下地幔的氦化合物—FeO2He

氦(He)元素是地球上的稀有元素之一,宇宙中其含量仅次于氢,但由于其化学惰性不能像氢元素一样与其他元素反应生成稳定的化合物,因此只有少量的地球形成初期保留下来的原始氦气存在于大气中。然而,科学家们发现有氦气从地幔俯冲带喷发出来(比如洛杉矶金施,Newport-Inglewood断层带)。因此推测地幔中可能存在氦的化合物。尽管如此,科学工作者一直未发现含有He元素的矿物,甚至在地幔温度压力下也未合成相关的含有氦元素的化合物。     

Sublethal effects of contamination on the Mediterranean sponge Crambe crambe: metal accumulation and biological responses

The effect of low levels of pollution on the growth, reproduction output, morphology and survival of adult sponges and settlers of the sponge Crambe crambe were examined. We transplanted sponges from a control area to a contaminated site and measured the main environmental variables (chemical and physical) of both sites during the study period. Except some punctual differences in particulate organic matter, silicates, nitrates, and water motion, most environmental variables in the water were similar at both sites during the study months. Mainly copper, lead and OM concentrations in the sediment, and water motion were significantly higher at the polluted site and may be implicated in the biological effects observed: decrease in the percentage of specimens with embryos, increase in shape irregularity and decrease in growth rate. Individuals naturally occurring at the polluted site and those transplanted there for four months accumulated ten times more copper than either untouched or transplant controls. Although lead concentration in sediment did not differ between sites, native specimens from the contaminated site accumulated this metal more than untouched controls. Vanadium concentration also tended to increase in the sponges living at or transplanted to the contaminated site but this difference was not significant. C. crambe is a reliable indicator of metal contamination since it accumulates copper, lead and vanadium in high amounts. At the contaminated site, sponge growth, fecundity and survival were inhibited, whereas sponge irregularity ending in sponge fission was promoted. All these effects may compromise the structure and dynamics of the sponge populations in sheltered, metal-contaminated habitats.     

我国发现的一种含锂新矿物——纤钡锂石 BaMg2LiAl3[Si2O6]2（OH）8

纤钡锂石产于湖南临武香花岭地区一水晶矿锂云母石英脉晶洞中,与锂云母、石英等矿物共生。矿物为浅黄白色,丝绢光泽,呈针状、纤维状、放射状或平行束状集合体,纤维长达1厘米。经X射线单晶及粉晶衍射测定:该矿物属斜方晶系,空间群Ccca,晶胞参数:a=13.60(?),b=20.24(?),e=5.16(?)。最强衍射线为:10.12(?)(100) 4.05(?)(78) 3.39(?)(91) 2.605(?)(31)2.390(?)(28)。     

DAMAGE EVALUATION BASED ON POINT-AREA INTEGRATED INFORMATION IN FLOOD DIVERSION BASIN

1 INTRODUCTION In recent years, the increased human activities in river basins have resulted in severe soil erosion and subsequent river sedimentation. Higher water levels for the same flow discharge imply that the flood risk has increased, as has the possibility of using flood diversion basins (FDB抯). To reduce the potential flood damage, rapid flood risk prediction and efficient flood damage evaluation are needed. The flood risk prediction is closely related to hydraulic information s…     

石炭纪杜内阶-维宪阶界线定义介绍

简要介绍了杜内阶 -维宪阶界线定义的历史和现状 ,包括舍费尔德会议原始定义 ,牙形石 Guathodus texa-nus带底界定义 ,有孔虫 Eoparastaffella形态演化定义。2 0 0 1年 9月在美国圣路易斯举行的国际石炭纪地层委员会现场会议期间 ,非正式通过了石炭纪杜内阶 -维宪阶界线新定义 ,即“有孔虫 Eoparastaffella ovalis类群— E. sim-plex谱系中 Eoparastaffella simplex的首次出现”     

热液合成的含金毒砂

热液合成的含金毒砂ＸｉｎＷｕＦｒａｎｃｏｉｓＤｅｉＢｏｖｅ邱隆伟译邱兆明校金在矿石中的化学状态对金矿床的勘探和冶炼（ｐｒｏｃｅｓｓｉｎｇ）都是很重要的。在自然界，金主要呈自然金和少量含金矿物的形式产出。然而，也有些金呈不可见状态散布于其它矿物中，不能...     

An outline of population geography of Jiangsu province,China

"Jiangsu (Kiangsu) Province [China] is located in the lower reaches of the Yangtze River which divides it into two parts, South Jiangsu and North Jiangsu. The area of the province is 102,000 sq. km with a population of 60,521,114 and a density of 605 per sq. km in 1982. The area of Jiangsu is slightly larger than that of Hungary (93,000 sq. km). But the population is 5.7 times and the density of population 5.2 times larger than those of Hungary. This paper states the tendency of population growth, the geographical distribution and present condition of urban and rural population, discussing briefly the rational redistribution of [the] population of Jiangsu."