Viola baoshanensis, a plant that hyperaccumulates cadmium

This paper reports upon the finding of Viola baoshanensis, a cadmium (Cd) hyperaccumulator through field survey and greenhouse experiments. Average Cd concentration in the shoots and roots of V. baoshanensis growing on Baoshan lead/zinc mine in Hunan Province, China, was 1168 and 981 mg/kg, respectively, varying from 456 to 2310mg/kg in the shoots, and from 233 to 1846 mg/kg in the roots.The ratio of Cd concentration in shoot to root (DW) and that in plant shoots to total concentration in surface soil was 1.32 and 2.38, respectively. Under nutrient solution culture, biomass (DW) of V. baoshanensis exposed to 0-30 mg/L Cd insolution increased with Cd supply increasing and reached a maximum at 30 mg/L Cd. Further increase of Cd concentration (40, 50 mg/L) in solution significantly reduced biomass.Cd concentration in the shoots was positively correlated with Cd concentration in the culture medium. Cd concentration in the shoots reached 4825 mg/kg at 50 mg/L Cd solution. Theratio of Cd concentration of shoots to roots in V. baoshanensis was greater than 1 at all Cd treatments, with an average of 1.67 (1.14-2.22). The results indicate that V. baoshanensis is a Cd hyperaccumulator plant.     

A new discovery of macroscopic fossils from the Ediacaran Doushantuo Formation in the Yangtze Gorges area

The Ediacaran section in the Yangtze Gorges area, South China, is one of the most important in the worldand contains abundant fossils[1-4]. The earliest discov- ery of macrofossils in 1984, including macroscopic algal fossils from the uppermost Doushantuo…     

Discovery of the budding phosphatized globular fossils from the Neoproterozoic Doushantuo Formation at Weng’an, Guizhou Province, China

There is much debate on biological affinities of the phosphatized globular fossils from the Neoproterozoic Doushantuo phosphorites at Weng’an, Guizhou Province. Here we report for the first time the budding structures of some of these globular fossils, which have previously been interpreted as the resting eggs and early cleavage embryos of metazoans. The budding structures are similar to the germinating tubes of the spore and zygote of living algae, suggesting that some globular fossils from the Doushantuo phosphorites bear affinity with algae. The present new information indicated various biological affinity of the phosphatized globular fossils from the Doushantuo phosphorites.     

福田红树林桐花树和秋茄的生长过程研究

对深圳福田红树林群落两个优势种桐花树（Ａｅｇｉｃｅｒａｓｃｏｒｎｉｃｕｌａｔｕｍ）和秋茄（Ｋａｎｄｅｌｉ－ａｃａｎｄｅｌ）进行横剖树干解析，研究这两个树种的胸径、地径、树高、材积生长量的年变化规律及形数年变化规律，结果为：胸径、地径、树高、材积生长量呈镊合状曲线态；其年生长量一般在其最大值的５０％～９８％之间；各种平均生长量随年龄的增加而平缓地增加，近峰值而未及，可见两树种有相当长的成熟及衰老期，它们的现存年龄为２０ａ左右；两树种的基部形数不随年龄的增加而呈规律性的变化，很难确定其经验形数值     

甲醇中用氨和环氧丙烷合成异丙醇胺

研究了在甲醇介质中用氨和环氧丙烷制备异丙醇胺的新工艺.考察了原料配比、反应温度、体系中的水含量对反应的影响.     

The first-principles study on the doping effect of Re in Ni3Al

Using first-principles density function for molecules method （DMol） and discrete variational method （DVM） based on the density functional theory, we studied the doping effect of Re in Ni3Al. The structure relaxation and the alloying energy show that Re has a strong Al site preference and leads to the local deformation, which is in agreement with the experimental results and other theoretical results. In addition, the charge density difference and the bond order show that Re can strongly enhance the interatomic interaction between the nearest neighbor atoms. From the density of states and the Pauli spectrum, we find that resonance states and localized states are induced by doping Re, and the doped Re atom forms the hybridized bond with the nearest neighbor atoms.     

中国主要红树科植物的分子系统发育

测定和分析了红树科（Ｒｈｉｚｏｐｈｏｒａｃｅａｅ）５属６种植物的ｒＤＮＡＩＴＳ区序列，所构建的ＩＴＳ区分子系统树图表明：红树科植物可形成１个单系的类群．但在部分属种ＩＴＳ序列分析的结果与红树科传统的分类系统有所不同，陆生红树科植物竹节树属（Ｃａｒａｌｉａ）的竹节树（Ｃｂｒａｃｈｉａｔａ）和旁杞木（Ｃｐｅｃｔｉｎｉｆｏｌｉａ）之间的分子差异很大，呈复系演化的特征．旁杞木与红树林主要植物秋茄属（Ｋａｎｄｅｌｉａ）的秋茄（Ｋｃａｎｄｅｌ）和红树属（Ｒｈｉｚｏｐｈｏｒａ）的红海榄（Ｒｓｔｙｌｏｓａ）的关系较近，竹节树则与另一红树林的主要种类角果木属（Ｃｅｒｉｏｐｓ）的角果木（Ｃｔａｇａｌ）呈姐妹群关系．     

色散力的探讨

用宏观处理方法导出色散能与距离Ｒ六次方成反比，讨论了其限制条件，并研究了温度对色散能的影响。     

郴州市大气PM2.5中无机元素污染特征及来源分析

利用电感耦合等离子体质谱仪(ICP-MS)测定了郴州市PM_(2.5)中无机元素的质量浓度,并通过元素的富集特征和主成分解析了它们的来源.结果表明,研究区域在春、夏、秋、冬四个季节PM_(2.5)平均质量浓度分别为28.7、30.7、41.4和58.1μg·m~(-3),无机元素的平均占比为15.63%,其中Al、Fe、Zn、Cu、Pb、Cr、Mn、As、Si和Ti占无机元素总量的90.6%.富集因子分析结果表明,Cd、Ag、Bi、Sb、As、Cu、Pb、Zn、Cr、Ni和V主要来自于人为污染,特别是有色金属元素的富集程度较高,这与郴州市是著名的有色金属之乡,有色金属开采及冶炼发达是相关的.主成分分析结果说明郴州市PM_(2.5)中无机元素主要来源于煤和石油的燃烧、汽车尾气排放、有色金属的冶炼以及土壤扬尘.     

Ni-Mo/TiO2催化剂上二苯并噻吩与4,6-二甲基二苯并噻吩的加氢脱硫反应规律

采用高压滴流床反应器,以二苯并噻吩(DBT)与4,6-二甲基二苯并噻吩(4,6-DMDBT)的正辛烷溶液作为模型溶液,在不同的反应温度、氢压、氢油体积比、液时空速(LHSV)、模型化合物初始质量分数的条件下,考察了DBT和4,6-DMDBT在Ni-Mo/TiO2催化剂上的加氢脱硫反应(HDS)规律。结果表明:提高反应温度以及增大氢油体积比均有利于DBT和4,6-DMDBT加氢脱硫反应的进行;氢分压对DBT和4,6-DMDBT转化率的提升也有很大影响,对4,6-DMDBT转化率的提升效果较大,但当氢分压较大时,增大氢分压对两者转化率的影响均较小。在反应温度350℃、氢压7 MPa、液时空速6 h-1、氢油体积比450、DBT和4,6-DMDBT初始质量分数分别为2.0%和0.2%的条件下,DBT的转化率可达98.80%,4,6-DMDBT的转化率可达98.12%。