Determination of Methanol Increment in Mobile Phase Consisting of Methanol and Water by On—line UV Spectrometry in Reversed Phase Liquid Chromatography

ＩｎｔｒｏｄｕｃｔｉｏｎＦｒｏｎｔａｌｃｈｒｏｍａｔｏｇｒａｐｈｙ (ＦＣ) ,ａｎｏｌｄｂｒａｎｃｈｉｎｌｉｑｕｉｄｃｈｒｏｍａｔｏｇｒａｐｈｙ (ＬＣ) ,1ｈａｓｂｅｅｎｓｕｃｃｅｓｓｆｕｌｌｙｅｍ ｐｌｏｙｅｄｉｎｔｈｅｓｏｌｕｔｉｏｎｏｆｍａｎｙｔｈｅｏｒｅｔｉｃａｌａｓｗｅｌｌａｓａｐ ｐｌｉｅｄｐｒｏｂｌｅｍｓ—ｓｕｃｈａｓｍｅａｓｕｒｉｎｇｂｉｎｄｉｎｇｃｏｎｓｔａｎｔｂｅ ｔｗｅｅｎｃｏｍｐｏｎｅｎｔｓ2 ａｎｄｋｉｎｅｔｉｃｐａｒａｍｅｔｅｒｓｏｆｃｈｅｍｉｃａｌｒｅａｃｔｉｏｎｓ ,3 ａｄｓ…     

Si(1 1 1)-H(1 × 1): A mirror for atoms characterized by AFM, STM, He and H2 diffraction

AFM, STM and diffraction of He and H₂ have been used to assess Si(1 1 1)-H(1 × 1) surfaces for their potential as mirrors for matter-waves. The H-passivated samples are produced by wet-chemical methods and delivered to a different laboratory for diffraction measurements. We show that the surface is flat and homogenous over lateral scales of microns and that absolute He and H₂ reflectivities of the order of ∼3% are obtained, even after 20 h storage under Ar and several days’ storage in UHV. These characteristics allow the use of Si(1 1 1)-H(1 × 1) as a highly reflective mirror for atoms and molecules, with application in a future He microscope or focused hydrogen nano-lithography system.     

Anomalous diffusion probes microstructure dynamics of entangled F-actin networks

We study the thermal motion of colloidal tracer particles in entangled actin filament (F-actin) networks, where the particle radius is comparable to the mesh size of the F-actin network. In this regime, the ensemble-averaged mean-squared displacement of the particles is proportional to tau(gamma), where 0相似文献   

Measurement of the phase diagram of DNA unzipping in the temperature-force plane

We separate double stranded lambda phage DNA by applying a fixed force at a constant temperature ranging from 15 to 50 degrees C, and measure the minimum force required to separate the two strands. The measurements also offer information on the free energy of double stranded DNA (dsDNA) at temperatures where dsDNA does not thermally denature in the absence of force. While parts of the phase diagram can be explained using existing models and free energy parameters, others deviate significantly. Possible reasons for the deviations between theory and experiment are considered.