Search

KDP crystals are restrained to grow along (100) direction by a new designed platform. Compared to conventional method, it enables us to grow KDP crystals with higher optical utilization and less labor costs in fabrication process of optical components. The size of the grown crystals is 20×20×10mm3. Its quality has been analyzed by UV-vis spectral, chemical etching and high resolution X-ray diffraction. The FWHM of diffraction curves is 32 and 36 arc s. The transparency measured by UV-vis spectrometer is up to 80%. The results from various characterization studies indicate that the optical quality is almost as same as the conventionally grown crystals.

A new mixed laser crystal, Yb0.006Y0.923Lu0.071VO4, has been successfully grown using the Czochralski method. X-ray powder diffraction analysis shows that the crystal has ZrSiO4 structure. Density, thermal expansion coefficients, specific heat and thermal diffusion coefficients were measured, and the thermal conductivity coefficients were determined.

The flux growrh method is employed to grow the Yb:LuPO4 crystal using lead pyrophosphate Pb2P2O7 as the high-timperature solvent. The infrared spectroscopy(IR) was tested to determine the purity of the obtained crystal. The absorption spectra of the 5% Yb-doped Yb:LuPO4 crystal was measured at room temperature. Three absorption peaks that located on 985nm, 976nm and 953nm were found, and the absorption cross sections on the absorption peaks were calculated respectively. The results shows that Yb:LuPO4 crystal has potential to be applied as laser material.

The method of growing ADP crystal along {100} direction rapidly has been studied. A platform was used to grow ADP crystal to improve its utilization and optical quality. Chemical etching was used to analyze the dislocation mechanism. It indicates that the crystal grown in the defined crystallographic direction {100} could be qualified for optical application. The grown crystals were characterized by optical transmission spectra. It can be observed that the transmittance of the sample grown by our method reached 85% in the visible region.

4-dimethylamino-N-methyl -4-stilbazolium tosylate(DAST) was synthesized by the condensation and ion exchange reaction of 4-methyl-N-methyl pyridinium tosylate, 4-N,N-dimethylamino -benzaldehyde and silver p-toluenesulfonate, the reaction procedure was easy with high efficiency. The purity of the product was further improved by successive abstersion and recrystallization. The powder was investigated by Fourier transform infrared spectrum, nuclear magnetic resonance and elemental analysis. The results showed that the quality of the powder as crystal raw material was very high, the product could meet the requirements for crystal growth, the procedure of washing the product by chloroform was important to achieve the high quality.

4-dimethyla-mino-N-methyl 4-stilbazolium tosylate（DAST） crystals were prepared by the slope nucleation method (SNM). The structural and optical properties of the grown crystals were studied by employing powder XRD and FIIR. The surface morphology of DAST crystals was observed by scanning electron microscope (SEM). The Vickers hardness studies were carried out on (001) and (110) faces of grown DAST crystal. The values of Meyer’s index number n and hardness were calculated from Hv. The results showed that the DAST crystals belong to the soft material category.

DAST (4-N, N-dimethylamino-4′-N′-methyl stilbazolium tosylate) crystal has been grown by slope nucleation method (SNM) at different cooling rates (0.5°С/d and 0.1°С/d). The morphology of crystal growing surfaces was observed by scanning electron microscope (SEM) and microscope. Different growth striations were found on the growth surfaces. The arrangements of crystal ions and cooling rate have a great influence on the crystal shape. The relationship between the DAST crystal molecular structure and the crystal shape was systematically studied by analyzing the growing surface morphology. Two-dimensional nucleation mechanism was found on growing faces with increasing supersaturation.

A kind of in-situ crystal growth observation system for solution temperature reduction method was designed. The growth surface morphology of KDP crystal was observed by this system. Dislocation hillocks with elliptical shape were clearly distinguished on the {100} face. The dynamics process of morphology evolvement on growth surface of KDP crystals was recorded and analyzed. The growth velocity of the step trains generated from dislocation hillocks was about ~10-4.

The unearthed textile is an important material for human existence. This paper describes the design processing of database system of unearthed textiles. The database is built under the Microsoft Office Access, which mainly contains the age of unearthed textiles, category, excavated site, collection information, character description of textiles, picture, and literature sources. The function of this database includes data input, data maintenance, data query, data mining and data application.