The explosion in demand for massive data processing and storage requires revolutionary memory technologies featuring ultrahigh speed, ultralong retention, ultrahigh capacity and ultralow energy consumption. Although a breakthrough in ultrafast floating-gate memory has been achieved very recently, it still suffers a high operation voltage (tens of volts) due to the Fowler–Nordheim tunnelling mechanism. It is still a great challenge to realize ultrafast nonvolatile storage with low operation voltage. Here we propose a floating-gate memory with a structure of MoS2/hBN/MoS2/graphdiyne oxide/WSe2, in which a threshold switching layer, graphdiyne oxide, instead of a dielectric blocking layer in conventional floating-gate memories, is used to connect the floating gate and control gate. The volatile threshold switching characteristic of graphdiyne oxide allows the direct charge injection from control gate to floating gate by applying a nanosecond voltage pulse (20 ns) with low magnitude (2 V), and restricts the injected charges in floating gate for a long-term retention (10 years) after the pulse. The high operation speed and low voltage endow the device with an ultralow energy consumption of 10 fJ. These results demonstrate a new strategy to develop next-generation high-speed low-energy nonvolatile memory.

With both the high efficiency and economic advantages, the incremental launching has been widely used in bridge construction. As the steel U girder of the composite bridge has not formed the designed section during the launching construction, it has small stiffness relatively and poor torsion resistance ability. The structure mechanical behaviors are complex. Bridge structure collapsed during the incremental launching construction had been reported. Real-time strain monitoring of the adverse sections of the structure during the launching has important significance. By taking the Hangzhou Jiubao Bridge as background, this article introduced the real-time strain monitoring of the steel U girder and analyzed the monitoring results. Effective mastery of the safe state of the structure during launching construction was achieved. It had ensured the launching construction finished successfully. The research results can provide a reference for the design and construction of other similar engineering.