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Association between intercellular adhesion molecule-1 to depression and blood-brain barrier penetration in cerebellar vascular disease
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作者 Ju-Luo Chen Rui Wang +2 位作者 Pei-Qi Ma You-Meng Wang Qi-Qiang Tang 《World Journal of Psychiatry》 SCIE 2024年第11期1661-1670,共10页
BACKGROUND Cerebral small vessel disease(CSVD)is a prevalent cerebrovascular disease in clinical practice that is often associated with macrovascular disease.A clear understanding of the underlying causes of CSVD rema... BACKGROUND Cerebral small vessel disease(CSVD)is a prevalent cerebrovascular disease in clinical practice that is often associated with macrovascular disease.A clear understanding of the underlying causes of CSVD remains elusive.AIM To explore the association between intercellular adhesion molecule-1(ICAM-1)and blood-brain barrier(BBB)penetration in CSVD.METHODS This study included patients admitted to Fuyang People’s Hospital and Fuyang Community(Anhui,China)between December 2021 and March 2022.The study population comprised 142 patients,including 80 in the CSVD group and 62 in the control group.Depression was present in 53 out of 80 patients with CSVD.Multisequence magnetic resonance imaging(MRI)and dynamic contrast-enhanced MRI were applied in patients to determine the brain volume,cortical thickness,and cortical area of each brain region.Moreover,neuropsychological tests including the Hamilton depression scale,mini-mental state examination,and Montreal cognitive assessment basic scores were performed.RESULTS The multivariable analysis showed that age[P=0.011;odds ratio(OR)=0.930,95%confidence interval(CI):0.880-0.983]and ICAM-1 levels(P=0.023;OR=1.007,95%CI:1.001-1.013)were associated with CSVD.Two regions of interest(ROIs;ROI3 and ROI4)in the white matter showed significant(both P<0.001;95%CI:0.419-0.837 and 0.366-0.878)differences between the two groups,whereas only ROI1 in the gray matter showed signi-ficant difference(P=0.046;95%CI:0.007-0.680)between the two groups.ICAM-1 was significantly correlated(all P<0.05)with cortical thickness in multiple brain regions in the CSVD group.CONCLUSION This study revealed that ICAM-1 levels were independently associated with CSVD.ICAM-1 may be associated with cortical thickness in the brain,predominantly in the white matter,and a significant increase in BBB permeability,proposing the involvement of ICAM-1 in BBB destruction. 展开更多
关键词 Cerebral small vessel disease Intercellular adhesion molecule-1 Blood-brain barrier penetration Cortical thickness White matter
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Simulation of the effects of different substrates, temperature,and substrate roughness on the mechanical properties of Al_2O_3 coating as tritium penetration barrier 被引量:2
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作者 Ze Liu Fei Meng Liang-Bi Yi 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第4期80-90,共11页
Residual thermal stress in the system is a serious problem that affects the application of tritium permeation barrier coatings in fusion reactors. The stress not only determines the adhesion between coating and substr... Residual thermal stress in the system is a serious problem that affects the application of tritium permeation barrier coatings in fusion reactors. The stress not only determines the adhesion between coating and substrate, but also changes the properties of the material. In this study,finite element analysis was used to investigate the relationship between the residual thermal stress and the mechanical properties of Al_2O_3 tritium penetration barrier systems. Moreover, the residual thermal stress influenced by factors such as different substrates, temperature, and substrate roughness was also analyzed. The calculation showed that the hardness and elastic modulus increased with increasing compressive stress. However, the hardness and elastic modulus decreased with increasing tensile stress. The systems composed of Al_2O_3 coatings and different substrates exhibited different trends in mechanical properties. As the temperature increased, the hardness and the elastic modulus increased in an Al_2O_3/316 L stainless steel system; the trend was opposite in an Al_2O_3/Si system.Apart from this, the roughness of the substrate surface in the system could magnify the change in hardness and elastic modulus of the coating. Results showed that all these factors led to variation in the mechanical properties of Al_2O_3 tritium permeation barrier systems. Thus, thedetailed reasons for the changes in mechanical properties of these materials need to be analyzed. 展开更多
关键词 Finite element analysis Thermal stress MECHANICAL properties AL2O3 tritium penetration barrier systems NANOINDENTATION
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Spatio-Temporal Distribution of Individual Filaments in a Square Superlattice Pattern in Atmospheric Dielectric Barrier Discharge 被引量:1
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作者 董丽芳 范伟丽 潘宇扬 《Plasma Science and Technology》 SCIE EI CAS CSCD 2010年第2期172-176,共5页
Spatio-temporal distribution of individual filament in a square superlattice pattern, which consists of large and small spots (filaments), is studied in atmospheric dielectric barrier discharges. The spatial distrib... Spatio-temporal distribution of individual filament in a square superlattice pattern, which consists of large and small spots (filaments), is studied in atmospheric dielectric barrier discharges. The spatial distributions of the two discharges for individual large filament along the direction perpendicular to the electrode are estimated by the distributions of light signals along the electrode. It is found that the discharge at the rising edge of the applied voltage is with a wider column, weaker current, and longer current pulse duration in comparison with that at the falling edge 展开更多
关键词 dielectric barrier charge square superlattice individual filament wall charge
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Utilizing partial least square and support vector machine for TBM penetration rate prediction in hard rock conditions 被引量:11
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作者 高栗 李夕兵 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期290-295,共6页
Rate of penetration(ROP) of a tunnel boring machine(TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. The objectives of this work are to compare the accu... Rate of penetration(ROP) of a tunnel boring machine(TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. The objectives of this work are to compare the accuracy of prediction models employing partial least squares(PLS) regression and support vector machine(SVM) regression technique for modeling the penetration rate of TBM. To develop the proposed models, the database that is composed of intact rock properties including uniaxial compressive strength(UCS), Brazilian tensile strength(BTS), and peak slope index(PSI), and also rock mass properties including distance between planes of weakness(DPW) and the alpha angle(α) are input as dependent variables and the measured ROP is chosen as an independent variable. Two hundred sets of data are collected from Queens Water Tunnel and Karaj-Tehran water transfer tunnel TBM project. The accuracy of the prediction models is measured by the coefficient of determination(R2) and root mean squares error(RMSE) between predicted and observed yield employing 10-fold cross-validation schemes. The R2 and RMSE of prediction are 0.8183 and 0.1807 for SVMR method, and 0.9999 and 0.0011 for PLS method, respectively. Comparison between the values of statistical parameters reveals the superiority of the PLSR model over SVMR one. 展开更多
关键词 tunnel boring machine(TBM) performance prediction rate of penetration(ROP) support vector machine(SVM) partial least squares(PLS)
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Simulation of thermal stress in Er2O3 and Al2O3 tritium penetration barriers by finite-element analysis 被引量:1
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作者 刘泽 汪渊 +2 位作者 余国刚 何安平 王玲 《Plasma Science and Technology》 SCIE EI CAS CSCD 2017年第9期121-130,共10页
The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316 L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal s... The physical vapor deposition method is an effective way to deposit Al2O3 and Er2O3 on 316 L stainless steel substrates acting as tritium permeation barriers in a fusion reactor. The distribution of residual thermal stress is calculated both in Al2O3 and Er2O3 coating systems with planar and rough substrates using finite element analysis. The parameters influencing the thermal stress in the sputter process are analyzed, such as coating and substrate properties, temperature and Young's modulus. This work shows that the thermal stress in Al2O3 and Er2O3 coating systems exhibit a linear relationship with substrate thickness, temperature and Young's modulus.However, this relationship is inversed with coating thickness. In addition, the rough substrate surface can increase the thermal stress in the process of coating deposition. The adhesive strength between the coating and the substrate is evaluated by the shear stress. Due to the higher compressive shear stress, the Al2O3 coating has a better adhesive strength with a 316 L stainless steel substrate than the Er2O3 coating. Furthermore, the analysis shows that it is a useful way to improve adhesive strength with increasing interface roughness. 展开更多
关键词 penetration stainless compressive modulus adhesive roughness barriers permeation sputtering bending
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A simple approach for the estimation of CO_2 penetration depth into a caprock layer 被引量:4
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作者 J.G.Wang Yang Ju +1 位作者 Feng Gao Jia Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2016年第1期75-86,共12页
Caprock is a water-saturated formation with a sufficient entry capillary pressure to prevent the upward migration of a buoyant fluid. When the entry capillary pressure of caprock is smaller than the pressure exerted b... Caprock is a water-saturated formation with a sufficient entry capillary pressure to prevent the upward migration of a buoyant fluid. When the entry capillary pressure of caprock is smaller than the pressure exerted by the buoyant CO2plume, CO2gradually penetrates into the caprock. The CO2penetration depth into a caprock layer can be used to measure the caprock sealing efficiency and becomes the key issue to the assessment of caprock sealing efficiency. On the other hand, our numerical simulations on a caprock layer have revealed that a square root law for time and pore pressure exists for the CO2penetration into the caprock layer. Based on this finding, this study proposes a simple approach to estimate the CO2penetration depth into a caprock layer. This simple approach is initially developed to consider the speed of CO2invading front. It explicitly expresses the penetration depth with pressuring time, pressure difference and pressure magnitude. This simple approach is then used to fit three sets of experimental data and good fittings are observed regardless of pressures, strengths of porous media, and pore fluids(water,hydrochloric acid, and carbonic acid). Finally, theoretical analyses are conducted to explore those factors affecting CO2penetration depth. The effects of capillary pressure, gas sorption induced swelling, and fluid property are then included in this simple approach. These results show that this simple approach can predict the penetration depth into a caprock layer with sufficient accuracy, even if complicated interactions in penetration process are not explicitly expressed in this simple formula. 展开更多
关键词 Fracture-matrix system Fully coupled model Two-phase flow model square root law Simple approach CO_2 penetration depth Caprock sealing efficiency
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Regressive approach for predicting bearing capacity of bored piles from cone penetration test data 被引量:3
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作者 Iyad S. Alkroosh Mohammad Bahadori +1 位作者 Hamid Nikraz Alireza Bahadori 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第5期584-592,共9页
In this study, th e least sq u are su p p o rt v ecto r m achine (LSSVM) alg o rith m w as applied to predicting th ebearing capacity o f b ored piles e m b ed d ed in sand an d m ixed soils. Pile g eo m etry an d c... In this study, th e least sq u are su p p o rt v ecto r m achine (LSSVM) alg o rith m w as applied to predicting th ebearing capacity o f b ored piles e m b ed d ed in sand an d m ixed soils. Pile g eo m etry an d cone p e n e tra tio nte s t (CPT) resu lts w ere used as in p u t variables for pred ictio n o f pile bearin g capacity. The d ata u se d w erecollected from th e existing litera tu re an d consisted o f 50 case records. The application o f LSSVM w ascarried o u t by dividing th e d ata into th re e se ts: a train in g se t for learning th e pro b lem an d obtain in g arelationship b e tw e e n in p u t variables an d pile bearin g capacity, and testin g an d validation sets forevaluation o f th e predictive an d g en eralization ability o f th e o b tain ed relationship. The predictions o f pilebearing capacity by LSSVM w ere evaluated by com paring w ith ex p erim en tal d ata an d w ith th o se bytrad itio n al CPT-based m eth o d s and th e gene ex pression pro g ram m in g (GEP) m odel. It w as found th a t th eLSSVM perform s w ell w ith coefficient o f d eterm in atio n , m ean, an d sta n d ard dev iatio n equivalent to 0.99,1.03, an d 0.08, respectively, for th e testin g set, an d 1, 1.04, an d 0.11, respectively, for th e v alidation set. Thelow values o f th e calculated m ean squared e rro r an d m ean ab so lu te e rro r indicated th a t th e LSSVM w asaccurate in p redicting th e pile bearing capacity. The results o f com parison also show ed th a t th e p roposedalg o rith m p red icted th e pile bearin g capacity m ore accurately th a n th e trad itio n al m eth o d s including th eGEP m odel. 展开更多
关键词 Bored piles Cone penetration test(CPT) Bearing capacity Least square support vector machine(LSSVM) TRAINING VALIDATION
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Overcoming the cellular barriers and beyond: Recent progress on cell penetrating peptide modified nanomedicine in combating physiological and pathological barriers 被引量:4
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作者 Yingke Liu Zhihe Zhao Man Li 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2022年第4期523-543,共21页
The complex physiological and pathological conditions form barriers against efficient drug delivery.Cell penetrating peptides(CPPs),a class of short peptides which translocate drugs across cell membranes with various ... The complex physiological and pathological conditions form barriers against efficient drug delivery.Cell penetrating peptides(CPPs),a class of short peptides which translocate drugs across cell membranes with various mechanisms,provide feasible solutions for efficient delivery of biologically active agents to circumvent biological barriers.After years of development,the function of CPPs is beyond cell penetrating.Multifunctional CPPs with bioactivity or active targeting capacity have been designed and successfully utilized in delivery of various cargoes against tumor,myocardial ischemia,ocular posterior segment disorders,etc.In this review,we summarize recent progress in CPP-functionalized nano-drug delivery systems to overcome the physiological and pathological barriers for the applications in cardiology,ophtalmology,mucus,neurology and cancer,etc.We also highlight the prospect of clinical translation of CPP-functionalized drug delivery systems in these areas. 展开更多
关键词 Cell penetrating peptide NANOMEDICINE Physiological barriers Drug delivery system
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CMAS corrosion resistance characteristics of RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)thermal barrier oxides in RE_(2)Zr_(2)O_(7)-RETaO_(4)systems 被引量:1
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作者 Shan-shan GONG Ming CHEN +1 位作者 Xun-peng HUANG Fan ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第12期4014-4029,共16页
The corrosion resistance characteristics of RE-rich RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)oxides in RE_(2)Zr_(2)O_(7)-RETaO_(4)systems to calcium-magnesium-alumino-silicate(CMAS)at 1300°C,and the influence of RE^(3+)... The corrosion resistance characteristics of RE-rich RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)oxides in RE_(2)Zr_(2)O_(7)-RETaO_(4)systems to calcium-magnesium-alumino-silicate(CMAS)at 1300°C,and the influence of RE^(3+)and Ta^(5+)on chemical reactions and reactive crystallization of CMAS melts were investigated.The results show that following the thermochemical reactions,apatite,pyrochlore,reprecipitated fluorite and residual Yb(Y)TaO4phases were the predominant reaction products.Formation abilities of apatite and pyrochlore were found to be proportional to the ionic radius of RE^(3+).The increase of Ta^(5+)amount can decrease the number of available RE^(3+)to form apatite.Moreover,the resistance characteristic to CMAS corrosion in RE_(50)Ta_(x)Zr_(50-x)O_(175+0.5x)systems was decided by the combined action of apatite and pyrochlore phases.The cohesive mixture of apatite and pyrochlore phases can generate a dense layer near the reaction front,which had a positive effect on suppressing CMAS infiltration.The ability of the fluorite+RETaO4two-phase field was determined to be sufficient to mitigate CMAS corrosion. 展开更多
关键词 thermal barrier coatings CMAS corrosion thermochemical reaction APATITE PYROCHLORE penetration experiment
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Oblique Wave Trapping by a Surface-Piercing Flexible Porous Barrier in the Presence of Step-Type Bottoms
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作者 H.Behera S.Ghosh 《Journal of Marine Science and Application》 CSCD 2019年第4期433-443,共11页
The present study deals with the oblique wave trapping by a surface-piercing flexible porous barrier near a rigid wall in the presence of step-type bottoms under the assumptions of small amplitude water waves and the ... The present study deals with the oblique wave trapping by a surface-piercing flexible porous barrier near a rigid wall in the presence of step-type bottoms under the assumptions of small amplitude water waves and the structural response theory in finite water depth.The modified mild-slope equation along with suitable jump conditions and the least squares approximation method are used to handle the mathematical boundary value problem.Four types of edge conditions,i.e.,clamped-moored,clamped-free,moored-free,and moored-moored,are considered to keep the barrier at a desired position of interest.The role of the flexible porous barrier is studied by analyzing the reflection coefficient,surface elevation,and wave forces on the barrier and the rigid wall.The effects of step-type bottoms,incidence angle,barrier length,structural rigidity,porosity,and mooring angle are discussed.The study reveals that in the presence of a step bottom,full reflection can be found periodically with an increase in(i)wave number and(ii)distance between the barrier and the rigid wall.Moreover,nearly zero reflection can be found with a suitable combination of wave and structural parameters,which is desirable for creating a calm region near a rigid wall in the presence of a step bottom. 展开更多
关键词 Oblique incident wave Wave trapping Surface-piercing Flexible porous barrier Mild-slope approximation Least squares approximation
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The bounding-surfaces record of a barrier spit from Huangqihai Lake,North China:implications for coastal barrier boundary hierarchy
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作者 单新 于兴河 +3 位作者 Peter D.CLIFT 王天意 谭程鹏 金丽娜 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第5期1097-1105,共9页
Ground-penetrating radar and trenching studies of a barrier spit on the north shore of Huangqihai Lake were made,that reveal important implications for the coastal washover barrier boundary hierarchy and interpretatio... Ground-penetrating radar and trenching studies of a barrier spit on the north shore of Huangqihai Lake were made,that reveal important implications for the coastal washover barrier boundary hierarchy and interpretations of this depositional record.A four-fold hierarchy bounding-surface model,representing different levels of impact and genesis,is defined.Each level of the hierarchy is enclosed by a distinct kind of surface characterized by different ground-penetrating radar reflection features,sedimentary characteristics(color,grain size,sorting,rounding and sedimentary structures) and origin.We suggest that this hierarchical model can be applied to any coastal washover barrier deposits. 展开更多
关键词 coastal barrier boundary hierarchy washover deposits ground-penetrating radar bounding surface Huangqihai Lake
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An Algorithm for Hybrid Nodes Barrier Coverage Based on Voronoi in Wireless Sensor Networks
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作者 Xiaochao Dang Rucang Ma +1 位作者 Zhanjun Hao Meixiu Ma 《国际计算机前沿大会会议论文集》 2017年第2期49-51,共3页
In order to make up for the deficiencies and insufficiencies that In order to make up for the deficiencies and insufficiencies that wireless sensor network is constituted absolutely by static or dynamic sensor nodes. ... In order to make up for the deficiencies and insufficiencies that In order to make up for the deficiencies and insufficiencies that wireless sensor network is constituted absolutely by static or dynamic sensor nodes. So a deployment mechanism for hybrid nodes barrier coverage (HNBC)is proposed in wireless sensor network, which collaboratively consists of static and dynamic sensor nodes. We introduced the Voronoi diagram to divide the whole deployment area. According to the principle of least square method, and the static nodes are used to construct the reference barrier line (RBL). And we implemented effectively barrier coverage by monitoring whether there is a coverage hole in the deployment area, and then to determine whether dynamic nodes need limited mobility to redeploy the monitoring area. The simulation results show that the proposed algorithm improved the coverage quality, and completed the barrier coverage with less node moving distance and lower energy consumption, and achieved the expected coverage requirements 展开更多
关键词 Wireless Sensor Network (WSN) VORONOI DIAGRAM HYBRID node barrier coverage Reference barrier Lines (RBL) The least square method
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动能侵彻弹装药起爆可靠性试验及敏感因素分析
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作者 杨慧 王可慧 +4 位作者 王伟光 李洋 沈子楷 段建 戴湘晖 《高压物理学报》 CAS CSCD 北大核心 2024年第4期124-136,共13页
为研究弹体结构设计对弹体装药起爆可靠性的影响,设计了一种低成本、便捷式引战静态匹配试验装置,开展了不同条件下引信与装药的传爆裕度试验。基于移动最小二乘法,构建了可表征起爆可靠性的多变量响应函数,定量分析了各敏感因素及其耦... 为研究弹体结构设计对弹体装药起爆可靠性的影响,设计了一种低成本、便捷式引战静态匹配试验装置,开展了不同条件下引信与装药的传爆裕度试验。基于移动最小二乘法,构建了可表征起爆可靠性的多变量响应函数,定量分析了各敏感因素及其耦合作用对起爆可靠性的影响规律。结果表明:传爆间隙和缓冲层厚度对弹体装药起爆影响较大,而隔板厚度在预设3~5 mm范围内的影响较小;为保证动能侵彻弹在使用环境温度范围内可靠作用,引信相对偏离位置、隔板厚度、传爆间隙以及缓冲层厚度分别不应超过25、3.5、25以及22 mm。该试验装置、分析方法及研究成果可为动能侵彻弹结构设计及可靠性验证提供借鉴和指导。 展开更多
关键词 动能侵彻弹 引战匹配 传爆裕度 传爆间隙 惰性缓冲层 移动最小二乘法
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中药挥发油透皮促渗苷类成分效果与经皮水分散失量的相关性研究
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作者 黄森兰 祝茜茜 +4 位作者 陆姗姗 宋芝超 董洁 王裔惟 陈军 《南京中医药大学学报》 CAS CSCD 北大核心 2024年第5期503-509,共7页
目的研究中药挥发油透皮促渗苷类成分效果与对经皮水分散失量(Transepidermal water loss,TEWL)的相关性。方法采用HPLC法测定3种苷类成分(栀子苷、龙胆苦苷、芍药苷)的含量及油水分配系数,采用改良Franz扩散池法以离体SD大鼠腹部皮肤... 目的研究中药挥发油透皮促渗苷类成分效果与对经皮水分散失量(Transepidermal water loss,TEWL)的相关性。方法采用HPLC法测定3种苷类成分(栀子苷、龙胆苦苷、芍药苷)的含量及油水分配系数,采用改良Franz扩散池法以离体SD大鼠腹部皮肤为透皮吸收屏障进行体外透皮实验,考察高良姜、干姜、薄荷、胡椒和吴茱萸5种中药挥发油对3种苷类成分的体外透皮促渗效果,采用经皮水分散失量评价5种中药挥发油对大鼠皮肤屏障功能的影响,通过相关性分析考察中药挥发油透皮促渗苷类成分效果与其对皮肤屏障功能影响之间的相关性。结果高良姜油、干姜油、薄荷油、胡椒油能促进3种苷类成分的透皮吸收,也能显著降低大鼠的皮肤屏障功能,相关性分析结果表明中药挥发油对苷类成分的透皮促渗效果与其对皮肤经皮水分散失量的影响显著相关。结论TEWL为中药挥发油透皮促渗剂的快速筛选提供了一种简便快捷的在体评价方法。 展开更多
关键词 中药挥发油 透皮促渗剂 经皮水分散失量 皮肤屏障功能 相关性分析
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波包入射对共振穿透现象的影响研究
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作者 邓志姣 李茂源 +2 位作者 沈咏 刘伟涛 陈平形 《大学物理》 2024年第3期1-4,10,共5页
共振穿透是一维量子散射中的一个重要的现象.一般教材中对该现象的阐述都是假定单色平面波入射,对于更加接近于实际情况的波包入射缺乏研究.本文利用解析推导并作图的方法,详细讨论了一维方势阱中波包散射的主要特点,以及入射波包的能... 共振穿透是一维量子散射中的一个重要的现象.一般教材中对该现象的阐述都是假定单色平面波入射,对于更加接近于实际情况的波包入射缺乏研究.本文利用解析推导并作图的方法,详细讨论了一维方势阱中波包散射的主要特点,以及入射波包的能量均值及展宽对共振穿透现象的影响.本文的研究内容不仅能加深对共振穿透现象的理解,而且为分析任意分段常势能函数的散射问题提供了一般方法. 展开更多
关键词 势能函数 量子散射 波包 散射问题 共振 一维方势阱 入射波 平面波
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不同方波脉冲模式下介质阻挡放电产生臭氧的研究
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作者 姜松 何园园 《电子科技》 2024年第2期30-35,共6页
为提高介质阻挡放电产生臭氧的浓度和产量,文中研究了不同方波脉冲模式下介质阻挡放电产生臭氧的特性。文中对系统放电特性进行分析,计算系统放电功率,研究其在不同极性、不同频率和不同脉宽下产生臭氧的浓度和产量,并对其产生的结果进... 为提高介质阻挡放电产生臭氧的浓度和产量,文中研究了不同方波脉冲模式下介质阻挡放电产生臭氧的特性。文中对系统放电特性进行分析,计算系统放电功率,研究其在不同极性、不同频率和不同脉宽下产生臭氧的浓度和产量,并对其产生的结果进行了分析和讨论。研究结果表明,在施加正负极性方波脉冲时,臭氧浓度最高,为8.8 g·Nm^(-3);在施加正极性方波脉冲时,臭氧产量最高,为55 g·kWh^(-1)。随着频率的增加,臭氧浓度和产量均呈现先增加后下降趋势。在放电频率为1 kHz时,臭氧浓度最大;在放电频率为1.5 kHz时,臭氧产量最高。在其它参数一定的情况下,随着脉宽的增加,臭氧浓度缓慢增加,臭氧的产量基本无变化。 展开更多
关键词 介质阻挡放电 低温等离子体 方波脉冲 不同脉冲模式 放电特性 累积电荷 臭氧浓度 臭氧产量
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一维三方势垒量子隧穿特性的研究
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作者 李海凤 陈康康 王欣茂 《大学物理》 2024年第2期1-4,32,共5页
本文通过严格求解定态薛定谔方程,研究了一维对称三方势垒的量子隧穿特性,解析地给出透射系数的精确表达式,并且数值模拟了势垒高度、势垒间距以及粒子入射能量对透射系数的影响.结果表明:当取不同的势垒宽度,或者不同的粒子入射能量时... 本文通过严格求解定态薛定谔方程,研究了一维对称三方势垒的量子隧穿特性,解析地给出透射系数的精确表达式,并且数值模拟了势垒高度、势垒间距以及粒子入射能量对透射系数的影响.结果表明:当取不同的势垒宽度,或者不同的粒子入射能量时,透射系数随着势垒间距的增加而呈现出明显的周期式振荡.将一维对称双方势垒和三方势垒进行比较,透射系数随着势垒间距的增大,均呈现周期性振荡,并且振荡周期相同,但三方势垒振荡更剧烈,振幅越大,并且三方对称势垒是双峰曲线,而双方对称势垒是单峰曲线.该特性为设计新型纳米器件以及共振隧穿量子器件等提供理论指导. 展开更多
关键词 三方势垒 量子隧穿 共振隧穿 定态薛定谔方程
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超晶格电子垂直输运的激子势垒穿透 被引量:15
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作者 李秀平 陈琼 +2 位作者 杨杰 王善进 罗诗裕 《半导体光电》 CAS CSCD 北大核心 2014年第1期53-56,共4页
激子的势垒穿透在超晶格的光电性质研究中有着十分重要的意义。文章在Fowler-Nordheim理论基础上,引入权重因子描述了激子库仑场和外场之间的竞争,并对不同的权重因子进行了仿真分析。结果表明,激子效应使势垒高度降低。用爱里函数和椭... 激子的势垒穿透在超晶格的光电性质研究中有着十分重要的意义。文章在Fowler-Nordheim理论基础上,引入权重因子描述了激子库仑场和外场之间的竞争,并对不同的权重因子进行了仿真分析。结果表明,激子效应使势垒高度降低。用爱里函数和椭圆积分严格地给出了激子的势垒穿透几率,为超晶格光电性质和垂直输运提供了基础分析。 展开更多
关键词 激子 超晶格 势垒穿透 椭圆积分
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双挡板透空堤透浪与反射系数实验研究 被引量:18
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作者 范骏 王宇楠 +3 位作者 杨斯汉 严士常 王伟 钱学生 《海洋工程》 CSCD 北大核心 2011年第4期60-67,共8页
设有挡浪板结构的透空式防波堤适用于水深较大的海域,且具有较好的消浪效果。采用物理模型试验,探究具有双侧挡浪板结构的透空式防波堤透浪系数与反射系数的影响因素与规律,研究包括外侧与内侧挡浪板入水深度,水平板板宽,结构上部挡浪... 设有挡浪板结构的透空式防波堤适用于水深较大的海域,且具有较好的消浪效果。采用物理模型试验,探究具有双侧挡浪板结构的透空式防波堤透浪系数与反射系数的影响因素与规律,研究包括外侧与内侧挡浪板入水深度,水平板板宽,结构上部挡浪墙的高度与位置,水平板超高与波浪要素等因素。通过比较各家透浪系数的理论计算公式与实验结果,进行透浪系数的计算方法研究,给出修正Wiegel公式拟合双侧挡浪板透空式防波堤的透浪系数计算公式,供工程设计参考与进一步研究。 展开更多
关键词 透浪系数 透空式防波堤 双挡板 反射系数
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PCT高压静电场的植物细胞效应及量子模型 被引量:6
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作者 谢菊芳 宋国清 +2 位作者 廖贡献 张菁 居超明 《电子学报》 EI CAS CSCD 北大核心 1999年第6期68-71,共4页
本文以压电陶瓷变压器(PCT)高压静电场对豌豆根尖生长点细胞学效应为实验题材,在强场情况下,运用势垒贯穿模型,从电子水平研究了植物细胞畸变的机理.
关键词 电场效应 DNA 势垒贯穿 植物 细胞效应 量子模型
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