丙烯直接氨氧化制丙烯腈工艺由于反应温度高,且反应器内的气相空间存在丙烯、丙烷、丙烯腈、乙腈、氧气、氮气等可燃性气体混合物,极易发生燃爆危险。为研究和评估该工艺装置反应器尾气的燃爆特性,采用11 L爆轰管测试在400℃、40 k Pa ...丙烯直接氨氧化制丙烯腈工艺由于反应温度高,且反应器内的气相空间存在丙烯、丙烷、丙烯腈、乙腈、氧气、氮气等可燃性气体混合物,极易发生燃爆危险。为研究和评估该工艺装置反应器尾气的燃爆特性,采用11 L爆轰管测试在400℃、40 k Pa (G)工艺条件下,装置开车进料及反应过程中不同进料配比时反应器尾气组成的爆炸极限,并以此绘制爆炸极限三元相图,最终得到爆炸极限和极限氧体积分数。结果表明:反应器内可燃尾气的爆炸上限随氧气体积分数增加而升高,爆炸下限没有明显变化;在开车进料及反应过程中,反应器可燃尾气的极限氧体积分数LOC范围在8. 0%～8. 5%。因此,为避免反应器气相空间在开车过程中发生燃爆危险,需监测反应器内氧气体积分数,并设置氧体积分数报警值小于8. 0%。展开更多
Nine limiting binaries of A12O3-SiO2- Re2O3 (Re=Nd, Sm, Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki, Bondar, Rolin and Coutures are optimized with the ...Nine limiting binaries of A12O3-SiO2- Re2O3 (Re=Nd, Sm, Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki, Bondar, Rolin and Coutures are optimized with the substitutional model of Kaufman and Nesor and the approximate formula of fusion free energy for rare earth element oxides of Wu and Pelton. The extracted Gibbs free energies of pure solid oxides and stoichiometric phases and the solution parameters are used to estimate the corresponding binaries, and a series of isothermal sections of four ternaries Al2O,-SiO2-Nd2O3, A12O3-SiO2-SiO2O3 , A12O3-SiO2-Gd2O3 and A12O3-SiO2-La2O3. In the Al2O3-SiO2-Gd2O3 system samples as fired at exact temperature with different compositions were analyzed by x-ray diffractometer and the detected results are fitted with the calculation of isothermal sections.展开更多
Nine limiting binaries of Al 2O 3 SiO 2 Re 2O 3 (Re=Nd,Sm,Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki, Bondar, Rolin and Coutures are optimized ...Nine limiting binaries of Al 2O 3 SiO 2 Re 2O 3 (Re=Nd,Sm,Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki, Bondar, Rolin and Coutures are optimized with the substitutional model of Kaufman and Nesor and the approximate formula of fusion free energy for rare earth element oxides of Wu and Pelton. The extracted Gibbs free energies of pure solid oxides and stoichiometric phases and the solution parameters are used to estimate the corresponding binaries, liquidus surfaces and a series of isothermal sections of four ternaries Al 2O 3 SiO 2 Nd 2O 3, Al 2O 3 SiO 2 Sm 2O 3, Al 2O 3 SiO 2 Gd 2O 3, and Al 2O 3 SiO 2 La 2O 3. In the Al 2O 3 SiO 2 Gd 2O 3 system samples as fired at exact temperature with different compositions were analyzed by X ray diffractometer and the detected results are fitted with the calculation of isothermal sections.展开更多
Run-length limited(RLL)codes can facilitate reliable data transmission and provide flicker-free illumination in visible light communication(VLC)systems.We propose novel high-rate RLL codes,which can improve error perf...Run-length limited(RLL)codes can facilitate reliable data transmission and provide flicker-free illumination in visible light communication(VLC)systems.We propose novel high-rate RLL codes,which can improve error performance and mitigate flicker.Two RLL coding schemes are developed by designing the finite-state machine to further enhance the coding gain by improving the minimum Hamming distance and using the state-splitting method to realize small state numbers.In our RLL code design,the construction of the codeword set is critical.This codeword set is designed considering the set-partitioning algorithm criterion.The flicker control and minimum Hamming distance of the various proposed RLL codes are described in detail,and the flicker performances of different codes are compared based on histograms.Simulations are conducted to evaluate the proposed RLL codes in on-off keying modulation VLC systems.Simulation results demonstrate that the proposed RLL codes achieve superior error performance to the existing RLL codes.展开更多
文摘丙烯直接氨氧化制丙烯腈工艺由于反应温度高,且反应器内的气相空间存在丙烯、丙烷、丙烯腈、乙腈、氧气、氮气等可燃性气体混合物,极易发生燃爆危险。为研究和评估该工艺装置反应器尾气的燃爆特性,采用11 L爆轰管测试在400℃、40 k Pa (G)工艺条件下,装置开车进料及反应过程中不同进料配比时反应器尾气组成的爆炸极限,并以此绘制爆炸极限三元相图,最终得到爆炸极限和极限氧体积分数。结果表明:反应器内可燃尾气的爆炸上限随氧气体积分数增加而升高,爆炸下限没有明显变化;在开车进料及反应过程中,反应器可燃尾气的极限氧体积分数LOC范围在8. 0%～8. 5%。因此,为避免反应器气相空间在开车过程中发生燃爆危险,需监测反应器内氧气体积分数,并设置氧体积分数报警值小于8. 0%。
文摘Nine limiting binaries of A12O3-SiO2- Re2O3 (Re=Nd, Sm, Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki, Bondar, Rolin and Coutures are optimized with the substitutional model of Kaufman and Nesor and the approximate formula of fusion free energy for rare earth element oxides of Wu and Pelton. The extracted Gibbs free energies of pure solid oxides and stoichiometric phases and the solution parameters are used to estimate the corresponding binaries, and a series of isothermal sections of four ternaries Al2O,-SiO2-Nd2O3, A12O3-SiO2-SiO2O3 , A12O3-SiO2-Gd2O3 and A12O3-SiO2-La2O3. In the Al2O3-SiO2-Gd2O3 system samples as fired at exact temperature with different compositions were analyzed by x-ray diffractometer and the detected results are fitted with the calculation of isothermal sections.
文摘Nine limiting binaries of Al 2O 3 SiO 2 Re 2O 3 (Re=Nd,Sm,Gd and La) system are assessed. The binary diagrams or experimental information from Toropov, Mizuno, Aramaki, Bondar, Rolin and Coutures are optimized with the substitutional model of Kaufman and Nesor and the approximate formula of fusion free energy for rare earth element oxides of Wu and Pelton. The extracted Gibbs free energies of pure solid oxides and stoichiometric phases and the solution parameters are used to estimate the corresponding binaries, liquidus surfaces and a series of isothermal sections of four ternaries Al 2O 3 SiO 2 Nd 2O 3, Al 2O 3 SiO 2 Sm 2O 3, Al 2O 3 SiO 2 Gd 2O 3, and Al 2O 3 SiO 2 La 2O 3. In the Al 2O 3 SiO 2 Gd 2O 3 system samples as fired at exact temperature with different compositions were analyzed by X ray diffractometer and the detected results are fitted with the calculation of isothermal sections.
基金Project supported by the Fundamental Research Funds for the Central Universities,China(No.2020QN15)。
文摘Run-length limited(RLL)codes can facilitate reliable data transmission and provide flicker-free illumination in visible light communication(VLC)systems.We propose novel high-rate RLL codes,which can improve error performance and mitigate flicker.Two RLL coding schemes are developed by designing the finite-state machine to further enhance the coding gain by improving the minimum Hamming distance and using the state-splitting method to realize small state numbers.In our RLL code design,the construction of the codeword set is critical.This codeword set is designed considering the set-partitioning algorithm criterion.The flicker control and minimum Hamming distance of the various proposed RLL codes are described in detail,and the flicker performances of different codes are compared based on histograms.Simulations are conducted to evaluate the proposed RLL codes in on-off keying modulation VLC systems.Simulation results demonstrate that the proposed RLL codes achieve superior error performance to the existing RLL codes.
