Label free non-invasive imaging of topically applied actives in reconstructed human epidermis by confocal Raman spectroscopy

Raman spectroscopy has become a versatile tool for the in vivo characterization of skin. Here we describe use of Raman spectroscopy for high resolution optical cross sectioning to resolve skin constituents and administered drugs at the cellular level. Percutaneous penetration is typically studied using permeation cells with biopsies of animals or human skin. Although this technique provides valuable clinical data, little insight is gained in the microstructure of drug penetration (intercellular or transcellular) or in the mode of action of applied vehicles or penetration enhancers. Therefore, a Raman microspectroscopic method was combined with a confocal scanning setup to image the microstructure of commercially available skin models (SkinEthic^®) and the spatial distribution of penetrated actives. The models’ microstructure was scanned without any special treatment or environment such as cutting, staining, freezing, or application of vacuum. The non-invasive Raman images reveal the layered structure of stratum corneum. This in particular for lipids while water tends to be more evenly distributed. When penetration of the hydrophilic active glycerol and the lipophilic octyl methoxycinnamate, OMC, was studied, a strong correlation between the local distribution of skin constituents and the hydrophilic/lipophilic character of the active was observed.     

一种超高耐久混凝土——梯度结构混凝土

分析超高耐久混凝土的研究现状,提出了一种高耐久、低成本的超高耐久混凝土--梯度结构混凝土(Gradient Structural Concrete,简称GSC),采用电量法和氯离子扩散系数法来评价梯度结构混凝土的抗氯离子渗透性能,最后进行梯度结构混凝土的寿命预测与成本分析.结果表明,高性能混凝土(High Performance Concrete,简称HPC)、无细观界面过渡区水泥基复合材料(Meso-interfacial transition zone-free cement-based materials,简称 MIF)和梯度结构混凝土MIF-HPC的6 h导电量和氯离子扩散系数的排列顺序均为:HPC>MIF-HPC>MIF,其抗氯离子渗透性能排列顺序为:MIF>MIF-HPC>HPC.梯度结构混凝土的成本会有所增加,但由于其氯离子渗透性能大幅降低,其使用寿命得到大幅延长,使得其年损耗费用大幅下降.     

About the Importance of Nanometer-Thick Intergranular Penetration in the Analysis of Liquid Metal Embrittlement

Liquid metal embrittlement (LME) of copper by liquid bismuth is investigated at 300°C. It is shown that a very rapid damage is due to the synergy between the external stress and the phenomenon of intergranular penetration (IGP). Tests of IGP, i.e. without external stress, were done at 300°C and at 600°C and have resulted in strong intergranular embrittlement due to the formation of nanometer-thick intergranular films, as measured and quantified by Auger electron spectroscopy (AES). The formation of these films is discussed with respect to apparently non-zero dihedral angles at 600°C. A general procedure based on mechanical testing and AES measurements, to check whether IGP has occurred or not, is outlined. This procedure can be seen as an alternative way to determine the wetting transition temperature. The presence of nanometer-thick films due to IGP is discussed with respect to the LME mechanisms.     

Effects of some parameters on the divertor plasma sheath characteristics and fuel retention in castellated tungsten tile gaps

Castellation of plasma facing components is foreseen as the best solution for ensuring the lifetime of future fusion devices. However, the gaps between the resulting surface elements can increase fuel retention and complicate fuel removal issues. To know how the fuel is retained inside the gaps, the plasma sheath around the gaps needs to be understood first. In this work, a kinetic model is used to study plasma characteristics around the divertor gaps with the focus on the H＋ penetration depth inside the poloidal gaps, and a rate-theory model is coupled to simulate the hydrogen retention inside the tungsten gaps. By varying the magnetic field strength and plasma temperature, we find that the H＋ cyclotron radius has a significant effect on the penetration depth. Besides, the increase of magnetic field inclination angle can also increase the penetration depth. It is found in this work that parameters as well as the penetration depth strongly affect fuel retention in tungsten gaps.     

截卵形弹头对混凝土靶侵彻性能的试验研究

介绍了截卵形弹头钻地弹对混凝土靶的侵彻试验研究结果。根据缩比钻地弹侵彻过程的高速录像和试验结果对弹丸运动状态进行了分析,得出了截卵形弹头钻地弹侵彻混凝土靶的速度变化曲线和阻力变化曲线;利用缩比理论,给出了标准钻地弹对混凝土靶侵彻性能的计算方法和分析结果。     

细长尖头刚性弹对金属靶板的斜侵彻/穿甲分析

给出细长尖头刚性弹（如尖卵、尖锥形）斜侵彻/穿甲金属靶的一个分析模型。在细长尖头弹对中厚度金属靶的斜穿甲中,韧性孔洞扩张为主要的穿甲机理;着靶初期,发生方向角的改变。研究表明,金属靶的斜穿甲仅由4个量纲一参数控制,即冲击函数I、弹体几何函数N、量纲一靶厚和撞击斜角。分析得到显式的侵彻深度、终点弹道极限、剩余速度和撞击方向改变角表达式。该模型可预期跳飞发生的临界条件。理论预期与实验结果吻合较好。     

卵形杆弹对铝靶的斜侵彻

在Lagrange有限元基础上,扼要介绍了一种适用于三维斜侵彻数值模拟计算的滑移面处理技术。该方法放弃了传统滑移计算中从单元的设置,而代之以预设从节点,从而避免三维斜侵彻数值计算中主从单元的相交、滑移面的识别、修正与再定义的困难。在确保计算精度的同时,有效地提高了计算效率。卵形杆弹对铝靶侵彻的系列数值模拟计算表明,无论对于正撞击或斜撞击,本文中所获结果与实验结果都有良好的一致性,这说明本文中所述方法和所建程序的合理性和有效性,为侵彻贯穿过程的数值分析提供了一种实用和有效的手段。     

着靶速度对刚玉块石混凝土抗侵彻性能的影响

着重对不同着靶速度下,弹体在刚玉块石混凝土中的侵彻情况进行了试验。研究结果表明,弹体的侵彻深度不随靶速度的提高而增加。这与弹体在普通混凝土和岩石中的侵彻现象明显不同,主要是由侵彻弹体发生破坏失去了继续侵彻能力造成的。而且,与普通混凝土或岩石相比,着靶速度越高,刚玉块石混凝土的抗侵彻性能越强。     

氢及其同位素在溴化丁基橡胶中渗透的分子模拟

使用分子动力学(MD)和巨正则蒙特卡罗(GCMC)的方法,对H_2,D_2,T_2在溴化丁基橡胶(BIIR)中的扩散和溶解行为进行了计算模拟,运用自由体积理论探讨了气体分子在聚合物内的扩散机理,并得出气体的运动轨迹。结果表明:对氢及其同位素而言,质量越小,运动速度越快,扩散系数越大,溶解度系数比较接近,渗透系数的模拟值与实验值基本吻合,为提高材料的阻隔性能提供了一定理论基础,同时预测出硫化溴化丁基橡胶对氚水也有较好的阻隔性能。     

弹丸侵彻混凝土加速度信号测试及分析

针对弹丸侵彻混凝土加速度信息获取及实测信号失效问题,采用弹载存储测试系统进行了实验,并基于LS-DYNA进行了高速碰撞过程的数值模拟,经处理后的数据曲线与实测侵深符合较好,数值模拟计算结果与实验结果较吻合。通过实验分析与理论推导相结合的方式对应力波、测试装置的基础运动和安装结构刚度、加速度计安装方式等部分影响因素进行了实测加速度信号的影响分析,分析结果对高g值冲击测试问题具有一定的参考价值。