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991.
Zhao W Zhai F Zhang D An Y Liu Y He Y Ge K Scrimshaw NS 《Food and nutrition bulletin》2004,25(2):123-129
The purpose of this study was to determine the impact of the fortification of wheat flour with lysine on selected health indicators among farm families obtaining 58% to 67% of their dietary protein from wheat. A man, a woman, and a child aged 5 to 12 years were studied from each of 88 families in a village near Huixian City, Henan Province, China. Half of the families received wheat flour fortified with 3 g of lysine per kilogram for three months, and the other half received wheat flour without fortification. The results showed a significantly greater gain in the height and weight of children receiving lysine-fortified wheat flour. Hemoglobin values were not affected. The mean prealbumin values of adult men and women were higher in those receiving lysine. The numbers of CD3 T cells increased significantly in women and children, as did the complement fraction C3 and IgG in men, IgA in women, and IgG, IgA, IgM, and C3 in children. These results indicate that lysine fortification of wheat flour can significantly improve some indicators of the nutritional status and immune function of family members consuming a wheat-based diet. 相似文献
992.
Zhai J Wang L Wang D Li H Zhang Y He DQ Xie T 《ACS applied materials & interfaces》2011,3(7):2253-2258
CdS nanowire/ZnO nanosphere materials (CdS/ZnO) with hierarchical structure were synthesized by a three-step solvothermal process. XRD, FESEM and TEM analysis confirmed the growth of ZnO nanospheres on the surface of CdS nanowires (NWs). The transient photovoltage (TPV) measurements revealed that the interface between CdS and ZnO can inhibit the recombination of photogenerated excess carriers and prolong the lifetime of excess carriers in CdS/ZnO materials. Moreover, the CdS/ZnO materials exhibit a dramatic improvement in optoelectronic performance and visible-light-irradiation gas sensing activity, which gave 1 order of magnitude larger than that of CdS NWs in response to formaldehyde. The enhancement of sensing properties is attributed to the interfacial transport of excess carriers. 相似文献
993.
Harrington SA Zhai J Denev S Gopalan V Wang H Bi Z Redfern SA Baek SH Bark CW Eom CB Jia Q Vickers ME Macmanus-Driscoll JL 《Nature nanotechnology》2011,6(8):491-495
Ferroelectric materials are used in applications ranging from energy harvesting to high-power electronic transducers. However, industry-standard ferroelectric materials contain lead, which is toxic and environmentally unfriendly. The preferred alternative, BaTiO(3), is non-toxic and has excellent ferroelectric properties, but its Curie temperature of ~130 °C is too low to be practical. Strain has been used to enhance the Curie temperature of BaTiO(3) (ref. 4) and SrTiO(3) (ref. 5) films, but only for thicknesses of tens of nanometres, which is not thick enough for many device applications. Here, we increase the Curie temperature of micrometre-thick films of BaTiO(3) to at least 330 °C, and the tetragonal-to-cubic structural transition temperature to beyond 800 °C, by interspersing stiff, self-assembled vertical columns of Sm(2)O(3) throughout the film thickness. The columns, which are 10 nm in diameter, strain the BaTiO(3) matrix by 2.35%, forcing it to maintain its tetragonal structure and resulting in the highest BaTiO(3) transition temperatures so far. 相似文献
994.
We demonstrate an aqueous solution method for the synthesis of a Ag-TiO2-reduced graphene oxide (rGO) hybrid nanostructure (NS) in which the Ag and TiO2 particles are well dispersed on the rGO sheet. The Ag-TiO2-rGO NS was then used as a template to synthesize Pt-TiO2-rGO NS. The resulting hybrid NSs were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM),
energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform
infrared (FTIR) spectroscopy, UV-vis spectroscopy, Raman spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS),
and catalytic studies. It was found that TiO2-rGO, Ag-TiO2-rGO and Pt-TiO2-rGO NSs all show catalytic activity for the reduction of p-nitrophenol to p-aminophenol by NaBH4, and that Pt-TiO2-rGO NS exhibits the highest catalytic activity as well as excellent stability and easy recyclability.
相似文献
995.
We used longitudinal data from a birth cohort study, the Fragile Families and Child Wellbeing Study, to investigate the links between Head Start and school readiness in a large and diverse sample of urban children at age 5 (N = 2,803; 18 cities). We found that Head Start attendance was associated with enhanced cognitive ability and social competence and reduced attention problems but not reduced internalizing or externalizing behavior problems. These findings were robust to model specifications (including models with city-fixed effects and propensity-scoring matching). Furthermore, the effects of Head Start varied by the reference group. Head Start was associated with improved cognitive development when compared with parental care or other nonparental care, as well as improved social competence (compared with parental care) and reduced attention problems (compared with other nonparental care). In contrast, compared with attendance at pre-kindergarten or other center-based care, Head Start attendance was not associated with cognitive gains but with improved social competence and reduced attention and externalizing behavior problems (compared with attendance at other center-based care). These associations were not moderated by child gender or race/ethnicity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
A waveguide-plasmonic scheme is constructed by coating the matrix of randomly distributed gold nanoisland structures with a layer of dye-doped polymer, which provides strong feedback or gain channels for the emission from the dye molecules and enables successful running of a random laser. Excellent overlap of the plasmonic resonance of the gold nanoislands with the photoluminescence spectrum of the dye molecules and the strong confinement mechanism provided by the active waveguide layer are the key essentials for the narrow-band and low-threshold operation of this random laser. This kind of feedback configuration potentially enables directional output from such random lasers. The flexible solution-processable fabrication of the plasmonic gold nanostructures not only enables easy realization of such a random laser but also provides mechanisms for the tuning and multicolor operation of the laser emission. 相似文献
997.
Zhai X Shi F Chen H Zhao D Zhang D Qin W 《Journal of nanoscience and nanotechnology》2011,11(11):9693-9696
Tm3+ and Yb3+ codoped NaYF4 upconversion (UC) nanoparticles (NPs) with intense ultraviolet (UV) fluorescence were synthesized using a solvothermal approach. NIR optical rewritable film incorporated with the UCNPs and dithienylethene (DTE) were performed for optical storage based on the photochromic reaction of DTE induced by the intense UV from themultiphoton UC fluorescence of NaYF4NPs. The photochromic DTE did not exhibit obvious fatigue after repetitious write/erase cycles using NIR/green irradiation. 相似文献
998.
999.
1000.
6061-T6铝合金高速高功率CO_2激光填丝焊接性的研究 总被引:4,自引:2,他引:2
为实现6061-T6铝合金薄板的高速高功率CO2激光填丝焊接,选用了ER4043,ER5356两种焊丝进行了焊接性试验。利用鱼骨状试样对两种焊丝的激光焊接铝合金6061-T6的热裂纹敏感性进行了分析;利用金相显微镜、扫描电镜、显微硬度计以及万能材料试验机分析了焊接接头的组织与性能。研究结果表明,与填充ER5356焊丝相比,填充ER4043焊丝的焊接接头热裂纹敏感性较低,焊接速度可达6 m/min。焊缝主要是柱状晶、等轴晶及少量树枝晶,显微硬度在60~80 HV,拉伸强度可达240~262 MPa,弯曲性能良好。 相似文献