期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
Multiscale simulations of surface adsorption characteristics of amino acids on zinc metal anode
1
作者 Yufan Xia Zijian Hong +6 位作者 Linming Zhou Shuang Chen Zhen Luo Shoutong Jin Yuhui Huang Yinzhu Jiang yongjun wu 《Journal of Energy Chemistry》 SCIE EI CSCD 2023年第12期153-161,I0006,共10页
Aqueous zinc-ion batteries(ZIBs) are considered promising power sources for grid storage,but they face several issues,including dendrite growth,corrosion,hydrogen evolution,etc.,which are related to the Zn metal/liqui... Aqueous zinc-ion batteries(ZIBs) are considered promising power sources for grid storage,but they face several issues,including dendrite growth,corrosion,hydrogen evolution,etc.,which are related to the Zn metal/liquid electrolyte interface.To address these challenges,many researchers have focused on modifying the Zn anode with surface adsorption.However,the underlying mechanism between the Zn surface and adsorbed/protective molecules has not been thoroughly explored.In this study,we built a multiscale simulation platform that integrates state-of-art simulation methods to comprehensively investigate the adsorption process of amino acids on the Zn metal surface.Our major finding is that adsorption sites,adsorbate–surface angle,and average distance are critical parameters for the stability and strength of surface adsorption.Additionally,ab initio molecular dynamics reveal the kinetics of the surface adsorption and molecule reorientation processes.Specifically,it can be discovered that the amino acids prefer to align parallel to the Zn metal surface,leading to better surface protection against corrosion and preventing dendrite growth.These findings pave the way for an in-depth understanding of the surface adsorption process,as well as providing concrete design principles for stable Zn metal anodes. 展开更多
关键词 Zn-ion battery First-principles calculations Surface adsorption Ab initio molecular dynamics
下载PDF
Stochastic averaging method for estimating first-passage statistics of stochastically excited Duffing-Rayleigh-Mathieu system 被引量:3
2
作者 yongjun wu Wang Fang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2008年第5期575-582,共8页
在宽带下面未击中 Rayleigh Mathieu 系统的第一经过的统计给噪音刺激涂颜色被使用随机的平均学习方法。原来的系统的运动方程在随机的平均以后被转变成振幅和阶段的两次同类的散开 Markovian 进程。为第一经过的问题的散开过程方法被... 在宽带下面未击中 Rayleigh Mathieu 系统的第一经过的统计给噪音刺激涂颜色被使用随机的平均学习方法。原来的系统的运动方程在随机的平均以后被转变成振幅和阶段的两次同类的散开 Markovian 进程。为第一经过的问题的散开过程方法被使用,相应向后的 Kolmogorov 方程和 Pontryagin 方程被构造并且解决了产出有条件的可靠性功能和吝啬的第一经过的时间与合适起始并且边界条件。分析结果被蒙特卡罗模拟证实。 展开更多
关键词 有色噪音 随机值 可靠性 统计学
下载PDF
Study on the solid-liquid suspension behavior in a tank stirred by the long-short blades impeller 被引量:1
3
作者 Zewen Chen yongjun wu +1 位作者 Jian Wang Peicheng Luo 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第7期79-88,共10页
We investigated the solid–liquid suspension characteristics in the tank with a liquid height/tank diameter ratio of 1.5 stirred by a novel long-short blades(LSB) impeller by the Euler granular flow model coupled with... We investigated the solid–liquid suspension characteristics in the tank with a liquid height/tank diameter ratio of 1.5 stirred by a novel long-short blades(LSB) impeller by the Euler granular flow model coupled with the standard k–ε turbulence model. After validation of the local solid holdup by experiments,numerical predictions have been successfully used to explain the influences of impeller rotating speed,particle density, particle size, liquid viscosity and initial solid loading on the solid suspension behavior,i.e. smaller particles with lower density are more likely to be suspended evenly in the liquid with higher liquid viscosity. At a low impeller rotating speed(N), increase in N leads to an obvious improvement in the solid distribution homogeneity. Moreover, the proposed LSB impeller has obvious advantages in the uniform distribution of the solid particles compared with single Rushton turbine(RT), dual RT impellers or CBY hydrofoil impeller under the same power consumption. 展开更多
关键词 Two-phase flow Computational fluid dynamics Kinetic theory of granular flow Stirred tank Long-short blades impeller
下载PDF
Effect of pitched short blades on the flow characteristics in a stirred tank with long-short blades impeller 被引量:1
4
作者 yongjun wu Pan You Peicheng Luo 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第5期143-152,共10页
This work focuses on the design improvement of the long-short blades(LSB)impeller by using pitched short blades(SBs)to regulate the flow field in the stirred vessel.After mesh size evaluation and velocity field valida... This work focuses on the design improvement of the long-short blades(LSB)impeller by using pitched short blades(SBs)to regulate the flow field in the stirred vessel.After mesh size evaluation and velocity field validation by the particle image velocimetry,large eddy simulation method coupled with sliding mesh approach was used to study the effect of the pitched SBs on the flow characteristics.We changed the inclined angles of the SBs from 30°to 60°and compared the flow characteristics when the impeller was operated in the down-pumping and up-pumping modes.In the case of down-pumping mode,the power number is relatively smaller and vortexes below the SBs are suppressed,leading to turbulence intensification in the bottom of the vessel.Whereas in the case of up-pumping mode,the axial flow rate in the center increased significantly with bigger power number,resulting in more efficient mass exchange between the axial and radial flows in the whole vessel.The LSB with 45°inclined angle of the SBs in the up-pumping mode has the most uniform distributions of flow field and turbulent kinetic energy compared with other impeller configurations. 展开更多
关键词 Stirred tank Computational fluid dynamics(CFD) Turbulent flow Long-short blades(LSB)impeller Pitched blades
下载PDF
New analytical imaging algorithm for general case airborne bistatic SAR
5
作者 Jianyun Zhang Jinhe Ran yongjun wu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第5期786-793,共8页
This paper focuses on the general case(GC) airborne bistatic synthetic aperture radar(SAR) data processing, and a new analytical imaging algorithm based on the extended Loffeld's bistatic formula(ELBF) is proposed... This paper focuses on the general case(GC) airborne bistatic synthetic aperture radar(SAR) data processing, and a new analytical imaging algorithm based on the extended Loffeld's bistatic formula(ELBF) is proposed. According to the bistatic SAR geometry, the track decoupling formulas that convert the bistatic geometry to the receiver-referenced geometry in a concise way are derived firstly. Then phase terms of ELBF are decomposed into two independent phase terms as the range phase term and the azimuth phase term in a new way. To get the focusing result, the bistatic deformation(BD) term is compensated in the two-dimensional(2-D) frequency domain, and the space-variances of the range phase term and the azimuth phase term are eliminated by chirp scaling(CS) and chirp z-transform(CZT), respectively. The effectiveness of the proposed algorithm is verified by the simulation results. 展开更多
关键词 成像算法 SAR 机载 合成孔径雷达 几何形状 线性调频脉冲 数据处理 频域补偿
下载PDF
Pd-catalyzed cascade cyclization of allenylethylene carbonates and indandiones: Synthesis of tetracyclic dihydrocyclopentaindenofuranone derivatives
6
作者 Yujie Dong Jun Liu +6 位作者 Xing Gao Ting Pan Biming Mao Songcheng Yu yongjun wu Cheng Zhang Hongchao Guo 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第10期131-134,共4页
A palladium-catalyzed cascade cyclization of allenylethylene carbonates with 1,3-indandiones was developed, providing biologically interesting tetracyclic dihydrocyclopentaindenofuranone derivatives having three conti... A palladium-catalyzed cascade cyclization of allenylethylene carbonates with 1,3-indandiones was developed, providing biologically interesting tetracyclic dihydrocyclopentaindenofuranone derivatives having three contiguous quaternary carbon centers in moderate to high yields with excellent diastereoselectivities. In this reaction, the allene moiety was fully fused into the cyclopentene ring. 展开更多
关键词 PALLADIUM Allenylethylene carbonates Indandiones Cascade cyclization DECARBOXYLATION
原文传递
超声速流边界层中的壁面正、负压力脉动
7
作者 尹琰鑫 吴勇军 +4 位作者 王润 任冲 屈强 张青青 刘晋 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2023年第2期114-125,共12页
本文对来流马赫数2.25、基于动量厚度的雷诺数4000的平板湍流边界层开展了直接数值模拟,通过聚类连通法和条件相关研究了壁面正、负压力脉动.负脉动比正脉动的特征长度小,但是二者特征时间接近.正脉动的对流速度略大.壁面压力脉动结构... 本文对来流马赫数2.25、基于动量厚度的雷诺数4000的平板湍流边界层开展了直接数值模拟,通过聚类连通法和条件相关研究了壁面正、负压力脉动.负脉动比正脉动的特征长度小,但是二者特征时间接近.正脉动的对流速度略大.壁面压力脉动结构的空间距离是自相似的,即空间距离与特征长度成正比.同类壁面压力结构在展向成串出现,正、负壁面压力脉动在流向成对。流向壁面剪切脉动大致在壁面压力脉动的下游,而展向壁面剪切脉动则与壁面压力脉动成对角线方式分布,二者的相关函数成“四极子”形式,其中壁面压力脉动与其上游的展向壁面剪切相关系数大于下游. 展开更多
关键词 Supersonic turbulent boundary layer Wall pressure fluctuation Negative and positive events
原文传递
^(18)F-FDG双时相及^(18)F-FDG联合^(11)C-CHO PET/CT多模态显像在原发性肝细胞肝癌中的诊断价值 被引量:8
8
作者 邬心爱 邬永军 +3 位作者 王雪梅 王城 王春梅 牛瑞龙 《国际放射医学核医学杂志》 2021年第3期139-146,共8页
目的探讨^(18)F-氟脱氧葡萄糖(FDG)PET/CT双时相显像及^(18)F-FDG联合^(11)C-胆碱(CHO)PET/CT多模态显像对原发性肝细胞肝癌(HCC)的诊断价值。方法回顾性分析2016年3月至20^(18)年12月于内蒙古医科大学附属医院就诊的临床疑似原发肝占... 目的探讨^(18)F-氟脱氧葡萄糖(FDG)PET/CT双时相显像及^(18)F-FDG联合^(11)C-胆碱(CHO)PET/CT多模态显像对原发性肝细胞肝癌(HCC)的诊断价值。方法回顾性分析2016年3月至20^(18)年12月于内蒙古医科大学附属医院就诊的临床疑似原发肝占位性病变的73例患者的临床资料,其中男性41例、女性32例,年龄58~72岁;47例患者行^(18)F-FDG PET/CT双时相显像,26例患者行^(18)F-FDG联合^(11)C-CHO PET/CT多模态显像。分别测量并计算每个病变的最大标准化摄取值(SUV_(max))、肝本底SUV_(max)、肿瘤SUV_(max)/肝本底SUV_(max)比值(T/L)。以病变良恶性为状态变量,分别以^(18)F-FDG、^(18)F-FDG延迟、^(18)F-FDG双时相的SUV_(max)和^(18)F-FDG、^(11)C-CHO、^(18)F-FDG联合^(11)C-CHO的SUV_(max)为检验变量绘制受试者工作特征(ROC)曲线并进行两两比较,以组织病理学检查或临床随访结果为“金标准”,对比分析各种显像方法的诊断效能。计量资料的比较采用配对t检验;采用Z秩和检验比较各组间ROC曲线的差异。结果(1)^(18)F-FDG PET/CT双时相显像:47例患者共检出49个病变(其中32个为高代谢病变),经组织病理学检查或临床随访结果证实,40个为HCC(高分化8个、中低分化32个),9个为良性病变。中低分化HCC的病变SUV_(max)、肝本底SUV_(max)和T/L的差异均有统计学意义(t=4.51、-2.53、4.80,均P<0.05);高分化HCC的病变SUV_(max)和T/L的差异均有统计学意义(t=2.76、2.62,均P<0.05);良性病变SUV_(max)的差异无统计学意义(t=0.00,P>0.05)。^(18)F-FDG PET/CT显像分别与其延迟显像、双时相显像的SUV_(max)的ROC曲线间的差异均有统计学意义(Z=2.315、2.376,均P<0.05);而延迟显像与双时相显像的SUV_(max)的ROC曲线间的差异无统计学意义(Z=0.252,P>0.05)。(2)^(18)F-FDG联合^(11)C-CHO PET/CT显像:26例患者共检出26个病变(其中^(18)个为高代谢病变),经组织病理学检查或临床随访证实,22个为HCC(高分化9个、中低分化13个),4个为良性病变。高分化HCC的病变SUV_(max)、肝本底SUV_(max)间的差异均有统计学意义(t=9.49、6.57,均P<0.001),而T/L的差异无统计学意义(t=2.01,P>0.05);中低分化HCC的病变SUV_(max)的差异无统计学意义(t=-1.68,P>0.05),肝本底SUV_(max)、T/L间的差异均有统计学意义(t=8.41、-5.43,均P<0.001);良性病变的SUV_(max)的差异无统计学意义(t=1.51,P>0.05)。^(18)F-FDG与其联合^(11)C-CHO PET/CT的SUV_(max)的ROC曲线间的差异有统计学意义(Z=2.037,P<0.05)。结论^(18)F-FDG PET/CT双时相显像及^(18)F-FDG联合^(11)C-CHO PET/CT多模态显像可分别提高中低及高分化原发性HCC的检出率,对肝癌患者治疗方案的决策及临床预后判定有重要的指导价值。 展开更多
关键词 肝细胞 氟脱氧葡萄糖F18 胆碱 正电子发射断层显像术 体层摄影术 X线计算机 最大标准化摄取值
原文传递
Development of a rapid and sensitivity magnetic chemiluminescence immunoassay for DNA methyltransferase 1 in human serum 被引量:4
9
作者 Sitian He Leiliang He +9 位作者 Beibei Liu Songcheng Yu Li'e Liu Yongmei Tian Jia Wang Lihua Ding Yilin Wang Lingbo Qu Fei Yu yongjun wu 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第5期1031-1034,共4页
DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(H... DNA methyltransferase 1(DNMT1)is a useful biomarker for lung cancer in early clinical diagnosis.A rapid magnetic chemiluminescence immunoassay(MCLIA)for DNMT1 in human serum has been developed.Horseradish peroxidase(HRP)-second-Ab was used to labeled polyclonal antibodies of anti-DNMT1.DNMT1 in sample integrates with specific immunomagnetic beads and can constitute a supersandwiched immunoreaction.In magnetic field,nonspecific materials can be separated.After luminescent substrate luminol-H2O2-BIP was added,the relative light unit(RLU)of HRP was detected and was discovered to be directly proportional to the content of DNMT1 in sample.The correlative variables involved in the MCLIA value were optimized and the methodological evaluation was carried out.After optimization,in the range of0.5–128 ng/mL,the linear regression equation was y=0.5014 x+1.769(x was logCDNMT1,y was relative luminescence units(RLU)/RLU0),and the limit of detection was 0.01 ng/mL.The RSD of intra-and interassays were 15.8%–16.9%and 14.3%–18.1%,respectively.The recovery was from 70.0%to 106.2%.Furthermore,paralleled with purchasable enzyme-linked immunosorbent assay(ELISA)kits,MCLEIA had lower detection limit,wider linear range and shorter detection time.Therefore,the MCLEIA established in this study could be used for the sensitive detection of DNMT1 in serum sample. 展开更多
关键词 DNA METHYLTRANSFERASE 1 BIOMARKER CHEMILUMINESCENCE IMMUNOASSAY MAGNETIC particles Human SERUM
原文传递
Mid-temperature thermoelectric performance of zone-melted Sb_(2)(Te,Se)_(3) alloys near phase transition boundary 被引量:1
10
作者 Beibei Li Renshuang Zhai +3 位作者 Teng Fang Kaiyang Xia yongjun wu Tiejun Zhu 《Journal of Materiomics》 SCIE EI 2019年第4期590-596,共7页
(Bi,Sb)_(2)(Te,Se)_(3) alloys are widely used commercial thermoelectric(TE)materials for solid-state refrigeration around room temperature.The composition-induced structural phase transition could be realized by varyi... (Bi,Sb)_(2)(Te,Se)_(3) alloys are widely used commercial thermoelectric(TE)materials for solid-state refrigeration around room temperature.The composition-induced structural phase transition could be realized by varying the compositions in these alloys,which may largely alter the electronic structure and phonon dispersion.Among them,the Se-alloyed Sb_(2)Te_(3) accompanied with structural transition is seldom reported.Herein,the interrelations of Se-alloying induced changes in structural phase transition,band structure and TE properties of p-type zone-melted Sb_(2)Te_(3-x)Se_(x)(x=1.5-2.4)alloys near phase transition boundary are systematically investigated.The results demonstrate that Sb_(2)Te_(3-x)Se_(x) shows a structural transition from a rhombohedral phase to mixed structure at x=2.0.The carrier concentration and bandgap at room temperature of Sb_(2)Te_(3)-xSex(x=1.5-2.4)constantly decrease with increasing Se contents x.The zT peak of the Sb_(2)TeSe_(2) matrix is improved and shifted to higher temperature by optimizing carrier concentration via Ag doping.A maximum zT of~0.4 is obtained at 680 K in Sb_(1.97)Ag_(0.03)TeSe_(2) alloy,about 100% enhancement compared with the undoped sample. 展开更多
关键词 Thermoelectric materials Zone melting Structural transition DOPING Thermoelectric properties
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部