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Monumental architecture at Aguada Fenix and the rise of Maya civilization 期刊论文
NATURE, 2020
作者:  Bedding, Timothy R.;  Murphy, Simon J.;  Hey, Daniel R.;  Huber, Daniel;  Li, Tanda;  Smalley, Barry;  Stello, Dennis;  White, Timothy R.;  Ball, Warrick H.;  Chaplin, William J.;  Colman, Isabel L.;  Fuller, Jim;  Gaidos, Eric;  Harbeck, Daniel R.;  Hermes, J. J.;  Holdsworth, Daniel L.;  Li, Gang;  Li, Yaguang;  Mann, Andrew W.;  Reese, Daniel R.;  Sekaran, Sanjay;  Yu, Jie;  Antoci, Victoria;  Bergmann, Christoph;  Brown, Timothy M.;  Howard, Andrew W.;  Ireland, Michael J.;  Isaacson, Howard;  Jenkins, Jon M.;  Kjeldsen, Hans;  McCully, Curtis;  Rabus, Markus;  Rains, Adam D.;  Ricker, George R.;  Tinney, Christopher G.;  Vanderspek, Roland K.
收藏  |  浏览/下载:30/0  |  提交时间:2020/07/03

Archaeologists have traditionally thought that the development of Maya civilization was gradual, assuming that small villages began to emerge during the Middle Preclassic period (1000-350 bc  dates are calibrated throughout) along with the use of ceramics and the adoption of sedentism(1). Recent finds of early ceremonial complexes are beginning to challenge this model. Here we describe an airborne lidar survey and excavations of the previously unknown site of Aguada Fenix (Tabasco, Mexico) with an artificial plateau, which measures 1,400 m in length and 10 to 15 m in height and has 9 causeways radiating out from it. We dated this construction to between 1000 and 800 bc using a Bayesian analysis of radiocarbon dates. To our knowledge, this is the oldest monumental construction ever found in the Maya area and the largest in the entire pre-Hispanic history of the region. Although the site exhibits some similarities to the earlier Olmec centre of San Lorenzo, the community of Aguada Fenix probably did not have marked social inequality comparable to that of San Lorenzo. Aguada Fenix and other ceremonial complexes of the same period suggest the importance of communal work in the initial development of Maya civilization.


Lidar survey of the Maya lowlands uncovers the monumental site of Aguada Fenix, which dates to around 1000-800 bc and points to the role of communal construction in the development of Maya civilization.


  
Adoption of improved biomass stoves in Kenya: a transect-based approach in Kiambu and Muranga counties 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2020, 15 (2)
作者:  Karanja, Alice;  Gasparatos, Alexandros
收藏  |  浏览/下载:9/0  |  提交时间:2020/07/02
stove adoption  clean stoves  improved biomass stoves  gender  geographical location  sub-Saharan Africa  
Wafer-scale single-crystal hexagonal boron nitride monolayers on Cu (111) 期刊论文
NATURE, 2020, 579 (7798) : 219-+
作者:  Luong, Duy X.;  Bets, Ksenia V.;  Algozeeb, Wala Ali;  Stanford, Michael G.;  Kittrell, Carter;  Chen, Weiyin;  Salvatierra, Rodrigo V.;  Ren, Muqing;  McHugh, Emily A.;  Advincula, Paul A.;  Wang, Zhe;  Bhatt, Mahesh;  Guo, Hua;  Mancevski, Vladimir;  Shahsavari, Rouzbeh
收藏  |  浏览/下载:80/0  |  提交时间:2020/07/03

Ultrathin two-dimensional (2D) semiconducting layered materials offer great potential for extending Moore'  s law of the number of transistors in an integrated circuit(1). One key challenge with 2D semiconductors is to avoid the formation of charge scattering and trap sites from adjacent dielectrics. An insulating van der Waals layer of hexagonal boron nitride (hBN) provides an excellent interface dielectric, efficiently reducing charge scattering(2,3). Recent studies have shown the growth of single-crystal hBN films on molten gold surfaces(4) or bulk copper foils(5). However, the use of molten gold is not favoured by industry, owing to its high cost, cross-contamination and potential issues of process control and scalability. Copper foils might be suitable for roll-to-roll processes, but are unlikely to be compatible with advanced microelectronic fabrication on wafers. Thus, a reliable way of growing single-crystal hBN films directly on wafers would contribute to the broad adoption of 2D layered materials in industry. Previous attempts to grow hBN monolayers on Cu (111) metals have failed to achieve mono-orientation, resulting in unwanted grain boundaries when the layers merge into films(6,7). Growing single-crystal hBN on such high-symmetry surface planes as Cu (111)(5,8) is widely believed to be impossible, even in theory. Nonetheless, here we report the successful epitaxial growth of single-crystal hBN monolayers on a Cu (111) thin film across a two-inch c-plane sapphire wafer. This surprising result is corroborated by our first-principles calculations, suggesting that the epitaxial growth is enhanced by lateral docking of hBN to Cu (111) steps, ensuring the mono-orientation of hBN monolayers. The obtained single-crystal hBN, incorporated as an interface layer between molybdenum disulfide and hafnium dioxide in a bottom-gate configuration, enhanced the electrical performance of transistors. This reliable approach to producing wafer-scale single-crystal hBN paves the way to future 2D electronics.


  
Adding fuel to fire? Social spillovers in the adoption of LPG in India 期刊论文
ECOLOGICAL ECONOMICS, 2020, 167
作者:  Srinivasan, Suchita;  Carattini, Stefano
收藏  |  浏览/下载:6/0  |  提交时间:2020/07/02
Clean cooking fuels  LPG  Technological adoption  Spillovers  India  
Which group should policies target? Effects of incentive policies and product cognitions for electric vehicle adoption among Chinese consumers 期刊论文
ENERGY POLICY, 2019, 135
作者:  Yang, Shu;  Cheng, Peng;  Li, Jun;  Wang Shanyong
收藏  |  浏览/下载:9/0  |  提交时间:2020/02/17
Electric vehicles  Policy perception  Product cognition  Adoption intention  
The impact of ambitious fuel economy standards on the market uptake of electric vehicles and specific CO2 emissions 期刊论文
ENERGY POLICY, 2019, 135
作者:  Fritz, Markus;  Ploetz, Patrick;  Funke, Simon A.
收藏  |  浏览/下载:11/0  |  提交时间:2020/02/17
Electric vehicle  CO2 fleet regulation  Fuel economy  EV market penetration  Technology adoption model  Climate policy  
Adoption of improved biomass stoves and stove/fuel stacking in the REACCTING intervention study in Northern Ghana 期刊论文
ENERGY POLICY, 2019, 130: 361-374
作者:  Dickinson, Katherine L.;  Piedrahita, Ricardo;  Coffey, Evan R.;  Kanyomse, Ernest;  Alirigia, Rex;  Molnar, Timothy;  Hagar, Yolanda;  Hannigan, Michael P.;  Oduro, Abraham Rexford;  Wiedinmyer, Christine
收藏  |  浏览/下载:35/0  |  提交时间:2019/11/27
Cookstoves  Technology adoption  Household air pollution  Energy transitions  
Participation in a programme for assisted replacement of wood-burning stoves in Chile: The role of sociodemographic factors, evaluation of air quality and risk perception 期刊论文
ENERGY POLICY, 2019, 129: 1220-1226
作者:  Boso, Alex;  Oltra, Christian;  Hofflinger, Alvaro
收藏  |  浏览/下载:5/0  |  提交时间:2019/11/26
Adoption of heating system  Wood pellets  Biomass  Risk perception  Air quality  
Geographical proximity and renewable energy diffusion: An empirical approach 期刊论文
ENERGY POLICY, 2019, 129: 422-435
作者:  Fadly, Dalia;  Fontes, Francisco
收藏  |  浏览/下载:8/0  |  提交时间:2019/11/26
Renewable energy  Trade  Geography  Policy adoption  Technology diffusion  Panel fixed effects  
Using willingness to pay to forecast the adoption of solar photovoltaics: A "parameterization plus calibration" approach 期刊论文
ENERGY POLICY, 2019, 129: 100-110
作者:  Dong, Changgui;  Sigrin, Benjamin
收藏  |  浏览/下载:5/0  |  提交时间:2019/11/26
Solar photovoltaics  Willingness to pay  Adoption forecasting  Parameterization  Calibration