A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O mixture.Results have been obtained and analyzed in the concentration range of 0%-10%and 90%-10...A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O mixture.Results have been obtained and analyzed in the concentration range of 0%-10%and 90%-100%D_(2)O.A proposed structure of tungsten scatterers in an aluminum host is studied.In order to detect the target material,a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D_(2)O is embedded.By changing the concentration of D_(2)O in the H_(2)O-D_(2)O mixture,the resonance frequency undergoes a frequency shift.Each 1%change in D_(2)O concentration in the H_(2)O-D_(2)O mixture causes a frequency change of about 120 Hz.The finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed sensor.The performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075,which are acceptable values for sensing purposes.The other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.展开更多
The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential,...The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential, the transport properties of CO2-N2 mixture are presented in a temperature range front 273.15 K to 3273.15 K at low density by employing the Chapman-Enskog scheme and the Wang Chang-Uhlenbeck de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.展开更多
Seven types of activated carbon were used to investigate the effect of their structure on separation of CO2 from（H2 ＋ CO2） gas mixture by the adsorption method at ambient temperature and higher pressures. The resul...Seven types of activated carbon were used to investigate the effect of their structure on separation of CO2 from（H2 ＋ CO2） gas mixture by the adsorption method at ambient temperature and higher pressures. The results showed that the limiting factors for separation of CO2 from 53.6 mol% H2 ＋ 46.4 mol% CO2 mixture and from 85.1 mol% H2 ＋ 14.9 mol% CO2 mixture were different at 20 °C and about 2 MPa. The best separation result could be achieved when the pore diameter of the activated carbon ranged from 0.77 to 1.20 nm, and the median particle size was about2.07 lm for 53.6 mol% H2 ＋ 46.4 mol% CO2 mixture and 1.41 lm for 85.1 mol% H2 ＋ 14.9 mol% CO2 mixture. The effect of specific area and pore diameter of activated carbon on separation CO2 from 53.6 mol% H2 ＋ 46.4 mol% CO2 mixture was more significant than that from 85.1 mol% H2 ＋ 14.9 mol% CO2 mixture. CO2 in the gas phase can be decreased from 46.4 mol% to 2.3 mol%–4.3 mol% with a two-stage separation process.展开更多
We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field streng...We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field strengths are decided by a balance of electron generation and loss based on chemical reactions estimated by the electron energy distribution function （EEDF）, which employs the Boltzmann equation method with two-term expanding approximation in the steady-state Townsend （SST） condition. During the insulation recovery phase, the hot CF3I/CO2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction （90.3 Td, 1 Td=10-21 V.m2） is only 38% of the original value before arc （234.9 Td）. The adverse insulation recovery ability of CF3I/CO2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.展开更多
柜式气体绝缘开关设备(cubicle gas insulatedswitchgear,C-GIS)由于其全可靠性能高、小型化等特点在电力系统中得到广泛的应用。但由于C-GIS开关柜的主要绝缘介质SF6气体具有较强的温室效应,且其成本较高,迫切需要减少或不用SF6气体。...柜式气体绝缘开关设备(cubicle gas insulatedswitchgear,C-GIS)由于其全可靠性能高、小型化等特点在电力系统中得到广泛的应用。但由于C-GIS开关柜的主要绝缘介质SF6气体具有较强的温室效应,且其成本较高,迫切需要减少或不用SF6气体。针对C-GIS开关柜较低的气压条件,探讨SF6混合气体替代SF6的可行性。采用圆形平板电极模拟均匀场,研究均匀场、较低气压(0.1~0.25 MPa)下SF6与N2、CO2两种气体的二元混合气体在不同配比、不同电压形式(工频和负极性雷电冲击)作用下的击穿特性。试验结果表明,气压在0.25 MPa以下时,适当增大SF6混合气体的压强可以使其达到纯SF6相同的绝缘强度,为新型C-GIS开关柜的设计制造提供了关键的试验依据。展开更多
目的观察热咳清合剂联合西医基础治疗对2型糖尿病合并社区获得性肺炎(痰热壅肺型)患者的临床疗效。方法选取2023年1月1日至2023年8月1日杭州市中医院武林院区及丁桥院区呼吸科收治的T2DM合并CAP(痰热壅肺型)患者108例,随机分为治疗组(n=...目的观察热咳清合剂联合西医基础治疗对2型糖尿病合并社区获得性肺炎(痰热壅肺型)患者的临床疗效。方法选取2023年1月1日至2023年8月1日杭州市中医院武林院区及丁桥院区呼吸科收治的T2DM合并CAP(痰热壅肺型)患者108例,随机分为治疗组(n=54)和对照组(n=54)。对照组给予西医基础治疗方案,治疗组给予热咳清合剂并联合西医基础治疗。比较两组中医证候积分、临床疗效、PSI评分、胸部CT平扫结果、实验室指标、血糖,记录不良事件。结果治疗前两组中医症候积分比较,差异无统计学意义(P>0.05);治疗后,治疗组中医证候积分低于对照组,差异有统计学意义(P<0.05);临床疗效治疗组总有效率高于对照组(P<0.05);治疗前两组PSI评分比较,差异无统计学意义(P>0.05);治疗后PSI评分治疗组低于对照组(P<0.05);治疗前两组实验室指标(WBC、CRP、PCT水平)比较,差异无统计学意义(P>0.05),治疗后治疗组实验室指标低于对照组(P<0.05);治疗前两组影像学(CT)差异无统计学意义(P>0.05),治疗后热咳清治疗组疗效优于对照组(P<0.05);治疗前两组FPG、2 h PG比较,差异无统计学意义(P>0.05),治疗后治疗组FPG低于对照组,差异有统计学意义(P<0.05),治疗后两组2 h PG比较,差异无统计学意义(P>0.05);两组患者均未出现不良反应。结论热咳清合剂治疗痰热壅肺型T2DM合并CAP安全有效,值得临床推广。展开更多
文摘A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O mixture.Results have been obtained and analyzed in the concentration range of 0%-10%and 90%-100%D_(2)O.A proposed structure of tungsten scatterers in an aluminum host is studied.In order to detect the target material,a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D_(2)O is embedded.By changing the concentration of D_(2)O in the H_(2)O-D_(2)O mixture,the resonance frequency undergoes a frequency shift.Each 1%change in D_(2)O concentration in the H_(2)O-D_(2)O mixture causes a frequency change of about 120 Hz.The finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed sensor.The performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075,which are acceptable values for sensing purposes.The other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.
基金supported by the National Natural Science Foundation of China (Grant No. 51006083)the China Postdoctoral Science Foundation (Grant No. 20110491658)the Fundamental Research Funds for the Central Universities
文摘The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential, the transport properties of CO2-N2 mixture are presented in a temperature range front 273.15 K to 3273.15 K at low density by employing the Chapman-Enskog scheme and the Wang Chang-Uhlenbeck de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.
基金the Talent Scientific Research Fund of LSHU (No. 2016XJJ-015)the fund of the Liaoning Provincial Department of Education (No. L2017LQN005)the National Natural Science Foundation of China (No. 21606120)
文摘Seven types of activated carbon were used to investigate the effect of their structure on separation of CO2 from（H2 ＋ CO2） gas mixture by the adsorption method at ambient temperature and higher pressures. The results showed that the limiting factors for separation of CO2 from 53.6 mol% H2 ＋ 46.4 mol% CO2 mixture and from 85.1 mol% H2 ＋ 14.9 mol% CO2 mixture were different at 20 °C and about 2 MPa. The best separation result could be achieved when the pore diameter of the activated carbon ranged from 0.77 to 1.20 nm, and the median particle size was about2.07 lm for 53.6 mol% H2 ＋ 46.4 mol% CO2 mixture and 1.41 lm for 85.1 mol% H2 ＋ 14.9 mol% CO2 mixture. The effect of specific area and pore diameter of activated carbon on separation CO2 from 53.6 mol% H2 ＋ 46.4 mol% CO2 mixture was more significant than that from 85.1 mol% H2 ＋ 14.9 mol% CO2 mixture. CO2 in the gas phase can be decreased from 46.4 mol% to 2.3 mol%–4.3 mol% with a two-stage separation process.
基金supported by National Natural Science Foundation of China(No.10875093)
文摘We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field strengths are decided by a balance of electron generation and loss based on chemical reactions estimated by the electron energy distribution function （EEDF）, which employs the Boltzmann equation method with two-term expanding approximation in the steady-state Townsend （SST） condition. During the insulation recovery phase, the hot CF3I/CO2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction （90.3 Td, 1 Td=10-21 V.m2） is only 38% of the original value before arc （234.9 Td）. The adverse insulation recovery ability of CF3I/CO2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.
文摘柜式气体绝缘开关设备(cubicle gas insulatedswitchgear,C-GIS)由于其全可靠性能高、小型化等特点在电力系统中得到广泛的应用。但由于C-GIS开关柜的主要绝缘介质SF6气体具有较强的温室效应,且其成本较高,迫切需要减少或不用SF6气体。针对C-GIS开关柜较低的气压条件,探讨SF6混合气体替代SF6的可行性。采用圆形平板电极模拟均匀场,研究均匀场、较低气压(0.1~0.25 MPa)下SF6与N2、CO2两种气体的二元混合气体在不同配比、不同电压形式(工频和负极性雷电冲击)作用下的击穿特性。试验结果表明,气压在0.25 MPa以下时,适当增大SF6混合气体的压强可以使其达到纯SF6相同的绝缘强度,为新型C-GIS开关柜的设计制造提供了关键的试验依据。
文摘目的观察热咳清合剂联合西医基础治疗对2型糖尿病合并社区获得性肺炎(痰热壅肺型)患者的临床疗效。方法选取2023年1月1日至2023年8月1日杭州市中医院武林院区及丁桥院区呼吸科收治的T2DM合并CAP(痰热壅肺型)患者108例,随机分为治疗组(n=54)和对照组(n=54)。对照组给予西医基础治疗方案,治疗组给予热咳清合剂并联合西医基础治疗。比较两组中医证候积分、临床疗效、PSI评分、胸部CT平扫结果、实验室指标、血糖,记录不良事件。结果治疗前两组中医症候积分比较,差异无统计学意义(P>0.05);治疗后,治疗组中医证候积分低于对照组,差异有统计学意义(P<0.05);临床疗效治疗组总有效率高于对照组(P<0.05);治疗前两组PSI评分比较,差异无统计学意义(P>0.05);治疗后PSI评分治疗组低于对照组(P<0.05);治疗前两组实验室指标(WBC、CRP、PCT水平)比较,差异无统计学意义(P>0.05),治疗后治疗组实验室指标低于对照组(P<0.05);治疗前两组影像学(CT)差异无统计学意义(P>0.05),治疗后热咳清治疗组疗效优于对照组(P<0.05);治疗前两组FPG、2 h PG比较,差异无统计学意义(P>0.05),治疗后治疗组FPG低于对照组,差异有统计学意义(P<0.05),治疗后两组2 h PG比较,差异无统计学意义(P>0.05);两组患者均未出现不良反应。结论热咳清合剂治疗痰热壅肺型T2DM合并CAP安全有效,值得临床推广。
