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Unlike other road materials, aeolian sand has some compaction characteristics that are key factors in construction qualities of highway in the desert. In order to study the characteristics, a series of laboratory and field tests were performed, including sieve analysis, standard modified compaction, vibrating compaction and field test. By analyzing the sieve analysis test data, it was found that the gradation of aeolian sand was bad, with fine grains whose diameters mostly ranged from 0.25 mm to 0.074 mm. Then, from the laboratory compaction test results, a compaction curve similar to the horizontallywritten letter S was obtained. That was quite different from the other kinds of road materials. There were two peak values in the curve with the increase of water content, which was the special characteristic of aeolian sand: to be well compacted whether it was dry or wet. Also, according to laboratory vibrating test results, the best vibrating frequency range was proposed. It was from 45 Hz to 50 Hz. Moreover, some field compaction tests were carried out. On the construction site of the highway, the aeolian sand subgrade was compacted in the condition of natural water content with optimizing construction machines. Its compaction degree reached 96%, meeting the current specifications. At last, comparative studies were carried through with electron microscope. It was shown that the microstructure of compacted dry aeolian sand is much denser than that of the natural one in the field test.

A compact in-fiber integrated fiber-optic Michelson interferometer based accelerometer is proposed and investigated. In the system, the sensing element consists of a twin-core fiber acting as a bending simple supported beam. By demodulating the optical phase shift, we obtain that the acceleration is proportional to the force applied on the central position of the twin-core fiber. A simple model has been established to calculate the sensitivity and resonant frequency. The experimental results show that such an accelerometer has a sensitivity of 0.09 rad/g at the resonant frequency of 680 Hz.

In this study, we demonstrate a quantitative and sensitive strategy for monitoring lipase concentration using a liquid crystal (LC) microfiber biosensor based on whispering-gallery mode (WGM). LC 4-cyano-4′-pentylbiphenyl (5CB) microfiber...

In this work, PtFeCu concave octahedron nanocrystals were synthesized by a one-pot solvothermal method. The PtFeCu concave octahedron nanocrystals were applied as an electrocatalyst for the electrooxidation of methanol and have shown high electrocatalytic activity and long-term durability. The electrocatalysis performances of the PtFeCu concave octahedron nanocrystals are better than those of the PtFe and PtCu nanocrystals and commercial Pt/C. The synergistic effect of the Pt, Fe, and Cu metals and the unique concave octahedron morphology may be the main cause of the superior electrocatalytic performances of the PtFeCu nanocrystals. The PtFeCu concave octahedron nanocrystals have a potential application as an anode catalyst for direct methanol fuel cells.

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