分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: It is well known that zeolite LTA membranes have poor acid resistance although they have been considered the best hydrophilic zeolite membranes for the dehydration of organic aqueous mixtures. In the present work, we develop a simple and effective road to enhance the acidic stability of the zeolite LTA membrane through the depositing of a graphene oxide (GO) layer as an acid-resisting barrier on the surface of the zeolite LTA membrane. A relatively thin (about 5.5 mm) but dense and firm LTA@GO composite membrane is obtained by using dopamine as a covalent linker between the zeolite LTA and GO layers. The presence of the protective GO layer effectively inhibits the degradation of the zeolite LTA membrane by acetic acid, which greatly enhances its acid-resistant stability, leading to a high selectivity and stability for the dehydration of acetic acid. For the separation of 95 wt% acetic acid/water mixture at 333 K, the separation factor and flux of the LTA@GO composite membrane are about 400 and 1.5 kg m 2 h 1, respectively, and keep almost constant for 168 h.
分类: 核科学技术 >> 粒子加速器 提交时间: 2021-12-31
摘要: The Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE) project will use 600 1.3 GHz fundamental power couplers, which are modified based on TTF-III power couplers, for continuous wave operation with input power up to approximately 7 kW. The first batch of 20 sets of 1.3 GHz coupler prototypes were fabricated from three domestic manufacturers for the SHINE project. To better characterize the radio frequency conditioning phenomena for validating the performance of power couplers, a room temperature test stand was designed, constructed, and commissioned for the SHINE 1.3 GHz power couplers. In addition, a horizontal test cryostat was built to test the 1.3 GHz superconducting cavities, fundamental power couplers, tuners, and other components as a set. The results of these tests indicate that the 1.3 GHz couplers are capable of handling up to 14 kW continuous waves. Herein, the main aspects of the radio frequency design and construction of the test stand, along with the test results of the high-power conditioning of the 1.3 GHz couplers, are described.