Light variations of a representative sample of 26 more or less periodically variable carbon stars were analyzed on the basis
of 2220 individual observations made by the Hipparcos satellite and 33 544 visual observations listed in AFOEV and VSOLJ databases
within the interval JD = 2 448 000 (1988) ±6 cycles. We found the osculating linear ephemerides of all stars and their mean
light curves, as well. We found that the light curves of the carbon Miras in our set can be satisfactorily expressed as a
linear combination of only two basic light curves. The analysis was done by an own method combining robust regression and
principal component analysis. 相似文献
Food-insecure households in many countries depend on international aid to alleviate acute shocks and chronic shortages. Some food security programmes (including Ethiopia’s Productive Safety Net Program–PSNP – which provides a case study for this article) have integrated aid in exchange for labour on public works to reduce long-term dependence by investing in the productive capacity and resilience of communities. Using this approach, Ethiopia has embarked upon an ambitious national programme of land restoration and sustainable land management. Although the intent was to reduce poverty, here we show that an unintended co-benefit is the climate-change mitigation from reduced greenhouse gas (GHG) emissions and increased landscape carbon stocks. The article first shows that the total reduction in net GHG emissions from PSNP’s land management at the national scale is estimated at 3.4 million?Mg?CO2e?y?1 – approximately 1.5% of the emissions reductions in Ethiopia’s Nationally Determined Contribution for the Paris Agreement. The article then explores some of the opportunities and constraints to scaling up of this impact.Key policy insights
Food security programmes (FSPs) can contribute to climate change mitigation by creating a vehicle for investment in land and ecosystem restoration.
Maximizing mitigation, while enhancing but not compromising food security, requires that climate projections, and mitigation and adaptation responses should be mainstreamed into planning and implementation of FSPs at all levels.
Cross-cutting oversight is required to integrate land restoration, climate policy, food security and disaster risk management into a coherent policy framework.
Institutional barriers to optimal implementation should be addressed, such as incentive mechanisms that reward effort rather than results, and lack of centralized monitoring and evaluation of impacts on the physical environment.
Project implementation can often be improved by adopting best management practices, such as using productive living livestock barriers where possible, and increasing the integration of agroforestry and non-timber forest products into landscape regeneration.
This paper uses a VAR model to empirically analyze the impact of economic growth, financial development, and urbanization on carbon emissions of the ASEAN countries from 2000 to 2013. The empirical results show that economic growth and carbon emissions, and financial development and carbon emissions have unidirectional Granger causality relationships. Economic growth and urbanization will increase carbon emissions, while financial development will reduce carbon emissions during the initial stage but have little impact on carbon emissions over the long term. Economic growth and urbanization are the main variables to forecast the degree of variance of carbon emissions, while financial development is the least important variable to forecast the degree of variance of carbon emissions. Finally, this study puts forward policy suggestions on improving environmental quality as economic growth, financial development and urbanization occur. 相似文献
This paper presents the possible alternative removal options for the development of safe drinking water supply in the trace
elements affected areas. Arsenic and chromium are two of the most toxic pollutants, introduced into natural waters from a
variety of sources and causes various adverse effects on living bodies. Performance of three filter bed method was evaluated
in the laboratory. Experiments have been conducted to investigate the sorption of arsenic and chromium on carbon steel and
removal of trace elements from drinking water with a household filtration process. The affinity of the arsenic and chromium
species for Fe/Fe3C (iron/iron carbide) sites is the key factor controlling the removal of the elements. The method is based on the use of powdered
block carbon (PBC), powder carbon steel and ball ceramic in the ion-sorption columns as a cleaning process. The PBC modified
is a satisfactory and practical sorbent for trace elements (arsenite and chromate) dissolved in water. 相似文献
Organic matter in sediments, for instance, carbon, nitrogen and phosphorus, can be used to reconstruct the paleoecological
and pollution history of lakes and their catchment basins. In this paper, the contents of allochthonous organic carbon (allochthonous
OC) and autochthonous organic carbon (autochthonous OC) in sediment cores taken from Wuliangsuhai Lake and Daihai Lake in
northern China are quantified by using a binary model, and phosphorus forms in the sediment cores from the two lakes are extracted
by sequential extraction techniques. The results indicate that the palaeoenvironment and paleoclimate of Daihai Lake and
its catchment basin in the recent 250 years can be well reconstructed based on the content of allochthonous OC. The climate
was relatively humid and warm in the period of 1865–2005, while relatively dry and cold in the period of 1765–1865. The sedimentary
information of allochthonous OC in the 22–42-cm portion of the sediment cores in Daihai Lake corresponds to the final cold
fluctuation of the Little Ice Age that occurred since the Middle Holocene. The difference of phosphorus forms in the sediment
cores between the two lakes indicates that phosphorus input to the lakes and the correlation between phosphorus forms and
distribution and the changes of environment are influenced by the eutrophication mechanisms and environmental conditions of
the two lakes. 相似文献