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.

Roles of urban vegetation on balance of carbon and oxygen in Guangzhou, China

The plant biomass and net primary production(NPP) of urban vegetation in Guangzhou were estimated by dimension analysis, tree truck volume, and harvest methods as well as relationship between biomass and NPP and so on. The biomass and NPP were respectively 2875150t and 1058122 t/a. They were respectively 392495t and 64948 t/a in the built-up area and 2482655t and 993147 t/a in the unbuilt-up area. It would make plant biomass, especially NPP decline obviously, if the unbuilt-up area were changed to the built-up area. The carbon content of plant was 1328649 for the total and 13.78 t/hm 2 for the mean, and amounts of carbon fixed and oxygen made by urban vegetation were respectively 4.80 t/(hm 2·a) and 12.79 t/(hm 2·a) for the mean and 462624 t/a and 1232430 t/a for the total, which were equal to 1.45 times and 1.04 times of those by human breathing. However, they were only equal to 7.61% and 4.97% of amount of carbon released and oxygen consumption in urban Guangzhou. The biomass and NPP of urban vegetation in Guangzhou only corresponded to 7.8% and 47.3% of those of southern subtropical evergreen broad-leaf forest in Dinghu Mountain. Therefore, the roles of Guangzhou urban vegetation in balance of carbon and oxygen would be increased greatly if it could be conserved and improved in some way.

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.

The effects of PaCO_2 on balance of cerebral oxygen supply and consumption during intravenous general anesthesia

Objective: To evaluate the effects of various degrees of hyperventilation on balance of cerebral oxygensupply and consumption during intravenous general anesthesia with jugular venous oxygen saturation monitoringMetbods: Sixty-six patients with supratentorial tumor undergoing intravenous general anesthesia for brain surgerywere randomly divided into three groups. In group Ⅰ, Ⅱ and Ⅲ, end-tidal pressure of Co2(PETCO2) were maintained at 3. 5, 4. 0 and 4. 5 kPa respectively. Radial arterial blood samples and jugular bulb blood samples weretaken synchronously at 60 min after hyperventilation to measure jugular venous oxygen saturation (SjvO2), cerebral extraction of oxygen (CEO2) and cerebral arteriovenous oxygen content difference (AVDO2) were calculatedResults: In group Ⅰ after hyperventilation, SjvO, and jugular venous oxygen content (CjvO2) were decreasedmarkedly while CEO2 was increased significantly, which was different significantly compared with the baseline andcorresponding value in group Ⅱ and Ⅲ (P<0. 05). After hyperventilation in group, and, SjvO2 CjvO2, CEO2and AVDO, remained unchanged. Conclusion: This study shows that sustained excessive hyperventilation (PETCO23.5 kPa) may account for the less favorable cerebral oxygen supply and consumption balance and maintained PETCO, at 4. 0~4. 5 kPa was optimal hyperventilation for brain surgery anesthesia.

Study on Ecological Land Demand of Shijiazhuang City Based on Carbon-Oxygen Balance Method

[Objective] The study aimed to analyze ecological land demand of Shijiazhuang City on the basis of carbon-oxygen balance method. [Method] Firstly, the release and absorption of CO2 and O2 in Shijiazhuang City during 2004 -2007 were studied by using carbon-oxygen balance method, and the ecological land area needed for carbon-oxygen balance was calculated, then the ecological land area needed for carbon-oxygen balance in 2015 was predicted. Finally, some measures to reduce the deficit of CO2 and O2 in Shijiazhuang were proposed. [Result] From 2004 to 2007, the unbalance between CO2 and O2 aggravated with the rapid development of Shijiazhuang City＇s economy, and the ecological land needed increased year by year. If the amount of CO2 released and 02 consumed grows constantly, the area of standard ecological land needed will be about doubled in 2015 compared with 2007 （ 1. 575 6 million hm2 ）, namely increasing to 3.566 million hm2. In addition, appropdately improving the area of mixed forest and other vegetation with higher net production, developing some green energy resources like nuclear energy and wind energy and controlling its population could be adopted to reduce the deficit of CO2 and 02 in Shijiazhuang City. ~ ConclusionJ The research could provide theoretical references for the overall plan of land utilization in Shijiazhuang City. Key words Shijiazhuang; Ecological land; Carbon-oxygen balance; Shijiazhuang City; China

基于氢氧同位素的平原湖荡地表水与地下水转化研究

地表水与地下水间的相互转化以及量化地下水补给量是湖泊水循环研究的重要内容。本文采集了元荡湖区域湖水、地下水样品,测试了其氢氧稳定同位素组成和水化学组成,运用Piper三线图分析其水化学类型、通过钻孔实测的地下水埋深绘制元荡湖区域旱季(2022年12月)和雨季(2023年6月)的地下水水位等值线图,结合电导率(EC)和溶解性总固体(TDS)定性分析地表水-地下水之间的转化关系,利用同位素水量平衡方程、线性端元混合模型定量评价了湖水、地下水、河水和降水之间的转化量。结果表明,研究区湖水和地下水的水化学类型均为HCO_(3)^(-)·SO_(4)^(2-)·Ca^(2+)·Na^(+)·Mg^(2+),旱季和雨季湖水均受到地下水的补给,拟合得到的湖水旱季、雨季氢氧稳定同位素线性回归方程表明雨季斜率较小,蒸发更为强烈。湖水主要由河水、地下水和降水补给,其三者在旱季的补给比例分别为59%、26%和15%,在雨季的补给比例分别为23%、39%和38%。本文成果为元荡湖区域以及太湖流域的综合治理提供了科学依据。

铜冶炼过程碳排放及自热熔炼分析

“双碳”背景下,我国铜冶炼作为高耗能高排放行业需突破资源、能源、供求关系等多重制约因素,方能迈上铜工业低碳绿色创新可持续发展道路。采用熔炼系统能量流平衡模型研究其能源利用收支情况,有利于进一步挖掘节能潜力,实现富氧底吹熔炼过程的低碳可持续化高效生产。通过计算铜冶炼厂底吹熔炼体系各类热量的收入和支出行为,解析无碳质燃料投入工况下的热量收支平衡关系,继而提出无碳自热熔炼的优化改进方案。因此,从原料适配、操作制度、设备优化等多方式调控以实现富氧底吹无碳自热熔炼。从碳源上减少或避免煤粉的加入,从而降低过程碳排放,以期为铜冶炼的清洁生产提供有益的思路和建议。

不同水分处理对甘平果实裂果及相关生理特性的影响

选取易裂果品种甘平作为研究对象,统计果实发育过程中不同土壤水分变化幅度及不同土壤相对含水量处理下裂果的发生率,检测各处理下树体及果实相关的生理指标变化,利用数据统计学探究其与裂果的相关性,进而解析水分调控对甘平裂果发生率的影响.结果显示,甘平裂果时间主要发生在盛花后120~150 d,即果实膨大期(每年7-8月),属于外裂果.水分控制试验结果显示,土壤相对含水量75%、变化幅度20%以内能有效控制裂果发生.与其他处理相比,75%土壤含水量下植株的光合速率最强,叶片和果实的相对含水量、水势、N、K和Ca含量显著增高,果实的总果胶、纤维素质量分数最高,而OFR,H_(2)O_(2),MDA的摩尔质量最低.相关性分析结果显示,叶片和果皮的水势和含水量、果皮细胞纤维素和总果胶的质量分数以及活性氧代谢与裂果率显著相关,推测在适宜的土壤含水量,植株能有效增强光合作用和抗逆性,进而通过增加果皮厚度和延展性增强果实的抗裂性.

“双碳”目标下中国社会——生态复合系统碳氧平衡时空格局分析

在“双碳”战略目标下,如何同步实现“稳增长”和“碳减排”,成为中国推进可持续发展、生态保护和高质量发展并重的焦点问题。论文基于碳氧平衡系数测算分析我国社会—生态复合系统2000—2020年排碳耗氧量、固碳释氧量以及碳氧平衡状况的时空格局。结果表明:2000年我国碳氧处于平衡状态,社会生态系统处于良性循环,随后,随着经济快速发展,排碳耗氧量剧增,同时,土地利用变化剧烈,林地和草地面积减少,固碳释氧量下降,导致碳氧处于失衡状态。进一步的碳氧平衡省际分析可知,2020年我国省际碳氧平衡差异明显,东部和中部大多数省份社会—生态复合系统处于碳氧失衡状态。测算分析社会—生态复合系统碳氧平衡时空格局,可为土地利用结构优化配置及不同区域间生态补偿和碳排放交易提供指导。

基于能质流平衡与数值仿真的浮渣转炉热工诊断与节能分析

通过对铜浮渣转炉进行热工综合测试,获取了转炉关键位置的温度、压力、烟气组分等炉况参数,分析了转炉能量利用状况和能质流路径。通过数值模拟技术,基于热工测试数据,模拟了炉膛内天然气的富氧燃烧过程。结果表明,铜浮渣转炉的热效率为19.96%,转炉漏风量过大、壁面散热量过大是转炉热效率较低的主要原因。此外,转炉粒煤用量在反应热理论计算中过量较多。根据热工诊断结果,提出的节能优化建议为:调整粒煤用量,达成最优配料;采取保温措施,减少表面散热;增强转炉密闭性,减少漏风量;调整烧嘴布置方式,强化烟气与熔体换热。

2025年京津冀陆地生态系统碳氧平衡分析

以2020年的京津冀地区数据为基准,测算出2020年释碳耗氧量、固碳释氧量,对2025年释碳耗氧量、固碳释氧量、生态用地需求面积进行预测。结果表明:2020年京津冀地区释碳量和耗氧量分别为125576.1万和143533.7万t。预测出2025年京津冀地区释碳量和耗氧量分别为135957.0万和163392.0万t。从2025年京津冀地区总体来看,维持碳平衡所需标准生态用地面积小于现有标准生态用地面积,说明不需要再另外增加面积。但分省(市)来看,北京、河北的生态用地面积均能够满足碳氧平衡需要,而天津还应增加标准生态用地,方能满足市内维持碳氧平衡的需要。在实际社会和经济发展过程中生态用地面积会略有调整,而且生态用地结构和质量也会发生变化,因此在实际生产和科研中,应根据每年生态用地的实际变化量来逐步修正。

三硝基甲基富氮杂环类高能氧化剂的合成研究进展

主要综述了近年来报道的三硝基甲基富氮杂环类高能氧化剂及其合成路线,分析总结了这类氧化剂的合成方法、理化性质和能量性能,并展望未来三硝基甲基富氮杂环类高能化合物的发展方向,为新型富氮杂环类高能氧化剂的设计与合成提供参考。

右美托咪定联合丙泊酚对颅内动脉瘤介入手术患者苏醒质量及脑供氧平衡的影响

目的 探讨右美托咪定联合丙泊酚对颅内动脉瘤介入术患者苏醒质量及脑供氧平衡的影响。方法 前瞻性选取2020年5月~2022年10月80例脑动脉瘤患者,按照就诊先后顺序,采用单双号法分为联合组、对照组,各40例。2组均接受颅内动脉瘤介入术,麻醉诱导前10 min,联合组给予右美托咪定负荷量1μg/kg,对照组给予等量生理盐水,随后行丙泊酚全身麻醉。比较2组苏醒质量、不良反应及不同时间点血流动力学[心率(HR)、平均动脉压(MAP)]、脑供氧平衡[脑灌注压(CPP)、脑氧摄取率(OER)、动-静脉血氧含量差(Da-jv O2)]、神经损伤指标[中枢神经特异蛋白(S-100β)、神经元特异性烯醇化酶(NSE)]。结果 联合组苏醒时间、清醒时间、气管拔除时间较对照组短(P<0.05);T1-3时,联合组HR、MAP较对照组低(P<0.05);T1-3时,联合组CPP高于对照组,OER、Da-jv O2较对照组低(P<0.05);T1-3时,联合组S-100β、NSE低于对照组(P<0.05);围术期间,联合组不良反应发生率5.00%与对照组10.00%相比,差异无统计学意义(P>0.05)。结论 右美托咪定联合丙泊酚能有效维持颅内动脉瘤介入术血流动力学稳定及脑供氧平衡,减轻神经损伤,提高苏醒质量。

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.

湖南省碳排放空间分异与碳平衡分区治理研究

“双碳”战略目标涉及经济社会系统广泛而深刻的历史变革,而国土空间规划则是新时代实现“双碳”目标的必要途径和技术保障。基于碳氧平衡理论,以湖南省为例,通过分析湖南省122个县域单元碳排放空间分异特征,探索构建碳平衡主体功能区,提出“高碳控制区、低碳优化区、碳氧平衡区以及生态碳汇区”碳平衡功能分区。各功能区内部再根据地域特征进一步划分碳平衡治理管控单元,明确管控单元碳排放产权责任。针对各级主体功能区进行分区施策,制定相应的目标指标及调控措施,推动碳排放权交易平台的建设。促进“分区施策、分级传导、精准反馈、精细治理”,更好实现国土空间“双碳”目标的科学调控、高效传导、协调统筹、有效治理。

小窑火区下采空区有害气体防治技术研究

小窑火区下回采工作面易发生上隅角低氧和有害气体超限,严重制约着矿井安全生产。为理清采空区有害气体的运移规律,以达西定律、扩散定律、流体动力弥散定律为基础构建了采空区气体运移的数学模型,利用COMSOL Multiphysics反演了沙坪矿13102工作面采空区有害气体的运移过程。结果表明:新鲜风流从进风巷道以及工作面流入采空区,然后从上隅角流出,在风流的带动下CH_(4)和CO从上隅角流出,导致工作面上隅角CH_(4)和CO体积分数超限、工作面低氧,在此基础上提出上隅角埋管抽采和均压通风的措施防治工作面上隅角低氧、有害气体超限,数值模拟发现上隅角埋管抽采只能防治工作面低氧的问题,而均压通风既能够防治工作面低氧还能阻止采空区有害气体涌向工作面。

电极孔径及温度对闭式氢氧燃料电池性能的影响机理研究

针对燃料电池内部复杂的水传输机制和水管理策略的影响因素,研究多孔电极的孔径对水传输和水分布情况的影响。建立燃料电池等温模型,通过改变多孔电极的孔径,模拟燃料电池催化层在不同孔径下的水浓度和水分布规律。同时,考虑温度可能带来的影响,在研究过程中选取了燃料电池常见的运行温度,在每个温度值下都进行了模拟。结果表明,在设定的温度下,孔径对水浓度和水分布情况的影响规律是相似的。孔径较大时,电极内的水浓度较低。随着孔径减小,电极内的水浓度不断增大。同时,孔径越小,水浓度增大的速度越快。气体浓度的分布与变化情况正好与水浓度相反。水浓度越高的区域气体浓度越低。随着孔径减小,气体浓度不断上升。从模拟结果来看,当气体扩散层具有微米级孔隙结构时,电极内多余的水分可以较好地排出,同时在较高的温度下水管理更容易较好地实现。阴极流道出口和中部比较容易发生水淹,所以应该对这些区域加设除水装置或设计自除水结构。

不同氧浓度进行培养液的平衡对辅助生殖临床结局的影响

目的探讨不同氧浓度进行培养液的平衡对辅助生殖临床结局的影响。方法回顾性分析2020年3月至2021年9月在福建省妇幼保健院生殖医学中心进行辅助生殖的患者资料,符合纳入标准的周期数共401个取卵周期,根据使用不同氧气浓度的培养箱分为大气氧平衡组和5%氧平衡组,其中大气氧平衡组有201个周期,5%氧平衡组有200个周期,比较分析两组患者的体外胚胎发育情况和临床结局。结果两组患者的基线资料比较,差异无统计学意义(P>0.05)。大气氧平衡组正常受精率、优质囊胚形成率均高于5%氧平衡组,差异有统计学意义(P<0.05)。两组患者多精受精率、D3优质胚胎率、囊胚形成率、临床妊娠率、种植率、流产率、新生儿妊娠天数、新生儿出生体重和新生儿出生身长比较,差异无统计学意义(P>0.05)。结论在常规体外授精和胚胎移植的周期中,使用大气氧浓度的普通培养箱进行培养液的平衡,可能有利于患者的正常受精和优质囊胚形成。

IF钢生产工艺优化

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