This work innovatively develops a dual solution-shearing method utilizing the semiconductor concentration region close to the solubility limit, which successfully generates large-area and high-performance semiconductor monolayer crystals on the millimeter scale. The monolayer crystals with poly(methyl methacrylate) encapsulation show the highest mobility of 10.4 cm 2 V −1 s −1 among the mobility values in the reported solutionprocessed semiconductor monolayers. With similar mobility to multilayer crystals, light is shed on the charge accumulation mechanism in organic field-effect transistors (OFETs), where the first layer on interface bears the most carrier transport task, and the other above layers work as carrier suppliers and encapsulations to the first layer. The monolayer crystals show a very low dependency on channel directions with a small anisotropic ratio of 1.3. The positive mobility-temperature correlation reveals a thermally activated carrier transport mode in the monolayer crystals, which is different from the band-like transport mode in multilayer crystals. Furthermore, because of the direct exposure of highly conductive channels, the monolayer crystal based OFETs can sense ammonia concentrations as low as 10 ppb. The decent sensitivity indicates the monolayer crystals are potential candidates for sensor applications.

This study examines the utility of resistant varieties and their associated resistance genes against brown planthopper, Nilaparvata lugens (Stål), populations from South and South East Asia. A collection of 39 rice accessions that included resistant, tolerant and susceptible varieties and breeding lines were examined for performance against populations of N. lugens from India (4), Bangladesh (1), Myanmar (1), Vietnam (1), Indonesia (1), China (1), Taiwan (1), and the Philippines (2). Planthopper virulence varied between regions; however only 6 varieties were generally less damaged than the susceptible check Taichung Native 1 (TN1) among ≥50% of the test populations. Each of these 6 varieties contained multiple resistance genes. One further variety, also with multiple resistance genes, and a modern cultivar (possibly with the Bph3 gene) were moderately effective against the South Asian populations, whereas a traditional variety with the Bph6 gene was effective against South East Asian populations. Bph1, bph2, bph5, bph7, bph8, Bph9, Bph10 and Bph18 were ineffective against most planthopper populations. Bph20, Bph21, and Bph17 have potential to be used in resistance breeding in both South and South East Asia, whereas BPH25 and BPH26 have potential for use in South Asia. The results indicate that only a few of the currently available resistance genes will be effective in monogenic rice lines; but that pyramiding of two or more genes with strong to weak resistance could improve resistance strength and durability as apparent with the most resistant, traditional varieties. Strategies to avoid planthopper adaptation to resistant rice varieties are discussed.

The degradation and reuse of epoxy thermosets have significant impact on the environments. We report that an epoxy−amine thermoset embedded with Diels−Alder (DA) bonds was transformed into soluble polymers via sonochemistry under mild temperature (ca. 20 °C) for the first time. Sonication could effectively induce the position-oriented cleavage of DA bonds (i.e., retro-DA) of the fully swelled epoxy thermoset in dimethyl sulfoxide (DMSO), leading to the soluble polymers. Of importance, such sonochemical process could be regulated on demand via switching on-and-off of the sonication. The obtained soluble polymers could be recured to form epoxy−amine thermosets via DA reaction. This sonochemical method might provide an unprecedented and efficient way to the controlled degradation and recycling of the epoxy thermosets containing the dynamic covalent bonds likes DA groups.

Meniscus-guided coating (MGC) is mainly applicable on the soluble organic semiconductors with strong π-π overlap for achieving single-crystalline organic thin films and high-performance organic field-effect-transistors (OFETs). In this work, four elementary factors including shearing speed (v), solute concentration (c), deposition temperature (T), and solvent boiling point (T b ) are unified to analyze crystal growth behavior in the meniscus-guided coating. By carefully varying and studying these four key factors, it is confirmed that v is the thickness regulation factor, while c is proportional to crystal growth rate. The MGC crystal growth rate is also correlated to latent heat (L) of solvents and deposition temperature in an Arrhenius form. The latent heat of solvents is proportional to T b . The OFET channels grown by the optimized MGC parameters show uniform crystal morphology (Roughness R q < 0.25 nm) with decent carrier mobilities (average µ = 5.88 cm 2 V −1 s −1 and highest µ = 7.68 cm 2 V −1 s −1 ). The studies provide a generalized formula to estimate the effects of these fabrication parameters, which can serve as crystal growth guidelines for the MGC approach. It is also an important cornerstone towards scaling up the OFETs for the sophisticated organic circuits or mass production.

This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, Sogatella furcifera, in Taiwan and the Philippines was also assessed. Phylogenetic analysis of the varieties using single-nucleotide polymorphisms (SNPs) indicated a clade of highly resistant varieties from South Asia with two further South Asian clades of moderate resistance. Greenhouse bioassays indicated that planthoppers can develop virulence against multiple resistance genes including genes introgressed from wild rice species. Nilaparvata lugens populations from Punjab (India) and the Mekong Delta (Vietnam) were highly virulent to a range of key resistance donors irrespective of variety origin. Sogatella furcifera populations were less virulent to donors than N. lugens; however, several genes for resistance to S. furcifera are now ineffective in East Asia. A clade of International Rice Research Institute (IRRI)-bred varieties and breeding lines, without identified leafhopper-resistance genes, were highly resistant to the green leafhopper, Nephotettix virescens. Routine phenotyping during breeding programs likely maintains high levels of

We demonstrate a cellulose-templating method for synthesizing a hierarchically porous carbon electrode that is capable of high-performance capacitive deionization (CDI). Hierarchically porous carbons (denoted as HPC-X, X = 500− 900 °C) of an exceptionally high surface area up to 2535 m 2 g −1 and wide-range pore size distribution (macro-, meso-, and micropores) were obtained via the pyrolysis of macroporous cellulose fibrous-templated resorcinol-formaldehyde-triaminopyrimidine (RF-TPF) polymers. The improved electrosorption performance of HPC-800 electrode can be ascribed to the enhanced specific surface area, favorable hierarchical structure, and excellent capacitive electric double layer behaviors.

The small brown planthopper, Laodelphax striatellus, is one of the most serious pest insects of rice plants.

No abstract