基于三角形网格的气象场等值线自动分析

针对矩形网格法的不足，提出了用三角形网格法实现气象场等值线自动分析方法。通过对站点资料的边界插值、三角形剖分等处理后，再在剖分出来的三角形网格中按照一定方式连接等值线即可实现等值线的自动分析。给出了等值线自动生成算法，并将实例的分析结果同Grads绘制图进行对比分析。结果表明，该方法不仅有效可行，而且分析的结果更为精确合理。     

冬春季切变类冰雹发生条件的对比分析

本文以 1996年 12月 31日和 1981年 5月 1日为例 ,对冬、春季节发生在江苏的较大范围的切变类冰雹天气过程作了对比分析。结果指出 ,无论冬季或春季当高原东部有深槽东移 ,冷暖空气在江淮地区交汇 ,地面抬升系统为暖切 ,并有大气层结不稳定 (Δθse( 50 0 - 850 ) <0℃ =中心和较强的风向和风速垂直切变、85 0hPa西南急流轴、85 0hPa最大水汽通量轴线、5 0 0和 85 0hPa正涡度中心等相配置时 ,就可能导致江苏地区较大范围强对流天气的发生。     

云南省Internet网络天气预报会商系统

云南省基于Internet网络的天气预报会商系统覆盖云南省、地 (州 )、县三级。系统采用了Internet网络技术、数据库技术 ,实现了省、地 (州 )、县天气预报发布及浏览查询、预报讨论BBS、天气预报会商室、系统管理 ,在线短消息互发等功能。     

深海无人系统大长径比环肋圆柱壳结构设计与试验研究

环肋圆柱壳是深海无人系统广泛采用的一种耐压结构形式,保障其结构安全是系统研制过程中非常重要的一环。针对环肋圆柱壳的结构特征推导了组合结构重量关系式和结构参数简化估算方法,并以一种超长型深海无人系统耐压结构为例,围绕大长径比环肋圆柱壳的结构形式、设计计算、仿真分析、模型验证等开展研究。研究表明提出的大长径比环肋圆柱壳结构设计参数简化估算方法具有较好的适应性。相关计算和分析结果可以为该型深海无人系统结构设计提供技术支撑,也可以为其他类似耐压结构设计提供参考。     

火山岩与地形联合约束下海岛土壤稀土元素地球化学空间分布异质性——以广西涠洲岛为例

海岛土壤地球化学特征的研究对于认识海岛表生地质环境有重要意义。本研究以我国最大的第四纪火山海岛——涠洲岛为案例,重点研究亚热带海岛环境下火山岩风化土壤的稀土元素（REE）地球化学特征,并探讨影响其空间分布的关键因素。结果表明,涠洲岛土壤REE总量（ΣREE）自然变化范围较大,介于59.07~575.30 mg/kg,平均值为285.53 mg/kg,高于中国大陆土壤背景值（163.86 mg/kg）,指示火山岩风化海岛具有较高的土壤REE丰度。反距离权重插值法（IDW）分析指示,岛内土壤的REE含量高低变化呈现出以带状和斑块状为主体形态的空间分布不均一性,推断其成因与母质岩石类型和地形位置等因素密切相关。3种不同岩性的成土母岩的ΣREE含量变化序列为：玄武岩（236.66 mg/kg）>火山碎屑岩（215.58 mg/kg）>含生物碎屑海滩沉积物（18.99 mg/kg）,对应的土壤ΣREE含量具有类似变化规律,即玄武岩土壤（307.20 mg/kg）>火山碎屑岩土壤（297.46 mg/kg）>含生物碎屑海滩沉积物土壤（89.73 mg/kg）。该证据指示母岩是控制岛内土壤REE含量变化的首位因素,玄武岩整体上易形成具有较高REE丰度的土壤,火山碎屑岩次之,而含生物碎屑海滩沉积物反之。此外,本研究还发现火山碎屑岩单一岩性区内,发育的土壤REE含量也会随地形地貌差异而出现显著变化,其原因是地形地貌制约了土壤矿物和化学风化程度,海蚀丘陵比海积平原更利于海岛土壤中REE次生富集作用的发生。

     

Platinum-group elements in alpine-type ultramafic rocks and related chromite ores of the main ophiolite belt of the Urals

On the basis of a representative collection of ultramafic rocks and chromite ores and a series of technological samples from the largest (Central and Western) deposits in the Rai-Iz massif of the Polar Urals and the Almaz-Zhemchuzhina and Poiskovy deposits in the Kempirsai massif of the southern Urals, the distribution and speciation of platinum-group elements (PGE) in various type sections of mafic-ultramafic massifs of the Main ophiolite belt of the Urals have been studied. Spectral-chemical and spectrophotometric analyses were carried out to estimate PGE in 700 samples of ultramafic rocks and chromite ores; 400 analyses of minerals from rocks, ores, and concentrates and 100 analyses of PGE minerals (PGM) in chromite ores and concentrates were performed using an electron microprobe. Near-chondritic and nonchondritic PGE patterns in chromitebearing sections have been identified. PGE mineralization has been established to occur in chromite ore from all parts of the mafic-ultramafic massifs in the Main ophiolite belt of the Urals. The PGE deposits and occurrences discovered therein are attributed to four types (Kraka, Kempirsai, Nurali-Upper Neiva, and Shandasha), which are different in mode of geological occurrence, geochemical specialization, and placer-forming capability. Fluid-bearing minerals of the pargasite-edenite series have been identified for the first time in the matrix of chromite ore of the Kempirsai massif (the Almaz-Zhemchuzhina deposit) and Voikar-Syn’ya massif (the Kershor deposit). The PGE grade in various types of chromite ore ranges from 0.1–0.2 to 1–2 g/t or higher. According to technological sampling, the average PGE grade in the largest deposits of the southeastern ore field of the Kempirsai massif is 0.5–0.7 g/t. Due to the occurrence of most PGE as PGM 10–100 mm in size and the proved feasibility of their recovery into nickel alloys, chromites of the Kempirsai massif can be considered a complex ore with elevated and locally high Os, Ir, and Ru contents. The Nurali-Upper Neiva type of ore is characterized by small-sized primary deposits, which nevertheless are the main source of large Os-Ir placers in the Miass and Nev’yansk districts of the southern and central Urals, respectively.     

中国及邻区现代构造应力场的数值模拟

我国及邻区的现代构造应力场作为一平面应力问题用有限单元法进行了计算。将本区地壳看成是一不均匀的弹性板,根据各地区杨氏模量E、泊松比v和地壳厚度T的不同,组成12种材料区。全区被分成288个三角形单元。考虑了五种应力和位移边界条件,这些边界条件分别反映了印度洋板块、太平洋板块及菲律宾海板块对我国及邻区施加应力的相对大小。将计算得到的最大剪应力值与强震分布进行对比,将最大主压应力方向与震源机制解的最大主压应力方向进行对比,选择一种和实际符合得最好的边界条件作为可取的模式。结果表明:来自印度洋板块的作用力最大,大约是来自太平洋板块和菲律宾海板块作用力的两倍。     

基于便携式X射线荧光光谱法的深海沉积物现场成分快速检测及适用性评估

远洋粘土、硅藻软泥、铁锰结核及结壳是常见的深海沉积成因物质类型,在开展深海地质调查工作时及时获得这些物质的成分信息,对于提升海上地质调查效率和认知能力十分重要。通过便携式X射线荧光光谱法（pXRF）对菲律宾海深水区域60个样品进行分析,并结合实验室测试结果,评估pXRF能测出的24种元素含量数据的稳定性、准确性及相关性,探讨pXRF在海上地质调查工作中对于深海沉积物现场成分快速检测的适用性。通过综合对比研究发现,Ca、Cu、Fe、K、P、Pb、Sr、Zn、Zr九种元素稳定性、准确性和相关性较好,可以直接用于定性乃至定量研究工作。Al、Ba、Mn、Mo、Ni、Rb、Si、Ti、Th、V十种元素的三项指标参数等级略低,可用于含量高低判定和趋势分析等定性研究工作。Bi、Cs、Mg、Sb、Sc五种元素的测试效果较差,本法不建议使用。取样量充足且分布均匀、湿样烘干至恒量后研磨过筛、封装时充分压实平整、测试时间增长、选择合适的标准物质校正和检验、重点和异常样品增加测试次数等措施的执行有利于获得高精度的pXRF海上测试数据。未来对更多类型和数量深海样品开展pXRF现场分析,将有利于建立更精准的测试方法流程,达到现场快速揭示样品成分特征、确定底质类型及圈定矿化异常等目的,为海上关键决策的部署和实施提供参考和借鉴。     

Impacts of primary deforestation upon limestone slopes in northern Vancouver Island, British Columbia

Effects of deforestation upon slopes in limestones and in volcanic rocks in the Benson River valley, northern Vancouver Island, have been investigated quantitatively. Postlogging soil erosion and vegetal regeneration success were assessed by measuring soil depth, percent bare rock and moss cover, and the numbers and diversity of trees, shrubs, and plants on 25 sampling sites, each containing ten measuring quadrats selected at random. Sixteen sites were on the Quatsino Formation, a well-karstified limestone, and nine on the Karmutsen Formation of basaltic lavas. Eight sites were of virgin forest, 16 were logged between 1970 and 1983, and one (on limestone) was logged in 1911. Both bedrock types were significantly affected by the cutting. There was greater loss of soil and an increase in bare rock on the limestones. Erosion was increased significantly by burning on the limestones but not on the volcanics. Within-group comparisons on the limestones determined that steeper slopes and harder burned areas suffered the most and are slowest to regenerate. Volume of timber on the 1911 site was 19 percent of that in similar uncut forest sites. It appears that complete recovery on the barren limestone slopes will require at least some centuries.