24 research outputs found
Complete chloroplast genome sequences of Lagotis brevituba (Plantaginaceae): a famous Tibetan medicine plant
Lagotis brevituba is a famous Tibetan medicine plant and its complete chloroplast genome is determined in this study. The complete chloroplast genome is 152,967 bp in length, with a large single-copy (LSC) region of 83,740 bp, a small single copy (SSC) region of 17,845 bp, and a pair of inverted repeats (IRs) of 25,691 bp. The whole genome contained 131 genes, including 86 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The phylogenetic tree showed that L. brevituba clustered with L. yunnanensis in family Plantaginaceae
Knowledge-Driven Manufacturing Process Innovation: A Case Study on Problem Solving in Micro-Turbine Machining
Micromachining techniques have been applied widely to many industrial sectors, including aerospace, automotive, and precision instruments. However, due to their high-precision machining requirements, and the knowledge-intensive characteristics of miniaturized parts, complex manufacturing process problems often hinder production. To solve these problems, a systematic scheme for structured micromachining process problem solving and an innovation support system is required. This paper presents a knowledge-based holistic framework that enables process planners to achieve micromachining innovation design. By analyzing innovation design procedures and available knowledge sources, an open multi-source Machining Process Innovation Knowledge (MPIK) acquisition paradigm is presented, including knowledge units and a knowledge network. Further, a MPIK network-driven structured process problem-solving and heuristic innovation design method was explored. Subsequently, a knowledge-driven heuristic design system for machining process innovation was integrated in the Computer-Aided Process Innovation (CAPI) platform. Finally, a case study involving specific process problem-solving and innovation scheme design for micro-turbine machining was studied to validate the proposed approach
Knowledge-Driven Manufacturing Process Innovation: A Case Study on Problem Solving in Micro-Turbine Machining
Micromachining techniques have been applied widely to many industrial sectors, including aerospace, automotive, and precision instruments. However, due to their high-precision machining requirements, and the knowledge-intensive characteristics of miniaturized parts, complex manufacturing process problems often hinder production. To solve these problems, a systematic scheme for structured micromachining process problem solving and an innovation support system is required. This paper presents a knowledge-based holistic framework that enables process planners to achieve micromachining innovation design. By analyzing innovation design procedures and available knowledge sources, an open multi-source Machining Process Innovation Knowledge (MPIK) acquisition paradigm is presented, including knowledge units and a knowledge network. Further, a MPIK network-driven structured process problem-solving and heuristic innovation design method was explored. Subsequently, a knowledge-driven heuristic design system for machining process innovation was integrated in the Computer-Aided Process Innovation (CAPI) platform. Finally, a case study involving specific process problem-solving and innovation scheme design for micro-turbine machining was studied to validate the proposed approach
Fundamentals and advances of ligand field theory in understanding structure-electrochemical property relationship of intercalation-type electrode materials for rechargeable batteries
The ion-intercalation-based rechargeable batteries are emerging as the most efficient energy storage technology for electronic vehicles, grids, and portable devices. These devices require rechargeable batteries with higher energy–density than commercial Li-ion batteries, which are intrinsically limited by specific capacities and electrochemical potentials of transition-metal (M) electrode materials. Over the past decades, a significant number of studies have focused on exploring coordination environments and electronic origins of these materials based on ligand field theory (LFT). However, studies to understand and manipulate the relationship between their local-structural characteristics and electrochemical properties are limited. In this review, we comprehensively discussed how the combining of LFT and first-principles calculations can be used to derive Fermi levels that determine electrochemical potential, crystal field stabilization energy, and anionic redox activity. Based on this, a series of strategies are proposed to improve the phase-stability and energy–density of intercalation-type electrode materials, such as ion-intercalation potential tuning of rigid-band systems and electrode phase stability regulations with different M periods. Two high energy–density cathode materials, M-free LiBCF2 and Li-free group-VB/VIB MX2 (X = S, Se), are successfully designed from the aforementioned principles derived. Finally, we also highlight further directions for designing better intercalation-type materials based on LFT and their opportunities/challenges.</p
Rapid synthesis of hexagonal mesoporous structured NiCo2O4 via rotary evaporation for high performance supercapacitors
Combining Oxymatrine or Matrine with Lamivudine Increased Its Antireplication Effect against the Hepatitis B Virus In Vitro
Some recent clinical reports have shown that the combination of oxymatrine, a phyto-derived drug, with lamivudine (3TC) could improve its curative effect against hepatitis B virus (HBV) infection. However, the experimental data in support of this combination strategy are lacking. In this study, we investigated the anti-HBV activity of the combination of 3TC and either oxymatrine or matrine on HepG2 2.2.15 in vitro. The activities of the combination and the solo compound, each in different concentrations, were compared on the 3rd, 6th, and 9th experimental days. The cytotoxicity results showed that the nontoxic concentrations of both oxymatrine and matrine to HepG2 2.2.15 cells were 800 μg/mL. We found that the single use of oxymatrine below 100 μg/ml, matrine below 200 μg/ml, and 3TC below 30 μg/ml showed weak inhibitory effects on the secretion of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and HBV-DNA in culture media; the combination of 3TC (30 μg/ml) with oxymatrine (100 μg/ml) or matrine (100 μg/ml) showed significant inhibitory effects that were higher than or equivalent to the single use of 3TC at 100 μg/ml. The results provide a new impetus to develop novel, multicomponent anti-HBV drugs through the combination of natural products with nucleoside analogs to enhance their activity