Surface ligand-mediated isolated growth of Pt on Pd nanocubes for enhanced hydrogen evolution activity

2015 ◽  
Vol 3 (47) ◽  
pp. 23660-23663 ◽  
Author(s):  
Fumin Ren ◽  
Haiyuan Lu ◽  
Haotian Liu ◽  
Zheng Wang ◽  
Yuen Wu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Diffusion Rate ◽  
Growth Mode ◽  
Island Growth ◽  
Mode Structure ◽  
High Diffusion ◽  
High Diffusion Rate ◽  
Layered Growth ◽  
Surface Ligand ◽  
Free Area

Br− ions can affect the growth mode of Pt on a Pd substrate. When Br− ions adsorb on some sites of the Pd cube, the newly formed Pt atoms tended to grow on the Br− free area, facilitating island growth mode. Otherwise, without Br− ions, because of the relatively high diffusion rate between Pt and Pd, Pt atoms can epitaxially deposit on the whole surface of the Pd nanocubes, forming a layered growth mode structure.

scholarly journals Improved impregnation efficiency and pulp yield of softwood kraft pulp by high effective alkali charge in the impregnation stage

Holzforschung ◽  
2016 ◽  
Vol 70 (11) ◽  
pp. 1031-1037 ◽  
Author(s):  
Elisabet Brännvall ◽  
Marie Bäckström
Keyword(s):  
Kraft Pulp ◽  
Yield Loss ◽  
Diffusion Rate ◽  
Pulp Yield ◽  
Yield Increase ◽  
High Diffusion ◽  
High Diffusion Rate ◽  
Rapid Loading ◽  
Softwood Kraft Pulp

Abstract A pulp yield increase up to 2% can be achieved by impregnation with a liquor containing 2 M effective alkali (EA) concentration instead of 1 M. The yield increase is due to higher cellulose and glucomannan contents in the pulp, which can be rationalized by less yield loss by peeling, as impregnation is more effective at an elevated EA level. A rapid loading of chips with alkali can be realized due to a high diffusion rate. When the temperature becomes higher in the cooking stage, enough alkali is available for delignification reactions without the risk of alkali depletion in the chip core, so that the delignification is more homogeneous.

Nitrogen-Doped Graphene Nanoscroll Foam with High Diffusion Rate and Binding Affinity for Removal of Organic Pollutants

Small ◽  
2017 ◽  
Vol 13 (14) ◽  
pp. 1603779 ◽  
Author(s):  
Qile Fang ◽  
Xufeng Zhou ◽  
Wei Deng ◽  
Yuewen Liu ◽  
Zhi Zheng ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Organic Pollutants ◽  
Diffusion Rate ◽  
Nitrogen Doped ◽  
High Diffusion ◽  
High Diffusion Rate ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Osmotic Conductance of the Peritoneum in Capd Patients with Permanent Loss of Ultrafiltration Capacity

1996 ◽  
Vol 16 (5) ◽  
pp. 488-496 ◽  
Author(s):  
Jacek Waniewski ◽  
Olof Heimbürger ◽  
Andrzej Werynski ◽  
Bengt Lindholm
Keyword(s):  
Linear Relationship ◽  
Absorption Rate ◽  
Diffusion Rate ◽  
Solute Diffusion ◽  
Time Model ◽  
High Diffusion ◽  
High Diffusion Rate ◽  
Permanent Loss ◽  
The Difference ◽  
Dialysate Volume

Objective To compare the effectiveness of osmotic pressure in the induction of fluid flow during continuous ambulatory peritoneal dialysis (CAPD) in patients with permanent loss of ultrafiltration capacity (UFC) and clinically stable patients. Design Estimation of osmotic conductance in individual CAPD patients using data from single CAPD dwell studies. Patients Twenty clinically stable CAPD patients with normal ultrafiltration rate (NUR group); 8 CAPD patients with permanent UFC loss due to high diffusion rate for small solutes [high diffusion rate (HDR) group]; 3 CAPD patients with permanent loss of UFC dueto high absorption rate (HAR) of peritoneal dialysate (HAR group). Design Six-hour dwell studies were carried out in each patient using 2 L of Dianeal 3.86% dialysis fluid. Dialysate volume and the peritoneal absorption rate were measured using radioiodinated serum albumin as a marker. The dialysate volume over dwell-time curves were examined using three mathematical models of fluid transport for solutions with a crystalloid osmotic agent: model P, based on a phenomenologically derived exponential function of time; model OS, based on the linear relationship between the rate of net volume change (Qv) to the difference of osmolality in dialysate and blood; and model G, based on the linear relationship between Qv and the difference of glucose concentration in dialysate and blood. Results All three models provided an accurate description of the measured dialysate volume over time curves. The osmotic conductance, defined as the coefficient of proportionality between the rate of ultrafiltration and the osmolality (or, alternatively, glucose) gradient between dialysate and blood plasma, was 30% lower in the HDR group than in the NUR group, but close to the normal value in the HAR group. Conclusion In the HDR group the changes in the peritoneal membrane, which resulted in the increased diffusion rate of small solutes, also yielded a decrease of osmotic conductance. In contrast, the changes in the membrane in the HAR group, which resulted in increased peritoneal absorption, did not change the osmotic con ductance or the solute diffusion rate. The detailed pathophysiological mechanisms for these two different types of UFC loss failure are still unknown.

Oxygen-induced high diffusion rate of magnesium dopants in GaN/AlGaN based UV LED heterostructures

2018 ◽  
Vol 20 (20) ◽  
pp. 13890-13895 ◽  
Author(s):  
Paweł Piotr Michałowski ◽  
Sebastian Złotnik ◽  
Jakub Sitek ◽  
Krzysztof Rosiński ◽  
Mariusz Rudziński
Keyword(s):  
Diffusion Rate ◽  
Uv Led ◽  
High Diffusion ◽  
High Diffusion Rate

Oxygen breaks up Mg–H complexes and induces high diffusion of Mg in GaN/AlGaN heterostructures.

scholarly journals Initial Growth and Crystallization Onset of Plasma Enhanced-Atomic Layer Deposited ZnO

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 291
Author(s):  
Alberto Perrotta ◽  
Julian Pilz ◽  
Roland Resel ◽  
Oliver Werzer ◽  
Anna Maria Coclite
Keyword(s):  
Atomic Layer ◽  
Layer Growth ◽  
Growth Mode ◽  
Ex Situ ◽  
Native Oxide ◽  
Layer By Layer ◽  
Initial Growth ◽  
Island Growth ◽  
X Ray ◽  
Crystallization Onset

Direct plasma enhanced-atomic layer deposition (PE-ALD) is adopted for the growth of ZnO on c-Si with native oxide at room temperature. The initial stages of growth both in terms of thickness evolution and crystallization onset are followed ex-situ by a combination of spectroscopic ellipsometry and X-ray based techniques (diffraction, reflectivity, and fluorescence). Differently from the growth mode usually reported for thermal ALD ZnO (i.e., substrate-inhibited island growth), the effect of plasma surface activation resulted in a substrate-enhanced island growth. A transient region of accelerated island formation was found within the first 2 nm of deposition, resulting in the growth of amorphous ZnO as witnessed with grazing incidence X-ray diffraction. After the islands coalesced and a continuous layer formed, the first crystallites were found to grow, starting the layer-by-layer growth mode. High-temperature ALD ZnO layers were also investigated in terms of crystallization onset, showing that layers are amorphous up to a thickness of 3 nm, irrespective of the deposition temperature and growth orientation.

Cross-sectional Cathodoluminescence Study in Ga-polar and N-polar GaN Epilayers

2000 ◽  
Vol 639 ◽  
Author(s):  
X. L. Du ◽  
D. H. Lim ◽  
K. Xu ◽  
B. L. Liu ◽  
A. W. Jia ◽  
...  
Keyword(s):  
Defect Formation ◽  
Growth Mode ◽  
Ion Scattering ◽  
Island Growth ◽  
Cross Sectional ◽  
Ion Scattering Spectroscopy ◽  
Low Pressure Mocvd ◽  
The Difference ◽  
Film Substrate ◽  
2D And 3D

ABSTRACTHighly spatial resolved cross-sectional cathodoluminescence (CL) has been used to study the difference in the defect-formation and growth-mechanism between Ga-polar and N-polar GaN epitaxial layers. These epilayers were grown on sapphire substrates by low pressure MOCVD. Their polarities were controlled by the sapphire nitridation and the trimethylaluminum (TMAl) pre-flow just before the conventional two-step growth, and were confirmed with the coaxial impact collision ion scattering spectroscopy (CAICISS). For the Ga-polar GaN epilayers, cross-sectional CL images show distinct two layers, the upper layer with dark lines along c-direction and the layer close to the film-substrate interface with pyramidal dark regions. These two layers correspond to quasi 2D and 3D growth mode respectively. Whereas, the crosssectional CL image taken on the N-polar epilayers is predominated with small dark spots which were randomly distributed throughout the whole GaN epilayer, illustrating the predominant island growth mode in N-polar films.

Direct Observation of a New Growth Mode: Subsurface Island Growth of Cu on Pb(111)

1995 ◽  
Vol 75 (16) ◽  
pp. 2976-2979 ◽  
Author(s):  
C. Nagl ◽  
E. Platzgummer ◽  
M. Schmid ◽  
P. Varga ◽  
S. Speller ◽  
...  
Keyword(s):  
Direct Observation ◽  
Growth Mode ◽  
Island Growth
Sign in / Sign up

Export Citation Format

Share Document