Resonant intrinsic spin hall effect in p-type GaAs quantum well structure

We study intrinsic spin Hall effect in p-type GaAs quantum well structure described by Luttinger Hamiltonian and a Rashba spin-orbit coupling arising from the structural inversion symmetry breaking. The Rashba term induces an energy level crossing in the lowest heavy hole subband, which gives rise to a resonant spin Hall conductance. The resonance may be used to identify the intrinsic spin Hall effect in experiments. © 2006 The American Physical Society.published_or_final_versio

Detection of serum midkine levels in cancer patients using rabbit anti-human midkine monoclonal antibodies

Midkine (MK) is a heparin-binding growth factor and was found to be highly expressed in many types of human carcinomas. MK may become a novel tumor marker. In this study, we used the rabbit specific antibodies against human MK to establish a double antibody sandwich enzyme-linked immunosorbent assay (ELISA) of MK system and applied it to detect serum MK levels in different types of cancer patients. The standard curve, precision and recovery rate were tested, respectively, and serum MK concentration of 102 cancers patients and 102 normal individuals were detected using this method. The detection range of this method was 0.2 to 10 ng/ml (R2 = 0.97). The average intra and intro-assay coefficients of variation (CVs) were 3.6 and 7.9%, respectively. The average recovery rate was 89.9% when some standard antigens were added into the serum. The medians (25th and 75th percentiles) of serum MK levels were 1.35 ng/ml (0.96 and 1.64) in cancer patients and 0.30 ng/ml (0.23 and 0.38) in the controls; the MK levels of the patients were significantly higher than those of the controls (P<0.05). Moreover, 87.2% of the patients showed more than 0.6 ng/ml levels of MK. Serum MK could serve as a general tumor marker with a good potential for clinical application.Key words: Midkine, rabbit monoclonal antibody, sandwich ELISA, tumor marker

Quadratic magnetic field dependence of magnetoelectric photocurrent

We experimentally study the spin and electric photocurrents excited by a linearly polarized light via direct interband transitions in an InGaAs/InAlAs quantum well. In the absence of a magnetic field, the linearly polarized light induces a pure spin current due to the spin-orbit coupling, which may be transformed into a measurable electric current by applying an in-plane magnetic field. The induced electric photocurrent is linear with the in-plane magnetic field. Here, we report a quadratic magnetic field dependence of the photocurrent in the presence of an additional perpendicular component of the magnetic field. We attribute the observation to the Hall effect of magnetoelectric photocurrent. © 2011 American Physical Society.published_or_final_versio

Magnetoelectric photocurrent generated by direct interband transitions in InGaAs/InAlAs two-dimensional electron gas

We report the observation of magnetoelectric photocurrent generated via direct interband transitions in an InGaAs/InAlAs two-dimensional electron gas by a linearly polarized incident light. The electric current is proportional to the in-plane magnetic field, which unbalances the velocities of the photoexcited carriers with opposite spins and consequently generates the electric current from a hidden spin photocurrent. The spin photocurrent can be evaluated from the measured electric current, and the conversion coefficient of spin photocurrent to electric current is self-consistently estimated to be 10-3-10 -2 per Tesla. The observed light-polarization dependence of the electric current is well explained by a theoretical model which reveals the wave vector angle dependence of the photoexcited carrier density. © 2010 The American Physical Society.published_or_final_versio

擋土墻填土邊坡水文響應過程分析:以賴屋山擋土墻填土邊坡為例

Several cracks were found to occur on the slope face of the Laiwushan retaining wall.In order to understand the mechanism of deformation and failure mechanism,automatic monitoring instruments,including piezometers,tensiometers,moisture probes and in-place inclinometers were installed at the top of fill slope.The following findings can be observed based on the monitoring data of piezometers,moisture probes and tensiometers:rainfall infiltration has little influence on the fluctuation of the groundwater table,possibly because the groundwater table was deep;the response of pore pressure and volumetric water content at various depths in the fill was delayed,depending on the soil depth.The rainwater can infiltrate into a depth of over 3m,and a perched water table can be observed at the depth of 3m,resulting in reduction in shear strength of soil and potential shallow failure. 深圳賴屋山的一擋墻表面出現數條裂縫,為了深入研究其變形破壞機制,在擋墻背后填土區布置自動監測儀器,主要包括滲壓計、張力計與水分計及固定式測斜儀。通過對滲壓計、張力計和水分計的監測數據分析表明:填土內地下水位埋深大,降雨對其影響小;土體中孔隙壓力和體積含水量對強降雨響應隨著埋深存在不同程度的滯后性,強降雨入滲深度大于3m,并且在3m處形成瞬態飽和地下水,抗剪強度降低,易于引起邊坡的淺層變形破壞

擋土墻填土邊坡水文響應過程分析:以賴屋山擋土墻填土邊坡為例

Several cracks were found to occur on the slope face of the Laiwushan retaining wall.In order to understand the mechanism of deformation and failure mechanism,automatic monitoring instruments,including piezometers,tensiometers,moisture probes and in-place inclinometers were installed at the top of fill slope.The following findings can be observed based on the monitoring data of piezometers,moisture probes and tensiometers:rainfall infiltration has little influence on the fluctuation of the groundwater table,possibly because the groundwater table was deep;the response of pore pressure and volumetric water content at various depths in the fill was delayed,depending on the soil depth.The rainwater can infiltrate into a depth of over 3m,and a perched water table can be observed at the depth of 3m,resulting in reduction in shear strength of soil and potential shallow failure. 深圳賴屋山的一擋墻表面出現數條裂縫,為了深入研究其變形破壞機制,在擋墻背后填土區布置自動監測儀器,主要包括滲壓計、張力計與水分計及固定式測斜儀。通過對滲壓計、張力計和水分計的監測數據分析表明:填土內地下水位埋深大,降雨對其影響小;土體中孔隙壓力和體積含水量對強降雨響應隨著埋深存在不同程度的滯后性,強降雨入滲深度大于3m,并且在3m處形成瞬態飽和地下水,抗剪強度降低,易于引起邊坡的淺層變形破壞

Interdependent network reciprocity in evolutionary games

Besides the structure of interactions within networks, also the interactions between networks are of the outmost importance. We therefore study the outcome of the public goods game on two interdependent networks that are connected by means of a utility function, which determines how payoffs on both networks jointly influence the success of players in each individual network. We show that an unbiased coupling allows the spontaneous emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the coordination between the interdependent networks is not disturbe

Narrow superconducting window in LaFe1-x Nix AsO

We have studied Ni-substitution effect in LaFe1-x Nix AsO (0≤x≤0.1) by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and heat capacity. The nickel doping drastically suppresses the resistivity anomaly associated with spin-density-wave ordering in the parent compound. Superconductivity emerges in a narrow region of 0.03≤x≤0.06 with the maximum Tc of 6.5 K at x=0.04, where enhanced magnetic susceptibility shows up. The upper critical field at zero temperature is estimated to exceed the Pauli paramagnetic limit. The much lowered Tc in comparison with LaFeAsO1-x Fx system is discussed. © 2009 The American Physical Society.published_or_final_versio

Thermodynamical Consistent Modeling and Analysis of Nematic Liquid Crystal Flows

The general Ericksen-Leslie system for the flow of nematic liquid crystals is reconsidered in the non-isothermal case aiming for thermodynamically consistent models. The non-isothermal model is then investigated analytically. A fairly complete dynamic theory is developed by analyzing these systems as quasilinear parabolic evolution equations in an $L^p-L^q$-setting. First, the existence of a unique, local strong solution is proved. It is then shown that this solution extends to a global strong solution provided the initial data are close to an equilibrium or the solution is eventually bounded in the natural norm of the underlying state space. In these cases, the solution converges exponentially to an equilibrium in the natural state manifold

Wisdom of groups promotes cooperation in evolutionary social dilemmas

Whether or not to change strategy depends not only on the personal success of each individual, but also on the success of others. Using this as motivation, we study the evolution of cooperation in games that describe social dilemmas, where the propensity to adopt a different strategy depends both on individual fitness as well as on the strategies of neighbors. Regardless of whether the evolutionary process is governed by pairwise or group interactions, we show that plugging into the "wisdom of groups" strongly promotes cooperative behavior. The more the wider knowledge is taken into account the more the evolution of defectors is impaired. We explain this by revealing a dynamically decelerated invasion process, by means of which interfaces separating different domains remain smooth and defectors therefore become unable to efficiently invade cooperators. This in turn invigorates spatial reciprocity and establishes decentralized decision making as very beneficial for resolving social dilemmas.Comment: 8 two-column pages, 7 figures; accepted for publication in Scientific Report