The change of electrical performances of silicon-germanium (SiGe)heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied as afunction of reactor fast neutron radiation fluence. Alt...The change of electrical performances of silicon-germanium (SiGe)heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied as afunction of reactor fast neutron radiation fluence. Alter neutron irradiation, the collector currentI_c and the current gain beta decrease, and the base current I_b increases generally for SiGe HBT.The higher the neutron irradiation fluence is, the larger I_b increases. For conventional Si BJT,I_c and I_b increase as well as beta decreases much larger than SiGe HBT at the same fluence. It isshown that SiGe HBT has a larger anti-radiation threshold and better anti-radiation performance thanSi BJT. The mechanism of performance changes induced by irradiation was preliminarily discussed.展开更多
Changes of the average brightness and non-uniformity of dark output images,and quality of pictures captured under natural lighting for the color CMOS digital image sensorsirradiated at different electron doses have be...Changes of the average brightness and non-uniformity of dark output images,and quality of pictures captured under natural lighting for the color CMOS digital image sensorsirradiated at different electron doses have been studied in comparison to those from theγ-irradiated sensors. For the electron-irradiated sensors, the non-uniformity increases obviouslyand a small bright region on the dark image appears at the dose of 0.4 kGy. The average brightnessincreases at 0.4 kGy, increases sharply at 0.5 kGy. The picture is very blurry only at 0.6 kGy,showing the sensor undergoes severe performance degradation. Electron radiation damage is much moresevere than γ radiation damage for the CMOS image sensors. A possible explanation is presented inthis paper.展开更多
The DC characteristics of SiGe HBT irradiated at different electron dose havebeen studied in a comparison with those of Si B JT. Generally, I_b and I_b - I_(b0) increase, I_c,I_c -I_(c0) and its +/- transition V_(be) ...The DC characteristics of SiGe HBT irradiated at different electron dose havebeen studied in a comparison with those of Si B JT. Generally, I_b and I_b - I_(b0) increase, I_c,I_c -I_(c0) and its +/- transition V_(be) as well as DC current gain ft decreases with increasingdose; increase of I_b -I_(b0) with increasing dose for Si BIT is much larger than that for SiGe HBT;beta increases with V_(be) or I_b, but decreases at I_b < 0.25 mA with I_b, and congregates athigher dose; and a damage factor d(beta) is much less at the same dose for SiGe HBT than for Si BJT.SiGe HBT has much better anti-radiation performance than Si BJT. Some anomalous phenomena forincrease of I_c, I_c -I_(c0), I_b -I_(b0) and beta at low dose have been found. Some electron trapshave been measured. The mechanism of changes of characteristics is discussed.展开更多
2-Carbonyl propionic acid-4-methyl benzoyl hydrazone （PAMH） has been synthe-sized by using 4-methyl benzoyl hydrazine and pyruvic acid as the chemicals and acetic acid asphase transfer catalyst under microwave radia...2-Carbonyl propionic acid-4-methyl benzoyl hydrazone （PAMH） has been synthe-sized by using 4-methyl benzoyl hydrazine and pyruvic acid as the chemicals and acetic acid asphase transfer catalyst under microwave radiation. Then the PAMH and TbCl3·6H20 are placed inthe methanol/acetone/water （3：2：4） mixture for coordination reaction, getting the Schiff complexTb（PAMH）3. The crystal structure is characterized by elemental analysis, X-ray Diffraction （XRD）and infrared spectrum. The compound crystallizes in the monoclinic space group P21/n, with a =1.4770（4）, b = 1.2864（3）, c = 1.9287（5） nm, β= 92.06（3）°, V= 3.6623（15） nm3 and Z= 4. Tb（Ⅲ） ionis nona-coordinated by three completely deprotonated PAMH ligands in a tricapped trigonal prismgeometry, leaving a zero-dimensional mononuclear configuration. The optical properties and thermalstability are studied by ultraviolet spectrum, fluorescence spectra and thermogravimetric analysis（TGA）. The antibacterial activities of the ligand and rare-earth complex are preliminarily studied,and found they have certain antibacterial activity on fusarium solani, and the complex is obviouslymore effective in suppressing fusarium solani than the ligand.展开更多
Background: The skin serves as the first line of defense for the human body. Direct sunlight contains damaging radiations that can speed up the ageing process of the skin, resulting in wrinkles, leathery skin, dark pa...Background: The skin serves as the first line of defense for the human body. Direct sunlight contains damaging radiations that can speed up the ageing process of the skin, resulting in wrinkles, leathery skin, dark patches, and solar elastosis. Objectives: To evaluate the effect of multiple solar irradiation related factors at the protein level in human dermal fibroblast (HDF). The overall effect of individual solar irradiations such as Infrared A (IRA), blue light (BL), UVA, and UVB on HDF cells and the extent of molecular level aberrations to be assessed and compared against each. Methods: Label-free quantitative proteomics (MS/MS) approach has been adopted in this study to observe the protein level changes induced in the HDF cells through various exposures of full light sources. Following that, downstream insilico analysis has been carried out. Results: In this study, it is demonstrated all the four different solar irradiations significantly contribute to the molecular degeneration of skin cells through various mechanisms. This study confirms that BL down-regulates DNA repair proteins and the skin cells-HDF stimulate the histone proteins as a response mechanism to maintain the chromosomal integrity. Conclusions: The proteomics experiment carried out in the current study intends to support the future sun care products based on full light protection technology that can be custom designed to provide complete protection from the solar radiation. Similar technology could enhance the further investigations for deeper understanding of induction, mode of action, and prevention of skin damage from extensive solar irradiation.展开更多
我国辐照食品技术发展迅速,是世界上辐照食品产量最大的国家。辐照技术具有处理效率高、处理时间短、处理量大、非热加工、易于产业化生产等优点,被广泛用于水果、蔬菜、海产品等的保鲜过程中,随着研究深入也被用于食品有害物质的降解...我国辐照食品技术发展迅速,是世界上辐照食品产量最大的国家。辐照技术具有处理效率高、处理时间短、处理量大、非热加工、易于产业化生产等优点,被广泛用于水果、蔬菜、海产品等的保鲜过程中,随着研究深入也被用于食品有害物质的降解、品质改善等过程中。尽管国际卫生组织(World Health Organization,WHO)强调低剂量辐照(小于10 kGy)对食品加工具有安全性,可以大量推广应用,但由于消费者对辐照食品的加工过程及其作用机制缺乏了解,普遍对其比较谨慎,往往担心产生辐射残留、生成新的危害物、破坏营养组分等。为了揭示辐照对食品组分及其营养安全性的影响,近年来国内外学者开展了大量研究,本文结合课题组前期研究成果及国内外相关研究进展,就辐照对食品组分中蛋白质及过敏原的影响研究进行简要综述。展开更多
文摘The change of electrical performances of silicon-germanium (SiGe)heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied as afunction of reactor fast neutron radiation fluence. Alter neutron irradiation, the collector currentI_c and the current gain beta decrease, and the base current I_b increases generally for SiGe HBT.The higher the neutron irradiation fluence is, the larger I_b increases. For conventional Si BJT,I_c and I_b increase as well as beta decreases much larger than SiGe HBT at the same fluence. It isshown that SiGe HBT has a larger anti-radiation threshold and better anti-radiation performance thanSi BJT. The mechanism of performance changes induced by irradiation was preliminarily discussed.
基金This project is financially supported by the Narional Natural Science Foundation of China(Nos 10375034 and 10075029) and the Basic Research Foundation of Tsinghua University (No. JC2002058).
文摘Changes of the average brightness and non-uniformity of dark output images,and quality of pictures captured under natural lighting for the color CMOS digital image sensorsirradiated at different electron doses have been studied in comparison to those from theγ-irradiated sensors. For the electron-irradiated sensors, the non-uniformity increases obviouslyand a small bright region on the dark image appears at the dose of 0.4 kGy. The average brightnessincreases at 0.4 kGy, increases sharply at 0.5 kGy. The picture is very blurry only at 0.6 kGy,showing the sensor undergoes severe performance degradation. Electron radiation damage is much moresevere than γ radiation damage for the CMOS image sensors. A possible explanation is presented inthis paper.
文摘The DC characteristics of SiGe HBT irradiated at different electron dose havebeen studied in a comparison with those of Si B JT. Generally, I_b and I_b - I_(b0) increase, I_c,I_c -I_(c0) and its +/- transition V_(be) as well as DC current gain ft decreases with increasingdose; increase of I_b -I_(b0) with increasing dose for Si BIT is much larger than that for SiGe HBT;beta increases with V_(be) or I_b, but decreases at I_b < 0.25 mA with I_b, and congregates athigher dose; and a damage factor d(beta) is much less at the same dose for SiGe HBT than for Si BJT.SiGe HBT has much better anti-radiation performance than Si BJT. Some anomalous phenomena forincrease of I_c, I_c -I_(c0), I_b -I_(b0) and beta at low dose have been found. Some electron trapshave been measured. The mechanism of changes of characteristics is discussed.
基金supported by the National Natural Science Foundation of China(21273171)Natural Science Foundation of Shangluo University(16SKY005)Special Scientific Research Project of Education Department of Shaanxi Province Government(17JK0242)
文摘2-Carbonyl propionic acid-4-methyl benzoyl hydrazone （PAMH） has been synthe-sized by using 4-methyl benzoyl hydrazine and pyruvic acid as the chemicals and acetic acid asphase transfer catalyst under microwave radiation. Then the PAMH and TbCl3·6H20 are placed inthe methanol/acetone/water （3：2：4） mixture for coordination reaction, getting the Schiff complexTb（PAMH）3. The crystal structure is characterized by elemental analysis, X-ray Diffraction （XRD）and infrared spectrum. The compound crystallizes in the monoclinic space group P21/n, with a =1.4770（4）, b = 1.2864（3）, c = 1.9287（5） nm, β= 92.06（3）°, V= 3.6623（15） nm3 and Z= 4. Tb（Ⅲ） ionis nona-coordinated by three completely deprotonated PAMH ligands in a tricapped trigonal prismgeometry, leaving a zero-dimensional mononuclear configuration. The optical properties and thermalstability are studied by ultraviolet spectrum, fluorescence spectra and thermogravimetric analysis（TGA）. The antibacterial activities of the ligand and rare-earth complex are preliminarily studied,and found they have certain antibacterial activity on fusarium solani, and the complex is obviouslymore effective in suppressing fusarium solani than the ligand.
文摘Background: The skin serves as the first line of defense for the human body. Direct sunlight contains damaging radiations that can speed up the ageing process of the skin, resulting in wrinkles, leathery skin, dark patches, and solar elastosis. Objectives: To evaluate the effect of multiple solar irradiation related factors at the protein level in human dermal fibroblast (HDF). The overall effect of individual solar irradiations such as Infrared A (IRA), blue light (BL), UVA, and UVB on HDF cells and the extent of molecular level aberrations to be assessed and compared against each. Methods: Label-free quantitative proteomics (MS/MS) approach has been adopted in this study to observe the protein level changes induced in the HDF cells through various exposures of full light sources. Following that, downstream insilico analysis has been carried out. Results: In this study, it is demonstrated all the four different solar irradiations significantly contribute to the molecular degeneration of skin cells through various mechanisms. This study confirms that BL down-regulates DNA repair proteins and the skin cells-HDF stimulate the histone proteins as a response mechanism to maintain the chromosomal integrity. Conclusions: The proteomics experiment carried out in the current study intends to support the future sun care products based on full light protection technology that can be custom designed to provide complete protection from the solar radiation. Similar technology could enhance the further investigations for deeper understanding of induction, mode of action, and prevention of skin damage from extensive solar irradiation.
文摘我国辐照食品技术发展迅速,是世界上辐照食品产量最大的国家。辐照技术具有处理效率高、处理时间短、处理量大、非热加工、易于产业化生产等优点,被广泛用于水果、蔬菜、海产品等的保鲜过程中,随着研究深入也被用于食品有害物质的降解、品质改善等过程中。尽管国际卫生组织(World Health Organization,WHO)强调低剂量辐照(小于10 kGy)对食品加工具有安全性,可以大量推广应用,但由于消费者对辐照食品的加工过程及其作用机制缺乏了解,普遍对其比较谨慎,往往担心产生辐射残留、生成新的危害物、破坏营养组分等。为了揭示辐照对食品组分及其营养安全性的影响,近年来国内外学者开展了大量研究,本文结合课题组前期研究成果及国内外相关研究进展,就辐照对食品组分中蛋白质及过敏原的影响研究进行简要综述。
