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31.
A simple regression method for quantifying endogenous leucine in S30 extract was developed. This method enabled the quantity of translated protein in a cell-free protein synthesis system to be exactly determined. 相似文献
32.
开发了一种用来描述火箭发动机点火时导弹发射管内燃气流及其与结构部件相互影响的初始瞬态响应数学模型,一系列重要事件是:点火器喷出,发射管后盖脱落以及沿发射管在导弹和发射管壁间的环形区内传播的压缩波。开发了一种相应的数值程序,通过有限差分法可以解不稳态欧拉方程,对数字解和得到的压力测量值以及闪光X-射照片进行了说细分析和比较。 相似文献
33.
Enyne metathesis (enyne bond reorganization) 总被引:1,自引:0,他引:1
34.
35.
Motion gradient vector flow: an external force for tracking rolling leukocytes with shape and size constrained active contours 总被引:5,自引:0,他引:5
Recording rolling leukocyte velocities from intravital microscopic video imagery is a critical task in inflammation research and drug validation. Since manual tracking is excessively time consuming, an automated method is desired. This paper illustrates an active contour based automated tracking method, where we propose a novel external force to guide the active contour that takes the hemodynamic flow direction into account. The construction of the proposed force field, referred to as motion gradient vector flow (MGVF), is accomplished by minimizing an energy functional involving the motion direction, and the image gradient magnitude. The tracking experiments demonstrate that MGVF can be used to track both slow- and fast-rolling leukocytes, thus extending the capture range of previously designed cell tracking techniques. 相似文献
36.
Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications 总被引:2,自引:0,他引:2
Jalali-Rad R Ghafourian H Asef Y Dalir ST Sahafipour MH Gharanjik BM 《Journal of hazardous materials》2004,116(1-2):125-134
Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (qmax values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in < 2 min and equilibrium reached within the first 30 min of contact. Biosorption of cesium by FASs1 derived from P. australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles. 相似文献
37.
The fragmental constant approach (FCA) was used to calculate water-sodium dodecyl sulfate (SDS) micelle partition coefficients, K(mw), for uncharged solutes from their structure. Subsequently, the availability of K(mw) values allows prediction of retention factor, k, in micellar electrokinetic chromatography (MEKC) using the simple relationship k = K(mw)phi, where phi is the phase ratio. The FCA model describes a micelle-water partition coefficient as the sum of the partition coefficients of the constituent atomic/molecular fragments, measured by fragmental constant values, f (i), as well as correction factors to account for various "intramolecular effects" that cause deviations from the predicted partition coefficients as, log K(mw) = sum(n)(i=1)aif i+sum(m)(i=1)kiCm. The fragmental constants for a set of 41 fragments were determined using a training set of 229 aromatic solutes and 198 aliphatic compounds. The K(mw) of the aromatic compounds in the training set were determined by MEKC, while the K(mw) of the aliphatic solutes were estimated using the linear solvation energy relationship (LSER) for the SDS micelles. The fragments consisted of both aromatic fragments (i.e., directly attached to an aromatic ring) and aliphatic fragments. The FCA predictions agree nicely with the observed and LSER partition coefficient values, even for complex molecular structures such as beta-blocker drugs. The results show the great potential of the FCA for a priori prediction of retention behavior in MEKC from solute structure. 相似文献
38.
A novel approach for three-dimensional (3-D) display systems implemented with a micromirror array was proposed, designed, realized, and tested. The major advantages of this approach include the following: (1) micromirrors are reflective and hence achromatic (panchromatic), (2) a wide variety of displays can be used as image sources, and (3) time multiplexing can be introduced on top of space multiplexing to optimize the viewing zone arrangements. A two-view (left and right) 3-D autostereoscopic display system was first constructed. Left- and right-eye views in the forms of both still and motion 3-D scenes were displayed, and viewers were able to fuse the stereo information. A multiview (two left and two right) 3-D autostereoscopic display system was then simulated. 相似文献
39.
The multidirectional asymmetrical microlens-array light-control film (MAMA-LCF) is developed for enhancing the image brightness and contrast ratio of various reflective liquid-crystal displays. By use of index-matching material, the interface reflection is greatly reduced. Through optimized designs, the surface-scattering effect is also suppressed; thus the contrast ratio is much enhanced. From experimental results, the MAMA-LCF leads to a approximately 1.5 x gain in brightness over the MgO standard white and a 15:1 contrast ratio for the reflective color super-twist nematic liquid-crystal display, 2.8 x MgO and a 23:1 contrast ratio for the polymer-dispersed liquid-crystal, and 2.8 x MgO and a 13:1 contrast ratio for the cholesteric liquid-crystal display. Potential applications of this low-cost plastic thin film for reflective liquid-crystal displays are foreseeable. 相似文献
40.
A new method of developing optical fiber pressure sensors by use of a fiber loop ringdown scheme is described. The fiber loop ringdown system is characterized in terms of the ringdown baseline stability, fiber transmission loss, and fiber refractive index. The overall sensor performance is demonstrated by use of sensing forces applied to the sensor head. The current device can sense pressures in the range of 0 to 9.8 x 10(6) Pa, converted approximately from the applied forces. The sensor's linear response, repeatability, detection sensitivity, measuring dynamic range, and temperature tolerance are explored. 相似文献