内蒙古海拉尔盆地演化研究

海拉尔盆地的形成和演化可分为断陷和坳陷两个时期。断陷期又可分为5个阶段:孕育阶段、强烈拉张阶段、快速沉降阶段、稳定拉张阶段和萎缩阶段。坳陷期拉张减弱,有扭性作用,盆地变浅。因此,海拉尔盆地为一“断陷-坳陷”转化型盆地。     

羊柴(Hedysarumleave)林沙地水分状况及其动态变化的研究

对毛乌素沙地中生长的人工羊柴林的沙地水分状况及其动态变化进行了研究．结果表明：受沙地机械组成粗的影响，羊柴林沙地的田间持水量为３．９７５％，凋萎湿度为０．７８１％；水分状况是４～７月初日趋变差，０．１％和２．０％含水量等值线持续下移；有效含水量在７月初达到最低值．７月份以后随降雨补给，其水分状况明显好转，有效水贮量在８月份达到最大值．受羊柴根系吸水的影响，沙地水分存在着空间异质性，在羊柴植丛基部、距羊柴植丛５０ｃｍ处和距羊柴植丛２００ｃｍ处的三个位点上，沙地平均有效水贮量依次增大．控制羊柴林的植丛密度，维持沙地水分的空间异质性，对实现羊柴林的持续生存有着极其重要的意义．适宜的植丛密度下，羊柴林不会恶化其沙地水分状况而限制其持续生存．     

Discovery of ophiolite in southeast Yunnan, China

The Babu ophiolite in Malipo County, SE Yunnan, consists of three units: ultramafic, mafic and basaltic rocks. Studies of geological mapping, petrology and geochemistry reveal that the gabbro is similar to that in the Troodos ophiolite, and the diabase and basalt belong to a normal MORB-type, analogous to the Shuanggou ophiolite in west Yunnan. The ophiolite studied as a thrust tectonic slab, was overthrust northwards onto the Late Paleozoic-Triassic deep marine deposits of continental margin. It is inferred to be relics of Paleotethyan ocean; namely, a branch of Paleotethys occurs in South China, where the tectonic nature and evolutional history of the area should be reconsidered.     

Characterization of the flagellar biosynthesis regulatory geneflbD inAzospirillum brasilense

A flagellar gene cluster fragment includingflbD ofAzospirillum brasilense was cloned and sequenced. TheflbD mutant strain was found to be nonmotile—losing both polar and lateral flagella (Fla⁻Laf⁻). Motility and flagella were regained by complementation with plasmid-borne multicopyflbD, but altered with larger swarming circle and fewer lateral flagella on the semisolid plate. This result indicated that FlbD plays an important role in the regulation of both polar and lateral flagellar biosynthesis inA. brasilense.     

The subducted slab of Yangtze Continental block beneath the Tethyan orogen in western Yunnan

The western Yunnan area is a natural laboratory with fully developed and best preserved Tethyan orogen in the world. Seismic tomography reveals a slab-like high velocity anomaly down to 250 km beneath the western Yunnan Tethyan orogen, to its west there is a low-velocity column about 300 km wide. in the region from Lancangjiang to Mojiang an obvious low velocity in the lower crust and uppermost mantle overlies on the slab. Synthesizing the available geological and geochemical results, the present paper demonstrates that this slab-like high velocity anomaly is a part of the subducted plate of Yangtze Continental segment after the closure of Paleotethys. The collision of India and Eurasia continent starting from 50-60 MaBP might trigger thermal disturbance in the upper mantle and cause the uprising of asthenosphere, in that case the subducted Yangtze plate could be broken off, causing Cenozoic magmatic activities and underplating in the Lancangjiang-Mojiang region.     

Orogen-parallel extension in Himalays:Is it the indicator of collapse or the product in process of compressive uplift?

Extensional structures developed extensively in Himalaya with their strikes perpendicular to that of the orogenic belt. The studies of such structures in Qusum, Burang, Lhozhag, Nyalam and Yadong show that they represent an orogen-parallel extension. The basins produced by the extension experienced orogen-perpendicular compression during their formation. The ages of the extension rang from 16 to 13 Ma and coincide with the intensive compressive stage in Southeastern Asia. Therefore, the extension is syn-shortening and the dominate tectonic movement in Himalaya was compression and uplift during the extension. The extension was the partition of compressive deformation rather than the indicator for the collapse and falling of the Tibetan Plateau.     

新型高聚合度聚氯乙烯树脂的颗粒形态研究

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翻译中文化缺省现象的补偿策略与方法

在翻译过程中,两种语言间的文化积淀相互冲突,文化因素就会显露出来,这就要求译者认真审视文化因素.事实上,文化因素决定了文化补偿方法的选用,因为文化因素决定了译者是否、在何种程度上以及用何种方法对各种意象进行调整,以便于目标语读者既能获得对译文的连贯理解,同时又能最大限度地获得文化探索的享受.     

Relationship between the microstructure and properties of thermomechanically processed Fe-17Mn and Fe-17Mn-3Al steels

Two austenitic Mn steels(Fe-17 Mn and Fe-17 Mn-3 Al(wt%, so as the follows)) were subjected to thermomechanical processing(TMP) consisting of forging followed by solutionization and hot rolling. The rolled samples were annealed at 650 and 800°C to relieve the internal stress and to induce recrystallization. The application of TMP and heat treatment to the Fe-17 Mn/Fe-17 Mn-3 Al steels refined the austenite grain size from 169 μm in the as-solutionized state to 9–13 μm, resulting in a substantial increase in hardness from HV 213 to HV 410 for the Fe-17 Mn steel and from HV 210 to HV 387 for the Fe-17 Mn-3 Al steel. The elastic modulus values, as evaluated by the nanoindentation technique, increased from(175 ± 11) to(220 ± 12) GPa and from(163 ± 15) to(205 ± 13) GPa for the Fe-17 Mn and Fe-17 Mn-3 Al steels, respectively. The impact energy of the thermomechanically processed austenitic Mn steels was lower than that of the steels in their as-solutionized state. The addition of Al to the Fe-17 Mn steel decreased the hardness and elastic modulus but increased the impact energy.