The use and transformation of carbon dioxide as a C1 source into valuable chemical products using cheap industrial chemicals under mild reaction conditions fulfill the requirements of atom economy in the chemical industry. In this paper, two new silver-cluster-based frameworks were synthesized by incorporating thiourea on the backbone of the tripodal ligands. Given their large pores, high density of catalytic sites, and appropriate coordination geometries, these heterogeneous materials could be used as high-efficiency π-activation catalysts in the atom-economical cycloaddition of propargylamines with carbon dioxide. The loading of 0.1 mol % catalysts enabled the almost complete transformation of the propargylamines into oxazolidinones at atmospheric pressure and room temperature. DFT calculations show significant charge accumulation regions with π* symmetry on C atoms associated with the acetylene bond along the Ag−C directions and charge depletion regions with σ symmetry along the C−C direction, further supporting the important role of silver-cluster-based catalysts in π* activation of substrates for subsequent reactions with approaching CO 2 . The crystallinity of the frameworks allowed the structure of the encapsulated substrates and the interactions of the CC bonds in the active intermediates to be clearly observed. The recyclability and high turnover number of the cycloaddition reaction demonstrate the broad potential applications of these designed materials as πactivation catalysts for practical applications in the chemical industry.

The evaluation of vegetable production process efficiency is of great significance for energy saving and waste reduction in production processes. However, few studies have considered the effect of greenhouse vegetable production process efficiency on energy saving and waste reduction. In this paper, data envelopment analysis (DEA) is used to analyze the production process efficiency and the effective use of input elements of greenhouse vegetables at the provincial level in China. The results reveal that many chemical fertilizers, farmyard manure, and pesticides in China are inefficient. On the other hand, the pure technical efficiency of greenhouse tomatoes and cucumbers is low in most areas of China. Meanwhile, the scale efficiency of greenhouse eggplants and greenhouse peppers is low in most areas of China. In order to save energy and develop green sustainable agriculture, we put forward some suggestions to improve the production efficiency of greenhouse vegetables in different provinces.

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ALD HfO2 films fabricated by a novel multi deposition multi annealing (MDMA) technique are investigated, we have included samples both with and without a Ti scavenging layer. As compared to the reference gate stack treated by conventional one-time deposition and annealing (D&A), devices receiving MDMA show a significant reduction in leakage current. Meanwhile, EOT growth is effectively controlled by the Ti scavenging layer. This improvement strongly correlates with the cycle number of D&A (while keeping the total annealing time and total dielectrics thickness the same). Transmission electron microscope and energy-dispersive X-ray spectroscopy analysis suggests that oxygen incorporation into both the high-k film and the interfacial layer is likely to be responsible for the improvement of the device. This novel MDMA is promising for the development of gate stack technology in a gate last integration scheme.

Layered transition metal dichalcogenides (LTMDs) have renewed interest as electronic materials, but the poor conductivities hinder their further development. Chemical doping can often significantly modify atomic structures and electronic functionalities of a wide range of materials and thus acts as one of the most effective ways to precisely tune material properties for technological application. Here, the geometries and band structures as well as the densities of states of pure NbSe2 and Ti-doped NbSe2 nanostructure are studied by employing the ab-initio plane-wave ultra-soft pseudo potential technique based on the density functional theory. We optimize the ground state of NbSe2 in the layered structure by using the generalized gradient approximation for the exchange-correlation potential. The computational structural parameters are in good agreement with experimental values within 2.5%. To investigate the stability of the doped system with changing the concentration of Ti atoms, 2×2×1 2H-NbSe2 supercells are taken into consideration. Meanwhile, we consider a total of three possible Ti-doping models: substitution, intercalation, and embedded model, and investigate the energy band diagrams, state densities and densities of partial wave state diagram before and after the doping. The results show that the energy electron density of states reaches a higher peak, and the band structure near Fermi level (EF) is changed obviously, resulting in the variations of the band gap and EF position and then the increase of electronic conductivity after doping. In addition, our calculations also predict that the electron transport properties can be enhanced by doping Ti and it can be regarded as a useful way to tailor electronic states so as to improve electron transport properties of 2H-NbSe2. Such a remarkable modification of electronic structure of 2H-NbSe2 by chemical doping offers an additional way of modulating performances of LTMDs and developing new electrical contact composite materials.

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After several decades of research, the traditional modeling methods, such as geometric model，feature model and integrated product model, can’t fully meet the integrated product information and the related knowledge that required. Meanwhile, lack of semantics, is not conducive to the using and sharing of knowledge. Semantic-based product design and process decision can shorten the product development cycle, reduce costs and allow the computer to participate in the design. Based on building of complex electronic products ontology and already been built OWL ontology file introduced into database, this paper combines Ontology model of complex electronic products with the semantic Web, studies a network design model based on the semantic Web and develops a product design and process decision Web platform based on semantic. The platform can realize product design, semantic search of the resources and decision of parts machining process, thus, to improve the productivity and enhance the efficiency and competitiveness of the company by the system.

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