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Urchin-like Co 3 O 4 hierarchical micro/nanostructures have been successfully synthesized by calcining urchin-like precursor CoCO 3 , which are prepared by a facile hydrothermal route. The particle size of the urchin-like Co 3 O 4 could be easily controlled by altering the calcination temperature. The morphology and structure of the as-prepared urchin-like products were characterized by XRD, FESEM and TEM. Photocatalytic measurement demonstrates that these urchin-like Co 3 O 4 micro/nanostructures show good photocatalytic effect and their degradation efficiency is strongly dependent on their particle size. Furthermore, a plausible reaction mechanism is also proposed to illustrate the photocatalytic processes of Co 3 O 4 .

In this Article, bulk-quantity one-dimensional polyaniline (1D PANI) nanowire/tubes with rough surface were prepared by a simple chemical oxidation method. This kind of PANI nanostructure can not only remove Cr(VI) rapidly and effectively in one step from aqueous solution by reducing Cr(VI) to Cr(III) as well as adsorbing the reduced Cr(III) simultaneously, but also be easily regenerated for reuse. During the removal of Cr(VI) process, the as-synthesized PANI was oxidized from emeraldine salt to pernigraniline, and pernigraniline could be reconverted into emeraldine salt by acid treatment. In addition, the morphology of the PANI was not changed after used for Cr(VI) removal. This study not only provides a facile way to fabricate bulk-quantity 1D PANI nanostructure, but also shows a reproducible material for removal of toxic Cr(VI) from wastewater.

Lipid microtubules with wound ribbon features were fabricated by self-assembling method, and the deposition patterns of colloidal Pd particles on tubular template were investigated. The result indicates that colloidal Pd nanoparticles are preferentially decorated on the helical markings in the interior and on the exterior of preformed tubule and to the edge of loosely helical ribbons to obtain helical deposition features. The multi-bilayer microstructure of tubules can be marked by fine Pd nanoparticles deposited at the edge of helical ribbon. There are the site-specific interactions between lipid tubular template and colloidal Pd particles at the helical edge. A new route was illustrated that colloidal Pd particles firmly attach at the edge of thin flat membranes, and then thin membranes roll up and reassemble into tubule together with particles to form helical deposition patterns. The site-specific deposition of Pd is unbeneficial to obtain the homogeneous metal film on tubules, but it can be utilized to reveal the different chemical nature of lipid molecular assembly.

In this paper, ZnGa2O4 hierarchical nanostructures with comb-like morphology are fabricated by a simple two-step chemical vapor deposition (CVD) method: first, the Ga2O3 nanowires were synthesized and employed as templates for the growth of ZnGa2O4 nanocombs; then, the as-prepared Ga2O3 nanowires were reacted with ZnO vapor to form ZnGa2O4 nanocombs. Before the reaction, the Au nanoparticles were deposited on the surfaces of Ga2O3 nanowires and used as catalysts to control the teeth growth of ZnGa2O4 nanocombs. The as-prepared ZnGa2O4 nanocombs were highly crystallized with cubic spinel structure. From the photoluminescence (PL) spectrum, a broad band emission in the visible light region was observed of as-prepared ZnGa2O4 nanocombs, which make it promising application as an optical material.

In this paper, submicrometer-sized Ga–In eutectic alloy particles were dispersed into polymethylmethacrylate (PMMA) matrix by ultrasonic vibration and sedimentation method. The solidification and melting processes of Ga–In eutectic alloy particles were studied by differential scanning calorimeter (DSC). Four endothermal peaks with the onset temperature located at 16, −11, −22, and −27 °C were observed in DSC heating curves, which corresponded to the melting process of the stable Ga–In phase α-Ga(In) and three metastable phases of β-Ga(In), δ-Ga(In) and γ-Ga(In), respectively. The stable phase α-Ga(In) can only be formed when the size of alloy particle was larger than 0.58 μm. Conversely, metastable phases β-Ga(In), δ-Ga(In) and γ-Ga(In) are mainly formed. The result shows that phase structures in Ga–In eutectic alloy are size dependent.

For the study of magnetic field-assisted assembly behavior, one-dimensional (1D) NiCo alloy nanostructures were solvothermally obtained at 180 °C under an in situ magnetic field (the magnetic field as applied during the chemical reduction) and ex situ field (after the chemical reduction was finished). Microscopic morphology and magnetic properties differences were investigated using scanning electronic microscope (SEM) and vibrating sample magnetometer (VSM) for these products. Magnetic measurement results show that 1D ordered microstructures under in situ magnetic field possess higher saturation magnetization Ms, remnant magnetization Mr, coercivity Hc and reduced magnetization Mr/Ms than 1D ordered microstructures under ex situ field, and the four magnetic parameters of the two ordered microstructures are much higher than those randomly distributed alloy particles prepared in the absence of external magnetic field.

Thermal instability of ZnSe nanowires in air results from the oxidation of ZnSe by O2. As a barrier to slow the diffusion, a SiO2 sheath improves the thermal stability of ZnSe nanowires. But thermal instability of ZnSe/SiO2 nanocables still exists at elevated temperatures, due to the diffusion of Zn2+, Se2−, and O2 under the driving force of concentration gradients inside and outside the SiO2 sheath. For a thin sheath, Zn2+ and Se2− diffuse through the SiO2 sheath to the surface, and meanwhile O2 diffuses inside and oxidizes residual ZnSe in the core. For thick sheath, the longer diffusion length makes Zn2+ and Se2− diffuse completely through the ZnSe−SiO2 interface before O2 diffuses to this interface. Therefore, an approach to enhance the thermal stability of non-oxide semiconductor nanowires as much as possible is to find a suitable sheath, in which the core material and O2 have a low diffusion coefficient.

Cu nanowires with different preferred orientations were successfully fabricated in porous anodic alumina membrane (PAAM) templates by an electrochemical method. Thermal expansion of as-prepared and...

Modular design method for designing and synthesizing microporous metal–organic frameworks (MOFs) with selective catalytical activity was described. MOFs with both nano-sized channels and potential catalytic activities could be obtained through self-assembly of a framework unit and a catalyst unit. By selecting hexaaquo metal complexes and the ligand BTC (BTC=1,3,5-benzenetricarboxylate) as framework-building blocks and using the metal complex [M(phen)2(H2O)2]2+ (phen=1,10-phenanthroline) as a catalyst unit, a series of supramolecular MOFs 1–7 with three-dimensional nano-sized channels, i.e. [M1(H2O)6]·[M2(phen)2(H2O)2]2·2(BTC)·xH2O (M1, M2 Co(II), Ni(II), Cu(II), Zn(II), or Mn(II), phen=1,10-phenanthroline, BTC=1,3,5-benzenetricarboxylate, x=22−24), were synthesized through self-assembly, and their structures were characterized by IR, elemental analysis, and single-crystal X-ray diffraction. These supramolecular microporous MOFs showed significant size and shape selectivity in the catalyzed oxidation of phenols, which is due to catalytic reactions taking place in the channels of the framework. Design strategy, synthesis, and self-assembly mechanism for the construction of these porous MOFs were discussed.

In this paper, single-crystal ZnS column arrays are prepared on the ZnS wafer. The ZnS column arrays are then utilized as a transition layer to achieve large-scale homoepitaxial growth of ZnS nanowire arrays. Through annealing ZnS columns coated with Au films at different temperatures, the Au particle density is controlled, and the ZnS nanowire density is controlled via a vapor−liquid−solid process ranging from 0.33 to 3.04 wires/μm2. This universal method can be easily applied to homoepitaxially grow nanowire arrays of other materials and tune the nanowire density.

We present an analysis of the interatomic force of Ni nanowires on the basis of the interatomic interaction potential energy curve, which is obtained from the results of in situ high temperature X-ray diffraction in the range of 25–800 °C. Compared with bulk Ni, Ni nanowires have larger interatomic force. Our research offers a simple method of studying the mechanical properties of the nanowires.

One-dimensional (1D) semiconductor nanomaterials attract much attention because they are ideal systems for investigation and studying the relationship between properties and structures and having extensive application future in the high technical field. They are expected to play an important role in fabrication of the next generation nanocircuits, nanotools, nanowires lasers, photon tunneling devices, near-field photo-waveguide devices, etc. This article described controlled growth, characterization of structures and morphologies and properties of 1D semiconductor nanomaterials based on our previous works. This article is organized into two parts: The first part is complicated nanostructures of semiconductors, which includes coaxial nanocables, heterostructure nanowires and nanowires with metal–semiconductor junction behavior, hierarchical structures, doping of the nanowires and nanobelts, porous materials and periodically twined nanowires and asymmetrical polytypic nanobelts. The second part contains semiconductor nanoarrays based on anodic alumina membrane (AAM) templates. Finally, we propose that further investigation of the influence of nanomaterial morphologies on properties and how to design the morphology of nanostructures to meet the property requirements of nanodevices are our future research directions in this field.

Co nanowires with a preferred orientation were fabricated by direct current electrodeposition into the pores of porous anodic alumina membrane, and the structure of Co nanowires was studied by X-ray diffraction and high-resolution transmission electron microscopy with selected-area electron diffraction. It is found that the crystal structure of Co nanowires lies on the deposition potential. When electrodeposition is performed far from equilibrium conditions, i.e., at a high potential, face-centered cubic Co nanowires are deposited, while hexagonal close packing Co nanowires are formed at the low potential. The experimental results indicate that the orientation of the nanowires has effects on the coercivity for both hexagonal close packing (hcp) and face-centered cubic (fcc) Co.

Silver (Ag) nanowires with different diameters (28, 38, 55, 80, 200 nm) have been successfully fabricated into the anodic alumina membranes (AAMs) by direct-current electrochemical deposition technique. X-ray diffraction and selected area electron diffraction analysis show that the as-synthesized samples have preferred (220) orientation independent of the nanowire diameters. Transmission electron microscopy and field-emission scanning electron microscopy investigation reveal that the large-area and highly ordered Ag nanowire arrays with smooth surface and uniform diameter are synthesized, and they have the high aspect ratio. The formation mechanism of the silver nanowires is also discussed. The nanowire arrays with different diameters may have potential applications in the future nanodevices.

Tubular halloysite can be used as a template to fabricate a novel metallized ceramic microstructure through electroless plating. Reduction of Pd ions by methanol is conducted to initiate Ni plating. There is a simultaneous deposition of Ni nanoparticles on the outer surface and discontinuous wires in the lumen site of the halloysite template obtained. The different deposition could be caused by the different composition distribution of ferric oxide impurity in the wall due to the isomorphic substitution during the formation of halloysite template. Its magnetic property is mainly attributed to the Ni nanoparticles, not the wires. The metallized ceramic microstructure has the potential to be utilized as a novel magnetic material.

The nanocomposites consist of nanometer silica fillers embedded in thermoset polymers, which were prepared by means of irradiation of ultraviolet light. The nanomechanic properties had been investigated by load–displacement analysis from nanoindentation experiments. The results obtained showed that the nanoindentation hardness is decreasing and tends to a certain value with increasing indentation depth, the value is among 1.91–4.11 GPa while the nanosilica contents varied from 0 to 5% within nanocomposites. Young’s modulus measured by nanoindentation is higher than the value by tensile test, namely EI = ET 1/4 2: 63 and the enhancement of Young’s modulus due to the presence of nanosilica with the above contents, EI = EI, 0 1/4 1: 7 2: 0 from 1: 8 2: 2 from tensile test, was compared to be consistent with each other in two different methods. So nanoindentation technique has been successfully applied for the valuation of the nanomechanic properties of nanocomposites with nanosilica.

Ordered Al nanowire arrays with the same nanowire density but the diameters decrease radially embedded in one piece of anodic alumina membranes were successfully fabricated by two-step synthesis: electrodeposition of Zn and replacement in AlCl3 solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected-area electron diffraction techniques were used to characterize the Al nanowires obtained. SEM and TEM images taken from the different areas of Al nanowire arrays show that we can control the growth of aligned Al nanowires with different diameters in a single process at the same time. The investigation results not only have potential applications in photoelectric devices but also open up a new method for fabricating nano-scale materials.

Polycrystalline CdS nanotubes (CNTs) were successfully achieved by a two-step treatment, i.e. (CdS+Cd) nanowires (electrodeposition and sulfuration process in anodic alumina membrane) ⇄ CNTs (dissolution method of removing Cd in 0.5 M HCl). Having been characterized using X-ray diffraction and scanning electron microscopy, the nanowires, the intermediate products, contain Cd and CdS, and have uniform diameters of about 80 nm and lengths of up to 25 μm, which correspond to the pore size and thickness of the membrane used. The average inner and outer diameters of the as-obtained CNTs are respectively 40 and 80 nm via transmission electron microscopy. Selected area electronic diffraction, X-ray diffraction and X-ray photoelectron energy spectroscopy investigations demonstrate that these CNTs with hexagonal wurtzite polycrystalline structure are pure and stoichiometric. The successful synthesis of these semiconductor CNTs may open up new possibilities for studies of fundamental properties and potential applications of semiconductor nanotubes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

We propose a composite magnetic-barrier structure, which is alternately arranged with two different kinds of magnetic barriers. We theoretically investigate the transport properties for electrons tunnelling through this type of magnetic-barrier structure with and without the interaction of the electronic spin and the magnetic field. It is shown that the composite magnetic barriers greatly enhance the wave-vector filtering properties in contrast to the corresponding non-composite magnetic barriers consisting of two identical magnetic barriers. It is also shown that the composite magnetic barriers exhibit a rather evident electron spin-polarization effect, especially in low-energy region, while the corresponding non-composite magnetic barriers do not possess the electron spin-polarization effect.

High-quality photonic crystals (PCs) based on the ordered pore arrays anodic alumina are fabricated by the anodic oxidation method using the newly-designed periodic oxidation voltage wave. The obtained PCs own uniform narrow photonic band gaps (PBGs), steep photonic band edges, zero transmittances inside of the PBGs and high transmittances outside of the PBGs. Importantly, the high-quality PBGs of the anodic alumina PCs are tunable and controllable in the range from 350 nm to 1330 nm by modifying the anodizing voltage waveform. The benefit of newly-designed periodic oxidation voltage wave is to improve the optical properties of anodic alumina PCs.

This communication reports an approach to fabricate large-scale ultrathin open-ended porous TiO2 membranes (UOP-TMs) with ordered straight-through pores. Bi nanodot arrays on Si substrates are obtained by using the UOP-TMs as surface patterning masks.

This study aimed to investigate the direct effects of advanced glycation end products (AGEs) on the mitochondrial structure and function of SH-SY5Y cells and the possible molecular mechanism(s) underlying mitochondria dysfunction by AGEs. SH-SY5Y cells were cultured in 400 μg/ml of AGE-bovine serum albumin (BSA) for 24 h, and changes in the mitochondrial function of SH-SY5Y cells were analysed as follows. Reactive oxygen species (ROS) were detected using 2′,7′-dichlorodihydrofluorescein diacetate molecular probes. Mitochondrial membrane potential (ΔΨm) was determined by flow cytometry using fluorescent probes. The expression of cytochrome c (Cyt c) protein level was assessed by Western blotting. Mitochondrial structures were observed by transmission electron microscopy. Our results showed that AGE-BSA induced an increase in ROS levels, a decrease in mitochondrial ΔΨm, and the release of Cyt c from mitochondria in SH-SY5Y cells. The mitochondria of SH-SY5Y cells showed remarkable swelling and vacuolisation, but these changes were recovered after pretreatment with neutralising anti-receptor for advanced glycation end products (RAGE) antibody. Our results suggested that AGE-BSA induced mitochondrial dysfunction in SH-SY5Y cells through RAGE pathways. Thus, AGEs are potential mechanistic links between diabetes mellitus and Alzheimer’s disease.

The bulk modulus of nanowires (NWs) and its temperature dependence were determined by a simple and convenient method based on temperature-dependent X-ray diffraction (XRD) measurement. It was found that the bulk moduli for Ni, Cu, and Ag NWs were much higher than that for their counterpart bulk materials in the temperature range from 25 °C to 800 °C and the influence of temperature on the bulk modulus for NWs was stronger than that for their counterpart bulk materials. A surface bond contraction model and the force–interatomic-distance curves were introduced to explain the experimental results.

Nanocrystalline GaSb embedded in SiO2 film was grown by radio frequency co-sputtering. The nonlinear optical properties of the GaSb–SiO2 composite film have been studied at 632.8 nm by use of Z-scan technology. The appearance of a two photon absorption is predicted energetically above the exciton resonance for quantum-dot radii, which are between the electron and hole radii. The nonlinear refractive index of the GaSb–SiO2 composite film is positive. It shows that the GaSb–SiO2 composite film posses a large third-order nonlinear susceptibility about 7.84×10−9 esu. Room temperature transmission spectrum shows that the absorption edge exhibits a very large blue shift of 2.7 eV compared with that of bulk GaSb, which is mainly explained by the quantum confinement effect.

A new kind of distributed Bragg reflector is made of layer-by-layer anodic alumina membrane using electrochemical anodization, which is consisted of periodically stacked main stem channel layers and branched channel layers with the period comparable to the optical wavelength. The first Bragg condition peak, which is characterized for main inhibition of incident light perpendicular to the surface of anodic alumina membrane, could be modulated from 727 to 1200 nm by modifying the anodizing voltage waveform. It possibly provides a plan to fabricate light filters in large area, which have very low transmissivity within stop band but high transmissivity in other ranges.

We studied the dynamic effects of an electromagnetic(EM) wave with circular polarization on a two-level damped atom. The results demonstrate interesting ac Stark split of energy levels of damped atom. The split levels have different energies and lifetimes, both of which depend on the interaction and the damping rate of atom. When the frequency of the EM wave is tuned to satisfy the resonance condition in the strong coupling limit, the transition probability exhibits Rabi oscillation. Momentum transfer between atom and EM wave shows similar properties as the transition probability under resonance condition. For a damped atom interacting with EM field, there exists no longer stable state. More importantly, if the angular frequency of the EM wave is tuned the same as the atomic transition frequency and its amplitude is adjusted appropriately according to the damping coefficients, we can prepare a particular 'Dressed State' of the coupled system between atom and EM field and can keep the system coherently in this 'Dressed state' for a very long time. This opens another way to prepare coherent atomic states., Comment: latex, 2 figures

Anodic aluminum oxide based photonic crystals with periodic porous structure have been prepared using voltage compensation method. The as-prepared sample showed an ultra-narrow photonic bandgap. Asymmetric line-shape profiles of the photonic bandgaps have been observed, which is attributed to Fano resonance between the photonic bandgap state of photonic crystal and continuum scattering state of porous structure. And the exhibited Fano resonance shows more clearly when the sample is saturated ethanol gas than air-filled. Further theoretical analysis by transfer matrix method verified these results. These findings provide a better understanding on the nature of photonic bandgaps of photonic crystals made up of porous materials, in which the porous structures not only exist as layers of effective-refractive-index material providing Bragg scattering, but also provide a continuum light scattering state to interact with Bragg scattering state to show an asymmetric line-shape profile.

Photoacoustic spectroscopy has been used to study various sizes of nanoscaled CoTiO 3 and NiTiO 3 powders. Three absorption bands (or peaks) are observed from ultraviolet to near-infrared (350–1200 nm) in the photoacoustic spectra. The analyses indicate that the absorptions located around 525 nm for CoTiO 3 and 445 nm for NiTiO 3 are induced by the transition of free excitons, but the absorptions located around 590 nm for CoTiO 3 and 505 nm for NiTiO 3 are related to that of bound excitons. Besides, the absorptions located around 840 nm both for CoTiO 3 and NiTiO 3 are corresponding to the electronic transition of additional energy levels caused by defects and impurities. The behavior of the characterized absorptions strongly depends on the grain sizes.

To explore mechanism of acupuncture for renal interstitial fibrosis (RIF) in hypertension rats.Twenty-four 24-week-old male spontaneously hypertensive rats were randomly divided into a model group, a perindopril group and an acupuncture group, eight cases in each one. In the acupuncture group, with rats tied up, electroacupuncture was applied at bilateral "Quchi" (LI 11) and "Zusanli" (ST 36) under mild vibration of needle handle for 20 min, once a day. In the perindopril group, perindopril (0.4 mg/kg) suspension liquid was applied for intragastric administration, once a day. In the model group, rats were tied up for 20 min a day without any treatment. Eight same-age same-race Wistar Kyoto (WKY) rats with normal blood pressure were taken as a control group, which was given with free diet but no treatment. The treatment was reuqired for six weeks. The systolic blood pressure of caudal artery was tested. Kidney morphological structure was observed by HE coloration. Deposition optical density of type I and III collagen in kidney was tested by immunohistochemistry. Expression of transforming growth factor-beta1 (TGF-beta1) mRNA was tested by reverse transcription polymerase chain reaction (RT-PCR) method.Compared with the model group, the blood pressure was significantly decreased in the acupuncture group (P0.01), the damage of kidney morphology was minor, positive depositional area of type I and III collagen was obviously decreased (both P0.05), and the expression of semi-quantitative analysis of TGF-beta1 mRNA was decreased (P0.05), which had similar effect as western medication perindopril.Acupuncture at "Quchi" (LI 11) and "Zusanli" (ST 36) probably intervenes the process of RIF by reducing synthesis of kidney type I , III collagen and restraining expression of TGF-beta1.

To investigate the effect of the eye-acupuncture therapy on cerebral intercellular adhesion molecule-1 (ICAM-1) expression in rats with acute cerebral ischemia-reperfusion injury (CI/RI) so as to reveal its underlying mechanism.Forty male SD rats were randomly and equally divided into normal, sham operation (sham), model and eye-acupuncture groups. Acute CI/RI model was established by occlusion of the middle cerebral artery with a modified suture-blocking method. Filiform needles were inserted into the "Qan" (Liver Area), "Shangjiao" (Upper Energizer Area), "Xiajiao" (Lower Energizer Area), etc. of the eye-acupuncture acupoints, and retained for 20 min. The treatment was conducted twice daily, 7 times altogether. Seventy-two hours after Acute CI/RI, the neurological behavior was assessed by ZeaLonga neurophysical impairment scale. Cerebral ICAM-1 protein and ICAM-1 mRNA expression levels were detected by Western blot (Penumbra area of the right cerebral infarction region) and real time-polymerase chain reaction (PCR) methods, respectively.After modeling, the neurophysical impairment score of the model group was increased from 0 to (2.63 +/- 0.92) points on the first day and (2.63 +/- 0.74) points 72 h following Acute CI/RI. Correspondingly, cerebral ICAM-1 protein and mRNA expression was up-regulated considerably in the model group than in the normal control group (P0. 01). In comparison with the model group, the neurologic impairment score, and cerebral ICAM-1 protein and mRNA expression levels of the eye-acupuncture group were down-regulated obviously (P0.01, P0.05). No significant differences were found between the normal control and sham groups in neurologic impairment score and the expression levels of the ICAM-1 protein and ICAM-1 mRNA(P0.05).Eye-acupuncture therapy can improve the cerebral ischemia-reperfusion injury induced behavior changes, which may be related to its effects in down-regulating the expression of cerebral ICAM-1 protein and gene.

Titanium oxide-Ag composite (TOAC) adsorbents were prepared by a facile solution route with Ag nanoparticles being homogeneously dispersed on layered titanium oxide materials. The as-synthesized TOAC exhibited a remarkable capability for trace Cr(VI) removal from an aqueous solution, where the concentration of Cr(VI) could be decreased to a level below 0.05 mg/L within 1h. We have systematically investigated the factors that influenced the adsorption of Cr(VI), for example, the pH value of the solution, and the contact time of TOAC with Cr(VI). We found that the adsorption of Cr(VI) was strongly pH-dependent. The adsorption behavior of Cr(VI) onto TOAC fitted well the Langmuir isotherm and a maximum adsorption capacity of Cr(VI) as 25.7 mg/g was achieved. The adsorption process followed the pseudo-second-order kinetic model, which implied that the adsorption was composed of two steps: the adsorption of Cr(VI) ions onto TOAC followed by the reduction of Cr(VI) to Cr(III) by Ag nanoparticles. Our results revealed that TOAC with high capacity of Cr(VI) removal had promising potential for wastewater treatment.

In this article, the porous-ZnO-nanobelt film was synthesized by oxidizing the ZnSe-nanobelt film in air. The experiment results show that the porous-ZnO-nanobelt film possesses enhanced photocatalytic activity compared with the ZnO-nanobelt film, and can be used as recyclable photocatalysts. The enhanced photocatalytic activity of the porous-ZnO-nanobelt film is attributed to the increased surface area. Therefore, turning the 1D-nanostructure film into porous one may be a feasible approach to meet the demand of photocatalyst application.

Nanocrystalline Ga0.62In0.38Sb embedded in SiO2 matrix has been fabricated by radio frequency magnetron co-sputtering. X-ray photoelectron spectroscopy strongly supports the existence of nanocrystalline Ga0.62In0.38Sb embedded in SiO2 matrix. The room-temperature Raman spectrum shows that the Raman peaks of the Ga0.62In0.38Sb-SiO2 composite film have a larger red shift of about 95.3 cm-1 (longitudinal-optic) and 120.1 cm-1 (transverse-optic) than those of the bulk GaSb. This can be explained by the phonon confinement and tensile stress effects. The room-temperature optical transmission spectra show that the absorption edge exhibits a large blue shift of about 2.43 eV compared with that of the bulk semiconductor, suggesting the existence of quantum size effects.

The phenomenon of extraordinary and multi-broadband optical transmission through sub-wavelength metallic grating with symmetry breaking has been theoretically investigated. Under normal incident light, the radiative and dark modes appear in adjacent slits of the grating with asymmetric heights. Through the destructive interference of alternative radiative and dark modes, multiple broadband transmission and enhanced light propagation is realized. The counter-propagating light circulation results in sharp dips in the transmission spectrum. These characteristics of the asymmetric grating could provide highly controllable ways to design novel devices.

Defect modes located at different position were prepared by introducing defect layers in the porous alumina based photonic crystals. Furthermore, experiments and simulations were carried out to investigate the properties of such defect modes. The results show that defect mode can be tuned easily by changing thickness and location of the defect layer, moreover, the optical properties of defect mode when changing the incident angle are also studied.

Silicon nanoparticles dispersed in 2-propanol were prepared by using an arc plasma with gas flow method in a new designed home-made apparatus. The particles are composed of silicon crystal core covered by oxidized amorphous silicon shell. The composition of the particle surface layer can be modified by preparing the sample in different atmosphere. The particles can be also obtained with different core composition and different size which we need.

Large-area ordered Ni nanowire arrays with different diameters have been fabricated by the direct current electrodeposition into the holes of porous anodic alumina membrane. The crystal structure and micrograph of nanowire arrays are characterized by X-ray diffraction, field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The results indicate that the growth orientation of Ni nanowires turns from [110] to [111] direction with increasing diameters of nanowires. The mechanism of the growth was discussed in terms of interface energy minimum principle. The size-dependent orientation of Ni nanowire arrays has the important significance for the design and control of nanostructures.

The relation between sizes and phase structures of gallium has been studied. Gallium droplets with different sizes dispersed in poly(methyl methacrylate) and silicone oil were studied by differential scanning calorimeter and transmission electron microscopy. The results showed that particles with different sizes corresponded to stable or metastable phases of gallium. The stable phase $\ensuremath{\alpha}$-gallium is dominantly formed when the average size of particles is no less than 0.8 micron, and the metastable phases $\ensuremath{\beta}$-, $\ensuremath{\gamma}$- and $\ensuremath{\delta}$-gallium are mainly formed when the average particle size is 0.8--0.6 micron, 0.6--0.3 micron, and below 0.3 micron, respectively. The phase selection in the solidification process under undercooling is used to explain the results.

The electronic structure of nanostructured SiO2 was studied by means of ultraviolet-near infrared absorption spectra. A strong and broad absorption band was observed in the wavelength range of ultraviolet-near infrared light. This band is caused by the electronic transition from the valence band to the defect energy level in the band-gap which was theoretically calculated by using molecular orbital approach. With increasing the annealing temperature, the red shift of this band was observed. The mechanism of this band is discussed.

Free-standing bamboo-like Ni nanowire arrays with periodic branches have been produced by electrochemical deposition in the pores of layer-by-layer anodic alumina membrane. This method could provid...

Multibranched TiO2 nanotubes have been controllably fabricated through a two-step anodization method. By tailoring the diameter ratio of the stem and branch accurate by multibranched, such as two-,...

Netlike mesoporous alumina membrane with layers of controllable pore size is fabricated by anodization and following chemical etching. All the nanochannels in this mesoporous membrane are connected...

In this work, we demonstrated the use of a promising sensor based on alumina Photonic Crystals (PC) which can be applied in the field of gas detection owing to the well structured PC with an ultra-narrow Photonic Bandgap (PBG), of which the full width at half maximum is only 30 nm. This type of PC was prepared successfully by using a compensation voltage mode method, which can effectively compensate for the chemical corrosion and the slowing down of ion exchange, resulting in a uniform diameter of the pores in the anodic alumina oxidation (AAO) from beginning to end. The as-prepared sample was applied to detect the concentration of organic vapor, such as ethanol, in this experiment. A large PBG shift is achieved when the concentration of ethanol changes, and the mechanism was also discussed theoretically. This sensor had a good repeatability due to the chemical and physical stability of the matrix material (alumina). These results indicate the potential applications of the as-prepared AAO based PC in the sensing field.

In this study, the free-standing and open-ended TiO2 nanotube arrays with large area are synthesized under high field anodization. The membrane is firstly self-detached from Ti foil during anodization followed by a pore opening process of in situ field-assisted chemical dissolution. A model of stress accumulation is proposed to explain the self-detachment of the as-formed TiO2 nanotube membrane from the underlying Ti substrate. It is believed that the stress accumulation in the membrane is the collective effects of the stress generation during tube growth and the stress release due to chemical dissolution. When the stress accumulates to a critical value, the TiO2 nanotube membrane would be self-detached from the Ti substrate. It is found that the magnitude of stress is associated with the thickness of a stressed layer rather than the thickness of the as-formed TiO2 membrane. By changing the anodization parameters, the stress accumulation rate can be facilely controlled, which finally determines the detaching time and thickness of the detached membrane.