季节长期天气预报的一个方法

本文从自然天气周期的分类,研究各类周期的韵律与前后关联,提出一种制作季节长期天气预报的办法。     

Three-Dimensional Reconstruction of Fossil Insects within Their Ecosystems

正Objective This work is designed to improve the quality,visual effect and production efficiency of ecological reconstruction of fossil insects by using various threedimensional software and exploring helpful methodologies     

Modelling of Random Waves over Submerged Breakwaters and Its Application to Reflection Estimation

1.IntroductionGreat efforts have been devoted to the protection of coastal areas over many years by erectingdikes,seawalls,groin systems,and detached breakwaters.The sea walls,jetties,detached breakwa-ters,etc.are traditionally adopted as absorbingfacilit…     

Samarium-neodymium and rubidium-strontium systematics of nakhlite Governador Valadares

Abstract— The Sm-Nd systematics of whole-rock and mineral separate samples from nakhlite Governador Valadares define a good ¹⁴⁷Sm-¹⁴³Nd mineral isochron age of 1.37 ± 0.02 Ga. This age is in excellent agreement with the ³⁹Ar-⁴⁰Ar and Rb-Sr ages obtained previously for this meteorite. However, the Rb-Sr isotopic data for our sample show that the isotopic system is disturbed. The lack of isotopic equilibrium is probably caused by the weathering of the sample as indicated by the presence of secondary alteration phases. The whole-rock and acid-washed mineral data yield a Rb-Sr age of 1.20 ± 0.05 Ga, which probably represents a lower limit to the crystallization age of the rock. The petrographic evidence indicates that this meteorite is a clinopyroxene cumulate that probably crystallized in a subsurface sill (McSween, 1994). Thus, the Sm-Nd isotopic age probably represents the age of such a magmatic event. The initial ε¹⁴³Nd value determined for the rock at 1.37 Ga is +17 ± 1, indicating that the parent magma of the rock came from a light-rare-earth-element-depleted source of ¹⁴⁷Sm/¹⁴⁴Nd = ～0.237 based on a simple two-stage evolution model. Results of the same model calculation for the initial ⁸⁷Sr/⁸⁶Sr ratio of the rock suggest that its source material was depleted in ⁸⁷Rb/⁸⁶Sr by ～50% relative to the estimated martian value at 1.37 Ga. Both the high Sm/Nd and low Rb/Sr values support a clinopyroxene-rich cumulate source for the genesis of the nakhlite Governador Valadares. Furthermore, our Sm-Nd age and ε¹⁴³Nd data and the previously published ε¹⁴²Nd datum for the rock (Harper et al., 1995) are consistent with early differentiation of the parent planet, formation of cumulate sources ～4.56 Ga ago, and late melting of the sources and formation of the rock ～1.37 Ga ago. The good agreement of isotopic ages and petrographic features among Governador Valadares, Nakhla, and Lafayette strongly suggests that all three nakhlites have undergone similar evolutionary histories. The nakhlite age data suggest that isotopic heterogeneity in the martian mantle sources existed up to ～1.37 Ga ago and early mantle structures probably have not been disturbed for a significant portion of martian history.     

New Fossil Beetles of the Family Ommatidae （Coleoptera： Archostemata） from the Jehol Biota of China

A new genus with one new species and five new species of genus Amblomma of fossil ommatids are described and illustrated： Euryomma tylodes gen. et sp. nov., Amblomma cyclodonta sp. nov., Amblomma miniscula sp. nov., Amblomma porrecta sp. nov., Amblomma eumeura sp. nov., and Amblomma protensa sp. nov. All of them were collected from the Upper Jurassic or Lower Cretaceous Yixian Formation of western Liaoning, China. A key to the species of Amblomma is given. The wide epipleural space shows that Euryomma may be a primitive genus in Ommatidae. Many different species of Amblomma occurred within the same sedimentary horizon in this area could be environmental changes caused by frequent volcanic activities during the deposition of the Yixian Formation.     

New Jurassic Pseudopolycentropodids from China (Insecta: Mecoptera)

Abstract: In this paper two new species of fossil Pseudopolycentropus Handlirsch, 1906 are described: Pseudopolycentropus janeannae sp. nov. and P. novokshonovi, sp. nov. All of them were recovered from the Middle Jurassic non-marine sedimentary strata of northeastern China. The new material from China reveals that the early diversification of pseudopolycentropodids was well underway by the Middle Jurassic.     

New Fossils of Eoptychopteridae (Diptera)from the Middle Jurassic of Northeastern China

Three new species of the extinct genus of Eoptychopterina from the Eoptychopteridae family, Eoptychopterina antica sp. nov., Eoptychopterina adnexa sp. nov., and Eoptychopterina mediata sp. nov., are described and illustrated. These three new species are established based on fossil specimens with bodies and complete wings. All were collected from the Middle Jurassic Jiulongshan Formation of Daohugou in eastern Inner Mongolia, China. Based on the new materials, the name of two species in Eoptychopterina from China--Eoptychopterina elenae Ren and Krzeminski and Eoptychopterina gigantea Zhang--is sysnonymum junius.     

New Pelecinid Wasps (Hymenoptera: Proctotrupoidea: Pelecinidae) from the Yixian Formation of Western Liaoning, China

Three well-preserved fossil Pelecinids from the Late Mesozoic Yixian Formation, Liaoning Province, China are described and assigned to two new species, Eopelecinus huangi sp. nov. and Eopelecinus tumidus sp. nov. in Eopelecinus Zhang, Rasnitsyn and Zhang, 2002. As of now, 17 species have been included in this genus, which is the most diverse in the Pelecinidae family. With new information and characters obtained from these new specimens, the diagnosis of Eopelecinus Zhang, Rasnitsyn and Zhang, 2002 is emended.     

Manganese‐chromium formation intervals for chondrules from the Bishunpur and Chainpur meteorites

Abstract— Whole‐chondrule Mn‐Cr isochrons are presented for chondrules separated from the Chainpur (LL3.4) and Bishunpur (LL3.1) meteorites. The chondrules were initially surveyed by instrumental neutron activation analysis. LL‐chondrite‐normalized Mn/Cr, Mn/Fe, and Sc/Fe served to identify chondrules with unusually high or low Mn/Cr ratios, and to correlate the abundances of other elements to Sc, the most refractory element measured. A subset of chondrules from each chondrite was chosen for analysis by a scanning electron microscope equipped with an energy dispersive x‐ray spectrometer prior to high‐precision Cr‐isotopic analyses. ⁵³Cr/⁵²Cr correlates with ⁵⁵Mn/⁵²Cr to give initial (⁵³Mn/⁵⁵Mn)_I = (9.4 ± 1.7) × 10^?6 for Chainpur chondrules and (⁵³Mn/⁵⁵Mn)_I = (9.5 ± 3.1) × 10^?6 for Bishunpur chondrules. The corresponding chondrule formation intervals are, respectively, Δ_tLEW = ?10 ± 1 Ma for Chainpur and ?10 ± 2 Ma for Bishunpur relative to the time of igneous crystallization of the Lewis Cliff (LEW) 86010 angrite. Because Mn/Sc correlates positively with Mn/Cr for both the Chainpur and Bishunpur chondrules, indicating dependence of the Mn/Cr ratio on the relative volatility of the elements, we identify the event dated by the isochrons as volatility‐driven elemental fractionation for chondrule precursors in the solar nebula. Thus, our data suggest that the precursors to LL chondrules condensed from the nebula 5.8 ± 2.7 Ma after the time when initial (⁵³Mn/⁵⁵Mn)_I = (2.8 ± 0.3) × 10^?5 for calcium‐aluminum‐rich inclusions (CAIs), our preferred value, determined from data for (a) mineral separates of type B Allende CAI BR1, (b) spinels from Efremovka CAI E38, and (c) bulk chondrites. Mn‐Cr formation intervals for meteorites are presented relative to average I(Mn) = (⁵³Mn/⁵⁵Mn)_Ch = 9.46 × 10^?6 for chondrules. Mn/Cr ratios for radiogenic growth of ⁵³Cr in the solar nebula and later reservoirs are calculated relative to average (I(Mn), ?(⁵³Cr)_I) = ((9.46 ± 0.08) × 10^?6, ?0.23 ± 0.08) for chondrules. Inferred values of Mn/Cr lie within expected ranges. Thus, it appears that evolution of the Cr‐isotopic composition can be traced from condensation of CAIs via condensation of the ferromagnesian precursors of chondrules to basalt generation on differentiated asteroids. Measured values of ?(⁵³Cr) for individual chondrules exhibit the entire range of values that has been observed as initial ?(⁵³Cr) values for samples from various planetary objects, and which has been attributed to radial heterogeneity in initial ⁵³Mn/⁵⁵Mn in the early solar system. Estimated ⁵⁵Mn/⁵²Cr = 0.42 ± 0.05 for the bulk Earth, combined with ?(⁵³Cr) = 0 for the Earth, plots very close to the chondrule isochrons, so that the Earth appears to have the Mn‐Cr systematics of a refractory chondrule. Thus, the Earth apparently formed from material that had been depleted in Mn relative to Cr contemporaneously with condensation of chondrule precursors. If, as seems likely, the Earth's core formed after complete decay of ⁵³Mn, there must have been little differential partitioning of Mn and Cr at that time.     

Identifying Indicator Species in Habitats Created by Coastal Structures

In this paper,three approachs were developed to find indicator species from the habitat created by coastal structures.These approachs consist of a model of species co-occurrence probability,a model of k-environmental factor probability and a composite model.Simultaneously,a case study was conducted in Hsinchu Fishing Port of north-western Taiwan.Based on the aforementioned models,three primary producer species,Ahnfeltiopsis flabelliformis,Chondrus ocellatus and Sarcodia montagneana,were chosen as the indicator species which had the highest co-occurrence probabilities and showed greater tolerance to more critical environment.It is imperative to understand how the three species under particular co-occurring conditions and environmental factors influence the composition of sessile assemblages in coastal water.The results indicate that for the purpose of increasing biodiversity,these models are feasible to find indicator species of artificial structures,and to help make it possible to design coastal structures based on biological considerations.This study provides an innovative approach for further advanced application in the artificial habitat of coast management.