Ultrafast Coulomb explosion imaging of molecules and molecular clusters

Taking an image of their structure and a movie of their dynamics of small quantum systems have always been a dream of physicists and chemists. Laser-induced Coulomb explosion imaging(CEI) provides a great opportunity to make this dream a reality for small molecules or their aggregation — clusters. The method is unique for identifying the atomic locations with angstrom spatial resolution and capturing the structural evolution with a femtosecond time scale, in particular for imaging transient state products. This review summarizes the determination of three-dimensional equilibrium geometry of molecules and molecular cluster system through the reconstruction from the fragments momenta, and also shows that the dissociation dynamics on the complex potential energy surface can be tracked in real-time with the ultrafast CEI(UCEI).Furthermore, the detailed measurement and analysis procedures of the CEI, theoretical methods, exemplary results, and future perspectives of the technique are described.

Measuring Charge Distribution of Molecular Cations by an Atomic Coulomb Probe Microscope

Imaging the charge distributions and structures of molecules and clusters will promote the understanding of the dynamics of the quantum system.Here,we report a method by using an Ar atom as a tip to probe the charge distributions of benzene(Bz)cations in gas phase.Remarkably,the measured charge distributions of Bz^(+)(δ_(H)=0.204,δ_(C)=-0.037)and Bz^(2+)(δ_(H)=0.248,δ_(C)=0.0853)agree well with the calculated Mulliken distributions,and the structures of Bz2 is reconstructed by using the measured charge distributions.The structures of two Bz2isomers(T-shaped and PD isomers)can be resolved from the measured inter-molecular potential V(R)between two Bz ions,and the structures of Bz dimer agree well with the theoretical predictions.

Food-medicine can promote cross-culture communication between East and West

Since the 18th National Congress of the Communist Party of China(CPC),the CPC Central Committee with Comrade Xi Jinping at its core has set an action plan for the Construction of a Healthy China Program,insisting on putting people’s health in the strategic position of prioritizing development.As an important part of traditional Chinese medicine(TCM)culture in China,food-medicines,the stuff consumed both as food and medicine,are one of the material foundations to prevent and treat chronic diseases and manage health ahead of sick,and an important carrier for China to promote the Belt and Road Initiative(BRI)and participate in global health governance.To enrich the knowledge system of food-medicine through cross-cultural exchanges between the East and the West,and to promote the research progress of food-medicine are of critical importance in the context of the current global pandemic of COVID-19,since it is a profound understanding of the spirit of General Secretary Xi Jinping’s important speech and a practice of giving priority to people’s health in the strategic position of development,which helps to provide strong support for the comprehensive promotion of the Healthy China strategy and human well-being(Huang et al.,2022).