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A hybrid planar micro-lattice made of functionally graded materials is proposed where the active and passive constituents are constructed by functionally graded beams with and without partially distributed piezoelectric attachments respectively. The analytical model for predicting complex band structure is presented via the spectral element method in combination with the modified couple stress theory and power law, whose accuracy is validated by the finite element method. By adjusting size dependence, feedback control gain, material gradient and arrangement of piezo-patches, controllable wave propagation and attenuation is achieved, which further advances the implementation of optimizations to obtain ultra-wide low frequency stop bands. [ABSTRACT FROM AUTHOR]

This study aims to identify the risk factors of suicidal ideation (SI) in a large sample of Chinese adults in the labour force. A total of 4136 eligible participants in the labour force were recruited from the routine health check-up cohort. Univariate and multivariate logistic regression were used to identify the factors associated with 12-month and lifetime SI. 175 (4.2%) subjects reported SI in the past twelve months, and 223 (5.4%) reported SI during their lifetime. The results showed that being divorced or widowed, religious belief, personal history of chronic disease and mental illness, family history of mental illness and suicide, and self-assessed childhood happiness were associated with both 12-month and lifetime SI. Additional associations were found between 12-month SI and the following factors: working overtime frequently, low monthly income, and having bachelor's degree. Moreover, being single is a risk factor of lifetime SI while not significant for 12-month SI. The present study identified several risk factors of 12-month and lifetime SI, which could potentially help develop targeted interventions for high-risk suicidal Chinese adults in the labour force. [ABSTRACT FROM AUTHOR]