Low bending loss and effectively single-mode all-solid photonic bandgap fiber with an effective area of 650 μm2

A large-mode-area all-solid photonic bandgap fiber with a seven-cell core and five high-index rod rings is investigated. Numerical simulations show that an effective area of more than 500 μm(2), a bending loss of less than 0.1 dB/m at a bending radius of 10 cm and effectively single-mode operation can be achieved simultaneously. A core diameter of 44.8 μm and an effective area of 650 μm(2) at 1064 nm are achieved in a fabricated fiber. Bending loss at 1064 nm is 0.09 dB/m at a bending radius of 7 cm. Effectively single-mode operation is also realized at a bending radius of 10 cm.     

Large-effective-area ten-core fiber with cladding diameter of about 200 μm

A multicore fiber with two-pitch layout is proposed to overcome the trade-off between core number and a cladding diameter of a standard hexagonal layout with a single-core pitch. A fabricated ten-core fiber simultaneously realizes effective area of about 120 μm(2) at 1550 nm, small crosstalk, and cladding diameter of 204 μm. The crosstalk between the center core and outer cores is about 30 dB smaller than that between outer cores. The small crosstalk of the center core would help to keep the transmission quality of the center core at the same level as that of the outer cores.     

Controllable Silver Plating on Silica for Surface-enhanced Raman Scattering

We proposed a facile and rapid method for preparing silica-silver core-shell(SSCS) substrates to use Ag electroless plating on SiO2@Au-seed particles.UV-Vis-NIR absorption spectrometer and SEM were employed to monitor the reaction process of the formation of Ag on the surfaces of silica beads,and the optical resonance of the substrate could shift from visible to NIR region.It has been found that surface-enhanced Raman scattering(SERS) enhancement changes with the electroless plating time and the SSCS substr...     

A Spectral-Mode-Splitting Scheme for CSRZ and CSRZ-DPSK Signal Transmission

We propose a spectral-mode-splitting scheme and how it can be applied to CSRZ and CSRZ-DPSK signal formats, and show that it provides both accurate chromatic dispersion detection in CSRZ application and robustness against linear cross talk and nonlinear impairment in CSRZ-DPSK applications.     

Structures of altiloxins a and b,phytotoxins from phomaasparagi sacc

By spectroscopic data, the structures of two new phytotoxins, altiloxins a and b from Phoma asparagi sacc., the incitant of stem blight disease on asparagus are elucidated.     

Synthetic studies on β-lactam antibiotics. 13. Transformation of 6-epipenicillins to 2R-{(1S, 5R)-2-oxa-6-oxo-4,7- diazabicyclo[3.2.0]hept-3-en-7-yl}-3-methylbut-3-enoates

Reaction of 2β-unsubstituted or functionalized-methyl 6-epipenicillin sulfoxides $\text{2}$ with tervalent phosphorus compounds gave azetidinone-epi-oxazolines $\text{3}$, important intermediates in synthesis of 7α-methoxy-1-oxacephems. Preparation of the 2β-functionalized-methyl substrates is described also.     

时间分辨与偏振红外光谱研究电场诱导下手性反铁电液晶的翻转过程

手性反铁电液晶分子中的各个不同片段、不同基团在电场诱导下展现不同的取向与取向分布.在交变电场的作用下,分子中各个部分的翻转动力学行为也表现的不同.     

Structures of the dimeric and monomeric chromanones, gonytolides A-C, isolated from the fungus Gonytrichum sp. and their promoting activities of innate immune responses

Innate immunity is the front line of self-defense against microbial infection. After searching for natural substances that regulate innate immunity using an ex vivo Drosophila culture system, we identified a novel dimeric chromanone, gonytolide A, as an innate immune promoter from the fungus Gonytrichum sp. along with gonytolides B and C. Gonytolide A also increased TNF-α-stimulated production of IL-8 in human umbilical vein endothelial cells.     

Titanium cation-exchanged montmorillonite as an active heterogeneous catalyst for the Beckmann rearrangement under mild reaction conditions

Titanium cation-exchanged montmorillonite acts as an efficient heterogeneous catalyst for the Beckmann rearrangement of a wide range of ketoximes including aromatic, aliphatic, and alicyclic ketoximes under mild reaction conditions. After the rearrangement reaction, titanium cation-exchanged montmorillonite is easily separated by simple filtration, and can be reused with retention of high efficiency.