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Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure 被引量:1
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作者 Ming Li Da-Hao Yuan +2 位作者 Zhi Yang Teng-Xiang Luw Xiao-Biao Zou 《World Journal of Clinical Cases》 SCIE 2024年第18期3461-3467,共7页
BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.Howeve... BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF. 展开更多
关键词 Serum cystatin c Monocyte/high-density lipoprotein-c ratio Uric acid coronary heart disease Heart failure Risk stratification
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Cost-Effective Monitoring of the Fuel Air Equivalence-Ratio with a Lambda Sensor and a Microcontroller in a Downdraft Biomass Gasifier
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作者 Jean Fidele Nzihou Salou Hamidou +2 位作者 Ousmane Zoundi Frederic Ouattara Bila Gerard Segda 《Open Journal of Applied Sciences》 2024年第2期545-560,共16页
The operation of biomass treatment devices such as gasifiers is based on the control of key parameters that play an important role in product formation. These include: temperature, excess oxygen, relative humidity and... The operation of biomass treatment devices such as gasifiers is based on the control of key parameters that play an important role in product formation. These include: temperature, excess oxygen, relative humidity and biomass composition. This work focuses on excess oxygen and temperature. Unfortunately, flue gas oxygen analyzers are expensive and not accessible to small industries. However, the equivalence ratio is linked to excess oxygen and has the advantage of not depending on biomass composition. This study therefore focuses on the design and development of a device for controlling this equivalence ratio by measuring oxygen concentration using a self-propelled Lambda probe, and a system for monitoring this equivalence ratio using an Arduino Uno 3 microcontroller. The temperature is recorded with an accuracy of ±1.5°C. For a heating time of 10 minutes, the response time to temperature change is around 3 seconds, which is sufficient for the device to function properly. This simple device is an efficient and cost-effective means of checking the equivalence ratio. 展开更多
关键词 Equivalence ratio Biomass GAsiFIcATION Lambda Sensor MIcROcONTROLLER c++
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Effects of Regulation of C/N Ratio Wheat Straw Application on Nitrogen,Phosphorus and Potassium Uptake in Tobacco 被引量:13
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作者 段宗颜 王瑞宝 +3 位作者 鲁耀 殷寿安 胡万里 陈拾华 《Agricultural Science & Technology》 CAS 2010年第5期77-81,共5页
[Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on th... [Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on the flue-cured tobacco yield,output value,nitrogen,phosphorus and potassium content and cumulative uptake of the upper,middle and bottom leaf were studied by using the field plot experiments at Banqiao town,Qujing city,Yunnan Province during the 2008-2009 summer growing seasons. [Result]The results showed that the application of wheat straw alone or after C/N regulation,could significantly increase tobacco production,potassium content,the potassium and nitrogen accumulation amount of leaf,and was more conducive to the potassium uptake of tobacco leaf with wheat straw application after C/N regulation. Compared with non-straw application,the yield of tobacco increased by 6.59%,3.58%,5.98%,8.80% with application of wheat straw alone,wheat straw and vetch,wheat straw and oilseed cake,wheat straw and urea nitrogen,the potassium content in tobacco leaf increased by 3.85%,7.76%,8.82%,11.21%,respectively,the total potassium cumulative amount of leaf increased by 10.71%,11.62%,15.32% ,21.01% and the total nitrogen cumulative amount increased by 9.76%,1.22%,8.14%,14.00%. However,the differences of tobacco leaf nitrogen content among the different treatments were not significant,the phosphorus uptake of tobacco leaf decreased. [Conclusion]application of high C/N ratio wheat straw in flue-cured tobacco production,which should be concerned not only to adjust C/N ratio by adding nitrogen,but also considering additional phosphorus application. 展开更多
关键词 Wheat straw c/N ratio regulation Flue-cured tobacco N P K uptake
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Cu含量以及Cu/Mg比对Al-Si-Cu-Mg合金组织和力学性能的影响
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作者 顾琪 周鹏飞 《铸造》 CAS 2024年第2期180-186,共7页
研究了Cu含量和Cu/Mg比对Al-Si-Cu-Mg合金组织和力学性能的影响。结果表明Al-Si-Cu-Mg合金凝固组织是否形成Mg_(2)Si、Q-Al_(5)Cu_(2)Mg_(8)Si_(6)以及θ-Al_(2)Cu取决于Cu含量以及Cu/Mg比。当Cu/Mg比相对低时形成Mg_(2)Si中间相,而Cu/M... 研究了Cu含量和Cu/Mg比对Al-Si-Cu-Mg合金组织和力学性能的影响。结果表明Al-Si-Cu-Mg合金凝固组织是否形成Mg_(2)Si、Q-Al_(5)Cu_(2)Mg_(8)Si_(6)以及θ-Al_(2)Cu取决于Cu含量以及Cu/Mg比。当Cu/Mg比相对低时形成Mg_(2)Si中间相,而Cu/Mg比高时则倾向于生成Q-Al_(5)Cu_(2)Mg_(8)Si_(6)和θ-Al_(2)Cu相。当Cu/Mg比相同时,高Cu含量和高Mg含量都会促进Q相θ相的形成。通过观察T6热处理后的组织发现Cu含量以及Cu/Mg比控制了初生相的溶解以及析出相的形成,从而影响合金的强度与韧性。通过控制Cu含量及Cu/Mg比使Al-9Si-2Cu-0.5Mg合金中析出较少数量的初生相,再通过热处理析出大量的Q′强化相,使合金具有较高的强度和相对适中的伸长率。 展开更多
关键词 Al-si-cu-Mg cU含量 cu/Mg比 组织 力学性能
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SiC纳米线对大气等离子喷涂硅涂层性能的影响
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作者 王博 庄辛鹏 +4 位作者 李归 王宇龙 李媛琪 施伟 李佳艳 《耐火材料》 CAS 北大核心 2024年第5期369-375,共7页
为提升C/SiC复合材料表面Si涂层的韧性及其与C/SiC复合材料的结合强度,首先以10 mm×10 mm×10 mm的C/SiC复合材料作为基体,在基体表面生成约20μm厚的SiC纳米线(SiCnws)多孔层;再用大气等离子体喷涂法分别将生长SiCnws的基体... 为提升C/SiC复合材料表面Si涂层的韧性及其与C/SiC复合材料的结合强度,首先以10 mm×10 mm×10 mm的C/SiC复合材料作为基体,在基体表面生成约20μm厚的SiC纳米线(SiCnws)多孔层;再用大气等离子体喷涂法分别将生长SiCnws的基体和未生长SiCnws的基体喷涂约30、60、90μm厚的Si涂层。研究SiCnws对涂层试样的结合强度和抗氧化性的影响,并借助XRD、SEM、TEM和EDS对所制备的SiCnws和SiCnws/Si涂层进行物相组成、显微结构的分析。结果表明:1)制备的SiCnws形状平直,表面光滑,取向随机,直径为100~200 nm,是沿[111]晶向择优生长的β-SiC;2)SiCnws引入到Si涂层后,SiCnws/Si涂层试样的结合强度均比相应的Si涂层试样的高,说明SiCnws增强了Si涂层与C/SiC复合材料的结合;3)从室温至1400℃经历12次热震循环后,SiCnws/Si涂层试样的质量损失率比相应Si涂层试样的低20.7%~37.2%,说明SiCnws能有效缓解热应力,抑制裂纹的形成和扩展,降低裂纹尺寸和数量,提高涂层的抗氧化性。 展开更多
关键词 c/sic复合材料 sic纳米线 si涂层 抗氧化性能 结合强度
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基于C++SuperMix库的SIS混频器的研究
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作者 魏苇 武向农 张毅闻 《上海师范大学学报(自然科学版中英文)》 2024年第2期254-259,共6页
基于C++SuperMix软件库对680 GHz接收机中的双槽双超导隧道结(SIS)混频器进行深入模拟研究.在环境温度为4.2 K、本地振荡器(LO)频率为680 GHz、本振功率为100 nW、中频频率中心为10 GHz和中频匹配阻抗为50Ω的条件下,采用二次谐波的谐... 基于C++SuperMix软件库对680 GHz接收机中的双槽双超导隧道结(SIS)混频器进行深入模拟研究.在环境温度为4.2 K、本地振荡器(LO)频率为680 GHz、本振功率为100 nW、中频频率中心为10 GHz和中频匹配阻抗为50Ω的条件下,采用二次谐波的谐波平衡法,在0~500 K热噪声源温度下对SIS混频器的输出噪声温度进行建模仿真研究.计算得出:当偏置电压在2~3 mV变化时,SIS混频器的输出噪声温度均小于50 K,表明所研究的SIS混频器具有较好的噪声性能. 展开更多
关键词 高频混频器 c++编程语言 SuperMix软件库 双槽双超导隧道结(siS)混频器
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Effect of C/S Ratio on Morphology and Structure of Hydrothermally Synthesized Calcium Silicate Hydrate 被引量:11
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作者 何永佳 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第4期770-773,共4页
The samples of the C-S-H series were synthesized by hydrothermal reaction of fumed silica, CaO and deionized water at initial C/S ratios between 1.0-1.7. Phase composition and structural and morphology characteristics... The samples of the C-S-H series were synthesized by hydrothermal reaction of fumed silica, CaO and deionized water at initial C/S ratios between 1.0-1.7. Phase composition and structural and morphology characteristics of C-S-H samples were analyzed by XRD, IR and SEM. The experimental results showed that the d-spacing of (002), (110) and (020) decreased, the d-spacing of (200) increased, and the d-spacing of (310) varied randomly, the polymerization of silica tetrahedra of C-S-H decreased, and morphology of C-S-H samples varied from sheet shapes to long reticular fibers as C/S ratio increased. 展开更多
关键词 calcium silicate hydrate c/S ratio MORPHOLOGY STRUcTURE hydrothermal synthesis
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Relationship Between Leaf C/N Ratio and Insecticidal Protein Expression in Bt Cotton as Affected by High Temperature and N Rate 被引量:8
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作者 ZHANG Xiang LU Chun-hua +3 位作者 CHEN Yuan WANG Gui-xia CHEN Yuan CHEN De-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第1期82-88,共7页
Expression of insecticidal protein for transgenic Bacillus thuringiensis (Bt) cotton is unstable and related to nitrogen metabolism. The objective of this study was to investigate the relationship between leaf carbo... Expression of insecticidal protein for transgenic Bacillus thuringiensis (Bt) cotton is unstable and related to nitrogen metabolism. The objective of this study was to investigate the relationship between leaf carbon nitrogen ratio (C/N) and insecticidal efficacy of two Bt cotton cultivars. C/N ratio and Bt protein content were both measured at peak square period and peak boll period respectively under 5-7 d high temperature and different nitrogen fertilizer rates on the Yangzhou University Farm and the Ludong Cotton Farm, China. All plants were grown in field. The results showed that the C/N ratio enhanced slightly and the Bt protein content remained stable at peak square period, but significant increases for the C/N ratio and decreases markedly for the leaf Bt protein concentration were detected at the peak boll period. The similar patterns at the two growth periods were found for the leaf C/N ratio and Bt protein content by different N fertilizer treatments. When nitrogen rate was from 0 to 600 kg ha-l, the C/N ratio was reduced by 0.017 and 0.006 for Sikang 1 and Sikang 3 at peak square period, compared to the 1.350 to 1.143 reduction for Sikang 1 and Sikang 3 at peak boll period, respectively. Correspondingly, the leaf Bt protein contents were bolstered by 2.6-11.8 and 26.9-36.9% at the two different growth periods, respectively. The results suggested that enhanced C/N ratio by high temperature and nitrogen application may result in the reduction of inseetiocidal efficacy in Bt cotton, especially in peak boll period. 展开更多
关键词 Bt cotton c/N ratio Bt protein insecticidal efficacy
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Effect of carbon and nitrogen ratio control on Artemia growth, water quality, biofloc microbial diversity under high salinity and zero-water exchange culture condition 被引量:3
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作者 WANG Shanyue CUI Xueping +2 位作者 XU Ruyi GAO Meirong SUI Liying 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第5期1768-1776,共9页
Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces... Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces the nitrogen level in the water and provides microbial protein to the animals. However, most of the studies and practical applications have been conducted in freshwater and marine environment. This paper focused on brine shrimp Artemia that lives in high salinity environment together with other halophilic or halotolerant microorganisms. The effect of carbon supplementation on Artemia growth, water quality, and microbial diversity of biofl ocs was studied in the closed culture condition without any water exchange. The salinity of the culture medium was 100. A 24-d culture trial was conducted through supplementing sucrose at carbon/nitrogen (C/N) ratio of 5, 15, and 30 (Su5, Su15, and Su30), respectively. The culture without adding sucrose was used as a control. Artemia was fed formulated feed at a feeding ration of 60% recommended feeding level. The results showed that sucrose supplementation at higher C/N ratio (15 and 30) signifi cantly improved the Artemia survival, growth and water quality ( P <0.05). Addition of sucrose at C/N ratio of 15 and 30 significantly increased biofloc volume (BFV)( P <0.05). The Illumina MiSeq sequencing analysis showed that supplementing carbon at C/N ratio of 15 had a better total bacterial diversity and richness, and shaped the microbial composition at genera level. This study should provide information for studying the mechanism of biofloc technology and its application in high salinity culture conditions. 展开更多
关键词 biofl OcS c/N ratio ARTEMIA GROWTH water quality MIcROBIAL diversity high throughput SEQUENcING
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Fe-C-Mn-Si-Al双相钢两相区加热过程中的奥氏体相变行为研究
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作者 谢钊远 林关强 +1 位作者 王定峰 蓝慧芳 《热加工工艺》 北大核心 2024年第17期127-130,共4页
采用Dictra软件模拟与实验验证相结合,研究了不同加热条件下铁素体+渗碳体向奥氏体的相变过程,重点分析了渗碳体溶解规律及其对奥氏体相变动力学的影响规律,借助场发射电子探针对不同加热路径下的铁素体及马氏体组织形貌及元素分布进行... 采用Dictra软件模拟与实验验证相结合,研究了不同加热条件下铁素体+渗碳体向奥氏体的相变过程,重点分析了渗碳体溶解规律及其对奥氏体相变动力学的影响规律,借助场发射电子探针对不同加热路径下的铁素体及马氏体组织形貌及元素分布进行观测,使用透射电镜对渗碳体和残余奥氏体进行了表征。结果表明,慢速加热至740℃长时间等温与加热至780℃较短时间等温对比发现,虽然渗碳体刚溶解完全时的奥氏体分数相差不大,但在渗碳体溶解的过程中,奥氏体相变的方式不尽相同。在慢速加热条件下,铁素体晶界处为奥氏体优先形核地点;快速加热条件下,由于形核驱动力提高,铁素体晶粒内部的渗碳体处同样可以形核。740℃等温结合快速加热,获得了马氏体与残余奥氏体的“壳-核”组织结构。 展开更多
关键词 Fe-c-Mn-si-Al钢 渗碳体溶解 奥氏体相变 残余奥氏体
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Platelet count/spleen diameter ratio to predict esophageal varices in Mexican patients with hepatic cirrhosis 被引量:19
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作者 Alejandro González-Ojeda Gabino Cervantes-Guevara +7 位作者 Manuela Chávez-Sánchez Carlos Dávalos-Cobián Susana Ornelas-Cázares Michel Dassaejv Macías-Amezcua Mariana Chávez-Tostado Kenia Militzi Ramírez-Campos Anaís del Rocío Ramírez-Arce Clotilde Fuentes-Orozco 《World Journal of Gastroenterology》 SCIE CAS 2014年第8期2079-2084,共6页
AIM: To validate whether the platelet count/spleen size ratio can be used to predict the presence of esophageal varices in Mexican patients with hepatic cirrhosis.
关键词 Platelet count/spleen diameter ratio Esophageal varices Hepatic cirrhosis Hepatitis c virus Mexican patients
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Preparation of Mo(Si,Al)_2 feedstock used for air plasma spraying
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作者 侯晖东 宁先进 +3 位作者 王全胜 高斌 柳彦博 刘颖 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第11期2939-2946,共8页
In order to prepare high quality Mo(Si,Al)2 feedstock characterized with C40 phase, higher Al doping amount andexcellent flowability, Mo(Si1-x,Alx)2 with different Al contents (x=0, 0.1, 0.2, 0.3, 0.4, 0.5) were... In order to prepare high quality Mo(Si,Al)2 feedstock characterized with C40 phase, higher Al doping amount andexcellent flowability, Mo(Si1-x,Alx)2 with different Al contents (x=0, 0.1, 0.2, 0.3, 0.4, 0.5) were synthesized by self-propagatinghigh-temperature synthesis first and Mo(Si0.6,Al0.4)2 was confirmed as the suitable material through X-ray diffraction analysis. Aseries of tests with different parameters of induction plasma spheroidization were applied to improving the flowability of feedstock.Mo(Si,Al)2 feedstock with excellent flowability (26.2 s/50 g) was prepared through adding hydrogen into sheath gas and decreasingthe powder feeding rate. The composition segregation occurred in the spheroidized powder after Al consumption and oxidation. Theinhomogeneous structure of the same particle was caused by the asymmetric heating and cooling when particle passed through theplasma jet. 展开更多
关键词 Mo(si Al)2 c40 phase self-propagating high-temperature synthesis induction plasma spheroidization compositionsegregation
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Experimental Investigation of the Anisotropic Thermal Conductivity of C/SiC Composite Thin Slab
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作者 毋克凡 张虎 唐桂华 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第3期48-60,共13页
Fiber-reinforced composites possess anisotropic mechanical and heat transfer properties due to their anisotropic fibers and structure distribution.In C/Si C composites,the out-of-plane thermal conductivity has mainly ... Fiber-reinforced composites possess anisotropic mechanical and heat transfer properties due to their anisotropic fibers and structure distribution.In C/Si C composites,the out-of-plane thermal conductivity has mainly been studied,whereas the in-plane thermal conductivity has received less attention due to their limited thickness. 展开更多
关键词 cOMPOsiTES c/si ANISOTROPIc
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Effect of compression ratio on microstructure evolution of Mg−10%Al−1%Zn−1%Si alloy prepared by SIMA process 被引量:3
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作者 Li-jie CAO Guo-rui MA +2 位作者 Chun-xia WANG Zheng-jian CHEN Jia-heng ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第9期2597-2605,共9页
A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experime... A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experimental alloy was investigated.The results indicate that the average size ofα-Mg grains decreases and spheroidizing tendency becomes more obvious with the compression ratios increasing from 0 to 40%.In addition,the eutectic Mg2Si phase in the Mg−10%Al−1%Zn−1%Si alloy transforms completely from the initial fishbone shape to globular shape by SIMA process.With the increasing of compression ratio,the morphology and average size of Mg2Si phases do not change obviously.The morphology modification mechanism of Mg2Si phase in Mg−10%Al−1%Zn−1%Si alloy by SIMA process was also studied. 展开更多
关键词 Mg−Al−Zn−si alloy compression ratio microstructure evolution eutectic Mg2si phase strain induced melt activation(siMA)process
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Enhancement of catalytic and anti-carbon deposition performance of SAPO-34/ZSM-5/quartz films in MTA reaction by Si/Al ratio regulation 被引量:2
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作者 Jiaxin Wu Chenxiao Wang +6 位作者 Xianliang Meng Haichen Liu Ruizhi Chu Guoguang Wu Weisong Li Xiaofeng Jiang Deguang Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第4期314-324,共11页
In order to further improve the catalytic performance of zeolite catalyst for methanol to aromatics(MTA)technology, the double-tier SAPO-34/ZSM-5/quartz composite zeolite films were successfully synthesized via hydrot... In order to further improve the catalytic performance of zeolite catalyst for methanol to aromatics(MTA)technology, the double-tier SAPO-34/ZSM-5/quartz composite zeolite films were successfully synthesized via hydrothermal crystallization. The Si/Al ratio of SAPO-34 film was used as the only variable to study this material. The composite zeolite material with 0.6Si/Al ratio of SAPO-34 has the largest mesoporous specific surface area and the most suitable acid distribution. The catalytic performance for the MTA process showed that 0.6-SAPO-34/ZSM-5/quartz film has as high as 50.3% benzene-toluenexylene selectivity and 670 min lifetime. The MTA reaction is carried out through the path we designed to effectively avoid the hydrocarbon pool circulation of ZSM-5 zeolite, so as to improve the aromatics selectivity and inhibit the occurrence of deep side reactions to a great extent. The coke deposition behavior was monitored by thermogravimetric analysis and gas chromatograph/mass spectrometer, it is found that with the increase of Si/Al ratio, the active intermediates changed from low-substituted methylbenzene to high-substituted methylbenzene, which led to the rapid deactivation of the catalyst. This work provides a possibility to employ the synergy effect of composite zeolite film synthesizing anti-carbon deposition catalyst in MTA reaction. 展开更多
关键词 composite zeolite film Methanol to aromatics Anti-carbon deposition si/Al ratio Hydrocarbon pool circulation mechanism
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Effect of Heat Treatment on Microstructure and Mechanical Properties of Multiscale SiC_p Hybrid Reinforced 6061 Aluminum Matrix Composites
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作者 吴健铭 许晓静 +3 位作者 ZHANG Xu LUO Yuntian LI Shuaidi HUANG Lin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期174-181,共8页
The performance of solid solution aging treatment on aluminum matrix composites prepared by powder metallurgy and reinforced with 6061 aluminum alloy powder as matrix;meanwhile, nano silicon carbide particles(nm Si Cp... The performance of solid solution aging treatment on aluminum matrix composites prepared by powder metallurgy and reinforced with 6061 aluminum alloy powder as matrix;meanwhile, nano silicon carbide particles(nm Si Cp), submicron silicon carbide particles(1 μm Si Cp) and Ti particles were studied. The Al/Si Cp composite powder was prepared by high-energy ball milling, and then cold-pressed, sintered, hotextruded, and then heat-treated with different solution temperatures and aging times for the extruded composites. Optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy(EDS), X-ray diffractometer(XRD) and extrusion testing were used to analyze and test the microstructure and mechanical properties of aluminum matrix composites. The results show that after the multi-stage solid solution at 530 ℃×2 h+535 ℃×2 h+540 ℃×2 h, the particles are mainly equiaxed grains and uniformly distributed. There is no reinforcement agglomeration, and the surface is dense and the insoluble phase is basically dissolved. In the matrix, the strengthening effect is good, and the hardness and compressive strength are 179.43 HV and 680.42 MPa, respectively. Under this solution process, when the aluminum matrix composites are aged at 170 ℃ for 10 h, the hardness and compressive strength can reach their peaks and increase to 195.82 HV and 721.48 MPa, respectively. 展开更多
关键词 aluminum matrix composites si c particles multiscale hybrid enhancement heat treatment mechanical properties
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Silica-alumina molar ratio and some factors effect on the synthesis of zeolites from fly ash 被引量:2
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作者 SUN Yue-zhi FU Ke-ming +1 位作者 ZHU Hong ZHU Tian-lin 《Journal of Coal Science & Engineering(China)》 2009年第4期430-433,共4页
In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, whi... In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, which is hydrothermally treated at about 104 ℃, and the liquid/solid ratio was controlled at 6:1. In order to control Si/Al molar ratio, SiO2 or Al2O3 powers were added to the fly ash. The results of XRD and SEM show that the alkali melted can activate fly ash and eliminate its quartz and mullite, along with the improvement of Si/Al molar ratio and alkalinity. In addition, zeolite Na-A changes into sodalite gradually, and nepheline is the synthesized intermediate product. Those results were discussed on the basis of a formation mechanism of zeolite from fly ash. 展开更多
关键词 fly ash ZEOLITE hydrothermal treatment si/Al molar ratio
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Activated Protein C Resistance in Patients with Pre-Eclampsia in Lagos, Nigeria
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作者 Nosimot O. Davies Titilope A. Adeyemo +2 位作者 Sunday I. Omisakin Akaninyene A. Udousoro Kabiru A. Rabiu 《Open Journal of Obstetrics and Gynecology》 2024年第4期575-590,共16页
Background: Preeclampsia is reported to complicate 2% - 8% of pregnancies globally and is an important cause of maternal and perinatal morbidity and mortality. The aetiology and pathogenesis are still poorly understoo... Background: Preeclampsia is reported to complicate 2% - 8% of pregnancies globally and is an important cause of maternal and perinatal morbidity and mortality. The aetiology and pathogenesis are still poorly understood and substantial improvement has not been made in the prediction, prevention and treatment of the disease. Objective: To compare the frequency of activated protein C resistance (APC-R) in patients with pre-eclampsia to that of normotensive pregnant women and to determine the correlation between activated protein ratio (APC-ratio) and the severity of pre-eclampsia. Methodology: A cross-sectional study was carried out in 100 pre-eclamptic patients and 100 normotensive pregnant controls. The APC-ratio was determined using the modified activated partial thromboplastin time. Study participants with APC-ratio of less than 2.0 were defined as having APC-R. Data was analyzed using SPSS version 22.0. Results: Mean APC-ratio was significantly lower in pre-eclamptics (2.89 ± 1.70) compared to normotensive pregnant women (3.57 ± 1.06) (p = 0.0008) and the levels were also higher in mild (2.95 ± 1.15) compared to severe pre-eclamptics (2.62 ± 1.14). The frequency of APC-R was 26% among women with pre-eclampsia compared to 4% among normotensive controls (p = 0.000). Among 100 pre-eclamptic women 7 (21.2%) out of 33 with mild pre–eclampsia had APC-R, while 19 (28.4%) out of 67 with severe pre-eclampsia had APC-R. APC-ratio had a significant negative correlation with mean arterial blood pressure (r = −0.324;p = 0.000) and proteinuria (r = −0.379;p = 0.000) among study participants. Conclusion: The frequency of activated protein c resistance is significantly higher in pre-eclamptics compared to normotensive pregnant women and this is more pronounced in those with severe pre-eclampsia compared with those with mild disease. APC-R may therefore be used as a marker of severity in the disease. 展开更多
关键词 Activated Protein c Resistance Activated Protein c ratio PRE-EcLAMPsiA
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Germanium/silica ratio and trace element composition of Early Cambrian siliceous rocks in Keping:implications for the siliceous rocks'formation and paleoenvironment interpretations 被引量:1
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作者 Zixuan Guan Shibiao Deng +2 位作者 Peixian Liu Yiqiu Jin Xingchun Cao 《Acta Geochimica》 EI CAS CSCD 2020年第6期797-810,共14页
This study used the germanium/silica(Ge/Si)ratios,together with rare earth elements and other trace elements to infer the siliceous source and sedimentary environment of the siliceous rocks located at the bottom of Yu... This study used the germanium/silica(Ge/Si)ratios,together with rare earth elements and other trace elements to infer the siliceous source and sedimentary environment of the siliceous rocks located at the bottom of Yuertusi Formation in Northwestern Tarim Basin,Keping,China.Previous studies have shown that this siliceous rock stratum formed at the edge of the carbonate platform on the continental shelf.Researchers suggest that these siliceous rocks were formed by hydrothermal activity,but some still draw different conclusions.Understanding the silicon source and depositional environment of these siliceous rocks would help us learn the processes of environmental changes and the causes of biological explosions during this period.The value of germanium/silica ratios of these siliceous rocks is from 0.15 to 0.37 pmol/mol and much lower than above 10|imol/mol values in siliceous rocks that are known formed by hydrothermal activity.All samples are rich in HREE,which differ from hydrothermal siliceous rocks that are rich in LREE.Most samples lack hydrothermal related elements.All these features show that the source of these siliceous rocks'siliceous is not hydrothermal flu ids.The samples'Ce/Ce*range from 0.88 to 1,and Th/U ratios range from 0.01 to 0.36.These features suggest these siliceous rocks were formed in an anoxic environment.Considering all the evidence,we conclude that the siliceous rock stratum at the bottom of the Lower Cambrian Yuertusi Formation in northwest Tarim Basin.Keping,was formed in anoxic seawater at the edge of the carbonate platform on the continental shelf.Its silicon source is seawater instead of hydrothermal fluid. 展开更多
关键词 siliceous rocks Trace elements Ge/si ratio Tarim Basin
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Si/C复合锂离子电池负极材料的制备及其性能
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作者 孙亚萍 《炼油与化工》 CAS 2024年第5期52-54,共3页
从电池性能的角度出发,合理设计电池负极材料是必要的,为此提出Si/C复合锂离子电池负极材料的制备及电化学性能分析研究。准备实验材料和仪器后,分别按照Si:石墨为1:9、2:8、3:7和4:6的比例准备混合料,按照料液比1:4加入无水乙醇作为球... 从电池性能的角度出发,合理设计电池负极材料是必要的,为此提出Si/C复合锂离子电池负极材料的制备及电化学性能分析研究。准备实验材料和仪器后,分别按照Si:石墨为1:9、2:8、3:7和4:6的比例准备混合料,按照料液比1:4加入无水乙醇作为球磨介质,在球磨机中进行球磨处理,干燥后得到Si含量分别为10%、20%、30%和40%的复合材料;按照质量比为90:5:2:3的比例活性物质(Si/C复合材料)、导电剂碳黑、分散剂乙二醇和粘结剂PVDF配置浆料,涂抹于锂箔表面,经热压成型机对极片进行压实处理,得到Si/C复合锂离子电池负极。在采用电池测试系统在100 mA/g下对硅含量分别为10%、20%、30%和40%的复合材料电极电化学性质进行测试,得出结论Si/C复合锂离子电池负极材料的放电容量受硅含量影响明显,并且不存在直接的线性相关关系;硅含量也会影响Si/C复合锂离子电池负极材料的库伦效率,过高或高低都会导致库伦效率下降。 展开更多
关键词 球磨处理 压实处理 si/c复合锂离子电池负极 放电容量 库伦效率
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