Abstract. We analyze summertime photochemistry near the surface in Beijing, China, using a 1-D photochemical model (Regional chEmical and trAnsport Model, REAM-1D) constrained by in situ observations, focusing on the budgets of ROx (OH + HO2 + RO2) radicals and O3 formation. While the modeling analysis focuses on near-surface photochemical budgets, the implications for the budget of O3 in the planetary boundary layer are also discussed. In terms of daytime average, the total ROx primary production rate near the surface in Beijing is 6.6 ppbv per hour (ppbv h−1, among the highest found in urban atmospheres. The largest primary ROx source in Beijing is photolysis of oxygenated volatile organic compounds (OVOCs), which produces HO2 and RO2 at 2.5 ppbv h−1 and 1.7 ppbv h−1, respectively. Photolysis of excess HONO from an unknown heterogeneous source is the predominant primary OH source at 2.2 ppbv h−1, much larger than that of O1D+H2O (0.4 ppbv h−1). The largest ROx sink is via OH + NO2 reaction (1.6 ppbv h−1), followed by formation of RO2NO2 (1.0 ppbv h−1) and RONO2 (0.7 ppbv h−1). Due to the large aerosol surface area, aerosol uptake of HO2 appears to be another important radical sink, although the estimate of its magnitude is highly variable depending on the uptake coefficient value used. The daytime average O3 production and loss rates near the surface are 32 ppbv h−1 and 6.2 ppbv h−1, respectively. Assuming NO2 to be the source of excess HONO, the NO2 to HONO transformation leads to considerable O3 loss and reduction of its lifetime. Our observation-constrained modeling analysis suggests that oxidation of VOCs (especially aromatics) and heterogeneous reactions (e.g. HONO formation and aerosol uptake HO2) play potentially critical roles in the primary radical budget and O3 formation in Beijing. One important ramification is that O3 production is neither NOx nor VOC limited, but in a transition regime where reduction of either NOx or VOCs could result in reduction of O3 production. The transition regime implies more flexibility in the O3 control strategies than a binary system of either NOx or VOC limited regime. The co-benefit of concurrent reduction of both NOx and VOCs in reducing column O3 production integrated in the planetary boundary layer is significant. Further research on the spatial extent of the transition regime over the polluted eastern China is critically important for controlling regional O3 pollution.

A benzoboroxole-functionalized monolithic column was synthesized, which exhibited the best specificity and affinity towards cis-diol containing biomolecules as compared with the boronate affinity monolithic columns reported as well as significant secondary separation capability under acidic conditions.

Bulk quantities of electronic conducting polymers such as polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene), having an unusual 2D nanoclip-like morphology is described using a general oxidative template assembly route which is orchestrated by an insoluble complex formed between an anionic oxidant (S(2)O(8)(2-)) and a cationic surfactant.

Conducting polymers (CPs) have been widely investigated due to their extraordinary advantages over the traditional materials, including wide and tunable electrical conductivity, facile production approach, high mechanical stability, light weight, low cost and ease in material processing.

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Through a facile and effective seeding polymerization reaction via a one-step redox/complexation process, which took place in aqueous medium at ambient temperature, silver nanoparticles (Ag NPs) embedded polyaniline nanofiber (PANI NF) networks were synthesized as antibacterial agents. During the reaction, not only NF morphology formation of the resulting conducting polymers (CPs) but also amplification of the aqueous silver nitrate (AgNO3) solutions' oxidative potentials were managed by vanadium pentoxide (V2O5) sol-gel nanofibers, which acted as well-known nanofibrous seeding agents and the auxiliary oxidative agent at the same time. The PANI/Ag nanocomposites were proven to exhibit excellent antibacterial property against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Antibacterial property performance and average life span of the nanocomposite network were optimized through the homogeneous distribution/embedment of Ag NPs within one-dimensional (1-D) PANI NF matrix. The antibacterial efficacy tests and nanocomposite material characterization results further indicated that the sole components of PANI/Ag have a synergistic effect to each other in terms of antibacterial property. Thus, this well-known catalytic seeding approach via a one-step oxidative polymerization reaction can be considered as a general methodology and a substantial fabrication tool to synthesize Ag NP decorated nanofibrillar PANI networks as advanced antibacterial agents.

High temperatures are known to reduce anthocyanin accumulation in a number of diverse plant species. In potato (Solanum tuberosum L.), high temperature significantly reduces tuber anthocyanin pigment content. However, the mechanism of anthocyanin biosynthesis in potato tuber under heat stress remains unknown. Here we show that high temperature causes reduction of anthocyanin biosynthesis in both potato tuber skin and flesh, with white areas forming between the vasculature and periderm. Heat stress reduced the expression of the R2R3 MYB transcription factors (TFs) StAN1 and StbHLH1, members of the transcriptional complex responsible for coordinated regulation of the skin and flesh pigmentation, as well as anthocyanin biosynthetic pathway genes in white regions. However, the core phenylpropanoid pathway, lignin, and chlorogenic acid (CGA) pathway genes were up-regulated in white areas, suggesting that suppression of the anthocyanin branch may result in re-routing phenylpropanoid flux into the CGA or lignin biosynthesis branches. Two R2R3 MYB TFs, StMYB44-1 and StMYB44-2, were highly expressed in white regions under high temperature. In transient assays, StMYB44 represses anthocyanin accumulation in leaves of Nicotiana tabacum and N. benthamiana by directly suppressing the activity of the dihydroflavonol reductase (DFR) promoter. StMYB44-1 showed stronger repressive capacity than StMYB44-2, with both predicted proteins containing the repression-associated EAR motif with some variation. StMYB44-1 conferred repression without a requirement for a basic helix–loop–helix (bHLH) partner, suggesting a different repression mechanism from that of reported anthocyanin repressors. We propose that temperature-induced reduction of anthocyanin accumulation in potato flesh is caused by down-regulation of the activating anthocyanin regulatory complex, by enhancing the expression of flesh-specific StMYB44 and alteration of phenylpropanoid flux.

in meeting the power requirements of these systems or facilitating their functionality by allowing for effi cient energy harvesting. To demonstrate fully transient systems, therefore, it becomes very important to design and develop a transient energy storage device featuring fast transience capability and good battery performance. Electrochemical energy storage techniques, specifi cally lithium-ion battery chemistry, demonstrate signifi cant advantage over other energy storage methods due to their high energy conversion effi ciency and superior energy density. [12][13][14][15][16][17][18][19] Therefore, the adoption of lithium-ion battery chemistry for transient applications is a promising strategy to the design of a transient energy storage device, thus becoming a natural extension of transience technology.Here, we report an approach to successfully fabricate transient batteries with fast transience and high areal energy density and demonstrate a transient platform for battery systems in which all of the components, including electrodes, separators, current collectors, and encapsulation, can be triggered to be transient by external alkali solution. The design consists of three novel components: a trilayer anode with integrated structure, a high-capacity origami cathode with high mass loading, and a bilayer battery packaging design having good water resistance. When these components are integrated together, the transient batteries exhibit a high areal capacity of ≈3 mAh cm −2 with a high working voltage above 2.0 V. In this transient platform, alkali such as potassium hydroxide (KOH) is used to decompose the transient battery system. Water, selected as the trigger material due to its simplicity, availability, and abundance in the environment, functions to release the KOH active material into the system. When the as-formed alkali solution meets the battery, the entire battery dissolves rapidly. Figure 1 presents the schematic diagram of a transient lithium-ion battery design. In this design, all of the components dissolve when submerged in alkali solution. The transient battery consists of many layers, including waterproof coating, encapsulation, current collector, cathode, separator, and anode with innovative designs:1. The waterproof material is a water-resistant polycarbonate (PC) polymer that is coated on the outer surfaces of encapsulation to protect the battery package from being corroded and damaged by moisture or water in the surrounding environment. The packaging material uses a polyvinyl alcohol (PVA) fi lm, which is cut and sealed by heating sealer to make a pouch for encapsulating cells. 2. The high-capacity cathode design takes inspiration from origami, the art of folding paper. A small, multilayered electrode with punctured holes was realized by cutting and folding a much larger piece of electrode. This origami cathode not only has increased areal energy density due to its folded electrode design; it also facilitates an increased rate of transience due However, while conventional devices are generall...