Selective Synthesis of Different-Sized Gold Nanoclusters through HCI-Etching and-Growth Effect

Controllable syntheses of different-sized gold nanoclusters are of great significance for their fundamental science and practical applications. In this work, we achieve the controllable and selective syntheses of Au7 and Au13 clusters through adding HCl to the traditional Aull synthetic route at different reaction time. Time-dependent mass spectra and UV- Vis spectra were ernployed to monitor these two HCl-directed processes, and revealed the distinct roles of HCl as an etchant or a growth prornotor, respectively. Furthermore, parallel experiments on independent synthetic routes involving only non-chlorine H＋ （acetic acid） or Cl （tetraethy larnrnoniurn chloride） instead of HCl were perforrned, which illustrated the main role of H^＋-etching and Cl^ -assisted growth in HCl-directed cluster synthetic routes. We propose the HCl-etching is mainly achieved via the H＋ action to break the Au（I）-PPh3 part of clusters, while the HCl-prornoted growth is realized via the attachment of Au-Cl species to the pre-forrned clusters.

Biological Effects of Low Energy Ar^+Ion Bombardment on Silkworm Eggs:a Novel Animal Model

In this study, we found for the first time that silkworm eggs were able to survive in vacuum for a long period of time. Subsequently, 10w energy Ar＋ ions with different energies and fluences were used to bombard silkworm eggs so as to explore the resulting biological effects. Results showed that （i） the exposure of silkworm eggs to vacuum within 10 rain did not cause significant impact on the hatching rates, while the irradiation of silkworm eggs by Ar＋ ions of 25 keV or 30 keV with fiuences ranging from 2.6×2.6× 10^15 ion/cm2 to 8×2.6 × 10^15 ion/cm2 caused a significant impact on the hatching rates, and the hatching rates decreased with the increase in the fluence and energy level; （ii） the irradiation of silkworm eggs by Ar＋ ions of 30 keV with a fluence of 8×2.6 × 10^15 ion/cm2 or 9×2.6 × 10^15 ion/cm2 resulted in a noticeable etching on the egg shell surface which could be observed by a scanning electron microscope; and （iii） the irradiation of silkworm eggs by Ar＋ ions of generated several mutant phenotypes which were 30 keV with a fiuence of 9×2.6× 10^15 ion/cm2 observed in the 5th instar silkworms and a moth.

Selective Synthesis of Hexagonal Ag Nanoplates in a Solution-Phase Chemical Reduction Process

Two-dimensional(2-D)Ag nanoplates have surface plasmon resonances which can be tuned from the visible to the near-IR by varying the size and morphology of the nanoplates.Due to their anisotropic structures and different surface energy distributions,Ag nanoplates-especially triangular ones-are kinetically stable and can transform into other nanostructures.Taking advantage of the synergetic effects of HNO_(3)and Cl-in the reduction solution,uniform Ag hexagonal nanoplates(HNPs)have been captured during the transformation of Ag triangular nanoplates(TNPs).The dimensions of the Ag HNPs can be controlled by changing the concentrations of reagents in the reaction or/and reduction solutions.Resonance absorption spectra of the obtained Ag HNPs indicated that their in-plane resonance peaks could be tuned from the visible to the near-IR region,showing their potential applications in medical diagnosis.

Structural analysis of quarter-wave resonators in IMP

The taper-shaped superconducting quarter wave resonators with frequency of 80.5 MHz, β of 0.041 and 0.085 have been pre-researched. The radio frequency （RF） design of the cavities has been completed, and the structural design is also an important aspect which will be discussed in the following. The frequency shift caused by the etching effects of the surface treatment, the helium bath pressure and the Lorentz force, and the mechanical modes caused by the microphonic excitation have been anMyzed. The results show that the frequency variation from the Lorentz force is not serious and stiffening rings are explored aimed at decreasing the deformation brought by the helium pressure and microphonic excitation.