Synthesis, Properties, and Their Potential Application of Covalent Organic Frameworks (COFs)

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous polymers, which are ingeniously assembled with organic building blocks through reversible covalent bonds. The well-defined crystalline porous structures, easy functional modification, high surface area, together with structural designability and diversity have offered the COFs superior potential in various applications, such as catalysis, gas adsorption and separation, and optoelectricity. Since the pioneer work of Omar Yaghi in 2005, this field has developed rapidly and attracted much attention from researchers with diverse expertise. In this chapter, we describe the basic design concepts, the recent synthetic advancements, and the frontiers of functional exploration in gas adsorption and storage. Special emphasis is placed on their potential application in heterogeneous catalysis field. Finally, the prospects of COFs and remaining issues in these fields are indicated

The Application of Internet of Things for Intelligent Electrical Meter Reading System

Combining Internet of Things with general packet radio service is a new development of the existing global system of mobile communication digital mobile communication system data bearer services, following the voice transmission services. The remote data transmission system has a self-evident importance. This paper focuses on the general packet radio service terminal of things technology and design. The terminal system is designed to achieve a complete transmission control protocol/internet protocol, with a strong versatility, only by simply extending the general packet radio service system which can be a different composition for being applied to various fields. Through applied data acquisition interface, plus related data processing steps on the basis of the existing microcontroller programming terminal can be applied to various types of monitoring on-site and the data acquisition system

The Monte Carlo Simulation of the Electronic Local Properties in the Two-Dimensional Disordered System

AbstractUsing Monte Carlo simulation method, we studied the influence of the disorder, eigenenergy and bandwidth on the localization length in disordered system. The results reveal that electronic states of system exhibited localization phenomena with the increase of degree of disorder and the localization length can be reduced by the increasing of disorder degree. Moreover the incremental range of localization length had a trend to descend with increase of bandwidth

Papel de la bahía de Jiaozhou como una fuente/depósito de CO2 durante un ciclo estacional

The seasonal evolution of dissolved inorganic carbon (DIC) and CO2 air-sea fluxes in the Jiaozhou Bay was investigated by means of a data set from four cruises covering a seasonal cycle during 2003 and 2004. The results revealed that DIC had no obvious seasonal variation, with an average concentration of 2035 µmol kg-1 C in surface water. However, the sea surface partial pressure of CO2 changed with the season. pCO2 was 695 µatm in July and 317 µatm in February. Using the gas exchange coefficient calculated with Wanninkhof’s model, it was concluded that the Jiaozhou Bay was a source of atmospheric CO2 in spring, summer, and autumn, whereas it was a sink in winter. The Jiaozhou Bay released 2.60 x 1011 mmol C to the atmosphere in spring, 6.18 x 1011 mmol C in summer, and 3.01 x 1011 mmol C in autumn, whereas it absorbed 5.32 x 1010 mmol C from the atmosphere in winter. A total of 1.13 x 1012 mmol C was released to the atmosphere over one year. The behaviour as a carbon source/sink obviously varied in the different regions of the Jiaozhou Bay. In February, the inner bay was a carbon sink, while the bay mouth and the outer bay were carbon sources. In June and July, the inner and outer bay were carbon sources, but the strength was different, increasing from the inner to the outer bay. In November, the inner bay was a carbon source, but the bay mouth was a carbon sink. The outer bay was a weaker CO2 source. These changes are controlled by many factors, the most important being temperature and phytoplankton. Water temperature in particular was the main factor controlling the carbon dioxide system and the behaviour of the Jiaozhou Bay as a carbon source/sink. The Jiaozhou Bay is a carbon dioxide source when the water temperature is higher than 6.6°C. Otherwise, it is a carbon sink. Phytoplankton is another controlling factor that may play an important role in behaviour as a carbon source or sink in regions where the source or sink nature is weaker.La evolución estacional del carbono inorgánico disuelto (DIC) y el intercambio de flujos de CO2 aire-mar en la bahía de Jiaozhou han sido investigados a partir de datos obtenidos en 4 campañas oceanográficas que cubren un ciclo estacional entre 2003 y 2004. Los resultados muestran que el DIC no presenta una clara variación estacional con una concentración promedio de 2035 μmol kg-1 C en el agua de superficie. No obstante la presión parcial de CO2 en el agua superficial cambiaba con la estación. La PCO2 era de 695 μatm en Julio y 317 μatm en febrero. Utilizando el coeficiente de intercambio de gases calculado con el modelo de Wanninkhof concluíamos que la bahía de Jiaozhou era una fuente de CO2 a la atmósfera en primavera, verano y otoño, mientras que era un depósito de CO2 en invierno. La bahía proporcionaba 2.60 × 1011 mmol C a la atmósfera en primavera, 6.18 × 1011 mmol C en verano, y 3.01 × 1011 mmol C in otoño, mientras absorbia 5.32 × 1010 mmol C desde la atmósfera en invierno. Un total de 1.13 × 1012 mmol C eran liberados a la atmósfera durante un año. El comportamiento como fuente/depósito de carbono, obviamente era diferente en las distintas regiones de la bahía de Jiaozhou. En Febrero, la parte interior de la bahía era un depósito para el carbono, mientras que la desembocadura y la parte exterior actuaba como fuente de carbono. En Junio y Julio, las partes interna y externa de la bahía eran fuentes de carbono, pero la intensidad era diferente, incrementando desde la parte interior a la exterior de la bahía. En Noviembre, la parte interior de la bahía era fuente de carbono, pero la desembocadura de la bahía se comportaba como depósito de carbono. El exterior de la bahía era una fuente poco importante de CO2. Estos cambios están controlados por muchos factores, siendo los mas importantes la temperatura y el fitoplancton. Especialmente, la temperatura del agua era el factor principal en el control del dióxido de carbono en el sistema y del comportamiento de la bahía de Jiaozhou como fuente/depósito de carbono. La bahía de Jiaozhou es una fuente de dióxido de carbono cuando la temperatura del agua es mas alta que 6.6ºC. Si no es así es un depósito de carbono. El fitoplancton es el otro factor de control que puede jugar un papel importante en el comportamiento como fuente o depósito de carbono en regiones donde el carácter de fuente o depósito es debil.