The electrocatalysts of Pt/C, PtRu/C and Ru/C were prepared by the impregnation method. The facet characterization, the dispersion and the particle size for the catalysts were determined by means of X ray diffractio...The electrocatalysts of Pt/C, PtRu/C and Ru/C were prepared by the impregnation method. The facet characterization, the dispersion and the particle size for the catalysts were determined by means of X ray diffraction and transmission electron microscopy. X ray photoelectron spectroscopy was also used to analyze the state and the valency of the noble metals. The results show that the particle size was in nanometer range and the binary metals have come into being an alloy. The platinum in the catalysts existed in zero valency. The valency of the ruthenium on the surface is different from that in the body, while the ruthenium on the surface existed in oxide form. PtRu/C and Pt/C are of good activity to the electrooxidation of hydrogen except Ru/C. PtRu/C is more tolerant of CO than Pt/C, and CO is only adsorbed on Pt.展开更多
Dear Editor,In recent years,owing to the fact that antibiotic-resistant bacteria have become more and more prevalent,there has been a resurgence of interest in the use of bacteriophages.However,bacteriophage therapy r...Dear Editor,In recent years,owing to the fact that antibiotic-resistant bacteria have become more and more prevalent,there has been a resurgence of interest in the use of bacteriophages.However,bacteriophage therapy remains an underutilized option in modern medicine due to technical hurdles such as limited host range,narrow spectrum of展开更多
We study the stochastic control problem of maximizing expected utility from terminal wealth and/or consumption, when the portfolio is constrained to take values in a given closed, convex subset of Ra, and in the prese...We study the stochastic control problem of maximizing expected utility from terminal wealth and/or consumption, when the portfolio is constrained to take values in a given closed, convex subset of Ra, and in the presence of a higher interest rate for borrowing. The setting is that of a continuous-time, Ito process model for the underlying asset prices. The solution of the unconstrained problem is given. In addition to the original constrained optimization problem, a so-called combined dual problem is introduced. Finally, the existence question of optimal processes for both the dual and the primal problem is settled.展开更多
Beyond the third generation mobile communications, high-capacity and high-speed wireless transmission causes serious Co-Channel Interference (CCI) and Inter-Symbol Interference (ISI). This paper first set up a kind of...Beyond the third generation mobile communications, high-capacity and high-speed wireless transmission causes serious Co-Channel Interference (CCI) and Inter-Symbol Interference (ISI). This paper first set up a kind of Space/Time transmission model, then proposed a Joint Space/Time Equalizer, which was based on Recursive Least Square (RLS) algorithm and composed of Adaptive Array Antenna (AAA) and Temporal Equalizer (TE). Being different from traditional equalizer using front feedback filter, this paper employed rear feedback filter which reduces the number of adaptive weight values from M×L to M+L. Simulation results show that the proposed scheme efficiently improves the ability of anti-interference in multi-path fading channel, raises the practical feasibility and reduces algorithm complexity.展开更多
基金Supported by the National 973project(No.G2 0 0 0 0 2 6 4 10 ) and Inovation Funds of Dalian Insitute of Chem icalPhysics
文摘The electrocatalysts of Pt/C, PtRu/C and Ru/C were prepared by the impregnation method. The facet characterization, the dispersion and the particle size for the catalysts were determined by means of X ray diffraction and transmission electron microscopy. X ray photoelectron spectroscopy was also used to analyze the state and the valency of the noble metals. The results show that the particle size was in nanometer range and the binary metals have come into being an alloy. The platinum in the catalysts existed in zero valency. The valency of the ruthenium on the surface is different from that in the body, while the ruthenium on the surface existed in oxide form. PtRu/C and Pt/C are of good activity to the electrooxidation of hydrogen except Ru/C. PtRu/C is more tolerant of CO than Pt/C, and CO is only adsorbed on Pt.
基金supported by the Natural Science Foundation of China(30571637)
文摘Dear Editor,In recent years,owing to the fact that antibiotic-resistant bacteria have become more and more prevalent,there has been a resurgence of interest in the use of bacteriophages.However,bacteriophage therapy remains an underutilized option in modern medicine due to technical hurdles such as limited host range,narrow spectrum of
文摘We study the stochastic control problem of maximizing expected utility from terminal wealth and/or consumption, when the portfolio is constrained to take values in a given closed, convex subset of Ra, and in the presence of a higher interest rate for borrowing. The setting is that of a continuous-time, Ito process model for the underlying asset prices. The solution of the unconstrained problem is given. In addition to the original constrained optimization problem, a so-called combined dual problem is introduced. Finally, the existence question of optimal processes for both the dual and the primal problem is settled.
文摘Beyond the third generation mobile communications, high-capacity and high-speed wireless transmission causes serious Co-Channel Interference (CCI) and Inter-Symbol Interference (ISI). This paper first set up a kind of Space/Time transmission model, then proposed a Joint Space/Time Equalizer, which was based on Recursive Least Square (RLS) algorithm and composed of Adaptive Array Antenna (AAA) and Temporal Equalizer (TE). Being different from traditional equalizer using front feedback filter, this paper employed rear feedback filter which reduces the number of adaptive weight values from M×L to M+L. Simulation results show that the proposed scheme efficiently improves the ability of anti-interference in multi-path fading channel, raises the practical feasibility and reduces algorithm complexity.
