Hierarchical Structure with Highly Ordered Macroporous-Mesoporous Metal-Organic Frameworks as Dual Function for CO2 Fixation.

As a major greenhouse gas, the continuous increase of carbon dioxide (CO2) in the atmosphere has caused serious environmental problems, although CO2 is also an abundant, inexpensive, and nontoxic carbon source. Here, we use metal-organic framework (MOF) with highly ordered hierarchical structure as adsorbent and catalyst for chemical fixation of CO2 at atmospheric pressure, and the CO2 can be converted to the formate in excellent yields. Meanwhile, we have successfully integrated highly ordered macroporous and mesoporous structures into MOFs, and the macro-, meso-, and microporous structures have all been presented in one framework. Based on the unique hierarchical pores, high surface area (592 m2/g), and high CO2 adsorption capacity (49.51 cm3/g), the ordered macroporous-mesoporous MOFs possess high activity for chemical fixation of CO2 (yield of 77%). These results provide a promising route of chemical CO2 fixation through MOF materials

Adoption of electronic supply chain management systems: the mediation role of information sharing

Purpose: Based on structural embeddedness theory and resource dependence theory, this research aims to examine the mediation role of information sharing in the relationship between deendency structures and electronic supply chain management system (eSCM) adoption and a firm's intention to adopt eSCMs. Design/methodology/approach: A survey questionnaire was undertaken from 212 companies based in Mainland China. Three-stage least squares (3SLS) regression was employed to test the research model. Findings: The results from 3SLS regressions showed that the effect of interdependence on eSCM adoption intention is fully mediated through information sharing when relationship duration is either below or about the mean. Interdependence and dependence disadvantage was shown to have significant positive effects on eSCM adoption while the effect of dependence advantage was statistically insignificant. Relationship duration was found to negatively moderate the relationship between information sharing and adoption intention. Originality/value: Through investigating factors of inter-organizational relationships, this study fills the knowledge gap in the traditional paradigms which ignore the collaborative nature of eSCM and analyse related problems based on a single firm's point of view

Theoretical investigation of heat and mass transfer for hollow fibre integrated evaporative cooling system

Due to the advantages of light weight, corrosive resistant and low cost, hollow fibres have been studied as the substitute for metallic materials. A novel hollow fibre integrated evaporative cooling system, in which the hollow fibre module constitutes as the humidifier and evaporative cooler, is proposed. This novel hollow fibre integrated evaporative cooling system will provide a comfortable indoor environment for hot and dry area. Moreover, the water vapour can permeate through the hollow fibre effectively, and the liquid water droplets will be prevented from mixing with the processed air. A mathematical model, which takes into account of the heat transfer between incoming air and the circulating water inside the fiber, and the water evaporation through the fibre, is developed and analyzed. The variations of incoming air velocity, fibre inside diameter, the incoming air temperature and humidity on the evaporative cooling effectiveness were discussed in this paper. The results showed that as the incoming air velocity increased from 0.2m/s to 0.8m/s, the saturation efficiency was between 0.52 and 0.84. The theoretical investigation revealed that this novel hollow integrated evaporative cooling system is compact, which offers relatively high heat and mass transfer performance.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Sub-5 nm single crystalline organic p-n heterojunctions.

The cornerstones of emerging high-performance organic photovoltaic devices are bulk heterojunctions, which usually contain both structure disorders and bicontinuous interpenetrating grain boundaries with interfacial defects. This feature complicates fundamental understanding of their working mechanism. Highly-ordered crystalline organic p-n heterojunctions with well-defined interface and tailored layer thickness, are highly desirable to understand the nature of organic heterojunctions. However, direct growth of such a crystalline organic p-n heterojunction remains a huge challenge. In this work, we report a design rationale to fabricate monolayer molecular crystals based p-n heterojunctions. In an organic field-effect transistor configuration, we achieved a well-balanced ambipolar charge transport, comparable to single component monolayer molecular crystals devices, demonstrating the high-quality interface in the heterojunctions. In an organic solar cell device based on the p-n junction, we show the device exhibits gate-tunable open-circuit voltage up to 1.04 V, a record-high value in organic single crystalline photovoltaics

Cassava genome from a wild ancestor to cultivated varieties

Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology

High Performance Metal Oxide Thin Film Transistors via Cluster Control and Interface Engineering

Around 100 years has passed since the first cathode ray tube has been fabricated. Fast and free transition of graphs provided much convenience for human communication. Generations of display were developed and flat panel display (FPD) techniques are developing tremendously recently. Various demands are raised including high definition, large area, flexibility, etc. Backplane need improving to meet these, especially the thin film transistor (TFT) units. High mobility, easy process and good interfaces are desired. Solution processed amorphous InGaZnO proves a competitive candidate for TFT semiconductor materials. Its electronic performance, uniformity and switching properties turned out among the best. However, problems remain to be solved including mechanism interpretation, precursor control, morphology and interface. Chapter 1 will introduce the history and state of art of TFT in more details.In the following parts of this dissertation, I’ll discuss the electronic behavior, morphology and interface of IGZO TFT. In Chapter 2, we performed gated four-probe measurements to extract the intrinsic mobility and contact resistance as functions of gate voltage and temperature. Contact resistance was proved to play a major role in mobility degradation at high gate bias, whereas, band-like transport dominates. We proposed UV-O3 which modified the contact regions and mobility was boosted from 23 to 30 cm2/Vs. In Chapter 3, clusters in precursor solution, which has critical effects on morphology, are discussed. Cluster size distribution was narrowed and size was brought down by acac. Small roughness of metal oxide was achieved and saturated mobility increased from 4.0 to 5.5 cm2/Vs. In a positive bias stress test, turn on voltage shift decreased from 1.6 to 0.3 V/10000s. Cluster size control is a promising way to tune the morphology of solution processed metal oxide film.Small sized high definition display is placing more challenge on backplane TFTs. IGZO is one of the candidates but the unsatisfactory performance of small sized IGZO TFTs is limiting their applicability. Hence, a novel weak acid modification (WAM) strategy was introduced to generate more oxygen vacancies for higher mobility, and to lower the surface roughness. Electrode-IGZO contact was enhanced. Contact resistance was reduced from 9.1 kΩmm to 2.3 kΩmm, as measured by the gated four probe (GFP) method. Field effect mobility for small sized devices was boosted from 1.5 cm2/Vs to 4.0 cm2/Vs. Additionally, a 12�12 transistor and organic light emission diode array built from the modified IGZO TFT devices has been demonstrated

High Performance Metal Oxide Thin Film Transistors via Cluster Control and Interface Engineering

Around 100 years has passed since the first cathode ray tube has been fabricated. Fast and free transition of graphs provided much convenience for human communication. Generations of display were developed and flat panel display (FPD) techniques are developing tremendously recently. Various demands are raised including high definition, large area, flexibility, etc. Backplane need improving to meet these, especially the thin film transistor (TFT) units. High mobility, easy process and good interfaces are desired. Solution processed amorphous InGaZnO proves a competitive candidate for TFT semiconductor materials. Its electronic performance, uniformity and switching properties turned out among the best. However, problems remain to be solved including mechanism interpretation, precursor control, morphology and interface. Chapter 1 will introduce the history and state of art of TFT in more details.In the following parts of this dissertation, I’ll discuss the electronic behavior, morphology and interface of IGZO TFT. In Chapter 2, we performed gated four-probe measurements to extract the intrinsic mobility and contact resistance as functions of gate voltage and temperature. Contact resistance was proved to play a major role in mobility degradation at high gate bias, whereas, band-like transport dominates. We proposed UV-O3 which modified the contact regions and mobility was boosted from 23 to 30 cm2/Vs. In Chapter 3, clusters in precursor solution, which has critical effects on morphology, are discussed. Cluster size distribution was narrowed and size was brought down by acac. Small roughness of metal oxide was achieved and saturated mobility increased from 4.0 to 5.5 cm2/Vs. In a positive bias stress test, turn on voltage shift decreased from 1.6 to 0.3 V/10000s. Cluster size control is a promising way to tune the morphology of solution processed metal oxide film.Small sized high definition display is placing more challenge on backplane TFTs. IGZO is one of the candidates but the unsatisfactory performance of small sized IGZO TFTs is limiting their applicability. Hence, a novel weak acid modification (WAM) strategy was introduced to generate more oxygen vacancies for higher mobility, and to lower the surface roughness. Electrode-IGZO contact was enhanced. Contact resistance was reduced from 9.1 kΩmm to 2.3 kΩmm, as measured by the gated four probe (GFP) method. Field effect mobility for small sized devices was boosted from 1.5 cm2/Vs to 4.0 cm2/Vs. Additionally, a 12�12 transistor and organic light emission diode array built from the modified IGZO TFT devices has been demonstrated