Creating Three-Dimensional Polymeric Microstructures by Multi-Beam Interference Lithography

It is attractive to produce true three-dimensional (3D) microstructures both rapidly and economically over a large area with negligible defects for a wide range of applications. Multi-beam interference lithography is one of the promising techniques that can create periodic microstructures in polymers without extensive lithography and etching steps. This review discusses the formation of interference patterns, their dependence on beam parameters, the lithographic process, and the applications to the formation of photonic crystals. Various photoresist systems, including thick films of negative-tone and positive-tone photoresists, liquid resins, organic-inorganic hybrids, and holographic polymer-dispersed liquid crystals, are also reviewed

Quantum spin Hall effect induced by electric field in silicene

We investigate the transport properties in a zigzag silicene nanoribbon in the presence of an external electric field. The staggered sublattice potential and two kinds of Rashba spin-orbit couplings can be induced by the external electric field due to the buckled structure of the silicene. A bulk gap is opened by the staggered potential and gapless edge states appear in the gap by tuning the two kinds of Rashba spin-orbit couplings properly. Furthermore, the gapless edge states are spin-filtered and are insensitive to the non-magnetic disorder. These results prove that the quantum spin Hall effect can be induced by an external electric field in silicene, which may have certain practical significance in applications for future spintronics device.Comment: 4 pages, 5 figure

Photonic Bandgap Structures of Core-Shell Simple Cubic Crystals from Holographic Lithography

We report the investigation of photonic bandgap properties of a core-shell simple cubic structure (air core with a dielectric shell) using a two-parameter level-set approach. The proposed structure can be obtained by partially backfilling high refractive index materials into a polymeric template fabricated by multi-beam interference lithography. We find that the shell formation in the inverted simple cubic structure increases the complete photonic bandgap width by 10–20% in comparison to that of a completely filled structure. The bandgap between the 5th and 6th bands begins to appear at a refractive index contrast of 2.7. This study suggests the importance to investigate the core-shell formation in three-dimensional photonic crystals through backfilling, which may offer an additional control over their photonic bandgap properties

Prevalence of Kaposi’s sarcoma-associated herpesvirus in Uygur and Han populations from the Urumqi and Kashgar regions of Xinjiang, China

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the infectious etiologic agent associated with Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease. It has been shown that high KSHV prevalence and high incidence of both classic KS and AIDSassociated KS are found mostly among people of Uygur ethnicity in Xinjiang, while people of Han ethnicity in Xinjiang have a higher KSHV seroprevalence than those of other Han populations in mainland China. However, it is still unclear why there is such geographical and population variation in KSHV distribution in China. In this work, we focused on the populations in the Kashgar region and Urumqi area, where a total of 1294 research subjects were randomly selected to investigate the potential correlation between KSHV prevalence and different ethnicities in endemic areas of Xinjiang, and to determine risk factors that may affect KSHV infection rates or KS incidence. We identified a high seroprevalence of KSHV and high peripheral blood DNA infection in the general Uygur and Han populations in both Urumqi and Kashgar regions of Xinjiang, and determined that advancing age, low education level, and stationary population status affect KSHV infection rates. Further, KSHV-positive Uygur participants were shown to have higher prevalence of neutralizing antibodies and neutralizing antibody titers than KSHV-positive Han participants

Fabricating Three-Dimensional Polymeric Photonic Structures by Multi-Beam Interference Lithography

The fabrication of true three-dimensional (3D) microstructures both rapidly and economically over a large area with negligible defects is attractive for a wide range of applications. In particular, multi-beam interference lithography is one of the promising techniques that can mass-produce polymeric 3D photonic crystals defect-free over a large area. This review discusses the relationship between beam geometry and the symmetry of the interference patterns, the lithographic process, and various types of photoresist systems, including thick films of negative-tone and positive-tone photoresists, organic-inorganic hybrids, hydrogels, and holographic polymer-dispersed liquid crystals

\u3cem\u3eMarattia aganzhenensis\u3c/em\u3e sp. nov from the Lower Jurassic Daxigou Formation of Lanzhou, Gansu, China

Marattia aganzhenensis sp. nov. from the Lower Jurassic Daxigou Formation of Lanzhou, Gansu, China, is the second species of Marattia known in fertile structure from China, in addition to Marattia asiatica. The new species demonstrates the variability of the genus through its distinct character states. This new species is distinguished by the absence of venuli recurrentes, the shorter synangia, exclusively monolete spores without surface ornamentation, and the low number of spores produced per sporangium

The “Competition” for Training Cross Border E-commerce Talents in China on the Background of “Internet Plus”

Under the background of “Internet plus,” more and more traditional industries have been integrated into the Internet through information technology. The international trade (foreign trade) industry has constantly been networked, informalized and electrolyzed. Based on the statistical analysis of the current development trend and market demand for cross-border e-commerce talents, this paper attempts to find out the causes of the current multidisciplinary “competition” for cross-border e-commerce talent training, analyze the advantages and disadvantages of this "competition," and put forward the development strategies of multidisciplinary cross-border e-commerce talent training. This study will be of essential reference and significance for applied universities, colleges and higher vocational colleges to adjust the cross-border e-commerce talent training positioning, orientation and professional layout