showedthat the populations C, D and E might be origined from one ancestor seed and population Amight be from another, whereas population B owned information of the two ancestor seeds. Itwas because that gene mutation within some individual or seed in the location of population Bwas likely to happen in the history of H. rhamnoides, which was the original ancestor of thehigh-altitude populations.

川西地区几种优势苔藓植株元素含量及其时空差异性

揭示苔藓植株元素含量及其时空差异性是深入开展利用苔藓植物指示环境和筛选理想监测藓种的科学基础。采用微波消解（ICP-AES）方法对九寨沟自然遗产地原始林景点停车场周围三个采样带：I为停车场植被小岛（PS），向外约120 m半径为II带（D120），再向外距离约1,000 m为III带（D1000）和3个方向上的大羽藓和毛尖青藓2种苔藓中13种元素（A1, S, Ca, P, Cu, Fe, K, Mg, Mn, Pb, Ni,Zn和Cd）含量进行了测定和比较，并对采自边坡方向（PS-3）上2005和2007年的4种苔藓植物（南木藓、大羽藓、平藓和厚角絹藓）也进行了13种元素含量的测定和比较。同时对九寨沟自然遗产地、黄龙自然遗产地、夹金山和梦笔山的冷杉原始林4个地区的3种苔藓中（大羽藓、锦丝藓和塔藓）的A1、Ca、Cu、Fe、K、Mg、P、Zn、C和N 10种元素含量进行测定和比较。 对大羽藓和毛尖青藓2种苔藓植物内13种元素的测定发现：1）同种苔藓对不同元素的富集能力不同。A1、Ca、K、Mg和P的元素含量在苔藓中的富集较其他元素的要高。2）不同种苔藓植物对同种元素的富集能力不同，毛尖青藓较大羽藓能够监测出更多的元素；对于被检测出的元素，毛尖青藓监测出的累积量大于大羽藓，其中累积量最大的元素是Ca为10 874.286 μg.g-1.year-1，最小的是Cu元素为5.438 μg.g-1.year-1。对05年和07年的平藓、大羽藓、南木藓和厚角絹藓元素含量的测定表明：元素在两年中的积累量是不同的。综合分析表明，苔藓生物监测方法可有效监测景点停车场机动车尾气中排放出的典型元素（如Cu、Pb、Ni、Zn、Cd等）含量，而毛尖青藓较大羽藓能更可靠的监测九寨沟自然遗产地单景点汽车尾气金属元素种类及其排放量。 对4个地区3种苔藓10种元素监测发现：1）Ca、Mg、Zn、K和Cu元素在黄龙地区的含量高于在其它地区的含量；P元素在梦笔山地区的含量为最高；Fe和Al元素在夹金山地区的含量高于在其它地区的含量。2）C元素在其它因素一致的情况下，进行不同年龄间的元素含量比较，结果显示元素含量在各年龄间并不存在明显的差异性；N元素含量与年龄的差异出现在黄龙林下及林窗的塔藓、九寨沟林下的锦丝藓及塔藓和梦笔山的塔藓中，而在锦丝藓中未出现元素含量与年龄的差异性；塔藓能检测出更多的元素种类其含量与年龄间存在显著差异，锦丝藓检测到的元素种类次之；除锦丝藓（锦丝藓在林窗中几乎检测不到元素含量与年龄间的差异性）外，其他两种藓在林窗中能检测出的元素种类大于在林下的检测种类。3）元素含量与生境间存在差异性的元素分别有：黄龙大羽藓中的Ca、P和Mg元素；九寨锦丝藓中的Zn元素；夹金山塔藓中的Al、Fe和Zn元素；梦笔山大羽藓中的Al、Fe和Mg元素及锦丝藓中的Ca元素。4）区域、年龄和生境因素对苔藓植株元素含量均达到了显著水平，但两两之间及三者之间的交互作用由于元素种类的不同存在差异。综合分析表明，苔藓植物中的元素含量受年龄、区域的影响较生境的更大。 The revelation of mosses elements content and its spatiotemporal differences is the scientific foundation of moss monitoring. To determine the feasibility of moss monitoring metal depositions derived from travel bus emiss ions in scenic spot, we collected one year-growth samples of two mosses Brachythecim piligerum and Thuidium cymbifolium with different distance (island center, 120m，1000m ) and different direction (north, south and east) far from parking site island from Yuanshilin Spot at Jiuzhaigou World Nature Heritage in the Western Sichuan of China and determined thirteen element （A1, S, Ca, P, Cu, Fe, K, Mg, Mn, Pb, Ni, Zn, Cd）contents by ICP-AES analysis method. And picked 4 kinds of mosses (Macrothamnium macrocarpu m（Reinw. etHornsch.）Fleisch.，Thuidium cymbifolium，Entodon concinnus (De Not.) Par., Neckera pennata) from the direction PS-3 in 2005 and 2007, determined 13 element contents. Collected 3 kinds of moss (Thuidium cymbifo lium, Actinothuidium Hookeri (Mitt.) and Hyolcomium splendens (Hedw.) from Jiuzhaigou natural heritage, Huanglong natural heritage, Mt. Jiajin and Mt. Mengbi in primeval forest with two habitat (undergrowth and forest gap), determined element contents of A1, Ca, Cu, Fe, K, Mg, P, Zn, C and N. We found that, 1) The elements content are difference in same type of moss. Content of A1, Ca, K, Mg and P are higher than others. 2) While the contents of A1, S, Ca, P, Cu, Fe, K and Zn had significant correlation with the different distances from parking site, the nearer the distance was, the more accumulation was; 2) Comparing to Thuidium cymbifolium, Brachythecium piligerum can test more elements which contents show the significant correlation with distances. And Brachythecium piligerum can have greater element accumulation than Thuidium cymbifolium. The element contents in two years (2005 and 2007) are different. The present study found that moss can reliably bio-indicate metal deposition from traffic emissions in one scenic spot and Brachythecium piligerum is a good moss for bio-indicating element content from traffic emissions at Jiuzhaigou World natural Heritage. Determined the 10 element contents in 4 areas through 3 kinds of moss we found that, 1) Ca, Mg, Zn, K and Cu element content is higher in the Huanglong area than in other areas, The P element content in Mt. Jiajin is higher than other areas, Fe and Al element content is higher in the Mt. Jiajin than in other areas. 2) The content of C had no significant correlation with age. As for N, this significant correlation found in Hyolcomium splendens (Hedw.) with 2 habitat in Huanglong, Actinothuidium Hookeri (Mitt.) and Hyolcomium splendens (Hedw.) with undergrowth in Jiuzhai, Hyolcomium splendens (Hedw.) in Mt. Mengbi. The types of elements which content showt he significant correlation are most in Hyolcomium splendens (Hedw.) and least in Thuidium cymbifolium. Except Actinothuidium Hookeri (Mitt.), the types of elements that content had significant correlation with age in forest gap are more than in undergrowth. 3) The elements which content had significant correlation with habitat are P, Ca and Mg in Thuidium cymbifolium in Huanglong, Zn in Actinothuidium Hookeri (Mitt.) in Jiuzhai, Al, Fe and Zn in Hyolcomium splendens (Hedw.) in Mt. Jiajin, in Mt. Mengbi Al, Fe and Mg in Thuidium cymbifolium and Ca in Actinothuidium Hookeri (Mitt.). 4）The region, the age and the habitat factor has coeffect element content. The correlationship between element contents and the age, the region is closer than habitat.

Neutron dose measurement in carbon ion radiation therapy at HIRFL (IMP)

For radiation protection purposes, the neutron dose in carbon ion radiation therapy at the HIRFL (Heavy Ion Research Facility in Lanzhou) was investigated. The neutron dose from primary C-12 ions with a specific energy of 100 MeV/u delivered from SSC was roughly measured with a standard Anderson-Broun rem-meter using a polyethylene target at various distances. The result shows that a maximum neutron dose contribution of 19 mSv in a typically surface tumor treatment was obtained, which is less than 1% of the planed heavy ion dose and is in reasonable agreement with other reports. Also the gamma-ray dose was measured in this experiment using a thermo luminescent detector.

Analytical potential energy function and spectroscopic parameters for the ground and excited states of NaH

set of energies at different internuclear distances for the ground electronic state and two excited electronic states of NaH molecule have been calculated using valence internally contracted multireference configuration interaction(MRCI) including Davidson correction and three basis sets. Then, a potential energy curve (PEC) for each state was determined by extrapolating MRCI energies to the complete basis sets limit. Based on the PECs, accurate vibrational energy levels and rotational constants were determined. The computational PECs are were fitted to analytical potential energy functions using the Murrell-Sorbie potential function. Then, accurate spectroscopic parameters were calculated. Compared with experimental results, values obtained with the basis set extrapolation yield a potential energy curve that gives accurate vibrational energy levels, rotational constants and spectroscopic parameters for the NaH molecule. (C) 2004 Elsevier B.V. All rights reserved.

Chemical Bonding and Electronic Structure of 4d-Metal Monosulfides

Bond distances, vibrational frequencies, dissociation energies, electron affinities, ionization potentials and dipole moments of the title molecules in neutral and charged ions were studied by use of density functional method. Ground states for each molecule were assigned. The calculated bond distance decreases with the increasing of atomic number of 4d metals, reaches minimum at RhS, then increases. For cationic molecules, the calculated bond distance decreases to the minimum at MoS+, then increases. The calculated vibrational frequency decreases from YS(YS+) to PdS(PdS+) for both neutral and cationic molecules. The bond ionic character decreases from YS(YS+) to PdS(PdS+) for neutral and cationic molecules. The bonding patterns are discussed and compared with the available studies.

Electronic structures and chemical bonding in diatomic ScX to ZnX (X = S, Se, Te)

Bond distances, vibrational frequencies, electron affinities, ionization potentials, dissociation energies, and dipole moments of the title molecules in neutral, positively, and negatively charged ions were studied using density functional method. Ground electronic state was assigned for each molecule. The bonding patterns were analyzed and compared with both the available data and across the series. It was found that, besides ionic component, covalent bonds are formed between the metal s, d orbitals, and the p orbital of S, Se, and Te. For neutral and cationic molecules, the covalent character increases from ScX to CrX and from FeX to CuX with an exception of decrease at MnX and ZnX, while for anionic molecules, the trend is not obvious. For both neutral and charged molecules, the sulfides have the shortest bond distance and largest vibrational frequency, while tellurides have the largest bond distance and smallest vibrational frequency. For neutral and anionic molecules, the dissociation energy of sulfides is the largest, that of tellurides is the smallest, while this only remains true for cationic molecules from ScX+ to FeX+.

Electronic structures and chemical bonding in 4d transition metal monohalides

Bond distances, vibrational frequencies, dipole moments, dissociation energies, electron affinities, and ionization potentials of NIX (XM = Y-Cd, X = F, Cl, Br, I) molecules in neutral, positively, and negatively charged ions were studied by density functional method, B3LYP. The bonding patterns were analyzed and compared with both the available data and across the series. It was found that besides ionic component, covalent bonds are formed between the 4d transition metal s, d orbitals, and the p orbital of halogen. For both neutral and charged molecules, the fluorides have the shortest bond distance, iodides the longest. Although the opposite situation is observed for vibrational frequency, that is, fluorides have the largest value, iodides the smallest. For neutral and anionic species, the dissociation energy tends to decrease with the increasing atomic number from Y to Cd, suggesting the decreasing or weakening of the bond strength. For cationic species, the trend is observed from Y to Ag.

Density functional studies of diatomic LaO to LuO

Bond distances, vibrational frequencies, electron affinities, ionization potentials, dissociation energies and dipole moments of the title molecules in neutral, positively and negatively charged ions were studied by use of density functional method. Ground electronic state was assigned for each molecule. The bonding patterns were analyzed and compared with both the available data and across the series. It was found that besides ionic component, covalent bonds are formed between the metal s, d and f orbitals and oxygen p orbitals. Contrary to the well known lanthanide contraction, the bond distance is not regular from LaO to LuO for both neutral and charged molecules. An obvious population at 5d orbital was observed through the lanthanide series. 4f electrons also participate the chemical bonding for CeO to NdO and TbO to TmO. For EuO, GdO, YbO and LuO, 4f electrons tend to be localized. The spin multiplicity is regular for neutral and charged molecules. The spin multiplicity of the charged molecules can be obtained by -1 (or +1 for TbO+, DyO+, YbO- and YbO+) compared with the corresponding neutral molecules.

Electronic structures of 4d transition metal monoxides by density functional theory

Bond distances, dissociation energies, ionization potentials and electron affinities of 4d transition metal monoxides from YO to CdO and their positive and negative ions were studied by use of density functional methods B3LYP, BLYP, B3PW91, BPW91, B3P86, BP86, SVWN, MPW1PW91 and PBE1PBE. It was found that calculated properties are highly dependent on the functionals employed, especially for dissociation energy. For most neutral species, pure density functionals BLYP, BPW91 and BP86 have good performance in predicting dissociation energy than hybrid density functionals B3LYP, B3PW91 and B3P86. In addition, BLYP gives the largest bond distance compared with other density functional methods, while SVWN gives shortest bond distance, largest dissociation energy and electron affinity. For the ground state, the spin multiplicity of the charged species can be obtained by +/- 1 of their corresponding neutral species.

Electronic structures of 5d transition metal monoxides by density functional theory

Bond distances, vibrational frequencies, electron affinities, ionization potentials, and dissociation energies of the diatomic 5d transition metal (except La) monoxides and their positively and negatively charged ions were studied by use of density functional methods B3LYP, BLYP, B3PW91, BPW91, B3P86, BP86, MPW1PW91, PBE1PBE, and SVWN. Our calculation shows that for each individual species, the calculated properties are quite sensitive to the method used. Compared with hybrid density functional method B3PW91 (B3P86), pure density functional method BPW91 (BP86) gives longer bond distance (lower vibrational frequency) from HfO to PtO for neutral species, HfO+ to IrO+ for cationic species, and HfO- to AuO- for anionic species. While for B3LYP and BLYP, the trend was observed for cationic species from HfO+ to IrO+ and anionic species from HfO- to AuO- (except TaO-), but not for neutrals. Pure density function methods BLYP, BPW91, and BP86 give larger dissociation energy compared with hybrid density functional methods B3LYP, B3PW91, and B3P86. SVWN in most cases gives the smallest bond distance, while BLYP gives the largest value. MPW1PW91 and PBE1PBE show the same performance in predicting the spectroscopic constants.

Theoretical investigation of 5D-metal monocarbide

Bond distances, vibrational frequencies, electron affinities, ionization potentials and dissociation energies of the title molecules in neutral, positively and negatively charged ions were studied by use of density functional method. The calculated results were compared with previous theoretical and experimental studies. Ground states for each molecule were assigned. It was found that for some molecules, low-lying state, in which the energy is much close to the ground state, was obtained. In this case, further studies both experimentally and theoretically are necessary in order to find the true global minimum.

Ground state of lutetium dimer by density functional methods

Bond distances, vibrational frequencies and dissociation energies for the ground state of Lu-2 were studied by density functional methods B3LYP, B3PW91, BLYP, BHLYP, BP86, B3P86, MPW1PW91, PBE1PBE and SVWN with CEP-121G and SDD basis sets. Singlet state is predicted to be the most stable. CEP-121G has a better overall performance than SDD. At CEP-121G basis set, all density functional methods used in this study perform well in reproducing the spectroscopic constants.

Electronic structures of 3d-metal mononitrides

Bond distances, vibrational frequencies, electron affinities, ionization potentials, and dissociation energies of the title molecules in neutral, positively, and negatively charged ions were studied by use of density functional methods B3LYP, BLYP, BHLYP, BPW91, and B3PW91. The calculated results are compared with experiments and previous theoretical studies. It was found that the calculated properties are highly dependent on the functionals employed, in particular for the dissociation energy and vibrational frequency. For neutral species, pure density functional methods BLYP and BPW91 have relatively good performance in reproducing the experimental bond distance and vibrational frequency. For cations, hybrid exchange functional methods B3LYP and B3PW91 are good in predicting the dissociation energy. For both neutral and charged species, BHLYP tends to give smaller dissociation energy.