Bosonization of quantum sine-Gordon field with a boundary

Boundary operators and boundary ground states in sine-Gordon model with a fixed boundary condition are studied using bosonization and q-deformed oscillators.We also obtain the form-factors of this model.Comment: Latex 25page

Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69±4.2, 5.19±3.8, and 6.23±3.9 μm at the center, paracenter, and mid-periphery, resp., P<0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r=0.438, 0.580, and 0.504, resp., P<0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia

Energy saving strategy for the development of icephobic coatings and surfaces

Aircraft are frequently exposed to cold environments and ice accumulation on aircraft surface may lead to catastrophic accidents. An effective solution of ice protection is a critical requirement in the aerospace industry. For the research and development of icephobic coatings, the current coating design target mainly focuses on lowering the ice adhesion strength between the ice and the surface. However, as a passive ice protection approach, the use of icephobic coating often has to be combined with an active ice protection solution (e.g. electro-thermal heating, hot air bleeding, and vibration, etc.), especially for the in-flight application where the reliability of ice protection must be ensured. Therefore, ice adhesion strength is no longer the sole criterion to evaluate the icephobic performance of a coating or a surface. It is a need to establish a more practical strategy for the design of icephobic coatings and surface. In this work, an energy saving strategy is proposed to assess the de-icing performance of the icephobic coating and surface when active heating is involved. The energy consumed for the de-icing operation assisted by the ice gravity is used as the key criterion for the overall performance of icephobic coating and surface. Successful validation has been achieved for evaluating the de-icing performance of selected coatings and surfaces, which demonstrates an alternative strategy for the design and practical application of icephobic coatings and surfaces in ice protection

1α,11α,15β-Triacet­oxy-7β-hydroxy-7α,20-ep­oxy-ent-kaur-16-en-6-one

The title compound, C26H34O9, a natural ent-kaurane diterpenoid, is composed of four rings with the expected cis and trans junctions. In the crystal structure, the mol­ecules stack along the a axis and are linked together by inter­molecular O—H⋯O hydrogen bonds

6β-Acet­oxy-1α,7β,11β,15β-tetra­hydr­oxy-7α,20-ep­oxy-ent-kaur-16-ene

The title compound, C22H32O7, a natural ent-kaurane diterpenoid also referred to as Maoyecrystal F, was obtained from the medicinal plant Isodon nervosa. There are four rings with the expected cis and trans junctions. Cyclohexane ring A adopts a chair conformation, rings B and C adopt boat conformations, while the five-membered ring has an envelope conformation. The mol­ecules stack along the a axis in the crystal and are linked together by inter­molecular O—H⋯O hydrogen bonds