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Due to spontaneous organization of cellulose nanocrystals (CNCs) into the chiral nematic structure that can selectively reflect circularly polarized light within a visible-light region, fabricating stretching deformation-responsive CNC materials is of great interest but is still a big challenge, despite such a function widely observed from existing creatures, like a chameleon, because of the inherent brittleness. Here, a flexible network structure is introduced in CNCs, exerting a bridge effect for the rigid nanomaterials. The as-prepared films display high flexibility with a fracture strain of up to 39%. Notably, stretching-induced structural color changes visible to the naked eye are realized, for the first time, for CNC materials. In addition, the soft materials show humidity- and compression-responsive properties in terms of changing apparent structural colors. Colored marks left by ink-free writing can be shown or hidden by controlling the environmental humidities. This biobased photonic film, acting as a new "smart skin", is potentially used with multifunctions of chromogenic sensing, encryption, and anti-counterfeit.

The structures and electronic properties of the gaseous M2Pt20/− clusters (M represents the alkaline earth metal) were investigated using the density functional theory (B3LYP and PBE0) and wave function theory (SCS-MP2, CCSD and CCSD (T)). The results indicate that the D2h isomers with the planar structures are more stable than the C2v isomers with smaller dihedral angles and shorter Pt-Pt bond lengths. The mutual competition of M(s,p)-Pt(5d) interaction and Pt-Pt covalent bonding contributes to the different stabilizations of the two kinds of isomers. The M(s,p)-Pt(5d) interaction favors the planar isomers with D2h symmetry, while the Pt-Pt covalent bonding leads to the C2v isomers with bending structures. Two different crossing points are determined in the potential energy curves of Be2Pt2 with the singlet and triplet states. But there is just one crossing point in potential energy curves of Ra2Pt2 and Ca2Pt2− because of flatter potential energy curves of Ra2Pt2 with the triplet state or Ca2Pt2− with quartet state. The results reveal a unique example of dihedral angle-bending isomers with the smallest number of atoms and may help the understanding of the bonding properties of other potential angle-bending isomers.

One-dimensional simulations with a detailed hydrogen-oxygen reaction mechanism have been performed to investigate detonation phenomenon in a combustion light gas gun (CLGG). Convection fluxes of the Navier-Stokes equations are solved using the WAF (weighted average flux) scheme HLLC Riemann solver. A high resolution fifth-order WENO scheme for the variable extrapolation at the volume interface and a fourth-order Runge-Kutta scheme for the time advancement are used. Validation tests of the stoichiometric hydrogen-oxygen deflagration to detonation transition process shows good agreement between the computed results and the analytical and documented solutions, demonstrating the reliability on the detonation simulation of the current scheme. Simulation results of the interior ballistic process of the CLGG show that the flame propagation experiences three distinct stages. The blast detonation wave causes a high-pressure shock and hazardous oscillations in the chamber and makes the projectile accelerate with fluctuations, but has only a small improvement to the muzzle velocity.

As one of the most efficient and environmentally benign strategies to treat organic dye pollution, TiO2 photocatalytic technology has attracted increasing and wide interests in environmental governance, for which dominantly exposed (001) facets and high porosity are of great importance for catalytic performance. To date, however, how to synergistically regulate the dominant growth of (001) facets and the formation of hierarchical pore structures still remains challenging. Here, we report a limited growth strategy mediated by the self-assembly of cellulose nanocrystal (CNC) to prepare anatase TiO2 nanocatalyst with dominantly exposed (001) reactive facets. Notably, crystal growth in the confined space of layered CNC structures favors exposing (001) facets, and the easy removal of the soft biotemplate facilitates creating hierarchical pores. Furthermore, the (001) facet percentage, pore size, and porosity can be easily modulated by controlling the CNC concentration. After introducing an up-conversion quantu...

Cellulose nanocrystal (CNC) is an interesting polysaccharide nanomaterial that can self-assemble into a chiral nematic liquid crystalline structure in aqueous solution, producing brightly structural color upon selectively reflection of visible light. However, till now, only iridescent structural colors can be created by such colloidal array, making it impossible to be used as colorimetric sensors. Here, inspired by longhorn beetle having short-range ordered but long-range disordered microstructures, it is demonstrated to develop low-/non-angle-dependent structural-color CNC composite films through interference against the long-range orders as a result of introducing positively charged poly (dimethyl diallyl ammonium chloride) (PDDA). By exploring balanced ordered/disordered structures, vivid angle-independent structural colors are realized, enabling accurate cognition for environmental signals, which is crucial to promising applications in sensing, anti-counterfeit, and decoration technology.

Microporous ZnO nanorods (NRs) in situ growth on indium tin oxide (ITO) glass substrate was successfully prepared via a simple hydrothermal reaction and without porous template. The special nanostructures of ZnO were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The results indicated that the nanostructures of ZnO were microporous in the top plane of the hexagonal wurtzite structure and uniformly distributed on the ITO substrate. Furthermore, the sensor constructed with microporous ZnO NRs/ITO exhibited extremely high and selectively electrocatalytic activity toward the oxidation of dopamine at 0.2 V with good detection limit of 0.45 μM and wide linear range from 2 μM to 777 μM even in the presence of ascorbic acid and uric acid.

In this work, a nickel cobalt oxide (Ni/Co oxide) nanoflake based electrochemical sensor for the fast determination of estriol in milk is presented for the first time. Nanostructured Ni/Co oxide with controlled morphology was synthesized by a facile hydrothermal method. The morphology and the electrochemical performance of the Ni/Co oxide were characterized by scanning electron microscopy transmission electron microscope, and energy dispersive X-ray spectroscopy, respectively. Results indicated that the porous hexagonal sheet-like Ni/Co oxide exhibited excellent electrocatalytic activity toward estriol, with a low detection limit of 0.42 nM, and linear range from 1 nM to 14 nM. Good specificity, stability and reproducibility were also demonstrated. Recovery was determined from 92.7% to 103.7% for spiked milk samples, providing a promising platform for fast screening of estriol.

In this work, a nonenzymatic electrochemical sensor based on nanoporous magnesium oxide (MgO) was developed for the rapid screening of hydrogen peroxide (H2O2) in milk. The nanoporous MgO, which was synthesized by a novel one-pot reaction process at low temperature, showed a large specific surface area and was favorable for constructing biosensors. Based on the nanoporous MgO, a nano-sensor for H2O2 was developed. The sensor exhibited extremely high electrocatalytic activity toward the oxidation of H2O2 with a detection limit of 3.3 μM and a wide linear range from 0.05 to 0.2 and 0.2 to 10 mM. The averaged recovery was determined to be from 94.3% to 119% for spiked milk samples. The proposed method is ideally suited for the fast screening of H2O2 misuse in milk at low cost.

A novel flocculus-like CuO microstructure exhibiting excellent electrochemical hydrogen capacity of 210 mAh/g were fabricated using Cu (OH)2 as precursor. By altering the initial concentration of NaOH, novel butter-like and flower-like CuO microstructures without electrochemical hydrogen capacity were also obtained. Field emission scanning microscopy (FESEM) and X-ray power diffraction (XRD) were characterized the as-obtained products. The dosage of NaOH plays a vital role in controlling the morphology, which affects electrochemical hydrogen capacity of final products.

Boron nitride (BN) was prepared by polymer-derived method using precursor poly [(alkylamino) borazin (PABZ). The evolution of composition and structure of precursor PABZ into BN ceramic during curing and pyrolysis process was investigated by FTIR, TG, XRD techniques and chemical analysis. The results showed that PABZ could fulfill curing heated at 80°C for 2hrs in NH3 atmosphere. During the curing process the both transamination reaction and condensation reaction occurred, resulting in cross-link between monomer molecular. With the proceeding of curing process, the new B-N bonds were formed and continued to expand in three dimensions. After cured treatment the thermal pyrolysis of PABZ in ammonia atmosphere was took place, and inorganic degree and crystallinity of products were better, which was more suitable for preparation of high purity hexagonal BN (h-BN) ceramic.

The definition and structure of high temperature proton conductors is reviewed. Discusses the high temperature proton conductors of commonly used several preparation methods.

In this paper, the chemical-thermal composite of coal gangue activation and influence factors is studied. Using adopting Al3+ dissolution rate as an evaluation index to determine the activation conditions, XRD is used to determine the crystal structure and SEM scanning electron microscopy (SEM) for crystal morphology. The results shows that the best activation conditions of calcination for coal gangue activation time is1.5h, under the condition of calcination temperature 650°C, water cooling, the Al3+ dissolution rate can reach 70.14%.After activation of coal gangue, the kaolinite convert directly into cetakaolinite, its active composition SiO2 and Al2O3 present loose shape, good activation, can be used as an adsorbent and catalyst materials.

Glutin-urea system was used to prepare ultrafine zirconia suspension for gelcasting. Premixed solution was prepared at deionized water/glutin/urea ratio of 90/10/5 (by weight). Adjusting pH value to11, zirconia powders and A-type dispersant (polyacrylic salt) were added. After ball-milled about 12 hours, 45vol% zirconia slurry was acquired and the viscosity of which was less than 1 PaS.

To investigate the microorganisms growth process and biostability of biological activated carbon by manual preparation, the microorganisms growth process were observed by the photos of optics and electronic microscope, and the microbial biomass was determined by phospholipids (Lipid-P) analysis. The bell bug, rotifer and eelworm were observed by the photos of optics and electronic microscope. The zoogloea size of the foster biological active carbon was big, the configuration was tight. The quantity of zoogloea on the top of BAC column was more than that on the below. The Lipid-P biomass of BAC on the top and below were 16nmolP/cm3 and 6.2nmolP/cm3 respectively, as same as that was the number of E. Coli cells were 1.6×109cfu/cm3 and 6.2×108cfu/cm3 respectively in 60-days. The Lipid-P biomass decreased to 90 days. The biological activated carbon was obtained by manual culture.

A technology of self-emulsification coacervation to prepare starch sodium octenyl succinate (SSOS) microcapsules consisting of evening primrose oil (EPO) as a core material has been illustrated in this report. The optimal microencapsulation conditions has been investigated and the morphology of the microcapsules has been observed by Optical microscope. The results show that the optimized microencapsulation condition is core-wall ratio 2 g/g , DS 0.050, coacervating agent 0.8 mL/mL emulsion, with the cross-linker 0.04 g/g SSOS, stirring speed 700 rpm for emulsification, and 350 rpm for coacervation. Meanwhile，the protective effect experiments via aeration method indicate that the increment of peroxide value (POV) of entrapped EPO is only 5.68％ compared to unencapsulated EPO after aeration for 48 h, which shows good protection performance of SSOS microcapsules to entrapped substances.

Objective: To study the antibacterial efficacy and the catalytic capability of nanocrystalline magnesia powder(nano-MgO). Methods: The antibacterial efficacy was evaluated in Bacteriostatic circle and the shake flask test and the catalytic capability was evaluated by paraoxon. Results: The nano-MgO had good antibacterial efficacy and highly catalytic capability. The catalytic capability was not influenced by light. When 50mL 20μg/L paraoxon solution was catalyzed by 0.5g nano-MgO for 5min, the disappearance of paraoxon was about 77.9%, and for 60min, the disappearances of them was 99.6％. Conclusion：The nano-MgO had good antibacterial efficacy and highly catalytic capability. Key words: nanocrystalline magnesia , antibacterial efficacy, paraoxon, catalytic degradation

The enhanced light transmission through an I-shape aperture is studied by simulation and theory. The transmission profile due to microcavities created in the entrance and exit of the aperture was modified and new peak was observed. By introducing a new formula the refractive index of layers is defined. The Fabry–Perot matrix method is employed to explore the role of Fabry–Perot resonator effect in modified slits, especially I-shape slit in the scope of this work. And the peaks correspond to this effect are determined. The effect of microcavity surface Plasmon polaritons is explored respectively. Both microcavity surface plasmons and Fabry–Perot resonator contribute in transmission enhancement and consider as the origin of extraordinary transmission for unsymmetrical slits.

We present a probe of scanning near-field optical microscope (SNOM) with large aperture and high resolution, which is added a metallic dipole nano-antenna onto the tip of the ordinary probe. Based on the FDTD algorithm we investigate numerically the measure results by different aperture probes for the same sample with the incident wavelength of 830nm and the scan height of 10nm. The results show that the resolution of the new probe is 100nm, 75nm, 50 nm, 45 nm, 50 nm, 70nm when the probe aperture is 50nm, 100nm, 130nm, 150nm, 170nm, 200nm respectively, and for the ordinary probe the resolution is 50nm，120 nm,140 nm,180 nm, 200nm, 220nm correspondingly. That is to say the resolution of the ordinary probe decrease rapidly with the increasing of the aperture, however the novel probe can maintain the high resolution.

A processable polyborazine precursor was synthesized via substitution reaction and deamine condensation reaction by using methylamine, propylamine and B-trichloroborazine (TCB) as the starting materials. The chemical composition, structure and properties of the obtained polymer were investigated using element analysis, FT-IR, NMR, XPS and TG. The results indicated that the backbone of the polymer was approximate linear arrangement of boron-nitride ring molecules with B-N(CH3)-B structure as bridge bond, meanwhile minor amount of methylamino and propylamino remained in polyborazine as the pendant or end group. The melting point, number average molecular weight and polydispersity index of polyborazine was 90°С , 1002 and 1.355, respectively. The polyborazine showed good processability and polyborazine precursor fibers with diameter of 10~15 µm could be obtained by melt-spinning in N2 atmosphere. The ceramic yield of the polyborazine at 1000°С in nitrogen atmosphere was 53.2 wt%, which suggested that the as-achieved polymer can be used as a precursor to boron nitride ceramic fibers and membranes.

In this research, NaA zeolite samples were synthesized from aluminosilicate solution through hydrothermal method. The effects of different parameters such as the SiO2/Al2O3, OH-/Si and H2O/Na2O molar ratios of the initial gel solution, crystallization time and temperature on the crystallinity and morphology of the synthesized zeolites were investigated. The final products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser particle size analyzer. The experiment results indicated that the SiO2/Al2O3 molar ratio had influence on morphology and size of the synthesized zeolites, the optimum range of SiO2/Al2O3 molar ratio for synthesizing NaA zeolite was 1.5-2. Alkalinity (OH-/Si and H2O/Na2O molar ratio) had a significant effect on particle sizes of the synthesized zeolites, the higher the alkalinity, the smaller the crystal particle size. In addition, it was found that crystallization temperature during hydrothermal treatment played an important role in reducing the over all reaction time. The crystallization time had effect on the crystallinity of the synthesized zeolites. Finally, the optimum synthesis parameters can be proposed in order to synthesize NaA zeolite with desirable particle size, crystallinity and morphology.

Holographic storage properties and Ultraviolet-Visible absorption spectra of LiNbO3:Fe:Hf crystals adoped with Hf(4 mol%)are measured and analysised.Ultraviolet-Visible absorption edges obviously shift to long waveleng.The ratio of [Fe2+]/[Fe3+] increases with the increasing of [Li]/[Nb],which results in the deceasing of diffraction efficiency,and improving response speed and sensitivity.Moreover,the ability of light scattering resistance decreased with the increasing of [Li]/[Nb].It is contributed to the change of Fe2+Li concentration in crystals.

The photochemical kinetics of phenanthrenequinone (PQ) doped poly (methyl methacrylate) photopolymer in holographic recording was studied theoretically and experimentally. The diffusion of PQ molecules during holographic recording was negligible because of its small diffusion coefficient at room temperature. A photochemical reaction kinetics model of PQ/PMMA was established. The analytical expressions for the temporal variations of transmittance and diffraction efficiency were derived. By fitting the experimental curves, some parameters related with the polymer components were obtained by the proposed model, which can be used to analyze the photochemical process and will be helpful to the optimization of material preparation.

In this article, we report the galvanic replacement reaction between an Ag template and HAuCl4 · 4H2O in aqueous solution transforms 33.3 nm hexagonal shape Ag to Ag@Au core-shell nanostructure in the presence of the surface-regulating polymer poly (vinyl pyrrolidone) (PVP). By controlling the molar ratio of Ag to HAuCl4 · 4H2O, the extinction peak of resultant can be continuously tuned from the blue to the near infrared sections for both absorption and scatting. The results of UV-vis, XRD, TEM, and SEM show the different characters on the Ag and Ag@Au core-shell nanostructure which suggest that the transformation of Ag into Ag@Au by controlling their dimensions as well as the thickness and porosity of their walls.

The colloidal crystal template or opal with a closed-packed face-centered cubic (fcc) lattice was prepared from monodisperse polystyrene (PS) spheres by vertical sedimentation. The template provided void space for infiltration of monomer precursor composed of acrylate acid, acrylamide and ammonium persulfate, as well as microgel from the subsequent copolymerization. The sample was immersed in dimethylbenzene for completely removing PS spheres to form PAM inverse opal hydrogels (IOH PAM ) or PAM/PAA inverse opal hydrogels (IOH PAM/PAA ) photonic crystals. The PS spheres were replaced by air spheres, which interconnected each other through the windows. The study of responses to pH show that there are two peaks for both IOH PAM and IOH PAM/PAA films, but the IOH PAM/PAA peaks shift to higher pH, and the peaks are independent with the AA content.

The microstructure of Fe85Ga15 ribbons, which show up large magnetostriction, has been investigated by means of XRD and TEM from room temperature up to 1000 K. It was found that the structural features of the crystal at room temperature resembles the modified D0(3) tetragonal structure and the inserted domains of about a few nanometers commonly appear in the materials along [10 1] zone-axis direction. In-situ heating TEM observations show that the high-temperature annealing could evidently affect the microstructure of Fe85Ga15 ribbons. (c) 2005 Elsevier B.V. All rights reserved.

The electromagnetic properties of the interface between a left-handed material and a conventional nonlinear material were investigated theoretically and numerically. We found a new phenomenon—optical bistability of the interface. It was shown that the incident intensity, incident angle and permeability ratio between the left-handed and the nonlinear materials could dramatically affect the optical bistable behaviour. We also compared the bistable behaviours of different electromagnetic modes. The results indicated that the TE mode was prior to the TM mode to obtain optical bistability for the same parameter.

We observe a novel hybrid optical bistability by using an electro-optically tuned cw fibre laser with a fibre Fabry–Perot filter. The principles of the optical bistable device in two operation manners are analysed. The applications in monitoring the wavelength shift of a tunable fibre laser and fibre sensor of digital type are also discussed.

We have proven theoretically that there are sublinear, linear and superlinear relations between the response rates and total incident intensity for different cases of traps in photorefractive polymer materials. These relations were observed in inorganic photorefractive crystals many years ago. Also, the steady-state space-charge field is a function of the total incident intensity, which has also been found in inorganic photorefractive crystals. We have measured the relations of the steady-state diffraction efficiency and the response rate with respect to the total incident intensity in the photorefractive composite consisting of the polymer (N-vinylcarbazole) (PVK) doped with 4,4'-n-pentylcyanobiphenyl (5CB) and C60. The results obtained show that the composite belongs to the case of low trap density.

A new scheme of coherent mutually pumped phase conjugate (MPPC) reflection that depends on the formation of self-pumped phase conjugate reflection of another beam has been demonstrated in a Cu:KNSBN crystal. The dependences of the MPPC reflectivity on the intensity ratio of the two incident beams and on the incident position of the signal beam were measured. We obtain phase conjugate reflectivities of greater than 90% at 488 nm.

The coupled wave equations and their analytic solutions in photorefractive crystals are presented for the case of two-beam writing, while the light-induced scattering is considered. Using this result, the diffraction efficiency for each writing beam is discussed in doped KNSBN crystals with unidirectional fan, which is explained theoretically and verified experimentally.

Surface plasmon (SP) microcavity recently has been proposed to enhance transmission through a subwavelength slit. Here we employed Fabry-Perot matrix method to predict the transmission profile of the structure. The result show good agreement with simulation result based on finite difference time domain (FDTD) method. The calculation shows that the SP microcavity standing waves and the Fabry-Perot resonance mode are responsible for transmission enhancement. For layered slits FP matrix method is a powerful method for prediction transmission behaviors.

Photorefractive properties of Hf:Fe:LiNbO3 crystals with various [Li]/[Nb] ratios have been investigated at 488 nm wavelength based on the two-wave coupling experiment. High diffraction efficiency and large recording sensitivity are observed and explained. The decrease in Li vacancies is suggested to be the main contributor to the increase in the photoconductivity and subsequently to the induction of the improvement of recording sensitivity. The saturation diffraction efficiency is measured up to 80.2%, and simultaneously the recording sensitivity of 0.91 cm/J is achieved to in the Hf:Fe:LiNbO3 crystal grown from the melt with the [Li]/[Nb] ratio of 1.20, which is significantly enhanced as compared with those of the Hf:Fe:LiNbO3 crystal with the [Li]/[Nb] ratio of 0.94 in melt under the same experimental conditions. Experimental results definitely show that increasing the [Li]/[Nb] ratio in crystal is an effective method for Hf:Fe:LiNbO3 crystal to improve its photorefractive properties.

The dynamic process of light-induced agglomeration of carbon nanotubes (CNTs), C60 and Escherichia coli (E.coli) in aqueous solutions is demonstrated using an optical tweezers system. Based on the results, the diameter of the agglomerated region and the agglomeration rate increase with the increasing laser power. After the saturation-stable period, CNTs diffuse completely, C60 clusters only diffuse partially, and E. coli never diffuses in the agglomeration region. Theoretical analyses show that the molecular polarization and thermal diffusion of particles play crucial roles in the diffusion process. The results indicate the possibility of using light to aggregate and sort nanoparticles.

Anisotropic diffraction patterns were observed on far-field screen induced by a weak (0.16 W/cm2) linearly polarized collimated beam passing through a homeotropic C60-doped nematic liquid crystal (5CB) cell. Based on orientational photorefractive effect, two-wave coupling experiment was carried out to induce liquid crystal molecule re-orientation. The form of space-charge field with the Gaussian distribution induced by the Gaussian beam incident on the sample is investigated. The outline of far-field diffraction pattern is concentric ring, and shows symmetrical gaps in the direction perpendicular to the direction of polarization of light. In addition, diffraction pattern changes when the polarization of the incident light is changed, effective nonlinear index coefficient is n20.3 cm2/W. The results showed that our theoretical analyzsis was consistent with the observed experimental phenomena.

In this paper, the Goos-H?nchen shift on the interface of uniaxially anisotropic left-handed materials is investigated exhaustively, and the analytical expressions of Goos-H?nchen shift is presented for the cases of the optical axis being perpendicular and parallel to the interface, respectively. Moreover, the conditions for the existence and the sign of Goos-H?nchen shift are determined. Under Fresnel approximation, the expression of Goos-H?nchen shift around the critical angle is obtained, and the result shows that the shift around the critical angle is a function of the beam waist and incident angle. A simple approximate expression of the lateral shift with incident angle equals the critical angle is also presented. Thus, the general expression of Goos-H?nchen shift for any incident angles is obtained.