Based on the BL09 terminal of China Spallation Neutron Source(CSNS),single event upset(SEU)cross sections of14 nm fin field-effect transistor(FinFET)and 65 nm quad data rate(QDR)static random-access memories(SRAMs)are...Based on the BL09 terminal of China Spallation Neutron Source(CSNS),single event upset(SEU)cross sections of14 nm fin field-effect transistor(FinFET)and 65 nm quad data rate(QDR)static random-access memories(SRAMs)are obtained under different incident directions of neutrons:front,back and side.It is found that,for both technology nodes,the“worst direction”corresponds to the case that neutrons traverse package and metallization before reaching the sensitive volume.The SEU cross section under the worst direction is 1.7-4.7 times higher than those under other incident directions.While for multiple-cell upset(MCU)sensitivity,side incidence is the worst direction,with the highest MCU ratio.The largest MCU for the 14 nm FinFET SRAM involves 8 bits.Monte-Carlo simulations are further performed to reveal the characteristics of neutron induced secondary ions and understand the inner mechanisms.展开更多
Aim To evaluate the effect of single or dual field irra- diation (IR) with the same dose on damage to miniature pig parotid glands. Methodology Sixteen miniature pigs were divided into two IR groups (n=6) and a co...Aim To evaluate the effect of single or dual field irra- diation (IR) with the same dose on damage to miniature pig parotid glands. Methodology Sixteen miniature pigs were divided into two IR groups (n=6) and a control group (n=4). The irradi- ation groups were subjected to 20 Gy X-radiation to one parotid gland using single-field or dual-field modality by linear accelerator. The dose-volume distributions between two IR groups were compared. Saliva from parotid glands and blood were collected at 0, 4, 8 and 16 weeks after irradiation. Parotid glands were removed at 16 weeks to evaluate tissue morphology.Results The irradiation dose volume distributions were significantly different between single and dual field irradi- ation groups (t----4.177, P=0.002), although dose volume histogramin (DVH) indicated the equal maximal dose in parotid glands. Saliva flow rates from IR side decreased dramatically at all time points in IR groups, especially in dual field irradiation group. The radiation caused changes of white blood cell count in blood, lactate dehydrogenase and amylase in serum, calcium, potassium and amylase in saliva. Morphologically, more severe radiation damage was found in irradiated parotid glands from dual field irradi- ation group than that from single field irradiation group. Conclusion Data from this large animal model demons- trated that the radiation damage from the dual field irradiation was more severe than that of the single field irradiation at the same dose, suggesting that dose-volume distribution is an important factor in evaluation of the radiobiology of parotid glands.展开更多
Objective:To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy.Methods: A total ...Objective:To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy.Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42) and the three-dimensional conformal radiotherapy group (n=42) according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated.Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3+,CD4+, and CD4+/CD8+ were significantly elevated, while CD8+ was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions:The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.展开更多
Background Helium-3-filled linear position-sensitive detectors(LPSDs)have been widely applied to neutron scattering instruments in recent decades owing to the high detection efficiency,the excellent neutron/gamma disc...Background Helium-3-filled linear position-sensitive detectors(LPSDs)have been widely applied to neutron scattering instruments in recent decades owing to the high detection efficiency,the excellent neutron/gamma discrimination,and the ability to construct the detector with large area coverage.More than 65%of neutron instruments at the China Spallation Neutron Source(CSNS)require ^(3)He LPSDs for the building of the detector system.The detector of a neutron scattering instrument is normally an array detector composed of a large number of ^(3)He LPSDs.However,no appropriate substitute detector is available for the ^(3)He LPSD for operation over a short period,and its specifications need to be customized to satisfy the requirements of different instruments.This necessitates the development of ^(3)He LPSDs with different specifications for building and upgrading the detectors of neutron scattering instruments at CSNS.Purpose To meet the general requirements specified by the neutron instruments at CSNS,a ^(3)He LPSD was developed and its performances were investigated by using the neutron beam.Methods The neutron beam experiments for this ^(3)He LPSD,including measurements of counting rate plateau curve,position calibration,and position resolution along the tube path,were carried out at the beamline-20 of CSNS.To evaluate its performance in the instrument operation,a detector module made of this ^(3)He LPSD has been installed in the multi-physics instrument(MPI),and the comparison test with the commercial ^(3)He LPSD has been conducted at neutron scattering experiments.Results and conclusion The experimental measurements for this ^(3)He LPSD based on the neutron beam showed that it satisfies the requirements for use in neutron scattering instruments.It reaches a plateau slope of 2.6%/100 V with a plateau range from 1750 to 1950 V and attained a minimal position resolution of 5.3 mm(FWHM),superior to the one achieved by the commercial ^(3)He LPSD.In addition,this ^(3)He LPSD detector module applied to the MPI has been working steadily for half of year and is available for use in experiments.These results provide a sound basis for the subsequent construction and upgradation of the detector of neutron scattering instruments at CSNS.展开更多
Emission of volatile organic compounds has important influence on complex air pollution and human health.In this paper,a series of tungsten-iron composite oxides with different proportions and preparation methods were...Emission of volatile organic compounds has important influence on complex air pollution and human health.In this paper,a series of tungsten-iron composite oxides with different proportions and preparation methods were synthesized and first used for catalytic combustion of chlorobenzene and toluene,as typical polluting gas sources.These WO_(3)-based solid catalytic materials were systematically characterized by modern analytical methods,and the results showed that there was strong electron interaction between W and Fe elements in the composite oxides,and the presence of a certain amount of tungsten oxide inhibited the crystallization of iron oxide,and vice versa,which were beneficial to the uniform dispersion of tungsten-iron components into each other and the improvement of redox properties.Compared with single-component oxide,the formation of tungsten-iron composite oxide affected the micro-structure,improved the specific surface area and optimized the pore structure of materials.The performance test results showed that the tungsten-iron composite oxide(FeWO_4-0.5 Fe_(2)O_(3),molar ratio of tungsten and iron was 1/2)prepared using citric acid-based sol-gel method was the optimal,and its catalytic degradation efficiency could reach 90%for chlorobenzene and 83%for toluene at 320℃,and maintain at least 60 h without obvious deactivation,with high selectivity to the formation of HCl and CO_(2).展开更多
基金Project supported by the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2019B010145001)the National Natural Science Foundation of China(Grant Nos.12075065 and 12175045)the Applied Fundamental Research Project of Guangzhou City,China(Grant No.202002030299)
文摘Based on the BL09 terminal of China Spallation Neutron Source(CSNS),single event upset(SEU)cross sections of14 nm fin field-effect transistor(FinFET)and 65 nm quad data rate(QDR)static random-access memories(SRAMs)are obtained under different incident directions of neutrons:front,back and side.It is found that,for both technology nodes,the“worst direction”corresponds to the case that neutrons traverse package and metallization before reaching the sensitive volume.The SEU cross section under the worst direction is 1.7-4.7 times higher than those under other incident directions.While for multiple-cell upset(MCU)sensitivity,side incidence is the worst direction,with the highest MCU ratio.The largest MCU for the 14 nm FinFET SRAM involves 8 bits.Monte-Carlo simulations are further performed to reveal the characteristics of neutron induced secondary ions and understand the inner mechanisms.
基金supported by the National Natural Science Foundation of China(Grant 30430690)Beijing Major Scientific Program Grants(D09 06007000091
文摘Aim To evaluate the effect of single or dual field irra- diation (IR) with the same dose on damage to miniature pig parotid glands. Methodology Sixteen miniature pigs were divided into two IR groups (n=6) and a control group (n=4). The irradi- ation groups were subjected to 20 Gy X-radiation to one parotid gland using single-field or dual-field modality by linear accelerator. The dose-volume distributions between two IR groups were compared. Saliva from parotid glands and blood were collected at 0, 4, 8 and 16 weeks after irradiation. Parotid glands were removed at 16 weeks to evaluate tissue morphology.Results The irradiation dose volume distributions were significantly different between single and dual field irradi- ation groups (t----4.177, P=0.002), although dose volume histogramin (DVH) indicated the equal maximal dose in parotid glands. Saliva flow rates from IR side decreased dramatically at all time points in IR groups, especially in dual field irradiation group. The radiation caused changes of white blood cell count in blood, lactate dehydrogenase and amylase in serum, calcium, potassium and amylase in saliva. Morphologically, more severe radiation damage was found in irradiated parotid glands from dual field irradi- ation group than that from single field irradiation group. Conclusion Data from this large animal model demons- trated that the radiation damage from the dual field irradiation was more severe than that of the single field irradiation at the same dose, suggesting that dose-volume distribution is an important factor in evaluation of the radiobiology of parotid glands.
文摘Objective:To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy.Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42) and the three-dimensional conformal radiotherapy group (n=42) according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated.Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3+,CD4+, and CD4+/CD8+ were significantly elevated, while CD8+ was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions:The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.
基金supported by the National Key R&D Program of China[Grant No.2021YFA1600703]the Strategic Priority Research Program of the Chinese Academy of Sciences[Grant No.XPB23]the National Natural Science Foundation of China[Grant No.12175254].
文摘Background Helium-3-filled linear position-sensitive detectors(LPSDs)have been widely applied to neutron scattering instruments in recent decades owing to the high detection efficiency,the excellent neutron/gamma discrimination,and the ability to construct the detector with large area coverage.More than 65%of neutron instruments at the China Spallation Neutron Source(CSNS)require ^(3)He LPSDs for the building of the detector system.The detector of a neutron scattering instrument is normally an array detector composed of a large number of ^(3)He LPSDs.However,no appropriate substitute detector is available for the ^(3)He LPSD for operation over a short period,and its specifications need to be customized to satisfy the requirements of different instruments.This necessitates the development of ^(3)He LPSDs with different specifications for building and upgrading the detectors of neutron scattering instruments at CSNS.Purpose To meet the general requirements specified by the neutron instruments at CSNS,a ^(3)He LPSD was developed and its performances were investigated by using the neutron beam.Methods The neutron beam experiments for this ^(3)He LPSD,including measurements of counting rate plateau curve,position calibration,and position resolution along the tube path,were carried out at the beamline-20 of CSNS.To evaluate its performance in the instrument operation,a detector module made of this ^(3)He LPSD has been installed in the multi-physics instrument(MPI),and the comparison test with the commercial ^(3)He LPSD has been conducted at neutron scattering experiments.Results and conclusion The experimental measurements for this ^(3)He LPSD based on the neutron beam showed that it satisfies the requirements for use in neutron scattering instruments.It reaches a plateau slope of 2.6%/100 V with a plateau range from 1750 to 1950 V and attained a minimal position resolution of 5.3 mm(FWHM),superior to the one achieved by the commercial ^(3)He LPSD.In addition,this ^(3)He LPSD detector module applied to the MPI has been working steadily for half of year and is available for use in experiments.These results provide a sound basis for the subsequent construction and upgradation of the detector of neutron scattering instruments at CSNS.
基金supported by the National Key R&D Program of China(2016YFA0401504,2017YFA0403301,2017YFB0503301,and 2018YFB0504302)the National Natural Science Foundation of China(11991073,61975229,61805006,and U1932219)+2 种基金the Key Program of Chinese Academy of Sciences(XDA25030400,and XDB17030500)the Civil Space Project(D040301)the Science Challenge Project(TZ2018005)。
基金financially supported by the Zhejiang Provincial Natural Science Foundation(Grant No.LQ19B030004)the National Natural Science Foundation of China(NSFC,Grant Nos.21906106 and 21808048)the soft science research project of Shaoxing Association of Science and Technology。
文摘Emission of volatile organic compounds has important influence on complex air pollution and human health.In this paper,a series of tungsten-iron composite oxides with different proportions and preparation methods were synthesized and first used for catalytic combustion of chlorobenzene and toluene,as typical polluting gas sources.These WO_(3)-based solid catalytic materials were systematically characterized by modern analytical methods,and the results showed that there was strong electron interaction between W and Fe elements in the composite oxides,and the presence of a certain amount of tungsten oxide inhibited the crystallization of iron oxide,and vice versa,which were beneficial to the uniform dispersion of tungsten-iron components into each other and the improvement of redox properties.Compared with single-component oxide,the formation of tungsten-iron composite oxide affected the micro-structure,improved the specific surface area and optimized the pore structure of materials.The performance test results showed that the tungsten-iron composite oxide(FeWO_4-0.5 Fe_(2)O_(3),molar ratio of tungsten and iron was 1/2)prepared using citric acid-based sol-gel method was the optimal,and its catalytic degradation efficiency could reach 90%for chlorobenzene and 83%for toluene at 320℃,and maintain at least 60 h without obvious deactivation,with high selectivity to the formation of HCl and CO_(2).