This paper presents a procedure to develop fragility curves of structures equipped with TMD considering multiple failure functions.The failure criteria considered are maximum inter-story drift ratio as a safety criter...This paper presents a procedure to develop fragility curves of structures equipped with TMD considering multiple failure functions.The failure criteria considered are maximum inter-story drift ratio as a safety criterion,maximum absolute acceleration as a convenience criterion and TMD stroke length.The relationship between intensity measure and responses of the structure was assumed to follow the power-law model,and a regression analysis was used to estimate its properties.A nonlinear eight-story shear building subjected to near-fault earthquakes was used for the numerical studies.Fragility curves using multiple and single failure functions for an uncontrolled structure and a structure equipped with optimal TMDs were developed.Numerical analysis showed that using multiple failure functions led to increasing the fragility when compared with using the single failure function for both the uncontrolled and controlled structures.However,TMDs slightly reduced the seismic fragility and have the capability to improve the reliability of the structure.Also,it was found that the fragility was significantly influenced by the values of the capacity thresholds of both the acceleration of the structure and TMD stroke length,which should be selected by considering the target performance and application of the structure and control device.展开更多
Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the pr...Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma.展开更多
This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulati...This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulation-mode MOS varactors(A-MOS)and two bias voltages.The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously,linearizing the effective capacitance and thus greatly reducing the amplitude-to-phase modulation(AM-PM)conversion.The circuit is validated by simulations and fabricated in a standard 0.18μm 1P6M CMOS process.Measured phase noise is lower than–91 dBc at 100 kHz offset from a 3.15 GHz carrier while measured tuning range is 21.5%as the control voltage varies from 0 to 1.8 V.The VCO including buffers consumes 2.8 mA current from a 1.8 V supply.展开更多
An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation tech...An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation technique,the frequency tuning curves agree well with the experiment.At a 3.3V supply,the LC-VCO measures a phase noise of -82.2dBc/Hz at a 10kHz frequency offset while dissipating 3.1mA current.The chip size is 0.86mm×0.82mm.展开更多
文摘This paper presents a procedure to develop fragility curves of structures equipped with TMD considering multiple failure functions.The failure criteria considered are maximum inter-story drift ratio as a safety criterion,maximum absolute acceleration as a convenience criterion and TMD stroke length.The relationship between intensity measure and responses of the structure was assumed to follow the power-law model,and a regression analysis was used to estimate its properties.A nonlinear eight-story shear building subjected to near-fault earthquakes was used for the numerical studies.Fragility curves using multiple and single failure functions for an uncontrolled structure and a structure equipped with optimal TMDs were developed.Numerical analysis showed that using multiple failure functions led to increasing the fragility when compared with using the single failure function for both the uncontrolled and controlled structures.However,TMDs slightly reduced the seismic fragility and have the capability to improve the reliability of the structure.Also,it was found that the fragility was significantly influenced by the values of the capacity thresholds of both the acceleration of the structure and TMD stroke length,which should be selected by considering the target performance and application of the structure and control device.
基金supported by the STI 2030-Major Projects 2022ZD0208500(to DY)the National Natural Science Foundation of China,Nos.82072011(to YX),82121003(to DY),82271120(to YS)+2 种基金Sichuan Science and Technology Program,No.2022ZYD0066(to YS)a grant from Chinese Academy of Medical Science,No.2019-12M-5-032(to YS)the Fundamental Research Funds for the Central Universities,No.ZYGX2021YGLH219(to KC)。
文摘Glaucoma is a leading cause of irreve rsible blindness wo rldwide,and previous studies have shown that,in addition to affecting the eyes,it also causes abnormalities in the brain.However,it is not yet clear how the primary visual cortex(V1)is altered in glaucoma.This study used DBA/2J mice as a model for spontaneous secondary glaucoma.The aim of the study was to compare the electrophysiological and histomorphological chara cteristics of neurons in the V1between 9-month-old DBA/2J mice and age-matched C57BL/6J mice.We conducted single-unit recordings in the V1 of light-anesthetized mice to measure the visually induced responses,including single-unit spiking and gamma band oscillations.The morphology of layerⅡ/Ⅲneurons was determined by neuronal nuclear antigen staining and Nissl staining of brain tissue sections.Eighty-seven neurons from eight DBA/2J mice and eighty-one neurons from eight C57BL/6J mice were examined.Compared with the C57BL/6J group,V1 neurons in the DBA/2J group exhibited weaker visual tuning and impaired spatial summation.Moreove r,fewer neuro ns were observed in the V1 of DBA/2J mice compared with C57BL/6J mice.These findings suggest that DBA/2J mice have fewer neurons in the VI compared with C57BL/6J mice,and that these neurons have impaired visual tuning.Our findings provide a better understanding of the pathological changes that occur in V1 neuron function and morphology in the DBA/2J mouse model.This study might offer some innovative perspectives regarding the treatment of glaucoma.
基金supported by the National High Technology Research and Development Program of China(No.2007AA12Z344)
文摘This paper presents a new CMOS LC-VCO with a 2.95–3.65 GHz tuning range.The large tuning range is achieved by tuning curve compensation using a novel varactor configuration,which is mainly composed of four accumulation-mode MOS varactors(A-MOS)and two bias voltages.The proposed varactor has the advantages of optimizing quality factor and tuning range simultaneously,linearizing the effective capacitance and thus greatly reducing the amplitude-to-phase modulation(AM-PM)conversion.The circuit is validated by simulations and fabricated in a standard 0.18μm 1P6M CMOS process.Measured phase noise is lower than–91 dBc at 100 kHz offset from a 3.15 GHz carrier while measured tuning range is 21.5%as the control voltage varies from 0 to 1.8 V.The VCO including buffers consumes 2.8 mA current from a 1.8 V supply.
文摘An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation technique,the frequency tuning curves agree well with the experiment.At a 3.3V supply,the LC-VCO measures a phase noise of -82.2dBc/Hz at a 10kHz frequency offset while dissipating 3.1mA current.The chip size is 0.86mm×0.82mm.
文摘目的评价感音神经性听力损失患者(耳蜗病变)与听神经病谱系障碍患者听觉系统的频率选择特异性,对比说明不同类型听力损失对听觉系统频率选择特异性的影响。方法使用测量心理物理调谐曲线(psychophysical tuning curve,PTC)的方法评价频率选择特异性,即当存在一个纯音信号,其频率和强度保持不变,加入另一个窄带噪声,噪声的中心频率和强度均发生变化,通过改变噪声的中心频率与强度掩蔽纯音信号,由此获得的窄带噪声中心频率与其强度的关系曲线。PTC越窄,尖部越尖锐说明频率选择特异性越好,使用测试频率与PTC曲线最小强度上10 d B的曲线宽度的比值(Q10dB)评价PTC曲线的尖锐程度。选取听力正常受试者11名,感音神经性听力损失受试者14例,听神经病谱系障碍患者17例,测量3个组受试者双耳在500Hz和1000Hz处的心理物理调谐曲线。结果听力正常受试者平均Q10dB结果为3.4±0.9,感音神经性听力损失受试者平均Q10d B结果为1.8±0.4,听神经病谱系障碍受试者平均Q10d B结果为3.5±1.0。听神经病谱系障碍患者组Q10 d B结果与听力正常组Q10dB结果间无显著性差异(P>0.05),而感音神经性听力损失组Q10dB结果与听力正常组(F=34.90,P<0.001)和听神经病谱系障碍组Q10dB结果间均存在显著性差异(F=31.09,P<0.001)。结论耳蜗病变会导致频率选择特异性障碍,而听神经病谱系障碍患者听觉系统的频率选择特异性可能基本正常。