Hybrid model for BOF oxygen blowing time prediction based on oxygen balance mechanism and deep neural network

The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based on oxygen balance mechanism (OBM) and deep neural network (DNN) was established for predicting oxygen blowing time in converter. A three-step method was utilized in the hybrid model. First, the oxygen consumption volume was predicted by the OBM model and DNN model, respectively. Second, a more accurate oxygen consumption volume was obtained by integrating the OBM model and DNN model. Finally, the converter oxygen blowing time was calculated according to the oxygen consumption volume and the oxygen supply intensity of each heat. The proposed hybrid model was verified using the actual data collected from an integrated steel plant in China, and compared with multiple linear regression model, OBM model, and neural network model including extreme learning machine, back propagation neural network, and DNN. The test results indicate that the hybrid model with a network structure of 3 hidden layer layers, 32-16-8 neurons per hidden layer, and 0.1 learning rate has the best prediction accuracy and stronger generalization ability compared with other models. The predicted hit ratio of oxygen consumption volume within the error±300 m^(3)is 96.67%;determination coefficient (R^(2)) and root mean square error (RMSE) are0.6984 and 150.03 m^(3), respectively. The oxygen blow time prediction hit ratio within the error±0.6 min is 89.50%;R2and RMSE are0.9486 and 0.3592 min, respectively. As a result, the proposed model can effectively predict the oxygen consumption volume and oxygen blowing time in the converter.

A New Carbon and Oxygen Balance Model Based on Ecological Service of Urban Vegetation

The application of human induced oxygen consumption and carbon emission theory in urban region was summed up and on this base a new model of urban carbon and oxygen balance (UCOB) was constructed by calculating the carbon and oxygen fluxes. The purpose was to highlight the role of vegetation in urban ecosystems and evaluate the effects of various human activities on urban annual oxygen consumption and carbon emission. Hopefully,the model would be helpful in theory to keep the regional balance of carbon and oxygen,and provide guidance and support for urban vegetation planning in the future. To test the UCOB model,the Jimei District of Xiamen City,Fujian Province,China,a very typical urban region,was selected as a case study. The results turn out that Jimei′s vegetation service in oxygen emission and carbon sequestration could not meet the demand of the urban population,and more than 31.49 times of vegetation area should be added to meet the whole oxygen consumption in Jimei while 9.60 times of vegetation area are needed to meet the carbon sequestration targets. The results show that the new UCOB model is of a great potential to be applied to quantitative planning of urban vegetation and regional eco-compensation mechanisms.

Ecological Assessment of Oxygen Balance:A Case Study of China’s Natural Oxygen Bars

Ecological assessment plays a vital role in sustainable development of the environment,and thus exploration of specific and integrated ecological assessment methods has become a critical task.In this study,based on the concept of oxygen balance and by accommodating both natural factors and socioeconomic elements,we establish an oxygen(O_(2))balance index(OBI),i.e.,the ratio of the O_(2)production from the ecosystem to the O_(2)consumption by human behavior,based on the net primary productivity(NPP),fuel consumption,gross domestic production(GDP),population data,and so on.The results show that the spatial distributions of OBI in China are intimately correlated to the regional vegetation and socioeconomic development.The estimated OBI values are then validated by statistical data from 27 counties in China,and it is found that the OBI reflects the ecological environment status well.Moreover,the average OBI values derived from 190 natural oxygen bars in China reveal extreme imbalance between O_(2)production and consumption in highly developed regions,especially in the cities,in contrast to good O_(2)balance in areas with high-quality ecological status and less industrialization.The findings from this study have quantitatively captured the regional ecological quality,providing guidance for sustainable natural and socioeconomic developments in local areas of China.

AN ANALYSIS OF THE OXYGEN BALANCE IN AN ANOXIC TIDAL RIVER

A time-dependent, mixed-segment, slack tide oxygen balance model has been developed for the study of a heavily polluted tidal river discharging to a coastal bay.Deoxygenation and reaeration, BOD settling, benthal demand, freshwater flushing, and tidal mixing are the key processes modelled. Significant features of the model include the oxygen balance formulation under anoxic conditions and the tidal exchange condition at the seaward boundary. The simple model enables a clear and consistent interpretation of a set of dry season water quality data and an assessment of the assimilative capacity of the river is also made.

Study on the Establishment of a Rat Model for Transfusion-related Acute Lung Injury with Coronary Heart Disease and its Oxygen Balance

Objective:To establish a rat model of transfusion-related acute lung injury(TRALI)with coronary heart disease(CHD),and to analyze the safety of blood transfusion through oxygen balance.Methods:Forty-five 10-day-old male Wistar rats were purchased,and 35 of them were fed with high-fat diet to establish coronary heart disease rat models,and then 20 of them were selected to establish rat models of transfusion-related acute lung injury with coronary heart disease(model group,10 rats),positive acute lung injury group(positive group,5 rats)and negative acute lung injury group(negative group,5 rats),and the lung histomorphology,pathological score and wet/dry weight ratio were compared.Then,another 15 rats with coronary heart disease were selected and infused with mutant Hb,rHb1.1 and rHb2.0 with the same osmotic pressure through femoral vein catheterization,respectively,and were divided into mutant Hb group,rHb1.1 group and rHb2.0 group,with 5 rats in each group,and 5 healthy rats were combined as control group.The MAP,HR and blood gas values of mesenteric artery of rats were compared at 0,30,60 and 90 min after infusion.Results:(1)Rats in the model group and the positive group showed symptoms such as irregular and shallow breathing,increased oral and nasal secretions,and audible wheezing,which were consistent with the symptoms of acute lung injury.Comparison of lung histological score and lung tissue wet/dry ratio in three groups:There was no significant difference in lung histological score and lung tissue wet/dry ratio(P>0.05),but they were higher than those in the negative group(P<0.05).(2)During hemoglobin infusion,the MAP of mutant Hb group,rHb1.1 group and rHb2.0 group was higher than that of the control group,while the pH and PaCO2were lower than those of the control group(P<0.05),and there was no significant difference in QSMA(P>0.05).In the mutant Hb group,MAP returned to normal at 30-60 min after infusion(P>0.05),but MAP increased again at 90 min after infusion(P<0.05),and QSMA increased significantly at 60 min after transfusion(P<0.05).The pH value was lower than the normal value and the PaCO2was higher than the normal value within 90 min of infusion(P<0.05),and the HCO3-level returned to normal after 30 min of infusion(P>0.05).In rHb 1.1 group,MAP returned to normal,QSMA remained at normal level(P>0.05),and pH,PaCO2and HCO3-returned to normal after 60 min of infusion(P>0.05);In rHb 2.0 group,the levels of MAP,pH,PaCO2and HCO3-returned to normal after 30 min of infusion(P>0.05),and QSMA remained normal during infusion(P>0.05).Conclusion:The rat model of transfusion-relatted acute lung injury with coronary heart disease can be successfully established by injecting LPS into the rat model of coronary heart disease,and the infusion of recombinant hemoglobin can improve the balance of blood supply in rats,in which the infusion of rHb2.0 can better correct the metabolic acidosis.

Theoretical Studies on Structures and Relative Stability for Polynitrohexaazaadamantanes

The density function theory at the B3LYP/6-31G＊ level was employed to study the structures, including the total energies （EZpE）, the geometries, the oxygen balances （OB100）, the dipole moments, of polynitrohexaazaadamantanes （PNHAAs） and the potential candidates of high energy density compounds （HEDCs）. The structural parameters of PNHAAs, such as the the maximum N-NO2 hond length （LBmax）, the least N-N Mulliken population （BN-N）, the least negative charge on the nitro group （QNO2） and OB100, were studied to predict their relative stability or sensitivity （the easiness for initiating a detonation, high sensitivity means low stability）. It was found that the same conclusion was drawn from the four parameters. With the number of nitro groups increasing, the stabilities of these compounds decrease. OB100 failed in identifying the isomers, but the EZpE energy and the dipole moment were considered to give more reliable results for the isomers.

Influence of Nitro Group Substitutes to the Stability and Energetic Properties of N-(2,4,6-trinitrophenyl)-1H-1,2,4-triazol-3-amine

In the paper, we aim to show N-(2,4,6-trinitrophenyl)-1H-1,2,4-triazol-3-amine (HM-I) as explosive material that satisfies requirements of sensitivity and hydrolytically stability. The influence of nitro group substitutions on the thermal and chemical stability as well as the explosive performance of HM-I is also investigated. We found that nitro group substitution to the triazole ring of HM-I can significantly improve the properties of this new material. Only -NH2 substitution position (but not their number) in the core molecule is appropriate to increase the stability and improve explosive performances of HM-I.

Iron- and Ferritin-Dependent Reactive Oxygen Species Distribution： Impact on Arabidopsis Root System Architecture

Iron （Fe） homeostasis is integrated with the production of reactive oxygen species （ROS）, and distribution at the root tip participates in the control of root growth. Excess Fe increases ferritin abundance, enabling the storage of Fe, which contributes to protection of plants against Fe-induced oxidative stress. AtFerl and AtFer3 are the two ferritin genes expressed in the meristematic zone, pericycle and endodermis of theAra- bidopsis thaliana root, and it is in these regions that we observe Fe stained dots. This staining disappears in the triple ferl-3-4 ferritin mutant. Fe excess decreases primary root length in the same way in wild-type and in ferl-3-4 mutant. In contrast, the Fe-mediated decrease of lateral root （LR） length and density is enhanced in ferl-3-4 plants due to a defect in LR emergence. We observe that this interaction between excess Fe, ferritin, and root system architecture （RSA） is in part mediated by the H_2O_2/O2·^- balance between the root cell proliferation and differentiation zones regulated by the UPB1 transcription factor. Meristem size is also decreased in response to Fe excess in ferritin mutant plants, implicating cell cycle arrest mediated by the ROS-activated SMR5/SMR7 cyclin-dependent kinase inhibitors pathway in the interaction between Fe and RSA.