Search

In order to explore the economic and carbon reduction benefits of photovoltaic-storage-charging integrated stations and achieve reasonable configuration of internal components, a multi-objective optimization configuration method for stations that takes into account economic and low-carbon aspects is proposed. Firstly, based on the functions and requirements of each module in the charging station, the sources of carbon emissions generated by station is explored, and a mathematical model for the cost and carbon emissions of each module in the station is established. Then, with the goal of minimizing the annual investment and operating cost of the system and carbon emissions, a multi-objective particle swarm optimization algorithm based on three-black-hole capturing strategy is used to optimize the configuration of various modules of stations in different load scenarios, and the optimal configuration plan for each component module of the station under three scenarios is obtained. The comparative results show that the method proposed in this article can effectively reduce the cost and carbon emissions during planning and operation, and improve the economic and environmental benefits of stations. Finally, the technique for order preference by similarity to ideal solution is used to provide a compromise optimization plan for the optimal scenario, which can provide reference for the current investment and construction of photovoltaic-storage-charging integrated stations.

Airborne mineral dust is sensitive to climatic changes, but its response to orbital forcing is still not fully understood. Here, we present a reconstruction of dust input to the Subarctic Pacific Ocean covering the past 190 kyr. The dust composition record is indicative of source moisture conditions, which were dominated by precessional variations. In contrast, the dust flux record is dominated by obliquity variations and displays an out‐of‐phase relationship with a dust record from the mid‐latitude North Pacific Ocean. Climate model simulations suggest precession likely drove changes in the aridity and extent of dust source regions. Additionally, the obliquity variations in dust flux can be explained by meridional shifts in the North Pacific westerly jet, driven by changes in the meridional atmospheric temperature gradient. Overall, our findings suggest that North Pacific dust input was primarily modulated by orbital‐controlled source aridity and the strength and position of the westerly winds. Plain Language Summary: Glacial‐interglacial climate variations can affect dust transport to the ocean, but the controls on past dust fluxes to the North Pacific Ocean remain poorly constrained. This region is important because fertilization of phytoplankton growth by dust‐borne iron may have contributed to lower glacial atmospheric CO2, and dust records could also constrain the past dynamics of the North Pacific westerly winds. Here, we highlight the dominance of obliquity cycles in modulating latitudinal shifts of the westerly winds and, in turn, dust inputs. In contrast, precession regulates the aridity of the dust source regions, which determines both dust emission rates and composition. Such orbital‐scale fluctuations in the dust flux could influence ocean‐atmosphere interactions in the middle and high northern latitudes, with implications for global atmospheric circulation and ocean carbon storage. Key Points: Moisture availability in Asian dust source regions to the North Pacific Ocean were controlled by precessionNorth Pacific dust flux reveals dominant obliquity variations, but is out‐of‐phase at different latitudesThe westerlies in the Northern Hemisphere were primarily modulated by obliquity cycles in the late Pleistocene [ABSTRACT FROM AUTHOR]

The presence of a late Quaternary ice sheet/ice shelf over the East Siberian Sea has been proposed in several papers. Here, we further document its duration/resilience based on the sedimentary, bulk mineralogical, and geochemical (organic matter content and its stable isotopic composition, U‐Th series) properties of a core raised from the southernmost Mendeleev Ridge. The chronostratigraphy of the studied core was mainly built from the 230Th excess (230Thxs) distribution and decay downcore. At the core‐top, peaking 230Thxs values during the early MIS 3 and mid‐MIS 1 encompassing an MIS 2 hiatus were observed. As documented in several papers, these peaks suggest seasonally open ice conditions over proximal continental shelves. Below, the interval spanning MIS 4 and possibly MIS 5d records major ice‐rafting events illustrated by overall high coarse‐fraction contents. Underlying MIS 5e, down to MIS 11, the sediment depicts relatively low sand (1.7±2.5 dw%), high clay (33.5±4.7 dw%), and very low organic carbon (0.10±0.06 dw%) contents, and low δ13Corg values (−24.3±0.9‰). This section is interpreted as recording fine sediment transport by deep currents and/or meltwater plumes below a resilient ice cover, only interrupted by a few short‐duration events. These events include (i) detrital carbonate pulses assigned to deglacial events along the NW Laurentide Ice Sheet margin (Termination (T) III), and (ii) intervals with some planktonic foraminifer occurrences, likely relating to their advection from open areas of the Arctic Ocean (MIS 5e, 9 and 11). All Terminations, but TII and the early MIS 3, show peaking Mn/Al values linked to the submergence of Arctic shelves under a rising sea level. We conclude that the resilient ice cover, likely an ice shelf, has been present over the southern Mendeleev Ridge during most of the interval after the Mid‐Pleistocene Transition and was favoured by the low summer insolation of the MIS 14 to 10 interval. [ABSTRACT FROM AUTHOR]

Based on tracer tests and the equivalent flow channel model, this study proposes a theoretical modelling framework to back-calculate the unknown parameters of geothermal reservoirs and predict the thermal breakthrough in production wells. The inverse modelling module combines the analytical solution of the tracer transport equation with the method of moving asymptotes, and then an analytical model that considers heat advection and transfer was used to predict the thermal breakthrough in a production well. Based on the results of tracer tests in the double geothermal wells, Xianxian geothermal field, China, two equivalent flow channels were determined, and their average flow velocity, dispersion coefficient, section area, and channel length were estimated using this theoretical framework. The possible thermal breakthrough in the production well and its main influencing factors are also discussed. The theoretical model was applied to the engineering case, and the tracer test data were used to carry out the parameter back analysis and obtain the goodness of fit ( R 2 )=0.7907 > 0.6, indicating that the optimization result strongly correlated with the measured value and the fit was good. The values of the thermal reservoir parameters from the tracer test’s back analysis were used to predict the thermal breakthrough for the geothermal well system. The results indicated that due to the lower tracer recovery rate, the hydraulic connection between the production well and the recharge well was poor. During the 100-year service life of a geothermal well system, the production water temperature will not obviously change, and no thermal breakthrough will occur.

The conglomeratic reservoirs of the Permian Wutonggou Formation in the Yingyeer area of the Turpan–Hami Basin are key petroliferous horizons, with enormous potential for hydrocarbon exploration. Existing studies on the conglomeratic reservoirs in this area mainly focus on the sedimentary environment and sand body distribution, while few of them concern the diagenesis and evolution of the conglomeratic reservoirs, leading to deficient knowledge about relevant mechanisms. By comprehensively utilizing the data from ordinary and casting thin section identification, the x-ray diffraction analysis of whole rock and clay, scanning electron microscopy, and other analyses and assays, this study analyzed and investigated the petrological characteristics, diagenetic types, and characteristics, and diagenetic evolutionary stages and mechanisms of the conglomeratic reservoirs of the Permian Wutonggou Formation in the Yingyeer area. The study results are as follows. Under the influence of sedimentary provenances, tectonic evolution, and paleogeomorphology, the conglomeratic reservoirs of the Permian Wutonggou formation have low clastic grain maturity and low structural maturity, suggesting proximal provenances. The reservoirs are subjected to various diagenesis, including carbonate cementation, which fills pores and throats; compaction as a major factor leading to poor reservoir quality, and dissolution, which significantly improves the reservoir properties. The conglomeratic reservoirs in the Wutonggou formation are generally in substage A of the middle diagenetic stage. The diagenetic evolution of the reservoirs generally underwent early mechanical compaction, calcite precipitation, secondary quartz overgrowth, the injection of organic fluids, the dissolution of feldspars and lithic grains, the transformation of clay minerals, and calcite cementation in sequence. Hydrocarbon charging mainly occurred during the late Middle Jurassic and was greatly influenced by early compaction and dissolution. [ABSTRACT FROM AUTHOR]

We report carbon isotopic values in total organic carbon (TOC) and pyrogenic carbon (PyC) preserved in two sediment cores from the Ross Sea, Antarctica. The δ13C values of PyC ranged from −10.9‰ to −17.2‰, with distinct differences from the δ13C values of TOC (−24.1‰ to −26.1‰) in the sediments. The radiocarbon ages of PyC were 9,128 and 8,410 years old on average in the two cores but were thousands of years younger than the ages of TOC at the same core depth. These isotopic records provide strong evidence indicating that the PyC was produced from ancient wildfires predominantly in C4 vegetation and transported to Antarctica in the atmosphere. We suggest that ancient wildfires in predominantly C4 grasslands likely frequently occurred on a large scale and at a high intensity in the Southern Hemisphere during the last deglaciation to mid‐Holocene period of 14,800–4,200 years ago. Plain Language Summary: A large fraction of pyrogenic carbon (PyC) is produced from incomplete combustion of biomass fires on Earth and is widely distributed on land and in the oceans. This study presents the first evidence of both radiocarbon and stable carbon isotopes in the PyC preserved in the slope sediments of the Ross Sea in Antarctica. The results revealed that PyC accounted for a significant fraction (10.0%–28.0%) of the sedimentary total organic carbon (TOC) buried in the sediments, and both the Δ14C and δ13C values of PyC showed distinctive differences compared with those of TOC. The well‐defined δ13C (−10.9‰ to −17.2‰) and Δ14C (−415‰ to −843‰) values of PyC in the sediments revealed that in ancient times, PyC was produced from wildfires of C4 vegetation in the Southern Hemisphere and was transported in the atmosphere to Antarctica. The isotopic records of PyC preserved in the Ross Sea sediments provide meaningful evidence for environmental changes. Key Points: Pyrogenic carbon (PyC) constitutes a significant fraction of total organic carbon (TOC) preserved in sediment of the Ross Sea, AntarcticaDistinctive differences in both radiocarbon and stable carbon isotope values exist between PyC and TOC in the Ross Sea sedimentThe isotopic records indicated that the PyC was produced from ancient wildfires in C4 grasslands and transported to Antarctica in atmosphere [ABSTRACT FROM AUTHOR]