We study the problem of instability in the following a priori unstable Hamiltonian system with a time-periodic perturbationare Morse potentials, and ε is a small nonzero parameter. Using geometric methods we prove that Arnold diffusion occurs for generic analytic perturbations H 1 . Indeed, the set of admissible H 1 is C ω dense and C 3 open. The proof also works for arbitrarily small V i . Our perturbative technique for the genericity is valid in the C k topology for allIn the present paper we focus on the C ω -genericity of Arnold diffusion in a priori unstable Hamiltonian systems. The a priori unstable Hamiltonian system consists of a rotor-pendulum system plus a time periodic perturbation, and it can be viewed as a scaled approximation on the dynamics near simple resonances of the a priori stable systems [15].

No abstract

Indigenous Japanese subjects have less immunity against HAV and HBV. The HBV carrier rate is higher in Chinese subjects, and attention should be paid to this issue in clinical practice. It might be important to control hepatitis viruses in Chinese subjects when doctors see them in Japan.

No abstract

SUMMARYA field experiment was conducted to quantify changes in soil aggregation and aggregate-associated soil organic carbon (SOC) concentration 1, 3, 5 and 10 years after abandoned, salinized land in the Manasi River Basin was reclaimed for cotton (Gossypium hirsutum L.). Results showed that reclamation significantly increased SOC concentrations and SOC stocks. Specifically, 10 years of cotton production increased SOC concentrations by 45% in the 0–60 cm depth and SOC stocks by 35%. The SOC concentrations and stocks decreased as soil depth increased. Reclamation time, season and soil depth had significant interaction effects on SOC. The SOC concentrations were significantly and positively correlated with available soil nitrogen and available soil phosphorus. Compared with abandoned farmland, macro-aggregate-associated (>250 µm) SOC concentrations in the 0–60 cm depth increased by 47% after 5 years of cotton production and by 53% after 10 years of cotton production. The contribution of macro-aggregate-associated SOC to total SOC in the 0–60 cm depth increased by 87% after 5 years of cotton production and by 69% after 10 years of cotton production. The findings indicate that soil aggregates were more stable after abandoned, salinized farmland was reclaimed for cotton production. Furthermore, cotton production can increase SOC concentrations and sequester C in this arid area.