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A 16-bit 18-MSPS flash-assisted SAR ADC with hybrid synchronous and asynchronous control logic

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Journal of Semiconductors 2024年第6期45卷 3-12页

作者： Junyao ji Xinao ji Ziyu Zhou Zhichao Dai Xuhui chen jie Zhang zheng jiang Hong Zhang School of Microelectronics Xi'an Jiaotong UniversityXi'an 710049China Qingdao Hi-image Tech.Co.Ltd. Qingdao 266100China

This paper presents a 16-bit,18-MSPS(million samples per second)flash-assisted successive-approximation-register(SAR)analog-to-digital converter(ADC)utilizing hybrid synchronous and asynchronous(HYSAS)timing control logic based on an on-chip delay-locked loop(DLL).The HYSAS scheme can provide a longer settling time for the capacitive digital-to-analog converter(CDAC)than the synchronous and asynchronous SAR ***,the issue of incomplete settling or ringing in the DAC voltage for cases of either on-chip or off-chip reference voltage can be solved to a large *** addition,the fore-ground calibration of the CDAC’s mismatch is performed with a finite-impulse-response bandpass filter(FIR-BPF)based least-mean-square(LMS)algorithm in an off-chip FPGA(field programmable gate array).Fabricated in 40-nm CMOS process,the proto-type ADC achieves 94.02-dB spurious-free dynamic range(SFDR),and 75.98-dB signal-to-noise-and-distortion ratio(SNDR)for a 2.88-MHz input under 18-MSPS sampling rate.

关键词： SAR ADC control logic reference ringing DAC incomplete settling

Ceramic-based meta-material absorber with high-temperature stability

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Rare Metals 2024年第9期43卷 4433-4440页

作者： Xing-Cong chen Wei-jia Luo Run-Ni Zhao Yong-zheng Wen ji Zhou State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua University

With the continuous exploration of uncharted and extreme environments,enhanced temperature robustness of passive devices has become particularly *** this study,a ceramic-based meta-material absorber with exceptional temperature stability is developed using a fusion design approach that combines rare metal-based tungsten bronze structural ceramics and ***,the absorbance of the meta-material array based on Mie resonance exceeds 49.0%in both waveguides and free space,approaching the theoretical *** to impedance analysis,the absorption performance can be distinctly correlated with the dielectric loss （Q_f）.Notably,the high-temperature robustness is verified to still be effective at 400℃.These advancements in our design allow for the use of monolithic materials in fabricating temperature-stable perfect absorbers,providing greater freedom in the dielectric performance and expanding their potential applications,including in space exploration and 5G millimeter-wave scenarios.

关键词： Meta-material absorber Microwave absorption Miniaturization Rare metal-based ceramics Temperature robustness

Theoretical and experimental study of a bi-stable piezoelectric energy harvester under hybrid galloping and band-limited random excitations

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 461-478页

作者： Haitao LI Tianyu zheng Weiyang QIN Ruilan TIAN Hu DING J.C.ji Liqun chen Department of Engineering Mechanics North University of ChinaTaiyuan 030051China Department of Engineering Mechanics Northwestern Polytechnical UniversityXi'an 710072China Department of Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang 050043China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechnoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China School of Mechanical and Mechatronic Engineering University of Technology SydneyNew South Wales 2007Australia

In the practical environment,it is very common for the simultaneous occurrence of base excitation and *** the combined energy of vibration and wind with a single energy harvesting structure is *** this purpose,the effects of the wind speed and random excitation level are investigated with the stochastic averaging method(SAM)based on the energy *** results of the analytical prediction are verified with the Monte-Carlo method(MCM).The numerical simulation shows that the introduction of wind can reduce the critical excitation level for triggering an inter-well jump and make a bi-stable energy harvester(BEH)realize the performance enhancement for a weak base ***,as the strength of the wind increases to a particular level,the influence of the random base excitation on the dynamic responses is weakened,and the system exhibits a periodic galloping response.A comparison between a BEH and a linear energy harvester(LEH)indicates that the BEH demonstrates inferior performance for high-speed *** experiments are conducted to investigate the validity of the theoretical prediction and numerical *** experimental findings also show that strong random excitation is favorable for the BEH in the range of low wind ***,as the speed of the incoming wind is up to a particular level,the disadvantage of the BEH becomes clear and evident.

关键词： bi-stability inter-well response galloping band-limited random

Modeling solubility of oxaprozin and irbesartan in biorelevant complex solutions based on a combination of pH-dependent and micellar solubilization models

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CHINESE JOURNAL OF CHEMICAL ENGINEERING 2024年第8期72卷 34-43页

作者： Shen, chen ji, Yuanhui Southeast Univ Sch Chem & Chem Engn Jiangsu Prov Hitech Key Lab Biomed Res Nanjing 211189 Peoples R China

Biological solubility is one of the important basic parameters in the development process of poorly soluble drugs, but the current measurement methods are mainly based on a large number of experiments, which are time-consuming and cost-intensive. There is still a lack of effective theoretical models to accurately describe and predict the biological solubility of drugs to reduce costs. Therefore, in this study, osaprazole and irbesartan were selected as model drugs, and their solubility in solutions containing surfactants and biorelevant media was measured experimentally. By calculating the parameters of each component using the perturbed-chain statistical associating fluid theory (PC-SAFT) model, combined with pH-dependent and micellar solubilization models, the thermodynamic phase behavior of the two drugs was successfully modeled, and the predicted results were in good agreement with the experimental values. These results demonstrate that the model combination used provides important basic parameters and theoretical guidance for the development and screening of poorly soluble drugs and related formulations. (c) 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Biorelevant media pH -dependent solubility Micellar solubilization PC-SAFT Active pharmaceutical ingredients POLYCYCLIC AROMATIC-HYDROCARBONS HUMAN GASTROINTESTINAL-TRACT PERTURBED-CHAIN SAFT THERMODYNAMIC MODEL DISSOLUTION MEDIA DRUG SURFACTANT TEMPERATURE BEHAVIOR SALT

Risk assessment of oil and gas investment environment in countries along the Belt and Road Initiative

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Petroleum Science 2024年第2期21卷 1429-1443页

作者： Bao-Jun Tang Chang-jing ji Yu-Xian zheng Kang-Ning Liu Yi-Fei Ma Jun-Yu chen Center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing100081China School of Management and Economics Beijing Institute of TechnologyBeijing100081China Collaborative Innovation Center of Electric Vehicles in Beijing BeijingChina Sustainable Development Research Institute for Economy and Society of Beijing BeijingChina Institute of Carbon Neutrality ShanghaiTech UniversityShanghai201210China

With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.

关键词： Belt and Road Initiative Oil and Gas Investment Risk assessment

Differences in Variations of Long-Lived and Short-Lived Summer Heat Waves during 1981-2020 over Eastern China and Their Corresponding Large-Scale Circulation Anomalies

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Journal of Meteorological Research 2024年第3期38卷 414-436页

作者： Liqun ji Haishan chen Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of EducationNanjing University of Information Science&TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing210044China

Using daily maximum temperature(Tmax)data from 516 observation stations in eastern China from 1981 to 2020,this study employed a relative threshold method to define short-and long-lived heat waves(HWs)by considering regional climate differences to investigate the spatial characteristics and evolution of large-scale circulation during summer *** results demonstrated spatial disparities in the frequency distribution of HWs of different durations and differences in the magnitude of duration and intensity between short-and long-lived *** orthogonal function analysis revealed three dominant spatial modes for both short-and long-lived *** first mode showed that short-lived HWs occur prominently in both northern and southern regions,whereas long-lived HWs mainly occur in the northern *** second mode was characterized by a meridional dipole pattern in both *** third mode exhibited a quadrupole pattern for short-lived HWs and a tripole pattern for long-lived *** in the center locations of anomalies in the 500-hPa geopotential height and 850-hPa wind fields significantly influenced the temperature and precipitation anomaly distribution of typical HWs by affecting the warm column in the lower troposphere,cloud distribution,and moisture ***,the atmospheric circulation evolution processes of typical HWs associated with the different modes of long-and short-lived HWs were linked to distinct teleconnection *** the three modes of long-lived(short-lived)HWs,there was stronger(weaker)wave flux activity with multiple(single)propagation *** westward Atlantic wave train activity at 300 hPa triggered the synergistic action of meridional and zonal wave fluxes,favoring the strengthening and maintenance of positive anomalies in geopotential height of 500 *** may have contributed to the formation of long-lived *** findings provide valuable insights to enhance our understanding and prediction of summer

关键词： short-lived heat waves(HWs) long-lived HWs empirical orthogonal function(EOF)modes large-scale atmospheric circulation

Shengmaisan combined with Liuwei Dihuang Decoction alleviates chronic intermittent hypoxia-induced cognitive impairment by activating the EPO/EPOR/JAK2 signaling pathway

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Chinese Journal of Natural Medicines 2024年第5期22卷 426-440页

作者： SI jianchao chen Xue QI Kerong LI Dongli LIU Bingbing zheng Yuying ji Ensheng YANG Shengchang Department of Physiology Hebei University of Chinese MedicineShijiazhuang 050000China Hebei Technology Innovation Center of TCM Combined Hydrogen Medicine Shijiazhuang 050000China Department of Geriatrics First People’s Hospital of XiaoganXiaogan 432000China

Chronic intermittent hypoxia(CIH),a principal pathophysiological aspect of obstructive sleep apnea(OSA),is associated with cognitive *** evidence suggests that a combination of Shengmaisan and Liuwei Dihuang Decoctions(SMS-LD)can enhance cognitive function by nourishing yin and strengthening the *** study aimed to assess the efficacy and underlying mechanisms of SMS-LD in addressing cognitive impairments induced by *** exposed C57BL/6N mice to CIH for five weeks(20%-5%O_(2),5 min/cycle,8 h/day)and administered SMS-LD intragastrically(15.0 or 30 g·kg^(-1)·day)30 min before each CIH ***,AG490,a JJanus kinase 2(JAK2)inhibitor,was administered via intracerebroventricular *** function was evaluated using the Morris water maze,while synaptic and mitochondrial structures were examined by transmission electron *** stress levels were determined using DHE staining,and the activation of the erythropoietin(ER)/ER receptor(EPOR)/JAK2 signaling pathway was analyzed through immunohistochemistry and Western *** further investigate molecular mechanisms,HT22 cells were treated in vitro with either SMS-LD medicated serum alone or in combination with AG490 and then exposed to CIH for 48 *** results indicate that SMS-LD significantly mitigated CIH-induced cognitive impairments in ***,SMS-LD treatment enhanced dendritic spine density,ameliorated mitochondrial dysfunction,reduced oxidative stress,and activated the EPO/EPOR/JAK2 signaling ***,AG490 negated SMS-LD’s neuroprotective and cognitive improvement effects under CIH *** findings suggest that SMS-LD’s beneficial impact on cognitive impairment and synaptic and mitochondrial integrity under CIH conditions may predominantly be attributed to the activation of the EPO/EPOR/JAK2 signaling pathway.

关键词： Chronic intermittent hypoxia Cognitive impairment Shengmaisan Liuwei Dihuang Decoction Oxidative stress EPO/EPOR/JAK2 signaling pathway

The neuroscience of pain,addiction,and anesthesia

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Zoological Research 2024年第3期45卷 709-710页

作者： ji Hu Ping zheng School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China State Key Laboratory of Medical Neurobiology Institutes of Brain ScienceMOE Frontier Center for Brain ScienceDepartment of Neurology of Zhongshan HospitalFudan UniversityShanghai 200032China

Researchers and clinicians have long been interested in the mechanisms of pain,anesthesia,and *** International Association for the Study of Pain(IASP)defines pain as an unpleasant sensory and emotional experience associated with,or resembling that associated with,actual or potential tissue damage(Raja et al.,2020).Drug addiction refers to a condition of reliance that develops from regular drug consumption,which may lead to withdrawal symptoms when use is *** involves the complete loss of consciousness induced by an inhaled or intravenous anesthetic(Tosello et al.,2022).In this special collection,Zoological Research presents research findings focused on pain,addiction,and anesthesia.

关键词： anesthesia damage

Boron nitride microribbons strengthened and toughened alumina composite ceramics with excellent mechanical,dielectric,and thermal conductivity properties

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Journal of Advanced Ceramics 2024年第4期13卷 496-506页

作者： jilin Wang Dongping Lu Weiping Xuan Yuchun ji Ruiqi chen Shaofei Li Wenbiao Li Wenzhuo chen Shilin Tang Guoyuan zheng Fei Long Guangxi Key Laboratory of Optical and Electronic Materials and Devices Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of ResourcesSchool of Materials Science and EngineeringGuilin University of TechnologyGuilin 541004China Key Laboratory of New Processing Technology for Nonferrous Metals and Materials of Ministry of Education Guilin University of TechnologyGuilin 541004China School of Materials Science and Engineering Peking UniversityBeijing 100871China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina

Aluminum oxide(Al_(2)O_(3))ceramics have been widely utilized as circuit substrates owing to their exceptional *** this study,boron nitride microribbon(BNMR)/Al_(2)O_(3)composite ceramics are prepared using spark plasma sintering(SPS).This study examines the effect of varying the amount of toughened phase BNMR on the density,mechanical properties,dielectric constant,and thermal conductivity of BNMR/Al_(2)O_(3)composite ceramics while also exploring the mechanisms behind the toughening and increased thermal conductivity of the fabricated *** results showed that for a BNMR content of 5 wt%,BNMR/Al_(2)O_(3)composite ceramics displayed more enhanced characteristics than pure Al_(2)O_(3)*** particular,the relative density,hardness,fracture toughness,and bending strength were 99.95%±0.025%,34.11±1.5 GPa,5.42±0.21 MPa·m^(1/2),and 375±2.5 MPa,*** values represent increases of 0.76%,70%,35%,and 25%,respectively,compared with the corresponding values for pure Al_(2)O_(3)***,during the SPS process,BNMRs are subjected to high temperatures and pressures,resulting in the bending and deformation of the Al_(2)O_(3)matrix;this leads to the formation of special thermal pathways within *** dielectric constant of the composite ceramics decreased by 25.6%,whereas the thermal conductivity increased by 45.6%compared with that of the pure Al_(2)O_(3)*** results of this study provide valuable insights into ways of enhancing the performance of Al_(2)O_(3)-based ceramic substrates by incorporating novel BNMRs as a second *** improvements are significant for potential applications in circuit substrates and related fields that require high-performance materials with improved mechanical properties and thermal conductivities.

关键词： boron nitride microribbons/aluminum oxide(BNMRs/Al_(2)O_(3))composite ceramics boron nitride microribbon(BNMR) spark plasma sintering(SPS) strengthening and toughening thermal conductivity