Ethyl lactate is widely used in food
and pharmaceutical industries,
but the complexity of the synthesis process, in particular, involving
the addition of organic solvents, hinders its application. Here, we
report a natural green strategy to produce ethyl lactate by exploiting
the synergistic fermentation of lactic acid bacteria and ester-producing
microbes using biomass as a substrate. Interestingly, it is worth
noting that the conjugate fermentation has a higher ethyl lactate
yield (3.05 g/L) compared to the mixed fermentation (1.32 g/L). The
ester production capacity was increased by 2.3 times. These entire
processes require only the addition of biomass without introducing
any organic solvent. In addition, the obtained catalytic esterification
system can reuse the ester-producing microbes by simple centrifugation
and maintain over seven cycles of catalysis while it retained a high
activity. We firmly believe that the results of this study will provide
new ideas for achieving sustainable green production of natural ethyl
lactate.
Passive optical remote sensing is one of the effective methods to measure the composition of the Martian atmosphere. A static wide field-of-view polarization Michelson interferometer is intended to be used to measure winds in the atmosphere of Mars. The highlight of the instrument is the application of a thin lens array and a polarizer array to obtain four interferograms simultaneously without moving parts; then the velocity and temperature can be deduced from the four interferograms. The thin lens array is used to divide the pupil, and this makes the optical system small and lightweight. Moreover, there is no influence on the recovered temperature and velocity when the lens array is misaligned. A fully compensation technology is applied to widen the field-of-view and fulfill achromatic and thermal compensation, and simulations show that the designed scheme responds well to theoretical expectation.
The novel static polarization wind imaging interferometer adopts four-face pyramid prism and polarization array to obtain four different phase interferograms on four sections of CCD once. It can detect the target in real time and overcome the moving mirror scan detection mode defect that leads to be unable to accurately detect the rapily changing target. For the signal beam that is split into four equal parts, their intensities drop significantly, so whether the signal can be detected is a key problem. In this paper, the target spectral characteristic of the airglow is taken as the starting point of analysis, then the optical transmission properties and response of the NSPWII system and CCD signal-to-noise ratio are analyzed. Finally the conclusion is obtained that weak signal (such as night airglow) cannot be detected in the conventional detecting mode. Some improving measure is presented which extends light integration time, adopts pixel merger technology and select high sensitivity CCD (as electron multiplication CCD), they all can improve the signal-to-noise ratio effectively. After integrated using the these measures, the signal-to-noise ratio and responsiveness of NSPWII system are calculated. In view of the rapid changes of cost and objectives, only pixel binning is adopted, and the simulated curve of signal-to-noise ratio versus digital output is obtained. The result shows that the weak signal as night airglow can be detected.
The static polarization wind imaging interferometer takes advantage of polarized-light beam to obtain interferogram, and beam transmission characteristic in core polarization components is a key issue. The Jones matrix is convenient and concise for analyzing the optics polarization state, and easy to obtain the relationship of key optical components in the system performance. The Jones matrix is introduced to describe the static polarization interferometer system respectively in a given case and in a general case. The variations of optical flux and interference fringe visibility are investigated as functions of polarization direction and wave plate azimuth associated with the key components, and their optimal values are ascertained. The optical flux can be improved by widening field of view and increasing the transmittance of the pyramid prism. The simulation results of the interference intensities confirm the theoretical expectations.The study provides a theoretical basis and practical guidance for the design, development and engineer of the static polarization wind imaging interferometer.
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