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It is essential to predict carbon prices precisely in order to reduce CO2 emissions and mitigate global warming. As a solution to the limitations of a single machine learning model that has insufficient forecasting capability in the carbon price prediction problem, a carbon price prediction model (GWO–XGBOOST–CEEMDAN) based on the combination of grey wolf optimizer (GWO), extreme gradient boosting (XGBOOST), and complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is put forward in this paper. First, a random forest (RF) method is employed to screen the primary carbon price indicators and determine the main influencing factors. Second, the GWO–XGBOOST model is established, and the GWO algorithm is utilized to optimize the XGBOOST model parameters. Finally, the residual series of the GWO–XGBOOST model are decomposed and corrected using the CEEMDAN method to produce the GWO–XGBOOST–CEEMDAN model. Three carbon emission trading markets, Guangdong, Hubei, and Fujian, were experimentally predicted to verify the model's validity. Based on the experimental results, it has been demonstrated that the proposed hybrid model has enhanced prediction precision compared to the comparison model, providing an effective experimental method for the prediction of future carbon prices. [ABSTRACT FROM AUTHOR]

Taking the HD1 well as the research target, through intensive core sampling, experimental test analysis, comprehensive logging interpretation and other methods, the fracability of shale reservoirs was discussed in this paper. The results show that the Gufeng–Dalong Formation in the HD1 well has a high organic carbon content, and the organic-rich shale developed in the lower part of the Gufeng and Dalong Formations with thicknesses of 30 m and 15 m, respectively. For the low-porosity and ultralow-permeability shale reservoir type, the natural fractures are undeveloped in the lower part of the Dalong Formation, with a lower linear density, while they are well developed in the Xiayao and Longtan Formations and the lower part of the Gufeng Formation, and the interlayer bedding fractures are relatively developed. The Gufeng–Dalong Formation shale also has a high mineral brittleness index (average of 44.5%), high static Young's modulus (20–70 GPa), low static Poisson's ratio (0.10–0.31), and high horizontal pressure difference coefficient of two phases (0.17–0.56). It is concluded that the shale reservoir is favorable for fracture development in the lower part of the Dalong Formation, with depths of 1249–1289.5 m, and the lower part of the Xiayao, Longtan and Gufeng Formations, with depths of 1300–1335.3 m. Overall, the fracable shale section with high brittleness and rock strength is beneficial to fracturing. However, the existence of a large number of shale bedding fractures increases the complexity of the fractures, and at the same time, it has a certain negative impact on fracture generation. Double wing fractures are easily formed because of the high two-phase horizontal pressure difference. Therefore, the leakage caused by shale bedding fractures and the influence on the fracture height and extension length should be considered comprehensively in fracturing design. [ABSTRACT FROM AUTHOR]

In this paper, a graph convolution network prediction model based on the lioness optimization algorithm (LsOA-GCN) is proposed to predict the cumulative number of confirmed COVID-19 cases in 17 regions of Hubei Province from March 23 to March 29, 2020, according to the transmission characteristics of COVID-19. On the one hand, Spearman correlation analysis with delay days and LsOA are used to capture the dynamic changes of feature information to obtain the temporal features. On the other hand, the graph convolutional network is used to capture the topological structure of the city network, so as to obtain spatial information and finally realize the prediction task. Then, we evaluate this model through performance evaluation indicators and statistical test methods and compare the results of LsOA-GCN with 10 representative prediction methods in the current epidemic prediction study. The experimental results show that the LsOA-GCN prediction model is significantly better than other prediction methods in all indicators and can successfully capture spatio-temporal information from feature data, thereby achieving accurate prediction of epidemic trends in different regions of Hubei Province. [ABSTRACT FROM AUTHOR]

Based on Geoscience Laser Altimeter System onboard the Ice, Cloud, and land Elevation Satellite (ICESat/GLAS) data, this paper analyzes the vertical accuracy of four kinds of digital elevation model (DEM)dataset in Hubei Province, and discusses the influence of the geographical factors (slope, aspect, geomorphic and land-use types) on DEM data accuracy. The results show that: (1) Among the four kinds of DEM data in Hubei Province, the ALOS World 3D -30 m (AW3D30) offers the highest data accuracy; (2) High slope and vegetation coverage will affect DEM data accuracy, and AW3D30 data accuracy is the least affected by this; (3) No obvious relationship has been found between data accuracy and aspect. In addition, using ICESat/GLAS data as reference, this paper also attempts to improve the vertical accuracy of DEM by employing five machine learning based methods, the results show that each DEM dataset obviously outperform themselves by using the models selected in this paper. [ABSTRACT FROM AUTHOR]

Red slipped and painted wares (RSW and RPW) were manufactured to cook, serve, or store foods and liquids in the middle Yangtze River valley (MYRV) of China some 8500 and 7800 years ago, respectively. Their primary use narrowed down to serving and drinking in the Upper Qujialing (5300–4500 cal BP) and Shijiahe (4500–4200 cal BP) periods when initial states (bang guo) took shape and developed in the region. The increasing social complexity in MYRV correlated with the formation of community and neighborhood identity through rituals and socio-economic ties involving the widespread use of RSW and RPW. How the two wares were produced and used helps us understand the relationships among productive activities, identity, and social inequality in MYRV. This paper presents the first overview of RSW and RPW in the Neolithic MRYV. It introduces a multi-analytical study of the two wares—mostly dating to the Shijiahe period—unearthed from the site of Fenghuangzui in Xianyang City of Hubei Province, China. Optical microscopic examination revealed that the paint of RPW—50 μm thick on average—was applied using a brush while the slip of RSW is thinner and finer and possibly formed by self-slipping. Handheld X-ray fluorescence (hhXRF) and benchtop micro-XRF analyses ascribed the red paint or slip to iron and iron oxide. Raman and X-ray absorption fine structure analyses confirmed that iron was present in the paint or slip in the form of hematite with a poorly developed crystalline structure. Furthermore, thin-section petrography implied that different pastes were used to produce RPW and RSW, and hhXRF data indicated that the Upper Qujialing and Shijiahe pottery differ in the concentrations of five elements (Zr, Fe, Mn, Ti, and Ba), which might be helpful in future provenance studies of RSW and RPW. Our study discloses the complexity of the manufacture of RSW and RPW at Fenghuangzui. More details of RSW and RPW production and use from our ongoing project shall reveal the role of the two wares in the social dynamics of the Late Neolithic MYRV. [ABSTRACT FROM AUTHOR]

Since the Ming Dynasty, the flood disaster has been one of the important natural disasters affecting our country. However, relatively few studies on the evolution law of flood disaster at large spatial–temporal scales have been reported. Based on the datasets of flood stations from 1470 to 2000, this paper quantitatively analyzes and discusses the spatial and temporal evolution pattrens of floods in China in the past 500 years by using regional gravity center model, wavelet analysis, Daniel index, and M–K test, and predicts the trend of flood disasters in the future. The results show that: (1) Since 1470, there has been an increasing trend of flood intensity index in China;(2) From 1470 to 2000, there were two high centers of flood disaster in 1560 and 1925, respectively, and one low center appeared in 1745; (3) Flood risk changes from easy occurrence in the eastern coastal area to uniform spatial distribution over the whole study region; (4) In the past 500 years, the graver center of flood disaster is located in Baokang County, Hubei Province, and the gravity center of flood disaster shows a trend of moving to northwest both at time scales of 50-year and 100 year; (5) The flood disaster in the studied area will still show an overall upward trend in the future.The research can provide decision support for the precise prevention and control of flood disasters in China. [ABSTRACT FROM AUTHOR]

This study is the first systematic assessment of the Lower Ordovician microbial carbonates in Songzi, Hubei Province, China. This paper divides the microbial carbonates into two types according to growth patterns, namely nongranular and granular. The nongranular types include stromatolites, thrombolites, dendrolites, leiolites and laminites; the granular types are mainly oncolites and may include a small amount of microbiogenic oolite. According to their geometric features, the stromatolites can be divided into four types: stratiform, wavy, columnar and domal. Additionally, dipyramidal columnar stromatolites are identified for the first time and represent a new type of columnar stromatolite. The thrombolites are divided into three types: speckled, reticulated and banded. The grazing gastropod Ecculiomphalus and traces of bioturbation are observed in the speckled and reticulated thrombolites. This paper considers these two kinds of thrombolites to represent bioturbated thrombolites. These findings not only fill gaps in the field of domestic Ordovician bioturbated thrombolites but also provide new information for the study of thrombolites. Based on the analysis of the sedimentary characteristics of microbialites, the depositional environments of the various types of microbialites are described, and the distribution patterns of their depositional environments are summarized. The relationship between the development of microbialites and the evolution and radiation of metazoans during the Early to Middle Ordovician is discussed. Consistent with the correspondence between the stepwise and rapid radiation of metazoans and the abrupt reduction in the number of microbialites between the late Early Ordovician and the early Middle Ordovician, fossils of benthonic grazing gastropods (Ecculiomphalus) were found in the stromatolites and thrombolite of the study area. It is believed that the gradual reduction in microbialites was related to the rapid increase in the abundance of metazoans. Grazers not only grazed on the microorganisms that formed stromatolites, resulting in a continuous reduction in the number of stromatolites, but also disrupted the growth state of the stromatolites, resulting in the formation of unique bioturbated thrombolites in the study area. Hydrocarbon potential analysis shows that the microbialites in the Nanjinguan Formation represent better source rocks than those in the other formations. [ABSTRACT FROM AUTHOR]

Social interaction has become one of the key factors affecting the spatial reconstruction of rural settlements (SRRS). However, most studies ignored the multi-scale impact of social networks on the identification of restructuring types of rural settlements. This paper, taking Ezhou City of Hubei Province, China as the case study area, developed a potential inter-settlement network through considering settlements as nodes, and inter-settlement interactions induced by the spatial disparity of public facilities as edges, divided towns in Ezhou City into three zones based on community structure at the town level, and then identified four types of rural settlements in light of the characteristics of cluster patterns and centrality at the patch level. The results show that the inter-settlement network in Ezhou City presents apparent disparities in terms of community structure, cluster patterns and centrality. In community analysis, high inter-community and intra-community interactions are concentrated in well-developed areas in the north and east, while weak interactions between communities occur in the southern areas dominated by traditional agricultural production. Accordingly, three zones are divided such as the urban-leading zone, urban-rural integration zone and rural-leading zone. For the network centrality and cluster patterns, high-level rural settlements are mainly distributed in the urban-leading zone, followed by the urban-rural integration zone and the rural-leading zone. Moreover, the lump cluster pattern is observed in each zone, but the chain pattern and dispersed pattern largely occur in the rural-leading zone. At same time, four types of rural settlements are identified, namely urbanized settlements, central settlements, grassroots settlements and relocated settlements. The corresponding plans are discussed in different zones regarding urbanization, integration and characteristics to provide meaningful insights for policymakers to guide SRRS. This study would contribute to our understanding of the impact of social network involved in daily life on rural settlement reconstruction, and expect to provide theoretical and methodological support for rural sustainable development in practice. [ABSTRACT FROM AUTHOR]

Landslide displacement evolution is important for predicting landslide geological disasters. Because landslide displacement monitoring data are limited, in this paper we propose a novel model for predicting landslide displacement, namely the kernel grey model with fractional operators (FKGM). By combining the advantages of fractional modeling, kernel function methods and grey models, we derived the theoretical framework of FKGM. The parameters of FKGM were obtained using particle swarm optimization algorithm. Then, FKGM was applied in a case study of a landslide in Hubei, China. The engineering geological characteristics of the landslide were analyzed, and seven factors including rainfall and the rate of the reservoir water-level change were selected as inputs. The results show that the mean absolute percentage error and mean square error of FKGM are smaller than those of the least square support vector machine (LSSVM) and the classical grey prediction model—GM(1,1). The influence of the FKGM parameters was investigated. Our results indicate that FKGM can be applied to reliably predict large deformation of landslides. [ABSTRACT FROM AUTHOR]

This paper proposes an eigenvector spatial filtering-based (ESF-based) regression model for land cover pattern simulation in China's Hubei province. The significance and influence of biophysical, climatic, and socio-economic factors have been detected and analyzed in the study region. The ESF-based multinomial logistic regression (spatial model) is constructed for discrete choices to take spatial autocorrelation into consideration. For the massive raster pixels, a segmentation processing (grid-based partition) approach is employed to resolve the large datasets to smaller ones to improve calculation efficiency. Both 32 × 32 and 64 × 64 cell sizes are used to compare the differences and influence of these approaches. For the 32 × 32 cell size, the hitting ratio increased from 0.70 to 0.89 and the deviance decreased 65.6%. For the 64 × 64 cell size, the hitting ratio increased from 0.68 to 0.77 and the deviance decreased 33.2%. The fitted results and maps show that spatial autocorrelation (SA) plays an important role in land cover patterns. Besides, the ESF-based spatial model can isolate SA in land cover pattern simulation, and therefore can improve the fitting accuracy and decrease the model uncertainty. The experiment shows that ESF-based multinomial logistic regression method provides a promising approach for discrete choice regression for massive raster datasets. [ABSTRACT FROM AUTHOR]

Much remains unknown concerning the origin of the novel pandemic coronavirus that has raged across the globe since emerging in Wuhan of Hubei province, near the center of the People's Republic of China, in December of 2019. All current members of the family Coronaviridae have arisen by a combination of incremental adaptive mutations, against the backdrop of many recombinational events throughout the past, rendering each a unique mosaic of RNA sequences from diverse sources. The consensus among virologists is that the base sequence of the novel coronavirus, designated SARS-CoV-2, was derived from a common ancestor of a bat coronavirus, represented by the strain RaTG13, isolated in Yunnan province in 2013. Into that ancestral genetic background, several recombination events have since occurred from other divergent bat-derived coronaviruses, resulting in localized discordance between the two. One such event left SARS-CoV-2 with a receptor binding domain (RBD) capable of binding the human ACE-2 receptor lacking in RaTG13, and a second event uniquely added to SARS-CoV-2 a site specific for furin, capable of efficient endoproteolytic cleavage and activation of the spike glycoprotein responsible for virus entry and cell fusion. This paper demonstrates by bioinformatic analysis that such recombinational events are facilitated by short oligonucleotide "breakpoint sequences", similar to CAGAC, that direct recombination naturally to certain positions in the genome at the boundaries between blocks of RNA code and potentially RNA structure. This "breakpoint sequence hypothesis" provides a natural explanation for the biogenesis of SARS-CoV-2 over time and in the wild. [ABSTRACT FROM AUTHOR]

Rice wine, a traditional fermented alcoholic beverage in China, is produced with grains such as rice, which are fermented with saccharifying starter-koji. Its flavor quality is closely associated to the starter culture-koji, which is made by mixing botanical materials with high-class glutinous rice in certain ecological context. However, there are few reports on the microbial community structure of rice wine koji. In this paper, bacterial community structures of rice wine koji were analyzed using 16S rRNA gene sequencing based on Illumina MiSeq high-throughput technology in 20 samples collected from Xiaogan area, Hubei province and Dazhu area, Sichuan province (10 from each area). We found rice wine koji flora mainly consisted of Weissella, Lactobacillus, Lactococcus, Bacillus, Enterococcus, and Cronobacter, with relative abundances of 29.49%, 10.93%, 8.85%, 4.75%, 1.16% and 1.15%, respectively, as well as an accumulative average relative abundance of 58.71%. They all belonged to Firmicutes and Proteobacteria—the two known dominant genus. Genus-level PCA (Principal component analysis) and OTU-level PCoA (Principal coordinates analysis) based on unweighted UniFrac distances showed that the bacterial community structure differed significantly between the samples from the 2 areas. 7 OTUs were detected in all samples, accounting for 4.4% of the total qualified assembly. Among the 7 OTUs, 3 OTUs were identified as Enterococcus, 2 OTUs were identified as Cronobacter, 1 OTU was identified as Bacillus and 1 OTU was identified as Alkaliphilus. Fifty-eight lactic acid bacteria (LAB) strains were isolated from the 20 koji samples with traditional microbial methods. Among them, Enterococcus faecium and Pediococcus pentosaceus were the dominant LAB isolates, with relative abundances of 51.72% and 31.03%. Despite the differences, a large number of shared bacteria were detected in samples from the two areas. [ABSTRACT FROM AUTHOR]

This paper discusses the applicability of Kalman filter in 3D dynamic monitoring of environmental cost. By selecting Kalman filtering algorithm which is suitable for dynamic environmental cost monitoring, the three-dimensional state-space model of environmental cost and the three-dimensional observation system were established based on the analysis and test of the three-dimensional dynamic data of environmental cost. In addition, by analyzing the algorithm of 3D dynamic monitoring model of environmental cost, a three-dimensional state-space monitoring model of environmental cost based on Kalman filter was constructed. Finally, empirical research study of the cement manufacturing enterprise of Ezhou city of Hubei province was carried out. [ABSTRACT FROM AUTHOR]

This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in Hubei Province, the viewpoint of ′point-axis-area′ in the ′point-axis system′ theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of Hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of ′Wuhan Metropolitan Area′, ′Yichang-Jingzhou-Jingmen City Group′ and ′Xiangyang-Shiyen-Suizhou City Group′, which are defined by local development strategy in Hubei Province, are different from the above three urban groups. [ABSTRACT FROM AUTHOR]

Precipitation is an important climatic parameter, and its variability severely affects regional hydrological processes and water resource management. In order to explore the changing spatial and temporal characteristics of precipitation-related indices, including precipitation amounts indices, extreme precipitation indices, and precipitation concentration indices, in Hubei province, central China during 1961-2010, several precipitation-related indices series were analyzed using the Mann-Kendall test, Pettitt test, and inverse distance weighted interpolation method in this paper. The results are as follows: (1) A clear south-north gradient is apparent in the spatial distribution of the majority of precipitation-related indices, while the distribution of other indices (i.e., CDD, PCD, and PCP) is just the opposite. Most part of Hubei province can experience mixed positive and negative trends in precipitation-related indices. (2) The majority of precipitation-related indices exhibit an increasing trend, but most of which are not significant. July has the largest positive trend, with a regional average of 14.76 mm/decade. As for extreme precipitation indices, there exist large variations in Hubei, especially in R95pTOT. Besides, no obvious trends are shown in precipitation concentration indices. (3) With the exception of consecutive dry days (CDD), most of extreme precipitation indices are strongly correlated with annual mean precipitation (AMP) in Hubei. And the extreme precipitation indices are well correlated with each other except CDD and consecutive wet days (CWD). For six precipitation-related indices (i.e., SDII, RX1day, RX5day, R95pTOT R99pTOT, and PCD), there are significant positive relationships with Northern Hemisphere Subtropical High (NHSH) but significant negative relationships with Northern Hemisphere Polar Vortex (NHPV). Furthermore, the majority of precipitation-related indices have significant negative correlations with East Asian summer monsoon index (EASMI) and South China Sea summer monsoon index (SCSSMI), and the correlation coefficient with EASMI is higher than that with SCSSMI. [ABSTRACT FROM AUTHOR]

In this paper, two ancient thin-walled bronze vessels unearthed in Anlu County of Hubei Province, China, were studied systematically by using optical microscopy (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), electron backscatter diffraction (EBSD) and nanoindentation system, and also we calculated the Sn diffusion in a Cu substrate based upon the substitutional mechanism at high temperature. The results indicated that the vessels were possibly fabricated using the following processes: (1) alloying the high-tin Cu-Sn bronze; (2) casting the preliminary shape of the vessels; (3) forging the vessels in the temperature range of 586-798C; (4) simply wiping tinning on the surface of the vessel at high temperature; (5) quenching the vessels to room temperature; and (6) at last, grinding and polishing the surface of the vessels. It seems that the present thin-walled bronze vessels provide an evidence of the spread of thin-walled high-tin bronze technology in China and its surrounding regions. [ABSTRACT FROM AUTHOR]

High Cr (VI) concentration is a potential serious risk to environment and ecologic system. Thus, it is essential to effectively monitor Cr contamination in water systems and scientifically evaluate its evolution trend. A new method of in-situ tracer technique by Cr isotopic analysis for quantitatively estimating Cr-contamination and its regional evolution in natural waters as well as a case application are reported in this paper. Based on documented literatures, an experimental procedure for chemical separation and purification of Cr in water samples and its analytical method for Cr isotopic measurement by thermal ionization mass spectrometry (TIMS) are established. Eleven samples collected around a chemical factory in Hubei Province were analyzed by this technique. These samples show δ53Cr values ranging from -1.7‰ to 7.3‰ and an elevating trend with an increasing in distance from the sampling site to pollution source. A functional correlation following Rayleigh fractionation law was established between sample's δ53Cr value and its extent of Cr contamination. This study suggests that Cr isotopic analysis is an effective method to reveal the spatial distribution and its evolution trend of Cr contamination in the regional water system. It is thus helpful to assessing the self-purifying ability of local water system according to Cr isotopic fractionation. [ABSTRACT FROM AUTHOR]