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Long period fiber grating is a kind of passive optical device which is sensitive to the surrounding environment. Owing to without retroreflection, high sensitivity to refractive index, miniature size, easy integration, immunity to electromagnetic interference, non-corrosiveness, without the need of reference electrode, long period fiber grating based optical sensors have attracted much attention in the field of refractive index sensing. Since Bentley research group first used long period fiber gratings to detect antigens in 2000, long-period gratings have made great progress in the detection of biological substances in recent years and have been utilized for the detection of many biological substances such as antigen-antibody, bacterial viruses, proteins, DNA, enzymes, nucleic acids, and so on. In this paper, the research progress and applications of long period fiber grating in the biosensing field in recent years are summarized and reviewed, and the future development trend of long period fiber grating in biological detection is also prospected.

Under the background of tourism affected by the fog and haze, this study takes Xi’an as a case, focuses on the tourists’ type and behavior, and forms the following conclusions. The tourist can be divided into blunt type, normal type and sensitive type based on the perception to the fog and haze. The blunt type has demographics of male, elderly people, lower educated, low income, and from the North of China. The sensitive type has demographics of female, single, middle-aged, higher educated, and from the South of China. The blunt and sensitive types who pay less attention to the fog and haze in the before travel stage, have a rational willingness behavior, and have a significant increase on the attention rate to future decision after this travel. But the sensitive type prefers to the quality and healthy behavior in the stage of during tour.

Experimental study on crystallization of polystyrene spheres and SrTiO3 particles in laser standing wave field is presented. The diameter of polystyrene, which are able to be trapped, is 7 times smaller than that reported by Burns, the corresponding lattice constant is reduced to 1.5 μm. The crystallization effect of SrTiO3 particles with a refractive constant of 2.5 in the visible range is observed for the first time. Based on the results above we believe that it is possible to construct photonic crystal with lattice constant extended to visible wave range by this method.

An overview is provided of (a) deaf education in China, (b) views of deaf Chinese, and (c) recent empowering international collaborations. China's national policy focuses on oral/aural education and hearing rehabilitation. However, everyday practice in schools for deaf children includes various forms of Chinese Sign Language. Early childhood education focuses on speech and hearing. Elementary and secondary school curricula reflect low expectations for deaf students and lack the same academic content provided to hearing students. There are limited higher education opportunities. There are no support services such as note takers or interpreters for mainstreamed students. There are no deaf teacher preparation or interpreter training programs. Jobs are few; the vast majority of deaf adults are unemployed. Deaf people interviewed for the article describe their needs, their dreams, and the changes they are witnessing, which result in part from recent empowering international collaborations.

A new liquid crystal hybrid bistable optical device (BOD) is introduced. The optical bistability of two modes of operation of this LC BOD have been observed. The use of LC BODs for optical logic elements and ultralinear modulation applications is described. The transient response of LC BODs has been studied and a "critical slowing down" phenomenon has been observed. The switch time has been measured. The experimental results are in agreement with Garmire's theory.

In this paper, we describe a hybrid nonlinear P-P Bistable Optical Device (BOD), the length of its cavity is controllable. The dynamic equations of the system and the equilibrium splution which shows the optical bistable nature are given. The bis-tability and linear modulation characteristics are discussed. The stability of the equilibrium state and the "critical slowing down" effect of transient behavior are analysed. The experimental demonstrations are in agreement with the theoretical evaluations.

Photodissociation of Fe(CO)5 have been achieved using U-V laser as the photolysis source, A middle- energy U-V laser pulse (～20 mJ/pulse) is directed into a specially designed gas cell which typically contains 10-20 Torr of Fe(CO)5. We have obtained some ultrafine powders from U-V laser photolys of lron-pentacarbonyl in gas cell. Through the analysis of products by using modern physical instruments, we identify that the resulting powders are iron oxide, ironcarbide; they also contain a little crystalline state of iron or carbon and oxygen. The particles in the powders are uniform in size (300-400 ?) and have catalytical activity. At appropriate laser power densities, U-V laser photodecomposition of Fe(CO)5 has also-achieved to produce Fe film on the window of the gas cell. The film composition was examined by X-ray fluorescence.