Simultaneous (M,N) Singular Value Decomposition of Matrices

A necessary and sufficient condition for the existence of simultaneous (M,N)singular value decomposition of matrices is given.Some properties about the weighted partial ordering are discussed with the help of the decomposition.

POSITIVE SOLUTIONS TO(k,n-k) NONHOMOGENEOUS BOUNDARYVALUE PROBLEM

By the Schauder fixed point theory,this paper establishes the existence of positive solutions to a(k,n k) m-point boundary value problem.We show that there exists a positive constant b such that the problem has at least one positive solution when the homogeneous boundary parameter is smaller than b,and no positive solution when this parameter is greater than b.

Qualitative analysis on adiabatic and dynamic stability of LTS/HTS hybrid conductor with concentric configuration

The I-V characteristic of a superconductor is generally described by power-law,in which the superconductor with a high n transfers quickly from superconducting state to the normal conducting state.With a high transport current,in the low n value area,flux flow voltage becomes lower than in the high n value area,so that the transient characteristics strongly affect its stability.Based on those properties,we propose a new hybrid conductor which is made of low temperature superconductor(LTS) and high temperature superconductor(HTS) with concentric configuration in which the HTS coat is located outside of the LTS core.According to their power-law models,the modified adiabatic and dynamic stability criteria are qualitatively obtained by taking account into not only their critical currents but also n values.As a result,the new hybrid conductors have potential applications with higher engineering current density and improved stability.

Nitrate reductase activity in high-mountain plants:a test across species,growth form and habitat type

Aims For many terrestrial plants,nitrate is the most important form of available soil nitrogen for growth.However,many plant species,which grow on acidic,ammonium-dominated soils,exhibit a con-stantly low level of nitrate reductase activity(NRA).Little is known about NRA in high-mountain vascular plants in similar conditions.We tested the hypothesis that high-mountain vascular plants in acidic and ammonium-dominated habitats have low levels of NRA.Methods Twenty-six plant species of the families Asteraceae,Ericaceae,Poaceae,Polygonaceae,Salicaceae,Pinaceae,Ranunculaceae,Woodsiaceae,Cyperaceae,Juncaceae,Rosaceae and Urticaceae representing different growth forms were investigated in seven native and anthropogenic habitats of subalpine and alpine belts of the Karkonosze(Hercynian middle-mountains,Central Europe),with respect to leaf NRA and mineral nitrogen forms in soil.NRA was measured by an in vivo assay for the first time directly in the field using portable water bath.Important Findings An NRA study of vascular plants from high mountains is presented for the first time,and most of the studied subalpine and alpine species were subjected to field measurements for the first time ever.Differences among species,families,growth forms and habitats for NRA were found.These differences reflected mainly the taxonomical position and in part ecological preferences.PERMANOVA analysis confirmed that variance component showed that enzyme activities were mostly explained by plant species and habitat.Overall,the subalpine and alpine species from their native habitats are characterized by very low and low ability for nitrate metabolism.We also compared NRA with Ellenberg’s N val-ues for the studied plants.Using a regression equation,N values of some species were calculated for the first time and corrected for the others.

Experimental investigation on frequency-dependent critical current of HTS tapes

Based on characteristics of alternating current （AC） critical current of high temperature superconducting （HTS） tapes on the frequency, this paper focuses on AC voltage-current （U-I） behaviors of two kinds of high temperature superconducting tapes, by which BSCCO and YBCO carrying different frequency AC currents are tested in liquid nitrogen temperature of 77 K. It is shown that the AC U-I characteristic curves of different tapes consist of two parts, that is, the resistive part and the hysteresis part. Additionally, the n values of the two parts and the relationship between AC critical current and frequency are obtained through experiments. The experimental results agree with calculated ones well, which is useful for the application of HTS tapes to power technology.

Electrical properties of Ge metal–oxide–semiconductor capacitors with high-k La_2O_3 gate dielectric incorporated by N or/and Ti

LaON,LaTiO and LaTiON films are deposited as gate dielectrics by incorporating N or/and Ti into La_2O_3 using the sputtering method to fabricate Ge MOS capacitors,and the electrical properties of the devices are carefully examined.LaON/Ge capacitors exhibit the best interface quality,gate leakage property and device reliability,but a smaller k value（14.9）.LaTiO/Ge capacitors exhibit a higher k value（22.7）,but a deteriorated interface quality,gate leakage property and device reliability.LaTiON/Ge capacitors exhibit the highest k value（24.6）,and a relatively better interface quality（3.1×10^（11） eV^（-1）cm^（-2））,gate leakage property（3.6 × 10^（-3） A/cm^2 at V_g = 1V＋V_（fb）） and device reliability.Therefore,LaTiON is more suitable for high performance Ge MOS devices as a gate dielectric than LaON and LaTiO materials.

Onset temperature of intrinsic pinning in a REBCO coated conductor from critical current anisotropy

The field‐angle dependence of the critical current in a REBa_(2)Cu_(3)O_(7) coated conductor has been measured over a fine range of temperatures from 15 K to 80 K.The particular sample is demonstrated to have a very low fraction of extrinsic planar defects by its near‐isotropic critical current at 77 K.At a representative magnetic field of 3 T we are able to track the emergence of the ab‐plane peak usually associated with intrinsic pinning and quantify its evolution with temperature by fitting to a maximum‐entropy function.We are also able to observe the evolution of dip and peak features in the angle dependence of the power‐law index n with decreasing temperature and show that a dip appearing at 65 K is supplanted by a sharper positive peak from 50 K.The combination of critical current and power‐law index temperature dependences shows the onset of intrinsic pinning at 50 K.