Single-photon light detection and ranging (lidar) offers single-photon sensitivity and picosecond timing resolution, which is desirable for high-precision three-dimensional (3D) imaging over long distances. Despite important progress, further extending the imaging range presents enormous challenges because only a few echo photons return and are mixed with strong noise. Here, we tackled these challenges by constructing a high-efficiency, low-noise coaxial single-photon lidar system and developing a long-range-tailored computational algorithm that provides high photon efficiency and good noise tolerance. Using this technique, we experimentally demonstrated active single-photon 3D imaging at a distance of up to 45 km in an urban environment, with a low return-signal level of ∼ 1 photon per pixel. Our system is feasible for imaging at a few hundreds of kilometers by refining the setup, and thus represents a step towards low-power and high-resolution lidar over extra-long ranges.

A Pd/norbornene/Cu cooperative catalysis for the efficient synthesis of 2-(arylthio)aryl ketones from aryl halides and thioesters has been developed. The first example of cooperative catalysis by palladium, norbornene, and copper, wherein the C(O)-S bond of thioesters is cleaved by a Pd(II) palladacycle with the assistance of CuI, has been observed.

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The CNTs/GCF shows long and stable discharge plateaus and the hybrid potassium storage mechanism of surface adsorption and intercalation.