Starch grains from dental calculus reveal ancient plant foodstuffs at Chenqimogou site, Gansu Province

National Natural Science Foundation of China [40771205]; National Science Fund for Distinguished Young Scholars [40625002]; Chinese Academy of Sciences [KZCX2-YW-315]

Nanostructured bulk novel hard material with "rounded" grains obtained by nanocrystalline "rounded" (W0.5Al0.5)C powders

A novel nano-scaled bulk hard material (W0.5Al0.5)C-Co with "rounded" grains was prepared by nanocrystalline "rounded" (W0.5Al0.5)C powders with "rounded" particle shape in this study. The nano-scaled "rounded" particles do not contain sharp edges, which form local tensile stress concentrations on loading of the composite, thus leading to improved toughness and reduced sensitivity to crack. Nanocrystalline (W0.5Al0.5)C powders with "rounded" particle shape were used as starting materials. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to characterize the samples.

Chemical constituents from the whole plant of Euphorbia altotibetic

Four new jatrophane diterpenoids, altotibetin A (1), altotibetin B (2), altotibetin C (3), altotibetin D (4), and nine known compounds, beta-sitosterol, cycloart-23-ene-3beta,25-diol, cycloart-25-ene-3beta,24-diol, lupeol acetate, scopoletin, kaempferol, uracil, uridine, astragalin, and daucosterol have been isolated from the whole plant of Euphorbia altotibetic PAULS. Their structures were established by spectral methods, and the configurations of 1 and 2 were confirmed by X-ray analysis.

塔里木盆地塔中—巴楚地区早二叠世岩浆岩地球化学特征及其成因

Tazhong-Bachu region is located in the Western Tarim basin.The early Permian magmatic rocks occur in the earth surface of Tazhong-Bachu region are mainly distributed in Kepintag,Mazhartag and Wajilitag region. There are a lot of wells, in which researchers found the early Permian magmatic rocks,in desert cover area.Most magmatic rocks are basic rocks, a few of which are ultrabasic rocks and intermediate-acid magmatic rocks.The ultrabasic rocks are are mainly occur in the Cryptoexplosive Breccia Pipes ,which is located in the volcanic complex body of Wajilitag region.The basic rocks can be divided into three rock types：The first type of the magmatic rocks in Tazhong-Bachu region is volcanic rock ,which occurs in the Lower Permian Kupukuziman Formation and Kaipaizileike Formation. Most Volcanic rocks are basalts,a few of which are volcanic breccias and pyroclastic rocks.The basalts are distributed in stratiform occurrences and interbeded the clastic rocks in Kepintag region.The attitudes of the basalts are nearly horizontal.Columnar Joints, gas pore textures and amygdaloidal structure are to develop in basalts.The second type of the magmatic rocks in Tazhong-Bachu region is diabase,which occurs in Mazhartag region.Diabase dike swarms occur in the stratums of Silurian, Devonian, Carboniferous and Lower Permian.They make from NNW direction to SSE direction, the obliquity of stratum is greater than 60°, and the dike thickness is form several cm to several meters. Diabasic texture is found in the rocks .The first type of the magmatic rocks in Tazhong-Bachu region are gabbro- pyroxenite rocks ,which occur in the Wajilitag igneous complex body. The intermediate-acid magmatic rocks, which are mainly syenites, are located in Mazhartag and Wajiltag region. But they are small in the whole Tazhong-Bachu region.There are intermediate-acid magmatic rocks,which are mainly dacite,in the northeast part of the wells in Tazhong-Bachu region.But ,it is not found in earth surface.Through systematical geochemical research of early Permian magmatic rocks,which are distributed in Kepintag,Mazhartag, Wajilitag region and the wells such as F1 well、Z1 well、Z13 well、TZ18 well、H3 well、H4 well et al., the focus on the geochronologic characteristics, the main element,trace element and REE geochemistry, the mineralogic characteristics, the Sr-Nd and Pb isotopic characteristics are put forward. The main points are: 1、A combined study of CL imaging and LA-ICP-MS U-Pb dating were carried out for zircon grains of the magmatic rocks in the Tazhong-Bachu region from the Tarim basin.The results of the systematic zircon LA-ICP-MS U-Pb dating reveal 272±6Ma to 291±10Ma for the magamatic rocks. It indicated that Early Permian is an important period of magmatic acvivity in the Tazhong-Bachu region. 2、There are a big hunch in the curves of primitive mantle-normalized trace element concentrations in the early Permian magmatic rocks from Kepintag, Mazhartag, Wajilitag region and the 14 wells. Light rare earth elements are comparatively rich and heavy rare earth elements are comparatively poor. The slope rates are same between light rare erath elements and heavy rare earth elements. It is not like the curves of the basalts in the convergent margin of plate , in which the slope rates of light rare erath elements is bigger than the alope rates of heavy rare erath elements, and the curves of heavy rare earth elements are comparatively flat. The magmatic rocks of Tazhong-Bachu region rarely have the characteristics of the basalts in the convergent margin of plate, which is that Tantalum, Niobium and Titanium are much poor, and Zirconium, Hafnium and Phosphorus are moderately poor. The magamatic rocks are mostly alkaline, which is indicated by the dots of the (Na2O+K2O)-SiO2 identification diagram. All of these indicate that the early Permian magmatic rocks were formed in an extension environment of intraplate. 3、The Thorium abundance is high and Tantalum abundance is low in most magmatic rocks from Tazhong-Bachu reguion, which is formed for crustal contamination.In the Th/Yb-Ta/Yb identification diagram，most dots are in the region, which means active continental margin, but a few dots are in the region, which means mantle source. It indicated the feeding of continental crust materials. 4、The magnesium content of the olvines from Wagilitag region is richest, and the olvines from Kepintag region is poorest in the tree region. 5、Through the the Sr-Nd and Pb isotopic study of the basalts and diabases from the F1 well core, Z1 well core, Z13 well core,TZ18 well core, and the basalts，gabbros, diabases(diabase-prophyrites) and pl-peridotites from Kepintag,Mazhartag, Wajilitag region , it indicated that all isotopic data is similar and close to enriched mantle.

滑坡型泥石流转化机理研究—以四川省达县青宁乡滑坡为例

Slide-debris flow is debris flow which is transformed from landslide consecutively in a short time, it comprises of two phases: First, Landslide starts to slide; Second, landslide changes to debris flow. Slide-debris flow which brings great property and life loss happens frequently at home and abroad. In order to forecast the happening possibility and scope of slide-debris flow, transfromation mechanism of Slide-debris flow must be studied. Research on transformation mechanism of slide-debris flow is intersectant science of landslide kinetics and debris flow starting theory, It is a fringe problem as well as front problem of geological hazard. This paper takes Qingning slide-debris flow in Da County, Sichuan Province for example and has studied the mechanism of its instability and transfromation into debris flow through indoor test (including usual soil test and ring shear test) and digital modeling method.The research gets the following conclusions. Qingning Landslide took place mainly because of confined water head arising from rainfall infiltration. Before Landslide occurring, it rained continuously for 22 days, accumulated precipitation arrived at 521.6mm.Investigation shows that strata of Qingning Landslide contains quaternary loose accumulation, slip soil and highly weathered bedrock, which is a good condition for formation of confined water in the slope. Further more, groundwater seepage in the slope body and corresponding slope safety factor before landslide occurring have been computed through finite element method. The result shows that because of infiltration of rainfall, confined water head in the slope arose sharply, accordingly, the safety factor of the slope declined quickly. The result also shows that force put on the slide body by the rock mass detached from Dazhaiyan mountain was the direct factor for landslide occurring. Qingning slide-debris transformation mode has been summarized, the process the landslide changed into debris flow is divided into three phases in the prospective of macroscopic geological condition: landslide occurring, transformation and debris flow. Landslide occurring phase is from slope’ local creeping slide to Landslide occurring; transformation phase contains slide body sliding on the slide bed after slide occurring and sliding on the slope after shearing opening; debris flow phase is that slide body breaks up completely and flows downward into the ditches. The transformation mechanism of Qingning slide-debris flow has been studied through indoor ring shear test of slip soil. The result shows that transformation mechanism contains two points: first, during slide body sliding on the slide bed and slope after shearing opening, shearing shrinkage, grain crushing and grain layering brought about declining of its volume and produced excess pore water pressure, and because producing velocity of excess pore water pressure is much greater than its dissipating velocity, shear strength of slide body decreased sharply because of accumulated pore water pressure. Second, grains crushing and grains layering during slide body sliding brought about thick liquefied layer at the bottom of the slidebody, liquefied layer contained high water content and its shear strength was very low, its thickness increased as the sliding displacement increasing. Liquefied layer makes slide body sliding fast and easily break down to debris flow. Excess pore water pressure and liquefied layer made shear strength of slidebody became very low, furthermore, water in the pit of slope joining in the slidebody was also a facter that made slidebody accelerate the transformation. Influence of slide body thickness and fine grains content to transformation of slide-debris flow has been studied through ring shear test. The result reaches two conclusions. First, thickness of slide body affects transformation of slide-debris flow by two ways, porewater pressure and effect of “soft base” increases as thickness of slide body increasing.so the thicker slide body is ,the easier transformation is. Second, actual dissipating velocity of porewater pressure should be considered when studying the influence of fine grains content to tranformation of slide-debris flow. There should be a critical content of fine grains which makes the difference of producing and dissipating velocity of water pore pressre greatest, this value is the best for slide-debris transformation. The whole process of slide-debris flow transformation is reproduced through discrete element method. Transformation mechanism of slide-debris flow is studied through monitoring various parameters including pore water pressure, grain crushing and grain layering in the slide body during the transformation. The result confirms and supplements the transformation mechanism of slide-debris flow got from ring shear test well.

阿尔金蛇绿混杂带构造岩石组合及其大地构造意义

The Alytn fault is a huge left-slip fault zone within the Asian continent, and locates such zone that is linked to main tectonic units in the western China, which makes it is very important to the tectonic framework and ore distribution in the western China. Selecting two ophiolite zones (namely Hongliugou-Lapeiquan ophiolite zone and Sulamutage ophiolite zone) respectively located within the southern and northern part of the Altyn fault and based on analysis of field geology characteristics and geochemistry, this paper recognized the rock types (mainly mafic and ultramafic rocks) within the melanges and subdivided each lithological unit based on tectonic environment. At last, this paper rebuilt the paleo-tectonic framework in the Alytn region by the method of tectonic facies and discussed its tectonic evolution with the theory of collision orogens. Combining former results with hard field observation and geochemical analysis, this paper acquired such recognitions to two ophiolte zones within the Altyn fault zone as follows: To the typical regions (Hongliugou, Lapeiquan, Mangya and Sulamutage) within the two ophiolte zones in the Altyn fault zone, this paper offered the field geology profiles. Field geology characteristics show that they are composed of melange bases (mainly abyssal flysch and carbonate rocks) and melange blocks from various tectonic environments, often with fault contact among each lithological units, belonging to typical ophiolitic melange zone. The ultramafic rocks outcropped at the Altyn region are all harzburgites. Remant grains of primary minerals have melted residual texture and elastic deformation texture under high temperature and pressure. The whole-rock analyses show their low TiO_2 contents (0.01～0.04%), low Al, Ca and high MgO contents and wide Mg~# range (89.35～95.57). Rare earth patterns have two types, namely tabacco pipe-shped and LREE-shaped, of which the former is often seen. The chondrite-nomalized Yb values of these analyses are all lower than 1. The spinels have low Ti and high Cr content and most spinels have Cr# higher than 60. All of the above characteristics show that the ultramafic rocks in the Altyn fault zone are components of metmorphic peridotites of ophiolite from depleted mantle source and most ophiolites from this zone belong to supra-subduction zone (SSZ) type ophiolite with a few mid-ocean ridge basalt (MORB) type. Geochemical analyses show that the melange blocks within the Altyn ophiolitic melange zone have different characteristics from various tectonic environments. This paper recognized such tectonic-lithological assemblages as mid-ocean basalts, oceanic island basalts, oceanic island arc tholeiites, island arc calalkaline basalts and island arc granites and inferred that these tectonic-lithological units respectively belongs to such tectonic units as ophiolites, oceanic islands and/or oceanic seamounts, oceanic island arc and a~creting arcs, which show these blocks from oceanic crust and subduction zone for the most part. For the Altyn ophiolites, the chronological data show they become new from the north to the south. Combined with the study on late slip of Altyn fault and North Qilianshan orogeny, the author inferred that the Altyn region had belonged to one part of the North Qilianshan accreting wedge-arc orogeny at paleozoic, and later huge left-slip made it locate modem site.

Line Kinematics for Whole-Arm Manipulation

A Whole-Arm Manipulator uses every surface to both sense and interact with the environment. To facilitate the analysis and control of a Whole-Arm Manipulator, line geometry is used to describe the location and trajectory of the links. Applications of line kinematics are described and implemented on the MIT Whole-Arm Manipulator (WAM-1).

Ocorrência do Barley/Cereal yellow dwarf virus e seus vetores em cereais de inverno no Rio Grande do Sul, Santa Catarina, Paraná e Mato Grosso do Sul em 2008.

2009

Ocorrência do Barley/Cereal yellow dwarf virus e seus vetores em cereais de inverno no Rio Grande do Sul em 2007.

2008

Milheto: um cereal com multiplos usos.

2001

The Territory of Television: S4C and the Representation of the 'Whole of Wales'

Jones, E. (2007). The Territory of Television: S4C and the Representation of the 'Whole of Wales.' In M. Cormack and N. Hourigan (Eds.), Minority Language Media: Concepts, Critiques and Case Studies (pp.188-211). No. 138. Bristol: Multilingual Matters. RAE2008

That Whole Business about the Cross

digital audio recording