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Effect of Instant Controlled Pressure Drop Process Coupled to Drying and Freezing on Antioxidant Activity of Green “Poblano” Pepper (<i>Capsicum annuum</i>L.)
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作者 Carmen Téllez-Pérez Anaberta Cardador-Martínez +3 位作者 Sabah Mounir José Gerardo Montejano-Gaitán Vaclav Sobolik Karim Allaf 《Food and Nutrition Sciences》 2013年第3期321-334,共14页
Different food operations have been intensified through assisting them by instant controlled pressure drop DIC treatment. Such processes should be defined in order to preserve the main nutritional and sensorial conten... Different food operations have been intensified through assisting them by instant controlled pressure drop DIC treatment. Such processes should be defined in order to preserve the main nutritional and sensorial contents of the raw material. The present paper is dedicated to study the evolution of the main bioactive compounds (total phenolics and flavonoids) and functional properties such as the antioxidant activity of processed samples in the case of Green “Poblano” Pepper (Capsicum annuum L.). Results issued from DIC-assisted hot air drying, and DIC-assisted freezing, allowed to identifying the impact of DIC studied operating parameters, which were the saturated steam pressure and the processing time, and the best DIC treatment correlated with the considered operation. 展开更多
关键词 Instant Controlled Pressure Drop CAPSICUM Phenols Flavonoids Antioxidant Activity DRYING FREEZING
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粤北大宝山高含硫多金属矿污染的水稻土壤污染元素的多元分析 被引量:26
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作者 李永涛 张池 +5 位作者 刘科学 Thierry BECQUE Cécile QUANTIN Marc BENEDETTI Patrick LAVELLE 戴军 《华南农业大学学报》 CAS CSCD 北大核心 2005年第2期22-25,34,共5页
调查了粤北大宝山高含硫多金属矿长期污染的水稻田的污染状况,用主成分分析法分析了环境变量间的关系及污染物在样点的空间分布.结果表明:长期的污灌导致了被调查水田土壤中铁矿、硫铜矿和铅锌矿酸性矿泥的沉积,引起土壤酸化和硫、铜、... 调查了粤北大宝山高含硫多金属矿长期污染的水稻田的污染状况,用主成分分析法分析了环境变量间的关系及污染物在样点的空间分布.结果表明:长期的污灌导致了被调查水田土壤中铁矿、硫铜矿和铅锌矿酸性矿泥的沉积,引起土壤酸化和硫、铜、铅和镉的积累.上述污染元素与pH及矿质元素铁、钙之间高度相关,而与锰和铬的相关性差. 展开更多
关键词 重金属污染 水稻土 主成分分析 大宝山 土壤污染
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直驱式永磁同步海流机叶轮不平衡故障建模与实验研究 被引量:5
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作者 张米露 王天真 汤天浩 《电机与控制学报》 EI CSCD 北大核心 2018年第7期44-50,共7页
为了研究复杂工况下叶轮不平衡故障对海流机运行的影响,建立从来流流速输入到定子电流输出的机电耦合数学模型。该模型与实验结果相匹配,不仅能呈现湍流下海流机叶轮不平衡故障特性,同时能够减少计算时的复杂运算。为了验证该模型模拟... 为了研究复杂工况下叶轮不平衡故障对海流机运行的影响,建立从来流流速输入到定子电流输出的机电耦合数学模型。该模型与实验结果相匹配,不仅能呈现湍流下海流机叶轮不平衡故障特性,同时能够减少计算时的复杂运算。为了验证该模型模拟实际海流机运行的可靠性,首先对直驱式永磁同步海流机在不同流速下正常运行模式和叶轮不平衡故障模式进行实验测试。其次,利用海流机实测正常运行数据对数学模型进行修正,在修正模型中添加不平衡故障模块得到叶轮不平衡故障仿真结果,并与实验结果对比。仿真结果得到了与实测值较为相近的结果,验证了该模型的有效性和可靠性。 展开更多
关键词 海流发电 不平衡故障 机电耦合模型 湍流
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TA15钛合金强流脉冲电子束表面改性 被引量:5
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作者 张向东 郝胜智 +1 位作者 高泰瑞 董闯 《金属热处理》 CAS CSCD 北大核心 2010年第12期40-43,共4页
研究强流脉冲电子束(HCPEB)处理TA15钛合金的表层组织和耐蚀性能变化。结果表明,样品表面凹凸不平,最外表面有2~3μm的单一α′马氏体重熔层,次层为3~5μm的热影响区。在5%NaCl溶液中进行动电位极化曲线测定,经5次脉冲处理样品的腐蚀... 研究强流脉冲电子束(HCPEB)处理TA15钛合金的表层组织和耐蚀性能变化。结果表明,样品表面凹凸不平,最外表面有2~3μm的单一α′马氏体重熔层,次层为3~5μm的热影响区。在5%NaCl溶液中进行动电位极化曲线测定,经5次脉冲处理样品的腐蚀速度最小。经强流脉冲电子束处理的TA15合金表层晶粒细小,成分均匀,有利于形成致密的钝化膜,增大极化电阻,降低腐蚀速度。 展开更多
关键词 强流脉冲电子束 TA15钛合金 显微组织 电化学腐蚀
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强流脉冲电子束处理纯钛的表面组织与性能 被引量:3
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作者 张向东 郝胜智 +1 位作者 高泰瑞 董闯 《核技术》 CAS CSCD 北大核心 2011年第1期22-26,共5页
研究了强流脉冲电子束处理纯钛的表层组织、显微硬度和耐蚀性能变化。经多脉冲处理的样品表面逐渐趋于平整,表层中出现非晶和纳米晶分层结构。样品表层显微硬度由原始的178 Hv提高到292 Hv。在5%NaCl溶液中进行动电位极化曲线测定,发现... 研究了强流脉冲电子束处理纯钛的表层组织、显微硬度和耐蚀性能变化。经多脉冲处理的样品表面逐渐趋于平整,表层中出现非晶和纳米晶分层结构。样品表层显微硬度由原始的178 Hv提高到292 Hv。在5%NaCl溶液中进行动电位极化曲线测定,发现经15次脉冲处理样品的耐腐蚀性能最佳,自腐蚀电位由–346.4 mV提高到–188.9 mV。分析结果表明,强流脉冲电子束处理诱发高密度缺陷组织及非晶、纳米晶层结构是样品表层硬度和耐蚀性能提高的主要原因。 展开更多
关键词 强流脉冲电子束 纯钛 表面处理 电化腐蚀 显微硬度
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miR-342-3p在鼻咽癌中的表达及意义 被引量:4
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作者 杜龙 易翔 +2 位作者 何光耀 孔令平 唐安洲 《广西医科大学学报》 CAS 2018年第6期747-751,共5页
目的:探讨miR-342-3p在鼻咽癌(NPC)中的表达及其意义。方法:miRNA芯片检测人永生化鼻咽上皮细胞系NP69和低分化NPC细胞CNE2中miRNA的差异表达;实时荧光定量PCR(qPCR)法检测NPC组织中miR-342-3p的表达;GO and Pathway分析miR-342-3p在NP... 目的:探讨miR-342-3p在鼻咽癌(NPC)中的表达及其意义。方法:miRNA芯片检测人永生化鼻咽上皮细胞系NP69和低分化NPC细胞CNE2中miRNA的差异表达;实时荧光定量PCR(qPCR)法检测NPC组织中miR-342-3p的表达;GO and Pathway分析miR-342-3p在NPC发生发展中可能涉及的功能及其参与的信号通路。结果:miRNA芯片结果表明,miR-342-3p在NPC细胞CNE2中低表达,qPCR结果进一步证实miR-342-3p在NPC组织中低表达;GO分析表明,具有显著差异的10个功能中,与NPC发生发展关系较为密切的是miR-342-3p。Pathway分析显示,miR-342-3p与丝裂原应激活化蛋白(MAPK)信号通路相关性较大。结论:miR-342-3p的低表达可能与NPC的发生和发展相关。 展开更多
关键词 鼻咽癌 miR-342-3p CNE2
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青藏高原东部和湄公河盆地晚第四纪风化剥蚀与东亚季风演化在南海中的记录 被引量:8
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作者 刘志飞 ChristopheColin +3 位作者 AlainTrentesaux DominiqueBlamart FranckBassinot GiuseppeSiani 《矿物岩石地球化学通报》 CAS CSCD 2005年第1期30-38,共9页
通过南海西南部湄公河口MD01-2393孔和MD97-2150孔的高分辨率粘土矿物和粒度分析,及铷、锶、钕同位素分析,揭示出青藏高原东部和湄公河盆地晚第四纪190 ka以来的风化剥蚀和东亚季风演化历史。铷、锶、钕同位素研究证实这两个孔的陆源碎... 通过南海西南部湄公河口MD01-2393孔和MD97-2150孔的高分辨率粘土矿物和粒度分析,及铷、锶、钕同位素分析,揭示出青藏高原东部和湄公河盆地晚第四纪190 ka以来的风化剥蚀和东亚季风演化历史。铷、锶、钕同位素研究证实这两个孔的陆源碎屑物质主要来源于湄公河流域的直接输入。蒙脱石/(伊利石+绿泥石)值和蒙脱石/高岭石值指示了化学风化历史,而陆源碎屑颗粒的粒径比值2.5-6.5μm/15-55μm则指示了湄公河沉积物的供给能力。相对高的比值发生在间冰期,表明强盛的夏季风降雨和减弱的冬季风环流;相对低的比值对应于冰期,表明强盛的冬季风和减弱的夏季风,揭示出东亚季风气候驱动的风化剥蚀演化历史。东亚季风演化的强弱与北半球夏季日射量基本呈线性关系,表明东亚季风演化的天文驱动机制。 展开更多
关键词 东亚季风 晚第四纪 冬季风 钕同位素 夏季风 南海 盆地 湄公河流域 供给能力 西南部
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傅里叶变换红外光谱(FTIR)方法在南海定量矿物学研究中的应用:以MD01-2393孔为例 被引量:8
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作者 刘志飞 Christophe Colin Alain Trentesaux 《地球科学(中国地质大学学报)》 EI CAS CSCD 北大核心 2005年第1期25-29,共5页
傅里叶变换红外光谱 (FTIR)方法以其测量多种矿物绝对含量的能力在古环境研究中有很大的优势 .运用FTIR方法分析了南海南部湄公河口MD0 1 - 2 393孔的矿物成分含量 ,对比运用X射线衍射 (XRD)的半定量分析方法 ,研究了青藏高原东部和湄... 傅里叶变换红外光谱 (FTIR)方法以其测量多种矿物绝对含量的能力在古环境研究中有很大的优势 .运用FTIR方法分析了南海南部湄公河口MD0 1 - 2 393孔的矿物成分含量 ,对比运用X射线衍射 (XRD)的半定量分析方法 ,研究了青藏高原东部和湄公河盆地晚第四纪 1 90ka以来风化剥蚀演化历史 .结果显示 ,全岩高岭石 /石英和粘土粒级 ( <2 μm)高岭石 /蒙脱石比率可用作陆源区风化侵蚀的矿物学标志 .晚第四纪 190ka以来 ,青藏高原东部和湄公河盆地机械侵蚀作用在冰期比间冰期强 ,化学风化作用在间冰期比冰期强 ,揭示出亚洲季风气候驱动的风化剥蚀演化历史 .全新世期间 ,虽然全岩高岭石 /石英与粘土粒级 ( <2 μm)蒙脱石 /高岭石比率指示相同趋势的风化剥蚀作用 ,但全岩高岭石 /石英比率显示更强的机械侵蚀能力 。 展开更多
关键词 粘土矿物 傅里叶变换红外光谱(FTIR) 晚第四纪 湄公河 南海
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湖北宜昌地区下-中奥陶统界线疑源类生物地层学意义 被引量:2
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作者 李军 燕夔 Thomas SERVAIS 《微体古生物学报》 CSCD 北大核心 2011年第4期357-369,共13页
根据牙形类Baltoniodus?triangularis的首现,中奥陶统和大坪阶底界已界定于湖北宜昌黄花场剖面大湾组底界之上10.57 m。对黄花场剖面以及邻近的大坪剖面大湾组疑源类研究表明,某些疑源类属种具有生物地层学意义,其首现可用于识别奥陶系... 根据牙形类Baltoniodus?triangularis的首现,中奥陶统和大坪阶底界已界定于湖北宜昌黄花场剖面大湾组底界之上10.57 m。对黄花场剖面以及邻近的大坪剖面大湾组疑源类研究表明,某些疑源类属种具有生物地层学意义,其首现可用于识别奥陶系下/中统界线。 展开更多
关键词 疑源类 下/中奥陶统界线 生物地层学 宜昌 湖北 华南
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甲基-苯基四氢吡啶对脑不对称小鼠纹状体内多巴胺和白介素含量的影响 被引量:1
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作者 申延琴 李康生 +1 位作者 E.MOZE P.J.NEVEU 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2005年第1期53-59,共7页
为探讨甲基-苯基四氢吡啶(MPTP) 注射后脑不对称小鼠纹状体内多巴胺降低程度,及纹状体内细胞因子水平变化,C57BL/6J小鼠经过伸爪取食试验,筛选为反映脑不对称的左利鼠和右利鼠,并接受25 mg/kg MPTP腹腔注射连续5天,检测注射后的第1天,第... 为探讨甲基-苯基四氢吡啶(MPTP) 注射后脑不对称小鼠纹状体内多巴胺降低程度,及纹状体内细胞因子水平变化,C57BL/6J小鼠经过伸爪取食试验,筛选为反映脑不对称的左利鼠和右利鼠,并接受25 mg/kg MPTP腹腔注射连续5天,检测注射后的第1天,第3天和第14天纹状体内多巴胺及代谢物含量和细胞因子IL-1茁、IL-6的动态水平. 结果表明,无论在左利鼠还是右利鼠,纹状体内多巴胺含量在MPTP注射后每个检测时间点都显著降低,纹状体内IL-1茁水平在第1天显著降低,纹状体内IL-6水平在MPTP注射后每个检测时间点也显著降低. 实验结果同时表明,左利鼠和右利鼠IL-1茁和IL-6的基础水平有显著不同. MPTP注射后,与右利小鼠相比,左利小鼠有较高的多巴胺翻转降低和较低的细胞因子表达,而且,纹状体内多巴胺水平与纹状体内IL-6水平呈正相关. 这些结果提示,MPTP诱导多巴胺丢失伴随着黑质纹状体系统内细胞因子水平的改变,而且,脑不对称有可能通过影响纹状体内细胞因子水平而进一步影响MPTP诱导的多巴胺降低的程度. 展开更多
关键词 甲基-苯基四氢吡啶 多巴胺 纹状体 白介素6(IL-6) 白介素1(IL-1) 脑不对称
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清开灵对小鼠腹腔巨噬细胞内游离钙及活性氧的作用
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作者 王芳 岳晓莉 +2 位作者 李萍 张颖 蒋玉凤 《中国病理生理杂志》 CAS CSCD 北大核心 2005年第8期1637-1637,共1页
目的:动态观察清开灵(QKL)对小鼠腹腔巨噬细胞内活性氧及游离钙的作用.方法:原代培养小鼠腹腔巨噬细胞,分别以荧光探针二氯荧光素二酯(H2 DCFDA)和Fluo-3-AM标记细胞内活性氧及游离钙,通过激光共聚焦系统动态观察QKL的作用.
关键词 小鼠腹腔巨噬细胞 细胞内游离钙 细胞内活性氧 清开灵 Fluo-3-AM 动态观察 二氯荧光素 激光共聚焦 原代培养
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脑热清对小鼠的腹腔巨噬细胞内游离钙及活性氧的作用
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作者 岳晓莉 王芳 +2 位作者 李萍 张颖 蒋玉凤 《中国病理生理杂志》 CAS CSCD 北大核心 2005年第8期1642-1642,共1页
目的:实时监测脑热清口服液(NRQ)对小鼠腹腔巨噬细胞内活性氧(ROS)及游离钙([Ca2+]i)的作用.方法:取小鼠腹腔巨噬细胞,原代培养24小时,分别以荧光探针二氯荧光素二酯(H2 DCFDA)和Fluo-3-AM标记细胞内ROS及[Ca2+]i,并用EDTA和维拉帕米螯... 目的:实时监测脑热清口服液(NRQ)对小鼠腹腔巨噬细胞内活性氧(ROS)及游离钙([Ca2+]i)的作用.方法:取小鼠腹腔巨噬细胞,原代培养24小时,分别以荧光探针二氯荧光素二酯(H2 DCFDA)和Fluo-3-AM标记细胞内ROS及[Ca2+]i,并用EDTA和维拉帕米螯合细胞外钙,阻断细胞膜钙离子通道,通过激光共聚焦显微系统动态观察NRQ的作用. 展开更多
关键词 小鼠腹腔巨噬细胞 细胞内游离钙 细胞内活性氧 脑热清口服液 Fluo-3-AM [CA^2+]I 细胞内ROS 二氯荧光素 钙离子通道
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Compressive behavior and energy absorption of metal porous polymer composite with interpenetrating network structure 被引量:15
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作者 LIU Yu GONG Xiao-lu 《中国有色金属学会会刊:英文版》 CSCD 2006年第B02期439-443,共5页
Interpenetrating phase composites (IPCs) are a new class of composite materials with improved combinations of mechanical and physical properties. This study was performed on a new type of IPC called metal porous polym... Interpenetrating phase composites (IPCs) are a new class of composite materials with improved combinations of mechanical and physical properties. This study was performed on a new type of IPC called metal porous polymer composite (MPPC) with an interpenetrating network structure. Aluminum-polypropylene (AI-PE) and Aluminum-epoxy resin (Al-Ep) composites were produced by infiltrating the polymer in the aluminum foam. The composite microstructures were characterized using SEM observation. The compressive behavior and energy absorption characteristics of MPPC were investigated and compared with the aluminum foams. The compressive modulus of composite was compared with the VOIGT-REUSS bounds and HASHIN-SHTRIKMAN (H-S) bounds models. The experimental modulus of compressive tests falls well within the theoretical models. 展开更多
关键词 金属多孔聚合物复合物 互穿网络结构 压缩行为 能量吸收 MPPC复合物
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Diabetes mellitus, insulin resistance and hepatitis C virus infection: A contemporary review 被引量:14
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作者 Anne-Claire Desbois Patrice Cacoub 《World Journal of Gastroenterology》 SCIE CAS 2017年第9期1697-1711,共15页
To summarise the literature data on hepatitis C virus (HCV)-infected patients concerning the prevalence of glucose abnormalities and associated risk.METHODSWe conducted a PubMed search and selected all studies found w... To summarise the literature data on hepatitis C virus (HCV)-infected patients concerning the prevalence of glucose abnormalities and associated risk.METHODSWe conducted a PubMed search and selected all studies found with the key words 'HCV' or 'hepatitis C virus' and 'diabetes' or 'insulin resistance'. We included only comparative studies written in English or in French, published from January 2000 to April 2015. We collected the literature data on HCV-infected patients concerning the prevalence of glucose abnormalities [diabetes mellitus (DM) and insulin resistance (IR)] and associated risk [i.e., severe liver fibrosis, response to antivirals, and the occurrence of hepatocellular carcinoma (HCC)].RESULTSHCV infection is significantly associated with DM/IR compared with healthy volunteers and patients with hepatitis B virus infection. Glucose abnormalities were associated with advanced liver fibrosis, lack of sustained virologic response to interferon alfa-based treatment and with a higher risk of HCC development. As new antiviral therapies may offer a cure for HCV infection, such data should be taken into account, from a therapeutic and preventive point of view, for liver and non-liver consequences of HCV disease. The efficacy of antidiabetic treatment in improving the response to antiviral treatment and in decreasing the risk of HCC has been reported by some studies but not by others. Thus, the effects of glucose abnormalities correction in reducing liver events need further studies.CONCLUSIONGlucose abnormalities are strongly associated with HCV infection and show a negative impact on the main liver related outcomes. 展开更多
关键词 Hepatitis C virus Diabetes mellitus Insulin resistance Liver fibrosis Treatment
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Pressureless sintering behavior and properties of Ag-SnO_2 被引量:3
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作者 Henri Desplats Elodie Brisson +2 位作者 Philippe Rogeon Patrick Carré Alexandre Bonhomme 《Rare Metals》 SCIE EI CAS CSCD 2019年第1期35-41,共7页
In this study, the results of measurements on pressureless sintering behavior of Ag-SnO_2(88%wt Ag,12%wt SnO_2) pellets were reported. Dilatometric measurements, relative densities, hardness values, rupture transverse... In this study, the results of measurements on pressureless sintering behavior of Ag-SnO_2(88%wt Ag,12%wt SnO_2) pellets were reported. Dilatometric measurements, relative densities, hardness values, rupture transverse strength and electrical conductivities function of sintering temperatures were presented. A constant thermal expansion coefficient was determined, and a threshold temperature of densification(T_d) was exhibited. Sintering kinetics were reported for different temperatures. Hardness values were measured, and no increase in hardness is found under Td. Three-points bending tests were used to determine the transverse rupture strength whose evolution appears importantly well under Td. In the same manner, the increase in initial electrical conductivities begins well under Td. Under the threshold temperature, the relative increase in electrical conductivity is found to be independent of initial density of green compact pellets. This work highlights different evolutions in function of sintering temperature for the electrical conductivity and transverse rupture strength on the one hand, and for the densification and hardness on the other hand. 展开更多
关键词 Ag-SnO2 Pressureless SINTERING Dilatometry MECHANICAL PROPERTIES ELECTRICAL CONDUCTIVITY
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Vapor and Pressure Sensors Based on Cellulose Nanofibers and Carbon Nanotubes Aerogel with Thermoelectric Properties 被引量:3
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作者 Rajendran Muthuraj Abhishek Sachan +3 位作者 Mickael Castro Jean-Francois Feller Bastien Seantier Yves Grohens 《Journal of Renewable Materials》 SCIE 2018年第3期277-287,共11页
In this work,thermally insulating and electrically conductive aerogels were prepared from cellulose nanofibers(CNF)and carbon nanotubes(CNTs)by environmentally friendly freeze-drying process.The thermal conductivity o... In this work,thermally insulating and electrically conductive aerogels were prepared from cellulose nanofibers(CNF)and carbon nanotubes(CNTs)by environmentally friendly freeze-drying process.The thermal conductivity of neat CNF aerogel is 24 mW/(m・K)with a density of 0.025 g/cm3.With the addition of CNTs into CNF aerogel,the electrical conductivity was significantly increased while the thermal conductivity was increased to 38 mW/(m・K).Due to these interesting properties,the Seebeck coefficient and the figure of merit(ZT)of the CNF/CNTs aerogels were measured and showed that CNF/CNTs aerogel thermoelectric properties can be improved.The compressibility and electrical resistance of the CNF/CNTs aerogel highlighted its pressure-responsive property.A set of volatile organic compounds(VOCs)were exposed to aerogels to monitor the resistance change.The CNF/CNTs aerogel showed high sensitivity and good response to both nonpolar and polar vapors due to the absorption by both CNF and CNTs networks.The prepared CNF/CNTs aerogel is therefore a good candidate for thermal insulation,thermoelectric material,VOCs sensing,and pressure-sensing applications. 展开更多
关键词 CNF/CNTs aerogel thermal conductivity pressure sensing thermoelectric materials VOCs sensing
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Microbial Activity Indices: Sensitive Soil Quality Indicators for Trace Metal Stress 被引量:11
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作者 LI Yong-Tao T. BECQUER2 +3 位作者 C. QUANTIN M. BENEDETTI P. LAVELLE DAI Jun 《Pedosphere》 SCIE CAS CSCD 2005年第4期409-416,共8页
Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a ... Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a long-term trace metal-contaminated paddy region of Guangdong, China were determined to assess the sensitivity of microbial indices to moderately metal-contaminated paddy soils. The mean contents of total Cu, Zn, Pb and Cd were 251, 250, 171, and 2.4 mg kg^-1 respectively. DTPA-extractable metals were correlated positively and significantly with total metals, CEC, and organic C (except for DTPA-extractable Cd), while they were negatively and highly significantly correlated with pH, totall Fe and Mn. Metal stress resulted in relatively low ratios of microbial biomass C to organic C and in remarkable inhibition of the microbial metabolic quotient and C mineralization rate, which eventually led to increases in soil organic C and C/N. Moreover, microbial respiratory activity showed a stronger correlation to DTPA-extractable metals than to total metal content. Likewise, in the acid paddy soils some “linked” microbial activity indices, such as metabolic quotient and ratios of basal respiration to organic C, especially during initial incubation, were found to be more sensitive indicators of soil trace metal contamination than microbial biomass C or basal respiration alone. 展开更多
关键词 AVAILABILITY INDICATION microbial characteristics trace metals
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Soot formation and oxidation during bio-oil gasification:experiments and modeling 被引量:3
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作者 Younes Chhiti Marine Peyrot Sylvain Salvador 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第5期701-709,共9页
A model is proposed to describe soot formation and oxidation during bio-oil gasification.It is based on the description of bio-oil heating,devolatilization,reforming of gases and conversion of both char and soot solid... A model is proposed to describe soot formation and oxidation during bio-oil gasification.It is based on the description of bio-oil heating,devolatilization,reforming of gases and conversion of both char and soot solids.Detailed chemistry (159 species and 773 reactions) is used in the gas phase.Soot production is described by a single reaction based on C2H2species concentration and three heterogeneous soot oxidation reactions.To support the validation of the model,three sets of experiments were carried out in a lab-scale Entrained Flow Reactor (EFR) equipped with soot quantification device.The temperature was varied from 1000 to 1400 C and three gaseous atmospheres were considered:default of steam,large excess of steam(H2O/C=8),and the presence of oxygen in the O/C range of 0.075–0.5.The model is shown to accurately describe the evolution of the concentration of the main gas species and to satisfactorily describe the soot concentration under the three atmospheres using a single set of identified kinetic parameters.Thanks to this model the contribution of different mechanisms involved in soot formation and oxidation in various situations can be assessed. 展开更多
关键词 SOOT GASIFICATION PYROLYSIS partial oxidation BIO-OIL
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A method to experimentally investigate injection-induced activation of fractures 被引量:3
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作者 Changdong Ding Yang Zhang +4 位作者 Qi Teng Dawei Hu Hui Zhou Jianfu Shao Chuanqing Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2020年第6期1326-1332,共7页
Natural fractures are generally well developed in most hydrocarbon and geothermal reservoirs,which can produce complex fracture networks due to the activation of fractures during hydraulic stimulation.The present pape... Natural fractures are generally well developed in most hydrocarbon and geothermal reservoirs,which can produce complex fracture networks due to the activation of fractures during hydraulic stimulation.The present paper is devoted to developing a method to investigate the activation characteristics of fracture under injection-shearing coupled condition at laboratory scale.The fluid is injected into the single-fractured granite until the fracture is activated based on the triaxial direct shear tests.The results show that injection process can significantly influence the shear stress distribution field,resulting in release of shear stress and relative slip between the opposite sides of the fractured surface.The injectioninduced activation of fracture is strongly dependent on the stress states.When the normal stress increases,the injection-induced activation pressure increases,and the comparatively high normal stress can restrain the fracture activation.The fracture deformation mechanisms during fluid injection are also discussed preliminarily with the experimental data.The sensitivity of shear stress to fluid injection increases with increase of shear stress level,while it decreases under high normal stress.The results can facilitate our understanding of the natural fracture activation behavior during fluid pressure stimulation. 展开更多
关键词 Natural fracture Fluid injection Induced activation Triaxial direct shear test Hydraulic fracturing
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Recent progress in Mg-based alloys as a novel bioabsorbable biomaterials for orthopedic applications 被引量:14
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作者 Fei Xing Shang Li +5 位作者 Dongdi Yin Jichang Xie Pol Maria Rommens Zhou Xiang Ming Liu Ulrike Ritz 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第6期1428-1456,共29页
Traditional orthopedic metal implants,such as titanium(Ti),Ti alloys,and cobalt-chromium(Co-Cr)alloys,cannot be degraded in vivo.Fracture patients is must always suffer a second operation to remove the implants.Moreov... Traditional orthopedic metal implants,such as titanium(Ti),Ti alloys,and cobalt-chromium(Co-Cr)alloys,cannot be degraded in vivo.Fracture patients is must always suffer a second operation to remove the implants.Moreover,stress shielding,or stress protection occurs when traditional orthopedic metal implants are applied in fractures surgery.The mechanical shunt produced by traditional orthopedic metal implants can cause bone loss over time,resulting in decreased bone strength and delayed fracture healing.Biodegradable metals that‘biocorrode’are currently attracting significant interest in the orthopedics field due to their suitability as temporary implants.As one of the biodegradable metals,magnesium(Mg)and Mg alloys have gained interest in the field of medicine due to their low density,excellent biocompatibility,high bioresorbability,and proper mechanical properties.Additionally,Mg ions released from the metal implants can promote osteogenesis and angiogenesis during the degradation process in vivo,which is substantially better for orthopedic fixation than other bioinert metal materials.Therefore,this review focuses on the properties,fabrication,biological functions,and surface modification of Mg-based alloys as novel bioabsorbable biomaterials for orthopedic applications. 展开更多
关键词 MAGNESIUM Mg alloys Biomedical implants Bone regeneration Surface modification
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