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The Liuhe Pagoda in Hangzhou, China, has a large number of brick carvings from the Southern Song Dynasty (1152 ce), covering an area of 464 m2. However, the exquisite brick carvings in the Liuhe Pagoda have deteriorated due to natural weathering and a high‐humidity environment. Through laboratory analysis and on‐site nondestructive testing, the physical and chemical properties of the brick carvings of Liuhe Pagoda were investigated, and the weathering mechanism of the brick carvings was further analyzed. The brick carving of Liuhe Pagoda is composed of brick, white plastering and black coating. CaCO3 is the main component in white plastering, and the black coating on the top surface contains Chinese lacquer. The weathering products of the brick were analyzed and a trace of CaSO4.2H2O was found. In addition, the brick carvings with high water content have low Leeb hardness and severe weathering. Therefore, water and soluble salt are the main factors in weathering of the brick carvings of the Liuhe Pagoda. [ABSTRACT FROM AUTHOR]

The highly reactive erythritol dicarbonate (EDC) allows facile design and preparation of solvent‐ and catalyst‐free epoxyurethane polymers. Diglycidyl ether of bisphenol‐A (DGEBA) and oligo polyhydroxyurethanes are used to produce epoxyurethane polymers (o‐PHUs). The o‐PHUs are prepared using cyclic carbonates derived from erythritol and various diamines (aliphatic amine and polyether amine) or polyamines (diethylene triamine (DETA) and triethylne tetramine (TETA)). Active secondary amino groups derived from o‐PHUs polyamines form hydrogen bonds between urethane carbonyls in epoxy hybrid networks with the highest cross‐linking density (1293 mol m−3), glass transition temperature Tg (93 °C), and ultimate tensile strength (34 MPa). And the ether bond provides a significant potential for hydrogen bonding between hydroxyl group and ether oxygen, forming strong hydrogen bond cross‐linking between molecular chains, with cross‐linking density and ultimate tensile strength comparable to polyepoxyurethane derived from polyamines, except for a lower Tg (27 °C). In addition, these polyepoxyurethanes have superior adhesion to wood, aluminum alloy, and polymethyl methacrylate (PMMA) substrates. This versatile oligo PHUs would provide a wide range of fabrication options for adhesive epoxyurethane polymers. [ABSTRACT FROM AUTHOR]

Reservoir classification is a key link in reservoir evaluation. However, traditional manual means are inefficient, subjective, and classification standards are not uniform. Therefore, taking the Mishrif Formation of the Western Iraq as an example, a new reservoir classification and discrimination method is established by using the K‐means clustering method and the Bayesian discrimination method. These methods are applied to non‐cored wells to calculate the discrimination accuracy of the reservoir type, and thus the main reasons for low accuracy of reservoir discrimination are clarified. The results show that the discrimination accuracy of reservoir type based on K‐means clustering and Bayesian stepwise discrimination is strongly related to the accuracy of the core data. The discrimination accuracy rate of Type I, Type II, and Type V reservoirs is found to be significantly higher than that of Type III and Type IV reservoirs using the method of combining K‐means clustering and Bayesian theory based on logging data. Although the recognition accuracy of the new methodology for the Type IV reservoir is low, with average accuracy the new method has reached more than 82% in the entire study area, which lays a good foundation for rapid and accurate discrimination of reservoir types and the fine evaluation of a reservoir. [ABSTRACT FROM AUTHOR]

With the rapid development of shale gas in northeastern Sichuan province, problems such as low drilling rate, long drilling cycle and serious bit wear are becoming more and more prominent in shale gas drilling process. This paper proposes new prediction theory with two steps based on logging data sensitive to lithology by introducing Bayesian classifier and Self Adaptive Double Chain Quantum Genetic Algorithm (S-DC-QGA) which could optimize BP neural network prediction model. In the first step, the Bayesian network classifier achieved the classification and recognition of lithology, improved the correlation of model sample data, and enhanced the accuracy and speed of lithology classification. In the second step, S-DC-QGA characterized as the global optimization is used to optimize the number of hidden layer nodes, weights and thresholds of the BP neural network. Results showed that Bayesian lithologies classification enhanced the correlation of samples, moreover optimized BP neural network solved overfitting, random initial weights of BP itself and oscillation of fitting and generalization ability with slight change of network parameters, improving the prediction accuracy of rock drillability parameters and the generalization ability of the model. The findings of this study can help for better drilling design and improvement of mechanical drilling speed. [ABSTRACT FROM AUTHOR]

As the tight reservoir of Lucaogou Formation in Jimsar sag is characterized as large burial depth and poor physical properties, hydraulic fracturing technology is greatly needed to increase the production. Firstly, based on elastic theory, the borehole displacement formula under stress is derived, then the borehole quasi-ellipse characteristic model is proposed, on this basis, the in-situ stress prediction model based on borehole deformation is constructed. Secondly, the force analysis of diamond bit during drilling is performed, and the continuous prediction formula of elastic modulus based on weight on bit (WOB) and torque parameters is derived. Combined with these two steps, a new model of continuous in-situ stress prediction based on borehole deformation and drilling parameters is established. Compared with the values measured by the acoustic emission method in the laboratory, the deviation between the predicted in-situ stress values and those measured by the acoustic emission method is less than 4%, which meets the accuracy requirements of the fracturing in the oil field. The prediction results show that the minimum horizontal principal stress of Lucaogou Formation is 51.1–62.7 MPa, and the maximum horizontal principal stress is 58.9–69.1 MPa, respectively. The maximum horizontal principal stress direction is NW–SE direction with an angle of about 159°. The results show that the fracture direction in the study area is in accordance with the present in-situ stress direction, which is beneficial to the secondary reconstruction of natural fractures and keeps good opening property of fractures. This study provides a theoretical basis for in-situ stress prediction and compressibility evaluation of tight reservoir. [ABSTRACT FROM AUTHOR]

Mud shale, used in drilling engineering, is prone to hydration and expansion, resulting in creep deformation that leads to wellbore shrinkage and pipe sticking incidents. Studying the creep characteristics of mud shale is significant for designing a reasonable well structure and determining the lower limit of drilling fluid density. The influence of moisture content on rock strength and creep mechanical properties were studied using water absorption, uniaxial compression, and creep tests. Test results show that with an increase in the moisture content, the mud shale was damaged and softened; moreover, the elastic modulus decreased with increase in moisture content. Under the same load level, the instantaneous strain increased with increasing moisture content. Under different loading stresses, the creep of the rock had nonlinear characteristics, which could be divided into three different creep stages: attenuation, second, and accelerated creep. A new improved creep model based on the Nishihara model was established to describe the accelerated creep characteristics of mud shale under different moisture contents. The ageing degradation and water-bearing weakening effects were introduced. The Levenberg–Marquardt nonlinear least-squares method was applied to invert the creep parameters. The results show that the simulated creep curves, generated using the new creep model, conform to the experimental ones. The relationship between the drilling fluid density and wellbore shrinkage ratio can be defined using this model; it provides a reference for reasonably determining the drilling fluid density. [ABSTRACT FROM AUTHOR]

Mud shale, used in drilling engineering, is prone to hydration and expansion, resulting in creep deformation that leads to wellbore shrinkage and pipe sticking incidents. Studying the creep characteristics of mud shale is significant for designing a reasonable well structure and determining the lower limit of drilling fluid density. The influence of moisture content on rock strength and creep mechanical properties were studied using water absorption, uniaxial compression, and creep tests. Test results show that with an increase in the moisture content, the mud shale was damaged and softened; moreover, the elastic modulus decreased with increase in moisture content. Under the same load level, the instantaneous strain increased with increasing moisture content. Under different loading stresses, the creep of the rock had nonlinear characteristics, which could be divided into three different creep stages: attenuation, second, and accelerated creep. A new improved creep model based on the Nishihara model was established to describe the accelerated creep characteristics of mud shale under different moisture contents. The ageing degradation and water-bearing weakening effects were introduced. The Levenberg–Marquardt nonlinear least-squares method was applied to invert the creep parameters. The results show that the simulated creep curves, generated using the new creep model, conform to the experimental ones. The relationship between the drilling fluid density and wellbore shrinkage ratio can be defined using this model; it provides a reference for reasonably determining the drilling fluid density. [ABSTRACT FROM AUTHOR]

In this study, porous hierarchical bronze/anatase phase junction TiO2 assembled by ultrathin two-dimensional nanosheets was prepared by a novel, green and simple deep eutectic solvent-regulated strategy. Due to its structural features, the TiO2 sample exhibited enhanced photocatalytic activities for multiple kinds of antibiotics, including ofloxacin, ciprofloxacin and chloramphenicol. [ABSTRACT FROM AUTHOR]

Based on data of core, thin section, well logging and capillary pressure curves, starting from rock and pore types, reservoir classification is carried out integrating macro and micro perspectives, which can comprehensively reflect the relationship between pore and permeability and micro-pore structure of reservoir and seepage ability. Studied area was subdivided into five kinds of reservoirs, i.e., Class I, Class II, Class III, and Class IV and Class V. Among them, quality of the Class I, dominated by rudstone, were the best with high-porosity and ultra-high-permeability. The quality of reservoirs gradually deteriorated from Class I to Class V. Studies revealed that the formation of reservoirs was affected by sequence stratigraphy, sedimentation, and diagenesis strongly. The high-water system tract and transgressive system tract form a vertical periodic distribution of reservoirs. Reef flats and open platform facies were more conducive to the formation of high-quality reservoirs, such as grainstone, while subtidal zone and lagoon facies were more favorable for the formation of mud supported structure, such as wackstone and mudstone. Late dissolution played major roles in the increase of secondary pores, such as vugs and moldic pores. Cementation, compaction and micritization reduced primary pore and reduced reservoir quality. The new reconstructed parameters RG (resistivity to natural gamma ray ratio, RG = ILD/GR) and RD (acoustic time difference to density ratio, RD = DT/ RHOB) could be used to accurately identify reservoir types. The results show that prediction accuracy of this method is up to 90%, which can meet the requirements of fine reservoir evaluation. [ABSTRACT FROM AUTHOR]

Rock typing is an extremely critical step in the estimation of carbonate reservoir quality and reserves in the Middle East. In order to recognize the rock types of carbonate reservoirs in the Mishrif Formation better, classify the reservoirs accurately, and establish the permeability model in line with the study area precisely, it is necessary to study the recognition method conforming to the actual situation of the study area. The practice shows that the current recognition methods based on capillary pressure curve, flow unit and NMR logging data can effectively distinguish rock types, but a large number of accurate experimental data are required, which can only be applied in a few cored well, however, cannot be applied in the whole oil field. In this study, based on core, thin section, logging data, the sedimentary characteristics of carbonate reservoir, logging response of four rock types as well as porosity and permeability characteristics of Mishrif Formation in W are comprehensively studied. Based on Bayesian stepwise discriminant theory in multivariate statistics, the Bayesian discrimination model based on conventional logging data is established. The examining results showed that, compared with the description of logging and coring, the accuracy of Bayesian discriminant model and cross confirmation rate have achieved more than 80% for the original sample. Reliability verification showed that the matching degree of the rock type recognized in the non-cored well with the core and mud logging was as high as 90%, which matched the depositional environment of the entire region. The study results confirm the validity and generalizability of the Bayesian method to identify and predict rock types, which can be applied to the entire Middle East region to solve the problem of the lack of core data to accurately evaluate the quality of non-cored wells and accurately predict production, meeting the needs of actual reservoir evaluation and production development in the Middle East. [ABSTRACT FROM AUTHOR]

Rock typing is an extremely critical step in the estimation of carbonate reservoir quality and reserves in the Middle East. In order to recognize the rock types of carbonate reservoirs in the Mishrif Formation better, classify the reservoirs accurately, and establish the permeability model in line with the study area precisely, it is necessary to study the recognition method conforming to the actual situation of the study area. The practice shows that the current recognition methods based on capillary pressure curve, flow unit and NMR logging data can effectively distinguish rock types, but a large number of accurate experimental data are required, which can only be applied in a few cored well, however, cannot be applied in the whole oil field. In this study, based on core, thin section, logging data, the sedimentary characteristics of carbonate reservoir, logging response of four rock types as well as porosity and permeability characteristics of Mishrif Formation in W are comprehensively studied. Based on Bayesian stepwise discriminant theory in multivariate statistics, the Bayesian discrimination model based on conventional logging data is established. The examining results showed that, compared with the description of logging and coring, the accuracy of Bayesian discriminant model and cross confirmation rate have achieved more than 80% for the original sample. Reliability verification showed that the matching degree of the rock type recognized in the non-cored well with the core and mud logging was as high as 90%, which matched the depositional environment of the entire region. The study results confirm the validity and generalizability of the Bayesian method to identify and predict rock types, which can be applied to the entire Middle East region to solve the problem of the lack of core data to accurately evaluate the quality of non-cored wells and accurately predict production, meeting the needs of actual reservoir evaluation and production development in the Middle East. [ABSTRACT FROM AUTHOR]

The uniqueness of brick-carved cultural relics causes a higher requirement for restoration techniques and repair materials. Considering the weather resistance and compatibility with the original substrate bricks, three types of inorganic binders were selected as alternative options for brick carving restoration: Ca-based hydraulic lime, Si-based silica sol, and Mg-based magnesium oxychloride. Multiple experiments were conducted to investigate the compatibility of the replica bricks produced using these binders. The adhesive properties and infiltration reinforcement of the binders were also taken into consideration to evaluate the feasibility of these materials' application for the restoration of brick-carving cultural relics. The results showed that the Mg-based cementitious material led to the best performance, maintaining their original physical properties while restoring the original cohesion. A successful in situ test was conducted on the Southern Song brick carvings (1152 CE) inside the Liuhe Pagoda (Fig. 1 a) in Hangzhou. • Inorganic magnesium based cementitious materials can be used to repair weathered brick carvings, with effective results. [ABSTRACT FROM AUTHOR]

Diagenesis is one of the most predominant factors controlling reservoir quality in the deeply buried siliciclastic sandstones of the third member in the Eocene Shahejie Formation (Es3), in the Raoyang Sag, the Bohai Bay Basin. In this study, thin section, cathodoluminescence (CL), scanning electron microscope (SEM), X-ray diffraction (XRD), Raman spectrum, carbon and oxygen isotopes, and fluid inclusion analyses are used to restructure paragenetic sequences and detect origins of carbonate cements recorded in this deeply buried member. Based on petrographic analyses, the Es3 sandstones are identified as lithic arkoses and feldspathic litharenites at present, but derived from original arkoses and lithic arkoses, respectively. Geohistorically, the Es3 sandstones have undergone two diagenetic episodes of eogenesis and mesogenesis. Events observed during eogenesis include chemical compaction, leaching of feldspar, development of chlorite coating and kaolinite, precipitation of the first generation of quartz overgrowth (QogI), dissolution of feldspar, and precipitation of calcite and nonferroan dolomite cement. Mesogenetic alterations include chemical compaction, precipitation of kaolinite aggregate and the second generation of quartz overgrowth (QogII), precipitation of ankerite, development of I/S and illite, and formation of pyrite. Carbon and oxygen isotopic data show that calcite cements are characterized by 13C ( δ 13 C PDB ranging from -0.7‰ to 1.0‰ with an average of 0.1‰) and 18O ( δ 18 O SMOW varying from 12.3‰ to 19.0‰ with an average of 16.2‰); these stable isotopic data combined with Z value (from 114.69 to 122.18) indicate skeletal debris ( δ 13 C PDB ranging from -1.2‰ to -1.1‰ with an average of -1.15‰; δ 18 O SMOW varying from 23.0‰ to 23.2‰ with an average of 23.1‰) and ooids in adjacent carbonate beds involved in meteoric water and seawater from outside jointly served as the carbon sources. For nonferroan dolomite, the δ 13 C PDB value of -4.1‰ is a little bit negative than the calcite, and the δ 18 O SMOW of 14.3‰ is coincident with the calcite, which suggest the nonferroan dolomites come from the diagenetic fluids with a similar oxygen isotopic composition to that of the calcite but modified by the external acidic δ 13C-depleted water. However, the ankerites are actually rich in 12C ( δ 13 C PDB ranging from -10.0‰ to -1.2‰, mean = − 4.3 ‰) and 16O ( δ 18 O SMOW varying from 10.1‰ to 19.4‰, mean = 14.9 ‰), when combined with the distribution of cutting down along the direction pointing to sand-body center from the margin and microthermometric temperature (Th's) data mainly varying between 115.2°C and 135.5°C with an average of 96.0°C, indicating the main origination from the Es3 source rocks with effective feldspar buffer action for the acidic fluids in the margins of the Es3 sandstones. In addition, the necessary elements for ankerite such as Fe2+, Ca2+, and Mg2+ ions also come from organic matter and clay minerals during thermal maturation of the Es3 source rocks. The study provides insights into diagenetic processes and origination of carbonate cements in the Es3 sandstones; it will facilitate the cognition of predictive models of deeply buried sandstone reservoirs to some extent, which can reduce the risks involved in oil and gas exploration and development. [ABSTRACT FROM AUTHOR]

Herein, novel coin tree-like TiO2 moieties with lots of anatase–rutile phase junctions were constructed by a general, simple, and environmentally friendly strategy. The anatase/rutile ratios can be easily tuned by changing the ratios of the two H-bond donors. Owing to this featured shape, the TiO2 sample displays robust photocatalytic activity and better stability. [ABSTRACT FROM AUTHOR]

Constraint relaxation is widely used in electricity market clearing to obtain an acceptable solution when the market model is infeasible facing conflicting operating requirements. However, the penalty factors added in the objective function cause extremely high price spikes. Such a problem is currently handled by ad-hoc manners in power industries. After summarizing the current industrial practice and relative problems, we present a unified pricing model under constraint violations, which considers the prices as decision variables. Theoretical proof shows that the proposed method is capable of representing LMP with price spikes and current industrial practice. Hence, the pricing model has the ability of achieving more desired prices under the same pricing requirements. Furthermore, this paper presents a practical implementation of this unified model. The minimization of uplift payments, which is caused by the split of pricing and scheduling, is used as the objective function. This model can be transformed to a linear formulation without accuracy loss. Case studies show that the proposed pricing method brings distinct advantages compared with current industrial practices. [ABSTRACT FROM AUTHOR]

This paper considers the cost-driven optimal energy management strategy under a complex environment, multimicrogrids system. To provide the flexibility of load in depth, the heating, ventilating, and air conditioning (HVAC) load is investigated and explicitly formulated incorporated with indoor temperature dynamic function. The operation cost of wind generation includes the basic cost and additional cost to deal with the uncertainty of wind generation, which provides the tradeoff between optimality and possibility. Furthermore, the energy management problem of multimicrogrid is presented according to different characteristics of generation devices, storage devices, and load. A distributed neurodynamic algorithm is presented to solve the nonsmooth optimization of energy management of multimicrogrids system. By this method, the only information exchanged among microgrids is the intermediate variable when computing. The simulation results validate the effectiveness of the proposed cost-driven energy management strategy. [ABSTRACT FROM AUTHOR]

A supersonic mixing layer at a convective Mach number of 0.8 was investigated by large eddy simulation. Turbulent structures and statistics of the mixing layer interacting with an oblique shock at different strengths in the self-preserving stage were investigated and compared with the shock-free mixing layer. An inflection point arises on the velocity profiles in the self-preserving region where the incident shock wave impinges, in addition to the three inflection points existing in the shock-free mixing layer. It is caused by the hairpin vortices induced through the baroclinic mechanism of the interaction of the incident shock wave. However, the induced hairpin vortices disappear quickly within a short distance. The vorticity thickness of the shocked-mixing layer experiences a sudden decrease in the vicinity of the shock impingement point, which is due to the induced hairpin vortices, followed by a more rapid growth than that of the shock-free mixing layer. So the incident shock has positive effects on the growth of the mixing layer. Both the hairpin vortices and the vortices originated from the hairpin vortices can result in a double-peak profile of the streamwise Reynolds stress in the transient stage of the mixing layer. In addition, the asymmetric profiles for the Reynolds stress are due to the hairpin vortices breakup earlier in the upper stream. The amplitudes of the Reynolds stress increase slightly and their peak positions move toward the center of the mixing layer even in the self-preserving stage. Moreover, the profiles of the transverse Reynolds stress and Reynolds shear stress have two peaks for the shocked-mixing layer which are caused by the reflected shock waves and the mixing layer. The incident shock increases energy transport and convection between the mixing layer and the mainstream. As a result, the mixing process of the shocked-mixing layer is enhanced. [ABSTRACT FROM AUTHOR]

Abstract: An unprecedented indium‐mediated palladium‐catalyzed allylic alkylation of isatins with alkynes is disclosed. This reaction provides a new, practical, and straightforward route to access 3‐allyl‐3‐hydroxy‐2‐oxindoles in good yields with broad substrate scope and scalability, exhibiting high atom and step economy. A primary mechanistic study reveals that indium played two roles in the reaction, first as a reductant and second as a Lewis acid. Compared with previous methods, our strategy eliminated the steps for the separation and purification of the reaction intermediates, as well as pre‐installing leaving groups to allylic substrates. Moreover, our reaction did not employ moisture‐sensitive allylic metal species and stoichiometric oxidants. [ABSTRACT FROM AUTHOR]

An efficient one-pot approach for the synthesis of spiro[2.5]octa-4,7-dien-6-ones by employing para-quinone methides has been developed. The reaction proceeded smoothly in high yields under mild conditions without the use of metals. Moreover, all products obtained herein contained two or three consecutive quaternary centers. [ABSTRACT FROM AUTHOR]

Abstract: Here, we introduce an integrated biochip which offers accurate thermal control and sensitive electrochemical detection of DNA amplification in real-time. The biochip includes a 10-μl microchamber, a temperature sensor, a heater, and a contactless impedance biosensor. A pair of interdigitated electrodes is employed as the impedance biosensor and the products of the amplification are determined directly through tracing the impedance change, without using any labels, redox indicators, or probes. Real-time monitoring of strand-displacement amplification and rolling circle amplification was successfully performed on the biochip and a detection limit of 1nM was achieved. Amplification starting at an initial concentration of 10nM could be discriminated from that starting at 1nM started concentration as well as from the negative control. Since an insulation layer covers the electrodes, the electrodes are spared from erosion, hydrolysis and bubble formation on the surface, thus, ensuring a long lifetime and a high reusability of the sensor. In comparison to bench-top apparatus, our chip shows good efficiency, sensitivity, accuracy, and versatility. Our system requires only simple equipments and simple skills, and can easily be miniaturized into a micro-scale system. The system will then be suitable for a handheld portable device, which can be applied in remote areas. It covers merits such as low cost, low-power consumption, rapid response, real-time monitoring, label-free detection, and high-throughput detection. [Copyright &y& Elsevier]

The original article can be found online at https://doi.org/10.1038/s41598-021-98154-x. Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-021-98154-x, published online 20 September 2021 In the original version of this Article Xinxin Fang and Hong Feng were incorrectly listed as equally contributing authors. [Extracted from the article]

[Display omitted] • We examined the association of SC/MCCPs with kidney function. • SC/MCCPs positively correlated with male eGFR. • SC/MCCPs were not associated with female eGFR. • SC/MCCPs may be a risk factor for early-stage kidney impairment in males. Chlorinated paraffins (CPs) are contaminants ubiquitously detected in environmental samples, and reports addressing CPs in human samples are expanding. While CP exposure was suggested to impair kidney function by in vivo / in vitro experiments, epidemiological evidence is lacking. To examine the associations between serum total short-chain CP and medium-chain CP concentrations (∑SCCPs and ∑MCCPs) with human kidney function. The study samples were obtained from 387 participants living in Jinan, North China. We quantified ∑SCCPs and ∑MCCPs in serum samples and evaluated the kidney function of included subjects by estimated glomerular filtration rate (eGFR). The associations between serum ∑SCCPs, ∑MCCPs and eGFR were estimated using multivariable linear regression and logistic regression. The possible gender-dependent effects were studied by stratified analysis. After adjusting for age, education, smoking status, drinking status, body mass index (BMI), family history of chronic kidney disease (CKD), fasting serum glucose, systolic blood pressure and diastolic blood pressure, higher concentrations of serum ∑SCCPs and ∑MCCPs were associated with higher male eGFR (β = 3.13 mL/min/1.73 m2 per one ln-unit increase of serum ∑SCCPs, 95%CI: 1.72, 4.54, p = 0.016; β = 3.52 mL/min/1.73 m2 per one ln-unit increase of serum ∑MCCPs, 95%CI: 1.89, 5.17, p = 0.011). Associations between serum ∑SCCPs, ∑MCCPs and female eGFR were null. Comparing higher (above the median serum CP levels) vs. lower exposure groups, serum ∑SCCPs and ∑MCCPs were associated with an elevated risk of glomerular hyperfiltration (GH, eGFR ≥ 135 mL/min/1.73 m2), which was associated with glomerular damage and represented as an early stage of chronic kidney disease (OR = 2.98; 95% CI: 1.24, 4.71 for SCCPs; OR = 3.25; 95% CI: 1.20, 5.29 for MCCPs). Our study suggests that male serum ∑SCCPs and ∑MCCPs are associated with an increased risk of GH, indicating early-stage kidney impairment. [ABSTRACT FROM AUTHOR]

A series of qualitative descriptions and quantitative analyses was used to determine the lithofacies characteristics and recognize the favorable shale intervals of Dawuba Formation in the Ziyun area of South Qian Depression. The qualitative descriptions include core description and scanning electron microscope (SEM) observation. The quantitative analyses include X-ray diffraction, total organic content analysis, vitrinite reflectance, maceral composition, porosity, and permeability, as well as gas and element composition. The Dawuba Formation could be divided into four members. In general, the shale in the first and third members showed similarly high organic matter content with most samples in range of 2–2.5% and higher brittle mineral content with a content of quartz 40.53% and 33.21%, respectively, compared with the other two members, as well as high gas content. However, the first member shale samples exhibited much higher porosity and permeability than the third member shale samples. Furthermore, the shale gas in the first member was chiefly composed of methane (average: 83.63%), while that in the third member mainly consisted of nitrogen (average: 79.92%). Hence, the first member should be regarded as the most favorable target. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "1,6-Conjugated Addition-Mediated [2 + 1] Annulation: Approach to Spiro[2.5]octa-4,7-dien-6-one." by Zhenbo Yuan published in the "Journal of Organic Chemistry" in 2015.

The scalable metal-free one-pot approach delivers the products with up to three consecutive quaternary centers in generally high yields. [ABSTRACT FROM AUTHOR]

Viruses encounter numerous host factors that facilitate or suppress viral infection. Although some host factors manipulated by viruses were uncovered, we have limited knowledge of the pathways hijacked to promote viral replication and activate host defense responses. Turnip mosaic virus (TuMV) is one of the most prevalent viral pathogens in many regions of the world. Here, we employed an isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomics approach to characterize cellular protein changes in the early stages of infection of Nicotiana benthamiana by wild type and replication-defective TuMV. A total of 225 differentially accumulated proteins (DAPs) were identified (182 increased and 43 decreased). Bioinformatics analysis showed that a few biological pathways were associated with TuMV infection. Four upregulated DAPs belonging to uridine diphosphate-glycosyltransferase (UGT) family members were validated by their mRNA expression profiles and their effects on TuMV infection. NbUGT91C1 or NbUGT74F1 knockdown impaired TuMV replication and increased reactive oxygen species production, whereas overexpression of either promoted TuMV replication. Overall, this comparative proteomics analysis delineates the cellular protein changes during early TuMV infection and provides new insights into the role of UGTs in the context of plant viral infection. [ABSTRACT FROM AUTHOR]

This study presents the reservoir characterization of the unconventional, organic-rich dolomitic tight-oil reservoir of the Lower Cretaceous Xiagou Formation in the Qingxi Sag, Jiuquan Basin. To better describe pore characteristics and understand contributors to pore development of the mixed siliciclastic-carbonate reservoirs, samples were examined by thin section, X-ray diffraction (XRD) analysis, total organic carbon (TOC) and Rock-Eval pyrolysis, porosity and permeability measurement, field emission scanning electron microscopy (FESEM), and nuclear magnetic resonance (NMR). Four types of laminations, including carbonate lamination, siliceous lamination, argillaceous lamination and organic matter lamination, are developed. The average TOC of 1.67% and calculated Ro of 0.72%–0.96% indicate that the Xiagou source rocks are qualifed oil-source. Various types of pores with different sizes and micro-fractures are observed in such tight, mixed siliciclastic–carbonate reservoirs. Compared to mudstone/shale and tight sandstone, the tight and mixed siliciclastic–carbonate reservoirs are characterized by: (1) widely developed and multiple types of lamina structure, (2) various pore types without secondary OM pores generated by organic matter conversion, (3) wide pore size distributions, and (4) abundant and multiple genetic types of micro-fractures. The difference in mineral composition is the primary cause of different pore structure characteristics. Dolomitic mudstone is dominated by interlayer pore of clay mineral, while argillaceous dolomite is characterized by interparticle fractures, interparticle pores, and micro-fractures (including shrinked micro-fracture). In dolomitic siltstone, the residual intergranular pore and intergranular dissolved pore are the most common pores. The nanopore occurs widely in all lithologies, but the proportion of micrometers-scale pores and macro-scale nanopore increases from dolomitic mudstone to argillaceous dolomite and dolomitic siltstone. The positive correlation between porosity/permeability and TOC indicate the existence of pores or micro-fractures within or along the edge of organic matters. The similar thermal maturity level (Ro 0.72%–0.96%) eliminates maturation as a variable in porosity development in the studying area. The lithofacies associations with high-quality source rocks and reservoirs (relatively high porosity and permeability or rich in brittle minerals) are the favorable targets. [ABSTRACT FROM AUTHOR]

Investigating shale pore characteristics has deepened our understanding of shale reservoir, while that of postmature-overmature shales is yet to be revealed, which is especially critical for shale gas evaluation in southern China. Ten Middle-Upper Devonian organic-rich shale samples were collected from well GY-1 in the Guizhong Depression, and the paleoenvironment, geochemistry, and pore system were analyzed with a series of experiments, including trace element analysis, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), low-pressure N2 adsorption, and source rock geochemistry. Results show that the Middle-Upper Devonian shales in the Guizhong Depression are organic-rich mudstones with TOC ranging from 0.14% to 6.21%, which is highest in the Nabiao Formation ( D 2 n) and Lower Luofu Formation ( D 2 l) that were deposited in the anoxic and weak hydrodynamic deep-water shelf. They are thermally postmature to overmature with equivalent vitrinite reflectance (EqV R o ) of 3.40%~3.76% and type I kerogen. The lithofacies in D 2 n and D 2 l are primarily siliceous/argillaceous mixed shale as well as a few siliceous argillaceous shales and argillaceous siliceous shales as well. Organic matter- (OM-) hosted pores within bitumen are primary storage volume, rather than inorganic pores (interparticle and intraparticle) which are rare. The total helium porosity of samples varies between 1.20% and 4.49%, while total surface area and pore volume are 2.39-14.22 m2/g and 0.0036-0.0171 ml/g, respectively. Porosity, pore surface area, and pore volume are in accordance with increasing TOC, R o , and siliceous mineral contents. Considerable OM-macropores are found in shales with R o > 3.6 % in our study which demonstrates that the porosity at postmature to overmature stage ( R o = 3.5 − 4.0 %) does not change fundamentally. The high level of maturity is not considered the main controlling factor that affects shale gas content, and more attention should be paid to preservation conditions in this area. [ABSTRACT FROM AUTHOR]

LOX/GCH4 pintle injector is suitable for variable-thrust liquid rocket engines. In order to provide a reference for the later design and experiments, three-dimensional numerical simulations with the Euler-Lagrange method were performed to study the effect of the initial particle diameter on the combustion characteristics of a LOX/GCH4 pintle rocket engine. Numerical results show that, as the momentum ratio between the radial LOX jet and the axial gas jet is 0.033, the angle between the LOX particle trace and the combustor axial is very small. Due to the large recirculation zones, premixed combustion mainly occurs in the injector wake region. As the initial LOX particle diameter increases, the LOX evaporation rate and the combustion efficiency decrease until the combustion terminates with the initial LOX particle diameter greater than 110 μm. The oscillation amplitude of the combustor pressure increases significantly along with the increase of the initial LOX particle diameter, and the low-frequency unstable combustion occurs when the initial LOX particle diameter exceeds 60 μm. The combustor pressure oscillation at about 40 Hz couples with the swinging process of spray and flame, while the unsteady LOX evaporation amplifies the combustor pressure oscillations at 80 Hz and its harmonic frequency. [ABSTRACT FROM AUTHOR]

The Qaidam Basin is the one of the three major petroliferous basins in northeastern Tibetan Plateau, which has experienced multiphase superimposition and transformation. The study of thermal history not only plays an important role on revealing the tectonic origin of the Qaidam Basin and the forming mechanism and uplift history of the Tibetan Plateau, but also can provide scientific evidence for the assessment of oil and gas resources. This work used balanced cross‐section technique and apatite fission track ages with modeling of fission track length distribution to infer that the eastern Qaidam Basin has experienced significant tectonic movement in the Early Jurassic movement (∼200 Ma), which caused the carboniferous uplift and denudation, the geological movement in the Late Cretaceous, characterized by early stretching and late northeast‐southwest extrusion; the Himalayan movement in multi‐stage development in eastern Qaidam Basin, which can be divided into the early Himalayan movement (41.1–33.6 Ma) and the late Himalayan movement (9.6–7.1 Ma, 2.9–1.8 Ma), and large‐scale orogeny caused pre‐existing faults reactivated in late Himalayan movement. On the basis of burial history reconstruction, the thermal history of eastern Qaidam Basin was restored. The result shows that the thermal history in eastern Qaidam Basin shows slow cooling characteristics; the paleo‐geothermal gradient of eastern Qaidam Basin was 38–41.5°C/km, with an average value of 39.0°C/km in the Late Paleozoic, 29–35.2°C/km, with an average value of 33.0°C/km in the Early Paleogene; the geothermal gradient of the Qaidam Basin increased in the Late Paleogene, which was similar to the present geothermal gradient in the Late Neogene. The characteristics of the tectono‐thermal evolution since Paleozoic in the eastern Qaidam Basin are mainly controlled by magmatic thermal events in the study area. [ABSTRACT FROM AUTHOR]

In the present study, according to the borehole transient electromagnetic method, the transceiver is placed into the borehole in front of the heading face for the purpose of detection. This can not only avoid the interference of metal support in the roadway, but also detect the hidden disaster-causing water body within a short distance. However, there is an issue of abnormal location in borehole transient electromagnetic method. In order to determine the location of transient electromagnetic anomalies in the borehole, the transient electromagnetic three-dimensional forward modeling is used to analyze the response characteristics of three components. According to the response characteristics of the horizontal component of the abnormal body in different quadrants, a method for calculating the rotation angle of the XOY plane of the abnormal center is proposed, based on the amplitude of the horizontal component and the abnormal quadrant. The resistivity of each depth calculated by the vertical component is regarded as an independent abnormal body, and the depths' mapping relationship with the sampling time is established. Next, based on K-means clustering, the corresponding characteristic value of horizontal component anomaly curve are binary classified, and the resistivity distribution quadrant of the entire data set is automatically divided. Finally, the borehole transient electromagnetic inversion resistivity stereo imaging method is obtained. The algorithm of this paper is used to calculate the stereo imaging of the three-dimensional numerical model, and the results show that the algorithm achieves good results for the small-scale and low resistivity abnormal body in the radial direction of the borehole. In summary, the method of borehole transient electromagnetic stereo imaging based on clustering is an organic combination of geophysics and machine learning, which can provide technical support for advanced detection and fine interpretation of hidden water damage in underground heading faces. • Summarizing characteristics of horizontal component of low resistivity abnormal • Proposing method of abnormal body quadrant and XOY plane rotation angle algorithm • Classifying whole data set of TEM horizontal component anomaly field with K means • Establishing mapping of vertical component radial inversion depth and sampling time • Deducing stereo imaging method of borehole radial inversion resistivity [ABSTRACT FROM AUTHOR]

Human exposure to chlorinated paraffins (CPs) has been expected and assessed by external pathways considering their pervasive environmental occurrence. However, the deficiency of external exposure assessment in characterizing human burden is unavoidable. In addition, the associations between health outcomes and CP contents in human biospecimen are rarely assessed. In this study, we reported the occurrence and homologue profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in serum samples from 145 residents aged from 50 to 84 in Jinan, Shandong Province of China using quadrupole time-of-flight high-resolution mass spectrometry coupled with atmospheric pressure chemical ionization source operated in negative ion mode (APCI-qTOF-HRMS). The associations between serum CP concentrations and hematologic parameters were further analyzed by linear regression. We identified high level of ∑SCCPs (median = 107 ng/g wet weight, ww; 13,800 ng/g lipid, lw), ∑MCCPs (median = 134 ng/g ww; 15,200 ng/g lw) and elevated ∑MCCPs/∑SCCPs (median = 1.12) in serum of the studied population. C 13 -CPs and C 14 -CPs were the most abundant SCCP and MCCP groups, respectively. While the predominant chlorine homologues among SCCPs and MCCPs were Cl 7 – 8 -CPs. ∑SCCPs, ∑MCCPs, ∑MCCPs/∑SCCPs and the homologue patterns presented no significant variance among age, sex and BMI groups. Further explorations suggested that perturbation of hematologic homeostasis could be induced by CP exposure in a sex-specific way, reflected by significant negative associations of serum SCCP and MCCP concentrations in lipid weight basis with sex-specific hematologic parameters. This study suffered from some limitations and should be interpreted with caution. However, the CP burdens of residents in China and the subsequent health risks must be underscored. Unlabelled Image • It is the first study exploring possible adverse effects of CP exposure to hematologic homeostasis in general population. • We identified high level of SCCPs, MCCPs and elevated ∑MCCPs/∑SCCPs in serum from residents in Jinan. • We found that perturbation of hematologic homeostasis could be induced by CP exposure in a sex-dependent way. • The exposure levels and hematologic perturbation effects of MCCPs and SCCPs were similar. [ABSTRACT FROM AUTHOR]

Reasonable electricity pricing is the foundation of electricity markets. Locational marginal price is a commonly used electricity pricing mechanism. However, the formulations of locational marginal price are not consistent in existing studies. Also, the properties of this pricing method, such as incentive compatibility and market surplus, are not formally proved in a general dispatch formulation. In this study, we generalize the price formulation and revisit the definition and property of electricity prices. We find that electricity price should be a service-level concept rather than a node-level concept, which means that the electricity price may deviate for different market participants at the same node due to their different contributions to the system-wide constraints. Under this service-level concept, the properties of the incentive compatibility and non-negative market surplus are proved. The specific price formulation is analyzed based on a co-optimization model of energy and reserve. Case studies show that using the proposed pricing method, the prices for wind power and load include an additional component as a charge for the requirement of spinning reserve. The nice pricing properties maintain for the proposed method, which has distinct advantages compared with the node-based LMP formulation. • The service-level LMP is defined and the physical insight is explained. • The nice properties of the proposed LMP formulation are formally proved. • The derived LMP has a new component reflecting wind/load uncertainties. [ABSTRACT FROM AUTHOR]