Computationally Directed Discovery of MoBi\u3csub\u3e2\u3c/sub\u3e

Incorporating bismuth, the heaviest element stable to radioactive decay, into new materials enables the creation of emergent properties such as permanent magnetism, superconductivity, and nontrivial topology. Understanding the factors that drive Bi reactivity is critical for the realization of these properties. Using pressure as a tunable synthetic vector, we can access unexplored regions of phase space to foster reactivity between elements that do not react under ambient conditions. Furthermore, combining computational and experimental methods for materials discovery at high-pressures provides broader insight into the thermodynamic landscape than can be achieved through experiment alone, informing our understanding of the dominant chemical factors governing structure formation. Herein, we report our combined computational and experimental exploration of the Mo–Bi system, for which no binary intermetallic structures were previously known. Using the ab initio random structure searching (AIRSS) approach, we identified multiple synthetic targets between 0–50 GPa. High-pressure in situ powder X-ray diffraction experiments performed in diamond anvil cells confirmed that Mo–Bi mixtures exhibit rich chemistry upon the application of pressure, including experimental realization of the computationally predicted CuAl2-type MoBi2 structure at 35.8(5) GPa. Electronic structure and phonon dispersion calculations on MoBi2 revealed a correlation between valence electron count and bonding in high-pressure transition metal–Bi structures as well as identified two dynamically stable ambient pressure polymorphs. Our study demonstrates the power of the combined computational–experimental approach in capturing high-pressure reactivity for efficient materials discovery

Seizing the window of opportunity to mitigate the impact of climate change on the health of Chinese residents

The health threats posed by climate change in China are increasing rapidly. Each province faces different health risks. Without a timely and adequate response, climate change will impact lives and livelihoods at an accelerated rate and even prevent the achievement of the Healthy and Beautiful China initiatives. The 2021 China Report of the Lancet Countdown on Health and Climate Change is the first annual update of China’s Report of the Lancet Countdown. It comprehensively assesses the impact of climate change on the health of Chinese households and the measures China has taken. Invited by the Lancet committee, Tsinghua University led the writing of the report and cooperated with 25 relevant institutions in and outside of China. The report includes 25 indicators within five major areas (climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement) and a policy brief. This 2021 China policy brief contains the most urgent and relevant indicators focusing on provincial data: The increasing health risks of climate change in China; mixed progress in responding to climate change. In 2020, the heatwave exposures per person in China increased by 4.51 d compared with the 1986–2005 average, resulting in an estimated 92% increase in heatwave-related deaths. The resulting economic cost of the estimated 14500 heatwave-related deaths in 2020 is US$176 million. Increased temperatures also caused a potential 31.5 billion h in lost work time in 2020, which is equivalent to 1.3% of the work hours of the total national workforce, with resulting economic losses estimated at 1.4% of China’s annual gross domestic product. For adaptation efforts, there has been steady progress in local adaptation planning and assessment in 2020, urban green space growth in 2020, and health emergency management in 2019. 12 of 30 provinces reported that they have completed, or were developing, provincial health adaptation plans. Urban green space, which is an important heat adaptation measure, has increased in 18 of 31 provinces in the past decade, and the capacity of China’s health emergency management increased in almost all provinces from 2018 to 2019. As a result of China’s persistent efforts to clean its energy structure and control air pollution, the premature deaths due to exposure to ambient particulate matter of 2.5 μm or less (PM2.5) and the resulting costs continue to decline. However, 98% of China’s cities still have annual average PM2.5 concentrations that are more than the WHO guideline standard of 10 μg/m3. It provides policymakers and the public with up-to-date information on China’s response to climate change and improvements in health outcomes and makes the following policy recommendations. (1) Promote systematic thinking in the related departments and strengthen multi-departmental cooperation. Sectors related to climate and development in China should incorporate health perspectives into their policymaking and actions, demonstrating WHO’s and President Xi Jinping’s so-called health-in-all-policies principle. (2) Include clear goals and timelines for climate-related health impact assessments and health adaptation plans at both the national and the regional levels in the National Climate Change Adaptation Strategy for 2035. (3) Strengthen China’s climate mitigation actions and ensure that health is included in China’s pathway to carbon neutrality. By promoting investments in zero-carbon technologies and reducing fossil fuel subsidies, the current rebounding trend in carbon emissions will be reversed and lead to a healthy, low-carbon future. (4) Increase awareness of the linkages between climate change and health at all levels. Health professionals, the academic community, and traditional and new media should raise the awareness of the public and policymakers on the important linkages between climate change and health.</p

The 2022 China report of the Lancet Countdown on health and climate change: leveraging climate actions for healthy ageing

A health-friendly, climate resilient, and carbon-neutral pathway would deliver major benefits to people's health and wellbeing in China, especially for older populations, while simultaneously promoting high-quality development in the long run. This report is the third China Lancet Countdown report, led by the Lancet Countdown Regional Centre based in Tsinghua University. With the contributions of 73 experts from 23 leading institutions, both within China and globally, this report tracks progress through 27 indicators in the following five domains: (1) climate change impacts, exposure, and vulnerability; (2) adaptation, planning, and resilience for health; (3) mitigation actions and health co-benefits; (4) economics and finance; and (5) public and political engagement. From 2021 to 2022, two new indicators have been added, and methods have been improved for many indicators. Specifically, one of the new indicators measures how heat affects the hours that are safe for outdoor exercise, an indicator of particular relevance given the boom in national sports triggered by the summer and winter Olympics. Findings in this report, which coincide with the UN Framework Convention on Climate Change 27th Conference of the Parties (COP27) hosted in Egypt (where much attention is being focused on adaptation for clinically vulnerable populations), expose the urgency for accelerated adaptation and mitigation efforts to minimise the health impacts of the increasing climate change hazards in China

Leveraging climate actions for healthy ageing

As China’s population ages rapidly, the health risks associated with a changing climate are becoming more threatening. The 2022 China report of the Lancet Countdown, led by Tsinghua University with the contributions of 73 experts from 23 leading global institutions, tracks progress in climate change and health in China through 27 indicators across five domains: (1) Climate change impacts, exposure, and vulnerability; (2) adaptation, planning, and resilience for health; (3) mitigation actions and health co-benefits; (4) economics and finance; and (5) public and political engagement. This report is the third China Lancet Countdown report, paying particular attention to the impacts on the elderly and highlighting the urgency of taking action. We selected the most urgent and relevant indicators to complete a policy brief that provides a better understanding of recent progress on climate change and health in China. We found heat-related health impacts increased from 2020 to 2021, increasing heat-related mortality, reducing labour capacity, and undermining the capacity to partake in physical activity due to rising temperature. In addition, exposure to wildfire, extreme drought, and extreme rainfall also increased in different regions across China. In 2021, compared with the 1986–2005 average, people in China had an average of 7.85 more heatwave days (which led to an extra 13185 heatwave-related deaths), and a loss of 0.67 more hours of safe outdoor physical exercise per day. The rising temperature also caused the annual average exposure to wildfire to increase by 60.0% between 2017–2021 compared with the 2001–2005 average. Meanwhile, the engagement on health and climate issues from individuals, scholars, and public sectors continues to grow rapidly. From 2020 to 2021, the number of climate-related articles and documents on the official websites of four Chinese Government departments grew by 1.83 times, and the number of climate-and-health-related articles and documents grew by 3.7 times. However, older populations received marginal attention on this issue in media coverage, although they are more vulnerable to the health threats of climate change than younger populations. In most provinces, people aged 65 years and older are facing higher health risks of climate change than the general population. In addition, we found that the inputs and attention to adaptation are still insufficient compared with the increasing health risks posed by climate change. Based on the findings, the following recommendations are made to protect climate change-related health risks: (1) Increasing adaptation across governmental departments and accelerating investment in climate resilience. Adaptation across governmental departments and investment in climate resilience must be substantially increased to protect the health of Chinese populations. (2) Developing a stand-alone Health National Climate Adaptation Plan. Leaders must strengthen the response of local efforts to national plans, for example, by establishing a nationwide heat and cold and health early warning system with regional characteristics. (3) Prioritise climate change in health policies, with a focus on the wellbeing of vulnerable populations. Leaders should include climate change health impact prevention and treatment as one of the key responsibilities of the new National Bureau of Disease Control and Prevention. (4) Accelerating coal reduction and integrating health considerations into China’s pathway to carbon neutrality. Leaders must strictly control the capacity of coal-fired power generation and accelerate the pace of coal reduction (especially in the household sector). (5) Promoting renewable energy generation and consumption by redirecting fossil fuel subsidies to China’s low-carbon economy. Leaders should keep encouraging renewable energy generation and consumption

Uncovering the roles of oxygen vacancies in cation migration in lithium excess layered oxides.

A novel oxygen vacancy assisted transition metal (TM) diffusion mechanism is proposed for the first time to explain the near-surface phase transformation in lithium excess transition metal layered oxides. Oxygen vacancies and TM migration have been observed at nm scale spatial resolution by Scanning Transmission Electron Microscopy and Electron Energy Loss Spectroscopy. Formation of (dilute) oxygen vacancies and their roles in assisting transition metal ion diffusion were further investigated using first principles calculations. The activation barriers of TM diffusion in the presence of oxygen vacancies are drastically reduced and consistently in a reasonable range for room temperature diffusion