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Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips
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作者 Jie Ren Yunfeng li +3 位作者 mingyu li Xingyu Wu Jiabao Wang Qingxuan Zeng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期309-316,共8页
Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ... Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems. 展开更多
关键词 Copper-based azide chips SPECTROPHOTOMETRY Separation method Quantitative analysis Ignition ability
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An Intelligent Control Method for the Low-Carbon Operation of Energy-Intensive Equipment
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作者 Tianyou Chai mingyu li +3 位作者 Zheng Zhou Siyu Cheng Yao Jia Zhiwei Wu 《Engineering》 SCIE EI CAS CSCD 2023年第8期84-95,共12页
Based on an analysis of the operational control behavior of operation experts on energy-intensive equipment,this paper proposes an intelligent control method for low-carbon operation by combining mechanism analysis wi... Based on an analysis of the operational control behavior of operation experts on energy-intensive equipment,this paper proposes an intelligent control method for low-carbon operation by combining mechanism analysis with deep learning,linking control and optimization with prediction,and integrating decision-making with control.This method,which consists of setpoint control,self-optimized tuning,and tracking control,ensures that the energy consumption per tonne is as low as possible,while remaining within the target range.An intelligent control system for low-carbon operation is developed by adopting the end-edge-cloud collaboration technology of the Industrial Internet.The system is successfully applied to a fused magnesium furnace and achieves remarkable results in reducing carbon emissions. 展开更多
关键词 Energy-intensive equipment Low-carbon operation Intelligent control End-edge-cloud collaboration technology
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Study on theoretical model for electrical explosion resistivity of Al/Ni reactive multilayer foil
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作者 Zehao Wang Tao Wang +2 位作者 Pengfei Xue mingyu li Qingxuan Zeng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期348-356,共9页
Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization ... Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization of EFIs.Al/Ni RMF with different bilayer thicknesses and bridge dimensions were prepared by MEMS technology and electrical explosion tests were carried out.According to physical and chemical reactions in bridge,the electrical explosion process was divided into 5 stages:heating of condensed bridge,vaporization and diffusion of Al layers,intermetallic combination reaction,intrinsic explosion,ionization of metal gases,which are obviously shown in measured voltage curve.Effects of interface and grain boundary scattering on the resistivity of film metal were considered.Focusing on variations of substance and state,the resistivity was developed as a function of temperature at each stage.Electrical explosion curves were calculated by this model at different bilayer thicknesses,bridge dimensions and capacitor voltages,which showed an excellent agreement with experimental ones. 展开更多
关键词 Al/Ni reactive multilayer foil Electrical explosion Resistivity model Phase transition CALCULATION
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Prediction of Ground Vibration Induced by Rock Blasting Based on Optimized Support Vector Regression Models
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作者 Yifan Huang Zikang Zhou +1 位作者 mingyu li Xuedong Luo 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3147-3165,共19页
Accurately estimating blasting vibration during rock blasting is the foundation of blasting vibration management.In this study,Tuna Swarm Optimization(TSO),Whale Optimization Algorithm(WOA),and Cuckoo Search(CS)were u... Accurately estimating blasting vibration during rock blasting is the foundation of blasting vibration management.In this study,Tuna Swarm Optimization(TSO),Whale Optimization Algorithm(WOA),and Cuckoo Search(CS)were used to optimize two hyperparameters in support vector regression(SVR).Based on these methods,three hybrid models to predict peak particle velocity(PPV)for bench blasting were developed.Eighty-eight samples were collected to establish the PPV database,eight initial blasting parameters were chosen as input parameters for the predictionmodel,and the PPV was the output parameter.As predictive performance evaluation indicators,the coefficient of determination(R2),rootmean square error(RMSE),mean absolute error(MAE),and a10-index were selected.The normalizedmutual information value is then used to evaluate the impact of various input parameters on the PPV prediction outcomes.According to the research findings,TSO,WOA,and CS can all enhance the predictive performance of the SVR model.The TSO-SVR model provides the most accurate predictions.The performances of the optimized hybrid SVR models are superior to the unoptimized traditional prediction model.The maximum charge per delay impacts the PPV prediction value the most. 展开更多
关键词 Blasting vibration metaheuristic algorithms support vector regression peak particle velocity normalized mutual information
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Physics-informed deep learning for fringe pattern analysis
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作者 Wei Yin Yuxuan Che +6 位作者 Xinsheng li mingyu li Yan Hu Shijie Feng Edmund Y.Lam Qian Chen Chao Zuo 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第1期4-15,共12页
Recently,deep learning has yielded transformative success across optics and photonics,especially in optical metrology.Deep neural networks (DNNs) with a fully convolutional architecture (e.g.,U-Net and its derivatives... Recently,deep learning has yielded transformative success across optics and photonics,especially in optical metrology.Deep neural networks (DNNs) with a fully convolutional architecture (e.g.,U-Net and its derivatives) have been widely implemented in an end-to-end manner to accomplish various optical metrology tasks,such as fringe denoising,phase unwrapping,and fringe analysis.However,the task of training a DNN to accurately identify an image-to-image transform from massive input and output data pairs seems at best naive,as the physical laws governing the image formation or other domain expertise pertaining to the measurement have not yet been fully exploited in current deep learning practice.To this end,we introduce a physics-informed deep learning method for fringe pattern analysis (PI-FPA) to overcome this limit by integrating a lightweight DNN with a learning-enhanced Fourier transform profilometry (Le FTP) module.By parameterizing conventional phase retrieval methods,the Le FTP module embeds the prior knowledge in the network structure and the loss function to directly provide reliable phase results for new types of samples,while circumventing the requirement of collecting a large amount of high-quality data in supervised learning methods.Guided by the initial phase from Le FTP,the phase recovery ability of the lightweight DNN is enhanced to further improve the phase accuracy at a low computational cost compared with existing end-to-end networks.Experimental results demonstrate that PI-FPA enables more accurate and computationally efficient single-shot phase retrieval,exhibiting its excellent generalization to various unseen objects during training.The proposed PI-FPA presents that challenging issues in optical metrology can be potentially overcome through the synergy of physics-priors-based traditional tools and data-driven learning approaches,opening new avenues to achieve fast and accurate single-shot 3D imaging. 展开更多
关键词 optical metrology deep learning physics-informed neural networks fringe analysis phase retrieval
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Safe and Stable Lithium Metal Batteries Enabled by an Amide-Based Electrolyte 被引量:2
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作者 Wanbao Wu Yiyang Bo +8 位作者 Deping li Yihong liang Jichuan Zhang Miaomiao Cao Ruitian Guo Zhenye Zhu lijie Ci mingyu li Jiaheng Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第3期120-133,共14页
The formation of lithium dendrites and the safety hazards arising from flammable liquid electrolytes have seriously hindered the development of high-energy-density lithium metal batteries.Herein,an emerging amide-base... The formation of lithium dendrites and the safety hazards arising from flammable liquid electrolytes have seriously hindered the development of high-energy-density lithium metal batteries.Herein,an emerging amide-based electrolyte is proposed,containing LiTFSI and butyrolactam in different molar ratios.1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropylether and fluoroethylene carbonate are introduced into the amide-based electrolyte as counter solvent and additives.The well-designed amide-based electrolyte possesses nonflammability,high ionic conductivity,high thermal stability and electrochemical stability(>4.7 V).Besides,an inorganic/organic-rich solid electrolyte interphase with an abundance of LiF,Li3N and Li-N-C is in situ formed,leading to spherical lithium deposition.The formation mechanism and solvation chemistry of amide-based electrolyte are further inves-tigated by molecular dynamics simulations and density functional theory.When applied in Li metal batteries with LiFePO4 and LiMn2O4 cathode,the amide-based electrolyte can enable stable cycling performance at room temperature and 60℃.This study provides a new insight into the development of amide-based electrolytes for lithium metal batteries. 展开更多
关键词 Amide-based electrolyte NONFLAMMABLE Inorganic/organic-rich solid electrolyte interphase Dendrite-free Lithium metal batteries
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Influence of Thermal Cycling on the Microstructure and Shear Strength of Sn3.5Ag0.75Cu and Sn63Pb37 Solder Joints on Au/Ni Metallization
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作者 Hongtao CHEN Chunqing WANG +1 位作者 mingyu li Dewen TIAN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2007年第1期68-72,共5页
The influence of thermal cycling on the microstructure and joint strength of Sn3.5Ag0.75Cu (SAC) and Sn63Pb37 (SnPb) solder joints was investigated. SAC and SnPb solder balls were soldered on 0.1 and 0.9 μm Au fi... The influence of thermal cycling on the microstructure and joint strength of Sn3.5Ag0.75Cu (SAC) and Sn63Pb37 (SnPb) solder joints was investigated. SAC and SnPb solder balls were soldered on 0.1 and 0.9 μm Au finished metallization, respectively. After 1000 thermal cycles between -40℃ and 125℃, a very thin intermetallic compound (IMC) layer containing Au, Sn, Ni, and Cu formed at the interface between SAC solder joints and underneath metallization with 0.1 μm Au finish, and (Au, Ni, Cu)Sn4 and a very thin AuSn-Ni-Cu IMC layer formed between SAC solder joints and underneath metallization with 0.9 μm Au finish. For SnPb solder joints with 0.1 μm Au finish, a thin (Ni, Cu, Au)3Sn4 IMC layer and a Pb-rich layer formed below and above the (Au, Ni)Sn4 IMC, respectively. Cu diffused through Ni layer and was involved into the IMC formation process. Similar interfacial microstructure was also found for SnPb solder joints with 0.9μm Au finish. The results of shear test show that the shear strength of SAC solder joints is consistently higher than that of SnPb eutectic solder joints during thermal cycling. 展开更多
关键词 Sn3.5Ag0.75Cu Solder joint Au finish Intermetallic compound
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Atmospheric and oceanic responses to Super Typhoon Mangkhut in the South China Sea:a coupled CROCO-WRF simulation 被引量:1
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作者 mingyu li Yijun HE Guoqiang liU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第4期1369-1388,共20页
The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense ... The South China Sea(SCS)is the largest marginal sea in the Northwest Pacific Ocean,and it encounters frequent typhoons.The atmosphere and ocean will create significant thermal and dynamic responses during the intense disturbance caused by typhoons.However,these responses have not been thoroughly investigated owing to the complicated marine environment.According to the satellite data,the SCS Basin was observed to have a strong sea surface temperature(SST)response to Typhoon Mangkhut,resulting in widespread SST cooling.A coupled model was used to investigate the atmospheric and oceanic responses to Typhoon Mangkhut.Best-track data,satellite SST,and ARGO measurements show that the coupled WRF-CROCO simulation displays better track,intensity,SST,temperature,and salinity profiles than those of the WRF-only simulation.Results show that the typhoon induced rightward intensifications in wind speed,ocean current,and SST.The following are some remarkable atmosphere and ocean responses:(1)the SST below the inner-core region is cooled by 1℃,resulting in a 37%-44%decrease in wet enthalpy,and the central pressure is increased by~9 hPa.Therefore,the changes in SST below the innercore region of the SCS Basin have a significant impact on air-sea fluxes under high-wind conditions;(2)the ocean boundary layer analysis shows that near-inertial oscillations on the right side of the typhoon track and a strong inertial current up to~2.28 m/s in the upper ocean were observed,which resonated with the local wind and flow field on the right side and induced strong SST cooling;(3)a decrease in SST decreased the moist static energy of the typhoon boundary layer,thereby weakening the typhoon’s intensity.The difference in equivalent potential temperature and sea surface pressure have a good correlation,indicating that the influence of moist static energy on typhoon intensity cannot be overlooked. 展开更多
关键词 Super Typhoon Mangkhut coupled ocean-atmosphere model wet enthalpy inertial current
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Mortality from cerebrovascular diseases in China:Exploration of recent and future trends 被引量:1
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作者 Bin Lv Ge Song +8 位作者 Feng Jing mingyu li Hua Zhou Wanjun li Jiacai lin Shengyuan Yu Jun Wang Xiangyu Cao Chenglin Tian 《Chinese Medical Journal》 SCIE CAS CSCD 2024年第5期588-595,共8页
Background:Cerebrovascular disease(CVD)ranks among the foremost factors responsible for mortality on a global scale.The mortality patterns of CVDs and temporal trends in China need to be well-illustrated and updated.M... Background:Cerebrovascular disease(CVD)ranks among the foremost factors responsible for mortality on a global scale.The mortality patterns of CVDs and temporal trends in China need to be well-illustrated and updated.Methods:We collected mortality data on patients with CVD from Chinese Center for Disease Control and Prevention’s Disease Surveillance Points(CDC-DSP)system.The mortality of CVD in 2020 was described by age,sex,residence,and region.The temporal trend from 2013 to 2019 was evaluated using joinpoint regression,and estimated rates of decline were extrapolated until 2030 using time series models.Results:In 2019,the age-standardized mortality in China(ASMRC)per 100,000 individuals was 113.2.The ASMRC for males(137.7/10^(5))and rural areas(123.0/10^(5))were both higher when stratified by gender and urban/rural residence.The central region had the highest mortality(126.5/10^(5)),the western region had a slightly lower mortality(123.5/10^(5)),and the eastern region had the lowest mortality(97.3/10^(5)).The age-specific mortality showed an accelerated upward trend from aged 55-59 years,with maximum mortality observed in individuals over 85 years of age.The age-standardized mortality of CVD decreased by 2.43%(95%confidence interval,1.02-3.81%)annually from 2013 to 2019.Notably,the age-specific mortality of CVD increased from 2013 to 2019 for the age group of over 85 years.In 2020,both the absolute number of CVD cases and the crude mortality of CVD have increased compared to their values in 2019.The estimated total deaths due to CVD were estimated to reach 2.3 million in 2025 and 2.4 million in 2030.Conclusion:The heightened focus on the burden of CVD among males,rural areas,the central and western of China,and individuals aged 75 years and above has emerged as a pivotal determinant in further decreasing mortalities,consequently presenting novel challenges to strategies for disease prevention and control. 展开更多
关键词 Cerebrovascular diseases MORTALITY EPIDEMIOLOGY Global Burden of Disease China COVID-19 pandemic
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抗癌药物引发间质性肺疾病流行病学及危险因素的研究现状
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作者 李明宇(综述) 高丽(审校) 《中国肿瘤临床》 CAS CSCD 北大核心 2023年第16期850-854,共5页
间质性肺疾病(interstitial lung disease,ILD)病因复杂多样,药物性间质性肺疾病(drug-induced interstitial lung disease,DIILD)又称药物性肺炎或药物性肺毒性,受抗癌药物作用机理及不同癌症发病率等多方面影响,不同种类抗癌药物诱发D... 间质性肺疾病(interstitial lung disease,ILD)病因复杂多样,药物性间质性肺疾病(drug-induced interstitial lung disease,DIILD)又称药物性肺炎或药物性肺毒性,受抗癌药物作用机理及不同癌症发病率等多方面影响,不同种类抗癌药物诱发DIILD发生率存在差异,并且某些抗癌药物相关DIILD的发生常预示着预后不良甚至高死亡率。然而与药物性肝肾损伤相比,药物性肺炎未引起足够的重视。目前多部专家共识对抗癌药物相关DIILD的诊断及治疗提出指导,但抗癌药物种类繁多,且治疗方案受到肿瘤类型的影响,某一类药物诱发DIILD的具体特征有待进一步阐明。本文对已发表的抗癌药物相关DIILD流行病学及危险因素进行综述,以期为进一步认识此类药物的不良事件提供帮助。 展开更多
关键词 抗癌药物 间质性肺疾病 药物性间质性肺疾病
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A systematic review of the inequality of health burdens related to climate change
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作者 Xinke Song Shihui Zhang +7 位作者 Hai Huang Qun Ding Fang Guo Yaxin Zhang Jin li mingyu li Wenjia Cai Can Wang 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2024年第5期137-153,共17页
Climate change significantly impacts human health,exacerbating existing health inequalities and creating new ones.This study addresses the lack of systematic review in this area by analyzing 2440 publications,focusing... Climate change significantly impacts human health,exacerbating existing health inequalities and creating new ones.This study addresses the lack of systematic review in this area by analyzing 2440 publications,focusing on four key terms:health,disparities,environmental factors,and climate change.Strict inclusion criteria limited the selection to English-language,peer-reviewed articles related to climate health hazards,ensuring the relevance and rigor of the synthesized studies.This process synthesized 65 relevant studies.Our investigation revealed that recent research,predominantly from developed countries,has broadened its scope beyond temperature-related impacts to encompass diverse climate hazards,including droughts,extreme weather,floods,mental health issues,and the intersecting effects of Coronavirus Disease 2019.Research has highlighted exposure as the most studied element in the causal chain of climate change-related health inequalities,followed by adaptive capability and inherent sensitivity.The most significant vulnerabilities were observed among populations with low socioeconomic status,ethnic minorities,and women.The study further reveals research biases and methodological limitations,such as the paucity of attention to underdeveloped regions,a narrow focus on non-temperature-related hazards,challenges in attributing climate change effects,and a deficit of large-scale empirical studies.The findings call for more innovative research approaches and a holistic integration of physical,socio-political,and economic dimensions to enrich climate-health discourse and inform equitable policy-making. 展开更多
关键词 Climate change Health impact Human well-being INEQUALITY VULNERABILITY
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A novel topology with controllable wideband baseband impedance for power amplifiers
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作者 Yao YAO Zhijiang DAI mingyu li 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2024年第2期308-315,共8页
This paper presents a novel topology to control the baseband impedance of a power amplifier(PA)to avoid performance deterioration in concurrent dual-band mode.This topology can avoid pure resonance of capacitors and i... This paper presents a novel topology to control the baseband impedance of a power amplifier(PA)to avoid performance deterioration in concurrent dual-band mode.This topology can avoid pure resonance of capacitors and inductors LC,which leads to a high impedance at some frequency points.Consequently,it can be applied to transmitters that are excited by broadband signals.In particular,by adjusting the circuit parameters and increasing stages,the impedance of the key frequency bands can be flexibly controlled.A PA is designed to support this design idea.Its saturated output power is around 46.7 dBm,and the drain efficiency is>68.2%(1.8-2.3 GHz).Under concurrent two-tone excitation,the drain efficiency reaches around 40%even under 5.5 dB back-off power with the tone spacing from 10 MHz to 500 MHz.These results demonstrate that the proposed topology is capable of controlling wideband baseband impedance. 展开更多
关键词 Baseband impedance Concurrent dual-band Power amplifier
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NiCo_(2)O_(4)/BiOCl/Bi_(24)O_(31)Br_(10) ternary Z-scheme heterojunction enhance peroxymonosulfate activation under visible light: Catalyst synthesis and reaction mechanism 被引量:1
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作者 Tianren li Yueyu Song +3 位作者 Jingjing Jiang mingyu li Yuhan Ma Shuangshi Dong 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第3期186-190,共5页
The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis ... The Z-scheme heterostructure for photocatalyst can effectively prolong the lifetime of photogenerated carriers and retain a higher conduction/valence band position,promoting the synergistic coupling of photocatalysis and peroxymonosulfate(PMS) activation.In order to fully utilize the luminous energy and realize the efficient activation of PMS,this work achieved successful construction of NiCo_(2)O_(4)/BiOCl/Bi_(24)O_(31)Br_(10) ternary Z-scheme heterojunction by simultaneously synthesizing BiOCl and NiCo_(2)O_(4) with NiCl_(2) and CoCl_(2) as the precursors.The intercalated BiOCl could serve as a carrier migration ladder to further achieve the spatial separation of electron-hole pairs,so that the oxidation and reduction processes separately occurred in different regions.Compared with the reported catalysts,the as-prepared composites exhibited the enhanced removal efficiency for tetracycline hydrochloride(TCH) in the visible light/PMS system,with a degradation efficiency of 85.30%in 2 min,and possessed good stability.Z-scheme heterojunction was shown to be beneficial for maximizing the superiority of photo-assisted Fenton-like reaction system.The experimental and characterization results confirmed that both non-radicals(^(1)O_(2)) and radicals(SO_(5)^(·-) and SO_(4)^(·-)) were involved in the reaction process and the SO_(5)^(·-)generated by the oxidation of PMS played a crucial role in the TCH degradation.The possible reaction mechanism was finally proposed.This study provided new insight into the Z-scheme heterostructure to promote the photo-assisted Fenton-like reaction. 展开更多
关键词 Peroxymonosulfate activation Photo-assisted Fenton-like reaction Z-scheme heterojunction Reaction mechanism Reactive oxygen species
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Failure Modes of Lead Free Solder Bumps Formed by Induction Spontaneous Heating Reflow
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作者 mingyu li Hongbo XU +1 位作者 Jongmyung KIM Hongbae KIM 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2007年第1期61-67,共7页
The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated thr... The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves (shear force vs displacement). From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes. 展开更多
关键词 Induction spontaneous heating reflow Lead free solder Shear test Failure mode
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Irregular Characteristics of Bond Interface Formation in Ultrasonic Wire Wedge Bonding
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作者 mingyu li Hongjun JI +3 位作者 Chunqing WANG Au Tai KUNG Han Sur BANG Hee Seon BANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第4期483-486,共4页
The mechanism of ultrasonic wire wedge bonding, one of the die/chip interconnection methods, was investigated based on the characteristics of the ultrasonic wire bonding joints. The Al-1%Si wire of 25 μm in diameter ... The mechanism of ultrasonic wire wedge bonding, one of the die/chip interconnection methods, was investigated based on the characteristics of the ultrasonic wire bonding joints. The Al-1%Si wire of 25 μm in diameter was bonded on Au/Ni/Cu pad and the joint cross-section was analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results indicated that it is irregular for the ultrasonic bond formation, non-welded at the centre but joining well at the periphery, especially at the heel and toe of the joint. Furthermore, the diffusion and/or reaction at the cross-section interface are not clear at C-zone, while there exists a strip layer microstructure at P-zone, and the composition is 78.96 at. pct Al and 14.88 at. pct Ni, close to the Al3Ni intermetallic compound. All these observations are tentatively ascribed to the plastic flow enhanced by ultrasonic vibration and repeated cold deformation driving interdiffusion between AI and Ni at bond interface. 展开更多
关键词 Ultrasonic bonding Irregular joint Interface diffusion Repeated cold deformation
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Effects of W^(6+) occupying Sc^(3+) on the structure, vibration, and thermal expansion properties of scandium tungstate
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作者 陈冬霞 孙强 +4 位作者 于占军 李明玉 郭娟 晁明举 梁二军 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第6期442-448,共7页
We experimentally investigate effects of W^(6+)occupying the sites of Sc^(3+)in the unit cell of Sc_(2) W_(3) O_(12)(Sc_(8) W_(12) O_(48))on the structure, vibration and thermal expansion. The composition and structur... We experimentally investigate effects of W^(6+)occupying the sites of Sc^(3+)in the unit cell of Sc_(2) W_(3) O_(12)(Sc_(8) W_(12) O_(48))on the structure, vibration and thermal expansion. The composition and structure of the doped sample(Sc_(6) W_(2))W_(12) O_(48±δ)(with two W^(6+)occupying two sites of Sc^(3+)in the unit cell of Sc_(8) W_(12) O_(48)) are analyzed and identified by combining the x-ray photoelectron spectroscopy and the synchronous x-ray diffraction with first-principles calculations based on density functional theory. Results show that the crystal with even W^(6+)occupying even Sc^(3+)in the unit cell is stable and maintains the orthorhombic structure at room temperature. The structure of the doped sample is similar to that of Sc_(2) W_(3) O_(12), and with even W occupying even positions of Sc in the unit cell and constituting the WO_(6) octahedra. Raman analyses show that the doped sample possesses stronger W–O bonds and wider Raman linewidths than those of Sc_(2) W_(3) O_(12). The sample doped with W also exhibits intrinsic negative thermal expansion in the measured range of 150 K–650 K. 展开更多
关键词 STRUCTURE negative thermal expansion Raman spectroscopy
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The prevalence of virulent clonal strains of mutans streptococci in vivo and co-culture succession of the strains in vitro—Virulence potential of mutans streptococci
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作者 mingyu li Guang-yun Lai Jun Wang 《Open Journal of Stomatology》 2011年第2期18-24,共7页
Purpose:To examine selected putative virulent prop-erties of mutans streptococci in two groups with dif-ferent caries activity and to examine co-culture hy-bridization of the strains in vitro. Methods: A set of strain... Purpose:To examine selected putative virulent prop-erties of mutans streptococci in two groups with dif-ferent caries activity and to examine co-culture hy-bridization of the strains in vitro. Methods: A set of strains from caries-free subjects (115) and another set from caries-active subjects (165) were isolated. Each strain was characterized for three virulence determi-nants. The clinical bacteria were then cocultured by three strains exhibiting the highest levels of virulence. Isolate colonies of last filial generation bacteria were enrichment-incubated and estimated for virulence again. RAPD-PCR and MLEE analyses were processed for parental bacteria and last filial genera-tion one. Results: No difference associated with caries activity of the subjects from whom the isolates origi-nated. Virulent properties of a filial generation strains was not different in the same generation, but was very different from their parent strains. Conclu-sion: The coexist properties of virulent polyclonal strain of MS may hold in a very general conditional sense in a dental plaque ecosystem in vivo, however, one of the co-culture strains may became dominant and displa- ced the others as the result of continuous ecological succession in vitro. 展开更多
关键词 Ecological Phenomenon MUTANS STREPTOCOCCI CO-CULTURE VIRULENT in Vitro
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Heterogeneous system synthesis of high quality PbS quantum dots for efficient infrared solar cells
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作者 Bo Wang mingyu li +6 位作者 Yuxuan liu Xinyi liang Yang Yang Xinzheng Lan liang Gao Jianbing Zhang Jiang Tang 《Nano Research》 SCIE EI CSCD 2023年第4期5750-5755,共6页
As promising optoelectronic materials,lead sulfide quantum dots(PbS QDs)have attracted great attention.However,their applications are substantially limited by the QD quality and/or complicated synthesis.Herein,a facil... As promising optoelectronic materials,lead sulfide quantum dots(PbS QDs)have attracted great attention.However,their applications are substantially limited by the QD quality and/or complicated synthesis.Herein,a facile new synthesis is developed for highly monodisperse and halide passivated PbS QDs.The new synthesis is based on a heterogeneous system containing a PbCl_(2)-Pb(OA)_(2)solid-liquid precursor solution.The solid PbCl_(2)inhibits the diffusion of monomers and maintains a high oversaturation condition for the growth of PbS QDs,resulting in high monodispersities.In addition,the PbCl_(2)gives rise to halide passivation on the PbS QDs,showing excellent stability in air.The high monodispersity and good passivation endow these PbS QDs with outstanding optoelectronic properties,demonstrated by a 9.43%power conversion efficiency of PbS QD solar cells with a bandgap of~0.95 eV(1,300 nm).We believe that this heterogeneous strategy opens up a new avenue optimizing for the synthesis and applications of QDs. 展开更多
关键词 heterogeneous system synthesis lead sulfide quantum dots high monodispersities halide passivation infrared solar cells
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Generation of mode‑locked states of conventional solitons and bright‑dark solitons in graphene mode‑locked fber laser
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作者 Zixiong li mingyu li +4 位作者 Xinyi Hou Lei Du lin Xiao Tianshu Wang Wanzhuo Ma 《Frontiers of Optoelectronics》 EI CSCD 2023年第2期71-80,共10页
This paper proposes a mode-locked fber laser based on graphene-coated microfber.The total length of the fber laser resonant cavity is 31.34 m.Under the condition of stable output of bright-dark soliton pairs from the ... This paper proposes a mode-locked fber laser based on graphene-coated microfber.The total length of the fber laser resonant cavity is 31.34 m.Under the condition of stable output of bright-dark soliton pairs from the fber laser,dual-wavelength tuning is realized by adjusting the polarization controller(PC),and the wavelength tuning range is 11 nm.Furthermore,the efects of polarization states on bright-dark solitons are studied.It is demonstrated that the mode-locking state can be switched between conventional solitons and bright-dark solitons in the graphene mode-locked fber laser.Bright-dark soliton pairs with diferent shapes and nanosecond pulse width can be obtained by adjusting the PC and pump power. 展开更多
关键词 Fiber laser GRAPHENE Conventional soliton Bright-dark soliton pairs
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A novel method for extending the output power back-off range of an asymmetrical Doherty power amplifier
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作者 mingyu li Xiaobing CHENG +3 位作者 Zhijiang DAI Kang ZHONG Tianfu CAI Chaoyi HUANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2023年第3期470-479,共10页
A novel method is proposed to extend the output power back-off(OPBO)range of the Doherty power amplifier(DPA).This study reveals that the OPBO range of the DPA can be extended by tuning the output impedance of the pea... A novel method is proposed to extend the output power back-off(OPBO)range of the Doherty power amplifier(DPA).This study reveals that the OPBO range of the DPA can be extended by tuning the output impedance of the peaking stage away from infinity and changing the phase delay of the output matching network of the carrier power amplifier.Based on this theory,a large-OPBO-range high-efficiency asymmetrical DPA working band from 1.55 to 2.2 GHz(35%relative bandwidth)is designed to verify the proposed method.Experimental results show that the DPA operates from 1.6 to 2.1 GHz.The range of the measured efficiency is 42.2%–52.1%in the OPBO state and 47%–62.7%in the saturation state.The OPBO range is 11.1–13.2 dB. 展开更多
关键词 Doherty power amplifier(DPA) Output power back-off(OPBO) Output impedance Network phase
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