Silicon‐based cells could convert more solar energy to electrical energy if the cells could absorb more light. However, the nanostructured cells have demonstrated relatively low power conversion efficiency even when its reflection is very low; thus, they are still far from becoming real products of the photovoltaic industry. Here, nanoscale pseudo‐pyramid textured multi‐crystalline silicon (Pmc‐Si) solar cells, with the best efficiency of ≈18.45%, are fabricated by using a metal‐catalyzed chemical etching plus a post alkaline etching on an industrial production line. Such Pmc‐Si solar cells have showed similar light trapping ability as single crystalline silicon solar cells of micrometer pyramid texture, and the improved efficiency is mainly ascribed to its enhanced light absorption while the nanostructured surface still keeps acceptable passivation quality, that is, the short‐circuit current density has an increase of ≈300 mA cell–1, while the open‐circuit voltage has only a slight decrease of ≈1 mV. Further elevations of the efficiency are expected by optimizing both micrometer‐ and nanotextures, and exploring more effective passivation technique. More excitingly, the technique presented here has been verified in the production line for several batches as a real technique of low cost and high efficiency.

Thoracic ossification of ligamentum flavum (OLF) caused by skeletal fluorosis is rare. Only six patients had been reported in the English literature. This study reports findings from the first clinical series of this disease. This was a retrospective study of patients with thoracic OLF due to skeletal fluorosis who underwent surgical management at the authors' hospital between 1993 and 2003. Diagnosis of skeletal fluorosis was made based on the epidemic history, clinical symptoms, radiographic findings, and urinalysis. En bloc laminectomy decompression of the involved thoracic levels was performed in all cases. Cervical open door decompression or lumbar laminectomy decompression was performed if relevant stenosis was present. Neurological status was evaluated preoperatively, at the third day postoperatively, and at the end point of follow-up using the Japanese Orthopaedic Association (JOA) scoring system of motor function of the lower extremities. A total of 23 cases were enrolled, 16 (69.6%) males and 7 (30.4%) females, age ranging from 42 to 72 years (mean 54.8 years). All patients came from a high-fluoride area, and 22 (95.7%) had dental fluorosis. Medical imaging showed OLF together with ossification of many ligaments and interosseous membranes, including interosseous membranes of the forearm (18/23 patients 78.3%), leg (14/23 patients 60.9%), and ribs (11/23 patients 47.8%). OLF was classified into five types based on MRI findings: localized (4/23 patients 17.4%), continued (12/23 patients 52.2%), skip (3/23 patients 13.0%), combining with anterior pressure (2/23 patients 8.7%), and combining with cervical and/or lumbar stenosis (2/23 patients, 8.7%). Urinalysis showed a markedly high urinary fluoride level in 14 of 23 patients (60.9%). Patients were followed up for an average duration of 4 years, 5 months. Paired t-test showed that the JOA score was slightly but nonsignificantly increased relative to preoperative measurement 3 days after surgery (P = 0.0829) and significantly increased at the end of follow-up (P = 0.0001). In conclusion, Fluorosis can cause ossification of thoracic ligamentum flavum, as well as other ligaments. Comparing with other OLF series, a larger number of spinal segments were involved. The diagnosis of skeletal fluorosis was made by the epidemic history, clinical symptom, imaging study findings, and urinalysis. En bloc laminectomy decompression was an effective method.

No abstract

The stable mechanical property polystyrene (PS) nanotubes with array structure were first prepared by filtrating a solution or melt of normal molecular weight PS (Mn ≈ 180,000) into anodic aluminum oxide (AAO) template with only 200-nm pores. The results of transmission electron microscopy and scanning electron microscopy illuminated that PS tubules were successfully obtained and the wall thickness of PS tubules prepared by the 2.5 wt%, 5.0 wt%, and 10.0 wt% PS solution were respectively 50 nm, 70 nm, and 80 nm. The structure of polymer nanotubes depends strongly on the concentration of PS solution. It was found that the wall of the nanotubes derived from melt is thicker than that of the nanotubes from solution. When the polymer solution wets AAO template, a thin polymer film will be formed on the inner porous wall. The thin film/AAO composite membrane acts as a “second-order” template and is soaked repeatedly. So PS solution wets the template and forms nanotubes according to the multi-time wetting mechanism.

A porous silicon and carbon composite (PSi/C) with granadilla-like structure as an anode material for lithium-ion batteries has been easily fabricated by spray drying and subsequent pyrolysis treatments. For the PSi/C, yolk-shell-structured Si/C nanobeads are equably distributed inside the porous carbon framework. The key point of this work is the combination of the advantages of both the yolk-shell structure and porous structure in one system. The void space inside the yolk-shell Si/C nanobeads and the interconnected three-dimensional porous carbon frameworks can effectively enhance the cyclic stability and conductivity of this composite. As expected, PSi/C with 15.4% silicon content exhibited a specific capacity as high as 1357.43 mAh g and retained 933.62 mAh g beyond 100 cycles at 100 mA g. Moreover, it showed a reversible specific capacity as high as 610.38 mAh g at 1000 mA g, even after 3000 cycles.

No abstract

Highly ordered Ni nanotube and nanowire arrays were fabricated via electrodeposition. The Ni microstructures and the process of the formation were investigated using conventional and high-resolution transmission electron microscope. Herein, we demonstrated the systematic fabrication of Ni nanotube and nanowire arrays and proposed an original growth mechanism. With the different deposition time, nanotubes or nanowires can be obtained. Tubular nanostructures can be obtained at short time, while nanowires take longer time to form. This formation mechanism is applicable to design and synthesize other metal nanostructures and even compound nanostuctures via template-based electrodeposition.

ABSTRACT:Non-polar polymer nanotubes and nanowires were fabricated using nanoporous Anodic Aluminium Oxide (AAO) template via a physical wetting of the polymer solution and melt. Testing results of field emission scanning electron microscopy (FESEM) demonstrate that non-polar polymer nanotubes can be prepared by polymer solution, while nanotubes and nanowires can be obtained by polymer melt at higher temperature and at lower temperature respectively. As for melt wetting method, there is a critical temperature for preparing nanotubes, and the structure of products depends on the viscosity and flowability of the polymer melt. The mechanism of melt wetting method is also discussed. In recent years, one-dimension (1D) polymer nanomaterials, such as nanotubes, nanowires and nanocables, have attracted considerable attention because of their outstanding functions and special applications. Especially, polymer nanotubes has attracted growing research interest due to their novel properties and wide potential application for nanodevices.