1|INTRODUCTION Black adults living in the United States experience shorter sleep durations,lower sleep efficiencies,and less slow‐wave sleep(SWS)than peers in other racial groups.^(1–3)As a social stressor that disp...1|INTRODUCTION Black adults living in the United States experience shorter sleep durations,lower sleep efficiencies,and less slow‐wave sleep(SWS)than peers in other racial groups.^(1–3)As a social stressor that disproportionately affects Black adults,racial discrimination is likely a contributor to racial disparities in sleep.^(4)展开更多
The dam heightening,which is an effective way to increase reservoir volume,has been paid close attention by engineers.Three problems should be dealt with when an arch dam needs to be heightened:stress state getting wo...The dam heightening,which is an effective way to increase reservoir volume,has been paid close attention by engineers.Three problems should be dealt with when an arch dam needs to be heightened:stress state getting worse at dam heel,cracking on new added concrete dam surface,and weak bonding between new added concrete and old dam.Taking Geba arch dam as an example,these problems are examined in details through simulation analysis by the finite element method.The tensile stresses on dam’s surface and joint face that have certain relations to the dam heightening can be controlled by some measures.展开更多
文摘1|INTRODUCTION Black adults living in the United States experience shorter sleep durations,lower sleep efficiencies,and less slow‐wave sleep(SWS)than peers in other racial groups.^(1–3)As a social stressor that disproportionately affects Black adults,racial discrimination is likely a contributor to racial disparities in sleep.^(4)
文摘The dam heightening,which is an effective way to increase reservoir volume,has been paid close attention by engineers.Three problems should be dealt with when an arch dam needs to be heightened:stress state getting worse at dam heel,cracking on new added concrete dam surface,and weak bonding between new added concrete and old dam.Taking Geba arch dam as an example,these problems are examined in details through simulation analysis by the finite element method.The tensile stresses on dam’s surface and joint face that have certain relations to the dam heightening can be controlled by some measures.
