Lanzhou is located in the northwest of China and famous for its petrochemical heavy industries China. The city has suffered long-term pollution metals recent years. Significant efforts, such as tax subsidies new energy vehicles treating solid waste, have been launched by municipal government to address since 2010. What current status metal Lanzhou? In this study, concentrations 12 (V, Cr, Mn, C...

OBJECTIVE Blood lead (B-Pb), one of the most used toxicological biomarker all kind, has serious limitations. Thus, the objective is to evaluate whether plasma lead (P-Pb) is more adequate. METHODS A long-term follow-up study of five cases of lead poisoning. P-Pb was analysed by inductively coupled plasma mass spectrometry. Kinetics after end of exposure was modelled. RESULTS P-Pb at severe ...

The Mesoproterozoic deep ocean is thought to have been largely anoxic, dominated by ferruginous conditions. Phosphate was scavenged from the water column iron oxyhydroxides, and dissolved nitrate rapidly reduced along redoxcline. Primary productivity therefore generally low, eukaryotic life restricted oxic marine margins. This model supported new nitrogen isotope data Lower Riphean (ca. 1.55 Ga...

Accumulations are higher-order operations on structured objects; they leave the shape of an object unchanged, but replace elements of that object with accumulated information about other elements. Upwards and downwards accumulations on trees are two such operations; they form the basis of many tree algorithms. We present two Erew Pram algorithms for computing accumulations on trees taking O(log...

Study of a mature petroleum play in the Western Canada Sedimentary Basin (WCSB) indicates that the spatial distribution of petroleum accumulations exhibits a self-affinity characteristic. This characteristic motivated the examination of a fractal model for a quantitative description of petroleum resource spatial distribution. The proposed approach transforms the spatial information with respect...

The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U-Pb and Lu-Hf isotope analyses o...

Introduction Let C be a convex bounded body in the n-dimensional Euclidean space E, and let B be its boundary. We use Busemann's notations: E(a,b) for the segment {(1 — p)a + pb: 0 < p ^ 1} from a to b, and S(z, p) for the sphere {x: \\z — x\\ = p). We now recall the definition of Hammer's associated bodies C(r). Let Cb(r) be the set obtained from C by a similitude transformation with a ratio r...

Downwards accumulations on binary trees are essentially functions which pass information down a tree, from the root towards the leaves. Under certain conditions, a downwards accumulation is bothèecient' (computable in a functional style in parallel time proportional to the depth of the tree) and`manipulable' (enjoying a number of distributivity properties useful in program construction). In thi...