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气候变化导致中国内陆水域的二氧化碳排放量大幅减少 快报文章
气候变化快报,2021年第7期
作者:  董利苹
Microsoft Word(15Kb)  |  收藏  |  浏览/下载:494/0  |  提交时间:2021/04/05
Decrease  CO2 Emissions  Chinese Inland Waters  Global Change  
Measuring and forecasting progress towards the education-related SDG targets 期刊论文
NATURE, 2020, 580 (7805) : 636-+
作者:  Hindell, Mark A.;  Reisinger, Ryan R.;  Ropert-Coudert, Yan;  Huckstadt, Luis A.;  Trathan, Philip N.;  Bornemann, Horst;  Charrassin, Jean-Benoit;  Chown, Steven L.;  Costa, Daniel P.;  Danis, Bruno;  Lea, Mary-Anne;  Thompson, David;  Torres, Leigh G.;  Van de Putte, Anton P.
收藏  |  浏览/下载:42/0  |  提交时间:2020/07/03

Education is a key dimension of well-being and a crucial indicator of development(1-4). The Sustainable Development Goals (SDGs) prioritize progress in education, with a new focus on inequality(5-7). Here we model the within-country distribution of years of schooling, and use this model to explore educational inequality since 1970 and to forecast progress towards the education-related 2030 SDG targets. We show that although the world is largely on track to achieve near-universal primary education by 2030, substantial challenges remain in the completion rates for secondary and tertiary education. Globally, the gender gap in schooling had nearly closed by 2018 but gender disparities remained acute in parts of sub-Saharan Africa, and North Africa and the Middle East. It is predicted that, by 2030, females will have achieved significantly higher educational attainment than males in 18 countries. Inequality in education reached a peak globally in 2017 and is projected to decrease steadily up to 2030. The distributions and inequality metrics presented here represent a framework that can be used to track the progress of each country towards the SDG targets and the level of inequality over time. Reducing educational inequality is one way to promote a fairer distribution of human capital and the development of more equitable human societies.


Great progress toward the education-related SDG targets has been made  however, global estimates of within-country distributions of education reveal gender disparities and high levels of total inequality in many parts of the world.


  
High-pressure strengthening in ultrafine-grained metals 期刊论文
NATURE, 2020
作者:  Yoshida, Kenichi;  Gowers, Kate H. C.;  Lee-Six, Henry;  Chandrasekharan, Deepak P.;  Coorens, Tim;  Maughan, Elizabeth F.;  Beal, Kathryn;  Menzies, Andrew;  Millar, Fraser R.;  Anderson, Elizabeth;  Clarke, Sarah E.;  Pennycuick, Adam;  Thakrar, Ricky M.;  Butler, Colin R.
收藏  |  浏览/下载:44/0  |  提交时间:2020/07/03

High-pressure diamond anvil cell experiments reveal that compression strengthening of nanocrystalline nickel increases as its grain sizes decrease to 3 nanometres, owing to dislocation hardening and suppression of grain boundary plasticity.


The Hall-Petch relationship, according to which the strength of a metal increases as the grain size decreases, has been reported to break down at a critical grain size of around 10 to 15 nanometres(1,2). As the grain size decreases beyond this point, the dominant mechanism of deformation switches from a dislocation-mediated process to grain boundary sliding, leading to material softening. In one previous approach, stabilization of grain boundaries through relaxation and molybdenum segregation was used to prevent this softening effect in nickel-molybdenum alloys with grain sizes below 10 nanometres(3). Here we track in situ the yield stress and deformation texturing of pure nickel samples of various average grain sizes using a diamond anvil cell coupled with radial X-ray diffraction. Our high-pressure experiments reveal continuous strengthening in samples with grain sizes from 200 nanometres down to 3 nanometres, with the strengthening enhanced (rather than reduced) at grain sizes smaller than 20 nanometres. We achieve a yield strength of approximately 4.2 gigapascals in our 3-nanometre-grain-size samples, ten times stronger than that of a commercial nickel material. A maximum flow stress of 10.2 gigapascals is obtained in nickel of grain size 3 nanometres for the pressure range studied here. We see similar patterns of compression strengthening in gold and palladium samples down to the smallest grain sizes. Simulations and transmission electron microscopy reveal that the high strength observed in nickel of grain size 3 nanometres is caused by the superposition of strengthening mechanisms: both partial and full dislocation hardening plus suppression of grain boundary plasticity. These insights contribute to the ongoing search for ultrastrong metals via materials engineering.


  
Systemic HIV and SIV latency reversal via non-canonical NF-kappa B signalling in vivo 期刊论文
NATURE, 2020, 578 (7793) : 160-+
作者:  Momcilovic, Milica;  Jones, Anthony;  Bailey, Sean T.;  Waldmann, Christopher M.;  Li, Rui;  Lee, Jason T.;  Abdelhady, Gihad;  Gomez, Adrian;  Holloway, Travis;  Schmid, Ernst;  Stout, David;  Fishbein, Michael C.;  Stiles, Linsey;  Dabir, Deepa V.;  Dubinett, Steven M.;  Christofk, Heather;  Shirihai, Orian;  Koehler, Carla M.;  Sadeghi, Saman;  Shackelford, David B.
收藏  |  浏览/下载:38/0  |  提交时间:2020/07/03

Activation of the non-canonical NF-kappa B signalling pathway by AZD5582 results in the induction of HIV and SIV RNA expression in the blood and tissues of antiretroviral-therapy-treated humanized mice and rhesus macaques.


Long-lasting, latently infected resting CD4(+) T cells are the greatest obstacle to obtaining a cure for HIV infection, as these cells can persist despite decades of treatment with antiretroviral therapy (ART). Estimates indicate that more than 70 years of continuous, fully suppressive ART are needed to eliminate the HIV reservoir(1). Alternatively, induction of HIV from its latent state could accelerate the decrease in the reservoir, thus reducing the time to eradication. Previous attempts to reactivate latent HIV in preclinical animal models and in clinical trials have measured HIV induction in the peripheral blood with minimal focus on tissue reservoirs and have had limited effect(2-9). Here we show that activation of the non-canonical NF-kappa B signalling pathway by AZD5582 results in the induction of HIV and SIV RNA expression in the blood and tissues of ART-suppressed bone-marrow-liver-thymus (BLT) humanized mice and rhesus macaques infected with HIV and SIV, respectively. Analysis of resting CD4(+) T cells from tissues after AZD5582 treatment revealed increased SIV RNA expression in the lymph nodes of macaques and robust induction of HIV in almost all tissues analysed in humanized mice, including the lymph nodes, thymus, bone marrow, liver and lung. This promising approach to latency reversal-in combination with appropriate tools for systemic clearance of persistent HIV infection-greatly increases opportunities for HIV eradication.


  
The past and future of global river ice 期刊论文
NATURE, 2020, 577 (7788) : 69-+
作者:  Yang, Xiao;  Pavelsky, Tamlin M.;  Allen, George H.
收藏  |  浏览/下载:40/0  |  提交时间:2020/05/13

More than one-third of Earth'  s landmass is drained by rivers that seasonally freeze over. Ice transforms the hydrologic(1,2), ecologic(3,4), climatic(5) and socio-economic(6-8) functions of river corridors. Although river ice extent has been shown to be declining in many regions of the world(1), the seasonality, historical change and predicted future changes in river ice extent and duration have not yet been quantified globally. Previous studies of river ice, which suggested that declines in extent and duration could be attributed to warming temperatures(9,10), were based on data from sparse locations. Furthermore, existing projections of future ice extent are based solely on the location of the 0-degrees C isotherm11. Here, using satellite observations, we show that the global extent of river ice is declining, and we project a mean decrease in seasonal ice duration of 6.10 +/- 0.08 days per 1-degrees C increase in global mean surface air temperature. We tracked the extent of river ice using over 400,000 clear-sky Landsat images spanning 1984-2018 and observed a mean decline of 2.5 percentage points globally in the past three decades. To project future changes in river ice extent, we developed an observationally calibrated and validated model, based on temperature and season, which reduced the mean bias by 87 per cent compared with the 0-degree-Celsius isotherm approach. We applied this model to future climate projections for 2080-2100: compared with 2009-2029, the average river ice duration declines by 16.7 days under Representative Concentration Pathway (RCP) 8.5, whereas under RCP 4.5 it declines on average by 7.3 days. Our results show that, globally, river ice is measurably declining and will continue to decline linearly with projected increases in surface air temperature towards the end of this century.


  
Different Precipitation Elasticity of Runoff for Precipitation Increase and Decrease at Watershed Scale 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2019, 124 (22) : 11932-11943
作者:  Tang, Yin;  Tang, Qiuhong;  Wang, Zhonggen;  Chiew, Francis H. S.;  Zhang, Xuejun;  Xiao, Han
收藏  |  浏览/下载:14/0  |  提交时间:2020/02/17
elasticity of runoff  precipitation increase  precipitation decrease  aridity  MOPEX  
Seismic Waves Could Decrease the Permeability of the Shallow Crust 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (12) : 6371-6377
作者:  Shi, Yun;  Liao, Xin;  Zhang, Da;  Liu, Chun-ping
收藏  |  浏览/下载:9/0  |  提交时间:2019/11/26
permeability decrease  seismic wave  water level  tidal response  
Recent radial growth decline in response to increased drought conditions in the northernmost Nothofagus populations from South America 期刊论文
FOREST ECOLOGY AND MANAGEMENT, 2018, 409: 94-104
作者:  Venegas-Gonzalez, Alejandro;  Junent, Fidel Roig;  Gutierrez, Alvaro G.;  Tomazello Filho, Mario
收藏  |  浏览/下载:11/0  |  提交时间:2019/04/09
Chilean Mediterranean-type forest  Dendroecology  Forest decline  Global warming  Precipitation decrease  ENSO