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"Wang, Yang"
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Troposphere Sensing Using Grazing‐Angle GNSS‐R Measurement From LEO Satellites
This paper studies a new concept of using global navigation satellite system (GNSS) signals coherently reflected over relatively smooth ocean and ice surfaces from very low elevation angles (below ∼8°) and received by low Earth orbit (LEO) satellites to retrieve the tropospheric information. This approach can provide horizontal profiles of tropospheric zenith delay and total column water vapor (TCWV) with centimeter‐level high precision and spatial resolutions of tens of km by ∼1 km, depending on the elevation angle, with a sampling spacing of ∼100 m. This approach can potentially be applied to most sea ice and calm ocean areas and provide tropospheric sensing data, which can complement and augment existing observation systems. A few case studies are conducted in this paper using the Spire grazing‐angle GNSS‐R data. The retrieved TCWV is compared to ERA5 products and the Sentinel‐3 Ocean and Land Color Instrument measurements and shows promising performances. The errors associated with the GNSS‐R tropospheric measurements are also discussed. Plain Language Summary The atmospheric water vapor is an important component for the weather and climate systems and is difficult to measure, especially over ocean and ice surfaces. This paper studies a new approach to measuring atmospheric water vapor using global navigation satellite system (GNSS) signals reflected off ocean and ice surfaces. If the reflection is from a low elevation angle (below ∼8°) and the reflected signal is coherent (all signal rays are reflected in the same direction), this approach can provide very high precision observation of the horizontal gradients of the tropospheric delay and the vertically integrated atmospheric water vapor with good spatial resolutions. This paper presents the methodology of the proposed approach and a few case studies to demonstrate the feasibility and performance by comparing the GNSS‐R retrieved water vapor measurements with models and the Sentinel‐3 satellite radiometry measurements. The errors associated with the GNSS Reflectometry (GNSS‐R) tropospheric measurements are also discussed. Key Points A new tropospheric sensing concept is studied that relies on coherent‐reflection global navigation satellite system (GNSS) signals off ocean and ice surfaces Algorithms are developed and demonstrated using Spire grazing‐angle GNSS‐R data to retrieve tropospheric delay and water vapor The presented approach provides high‐precision tropospheric delay and total column water vapor horizontal profiles, as validated using the Sentinel‐3 Ocean and Land Color Instrument data
Journal Article
Molecular engineering of dispersed nickel phthalocyanines on carbon nanotubes for selective CO2 reduction
Electrochemical reduction of CO
2
is a promising route for sustainable production of fuels. A grand challenge is developing low-cost and efficient electrocatalysts that can enable rapid conversion with high product selectivity. Here we design a series of nickel phthalocyanine molecules supported on carbon nanotubes as molecularly dispersed electrocatalysts (MDEs), achieving CO
2
reduction performances that are superior to aggregated molecular catalysts in terms of stability, activity and selectivity. The optimized MDE with methoxy group functionalization solves the stability issue of the original nickel phthalocyanine catalyst and catalyses the conversion of CO
2
to CO with >99.5% selectivity at high current densities of up to −300 mA cm
−2
in a gas diffusion electrode device with stable operation at −150 mA cm
−2
for 40 h. The well-defined active sites of MDEs also facilitate the in-depth mechanistic understandings from in situ/operando X-ray absorption spectroscopy and theoretical calculations on structural factors that affect electrocatalytic performance.
Widespread deployment of electrochemical CO
2
reduction requires low-cost catalysts that perform well at high current densities. Zhang et al. show that methoxy-functionalized nickel phthalocyanine molecules on carbon nanotubes can operate as high-performing molecularly dispersed electrocatalysts at current densities of up to −300 mA cm
–2
.
Journal Article
Thermally modulated lithium iron phosphate batteries for mass-market electric vehicles
The pursuit of energy density has driven electric vehicle (EV) batteries from using lithium iron phosphate (LFP) cathodes in early days to ternary layered oxides increasingly rich in nickel; however, it is impossible to forgo the LFP battery due to its unsurpassed safety, as well as its low cost and cobalt-free nature. Here we demonstrate a thermally modulated LFP battery to offer an adequate cruise range per charge that is extendable by 10 min recharge in all climates, essentially guaranteeing EVs that are free of range anxiety. Such a thermally modulated LFP battery designed to operate at a working temperature around 60 °C in any ambient condition promises to be a well-rounded powertrain for mass-market EVs. Furthermore, we reveal that the limited working time at the high temperature presents an opportunity to use graphite of low surface areas, thereby prospectively prolonging the EV lifespan to greater than two million miles.
Ternary layered oxides dominate the current automobile batteries but suffer from material scarcity and operational safety. Here the authors report that, when operating at around 60 °C, a low-cost lithium iron phosphate-based battery exhibits ultra-safe, fast rechargeable and long-lasting properties.
Journal Article
Engaging social media in China : platforms, publics, and production
\"Introducing the concept of state-sponsored platformization, the book shows that, although party-state plays a central role in shaping social media platforms, state-sponsored platformization does not necessarily produce the Chinese Communist Party's desired outcomes\"-- Provided by publisher.
BOOK
Towards High-Energy and Anti-Self-Discharge Zn-Ion Hybrid Supercapacitors with New Understanding of the Electrochemistry
HighlightsA surface engineering strategy was proposed to design hierarchically porous structure on fibrous carbon cathodes with O/N heteroatom functional groups.High-energy and anti-self-discharge Zn-ion hybrid supercapacitors (ZHSs) were realized.ZHS electrochemistry was investigated and new insights were provided.Aqueous Zn-ion hybrid supercapacitors (ZHSs) are increasingly being studied as a novel electrochemical energy storage system with prominent electrochemical performance, high safety and low cost. Herein, high-energy and anti-self-discharge ZHSs are realized based on the fibrous carbon cathodes with hierarchically porous surface and O/N heteroatom functional groups. Hierarchically porous surface of the fabricated free-standing fibrous carbon cathodes not only provides abundant active sites for divalent ion storage, but also optimizes ion transport kinetics. Consequently, the cathodes show a high gravimetric capacity of 156 mAh g−1, superior rate capability (79 mAh g−1 with a very short charge/discharge time of 14 s) and exceptional cycling stability. Meanwhile, hierarchical pore structure and suitable surface functional groups of the cathodes endow ZHSs with a high energy density of 127 Wh kg−1, a high power density of 15.3 kW kg−1 and good anti-self-discharge performance. Mechanism investigation reveals that ZHS electrochemistry involves cation adsorption/desorption and Zn4SO4(OH)6·5H2O formation/dissolution at low voltage and anion adsorption/desorption at high voltage on carbon cathodes. The roles of these reactions in energy storage of ZHSs are elucidated. This work not only paves a way for high-performance cathode materials of ZHSs, but also provides a deeper understanding of ZHS electrochemistry.
Journal Article
Reading development and difficulties in monolingual and bilingual Chinese children
This volume explores Chinese reading development, focusing on children in Chinese societies and bilingual Chinese-speaking children in Western societies. The book is structured around four themes: psycholinguistic study of reading, reading disability, bilingual and biliteracy development, and Chinese children's literature. It discusses issues that are pertinent to improving language and literacy development, and complex cognitive, linguistic, and socio-cultural factors that underlie language and literacy development. In addition, the book identifies instructional practices that can enhance literacy development and academic achievement. This volume offers an integrative framework of Chinese reading, and deepens our understanding of the intricate processes that underlie Chinese children's literacy development. It promotes research in reading Chinese and celebrates the distinguished and longstanding career of Richard C. Anderson.
Book
Modelling and prediction of global non-communicable diseases
Background
Non-communicable diseases (NCDs) are the main health and development challenge facing humankind all over the world. They are inextricably linked to socio-economic development. Deaths caused by NCDs should be different in different socio-economic development stages. The stratified heterogeneity of NCD deaths is currently not fully explored.
Methods
Countries were classified according to their socio-economic types and development stages, which were illustrated as a tree-like structure called Geotree. NCD deaths were linked to the countries and so were attached to the Geotree, which was modelled by a multilevel model (MLM) approach. Accordingly, the levels of NCD death indexes were predicted for 2030.
Results
Through the Geotree structure constructed in the study, it can be seen that the NCD death index has obvious stratified heterogeneity; that is, the NCD death index shows different trends in different country types and socio-economic development stages. In the first-level branches (country type), as national income increases, NCD mortality rate decreases and the proportion of NCD deaths to total deaths increases. In the secondary-level trunks (socio-economic development stage), as a country’s development stage rises, the NCD mortality rate decreases and the proportion of NCD deaths to total deaths increases. In addition, combined with the hierarchical nature of the evolution tree model, the MLM was used to predict the global NCD death index for 2030. The result was that by 2030, the global average age-standardized NCD mortality rate would be 510.54 (per 100,000 population) and the global average mortality for NCD deaths of the total number of deaths would be 75.26%.
Conclusions
This study found that there is a significant association between socio-economic factors and NCD death indicators in the tree-like structure. In the Geotree, countries on the same branch or trunk can learn from countries with higher development stages to formulate more effective NCD response policies and find the right prevention and treatment path.
Journal Article