The China Spallation Neutron Source started delivering neutron beams to users in March 2018. To upgrade the beam power to 500 kW and improve the performance of the ion source, an RF-driven negative hydrogen (H) ion source is under development. The source has a silicon nitride ceramic plasma chamber surrounded by a 4.5-turn antenna. The plasma is ignited by a pulsed DC spark gap and then driven by a 2 MHz solid-state amplifier with a repetition rate of 25 Hz. The commissioning of the source started in January 2019. When uncesiated, it produced about 20 mA beam at an RF power of 32 kW and pulse width of 450 μs. This paper describes the configuration of the ion source, several peculiar technologies used in it, and the first negative hydrogen (H) ion beam extraction.
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http://dx.doi.org/10.1063/1.5128553 | DOI Listing |
Environ Pollut
January 2025
Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, PR China. Electronic address:
Antibiotic resistance genes (ARGs) have escalated to levels of concern worldwide as emerging environmental pollutants. Increasing evidence suggests that non-antibiotic antimicrobial substances expedite the spread of ARGs. However, the drivers and mechanisms involved in the generation and spread of ARGs in the atmosphere remain inadequately elucidated.
View Article and Find Full Text PDFSci Total Environ
January 2025
Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangzhou, 510000, China.
OH-mediated advanced oxidation processes (AOPs) are widely used in wastewater treatment and drinking water purification. Recently, an increasing number of studies have indicated that common inorganic nitrogen ions can efficiently generate •OH under UV irradiation, demonstrating strong performance in the degradation of various contaminants. Conversely, the presence of inorganic nitrogen ions in UV or other oxidation processes dramatically increases the yield of toxic nitro (so)-aromatic products and the formation potential of nitrogenous disinfection by-products with high genotoxicity and cytotoxicity.
View Article and Find Full Text PDFJ Pharm Biomed Anal
January 2025
Key Laboratory of Forensic Medicine, Ministry of Justice, Shanghai Forensic Service Platform, Shanghai Key Laboratory of Forensic Science, Academy of Forensic Science, Guangfu West Road 1347, Shanghai 200063, China. Electronic address:
Etomidate and its structural analogues, which have anesthetic effects, are classified as controlled psychotropic drugs. Electronic cigarettes (e-cigarettes) have become more and more popular. With the increase of adding etomidate and its analogues to electronic liquids (e-liquids), there is a trend of abuse, which is a tough problem urgently need to be solved.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
January 2025
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China; Jiangxi Province Key Laboratory of Additive Manufacturing of Implantable Medical Device, Jiangxi University of Science and Technology, Nanchang 330013, China. Electronic address:
Electrical stimulation displayed tremendous potential in promoting nerve regeneration. However, the current electrical stimulation therapy required complex traversing wires and external power sources, which significantly limited its practical application. Herein, a self-powered nerve scaffold based on primary battery principle was gradient printed by laser additive manufacturing technique.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, China University of Geosciences, Wuhan 430074, China.
Groundwater faces a pervasive threat from anthropogenic nitrate contamination worldwide, particularly in regions characterized by intensive agricultural practices. This study examines groundwater quality in the Nansi Lake Basin (NSLB), emphasizing nitrate (NO-N) contamination. Utilizing 422 groundwater samples, it investigates hydrochemical dynamics and the impact of land use on groundwater composition.
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