bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spin–orbit correlations and exchange-bias control in twisted Janus dichalcogenide multilayers
Authors: Soriano D , Lado J L 
Published: July 2021

AbstractJanus dichalcogenide multilayers provide a paradigmatic platform to engineer electronic phenomena dominated by spin–orbit coupling. Their unique spin–orbit effects stem from the mirror symmetry breaking in each layer, which induces a colossal Rashba spin–orbit effect in comparison with the conventional dichalcogenide counterparts. Here we put forward twisted Janus dichalcogenide bilayers as a simple platform to realize spin–orbit correlated states. We demonstrate the emergence of flat bands featuring strong spin-momentum locking and the emergence of symmetry broken states with associated non-coplanar magnetization when interactions are included. We further show that the symmetry broken states can be controlled by means of a magnetic substrate, strongly impacting the non-coplanar magnetic texture of the moire unit cell. Our results put forward twisted Janus multilayers as a powerful platform to explore spin–orbit correlated physics, and highlighting the versatility of magnetic substrates to control unconventional moire magnetism.
Linearized propagation equations for metric fluctuations in a general (non-vacuum) background geometry
Authors: Fanizza G. , Gasperini M. , Pavone E. , Tedesco L. 
Published: July 2021

Abstract
The linearized dynamical equation for metric perturbations in a fully general, non-vacuum, background geometry is obtained from the Hamilton variational principle applied to the action up to second order. We specialize our results to the case of traceless and transverse metric fluctuations, and we discuss how the intrinsic properties of the matter stress tensor can affect (and modify) the process of gravity wave propagation even in most conventional geometric scenarios, like (for instance) those described by a FLRW metric background. We provide explicit examples for fluid, scalar field and electromagnetic field sources.
Looking down: a model for visual route following in flying insects
Authors: Stankiewicz J , Webb B 
Published: July 2021

Abstract
Insect visual navigation is often assumed to depend on panoramic views of the horizon, and how these change as the animal moves. However, it is known that honey bees can visually navigate in flat, open meadows where visual information at the horizon is minimal, or would remain relatively constant across a wide range of positions. In this paper we hypothesise that these animals can navigate using view memories of the ground. We find that in natural scenes, low resolution views from an aerial perspective of ostensibly self-similar terrain (e.g. within a field of grass) provide surprisingly robust descriptors of precise spatial locations. We propose a new visual route following approach that makes use of transverse oscillations to centre a flight path along a sequence of learned views of the ground. We deploy this model on an autonomous quadcopter and demonstrate that it provides robust performance in the real world on journeys of up to 30 m. The success of our method is contingent on a robust view matching process which can evaluate the familiarity of a view with a degree of translational invariance. We show that a previously developed wavelet based bandpass orientated filter approach fits these requirements well, exhibiting double the catchment area of standard approaches. Using a realistic simulation package, we evaluate the robustness of our approach to variations in heading direction and aircraft height between inbound and outbound journeys. We also demonstrate that our approach can operate using a vision system with a biologically relevant visual acuity and viewing direction.
Atmospheric moisture contribution to the growing season in the Amazon arc of deforestation
Authors: O’Connor John C , Santos Maria J , Dekker Stefan C , Rebel Karin T , Tuinenburg Obbe A 
Published: July 2021

Abstract
The Amazon moisture recycling system has been widely examined because it is fundamental to maintain some of the global climate processes, however, we have yet to know to what extent the agricultural growing season is dependent on the evapotranspiration contribution from the Amazon forest. Here we use a moisture tracking model to calculate the forest’s contribution to downwind precipitation. Specifically, we calculate the influence of moisture recycling on the seasonality of precipitation in the arc of deforestation with respect to the agricultural growing season. We calculated the wet season start, end and length using three scenarios (a) total precipitation with existing vegetation cover; (b) where we replace forest’s contribution to precipitation by replacing it with the equivalent from short vegetation; (c) where the forest’s contribution to precipitation is completely removed. We found that forest moisture recycling contributes up to 40% of monthly precipitation in the arc of deforestation. However, there is a strong spatial gradient in the forest’s contribution to precipitation, which decreases from west to east. This gradient also coincides with suitability for double-cropping agriculture. Our scenarios excluding precipitation originating from forest indicated that forest is a key contributing factor in determining the wet season start. We found that even when the precipitation originating from forest was replaced by short vegetation there was a significant delay in the wet season start in our study regions. Interestingly the wet season end was more resilient to changes in precipitation source. However it is clear that moisture recycling plays a key role in determining the wet season end as when forest’s contribution to precipitation was entirely removed the wet season end arrived significantly earlier. These differences in wet season length were not detectable in the eastern states of Tocantins and Maranhão, as much less of the precipitation in these states originates from the forest. Our findings demonstrate the importance of forest in supporting double-cropping agriculture in the arc of deforestation. As agricultural intensification by double-cropping increases land-use efficiency, it may also reduce the demand for further deforestation. Therefore it is important to identify how the current forest extent provides this important ecosystem service.
Do persons with low socioeconomic status have less access to greenspace? Application of accessibility index to urban parks in Seoul, South Korea
Authors: Heo Seulkee , Nori-Sarma Amruta , Kim Sera , Lee Jong-Tae , Bell Michelle L 
Published: July 2021

Abstract
Access to urban greenspace has many benefits such as improved health and social cohesion. If access differs by population, these benefits make access to greenspace an environmental justice issue, but little is known regarding accessibility of parks among different sub-groups in Seoul, South Korea. We explored potential socioeconomic inequities for access to parks in Seoul measuring two park provision metrics: total park area per capita (TPPC), and park accessibility index determined by size and proximity of parks. We assessed correlations between a deprivation index for the 25 Gus (administrative unit equivalent to the US borough) and each park provision metric. Regression analyses were applied for the associations between eight socioeconomic indicators of the 424 Dongs (equivalent to the US neighborhood) and each park provision metric. An interquartile range (IQR) increase in percent elderly (⩾65 years) (3.2%) was significantly associated with larger TPPC (1.6 m2/person, 95% CI: 0.8, 2.4). Park accessibility index was associated with more socioeconomic variables than was TPPC. An IQR increase in percent elderly and divorce rates (1.2/1000 population) was associated with increased park accessibility by 3571 km (95% CI: 1103, 6040) and decreased park accessibility by 1387 (95% CI: −2706, −67), respectively. An IQR increase in percentage of the population receiving social low-income support aid (2.2%) was associated with increased park accessibility (reflecting park size and proximity of parks) of residential parks near residential areas by 1568 (95% CI: 15, 3120). Results suggest higher park access for socioeconomically disadvantaged regions. Findings indicate that measures of detailed park access considering spatial proximity and park size may more accurately measure park inequity compared to more basic metrics (e.g. TPPC), which may bias estimation of park inequity by capturing only one characteristic of parks. Detailed park measures should be considered in urban planning and health studies of greenspace.
The sudden stratospheric warming in January 2021
Authors: Lu Qian , Rao Jian , Liang Zhuoqi , Guo Dong , Luo Jingjia , Liu Siming , Wang Chun , Wang Tian 
Published: July 2021

Abstract
Using the ERA5 reanalysis, sea surface temperature and sea ice observations, and the real-time multivariate Madden–Julian index, this study explores a sudden stratospheric warming (SSW) in January 2021, its favorable conditions, and the near surface impact. Wavenumbers 1 and 2 alternately contributed to the total eddy heat flux from mid-December 2020 to late January 2021, and the wavenumber 2 during the onset period nearly split the stratospheric polar vortex. In mid-December 2020 and during the 2021 New Year period (1–5 January 2021), a blocking developed over the Urals, which enhanced the local ridge and the climatological wavenumber 2. Composite results confirm that the Arctic sea ice loss in autumn and La Niña favor the deepening of the high latitude North Pacific low and the increase of the Urals height ridge, which together enhance the planetary waves and hence disturb the stratospheric polar vortex. However, the Madden–Julian oscillation (MJO) in the tropics was dormant in mid-to-late December 2020 and early January 2021, and the well-established statistical relationship between the MJO convection over the western Pacific and the SSW is not applicable to this special case. The cold air outbreak in China during the 2021 New Year period before the January 2021 SSW onset is not explained by the SSW signal which developed in the stratosphere. In contrast, the downward-propagating signal reached the near surface in mid-February 2021, which may contribute to the cold air outbreak in US and may help to explain the extreme coldness of Texas in middle February.
Prediction of CO2 hydrate formation in supercritical CO2 long-distance pipeline network by simulation
Authors: Chen Bing , Fang Qichao , Zhao Qiong 
Published: July 2021

Abstract
Various impurities are dissolved in industrially captured CO2, which will change the physical properties and phase characteristics of CO2, and bring many technical difficulties in CO2 pipeline transportation. In particular, the dissolved water may generate CO2 hydrate, which threatens the safety operation of the pipeline. In order to investigate whether the CO2 fluid with low water content will form hydrates in the pipeline, in this paper, the phase equilibrium curve of impurity-containing CO2 hydrate calculated by vdW-P hydrate phase equilibrium model, and import it into the OLGA multiphase flow software. Predict and analyze the hydrate formation conditions and possible hazards during the stable operation of the actual supercritical CO2 transportation pipeline network.
The effect of composite flux on the melting temperature of fly ash based wall insulation materials
Authors: Zhao Liang , Liu Zhuo , Pi Hao , Yao Shuang , Nan Yunxi 
Published: July 2021

Abstract
Fly ash was used as the main raw material, potassium feldspar and dolomite as fluxes to preparate wall insulation materials, the image sintering point tester was used to observe the changes in volume shrinkage, expansion passivation and globalization of the sample under high temperature conditions, and corresponding temperatures were recorded when the various situation occurred. The relationship between the adding ratio of the composite flux and the melting temperature was studied, and the basic formula for the preparation of fly ash foam ceramics was determined. The experimental results show that when the raw material composition is 60wt% fly ash, the total added amount of composite flux is 40wt%, potash feldspar: dolomite = 3:1, and the melting temperature range of the sample is 1150∼1365 °C, not only the initial melting temperature is lower, but the melting temperature range is also wider.
Study on formation mechanism of ground fissures and disaster prevention and reduction measures for buildings-- A case study of Qingxu area in Shanxi Province
Authors: Pan Chunjuan , Fan Yuhai , Wang Hui , Wang Junfeng , Cui Sheng 
Published: July 2021

Abstract
In recent years, Pingquan village of Qingyuan town and dongmayu village of Mayu Township in Qingxu area of Taiyuan City, under the action of regional tectonic stress, the plane distribution of ne60-80 has appeared one after another along the border mountains. There are many parallel ground fissures, which lead to serious damage to some villagers’ houses. Through field investigation and data analysis, the distribution characteristics and formation mechanism of Qingxu ground fissures are elaborated in detail, and the corresponding defense countermeasures are put forward.
Analysis of landslide disaster characteristics of Zugong highway (G4218) line
Authors: Fan Yuhai , Wang Hui , Pan Chunjuan 
Published: July 2021

Abstract
Landslide is a kind of common geological disaster in mountainous areas. The soil and rock mass on the slope have been scoured by rivers or artificially cut slope for a long time. Under the action of gravity, it will slide downward. Landslides are developed in the third section of the highway from Zhubarong to Bangda Bingzhan along G4218 line (Zuogong Highway), but the distribution of hazardous landslides is relatively concentrated. The landslide shear outlet is above the highway, then a large number of gravel and blocks of sliding bodies are piled up and buried on the road surface. Not only is the workload of cleaning up the earth and stones huge and takes a long time, but also after the slope foot is cleared, it will cause the slide of the upper body to further slide, causing the slope of the highway to be moved together with the highway, so that the highway is completely damaged. Therefore, it is of great significance to strengthen the research on the development and prevention of landslide disaster.
Study on the Identification Method of Pyrogenetic Rock Based on N -DP Intersection Graph
Authors: Hu Gang , Mao Zhiqiang , Yan Ping , Yin Qian , Wang Xiyu , Lai Fuqiang 
Published: July 2021

Abstract
Igneous rocks have the characteristics of “diversification of eruption mode, diversification of lithologic origin and multiple changes of mineral assemblages ", so it is difficult to identify fine. This study is based on a real case study of igneous carboniferous reservoir in Jinlong 10 block at Junggar basin. The distinguish of the reservoir-developed rocks are catalyzed to basalt, andesite, dacite, granite, tuff and volcanic breccia rock, based on a combination of core and thin sheet analysis data. Based on the characteristics of log response of different lithology, the basic basalt, neutral andesite and acidic granite are quickly distinguished by N-DP intersection map method, and the idea of “step by step stripping” is adopted in the interval, and tuff and volcanic breccia are identified by intersection map method. The results of lithology identification and the conclusion of core sheet analysis have a high degree of anastomosis, which effectively improves the accuracy of lithology identification.
Characteristics and evolution of the Paleogene overpressured top seal in Niuzhuang Sub-sag, Dongying Sag, Bohai Bay Basin
Authors: Zhang Tianjiao , Hu Yang , Feng Yuelin , Wang Yongshi , Han Hongwei , Yu Jingqiang , Zhang Weizhong , Shi Shilong , Li Xiaochen 
Published: July 2021

Abstract
The buried depth of overpressured top seal layer in Niuzhuang sub-sag is mainly 2700–3600m, which is characterized by deep center and shallow edge in plane. Its lithology is a combination of dark grey, grey mudstone and sandy mudstone. There are a large number of carbonate cements and clay minerals in the argillaceous rocks that form the top sealing layer. The diagenesis of mudstone occurs in the rapid transformation period of illite/smectite mixed layer minerals, and corresponds to a large number of carbonate cements. The displacement pressure, thickness and diagenetic intensity of overpressured top seal are important factors affecting its physical sealing ability. There are five evolution stages of overpressured top seal, namely, at the initial stage of settlement, the strata are normally compacted, and the development of overpressured top seal is not obvious; During the first stage of accumulation, the low-amplitude hydrocarbon generation in the deep sag was supercharged, and the overpressured top seal was initially formed. Intermittent period of reservoir formation, overpressure top seal uplift erosion; During the rapid subsidence period, the strata are undercompacted to form overpressure, and the overpressure top seal is re-formed. During the second stage of storage, the thickness of overpressure top seal increased to the maximum.
Experimental study on oil supply efficiency of under-race lubrication based on radial oil scoop
Authors: Qin Jingwen , Jiang Huiqing , Guo Hui , Wang Fuliang , Zhu Hui 
Published: July 2021

Abstract
Under-race lubrication is an efficient lubrication method of aeroengine bearings for achieving high DN values. In this paper, an experimental study on oil supply efficiency of under-race lubrication structure based on high rotation speed and small size radial oil scoop is carried out. The influence of rotation speed, nozzle diameter and oil temperature on oil supply efficiency are analysed. The research results can be used to guide the design of oil nozzle and under-race lubrication structure.
Discussion and application of establishing oil saturation model by stages
Authors: Liu Yanyu , Fu Xiaoliang , Zhao Zhi , Ma Hanying , Fu Xiaoli , Li Xuewei 
Published: July 2021

Abstract
Most of the old oilfields in China have entered the stage of ultra-high water cut development. In order to guide drilling wells and further exploitation, it is necessary to describe the remaining oil distribution at present accurately and quantitatively. At the same time, the focus of work should be shifted to the study of remaining oil distribution between wells. For the oilfields with wide area, large thickness, long history of production and many injection production wells, the calculation of numerical simulation is too large and the grid precision is coarse. Although the traditional modeling method of mixing new and old wells can ensure the grid precision, it cannot represent the current situation of the reservoir and play a guiding role in production, so it needs a new way, ensures the plane and vertical precision of the model (accuracy 10×10×0.5m), and through certain constraints, can accurately describe the current plane and vertical oil saturation distribution law of the oilfield, which provides a new direction for further exploitation of the oilfield.
Research on access efficiency and optimization of massive seismic data
Authors: Chen Fang , Wan Xiaolong , Wang Juan , Liu Feng , Yang Fenxiu 
Published: July 2021

Abstract
With the continuous development of exploration technology, the magnitude of seismic data is getting larger and larger, and the access efficiency of seismic data has become the main bottleneck in the process of seismic data processing. The cluster structure realizes the separation of computing and storage. The data is stored in the disk array, and the data is calculated in the computing node. The maximum network speed between each computing node and the management node is 1GB/s, and the total maximum network speed of all computing nodes is 5GB/S (peak value). In addition, for disk array, the maximum read speed can be ignored (more than 1GB/s) without considering the network bandwidth, while the maximum write speed is 350MB/s. In the process of data processing, it needs to flow between the disk array and the computing node, and its speed must be affected by the network bandwidth. Therefore, the theoretical maximum I/O speed of the system is 1GB/s for reading and 350MB/s for writing. To build a multi format seismic data model, the loading of the system before optimization can not support the original seismic data format, so the original seismic data (such as SEGY and SEGD) needs to be converted into the internal ATT format of the system. In this process, the whole original data needs to be read circularly, and the new file is written circularly, and then the new file is decompiled, Save the header part into the table in the database. Export is the opposite process, which needs to convert ATT format to SEGY or SEGD format.
Analysis on the geo-resistivity anomaly at Baoji Seismic Station of the Jiuzhaigou Ms7.0 earthquake
Authors: Sun Yu , Zhang Weichao 
Published: July 2021

Abstract
According to the geological structure and observation characteristics of Baoji Seismic Station, a variety of methods are used to process and analyze the geo-resistivity data of Baoji Seismic Station from 2014 to 2018, such as the fourier sliding method that removing annual variation, the anisotropic degree method of the geo-resistivity, the normalized monthly rate method and the difference method. The analysis of these geo-resistivity data was used to extract the precursory anomalies of the geo-resistivity at Baoji Seismic station before the Jiuzhaigou Ms7.0 earthquake, obtain the characteristics of the changes in the geo-resistivity data before and after the earthquake, find the possible causes of the data changes, and evaluate the observation efficiency of the geo-resistivity at Baoji Seismic Station.
Research on Coal Bolt Grouting and Solidification Technology for Increasing the Drainage Concentration of Along-bed Boreholes
Authors: Li Shengzhou 
Published: July 2021

Abstract
In order to increase the coal seam’s along-bed drilling concentration and to prevent roof leakage in roadways, the test has carried out research on coal bolt grouting and solidification to increase the along-bed drilling concentration. The results of the field investigation show that the coal After the body is grouted and solidified, it presents a shape similar to a cement block. The slurry enters the cracks of the coal body and forms a stronger whole after solidification. No roof leakage occurred in the coal roadway in the solidification section, and the roadway integrity was well controlled. After the anchor rod is grouted and solidified, the concentration of gas drainage in bedding boreholes is generally higher. The concentration of gas drainage in the initial drilling of the test group was 30% to 60%, and the average drainage concentration during the investigation was about 40%, and the attenuation was slower than that of the drilling in the control group. The effect of bolt grouting to solidify coal is obvious.
Experiment on formation mechanism of water film thickness in sandstone reservoir
Authors: Zhai Shuo , Li Yao , Gong Yufeng 
Published: July 2021

Abstract
In hydrophilic reservoirs, formation water exists in the rock void in the form of water film, and the existence of water film has a great influence on the oil and gas seepage in the formation. In this paper, based on Archie’s formula, the water film thickness in sandstone reservoir is tested, so as to study the formation mechanism of water film thickness. The results show that the larger the water saturation, the thicker the water film thickness and the smaller the gas flow channel.