Phase Chemistry Study of the Zabuye Salt Lake Brine: Isothermal Evaporation at 15°C and 25°C

Zabuye Salt Lake in Tibet, China is a carbonate-type salt lake, which has some unique characteristics that make it different from other types of salt lakes. The lake is at the latter period in its evolution and contains liquid and solid resources. Its brine is rich in Li, B, K and other useful minor elements that are of great economic value. We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15°C and 25°C. The crystallization sequence of the primary salts from the brine at 25°C is halite (NaCl) → aphthitalite (3K2SO4·Na2SO4) → zabuyelite (Li2CO3)→ trona (Na2CO3·NaHCO3·2H2O) → thermonatrite (Na2CO3·H2O) → sylvite (KCl), while the sequence is halite (NaCl) → sylvite (KCl) → trona (Na2CO3·NaHCO3·2H2O) → zabuyelite (Li2CO3) → thermonatrite (Na2CO3·H2O) → aphthitalite (3K2SO4·Na2SO4) at 15°C. They are in accordance with the metastable phase diagram of the Na+, K+-Cl?, CO32?, SO42?-H2O quinary system at 25°C, except for Na2CO3·7H2O which is replaced by trona and thermonatrite. In the 25°C experiment, zabuyelite (Li2CO3) was precipitated in the early stage because Li2CO3 is supersaturated in the brine at 25°C, in contrast with that at 15°C, it precipitated in the later stage. Potash was precipitated in the middle and late stages in both experiments, while boron was concentrated in the early and middle stages and precipitated in the late stage.     

辽北地区钾长石矿地质特征及开发应用方向

以铁岭县湾龙背地区的钾长石矿为例,研究了辽北地区伟晶岩型钾长石矿的分异相带特点及空间分布规律。指出具新太古代壳源岩浆成因的钾长石分异相带明显,可分为内中外三个相带,其中内部相带的块体状钾长石、中间相带的团块状具文象结构的钾长石质量好,并在对国内的钾长石的市场潜力分析的基础上,指明了辽北地区钾长石矿的开发利用方向。     

东天山伊吾二叠纪花岗质杂岩体的锆石定年、地球化学及其构造意义

伊吾花岗质杂岩体主要由二长花岗岩和碱长花岗岩构成。锆石LA-ICP-MS U-Pb定年分析得到二长花岗岩和碱长花岗岩的侵位年龄分别为284.6±1.4Ma和284.0±1.1Ma。结合地质证据,此年龄表明该杂岩体形成于碰撞之后的二叠纪早期挤压-伸展转折阶段。岩石学、地球化学和同位素等方面的对比研究表明这两种岩石为同一岩浆演化的产物。与二长花岗岩相比,碱长花岗岩表现为硅、碱的含量较高,而铝的含量较低;富Th、U、Nb、Ta,贫Sr、P、Ti、Sm;DI和Rb/Sr升高,Nb/Ta和Zr/Hf下降,从二长花岗岩到碱长花岗岩表现出连续分异演化的趋势。计算得到二长花岗岩和碱长花岗岩的模式年龄(t_(DM))分别为693Ma和763Ma,ε_(Nd)(t)分别为+4.53和+4.64,(~(87)Sr/~(86)Sr)_i分别为0.703858和0.703855,表现出高ε_(Nd)(t)低(~(87)Sr/~(86)Sr)_i的特征。这些特征表明,伊吾岩体的岩浆来自新元古代时从亏损地幔分离出来的初生地壳源区。二长花岗岩岩浆是这种初生地壳岩浆演化的产物,而碱长花岗岩形成于二长花岗岩母岩浆经斜长石、磷灰石、钛铁氧化物、榍石、独居石、褐帘石和锆石等矿物分离结晶后的残留岩浆。     

Genetic variation of the small yellow croaker (Larimichthys polyactis) inferred from mitochondrial DNA provides novel insight into the fluctuation of resources

The small yellow croaker (Larimichthys polyactis) belongs to the family Sciaenidae, which is an offshore warm fish species and widely distributed in the western Pacific. In this study, the variation of genetic diversity and genetic differentiation among L. polyactis populations was analyzed by mitochondrial DNA control region. A total of 110 polymorphic sites were checked, which defined 134 haplotypes. High level of haplotype diversity (h=0.993±0.002) was detected in the examined range. Population genetic structure analyse (analysis of molecular variance, F_st) showed there were high gene flow among L. polyactis populations. The result showed that there were relatively high genetic diversity and low genetic differentiation among the Yellow Sea and the East China Sea populations, which can be attributed to diverse habitats, wide distribution range and high mutation rate of control region. Using phylogenetic methods, coalescent analyses (neutrality tests, mismatch distribution analysis, Bayesian skyline analyses) and molecular dating interpreted in conjunction with paleoclimatic and physiographic evidence, we inferred that the genetic make-up of extant populations of L. polyactis was shaped by Pleistocene environmental impacts on the historical demography of this species. Besides, relatively constant genetic diversity and larger effective population size were detected in recent L. polyactis population. The result showed that the fishing policy certainly, such as the summer closed fishing, played a role in protecting resources of L. polyactis. This study can offer a wealth of biological novelties which indicates genetic structure of L. polyactis population and provides the foundation for resources protection and policy setting.     

基于线粒体控制区的中国东南沿海黄鳍棘鲷群体遗传多样性和遗传分化

本研究通过对线粒体控制区序列进行分析的技术手段,对中国宁德（ND）、厦门（XM）、漳浦（ZP）、南澳岛（NAD）、湛江（ZJ）、海口（HK）与北海（BH）的7个野生黄鳍棘鲷（Acanthopagrus latus）群体的遗传多样性和遗传分化进行比较分析。结果表明：中国东南沿海的野生黄鳍棘鲷群体呈现出中等以上的遗传多样性特征,48个黄鳍棘鲷样品的控制区序列长度为580 bp,单倍型数目为44个,总体的单倍型多样性指数（Hd）和核苷酸多样性指数（Pi）分别为0.996和0.017 30。7个野生黄鳍棘鲷群体间的遗传分化程度较低,各群体间的遗传距离为0.010 28~0.029 87。群体间的遗传分化系数（FST）为-0.068 41~0.545 86,北海群体和其他群体间存在一定程度的遗传分化。AMOVA分析显示群体内的遗传变异占比为83.34%,大部分遗传变异发生在组群内;但北海群体与其他6个群体分为两个组群后,组群间的遗传变异占比为42.66%,两个组群间存在较大程度的遗传变异。基于Kimrua距离法构建的系统进化树中显示北海群体聚为一个分支,另外6个群体聚为一支。基于TCS network构建的单倍型网络图中44个单倍型混杂在一起,未按照水系格局和地理距离进行分布,表明黄鳍棘鲷群体间未形成多个单系群。本研究可为中国东南沿海野生黄鳍棘鲷群体的种质资源利用和保护提供科学依据。     

A comparison of different Gracilariopsis lemaneiformis (Rhodophyta) parts in biochemical characteristics,protoplast formation and regeneration

Gracilariopsis lemaneiformis is a commercially exploited alga. Its filaceous thallus can be divided into three parts, holdfast, middle segment and tip. The growth and branch forming trend and agar content of these three parts were analyzed, respectively, in this study. The results showed that the tip had the highest growth rate and branched most, although it was the last part with branch forming ability. The holdfast formed branches earliest but slowly. Holdfast had the highest agar content. We also assessed the difference in protoplast formation and regeneration among three parts. The middle segment displayed the shortest enzymolysis time and the highest protoplast yield; whereas the tip had the strongest vitality of protoplasts formation. Juvenile plants were only obtained from the protoplasts generated from the tip. These results suggested that the differentiation and function of G. lemaneiformis was different.     

梭梭(Haloxylon ammodendron)主根周围土壤特征

通过建立米级的空间尺度进行分层取样,研究了准噶尔盆地南缘建群种——梭梭(Haloxylon ammodendron)主根周围土壤的含水率、容重、pH值、电导率和养分含量的变化状况。结果表明:(1)土壤含水量在表层5cm处最小,土壤容重在0~40cm土层变动幅度不大,但随着与茎基垂线距离的增加,二者出现显著变化(p0.05)。(2)土壤pH值和电导率在主根区周围呈现聚集现象,最大聚集率均在0~1m圈层,但随着距离的增加,土层深度逐渐成为主导因素。(3)土壤养分在表层5cm处聚集,但水平聚集范围中除有机质和全氮可扩增到3~4m外,全磷和速效养分均在0~2m。本研究结论对于荒漠区耐盐性植被的合理密植有一定的理论意义。     

1960-2010年中国降水区域分异及年代际变化特征

利用1960-2010年中国1840个台站年降水量数据,采用经验正交函数(EOF)和旋转经验正交函数分解方法(REOF)对降水进行分区,并对各区降水的变化特征进行了研究.结果表明:基于多站点资料结合REOF方法实现的降水分区与中国降水实际区域分异特征比较符合,并与中国气候区划相一致.中国各区降水变化特征分析表明,东部各区降水在20世纪70年代末、80年代末-90年代初和21世纪初发生雨带的南北移动过程,其中夏季雨带的移动主要受东亚夏季风和大气环流年代际变化的影响.西北地区降水以1985/1986年为突变年,西北西部地区降水由前期偏少转为偏多,主要与来自阿拉伯海和里海异常偏多的水汽输送有关;西北东部地区降水由前期偏多转为偏少,主要与季风的年代际减弱有关.东北地区降水在80年代初由前期接近正常转为偏多,90年代末降水由前期偏多转为偏少,主要与季风和西北太平洋水汽输送的年代际变化相关.西南部各区降水阶段性变化明显,2000年以前西南东北部地区降水与西部地区基本呈反向变化,主要受青藏高原地形、东亚季风和副热带高压等因素的影响,降水阶段性变化明显、成因复杂.     

Analysis of genetic diversity and differentiation of seven stocks of Litopenaeus vannamei using microsatellite markers

Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content(PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles(Na) and effective alleles(Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity(Ho) values were lower than the expected heterozygosity(He) values(0.526–0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. Fis values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise Fst values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks(11.3%) was much lower than that within stocks(88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.     

中国近海浮游桡足类中华哲水蚤（Calanussinicus Brodsky）的分子系统地理学和种群遗传结构研究

Planktonic copepod Calanus sinicus is the dominant meso-zooplankton in the Northwest Pacific Ocean. To better understand its population dynamics and phylogeographic patterns, 243 C. sinicus individuals were collected from seven locations across the shelf waters of China and its population genetics was studied by mitochondrial DNA cytochrome oxidase I(mtCOI) sequences analyses. Thirty-nine different sequences, or haplotypes, were detected with moderate haplotype diversity(h=0.749) and low nucleotide diversity(π=0.003) for all populations. The evolutionary divergence between geographic populations varied from 0.24% to 0.37%, indicative of very limited genetic differentiation. Visualized minimum spanning network(MSN) and phylogenetic analysis of all the detected haplotypes did not reveal any clear phylogeographic pattern. Furthermore, AMOVA data showed no significant spatial population differentiation existed among the individuals collected across China shelf waters. Pairwise FST values showed that population collected from northwest of the East China Sea(ECS) displayed a low difference to other populations. Mismatch distribution analyses and neutrality tests indicated that C. sinicus might undergo a demographic/population expansion. No significant population genetic structuring was detected, indicating an extensive gene flow among the C. sinicus populations. Our results provide molecular evidence for the hypothesis that C. sinicus in the northwestern South China Sea in winter is transported from the East China Sea and the Yellow Sea by the China Coastal Current during the northeast monsoon period.