1 “... represents an attempt to jump the hurdle to an intuitive understanding of wave mechanics by using...”

2 “..., although certain equilibrium systems also present serious hurdles. Where possible, pairwise articles focus...”

3 “... of the equations of general relativity has been (and still remains) a major hurdle in the formulation of concrete...”

4 “... mirrors; reliability is always a huge hurdle for commercilization; and the tradeoffs among the speed...”

5 “... this technical hurdle by producing ultracold cesium atoms in a quasi-2D optical box potential. The exquisite...”