ALBERT

Description: A correction to this paper has been published: 10.1140/epjc/s10052-021-09344-w

Description: The results of a search for gluino and squark pair production with the pairs decaying via the lightest charginos into a final state consisting of two W bosons, the lightest neutralinos ($$ilde{chi }^0_1$$ χ ~ 1 0 ), and quarks, are presented: the signal is characterised by the presence of a single charged lepton ($$e^{pm }$$ e ± or $$mu ^{pm }$$ μ ± ) from a W boson decay, jets, and missing transverse momentum. The analysis is performed using 139 fb$$^{-1}$$ - 1 of proton–proton collision data taken at a centre-of-mass energy $$sqrt{s}=13$$ s = 13   delivered by the Large Hadron Collider and recorded by the ATLAS experiment. No statistically significant excess of events above the Standard Model expectation is found. Limits are set on the direct production of squarks and gluinos in simplified models. Masses of gluino (squark) up to 2.2  (1.4 ) are excluded at 95% confidence level for a light $$ilde{chi }^0_1$$ χ ~ 1 0 .

Description: Impedance/admittance models (IM/AMs) have been widely used to analyze the small-signal stability of grid-tied power electronic devices, such as the voltage source converter (VSC). They can be either derived from theoretical analysis under white-box conditions, where all parameters and control structures are fully known, or measured based on experiments under black-box conditions, where the topology and parameters of the controllers are completely unknown. As the IM/AMs depend on specific operating conditions, it is highly desirable to develop fast algorithms for IM/AM prediction (or estimation) under the black-box and variable-operating-point conditions. This article extends the nearly-decoupled AM method for sequence AMs proposed recently by Liu et al to fit any unknown control structure, including not only grid-following VSC, but also grid-forming VSC. It is, therefore, referred to as the fully-decoupled IM (FDIM) method. Furthermore, a curve fitting method for the transfer function is proposed to expedite the algorithm, based on the information of a few disturbance frequencies only. Finally, the algorithm is verified by wide simulations and experiments under different situations, including the direct-drive wind turbine generator. The whole approach is expected to be broadly applicable to the stability analysis of power-electronic-based power systems under variable operating conditions.

Description: Responses of global crop yields to warmer temperatures are fundamental to sustainable development under climate change but remain uncertain. Here, we combined a global dataset of field warming experiments (48 sites) for wheat, maize, rice and soybean with gridded global crop models to produce field-data-constrained estimates on responses of crop yield to changes in temperature (ST) with the emergent-constraint approach. Our constrained estimates show with 〉95% probability that warmer temperatures would reduce yields for maize (−7.1 ± 2.8% K−1), rice (−5.6 ± 2.0% K−1) and soybean (−10.6 ± 5.8% K−1). For wheat, ST was 89% likely to be negative (−2.9 ± 2.3% K−1). Uncertainties associated with modelled ST were reduced by 12–54% for the four crops but data constraints do not allow for further disentangling ST of different crop types. A key implication for impact assessments after the Paris Agreement is that direct warming impacts alone will reduce major crop yields by 3–13% under 2 K global warming without considering CO2 fertilization effects and adaptations. Even if warming was limited to 1.5 K, all major producing countries would still face notable warming-induced yield reduction. This yield loss could be partially offset by projected benefits from elevated CO2, whose magnitude remains uncertain, and highlights the challenge to compensate it by autonomous adaptation.

Description: Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge (MAR). To better understand its origin and evolution, magnetic data were used to generate a magnetic anomaly grid, which was inverted to determine crustal magnetization. The magnetization model reveals quasi-linear polarity zones crossing the plateau and following expected MAR paleo-locations, implying formation by seafloor spreading over ∼4 Myr during the formation of anomalies C34n-C33r. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 confirm the magnetic interpretation. Anomaly C33r is split into two negative bands, likely by a westward ridge jump. One of these negative anomalies coincides with deep rift valleys, indicating their age and mechanism of formation. These findings imply that VB originated by seafloor spreading-type volcanism during a plate reorganization, not from a vertical stack of lava flows as expected for a large volcano. Key Points - Valdivia Bank is characterized by quasi-linear magnetic anomalies that are parallel to the inferred paleo-Mid-Atlantic Ridge - Magnetic anomalies imply that the plateau becomes younger E-W consistent with formation via seafloor spreading during anomalies C34n-C33r - Rift valleys, division of C33r, and anomaly curvature imply complex ridge tectonics and a ridge jump

Description: The past ∼200 million years of Earth's geomagnetic field behavior have been recorded within oceanic basalts, many of which are only accessible via scientific ocean drilling. Obtaining the best possible paleomagnetic measurements from such valuable samples requires an a priori understanding of their magnetic mineralogies when choosing the most appropriate protocol for stepwise demagnetization experiments (either alternating field or thermal). Here, we present a quick, and non‐destructive method that utilizes the amplitude‐dependence of magnetic susceptibility to screen submarine basalts prior to choosing a demagnetization protocol, whenever conducting a pilot study or other detailed rock‐magnetic characterization is not possible. We demonstrate this method using samples acquired during International Ocean Discovery Program Expedition 391. Our approach is rooted in the observation that amplitude‐dependent magnetic susceptibility is observed in basalt samples whose dominant magnetic carrier is multidomain titanomagnetite (∼TM 60–65 , (Ti 0.60–0.65 Fe 0.35–0.40 )Fe 2 O 4 ). Samples with low Ti contents within titanomagnetite or samples that have experienced a high degree of oxidative weathering do not display appreciable amplitude dependence. Due to their low Curie temperatures, basalts that possess amplitude‐dependence should ideally be demagnetized either using alternating fields or via finely‐spaced thermal demagnetization heating steps below 300°C. Our screening method can enhance the success rate of paleomagnetic studies of oceanic basalt samples. Plain Language Summary Oceanic basalts are ideal recorders of the Earth's magnetic field. To decipher magnetic histories recorded in rocks, paleomagnetists need to isolate the magnetization directions and intensities within rocks by one of two possible methods. One method typically involves progressively heating the samples to high temperatures. The other method involves exposing samples to alternating magnetic fields with increasing peak field intensities. Both of these methods are ultimately destructive to the original magnetization preserved within rocks. However, without knowledge of a given rock's magnetic mineralogy, randomly choosing thermal or alternating field demagnetization methods may result in high failure rates. We developed a pre‐screening method to help decide which cleaning method will likely be more successful for a given sample based on low‐field magnetic susceptibility measurements. These measurements do not affect the original magnetic information recorded in a rock, thereby permitting subsequent paleomagnetic studies on the same sample. Our technique can be performed as rapidly as 2 min per sample, is non‐destructive, and does not require complicated sample preparation. Key Points Paleomagnetic studies utilize either alternating field or thermal demagnetization, but it is difficult to choose the best protocol a priori Amplitude‐dependence of magnetic susceptibility measurements permits preliminary magnetic mineralogy characterization in submarine basalts Rapid amplitude‐dependence measurements may aid in deciding upon the best demagnetization protocol for submarine basalt samples

Description: Evaluating the embodied environmental impact of solar photovoltaic (PV) technology has been an important topic in addressing the sustainable development of renewable energy. While monetization of environmental externality is a remaining issue, which should be carried out in order to allow for an easy-to-understand comparison between direct economic and external cost. In this study, the environmental impact of solar PV power is monetized through conversion factors between midpoint and endpoint categories of life cycle analysis and the monetization weighting factor. Then, the power generation capacity and generation life of PV and coal-fired power plants are assumed to be consistent in order to compare the total cost of PV and coal-fired power generation. Results show that the cost of PV technology is higher than coal-fired in 2026 to 2030, taking into account environmental external costs and production costs. However, by 2030, the total cost of coal-fired power will be higher than that of solar PV. The life span cost per kWh is $3.55 for solar PV and $116.25 for coal-fired power. Although solar PV power seems more environmentally effective than coal-fired power in the life span, our results reveal the high environmental external cost of producing solar photovoltaic modules, which reminds us to pay more attention to the environmental impact when conducting cost-benefit analysis of renewable technologies. Without incorporating the environmental cost, the real cost of renewable technology will be underestimated.

Description: Boosted by impressive technological innovation and cost reductions, renewable energy in a growing number of countries is now primarily considered for its social and economic benefits. Among the renewable energy promotion actions at the global level, photovoltaic poverty alleviation (PVPA) program in China is very unique since the targeted users are villagers in poverty regions. Under this condition, it would be quite necessary to understand how are the PVPA program carrying out. In this study, three poverty villages are selected in the northwestern part of China to conduct the social impact analysis. An evaluation system including four categories and thirteen indicators was established. Site investigation and questionnaire interview was carried out to collect required information. Our findings reveal that the poor families in the three counties can increase their income by around 3000 RMB per year with the implementation of PVPA program. The final social impact indicator of Yanchi County, Dingbian County and Guazhou County are 2.61, 2.09 and 2.15 respectively. Villagers’ living standards in the three counties are prominently improved because of the solar power supply. The factors that hinder the development of PVPA projects are the lack of investment funds, poor quality of solar panels, low public awareness, high abandon rate of photovoltaic, etc. Recommendations for improving the sustainable development of PVPA program based on the findings are also proposed.

Description: Climate change–induced precipitation anomalies during extremely wet years (EWYs) result in substantial nitrogen losses to aquatic ecosystems (Nw). Still, the extent and drivers of these losses, and effective mitigation strategies have remained unclear. By integrating global datasets with well-established crop modeling and machine learning techniques, we reveal notable increases in Nw, ranging from 22 to 56%, during historical EWYs. These pulses are projected to amplify under the SSP126 (SSP370) scenario to 29 to 80% (61 to 120%) due to the projected increases in EWYs and higher nitrogen input. We identify the relative precipitation difference between two consecutive years (diffPr) as the primary driver of extreme Nw. This finding forms the basis of the CLimate Extreme Adaptive Nitrogen Strategy (CLEANS), which scales down nitrogen input adaptively to diffPr, leading to a substantial reduction in extreme Nw with nearly zero yield penalty. Our results have important implications for global environmental sustainability and while safeguarding food security.