In oil and gas field, the application of kinetic hydrate inhibitors （KHIs） independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the c...In oil and gas field, the application of kinetic hydrate inhibitors （KHIs） independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the combined use of KHIs and some synergists, which would enhance KHIs’ inhibitory effect on both hydrate nucleation and hydrate crystal growth. In this study, a novel kind of KHI copolymer poly（N-vinyl-2-pyrrolidone-co-2-vinyl pyridine）s （HGs） is used in conjunction with TBAB to show its high performance on hydrate inhibition. The performance of HGs with different monomer ratios in structure II tetrahydrofuran （THF） hydrate is investigated using kinetic hydrate inhibitor evaluation apparatus by step-cooling method and isothermal cooling method. With the combined gas hydrate inhibitor at the concentration of 1.0 wt%, the induction time of 19 wt% THF solution could be prolonged to 8.5 h at a high subcooling of 6℃. Finally, the mechanism of HGs inhibiting the formation of gas hydrate is proposed.展开更多
In this work,highly dispersed atomically-thin MoS2 nanosheets were fabricated at one thousandth of the commercial cost using sepiolite(SEP)mineral nanofibers as carriers via a microwave hydrothermal method.Atomresolve...In this work,highly dispersed atomically-thin MoS2 nanosheets were fabricated at one thousandth of the commercial cost using sepiolite(SEP)mineral nanofibers as carriers via a microwave hydrothermal method.Atomresolved microscopy revealed the MoS2 nanosheets were only 1–4 atomic layers thick.The Mo atoms anchored on the mineral surface served as nucleation sites for the nanosheet growth.The MoS2 layers were in staggered stacking yielding abundant atomic steps at the nanosheets’edges,where catalytically active molybdenum terminations dominated instead of the inert sulfur atoms commonly reported.DFT calculations disclosed that the bonding of Mo(MoS2)and O(SEP)at the MoS2/sepiolite(MSEP)interface enabled SEP to be a unique support,superior to the other minerals for growing such highly-dispersed ultrathin MoS2 architecture.In a typical photocatalyisis application,the MSEP demonstrated a significantly improved photocatalytic performance for RhB degradation compared with the MoS2 nanosheets assembled microspheres.This work provides an important new strategy for low-cost batch preparation of high quality 2D materials via assembly on mineral materials.展开更多
We propose a single-beam leaky-wave antenna(LWA) with a wide-scanning angle and a high-scanning rate based on spoof surface plasmon polariton(SSPP) in this paper. The SSPP transmission line(TL) is etched with periodic...We propose a single-beam leaky-wave antenna(LWA) with a wide-scanning angle and a high-scanning rate based on spoof surface plasmon polariton(SSPP) in this paper. The SSPP transmission line(TL) is etched with periodically arranged circular patches, which converts the slow-wave mode into the fast-wave region for radiation. The proposed LWA is designed, fabricated, and tested. The simulated results imply that the proposed LWA not only achieves a high radiation efficiency of about 81.4%, and a high scanning rate of 12.12, but also has a large scanning angle of 176° over a narrow operation bandwidth of 8.3-9.6 GHz(for |S_(11)| <-10 dB). In addition, the simulated average gain of the LWA can reach as high as 10.9 d Bi. The measured scanning angle range is 175° in the operation band of 8.2-9.6 GHz, and the measured average gain is 10.6 dBi. The experimental results are consistent with the simulation, validating its performance. An antenna with high radiation efficiency, wide scanning angle range, and high scanning rate has great potential for application in radar and wireless communication systems.展开更多
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2009CB219504-03)the National Natural Science Foundation of China (Grant No 51106054)the Colleges and Universities High-level Talents Program of Guangdong
文摘In oil and gas field, the application of kinetic hydrate inhibitors （KHIs） independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the combined use of KHIs and some synergists, which would enhance KHIs’ inhibitory effect on both hydrate nucleation and hydrate crystal growth. In this study, a novel kind of KHI copolymer poly（N-vinyl-2-pyrrolidone-co-2-vinyl pyridine）s （HGs） is used in conjunction with TBAB to show its high performance on hydrate inhibition. The performance of HGs with different monomer ratios in structure II tetrahydrofuran （THF） hydrate is investigated using kinetic hydrate inhibitor evaluation apparatus by step-cooling method and isothermal cooling method. With the combined gas hydrate inhibitor at the concentration of 1.0 wt%, the induction time of 19 wt% THF solution could be prolonged to 8.5 h at a high subcooling of 6℃. Finally, the mechanism of HGs inhibiting the formation of gas hydrate is proposed.
基金supported by the National Natural Science Foundation of China(No.51874115)the CAS Youth Innovation Promotion Association(No.2019190)+2 种基金the Postdoctoral Science Foundation funded project of China(No.2020T130166)the Major Projects of the Natural Science Foundation of Gansu Province,China(No.18JR4RA001)the Excellent Young Scientist Foundation of Hebei Province,China(No.E2018202241).
文摘In this work,highly dispersed atomically-thin MoS2 nanosheets were fabricated at one thousandth of the commercial cost using sepiolite(SEP)mineral nanofibers as carriers via a microwave hydrothermal method.Atomresolved microscopy revealed the MoS2 nanosheets were only 1–4 atomic layers thick.The Mo atoms anchored on the mineral surface served as nucleation sites for the nanosheet growth.The MoS2 layers were in staggered stacking yielding abundant atomic steps at the nanosheets’edges,where catalytically active molybdenum terminations dominated instead of the inert sulfur atoms commonly reported.DFT calculations disclosed that the bonding of Mo(MoS2)and O(SEP)at the MoS2/sepiolite(MSEP)interface enabled SEP to be a unique support,superior to the other minerals for growing such highly-dispersed ultrathin MoS2 architecture.In a typical photocatalyisis application,the MSEP demonstrated a significantly improved photocatalytic performance for RhB degradation compared with the MoS2 nanosheets assembled microspheres.This work provides an important new strategy for low-cost batch preparation of high quality 2D materials via assembly on mineral materials.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62171460 and 61801508)the Natural Science Basic Research Program of Shaanxi Province, China (Grant Nos. 2020JM-350, 20200108, 20210110, and 2020022)the Postdoctoral Innovative Talents Support Program of China (Grant Nos. BX20180375, 2019M653960, and 2021T140111)。
文摘We propose a single-beam leaky-wave antenna(LWA) with a wide-scanning angle and a high-scanning rate based on spoof surface plasmon polariton(SSPP) in this paper. The SSPP transmission line(TL) is etched with periodically arranged circular patches, which converts the slow-wave mode into the fast-wave region for radiation. The proposed LWA is designed, fabricated, and tested. The simulated results imply that the proposed LWA not only achieves a high radiation efficiency of about 81.4%, and a high scanning rate of 12.12, but also has a large scanning angle of 176° over a narrow operation bandwidth of 8.3-9.6 GHz(for |S_(11)| <-10 dB). In addition, the simulated average gain of the LWA can reach as high as 10.9 d Bi. The measured scanning angle range is 175° in the operation band of 8.2-9.6 GHz, and the measured average gain is 10.6 dBi. The experimental results are consistent with the simulation, validating its performance. An antenna with high radiation efficiency, wide scanning angle range, and high scanning rate has great potential for application in radar and wireless communication systems.
