No abstract

The OH-initiated oxidation of vinyl alcohol (VA) produced by phototautomerization of acetaldehyde is thought to be a source of formic acid (FA) in the atmosphere. A recent theoretical study predicted that the VA + OH + O 2 reaction 1 proceeds by OH addition at α-C (66%) and β-C (33%) of VA and that FA is a main product of reaction 1. However, the metastable reactant (anti-VA, ∼18% at 298 K, 1.42 kcal mol −1 higher than syn in energy) used in that study inspired us to reinvestigate reaction 1. Using the state-of-the-art quantum−chemical and kinetic calculations, we first found that a conformer of VA has a significant influence on the rate coefficient and branching ratio of reaction 1. Upon derivation, it is found that ∼84% of reaction 1 takes place through the β-C-addition channel and ∼16% of reaction 1 happens by the α-Caddition channel. The calculated total initial rate coefficient at 298 K is 1.48 × 10 −11 cm 3 molecule −1 s −1 , which is in reasonable agreement with the experimental values of similar systems (vinyl ethers + OH reactions). The predicted main products of reaction 1 are glycolaldehyde and the HO 2 radical, whereas FA is just a byproduct.

No abstract

The majority of innovations are developed by multi-sector firms. The knowledge needed to invent new products is more easily adapted from some sectors than from others. We study this network of knowledge linkages between sectors and its impact on firm innovation and aggregate growth. We first document a set of sectoral-level and firm-level observations on knowledge applicability and firms’ multi-sector patenting behaviour. We then develop a general equilibrium model of firm innovation in which inter-sectoral knowledge linkages determine the set of sectors a firm chooses to innovate in and how much R&D to invest in each sector. It captures how firms evolve in the technology space, accounts for cross-sector differences in R&D intensity, and describes an aggregate model of technological change. The model matches new observations as demonstrated by simulation. It also yields new insights regarding the mechanism through which sectoral fixed costs of R&D affect growth.

No abstract