酚醛玻璃钢动态本构关系的实验研究

本文叙述了在轻气炮上作高速撞击实验,使用碳膜压阻传感器,一次记录多个应力历史波形,用Lagrange分析和路径线方法,求材料动态本构关系的方法。给出了应力在2 GPa、应变率4105S-1以下酚醛玻璃钢的数值形式本构关系。探讨了强应力脉冲在酚醛玻璃钢中传播衰减的物理原因。     

岩石细观损伤破坏的观测研究

利用扫描电镜（ Ｓ Ｅ Ｍ ）,对香港白岗岩等岩样在单轴压缩状态下,进行细观结构（μｍ 尺度）观察,研究其微损伤的萌生、扩展、连接直至破坏的行为,分析了白岗岩等岩石的细观破坏机制及其与宏观力学行为的关系,得到了一些重要的感性认识和若干观察记录．为认识岩爆发生的机理及复杂应力状态下岩石损伤破坏的理论分析提供了实验依据     

Uncovering toxicological complexity by multi-dimensional screenings in microsegmented flow: modulation of antibiotic interference by nanoparticles

The technique of microsegmented flow was applied for the generation of two- and higher dimensional concentration spaces for the screening of toxic effects of selected substances on the bacterium Escherichia coli at the nanolitre scale. Up to about 5000 distinct experiments with different combinations of effector-concentrations could be realized in a single experimental run. This was done with the help of a computer program controlling the flow rates of effector-containing syringe pumps and resulted in the formation of multi-dimensional concentration spaces in segment sequences. Prior to the application of this technique for toxicological studies on E. coli the accuracy of this method was tested by simulation experiments with up to five dissolved dyes with different spectral properties. Photometric microflow-through measurement of dye distribution inside the concentration spaces allowed the monitoring of microfluid segment compositions. Finally, we used this technique for the investigation of interferences of the antibiotics ampicillin and chloramphenicol towards E. coli cultures and their modulation by silver nanoparticles by measuring bacterial autofluorescence. Each concentration point in this three-dimensional concentration space was represented by 4 or 5 single segments. Thus, a high reliability of the measured dose/response relations was achieved. As a result, a complex response pattern was discovered including synergistic and compensatory effects as well as the modulation of the range of stimulation of bacterial growth by a sublethal dose of chloramphenicol by silver nanoparticles.     

呋喃西林,呋喃西林类似物及其铜(Ⅱ)、锌(Ⅱ)、镍(Ⅱ)络合物的合成和抑菌作用

近年来,文献上报导了许多缩氨基脲、缩氨基硫脲及其金属配合物的抗癌、抗微生物活性,发现金属配合物往往比配体表现出更高和更广泛的生物活性。呋喃西林(O₂N-C₄H₂O-CH=NNHCONH₂)是一种曾用于临床的硝基呋喃类广谱抗菌药物。但由于副作用大不再用于体内。近年来耐药菌株不断增加以及交叉耐药性的出现,使得治疗耐药菌株感染成为医学上的一大难题。     

Oxygen sensor nanoparticles for monitoring bacterial growth and characterization of dose–response functions in microfluidic screenings

Microchimica Acta - We are presenting a microfluidic droplet-based system for non-invasive, simultaneous optical monitoring of oxygen during bacterial cultivation in nL-sized droplets using...     

碳膜压阻传感器的静压加卸载标定

本文报告了对破膜压阻传感器进行的静压加载和卸载标定,量程范围为MPa-1.5GPa.文中介绍了实验方法,给出了四次标定曲线.     

Monitoring cell cultivation in microfluidic segments by optical pH sensing with a micro flow-through fluorometer using dye-doped polymer particles

Polymer microparticles containing an immobilized pH-sensitive dye are used for determination of pH inside microfluidic segments. The particles possess a hydrophilic surface in order to get a homogenous distribution inside the aqueous phase of microfluidic segments. The dye is coupled to the polymer matrix by a covalent bond. The pH can be determined by the read-out of fluorescence intensity. In contrast to dissolved indicator dyes, the chemical interference of the sensor particles with the surrounding solution is negligible. So, the particle-based sensing can easily be applied to the determination of pH changes during the cultivation of cells inside the microfluidic segments. The typical change of pH during cell cultivation can be used for monitoring the kinetic of cell cultivation inside single volumes in the nanoliter range, so that information about the metabolic activity of the organism can be obtained. An LED-based miniaturized flow-through fluorometer was developed to determine the fluorescence directly inside microtubes of an inner diameter of 0.5 mm. It allows measurement frequencies up to 60 Hz and is suited for characterization of fast moving large sequences of microfluidic segments.     

一类两步Runge-Kutta方法的代数稳定性

1引言 考虑刚性常微分方程初值问题 {y'(x)=f(y(x)),X∈[a,b],y(a)=yo, yo=Rn,(1.1) 这里及下文中,RN表示Ⅳ维欧氏空间,<·,·>是其中内积,∥·∥是相应的内积范数.