环境样品中铈,钇和钍的测定

以下介绍海水、孔隙水,悬浮物,沉积物和生物群中Ce、Y和Th 的测定方法。该法包括用Mg(OH)_2和 CaC_2O_4双共沉淀法以便预富集海水和孔隙水中的Ce,Y和Th,同时在敞开容器进行酸溶以使沉积物、悬浮物和生物群溶解。用电感耦合等离子体原子发射光谱法进行测定。在不同步骤用放射示踪剂(~(144)Ce、~(88)Y和~(228)Tn)检验方法的化学效率。获得了生物群和沉积物(水)中的检测极限为 Ce,44ngg~(-1)(0.005ngml~(-1)),Y,0.62ngg~(-1)(0.0003ngml~(-1))和 Th。15ngg~(-1)(0.003ngml~(-1))。给出了从第勒尼安(Tyrrhenian)海收集到的海水、孔隙水、悬浮物、沉积物和生物群样品中 Ce、Y 和 Th 的测定结果。获得了各种海洋环境样品中的 Ce、Y 和Th 的高富集因子和回收率。采用较大数量的样品,以增大富集因子并改善检测极限。     

Meiofauna as descriptor of tourism-induced changes at sandy beaches

Tourism has long been considered as a 'clean industry' with almost no negative effects on the environment. This study demonstrated, in two different coastal systems (Mediterranean and Baltic), that tourism related activities are particularly affecting the sandy beach meio- and nematofauna in the upper beach zone, the specific ecotone in which many meiofauna species from both the marine and the terrestrial environment congregate. Tourist upper beaches are characterized by a lower % total organic matter (%TOM), lower densities, lower diversities (absence of Insecta, Harpacticoida, Oligochaeta, terrestrial nematodes and marine Ironidae nematodes) and higher community stress compared to nearby non-tourist locations. The %TOM was found to be the single most important factor for the observed differences in meiofauna assemblage structure at tourist versus non-tourist beaches in both the Mediterranean and the Baltic region. The free-living nematode assemblages from tourist upper zones depart significantly from expectations based on random selections from the regional nematode species pool. Furthermore upper zone assemblages are characterised by a low species diversity consisting of taxonomically closely related nematode species with r-strategist features. Generally, faunal differences between tourist and non-tourist beaches are decreasing towards the lower beach zones.     

A growth model for a hyalid amphipod Hyale perieri in the coastal water of Alexandria (Egypt)

Abstract-The growth rate of the hyalid amphipod Hyale perieri was studied on the bases of Ikeda'sgrowth model which is based on the inter moult period (IP) and moult increament (ΔBL). To applythis approach, laboratory experiments were carried out at three temperatures regimes (15℃, 20℃,25℃) to gain accurate data of IP and BL. The total number of specimens used in this study was 86 at15℃, 24 at 20℃ and 70 at 25℃. The number of flagellar segments of both antennae of the Hyaleperieri could not be used as an index of growth (instar criterion). The obtained results indicated that,the predicted IP of the specimens was inversely related to temperature and in good agreement with theobserved values at the experimental temperatures. IP data obtained from laboratory-reared specimes arecombined with ΔBL data to establish a growth model for Hyale perieri from its release from the mar-supium (1.64 mm BL) to the maximum size (12.67 mm BL) as a function of temperature. The maxi-mum numbers of consecutive moults     

1993~1996年南海中部海洋沉降颗粒通量的季节和年际变化

通过对南海中部1993~1996年获得的浅层和深层时间系列沉积物捕获器的样品分析,发现了稳定同位素值、颗粒总通量、碳酸盐、生物蛋白石、有机碳、表层初级生产力、浮游有孔虫总通量和属种的分布存在明显的季节性变化,其通量都是在东北季风和西南季风盛行期出现高值,在季风转向期出现低值.浮游有孔虫Globigerinoides sacculifer,G.ruber,Globigerinita glutinata,Neo-globoquadrina dutertrei等种的通量和相对百分含量也是在东北季风和西南季风盛行期都出现高值,但Globigerina bulloides,Globorotalia menardii和Pulleniatina obliquiloculata等种则在东北季风盛行期出现高值.分析还发现Globigerinoides sacculifer和Globorotalia menardii等种的通量和百分含量以及有孔虫总通量和碳酸盐通量等从1993到1996年存在下降趋势,而Globigerina.bulloides和Globigerinita glutinata的通量和百分含量以及生物蛋白石通量等在该期间显示为上升趋势.浅层捕获器样品中的碳酸盐和有机碳的通量比深层的高.研究表明海洋沉降通量和浮游有孔虫属种的季节和年际变化主要受与东亚季风相关的表层初级生产力和海洋水文条件变化所控制,深层捕获器样品中的碳酸盐和有机碳的通量低应与碳酸盐溶解作用有关.     

S. E. M. analysis of quartz sand grains from selected Hong Kong and Chinese littoral environments

This pilot study attempts to demonstrate some underlying scanning electron microscopy themes of quartz grain surface textures. A variety of textural patterns and individual features are described for grains selected from various littoral environments. An attempt was made to differentiate samples on surface textures alone, but limitations of using this technique in sedimentological isolation were apparent. Statistical analysis of checklist data and photographic evidence revealed some of the more important feature combinations used in environmental diagnosis. The use of discriminant analysis provided quantitative sample separation.     

重量稀释的和浓缩的标准海水的电导率同盐度和温度的函数关系

在-2℃至35℃的整个海洋温度范围和0至42‰S盐度范围内测量准确已知盐度的海水样品电导率和同温度下标准海水电导率的比值R_(s.t.o)。盐度S<35‰的海水样品是由蒸馏水准确重量稀释标准海水制备的,快速蒸发标准海水制备高盐度海水样品继而重量稀释到已经确定的<35‰S范围。推导出了非常准确地表示1～42‰S和全部温度范围内的S与R_(s.t.o)关系式,即 S=f_1(R_(s.t.o)) f_2(R_(s.o,t.)t)=sum from n=0 to 5 a_1R~(a/2) △t/(1 k△t)sum from n=0 to 5 b_nR~(n/2)式中△t=t-15℃,R=R_(s.t.o),只有第一项f_1要求15℃。也确定了温度对标准海水电导率的影响,用t的四次方程非常准确地表示温度t时的电导率的比值的r_(tt)(C_(35.t.o)/C_(35.15.o)),即:(?)_t=sum from n=0 to 4 C_nt~n 这两个方程足以满足常压下所有盐度测量。     

Tributyltin and triphenyltin induce spermatogenesis in ovary of female abalone,Haliotis gigantea

Two-month flow-through exposure experiments of tributyltin (TBT) and triphenyltin (TPhT) were conducted with abalone, Haliotis gigantea. Nominal concentrations of 100 ng TBT/l and 100 ng TPhT/l caused significant spermatogenesis in ovaries of exposed females. There were also significantly more contracted primary oocytes observed in females exposed to either TBT or TPhT than controls. The incidence of two types of unknown cells was also significant in females exposed to TPhT. No significant histological changes were observed in testis of exposed males. This ovarian spermatogenesis caused by TBT and/or TPhT resembles gastropod imposex. Remarkably high concentrations of TBT and TPhT were observed in the head (including central nervous system ganglia), compared to muscles concentrations. Accumulation of TBT and TPhT in the head may disturb reproductive hormonal regulators through neuropeptides released from ganglia. This, as well as possible aromatase inhibition, may be one of the inducers for spermatogenesis in the abalone ovaries.     

根据树轮密度和宽度对公元1600年以来中国中北部降雨量的初步重建

根据树轮密度和宽度对公元１６００年以来中国中北部降雨量的初步重建Ｍ．Ｋ．Ｈｕｇｈｅｓ等华山松测试材料采自华山（３４°２９＇Ｎ，１１０°０５＇Ｅ，海拔２０６０ｍ），该地点的树心年代范围在４２６年以内，采样的树木接近一个建于１９５３年的气象观测站，在相同...     

The relative abundance of ethane to acetylene in the Jovian stratosphere

The observed ratio of C2H6 to C2H2 in the Jovian stratosphere increases from approximately 55 at 2 mbar to approximately 277 at 12 mbar. In current photochemical models this ratio typically increases between 2 and 12 mbar by a factor of < or = 3. Recent laboratory kinetics studies on the reaction between C2H3 and H2 to form C2H4 suggest an efficient chemical mechanism for hydrogenation of C2H2 to C2H6. Inclusion of this scheme as part of a comprehensive updated model for hydrocarbon photochemistry in the atmosphere of Jupiter provides an explanation of the altitude variation of the C2H6/C2H2 ratio. The sensitivity of these results to uncertainties in the key rate constants at low temperatures is illustrated, identifying needs for additional laboratory measurements. Since the key reaction rate constants decrease with decreasing temperature, the hydrogenation of C2H2 as proposed predicts a qualitatively decreasing trend in the C2H6/C2H2 value with decreasing distance from the Sun. The observed variation between Jupiter and Saturn is consistent with this prediction.     

Minor constituents in the Martian atmosphere from the ISM/Phobos experiment

Global Martian atmospheric results derived from the infrared imaging spectrometer ISM flown aboard the Phobos 2 Soviet spacecraft are presented. Over low altitude regions the expected CO mixing ratio of (8 +/- 3) x 10(-4) is measured. Variations of the 2.35-micrometers feature are inconsistent with this value over the Great Martian Volcanoes. If the 2.35-micrometers band is entirely attributable to carbon monoxide, the CO mixing ratio is typically depleted by a factor of 3 over these high altitude areas. Orography should play a major role in the existence of this CO "hole." If, however, these spectral variations at 2.35 micrometers are due to the surface composition, the fraction of the surface covered by the responsible mineral must smoothly decrease as the surface elevation decreases. This phenomenon implies a strong interaction between the surface and the atmosphere for the Great Martian Volcanoes. Diurnal behavior and latitudinal variations of water vapor are globally consistent with Viking measurements. During the Phobos observations, the water vapor amounts over the bright equatorial regions range around 11 pr-micrometers during the day. These amounts are slightly larger than those inferred from 1976 to 1979. The lack of global dust storms during 1988-1989 could explain the enhancement of H2O in the atmosphere.