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High temperature oxidation of inoculated high Si/SiMo ductile cast irons in air and combustion atmospheres
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作者 Iuliana Stan Mihai Chisamera +5 位作者 Robert Lascu Codrut Cariga Eduard Stefan Stelian Stan Denisa Anca Iulian Riposan 《China Foundry》 SCIE EI CAS CSCD 2024年第5期555-562,共8页
The present work aims to investigate the effect of heating temperature(400,600 and 800°C)and inoculating elements(Ca,Ca-Ba,Ca-RE)on oxidation behavior of ductile irons containing 5.25%Si and 4.8%Si-2.3%Mo in dry ... The present work aims to investigate the effect of heating temperature(400,600 and 800°C)and inoculating elements(Ca,Ca-Ba,Ca-RE)on oxidation behavior of ductile irons containing 5.25%Si and 4.8%Si-2.3%Mo in dry air and combustion gas containing water vapour(natural gas burning).The oxidation is influenced by the gas atmosphere type,the iron alloying system,and the inoculating elements depending on the heating temperature.The weight gain increases from 0.001%-0.1%(400°C)to 0.05%-0.70%(600°C)and up to 0.10%-2.15%(800°C).No particular effects of the considered influencing factors are found when heating at 400°C,while at 600°C,mainly the oxidation gas atmosphere type shows a visible influence.At the highest heating temperature of 800°C,a limited increase of the weight gain is found for dry air atmosphere(up to 0.25%),but it drastically increases for combustion atmospheres(0.65%-2.15%).The water vapour presence in the combustion atmosphere is an important oxidising factor at 600-800°C.The alloying system appears to influence the oxidation behavior mainly at a heating temperature of 800°C in the combustion atmosphere,as evidenced by the lower weight gain in 5.25%silicon cast iron.Positive effects of inoculating elements increase with the heating temperature,with Ca and Ba-FeSi inoculation generally showing better performance.Irons inoculated with CaRE-FeSi exhibit a higher degree of oxidation.These results are in good relationship with the previous reported data:Ca-Ba-inoculation system appears to be better than simple Ca for improving the graphite parameters,while RE-bearing inoculant negatively affects the compactness degree of graphite particles in high-Si ductile irons.As the lower compactness degree is typical for graphite nodules in high-Si ductile irons,which negatively affects the oxidation resistance,it is necessary to employ specific metallurgical treatments to improve nodule quality.Inoculation,in particular,is a potential method to achieve this improvement. 展开更多
关键词 ductile iron spheroidal graphite si/siMo oxidation air/combustion atmospheres FesiCaMgRE treatment Ca Ca-Ba Ca-RE inoculation structure characteristics
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高Si含量耐磨钢热轧钢带表面质量优化
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作者 田智文 任树洋 +1 位作者 冯晓勇 杨志南 《山西冶金》 CAS 2024年第8期209-211,共3页
通过对河钢唐钢高Si含量NM300热轧钢进行化学成分、表面缺陷形貌及特征分析,初步推断NM300表面色差形成的主要原因是Si含量高,导致在加热和轧制的过程中形成铁橄榄石相Fe_(2)SiO_(4)造成的。通过优化板坯加热时间、粗轧除磷温度及制度,... 通过对河钢唐钢高Si含量NM300热轧钢进行化学成分、表面缺陷形貌及特征分析,初步推断NM300表面色差形成的主要原因是Si含量高,导致在加热和轧制的过程中形成铁橄榄石相Fe_(2)SiO_(4)造成的。通过优化板坯加热时间、粗轧除磷温度及制度,能够有效地控制缺陷疏松颗粒层的厚度,有利于除鳞打击时裂纹扩展至基体,从而完全去除表面质量缺陷。 展开更多
关键词 si NM300 表面 铁橄榄石
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The Potential Clinical Significance of the Serum Iron and Ferritin Status in Lung Cancer Patients
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作者 Fei Fei Guo Shi Jia Cheng +1 位作者 Yi Ning Liu Jiu Wei Cui 《Journal of Nutritional Oncology》 2020年第4期189-195,共7页
Background An increasing number of studies have shown that iron,one of the indispensable trace elements in the human body,is closely related to the occurrence and development of cancer.However,few studies have clearly... Background An increasing number of studies have shown that iron,one of the indispensable trace elements in the human body,is closely related to the occurrence and development of cancer.However,few studies have clearly demonstrated the role of the iron levels in lung cancer patients,or the potential effects of inflammation on iron levels.Methods The clinical data for lung cancer patients and non-lung cancer participants were retrospectively analyzed.The serum iron and ferritin levels were measured and compared using a rank-sum test.The correlation between the serum iron/ferritin and C-reactive protein(CRP)was analyzed by rank correlation.The cut-off values for continuous variables were obtained by the receiver operating characteristic curve(ROC)method.An analysis of potential prognostic factors in lung cancer patients was conducted by univariate and multivariate survival analyses.Results The serum iron levels in patients with extensive small-cell lung cancer(SCLC)were lower than those with limited-stage SCLC,and the levels of serum ferritin and CRP in those with extensive SCLC were higher than those with limited-stage SCLC.Similarly,the serum iron levels in patients with stage IV non-small cell lung cancer(NSCLC)were lower than those of patients with stageⅠ-Ⅲdisease,and the levels of serum ferritin and CRP in those with stage IV NSCLC were higher than those in stagesⅠ-Ⅲ.The serum iron level was negatively correlated with the level of CRP,while the serum ferritin level was positively correlated with CRP.The stage of lung cancer,but not the serum iron/ferritin level,was an independent prognostic factor in lung cancer patients.Conclusions The serum iron and ferritin levels are associated with the staging of lung cancer.The later stages of lung cancer are associated with a lower serum iron level,a higher serum ferritin level,and a higher CRP level.Inflammation may play an important role in regulating the serum iron and ferritin levels in lung cancer patients. 展开更多
关键词 serum iron serum ferritin Lung cancer INFLAMMATION iron metabolism
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Reconstruction of broken Si–O–Si bonds in iron ore tailings (IOTs) in concrete 被引量:12
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作者 Juan-hong Liu Yu-cheng Zhou +1 位作者 Ai-xiang Wu Hong-jiang Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第10期1329-1336,共8页
This paper reports a study on the reconstruction of broken Si O Si bonds in iron ore tailings (IOTs) in concrete. Limestone and IOTs were used to investigate the influence of different types of coarse aggregates on th... This paper reports a study on the reconstruction of broken Si O Si bonds in iron ore tailings (IOTs) in concrete. Limestone and IOTs were used to investigate the influence of different types of coarse aggregates on the compressive strengths of concrete samples. The dif- ferences in interfacial transition zones (ITZs) between aggregate and paste were analyzed by scanning electron microscopy (SEM) and ener- gy-dispersive spectroscopy (EDS). Meanwhile, X-ray diffraction (XRD) and infrared spectroscopy (IR) were used to study microscopic changes in limestone and IOTs powders in a simple alkaline environment that simulated cement. The results show that the compressive strengths of IOTs concrete or paste are higher than those of limestone concrete or paste under identical conditions. The Ca/Si atom ratios in the ITZs of IOTs con- crete samples are lower than those of limestone concrete;the diffraction peak of the calcium silicate phase at 2θ = 29.5°, as well as the bands of Si O bonds shifting to lower wavenumbers, indicates reconstruction of the broken Si-O-Si bonds on the surfaces of IOTs with Ca(OH)2. 展开更多
关键词 iron ore TAILINGS broken si O si BONDS ALKALINE environment RECONSTRUCTION
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Influence of iron on the severity of hepatic fibrosis in patients with chronic hepatitis C 被引量:1
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作者 Tsung-Jung Lin Li-Ying Liao +2 位作者 Shyr-Yi Lin Chih-Lin Lin Ting-An Chang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第30期4897-4901,共5页
AIM: To evaluate the association among hepatic fibrosis, serum iron indices, and hepatic iron stores in patients with Chronic Hepatitis C (CHC). METHODS: Thirty-two CHC patients were included in our study. The his... AIM: To evaluate the association among hepatic fibrosis, serum iron indices, and hepatic iron stores in patients with Chronic Hepatitis C (CHC). METHODS: Thirty-two CHC patients were included in our study. The histological degree of fibrosis and inflammation activity was assessed according to the Metavir system. The serum iron indices including ferritin, iron and transferrin saturation were measured. Hepatic iron deposition was graded by Perls' stain. RESULTS: The CHC patients with severe hepatic fibrosis (n = 16) were significantly older than CHC patients with mild fibrosis (n = 16) (P = 0.024). The serum iron indices, increased serum iron store and positive hepatic iron stain were not significantly different between the two groups. In multivariate logistic regression analysis, the age at biopsy was an independent predictor of severe hepatic fibrosis (Odds ratio = 1.312; P = 0.035). The positive hepatic iron stain was significantly associated with the values of alanine aminotransferase (ALT) (P = 0.017), ferritin (P = 0.008), serum iron (P = 0.019) and transferrin saturation (P = 0.003). The ferritin level showed significant correlation with the value ofALT (r = 0.531; P = 0.003), iron (r = 0.467; P = 0.011) and transferrin saturation (r = 0.556; P = 0.002). CONCLUSION: Our findings suggest that the severity of hepatitis C virus (HCV)-related liver injury is associated with patient age at biopsy. Both serum iron indices and hepatic iron deposition show correlation with serum indices of chronic liver disease but are not related to grade and stage of liver histology. 展开更多
关键词 Chronic hepatitis C Hepatitis C virus Hepatic iron serum iron Hepatic fibrosis
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Effect of Microstructure on Impact Fatigue Resistance and Impact Wear Resistance of Medium Cr-Si Cast Iron 被引量:7
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作者 LI Wei 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2007年第3期47-50,共4页
A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue ... A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron (Cr of 15%) is not high sometimes, but its cost is not low. Thus, medium Cr-Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball-on-ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of medium Cr-Si cast iron are superior to those of martensitic high chromium cast iron (Cr of 15%). The main reasons are that (1) the stress in medium Cr-Si cast iron is released in the as-cast state; (2) the matrix is fine pearlite with better toughness and plasticity; (3) the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; (4) high silicon content im- proves the morphology of eutectic carbide; (5) there is no seeondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear. 展开更多
关键词 medium Cr-si cast iron MICROSTRUCTURE impact fatigue impact wear
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Material and technique of Si-Mo heat-resistant vermicular iron exhaust manifold 被引量:3
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作者 JIN Yong-xi (Shanghai Sandman Foundry Co., Ltd.) 《China Foundry》 SCIE CAS 2006年第3期175-183,共9页
Si-Mo vermicular iron is an ideal material for exhaust manifold that works in high temperature and thermal cycle conditions because its properties of thermal fatigue resistance and thermal distortion resistance are si... Si-Mo vermicular iron is an ideal material for exhaust manifold that works in high temperature and thermal cycle conditions because its properties of thermal fatigue resistance and thermal distortion resistance are significantly better than that of gray cast iron and nodular iron. This paper explains that the vermicularity of Si-Mo vermicular iron is better to be controlled approximately to 50% for the applications of exhaust manifold castings, and generalizes the successful experience of vermicularizing technique that uses sandwich (pour over) process combining with cored-wire injection in trough process together, and uses rare earths-magnesium-silicon as vermicularizing alloy in Disa high speed molding line and automatic plug rod air pressure pouring furnace. In addition, this paper also describes the method to solve the shrinkage hole and porosity defects in the exhaust manifold production. 展开更多
关键词 si-Mo vermicular CAST iron: EXHAUST MANIFOLD vermicularity: vermicularizing alloy: vermicularizing technique
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SEGREGATION OF Mn AND Si IN GREY CAST IRON
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作者 FAN Zhikang WANG Yiqing Shanxi Institute of Mechanical Engineering,Xi’an,ChinaHUANG Huisong Tsinghua University,Beijing,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1992年第4期297-300,共4页
An optimal two-dimensional transverse section of eutectic cells or ellipsoid austenite dendrites in the grey cast iron specimen was prepared by polishing layer by layer together with etching and coloring.The segregati... An optimal two-dimensional transverse section of eutectic cells or ellipsoid austenite dendrites in the grey cast iron specimen was prepared by polishing layer by layer together with etching and coloring.The segregation of Mn and Si with relation to their contents in the grey cast iron was examined by EMPA.The actual partition and segregation coefficients of Mn and Si in the grey cast iron were found to be not varied with their contents,but their segregation gra- dient to be different to various contents of them. 展开更多
关键词 cast iron SEGREGATION MN si
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Bovine Serum Albumin-Conjugated Ferrimagnetic Iron Oxide Nanoparticles to Enhance the Biocompatibility and Magnetic Hyperthermia Performance
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作者 Viveka Kalidasan Xiao Li Liu +2 位作者 Tun Seng Herng Yong Yang Jun Ding 《Nano-Micro Letters》 SCIE EI CAS 2016年第1期80-93,共14页
Magnetic hyperthermia is a fast emerging, non-invasive cancer treatment method which is used synergistically with the existing cancer therapeutics. We have attempted to address the current challenges in clinical magne... Magnetic hyperthermia is a fast emerging, non-invasive cancer treatment method which is used synergistically with the existing cancer therapeutics. We have attempted to address the current challenges in clinical magnetic hyperthermia-improved biocompatibility and enhanced heating characteristics, through a single combinatorial approach. Both superparamagnetic iron oxide nanoparticles(SPIONs) of size 10 nm and ferrimagnetic iron oxide nanoparticles(FIONs) of size 30 nm were synthesized by thermal decomposition method for comparison studies. Two different surface modifying agents, viz, Cetyl Trimethyl Ammonium Bromide and 3-Aminopropyltrimethoxysilane, were used to conjugate Bovine Serum Albumin(BSA) over the iron oxide nanoparticles via two different methods—surface charge adsorption and covalent amide bonding, respectively. The preliminary haemolysis and cell viability experiments show that BSA conjugation mitigates the haemolytic effect of the iron oxide nanoparticles on erythrocytes and is non-cytotoxic to the healthy Baby Hamster Kidney cells. It was observed from the results that due to better colloidal stability, the SAR value of the BSA-iron oxide nanoparticles is higher than the iron oxide nanoparticles without BSA, irrespective of the size of the iron oxide nanoparticles and method of conjugation. The BSA-FIONs seem to show improved biocompatibility, as the haemolytic index is less than 2 % and cell viability is up to 120 %, when normalized with the control. The SAR value of BSAFIONs is 2300 Wg^(-1) when compared to 1700 Wg^(-1) of FIONs without BSA conjugation. Thus, we report here that BSA conjugation over FIONs(with a high saturation magnetization of 87 emug^(-1)) provide a single combinatorial approach to improve the biocompatibility and enhance the SAR value for magnetic hyperthermia, thus addressing both the current challenges of the same. 展开更多
关键词 Magnetic HYPERTHERMIA FERRIMAGNETIC iron oxide nanoparticles Bovine serum ALBUMIN HAEMOLYsiS Cell VIABILITY Specific absorption rate
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Si对蠕墨铸铁金属基体合金微观组织及导热的影响
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作者 张笑笑 杨忠 +2 位作者 史国庆 李远 段洪波 《热加工工艺》 北大核心 2023年第19期46-52,57,共8页
通过对已有缸盖本体进行EDS能谱分析和相图模拟,得到蠕墨铸铁的金属基体成分Fe-x Si-0.6C-0.1Mn-0.05V(x=1.2、1.5、1.8、2.1wt%)。采用真空电弧熔炼制备该基体合金,并进行930℃保温2 h随炉冷却处理。使用XRD、光学显微镜(OM)和扫描电镜... 通过对已有缸盖本体进行EDS能谱分析和相图模拟,得到蠕墨铸铁的金属基体成分Fe-x Si-0.6C-0.1Mn-0.05V(x=1.2、1.5、1.8、2.1wt%)。采用真空电弧熔炼制备该基体合金,并进行930℃保温2 h随炉冷却处理。使用XRD、光学显微镜(OM)和扫描电镜(SEM)对基体合金的微观组织进行分析和表征,通过激光导热仪(TA)测量了不同温度下的热扩散系数,研究Si对蠕墨铸铁基体导热性能的影响。结果表明:蠕墨铸铁金属基体合金为珠光体和铁素体,随着Si含量升高,珠光体的含量逐渐降低,晶格畸变程度先加剧后减缓,热扩散系数和导热系数先降低后升高,比热容变化不明显。Si含量为1.8%时,基体合金的晶格畸变程度最严重,热扩散系数最低,导热系数越低。随着温度的升高,热扩散系数降低,比热容升高,导热系数增大,不同Si含量基体合金的热扩散系数差异减小。 展开更多
关键词 蠕墨铸铁 si含量 晶格畸变 热扩散系数 导热系数
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Correlation of serum iron levels with myocardial injury and pump failure in patients with acute ST-elevation myocardial infarction
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作者 Hong-Mei Li 《Journal of Hainan Medical University》 2017年第3期21-24,共4页
Objective:To analyze the correlation of serum iron levels with myocardial injury and pump failure in patients with acute ST-elevation myocardial infarction. Methods:80 patients with acute ST-elevation myocardial infar... Objective:To analyze the correlation of serum iron levels with myocardial injury and pump failure in patients with acute ST-elevation myocardial infarction. Methods:80 patients with acute ST-elevation myocardial infarction were divided into high iron group (serum iron≥8.95μmol/L) (n=43) and low iron group (serum iron<8.95μmol/L) (n=37) according to serum iron levels, differences in myocardial injury markers, ventricular remodeling indexes and pump failure-related indexes on admission were compared between two groups of patients, and the correlation of serum iron levels with myocardial damage and pump failure in patients with acute ST-elevation myocardial infarction was further analyzed. Results:Serum myocardial injury markers troponin I (cTnI), creatine kinase isoenzyme (CK-MB), myoglobin (Myo), ischemia modified albumin (IMA) and hydroxybutyrate dehydrogenase (HBDH) content of high iron group on admission were significantly lower than those of low iron group (P<0.05);left ventricular posterior wall thickness (LVPWT), left ventricular end-systolic interventricular septal thickness (IVST), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), end-systolic volume index (ESVI), end-diastolic volume index (EDVI), and the left ventricular mass index (LVMI) levels under color Doppler ultrasound were lower than those of low iron group (P<0.05);serum N-terminal pro-brain natriuretic peptide (NT-proBNP), galectin-3, adiponectin (APN), soluble P-selectin (sP-selectin) and Copeptin content were lower than those of low iron group (P<0.05). Pearson test showed that serum iron level was directly correlated with the degree of myocardial injury and pump failure in patients with acute ST-elevation myocardial infarction. Conclusions:Low serum iron levels is one of key factors causing severe cases and pump failure in STEMI patients, and early iron supplementation is expected to improve outcomes in STEMI patients with iron deficiency. 展开更多
关键词 ACUTE ST-elevation MYOCARDIAL INFARCTION serum iron MYOCARDIAL injury PUMP failure
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T5热处理对Al-Si-Cu-Mg-Mn-B合金组织和性能的影响
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作者 施豪杰 庞亚飞 杜晓东 《科学技术创新》 2023年第20期22-26,共5页
通过对Mn、B元素复合添加的Al-8Si-1Cu-0.35Mg合金进行T5热处理,使用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)、力学性能测试等方法,探究了T5热处理对合金组织和性能的影响规律。结果表明,合金中的共晶Si发生球化,针棒状的... 通过对Mn、B元素复合添加的Al-8Si-1Cu-0.35Mg合金进行T5热处理,使用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)、力学性能测试等方法,探究了T5热处理对合金组织和性能的影响规律。结果表明,合金中的共晶Si发生球化,针棒状的β-Fe相转变为汉字状的α-Fe相,合金中析出Al-Cu相、Al-B-Si-Mg和Al-Si-Cu-Mg相等大量强化相。Al-8Si-1Cu-0.35Mg-0.6Mn-0.2B合金T5热处理后合金的抗拉强度和延伸率都达到最大值,为294 MPa和10.8%。 展开更多
关键词 Al-si-Cu-Mg铝合金 热处理 微观组织 富铁相
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缺铁性贫血患者sTfR、SF、SI、UIBC、TRF检测的临床意义研究
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作者 蔡永梅 《中国医学工程》 2023年第11期98-102,共5页
目的研究缺铁性贫血患者可溶性转铁蛋白受体(sTfR)、血清铁蛋白(SF)、血清铁(SI)、不饱和铁结合力(UIBC)和转铁蛋白(TRF)检测的临床意义。方法选择2021年1月至2023年2月济源市人民医院收治的30例单纯缺铁性贫血患者作为缺铁性贫血组,30... 目的研究缺铁性贫血患者可溶性转铁蛋白受体(sTfR)、血清铁蛋白(SF)、血清铁(SI)、不饱和铁结合力(UIBC)和转铁蛋白(TRF)检测的临床意义。方法选择2021年1月至2023年2月济源市人民医院收治的30例单纯缺铁性贫血患者作为缺铁性贫血组,30例单纯慢性病贫血患者作为慢性病贫血组,同期选择30例健康体检人群为健康对照组。对比三组患者的sTfR、SF、SI、UIBC、TRF水平,分析sTfR、SF、SI、UIBC、TRF在不同程度缺铁性贫血中的表达,并采用Pearson相关性分析不同贫血程度与sTfR、SF、SI、UIBC、TRF的相关性;受试者工作特征(ROC)曲线评估sTfR、SF、SI、UIBC、TRF对缺铁性贫血的诊断效能。结果缺铁性贫血组、慢性病贫血组与健康对照组的sTfR、SF、SI、UIBC和TRF水平差异均有统计学意义(P<0.05)。sTfR、UIBC、TRF:轻度患者低于中度患者,而中度患者低于重度患者(P<0.05);SF、SI:轻度患者高于中度患者,而中度患者高于重度患者(P<0.05)。Pearson相关性显示,缺铁性贫血患者的Hb与SF、SI呈正相关,与sTfR、UIBC、TRF呈负相关(P<0.05)。ROC曲线显示,sTfR的曲线下面积(AUC)为0.857(0.771~0.943),SF的AUC为0.779(0.683~0.876),SI的AUC为0.745(0.643~0.847),UIBC的AUC为0.708(0.580~0.836),TRF的AUC为0.761(0.662~0.861),联合检测的AUC为0.968(0.771~0.943)(P<0.05)。结论sTfR、SF、SI、UIBC、TRF在缺铁性贫血、慢性病贫血和健康人群中的表达均有明显差异,同时各指标受生理或病理因素影响,不能单独用于缺铁性贫血的诊断。故应综合多项指标检测,以便为缺铁性贫血患者的早期筛查和诊断提供参考依据。 展开更多
关键词 缺铁性贫血 可溶性转铁蛋白受体 血清铁蛋白 不饱和铁结合力 转铁蛋白
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利用高硅铁尾矿制备蒸压加气混凝土
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作者 黄炜 唐达 +4 位作者 张瑞康 孙文博 苗欣蔚 侯莉娜 权文立 《新型建筑材料》 2024年第7期1-5,共5页
利用高硅铁尾矿(HIT)制备高硅铁尾矿蒸压加气混凝土(HIT-AAC),研究了HIT细度、钙硅比对HIT-AAC料浆性能和试块物理力学性能的影响;结合XRD、FTIR和SEM对HIT-AAC进行微观分析。结果表明:随着HIT细度的增大,料浆扩散度、发气速率、发气高... 利用高硅铁尾矿(HIT)制备高硅铁尾矿蒸压加气混凝土(HIT-AAC),研究了HIT细度、钙硅比对HIT-AAC料浆性能和试块物理力学性能的影响;结合XRD、FTIR和SEM对HIT-AAC进行微观分析。结果表明:随着HIT细度的增大,料浆扩散度、发气速率、发气高度均有所降低,最终发气时间缩短,试块的干密度和抗压强度均有所提高;随着钙硅比的增大,料浆扩散度减小和试块干密度先下降后上升,发气速率和发气高度增加,最终发气时间缩短,抗压强度先提高后降低,当钙硅比为0.65时抗压强度最高,为4.29 MPa。水化产物主要为石英和托贝莫来石,随着钙硅比的增大,托贝莫来石由针棒状结构转为片状结构。 展开更多
关键词 高硅型铁尾矿 蒸压加气混凝土 细度 钙硅比 水化产物
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辽宁鞍本地区沉积变质型富铁矿的成因:Fe、Si、O、S同位素证据 被引量:28
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作者 李延河 张增杰 +3 位作者 侯可军 段超 万德芳 胡古月 《地质学报》 EI CAS CSCD 北大核心 2014年第12期2351-2372,共22页
辽宁鞍本地区是我国最重要的鞍山式沉积变质型(BIF)铁矿矿集区,弓长岭铁矿是我国唯一的由鞍山式贫铁矿经后期热液改造形成的大型磁铁富矿。本文在前人工作基础上,对比研究了鞍本地区贫铁矿、富铁矿和蚀变围岩的铁、硅、氧、硫同位素组... 辽宁鞍本地区是我国最重要的鞍山式沉积变质型(BIF)铁矿矿集区,弓长岭铁矿是我国唯一的由鞍山式贫铁矿经后期热液改造形成的大型磁铁富矿。本文在前人工作基础上,对比研究了鞍本地区贫铁矿、富铁矿和蚀变围岩的铁、硅、氧、硫同位素组成特征和空间变化规律,结合磁铁富矿的地质特征,对成矿流体的性质、来源、成矿作用和富矿成矿机制提出了新的认识。指出鞍本地区富铁矿的成矿作用与辽东地区古元古代造山运动结束后(1.85Ga)地壳抬升引发的非造山岩浆侵入和热液活动有关,成矿溶液由大气降水演化形成,而非变质热液或混合岩化热液;成矿溶液淋滤了辽河群蒸发盐地层中富13 C碳酸盐、富34 S石膏、CH4等成矿物质,成矿溶液具偏酸性弱还原特征;铁质活化再富集是鞍本地区富铁矿形成的重要机制,成矿溶液与贫铁矿及围岩反应使铁质以Fe2+形式活化迁移。温度降低、氧逸度升高或与大气降水混合是溶液中Fe2+氧化形成磁铁矿沉淀的主要原因;在Fe2+被氧化形成磁铁矿的同时,成矿溶液中的CH4被氧化形成石墨,与磁铁矿一起沉淀下来,形成含石墨磁铁富矿;溶液中SO42-被还原形成富34S黄铁矿。 展开更多
关键词 弓长岭富铁矿 铁硅氧硫同位素 铁质活化再富集 辽河群蒸发盐
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铸铁中Mn和Si偏析行为的研究 被引量:8
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作者 范志康 王贻青 黄惠松 《金属学报》 SCIE EI CAS CSCD 北大核心 1992年第2期A083-A086,共4页
通过逐层抛磨,结合着色腐蚀法获得铸铁中共晶团及卵形枝晶横向最大二维切面,应用电子探针研究了其中Mn和Si的偏析分布与含量的关系。结果表明:在凝固速度不变时,Mn和Si在其中的实际分配系数K,偏析系数Ks不随其含量而变化;而Mn和Si的偏... 通过逐层抛磨,结合着色腐蚀法获得铸铁中共晶团及卵形枝晶横向最大二维切面,应用电子探针研究了其中Mn和Si的偏析分布与含量的关系。结果表明:在凝固速度不变时,Mn和Si在其中的实际分配系数K,偏析系数Ks不随其含量而变化;而Mn和Si的偏析梯度K_R却随其含量的变化而变化。 展开更多
关键词 铸铁 偏析
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Al-Si合金中富铁相形态及其影响因素研究进展 被引量:13
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作者 宋东福 王顺成 +2 位作者 周楠 农登 郑开宏 《材料工程》 EI CAS CSCD 北大核心 2016年第5期120-128,共9页
综述了Al-Si合金中富铁相的存在形态、形成条件以及富铁相影响因素的研究进展,重点讨论了Al-Si合金中合金元素、熔炼铸造工艺对富铁相形态与分布影响的最新研究现状。研究现状表明,针状富铁相对Al-Si合金性能危害极大,而汉字状富铁相对... 综述了Al-Si合金中富铁相的存在形态、形成条件以及富铁相影响因素的研究进展,重点讨论了Al-Si合金中合金元素、熔炼铸造工艺对富铁相形态与分布影响的最新研究现状。研究现状表明,针状富铁相对Al-Si合金性能危害极大,而汉字状富铁相对合金性能的危害要小得多,合金元素和熔铸工艺对富铁相形态具有重要的影响;因此,研究合金元素与熔铸工艺对富铁相形态的交互作用及其影响规律,从而获得有益的富铁相形态,或减少合金中Fe含量是Al-Si合金中减缓富铁相危害的重要研究趋势。 展开更多
关键词 AL-si合金 富铁相形态 影响因素
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锶对铸造Al-Si合金中铁相的影响 被引量:10
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作者 张良明 廖恒成 孙国雄 《铸造》 CAS CSCD 北大核心 2001年第11期654-657,共4页
本文简要介绍了铸造Al Si合金中的Fe相问题及其组织形貌改善的一些方法 ,着重回顾了Sr对Fe相影响的研究进展 ,总结了Sr对Fe相影响的四种机理 :AlP晶核理论 ,毒化理论 ,碎裂和溶解理论 ,先共晶形核理论 。
关键词 铁相 变质 铝合金 铸造
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Fe相及其形貌对共晶Al-Si合金性能的影响 被引量:13
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作者 吴晓波 张恒华 +3 位作者 李敏敏 邵光杰 杨弋涛 许珞萍 《特种铸造及有色合金》 CAS CSCD 北大核心 2007年第1期64-67,共4页
应用光学显微镜、万能拉伸实验机及XRD等,研究了不同Fe含量及其Fe相形貌对共晶Al-Si合金(ADC12)组织性能的影响,并利用扫描电镜(SEM)及能谱分析了Fe相的含量、形貌及铸件中Fe等元素的面分布。试验发现,随着Fe含量的上升,铸件的抗拉强度... 应用光学显微镜、万能拉伸实验机及XRD等,研究了不同Fe含量及其Fe相形貌对共晶Al-Si合金(ADC12)组织性能的影响,并利用扫描电镜(SEM)及能谱分析了Fe相的含量、形貌及铸件中Fe等元素的面分布。试验发现,随着Fe含量的上升,铸件的抗拉强度及伸长率逐渐下降;当Fe的质量分数在1·0%左右时,其抗拉强度急剧下降,伸长率也下降很多。在Fe含量高的Al-Si合金中按一定的w(Mn)/w(Fe)比加入Mn,使铁相形貌由针状向块状和“田”字状转变,铸件的抗拉强度提高180%。 展开更多
关键词 AL-si合金 Fe相 组织性能
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喷射轧制Fe-4.5%Si硅钢片的组织和性能 被引量:10
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作者 杨林 田冲 +2 位作者 陈桂云 张永昌 叶恒强 《材料科学与工艺》 EI CAS CSCD 2002年第1期55-58,共4页
摘要:采用喷射成形和轧制工艺制备了厚度为0.5mm的Fe-4.5%Si高硅钢片,并对其密度、显微组织和电磁性能进行了测试分析.研究结果表明:在最佳的喷射成形和轧制工艺条件下,所制备硅钢片的磁感应强度B25为1.544T、B50为1.641T;铁损P10/50为1... 摘要:采用喷射成形和轧制工艺制备了厚度为0.5mm的Fe-4.5%Si高硅钢片,并对其密度、显微组织和电磁性能进行了测试分析.研究结果表明:在最佳的喷射成形和轧制工艺条件下,所制备硅钢片的磁感应强度B25为1.544T、B50为1.641T;铁损P10/50为1.437W/kg、P15/50为3.43W/kg,说明喷射成形轧制技术可以制备出高磁感应强度、低铁损的高硅钢片. 展开更多
关键词 喷射成形 高硅硅钢片 轧制 铁损 磁感应强度 组织 性能
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