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高韧性PVA-SHCC多缝开裂后吸水特性研究

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建筑材料学报 2011年第3期14卷 324-328,334页

作者：张鹏 f. H. WITTMANN 赵铁军 E．LEHMANN 田砾青岛理工大学土木工程学院山东青岛266033 弗莱堡Aedificat研究所弗莱堡D-79100 Paul Scherrer Institute裂变中子源中心 VilligenPSICH-5232

制备了高韧性PVA-SHCC(聚乙烯醇-应变硬化水泥基复合材料)试件,通过吸水试验和中子成像试验,研究了未开裂和直拉多缝开裂情况下SHCC的吸水特性.结果表明:中子成像能够对无裂缝和多缝开裂SHCC试件的吸水过程进行可视化追踪和定量分析计算... 详细信息

制备了高韧性PVA-SHCC(聚乙烯醇-应变硬化水泥基复合材料)试件,通过吸水试验和中子成像试验,研究了未开裂和直拉多缝开裂情况下SHCC的吸水特性.结果表明:中子成像能够对无裂缝和多缝开裂SHCC试件的吸水过程进行可视化追踪和定量分析计算;SHCC在无裂缝时吸水很少,中子成像无肉眼可见的水分前锋;多缝开裂后,能够清晰探测到水分沿80～140μm的裂缝迅速侵入材料内部,并通过遭横向拉拔破坏的纤维与水泥基体界面而充满裂缝区;在这种情况下,应从耐久性角度限制SHCC多重裂缝宽度.

关键词：应变硬化水泥基复合材料聚乙烯醇纤维多缝开裂吸水中子成像

Cr^（2＋）在橄榄石、斜方辉石和尖晶石中溶解度的实验研究

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地球化学 1995年第3期24卷 235-244页

作者：李建平 Seife.,f 中国科学院广州地球化学研究所

为了研究Ｃｒ^（２＋）在橄榄石、斜方辉石和尖晶石中的溶解度及其在各相间的分配，在压力为０－２．８８ＧＰａ和温度为ｌｌ００－１４５０℃的条件下，于ＭｇＯ－ＳｉＯ_２－Ｃｒ－Ｏ体系中完成了一系列实验。实验起始成分由高纯度的... 详细信息

为了研究Ｃｒ^（２＋）在橄榄石、斜方辉石和尖晶石中的溶解度及其在各相间的分配，在压力为０－２．８８ＧＰａ和温度为ｌｌ００－１４５０℃的条件下，于ＭｇＯ－ＳｉＯ_２－Ｃｒ－Ｏ体系中完成了一系列实验。实验起始成分由高纯度的ＭｇＯ、ＳｉＯ_２、Ｃｒ_２Ｏ_３和Ｃｒ混合得到。通过Ｃｒ_２Ｏ_３。和Ｃｒ等化学混合得到所需的ＣｒＯ，且加有过量（５０％）的Ｃｒ，使得实验产物和金属Ｃｒ保持平衡。此外，还加入占起始混合物重量１０％的ＢａＯ＋Ｂ_２Ｏ_３作为流体成分，以保证实验的平衡和有利于晶体的生长。样品容器材料为金属Ｃｒ。实验产物先经粉晶Ｘ射线定性鉴定，再进行电子探针定量分析，然后通过化学计量法算得ＣｒＯ在不同相（橄榄石、斜方辉石、尖晶石）中的含量。结果表明，在橄榄石和斜方辉石中Ｃｒ^（３＋）可忽略不计。实验结果显示：随着温度的升高、压力的降低，Ｃｒ^（２＋）在橄榄石、斜方辉石和尖晶石中的溶解度逐渐增大；随着温度的升高，Ｍｇ－Ｃｒ^（２＋）在橄榄石－斜方辉石之间的分配系数降低，在斜方辉石－尖晶石之间的分配系数增大，而在橄榄石－尖晶石之间的分配系数变化不大。压力对以上各分配系数的影响可忽略不计。

关键词：铬离子溶解度橄榄石斜方辉石尖晶石实验

Assessment of necessity of neuronavigation in localization of calvarial extra-axial lesions in the setting of limited resources

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Chinese Neurosurgical Journal 2022年第1期8卷 26-30页

作者： Hussein Soffar Mohamed f.Alsawy Neurosurgery Department Kasr Alainy Faculty of MedicineCairo UniversityAl-Saray StreetEl ManialCairoEgypt

Background:Neuronavigation is a very beneficial tool in modern neurosurgical ***,the neuronavigation is not available in most of the hospitals in our country raising the question about its importance in localizing the calvarial extra-axial lesions and to what extent it is safe to operate without ***:We studied twenty patients with calvarial extra-axial lesions who underwent surgical *** lesions were preoperatively located with both neuronavigation and the usual linear *** methods were compared regarding the time consumed to localize the tumor and the accuracy of each method to anticipate the actual center of the ***:The mean error of distance between the planned center of the tumor and the actual was 6.50±1.762 mm in conventional method,whereas the error was 3.85±1.309 mm in IGS *** more time was consumed during the neuronavigation method including booting,registration,and positioning.A statistically significant difference was found between the mean time passed in the conventional method and IGS method(2.05±0.826,24.90±1.334,respectively),P-valuef limited resources,the linear measurement localization method seems to have an accepted accuracy in the localization of calvarial extra-axial lesions and it saves more time than neuronavigation method.

关键词： Calvarial Extra-axial Meningioma Neuronavigation Streotaxy

Antioxidant Property of a Dietary Supplement of Moringa oleifera Leaves and Pleurotus ostreatus in Wistar Rats Subjected to forced Swimming Endurance Test

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food and Nutrition Sciences 2022年第5期13卷 493-503页

作者： fatou Corka Kane Djimadoum Kimassoum Simo fredy Brice Moundipa f. Paul Wilfred f. Mbacham Department of Biochemistry Faculty of Science University of Yaoundé I Yaoundé Cameroon Mushroom Biotechnology Laboratory Department of Plant Biology and Physiology Faculty of Sciences Cheikh Anta Diop University of Dakar Dakar Senegal Laboratory for food and Drug Safety and Publci Health Biotechnologies University of Yaoundé I Yaoundé Cameroon Centre for Health Inplementation and Translattional Research The Fobang Institutes Yaoundé Cameroon

The antioxidant property of Moringa oleifera leaves and Pleurotus ostreatus on swimming performance and related biochemical parameters were investigated in thirty adult male and female wistar rats. Purpose: The aim of the present study was to evaluate the antioxidant property of M. oleifera and P. ostreatus mixture in specific proportions in wistar rats. Material and Methods: The mushroom species and M. oleifera leaves were cultivated at the biotechnology laboratory of the University Cheikh Anta Diop de Dakar, Senegal. Oxidative stress in rats was induced by swimming. The dietary supplement was composed of a mixture of powders of Moringa oleifera and Pleurotus ostreatus in 2:1 ratio. Three groups received different doses of dietary supplements 500 mg/kg, 1000 mg/kg, and 1500 mg/kg, with one group being the stressed and the other the control group. Parameters in serum such as serum glutamyl oxaloacetate transaminase, serum glutamyl pyruvate transaminase, albumin, Testosterone, creatinine, and, oxidative stress parameters (catalase, reduced glutathione, and malondialdehyde) were measured. Results: Results showed that the dietary supplement has an effect on oxidative stress because it increases the activity of catalase and the level of cellular glutathione in rats. The 500 mg/kg dose would be the most appropriate dose for stressful conditions. The 1000 mg/kg dose would be the most appropriate dose for liver damage. Conclusion: This study shows that the antioxidant properties of M. oleifera leaves and Pleurotus ostreatus are demonstrated by their ability to improve body energy stores and tissue antioxidant capacity. The dietary supplement of M. oleifera leaves and P. ostreatus powders mixture could be good in stressful conditions.

关键词： Moringa oleifera Pleurotus ostreatus Dietary Supplement Antioxidant Oxidative Stress

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北美斑岩矿床的某些时空分布特征

地质科技情报 1991年第1期10卷 63-68,54页

作者： J.f.Davies 谢荣举

斑岩矿床可能是北美研究最深入的一类矿床.但是,正如对斑岩岩浆及有关金属的来源一样,对地幔、俯冲、洋壳、大陆壳、前寒武纪克拉通的作用还存在着争论.矿床空间分布的有关方面,比如斑岩矿区相对于克拉通的位置值得注意.美国的斑岩矿床... 详细信息

斑岩矿床可能是北美研究最深入的一类矿床.但是,正如对斑岩岩浆及有关金属的来源一样,对地幔、俯冲、洋壳、大陆壳、前寒武纪克拉通的作用还存在着争论.矿床空间分布的有关方面,比如斑岩矿区相对于克拉通的位置值得注意.美国的斑岩矿床分布于克拉通上,而加拿大的则远离克拉通位于增生地体内.矿床之间的时间联系同样要注意.在美国西南部,许多铜矿的平均年龄为65Ma,而钼矿为25Ma;在蒙大拿州和爱达荷州中部,钼矿床平均年龄为55Ma,而蒙大拿Butte铜矿为75Ma.加拿大斑岩矿化的主要成矿期为:Cu200~175Ma和90~20Ma;Mo60~50Ma.不列颠哥伦比亚省中部的两个钼矿形成于140Ma和102Ma.总之,加拿大的Cu。

关键词：斑岩矿床时空分布

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蒸压DSP浆体的反应产物研究

硅酸盐学报 1992年第2期20卷 111-116页

作者：孙国匡 J.f.Young 中国建筑材料科学研究院水泥研究所美国依利诺大学水泥复合材料中心

将以白水泥和硅灰制成的DSP水泥浆体于120℃、183℃、240℃下蒸压。用X射线粉末衍射法、固体核磁共振和扫描电子显微镜检验反应产物。研究了C/S、蒸压温度、蒸压时间对反应的影响。在较低温度下,主要水化产物为结晶差的C-S-H凝胶,随蒸... 详细信息

将以白水泥和硅灰制成的DSP水泥浆体于120℃、183℃、240℃下蒸压。用X射线粉末衍射法、固体核磁共振和扫描电子显微镜检验反应产物。研究了C/S、蒸压温度、蒸压时间对反应的影响。在较低温度下,主要水化产物为结晶差的C-S-H凝胶,随蒸压温度升高,可检测到硬硅钙石、托勃莫来石、自钙沸石、含水斜方硅钙石和含水8CaO·5SiO_1等晶体。初始混合物的C/S在1.3和1.1之间,水化产物有明显变化。实验表明,^(29)Si核磁共振是研究硅酸盐聚合度的有效方法。

关键词：水泥蒸压浆体反应产物

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全球气候模式(GCM)对辐射强迫的响应

应用气象学报 1997年第A期8卷 78-86页

作者：沈元芳 f.Baer 国家气象中心美国马里兰大学气象系

长波辐射加热（ＬＷＲＨ）对气候预报有显著作用．文章比较了６种取自ＧＣＭ的ＬＷＲＨ算法所产生的加热率廓线，表明在有云情况下，ＬＷＲＨ算法对输入变量的敏感性．ＬＷＲＨ算法对ＧＣＭ变化的敏感性测试结果表明，加热率强烈地依赖... 详细信息

长波辐射加热（ＬＷＲＨ）对气候预报有显著作用．文章比较了６种取自ＧＣＭ的ＬＷＲＨ算法所产生的加热率廓线，表明在有云情况下，ＬＷＲＨ算法对输入变量的敏感性．ＬＷＲＨ算法对ＧＣＭ变化的敏感性测试结果表明，加热率强烈地依赖于模式截断、模式变化（包括长波辐射ＬＷＲ算法）和地表强迫（ＳＳＴ）．引入假观测评价各种ＬＷＲ算法所产生加热率的精确性．在ＣＣＭ２模式中应用ＮＣＡＲ原版本和移植的ＥＣＭＷＦ方案计算ＬＷＲ，结果表明ＥＣＭＷＦ方案比ＣＣＭ２方案在南半球热带地区产生更强的加热率．

关键词：全球气候模式辐射强迫加热率天气预报

THE REINfORCING MECHANISM Of TiB2 IN TiB2/A357 COMPOSITE

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 375-378页

作者： B.Yu Y.J.Zhang Z.X.Zhao~ f.X.Zhao: Q.K.Cai C.S.Liu ShenyangResearchInstituteoffoundry TheChineseAcademyofMachinerySciencesShenyang110022China EastChinaUniversityofScienceandTechnology Shanghai200237China SchoolofMaterials&Metallurgy NortheasternUniversityShenyang110004China

Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Micro structures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200) Al and (101)TiB2 with [011]//Al [101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0.1μm in diameter and dislocation multiplication near TiB2 particles.

关键词： TiB2/Al in situ composite reinforcing mechanism

Optimization Study of Pulsed DC Nitrogen-Hydrogen Plasma in the Presence of an Active Screen Cage

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Plasma Science and Technology 2014年第5期16卷 460-464页

作者： A.SAEED A.W.KHAN f.JAN H.U.SHAH M.ABRAR M.ZAKA-UI-ISLAM M.KHALID M.ZAKAULLAH National Centre for Physics Quaid-i-Azam University Campus Islamabad Department of Physics Gomal University Department of Physics Quaid-i-Azam University Department of Physics Hazara University Mansehra Department of Physics Faculty of ScienceUniversity of Jazan

A glow discharge plasma nitriding reactor in the presence of an active screen cage is optimized in terms of current density,filling pressure and hydrogen concentrations using optical emission spectroscopy（OES）.The samples of AISI 304 are nitrided for different treatment times under optimum *** treated samples were analyzed by X-ray diffraction（XRD） to explore the changes induced in the crystallographic *** XRD pattern confirmed the formation of iron and chromium nitrides arising from incorporation of nitrogen as an interstitial solid solution in the iron lattice.A Vickers microhardness tester was used to evaluate the surface hardness as a function of treatment time（h）.The results showed clear evidence of improved surface hardness and a substantial amount of decrease in the treatment time compared with the previous work.

关键词： optical diagnostics plasma nitriding austenitic stainless steel