An ultra-thin piezoelectric nanogenerator with breathable,superhydrophobic,and antibacterial properties for human motion monitoring

Piezoelectric nanogenerators(PENGs)are promising for harvesting renewable and abundant mechanical energy with high efficiency.Up to now,published research studies have mainly focused on increasing the sensitivity and output of PENGs.The technical challenges in relation to practicability,comfort,and antibacterial performance,which are critically important for wearable applications,have not been well addressed.To overcome the limitations,we developed an all-nanofiber PENG(ANF-PENG)with a sandwich structure,in which the middle poly(vinylidene fluoride-co-hexafluoropropylene(P(VDF-HFP))/ZnO electrospun nanofibers serve as the piezoelectric layer,and the above and below electrostatic direct-writing P(VDF-HFP)/ZnO nanofiber membranes with a 110 nm Ag layer on one side that was plated by vacuum coating technique serve as the electrode layer.As the ANF-PENG only has 91μm thick and does not need further encapsulating,it has a high air permeability of 24.97 mm/s.ZnO nanoparticles in ANF-PENG not only improve the piezoelectric output,but also have antibacterial function(over 98%).The multifunctional ANF-PENG demonstrates good sensitivity to human motion and can harvest mechanical energy,indicating great potential applications in flexible self-powered electronic wearables and body health monitoring.

Quantifying and mapping spatial variability of Shanghai household carbon footprints

Understanding the spatial variability of house- hold carbon emissions is necessary for formulating sustainable and low-carbon energy policy. However, data on household carbon emissions is limited in China, the world＇s largest greenhouse gases emitter. This study quantifies and maps household carbon emissions in Shanghai using a city-wide household survey. The findings reveal substantial spatial variability in household carbon emissions, especially in transport-related emissions. Low emission clusters are founded in Hongkou, Xuhui, Luwan, Jinshan, and Fengxian. High emission clusters are located in Jiading and Pudong. Overall, the spatial pattern of household carbon emissions in Shanghai is donut-shaped： lowest in the urban core, increasing in the surrounding suburban areas, and declining again in the urban fringe and rural regions. The household emissions are correlated with a number of housing and socioeconomic factors, including car ownership, type of dwelling, size of dwelling, age of dwelling, and income. The findings underscore the importance of a localized approach to low-carbon policy- making and implementation.

Effects of mycorrhizal fungus Mycena sp. on the growth and poly-saccharide properties of Dendrobium officinale

Dear Editor,Dendrobium officinale Kimura et Migo（Orchidaceae）,an endangered species,is a medicinal plant and the sole origin plant of Dendrobii Officinalis Caulis（Tiepishihu）,a rare Chinese herbal medicine.Several photosynthetic orchids

Carbon nanotube promotes contraction and electrical activity of neonatal cardiomyocytes by targeting sodium/calcium exchanger NCX1

Dear Editor,The conductive nanomaterials,such as carbon nanotubes(CNTs),have attracted much attention in biomedical applications.Particularly,it has been found that CNTs can promote the electrical activity of cardiomyocytes,but little is known about the mechanism.^(1,2)To better understand the CNTs’biological effects on cardiomyocytes and the underlying mechanism.