Structural and Kinetics Understanding of Support Effects in Pd-Catalyzed Semi-Hydrogenation of Acetylene

In this study,the support effects on the Pd-catalyzed semi-hydrogenation of acetylene have been investigated from the structural and kinetic perspectives.According to the results of kinetic analysis and X-ray photoelectron spectroscopy,hydrogen temperature-programmed reduction,temperature-programmed hydride decomposition,and in situ X-ray diffraction measurements,using carbon nanotubes as support for Pd nanocatalysts with various sizes instead of a-Al_(2)O_(3) decreases the Pd^(0)3d binding energy and suppresses the formation of undesirable palladium hydride species,thus increasing the ethylene yield.Furthermore,X-ray absorption spectroscopy,high-resolution transmission electron microscopy,and C_(2)H_(4) temperature-programmed desorption studies combined with density-functional theory calculations reveal the existence of a unique Pd local environment,containing subsurface carbon atoms,that produces positive geometric effects on the acetylene conversion reaction.Therefore,tailoring the Pd local environment and electronic properties represents an effective strategy for the fabrication and design of highly active and selective Pd semi-hydrogenation catalysts.

Characterization of lipid-based nanomedicines at the single-particle level

Lipid-based nanomedicines(LBNMs),including liposomes,lipid nanoparticles(LNPs)and extracellular vesicles(EVs),are recognized as one of the most clinically acceptable nano-formulations.However,the bench-to-bedside translation efficiency is far from satisfactory,mainly due to the lack of in-depth understanding of their physical and biochemical attributes at the single-particle level.In this review,we first give a brief introduction of LBNMs,highlighting some milestones and related scientific and clinical achievements in the past several decades,as well as the grand challenges in the characterization of LBNMs.Next,we present an overview of each category of LB-NMs as well as the core properties that largely dictate their biological characteristics and clinical performance,such as size distribution,particle concentration,morphology,drug encapsulation and surface properties.Then,the recent applications of several analytical techniques including electron microscopy,atomic force microscopy,fluorescence microscopy,Raman microscopy,nanoparticle tracking analysis,tunable resistive pulse sensing and flow cytometry on the single-particle characterization of LBNMs are thoroughly discussed.Particularly,the com-parative advantages of the newly developed nano-flow cytometry that enables quantitative analysis of both the physical and biochemical characteristics of LBNMs smaller than 40 nm with high throughput and statistical ro-bustness are emphasized.The overall aim of this review article is to illustrate the importance,challenges and achievements associated with single-particle characterization of LBNMs.

关于完善我国集成电路产业税收优惠政策的思考

集成电路产业是我国战略性新兴产业之一,通过税收优惠扶持该产业发展是国际上的普遍做法。本文简要阐述了我国集成电路产业的发展现状,分税种整理了我国现行的集成电路产业税收优惠政策,并分析了其存在的问题,在借鉴我国台湾地区、美国等集成电路产业发达国家(地区)先进经验的基础上,对完善我国大陆集成电路产业税收优惠政策提出建议。

Corrigendum to‘Characterization of lipid-based nanomedicines at the single-particle level’[Fundamental Research 3(2023)488-504]

The authors regret that the original version of this article unfortunately contained a mistake[1].It is stated that:“Based on TIRF,another strategy for resolution increase…However,this technique requires the chemical modification to immobilize an individual particle,which may in turn alter their physical and biochemical properties.”on page 494-495.This is incorrect and should be replaced by:“Another strategy for resolution increase…This technique doesn’t require the chemical modification to immobilize an individual particle,which avoids altering their physical and biochemical properties.”