区域气候与中国柳属物种多样性格局的关系研究

利用地理信息系统技术与空间统计相结合的方法,研究了柳属物种多样性在中国区域尺度上的空间分布格局,并且采用逐步广义线性回归分析方法研究了柳属物种多样性与主要气候因子的关系。结果表明:1)柳属物种多样性在中国的分布格局表现为区域广泛,局部聚集:聚集区分布在新疆阿勒泰地区、东北地区和西南地区,其中西南分布区的青藏高原与横断山脉毗连处为中国柳属物种多样性分布中心。2)柳属物种多样性在经度、纬度、气温、降水、蒸散量等气候气候因子一维格局上的分布随着因子梯度先增加后减小,均存在一个最适区间。3)柳属物种多样性与水分因子呈正相关、与能量因子呈负相关关系。水分因子是影响柳属物种多样性的主导因子,能量与水分间的交互作用对物种多样性影响微弱。4)结论部分地支持了水—热动态假说和生态位保守假说,但柳属物种多样性格局成因并非由任何单一假说来完全地解释,这表明其他因子如历史因素、地形异质性、土壤因素或扰动等也可能是形成柳属物种多样性格局的重要因素。     

完备格上的表现定理及其应用

在完备格的条件下讨论了Ｌ集合套的性质,给出了表现定理,最后指出了表现定理在ＬＦ代数理论中的应用。     

Chronic dietary exposure to copper affects growth, tissue lipid peroxidation, and metal composition of the grey mullet, Chelon labrosus

Juvenile grey mullet (Chelon labrosus) were fed either a basal (4.4 mg Cu/kg dry wt) or high-Cu diet (2400 mg Cu metal/kg dry wt) for 10 weeks to assess the relationship between growth and Cu-induced oxidative damage. No mortalities were observed, but growth rate and food intake were reduced by 43 and 29%, respectively, in the high-Cu group. This was not only attributed to peroxidative damage of the food which reduced food intake (palatability), but also to direct effects of hepatic lipid peroxidation. Hepatic α-tocopherol concentrations were 63% lower, while malondialdehyde (MDA) increased by 304% in mullet fed a high-Cu diet for 67d. Cu-exposure reduced apparent α-tocopherol retention by 420%. Hepatic Fe and Zn levels fell, while Cu increased (p < 0.05). The results show that oral Cu exposure induces oxidative stress in grey mullet. Quantification of lipid peroxidation (rancidity) in the food, reflecting palatability, is essential to differentiate the direct toxic effects of Cu on growth from the secondary influences of reduced food intake.     

赤卫沟金矿池浸生产实践

本文从赤卫沟金矿的矿石性质、矿石加工、池浸方法、金银回收方面,介绍了贫硫化物、金颗粒细微、有一定氧化程度的金矿池浸生产实践。从而推荐一种简便、回收率高、投资少、见效快的提工方法－池浸,以便促进矿业开发工作更快发展。     

微型钢桩在基础托换中的应用

介绍广州二沙岛消防站基础托换的方案选择,在地下室内克服地下水承压性进行托换的施工工艺,堵水防潮的处理方法。     

天文大地网与空间网联合平差中用共轭梯度法解算高阶法方程的某些策略

本文研究了用共轭梯度法解算天文大地网与空间网联合平差中２０万阶法方程的有关问题,提出了“系数调整策略”和“平差与求逆既分又合的策略”。利用的天文大地网（４７０５７点）和空间网（４７６点）在ＰＩＩ／２３３微机上解算１４．１万阶方程组共迭代４９９３次,花费机时２８分４７秒,与未进行系数调整相比,功效提高４０多倍。     

Seasonal Variation in the Phytoplanktonic Community,Seston and Environmental Variables During a 2-Year Period and Oyster Growth at Two Mariculture Sites,Southern Chile

Phytoplankton and its relationships with physical and chemical variables were analysed over a 2-year period in Hueihue and Linao Bays (southern Chile). Samples were collected on a monthly basis from May 1991 to May 1993. The growth rate of a single stock of hatchery-produced oysters (Ostrea chilensis) distributed between these two bays was also monitored monthly. The growth rate of oysters maintained at Linao Bay (site associated with a fish farm) was significantly higher, at every depth, compared with the oysters maintained at Hueihue Bay. Temperature and salinity values and their annual fluctuations were similar at both locations, presenting higher variations at the surface (1 m) due to the influence of air temperature and local precipitation than at depth. However, significant differences in phytoplankton abundance and composition were found between the two locations. The phytoplankton community was characterized by high biomass values during spring and summer, the dominance of diatoms and an inverse relationship between temperature and species diversity. However, phytoplankton cell abundance, biovolume and chlorophyll a concentration were significantly higher at Linao at every depth sampled. Cell abundance ranged between 4.49 × 10⁴ and 7.45 × 10⁶ cells · l^?1 in Hueihue and between 6.48 × 10⁴ and 8.71 × 10⁶ cells ·1^?1 in Linao. The influence of temperature on chlorophyll a concentration was significant except at 8 m at both locations. The instantaneous oyster growth rate was found to be positively correlated with temperature, chlorophyll a concentration and particulate organic matter at both locations. A significant negative relationship between oyster growth and amount of particulate inorganic matter was found; this confirms the important role played by seston composition in oyster growth. The demonstration of variation in oyster growth rate associated with differences in food availability between the two locations provides insight into the ecological role played by fish farms in southern Chile. The results suggest a strong link between food availability and oyster growth.     

L-抗坏血酸-2-磷酸酯镁的合成

以Ｌ抗坏血酸为基本原料合成Ｌ抗坏血酸２磷酸酯镁。对两种合成方法直接酰化法和基团保护法作实验比较和改进。直接酰化法中,采用混合碱（ 包括氧化镁） 可使磷酰化与成盐反应合并为一步进行,并能提高产率,而采用基团保护法能取得最佳的合成效果。     

Application of conditional geostatistical simulation to calculate the probability of occurrence of earthquakes belonging to a seismic series

Geostatistics offers various techniques of estimation and simulation that have been satisfactorily applied in solving geological problems. In this sense, conditional geostatistical simulation is applied to calculate the probability of occurrence of an earthquake with a lower than or equal magnitude to one determined during a seismic series. It is possible to calculate the energy of the next most probable earthquake from a specific time, given knowledge of the structure existing among earthquakes occurring prior to a specific moment.