Enhancing electrochemical performance of SnO_(2) anode with humic acid modification

Humic acid(HA)was studied as a modifier in the SnO_(2) anode preparation for the electrochemical performance improvement.Scanning electron microscopy,180°peel test,and nanoindentation experiment were used to examine the influence of the HA on electrode.The results showed that the addition of HA could improve the dispersion uniformity of all particles.The components were tightened,increasing the difficulty of peeling off the film from the current collector.The deformation resistance of the electrode was greatly enhanced by the HA modification.The electrochemical test results showed that the anode from the normal micron-sized SnO_(2)particles with the HA modifier exhibited significant progress in electrochemical performance compared with those without HA.The reversible specific capacity of the SnO_(2) anode can be maintained as high as 733.4 mA·h/g at a current density of 100 mA/g after 50 cycles.Therefore,HA is a promising modifier for anode preparation of lithium-ion batteries.

Hydrothermal synthesis and electrochemical sensing properties of copper vanadate nanocrystals with controlled morphologies

Morphology-controlled synthesis of copper vanadate nanocrystals is of great significance in electrochemical sensing applications.A facile hydrothermal process for synthesizing copper vanadate nanocrystals with various morphologies(e.g.,nanoparticles,nanobelts and nanoflowers)was reported.Phase,morphology and electrochemical performance of the as-synthesized copper vanadate nanocrystals were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM)and cyclic-voltammogram(CV)techniques.The results revealed that the morphologies of the Cu3V2O7(OH)2·2H2O(CVOH)nanocrystals could be controlled by changing copper salts,surfactants and pH values.The CVOH samples showed enhanced electrochemical response to ascorbic acid.Comparatively,the CVOH nanobelts had the higher electrochemical sensing performance than those of CVOH nanoparticles and nanoflowers.The CVOH-nanobelts-modified GCEs had a linear relationship between the peak currents in their CVs and ascorbic acid concentration.The CVOH nanocrystals can be used as potential electrochemical active materials for the determination of ascorbic acid.

Demographic Genetic Structure of Cryptomeria japonica var. sinensis in Tianmushan Nature Reserve, China

Genetic changes over space and time provide insights into the relative roles of evolutionary factors in shaping genetic patterns within plant populations. However, compared with spatial genetic structure, few studies have been conducted on genetic changes over time. In this study, we used six polymorphic microsatellite loci to assess genetic variation of six size-classes of the population of Liushan, Cryptomeriajaponica var. sinensis, in the Tianmushan National Nature Reserve, whose origin was debatable. The mean number of alleles per locus and expected heterozygosity were 4.583 and 0.5999 respectively, lower than other conifers with the same life history characteristics. FST was 0.0024-0.003, and the pairwise test revealed no significant differentiation in any pair of size classes. Significant heterozygosity excesses were detected in five size classes except the oldest one, indicating bottleneck event（s）. The above results support the hypothesis that Tianmushan population was introduced and followed by natural regeneration.