A fixed-geometry two-dimensional mixed-compression supersonic inlet with sweep-forward high-light and bleed slot in an inverted ＂X＂-form layout was tested in a wind tunnel. Results indicate： （1） with increases of...A fixed-geometry two-dimensional mixed-compression supersonic inlet with sweep-forward high-light and bleed slot in an inverted ＂X＂-form layout was tested in a wind tunnel. Results indicate： （1） with increases of the free stream Mach number, the total pressure recovery decreases, while the mass flow ratio increases to the maximum at the design point and then decreases; （2） when the angle of attack, a, is less than 6°, the total pressure recovery of both side inlets tends to decrease, but, on the lee side inlet, its values are higher than those on the windward side inlet, and the mass flow ratio on lee side inlet increases first and then falls, while on the windward side it keeps declining slowly with the sum of mass flow on both sides remaining almost constant; （3） with the attack angle, a, rising from 6° to 9°, both total pressure recovery and mass flow ratio on the lee side inlet fall quickly, but on the windward side inlet can be observed decreases in the total pressure recovery and increases in the mass flow ratio; （4） by comparing the velocity and back pressure characterristics of the inlet with a bleed slot to those of the inlet without, it stands to reason that the existence of a bleed slot has not only widened the steady working range of inlet, but also made an enormous improvement in its performance at high Mach numbers. Besides, this paper also presents an example to show how this type of inlet is designed.展开更多
BACKGROUND Thiopurine-induced leukopenia(TIL)is a life-threatening toxicity and occurs with a high frequency in the Asian population.Although nucleoside diphosphate-linked moiety X-type motif 15(NUDT15)variants signif...BACKGROUND Thiopurine-induced leukopenia(TIL)is a life-threatening toxicity and occurs with a high frequency in the Asian population.Although nucleoside diphosphate-linked moiety X-type motif 15(NUDT15)variants significantly improve the predictive sensitivity of TIL,more than 50%of cases of this toxicity cannot be predicted by this mutation.The potential use of the 6-thioguanine nucleotide(6TGN)level to predict TIL has been explored,but no decisive conclusion has been reached.Can we increase the predictive sensitivity based on 6TGN by subgrouping patients according to their NUDT15 R139C genotypes?AIM To determine the 6TGN cut-off levels after dividing patients into subgroups according to their NUDT15 R139C genotypes.METHODS Patients’clinical and epidemiological characteristics were collected from medical records from July 2014 to February 2017.NUDT15 R139C,thiopurine S methyltransferase,and 6TGN concentrations were measured.RESULTS A total of 411 Crohn’s disease patients were included.TIL was observed in 72 individuals with a median 6TGN level of 323.4 pmol/8×10^8 red blood cells(RBC),which was not different from that of patients without TIL(P=0.071).Then,we compared the 6TGN levels based on NUDT15 R139C.For CC(n=342)and CT(n=65)genotypes,the median 6TGN level in patients with TIL was significantly higher than that in patients without(474.8 vs 306.0 pmol/8×10^8 RBC,P=9.4×10-^5;291.7 vs 217.6 pmol/8×10^8 RBC,P=0.039,respectively).The four TT carriers developed TIL,with a median 6TGN concentration of 135.8 pmol/8×10^8 RBC.The 6TGN cut-off levels were 411.5 and 319.2 pmol/8×108 RBC for the CC and CT groups,respectively.CONCLUSION The predictive sensitivity of TIL based on 6TGN is dramatically increased after subgrouping according to NUDT15 R139C genotypes.Applying 6TGN cut-off levels to adjust thiopurine therapies based on NUDT15 is strongly recommended.展开更多
Two X-type chromophores, 2-[4-(4,5-di(4-nitrophenyl) imidazolyl) phenyl]-4,5-di(4-methoxyphenyl)-imidazole (DNPIPDMOPI), 2-[4-(4,5-di(4-nitrophenyl)-imidazolyl) phenyl]-4,5-di(4-aminophenyl)-imidazole (DNPIPDAPI), wer...Two X-type chromophores, 2-[4-(4,5-di(4-nitrophenyl) imidazolyl) phenyl]-4,5-di(4-methoxyphenyl)-imidazole (DNPIPDMOPI), 2-[4-(4,5-di(4-nitrophenyl)-imidazolyl) phenyl]-4,5-di(4-aminophenyl)-imidazole (DNPIPDAPI), were synthesized and characterized. The results show that they possess good nonlinearity, considerable blue-shifted absorption (385 nm and 379 nm in THF) and high decomposition temperature (377 'C and 405 'C). These mean that the X-type chromophores possess a rather good nonlinearity-transparency-thermal stability trade-off. The multi-step corona-poling technique at elevated temperature and in-situ SHG measurements were used to obtain and evaluate the poled films of these chromophores doped in PMMA. The largest SHG signals appeared at 110-120°C, which are 12.5 pm/V and 16.7 pm/V respectively. The dependence of poling induced orientation stability on temperature was measured by depoling experiments and the results indicate that the poling-induced orientation of the films is stable at about 100°C. Theoretic analyses imply that better orientation stability arises from the X-type structure of chromophore. The X-type chromophore has two crossed intramolecular CT, both β xxx and β xyy can contribute to the second-order susceptibility, and the ratio of the tensorial components (γ= β xyy /β xxx ) is about 1/3, so the orientation decay of the films induced by rising temperature will provide a certain compensation for the contribution of β xyy of chromophores.展开更多
The present study investigates the influence of La<sup>3+</sup> and Pr<sup>3+</sup> doping on the structural, magnetic properties, and hyperfine fields of Sr<sub>0.7</sub>RE<sub&...The present study investigates the influence of La<sup>3+</sup> and Pr<sup>3+</sup> doping on the structural, magnetic properties, and hyperfine fields of Sr<sub>0.7</sub>RE<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub>, (RE: La<sup>3+</sup> and Pr<sup>3+</sup>, <em>x</em> = 0.0 - 0.8) hexaferrite compounds prepared via auto-combustion technique. The XRD analysis shows a linear decrease in a and c lattice and unit cell volume contraction with the content <em>x</em>. The room temperature magnetic study shows that for the Pr<sup>3+</sup> doped Sr<sub>0.7</sub>Pr<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (Pr<sup>3+</sup>-SrM), the magnetization value monotonically decreases while for La<sup>3+</sup> doped Sr<sub>0.7</sub>La<sub>0.3</sub>Fe<sub>12-2x</sub>Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (La<sup>3+</sup>-SrM) magnetization value shows a noticeable increase in magnetization value with <em>x</em>. The coercivity of the Pr<sup>3+</sup>-SrM compound was observed to decrease while that of the La<sup>3+</sup>-SrM compound showed a marked 40% increase at <em>x</em> = 0.2 (~5829 Oe) in comparison to undoped SrFe<sub>12</sub>O<sub>19</sub> (~3918 Oe). A difference in Curie temperature was also observed, with Tc ~ 525<span style="white-space:nowrap;">°</span>C at <em>x</em> = 0.4 for Pr<sup>3+</sup>-SrM and Tc = 505<span style="white-space:nowrap;">°</span>C for <em>x</em> = 0.4 for La<sup>3+</sup>-SrM compound. The observed differences in magnetic properties have been explained on the basis of the site occupancy of Co<sup>2+</sup> and Al<sup>3+</sup> in the presence of rare-earth ions. The presence of non-magnetic rare-earth ion, La<sup>3+</sup>, improved saturation magnetization, and coercivity and deemed suitable replacement for Sr<sup>2+</sup>. The hyperfine parameters namely quadrupole shift showed a decrease with the La3<sup>+</sup> or Pr<sup>3+</sup> doping independent of (Co<sup>2+</sup>-Al<sup>3+</sup>) ions doping. Overall, the Mossbauer analysis suggests that the (Co<sup>2+</sup>-Al<sup>3+</sup>) impurities prefer occupancy at 2<em>a</em> site.展开更多
The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device （operated with argon gas）. The analysis is based on the effect of anomalous resista...The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device （operated with argon gas）. The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 （J/Sr） and 0.04 ±0.01 （J/Sr）, respectively. The total energy of the emitted hard X-ray （〉 15 keV） was around 0.12± 0.02 （J/Sr）.展开更多
文摘A fixed-geometry two-dimensional mixed-compression supersonic inlet with sweep-forward high-light and bleed slot in an inverted ＂X＂-form layout was tested in a wind tunnel. Results indicate： （1） with increases of the free stream Mach number, the total pressure recovery decreases, while the mass flow ratio increases to the maximum at the design point and then decreases; （2） when the angle of attack, a, is less than 6°, the total pressure recovery of both side inlets tends to decrease, but, on the lee side inlet, its values are higher than those on the windward side inlet, and the mass flow ratio on lee side inlet increases first and then falls, while on the windward side it keeps declining slowly with the sum of mass flow on both sides remaining almost constant; （3） with the attack angle, a, rising from 6° to 9°, both total pressure recovery and mass flow ratio on the lee side inlet fall quickly, but on the windward side inlet can be observed decreases in the total pressure recovery and increases in the mass flow ratio; （4） by comparing the velocity and back pressure characterristics of the inlet with a bleed slot to those of the inlet without, it stands to reason that the existence of a bleed slot has not only widened the steady working range of inlet, but also made an enormous improvement in its performance at high Mach numbers. Besides, this paper also presents an example to show how this type of inlet is designed.
基金Supported by the National Natural Science Foundation of China,No.81573507,No.81473283,No.81173131,and No.81320108027Guangdong Provincial Key Laboratory Construction Foundation,No.2017B030314030+1 种基金The National Key Research and Development Program,No.2016YFC0905003the 111 Project,No.B16047
文摘BACKGROUND Thiopurine-induced leukopenia(TIL)is a life-threatening toxicity and occurs with a high frequency in the Asian population.Although nucleoside diphosphate-linked moiety X-type motif 15(NUDT15)variants significantly improve the predictive sensitivity of TIL,more than 50%of cases of this toxicity cannot be predicted by this mutation.The potential use of the 6-thioguanine nucleotide(6TGN)level to predict TIL has been explored,but no decisive conclusion has been reached.Can we increase the predictive sensitivity based on 6TGN by subgrouping patients according to their NUDT15 R139C genotypes?AIM To determine the 6TGN cut-off levels after dividing patients into subgroups according to their NUDT15 R139C genotypes.METHODS Patients’clinical and epidemiological characteristics were collected from medical records from July 2014 to February 2017.NUDT15 R139C,thiopurine S methyltransferase,and 6TGN concentrations were measured.RESULTS A total of 411 Crohn’s disease patients were included.TIL was observed in 72 individuals with a median 6TGN level of 323.4 pmol/8×10^8 red blood cells(RBC),which was not different from that of patients without TIL(P=0.071).Then,we compared the 6TGN levels based on NUDT15 R139C.For CC(n=342)and CT(n=65)genotypes,the median 6TGN level in patients with TIL was significantly higher than that in patients without(474.8 vs 306.0 pmol/8×10^8 RBC,P=9.4×10-^5;291.7 vs 217.6 pmol/8×10^8 RBC,P=0.039,respectively).The four TT carriers developed TIL,with a median 6TGN concentration of 135.8 pmol/8×10^8 RBC.The 6TGN cut-off levels were 411.5 and 319.2 pmol/8×108 RBC for the CC and CT groups,respectively.CONCLUSION The predictive sensitivity of TIL based on 6TGN is dramatically increased after subgrouping according to NUDT15 R139C genotypes.Applying 6TGN cut-off levels to adjust thiopurine therapies based on NUDT15 is strongly recommended.
基金This work was supported by the National Natural Science Foundation of China (No. 90201005).
文摘Two X-type chromophores, 2-[4-(4,5-di(4-nitrophenyl) imidazolyl) phenyl]-4,5-di(4-methoxyphenyl)-imidazole (DNPIPDMOPI), 2-[4-(4,5-di(4-nitrophenyl)-imidazolyl) phenyl]-4,5-di(4-aminophenyl)-imidazole (DNPIPDAPI), were synthesized and characterized. The results show that they possess good nonlinearity, considerable blue-shifted absorption (385 nm and 379 nm in THF) and high decomposition temperature (377 'C and 405 'C). These mean that the X-type chromophores possess a rather good nonlinearity-transparency-thermal stability trade-off. The multi-step corona-poling technique at elevated temperature and in-situ SHG measurements were used to obtain and evaluate the poled films of these chromophores doped in PMMA. The largest SHG signals appeared at 110-120°C, which are 12.5 pm/V and 16.7 pm/V respectively. The dependence of poling induced orientation stability on temperature was measured by depoling experiments and the results indicate that the poling-induced orientation of the films is stable at about 100°C. Theoretic analyses imply that better orientation stability arises from the X-type structure of chromophore. The X-type chromophore has two crossed intramolecular CT, both β xxx and β xyy can contribute to the second-order susceptibility, and the ratio of the tensorial components (γ= β xyy /β xxx ) is about 1/3, so the orientation decay of the films induced by rising temperature will provide a certain compensation for the contribution of β xyy of chromophores.
文摘The present study investigates the influence of La<sup>3+</sup> and Pr<sup>3+</sup> doping on the structural, magnetic properties, and hyperfine fields of Sr<sub>0.7</sub>RE<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub>, (RE: La<sup>3+</sup> and Pr<sup>3+</sup>, <em>x</em> = 0.0 - 0.8) hexaferrite compounds prepared via auto-combustion technique. The XRD analysis shows a linear decrease in a and c lattice and unit cell volume contraction with the content <em>x</em>. The room temperature magnetic study shows that for the Pr<sup>3+</sup> doped Sr<sub>0.7</sub>Pr<sub>0.3</sub>Fe<sub>12-2x</sub> Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (Pr<sup>3+</sup>-SrM), the magnetization value monotonically decreases while for La<sup>3+</sup> doped Sr<sub>0.7</sub>La<sub>0.3</sub>Fe<sub>12-2x</sub>Co<sub>x</sub>Al<sub>x</sub>O<sub>19</sub> (La<sup>3+</sup>-SrM) magnetization value shows a noticeable increase in magnetization value with <em>x</em>. The coercivity of the Pr<sup>3+</sup>-SrM compound was observed to decrease while that of the La<sup>3+</sup>-SrM compound showed a marked 40% increase at <em>x</em> = 0.2 (~5829 Oe) in comparison to undoped SrFe<sub>12</sub>O<sub>19</sub> (~3918 Oe). A difference in Curie temperature was also observed, with Tc ~ 525<span style="white-space:nowrap;">°</span>C at <em>x</em> = 0.4 for Pr<sup>3+</sup>-SrM and Tc = 505<span style="white-space:nowrap;">°</span>C for <em>x</em> = 0.4 for La<sup>3+</sup>-SrM compound. The observed differences in magnetic properties have been explained on the basis of the site occupancy of Co<sup>2+</sup> and Al<sup>3+</sup> in the presence of rare-earth ions. The presence of non-magnetic rare-earth ion, La<sup>3+</sup>, improved saturation magnetization, and coercivity and deemed suitable replacement for Sr<sup>2+</sup>. The hyperfine parameters namely quadrupole shift showed a decrease with the La3<sup>+</sup> or Pr<sup>3+</sup> doping independent of (Co<sup>2+</sup>-Al<sup>3+</sup>) ions doping. Overall, the Mossbauer analysis suggests that the (Co<sup>2+</sup>-Al<sup>3+</sup>) impurities prefer occupancy at 2<em>a</em> site.
文摘The multi-radiation of X-rays was investigated with special attention to their energy spectrum in a Mather-type plasma focus device （operated with argon gas）. The analysis is based on the effect of anomalous resistances. To study the energy spectrum, a four-channel diode X-ray spectrometer was used along with a special set of filters. The filters were suitable for detection of medium range X-rays as well as hard X-rays with energy exceeding 30 keV. The results indicate that the anomalous resistivity effect during the post pinch phase may cause multi-radiation of X-rays with a total duration of 300 ± 50 ns. The significant contribution of Cu-Kα was due to the medium range X-rays, nonetheless, hard X-rays with energies greater than 15 keV also participate in the process. The total emitted X-ray energy in the forms of Cu-K and Cu-K/3 was around 0.14 ± 0.02 （J/Sr） and 0.04 ±0.01 （J/Sr）, respectively. The total energy of the emitted hard X-ray （〉 15 keV） was around 0.12± 0.02 （J/Sr）.
