The investigation of the effect of electrical and mechanical errors on the performance of a large active phased array antenna is studied. These errors can decrease the antenna performance, for instance, the gain reduc...The investigation of the effect of electrical and mechanical errors on the performance of a large active phased array antenna is studied. These errors can decrease the antenna performance, for instance, the gain reduction, side lobe level enhancement, and incorrect beam direction. In order to improve the performance of the antenna in the presence of these errors, phase error correction of large phased array antennas using the genetic algorithm(GA) is implemented. By using the phase compensation method, the antenna overall radiation pattern is recovered close to the ideal radiation pattern without error. By applying the simulation data to a 32×40 array of elements with a square grid at the frequency of S-band and measurement of the radiation pattern, the effectiveness of the proposed method is verified.展开更多
With 40 years of development, bio-macromolecule cryo-electron microscopy(cryo-EM) has completed its revolution in terms of resolution and currently plays a highly important role in structural biology study. Accordin...With 40 years of development, bio-macromolecule cryo-electron microscopy(cryo-EM) has completed its revolution in terms of resolution and currently plays a highly important role in structural biology study. According to different specimen states, cryo-EM involves three specific techniques: single-particle analysis(SPA), electron tomography and subtomogram averaging, and electron diffraction. None of these three techniques have realized their full potential for solving the structures of bio-macromolecules and therefore need additional development. In this review, the current existing bottlenecks of cryo-EM SPA are discussed with theoretical analysis, which include the air–water interface during specimen cryo-vitrification, bio-macromolecular conformational heterogeneity, focus gradient within thick specimens, and electron radiation damage. Furthermore, potential solutions of these bottlenecks worthy of further investigation are proposed and discussed.展开更多
A combined plasma photolysis (CPP) reactor that utilized the dielectric barrier discharge (DBD) plasma together with DBD-driven KrI^* excimer ultraviolet emission was applied to the decomposition of H2S gas. The ...A combined plasma photolysis (CPP) reactor that utilized the dielectric barrier discharge (DBD) plasma together with DBD-driven KrI^* excimer ultraviolet emission was applied to the decomposition of H2S gas. The effects of applied voltage, input current, gas flow velocity, original concentration as well as the ratio of Kr/I2 mixture on H2S removal efficiency were investigated. Gas streams containing H2S were separately treated with single DBD and CPP reactor under the same conditions. In comparison to DBD, CPP could greatly enhance the H2S removal efficiency at the same applied voltage, inlet gas concentration and gas flow velocity. In addition, the reaction mechanism was also discussed in this paper.展开更多
OBJECTIVE: To investigate the effects of Zhuyesh- igao granule (ZSG) on tumor necrosis factor-a (TNF-a), interleukin-1 (IL-1), IL-2, IL-6, and IL-8 in rats with radiation esophagitis. METHODS: Fifty Wistar rat...OBJECTIVE: To investigate the effects of Zhuyesh- igao granule (ZSG) on tumor necrosis factor-a (TNF-a), interleukin-1 (IL-1), IL-2, IL-6, and IL-8 in rats with radiation esophagitis. METHODS: Fifty Wistar rats were randomly divid- ed into five groups (10 rats in each group): con- trol (without radiation), saline-treated, and low, medium, and high-dose ISG-treated groups. Rats were given normal saline (10 mL/kg) or 1.15, 2.3, or 4.6 g/kg ZSG by intragastric administration once a day for 7 days. A rat model of radiation esophagi- tis was established by local irradiation of Co60 (490.25 cGy/min, totaling 30 Gy). The administra- tion of ZSG was continued for another 7 days and on the 7th day post-irradiation, inferior vena cavablood was collected. The serum was separated, and TNF-a, IL-1, IL-2, 11_-6, and IL-8 protein levels were determined. RESULTS: Inflammatory response factors were found in the serum of each group. However, levels in ZSG-treated groups were significantly lower than in the saline-treated group (P〈0.05). CONCLUSION: ZSG may prevent the development of radiation esophagitis, perhaps by inhibiting the generation and release of the inflammatory re- sponse factors TNF-a, IL-1, IL-2, IL-6, and IL-8.展开更多
文摘The investigation of the effect of electrical and mechanical errors on the performance of a large active phased array antenna is studied. These errors can decrease the antenna performance, for instance, the gain reduction, side lobe level enhancement, and incorrect beam direction. In order to improve the performance of the antenna in the presence of these errors, phase error correction of large phased array antennas using the genetic algorithm(GA) is implemented. By using the phase compensation method, the antenna overall radiation pattern is recovered close to the ideal radiation pattern without error. By applying the simulation data to a 32×40 array of elements with a square grid at the frequency of S-band and measurement of the radiation pattern, the effectiveness of the proposed method is verified.
基金supported by the Science Funds from the Chinese Academy of Sciences(Grant Nos.ZDKYYQ20170002 and XDB08030202)the Science Funds from the Ministry of Science and Technology of China(Grant Nos.2017YFA0504700 and 2014CB910700)
文摘With 40 years of development, bio-macromolecule cryo-electron microscopy(cryo-EM) has completed its revolution in terms of resolution and currently plays a highly important role in structural biology study. According to different specimen states, cryo-EM involves three specific techniques: single-particle analysis(SPA), electron tomography and subtomogram averaging, and electron diffraction. None of these three techniques have realized their full potential for solving the structures of bio-macromolecules and therefore need additional development. In this review, the current existing bottlenecks of cryo-EM SPA are discussed with theoretical analysis, which include the air–water interface during specimen cryo-vitrification, bio-macromolecular conformational heterogeneity, focus gradient within thick specimens, and electron radiation damage. Furthermore, potential solutions of these bottlenecks worthy of further investigation are proposed and discussed.
基金supported by Natural Science Foundation of Shanghai (No.07ZR14004)
文摘A combined plasma photolysis (CPP) reactor that utilized the dielectric barrier discharge (DBD) plasma together with DBD-driven KrI^* excimer ultraviolet emission was applied to the decomposition of H2S gas. The effects of applied voltage, input current, gas flow velocity, original concentration as well as the ratio of Kr/I2 mixture on H2S removal efficiency were investigated. Gas streams containing H2S were separately treated with single DBD and CPP reactor under the same conditions. In comparison to DBD, CPP could greatly enhance the H2S removal efficiency at the same applied voltage, inlet gas concentration and gas flow velocity. In addition, the reaction mechanism was also discussed in this paper.
基金Supported by National Natural Science Fund of China(Effect of Modified Zhuyeshigao granule and Its Componentson Preventing Radiation Esophagitis of Rats)(No.81173195)Capital Medical Development Fund(Traditional Chinese Medicine Class,No.SF-2009-III-45)
文摘OBJECTIVE: To investigate the effects of Zhuyesh- igao granule (ZSG) on tumor necrosis factor-a (TNF-a), interleukin-1 (IL-1), IL-2, IL-6, and IL-8 in rats with radiation esophagitis. METHODS: Fifty Wistar rats were randomly divid- ed into five groups (10 rats in each group): con- trol (without radiation), saline-treated, and low, medium, and high-dose ISG-treated groups. Rats were given normal saline (10 mL/kg) or 1.15, 2.3, or 4.6 g/kg ZSG by intragastric administration once a day for 7 days. A rat model of radiation esophagi- tis was established by local irradiation of Co60 (490.25 cGy/min, totaling 30 Gy). The administra- tion of ZSG was continued for another 7 days and on the 7th day post-irradiation, inferior vena cavablood was collected. The serum was separated, and TNF-a, IL-1, IL-2, 11_-6, and IL-8 protein levels were determined. RESULTS: Inflammatory response factors were found in the serum of each group. However, levels in ZSG-treated groups were significantly lower than in the saline-treated group (P〈0.05). CONCLUSION: ZSG may prevent the development of radiation esophagitis, perhaps by inhibiting the generation and release of the inflammatory re- sponse factors TNF-a, IL-1, IL-2, IL-6, and IL-8.