Effect of Rare Earths on Microstructure and Properties of Sn2.0Ag0.7CuRE Solder Alloy for Surface Mount Technology

A new type of lead-free solder alloy Sn2.0Ag0.7CuRE was fabricated under vacuum condition. The microstructure and properties of the material, such as tensile strength, elongation, melting range, conductance and spreading area were all investigated. Result shows that when the content of RE ≤ 0.1% （mass fraction）, RE distribute uniformly in the solder alloy, and the tensile strength and conductance of Sn2.0Ag0.7CuRE solder alloy are better than those of traditional Sn37Pb solder. Its elongation and spreading area are almost equal to those of Sn37Pb solder. When the content of RE reaches 0.5%, RE compounds can be easily found around the boundaries of grains and phases, and the tensile strength and elongation and spreading area of Sn2.0Ag0.7CuRE solder alloy all decrease sharply. Therefore, RE amount added to the Sn2.0Ag0.7CuRE solder alloy under 0.1% is proper.

Review of Fiber-Optic Localized Surface Plasmon Resonance Sensors:Geometries,Fabrication Technologies,and Bio-Applications

Localized surface plasmon resonance(LSPR)biosensors,which enable nanoscale confinement and manipulation of light,offer the enhanced sensitivity and electromagnetic energy localization.The integration of LSPR with the fiber-optic technology has led to the development of compact and versatile sensors for miniaturization and remote sensing.This comprehensive review explores various sensor configurations,fiber types,and geometric shapes,highlighting their benefits in terms of sensitivity,integration,and performance improvement.Fabrication techniques such as focused non-chemical bonding strategies and self-assembly of nanoparticles are discussed,providing control over nanostructure morphology and enhancing sensor performance.Bio-applications of fiber-optic LSPR(FOLSPR)sensors are detailed,specifically in biomolecular interactions and analysis of proteins,pathogens and cells,nucleic acids(DNA and RNA),and other small molecules(organic compounds and heavy metal ions).Surface modification and detection schemes are emphasized for their potential for label-free and real-time biosensing.The challenges and prospects of FOLSPR sensors are addressed,including the developments in sensitivity,fabrication techniques,and measurement reliability.Integration with emerging technologies such as nanomaterials is highlighted as a promising direction for future research.Overall,this review provides insights into the advancements and potential applications of FOLSPR sensors,paving the way for sensitive and versatile optical biosensing platforms in various fields.

Wafer-scale engineering of two-dimensional transition metal dichalcogenides

Moore’s Law has been the driving force behind the semiconductor in-dustry for several decades,but as silicon-based transistors approach their physical limits,researchers are searching for new materials to sustain this exponential growth.Two-dimensional transition metal dichalcogenides(TMDs),with their atomically thin structure and en-ticing physical properties,have emerged as the most promising can-didates for downsizing and improving device integration.Embold-ened by the direction of achieving large-area and high-quality TMDs growth,wafer-scale TMDs growth strategies have been continuously developed,suggesting that TMDs are poised to become a new plat-form for next-generation electronic devices.In this review,advanced synthesis routes and inherent properties of wafer-scale TMDs were critically assessed.In addition,the performance in electronic devices was also discussed,providing an outlook on the opportunities and challenges that lie ahead in their development.

PLGA-based implants for sustained delivery of peptides/proteins:Current status,challenge and perspectives

Peptide and protein drugs with therapeutic effects suffer from their short half-life and low stability,albeit their high efficiency and specificity.To overcome these demerits,long-acting drug delivery systems have been developed,wherein poly(lactic-co-glycolic acid)(PLGA)implants are most preferred owing to their excellent biodegradability and biocompatibility.Dozens of PLGA based products have been approved since1986,when the first product,named Decapeptyl R,successfully marched into market.To meet the increasing demand for delivering various peptides and proteins,different kinds of technologies have been developed for lab-scale fabrication or industrial manufacture.This review aims to introduce recent advances of PLGA implants,and give a brief summary of fundamental properties of PLGA,fabrication technologies of peptides/proteins-loaded PLGA implants as well as factors influencing the drug release processes.Moreover,challenges and future perspectives are also highlighted.

Investigation on the fabrication of the 3rd harmonic superconducting cavity for the SSRF storage ring

A third harmonic superconducting niobium cavity has been proposed for installation in the Shanghai Synchrotron Radiation Facility （SSRF） storage ring to improve the Touschek lifetime. In order to investigate the feasibility of the superconducting cavity fabrication indigenously and the possibility to master the fabrica tion techniques, cavities were fabricated from copper and niobium sheets by deep drawing and electron-beam welding, and a series of measurements, such as resonant frequency, shape dimensions and wall thickness, were carried out during this process. After analysis of various problems existing in the fabrication process, technique improvements were proposed, and finally the precise shape as designed and resonant frequency within 1.2 MHz were achieved for the new completed cavities. In addition, full annealing was finally proved to be a good cure for niobium sheets＇ tearing up during deep drawing. By fabricating niobium cavities successfully, some problems to the next step were cleared. This paper introduces the process of cavity fabrication and its technique improvements towards forming, and the initial vertical test result of niobium cavity is also presented.