Thermal Analysis of Organic Light Emitting Diodes Based on Basic Heat Transfer Theory

We investigate the thermal characteristics of standard organic light-emitting diodes （OLEDs） using a simple and clear 1D thermal model based on the basic heat transfer theory. The thermal model can accurately estimate the device temperature, which is linearly with electrical input power. The simulation results show that there is almost no temperature gradient within the OLED device working under steady state conditions. Furthermore, thermal analysis simulation results show that the surface properties （convective heat transfer coetficient and surface emissivity） of the substrate or cathode can significantly affect the temperature distribution of the OLED.

Analysis of China's sporting products industry based on the SCP framework

The SCP framework is a classical theory of industrial organization,which refers to the market structure,market conduct and market performance.This analysis is based on the SCP framework,choosing the current sporting products industry as object.Study found that China's sporting products industry's geographical layout has a"strong in South and East,weak in North and West"regional development trend,the proportion of abovedesignated enterprises is relatively low,rate of market concentration is not high,product homogenization remain quite serious.With high-speed technological progress and rapid scientific and technological updates,in the future,the sporting products industry will be reorganized according to the subdivision industries,getting rid of homogenization of competition and meeting the needs of consumers in smart wearable,health monitoring and other aspects.

THE EMERGING CHALLENGE:THE VALIDITY OF COMPUTATIONAL ORGANIZATION MODEL AND METHODOLOGY

The validity of the computational organization model is a necessary condition and also poses a bottleneck in computational organization theory development.Established on the frontline of computational organization theory,this paper provides an overall discussion on the difficulties in validation and validation methodology of the computational organization model.First,different from natural engineering system model,and also exceeding the traditional empirical method,the computational organization model is faced with various subjective and objective difficulties during the validation progress;second,in developing the situational validation methodology based on relationships among problem field,modeling purpose and referents,it is important for the computational organization model that the validation is conducted according to certain degree;third,the establishment of verification,validation and accreditation approach(VV&A),which is different from the natural engineering system,is an irresistible trend for future development of the computational organization model.Model validation should be focused on concept validation,operation validation,and data validation,as well as the principle of iterative validation approach and such validation should be conducted throughout the modeling process;finally,the validation of computational organization model should be the process to enhance people’s confidence in the model.From the perspective of review,if the model is able to pass through all the validation tests,it is helpful for a better understanding of the model’s ability,limitation and applicability.In this case,research from interdisciplinary experts is required urgently.

Nanostructured organic electrode materials grown on graphene with covalent-bond interaction for high-rate and ultra-long-life lithium-ion batteries

Nanostructured organic tetralithium salts of 2,5-dihydroxyterephthalic acid （Li4C8H2O6） supported on graphene were prepared via a facile recrystallization method. The optimized composite with 75 wt.% Li4C8H2O6 was evaluated as an anode with redox couples of Li4C8H2O6/Li6C8H2O6 and as a cathode with redox couples of Li4C8H2O6/Li2C8H2O6 for Li-ion batteries, exhibiting a high-rate capability （10 C） and long cycling life （1,000 cycles）. Moreover, in an all-organic symmetric Li-ion battery, this dual-function electrode retained capacities of 191 and 121 mA.h·g-1 after 100 and 500 cycles, respectively. Density functional theory calculations indicated the presence of covalent bonds between Li4CsH206 and graphene, which affected both the morphology and electronic structure of the composite. The special nanostructures, high electronic conductivity of graphene, and covalent-bond interaction between Li4C8H2O6 and graphene contributed to the superior electrochemical properties. Our results indicate that the combination of organic salt molecules with graphene is useful for obtaining high-performance organic batteries.

Unraveling the mark of surface defects on a spinterface： The nitronyl nitroxide/TiO2（110） interface

Metal-free organic radicals are fascinating materials owing to their unique properties. Having a stable magnetic moment coupled to light elements makes these materials central to develop a large variety of applications. We investigated the magnetic spinterface coupling between the surface of a single rutile TiO2（110） crystal and a pyrene-based nitronyl nitroxide radical, using a combination of thickness-dependent X-ray photoelectron spectroscopy and ab initio calculations. The radicals were physisorbed, and their magnetic character was preserved on the （almost） ideal surface. The situation changed completely when the molecules interacted with a surface defect site upon adsorption. In this case, the reactivity of the defect site led to the quenching of the molecular magnetic moment. Our work elucidates the crucial role played by the surface defects and demonstrates that photoemission spectroscopy combined with density functional theory calculations can be used to shed light on the mechanisms governing complex interfaces, such as those between magnetic molecules and metal oxides.

Theoretical investigations of transport properties of organic solvents in cation-functionalized graphene oxide membranes： Implications for drug delivery

We perform detailed quantum chemical calculations to elucidate the origin and mechanism of the selective permeability of alkali and alkaline earth cation- decorated graphene oxide （M-GO） membranes to organic solvents. The results show that the selectivity is associated mainly with the transport properties of solvents in the membranes, which depends on two regions of the flow path： the sp3 C-O matrix of the GO sheets and the cation at the center of the hexagon rather than the sp~ region. According to the delocalization of ~ states in sp2 regions, we propose a design guide for high-quality M-GO membranes. The solvent-cation interaction essentially causes directional transport of molecules in the M-GO membranes under the transmembrane pressure, indicating a site-to-site mech- anism. The solvent-sp3 C-O matrix interaction may inhibit molecular transport between two fixed cations by consuming energy. The competition between energy consumption by the solvent-cation interaction and energy expenditure by the solvent-sp3 C-O matrix interaction leads to various transport properties of solvents and thus allows for the selective permeability of the M-GO membranes. Findings from the study are helpful for the future design of multifunctional M-GO macro-membranes as cost-effective solution nanofilters in chemical, biological, and medical applications