晚期糖基化末端产物(Advanced Glycation End Products,AGEs)是美拉德反应、脂肪氧化等反应过程中的生成物,对人体健康有一定的危害。为研究3种食品天然抗氧化剂对晚期糖基化末端产物的抑制作用,建立牛血清蛋白和葡萄糖的美拉德模拟反...晚期糖基化末端产物(Advanced Glycation End Products,AGEs)是美拉德反应、脂肪氧化等反应过程中的生成物,对人体健康有一定的危害。为研究3种食品天然抗氧化剂对晚期糖基化末端产物的抑制作用,建立牛血清蛋白和葡萄糖的美拉德模拟反应体系。在试验组中分别添加质量浓度梯度为0、50、100、150、200μg/mL的茶多酚、甘草提取物、迷迭香提取物,在阳性对照组加入相应浓度梯度的氨基胍(AG),37℃下反应7、14、21、28d,在激发波长370nm、发射波长440nm下测定荧光强度,以荧光强度表示AGEs含量。结果表明,3种食品抗氧化剂对AGEs的形成有显著的抑制作用,其中未加抗氧化剂的试验组与其他试验组间有极显著差异(P<0.01)。当抗氧化剂添加质量浓度为200μg/mL,反应28d后,迷迭香浓度对AGEs的抑制率为87.79%,甘草提取物和茶多酚的抑制率分别为83.56%、81.03%,而阳性对照氨基胍的抑制率为69.15%。展开更多
To reveal the nature of locusts’visual reaction when stimulated by light,and to clarify the regulation characteristics of locusts’phototactic visual physiology and obtain good spectral light features for locusts’ph...To reveal the nature of locusts’visual reaction when stimulated by light,and to clarify the regulation characteristics of locusts’phototactic visual physiology and obtain good spectral light features for locusts’phototactic action,this study investigated locusts’visual spectrum response by characterizing their photoreceptive reaction to LED light using an AvaSpec fiber-optic spectrometer system.Locusts’phototactic response to spectral light was compared using this system.The results showed that locusts’visual reaction characterization presents a photo-induced vision spectrum effect and that by offsetting the main wavelength of light and the spectral peak intensity,a time-varying bio-regulation effect emerges.In addition,locusts’visual regulation ability to UV light is higher than that to violet light,whereas their reaction intensity is lower than to violet light,and the visual bio-regulatory force of locusts’visual system absorbing orange light to react sensitively becomes gradually higher than when absorbing green light as time goes on.Moreover,corresponding to nominal illumination with the same radiant energy and a visual spectrum response stimulated by UV,violet,orange,and green light,it appears that the visual spectrum window is symmetrical around 382 nm,400 nm,602 nm,and 530 nm,respectively,with no significant difference between spectral amplitudes and having a time-varying incremental characteristic with amplitude peak width.This indicates that the stimulus intensity of UV,violet,orange,and green light exceeds locusts’visual tolerance,causing them to generate regulation inactivation as a visual physiological reaction,whereas the visual window response effect stimulated by UV light presents an illumination timeliness effect.Simultaneously,time-varying characteristics of locusts’bio-behavior intensity show that light intensity can make up for locusts’visual sensitivity differences at various spectral wavelengths.Presented with differential response time,photosensitive behavior intensity,展开更多
YBO3：2 at.% Eu3＋ was prepared by the solid state reaction and its temperature dependent luminescence was investigated for possible applications in temperature sensing. Phase composition of this material was confirme...YBO3：2 at.% Eu3＋ was prepared by the solid state reaction and its temperature dependent luminescence was investigated for possible applications in temperature sensing. Phase composition of this material was confirmed by X-ray powder diffraction analysis and excitation and emission spectra were also provided. Under excitation of 355 nm, the fluorescence originating from 5D0 and 5D1 states varied as the temperature rose in a region from 333 to 773 K. The fluorescence intensity ratio （FIR） of SD0 and 5D1 was investigated which increased significantly with the rise of temperature. The maximal relative sensitivity in the whole temperature range was 1.8% K-1（at 333 K）. The results recommended YBO3：Eu3＋ as a new material of the FIR method for non-contact optical thermometry.展开更多
The assessment of emotions with fractal dimensions of EEG signals has been attempted before, but the quantification of the intensity and duration of sudden and short emotions remains a challenge. This paper suggests a...The assessment of emotions with fractal dimensions of EEG signals has been attempted before, but the quantification of the intensity and duration of sudden and short emotions remains a challenge. This paper suggests a method for this purpose, by using a new fractal dimension algorithm and by adjusting the amplitude of the EEG signal in order to obtain maximal separation of high and low fractal dimensions. The emotion was induced by embedding a scary image at 20 seconds in landscape videos of 60 seconds length. The new method did not only detect the onset of the emotion correctly, but also revealed its duration and intensity. The intensity is based on the magnitude and impulse of the fractal dimension signal. It is also shown that Higuchi’s method does not always detect emotion spikes correctly;on the contrary, the region of the expected emotional response can be represented by fractal dimensions smaller than the rest of the signal, whereas the new method directly reveals distinct spikes. The duration of these spikes was 10 - 11 seconds. The magnitude of these spikes varied across the EEG channels. The build-up and cool-down of the emotions can occur with steep and flat gradients.展开更多
利用X’Pert PRO X-射线衍射分析仪、分光光度仪等手段,系统评价了石英在60℃条件下,与5%HCl、5%HCl+0.5%HF、5%HCl+1.0%HF、0.5%HF、1.0%HF、8%HBF4和5%HCl+7%HBF4七种常见酸体系反应的化学行为,重点分析了酸液中可溶硅离子浓度变化特...利用X’Pert PRO X-射线衍射分析仪、分光光度仪等手段,系统评价了石英在60℃条件下,与5%HCl、5%HCl+0.5%HF、5%HCl+1.0%HF、0.5%HF、1.0%HF、8%HBF4和5%HCl+7%HBF4七种常见酸体系反应的化学行为,重点分析了酸液中可溶硅离子浓度变化特征及影响因素。研究表明:石英与HF酸、土酸反应快速强烈,前2h硅离子浓度波动大,是硅质沉淀形成的主要时期;与氟硼酸体系反应慢,达最大反应强度长于12h。酸蚀后矿物结构无明显变化,可溶硅离子浓度与长石矿物、粘土矿物上述酸化体系中平均浓度相近。通过快速返排残酸,使用低浓度的HF酸进行酸化,采用过量的后置酸液以及在酸化液中加入相应的阻垢剂可预防砂岩酸化时硅质沉淀的产生。展开更多
No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P+(CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be ob...No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P+(CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be observed only.Each compound forms a very characteristic ion(O=PPbj-1)+ at m/z 277 through hydroxyl rearrangement reaction.The intensity of this ion is closely related with the size of the carbon chain of hydroxyalkyl and with temperature of ion source and temperature of sample probe.The above rearrangement reaction and the reaction to form ion at m/z 262 take place simultaneously,thus leading to strong competition.At n=2,ion at m/z 277 is the most powerful and becomes continuously the base peak.At n=3 and n=4,the intensity of ion at m/z 262 reaches the maximum,and is always the base peak,and the relative abundance of m/z 277 is only around 2%.At n=5,6,8,9,10,m/z 277 becomes base peak when the temperature of probe is below 300℃.But,when the temperature increases from 300℃to 350℃,m/z 262 suddenly becomes the base peak,which is not in direct proportional relation with the size of carbon chain.It is proved by MIKES and accurate mass that ion at m/z 277 produces a fragment ion(O=PPh2-2)+ at m/z 199 with the loss of the neutral benzene molecule.展开更多
A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR...A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR） and silicone rubber（SiR） were used as the substrate for Eu（TTA）3 AA to prepare fluorescence composites.The neat Eu（TTA）3 AA complex showed the ability of self-polymerization when it was heated at 145 °C.It was found that the fluorescence intensity of the neat Eu（TTA）3 AA decreased over 70% when the polymerization time was over 25 min at 145 °C.The results also revealed that the polymerizated Eu（TTA）3 AA could be dispersed in nano-scale in two matrices and the luminescent intensities decreased 52% in NBR matrix,and 95% in SiR matrix compared with two relative compounds without crosslinking.To optimize the luminescence intensity of the composites,the Eu（TTA）3 AA polymerization kinetic process in matrix was investigated in detail by controlling the temperature,the crosslinking agent,etc.The results showed that the peroxide could accelerate Eu（TTA）3 AA self-polymerization in the rubber matrix,and therefore improved the dispersion,but not be helpful for the luminescence intensity enhancement.In addition,the relatively higher luminescence intensity in Eu（TTA）3 AA/NBR in comparison to that of Eu（TTA）3 AA/SiR might contribute to the interaction between nitrile group（–CN） in NBR and Eu-complexes,suggesting that the luminescence intensity of the composites also depended on the matrix characteristics.展开更多
利用X'Pert PRO X-射线衍射分析仪和分光光度仪,系统地评价石英在一定温度下与常见酸体系反应的化学行为,重点分析酸液中可溶硅离子浓度变化特征及影响因素。研究表明,石英与HF、土酸反应快速强烈,前2h硅离子浓度波动大,是硅质沉淀...利用X'Pert PRO X-射线衍射分析仪和分光光度仪,系统地评价石英在一定温度下与常见酸体系反应的化学行为,重点分析酸液中可溶硅离子浓度变化特征及影响因素。研究表明,石英与HF、土酸反应快速强烈,前2h硅离子浓度波动大,是硅质沉淀形成的主要时期,与氟硼酸体系反应慢,达最大反应强度需12h。酸蚀后矿物结构无明显变化,可溶硅离子浓度与长石矿物、粘土矿物上述酸化体系中平均浓度相近。通过快速反排残酸,使用低浓度的HF酸进行酸化,采用过量的后置酸液以及在酸化液中加入相应的阻垢剂可预防砂岩酸化时硅质沉淀的产生。展开更多
文摘晚期糖基化末端产物(Advanced Glycation End Products,AGEs)是美拉德反应、脂肪氧化等反应过程中的生成物,对人体健康有一定的危害。为研究3种食品天然抗氧化剂对晚期糖基化末端产物的抑制作用,建立牛血清蛋白和葡萄糖的美拉德模拟反应体系。在试验组中分别添加质量浓度梯度为0、50、100、150、200μg/mL的茶多酚、甘草提取物、迷迭香提取物,在阳性对照组加入相应浓度梯度的氨基胍(AG),37℃下反应7、14、21、28d,在激发波长370nm、发射波长440nm下测定荧光强度,以荧光强度表示AGEs含量。结果表明,3种食品抗氧化剂对AGEs的形成有显著的抑制作用,其中未加抗氧化剂的试验组与其他试验组间有极显著差异(P<0.01)。当抗氧化剂添加质量浓度为200μg/mL,反应28d后,迷迭香浓度对AGEs的抑制率为87.79%,甘草提取物和茶多酚的抑制率分别为83.56%、81.03%,而阳性对照氨基胍的抑制率为69.15%。
基金The authors acknowledge that this work was financially supported by the Scientific and technological project in Henan Province(Grant No.212102110139)the China Agricultural Research System(Grant No.CARS-03)the Henan Engineering Research Center of Biological Pesticide&Fertilizer Development and Synergistic Application.
文摘To reveal the nature of locusts’visual reaction when stimulated by light,and to clarify the regulation characteristics of locusts’phototactic visual physiology and obtain good spectral light features for locusts’phototactic action,this study investigated locusts’visual spectrum response by characterizing their photoreceptive reaction to LED light using an AvaSpec fiber-optic spectrometer system.Locusts’phototactic response to spectral light was compared using this system.The results showed that locusts’visual reaction characterization presents a photo-induced vision spectrum effect and that by offsetting the main wavelength of light and the spectral peak intensity,a time-varying bio-regulation effect emerges.In addition,locusts’visual regulation ability to UV light is higher than that to violet light,whereas their reaction intensity is lower than to violet light,and the visual bio-regulatory force of locusts’visual system absorbing orange light to react sensitively becomes gradually higher than when absorbing green light as time goes on.Moreover,corresponding to nominal illumination with the same radiant energy and a visual spectrum response stimulated by UV,violet,orange,and green light,it appears that the visual spectrum window is symmetrical around 382 nm,400 nm,602 nm,and 530 nm,respectively,with no significant difference between spectral amplitudes and having a time-varying incremental characteristic with amplitude peak width.This indicates that the stimulus intensity of UV,violet,orange,and green light exceeds locusts’visual tolerance,causing them to generate regulation inactivation as a visual physiological reaction,whereas the visual window response effect stimulated by UV light presents an illumination timeliness effect.Simultaneously,time-varying characteristics of locusts’bio-behavior intensity show that light intensity can make up for locusts’visual sensitivity differences at various spectral wavelengths.Presented with differential response time,photosensitive behavior intensity,
基金Project supported by the National Key Basic Research Program of China(2013CB921800)the National Natural Science Foundation of China(11374291,11204292,11274299 and 11311120047)the Fundamental Research Funds for the Central Universities(WK2030020021)
文摘YBO3：2 at.% Eu3＋ was prepared by the solid state reaction and its temperature dependent luminescence was investigated for possible applications in temperature sensing. Phase composition of this material was confirmed by X-ray powder diffraction analysis and excitation and emission spectra were also provided. Under excitation of 355 nm, the fluorescence originating from 5D0 and 5D1 states varied as the temperature rose in a region from 333 to 773 K. The fluorescence intensity ratio （FIR） of SD0 and 5D1 was investigated which increased significantly with the rise of temperature. The maximal relative sensitivity in the whole temperature range was 1.8% K-1（at 333 K）. The results recommended YBO3：Eu3＋ as a new material of the FIR method for non-contact optical thermometry.
文摘The assessment of emotions with fractal dimensions of EEG signals has been attempted before, but the quantification of the intensity and duration of sudden and short emotions remains a challenge. This paper suggests a method for this purpose, by using a new fractal dimension algorithm and by adjusting the amplitude of the EEG signal in order to obtain maximal separation of high and low fractal dimensions. The emotion was induced by embedding a scary image at 20 seconds in landscape videos of 60 seconds length. The new method did not only detect the onset of the emotion correctly, but also revealed its duration and intensity. The intensity is based on the magnitude and impulse of the fractal dimension signal. It is also shown that Higuchi’s method does not always detect emotion spikes correctly;on the contrary, the region of the expected emotional response can be represented by fractal dimensions smaller than the rest of the signal, whereas the new method directly reveals distinct spikes. The duration of these spikes was 10 - 11 seconds. The magnitude of these spikes varied across the EEG channels. The build-up and cool-down of the emotions can occur with steep and flat gradients.
文摘利用X’Pert PRO X-射线衍射分析仪、分光光度仪等手段,系统评价了石英在60℃条件下,与5%HCl、5%HCl+0.5%HF、5%HCl+1.0%HF、0.5%HF、1.0%HF、8%HBF4和5%HCl+7%HBF4七种常见酸体系反应的化学行为,重点分析了酸液中可溶硅离子浓度变化特征及影响因素。研究表明:石英与HF酸、土酸反应快速强烈,前2h硅离子浓度波动大,是硅质沉淀形成的主要时期;与氟硼酸体系反应慢,达最大反应强度长于12h。酸蚀后矿物结构无明显变化,可溶硅离子浓度与长石矿物、粘土矿物上述酸化体系中平均浓度相近。通过快速返排残酸,使用低浓度的HF酸进行酸化,采用过量的后置酸液以及在酸化液中加入相应的阻垢剂可预防砂岩酸化时硅质沉淀的产生。
基金Project (No. 29775004) supported by the National Natural Science Foundation of China
文摘No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P+(CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be observed only.Each compound forms a very characteristic ion(O=PPbj-1)+ at m/z 277 through hydroxyl rearrangement reaction.The intensity of this ion is closely related with the size of the carbon chain of hydroxyalkyl and with temperature of ion source and temperature of sample probe.The above rearrangement reaction and the reaction to form ion at m/z 262 take place simultaneously,thus leading to strong competition.At n=2,ion at m/z 277 is the most powerful and becomes continuously the base peak.At n=3 and n=4,the intensity of ion at m/z 262 reaches the maximum,and is always the base peak,and the relative abundance of m/z 277 is only around 2%.At n=5,6,8,9,10,m/z 277 becomes base peak when the temperature of probe is below 300℃.But,when the temperature increases from 300℃to 350℃,m/z 262 suddenly becomes the base peak,which is not in direct proportional relation with the size of carbon chain.It is proved by MIKES and accurate mass that ion at m/z 277 produces a fragment ion(O=PPh2-2)+ at m/z 199 with the loss of the neutral benzene molecule.
基金Program for Chang Jiang Scholars and Innovative Research Team in University(PCSIRT,IRT0807)National Natural Science Foundation of China(51073008,51103005)the Fundamental Research Funds for the Central Universities in China
文摘A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR） and silicone rubber（SiR） were used as the substrate for Eu（TTA）3 AA to prepare fluorescence composites.The neat Eu（TTA）3 AA complex showed the ability of self-polymerization when it was heated at 145 °C.It was found that the fluorescence intensity of the neat Eu（TTA）3 AA decreased over 70% when the polymerization time was over 25 min at 145 °C.The results also revealed that the polymerizated Eu（TTA）3 AA could be dispersed in nano-scale in two matrices and the luminescent intensities decreased 52% in NBR matrix,and 95% in SiR matrix compared with two relative compounds without crosslinking.To optimize the luminescence intensity of the composites,the Eu（TTA）3 AA polymerization kinetic process in matrix was investigated in detail by controlling the temperature,the crosslinking agent,etc.The results showed that the peroxide could accelerate Eu（TTA）3 AA self-polymerization in the rubber matrix,and therefore improved the dispersion,but not be helpful for the luminescence intensity enhancement.In addition,the relatively higher luminescence intensity in Eu（TTA）3 AA/NBR in comparison to that of Eu（TTA）3 AA/SiR might contribute to the interaction between nitrile group（–CN） in NBR and Eu-complexes,suggesting that the luminescence intensity of the composites also depended on the matrix characteristics.
文摘利用X'Pert PRO X-射线衍射分析仪和分光光度仪,系统地评价石英在一定温度下与常见酸体系反应的化学行为,重点分析酸液中可溶硅离子浓度变化特征及影响因素。研究表明,石英与HF、土酸反应快速强烈,前2h硅离子浓度波动大,是硅质沉淀形成的主要时期,与氟硼酸体系反应慢,达最大反应强度需12h。酸蚀后矿物结构无明显变化,可溶硅离子浓度与长石矿物、粘土矿物上述酸化体系中平均浓度相近。通过快速反排残酸,使用低浓度的HF酸进行酸化,采用过量的后置酸液以及在酸化液中加入相应的阻垢剂可预防砂岩酸化时硅质沉淀的产生。
