Properties and Application of Slide Nozzle Plate for High Oxygen Steel

Several kinds of slide nozzle plate such as A12O3-C-ZrO2, MgO, Al2O3, Spinel-C and A12O3-C SN plate for high oxygen steel used in BaoSteel have been analysed, the appearance and size of the SN plate after using have been measured. The Al2O3-C SN plate has longer service life in casting high oxygen steel, and the wear mechanism of different SN plates is discussed.

Energy Efficiency Analysis of Oxy-Fuel Circulating Fluidized Bed Combustion System with High Oxygen Concentration

The low net efficiency of oxy-fuel circulating fluidized bed(CFB)combustion is mainly due to the addition of air separation unit(ASU)and carbon dioxide compression and purification unit(CPU).High oxygen concentration is one of the effective methods to improve the net efficiency of oxy-fuel combustion technology in CFB.In this research,a series of calculation and simulation were carried out based on Aspen Plus platform to provide valuable information for further investigation on the CFB oxy-fuel combustion system with high oxygen concentration(40%,50%).A CFB oxy-fuel combustion system model with high oxygen concentration was established including ASU,CPU and CFB oxy-fuel combustion and heat exchange unit.Based on the simulation data,energy and exergy efficiency were analyzed to obtain the following results.The cross-sectional area of furnace and tail flue of 50%CFB oxy-fuel combustion boiler are 43%and 56%of the original size respectively,reducing the construction and investment cost effectively.With the increase of oxygen concentration,the net efficiency of power generation increased significantly,reaching 24.85%and increasing by 6.09%under the condition of 50%oxy-fuel combustion.The total exergy loss increases with the increase of oxygen concentration.In addition,the exergy loss of radiation heat transfer is far higher than convection heat transfer.

Effects of grape seed extract on meat color and premature browning of meat patties in high-oxygen packaging

This study investigated the effects of grape seed extract(GSE)on fresh and cooked meat color and premature browning(PMB)in ground meat patties(85% beef and 15% pork back fat)packaged under high-oxygen modified atmospheres(HiOx-MAP).The GSE was added to patties at concentrations of 0,0.10,0.25,0.50 and 0.75 g kg^(-1).This study evaluated the surface color,pH,lipid oxidation,and total viable counts(TVC)of raw patties,and the internal color and pH of patties cooked to a temperature of 66 or 71℃ over 10-day storage at 4℃.Compared with the control(0 g kg^(-1) GSE),GSE improved the color stability(P<0.05)and significantly inhibited the lipid and myoglobin oxidation of raw patties from day 5 to 10,but GSE had no effect(P>0.05)on TVC.Patties containing 0.50 and 0.75 g kg^(-1) GSE cooked to 66℃ exhibited greater(P<0.05)interior redness than the control and reduced the PMB of cooked patties in the late storage stage.These results suggested that 0.50 and 0.75 g kg^(-1) GSE can improve fresh meat color and minimize PMB of HiOx-MAP patties.

High-flow nasal oxygen availability for sedation decreases the use of general anesthesia during endoscopic retrograde cholangiopancreatography and endoscopic ultrasound

AIM To examine whether high-flow nasal oxygen(HFNO) availability influences the use of general anesthesia(GA) in patients undergoing endoscopic retrograde cholangiopancreatography(ERCP) and endoscopic ultrasound(EUS) and associated outcomes.METHODS In this retrospective study, patients were stratified into 3 eras between October 1, 2013 and June 30, 2014 based on HFNO availability for deep sedation at the time of their endoscopy. During the first and last 3-mo eras(era 1 and 3), no HFNO was available, whereas it was an option during the second 3-mo era(era 2). The primary outcome was the percent utilization of GA vs deep sedation in each period. Secondary outcomes included oxygen saturation nadir during sedation between periods, as well as procedure duration, and anesthesia-only time between periods and for GA vs sedation cases respectively.RESULTS During the study period 238 ERCP or EUS cases were identified for analysis. Statistical testing was employed and a P < 0.050 was significant unless the Bonferroni correction for multiple comparisons was used. General anesthesia use was significantly lower in era 2 compared to era 1 with the same trend between era 2 and 3(P = 0.012 and 0.045 respectively). The oxygen saturation nadir during sedation was significantly higher in era 2 compared to era 3(P < 0.001) but not between eras 1 and 2(P = 0.028) or 1 and 3(P = 0.069). The procedure time within each era was significantly longer under GA compared to deep sedation(P ≤ 0.007) as was the anesthesia-only time(P ≤ 0.001).CONCLUSION High-flow nasal oxygen availability was associated with decreased GA utilization and improved oxygenation for ERCP and EUS during sedation.

Improving mechanical properties of AZ91D magnesium/A356 aluminum bimetal prepared by compound casting via a high velocity oxygen fuel sprayed Ni coating

In this paper,a Ni coating was deposited on the surface of the A356 aluminum alloy by high velocity oxygen fuel spraying to improve the performance of the AZ91D magnesium/A356 aluminum bimetal prepared by a compound casting.The effects of the Ni coating as well as its thickness on microstructure and mechanical properties of the AZ91D/A356 bimetal were systematically researched for the first time.Results demonstrated that the Ni coating and its thickness had a significant effect on the interfacial phase compositions and mechanical properties of the AZ91D/A356 bimetal.The 10μm’s Ni coating cannot prevent the generation of the Al-Mg intermetallic compounds(IMCs)at the interface zone of the AZ91D/A356 bimetal,while the Ni coating with the thickness of 45μm and 190μm can avoid the formation of the Al-Mg IMCs.When the Ni coating was 45μm,the Ni coating disappeared and transformed into Mg-Mg_(2)Ni eutectic structures+Ni_(2)Mg_(3)Al particles at the interface zone.With a thickness of 190μm’s Ni coating,part of the Ni coating remained and the interface layer was composed of the Mg-Mg_(2)Ni eutectic structures+Ni_(2)Mg_(3)Al particles,Mg_(2)Ni layer,Ni solid solution(SS)layer,Al_(3)Ni_(2) layer,Al_(3)Ni layer and sporadic Al_(3)Ni+Al-Al_(3)Ni eutectic structures from AZ91D side to A356 side in sequence.The interface layer consisting of the Mg-Ni and Al-Ni IMCs obtained with the Ni coating had an obvious lower hardness than the Al-Mg IMCs.The shear strength of the AZ91D/A356 bimetal with a Ni coating of 45μm thickness enhanced 41.4%in comparison with that of the bimetal without Ni coating,and the fracture of the bimetal with 45μm’s Ni coating occurred between the Mg matrix and the interface layer with a mixture of brittle fracture and ductile fracture.

High-flow nasal cannula oxygen therapy during anesthesia recovery for older orthopedic surgery patients: A prospective randomized controlled trial

BACKGROUND Hypoxemia is a common complication in older patients during postoperative recovery and can cause pulmonary complications.Therefore,reducing the incidence of postoperative hypoxemia is a clinical concern.AIM To investigate the clinical efficacy of high-flow nasal cannula oxygen(HFNCO)in the resuscitation period of older orthopedic patients.METHODS In this prospective randomized controlled trial,60 older patients who underwent orthopedic surgery under general anesthesia were randomly divided into two groups:those who used conventional face mask and those who used HFNCO.All patients were treated with 60%oxygen for 1 h after extubation.Patients in the conventional face mask group were treated with a combination of air(2 L)and oxygen(2 L)using a traditional mask,whereas those in the HFNCO group were treated with HFNCO at a constant temperature of 34℃ and flow rate of 40 L/min.We assessed the effectiveness of oxygen therapy by monitoring the patients’arterial blood gas,peripheral oxygen saturation,and postoperative complications.RESULTS The characteristics of the patients were comparable between the groups.One hour after extubation,patients in HFNCO group had a significantly higher arterial partial pressure of oxygen(paO_(2))than that of patients in conventional face mask group(P<0.001).At extubation and 1 h after extubation,patients in both groups showed a significantly higher arterial partial pressure of carbon dioxide(paCO_(2))than the baseline levels(P<0.001).There were no differences in the saturation of peripheral oxygen,paO_(2),and paCO_(2) between the groups before anesthesia and before extubation(P>0.05).There were statistically significant differences in paO_(2) between the two groups before anesthesia and 1 h after extubation and immediately after extubation and 1 h after extubation(P<0.001).However,there were no significant differences in the oxygen tolerance score before leaving the room,airway humidification,and pulmonary complications 3 d after surgery between the two groups(P>0.05).CONCLUSION HFNCO can improve oxygen partial pressure and respiratory function in elderly patients undergoing orthopedic surgery under general endotracheal anesthesia.Thus,HFNCO can be used to prevent postoperative hypoxemia.

High Energy and High Coercivity Sintered NdFeB Magnets by Low Oxygen Process

Using ball milling and single direction pressing, we can produce high performance NdFeB sintered magnets. The oxygen content of sintered magnets can be controlled under 1500xl0^-6 and the magnetic performance can be improved by using low oxygen processing. The high preformance NdFeB sintered magnets with Br=(1.4 ± 0.2)T, iHc>796 kA/m and (BH)max=(390± 16) kJ/m^3, have been batch produced.

Experimental Study on the Electrical Conductivity of Orthopyroxene at High Temperature and High Pressure under Different Oxygen Fugacities

At presure 1.0-4.0 GPa and temperature 1073-1423 K and under oxygen partial pressure conditions, a YJ-3000t multi-anvil solid high-pressure apparatus and Sarltron-1260 Impedance/Gain-Phase analyzer were employed to conduct an in-situ measurement of the electrical conductivity of orthopyroxene. The buffering reagents consist of Ni＋NiO, Fe＋Fe3O4, Fe＋FeO and Mo＋MoO2 in order to control the environmental oxygen fugacity. Experimental results made clear that： （1） within the measuring frequency range from 10-1 to 106 Hz, the complex impedance （R） is of intensive dependence on the frequency; （2） The electrical conductivity （a） tends to increase along to the rise of temperature （T）, and Log a vs. 1/ T fit the Arrenhius linear relations; （3） Under the control of oxygen buffer Fe＋Fe3O4, with the rise of pressure, the activation enthalpy tends to increase whereas the electrical conductivity tends to decrease. The activation energy and activation volume of the main current carders of orthopyroxene have been obtained, which are （1.715±0.035） eV and （0.03±0.01） cm^3/mol, respectively; （4） Under given pressure and temperature, the electrical conductivity tends to increase with increasing oxygen fugacity, while under given pressure the activation enthalpy tends to decrease with increasing oxygen fugacity; and （5） The sample＇s small polarons mechanism has provided a reasonable explanations to the conduction behavior at high temperature and high pressure.

Sintering Caβ″/β/α-Al_2O_3 High Temperature Oxygen Sensor

An extended-life and ultra-low oxygen sensor has been fabricated by using polycrystalline Caβ″/β/α-Al2O3 as a solid electrolyte. Five reference electrodes CaO+O2, Caβ″/β/α-Al2O3 (powder)+O2,Cr+Cr2O3, Nb+NbO and Mo+MoO2 were tested in order to select a better reference electrode for this sensor. The limit of determining oxygen activity and the extended-life of the sensor were also tested in this study.

ISOLATION AND STRUCTURE DETERMINATION OF LAMIOPHLOMICL C,A NEW HIGHLY OXYGENATED IRIDOID FROM LAMIOPHLOMIS ROTATA

A new highly oxygenated iridoid,lamiophlomiol C,was isolated from the roots of Lamiophlomis rotata and its structure was elucidated by spectrosoopic techniques and X-ray diffraction.

Sleep Quality for Patients Receiving Noninvasive Positive Pressure Ventilation and Nasal High-Flow Oxygen Therapy in an ICU: Two Case Studies

Aim: The purpose of this case study was to examine the sleep quality of patients receiving noninvasive positive pressure ventilation (NPPV) or nasal high-flow oxygen therapy (NHF) in an intensive care unit and to investigate what types of nursing support are offered to such patients. Methods: We examined one patient each for NPPV and NHF. Polysomnography (PSG), review of the patient charts, and semi-structured interviews were used to collect the data for analysis. Results: Patients treated with NPPV or NHF demonstrated a noticeable reduction in deep sleep, with most of their sleep being shallow. Their sleep patterns varied greatly from those of healthy individuals. These results suggest that, in addition to experiencing extremely fragmented sleep, sleep in these patients was more likely to be interrupted by nursing interventions, such as during auscultation of breath sounds. Furthermore, it was revealed that “anxiety or discomfort that accompanies the mask or air pressure” in patients treated with NPPV and “discomfort that accompanies the nasal cannula or NHF circuit” in patients treated with NHF may be primary causes of disrupted sleep. Our results suggest a need for nursing care aimed at improving sleep quality in patients treated with NPPV or NHF.

High glucose induces myocardial cell injury through increasing reactive oxygen species production

Objective: To study the injury effect and molecular mechanism of high glucose on myocardial cells. Methods: Myocardial cells H9 c2 were cultured and divided into the control group treated with DMEM containing 5.5 mmol/L glucose, the high glucose group treated with DMEM containing 35 mmol/L glucose, and the N-acetylcysteine(NAC) group pre-treated with 1000μmol/L NAC and treated with DMEM containing 1000 μmol/L NAC and 35 mmol/L glucose.The production of ROS and the expression of mitochondria pathway apoptosis molecules in cells as well as the contents of collagen and collagen metabolism molecules were measured.Results: After 8 h, 16 h and 24 h of treatment, ROS RFU as well as Bax, CytC, Caspase-3 and Caspase-9 protein expression in cells and Col-I, Col-Ⅲ, PINP and PⅢNP protein levels in culture medium of high glucose group were higher than those of control group, Bcl-2 protein expression were lower than those of control group, but CTX-Ⅰ protein levels in culture medium were not significantly different from those of control group; after 24 h of treatment, Bax, CytC,Caspase-3 and Caspase-9 protein expression in cells as well as Col-Ⅰ, Col-Ⅲ, PINP and PIIINP protein levels in culture medium of NAC group were lower than those of high glucose group whereas Bcl-2 protein expression was higher than that of high glucose group. Conclusions:High glucose can induce myocardial cell apoptosis, increase collagen synthesis and accelerate interstitial fibrosis by increasing the production of reactive oxygen species.

A new technology for controlling in-situ oxygen fugacity in diamond anvil cells and measuring electrical conductivity of anhydrous olivine at high pressures and temperatures

We present a novel technique for controlling oxygen fugacity,which is broadly used to in-situ measure the electrical conductivities in minerals and rocks during diamond anvil cell experiments.The electrical conductivities of olivine are determined under controlled oxygen fugacity conditions(Mo–MoO2)at pressures up to 4.0 GPa and temperatures up to 873 K.The advantages of this new technique enable the measuring of the activation enthalpy,activation energy,and activation bulk volume in the Arrhenius relationship.This provides an improved understanding of the mechanism of conduction in olivine.Electrical conduction in olivine is best explained by small polaron movement,given the oxygen fugacity-dependent variations in conductivity.

Fundamental Study on Coke Degradation in BF with Oxygen Enriched Blast and High Hydrogen Atmosphere

The effects of gas composition, temperature, ore to coke ratio and prereduction rate of ore on coke degradation were studied. The results showed that 1% increment in solution loss of coke reduces coke strength by 0.6%, and the coke degradation is accelerated with the temperature. The higher the temperature, the more coke surface is involved in reactions, and the less negative effect on coke strength is. Hydrogen exerts stronger effect on coke degradation than CO at high temperature. The coke degradation is decreased with the reduction of ore to coke ratio and increase of ore prereduction rate.

A superhigh discharge capacity induced by a synergetic effect between high-surface-area carbons and a carbon paper current collector in a lithium–oxygen battery

This paper invesitages the synergetic effect between high-surface-area carbons, such as Ketjan Black(KB) or Super P(SP) carbon materials, and low-surface-area carbon paper(CP) current collectors and it also examines their influence on the discharge performance of nonaqueous Li–O2cells. Ultra-large specific discharge capacities are found in the KB/CP cathodes, which are much greater than those observed in the individual KB or CP cathodes. Detailed analysis indicates that such unexpectedly large capacities result from the synergetic effect between the two components. During the initial discharges of KB or SP materials, a large number of superoxide radical(O·-2) species in the electrolytes and Li2O2 nuclei at the CP surfaces are formed, which activate the CP current collectors to contribute considerable capacities. These results imply that CP could be a superior material for current collectors in terms of its contribution to the overall discharge capacity.On the other hand, we should be careful to calculate the specific capacities of the oxygen cathodes when using CP as a current collector; i.e., ignoring the contribution from the CP may cause overstated discharge capacities.

高熵合金在电催化氧还原反应中的应用及发展

开发用于氧气还原反应(ORR)的高效催化剂是提高燃料电池和金属-空气电池性能的关键。然而,ORR是动力学缓慢反应,存在着很高的过电势,从而降低了燃料电池和金属-空气电池的能量转换效率。高熵合金是由5种或5种以上金属元素等(近)物质的量比形成的一种新型合金材料。凭借其独特的组分与结构优势,高熵合金能够高效加速ORR、降低ORR过电势,表现出对ORR的显著催化作用。文章主要综述了高熵合金的结构、性能特点、制备方法以及在催化ORR方面的应用,并提出了挑战和发展展望。

欧洲呼吸协会2022版《急性呼吸衰竭患者经鼻高流量氧疗临床实践指南》解读

欧洲呼吸协会于2022年发布了《急性呼吸衰竭患者经鼻高流量氧疗临床实践指南》,该指南旨在为急性低氧性呼吸衰竭、手术患者术后拔管、非手术患者拔管以及高碳酸血症型呼吸衰竭4种情境下的氧疗管理提供指导。涵盖了8个主题,下设相应的推荐意见。尽管该指南的制订方法规范严谨,但需要指出的是,现有的临床证据质量等级并不高,尚需更多研究来进一步支持这些推荐意见的有效性。尽管如此,这份指南仍可帮助急诊医护人员更好地开展急性呼吸衰竭患者的氧疗实践。

诱导轮对高速液氧泵空化流场影响研究

高抗空化诱导轮可以改善液氧泵的空化特性,提高大推力火箭的可靠性。基于计算流体力学方法,建立了高速液氧泵的流动仿真模型,通过三组试验工况验证了模型准确性,研究了诱导轮叶片数对液氧泵性能和空化特性的影响。结果表明:使用诱导轮可以减小离心轮空化面积,代偿离心轮的汽蚀,提高液氧泵扬程;在入口流量和出口压力不变的条件下,增加诱导轮叶片数,液氧泵的效率增加,扬程降低,离心轮空化面积增加,诱导轮代偿离心轮汽蚀能力削弱。综合考虑液氧泵性能参数和空化特性,三叶片诱导轮能够满足大推力液体火箭的高可靠性要求。

经鼻加温湿化高流量氧疗对重症肺炎患儿血气指标、MMP-9及TNF-α的影响

目的 探讨经鼻加温湿化高流量氧疗(HFNC)治疗小儿重症肺炎的疗效及对血气指标、基质金属蛋白酶9(MMP-9)、肿瘤坏死因子α(TNF-α)的影响。方法 选取2018年5月—2020年8月河北省人民医院收治的123例重症肺炎患儿作为研究对象,按照随机抽样法分为观察组(HFNC治疗,n=62)与对照组(面罩吸氧治疗,n=61)。对比两组临床症状、动脉血二氧化碳分压(PaCO_(2))、血氧分压(PaO_(2))、TNF-α、MMP-9、血氧饱和度/吸入氧浓度与呼吸频率的比值(ROX指数)。结果 观察组的退热时间、体征消失时间、咳嗽咳痰消失时间、住院时间分别为(5.21±1.02)d、(10.02±1.32)d、(7.41±0.96)d、(9.02±2.69)d,均短于对照组(t=5.688、10.332、10.253、2.180,P<0.05)。观察组治疗后2、6、12、24 h的ROX指数分别为(6.31±1.62)、(9.85±1.96)、(11.65±2.39)、(13.46±3.25),均高于对照组(t=2.467、3.380、4.251、4.902,P<0.05);治疗后,观察组的PaCO_(2)(35.69±5.21)mmHg低于对照组,而PaO_(2)(87.52±18.69)mmHg高于对照组(t=2.379、4.647,P<0.05);治疗后,观察组的MMP-9、TNF-α分别为(6.32±1.05)pg/mL、(10.40±1.30)pg/mL,低于对照组(t=13.425、13.060,P<0.05)。结论 HFNC用于重症肺炎患儿中具有显著效果,有利于改善患儿血气指标,降低MMP-9、TNF-α水平。

老年急性脑卒中患者经鼻高流量氧疗后呼吸困难信念现状及相关影响因素分析

目的 探讨老年急性脑卒中(CVA)患者经鼻高流量氧疗后(HFNC)呼吸困难信念现状及影响因素。方法 回顾性选取2022年1月-2023年1月首都医科大学附属北京天坛医院收治的136例老年CVA经HFNC患者作为研究对象,采用呼吸困难信念问卷(BBQ)进行呼吸困难信念评分,得分率=分值/满分×100%,将得分率<满分的60%设为低呼吸困难信念组,得分率≥满分的60%设为高呼吸困难信念组。比较2组文化程度、性别、领悟社会支持量表(PSSS)、住院时间、日常生活活动能力(ADL)、 24项自我效能感量表(SEES)差异,并通过二元Logistic回归分析高呼吸困难信念的影响因素。结果 研究共纳入136例老年CVA经HFNC患者,其中低呼吸困难信念组87例,高呼吸困难信念组49例;低呼吸困难信念组年龄、肺部感染控制、昏迷、吞咽功能、咳嗽反射、 SEES评分、 PSSS评分、 ADL、是否规律体育锻炼、 HFNC设置温度、发病后救治时间评估值与高呼吸困难信念组差异均有统计学意义(P<0.05);二元Logistic分析结果显示,年龄>75岁(OR=1.719,P=0.004)、吞咽功能越差(OR=1.735,P=0.006)、咳嗽反射越差(OR=1.898,P=0.0004)、 SEES评分低(OR=1.785,P=0.002)、 PSSS评分低(OR=1.599,P=0.006)、不规律体育锻炼(OR=1.634,P=0.003)、 HFNC设置温度≥37℃(OR=1.621,P=0.006)均为影响老年CVA患者HFNC后呼吸困难信念的独立危险因素(P<0.05);构建老年CVA患者HFNC后高呼吸困难信念的风险预测模型,以模型新生成概率值为依据,绘制预测模型ROC曲线,得到AUC=0.769 0(95%CI为0.681~0.759)>0.75;Hosmer-Lemeshow检验评价模型校准能力(χ^(2)=3.543,P=0.896>0.05)。结论 老年CVA患者经HFNC后呼吸困难信念总体处于较低水平,临床工作者应早期识别患者经HFNC后呼吸困难的动机,纠正他们对呼吸困难的灾害性认识,制定针对性干预措施,促进患者心理调适和疾病康复。