Ni—Cr合金镀液中镍铬含量的快速测定

用分光光度法在３９０ｎｍ和４１０ｎｍ处测定含有一定深度的镍铬溶液的吸光系数,测定镀液在３９０ｎｍ和４１０ｎｍ处的总吸光度,通过联立方程求出镍铬的含量。     

BaClF：Eu^2＋的微波辐射合成

报道了用微波辐射法合ＢａＣｌＦ：Ｅｕ＾２＋荧光体，Ｘ－射线粉末衍射测定其相结构为四方晶系，晶胞参数为ａ＝０．４３８９３ｎｍ，ｃ＝０．７２２３ｎｍ测定了最大激发峰和最大发射峰；在２５４ｎｍ光激发下，测定了色坐标。     

用含水冷冻电镜技术测定的水稻矮缩病毒的三维结构

用含水冷冻电镜技术和计算机数据处理方法分别测定了水稻矮缩病毒（ＲＤＶ）完整颗粒和只含内壳层的颗粒的三维结构，其分辨率分别为２．６ｎｍ和３．３ｎｍ。从完整颗粒的结构中可以清晰地看到它的外层和内壳层的双层结构及其内部的ＲＮＡ或非结构蛋白质的电子密度。完整颗粒和内壳层的直径分别为６９．８ｎｍ和５４．０ｎｍ，外壳层和内壳层的厚度分别为６．９ｎｍ和２．５ｎｍ。外壳层表面的三角形剖分数Ｔ＝１３。外壳层由２６０     

Ni-Cr合金镀液中镍铬含量的快速测定

用分光光度法在３９０ｎｍ和４１０ｎｍ处测定含有一定浓度的镍铬溶液的吸光系数，测定镀液在３９０ｎｍ和４１０ｎｍ处的总吸光度，通过联立方程求出镍铬的含量     

Si作过渡层的Co/Cu/Co三明治膜中高灵敏度巨磁电阻效应和平面内磁各向异性

用高真空电子束蒸发方法制备了以半导体材料Ｓｉ 为过渡层的Ｃｏ／Ｃｕ／Ｃｏ三明治膜并研究了其巨磁电阻效应。当Ｓｉ 过渡层厚度达到０．９ｎｍ 时,三明治膜中开始出现较强的平面内磁各向异性。在Ｓｉ１．５ｎｍ／Ｃｏ ５ｎｍ／Ｃｕ ３ｎｍ／Ｃｏ ５ｎｍ结构中,在其易轴上得到了５ ．５％ 的巨磁电阻值和０．９ ％／Ｏｅ 的高磁场灵敏度。研究了过渡层Ｓｉ／Ｃｏ 界面之间的相互扩散,发现在过渡层Ｓｉ 与Ｃｏ 层间形成了ＣｏＳｉ 化合物。这个硅化物界面层诱导了三明治膜的平面内磁各向异性,从而导致了易轴上高灵敏度巨磁电阻效应。     

LUMINOL及其NaOH水溶液的吸收光谱

ｌｕｍｉｎｏｌ水溶液的吸收光谱有３个吸收带,它们的最大吸收波长分别是２２０．７ｎｍ、２９４．４ｎｍ和３５１．４ｎｍ,超声空化作用后主要呈羽增色效应,但其吸收光谱的基本形状无明显变化。ｌｕｍｉｎｏｌ－ＮａＯＨ水溶液经超声空化作用后也有较弱的增色效应和减效应,但不论是否经历超声空化作用,其吸收光谱都与ｌｕｍｉｎｏｌ水溶液的吸收光谱相似。而在ｌｕｉｎｏｌ－ＮａＯＨ－Ｃｕ％２＋水溶液中,如果Ｃｕ＾２＋Ｒ     

用化学合成法制备ZnS∶Mn纳米晶

报道了一种用化学合成法制备ＺｎＳ∶Ｍｎ纳米晶的方法。制得纳米晶直径分别为３．０ｎｍ和３．６ｎｍ，紫外吸收峰分别在２６７ｎｍ和２７５ｎｍ，相对于体材料吸收带边的３４０ｎｍ有明显的兰移。３１０ｎｍ光激发的发射光谱峰值分别为５７９ｎｍ和５８２ｎｍ，表明Ｍｎ已掺入ＺｎＳ纳米晶之内。     

镱原子和钠原子的激光增强电离光谱

用脉冲可调谐染料激光器激励火焰中的镱原子和钠原子．测定了镱的一条新的ＬＥＩ光谱线ＹｂＩ５７１．９９ｎｍ，其检出限为３×１０－１０ｇ／ｍｌ，钠的二条新的ＬＥＩ光谱线ＮａＩ５６８．２６ｎｍ，ＮａＩ５６８．８２ｎｍ．     

SrS（Cu,Sm）的红外激励上转换发光及光存储特性

本文首次报道了ＳｒＳ（Ｃｕ，Ｓｍ）的红外激励上转换发光及光存储特生，给出了二种典型样品的光致发光的激光光谱，测定红外激励发光和激励光谱，结果表明ＳｒＳ９Ｃｕ，Ｓｍ）具有极好的可擦除可重写的光存储功能，其最长的写入光波段在３５０ｎｍ附近，读出光波长约在８００－１４００ｎｍ附近，发射兰绿光峰波长在５１５ｎｍ附近。     

用沉淀-水解法制备ZrO2纳米晶须

用沉淀－水解法制备的ＺｒＯ２纳米晶须，其平均尺寸为直径４ｎｍ，长１０～２０ｎｍ，其晶相由Ｘ射线衍射确认为单斜相，对其开头和大小进行了透射电镜和激光散射分析，ＺｒＯ２纳米晶须在水溶液中出现软团聚，团聚体平均尺寸约为９０ｎｍ，纳米级ＺｒＯ２粒子对乙醇及丁烷有好的气敏性，比用直接水热法制备的敏感性能提高３０％左右。     

Thermal blooming and photoluminescence characterizations of sol–gel CdO–SiO<Subscript>2</Subscript> with different nanocomposite

The CdO NPs was synthesized using the sol–gel method and the nanoparticles were characterized using an UV–Vis spectrophotometer, with shape and size were examined by SEM and XRD. The XRD analysis respects the Bragg’s law and confirmed the crystalline nature of CdO nanoparticles. From the XRD, the average size of CdO NPs was found to be around 41 nm. The photoluminescence spectra of the CdO NPs, as recorded at room temperature, were excited at 300 nm wavelength. The broad emission peaks were between 600 and 650 nm (orange emission). The optical limiting performance of the nanocomposite was described in the sol–gel state. Also, this study has observed and studied the diffraction rings generated in CdO NPs using the same CW laser. The number of rings increases almost exponentially with an increasing volume fraction of SiO₂ in the nanocomposites. The refractive index change, Δn, and effective nonlinear refractive index, n ₂, were found to be 10^?4 and 10^?8 cm²/W, respectively. The effective nonlinear refractive index, n ₂, was determined based on the observed number of rings. The threshold values of the CdO, CdO–2SiO₂ and CdO–5SiO₂ nanocomposites are 7.1, 6.55 and 6.34 mW, respectively. This large nonlinearity is attributed to the thermal effect. The present studies suggest that the nanocomposite is a potential candidate for optical device applications such as the optical limiters. The thermal blooming technique was applied to evaluate the thermo-optic coefficient and thermal diffusivity of the CdO NPs. In the thermal blooming experimental setup a transistor–transistor logic modulated CW laser of wavelength 532 nm was used as the excitation source.     

CdS nanoparticles incorporated onion-like mesoporous silica films: Ageing-induced large stokes shifted intense PL emission

CdS nanoparticles (NPs) were generated in onion-like ordered mesoporous SiO₂ films through a modified sol–gel process using P123 as a structure directing agent. Initially Cd²⁺ doped (12 equivalent mol% with respect to the SiO₂) mesoporous SiO₂ films were prepared on glass substrate. These films after heat-treatment at 350 °C in air yielded transparent mesoporous SiO₂ films having hexagonally ordered onion-like pore channels embedded with uniformly dispersed CdO NPs. The generated CdO NPs were transformed into CdS NPs after exposing the films in H₂S gas at 200 °C for 2 h. The as-prepared CdS NPs incorporated mesoporous SiO₂ films (transparent and bright yellow in color) showed a band-edge emission at 485 nm and a weak surface defect related emission at 530 nm. During ageing of the films in ambient condition the band-edge emission gradually weakened with time and almost disappeared after about 15 days with concomitant increase of defect related strong surface state emission band near 615 nm. This transformation was related to the decay of initially formed well crystalline CdS to relatively smaller and weakly crystalline CdS NPs with surface defects due to gradual oxidation of surface sulfide. At this condition the embedded CdS NPs show large Stokes shifted (∼180 nm) intense broad emission which could be useful for luminescent solar concentrators. The detailed process was monitored by UV–Visible, FTIR and Raman spectroscopy, XPS, XRD and TEM studies. The evolution of photoluminescence (PL) and life times of CdS/SiO₂ films were monitored with respect to the ageing time.     

CdO nanoparticles,c‐MWCNT nanoparticles and CdO nanoparticles/c‐MWCNT nanocomposite fibres: in vitro assessment of anti‐proliferative and apoptotic studies in HeLa cancer cell line

A simple ultrasonic assisted chemical technique was used to synthesise cadmium oxide (CdO) nanoparticles (NPs) and CdO NPs/c‐Multiwalled carbon nanotube (c‐MWCNT) nanocomposite fibres.To confirm the physio‐chemico properties and to analyse surface morphology of the obtained nanomaterials X‐Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) were performed. To evaluate the anti‐cancer property of CdO NPs, c‐MWCNT NPs and CdO NPs/c‐MWCNT nanocomposite fibres, an anti‐proliferative assay test (Methylthiazolyl diphenyl‐ tetrazolium bromide ‐ MTT assay) were performed on HeLa cells which further estimated IC50 value (Least concentration of sample in which nearly 50% of cells remain alive) under in‐vitro conditions. On comparison, CdONPs/c‐MWCNT based system was found to be superior by achieving 52.3% cell viability with its minimal IC50 value of 31.2 μg/ml. Lastly, the CdO NPs based system was taken up for an apoptotic study using DNA fragmentation assay for estimating its ability to cleave the DNA of the HeLa cells into internucleosomal fragments using the agarose gel electrophoresis method. In conclusion, based on our observations, CdO NPs/c‐MWCNT hybrid based system can be further used for the development of efficient drug delivery and therapeutic systems.Inspec keywords: drug delivery systems, electrophoresis, oxidation, toxicology, DNA, nanoparticles, drugs, field emission electron microscopy, scanning electron microscopy, nanofabrication, surface morphology, cancer, X‐ray diffraction, nanomedicine, cellular biophysics, filled polymers, biomedical materials, molecular biophysics, biochemistry, Fourier transform infrared spectra, multi‐wall carbon nanotubesOther keywords: c‐MWCNT nanoparticles, apoptotic study, HeLa cancer cell line, cadmium oxide nanoparticles, c‐MWCNT NPs, anti‐proliferative assay test [methyl thiazolyl diphenyl‐tetrazolium bromide assay], human epithelioid cervix carcinoma cells, live cells, CdO NP‐based system, IC50 concentration, HeLa cell line, cell deaths, CdO‐C     

Studies on the synthesis of CdCO3 nanowires and porous CdO powder

In the present study, we demonstrate the self transformation of aqueous cadmium acetate into CdCO₃ nanowires through hydrothermal reaction. The reaction temperature and the volume ratio of water to ethanol were found to be crucial for the formation of CdCO₃ nanowires. The nanowires are of single crystal in nature having width ∼ 17-30 nm as observed from selected area electron diffraction (SAED) pattern and transmission electron microscopic (TEM) results. The major weight loss found in thermogravimetric analysis (TGA) corresponds to the formation of CdO and CO₂. The powder X-ray diffraction (PXRD) patterns of CdCO₃ and CdO are respectively indexed to pure rhombohedral and cubic phases. The photoluminescence (PL) spectrum of CdO exhibits an emission peak at 483 nm due to the transition between the valence and conduction bands.     

Optimization of CdO nanoparticles by Zr<Superscript>4+</Superscript> doping for better photocatalytic activity

Chemically controlled co-precipitation method has been adopted for the fabrication of pure and different wt% Zr doped CdO photocatalysts. Conventionally, the crystallite size and crystalline phase of CdO are in the midst of the parameters involved in the control of the photocatalytic activity. Aiming utterly at the size effect that modifies other attributes which are important to assess the photocatalytic activity of nanometric CdO, it was explored to synthesize CdO nanoparticles with controlled size, highly comparable morphology and analogous phase. The crystal structure and the crystallite size were estimated from the X-ray diffraction patterns and were confirmed through transmission electron microscope. The degree of crystallinity varied on Zr doping and the calculated crystallite sizes were in the range of 16–81 nm. The dopant ion Zr⁴⁺ have been detected through X-ray photoelectron spectroscopy (XPS) analysis signifying the dopant to substitute for cadmium (Cd²⁺) in the lattice of CdO. Particle size dependent optical band gaps calculated in the range 2.02–2.57 eV informed the viability of the materials to initiate photocatalytic reaction in the visible light region. Lesser recombination rate of the generated electrons and holes under light irradiation produced low intense photoluminescence peaks that displayed the appropriateness as photocatalysts. Zr⁴⁺ doping resulted in the enhancement of photocatalytic activity, evaluated by monitoring the degradation of methylene blue solution. 0.5 wt% Zr doped CdO nanoarticles calcined at 400 °C exhibited the highest photocatalytic activity with better percentage of color abatement (80.95%). The pseudo-first-order reaction rate became faster on Zr doping such that the rate constant is ~?0.4–0.5 h^?1 for Zr doped CdO while that for pure CdO is ~?0.3 h^?1.     

Shape Controlled Plasmonic Sn Doped CdO Colloidal Nanocrystals: A Synthetic Route to Maximize the Figure of Merit of Transparent Conducting Oxide

The synthesis of different anisotropic shaped (eight different shapes) Sn⁴⁺ doped CdO (Sn:CdO) colloidal nanocrystals (NCs) by precise tuning of precursor reactivity and proper choice of capping agent is reported. In all these systems, formation of Sn:CdO quantum dots (QDs) of 2–3 nm is identified at very early stage of reaction. The colloidally stable QDs act as a continuous source for the formation of primary nanoparticles that can be transformed selectively into specific type of nanoparticle morphology. The specific facet stabilization of fcc (face centered cubic)CdO is predicted by particular choice of ligand. Fine tuning of plasmonic absorbance band can be achieved by variation of Sn⁴⁺ doping concentration. Different anisotropic Sn:CdO NCs exhibit interesting shape dependent plasmonic absorbance features in NIR region. High quality crack free uniform dense thin film has been deposited on glass substrate to make high quality transparent conducting oxide (TCO) coatings. figure of merit of TCO can be maximized as high as 0.523 Ω^?1 with conductivity of 43 600 S cm^?1 and visible transmittance of ≈85% which is much higher than commercially available tin doped indium oxide and other transparent electrodes.     

Single molecule spectroscopy of organic dye nanoparticles

Organic dye nanoparticles 1-13 nm in height and 10-45 nm in width were prepared by the reprecipitation method. With single-molecule/nanoparticle spectroscopy, two distinct types of nanoparticles were found: particles with blue emission and particles with red emission. The difference in spectral characteristics is attributed to the presence of two morphological types of particles in the samples. The presence of two types of nanoparticles in the samples was further corroborated by our ability to separate blue nanoparticles from red nanoparticles by centrifugation.     

Sm doping effect on structural,morphological, luminescence and antibacterial activity of CdO nanoparticles

Undoped cadmium oxide along with samarium doped CdO are synthesized by simple soft precipitation method. Resulting precursor was calcined at 400 °C for 2 h. As a result of heating, a pure material was produced. The obtained compound possesses a cubic crystalline structure at nanoscale. Also, FESEM image showed that the resulting material is composed of nanoparticles and its size decreases with increase of Sm doping relative with the particle size calculated from XRD. The photoluminescence shows the emission of violet and blue colour peaks and the peak at 468 nm which is responsible for a better antibacterial activity. The synthesized nanopowders are subjected to two different gram positive (Staphylococcus aureus and Enterococcus faecalis) and two different gram negative (Escherichia coli and Klebsiella pneumoniae) bacterial strains respectively. It is noted that there are high activity of the Sm doped CdO towards gram negative bacteria.     

Stability and nonlinear optical properties of ZnO nanoparticles

Photoluminescence (PL) of ZnO nanoparticles of different surface states and sizes grown by several methods has been measured. The origin of luminescence and dependence of the luminescence spectrum shape and intensity on 325 nm excitation laser power are studied. Strong ultraviolet emission at 3.26 eV, weak violet emission around 3.12 eV and weak green emission at 2.40 eV have been observed in 16 nm nanoparticles capped by octylamine grown by non-hydrolytic method. The nanoparticles are stable under high power laser radiation and their PL intensity increases nonlinearly with an increasing laser power. As the nanoparticle size decreases to 12 nm, high power laser produces nonradiative centers which may quench the luminescence in a degree. Nanoparticles of 8 nm capped by PVP and uncapped nanoparticles of 14 nm are unstable and their luminescence depends on the excitation laser power. High power laser can quench O vacancy emission and enhance ultraviolet emission in PVP capped nanoparticles while vacancy emission can not be quenched in uncapped nanoparticles.     

Synthesis and study of the photoluminescence and optical characteristics of Cd/CdO nanorods prepared by the electrospinning process

Researchers are facing difficulties to synthesize a nanostructure containing pure cadmium due to the low melting point of this metal. In this study, for the first time, pure cadmium metal could be successfully incorporated in a one-dimensional nanostructure. A composite from Cd and CdO in a shape of nanorods were prepared using the electrospinning technique. Sintering of electrospun nanofibers consisting of cadmium acetate dihydrate and poly(vinyl alcohol) in an argon atmosphere at 300 °C led to produce nanorods composed of pure cadmium and cadmium oxide. Increasing the calcination temperature resulted in enhancing the cadmium content, however led to a complete destruction of the one-dimensional nanostructure. Compared with the reported one-dimensional CdO nanostructures, embedding the cadmium with the CdO in a single nanorod causes to increase the band gap from 2.53 to 4.95 eV, and shifts the location of the PL emission peak from 550 to 593 nm which may open a new avenue for different application fields.