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High-strength metallic materials with low hydrogen embrittlement (HE) susceptibility have always been regarded as ideal commercial materials in the hydrogen energy field. This work proposed a low-cost laminated metal composite (LMC-CS) consisting of austenitic stainless steel (ASS) layer and martensitic steel (MART) layer, which simultaneously achieved high mechanical strength with excellent HE resistance. The ASS layers provide additional strain-hardening capability and the MART layer contributes high strength to LMC-CS after H-charging. Additionally, the composite interface displays semi-coherent characteristics, and the atomic arrangement on both sides follows the Kurdjumov-Sachs orientation relationship with (11¯0)α-Fe // (1¯11¯)γ-Fe and [111]α-Fe // [110]γ-Fe and the Nishiyama–Wassermann orientation relationship with (1¯1¯0)α-Fe // (1¯11)γ-Fe and [001]α-Fe // [011¯]γ-Fe., which coordinates deformation between layers and hinders hydrogen-induced cracks initiation at the interface. The as-designed LMC-CS achieves an ultimate tensile strength of 1102 MPa and an elongation loss of 14.8% after long-time hydrogen charging with sides sealed, outperforming a wide range of metallic materials. This work provides a fresh perspective on developing commercial materials with high strength and superior HE resistance for application in severe hydrogen environments.

Sintered metal fiber sheets (MFSs) made by sequential-overlap method are transversely isotropic open-cell cellular materials with paper-like fiber network architectures, which exhibit auxeticity and are promising for various potential applications due to the reentrant micro-structure. The thickness effect on the out-of-plane auxeticity (negative Poisson's ratio) of MFSs samples of 2–20 mm thick subjected to in-plane tensile loading is investigated with digital image correlation technique. Furthermore, the deformation modes of fibers within MFSs during various loading stages are examined with X-ray tomography. It is found that in addition to the straightening of reentrant fibers, fiber layers with defects and joints failure induced slippage between adjacent layers leads to local shear and results in unique umbrella-like local deformation termed umbrella effect, which gradually dominates the auxeticity during tensile loading. Although remarkably increasing lateral deformation, the umbrella effect significantly diminishes the in-plane mechanical performance such as rigidity and strength. In particular, this effect is suppressed by sample thickness: the overall performance tends to stabilize with sample thickness greater than a certain value, provided that the MFS is uniform with all fibers randomly distributed. The finding facilitates wider application of auxetic MFSs with further understanding on the relationship between the thickness effect and performance. Keywords: Metal fiber network, Auxetic behavior, Micro-structure, Size effect

Impurity transport in the scrape-off layer (SOL) has been studied in ohmically heated discharges of the HL-2A tokamak based on space-resolved vacuum ultraviolet spectroscopy. The vertical profile (from the plasma center to the lower X-point) of carbon emissions of CIII (977 Å: 2s2 1S0-2s2p ) and CIV (1548 Å: 2s 2S-2p 2P) as well as the ratio of CIV to CIII were measured to investigate the edge impurity transport with relation to impurity source locations and sputtering characteristics. The experimental result shows that the impurity profile in the SOL has been clearly changed against different source locations. The emission of CIII and CIV from the mid-plane is stronger than that from the X-point when the impurity source is located at the divertor plate. The profile becomes flat as a result. When the impurity source changes to the dome source, the profile clearly changes to a slightly peaked one, indicating the edge carbon emission at the X-point is stronger than the mid-plane. The change to the limiter source makes the profile further peaked by increasing the carbon emission at the X-point. In the case of the dome impurity source, the intensity of CIII/ne and CIV/ne, normalized to line-averaged electron density, ne, decreases with ne at low ne (ne  ⩽  2.6   ×   1019 m−3) and becomes saturated at high ne (ne  >  2.6   ×   1019 m−3). In contrast, the ratio of CIV to CIII increases with ne at low ne and starts to decrease at high ne. A numerical simulation with 3D edge plasma transport code, EMC3-EIRENE, suggests that a poloidal asymmetry in the impurity flow profile and an enhanced physical sputtering play an important role in the edge impurity distribution, particularly in the screening efficiency of C2+ and C3+ ions in the SOL region of the HL-2A tokamak. [ABSTRACT FROM AUTHOR]

Background: Insufficient data on the rate and distribution of SARS-CoV-2 infection in Canada has presented a substantial challenge to the public health response to the COVID-19 pandemic. Our objective was to assess SARS-CoV-2 seroprevalence in a representative sample of pregnant people throughout Canada, across multiple time points over 2 years of the pandemic, to describe the seroprevalence and show the ability of this process to provide prevalence estimates., Methods: This Canadian retrospective serological surveillance study used existing serological prenatal samples across 10 provinces over multiple time periods: Feb. 3-21, 2020; Aug. 24-Sept. 11, 2020; Nov. 16-Dec. 4, 2020; Nov. 15-Dec. 3, 2021; and results from the province of British Columbia during a period in which the SARS-CoV-2 B.1.1.529 (Omicron) variant was predominant, from Nov. 15, 2021, to June 11, 2022. Age and postal code administrative data allowed for comparison with concurrent polymerase chain reactivity (PCR)-positive results collected by Statistics Canada and the Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID-Preg) project., Results: Seropositivity in antenatal serum as early as February 2020 indicates SARS-CoV-2 transmission before the World Health Organization's declaration of the pandemic. Seroprevalence in our sample of pregnant people was 1.84 to 8.90 times higher than the recorded concurrent PCR-positive prevalence recorded among females aged 20-49 years in November-December 2020. Overall seropositivity in our sample of pregnant people was low at the end of 2020, increasing to 15% in 1 province by the end of 2021. Seroprevalence among pregnant people in BC during the Omicron period increased from 5.8% to 43% from November 2021 to June 2022., Interpretation: These results indicate widespread vulnerability to SARS-CoV-2 infection before vaccine availability in Canada. During the time periods sampled, public health tracking systems were under-reporting infections, and seroprevalence results during the Omicron period indicate extensive community spread of SARS-CoV-2 infection., Competing Interests: Competing interests: Lori Beach reports receiving funding from the Public Health Agency of Canada (PHAC) and from the Canadian Diagnostic Executive Forum, Toronto, for support for travel to speak at a meeting. Dr. Beach is also division head of Public Outreach and Communications for the Canadian Society of Clinical Chemists. Shelly Bolotin reports receiving support for the present manuscript from COVID-19 Immunity Task Force and Public Health Ontario. Dr. Bolotin is co-investigator on several COVID-19 grants funded by the Canadian Institutes of Health Research (CIHR), the Canadian Immunity Taskforce, the Canadian Immunization Research Network and PHAC. Dr. Bolotin is associate professor at the University of Toronto and, as part of that role, is director of the centre for Vaccine Preventable Diseases at the university. The centre is supported by the Dalla Lana School of Public Health (DLSPH), which receives funding from government, philanthropic, not-for-profit and private-sector organizations. Private-sector funding sources include vaccine manufacturers, specifically Merck, Sanofi and Pfizer. A set of governance processes are in place at the DLSPH to ensure independent operation of the centre. Isabelle Boucoiran reports receiving grants or contracts from Altona, the National Institutes of Health, CIHR and the Québec Ministère de la Santé et des Services Sociaux, and consulting fees from Pfizer. Dr. Boucoiran has also received equipment, materials, drugs, medical writing, gifts or other services from Altona. Mel Krajden reports receiving reagent support from Siemens to assess SARS-CoV-2 serology and had a contract with Hologic to support respiratory virus testing. Vanessa Poliquin reports receiving grants or contracts from GSK as the site principal investigator for a respiratory syncytial virus vaccine study. Dr. Poloquin has received an honorarium from Sanofi Pasteur for teaching at a continuing medical education event and payment for expert testimony from the Department of Justice Canada. George Zahariadis reports receiving support for the current manuscript from the Public Health Agency of Canada, as well as grants or contracts from Genome Atlantic and CIHR. Dr. Zahariadis also reports receiving unrestricted educational funding from Roche and Abbott to the Eastern Health Regional Health Authority to attend virtual meetings and in specific restricted circumstances, travel to educational, technical and research meetings. Dr. Zahariadis is the past president of the National Molecular Users Group. Jason Robinson reports receiving a Roche Ideas Grant including in-kind reagents for previous work on salivary antibody detection. Vanessa Tran reports receiving grants from CIHR, the COVID-19 Immunity Task Force, Canadian Immunization Research Network and PHAC, outside the submitted work. Dr. Tran is also a member of Canadian Immunization Research Network Management Committee and the COVID-19 Immunity Task Force Leadership Group. Deborah Money reports receiving support for the present manuscript from PHAC, paid to the institution on behalf of the COVID-19 Immunity Task Force. Dr. Money has also received past funding for unrelated work from Merck, GSK, Sanofi and Novartis, paid to the institution. No other competing interests were declared., (© 2023 CMA Impact Inc. or its licensors.)