scholarly journals Response of Molecular Structures and Methane Adsorption Behaviors in Coals Subjected to Cyclical Microwave Exposure

ACS Omega ◽  
2021 ◽  
Author(s):  
Liankun Zhang ◽  
Tianhe Kang ◽  
Jianting Kang ◽  
Xiaoyu Zhang ◽  
Bin Zhang ◽  
...  
Keyword(s):  
Methane Adsorption ◽  
Molecular Structures ◽  
Microwave Exposure ◽  
Adsorption Behaviors

Effect of nitrogen-containing groups on methane adsorption behaviors of carbon spheres

2014 ◽  
Vol 107 ◽  
pp. 204-210 ◽  
Author(s):  
Yanyan Feng ◽  
Wen Yang ◽  
Ning Wang ◽  
Wei Chu ◽  
Daijun Liu
Keyword(s):  
Methane Adsorption ◽  
Carbon Spheres ◽  
Adsorption Behaviors

Roles of the Porosity and Surface Oxygen Groups on the Adsorption of Methane on Coals

2013 ◽  
Vol 781-784 ◽  
pp. 2415-2419 ◽  
Author(s):  
Shi Xiong Hao ◽  
Zu Xiao Yu ◽  
Xing Yong Liu
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Methane Adsorption ◽  
Coal Surface ◽  
Surface Oxygen Groups ◽  
Adsorption Behaviors ◽  
Two Samples ◽  
Adsorption Data ◽  
Oxygen Groups ◽  
Adsorption Of Methane

One bituminous coal was modified with H2O2, (NH4)2S2O8 and HNO3 respectively, to prepare coal samples with different surface properties. The oxygen groups on coal surface were characterized by X-ray photoelectron spectroscopy (XPS). The textures of the coal samples were investigated by N2 adsorption at 77 K. The methane adsorption behaviors of the coal samples were measured at 303 K in pressure range of 0-5.3 MPa by a volumetric method. The methane adsorption data were fitted to the Langmuir model. It was observed that there was, in general, a positive correlation between the methane adsorption capacity and the SBET of coals while a negative correlation between methane saturated adsorption capacity and the Ototal/Ctotal. The methane adsorption capacity was determined by the coal surface chemistry when the microporosity parameters of two samples were similar. Coal with a higher amount of oxygen surface groups, and consequently with a less hydrophobic character, had lower methane adsorption capacity.

Molecular simulation of methane adsorption in slit-like quartz pores

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 110808-110819 ◽  
Author(s):  
Jian Xiong ◽  
Kai Liu ◽  
Xiangjun Liu ◽  
Lixi Liang ◽  
Qun Zeng
Keyword(s):  
Structural Properties ◽  
Molecular Simulation ◽  
Methane Adsorption ◽  
Adsorption Behaviors

The GCMC and MD methods were used to investigate the structural properties and adsorption behaviors of methane in quartz nanopores.

Adsorption of methanol, methanal, toluene, ethylbenzene, and styrene in zeolites: a grand canonical Monte Carlo simulation study

2017 ◽  
Vol 95 (12) ◽  
pp. 1241-1247
Author(s):  
Fei Zhao ◽  
XiShang Sun ◽  
Ruifeng Lu ◽  
Lihua Kang
Keyword(s):  
Monte Carlo ◽  
Adsorption Capacity ◽  
Molecular Structures ◽  
Grand Canonical Monte Carlo ◽  
Monte Carlo Simulation Study ◽  
Binary Component ◽  
Adsorption Behaviors ◽  
Increasing Temperature ◽  
Grand Canonical ◽  
Component Adsorption

In this study, the adsorption behaviors of methanol, methanal, toluene, ethylbenzene, and styrene molecules in FAU, FER, CON, and MWW zeolites were investigated. The adsorption isotherms of the five adsorbates in the four zeolites at 298 and 350 K were simulated using grand canonical Monte Carlo simulations. Moreover, binary component adsorptions were considered. The results revealed that the saturated adsorption capacity of single components in different zeolites decreased in the order of FAU > MWW > CON > FER, and the adsorption capacity of the five adsorbates in the same zeolite decreased in the order of methanal > methanol > toluene > styrene > ethylbenzene. The equilibrium adsorption capacity slightly decreased with increasing temperature. In terms of binary component adsorption, intense competition existed between the smaller adsorbed molecules. As the differences among the molecular structures increased, the competition in adsorption became more intense.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

Molecular architecture and functions of the neuronal cytoskeleton

1990 ◽  
Vol 48 (3) ◽  
pp. 2-3
Author(s):  
Nobutaka Hirokawa
Keyword(s):  
Major Elements ◽  
Molecular Structures ◽  
Organelle Transport ◽  
Molecular Architecture ◽  
Neuronal Morphogenesis ◽  
Microtubule Associated Proteins ◽  
Associated Proteins ◽  
And Function ◽  
Small Clusters

In this symposium I will present our studies about the molecular architecture and function of the cytomatrix of the nerve cells. The nerve cell is a highly polarized cell composed of highly branched dendrites, cell body, and a single long axon along the direction of the impulse propagation. Each part of the neuron takes characteristic shapes for which the cytoskeleton provides the framework. The neuronal cytoskeletons play important roles on neuronal morphogenesis, organelle transport and the synaptic transmission. In the axon neurofilaments (NF) form dense arrays, while microtubules (MT) are arranged as small clusters among the NFs. On the other hand, MTs are distributed uniformly, whereas NFs tend to run solitarily or form small fascicles in the dendrites Quick freeze deep etch electron microscopy revealed various kinds of strands among MTs, NFs and membranous organelles (MO). These structures form major elements of the cytomatrix in the neuron. To investigate molecular nature and function of these filaments first we studied molecular structures of microtubule associated proteins (MAP1A, MAP1B, MAP2, MAP2C and tau), and microtubules reconstituted from MAPs and tubulin in vitro. These MAPs were all fibrous molecules with different length and formed arm like projections from the microtubule surface.

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