Drive the Discovery of Green Catalysts for Biomass Conversion using Inverse Molecular Design

Designing efficient catalysts is the key for the development of next-generation technologies of converting biomass into value-added chemicals such as liquid fuels. However, designing biomass catalysts based on earth-abundant metals that can work under mild conditions (e.g., low pressure, low temperature, and with green solvents) remains a challenge. In this talk, I will present the recent research effort in our laboratory on developing new inverse design methods to drive the discovery of novel green catalysts for biomass conversion. First, we explored the theoretical limits of reaction conditions for the hydrogenation and hydrogenolysis of biomass model compounds, using quantum chemistry calculations based on density function theory. Our results showed that thermodynamically it is indeed possible to design green hydrogenation catalysts that can work at the mildest conditions for converting biomass molecules into value-added chemicals. The thermodynamic study also helped us to understand the selectivity of an existing Cu-doped hydrotalciate catalyst in experiments. Second, we developed a new inverse molecular design method based on tight-binding electronic structure theory to search for novel hydrogenation catalysts. Our approach of inverse design aims at searching for optimum points on the hypersurfaces defining the property-structure relationships for catalysts, and then mapping out the catalyst structures at the optimum points, leading to enhanced success rate of catalysts discovery. Our new inverse design method showed to be effective on searching for novel hydrogenation catalysts with higher activity

Research on the Plate Cavity Geometry of the Squeezed Branch Pile

AbstractThis paper deduced the cavity geometry of the plate under the action of one-way and two-way squeeze equipment which is hyperbolic for two-way squeezed, hyperbolic and arc for one-way squeezed. This paper points out the different stress characteristics and applicable conditions of bearing plate for the two kinds of squeezed branch pile, and provides references for the development of the squeezed branch pile

Highly Selective Hydrogenation and Hydrogenolysis Using a Copper-doped Porous Metal Oxide Catalyst

A copper-doped porous metal oxide catalyst in combination with hydrogen shows selective and quantitative hydrogenolysis of benzyl ketones and aldehydes, and hydrogenation of alkenes. The approach provides an alternative to noble-metal catalysed reductions and stoichiometric Wolff-Kishner and Clemmensen methods

A Hierarchical Approach for Creating Electrically Conductive Network Structure in Polyurethane Nanocomposites using a Hybrid of Graphene Nanoplatelets, Carbon Black and Multi-Walled Carbon Nanotubes

Hierarchical organization of carbon nanomaterials is the best strategy to combine desirable factors and synergistically impart mechanical and electrical properties to polymers. Here, we investigate the relaxation behavior of carbon nanofillers filled polyurethane (PU) with special reference to particle size and aspect ratio, filler morphology, filler loading to understand the conductive network formation of fillers in the PU matrix. Typically, an addition of 2 wt% hybrid fillers of graphene nanoplatelets (GNPs), conductive carbon black (CB) and multiwalled carbon nanotubes (MWCNTs) in PU at 1:1:2 mass ratio (GCM112-PU2) showed lowest surface resistivity ~106.8 ohm/sq along with highest improved mechanical properties. Our results demonstrate how hierarchical compositions may function in polymer configurations that are useful for thermal and electrical systems

Does Fintech affect the psychological traits of managers? Based on the perspective of manager overconfidence

Overconfidence has undertaken an indispensable role in the psychology of managers and places important significance on managers’ behavior and decision-making. This study investigates the effect of Fintech on the psychological traits of managers from the perspective of overconfidence based on the panel data of Chinese A-share non-financial listed firms and the digital inclusive finance index of Chinese prefecture-level cities between 2011 and 2020. The empirical results show that (1) Fintech exerts a negative effect on manager overconfidence; (2) the main channels of the negative effect of Fintech on manager overconfidence include Fintech coverage breadth and Fintech usage depth; (3) for firms with severe financing constraints and lower power concentration, the negative effect of Fintech on manager overconfidence is more prominent; and (4) our benchmark results still hold after a series of robust tests, including IV regression, altering the measurement of Fintech and manager overconfidence, and employing logit model re-estimation. Based on the above findings, this study provides some insights into the cause for managers’ psychological traits, maintaining managers’ mental health, and empowering the firms’ sustainable development by adopting Fintech

Effects of Thiophene Units on Substituted Benzothiadiazole and Benzodithiophene Copolymers for Photovoltaic Applications

Two conjugated copolymers, P1 and P2, comprising of benzodithiophene and 5, 6-dioctyloxy-benzothiadiazole (DOBT) derivatives with/without thiophene unit, were synthesized via Stille cross-coupling polymerization reaction. These copolymers are promising for the applications in BHJ solar cells due to their good solubilities， proper thermal stability and moderate hole mobility as well as low bandgap. The photovoltaic properties of the copolymers were investigated based on the blend of the different polymer/PC71BM weight ratio under AM1.5G illumination, 100 mW/cm2. The device with ITO/PEDOT:PSS/P2: PC71BM (1:2, w/w)/Ca/Al gave relatively better photovoltaic performance, with a power conversion efficiency of 1.55%

Histological and Biomechanical Evaluation of the Preserved Degenerative Dermis in Rat Autologous Skin Transplant Models after a Deep Second Degree Burn

To describe the histological and biomechanical changes of the preserved degenerative dermis in rat  autologous skin transplant models after a deep second-degree burn. 50 SD rats were divided into 5 groups  randomly of 10 rats of each: 7-days group, 9-days group, 14-days group, 21-days group, and 60-days group.  Deep second-degree burn wounds were prepared on the back of rats sized 3.5cm×3.5cm. Super tangential  excision was performed on the burn wound to preserve the degenerative dermis. Then, autologous epidermis  was grafted on the wound. After that, the histological changes of the preserved degenerative dermis tissues  and the graft areas were observed by macroscopic, light microscope and electron microscope in the 7, 9, 14,  21, 60 days after the operation. Moreover, the tensile properties of healing deeply burned rat skin were also  tested for each group at the same time points mentioned above. Results: (1) According to the macroscopic  observation, 7 days after the operation, the grafted skin was fused with the area of burn wound; A few hairs  were growing out on the skin at the 14th day; the injured skin recovered to normality by the 60th day. (2)  Hyaline change occurred in the preserved degenerative dermis tissues based on the observation by light  microscope. At the 7th day after operation, the dermis papillae and reticular layer could be discerned; by  the 21st day, the thickness, structures and morphology of grafted skin were similar to the normal tissues. (3)  7 days after operation, ballooning changes were observed by the electron microscope in the mitochondria  and endoplasmic reticulum of damaged cells and the number of the ribosomes was obviously reduced. The  subcellular wound improved continuously and approached normality by the 21st day. (4) 9 days after the  operation, the tensible strength and maximal strain of the grafting rat skin approached 70% and 90% of  natural skin, respectively. (5) 60 days after the operation, the tensile performance of the healing rat skin  recovered to the natural level. Conclusion: The histological and biomechanical changes of the denatured dermis of a deep second  degree burn wound may gradually recover to normality after being covered by autologous skin.

Documentos para a história de Portugal no século XX : a conjuntura do ano de 1946

Successfully predicting the frequency dispersion of electronic hyperpolarizabilities is an unresolved challenge in materials science and electronic structure theory. We show that the generalized Thomas−Kuhn sum rules, combined with linear absorption data and measured hyperpolarizability at one or two frequencies, may be used to predict the entire frequency-dependent electronic hyperpolarizability spectrum. This treatment includes two- and three-level contributions that arise from the lowest two or three excited electronic state manifolds, enabling us to describe the unusual observed frequency dispersion of the dynamic hyperpolarizability in high oscillator strength M-PZn chromophores, where (porphinato)zinc(II) (PZn) and metal(II)polypyridyl (M) units are connected via an ethyne unit that aligns the high oscillator strength transition dipoles of these components in a head-to-tail arrangement. We show that some of these structures can possess very similar linear absorption spectra yet manifest dramatically different frequency-dependent hyperpolarizabilities, because of three-level contributions that result from excited state-to-excited state transition dipoles among charge polarized states. Importantly, this approach provides a quantitative scheme to use linear optical absorption spectra and very limited individual hyperpolarizability measurements to predict the entire frequency-dependent nonlinear optical response