Phase-shift Perfluoropentane Nanoemulsions Enhance Pulsed High-intensity Focused Ultrasound Ablation in an Isolated Perfused Liver System and Their Potential Value for Cancer Therapy.

PURPOSE: To investigate whether phase-shift perfluoropetane (PFP) nanoemulsions can enhance pulsed high-intensity focused ultrasound (HIFU) ablation. METHODS: PFP was encapsulated by poly(lactic-co-glycolic acid) (PLGA) to form a nanometer-sized droplet (PLGA-PFP), which was added to an isolated perfused liver system. Meanwhile, phosphate-buffered saline (PBS) was used as a control. The perfused liver was exposed to HIFU (150 W, t = 3/5/10 s) at various duty cycles (DCs). The ultrasound images, cavitation emissions, and temperature were recorded. Rabbits with subcutaneous VX2 tumors were exposed to HIFU (150 W) at various DCs with or without PLGA-PFP. After ablation, necrosis volume and energy efficiency factor were calculated. Pathologic characteristics were observed. RESULTS: Compared to the PBS control, PLGA-PFP nanoemulsions markedly enhanced HIFU-induced necrosis volume in both perfused livers and subcutaneous VX2 tumor-bearing rabbits (P <.05). Inertial cavitation was much stronger in the pulsed-HIFU exposure at 10% than that in the continuous-wave HIFU exposure (P <.01). Peak temperature at 100% DC was significantly higher than that at 10% (P <.05). Compared to 100% DC HIFU exposure, the mean necrosis volume induced by 10 s exposure at 50% DC was significantly larger (P <.005) but lower at 10% DC in the isolated perfused livers (P <.05). In addition, the mean necrosis volume in subcutaneous VX2 tumor-bearing rabbits was significantly increased after HIFU exposure at 10% DC when compared to those at 100% DC (P <.05). Histopathologic analysis showed liquefaction necrosis in pulsed HIFU. CONCLUSION: PLGA-PFP nanoemulsions can enhance HIFU ablation in the isolated perfused livers and promote tumor ablation in the subcutaneous xenograft rabbit model. Appropriate pulsed HIFU exposure may increase the necrosis volume and reduce total ultrasound energy required for HIFU ablation.

Effect of Surfactant Polyvinyl Pyrrolidone on the Properties of Microporous Carbon Nanospheres Reinforced Magnesium Matrix Composites.

Microporous carbon nanospheres (PCNS)-reinforced magnesium (Mg) composites were prepared using polyvinyl pyrrolidone (PVP) as surfactant and PCNS as reinforcement. The influence of PVP treatment and the effectiveness of PCNS on the mechanical properties of Mg-based composites were investigated. The results show that the PCNS can enhance the properties of the Mg matrix. Moreover, the PVP can effectively improve the dispersion of PCNS in the Mg matrix but had a negative influence on the tensile properties of composites. The MgO films with high tensile strength were produced between matrix and reinforcement after removing PVP, which effectively promotes the interface compatibility and improves the properties of the composite. The tensile yield strength and specific strength of PCNS-reinforced Mg matrix composite exhibited 177 MPa and 102.4 × 103 N∙m/kg, respectively, which were 77% and 78% higher than those of the Mg matrix.

Racial segregation, testing sites access, and COVID-19 incidence rate in Massachusetts, USA

The U.S. has merely 4% of the world population but 25% of the worlds COVID-19 cases. Massachusetts has been in the leading position of total cases since the outbreak in the U.S. Racial residential segregation is a fundamental cause of racial disparities in health. Moreover, disparities of access to health care have a large impact on COVID-19 cases. Thus, this study estimates racial segregation and disparities in testing sites access and employs economic, demographic, and transportation variables at the city/town level in Massachusetts. Spatial regression models are applied to evaluate the relationships between COVID-19 incidence rate and related variables. This is the first study to apply spatial analysis methods across neighborhoods in the U.S. to examine the COVID-19 incidence rate. The findings are: 1) residential segregations of Hispanic and Non-Hispanic Black/African Americans have a significantly positive association with COVID-19 incidence rate, indicating the higher susceptibility of COIVD-19 infections among minority; 2) The Black has the shortest drive time to testing sites, followed by Hispanic, Asian, and Whites. The drive time to testing sites is significantly negatively associated with the COVID-19 incidence rate, implying the importance of testing location being accessed by all populations; 3) Poverty rate and road density are significant explanatory variables. Importantly, overcrowding represented by more than one person per room is a significant variable found to be positively associated with COVID-19 incidence rate, suggesting the effectiveness of social distancing for reducing infection; 4) Different from previous studies, elderly population rate is not statistically significant with incidence rate because the elderly population in Massachusetts is less distributed in the hot spot regions of COVID-19 infections. The findings in this study provide useful insights for policymakers to propose new strategies to contain the COVID-19 transmissions in Massachusetts.

Whole genomes and transcriptomes reveal adaptation and domestication of pistachio.

BACKGROUND: Pistachio (Pistacia vera), one of the most important commercial nut crops worldwide, is highly adaptable to abiotic stresses and is tolerant to drought and salt stresses. RESULTS: Here, we provide a draft de novo genome of pistachio as well as large-scale genome resequencing. Comparative genomic analyses reveal stress adaptation of pistachio is likely attributable to the expanded cytochrome P450 and chitinase gene families. Particularly, a comparative transcriptomic analysis shows that the jasmonic acid (JA) biosynthetic pathway plays an important role in salt tolerance in pistachio. Moreover, we resequence 93 cultivars and 14 wild P. vera genomes and 35 closely related wild Pistacia genomes, to provide insights into population structure, genetic diversity, and domestication. We find that frequent genetic admixture occurred among the different wild Pistacia species. Comparative population genomic analyses reveal that pistachio was domesticated about 8000 years ago and suggest that key genes for domestication related to tree and seed size experienced artificial selection. CONCLUSIONS: Our study provides insight into genetic underpinning of local adaptation and domestication of pistachio. The Pistacia genome sequences should facilitate future studies to understand the genetic basis of agronomically and environmentally related traits of desert crops.

The different impact between late-phase of limb ischemia preconditioning and early-phase on patients with percutaneous coronary intervention / 中国介入心脏病学杂志

Objective To investigate the difference of late-phase of limb ischemia preconditioning (L-LIP) verse early-phase (E-LIP) on patients with percutaneous coronary intervention (PCI).Methods A total of 160 patients with unstable angina pectoris who were planned to undergo PCI were divided equally into two groups at random.The late-phase of limb ischemia preconditioning group (80 patients) were provided with L-LIP (three 5-minute inflations up to 200mmHg by applying the sphygmomanometer cuff around the right upper arm,followed by 5-min intervals of reperfusion,twice a day) 3 days before PCI.The Earlyphase of limb ischemia preconditioning group (80 patients) were provided with E-LIP (method as above)2 hours before PCI.Comparison of procedural parameters during PCI and the levels of cTnT,CK-MB,hs-CRP were made 24 hours after PCI.Estimation of the rate of adverse events at 1 year between the two groups was evaluated by Kaplan-Meier analysis.Results Compared to the E-LIP group,the rates of angina,arrhythmia and TIMI flow ≤ 2 during PCI were significantly lower in the L-LIP group (all P ＜ 0.05).At 24 hours after PCI,the levels of cTnT and CK-MB were declined more significantly in the L-LIP group[(11.52±2.41) pg/ml vs.(27.53±4.78)pg/ml,P =0.021;(14.11±2.87)Iu/L vs.(30.23±5.17)Iu/L,P =0.032].There was no difference in the level of hs-CRP between the 2 groups [(128±0.71)mg/dl vs.(1.33±0.69)mg/dl,P =0.742].The Kaplan-Meier survival curve showed that the incidence rate of adverse events in the L-LIP group at l year was lower than the E-LIP group (3.75％ vs.13.75％,P =0.024).Conclusions L-LIP is more effective to in protecting myocardial cell in patients with unstable angina pectoris undergoing elective PCI and may reduce the rate of future adverse event.

[Physiological response and salt-tolerance of Gleditsia microphylla under NaCl stress].

In order to exploit the salt-tolerance ability and mechanism of Gleditsia microphylla, the plant growth, cell membrane permeability, the activities of cell protective enzymes, and the distri- butions of Na+ and K+ in different tissues were investigated under various NaCl stress (0.053%, 0.15%, 0.3%, 0.45% and 0.6%) with potted two-year seedlings. The results were as follows: With the increase of NaCl concentration, the seedling growth decreased while the salt injured index in- creased, and the salt-tolerance thresholds of seedling was 0.42% NaCl. With the NaCl concentration increasing, the membrane permeability, superoxide anion radical generating rate and MDA content increased grandly, while the activities of SOD, POD and CAT demonstrated an increase-decrease curve which reached the peak at 0.3% or 0.45%. Under the high salt stress condition, the supero- xide anion could be consumed timely by increasing the activities of SOD, POD and CAT enzymes, which was useful to avoid cell injure. Under salt stress condition, the Na+ content in different tissues increased gradually, following the order of root > leaf > stem, and the K+ content and K+/Na+ in different tissues decreased, following the order of leaf > root > stem. The K+-Na+ selective transpor- tation coefficients (S(K+) · Na+) of stem and leaf tissues under the soil NaCl stress condition were both increased, following the order of leaf > stem. In conclusion, the findings suggested that the salt- adaptation mechanisms of G. microphylla were root salt-rejection by Na+ accumulation and restriction in root tissue and leaf salt-tolerance by a remarkably increased ability of K+ selective absorption and accumulation in leaf tissue.

[Effects of NaCl stress on photosynthesis characteristics and fast chlorophyll fluorescence induction dynamics of Pistacia chinensis leaves].

By using fast chlorophyll fluorescence induction dynamics analysis technique (JIP-test), this paper studied the photosynthesis characteristics and fast chlorophyll fluorescence induction dynamics of 1-year old Pistacia chinensis seedlings under the stress of NaCl at the concentrations 0% (CK), 0.15%, 0.3%, 0.45%, and 0.6%. With the increasing concentration of NaCl, the contents of Chl a, Chl b, and Chl (a+b) in the seedlings leaves decreased, the Chl a/b ratio decreased after an initial increase, and the carotenoid content increased. The net photosynthetic rate (P(n)) and stomatal conductance (g(s)) decreased gradually with increasing NaCl concentration. The decrease of P(n) was mainly attributed to the stomatal limitation when the NaCl concentration was lower than 0.3%, and to the non-stomatal limitation when the NaCl concentration was higher than 0.3%. The trapped energy flux per RC (TR0/CS0), electron transport flux per RC (ET0/CS0), density of RCs (RC/CS0), and yield or flux ratio (psi(0) or phi(E0)) decreased, but the absorption flux per CS (ABS/CS0) and the K phase (W(k)) and J phase (V) in the O-J-I-P chlorophyll fluorescence induction curves increased distinctly, indicating that NaCl stress damaged the leaf oxygen-evolving complex (OEC), donor sides, and PS II reaction centers. When the NaCl concentration reached 0.3%, the maximum photochemical efficiency (F(v)/F(m)) and performance index (PI(ABS)) decreased 17.7% and 36.6%, respectively, as compared with the control.

[Investigation of synthesis and luminescent properties of the Sr2CeO4: Dy3+].

In the present article, Sr2CeO4:Dy3+ was synthesized with N,N-methylene bisacrylamide (MBAA) as the net agent. The structure, morphology and luminescent properties were also characterized. It is indicated that Sr2CeO4:Dy3+ was single-phased without other phase existing and also had good dispersion The UV-visible absorption spectra suggested that the absorption bands were almost at 480 nm. The excitation spectrum for 270 nm emission has several excitation bands; The emission spectrum of Sr2 CeO4:Dy3+ shows two broad bands at 292 and 338 nm under the 370 nm excitation. The effects of Dy3+ doping concentration on the emission spectrum intensity of Sr2 CeO4:Dy3+ were also studied, the results showed that the ratio of yellow emission to blue emission increases with increasing the D/3+ doping concentration, but with increasing the Dy3+ doping concentration, the emission intensity firstly increased, then decreased, and the maximal emission intensity was at 0.4 mol% Dy3+ concentration.

[Research on synthesis and luminous mechanism of a soluble blue-light luminescence material derived from carbazole].

In the present paper, a kind of blue light-emitting organic small molecule luminescent materials was designed and synthesized, which is composed of carbazole and 8-benzyloxyquinoline functional groups. Alkyl chain can effectively play the role of electron transfer barrier. The synthesis principle was on the basis of the mechanisms of SN1 nucleophilic reaction and SUZUKI coupling reaction mechanisms. It is entitled N-[6-(8-benzylquinoline)-hexyl] carbazole (CzBQ). Its molecular structure was simulated and optimized by Gaussian03. Its chemical structure was identified by measurements of ultraviolet-visible spectra and H1 NMR spectra. It photo physical property was characterized by method of fluorescence spectra. t is indicated that CzBQ was a kind of blue-light luminescence material and its optical band gap is 3.02 eV. Ethanol solution of CzBQ exhibits the maximal emission peak at 410 nm in photoluminescence spectra In the luminescence process of CzBQ, carbazole groups and 8-benzylquinoline groups were separately involved in excitation and light emission. This kind of blue-light luminescence material possesses excellent solubility, It can be dissolved in different solvents such as ethanol and ethyl acetate and dichloromethane. The test results of AFM show that CzBQ was provided with very good film formability. It is expected to be utilized in blue-light organic light-emitting device fabricated by wet method such as spin-coding method and screen printing.

[Cold resistance of Pistacia chinensis and Koelreuteria integrifoliola].

Taking one-year-old dormant shoots of Pistacia chinensis and Koelreuteria integrifoliola as test materials and the shoots of northern indigenous tree species K. paniculata as the control, the changes of their membrane-lipid peroxidation, antioxidative enzyme activity, and organic osmoregulatory substance content under artificial cooling were studied, aimed to analyze the differences of the three tree species in cold resistance. With the decrease of temperature, the ion leakage percentage of the three tree species increased in S-shape, and the SOD and POD activities decreased after an initial increase. The MDA, soluble protein, and soluble sugar contents of K. integrifoliola and K. paniculata under decreasing temperature decreased after an initial increase, while those of P. chinensis had an increasing trend. The semi-lethal temperature (LT50 ) of K. paniculata, K. integrifoliola, and P. chinensis calculated by the Logistic equation of ion leakage percentage was -27.2 degrees C, -23.7 degrees C, and -27.0 degrees C, respectively. Among the three tree species, K. paniculata had the strongest cold resistance, followed by P. chinensis, and K. integrifoliola.

Structural characteristics of nanocrystalline copper after carbon ion implantation.

A gradient structure was produced in a pure copper plate by means of surface mechanical attrition treatment (SMAT). The microstructure of the surface layer was reduced to nanoscale and the grain size increased gradually along the depth of the treated sample. In situ transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) observation was performed on the nanocrystalline copper after implantation of carbon. Carbon atoms first precipitated along the edges of the copper substrate or at the surface, then formed amorphous carbon layers. Subsequently, onion-like fullerenes were formed under electron-beam irradiation. The effects of ion implantation, electron beam irradiation, nanostructure of the substrate and interaction of C and Cu atoms on the formation of the onion-like fullerenes are discussed.

[Molecular structure and luminescent property of bis(2-(4-methyl-2-hydroxyphenyl)benzothiazolate) zinc].

Bis(2-(4-methyl-2-hydroxyphenyl)benzothiazolate) zinc(Zn(4-MeBTZ)2) was synthesized. Its molecular structure was confirmed by single-crystal x-ray diffraction. Single-crystal data are as follows: space group triclinic, P-1; a = 8.989 9(11) angstroms, b =12.161 7 (15) angstroms, c = 12.871 9 (16) angstroms, alpha = 63.492 (2) degrees, beta = 84.825 (2) degrees, gamma =71.187 (2) degrees. The steric hindrance provided by introduction methyl groups on phenoxide ring prohibited effectively the formation of pentacoordinate complex. There is distinct intermolecular pi-pi interaction between molecules. The dihedral angle between the phenol and benzothiazolate rings of Zn(4-MeBTZ)2 is 2.166 degrees. The HOMO energy, LUMO energy and optical gap are -5.84, -3.46 and 2.37 eV, respectively. The maximum wavelength peak of PL spectra located at 470 nm. The double-layer devices were employed using Zn(4-MeBTZ)2 as emitter and NPB as hole-transport material. The EL spectra split into two peaks located at 501 and 544 nm respectively. The broadened EL spectra were demonstrated to be originated from the exciplexes formed at the interface between NPB and Zn(4-MeBTZ)2.

[A new type of iridium (III) phenylpyrazole complexes: synthesis, photophysical characterization].

New heteroleptic iridium(III) complexes (ppz)2Ir(LX), which consist of two cyclometalated ligands ppz(1-phenylpyrazole) together with an ancillary ligand LX (LX= 2-(2'-hydroxylphenyl)benzothiazole (BTZ), 2-(3'-methyl-2'-hydroxylphenyl) benzothiazole (3-MeBTZ), 2-(4'-methyl-2'-hydroxylphenyl) benzothiazole (4-MeBTZ) and 2-(4'-Trifluoromethyl-2'hydroxylphenyl) benzothiazole (4-tfmBTZ)), were synthesized and characterized. The molecular structures and photophysical properties were characterized and analyzed comparatively. The results show that the four complexes have basically similar UV-Vis absorption spectra, fluorescence excitation and emission spectra. Their maximum emission peaks are located at 583-615 nm, and accompanied by a lower intensity emission band around 400 nm. The weak emissions around 400 nm are ascribed to the radi ation transition of single state excition from ancillary ligand BTZ perturbed by metallic ion, and light emission around long-wave-length to the radiation transition of 3MLCT of Ir(BTZ) fragment. While the triplet state 3 MLCT of Ir(ppz)2 fragment might be quenched at room temperature. For all complexes, the excitations with maximum efficiency are located at 250-310 nm, which indicates that main contributor to light emitting is ligand-centered absorption (1pi-pi*) of ppz and BTZ rather than 3MLCT transitions, and thus provides a striking evidence that there is intersystem crossing from 1pi-pi* state to 3MLCT state in these complexes. Compared with Ir(ppz)3, these complexes not only have stronger phosphorescence at room temperature but also their emission color can be tuned by modifying ancillary ligand.

[Study on the conversion of acrylic C=C double bonds during dark reaction after UV curing using infrared spectroscopy].

Infrared spectroscopy was used to determine 1,648-1,589 cm(-1) characteristic absorption peak area so as to study the conversation of acrylic C=C double bonds after UV curing. The effects of phototinitiators, active diluents and UV curing resins on the conversion of C=C double bonds were also investigated. The results showed that 40%-85% of C=C double bonds were conversed during dark reaction after 45 s UV curing. Dark reaction will be changed gently after 1.75 h, but 95% conversion of C=C double bonds needed more than 24 h. The rates of polymerization and conversation were affected by photoinitiators, the concentration of photoinitiator, oxygen inhibition, and C=C functional groups of active diluents. The rate of polymerization was affected by the C=C functional groups and types of UV curing resins, but conversation was not.

[New highly phosphorescent heteroleptic tris-cyclometalated iridium (III) complexes: synthesis and photophysical characterization].

New heteroleptic tris-cyclometalated iridium(III) complexes (ppy)2 Ir(LX) (ppy==2-phenylpyridine, LX==Sal (salicylic acid), Msal (4-methylsalicylic acid), FSal(4-trifluoro methyl salicylic acid)) was synthesized and characterized. The molecular structure, photophysical properties and thermal stability were tested and analyzed. The results show that the absorption peaks were located around 270, 370, 450 and 484 nm respectively at room temperature. The two former peaks at 270 and 370 nm should belong to 1pi--pi* transition at ppy and transition from salicylic acid ligands to 2-phenylpyridine; The peaks around 450 and 484 nm can be assigned to the charge transfer transition from Ir to ligand (1MLCT and 3MLCT) and 3pi--pi* transition respectively. The PL emission peaks were located at 520, 522, and 510 nm, respectively. The emission of (ppy), Ir(Sal) and (ppy), Ir (MSal) was mainly ascribed to the radiation transition of triple state 3MLCT, while the emission of (ppy)2 Ir(FSal) was mainly from the radiation transition between Sal and ppy, partly from the radiation transition of single state 1MLCT and triple state 3MLCT. The quantum efficiencies of these complexes were 0.37, 0.33 and 0.29 respectively. The thermal decomposition temperature was from 306 to 328 degrees C. (ppy)2 Ir(LX), being a series of efficient phosphorescent materials with good thermal stability, can be used in the organic electroluminescent devices.

[Spectral analysis and band gap of RbVO3].

In the present paper, RbVO3 was prepared by wet chemistry synthesis from hybrid precursor. The structure of RbVO3 was characterized by X-ray diffraction (XRD) pattern and FTIR spectra. Photoluminescent (PL) properties were investigated by UV-Vis absorption spectrum and PL spectrum. In addition, the band gap of RbVO3 was calculated by using the CASTEP code with density-functional theory (DFT) method. The results indicated that RbVO3 could emit intense green-white fluorescence with peak wavelength at 525 nm and the color coordinates was (0.318 0, 0.430 9) under UV excitation at 357 nm. It was demonstrated that the theoretical result of band gap, which is 2.67 eV, agreed well with the experiment.

[Characterization and photoluminescence properties of a blue-light-emitting material].

Tris (2-methyl-8-hydroxyquinoline) aluminum (AlMeq3) was synthesized and purified by vacuum sublimation. The structure of the complex was characterized by 1H NMR, FTIR spectra and elemental analysis techniques. AlMeq3 consists of three 2-methyl-8-hydroxyquinoline ligands and one aluminum atom. Its thermal stability was studied by TG and DSC analysis and the result shows that AlMeq3 is a thermally stable material, with decomposition and crystalline transition temperature being 357 and 158 degrees C, respectively. Energy band structure was investigated by UV-Vis absorption spectra and fluorescence emission spectra. Experimental results show that its UV absorption bands were at about 246 and 390 nm, and the absorption band at about 246 nm can be assigned to pi--pi* of phenyl ring. AlMeq2 displays 8-hydroxyquinoline-oriented photophysical properties. The optical gap of AlMeq3: was about 2.85 eV, as determined by intrinsic absorption band edge of the complex in ethanol solution. Under UV excitation at 365 nm, the complex in ethanol solution emitted intensive blue fluorescence with the maximum emission peak at 479 nm, while the effective energy-transfer from the ligand to the central AlP+ ion occurred in the complex. AlMeq3 with bright blue photoluminescence can be applied as luminescent material in OLEDs.

[Synthesis and spectral properties of polymer of Tis (5, 5'-methylene-bis (8-hydroxy-quinoline) gallium with orange-red light emitting].

A ligand 5,5'-methylene-bis(8-hydroxyquinoline)(Hqq) was synthesized by condensation reaction at low temperature and was subsequently coordinated to gallium ions to prepare the polymer of tis(5,5'-methylene-bis(8-hydroxyquinoline) gallium (Gaqq3)n. Both chemical structure and phase structure of the ligand and complexes were characterized by Infrared absorption spectrum and X-ray diffraction (XRD). The thermal stability of the complexes was studied by thermogravimetry (TG). The photo-physical properties of the complexes were investigated by ultraviolet absorption spectrum (UV), fluorescence excitation spectrum and emission spectrum. The result indicated that (Gaqq3)n is a thermally stable material, whose decomposition temperature is 443.6 degrees C. The ultraviolet absorption bands of (Gaqq3)n are in the range of 250-500 nm, with a relatively strong band tail absorption between 500 and 650 nm, which shows that the band-gap defect states exists in the forbidden band. The fluorescence excitation band of (Gaqq3)n is located at 380-456 nm, and (Gaqq3)n. emits orange-red fluorescence with the emission peak at 568 nm, which shows that the fluorescence emission of (Gaqq3), is mainly attributed to the charge transfer transitions from phenol to ring pyridine ring, while the pi-->pi* transition of benzene ring is deactivated by non-radiative transition, and makes no contribution to fluorescence emission. (Gaqq3)n optical band gap is 2.49 eV. Compared with the fluorescence emission peak of Gaq3, the fluorescence intensity of (Gaqq3), decreases, which is attributed to the distortion of the two quinoline rings connected to the methylene, hence leads to the poor rigidity and coplanarity of (Gaqq3)n, thus affects fluorescence emission intensity. Because of the extending of the molecular conjugation system, pi electron of (Gaqq3)n is more delocalized, resulting in the redshift of fluorescence emission peak (Gaqq3)n is expected to be applied in organic light emitting display and organic photovoltaic devices.

[Spectral analysis and photoluminescence properties of Eu-Tb codoped polymer].

In the present paper, Eu0.5 Tb0.5 (TTA)3 Phen was synthesized and Eu0.5 Tb0.5 (TTA)3 Phen/PMMA was prepared by in-situ polymerization. The structure of Eu0.5 Tb0.5 (TTA)3 Phen/PMMA was characterized by FTIR spectra. Microscopic morphology and photoluminescence properties were investigated by SEM photographs and fluorescence spectra. The results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent materials. And Eu0.5 Tb0.5 (TTA)3 Phen/PMMA could emit mostly characteristic fluorescence of europium ion and intense red fluorescence with a peak wavelength at 611.8 nm and a bandwidth of 10.4 nm (Purity: 0.9905) under UV excitation at 365 nm. Its fluorescence intensity was found to be influenced with the content of MMA. It w as demonstrated that Eu0.5 Tb0.5 (TTA)3 Phen/PMMA was an excellent red photoluminescent rare-earth polymer material.

[Studies on a new type structure OELD with interinserting interface].

A new type organic electroluminescent device with interinserting interface was fabricated. The basic structure of the device is ITO/NPB/Alq3/Al. By tailor-made template, the two interinserting interfaces were fabricated with NPB/Alq3 and Alq3/Al, respectively. The charge distribution on the interface and the electric field distribution in the organic layer were changed by introducing interinserting interfaces, thus the electron injection was improved, and the balance of the number of the electrons and holes at the interface was obtained. Therefore, the formation probability of exciton was enhanced and the leakage current was reduced. Compared to the traditional two-layer structure devices, the interinserting structure device has lower turn-on voltage and higher luminous efficiency. The driving-voltage of the interinserting structure OELD decreased while the brightness increased with the increase in the number of the interinsertion. As the current density increased, all the devices with interinserting interface showed high optical-electrical stability. The turn-on voltage of the device e is 3 V, and was made using the three slots template. At the current density of 54 mA x cm(-2), the device e gets its maximum efficiency, which is 34% higher than the traditional structure device a.