青海省活动断裂带分布发育特征研究

青海省活动断裂带在印度板块的推挤作用下具有各自不同的空间展布和运动学特征,通过对省内24条活动断裂带的研究,得出NNW向断裂带右旋走滑的同时还具有逆时针旋转的运动特性,柴达木盆地西南边缘的茫崖—油沙山断裂的形成可能是阿尔金断裂带左旋走滑的压应力分量和持续板块推挤在青藏高原北部的一种响应,中更新世以来的构造运动决定了现今青海构造地貌的基本形态,现今高原北部的隆升主要集中在柴达木盆地西侧和祁连山地区,挤压应力分布表现为南北强于中部、东部强于西部。     

Self-sustained oscillations and bifurcations of transonic flow past simple airfoils

A turbulent flow past two symmetric airfoils, whose bow and aft portions are circular arcs, whereas midparts are flat, is studies numerically. The amplitude of lift coefficient oscillations versus the free-stream Mach number M _∞ is analyzed at zero angle of attack. Ranges of M _∞ in which there exist flow bifurcations are determined. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 37–44, November–December, 2008     

三温区坩埚下降法生长硫镓银晶体

本文通过对硫镓银单晶生长习性的分析研究,设计组装了三温区单晶炉,采用三温区坩埚下降法生长出了外形完整、无裂纹的AgGaS2单晶体,尺寸达10mm×25mm.实验测定了AgGaS2晶体的差热分析曲线和红外透射谱,以及单晶{112}解理面的X射线衍射谱,结果表明生长晶体的质量较高.     

Non-conservation of grain volume during diffusion creep and its effect on denuded zones

It is reasoned in this paper that the traditional assumption of grain volume conservation during diffusion creep is correct only for special grain configurations. An analysis is presented that illustrates this, using a hypothetical arrangement of grains specifically chosen to be stable against both grain boundary sliding and grain rotation, so that the extent of grain volume non-conservation can be illustrated in the absence of these factors. The influence on the development of the ‘denuded’ zones that characterize diffusion creep in particle-containing materials is addressed. The analysis contributes to an explanation for the discrepancies between the creep strain estimated from zone sizes and the overall specimen strain, a discrepancy that has been used in the past as counter evidence for the diffusion creep mechanism. Suggestions are made for the improved modelling of diffusion creep in polycrystalline materials and duplex structures.     

Influence of climatic conditions on the phenolic composition of Vitis vinifera L. cv. Graciano

The influence of different climatic conditions on the phenolic composition of grape skins and seeds of Vitis vinifera L. cv. Graciano – an autochthonous cultivar from Rioja and Navarra regions (Spain) – was evaluated during ripening in a separate way. Graciano grapes from two different vineyards with different climatic conditions and from two different vintages (2008 and 2009) were analysed. Clear differences between phenolic maturity pattern of grape skins and seeds were observed. In this context, it may be important to evaluate the phenolic maturity of seeds and skins in a separate way in order to decide the optimal harvest time. It was also noticeable that the effect of vintage (mainly due to changes in climatic conditions) may affect the changes in the phenolic composition of both grape skins and seeds. Although in a lesser extent, the effect of the vineyard was also observable, and it was especially relevant in vintages with irregular climatic conditions such as 2008 vintage.     

Zonal disintegration of deep crack-weakened rock masses: A non-Euclidean model

Rock masses are characterized by the existence of distributed joints and fractures. One of behaviors of the deep rock masses is high in situ stresses. The internal space of rock-like materials subjected to high in situ stresses after deformation is treated as a non-Euclidean one. The incompatible deformation of the deep rock masses is induced by high in situ stresses within the framework of non-Euclidean geometric space. A non-Euclidean model in which effects of cracks on zonal disintegration phenomenon of the deep crack-weakened rock masses is taken into account is established. Based on the non-Euclidean model, the elastic stress-field distribution of the deep surrounding rock masses induced by compatible deformation of non-fractured zones and incompatible deformation of fractured zones is determined. The stress intensity factors at the tips of cracks is given out. The strain energy density factor is applied to investigate the occurrence of disintegration zones. It is observed from the numerical results that the magnitude and site of fractured zones depend on the value of in situ stress, mesomechanical parameters and non-Euclidean parameters.     

Diagnosis of magnetoresponsive aromatic and antiaromatic zones in three‐membered rings of d‐ and f‐block elements

Magnetoresponsive three‐membered rings of d‐ and f‐block elements have been thoroughly investigated with the help of electronic structure calculation methods. The magnetic response of the clusters was evaluated by the Nucleus Independent Chemical Shifts (NICS)_zz‐scan curves, which in conjunction with symmetry‐based selection rules for the most significant translationally and rotationally allowed transitions helped rationalize and predict the orbital‐type of aromaticity/antiaromaticity of the clusters. The magnetoresponsive early (Groups 3, 4, and 5) transition metal M₃ rings exhibit successive aromatic and antiaromatic zones separated by a nodal plane. The magnetoresponsive late (Groups 11 and 12) transition metal M₃ rings exhibit long‐range aromatic zone with the NICS_zz(R) values decaying rapidly and monotonically with respect to R. The magnetic response of Group 10 transition metal M₃ rings is similar to that of the early transition metal M₃ rings, but it is long‐range antiaromatic only for the [c‐Ni₃] cluster. The NICS_zz‐scan curve of the [(H_tLa)₃(μ₂‐H)₆] cluster is indicative of weak pure σ‐aromaticity due to the induced diatropic ring current from the translationally allowed a → e′ and e′ → a transitions. The aromatic–antiaromatic behavior of the [(H_tCe)₃(μ₂‐H)₆]⁺ and [(H_tTm)₃(μ₂‐H)₆]²⁻ clusters is similar to that of the early d‐block elements. The magnetic response of [(H_tYb)₃(μ₂‐H)₆]³⁻ is similar to that of [c‐Hg₃]²⁻. The [(H_tLu)₃(μ₂‐H)₆] cluster can be considered as a doubly (σ + π) aromatic system, with the σ‐aromatic component being much stronger than the π‐aromatic one. Finally, the [(X_tRe)₃(μ₂‐X)₆] and [(X_tRu)₃(μ₂‐X)₆]⁺ (X = Cl, Br, I) clusters exhibit significant aromatic character with the greatest contribution to the induced diatropic ring currents coming from π‐type transitions. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010     

Flow-through immunomagnetic separation system for waterborne pathogen isolation and detection: Application to Giardia and Cryptosporidium cell isolation

Simultaneous sample washing and concentration of two waterborne pathogen samples were demonstrated using a rotational magnetic system under continuous flow conditions. The rotation of periodically arranged small permanent magnets close to a fluidic channel carrying magnetic particle suspension allows the trapping and release of particles along the fluidic channel in a periodic manner. Each trapping and release event resembles one washing cycle.The performance of the magnetic separation system (MSS) was evaluated in order to test its functionality to isolate magnetic-labelled protozoan cells from filtered, concentrated tap water, secondary effluent water, and purified water. Experimental protocols described in US Environmental Protection Agency method 1623 which rely on the use of a magnetic particle concentrator, were applied to test and compare our continuous flow cell separation system to the standard magnetic bead-based isolation instruments. The recovery efficiencies for Giardia cysts using the magnetic tube holder and our magnetic separation system were 90.5% and 90.1%, respectively, from a tap water matrix and about 31% and 18.5%, respectively, from a spiked secondary effluent matrix. The recovery efficiencies for Cryptosporidium cells using the magnetic tube holder and our magnetic separation system were 90% and 83.3%, respectively, from a tap water matrix and about 38% and 36%, respectively, from a spiked secondary effluent matrix. Recoveries from all matrices with the continuous flow system were typically higher in glass tubing conduits than in molded plastic conduits.     

Morphological modification of nanostructured ultrathin-layer chromatography stationary phases

Ultrathin-layer chromatography (UTLC) provides the high sensitivities and rapid separations over short distances desirable in many analytical applications. The dependence of these performance benefits on UTLC layer microstructure motivates continued stationary phase engineering efforts. A new method of modifying the elution behaviours of nanostructured thin film UTLC stationary phases is investigated in this report. Macroporous normal phase silica thin films ～5 μm thick were fabricated using glancing angle deposition (GLAD). Reactive ion etching (RIE) and a subsequent annealing treatment modified stationary phase morphology to tune migration velocity, analyte retention, and overall separation performance. Combining this technique with a RIE shadow mask enabled fabrication of adjacent concentration and separation zones with markedly different elution properties. Although produced using an entirely new approach, GLAD UTLC concentration zone media behaved in a manner consistent with traditional thin-layer chromatography (TLC) and high-performance TLC (HPTLC) concentration zone plates. In particular, these new media focused large volume, low concentration dye mixture spots into narrow bands to achieve high-quality separations. The described approach to modifying the morphology and resultant elution behaviours of nanostructured stationary phases expands the capabilities of the GLAD UTLC technique.