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Post-layout simulation driven analog circuit sizing

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Science China(Information Sciences) 2024年第4期67卷 289-300页

作者： Xiaohan GAO Haoyi ZHANG Siyuan ye Mingjie liu David Z.PAN Linxiao SHEN runsheng WANG Yibo LIN ru HUANG School of Integrated Circuits Peking University School of Computer Science Peking University Department of Electrical and Computer Engineering University of Texas at Austin Institute of Electronic Design Automation Peking University

Post-layout simulation provides accurate guidance for analog circuit design, but post-layout performance is hard to be directly optimized at early design stages. Prior work on analog circuit sizing often utilizes pre-layout simulation results as the optimization objective. In this work, we propose a post-layoutsimulation-driven(post-simulation-driven for short) analog circuit sizing framework that directly optimizes the post-layout simulation performance. The framework integrates automated layout generation into the optimization loop of transistor sizing and leverages a coupled Bayesian optimization algorithm to search for the best post-simulation performance. Experimental results demonstrate that our framework can achieve over 20% better post-layout performance in competitive time than manual design and the method that only considers pre-layout optimization.

关键词： analog EDA transistor sizing Bayesian optimization post-layout simulation

Endogenous biosynthesis of docosahexaenoic acid(DHA)regulates fish oocyte maturation by promoting pregnenolone production

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Zoological Research 2024年第1期45卷 176-188页

作者： Yi Li Xuehui Li Ding ye ru Zhang Chengjie liu Mudan He Houpeng Wang Wei Hu Yonghua Sun State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyInnovation Academy for Seed DesignChinese Academy of SciencesWuhanHubei 430072China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China Hubei Hongshan Laboratory WuhanHubei 430070China

Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including ***,the underlying mechanism related to this phenomenon remains largely *** this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and *** show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype *** deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone *** study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during *** turn,the hypothalamic-pituitary-gonadal axis was enhanced by *** conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.

关键词： Docosahexaenoic acid Oocyte maturation Oocyte quality Pregnenolone Microtubule

Research progress and prospect of low-carbon biological technology for nitrate removal in wastewater treatment

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 1-21页

作者： ru Zheng Kuo Zhang Lingrui Kong Sitong liu College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China Key Laboratory of Water and Sediment Sciences Ministry of Education of ChinaBeijing 100871China Eco-Environment and Resource Efficiency Research Laboratory School of Environment and EnergyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Wastewater treatment plants are the major energy consumers and significant sources of greenhouse gas emissions,among which biological nitrogen removal of wastewater is an important contributor to carbon ***,traditional heterotrophic denitrification still has the problems of excessive residual sludge and the requirement of external carbon ***,the development of innovative low-carbon nitrate removal technologies is *** review outlines the key roles of sulfur autotrophic denitrification and hydrogen autotrophic denitrification in low-carbon wastewater *** discovered nitrate/nitrite dependent anaerobic methane oxidation enables sustainable methane emission reduction and nitrogen removal by utilizing available methane in *** microorganisms exhibited a promising potential to achieve carbon-negative nitrate ***,the algal-bacterial symbiosis system and photogranules offer effective and prospective low-carbon options for nitrogen ***,the emerging nitrate removal technology of photoelectrotrophic denitrification and the underlying,photoelectron transfer mechanisms are ***,we summarize and prospect these technologies,highlighting that solar-driven biological nitrogen removal technology is a promising area for future sustainable wastewater *** review has important guiding significance for the design of low-carbon wastewater treatment systems.

关键词： Carbon emissions Low-carbon Biological nitrogen removal Denitrification

Upconversion luminescence and temperature sensing performance of Er^(3+) ions doped self-activated KYb(MoO_(4))_(2) phosphors

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Journal of Rare Earths 2024年第8期42卷 1507-1513,I0004页

作者： ye Tong Wenpeng liu Shoujun Ding School of Microelectronics and Data Science Anhui University of TechnologyMaanshan243002China Advanced Laser Technology Laboratory of Anhui Province Hefei230037China Anhui Institute of Optics and Fine Mechanics Chinese Academy of SciencesHefei230031China

In this work,a series of self-activated KYb(MoO_(4))_(2) phosphors with various x at% Er^(3+) doping concentrations(x=0.5,1,3,5,8,10,15) was synthesized by the solid-state reaction *** phase structure of the as-prepared samples was analyzed by X-ray diffraction(XRD),XRD Rietveld refinement and Fourier transform infrared(FT-IR) *** as-prepared samples retain the orthorhombic structure with space group of Pbcn even Er^(3+) doping concentration up to 15 at%.High-purity upconversion(UC) green emission with green to red intensity ratio of 55 is observed from the as-prepared samples upon the excitation of 980 nm semiconductor laser and the optimum doping concentration of Er^(3+) ions in the self-activated KYb(MoO_(4))_(2) host is revealed as 3 at%.The strong green UC emission is confirmed as a two-photon process based on the power-dependent UC *** addition,the fluorescence intensity ratios(FIRs) of the two thermally-coupled energy levels,namely ^(2)H_(11/2) and ^(4)S_(3/2).of Er^(3+) ions were investigated in the temperature region 300-570 K to evaluate the optical temperature sensor behavior of the *** maximum relative sensitivity(S_(R)) is determined to be 0.0069 K^(-1) at300 K and the absolute sensitivity(S_(A)) is determined to be 0.0126 K^(-1) at 300 *** S_(A) of self-activated KYb(MoO_(4))2:Er^(3+)is almost twice that of traditional KY(MoO_(4))2:Er^(3+)/Yb^(3+)codoping *** results demonstrate that Er^(3+) ions doped self-activated KYb(MoO_(4))2 phosphor has promising application in visible display,trademark security and optical temperature sensors.

关键词： Er^(3+)ions doped KYb(MoO_(4))_(2) Self-activated phosphors Upconversion luminescence Solid-state reaction method Optical temperature sensors Rare earths

Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

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Nuclear Science and Techniques 2024年第1期35卷 81-95页

作者： Ming Xia Yong-Jun ye Shu-Yuan liu School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001China

Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the *** these measurement methods,the closed-loop method is frequently ***,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation *** CFD-based technique was applied to predict the radon concentration distribution in a limited space,allowing radon accumulation and exhalation inside the chamber intuitively and *** this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the *** consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was *** effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were *** on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion *** CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate.

关键词： Radon exhalation Numerical simulation Accumulation chamber

Modeling and analysis of air combustion and steam regeneration in methanol to olefins processes

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Chinese Journal of Chemical Engineering 2024年第2期66卷 94-103页

作者： Jinqiang Liang Danzhu liu Shuliang Xu Mao ye Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116021China University of Chinese Academy of Sciences Beijing 100049China

Light olefins is the incredibly important materials in chemical *** to olefins(MTO),which provides a non-oil route for light olefins production,received considerable attention in the past ***,the catalyst deactivation is an inevitable feature in MTO processes,and regeneration,therefore,is one of the key steps in industrial MTO *** the MTO catalyst is regenerated by removing the deposited coke via air combustion,which unavoidably transforms coke into carbon dioxide and reduces the carbon utilization *** study shows that the coke species over MTO catalyst can be regenerated via steam,which can promote the light olefins yield as the deactivated coke species can be essentially transferred to industrially useful synthesis gas,is a promising pathway for further MTO processes *** this work,we modelled and analyzed these two MTO regeneration methods in terms of carbon utilization efficiency and technology *** shown,the steam regeneration could achieve a carbon utilization efficiency of 84.31%,compared to 74.74%for air combustion *** MTO processes using steam regeneration can essentially achieve the near-zero carbon *** addition,light olefins production of the MTO processes using steam regeneration is 12.81%higher than that using air combustion *** this regard,steam regeneration could be considered as a potential yet promising regeneration method for further MTO processes,showing not only great environmental benefits but also competitive economic performance.

关键词： Model Methanol to olefins Regeneration Greenhouse gas Processes simulation

Enhancing blocking temperature using inverse hydrogen bonds for non-radical bridged dimeric Dy(Ⅲ) single-molecule magnets

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Science China Chemistry 2024年第10期67卷 3328-3338页

作者： Peng-Bo Jin Qian-Cheng Luo ye-ye liu Yan-Zhen Zheng Frontier Institute of Science and Technology State Key Laboratory of Electrical Insulation and Power EquipmentMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi'an Key Laboratory of Electronic Devices and Material Chemistry and School of ChemistryXi'an Jiaotong University

Single-molecule magnets（SMMs） are a kind of nanosized magnetic materials that are capable of storing massive bytes of *** coupling the spin centers in a proper manner is a usual approach to promote the working temperature（or blocking temperature） for *** delocalized radicals have been widely employed to accomplish this ***,we show a new manner by using weak but multiple B–Hδ-···Dy3+inverse hydrogen bonding（IHB） interactions to control the magnetic couplings in a series of dimeric dysprosiacaborane *** approach leads to a record high TB100sof 10 K among non-radical bridged dimeric SMMs,which is mainly ascribed to strong ferromagnetic coupling(4.38 cm-1) and the proper alignment of the magnetic principle axes of the adjacent dysprosium（Ⅲ） *** verifying by theoretical calculations,these results demonstrate that IHB interactions can be used to construct strong axial ferromagnetic coupling and enhancing magnetic blocking temperature for SMMs.

关键词： single-molecule magnets carborane dysprosium ferromagnetic coupling inverse hydrogen bond

Disturbance failure mechanism of highly stressed rock in deep excavation:Current status and prospects

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 611-627页

作者： Tao Wang Weiwei ye Liyuan liu Kai liu Naisheng Jiang Xianhui Feng School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China Department of Engineering Science University of OxfordParks RoadOxford OX13PJUK School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

This article reviews the current status on the dynamic behavior of highly stressed rocks under ***,the experimental apparatus,methods,and theories related to the disturbance dynamics of deep,high-stress rock are reviewed,followed by the introduction of scholars’research on deep rock deformation and failure from an energy ***,with a backdrop of highstress phenomena in deep hard rock,such as rock bursts and core disking,we delve into the current state of research on rock microstructure analysis and residual stresses from the perspective of studying the energy storage mechanisms in ***,the current state of research on the mechanical response and the energy dissipation of highly stressed rock formations is briefly ***,the insufficient aspects in the current research on the disturbance and failure mechanisms in deep,highly stressed rock formations are summarized,and prospects for future research are *** work provides new avenues for the research on the mechanical response and damage-fracture mechanisms of rocks under high-stress conditions.

关键词： deep rock with high stress highly stressed rock rock failure residual stress energy release

Accelerating H^(*)desorption of hollow Mo_(2)C nanoreactor via in-situ grown carbon dots for electrocatalytic hydrogen evolution

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Journal of Energy Chemistry 2024年第9期96卷 464-471页

作者： Mengmeng liu Yuanyuan Jiang Zhuwei Cao Lulu liu Hong Chen Sheng ye School of Materials and Chemistry Anhui Agricultural UniversityHefei 230036AnhuiChina

Molybdenum carbide(Mo_(2)C)is a promising non-noble metal electrocatalyst with electronic structures similar to Pt for hydrogen evolution reaction(HER).However,strong H^(*)adsorption at the Mo sites hinders the improvement of HER ***,we synthesized monodisperse hollow Mo_(2)C nanoreactors,in which the carbon dots(CD)were in situ formed onto the surface of Mo_(2)C through carburization *** to finite element simulation and analysis,the CD@Mo_(2)C possesses better mesoscale diffusion properties than Mo_(2)C *** optimized CD@Mo_(2)C nanoreactor demonstrates superior HER performance in alkaline electrolyte with a low overpotential of 57 mV at 10 mA cm^(−2),which is better than most Mo_(2)C-based ***,CD@Mo_(2)C exhibits excellent electrochemical stability during 240 h,confirmed by operando Raman and X-ray diffraction(XRD).Density functional theory(DFT)calculations show that carbon dots cause the d-band center of CD@Mo_(2)C to shift away from Fermi level,promoting water dissociation and the desorption of H^(*).This study provides a reasonable strategy towards high-activity Mo-based HER eletrocatalysts by modulating the strength of Mo–H bonds.

关键词： Mo_(2)C nanoreactor Carbon dots H^(*)desorption Electrocatalytic hydrogen evolution