37results about How to "Stable growth process" patented technology

The invention discloses a chromium-doped lithium tungstate magnesium crystal as well as a preparation method and an application thereof. The molecular formula of the crystal is Cr3+:Li2Mg2(WO4)3, the crystal belongs to an orthorhombic crystal system and a Pnma space group, and the cell parameter is as follows: Z=4. The crystal grows in a top seeded solvent growth method, the mixture of 75% Li2WO4 and 25% WO3 is used as a fluxing agent, the concentration ratio of the fluxing agent in the growth raw material is 55 to 80 percent, and the growth parameters are as follows: the cooling rate is 0.5 to 5 DEG C / day, the growth temperature is 800 to 880 DEG C, and the rotation speed is 5 to 30 turns / min. The crystal has the characteristics such as moderate mechanical performance, large transmission cross section and the like, the tunable range is 750nm to 1050nm, and the crystal is expected to become a novel tunable laser crystal and can be actually used.

The invention discloses a tunable laser crystal blended chrome-molybdenum acid aluminium potassium crystal and preparing method, which is characterized by the following: adopting fused salt top seed crystal method; adopting 60-80at%K2Mo3O10 as fluxing agent; setting detemperature rate at 1-5 deg. c / day; setting revolution rate at 5-30 rotation per min; growing out Cr3+:KAl(MoO4)2 crystal with high quality and bigger size; belonging to trigonal crystal system; possessing P3ml(D3d3) space group structure with refractive index at 1.74. This crystal can be used as tunable laser crystal with tunable range at 700-950 nm, which can be used to spectrography, biological medicine and military domain.

The invention discloses a method for improving the tobacco quality by the modest extension of a vegetative growth period of flue-cured tobaccos. The method comprises the processes of primed pelleted seeds of flue-cured tobaccos, seeding, seedbed growing, transplanting, growth in field and the like, wherein the seeds germinate again before sowing the primed pelleted seeds of flue-cured tobaccos; the nutritional regulation is performed for the first time 10 days after transplanting in the field, the dosage is 5 kg per acre; the nutritional regulation is performed for the second time 35 days after transplanting in the field, the dosage is 10 kg per acre. The method is convenient for the flue-cured tobaccos to fully absorb nutrients in the vegetative growth period, is more conducive to accumulating dry matters of leaves, improving the chemical components, appearance quality and sensory evaluation of the flue-cured tobaccos and improving the quality of tobaccos by delaying the flower bud differentiation time of the flue-cured tobaccos, extending the vegetative growth period of the flue-cured tobaccos and shortening a reproductive growth period of the flue-cured tobaccos.

The invention discloses a dysprosium-doped strontium calcium molybdate green laser crystal. The molecular formula for the crystal is Dy<3+>:Sr2CaMoO6, which belongs to an orthorhombic system and a Pmm2 space group, crystal cell parameters are alpha=beta=gamma=90 DEG, a=8.1513 angstrom, b=5.7416 angstrom, c=5.8385 angstrom and Z=2. The invention also provides a method of preparing the above dysprosium-doped strontium calcium molybdate green laser crystal. A molten salt top-seeded solution growth method is adopted; K2Mo2O7-MoO3 serves as a fluxing agent; the growth parameters are: a cooling rate of 0.5 to 3 DEG C per day, growth temperature of 750 to 790 DEG C, and a rotation speed of 5 to 30 revolutions per minute; the Dy<3+>:Sr2CaMoO6 crystal grows; and the doping concentration of Dy<3+> is 1at.% to 15at.%. The crystal of the invention can be used as a laser working material in a solid-state laser, a flash or a laser diode is used as a pumping source, and green laser is excited and generated and outputted.

The invention relates to a rare earth ion Ln<3+>-doped gadolinium strontium aluminate laser crystal. The laser crystal is Ln<3+>:Gd2SrAl2O7, wherein Ln<3+> is equal to Nd<3+>, Yb<3+>, Tm<3+>, Dy<3+>, Er<3+> and Ho<3+>, and the doping concentration is 0.1at%-50at%; and the single crystal belongs to a tetragonal system, the space group is I4 / mmm, the cell parameters are as follows: a and b are equal to 3.7052-3.73149 angstroms, c is equal to 19.781-19.9857 angstroms, alpha, beta and gamma are equal to 90 degrees, V is equal to 271.56-278.28 cubic angstroms, and z is equal to 2. According to the single crystal, the lattice site of a trivalent gadolinium ion in a lattice is replaced with a trivalent rare earth ion. The compound is a congruent melting compound with a melting point of 1780 DEG C, and the single crystal with high optical quality and large size can grow by virtue of a pulling method and can be taken as the laser crystal.

The invention relates to a neodymium-doped gadolinium barium lithium tungstate laser crystal and a preparation method and application thereof. The high-quality crystal with large size is grown by using 30-60at% Li2WO4 as a fluxing agent under the conditions that the cooling rate is 0.5-2 DEG C / day and the rotating speed is 5-30r / min. The crystal belongs to the monoclinic system and has C2 / c spacegroup structure. The main absorption peak of the Nd<3+>:Li3Ba2Gd3(WO4)8 crystal is 804nm, the half-peak width is 19nm and the absorption transition cross section is 5.37*10<-20>cm<2>, and the crystalis suitable for being pumped by the AsGaAl semiconductor laser. A quite wide emission band exists in the range from 850nm-1400nm. The emission transition cross section at the emission peak of 1064nm is 12.08*10<-20>cm<2>, the fluorescence lifetime is 0.153ms, and the crystal is easy to generate and output lasers with wavelength being 1064nm.

In this invention, C20chralski method is used for the growth of neodymium doped lithium lanthanum barium tungstate laser crystal. The growth conditions are: growth temperature 1410 deg.C, crystal rotation rate 15-20 r.p.m, pulling speed 1.5-3 mm / h. This crystal is of cubic crystal, space group being of Fm3m, single cell parameter a=0.859 angstrom, Z=4, single cell volum V=523.41 cubic angstrom. This invented crystal is a novel kind of laser crystal, it can produce laser output at about 1.06 micron wave length, and being prospected to be real utilization.

Self-activated laser crystal scandium strontium neodymium borate and preparation method thereof relate to the field of artificial crystals, in particular to a self-activated laser crystal scandium strontium neodymium borate (NdSr 6 Sc(BO 3 ) 6 ) and its preparation method. Using the pulling method or molten salt method, high-quality, large-sized NdSr 6 Sc(BO 3 ) 6 crystals. The crystal belongs to 3 - Space group, density 4.37g / cm 3 , the refractive index is 1.75. Spectral calculation shows that the crystal has a strong absorption peak at 808nm, and the absorption coefficient is 36.10cm -1 , half peak width 18.00nm, absorption cross section 1.46×10 -20 cm 2 , suitable for pumping by laser diode (LD); in addition, it has a strong fluorescence emission peak at a wavelength of 1060nm, and the emission transition cross section is 1.31×10 -19 cm 2 , The half-peak width is 28nm, and it is easy to produce laser output with a wavelength of 1060nm. Solid-state lasers made of this crystal can be used in many fields such as spectroscopy, biomedicine, and military affairs.

The invention relates to a vacuum brazing method for a seed crystal substrate for homoepitaxial growing of monocrystal diamond. The method aims to solve the problems that in an existing MWCVD growth system, seed crystal is prone to being blown by airflow to deviate from the optimum position, and heat is difficult to conduct between the seed crystal and a metallic molybdenum substrate; a traditional welding medium is too low in melting point and poor in compatibility with the diamond or reacts with the diamond seriously to damage the seed crystal, and the high-quality growth requirement for the diamond cannot be met. The method comprises the steps of 1 cleaning, 2 welding medium selection, 3 sample placing and 4 vacuum brazing. In this way, the vacuum brazing for the seed crystal substrate for homoepitaxial growing of the monocrystal diamond is achieved.