The object of this study is to synthesize Li 3 Ba 2 Gd 3 (MoO 4 ) 8 doped with Eu 3+ ions and prepared with solidstate reaction technology. The results show that the dominant emission peak of Li 3 Ba 2 Gd 3-x (MoO 4 ) 8 :Eu x phosphor is 5 D 0 f 7 F 2 (614 nm). The intensity of the emission from 5 D 0 to 7 F 2 is 3.8 times higher than that of commercial phosphors, ZnS:(Mn 2+ ,Te 2+ ) when the Eu 3+ concentration is x ) 2.4. The CIE chromaticity coordinates of the red emission of the Li 3 Ba 2 Gd 0.6 Eu 2.4 (MoO 4 ) 8 phosphor are (0.67, 0.33), which is the NTSC system standard for red chromaticity. Because there are two regions in the excitation spectra of Li 3 Ba 2 Gd 3 (MoO 4 ) 8 :Eu 3+ phosphor, one is assigned from the charge-transfer state (CTS) band at about 320 nm, and the other is from the intra-4f transitions from 350 to 500 nm. Hence, the phosphors could be strongly excited by near-UV and blue LED in solid-state lighting technology. The analysis of the lifetime, decay curves, and efficiency of the 5 D 0 f 7 F 2 emission indicates the weak energy transfer between Eu 3+ pairs. The temperature dependence PL and absorption spectra study shows that thermal quenching behavior can be attributed to crossover from the 5 D 0 excited state to the CTS band.

Microalgae serve as a promising source for the production of biofuels and bio-based chemicals. They are superior to terrestrial plants as feedstock in many aspects and their biomass is naturally rich in lipids, carbohydrates, proteins, pigments, and other valuable compounds. Due to the relatively slow growth rate and high cultivation cost of microalgae, to screen efficient and robust microalgal strains as well as genetic modifications of the available strains for further improvement are of urgent demand in the development of microalgae-based biorefinery. In genetic engineering of microalgae, transformation and selection methods are the key steps to accomplish the target gene modification. However, determination of the preferable type and dosage of antibiotics used for transformant selection is usually time-consuming and microalgal-strain-dependent. Therefore, more powerful and efficient techniques should be developed to meet this need. In this review, the conventional and emerging genome-editing tools (e.g., CRISPR-Cas9, TALEN, and ZFN) used in editing the genomes of nuclear, mitochondria, and chloroplast of microalgae are thoroughly surveyed. Although all the techniques mentioned above demonstrate their abilities to perform gene editing and desired phenotype screening, there still need to overcome higher production cost and lower biomass productivity, to achieve efficient production of the desired products in microalgal biorefineries.

Color-tunable phosphors of BaY2−xEuxZnO5 (x=0.001–0.9) were synthesized using a vibrating milled solid state reaction. The results indicate that the emission spectra of BaY2−xEuxZnO5 samples excited at 395 nm exhibit a series of shaped peaks assigned to the D50→F7J (J=0,1,2,3,4) transitions. Luminescence from the higher excited states, such as D51, D52, and D53, were also observed even though the Eu3+ concentration was up to x=0.2. The chromaticity coordinate of BaY2−xEuxZnO5 phosphors varies with the Eu3+-doped concentrations from blue, white, to red, and which may be potentially applicable as a white light emitting phosphor for ultraviolet light emitting diodes.

A strategy for the optimization of an expanded bed adsorption process has been developed by studying a model system involving the adsorption of lysozyme onto the adsorbent STREAMLINE SP. The hydrodynamic and adsorption properties of this ion exchange adsorbent in a variety of viscosities of feedstocks have been compared by analyzing bed expansion characteristics, liquid phase dispersion characteristics, equilibrium adsorption isotherms, and mass transfer characteristics. Additionally, the influences of the degree of bed expansion on adsorption performance have been investigated by frontal analysis. In these experiments, viscous feedstocks were simulated bythe inclusion of glycerol in the adsorption buffers. Breakthrough curves for lysozyme were characterized and compared in terms of overall purification processing time and productivity. On the basis of these results, the relative productivities of different operating modes with the same process liquid were found to be almost the same. However, the processing time for each purification cycle decreased with increasing velocity of process liquid. It is demonstrated that an adsorption process carried out at a constant degree of bed expansion (twice its settled bed height, corresponding to bed voidage of 0.7) is more efficient, when characterized by the apparent dynamic binding capacity, than operation at a constant liquid velocity of 300 cm/h. These results have significant implications on the design and operation of the expanded bed adsorption procedures. The advantages and problems encountered in the use of expanded bed techniques for the direct extraction of proteins from unclarified feedstocks are also discussed. 0 1996 John Wiley & Sons, Inc.