[Fiber Humidity Sensor Based on Fiber Bragg Grating Sandwiched in SMS Fiber Structure].

A fiber humidity sensor based on Fiber-Bragg Grating (FBG) sandwiched in single-mode-multimode fiber core-single mode (SMS) fiber structure is proposed and demonstrated. When the surrounding humidity changes, the central wavelength of FBG remains unchanged for it is insensitive to humidity, while the interference spectrum of SMS fiber structure will shift for it is sensitive to the surrounding humidity. Hence, the shift of the SMS fiber structure interference spectrum with humidity could modulate the FBG core mode.

Theoretical and experimental study of structural slow light in a microfiber coil resonator.

In this paper, a compact slow-light microfiber coil resonator (MCR) is fabricated and the slow-light properties of it are analyzed and tested. Based on coupled-wave theory, a theoretical model for describing the slow-light propagation in the MCR is established. Experimentally, the MCR slow-light element is fabricated and its relative slow-light time delay is measured.

Divalent cations and molecular crowding buffers stabilize G-triplex at physiologically relevant temperatures.

G-triplexes are non-canonical DNA structures formed by G-rich sequences with three G-tracts. Putative G-triplex-forming sequences are expected to be more prevalent than putative G-quadruplex-forming sequences. However, the research on G-triplexes is rare.

Photoluminescent sensing for acidic amino acids based on the disruption of graphene quantum dots/europium ions aggregates.

A simple mix-and-detect photoluminescence method was developed for the turn-on detection of acidic amino acids. To achieve this, graphene quantum dots (GQDs), which emit both down-conversion and up-conversion photoluminescence were prepared by solvothermal synthesis. The carboxylic acid-rich surface not only increases the water solubility of the prepared GQDs, but also makes Eu(3+)-triggered GQDs aggregation possible, thus causing the photoluminescence quenching of GQDs.

[Research on high sensitivity temperature sensor based on Mach-Zehnder interferometer with waist-enlarged fiber bitapers].

Optical fiber sensing technology is one of the very promising techniques in sensing fields. A high sensitivity high temperature sensor based on inline optical fiber Mach-Zehnder(M-Z) interferometer by using standard single mode fiber with two waist-enlarged bitapers is proposed in the present paper. The waist-enlarged bitapers are considered as couplers, the distance between the two bitapers is the sensing arm.

Stress and temperature sensitivity of photonic crystals resonant cavity.

The temperature and stress characteristic of photonic band gap structure resonant cavities with square and graphite lattice have been studied by finite-difference time-domain method. The results show that the resonant cavities, both square and graphite lattice, have more and more resonant frequency with the cavity enlarging. And the curves between the resonant frequency and stress have better linearity.

[Simultaneous measurement of temperature and strain based on long-period fiber grating and Sagnac interferometer spectrum].

A simultaneous measurement system of temperature and strain is proposed and fabricated, which has advantages of low cost and easy structure. The system is formed by combining a long period fiber grating with a polarization-maintaining fiber Sagnac loop. The transmission spectrum of the fiber Sagnac interferometer is modulated by LPFG.

[Application of fuzzy comprehensive assessment in risk assessment of water pollution conditions in downriver area of Dahuofang reservoir].

Fuzzy comprehensive model was used to assess water quality state in Hunhe river of Dahuofang reservoir from 1996 to 2004. It was found that the water quality of Hunhe river changed fluctuantly and belonged to II and serious III state besides in 1997, 2001, and 2003. The main pollutants were organic pollutants, oil and ammonia.