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A series of novel ABCBA-type miktoarm H-shaped copolymers with poly(3-hexylthiophene) segments have been synthesized and applied to phototransistor memory device materials, showing excellent memory properties and ductility/elasticity.

A novel A-b-poly(3-hexylthiophene)(P3HT)-b-C type triblock copolymer was successfully synthesized by the bilateral Cu-catalyzed azide alkyne cycloaddition reaction using α,ω-bifunctionalized P3HT.

The development of a π-conjugated polymer with hydrogen-bonding moieties has aroused great attention because of the improved molecular stacking and the hydrogen-bonding network. In this study, PDPPTVT (diketopyrrolopyrrole-thiophenevinylenethiophene) and PDPPSe (diketopyrrolopyrrole-selenophene) alkylated with a carbosilane (SiC8) side chain and poly(acryl amide) (PAM)-incorporated alkyl side chain were prepared, and their structure-performance and structure-stretchability correlation were evaluated. By incorporating the DPPTVT backbone and 0, 5, 10, or 20% PAM-incorporated alkyl side chain, the μh value could reach 2.0, 0.97, 0.74, and 0.42 cm2 V-1 s-1, respectively (P1 to P4). The polymer with the PDPPSe backbone and 5% PAM-incorporated alkyl side-chain (P5) exhibited the maximum μh value of 0.96 cm2 V-1 s-1. By extending the PAM moiety from the backbone with alkyl spacers, the solid-state packing and edge-on orientation can be properly maintained. Surprisingly, the PAM-incorporated alkyl side-chain can provide a hydrogen-bonding network serving as sacrificial bonding to mechanical deformation. Therefore, the relevant changes in the crystallographic parameters including the crystalline size and the in-plane π-π stacking distance with a 100% external strain were less than 4 and 0.8%, respectively, from P1 to P3. Therefore, P3 achieved an excellent stretchability while maintaining its molecular orientation and charge-transporting performance. Even with 100% external strain, P3 still provided an orthogonal μh over 0.1 cm2 V-1 s-1. Moreover, by substituting the TVT moiety with the Se moiety, the ductility of the backbone can be further increased when the elastic modulus decreases from 0.80 to 0.36 GPa for P2 to P5. The achieved high μh retention is over 20% after 500 stretching-releasing cycles with a 60% external strain perpendicular to the channel direction for the polymer composed of PDPPSe and 5% PAM content. The results manifest that our newly designed DPP with the PAM-incorporated alkyl side chain provides a promising approach to promote the intrinsic stretchability of the π-conjugated polymers.

Fusarium fujikuroi, the causative agent of bakanae disease in rice, produces many kinds of secondary metabolites. Recently, two phylogenetic subgroups (F and G groups) of Japanese F. fujikuroi have been identified and found to have differences in their gibberellin (GA) and fumonisin production. G‐group F. fujikuroi produces large amounts of GA, but is a fumonisin nonproducer. F‐group produces large amounts of fumonisin, but is a GA low or nonproducer. We investigated the cause of low GA production in the F‐group. Genetic mapping suggests that low GA production in the F‐group strain Gfc0825009 is due to a GA gene cluster for GA biosynthesis. Analysis of the nucleotide and amino acid sequences of the genes in the GA gene cluster showed >98.4% homology between the F‐group strain Gfc0825009 and the G‐group strain Gfc0801001. Following a 7‐day culture under low nitrogen conditions, we found that expression of P450‐1, P450‐4, and P450‐2 in the cluster increased in the G‐group strain and not in the F‐group strain. We hypothesized that complementation by GA genes in the G‐group strain would be required to increase GA production in the F‐group strain. However, we found that this occurred with a single gene complementation of DES, P450‐1, P450‐4, or P450‐2. Simultaneous increase in the expression of P450‐1, P450‐4, and P450‐2 were detected in the complementary transformants. Moreover, the same phenomenon was observed by reintegration of its own P450‐1. Our results suggest the presence of unknown regulatory mechanisms of the GA gene cluster in F. fujikuroi.

Regioregular polythiophenes have been widely used in organic electronic applications due to their solution processability with chemical modification through side chain engineering, as well as their microstructural organization and good hole transport properties. Here, we introduce alkylthio side chains, (poly[(3-alkylthio)thiophene]s; P3ATTs), with strong noncovalent sulfur molecular interactions, to main chain thienyl backbones. These P3ATTs were compared with alkyl-substituted polythiophene (poly(3-alkylthiophene); P3AT) variants such that the effects of straight (hexyl and decyl) and branched (2-ethylhexyl) side chains (with and without S atoms) on their thin-film morphologies and crystalline states could be investigated. P3ATTs with linear alkylthio side chains (P3HTT, hexylthio; P3DTT, decylthio) did not attain the expected higher organic field-effect transistor (OFET) mobilities with respect to P3HT (hexyl) and P3DT (decyl) mainly due to their lower regioregularity (76-78%), although P3ATTs exhibit an enhanced tendency for aggregation and compact molecular packing, as indicated by the red-shifting of the absorption spectra and the shortening of the π-π stacking distance, respectively. Moreover, the loss of regioregularity issue can be solved by introducing more soluble 2-ethylhexylthio branched side chains to form poly[3-(2-ethylhexylthio)thiophene] (P3EHTT), which provides enhanced crystallinity and efficient charge mobility (increased by up to a factor of 3) with respect to the poly(2-ethylhexylthiophene) (P3EHT) without S atoms in the side moieties. This study demonstrates that the presence of side chain alkylthio structural motifs with nonbonded interactions in polythiophene semiconductors has a beneficial impact on the molecular conformation, morphologies, structural packing, and charge transport in OFET devices.

Chain-end-functionalized poly(3-hexylthiophene)s (P3HTs) with benzyl alcohol (─PhCH2 OH), phenol (─PhOH), and benzoic acid (─PhCOOH) groups are directly synthesized based on the Negishi catalyst-transfer polycondensation method utilizing the zincate complex of t Bu4 ZnLi2 . In this system, neither protection nor deprotection steps are required, and also providing a living polymerization system to control the molecular weight while maintaining a low molar mass dispersity (ÐM ) of the obtained P3HT derivatives. Indeed, the chain-end-functionalized P3HTs can be synthesized along with controlled number-average molecular weights (Mn = 5100-20 000), low ÐM (1.06-1.14), and high chain-end functionality (Fn = 46-86%). The Fn values for the alcohol and phenol groups are found to be high (86% for ─PhCH2 OH and 71% for ─PhOH based on 1 H NMR, respectively), as also confirmed by matrix-assisted laser desorption/ionization time of flight mass spectroscopy. The easily synthesizable chain-end-functionalized P3HTs will be applicable for the facile synthesis of block and branched polymers containing P3HT as well as its related semiconducting polymer segments.

Neuromorphic computation possesses the advantages of self-learning, highly parallel computation, and low energy consumption, and is of great promise to overcome the bottleneck of von Neumann computation. In this work, a series of poly(3-hexylthiophene) (P3HT)-based block copolymers (BCPs) with different coil segments, including polystyrene, poly(2-vinylpyridine) (P2VP), poly(2-vinylnaphthalene), and poly(butyl acrylate), are utilized in photosynaptic transistor to emulate paired-pulse facilitation, spike time/rate-dependent plasticity, short/long-term neuroplasticity, and learning-forgetting-relearning processes. P3HT serves as a carrier transport channel and a photogate, while the insulating coils with electrophilic groups are for charge trapping and preservation. Three main factors are unveiled to govern the properties of these P3HT-based BCPs: i) rigidity of the insulating coil, ii) energy levels between the constituent polymers, and iii) electrophilicity of the insulating coil. Accordingly, P3HT-b-P2VP-based photosynaptic transistor with a sought-after BCP combination demonstrates long-term memory behavior with current contrast up to 10

SOFCs can achieve high electrical efficiency by utilizing steam reforming because the absorption reformate heat could be supplied from the heat from the stack and the anode off-gas combustor in the hotbox. However, water supply system leads to high manufacturing cost in BOP and may lead to decreased reliability of systems because of sensitive control. On the other hand, partial oxidation (POX) reforming system ensures the simplified system, while POX reforming system leads to lower electrical efficiency than in that of steam reforming because of fuel consumption in reforming. From the background written above, we are focusing adapting full-scale CO2reforming (dry reforming) to SOFC systems to expand the capability of SOFCs. To reveal the feasibility of the dry reforming SOFC system, we have previously investigated the performance and durability of catalysts (reformer) and a cell stack in simulated dry reforming by comparing with that of steam reforming. In this study, we investigated the performance of SOFC hotbox adapting dry reforming. The thermally self-supported state was successfully demonstrated in dry reforming operation. Additionally, this study discusses the heat balances of a hotbox under dry and steam reforming conditions. From the obtained results, we will introduce the problem and capability of the dry reforming SOFC system and discuss its feasibility.

The drainage pumping plants are the main facilities in flood control infrastructure. Many of them have deteriorated and their maintenance, especially replacement, has become a large issue in Japan. The plant consists of many different types of equipment. Each of them has its own lifespan. The lifespan has uncertainty. A method is proposed to schedule the replacement of equipment under uncertainty, considering the two properties of rationality and robustness. The rationality means that the schedule is logical and feasible. It is evaluated by the replacement cost in the scheduling period under the constraints of the reliability and annual cost. The robustness means that the schedule is hard to be affected by the uncertainty of the equipment lifespan. It is evaluated by the expected value of the time difference between the actual replacement and the scheduled replacement based on the probability distribution of equipment lifespan. The problem is modeled as a multi-objective optimization one on the rationality and the robustness of the schedule. Pareto optimal solutions are derived. The effectiveness of the proposed method is illustrated by case studies based on the practical conditions. The characteristics of Pareto optimal solutions are made clear by comparing non Pareto optimal ones. The contribution of this paper is to propose a method to design the replacement schedule which is hard to be affected by the uncertainty of the equipment lifespan.