A coupled model for predicting thermophysical properties of saturated steam in dual-tubing SAGD horizontal wells with toe-point injection technique

In this paper, a coupled numerical model to simulate dual-tubing steam-assisted gravity drainage (SAGD) process with toe-point injection technique was developed, specially, a more rigorous approach was used to calculate the steam pressure. Based on the model, the distribution of thermophysical properties of steam along the wellbore is investigated. The results indicate that improving the annulus steam temperature uniformity in circulation stage and the annulus steam quality uniformity in production stage is the key to enhancing the reservoir heating uniformity. The influence of the heat transfer from the wellbore to the reservoir on reservoir heating is significant with a low steam injection rate, but the influence is weak with a high steam injection rate. The reservoir temperature nonuniformity is more likely to occur during production stage than during circulation stage, and more attention needs to be paid to optimizing the reservoir temperature uniformity during production stage. A “toe-good” heating effect can be observed with toe-point injection technique, and simultaneous dual-tubing injection technology is a suitable method for solving this problem. The findings of this study can help to better understand the relationship between the distribution of thermophysical properties of saturated steam along the wellbore and reservoir nonuniform heating.</p

The Core/Shell Composite Nanowires Produced by Self-Scrolling Carbon Nanotubes onto Copper Nanowires

We demonstrated a novel method to produce core/shell composite nanowires (NWs) by self-scrolling carbon nanotubes (CNTs) onto copper NWs via forced-field-based molecular dynamic (MD) simulations. When large diameter CNTs are placed beside the copper NWs, the CNTs approach the NWs, collapse, and self-scroll onto the NWs, resulting in coaxial core/shell composite NWs. It is found that the van der Waals force plays an important role in the formation of the composite NWs. The expected outcome of this novel method is to determine various strategies on how to produce composite NWs. Coaxial core/shell composite NWs represent an important class of nanoscale building blocks with substantial potential for exploring new concepts and functional materials

The Core/Shell Composite Nanowires Produced by Self-Scrolling Carbon Nanotubes onto Copper Nanowires

We demonstrated a novel method to produce core/shell composite nanowires (NWs) by self-scrolling carbon nanotubes (CNTs) onto copper NWs via forced-field-based molecular dynamic (MD) simulations. When large diameter CNTs are placed beside the copper NWs, the CNTs approach the NWs, collapse, and self-scroll onto the NWs, resulting in coaxial core/shell composite NWs. It is found that the van der Waals force plays an important role in the formation of the composite NWs. The expected outcome of this novel method is to determine various strategies on how to produce composite NWs. Coaxial core/shell composite NWs represent an important class of nanoscale building blocks with substantial potential for exploring new concepts and functional materials

NJB 1795

NJB 179

Chemical Modification: an Effective Way of Avoiding the Collapse of SWNTs on Al Surface Revealed by Molecular Dynamics Simulations

The rapid collapse of intrinsic single-walled carbon nanotube (SWNT) on the aluminum surface is observed using molecular dynamics simulation. The collapsing threshold is ∼10 Å, and the length has no influence on its collapse. Furthermore, we report that the structural stability of cylindrical SWNTs on the aluminum surface can be improved through the surface modification method. The stability of SWNTs can be enhanced by increasing the modification coverage. When the modification coverage exceeds 3.3% and 3.8% coverage, respectively, both amidogen- and carboxyl-modified SWNTs can basically maintain the cylindrical structure in our described systems. The results also show that, to avoid SWNTs collapse by chemical modification, the longer and larger SWNTs are, the more modification coverage SWNTs require, and vice versa. Our method allows potentially used modified SWNTs as nanocontainers for maintaining or transporting molecules, etc

Molecular Design and Photothermal Application of Thienoisoindigo Dyes with Aggregation-Induced Emission

Organic fluorescent dyes with aggregation-induced emission (AIE) property have an extensive application range, especially in the fields of imaging, labeling, and adjusting microprocesses in aggregated environments. In particular, the thienoisoindigo skeleton, which exhibits an outstanding electron-withdrawing capacity in optoelectronic materials, has been defined as a promising AIE candidate. For instance, by installing AIE blocks or other rotatable groups at two terminal sites, such as various arylamine groups, thienoisoindigo derivatives can be efficiently turned to be functional AIE structures. In this work, a thienoisoindigo derivative with AIE characteristics, namely, TII-TPE, was developed. This AIE system was expanded by linking typical AIE fragments, namely, tetraphenylethene, with the proposed thienoisoindigo derivative, which exhibited typical AIE fluorescence in the 600–850 nm range and maintained high photostability. Then, employing the reported derivative TII-TPA coating thienoisoindigo and triphenylamine as a contrast, aggregated TII-TPE and TII-TPA nanoparticles were prepared and demonstrated photothermal conversion efficiencies of 36.2 and 35.6%, respectively. Moreover, both nanoparticles were evaluated as photothermal therapeutic (PTT) agents in a tumor mouse model, which showed to significantly inhibit tumor growth after four treatment cycles in vivo. This work not only presents an enriched thienoisoindigo system but also provides a pattern for subsequent construction of functional AIE molecules

Chemical Modification: an Effective Way of Avoiding the Collapse of SWNTs on Al Surface Revealed by Molecular Dynamics Simulations

The rapid collapse of intrinsic single-walled carbon nanotube (SWNT) on the aluminum surface is observed using molecular dynamics simulation. The collapsing threshold is ∼10 Å, and the length has no influence on its collapse. Furthermore, we report that the structural stability of cylindrical SWNTs on the aluminum surface can be improved through the surface modification method. The stability of SWNTs can be enhanced by increasing the modification coverage. When the modification coverage exceeds 3.3% and 3.8% coverage, respectively, both amidogen- and carboxyl-modified SWNTs can basically maintain the cylindrical structure in our described systems. The results also show that, to avoid SWNTs collapse by chemical modification, the longer and larger SWNTs are, the more modification coverage SWNTs require, and vice versa. Our method allows potentially used modified SWNTs as nanocontainers for maintaining or transporting molecules, etc

Chemical Modification: an Effective Way of Avoiding the Collapse of SWNTs on Al Surface Revealed by Molecular Dynamics Simulations

The rapid collapse of intrinsic single-walled carbon nanotube (SWNT) on the aluminum surface is observed using molecular dynamics simulation. The collapsing threshold is ∼10 Å, and the length has no influence on its collapse. Furthermore, we report that the structural stability of cylindrical SWNTs on the aluminum surface can be improved through the surface modification method. The stability of SWNTs can be enhanced by increasing the modification coverage. When the modification coverage exceeds 3.3% and 3.8% coverage, respectively, both amidogen- and carboxyl-modified SWNTs can basically maintain the cylindrical structure in our described systems. The results also show that, to avoid SWNTs collapse by chemical modification, the longer and larger SWNTs are, the more modification coverage SWNTs require, and vice versa. Our method allows potentially used modified SWNTs as nanocontainers for maintaining or transporting molecules, etc

Chemical Modification: an Effective Way of Avoiding the Collapse of SWNTs on Al Surface Revealed by Molecular Dynamics Simulations

The rapid collapse of intrinsic single-walled carbon nanotube (SWNT) on the aluminum surface is observed using molecular dynamics simulation. The collapsing threshold is ∼10 Å, and the length has no influence on its collapse. Furthermore, we report that the structural stability of cylindrical SWNTs on the aluminum surface can be improved through the surface modification method. The stability of SWNTs can be enhanced by increasing the modification coverage. When the modification coverage exceeds 3.3% and 3.8% coverage, respectively, both amidogen- and carboxyl-modified SWNTs can basically maintain the cylindrical structure in our described systems. The results also show that, to avoid SWNTs collapse by chemical modification, the longer and larger SWNTs are, the more modification coverage SWNTs require, and vice versa. Our method allows potentially used modified SWNTs as nanocontainers for maintaining or transporting molecules, etc

The Core/Shell Composite Nanowires Produced by Self-Scrolling Carbon Nanotubes onto Copper Nanowires

We demonstrated a novel method to produce core/shell composite nanowires (NWs) by self-scrolling carbon nanotubes (CNTs) onto copper NWs via forced-field-based molecular dynamic (MD) simulations. When large diameter CNTs are placed beside the copper NWs, the CNTs approach the NWs, collapse, and self-scroll onto the NWs, resulting in coaxial core/shell composite NWs. It is found that the van der Waals force plays an important role in the formation of the composite NWs. The expected outcome of this novel method is to determine various strategies on how to produce composite NWs. Coaxial core/shell composite NWs represent an important class of nanoscale building blocks with substantial potential for exploring new concepts and functional materials