Study the Influence of Quantum Interference on the Electrical Conductance and Thermoelectric Properties of Molecular Junctions : Synthesis and Thermoelectricity

This thesis mainly describes our efforts towards the study of the quantum interference of electronic conductance and thermoelectric properties in molecular junctions. Chapter 1 introduces the concepts of the charge transport in single-molecule junctions, include the electrical conductivity and thermopower which are the main parameters to assess the efficiency of the single-molecule junctions. Chapter 2 describes the design and synthesis of the molecules used in the single-molecule junctions, and shows our progress how to tune the electron transport by manipulating the structures of molecules in the single-molecule junctions.Chapter 3 mainly describes the optimization of the Sonogashira coupling and Ti-mediated functional group transformation for the synthesis of meta-OPE3 derivatives. These derivatives offer a chance to systematically study the correlation between the molecular structures and trasport properties in the single-molecule junctions. Chapter 4 is aiming at providing a possible strategy for synthesis of β-substituted porphyrins using the MacDonald [2+2] approach and [3+1] method. These porphyrins are designed for the use in the single-molecule junctions

Macroeconomics After the Great Recession: Consensus or Conflict?

Unlike microeconomics where there are relatively few disagreements, the field of macroeconomics has always been the arena of several competing theories. Despite that history of conflict, in the late 1980s during the Great Moderation, the New Classicals and the New Keynesians reached an agreement, known as the New Consensus during the Great Moderation. For decades, the New Consensus has dominated macroeconomic theory and policymaking not only in the U.S., but also throughout the world. After many years of calm, however, the 2007-2008 subprime mortgage crisis and its consequent Great Recession demonstrated that how fragile that consensus was. While the debate regarding the collapse of the consensus still continues, this thesis aims to understand the implications of the collapse in terms of the future of macroeconomic theory and of policy-making from a critical and historical perspective. To achieve this goal, this thesis will explore the rise and the fall of the New Consensus Theory by first showing, the process that successfully incorporated the once opposing ideologies into one system; second, this paper will study the collapse of the consensus soon after the arrival of the Great Recession. This is followed by a section that aims to draw some lessons learned from the failure of the New Consensus Theory. Finally, the thesis examines the problems associated with policy-making, deficiencies in economic theory and modeling, and the appropriateness of the methodology in the foundations of the New Consensus. Based on these critical and historical evaluations, the thesis concludes with some remarks concerning the future of macroeconomic theory and policy-making

Metal Amidoboranes and Their Derivatives for Hydrogen Storage

As potential hydrogen storage mediums, ammonia borane and its derivatives have been paid an increasing attention owing to their higher hydrogen capacities and facile dehydrogenation properties under moderate conditions. In this chapter, we presented extensive studies on thermodynamic tailoring of dehydrogenation of metal amidoboranes, metal borohydride-ammonia borane complexes, and metal amidoborane ammoniates as well as their derivatives, with special focus on the syntheses, crystal structures, and dehydrogenation properties. Finally, future perspective was given toward the practical applications

The effect of salt stress on the chlorophyll level of the main sand-binding plants in the shelterbelt along the Tarim Desert Highway

Based on the fact that only high saline water irrigated to the shelterbelt along the Tarim Desert Highway, the experiment about three species with six degree of salinity was carried out to analyze the relation between chlorophyll content and salt stress. The results show that: (1) the chlorophyll content of tree species decreases with aggravating the salt stress, which explains that salt stress can affect chlorophyll accumulation of three plants; (2) from chlorophyll content with different salinity, the chlorophyll content of three shrubs also has twice obvious decrease, which indicates that some plants adapt to salt stress. We divided salt resistance of the plant into three grades, namely the slight salt resistance, the heavy salt resistance and the extreme salt resistance; and (3) according to the experimental results, the salt stress of each plant was divided, which can provide theoretical guidance for constructing the shelterbelt along the Tarim Desert Highway

PB2 segment promotes high-pathogenicity of H5N1 avian influenza viruses in mice

H5N1 influenza viruses with high lethality are a continuing threat to humans and poultry. Recently, H5N1 high-pathogenicity avian influenza virus (HPAIV) has been shown to transmit through aerosols between ferrets in lab experiments by acquiring some mutation. This is another deeply aggravated threat of H5N1 HPAIV to humans. To further explore the molecular determinant of H5N1 HPAIV virulence in a mammalian model, we compared the virulence of A/Duck/Guangdong/212/2004 (DK212) and A/Quail/Guangdong/90/2004 (QL90). Though they were genetically similar, they had different pathogenicity in mice, as well as their 16 reassortants. The results indicated that a swap of the PB2 gene could dramatically decrease the virulence of rgDK212 in mice (1896-fold) but increase the virulence of rgQL90 in mice (60-fold). Furthermore, the polymerase activity assays showed that swapping PB2 genes between these two viruses significantly changed the activity of polymerase complexes in 293T cells. The mutation Ser715Asn in PB2 sharply attenuated the virulence of rgDK212 in mice (2710-fold). PB2 segment promotes high-pathogenicity of H5N1 avian influenza viruses in mice and 715 Ser in PB2 plays an important role in determing high virulence of DK212 in mice