分类: 物理学 >> 核物理学 提交时间: 2023-11-22
摘要: BL10U2 is an undulator-based macromolecular crystallography (MX) beamline located at the 3.5-GeV Shanghai Synchrotron Radiation Facility. BL10U2 is specifically designed for conducting routine and bio safety level-2 (BSL-2) MX experiments utilizing high-flux tunable X-rays with energies from 7 to 18 keV, providing a beam spot size of 20 m (horizontal) 10 m (vertical) at the sample point. Certification by the Shanghai Pudong Municipal Health Commission confirmed the capability to perform BSL-2 MX experiments. The beamline is currently equipped with an Eiger X 16M detector and two newly developed in-house high-precision diffractometers that can be switched to perform conventional or in situ crystal diffraction experiments. An automatic sample changer developed in-house allows fast sample exchange in less than 30s, supporting high-throughput MX experimentation and rapid crystal screening. Data collection from both the diffractometer and detector was controlled by an in-house developed data collection software (Finback) with a user-friendly interface for convenient operation. This study presents a comprehensive overview of the facilities, experimental methods, and performance characteristics of the BL10U2 beamline.
分类: 物理学 >> 核物理学 提交时间: 2023-11-15
摘要: Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility hasbeenrelocated, upgraded, and given a newID (BL02U1). It now deliversX-rays intheenergyrangeof616 keV, withafocusedbeamof11.6m 4.8 m andphotonfluxgreater than 10^12phs/s. Thehighcredibilityandstabilityofthebeamandgoodtimingsynchronizationof the equipmentsignificantly improvetheexperimentalefficiency. SinceJune2021, whenitofficially openedtousers, over4200 hofbeamtimehavebeenprovidedto over200 researchgroupstocollectdataatthebeamline. Its goodperformanceandstableoperationhave led to the resolution of several structuresbasedondatacollectedatthebeamline.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Non-Abelian braiding has attracted significant attention because of its pivotal role in describing the exchange behaviors of anyons--a candidate for realizing quantum logics. The input and outcome of non-Abelian braiding are connected by a unitary matrix which can also physically emerge as a geometric-phase matrix in classical systems. Hence it is predicted that non-Abelian braiding should have analogues in photonics, but a feasible platform and the experimental realization remain out of reach. Here, we propose and experimentally realize an on-chip photonic system that achieves the non-Abelian braiding of up to five photonic modes. The braiding is realized by controlling the multi-mode geometric-phase matrix in judiciously designed photonic waveguide arrays. The quintessential effect of braiding--sequence-dependent swapping of photon dwell sites is observed in both classical-light and single-photon experiments. Our photonic chips are a versatile and expandable platform for studying non-Abelian physics, and we expect the results to motivate next-gen non-Abelian photonic devices.
分类: 动力与电气工程 >> 工程热物理学 提交时间: 2017-06-26 合作期刊: 《热科学学报》
摘要: This paper presents the numerical investigation of thermal protection of scramjet strut by opposing jet in supersonic stream of Mach number 6 with a hydrogen fueled scramjet strut model using CFD software. Simulation results indicate that when a small amount of fuel is injected from the nose of the strut, the bow shock is pushed away from the strut, and the heat flux is reduced in the strut, especially at the leading edge. Opposing jet forms a recirculation region near the nozzle so that the strut is covered with low temperature fuel and separated from free stream. An appropriate total pressure ratio can be used to reduce not only aerodynamic heating but also the drag of strut. It is therefore concluded that thermal protection of scramjet strut by opposing jet is one of the promising ways to protect scramjet strut in high enthalpy stream.