Fast Fabrication of Fishnet Optical Metamaterial Based on Femtosecond Laser Induced Stress Break Technique.

To speed up the fabrication of optical metamaterials by making use of the fast speed advantage of femtosecond laser preparation, a metamaterial appropriate for femtosecond laser processing was designed, and the interaction between femtosecond laser and metal-dielectric-metal fishnet stacks was investigated in detail. Two kinds of processing mechanisms, thermal melting and stress break, were revealed during the fabrication. The thermal melting process, dominated by the interaction of femtosecond laser with metals, makes the upper and lower metal layers adhere to each other, which leads to the magnetic resonance impossible. The stress break process, dominated by the interaction of femtosecond laser with dielectrics, can keep the upper and lower metal coatings isolated. Fishnet optical metamaterial was fabricated by femtosecond laser-induced stress break technique, using back side ablation, high numerical aperture and super-Gaussian beam. The resolution and speed can reach 500 nm, and 100 units/s, respectively. Spectrophotometer measurement results proved that the magnetic resonances were found in the fishnet nanostructure. The theoretical refractive index of the metamaterial on a glass substrate reached -0.12 at the wavelength of 3225 nm. It proved that femtosecond laser-induced stress break was a good and fast tool during the fabrication of optical metamaterials.

The clinical experiences of Dr. CAI Gan in treating chronic constipation.

Prof. CAI Gan is an academic leader in TCM treatment of the spleen and stomach disease. He insisted that liver depression, spleen deficiency and poor nourishment of the intestines are the core of pathogenesis for chronic constipation. Therefore he often treats the disease by strengthening the spleen, relieving the depressed liver, nourishing yin and moistening the intestines. Meanwhile he attaches great importance to syndrome differentiation and comprehensive regulation and treatment. As a result, good therapeutic effects are often achieved. The authors summarized his ways for treating chronic constipation with the following 10 methods, which are introduced below.

6-(2-Fluoro-phen-yl)-5,6-dihydro-benzimidazolo[1,2-c]quinazoline.

In the title compound, C(20)H(14)FN(3), the pyrimidine ring adopts a half-chair conformation. The dihedral angle between the benzimidazole ring system and the fluoro-phenyl ring is 84.18 (10)°. In the crystal structure, mol-ecules are linked into a two-dimensional network parallel to the bc plane by N-H⋯N and C-H⋯F hydrogen bonds.