Flow zone distribution and mixing time in a Peirce-Smith copper converter

Peirce-Smith copper converting involves complex multiphase flow and mixing.In this work,the flow zone distribution and mixing time in a Peirce-Smith copper converter were investigated in a 1:5 scaled cold model.Flow field distribution,including dead,splashing,and strong-loop zones,were measured,and a dimensionless equation was established to determine the correlation of the effects of stirring and mixing energy with an error of<5%.Four positions in the bath,namely,injection,splashing,strong-loop,and dead zones,were selected to add a hollow salt powder tracer and measure the mixing time.Injecting a quartz flux through tuyeres or into the backflow point of the splashing wave through a chute was recommended instead of adding it through a crane hopper from the top of the furnace to improve the slag-making reaction.

Computational screening and design of nanoporous membranes for efficient carbon isotope separation

Stable isotopes have been routinely used in chemical sciences,medical treatment and agricultural research.Conventional technologies to produce high-purity isotopes entail lengthy separation processes that often suffer from low selectivity and poor energy efficiency.Recent advances in nanoporous materials open up new opportunities for more efficient isotope enrichment and separation as the pore size and local chemical environment of such materials can be engineered with atomic precision.In this work,we demonstrate the unique capability of nanoporous membranes for the separation of stable carbon isotopes by computational screening a materials database consisting of 12,478 computation-ready,experimental metal-organic frameworks(MOFs).Nanoporous materials with the highest selectivity and membrane performance scores have been identified for separation of^(12)CH_4/^(13)CH_4 at the ambient condition(300 K).Analyzing the structural features and metal sites of the promising MOF candidates offers useful insights into membrane design to further improve the performance.An upper limit of the efficiency has been identified for the separation of^(12)CH_4/^(13)CH_4 with the existing MOFs and those variations by replacement of the metal sites.

Theoretical insights on the hydration of quinones as catholytes in aqueous redox flow batteries

Quinones have been widely studied as a potential catholyte in water-based redox flow batteries(RFBs)due to their ability to carry both electrons and protons in aqueous solutions.The wide variety of quinones and derivatives offers exciting opportunities to optimize the device performance while poses theoretical challenges to quantify their electrochemical behavior as required for molecular design.Computational screening of target quinones with high performance is far from satisfactory.While solvation of quinones affects their potential application in RFBs in terms of both electrochemical windows,stability,and charge transport,experimental data for the solvation structure and solvation free energies are rarely available if not incomplete.Besides,conventional thermodynamic models are mostly unreliable to estimate the properties of direct interest for electrochemical applications.Here,we analyze the hydration free energies of more than 1,400 quinones by combining the first-principles calculations and the classical density functional theory.In order to attain chemical insights and possible trends,special attention is placed on the effects of"backbones"and functional groups on the solvation behavior.The theoretical results provide a thermodynamic basis for the design,synthesis,and screening of high-performance catholytes for electrical energy storage.

Noise reduction and periodic signal extraction for GNSS height data in the study of vertical deformation

Global navigation satellite system(GNSS)technique has irreplaceable advantages in the continuous monitoring of surface deformation.Reducing noise to improve the signal-to-noise ratio(SNR)and extract the concerned signals is of great significance.As an improved algorithm of empirical mode decomposition(EMD),complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)algorithm has better signal processing ability.Using the CEEMDAN algorithm,the height time series of 29GNSS stations in Chinese mainland were analyzed,and good denoising effects and extraction from periodic signals were achieved.The numerical results showed that the annual signal obtained with the CEEMDAN algorithm was significantly based on Lomb_Scargle spectrum analysis,and large differences in the long-term signals were found between the stations at different locations in Chinese mainland.With respect to data denoising,compared with the EMD and wavelet denoising algorithms,the CEEMDAN algorithm respectively improved the SNR by 29.35% and 36.54%,increased the correlation coefficient by 8.67% and 11.96%,and reduced root mean square error(RMSE)by 44.68% and 43.48%,indicating that the CEEMDAN algorithm had better denoising behavior than the other two algorithms.In addition,the results demonstrated that different denoising methods had little influence on estimating the annual vertical deformation velocity.The extraction of periodic signals showed that more components were retained by using the CEEMDAN algorithm than the EMD algorithm,which indicated that the CEEMDAN algorithm had advantages over frequency aliasing.In conclusion,the CEEMDAN algorithm was recommended for processing the GNSS height time series to analyze the vertical deformation due to its excellent features of denoising and the extraction of periodic signals.

Spatially distributed cytokinins:Metabolism,signaling,and transport

Cytokinins are mobile phytohormones that regulate plant growth,development,and environmental adaptability.The major cytokinin species include isopentenyl adenine(iP),trans-zeatin(tZ),cis-zeatin(cZ),and dihydrozeatin(DZ).The spatial distributions of different cytokinin species in different organelles,cells,tissues,and organs are primarily shaped by biosynthesis via isopentenyltransferases(IPT),cytochrome P450 monooxygenase,and 50-ribonucleotide phosphohydrolase and by conjugation or catabolism via glycosyltransferase or cytokinin oxidase/dehydrogenase.Cytokinins bind to histidine receptor kinases in the endoplasmic reticulum or plasma membrane and relay signals to response regulators in the nucleus via shuttle proteins known as histidine phosphotransfer proteins.The movements of cytokinins from sites of biosynthesis to sites of signal perception usually require long-distance,intercellular,and intracellular transport.In the past decade,ATP-binding cassette(ABC)transporters,purine permeases(PUP),AZA-GUANINE RESISTANT(AZG)transporters,equilibrative nucleoside transporters(ENT),and Sugars Will Eventually Be Exported transporters(SWEET)have been characterized as involved in cytokinin transport processes.This review begins by introducing the spatial distributions of various cytokinins and the subcellular localizations of the proteins involved in their metabolism and signaling.Highlights focus on an inventory of the characterized transporters involved in cytokinin compartmentalization,including long-distance,intercellular,and intracellular transport,and the regulation of the spatial distributions of cytokinins by environmental cues.Future directions for cytokinin research are also discussed.

Myelin Oligodendrocyte Glycoprotein-IgG Contributes to Oligodendrocytopathy in the Presence of Complement, Distinct from Astrocytopathy Induced by AQP4-IgG

Immunoglobulin G against myelin oligodendrocyte glycoprotein(MOG-Ig G) is detectable in neuromyelitis optica spectrum disorder(NMOSD) without aquaporin-4 Ig G(AQP4-Ig G), but its pathogenicity remains unclear.In this study, we explored the pathogenic mechanisms of MOG-Ig G in vitro and in vivo and compared them with those of AQP4-Ig G. MOG-Ig G-positive serum induced complement activation and cell death in human embryonic kidney(HEK)-293 T cells transfected with human MOG. In C57 BL/6 mice and Sprague-Dawley rats, MOG-Ig G only caused lesions in the presence of complement. Interestingly, AQP4-Ig G induced astroglial damage, while MOGIg G mainly caused myelin loss. MOG-Ig G also induced astrocyte damage in mouse brains in the presence ofcomplement. Importantly, we also observed ultrastructural changes induced by MOG-Ig G and AQP4-Ig G. These findings suggest that MOG-Ig G directly mediates cell death by activating complement in vitro and producing NMOSDlike lesions in vivo. AQP4-Ig G directly targets astrocytes,while MOG-Ig G mainly damages oligodendrocytes.

IV期C级牙周炎的口腔综合治疗1例

目的:本文通过展示一例Ⅳ期C级牙周炎的牙周-牙体-牙槽外科-正畸-修复联合治疗,为重度牙周炎患者治疗计划的制定及实施提供思路。诊治经过:患者因重度牙周炎导致前牙移位,多牙松动,个别后牙缺失,并伴有个别牙龋坏及下颌阻生第三磨牙。经过医患沟通,临床治疗过程依次为:牙周基础治疗,充填治疗、根管治疗,预后无望的松动牙及阻生第三磨牙的拔除,牙周手术治疗,正畸治疗,缺失牙的种植修复以及牙周维护治疗。结果:经过上述综合治疗,患者牙周情况恢复健康,前牙间隙关闭,咬合关系改善,牙列完整性得到恢复。结论:重度牙周炎患者的诊疗需要综合考量,通过多学科配合可达到良好的治疗效果。

Prediction of network public opinion features in urban planning based on geographical case-based reasoning

As a significant part of sustainable urban development proposed by the United Nations,urban planning is related to the ecological environment and transportation,especially affecting quality of life and social well-being. In the process of urban planning,the public express their opinions on open network platforms,resulting in large quantities of network public opinion data,which has important implications for evaluating urban planning. Based on the idea of geographical case-based reasoning (CBR),this paper constructs an expression framework for urban planning cases in the form of a ‘case problem–case attribute–case result’ triad. On this basis,this paper proposes a similarity calculation method of urban planning cases that integrates case attribute. Finally,based on an improvement to the traditional k-nearest neighbors method,the proposed public opinion feature calculation model considers similarity weights,which allow us to predict network public opinion features,including viewpoint-level emotional tendency and concerned groups of urban planning cases. The experimental result shows similarity weights (SWs) model could effectively improve the prediction accuracy,where the average MIC-F1 score reached more than 74%. Based on CBR,the proposed method can predict the development trends of public opinion in future planning cases,and provide scientific and reasonable decision support for urban planning.

Application of Improved UNet and EnglightenGAN for Segmentation and Reconstruction of In Situ Roots

The root is an important organ for crops to absorb water and nutrients.Complete and accurate acquisition of root phenotype information is important in root phenomics research.The in situ root research method can obtain root images without destroying the roots.In the image,some of the roots are vulnerable to soil shading,which severely fractures the root system and diminishes its structural integrity.The methods of ensuring the integrity of in situ root identification and establishing in situ root image phenotypic restoration remain to be explored.Therefore,based on the in situ root image of cotton,this study proposes a root segmentation and reconstruction strategy,improves the UNet model,and achieves precise segmentation.It also adjusts the weight parameters of EnlightenGAN to achieve complete reconstruction and employs transfer learning to implement enhanced segmentation using the results of the former two.The research results show that the improved UNet model has an accuracy of 99.2%,mIOU of 87.03%,and F1 of 92.63%.The root reconstructed by EnlightenGAN after direct segmentation has an effective reconstruction ratio of 92.46%.This study enables a transition from supervised to unsupervised training of root system reconstruction by designing a combination strategy of segmentation and reconstruction network.It achieves the integrity restoration of in situ root system pictures and offers a fresh approach to studying the phenotypic of in situ root systems,also realizes the restoration of the integrity of the in situ root image,and provides a new method for in situ root phenotype study.