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1.
Jens Mller Anne Busch Christian Berens Helmut Hotzel Andreas Burkovski 《International journal of molecular sciences》2021,22(7)
Corynebacterium silvaticum is a newly identified animal pathogen of forest animals such as roe deer and wild boars. The species is closely related to the emerging human pathogen Corynebacterium ulcerans and the widely distributed animal pathogen Corynebacterium pseudotuberculosis. In this study, Corynebacterium silvaticum strain W25 was characterized with respect to its interaction with human cell lines. Microscopy, measurement of transepithelial electric resistance and cytotoxicity assays revealed detrimental effects of C. silvaticum to different human epithelial cell lines and to an invertebrate animal model, Galleria mellonella larvae, comparable to diphtheria toxin-secreting C. ulcerans. Furthermore, the results obtained may indicate a considerable zoonotic potential of this newly identified species. 相似文献
2.
采用有限元模拟和实验研究了挤压钛合金弯曲管件。通过实验验证了工件的形状和尺寸精度,并通过有限元模拟分析了工艺参数对挤出过程中变形体的平均压应力分布情况和挤出弯管件的曲率半径的影响规律。结果表明:有限元模拟中,弯管件的曲率半径误差为6.03%,弯管直径误差为3.82%;在靠近定径带处,平均压应力呈非均匀分布;在焊合腔内,靠近细分流孔区域的平均压应力小于靠近粗分流孔区域的平均压应力,平均压应力的大小顺序在通过粗、细分流孔前后相反;在模具结构固定不变时,弯管件的曲率半径随挤压速度的减小而增大,不随挤压温度的变化而变化。 相似文献
3.
梯度分层铝合金蜂窝板是一种有效的吸能结构,本工作在梯度铝蜂窝结构的基础上根据梯度率的概念,通过改变蜂窝芯层的胞壁长度,设计了4种质量相同、梯度率不同的铝蜂窝夹芯结构。通过准静态压缩实验,并结合非线性有限元模拟准静态及冲击态下梯度铝蜂窝夹芯结构的变形情况及其力学性能,分析对比了相同质量下梯度铝蜂窝夹芯结构在准静态下的变形模式以及冲击载荷下分层均质蜂窝结构和不同梯度率的分层梯度蜂窝结构的动态响应和能量吸收特性。结果表明:在准静态压缩过程中,铝蜂窝梯度夹芯板的变形具有明显的局部化特征,蜂窝芯的变形为低密度优先变形直至密实,层级之间的密实化应变差随芯层密度的增大而逐渐减小;在高速冲击下,梯度蜂窝板并非严格按照准静态过程中逐级变形直至密实,而是在锤头冲击惯性及芯层密度的相互作用下整体发生的线弹性变形、弹性屈曲、塑性坍塌及密实化;另外,在本工作所设计的梯度率中,当梯度率为γ1=0.0276时,梯度蜂窝夹芯板的吸能性达到最好,相较于同等质量下的均质蜂窝夹芯板,能量吸收提高了10.63%。 相似文献
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6.
《Advanced Powder Technology》2022,33(3):103507
This study investigates the effect of intermediate stress ratio (b) on the mechanical behaviour of granular soil in true triaxial tests. A CFD-DEM solver with the ability to model compressible fluid and moving mesh has been developed and calibrated based on existing experimental test results on Nevada sand. The effect of b on the undrained true triaxial test, which has been neglected in the literature, was investigated using a reasonable number of models. The effects of the initial confining stress and initial void ratio also have been studied. The developed model was used to calculate the hydrodynamic forces on the particles and evaluate the ratio of the particle–fluid interaction force to the resultant force on the particles. It has been demonstrated that, in numerical studies, the effect of these forces cannot be neglected. 相似文献
7.
《International Journal of Hydrogen Energy》2022,47(36):16121-16131
Ammonia is considered as a promising hydrogen or energy carrier. Ammonia absorption or adsorption is an important aspect for both ammonia removal, storage and separation applications. To these ends, a wide range of solid and liquid sorbents have been investigated. Among these, the deep eutectic solvent (DES) is emerging as a promising class of ammonia absorbers. Herein, we report a novel type of DES, i.e., metal-containing DESs for ammonia absorption. Specifically, the NH3 absorption capacity is enhanced by ca. 18.1–36.9% when a small amount of metal chlorides, such as MgCl2, MnCl2 etc., are added into a DES composed of resorcinol (Res) and ethylene glycol (EG). To our knowledge, the MgCl2/Res/EG (0.1:1:2) DES outperforms most of the reported DESs. The excellent NH3 absorption performances of metal–containing DESs have been attributed to the synergy of Lewis acid–base and hydrogen bonding interactions. Additionally, good reversibility and high NH3/CO2 selectivity are achieved over the MgCl2/Res/EG (0.1:1:2) DES, which enables it to be a potential NH3 absorber for further investigations. 相似文献
8.
《International Journal of Hydrogen Energy》2022,47(84):35790-35809
PEMFC system is a complex new clean power system. Based on MATLAB/Simulink, this paper develops a system-level dynamic model of PEMFC, including the gas supply system, hydrogen supply system, hydrothermal management system, and electric stack. The neural network fits the electric stack model to the simulation data. The effects of different operating conditions on the PEMFC stack power and system efficiency are analyzed. Combining the power of the reactor and the system efficiency to define the integrated performance index, the particle swarm optimization (PSO) algorithm is introduced to optimize the power density and system efficiency of the PEMFC with multiple objectives. The final optimal operating point increases the power density and system efficiency by 1.33% and 12.8%, respectively, which maximizes the output performance and reduces the parasitic power. 相似文献
9.
《International Journal of Hydrogen Energy》2022,47(15):9209-9219
Highly active, low-cost, and durable electrocatalysts toward hydrogen evolution reaction (HER) are crucial for electrochemical water splitting. Herein, a green, facial, and effective strategy was proposed to develop CoP on carbon cloth (CoP/o-CC) as efficient self-supported hydrogen evolution electrodes. The designed CoP/o-CC exhibits superior catalytic activity with overpotentials of 118 mV and 95.45 mV to deliver a current density of 10 mA cm?2 in acidic and alkaline solution, respectively, which is superior to most reported studies. In addition, the designed CoP/o-CC electrode also possesses excellent stability even under a large current density of 100 mA cm?2. The origin of significantly enhanced stability thereby was further systematically investigated. Experimental study reveals that the oxygenated functional groups on carbon cloth play the role to bind the CoP electrocatalysts, forming C-O-Co bonds. Thus, the enhanced electrochemical and structural stability of CoP/o-CC is predominantly caused by the interfacial interaction of the C-O-Co bonds between the CoP active materials and surface oxygenated functional groups of carbon fiber. Therefore, we believe that this work provides an in-depth insight into the role of interfacial interaction between the substrate and the catalysts and offers a new methodology to design durable and efficient electrocatalysts. 相似文献
10.
目的为了以更加客观的方式评估用户体验,拓展用户研究的途径,引入表情识别技术对已有用户研究方法进行优化与探索。方法以阅读APP为研究载体,以表情识别与卷积神经网络算法为技术手段,通过设计人机交互实验将其应用于用户研究过程中,建立用户面部表情与用户主观满意度的映射关系。结果针对阅读APP"X",开展了基于表情识别技术和传统问卷访谈的双向设计研究,并采用对比验证的方法得出了基于表情识别技术的用户满意度客观度量方法的有效性和可行性,进而挖掘了基于表情识别方法的用户研究优势。结论基于表情识别技术的用户研究方法在产品交互设计中具有一定的通用性。通过识别分析用户与产品进行人机交互时的面部表情动态变化,可以使用户体验评估更加客观并容易解读,准确定位产品交互体验问题,为设计领域中的用户研究和认识提供了新思路,同时也为表情识别技术与产品设计的交叉融合提供了理论和实践意义的参考。 相似文献