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Based on the advantages of independent component analysis (ICA) and cepstrum, this paper adopts a novel feature extraction scheme for rolling bearing fault diagnosis utilizing improved independent component analysis and cepstrum analysis. Firstly, the fast fixed-point algorithm (FastICA) based on negative entropy was used here as the ICA approach to separate the mixed observation signals of rolling bearing vibration. Then, the largest spectral kurtosis value was used to confirm the characteristic separated signal associated with the Rolling bearing faults. Finally, cepstrum analysis was employed to deal with the selected signal to extract the original fault feature. The experimental results show that sensitive fault feature can be extracted prominently after the presented processing, and the proposed diagnostic method is effective for the fault diagnosis of rolling bearing. In addition, the proposed method provides an effective technical means for weak fault diagnosis.

In this paper, we report a simple and smart biomimetic process for constructing TiO 2 nanofibers in aqueous system and its derivatives with Pt nanoparticles uniformly embedded inside. It was found that regularly structured TiO 2 -LPEI hybrids with fibrous networks could be easily produced when linear polyethyleneimine (LPEI) aggregates were used as a regulator in the hydrolytic condensation of water-soluble titanium bislactates (TiLact). In the XRD patterns of the as-prepared TiO 2 -LPEI hybrids, a strong peak appeared at a low diffraction angle of about 4°, which indicated the formation of regularly layered domains consisting of TiO 2 and LPEI residues in the fibrous hybrids. TEM observations showed that in the as-prepared TiO 2 -LPEI hybrids very tiny crystallites less than 3 nm in size were closely packed to each other, whereas the crystalline domains increased to 10 nm after the hybrids were calcined at 500 °C. Raman spectroscopy measurement confirmed the existence of anatase phase in the as-prepared hybrids. Simply mixing the TiO 2 -LPEI hybrids with an aqueous solution of PtCl 4 2- spontaneously resulted in the formation of Pt nanoparticles embedded in the Ti0 2 -LPEI fibers. TEM images revealed that the Pt nanoparticles homogeneously distributed in the TiO 2 -LPEI hybrids without any damage to their fibrous morphologies. A typical photocatalysis evaluation revealed that under visible-light irradiation the Pt-embedded TiO 2 fibers exhibited two times higher activity in the photodecomposition of methylene blue than that of the pure TiO 2 fibers.

Silica deposition by mediation of aggregated linear poly(ethyleneimine) (LPEI) from a basic aqueous solution of sodium silicate can produce ordered silica with fibrous bundle structure hybridized with LPEIvia zero-emission of organic by-products. By changing the polymer concentration and pH value of the aqueous solution of sodium silicate, we were able to control the architecture of the resulting silica. This process is environmentally benign and inexpensive and thus would be feasible for industrial scale-up for the fabrication of silica nanomaterials. In addition, a typical fibrous silica bundle was characterized by fluorescence X-ray analysis, solid state 29Si (CP/MAS) NMR, TG/DTA, thermo-calcination, N2/He adsorption–desorption experiments, and high resolution TEM. Interestingly, the fibrous silica bundle, which contains about 25% LPEI, served as an effective nanoreactor to reduce metal ions into nearly cluster-size metallic nanoparticles inside the silica.

Linear poly(ethylene imine) (PEI) can self-organize into fibrous aggregates with a crystalline core and a brushlike shell of ethyleneimine (EI) segments. Silicification from alkoxysilane mediated by PEI aggregates easily produces silica nanofibers (20–23 nm in diameter) with a core of axial, crystalline PEI filaments (5–7 nm in width) and a shell of silica (6–8 nm in thickness). Removing the axial filament of PEI from the silica nanofiber by calcination produces silica nanotubes. More interestingly, a nanowire-like platinum lining is formed in the silica nanofiber—a result of the PEI filament's ability to reduce PtCl42–. The degree of polycondensation, composition, and surface area of the resulting silica are investigated by 29Si magic angle spinning NMR spectroscopy, elemental analysis, and N2/He adsorption–desorption measurements. The time course of the reaction and the amount of silica source needed for silica-fiber formation confirm that silica deposition occurs exclusively and site selectively on the surface of the organized, fibrous PEI. Thus, the fibrous aggregates of PEI appear to be highly suitable for depositing silica fibers from both tetramethoxysilane and tetraethoxysilane.

A novel heteroglycan, Cordyceps sinensis polysaccharide 1 (molecular weight 1 17 × 105 Da), was isolated and purified from mycelia of the fungus C. sinensis obtained by solid-state culture. Structural characterization by chemical analysis, GC-MS, FTIR, and NMR spectroscopy showed that C. sinensis polysaccharide 1 was mainly composed of (1 → 6)-linked α-D-Glc and α-D-Gal, with minor β-(1 → 4)-D-Xyl and β-(1 → 4)-D-Man residues probably located in the side chains with a trace amount of α-(1 → 3)-L-Rha residue. In biological assays, C. sinensis polysaccharide 1 significantly inhibited proliferation of sarcoma 180 cells and induced apoptosis in a dose-dependent manner. Further studies will elucidate the antitumor mechanism of C. sinensis polysaccharide 1 and promote its utilization for the development of novel, effective anticancer drugs.

The formation of hierarchical aggregates from linear polyethyleneimine (LPEI) was performed in aqueous media containing a series of divalent metal ions (MnII, FeII, CoII, NiII, CuII, ZnII) and their organization processes are investigated by transcribing the structure into hard silica frames which can be appropriately characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) measurements. Coexisting metal salts interact with LPEIvia coordination bonds between metal ions and amine groups in ethyleneimine (EI) units to form water-soluble complexes. Without suitable complexation, LPEI crystallizes without restriction and forms non-well controlled hierarchical microstructures even in the presence of metal ions. The molar ratios of EI units and metal ions strongly affect the morphologies of crystalline precipitates. Low values of the ratios lead to intricate flower-like structures composed of leaf-like fibers assembled in a random fashion. On the other hand, an increase of the ratios makes the structures well-shaped and flattened for constructing 2-D turbine-like morphology. These structures consist of numerous sheet structures grown in a radial fashion. XRD and XRF measurements reveal that these resulting solids are mainly composed of hydrated LPEI and imply that coordinating metal ions are located in the peripherals of LPEI microstructures. Finally, temporal morphological evolution experiments indicate that a metal ion which can coordinate with EI units serves as a regulator in the crystallization of LPEI and abundant crystal growth can proceed.