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[en] Highlights: • With moderate Er substitution, both the piezoelectric and ferroelectric properties are improved. • BNT-xEr ceramics show the optimal piezoelectric and luminescence properties when x = 0.01. • The green emission of the prepared ferroelectric ceramics after poling is enhanced about 18%. • Poling is an effective way to enhance the luminescence of rare-earth doped ferroelectrics. -- Abstract: The influences of Er content on the dielectric and photoluminescence performances of Bi0.5Na0.5TiO3-xEr (x = 0, 0.005, 0.01, 0.015, 0.02, 0.03) ceramics have been investigated. The results show that Bi0.5Na0.5TiO3-xEr ceramics with x = 0.01 Er have maximum values of photoluminescence and piezoelectric properties. A bright green emission at 550 nm and enhanced piezoelectric response are achieved in the ceramic Bi0.5Na0.5TiO3-0.01Er at room temperature. Furthermore, the photoluminescence performance of the ceramics is significantly enhanced by electric poling
[en] Fe, Ni and Cr are the important structural material nuclides for fusion application. The experimental data of scattering cross sections at small angle are very scarce for Fe and Ni but for Cr have not published yet. The measurements of the small angle scattering cross section were carried out on the cockcroft-walton accelerator with rotational target. The experimental data are corrected for the multiple neutron scattering and flux attenuation effects in the samples by Monte Carlo method. The results of differential elastic cross section for 14.8 MeV neutrons from Fe, Cr and Ni are presented
[en] In this article, the authors report a novel method for preparation of Pd nanocrystals embedded in TiO2 film; i.e., the TiPdO films are first deposited by reactively cosputtering Ti and Pd targets in a plasma mixture of O2 and Ar, followed by rapid thermal annealing (RTA). The experimental results indicate that the TiPdO film with a high content of Pd is inclined to produce big nanocrystals. Furthermore, the higher the RTA temperature, the bigger the Pd nanocrystals become. In addition, our analyses of the x-ray photoelectron spectroscopy spectra reveal that PdO, PdO2, Ti2O3, and TiO2 coexist in the as-deposited film, and the RTA at 600 deg. C leads to decomposition of the entire PdO2 and partial PdO, together with the growth of Pd nanocrystals. At the same time, the released oxygen oxidizes fully Ti2O3 into TiO2 during the decomposition. As the RTA temperature is increased up to 900 deg. C, more and more PdO is decomposed and the Pd nanocrystals become bigger and bigger.
[en] To observe the levels of serum IL-8 in patients with severe acute respiratory syndrome (SARS), the levels of serum IL-8 in 66 patients with SARS were measured by RIA, in comparison with controls. The results showed that levels of serum IL-8 in patients with SARS were significantly higher than those in controls. In the convalescent patient, the levels of IL-8 were various. Conclusion: There is immunoreaction abnormality in patients with SARS. The change of IL-8 in patients with SARS might play an important role in it s pathogenesis
[en] A-site vacancies were created in lead-free piezoelectric non-stoichiometric ceramics Bi0.5+x (Na1-yKy)0.5-3xTiO3 and Bi0.5+x (Na0.82K0.18)0.5TiO3, which were synthesized by a conventional solid-state reaction process. The ferroelectric properties, piezoelectric performances and strain behaviours of the as-prepared ceramics were characterized, and the effects of A-site vacancies on the ferroelectric properties, piezoelectric performances and strain behaviours of the ceramics were discussed. The results show that moderate A-site vacancies in the prepared ceramics enhance the piezoelectric performance of the ceramics, meanwhile, A-site vacancies lead to a decrement of depolarization temperature Td. A large bipolar strain of 0.35% is achieved in the Bi0.505(Na0.74K0.26)0.485TiO3 ceramic at room temperature.
[en] To study the clinical significance of serum collagen type IV in patients with severe acute respiratory syndrome (SARS), the level of serum collagen type IV in 66 patients with SARS was measured by RIA and compared with control group. The results showed that level of serum collagen type IV in patients with SARS was significantly higher than that in control group. The positive rate of level of collagen type IV in convalescent patients was 28.7%. Higher level of serum collagen type IV was found in patients whose chest X-ray examination showed that the focus was absorbed slowly. There was higher level of serum collagen type IV in some patients with SARS and this was related to focus absorption and extent of fibrosis. The level of serum collagen type IV may be a better indicator of monitoring extent of pneumonofibrosis
[en] To study the clinical significance of serum SOD in patients with severe acute respiratory syndrome (SARS), the level of serum SOD in 66 patients with SARS was measured by RIA and compared with control group. The results showed that the level of serum SOD in patients with SARS was significantly lower than that in control group. The serum SOD level in severe type of patients was lower than that in general type. The serum SOD level in convalescent patients was increased, but still lower than that in control group. There were excessively free radicals in patients with SARS, so SOD was depleted excessively. The change of SOD in patients with SARS maybe reflect the severe degree of ill. Dynamic detection of serum SOD level was helpful in analyzing serious or mild SARS. It may be an important therapeutic measure that excessively free radicals were eliminated from the body
[en] Polycrystalline CoFe2O4/NiFe2O4 powders were prepared by auto-combustion method using a novel amino-based gel. The thermal evolution of gel precursors, as well as the microstructure, morphology and magnetic properties of as-synthesized powders were studied in detail. Energy dispersive x-ray spectroscopy indicated that the ratios of Ni:Fe was close to the theoretical value (Ni:Fe = 1:2), suggesting high purity of synthesized NiFe2O4 powders. The saturated magnetization (M s) and residual magnetization (M r) of CoFe2O4 were highly dependent upon the annealed temperatures. The M s increased from 77.5 to 84.7 emu g−1, and M r increased from 37.7 emu g−1 to 42.5 emu g−1 by annealing from room temperature to 600 °C. The M s of NiFe2O4 was 38.7 emu g−1, much lower than that of CoFe2O4. The experimental results indicated that this auto-combustion method using amino-based gel was a suitable method for synthesizing high-quality CoFe2O4/NiFe2O4 powders. (paper)
[en] To investigate drug resistance of mycobacterium tuberculosis in different age group, compare detecting effect of two methods and evaluate their the clinical application value, all of the strains of mycobacterium tuberculosis were tested for resistance to RFP, INH SM PZA and EMB by the absolute concentration method on Lowenstein-Jensen medium and the mutation of the rpoB, katG, rpsL, pncA and embB resistance genes in M. tuberculosis was tested by PCR-SSCP. In youth, middle and old age group, the rate of acquired drug resistance was 89.2%, 85.3% and 67.6% respectively, the gene mutation rate was 76.2%, 81.3% and 63.2% respectively. The rate of acquired drug resistance and multiple drug resistance in youth group was much higher than those in other groups. The gene mutation was correlated with drug resistance level of mycobacterium tuberculosis. The gene mutation rate was higher in strains isolated from high concentration resistance than those in strains isolated from low concentration resistance. The more irregular treatment was longer, the rate of drug resistance was higher. Acquired drug resistance varies in different age group. It suggested that surveillance of drug resistence in different age group should be taken seriously, especially in youth group. PCR - SSCP is a sensitive and specific method for rapid detecting rpoB, katG, rpsL, pncA and embB genes mutations of MTB. (authors)
[en] Highlights: • The testing device of HPS PV/T heat pump system was established by a finished product of PV panel. • A detailed mathematical model of heat pump was established to investigate the performance of each component. • The dynamic and static method was combined to solve the mathematical model of HPS PV/T heat pump system. • The HPS PV/T heat pump system was optimized by the mathematical model. • The influence of six factors on the performance of HPS PV/T heat pump system was analyzed. - Abstract: A heat-pipe solar (HPS) photovoltaic/thermal (PV/T) heat pump system, combining HPS PV/T collector with heat pump, is proposed in this paper. The HPS PV/T collector integrates heat pipes with PV panel, which can simultaneously generate electricity and thermal energy. The extracted heat from HPS PV/T collector can be used by heat pump, and then the photoelectric conversion efficiency is substantially improved because of the low temperature of PV cells. A mathematical model of the system is established in this paper. The model consists of a dynamic distributed parameter model of the HPS PV/T collection system and a quasi-steady state distributed parameter model of the heat pump. The mathematical model is validated by testing data, and the dynamic performance of the HPS PV/T heat pump system is discussed based on the validated model. Using the mathematical model, a reasonable accuracy in predicting the system’s dynamic performance with a relative error within ±15.0% can be obtained. The capacity of heat pump and the number of HPS collectors are optimized to improve the system performance based on the mathematical model. Six working modes are proposed and discussed to investigate the effect of solar radiation, ambient temperature, supply water temperature in condenser, PV packing factor, heat pipe pitch and PV backboard absorptivity on system performance by the validated model. It is found that the increase of solar radiation, ambient temperature and PV backboard absorptivity leads to the increase of the coefficient of performance based on thermal (COP_t_h) of HPS PV/T heat pump system, while the increase of supply water temperature in condenser, PV packing factor and heat pipe pitch leads to the decrease of COP_t_h. Furthermore, the increase of solar radiation and packing factor leads to the increase of the advanced coefficient of performance based on both thermal and electrical performances (COP_P_V_/_T), while the COP_P_V_/_T decreases as the ambient temperature, supply water temperature in condenser and heat pipe pitch increase. The PV backboard absorptivity has little influence on the COP_P_V_/_T of HPS PV/T heat pump system.