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激光散射法对尿液中纳米微晶粒径及其分布的研究 总被引:2,自引:1,他引:1
泌尿系结石已经成为威胁人类健康的一种常见病、多发病,目前对其形成的机制尚不清楚。文章采用激光散射法测定了正常人尿液和尿石症患者尿液中纳米粒子的粒径和粒径分布,该方法快速准确、经济、容易操作。正常人尿液比尿石症患者尿液的稳定性好,归因于正常人尿液中纳米微晶尺寸分布均匀,不容易聚集,而尿石症患者尿液的纳米微晶尺寸分布不均匀,粒子间容易聚集而沉降。通过分析尿样稀释、离心或者用微孔滤膜过滤后体系的光强-自相关函数曲线,得到了制备稳定的尿样悬浮液的方法:尿样先稀释20%,然后离心或用1.2 μm微孔滤膜过滤,可得到稳定的尿液悬浮液。激光散射法结果与TEM检测结果一致。从尿液中存在的范德华力、尿液粘度、酸碱性、离子强度、尿液中纳米微晶的表面电荷和Zeta电位等方面解释了尿液稳定的原因。 相似文献
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纳米尺寸CdS半导体微晶的光致发光线宽宽化研究 总被引:2,自引:1,他引:1
测量了各种温度下玻璃中掺杂纳米尺寸CdS半导体微晶的光致发光光谱,研究了其光致发光带的峰值能量和线宽对温度的依赖关系.考虑CdS微晶的LO声子的相互作用,拟合了其带隙发光带的线宽随温度的变化曲线,获得样品的非均匀线宽.CdS微晶的非均匀线宽主要是由于微晶的尺寸分布引起的. 相似文献
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"利用Sr(NO3)2和V2O5作为反应前驱物, 已二酸作为矿化剂,在水热法反应条件下成功制备了微米尺寸蒲公英状及纳米尺寸的纳米带状β-SrV2O6晶微体. 通过粉末X衍射和电子显微镜的研究分析,结果表明所得的反应生成物属于正交晶系,其晶格常数为a=9.694 ?,b=3.687 ?,c=12.570 ? (空间群Pnma). 电子显微结果表明蒲公英状的微晶是揭示许多棒状微晶呈球型放射状构成的图案,而纳米带状的β-SrV2O6则呈现显示良好的挠性. 两者的微晶体生长方向沿h010i晶轴方向. 详细探讨了水 相似文献
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《发光学报》2021,(6)
通过熔融淬火和后续热处理,成功制备了Tb~(3+)掺杂含LaF_3纳米晶透明锗酸盐微晶玻璃。详细研究了所制备的玻璃和微晶玻璃的发光性质。X射线衍射结果表明,玻璃基体中析出的晶相为纯LaF_3晶体,晶粒尺寸在16~21 nm之间。在377 nm紫外光和X射线激发下,Tb~(3+)掺杂含LaF_3纳米晶的微晶玻璃比Tb~(3+)掺杂的锗酸盐玻璃表现出更强的绿光发射,且绿光发射强度随热处理温度升高和时间的延长而增强。微晶玻璃在X射线激发下的最大积分发光强度约为商用闪烁晶体Bi_4Ge_3O_(12)的40.3%。本研究表明,掺Tb~(3+)含LaF_3纳米晶锗酸盐微晶玻璃在X射线探测中具有潜在的应用前景。 相似文献
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通过熔融淬火和后续热处理,成功制备了Tb^(3+)掺杂含LaF_(3)纳米晶透明锗酸盐微晶玻璃。详细研究了所制备的玻璃和微晶玻璃的发光性质。X射线衍射结果表明,玻璃基体中析出的晶相为纯LaF_(3)晶体,晶粒尺寸在16~21 nm之间。在377 nm紫外光和X射线激发下,Tb^(3+)掺杂含LaF_(3)纳米晶的微晶玻璃比Tb^(3+)掺杂的锗酸盐玻璃表现出更强的绿光发射,且绿光发射强度随热处理温度升高和时间的延长而增强。微晶玻璃在X射线激发下的最大积分发光强度约为商用闪烁晶体Bi_(4)Ge_(3)O_(12)的40.3%。本研究表明,掺Tb^(3+)含LaF_(3)纳米晶锗酸盐微晶玻璃在X射线探测中具有潜在的应用前景。 相似文献
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Hamed Akbari Khorami Mansoor Keyanpour-RadMohammad Reza Vaezi 《Applied Surface Science》2011,257(18):7988-7992
In this paper, we report the synthesis of SnO2/ZnO composite nanofibers via electrospinning method. Polyvinyl alcohol (PVA)/zinc acetate/stannous chloride nanofibers were electrospun using a solution containing PVA, zinc acetate and stannous chloride in distilled-water followed by calcination at 650 °C for 2 h, obtaining the related composite nanofibers. The nanofibers were characterized by simultaneous thermal analysis (STA), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectroscopy (FTIR). Ethanol sensing of the nanofibers showed a good and desirable sensing behavior such as high sensitivity, quick response and recovery times. 相似文献
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S. ZandiP. Kameli H. SalamatiH. Ahmadvand M. Hakimi 《Physica B: Condensed Matter》2011,406(17):3215-3218
In this investigation, ZnO nanoparticles were prepared by a simple and rapid method. This method is based on the short time solid state milling and calcinations of zinc acetate and citric acid powders. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, photoluminescence and UV-vis spectroscopy. It was shown that the calcination temperature significantly affected the particle size and optical properties of the synthesized ZnO nanoparticles. Calculation based on the XRD data shows that the average sizes of ZnO particles are in agreement with those from TEM images and the size of the particles increases on increasing the calcination temperature. Also the band gap of samples decreased from 3.29 to 3.23 eV on increasing the calcination temperature from 350 to 600 °C. Photoluminescence analyses show that many defects such as interstitial zinc, zinc vacancy and oxygen vacancy are responsible for the observed optical properties. 相似文献
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Thermal decomposition of pristine and γ-irradiated zinc uranyl acetate was investigated in air using isothermal and dynamic thermogravimetric techniques. The decomposition proceeded via one major process with the formation of triuranates ZnU3O10 as solid residues. Kinetic analysis of isothermal data, when compared with various solid-state reaction models, showed that the decomposition reaction is best fitted by the phase-boundary model. Kinetic analysis of the dynamic TG curves was discussed with reference to integral methods of modified Coats and Redfern equations. Kinetic and thermodynamic parameters were calculated and evaluated. IR spectroscopy and X-ray powder diffraction techniques were employed to follow the chemical composition of solid residue at different calcination temperatures. The results display that the triuranate ZnU3O10 starts forming by calcination of zinc uranyl acetate at temperatures?>?300 °C and undergoes decomposition at higher temperatures (>600 °C) with the formation of U3O8. The results were evaluated regarding the utilization of zinc uranyl acetate as an important source of diuranates and triuranates. 相似文献
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由于壳聚糖的大分子键上分布着大量的氨基、羟基和N-乙酰基等活性功能基团,将其改性作为天然绿色絮凝剂越来越受到关注,但对其的接枝共聚产物的光谱学表征研究鲜有报道。因此,对壳聚糖基絮凝剂进行光谱学表征与分析研究具有重要意义。论文以壳聚糖(CS)、丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)为接枝共聚单体,采用光聚合技术制备壳聚糖基絮凝剂CS-P(AM-DMDAAC)。采用X射线衍射(XRD)、紫外光谱(UV)、红外光谱(IR)研究其结构特征;分析了壳聚糖、丙烯酰胺、二甲基二烯丙基氯化铵及三者接枝共聚产物的X射线衍射(XRD)、紫外光谱(UV)、红外光谱(IR)的图谱特征和振动吸收峰归属。研究了壳聚糖脱乙酰度、壳聚糖浓度、阳离子度对接枝共聚产物壳聚糖基絮凝剂CS-P(AM-DMDAAC)的X射线衍射(XRD)、紫外光谱(UV)、红外光谱(IR)的影响。UV光谱和IR光谱研究结果证明CS,AM和DMDMAAC成功发生接枝共聚反应制备出CS-P(AM-DMDAAC),壳聚糖浓度增加导致其光谱对称性减弱。XRD图谱研究表明接枝共聚反应使得壳聚糖的晶型结构趋向不定型结构转变,不定型结构相比于晶型结构更易于水化,故接枝共聚产物具有更加优异的溶解性。 相似文献
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Ultrasound irradiation is used for anchoring zinc oxide submicron crystals with a main diameter and length of 280 nm and 470 nm, respectively, onto the surface of poly(methyl methacrylate) PMMA chips (2 mm diameter), and zinc oxide crystals with a mean diameter and length of 150 nm and 230 nm, respectively, onto the surface of the PMMA spheres (1–10 μm). The zinc oxide crystals were obtained by sonochemical irradiation of a mixture containing the PMMA, zinc (II) acetate dihydrate, ethanol, water, and 24 wt.% aqueous ammonia for 2 h, yielding a PMMA–zinc oxide composite. By controlling the atmosphere and reaction conditions, we could achieve well-adhered zinc oxide crystals on the surface of poly(methyl methacrylate). The resulting zinc oxide–PMMA composite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray analysis (EDX), high-resolution scanning electron microscopy (HRSEM), and photoluminescence (PL) spectroscopy. The zinc oxide-deposited PMMA chips (loaded with 0.03–1.0 wt.% ZnO) were successfully homogenized in melt by extrusion and then injection molded into small, disc-shaped samples. These samples were analyzed with respect to their directional spectral optical properties in UV, Vis and IR spectroscopy. 相似文献
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以壳聚糖为原料,经羧甲基化、纳米化与Ca~(2+)、Zn~(2+)复合制备出纳米羧甲基壳聚糖含钙、锌复合物,采用红外光谱、X射线衍射光谱、扫描电镜等光学手段对样品进行结构表征,考察了复合物的凝血、止血性能。结果表明:纳米羧甲基壳聚糖结构中含有磷酸盐结构,Ca/Zn-纳米羧甲基壳聚糖结构中含有Ca~(2+)与Zn~(2+),Ca~(2+)和Zn~(2+)与纳米羧甲基壳聚糖成功复合;复合物的结晶性下降、溶解性提高、形貌均匀圆整,且凝血、止血时间明显缩短;Ca-纳米羧甲基壳聚糖比Zn-纳米羧甲基壳聚糖结构更稳定,凝血、止血效果更好。 相似文献
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Christian Fauteux My Ali El Khakani Joseph Pegna Daniel Therriault 《Applied Physics A: Materials Science & Processing》2009,94(4):819-829
ZnO nanorods, nanoneedles, nanoparticles, and nanoballs were synthesized on fused quartz substrates upon irradiation of a
droplet of methanolic zinc acetate dihydrate solution by an infrared (IR) continuous wave CO2 laser for a few seconds. The addition of monoethanolamine and water to the solution improved the alignment of the nanorods
and had a significant effect on the volume and morphology of the deposits. An increase of the zinc acetate concentration was
found to lead to an increase of the thickness and area covered by the initial ZnO seed layer on which the nanostructures grew.
By investigating the crystal structure of the deposits using X-ray and electron diffraction, we were able to show that the
nanorods grow along the c axis with a high crystalline quality. Raman and photoluminescence spectroscopy confirmed the high quality of the grown ZnO
nanostructures. As a matter of fact, their photoluminescence spectra are dominated by an intense UV emission around 390 nm. 相似文献
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Nanostructure and optical properties of M doped ZnO (M=Ni, Mn) thin films prepared by sol-gel process 总被引:1,自引:0,他引:1
Xiaolu YanDan Hu Hangshi LiLinxiao Li Xiaoyu ChongYude Wang 《Physica B: Condensed Matter》2011,406(20):3956-3962
The transparent thin films of undoped, Mn-doped, and Ni-doped zinc oxide (ZnO) have been deposited on glass substrates via sol-gel technique using zinc acetate dehydrate, nickel chloride, and manganese chloride as precursors. The structural properties and morphologies of the deposited undoped and doped ZnO thin films have been investigated. X-ray diffraction (XRD) spectra, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) were used to examine the morphology and microstructure of the thin films. Optical properties of the thin films were determined by photoluminescence (PL) and UV/vis spectroscopy. The analyzed results indicate that the obtained films are of good crystal quality and have smooth surfaces, which have a pure hexagonal wurtzite ZnO structure without any Mn or Ni related phases. The band gap energy was estimated by Tauc's method and found to be 3.28, 3.26, and 3.34 eV for ZnO, Ni-doped ZnO, and Mn-doped ZnO thin films at room temperature, respectively. Room temperature photoluminescence is observed for the ZnO, Ni-doped ZnO, and Mn-doped ZnO thin films. 相似文献
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《Composite Interfaces》2013,20(5):365-377
In this report, chitosan (CS) encapsulated zinc oxide (ZnO) hybrid composite was prepared by chemical precipitation method. The CS-ZnO composite was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis (TGA), transmission electron microscopy, and zeta potential. The composite exhibited high photocatalytic activity as evident from the degradation of methylene blue dye under UV irradiation. Approximately, 64% of the dye was degraded under UV irradiation within 3?h. In addition, the CS-ZnO composite showed excellent antibacterial activity against Escherichia coli as measured by colony forming units. Based on the data of present investigation, the composite being a biocompatible, eco-friendly, and low-cost material could find potential applications in various fields. 相似文献
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Ying Wang Yinhua Li Zhengzhi Zhou Xihong Zu Yulin Deng 《Journal of nanoparticle research》2011,13(10):5193-5202
A series of nanostructured zinc compounds with different nanostructures such as nanobelts, flake-like, flower-like, and twinning
crystals was synthesized using zinc acetate (Zn(Ac)2) as a single-source. The evolution of the zinc compounds from layered basic zinc acetate (LBZA) to bilayered basic zinc acetate
(BLBZA) and twinned ZnO nano/microcrystal was studied. The low-angle X-ray diffraction spectra indicate the layered spacing
is 1.34 and 2.1 nm for LBZA and BLBZA, respectively. The Fourier transform infrared (FTIR) spectra results confirmed that
the bonding force of acetate anion with zinc cations decreases with the phase transformation from Zn(Ac)2 to BLBZA, and finally to LBZA. The OH− groups gradually replaced the acetate groups coordinated to the matrix zinc cation, and the acetate groups were released
completely. Finally, the Zn(OH)2 and ZnO were formed at high temperature. The conversion process from Zn(Ac)2 to ZnO with release of acetate anions can be described as Zn(Ac)2 → BLBZA → LBZA → Zn(OH)2 → ZnO. 相似文献