Production of Centimeter-Scale Gradient Patterns by Graded Elastomeric Tip Array

Large-area patterned surfaces with chemical and/or morphological gradients have significant applications in biology, chemistry, and materials science. In this work, we developed a unique lithographic strategy to fabricate 2D and 3D gradient patterns with gradually varying feature size or height over centimeter-scale areas by utilizing a large-area polydimethylsiloxane (PDMS) tip array with programmable tip apex as a conformal photomask in near-field photolithography. Meanwhile, a new strategy was developed to create the PDMS tip array with graded apex size, which was employed to fabricate gradient patterns with the lateral feature sizes changing from sub-100 nm to several microns on one single substrate over macroscopic (square centimeter) areas. Furthermore, 3D gradient patterns with spatially varying feature height were enabled by employing gradient exposure dose. The formation of gradient feature size was ascribed either to gradient contact areas between tips and substrates or to exposure dose gradient. This lithography strategy combines the advantages of a wide range of feature sizes, simplicity, high-throughput, low-cost and diversified feature shapes, making it a facile and flexible approach to manufacture various functional gradient structures

Genetic variants in MiR-29a associated with high myopia

Genetic variants in MiR-29a associated with high myopi

Map of Hongfeng and Baihua Reservoirs on the Yunnan-Guizhou Plateau, Southwest China.

<p>Map of Hongfeng and Baihua Reservoirs on the Yunnan-Guizhou Plateau, Southwest China.</p

An energy-efficient failure detector for vehicular cloud computing

<div><p>Failure detectors are one of the fundamental components for maintaining the high availability of vehicular cloud computing. In vehicular cloud computing, lots of RSUs are deployed along the road to improve the connectivity. Many of them are equipped with solar battery due to the unavailability or excess expense of wired electrical power. So it is important to reduce the battery consumption of RSU. However, the existing failure detection algorithms are not designed to save battery consumption RSU. To solve this problem, a new energy-efficient failure detector 2E-FD has been proposed specifically for vehicular cloud computing. 2E-FD does not only provide acceptable failure detection service, but also saves the battery consumption of RSU. Through the comparative experiments, the results show that our failure detector has better performance in terms of speed, accuracy and battery consumption.</p></div

Comparison of heavy metal concentrations in sediments.

<p>(HFT: sites at inlets of main tributaries in the Hongfeng Reservoir, namely sites 1–5; HFR: representative sites within Hongfeng Reservoir, namely sites 6–13; BHT: sites at inlets of main tributaries in the Baihua Reservoir (except site 14), namely sites 15–22; BHR: representative sites within the Baihua Reservoir, namely sites 23–26).</p

Principal Component Analysis (PCA) for heavy metals in surface sediments from the Hongfeng and Baihua Reservoirs.

<p>Factor loadings smaller than 0.3 have been removed.</p><p>Extraction method: PCA, Rotation method: Varimax with Kaiser normalization.</p

Query accuracy probability and mistake rate.

<p>Query accuracy probability and mistake rate.</p

Improved Selectivity and Sensitivity of Gas Sensing Using a 3D Reduced Graphene Oxide Hydrogel with an Integrated Microheater

Low-cost, one-step, and hydrothermal synthesized 3D reduced graphene oxide hydrogel (RGOH) is exploited to fabricate a high performance NO₂ and NH₃ sensor with an integrated microheater. The sensor can experimentally detect NO₂ and NH₃ at low concentrations of 200 ppb and 20 ppm, respectively, at room temperature. In addition to accelerating the signal recovery rate by elevating the local silicon substrate temperature, the microheater is exploited for the first time to improve the selectivity of NO₂ sensing. Specifically, the sensor response from NH₃ can be effectively suppressed by a locally increased temperature, while the sensitivity of detecting NO₂ is not significantly affected. This leads to good discrimination between NO₂ and NH₃. This strategy paves a new avenue to improve the selectivity of gas sensing by using the microheater to raise substrate temperature

Correlations between heavy metals in surface sediments from the Hongfeng and Baihua Reservoirs.

<p>Hongfeng Reservoir in the upper right corner (blod); Baihua Reservoir in the lower left corner.</p><p>Levels of significance: *p<0.05; **p<0.01.</p

Mean PEC quotient (a) and potential ecological risk indexes (b) of heavy metals in sediments.

<p>Mean PEC quotient (a) and potential ecological risk indexes (b) of heavy metals in sediments.</p