The 1/fγ noise characteristic parameter Sfγ model in an n-MOSFET under DC hot carrier stress is studied. A method characterizing the MOSFET abilities of an anti-hot carrier with noise parameter Sfγ is presented. Th...The 1/fγ noise characteristic parameter Sfγ model in an n-MOSFET under DC hot carrier stress is studied. A method characterizing the MOSFET abilities of an anti-hot carrier with noise parameter Sfγ is presented. The hot carrier degradation effect of n-MOSFET in high-,mid-,and low gate stresses and its 1/fγ noise feature are studied. Experimental results agree well with the developed model.展开更多
It is found that ionizing-radiation can lead to the base current and the 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region of the em...It is found that ionizing-radiation can lead to the base current and the 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region of the emitter-base junction is the main source of the base surface 1/f noise. A model is developed which identifies the parameters and describes their interactive contributions to the recombination current at the surface of the space charge region. Based on the theory of carrier number fluctuation and the model of surface recombination current, a 1/f noise model is developed. This model suggests that 1/f noise degradations are the result of the accumulation of oxide-trapped charges and interface states. Combining models of ELDRS, this model can explain the reason why the 1/f noise degradation is more severe at a low dose rate than at a high dose rate. The radiations were performed in a Co60 source up to a total dose of 700 Gy（Si）. The low dose rate was 0.001 Gy（Si）/s and the high dose rate was 0.1 Gy（Si）/s. The model accords well with the experimental results.展开更多
In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AIGaN/GaN high electron mobility transistor （HEMT）. Based on both mobility fluctuation and carrier number fluctuati...In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AIGaN/GaN high electron mobility transistor （HEMT）. Based on both mobility fluctuation and carrier number fluctuation in a two- dimensional electron gas （2DEG） channel of AlGaN/GaN HEMT, a unified drain current 1/f noise model containing a piezoelectric polarization effect and hot carrier effect is built. The drain current 1/f noise induced by the piezoelectric polarization effect is distinguished from that induced by the hot carrier effect through experiments and simulations. The simulation results are in good agreement with the experimental results. Experiments show that after hot carrier injection, the drain current 1/f noise increases four orders of magnitude and the electrical parameter degradation Agm/gm reaches 54.9%. The drain current 1/f noise degradation induced by the piezoelectric effect reaches one order of magnitude; the electrical parameter degradation Agm/gm is 11.8%. This indicates that drain current 1/f noise of the GaN-based HEMT device is sensitive to the hot carrier effect and piezoelectric effect. This study provides a useful reliability characterization tool for the A1GaN/GaN HEMTs.展开更多
The 1/f noise in multiwalled carbon nanotubes bundles has been investigated between the frequency range of 0.1 to 30 Hz. At room temperature the noise spectrum is standard 1/f, and its level is proportional to the squ...The 1/f noise in multiwalled carbon nanotubes bundles has been investigated between the frequency range of 0.1 to 30 Hz. At room temperature the noise spectrum is standard 1/f, and its level is proportional to the square of the bias voltage. With decreasing temperature the noise level also decreases. At 4.2 K the noise level follows a non-monotonic dependence against the bias voltage, showing a peak at a certain bias voltage, meanwhile its frequency dependence also deviates from the 1/f trend. This anomalous behaviour is discussed within the picture of environmental quantum fluctuation of charge transport in the samples.展开更多
After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrela...After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrelating 1/f noise using the wavelet transform and deduces the relative expressions. The results of computer simulation show good effectiveness.展开更多
目的:探究核受体亚家族4A组成员1(nuclear receptor subfamily 4 group A member 1,Nr4a1)Nr4a1激动剂胞孢子酮B(cytosporone B,Csn-B)对小鼠噪声暴露后听力损失的治疗作用。方法:采用双氧水刺激HEI-OC1毛细胞系的方法构建氧化应激细胞...目的:探究核受体亚家族4A组成员1(nuclear receptor subfamily 4 group A member 1,Nr4a1)Nr4a1激动剂胞孢子酮B(cytosporone B,Csn-B)对小鼠噪声暴露后听力损失的治疗作用。方法:采用双氧水刺激HEI-OC1毛细胞系的方法构建氧化应激细胞模型;通过实时荧光定量PCR(quantitative real-time PCR,q PCR)检测细胞中Nr4a1的mRNA表达水平;分别通过细胞计数试剂盒(cell counting kit-8,CCK8)及流式细胞术的方法检测细胞活力和细胞凋亡水平以评估Csn-B预处理后经双氧水刺激的细胞状态。构建小鼠噪声性听力损失模型,运用qPCR和免疫荧光技术检测噪声暴露后Nr4a1在小鼠耳蜗中的表达;通过检测听性脑干反应(auditory brainstem response,ABR)评估噪声暴露后以及Csn-B连续治疗13 d后小鼠听力情况。结果:双氧水刺激后HEI-OC1毛细胞中Nr4a1表达上升,细胞活力显著下降,凋亡水平显著升高;Csn-B预处理HEI-OC1毛细胞经双氧水刺激,细胞活力显著高于对照组而凋亡水平则显著低于对照组。在体研究结果显示,噪声暴露后小鼠听力显著降低,Nr4a1在小鼠耳蜗中的表达水平显著升高。噪声暴露后经Csn-B治疗小鼠听力得到改善,主要表现为Click-ABR以及Tone Burst-ABR(4000、8000Hz处)阈值下降。结论:Nr4a1激动剂Csn-B增强内耳毛细胞对氧化应激损伤的抵御能力,部分改善噪声暴露后的小鼠听力。展开更多
The influence of positive bias temperature instability(PBTI)on 1/f noise performance is systematically investigated on n-channel fin field-effect transistor(FinFET).The FinFET with long and short channel(L=240 nm,16 n...The influence of positive bias temperature instability(PBTI)on 1/f noise performance is systematically investigated on n-channel fin field-effect transistor(FinFET).The FinFET with long and short channel(L=240 nm,16 nm respectively)is characterized under PBTI stress from 0 s to 104 s.The 1/f noise features are analyzed by using the unified physical model taking into account the contributions from the carrier number and channel mobility fluctuations.The I d-V g,I d-V d,I g-V g tests are conducted to support and verify the physical analysis in the PBTI process.It is found that the influence of the channel mobility fluctuations may not be neglected.Due to the mobility degradation in a short-channel device,the noise level of the short channel device also degrades.Trapping and trap generation regimes of PBTI occur in high-k layer and are identified based on the results obtained for the gate leakage current and 1/f noise.展开更多
Objective To study effects of Adenovirus -mediated Hath1 expression in guinea pig cochlea at one month after exposure to intensive noise. Methods Normal hearing guinea pigs, weighing 250-300g, received exposure to 200...Objective To study effects of Adenovirus -mediated Hath1 expression in guinea pig cochlea at one month after exposure to intensive noise. Methods Normal hearing guinea pigs, weighing 250-300g, received exposure to 200 rounds of impulse noise at 170 dB sound pressure level (SPL). The virus vector was inoculated into the left cochlea 1 month after noise exposure. Animals were tested using ABR and prepared for morphological examinations includeing immunocytochemistry and SEM 4 weeks after vector inoculation. Results The adenovirus mediated report gene expressed in the damaged area. There were no significant differences between treated and control animal in ABR threshold and morphologic changes. No new hair cells appeared in the Hath1 treated animals. Conclusion Forced hath1 over-expression in the cochlea 1 month after noise exposure does not lead to appearance of new hair cells.展开更多
A new analysis of a previously studied traveling agent model, showed that there is a relation between the degree of homogeneity of the medium where the agents move, agent motion patterns, and the noise generated from ...A new analysis of a previously studied traveling agent model, showed that there is a relation between the degree of homogeneity of the medium where the agents move, agent motion patterns, and the noise generated from their displacements. We proved that for a particular value of homogeneity, the system self organizes in a state where the agents carry out Lévy walks and the displacement signal corresponds to 1/f noise. Using probabilistic arguments, we conjectured that 1/f noise is a fingerprint of a statistical phase transition, from randomness (disorder) to predictability (order), and that it emerges from the contextuality nature of the system which generates it.展开更多
The branching ratios of ions and the angular distributions of electrons ejected from the Eu 4f^76p_（1/2）nd auto-ionizing states are investigated with the velocity-map-imaging technique.To populate the above auto-ion...The branching ratios of ions and the angular distributions of electrons ejected from the Eu 4f^76p_（1/2）nd auto-ionizing states are investigated with the velocity-map-imaging technique.To populate the above auto-ionizing states,the relevant bound Rydberg states have to be detected first.Two new bound Rydberg states are identified in the region between41150 cm^（-1）and 44580 cm^（-1）,from which auto-ionization spectra of the Eu 4f^76p_（1/2）nd states are observed with isolated core excitation method.With all preparations above,the branching ratios from the above auto-ionizing states to different final ionic states and the angular distributions of electrons ejected from these processes are measured systematically.Energy dependence of branching ratios and anisotropy parameters within the auto-ionization spectra are carefully analyzed,followed by a qualitative interpretation.展开更多
Low frequency noise has been investigated at room temperature for asymmetric double barrier magnetic tunnel junctions（DBMTJs）, where the coupling between the top and middle CoFeB layers is antiferromagnetic with a 0...Low frequency noise has been investigated at room temperature for asymmetric double barrier magnetic tunnel junctions（DBMTJs）, where the coupling between the top and middle CoFeB layers is antiferromagnetic with a 0.8-nm thin top Mg O barrier of the CoFeB/MgO/CoFe/CoFeB/MgO/CoFe B DBMTJ. At enough large bias, 1/f noise dominates the voltage noise power spectra in the low frequency region, and is conventionally characterized by the Hooge parameter αmag.With increasing external field, the top and bottom ferromagnetic layers are aligned by the field, and then the middle free layer rotates from antiparallel state（antiferromagnetic coupling between top and middle ferromagnetic layers） to parallel state. In this rotation process αmag and magnetoresistance-sensitivity-product show a linear dependence, consistent with the fluctuation dissipation relation. With the magnetic field applied at different angles（θ） to the easy axis of the free layer,the linear dependence persists while the intercept of the linear fit satisfies a cos（θ） dependence, similar to that for the magnetoresistance, suggesting intrinsic relation between magnetic losses and magnetoresistance.展开更多
文摘The 1/fγ noise characteristic parameter Sfγ model in an n-MOSFET under DC hot carrier stress is studied. A method characterizing the MOSFET abilities of an anti-hot carrier with noise parameter Sfγ is presented. The hot carrier degradation effect of n-MOSFET in high-,mid-,and low gate stresses and its 1/fγ noise feature are studied. Experimental results agree well with the developed model.
基金supported by the National Natural Science Foundation of China(Grant Nos.61076101 and 61204092)
文摘It is found that ionizing-radiation can lead to the base current and the 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region of the emitter-base junction is the main source of the base surface 1/f noise. A model is developed which identifies the parameters and describes their interactive contributions to the recombination current at the surface of the space charge region. Based on the theory of carrier number fluctuation and the model of surface recombination current, a 1/f noise model is developed. This model suggests that 1/f noise degradations are the result of the accumulation of oxide-trapped charges and interface states. Combining models of ELDRS, this model can explain the reason why the 1/f noise degradation is more severe at a low dose rate than at a high dose rate. The radiations were performed in a Co60 source up to a total dose of 700 Gy（Si）. The low dose rate was 0.001 Gy（Si）/s and the high dose rate was 0.1 Gy（Si）/s. The model accords well with the experimental results.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61076101,61204092,61334002,and JJ0500102508)
文摘In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AIGaN/GaN high electron mobility transistor （HEMT）. Based on both mobility fluctuation and carrier number fluctuation in a two- dimensional electron gas （2DEG） channel of AlGaN/GaN HEMT, a unified drain current 1/f noise model containing a piezoelectric polarization effect and hot carrier effect is built. The drain current 1/f noise induced by the piezoelectric polarization effect is distinguished from that induced by the hot carrier effect through experiments and simulations. The simulation results are in good agreement with the experimental results. Experiments show that after hot carrier injection, the drain current 1/f noise increases four orders of magnitude and the electrical parameter degradation Agm/gm reaches 54.9%. The drain current 1/f noise degradation induced by the piezoelectric effect reaches one order of magnitude; the electrical parameter degradation Agm/gm is 11.8%. This indicates that drain current 1/f noise of the GaN-based HEMT device is sensitive to the hot carrier effect and piezoelectric effect. This study provides a useful reliability characterization tool for the A1GaN/GaN HEMTs.
文摘The 1/f noise in multiwalled carbon nanotubes bundles has been investigated between the frequency range of 0.1 to 30 Hz. At room temperature the noise spectrum is standard 1/f, and its level is proportional to the square of the bias voltage. With decreasing temperature the noise level also decreases. At 4.2 K the noise level follows a non-monotonic dependence against the bias voltage, showing a peak at a certain bias voltage, meanwhile its frequency dependence also deviates from the 1/f trend. This anomalous behaviour is discussed within the picture of environmental quantum fluctuation of charge transport in the samples.
文摘After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrelating 1/f noise using the wavelet transform and deduces the relative expressions. The results of computer simulation show good effectiveness.
基金Project supported by the National Natural Science Foundation of China(Grant No.61634008).
文摘The influence of positive bias temperature instability(PBTI)on 1/f noise performance is systematically investigated on n-channel fin field-effect transistor(FinFET).The FinFET with long and short channel(L=240 nm,16 nm respectively)is characterized under PBTI stress from 0 s to 104 s.The 1/f noise features are analyzed by using the unified physical model taking into account the contributions from the carrier number and channel mobility fluctuations.The I d-V g,I d-V d,I g-V g tests are conducted to support and verify the physical analysis in the PBTI process.It is found that the influence of the channel mobility fluctuations may not be neglected.Due to the mobility degradation in a short-channel device,the noise level of the short channel device also degrades.Trapping and trap generation regimes of PBTI occur in high-k layer and are identified based on the results obtained for the gate leakage current and 1/f noise.
基金supported by a Natural ScienceFoundation of China (NSFC) grant (# 30571017) to SMYJoint Research Fund for Overseas Chinese Young Scholars by NSFC (# 30628030) to DH and SMYNIH grant R01 DC 004696 from the NIDCD to DH
文摘Objective To study effects of Adenovirus -mediated Hath1 expression in guinea pig cochlea at one month after exposure to intensive noise. Methods Normal hearing guinea pigs, weighing 250-300g, received exposure to 200 rounds of impulse noise at 170 dB sound pressure level (SPL). The virus vector was inoculated into the left cochlea 1 month after noise exposure. Animals were tested using ABR and prepared for morphological examinations includeing immunocytochemistry and SEM 4 weeks after vector inoculation. Results The adenovirus mediated report gene expressed in the damaged area. There were no significant differences between treated and control animal in ABR threshold and morphologic changes. No new hair cells appeared in the Hath1 treated animals. Conclusion Forced hath1 over-expression in the cochlea 1 month after noise exposure does not lead to appearance of new hair cells.
文摘A new analysis of a previously studied traveling agent model, showed that there is a relation between the degree of homogeneity of the medium where the agents move, agent motion patterns, and the noise generated from their displacements. We proved that for a particular value of homogeneity, the system self organizes in a state where the agents carry out Lévy walks and the displacement signal corresponds to 1/f noise. Using probabilistic arguments, we conjectured that 1/f noise is a fingerprint of a statistical phase transition, from randomness (disorder) to predictability (order), and that it emerges from the contextuality nature of the system which generates it.
基金Project supported by the National Natural Science Foundation of China(Grant No.11174218)
文摘The branching ratios of ions and the angular distributions of electrons ejected from the Eu 4f^76p_（1/2）nd auto-ionizing states are investigated with the velocity-map-imaging technique.To populate the above auto-ionizing states,the relevant bound Rydberg states have to be detected first.Two new bound Rydberg states are identified in the region between41150 cm^（-1）and 44580 cm^（-1）,from which auto-ionization spectra of the Eu 4f^76p_（1/2）nd states are observed with isolated core excitation method.With all preparations above,the branching ratios from the above auto-ionizing states to different final ionic states and the angular distributions of electrons ejected from these processes are measured systematically.Energy dependence of branching ratios and anisotropy parameters within the auto-ionization spectra are carefully analyzed,followed by a qualitative interpretation.
基金supported by the National Basic Research Program of China(Grant Nos.2011CBA00106,2012CB927400,2010CB934401,and 2014AA032904)the National High Technology Research and Development Program of China(Grant No.2014AA032904)the National Natural Science Foundation of China(Grant Nos.11434014 and 11104252)
文摘Low frequency noise has been investigated at room temperature for asymmetric double barrier magnetic tunnel junctions（DBMTJs）, where the coupling between the top and middle CoFeB layers is antiferromagnetic with a 0.8-nm thin top Mg O barrier of the CoFeB/MgO/CoFe/CoFeB/MgO/CoFe B DBMTJ. At enough large bias, 1/f noise dominates the voltage noise power spectra in the low frequency region, and is conventionally characterized by the Hooge parameter αmag.With increasing external field, the top and bottom ferromagnetic layers are aligned by the field, and then the middle free layer rotates from antiparallel state（antiferromagnetic coupling between top and middle ferromagnetic layers） to parallel state. In this rotation process αmag and magnetoresistance-sensitivity-product show a linear dependence, consistent with the fluctuation dissipation relation. With the magnetic field applied at different angles（θ） to the easy axis of the free layer,the linear dependence persists while the intercept of the linear fit satisfies a cos（θ） dependence, similar to that for the magnetoresistance, suggesting intrinsic relation between magnetic losses and magnetoresistance.
