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 bacteria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
The current geographic routing protocols arise data congestion if a multi-flow bypasses a hole simultaneously and excessive energy consumption of hole boundary nodes because these protocols tend to route data packets ...The current geographic routing protocols arise data congestion if a multi-flow bypasses a hole simultaneously and excessive energy consumption of hole boundary nodes because these protocols tend to route data packets along the boundaries of void areas （holes） by perimeter routing scheme.This scheme possibly enlarges the holes phenomenon （called hole diffusion problem） and shortens the life span of the network. A novel geographical routing algorithm based on a potential field approach （PFA） is proposed to deal with multiple holes scenario and restrict data to forward near boundary of a hole. That is, data packets are attracted to its sink and are repulsed away from the hole （s）. Simulation results show that PFA is superior to other protocols in terms of packet delivery ratio, network lifetime.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
Successful prediction of protein domain boundaries provides valuable information not only for the computational structure prediction of muhi-domain proteins but also for the experimental structure determination. A nov...Successful prediction of protein domain boundaries provides valuable information not only for the computational structure prediction of muhi-domain proteins but also for the experimental structure determination. A novel method for domain boundary prediction has been presented, which combines the support vector machine with domain guess by size algorithm. Since the evolutional information of multiple domains can be detected by position specific score matrix, the support vector machine method is trained and tested using the values of position specific score matrix generated by PSI-BLAST. The candidate domain boundaries are selected from the output of support vector machine, and are then inputted to domain guess by size algorithm to give the final results of domain boundary, prediction. The experimental results show that the combined method outperforms the individual method of both support vector machine and domain guess by size.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 bacteria
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The current geographic routing protocols arise data congestion if a multi-flow bypasses a hole simultaneously and excessive energy consumption of hole boundary nodes because these protocols tend to route data packets along the boundaries of void areas （holes） by perimeter routing scheme.This scheme possibly enlarges the holes phenomenon （called hole diffusion problem） and shortens the life span of the network. A novel geographical routing algorithm based on a potential field approach （PFA） is proposed to deal with multiple holes scenario and restrict data to forward near boundary of a hole. That is, data packets are attracted to its sink and are repulsed away from the hole （s）. Simulation results show that PFA is superior to other protocols in terms of packet delivery ratio, network lifetime.
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.
基金Supported by the National Natural Science Foundation of China （No. 60435020）
文摘Successful prediction of protein domain boundaries provides valuable information not only for the computational structure prediction of muhi-domain proteins but also for the experimental structure determination. A novel method for domain boundary prediction has been presented, which combines the support vector machine with domain guess by size algorithm. Since the evolutional information of multiple domains can be detected by position specific score matrix, the support vector machine method is trained and tested using the values of position specific score matrix generated by PSI-BLAST. The candidate domain boundaries are selected from the output of support vector machine, and are then inputted to domain guess by size algorithm to give the final results of domain boundary, prediction. The experimental results show that the combined method outperforms the individual method of both support vector machine and domain guess by size.
