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This paper analyzes the impact of economic policy uncertainty on firm performance. Utilizing a news-based index of economic policy uncertainty and firm-level data in China, firm investment, employment, and revenue are found to be negatively associated with policy-related economic uncertainty. This negative relationship is weakened in state-owned enterprises (a fall in investment of 5.61%, employment growth of 0.09%, and sales growth of 0.31%) compared to that of non-state-owned enterprises (a fall in investment of 7.79%, employment growth of 0.14%, and sales growth of 0.34%). We explore several potential explanations and find evidence supporting that economic policy uncertainty reduces the incentives of firms to expand their operation through the mechanism of risk-taking, cash holdings and tax burden. Given this microscopic study on mechanisms, our analysis provides a reference for policy-makers to effectively reduce economic fluctuations. [ABSTRACT FROM AUTHOR]

Let L $ \mathcal{L}$ be a set which consists of some connected graphs. Let E be a spanning subgraph of graph G. It is called a L $ \mathcal{L}$ -factor if every component of it is isomorphic to the element in L $ \mathcal{L}$. In this contribution, we give the lower bounds of four parameters (t(G), I(G), I′(G),bind (G)) of G, which force the graph G admits a ({K1,i: q ≤ i ≤ 2q − 1} ∪ {K2q+1})-factor for q ≥ 2 and a {P2, P2q+1}-factor for q ≥ 3 respectively. The tightness of the bounds are given. [ABSTRACT FROM AUTHOR]

The hydrogen absorption behavior of C15 Laves phase compounds ZrV2 has been systematically investigated by the first-principles calculations. In the C15 Laves phase, hydrogen atoms can occupy three possible tetrahedral interstitial positions—2A2B, 1A3B, and 4B—in which the 2A2B site, being the largest interstitial space among the three possible positions, is the most favorable interstitial site. In addition, 2A2B and 1A3B sites can form some ordered clathrate-type structures to provide diffusion paths for hydrogen atoms to move inside the ZrV2 compounds. According to the calculated barrier energies of H atoms in different diffusion paths in ZrV2, it is found that hydrogen atoms prefer intra-ring diffusion to inter-ring diffusion, although inter-ring diffusion provides a non-negligible contribution to the overall H diffusion process. However, the existence of 1A3B sites can facilitate the diffusion of hydrogen atoms in adjacent six-membered rings. Finally, the absorption energies and electronic structures of ZrV2Hx (x = 0.5, 1, 2, 3, 4, 6, 7, and 12) were computed, and the results show that the hydrogen content reaches its maximum on the condition of 6 < x < 7. Moreover, hydrogen atoms make a stronger covalent bond with V atoms than with Zr atoms. [ABSTRACT FROM AUTHOR]

The hydrogen absorption behavior of C15 Laves phase compounds ZrV2 has been systematically investigated by the first-principles calculations. In the C15 Laves phase, hydrogen atoms can occupy three possible tetrahedral interstitial positions—2A2B, 1A3B, and 4B—in which the 2A2B site, being the largest interstitial space among the three possible positions, is the most favorable interstitial site. In addition, 2A2B and 1A3B sites can form some ordered clathrate-type structures to provide diffusion paths for hydrogen atoms to move inside the ZrV2 compounds. According to the calculated barrier energies of H atoms in different diffusion paths in ZrV2, it is found that hydrogen atoms prefer intra-ring diffusion to inter-ring diffusion, although inter-ring diffusion provides a non-negligible contribution to the overall H diffusion process. However, the existence of 1A3B sites can facilitate the diffusion of hydrogen atoms in adjacent six-membered rings. Finally, the absorption energies and electronic structures of ZrV2Hx (x = 0.5, 1, 2, 3, 4, 6, 7, and 12) were computed, and the results show that the hydrogen content reaches its maximum on the condition of 6 < x < 7. Moreover, hydrogen atoms make a stronger covalent bond with V atoms than with Zr atoms. [ABSTRACT FROM AUTHOR]