THE CREATION AND SPREAD OF TECHNOLOGY AND TOTAL FACTOR PRODUCTIVITY IN CHINA'S AGRICULTURE

The studys overall goal is to create a framework for assessing the trends of China's national and international investment in agricultural research and to measure its impact on total factor productivity. The main methodological contribution is to provide more convincing measures of crop-specific technologies from China's national research program and of those imported from the international agricultural research system. Our results find that from 1980-95, China's total factor productivity for rice, wheat and maize grew rapidly and new technology accounts for most of the productivity growth.Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,

Rational Design of Low-Band Gap Star-Shaped Molecules With 2,4,6-Triphenyl-1,3,5-triazine as Core and Diketopyrrolopyrrole Derivatives as Arms for Organic Solar Cells Applications

A series of D–A novel star-shaped molecules with 2,4,6-triphenyl-1,3,5-triazine (TPTA) as core, diketopyrrolo[3,4-c]pyrrole (DPP) derivatives as arms, and triphenylamine (TPA) derivatives as end groups have been systematically investigated for organic solar cells (OSCs) applications. The electronic, optical, and charge transport properties were studied using density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches. The parameters such as energetic driving force ΔEL−L, adiabatic ionization potential AIP, and adiabatic electron affinity AEA were also calculated at the same level. The calculated results show that the introduction of different groups to the side of DPP backbones in the star-shaped molecules can tune the frontier molecular orbitals (FMOs) energy of the designed molecules. The designed molecules can provide match well with those of typical acceptors PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) and PC71BM ([6,6]-phenyl-C71-butyric acid methyl ester). Additionally, the absorption wavelengths of the designed molecules show bathochromic shifts compared with that of the original molecule, respectively. The introduction of different groups can extend the absorption spectrum toward longer wavelengths, which is beneficial to harvest more sunlight. The calculated reorganization energies suggest that the designed molecules are expected to be the promising candidates for ambipolar charge transport materials except molecule with benzo[c]isothiazole group can be used as hole and electron transport material. Moreover, the different substituent groups do not significantly affect the stability of the designed molecules

Privatization, Public R&D Policy, and Private R&D Investment in China's Agriculture

Private R&D is a major source of innovation and productivity growth in agriculture worldwide. This paper examines trends and determinants of agricultural R&D in China. Results show that while the public sector monopolized agricultural research until recently, private agricultural R&D has grown rapidly since 2000, driven largely by agribusiness privatization. Public-sector R&D investments in basic research also encouraged private R&D research, but public investments in technology development crowded out private R&D investment. China’s private R&D investment would grow more rapidly if the government shifted public resources from technology development to basic research.Agriculture, China, Private R&D, Privatization, Public R&D, Research and Development/Tech Change/Emerging Technologies,

Theoretical Study on the Radical Scavenging Activity of Shikonin and its Ester Derivatives

Abstract: Aim of study is to get a further insight on the contribution of the structural features to the radical scavenging potential of shikonin and its ester derivatives. The radical scavenging activity of shikonin and its ester derivatives have been studied by using density functional theory. The hydrogen bond property of the studied structures has been investigated by using the Atoms in Molecules (AIM) theory. The calculated results reveal that the hydrogen bond is important for good scavenging activity. The hydrogen atom transfer mechanism for shikonin and its ester derivatives are difficult to occur. However, shikonin and its ester derivatives appear to be good candidates for the one-electron-transfer mechanism. The shikonin ester derivatives investigated in this study are expected to be of high radical scavenging activity compared with parent compound shikonin. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view

Theoretical Investigations of the Photophysical Properties of Star-Shaped π-Conjugated Molecules with Triarylboron Unit for Organic Light-Emitting Diodes Applications

The density functional theory (DFT) and time-dependent DFT (TD-DFT) methodologies have been applied to explore on a series of star-shaped π-conjugated organoboron systems for organic light-emitting diode (OLED) materials. The compounds under investigation consist of benzene as π-bridge and different core units and triarylboron end groups. Their geometry structures, frontier molecular orbital (FMO) energies, absorption and fluorescence spectra, and charge transport properties have been investigated systematically. It turned out that the FMO energy levels, the band gaps, and reorganization energies optical are affected by the introduction of different core units and triarylboron end groups. The results suggest that the designed compounds are expected to be promising candidates for luminescent materials. Furthermore, they can also serve as hole and/or electron transport materials for OLEDs

Rational Design of Diketopyrrolopyrrole-Based Small Moleculesas Donating Materials for Organic Solar Cells

A series of diketopyrrolopyrrole-based small molecules have been designed toexplore their optical, electronic, and charge transport properties as organic solar cell(OSCs) materials. The calculation results showed that the designed molecules can lowerthe band gap and extend the absorption spectrum towards longer wavelengths.The designed molecules own the large longest wavelength of absorption spectra,the oscillator strength, and absorption region values. The optical, electronic, and chargetransport properties of the designed molecules are affected by the introduction of differentπ-bridges and end groups. We have also predicted the mobility of the designed moleculewith the lowest total energies. Our results reveal that the designed molecules are expectedto be promising candidates for OSC materials. Additionally, the designed molecules areexpected to be promising candidates for electron and/or hole transport materials. On thebasis of our results, we suggest that molecules under investigation are suitable donors for[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and its derivatives as acceptors of OSCs