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A novel selenadiazole-fused pyrene derivative PySe was successfully synthesized and characterized. Its single structure is almost planar and adopts a sandwich-herringbone packing model. The self-assembly behaviors based on compound PySe and its analogue thiadiazole-fused pyrene derivative PyS were studied in detail and the as-formed nanostructures were fully characterized by means of UV-vis absorption, emission spectra, X-ray diffraction, field emission SEM and TEM. We attribute the bathochromic shift absorption and emission spectra of PyS and PySe in aqueous solution to the formation of J-type aggregation. In addition, our investigation demonstrated that the shape and size of the as-prepared nanostructures could be tuned by different chalcogen analogues and the volume ratio of water to organic solvent.

In this paper, we have demonstrated a novel and simple way to prepare transparent composite fluorescent films by using poly (acrylic acid) co-polymer as a matrix and silica coated photoluminescence (PL) quantum dots (QDs) as light-emitting materials. The strategies include preparing aqueous amphiphilic oligomer (polymaleic acid n-hexadecanol ester, PMAH) modified QDs, encapsulating the aqueous QDs in silica with a modified Stöber method and fabricating the QD-PMAH-SiO(2)-polymer composite fluorescent films with a spin-coating method. The obtained light-emitting thin films were transparent under room light and showed bright red, green and deep-blue light under the irradiation of UV light. The PL intensity of the composite films increased incrementally with the number of layers and the concentration of QD-PMAH-SiO(2) within each film. A white light emitting film was also fabricated by combining the silica coated red, green and deep-blue QDs in a proper ratio. Moreover, the photochemical stability of the QD-PMAH-SiO(2) in composite film was enhanced significantly compared with PMAH coated QDs, because of a thicker and compact passivating silica layer formed on the surfaces of the PL QDs.

In this paper, we have developed a “green” method for the synthesis of metal telluride nanocrystals. In this method, di-n-octylphosphine oxide (DOPO) has been used to disperse Te and form Te–DOPO precursor. This new Te precursor was found to be highly reactive and suitable for the synthesis of metal telluride nanocrystals in various monodispersity, size, and shape. Dot-/tetrapod-shaped CdTe, dot-shaped ZnTe, dot-/cubic-shaped PbTe, dot-/rod-shaped Ag2Te, cubic-shaped Cu2−xTe, ternary alloyed CuInTe2, and quaternary alloyed Cu2ZnSnTe4 semiconductor nanocrystals all have been well-controlled synthesized. The photoluminescence emission of as-synthesized CdTe nanocrystals covered a wide range (570–735 nm) and the quality of as-synthesized metal telluride nanocrystals were reached or exceed the level compared with the traditional method using phosphine–Te precursor. The possible dissolving molecular mechanism of Te in DOPO in this synthesis was specially studied and illustrated that intramolecular proton transfer from the phosphorus (formation of DOPO–Te complex) was essential in the synthesis of metal telluride nanocrystals. This method provided a greener and less expensive route to large-scale synthesis of all kinds of high quality metal telluride nanocrystals.

A structurally flexible porous metal–organic framework, [CuII(bped)2(H2O)2(SiF6)] ⊃ 4H2O (Cu-MOF-SiF6) was prepared from CuSiF6 and meso-1,2-bis(4-pyridyl)-1,2-ethanediol (bped) in EtOH–H2O. Cu-MOF-SiF6 is a three-dimensional (3D) polycatenated framework consisting of two-dimensional (2D) (4,4) topological grid networks which display 2-fold inclined interpenetration in the crystal lattice. The SiF62− anions hosted in the one-dimensional channels of Cu-MOF-SiF6 can be readily exchanged with NO3− anions while keeping the framework intact, leading to isomorphous Cu-MOF-NO3. The Cu-MOFs show selective adsorption behaviors due to the host–guest interaction, which is dependent on the anions and the guest size. The MeOH uptake investigation indicates that Cu-MOF-SiF6 demonstrates a breathing effect, while Cu-MOF-NO3 exhibits distinctive stepwise MeOH sorption due to the smaller size of NO3− and the larger voids in the crystal lattice. Cu-MOF-NO3 also exhibits stepwise sorption for larger EtOH guests, while the uptake of EtOH is blocked in Cu-MOF-SiF6. In addition, the solids show anion-responsive catalytic properties. Both Cu-MOF-SiF6 and Cu-MOF-NO3 efficiently oxidize benzylic compounds to the corresponding carbonyl functionality under mild and convenient reaction conditions, but improved catalytic activity was observed for Cu-MOF-NO3. The catalysts can be reused with the framework left intact at least three times without losing of any activity.

This paper studied the factors affecting surface roughness in ultra-precision raster milling (UPRM). Through the investigation on the surface generation mechanism, factors including cutting parameters, tool path generation (TPG) and tool geometry are taken into consideration. A series of cutting experiments is conducted to investigate the influences of three factors including feed direction, depth of cut and entry distance on surface roughness profiles and the surface quality of the ultra-precision raster milled surface. The results show that the surface finishing in horizontal cutting is better than that in vertical cutting and the surface roughness in UPRM can be minimised by selecting the optimal values of depth of cut and entry distance.

Seven new sesquiterpenes (1-7), together with seven known sesquiterpenes, aplysin (8), aplysinol (9), gossonorol (10), 7,10-epoxy-ar-bisabol-11-ol (11), 10-epi-7,10-epoxy-ar-bisabol-11-ol (12), johnstonol (13), and laurebiphenyl (14), have been isolated from the red alga Laurencia tristicha. The structures of new compounds were established as laur-11-en-2,10-diol (1), laur-11-en-10-ol (2), laur-11-en-1,10-diol (3), 4-bromo-1,10-epoxylaur-11-ene (4), cyclolauren-2-ol (5), laurentristich-4-ol (6), and ar-bisabol-9-en-7,11-diol (7) by means of spectroscopic methods including IR, HRMS, and 1D and 2D NMR techniques. Compound 6 possessed a novel rearranged skeleton. All compounds were tested against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), hepatoma (Bel 7402), colon cancer (HCT-8), and HELA cell lines. Laurebiphenyl (14) showed moderate cytotoxicity against all tested cell lines, with IC(50) values of 1.68, 1.22, 1.91, 1.77, and 1.61 microg/mL, respectively. Other compounds were inactive (IC(50)10 microg/mL).

Freeform surfaces possessing no symmetry in rotation are widely used in many fields such as space optics for their superior optical properties. Due to their geometric complexities, the growth of application of these surfaces in precision industries is still hindered by a lack of definitive methodologies for traceable measurement of manufactured freeform surfaces. This paper presents a method for quantitative analysis of the measurement uncertainty in the form characterization of freeform surfaces. The study starts from developing a method for the form characterization of freeform surfaces, and the associated uncertainties are evaluated based on Monte Carlo simulation by quantitatively analyzing the uncertainty induced by the sampling strategy and the evaluation method. To integrate the effect of the workpiece form deviation, a profile simulation method is developed based on fractional Brownian motion, which can be used to generated random surface form error with given magnitude. Based on computer simulation, mathematical relationships between the magnitude of the critical errors and the resulting uncertainties are identified so that an estimation of uncertainty can be given for the measured surface parameters in a specific measurement. A case study is conducted to demonstrate the effectiveness of the proposed study which provides a better understanding of the associated uncertainty in the form characterization of freeform surfaces.