Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet

Laser action in methyl methacrylate （MMA） co-doped with sulforhodamine B and crystal violet dyes was investi- gated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd：YAG laser. Distributed feedback dye laser （DFDL） action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor-donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor-donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

Applications of Floquet-Magnus and Fer Expansion Approaches during Cross Polarization Radiation in Solid State NMR

This paper investigates the concept of Cross Polarization (CP) experiment in addition to revisiting the two potential expansion schemes recently developed in the field of solid-state nuclear magnetic resonance (SSNMR): namely, the Floquet-Magnus expansion and the Fer expansion. We use the aforementioned expansion schemes for the calculation of effective Hamiltonians and propagators when the spin system undergoes Cross Polarization radiation. CP is the gateway experiment into SSNMR. An in-depth comprehension of the underlying mechanics of spin dynamics during the cross-polarization experiment is pivotal for further experimental developments and optimization of more complex solid-state NMR experiments. The main contribution of this work is a prospect related to spin physics;particularly regarding to generalization of the calculation. This work reports original yet interesting novel ideas and developments that include calculations performed on the CP experiment. In fact, the approach presented could play a major role in the interpretation of several fine NMR experiments in solids, which would in turn provide significant new insights in spin physics. The generality of the work points towards potential applications in problems related in solid-state NMR and theoretical developments of spectroscopy as well as interdisciplinary research areas as long as they include spin dynamics concepts.

Microstructure and mechanical properties of Mg-Zn-Y-Zr alloy prepared by solid state recycling

Machined chips of Mg-Zn-Y-Zr alloy were consolidated by cold pressing and then hot extrusion under various processing temperatures and extrusion ratios. The results show that the microstructure of the chip-extruded alloy is marked by a large number of recrystallized grains and some unrecrystallized grains, which results in high strength but low ductility at temperatures below 320 ℃. With increasing processing temperature up to 360 ℃, entirely recrystallized and equiaxed grains are obtained. Mg-Zn-Y-Zr alloy with low strength but high ductility is obtained compared with the alloy processed at low temperature. At 420℃, coarse and equiaxed grains are formed, which results in the drastic decrease of mechanical properties. With increasing extrusion ratio from 8 to 16, the grain refinement is more obvious and the mechanical properties at room temperature are improved effectively. However, the yield strength and ultimate tensile strength are improved a little with further increasing extrusion ratio.

Supercritical-hydrothermal accelerated solid state reaction route for synthesis of LiMn_2O_4 cathode material for high-power Li-ion batteries

Synthesis of the spinel structure lithium manganese oxide （LiMn2O4） by supercritical hydrothermal （SH） accelerated solid state reaction （SSR） route was studied. The impacts of the reaction pressure, reaction temperature and reaction time of SH route, and the calcination temperature of SSR route on the purity, particle morphology and electrochemical properties of the prepared LiMn2O4 materials were studied. The experimental results show that after 15 min reaction in SH route at 400 ℃ and 30 MPa, the reaction time of SSR could be significantly decreased, e.g. down to 3 h with the formation temperature of 800 ℃, compared with the conventional solid state reaction method. The prepared LiMn2O4 material exhibits good crystallinity, uniform size distribution and good electrochemical performance, and has an initial specific capacity of 120 mA.h/g at a rate of 0.1C （1C=148 mA/g） and a good rate capability at high rates, even up to 50C.

Salt-assisted Low Temperature Solid State Synthesis of High Surface Area CoFe_2O_4 Nanoparticles

A novel salt-assisted low temperature solid state method using CoCl2.6H2O, FeCl3.6H2O and NaOH as precursor and using NaCI as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Brunauer, Emmett and Teller （BET） surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursor led to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m^2/g, and the saturation magnetization is 84.6 emu/g.

Isothermal superplastic solid state bonding of 40Cr and Cr12MoV steels based on surface modification

Based on the feasibility of isothermal superplastic solid state bonding of 40Cr and Cr12MoV steels, the surfaces of both steels to be bonded were ultra-fined through high frequency hardening, then the superplastic solid state bonding were conducted, the microstructure and fracture surface of bonded joint were observed and analysed, and bonding mechanisms was researched. The experimental results show that with the sample surfaces of 4OCr and Cr12MoV steels after the high frequeney hardening, under the prepressing stress of 56. 6 MPa, initidl strain rate of 1.5 × 10^ -2 min^-1 and at the bonding temperature of800 -820℃, the superplastic solid state bonding can be carried out in about 3.5 min, and the joint strength is up to that of 40Cr steel base metal and the radial expansion ratio of the joint does not exceed 6%. The saperplastic solid state bonding parameter of both steels is within the ranges of the isothermal compressive superplastic deformation of Cr12MoV steel, and the deformation in Cr12MoV steel side near the interfacial zone of joint presents the characteristic of superplasticity. In bonding process, the atoms in two sides of joint interface have diffused each other.

New Progress on All Solid State Laser Technology in China

1 Significance of All Solid State Laser (DPL) Technology in Field of LaserBecause of the advantages of high conversion efficiency, good beam quality, small size and light weight, DPL becomes the hotspot and priority of development of laser technology. It may be the main body of laser in the future and replace gas laser and liquid laser. It is a great revolution of laser technology.The developed countries vie in developing DPL. China has achieved great success in this field, but there is a wide gap between the developed countries and us. We should attach great importance to it.

THE SOLID STATE ALDOL CONDENSATION REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES

The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.

Low-Temperature Solid State Synthesis and Characterization of Superconducting Vanadium Nitride

Superconducting vanadium nitride （VN） is successfully synthesized by a solid-state reaction of vanadium pentox- ide, sodium amide and sulfur in an autoclave at a relatively low temperature （240-400℃）. The obtained samples are characterized by x-ray diffraction, x-ray photoelectron spectroscopy and transmission electron microscopy. The result of the magnetization of the obtained VN product as a function of temperature indicates that the onset superconducting transition temperature is about 8.4K. Furthermore, the possible reaction mechanism is also discussed.

Chemical Kinetic Aspects of Solid State Reaction Producing Wollastonite from Rice Husk Silica and Limestone

An industrial mineral wollastonite (CaSiO3) was produced under solid state conditions from rice husk silica and limestone. Reaction was carried out at 900'C to 1300'C for 1 h. The product batches were subjected to XRD and chemical analysis techniques specific for wollastonite. Mole fractions of different product batches were calculated on the basis of accumulated data to study the kinetics. Specific rate constants and reaction rate were also found out. Various probable models of mechanism for reaction were considered and testified with the laid down criterion for suggesting the suitable one. The resulting data were treated with Arrhenius equation as well and activation energy was calculated--therefrom. In addition to finding it's value from the slope of Arrhenius curve, an alternate method was also applied for this purpose. Both of the values were observed to be comparable. The activation energy required for performed reaction was found to be almost one third of that reported for synthesizing CaSiO3 by using quartz. This referred to the economical preparation of wollastonite by using rice husk as a source of silica instead of quartz.

Infrared Laser Pumped Green and Blue Laser Emissions from a Single Solid State Material Doped by Rare Earth Ions

The possible ways and progress of infrared or red laser pumped green and blue laser emissions from a single solid state material doped by rare earth ions are outlined. The green and blue lasers realized from infrared laser pumped rare earth doped nonlinear laser crystals by means of self frequency conversion and from infrared laser pumped rare earth doped bulk, fiber and microsphere materials by means of frequency upconversion are introduced in detail. Other kinds of devices and methods are also compared. The typical nonlinear laser crystals such as YAl 3(BO 3) 4, GdAl 3(BO 3) 4, YCa 4O(BO 3) 3 , GdCa 4O(BO 3) 3, and the typical upconversion fluoride fibers are compared and analyzed. The major problems remaining to be solved and the developing trends in the area are also discussed.

Interfacial Issues of All Solid State Lithium Batteries

All solid state lithium battery is a promising next generation battery system with improved cycle life, en ergy density, especially safety. However, its development is greatly hampered by a large impedance between the solid state electrolyte/electrode interface. How to build an ideal electrolyte/electrode interface to improve the inter facial stability and reduce the interracial resistance is a huge challenge for improving battery performance. This pa per reviews interracial problems and introduces the formation mechanism of different interface layers between elec trodes and electrolytes. In addition, the strategies for improving interracial contact and reducing interracial resist ance are described in detail. Finally, the research directions for engineering interfaces in all solid state lithium bat teries are proposed.

Laboratory of Solid State Microstructures(LSSMS)

1. General Survey The Laboratory of Solid State Microstruc-tures (LSSMS) of Nanjing University islocated in the centre of the historic cityNanjing. It is one of the major labs establi-shed with the approval and special grantfrom the National Planning Commissionof China in 1984, based on the Instituteof Solid State Physics of Nanjing University. The research direction of LSSMS focuses

STUDIES ON SOLID STATE REACTIONS OF COORDINATION COMPOUNDS(LXⅡ)Solid state synthesis and crystal structure of the complex ICu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)CIJ·0.5CS_2

[Cu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)Cl]·0.5CS_2=,Mr=895.79,monoclinic,space group P2_1/a,a=17.231(3),b=14.611(2),c=18.000(3) ,β=105.56(2)°,V=4365(1) ~3, Z=4,D_c=1.37g/cm^3.,λ(MoK_α)=0.71073 ,μ=12.15cm^(-1),F(000)=1855,R=0.052, R_W=0.045 for 3930 observed reflections with Ⅰ>1.5σ(Ⅰ).The central metal atom has a dis. torted tetrahedral geometry with bond lengths Cu-S=2.384(2) (Au-S=2.389(4)), Cu-Cl=2.481(3)(Au-Cl=2.474(1))and Cu-P=2.269(2)-2.289(2)(Au-P=2.270(4)-2.279(4)) .

THE SOLID STATE CONTROLLED PHOTOCHEMICAL REACTION OF NITROBENZALDEHYDE WITH INDOLE

The solid state photochemical reaction of nitrobenzaldehyde with indole was investigated. Seven hey products were identified by IR, MS,^(1)H HMR and elemental analysis.

Ag3PO4 Microcrystals Synthesized by Room-Temperature Solid State Reaction:Enhanced Photocatalytic Activity and Photoelectronchemistry Performance

Ag3PO4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the asprepared Ag3PO4 microcrystMs are characterized by x-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra. The photocatalytie properties of Ag3PO4 are investigated by the degradation of both methylene blue and methyl orange dyes under visible light irradiation. The as-prepared Ag3PO4 microcrystals possess high photocatalytic oxygen production with the rate of 673μmolh-1g-1. Moreover, the as-prepared Ag3PO4 microcrystals show an enhanced photoelectrochemistry performance under irradiation of visible light.

STUDIES ON THE CHEMICAL STRUCTURES OFACTIVATED CARBON FIBERS BY SOLID STATE NMR

The solid stale C13-NMR spectra of different ACFs from various precursor fiberswere recorded in this paper. The effects of activation conditions on chemical structuresOf ACFs, as well as the changes of chemical structures during carbonization and redoxreaction were investigated by NMR technique. At same time, the solid state P31-NMRspectra of ACFs are studied The C13-NMR spectra of ACFs can be divided into sixbands that are assigned to methyl and methylene groups, hydroxyl and ether groups,acetal (or methylenedioxy carbon, graphite-like aromatic carbon structure, phenol,and quinone groups, respectively. Only phosphorous pentoxide exists on ACFs andCFs. Moreover, most of them are stuck over the crystal face but not at the edge ofgraphite-like micro-crystaL The carbonization and activation conditions affect theC13-NMR spectra of ACFs. The experimental results indicate that the redox reactionof ACFs with oxidants greatly consumes C-H group.

Utilization of winery wastes for Trichoderma viride biocontrol agent production by solid state fermentation

Biocontrol agents are safe and environmental friendly alternatives for pesticides in agriculture application. Trichoderma viride WEBL0703 performed a high level of antagonistic activity toward a broad spectrum of phytopathogens and was determined as a biocontrol agent, which was produced by solid state fermentation using grape marc and wine lees. The maximum yield of T. viride conidia was up to 6.65 × 10^9 CFU/g initial dry substrate （IDS） after 10 d fermentation. As important enzymes for protecting plants from disease, chitinase, β-glucanase, and pectinase yields were 47.8 U/g IDS, 8.32 U/g IDS and 9.83 U/g IDS, respectively. These results show that it is feasible to convert winery wastes to a value-added and environmental friendly biocontrol agent.

A Dye-sensitized Nanocrystalline Solid State Photovoltaic Cell

A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-CuI heterojunction was fabricated. Tetra-carboxyphenyl porphyrine (TPP-(COOH)(4)), squarylium cyanine derivative (SQ-(CH2),(SO3Py+)-Py-.) and ruthenium bipyridyl complex (RuL2(NCS)(2)) were used as photosensitizers. Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.