Methyl 2-hydr-oxy-3-nitro-benzoate.

The title compound, C(8)H(7)NO(5), assumes an approximately planar mol-ecular structure with an intra-molecular O-H⋯O hydrogen bond between the hydr-oxy and carboxyl-ate groups. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

Continuous control of chaos based on the stability criterion.

A method of chaos control based on stability criterion is proposed in the present paper. This method can stabilize chaotic systems onto a desired periodic orbit by a small time-continuous perturbation nonlinear feedback. This method does not require linearization of the system around the stabilized orbit and only an approximate location of the desired periodic orbit is required which can be automatically detected in the control process.