Pool of Dust Particles over the Asian Continent: Balloon-borne Optical Particle Counter and Ground-based Lidar Measurements at Dunhuang, China

Measurements of aerosols were made in 2001 and 2002 at Dunhuang (40 degrees 00'N, 94 degrees 30'E), China to understand the nature of atmospheric particles over the desert areas in the Asian continent. Balloon-borne measurements with an optical particle counter suggested that particle size and concentration had noticeable peaks in super micron size range not only in the boundary mixing layer but also in the free troposphere. Super-micron particle concentration largely decreased in the mid tropopause (from 5 to 10 km; above sea level, a.s.l.). Lidar measurements made during August 2002 at Dunhuang suggested the possibility that mixing of dust particles occurred from near the ground to about 6 km even under calm weather conditions, and a large depolarization ratio of particulate matter was found in the aerosol layer. The top of the aerosol layer was found at heights of nearly 6 km (a.s.l.). It is strongly suggested that nonspherical dust particles (Kosa particles) frequently diffused in the free atmosphere over the Taklamakan desert through small-scale turbulences and are possible sources of dust particles of weak Kosa events that have been identified in the free troposphere not only in spring but also in summer over Japanese archipelago. Electron microscopic experiments of the particles collected in the free troposphere confirmed that coarse and nonspherical particles observed by the mineral particle were major components of coarse mode (diameter larger than 1 microm) below about 5 km over Dunhuang, China.     

Polycyclic aromatic compounds in Northwest Atlantic COD (Gadus morhua)

Twenty-seven polycyclic aromatic compounds (PAC) including polycyclic aromatic hydrocarbons (PAH) and polycyclic aromatic sulphur heterocycles were analysed in muscle, liver and ovaries of cod (Gadus morhua) from the Northwest Atlantic. These PAC include the 16 PAH priority pollutants (EPA recommendation), alkylated naphthalenes, phenanthrene-anthracenes as well as dibenzothiophenes (DBT). Aromatics were undetectable in muscle. One of the analysed PAC was detected in one ovary and six in another ovary sample. Liver samples contained between 1 and 9 PAC. Of the parental PAH, only acenapthene (18 ng/g, dry weight), fluorene (28 ng/g) and chrysene (22 ng/g) were detected once each in two liver samples, while fluorene (72 ng/g) was detected once in one of the ovaries. C-2 DBT was the major component in ovaries and liver (8-86 ng/g), while C-3 and C-4 alkylated phenanthrene-anthracene (12-78 ng/g) were the next major components detected in the liver samples. This is the first detailed study of PAH and PAC in finfish from the Northwest Atlantic.     

Effects of acid rain on growth and nutrient concentrations in Scots pine and Norway spruce seedlings grown in a nutrient-rich soil

The effects of artificially applied acid precipitation on growth and nutrient concentrations of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst.) seedlings were investigated in a long-term acid irrigation experiment in field conditions. Seedlings of northern and southern origin were planted in boxes containing peat and composted soil rich in nutrients, and sprinkler irrigated with water acidified with nitric and sulphuric acids to pH 3 or pH 4 for periods varying from two to three and a half growing seasons during 1986-1989. Water irrigated (pH 5.4-7.6) and non-irrigated groups of seedlings were also included in the experiment. At the end of the experiment needles, main and lateral shoots and roots were collected from the seedlings for the determination of height growth and biomass partitioning, and for the analysis of S, N, Mg, P, K, Ca, Mn and Fe concentrations. The treatment effects compared to the irrigated control were studied using multivariate analyses of variance and covariance. In the pine seedlings the total dry matter production increased by 25-70% compared with the irrigated controls when the total wet deposition to the seedlings exceeded 67 kg S ha(-1) and 36 kg N ha(-1) (e.g. after two growing seasons' exposure of the pH 3 treatment). The increase was mainly due to an increase in needle dry weight (54-72% greater at pH 3) and root weight (20-65% greater at pH 3), whereas the height growth or shoot weight growth were less affected. The northern provenance pine seedlings responded more clearly to the pH 3 irrigation than the southern ones. The treatments had no consistent effects on any of the growth variables studied in the spruce seedlings, however. The pines had higher root and foliage Ca concentrations as a result of the acid irrigation, whereas in spruce, acid rain decreased the Ca concentration in needles and shoots. Root Mn and Fe concentrations were higher in both species as a result of the pH 3 treatment. A higher soil conductivity and Ca concentration resulted from the prolonged pH 3 treatment. The results strongly support the hypothesis that the long-term growth and nutrient allocation response of conifers to acid precipitation is dependent both on the tree species and on the nutritional status of the soil.     

地球化学

<正> 无论从空间无线电光谱、遥感来考虑,还是从检测晶体表面少数原子来看,地球化学技术在灵敏度和显示器方面都有很大的改进。随着技术的改进,新的认识层出不穷。地球化学令人向往的领域,仍然包括宇宙空间中元素和天体起源的经典范围,但是,地球化学新技术对于我们了解当前环境的紧迫问题,已是必不可少的了。地球化学家仍然是分析化学的先导。本文只举几个事件。     

煤转化废水可处理性能的评价

引言大多数煤转化工艺都含有或设计有好氧生物处理,以作为从工艺废水中去除酚和其它有机杂质的主要方法。但是,在这些其它的有机物质中,有一些迄今连种类和生物可降解性都不清楚,所以也不能确切地予断它们能被生物处理法去除到何种程度。而实际废水的复杂性所导致的协合作用和对抗作用更是千变万化,不可捉摸。因为生物处理法在最佳运行状态下,具     

关于斜长岩体成因的理论

这里提出各种斜长岩体,均由安山岩岩浆或玄武岩岩浆在粒变岩的变质条件下,经结晶和分离作用所形成。对于任何一个单独的岩体,其母岩浆的类型可以通过检验伴生岩石类型的垂直层序来确定。     

坦桑尼亚霞水母章鱼(Octopus cyanea Gray)的个体渔业

2000年4月期间坦桑尼亚霞水母章鱼(1849)个体渔业的初步结果到2001年6月才被提供.对在坦噶、马菲亚岛和姆特瓦拉三地的2546个单个渔获物和15 473个样品进行了分析.     

一种用裂变径迹数据和热模拟探讨上冲带上升历史的方法

本文提出了用裂变径迹(FT)数据重建上冲带上升历史的一种试验性方法。由于完全可以证实,在山脉演化过程中热梯度随时间和深度变化而发生显著的变化,故我们采用一种与时间有关的热模式来推导所采岩石样品的温度/时间历史,只要给出诸如上冲地块厚度(T_t)、侵蚀速度(V(t))这类参数的话。这些参数可以在大量试验(“蒙特卡洛”模拟)的可供接受的范围内随机选取。我们将这个方法应用于科西嘉岛。那是阿尔卑斯上冲带的很好实例。最令人惊讶的结果是,同样一组FT数据,可以用变化范围很大的不同的侵蚀历史来解释。因此,为了给出合理的结果,就需要更多的地质限制条件。就科西嘉岛的情况来说,只要有关于最小的侵蚀厚度及侵蚀阶段的相对范围的资料,就可以对上冲以来的侵蚀/上升历史提出充分的限制条件。     

非洲和阿拉伯主要断裂的成矿意义

<正> 为了系统总结有关构造断裂破坏在空间和时间上分布的资料,全苏国外地质科学研究所编制了面积超过3500万平方公里的非洲和阿拉伯及其临近海域的1:5000000的断裂图。该图包括非洲和阿拉伯全区,土耳其南部和伊朗西部(外扎格罗斯),它反映了红海和地中海水域以及大西洋和印度洋大陆架带范围内的断裂构造。图中的     

中大西洋中脊37°N洋底玄武岩的稀土元素特征

一、引言 根据以往的认识,稀土的丰度对于区分各种类型的玄武岩具有特殊的意义。据此,所谓的深海拉斑玄武岩的球粒陨石标准化稀土分布模式不同于所有其它的玄武岩类型,前者轻稀土元素(LREE)的亏损大于重稀土元素(HREE),而且HREE的富集因子(e.f.)通常比较低。