Flächenwirkung: Der Photoabbau von Rhodamin B an α‐Fe2O3 in Gegenwart von H2O2 durch sichtbares Licht wurde untersucht (siehe Bild; von links nach rechts: 1D‐Nanostäbe, 2D‐Nanoplättchen, ...3D‐Nanowürfel). Eine Beziehung zwischen den exponierten Flächen von α‐Fe2O3‐Strukturen und ihrer Photoreaktivität gemäß {110}>{012}≫{001} wurde gefunden.
Since the discovery of carbon nanotubes in 1991 1, they have been regarded as ideal materials for use in nanoscale devices because of their small diameter 2, fascinating electronic properties 3, ...incredible mechanical strength 4 and elasticity 5. For the application of single-walled carbon nanotubes (SWNTs) in nanoscale devices, it is highly desirable to modify nanotubes in specific positions, especially in an individual tube. Although many efforts have been made to fabricate SWNT-based nanostructures either by post-synthesis manipulation 6 or by controlled growth formation 7, it still remains a great challenge for scientists to find an effective way to modify or transform nanotubes at expected locations. We demonstrate here an in-situ observation of the structural transformations, such as, amorphism, cutting, and welding of the SWNTs under electron beam irradiation in TEM. The results indicate that SWNTs with defects, such as dangling bonds, vacancies, interstitials, pentagon-heptagon pair defects etc., tend to show preferential transformation compared to tubes without defects. Clearly such electron beam fabrication technique might be a useful method to modify the structure of carbon nanotubes.
Herein we reported a simple way to enrich the large-diameter single-walled carbon nanotubes (SWNTs) by using a mixed concentrated H2SO4/HNO3 treatment. The proportion of the SWNTs with diameter ...larger than 2 nm measured from transmission electron microscopy was only ca. 3% in the original sample prepared by chemical vapor deposition method. It is found that this proportion becomes remarkably increased with treatment time and reached ca. 20% after 96 h of acid treatment.
We report here a single molecular approach using chaperone-like molecular modulators for modulating the aggregation behavior of a vital analogue of beta-amyloid peptide (Abeta) by using scanning ...tunneling microscopy. The molecular structures of the beta-sheets for Abeta33-42 peptide are revealed, which are keen to the aggregation of Abeta42 relating to Alzheimer's disease. It was identified that the introduction of chaperone-like modulators could regulate the assembling behavior of the peptide at molecular level. Furthermore, the modulators could also significantly accelerate the aggregation of the peptide in aqueous solution as revealed by light scattering studies. These observations of the molecular modulator effect in peptide assemblies could provide a novel approach toward modulating Abeta peptide aggregations.
Sharp-featured Au@Ag core/shell nanocuboids were synthesized. Simulation and experimental results demonstrated that the sharp features and in-cuboid, out-of-cuboid LSPR coupling of the nanocuboids ...enabled high SERS activities. The ultrasensitive detection of single-point mutations of TDP-43 proteins was demonstrated at 10 pM for the first time. This could be a general strategy for single-point mutation detection in proteins.
Sharp-featured Au@Ag core/shell nanocuboids were synthesized.
The strongly induced circular dichroism (ICD) signals of DNA wrapped around single-walled carbon nanotubes (SWCNTs) are shown by the Synchrotron Radiation Facility. In solution, trace amounts of Hg ...ions have a strong affinity to bind the nucleic bases of DNA-SWCNTs via a pseudo-first-order kinetic reaction. The Hg binding to the bases of DNA results in partial DNA disassociation from the SWCNTs. Such disassociation of DNA from the SWCNTs will decrease the coupling effects of the transition dipole moments between DNA and SWCNTs, thus inducing the ICD signal of DNA-SWCNTs to decrease significantly. Herein, the ICD of DNA-SWCNTs is applied to detect the concentration of Hg ions at nM level.
In 2009, terrestrial ecosystems in China were hit by a series of droughts in different seasons. However, the degree at which net primary productivity (NPP) of terrestrial ecosystems was affected in ...China is not clear yet. In this study, the remote sensing driven process-based Boreal Ecosystem Productivity Simulator (BEPS) model was used to estimate NPP decrease in China's terrestrial ecosystems caused by the abnormal droughts in 2009. The results show that the BEPS model is able to estimate gross primary productivity (GPP) and NPP of China's terrestrial ecosystems reliably. Estimated GPP and NPP show similar spatial patterns, decreasing from east to west and from south to north. In 2009, annual NPP was lower than the averages over the period from 2000 to 2010 in most regions of China, especially in areas of southern China. The decrease of annual NPP in 2009 over southeast Tibet and southeast coastal areas was even more than 100 g C m −2 yr −1 . The annual total NPP of Hunan and Yunnan provinces, Guangxi and Tibet autonomous regions in 2009 decreased by 4% to 6% of multi-year means, owing to the impact of consecutive drought from summer to winter in these areas. The national total of NPP in this year decreased about 35.5 Tg C yr −1 , approximately equivalent to 1% of annual total NPP in China's terrestrial ecosystems averaged during the period from 2000 to 2010.
Reported values (0.2 MPa ~ 7.0 GPa) of the interlayer shear strength (ISS) of graphite are very dispersed. The main challenge to obtain a reliable value of ISS is the lack of precise experimental ...methods. Here we present a novel experimental approach to measure the ISS, and obtain the value as 0.14 GPa. Our result can serve as an important basis for understanding mechanical behavior of graphite or graphene-based materials.
