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基于“神威·太湖之光”的区域海洋模式并行优化 预览
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作者 吴琦 倪裕芳 黄小猛 《计算机研究与发展》 EI CSCD 北大核心 2019年第7期1556-1566,共11页
海洋模式作为地球数值模拟中重要的组成模块,在很多领域都起到了至关重要的作用,不仅是研究海洋、河口和海岸不可或缺的科研手段,基于海洋模式搭建的预报系统还能够实时预测台风、海啸等现象.为了模拟更细粒度的海洋变化,海洋模式朝着... 海洋模式作为地球数值模拟中重要的组成模块,在很多领域都起到了至关重要的作用,不仅是研究海洋、河口和海岸不可或缺的科研手段,基于海洋模式搭建的预报系统还能够实时预测台风、海啸等现象.为了模拟更细粒度的海洋变化,海洋模式朝着更高的分辨率和更多的物理参数化方案发展,一般的计算机已无法满足其需求.随着散热和功耗成为通用处理器的主要瓶颈,多核、众核以及由此导致的异构已成为下一代超级计算机的发展趋势,这也为发展高分辨率海洋模式提供了坚实的基础平台.基于国产超级计算机“神威·太湖之光”,利用其异构众核体系结构的优势对普林斯顿海洋模式(Princeton ocean model, POM)进行移植和优化,从而充分发挥了国产异构众核平台的特点和优势.基于神威的高分辨率海洋模式swPOM(Sunway Princeton ocean model)在主从核协作下运行效率达到纯主核的13倍,是通用Intel平台的2.8倍左右,可扩展到25万核上运行,为实时预报系统提供了保障. 展开更多
关键词 普林斯顿海洋模式 高分辨率 神威太湖之光 异构 并行优化
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BZ油田注水井调剖酸化联作体系研究 预览
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作者 刘平礼 张峰超 +3 位作者 高尚 陶卫东 冉进喜 皇扶杉 《油气藏评价与开发》 CSCD 2019年第2期60-64,共5页
针对BZ油田注水井地层非均质强,单一酸化、调剖无法同时满足增注和减小层间矛盾的问题,在室内开展了酸化、调剖联作体系研究。所用配套酸液体系为单步酸酸液体系,实验评价了其缓速、抑制二次沉淀、溶蚀和配伍性等性能,单岩心酸化后渗透... 针对BZ油田注水井地层非均质强,单一酸化、调剖无法同时满足增注和减小层间矛盾的问题,在室内开展了酸化、调剖联作体系研究。所用配套酸液体系为单步酸酸液体系,实验评价了其缓速、抑制二次沉淀、溶蚀和配伍性等性能,单岩心酸化后渗透率恢复效果良好。配套调剖剂体系主剂采用阴离子型聚合物,评价了其耐酸性能和岩心封堵能力。采用双岩心夹持流动实验装置模拟非均质地层,分析调剖和酸化的注液顺序对联作处理效果的影响。模拟实验结果显示,先调剖后酸化效果明显,低渗岩心渗透率改善倍比为1.52,高渗岩心得到封堵,渗透率改善倍比为0.29,实现了既缩小层间渗透率差异又启动低渗岩心的目标。 展开更多
关键词 注水井 非均质 调剖 酸化 解堵 联作
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Heterogeneous oxidization of graphene nanosheets damages membrane
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作者 QianChun Wang XiaoBo Zhai +6 位作者 Michael Crowe Lu Gou YinFeng Li DeChang Li Lei Zhang JiaJie Diao BaoHua Ji 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2019年第6期45-54,共10页
Graphene-based materials exhibit unique properties that have been sought to utilize for various potential applications. Many studies suggest that graphene-based materials can be cytotoxic, which may be attributed to d... Graphene-based materials exhibit unique properties that have been sought to utilize for various potential applications. Many studies suggest that graphene-based materials can be cytotoxic, which may be attributed to destructive effects on cell membranes.However, there still are conflicting results regarding interactions between graphene-based materials and lipid membranes. Here,through cryo-electron microscopy(Cryo-EM) and dye-leakage experiments along with in silico methods, we found that graphene oxide nanosheets induce significant membrane damage, while the effect of pristine graphene is negligible. We revealed the importance of heterogeneous oxidization of graphene-based nanosheets in damaging vesicle membranes. Moreover, that not only the oxidization degree but also the oxidization loci and membrane tension play important roles in the cytotoxicity of the graphene-based nanosheets. 展开更多
关键词 GRAPHENE GRAPHENE oxide HETEROGENEOUS OXIDIZATION CYTOTOXICITY lipid MEMBRANE
Activity Enhancement of MgCl2-supported Ziegler-Natta Catalysts by Lewis-acid Pre-treatment for Ethylene Polymerization
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作者 Matthieu Humbert Sebastien Norsic +1 位作者 Jean Raynaud Vincent Monteil 《高分子科学:英文版》 SCIE CAS CSCD 2019年第10期1031-1038,I0006共9页
Ziegler-Natta precatalysts were synthetized from Lewis-base-modified-MgCl2 supports and treated by various Lewis acids,prior to activation by triethylaluminum, in order to increase their activity in ethylene polymeriz... Ziegler-Natta precatalysts were synthetized from Lewis-base-modified-MgCl2 supports and treated by various Lewis acids,prior to activation by triethylaluminum, in order to increase their activity in ethylene polymerization. BCl3 provided the highest increase in activity. Interestingly, polymerization results showed no substantial modification of polymer properties, which is consistent with that Lewis acid only promotes the creation of new active sites, after activation by TEA, possessing very similar features to the original ones achievable with conventional precatalysts(i.e. without Lewis-acid treatment). 展开更多
关键词 ZIEGLER-NATTA CATALYSIS Ethylene polymerization Heterogeneous CATALYSIS LEWIS ACIDS
“一体”与“主从”:王阳明对体用关系的理解与运用 预览
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作者 龚开喻 《赣南师范大学学报》 2019年第4期108-113,共6页
从王阳明对《大学》的理解开始,逐步拓展到阳明对儒家经典、三教异同、万物一体的理解,来考察王阳明对体用关系的理解与运用,指出王阳明有两种不同的体用结构:一个是体用一源、圆融一体的同质同层的体用结构,另一个则为异质异层、既分... 从王阳明对《大学》的理解开始,逐步拓展到阳明对儒家经典、三教异同、万物一体的理解,来考察王阳明对体用关系的理解与运用,指出王阳明有两种不同的体用结构:一个是体用一源、圆融一体的同质同层的体用结构,另一个则为异质异层、既分又合、有主有从的“主——从”式的体用关系。这两种体用结构既互相相关,又存在着张力。 展开更多
关键词 王阳明 体用观 同质同层 异质异层
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Synthesis of Cu^Ⅱ/ZIF-8 Metal-organic Framework Catalyst and Its Application in the Aerobic Oxidation of Alcohols
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作者 HOU Junying HAO Jianjun +1 位作者 WANG Yaya LIU Jingchun 《高等学校化学研究:英文版》 SCIE CAS CSCD 2019年第5期860-865,共6页
The tliree-dimensional copper-doped zeolitic imidazolate framework ZIF-8(Cu^Ⅱ/ZIF-8) was prepared by a metal ion exchange process, using reaction of three different copper salts, zinc nitrate hexahydrate[Zn(NO)3·... The tliree-dimensional copper-doped zeolitic imidazolate framework ZIF-8(Cu^Ⅱ/ZIF-8) was prepared by a metal ion exchange process, using reaction of three different copper salts, zinc nitrate hexahydrate[Zn(NO)3·6H2O] and 2?methylimidazole(2-MelM) under nitrogen atmosphere at the room temperature. The TEM and PXRD results indicated that the morphology of Cu^Ⅱ/ZIF-8 was rhombic dodecahedron and the structure was intact after copper was doped into the porous ZIF-8. The synthesized Cu(NO3)2/ZIF-8 heterogeneous catalyst showed an excellent activity for tlie aerobic oxidation of primary alcohols employing molecular oxygen as oxidant. Moreover, tlie Cu(NO3)2/ZIF-8 heterogeneous catalyst can cycled 15 times without leaching of copper. 展开更多
关键词 Metal ORGANIC framework HETEROGENEOUS CATALYST MOLECULAR OXYGEN
面向人群疏散仿真的异构情绪感染模型 预览
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作者 王梦思 张桂娟 刘弘 《计算机科学》 CSCD 北大核心 2019年第3期287-297,共11页
在人群疏散过程中,个体往往会聚集成小的分组,而分组内部也存在个体差异,但是现有的情绪感染模型大都没有考虑这些因素的影响。为了提高疏散模拟的真实性,以社会比较理论为研究基础,提出一种基于异构情绪感染模型的人群疏散仿真方法。首... 在人群疏散过程中,个体往往会聚集成小的分组,而分组内部也存在个体差异,但是现有的情绪感染模型大都没有考虑这些因素的影响。为了提高疏散模拟的真实性,以社会比较理论为研究基础,提出一种基于异构情绪感染模型的人群疏散仿真方法。首先,设计了一种基于Durupinar模型的异构情绪感染计算方法,在该方法中,提出了一种基于分组的情绪感染计算方法,根据个体间的距离和关系对人群进行分组,研究分组对情绪感染计算的影响;在此基础上,提出基于特征的恐慌程度计算方法,根据个性、性别、年龄的特征差异将个体特殊化,并利用上述特征进行情绪恐慌程度计算。其次,将异构情绪感染模型应用于人群运动过程,通过异构情绪驱动人群运动行为。最后,利用真实感渲染平台模拟人群运动仿真效果。基于异构情绪感染模型的人群疏散仿真方法可以逼真地模拟不同场景下的人群运动过程,与以往方法相比,该方法考虑了分组和个体特征差异对情绪的影响,体现了个体之间的异构性。实验结果表明,使用所提方法进行人群运动过程模拟更加符合现实情况。 展开更多
关键词 异构 社会比较理论 分组 个体差异 人群疏散
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Preparation and characterization of AlN seeds for homogeneous growth 预览
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作者 Li Zhang Haitao Qi +2 位作者 Hongjuan Cheng Lei Jin Yuezeng Shi 《半导体学报:英文版》 CSCD 2019年第10期104-107,共4页
Large size AlN bulk crystal has been grown on SiC heterogeneous seed by physical vapor transport (PVT). The properties of AlN wafer were characterized by high resolution X-ray diffraction (HRXRD), Raman spectroscopy, ... Large size AlN bulk crystal has been grown on SiC heterogeneous seed by physical vapor transport (PVT). The properties of AlN wafer were characterized by high resolution X-ray diffraction (HRXRD), Raman spectroscopy, etched method and atomic force microscope (AFM). Growth mechanism of AlN crystal grown on heterogeneous SiC seeds was proposed. Crystallization quality of AlN samples were improved with the growth process, which is associated with the growth mechanism. AlN single wafer has excellent crystallization quality, which is indicated by HRXRD showing the (0002),(1012) XRD FWHM of 76.3,52.5 arcsec, respectively. The surface of the AlN wafer is measured by AFM with a roughnessof 0.15 nm, which is a promising seed for AlN homogeneous growth. 展开更多
关键词 heterogeneous GROWTH ALN SEEDS CRYSTALLIZATION quality CHARACTERIZATION
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Time-domain ICIC and optimized designs for 5G and beyond:a survey
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作者 Ling LIU Yiqing ZHOU +2 位作者 Athanasios V.VASILAKOS Lin TIAN Jinglin SHI 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第2期14-41,共28页
Time-domain enhanced inter-cell interference coordination(eI CIC)is an effective technique to reduce the cross-tier inter-cell interference(ICI)in long term evolution(LTE)-based heterogeneous small cell networks(HetSC... Time-domain enhanced inter-cell interference coordination(eI CIC)is an effective technique to reduce the cross-tier inter-cell interference(ICI)in long term evolution(LTE)-based heterogeneous small cell networks(HetSCNs).This paper first clarifies two main communication scenarios in HetSCNs,i.e.,macrocells deployed with femtocells(macro-femto)and with picocells(macro-pico).Then,the main challenges in HetSCNs,particularly the severe cross-tier ICI in macro-femto caused by femtocells with closed subscribe group(CSG)access or in macro-pico caused by picocells with range expansion are analyzed.Based on the prominent feature of dominant interference in HetSCNs,the main idea of time-domain interference coordination and two basic schemes in the eI CIC standardization,i.e.,almost blank subframe(ABS)and orthogonal frequency division multiplexing symbol shift are presented,with a systematic introduction to the interactions of these techniques with other network functions.Then,given macro-femto and macro-pico HetSCNs,an overview is provided on the advanced designs of ABS-based eI CIC,including self-optimized designs with regard to key parameters such as ABS muting ratio,and joint optimized designs of ABS-based eI CIC and other radio resource management techniques,such as user association and power control.Finally,the open issues and future research directions are discussed. 展开更多
关键词 eICIC ALMOST BLANK SUBFRAME joint optimized design HETEROGENEOUS small cell networks 5G and BEYOND
伊朗北阿碳酸盐岩油田酸化液体系性能评价 预览
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作者 吴玉滨 《石化技术》 CAS 2019年第7期116-117,106共3页
通过对酸化施工中遇到的问题进行分析与改进,结合室内实验对北阿油田酸化液配方的评价,形成了适合北阿油田大斜度长井段非均质油井的配套酸化液。实验证明,北阿油田现行的酸化液是适合北阿油田储层特征及完井特点的合理选择。现行的配... 通过对酸化施工中遇到的问题进行分析与改进,结合室内实验对北阿油田酸化液配方的评价,形成了适合北阿油田大斜度长井段非均质油井的配套酸化液。实验证明,北阿油田现行的酸化液是适合北阿油田储层特征及完井特点的合理选择。现行的配套酸化工艺经济、高效、安全,成效显著,为完成北阿一期的产量目标奠定了坚实基础。 展开更多
关键词 水平井 大斜度井 非均质 碳酸盐岩 酸化添加剂 酸化工艺 评价
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复杂非均质地层的等值线生成算法研究 预览
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作者 孙歧峰 赵琰 +1 位作者 段友祥 刘培刚 《计算机应用研究》 CSCD 北大核心 2019年第5期1581-1584,共4页
针对地层数据特点,研究和分析了复杂非均质地层数据等值线绘制方法的不足,提出一种新的分区方法,实现了带断层的数据集合划分。基于Delaunay三角剖分算法,并以几何多边形为雏形,建立了带约束的三角网格模型。采用约束Delaunay三角网的... 针对地层数据特点,研究和分析了复杂非均质地层数据等值线绘制方法的不足,提出一种新的分区方法,实现了带断层的数据集合划分。基于Delaunay三角剖分算法,并以几何多边形为雏形,建立了带约束的三角网格模型。采用约束Delaunay三角网的拓扑结构,选用改进的反距离加权插值算法,有效地解决了断层两侧高程值问题,并结合实际应用要求在VC++与OpenSceneGraph的开发环境下,实现了非均质带断层的地层等值线的绘制。通过对国内某采油厂的实际油气储集地层数据等值线图的绘制和可视化,证明了方法的可行性和准确性。 展开更多
关键词 非均质 DELAUNAY三角剖分 约束三角网 反距离加权
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非均质碳酸盐岩油气藏酸压数值模拟研究进展与展望 预览
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作者 苟波 马辉运 +2 位作者 刘壮 周长林 王琨 《天然气工业》 EI CAS CSCD 北大核心 2019年第6期87-98,共12页
要实现深层、超深层海相碳酸盐岩油气藏的高效开发,亟需相关酸化压裂技术理论的突破与创新。为了指导多种酸压工艺的现场实践,通过系统梳理和总结酸压数值模拟技术的已有研究成果,结合目前深层、超深层海相碳酸盐岩油气藏酸压工程的技... 要实现深层、超深层海相碳酸盐岩油气藏的高效开发,亟需相关酸化压裂技术理论的突破与创新。为了指导多种酸压工艺的现场实践,通过系统梳理和总结酸压数值模拟技术的已有研究成果,结合目前深层、超深层海相碳酸盐岩油气藏酸压工程的技术需求,探索研究了当前酸压数值模拟面临的新挑战和需要突破的方向。研究结果表明:①酸压三维数值模拟基于解耦思想,将酸压模型分为水力裂缝初始形态构建、酸刻蚀模拟及导流能力计算等3个模块,其中酸刻蚀模拟模块是酸压数值模拟的核心;②地质统计学参数方法在水力裂缝初始形态建模中的应用已较为成熟,酸刻蚀模拟通过N-S方程组、酸平衡方程、酸液滤失模型及酸岩反应溶蚀力方程耦合求解,已初步实现了精细化和油藏工程尺度的模拟,酸蚀裂缝导流能力的计算主要基于局部立方定律进行求解,并考虑了多重因素对导流能力的影响。结论认为,酸压数值模拟面临的新挑战包括酸液在复杂流动介质中的多场耦合高效计算、酸刻蚀过程的精细模拟、酸蚀裂缝导流能力的准确计算以及酸压数值模拟与酸压工程应用的匹配;需要突破的方向是实现多场、多尺度的酸压数值模拟。 展开更多
关键词 非均质 碳酸盐岩 油气藏 酸化压裂 数值模拟 研究进展 发展趋势
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多孔聚合物催化剂高效催化甲酸分解制氢 预览
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作者 张岩 吕元 +3 位作者 王玉清 李存耀 姜淼 丁云杰 《催化学报》 SCIE EI CAS CSCD 北大核心 2019年第2期147-151,共5页
氢能作为一种新型能源被认为是未来最理想的二次能源,与传统能源相比,具有能量密度高、热效率高、零污染的特点.然而,通常状态下氢能以低密度的气体形式存在,易燃易爆,给储存和运输带来诸多困难.因此,研发出安全高效的储氢方法尤为重要... 氢能作为一种新型能源被认为是未来最理想的二次能源,与传统能源相比,具有能量密度高、热效率高、零污染的特点.然而,通常状态下氢能以低密度的气体形式存在,易燃易爆,给储存和运输带来诸多困难.因此,研发出安全高效的储氢方法尤为重要.甲酸在室温下为液体,无毒,挥发性低,方便储存和运输;而且甲酸的体积储氢量高达53g/L,并能够通过催化甲酸分解反应释放出氢气和催化二氧化碳加氢反应将氢气转化成甲酸,因而甲酸被认为是理想的氢能载体.对于甲酸分解反应,制备出高活性的催化剂是关键,常用的催化剂包括均相催化剂和多相催化剂两类.均相催化剂主要是有机膦、有机胺等有机配体与金属离子(Ru、Ir、Rh、Fe等)配位得到的配合物,多相催化剂主要是多孔材料(活性炭、分子筛、二氧化硅等)负载的Au、Pd、Pt等单金属或其合金.均相催化剂具有高活性、高选择性的优点,而多相催化剂易于分离.为了结合均相催化剂和多相催化剂的优点,本文基于均相催化剂和多孔聚合物材料的发展,将均相催化剂锚定在多孔有机聚合物载体上,制备出Ru@POPs-PPh3及Ru@POPs-TPP催化剂.首先,对制备的催化剂进行了一系列表征.通过13C和31P固体核磁谱图证实了催化剂的结构;热重分析结果显示催化剂的分解温度高于400℃,表明此催化剂具有优良的热稳定性;N2物理吸附结果表明该催化剂具有非常高的比表面积和丰富的孔道结构;原位一氧化碳吸附红外光谱结果表明聚合物配体对中心金属离子的电子态具有重要影响.随后,对制备的催化剂进行了活性评价实验.结果显示,Ru@POPs-PPh3及Ru@POPs-TPP催化剂均能催化甲酸分解脱氢,并通过热过滤实验证明催化过程是多相催化过程.使用前后催化剂的透射电子显微镜表征显示,使用前Ru@POPs-PPh3及Ru@POPs-TPP催化剂上均未发现Ru纳米粒子,在使用后的Ru@ 展开更多
关键词 多相催化 多孔聚合物 甲酸 分解 氢能
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Challenges and opportunities in IR nanospectroscopy measurements of energy materials
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作者 Elad Gross 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第9期2200-2210,共11页
The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneiti... The performance of functional materials and specifically energy-related functional materials,such as fuel cells,solar cells,batteries and catalysts depends on the their local,nanoscale properties.However,heterogeneities in the phase,structure and composition of these functional materials makes it difficult to directly monitor and identify the influence of local physicochemical parameters on their global functionality.In this review we will discuss recent developments in the field of IR nanospectroscopy that enables the extraction of detailed chemical information at the nanoscale and the identification of nanoscale properties that influence the global performances of functional materials.Specifically,we will discuss the ways by which infrared (IR) nanospectroscopy techniques,namely photo thermal induced resonance (PTIR) and scattering scanning near-field optical microscopy (s-SNOM),are utilized in order to identify nanoscale properties and their influence on the functionality of halide-perovskite solar cells and catalytic nanoparticles.In the last part of this review we will address the technical challenges and opportunities in expanding the scope of IR nanospectroscopy measurements into the field of electrochemistry-based functional materials. 展开更多
关键词 infrared(IR)nanospectroscopy photo thermal in duced resonance(PTIR) scattering sea nning n ear-field optical microscopy(s-SNOM) heterogeneous CATALYSIS PEROVSKITE solar cells
Improved Performance for a Heterogeneous Satellite-Cooperative Network with Best Relay Node Selection 预览
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作者 Pedram hajipour Ali Shahzadi Saeed Ghazi-Maghrebi 《中国通信:英文版》 SCIE CSCD 2019年第5期93-105,共13页
Nowadays, hybrid satellite-terrestrial cooperative network has emerged as a key technology to provide a great variety of communication services. The deployment of this network will improve coverage and capacity in rem... Nowadays, hybrid satellite-terrestrial cooperative network has emerged as a key technology to provide a great variety of communication services. The deployment of this network will improve coverage and capacity in remote areas. Despite the benefits of this network, by increasing the number of users, communication efficiency based on interference management is a major challenge in satellite-based system. Also, the direct links between satellite system and the terrestrial equipment do not always have desirable channel condition. In order to avoid serious throughput degradation, choosing a cooperative relay node is very important. In this paper, Stackelberg game is exploited for interference management that is raised by satellites in down link over terrestrial equipment. Then, for interference management between ground station and relay node with other mobile users, CVX is used to allocate optimum power. Also, the best relay node in this structure is selected based on the harmonic mean function. Thus, the performance of the heterogeneous satellite-cooperative network is investigated based on three benchmarks, namely, successful transmission, energy consumption and outage probability. Finally, the simulation results showed the effect of proposed system model on the performance of next generation satellite networks. 展开更多
关键词 HETEROGENEOUS STACKELBERG game CONVEX optimization RELAY NODE COOPERATIVE communication
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Precise geoid computation using Stokes-Helmert’s scheme and strict integrals of topographic effects
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作者 Dongmei Guo Huiyou He Peng Sang 《大地测量与地球动力学:英文版》 2019年第4期290-296,共7页
The high-precision local geoid model was computed based on the improved Stokes-Helmert0 s boundary value problem and strict integrals of topographic effects. This proposed method involves three steps.First, the mathem... The high-precision local geoid model was computed based on the improved Stokes-Helmert0 s boundary value problem and strict integrals of topographic effects. This proposed method involves three steps.First, the mathematical form of Stokes-Helmert0 s boundary value problem was derived, and strict computational formulas regarding topographic effects were provided to overcome the disadvantage of planar approximations. Second, a gravimetric geoid model was constructed using the proposed StokesHelmert0 s scheme with a heterogeneous data set. Third, a least squares adjustment method combined with a multi-surface function model was employed to remove the bias between the gravimetric geoid model and the GNSS/leveling data and to refine the final local geoid model. The accuracy of the final geoid model was evaluated using independent GNSS/leveling data. Numerical results show that an external precision of 1.45 cm is achievable. 展开更多
关键词 GEOID COMPUTATION Stokes-Helmert’s method Surface integration Heterogeneous HEIGHTS
Magnetic separation of metal sulfides/oxides by Fe3O4 at room temperature and atmospheric pressure
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作者 Jia-Hui Ji Yi-Fei Xiao +3 位作者 Bin Shen Qiu-Ying Yi Jin-Long Zhang Ming-Yang Xing 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第5期379-389,共11页
The recovery of heterogeneous catalysts can save costs and avoid secondary pollution,but its separation efficiency and recovery cost are limited by conventional separation methods such as precipitation–flocculation,c... The recovery of heterogeneous catalysts can save costs and avoid secondary pollution,but its separation efficiency and recovery cost are limited by conventional separation methods such as precipitation–flocculation,centrifugation and filtration.In this paper,we found that surface-defective metal sulfides/oxides(WS2,CuS,ZnS,MoS2,CdS,TiO2,MoO2 and ZnO)commonly used in advanced oxidation processes(AOPs)could be magnetically recovered at room temperature and atmospheric pressure by mechanically mixing with Fe3O4.Zeta potential,Raman,X-ray photoelectron spectroscopy(XPS)and electro-spin resonance(ESR)spectra were measured to explore the mechanism of the magnetic separation phenomenon.The exposed active metal sites on the surface of defective metal sulfides/oxides are beneficial for the formation of chemical bonds,which are combined with electrostatic force to be responsible for the magnetic separation.Moreover,other factors affecting the magnetic separation were also investigated,such as the addition of amount of Fe3O4,different solvents and particle sizes.Finally,WS2 was chosen to be applied as a co-catalyst in Fenton reaction,which could be well separated by the magnetic Fe3O4 to achieve the recycle of catalyst in Fenton reaction.Our research provides a general strategy for the recycle of metal sulfides/oxides in the catalytic applications. 展开更多
关键词 MAGNETIC PRESSURE HETEROGENEOUS
Polymer hydrogels with enhanced stability and heterogeneous Fenton activity in organic pollutant removal
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作者 Yuan Zhuang Baoyou Shi 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第11期147-155,共9页
Polymer hydrogel-based materials have been shown to act as novel Fenton catalysts for water treatment,but the rational design of hydrogel-based catalysts with good stability has been a great challenge.To increase the ... Polymer hydrogel-based materials have been shown to act as novel Fenton catalysts for water treatment,but the rational design of hydrogel-based catalysts with good stability has been a great challenge.To increase the stability and activity of polymer-based Fenton catalysts,uniform urchin-like α-Fe2O3 was grown in situ in a PVA carrier matrix here.PVA molecules promoted the growth of urchin-like α-Fe2O3,and then the PVA hydrogel acted as a barrier and carrier to reduce agglomeration.Through coordination by hydroxyl groups,PVA had good combination with Fe ions and α-Fe2O3.The formation of Fe-O-C bonds between iron oxides and polymers was reported for the first time,enhancing the material stability during catalysis.Under higher PVA concentrations,the resulting composite hydrogel could generate more OH due to the increase in the number of active sites because of the hairy urchin-like structure.In tetracycline degradation through a heterogeneous Fenton reaction,the resulting material had good catalytic activity from pH 2 to pH 10 with low iron leaching,good reusability and remained at a level of nearly 90% after five consecutive cycles.Density functional theory calculations were used to further prove the mechanism of structural change of the iron oxides.The HOMO and LUMO energies of the iron oxides changed from 5.428 and 4.899 eV to 5.926 and 5.310 eV,indicating that the presence of PVA could influence the charge of the iron atom.The results provide new insights into the preparation of polymer hydrogel-based heterogeneous Fenton catalysts with enhanced stability for water treatment. 展开更多
关键词 HETEROGENEOUS FENTON TETRACYCLINE POLYMER STABILITY
面向异构无人驾驶车辆的互操作性研究 预览
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作者 余雪玮 赵熙俊 苏波 《汽车技术》 CSCD 北大核心 2019年第2期26-32,共7页
为满足无人驾驶车辆集群应用场景中异构无人驾驶车辆之间的互操作性需求,对比当前互操作性解决方案,并结合中间件技术,基于自动发现、去中心化、松散耦合、支持一对多通信的原则设计了面向异构无人驾驶车辆的互操作通信系统,在机器人操... 为满足无人驾驶车辆集群应用场景中异构无人驾驶车辆之间的互操作性需求,对比当前互操作性解决方案,并结合中间件技术,基于自动发现、去中心化、松散耦合、支持一对多通信的原则设计了面向异构无人驾驶车辆的互操作通信系统,在机器人操作系统(ROS)架构与4维实时控制系统(4D/RCS)架构间实现了异构无人驾驶车辆间的通信并通过仿真验证了所提出方法的有效性。 展开更多
关键词 异构 无人驾驶车辆 互操作性 标准 中间件
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Heterogeneous Network-Based Chronic Disease Progression Mining
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作者 Chenfei Sun Qingzhong Li +2 位作者 Lizhen Cui Hui Li Yuliang Shi 《大数据挖掘与分析(英文)》 2019年第1期25-34,共10页
Healthcare insurance fraud has caused billions of dollars in losses in public healthcare funds around the world. In particular, healthcare insurance fraud in chronic diseases is especially rampant. Understanding disea... Healthcare insurance fraud has caused billions of dollars in losses in public healthcare funds around the world. In particular, healthcare insurance fraud in chronic diseases is especially rampant. Understanding disease progression can help investigators detect healthcare insurance frauds early on. Existing disease progression methods often ignore complex relations, such as the time-gap and pattern of disease occurrence. They also do not take into account the different medication stages of the same chronic disease, which is of great help when conducting healthcare insurance fraud detection and reducing healthcare costs. In this paper, we propose a heterogeneous network-based chronic disease progression mining method to improve the current understanding on the progression of chronic diseases, including orphan diseases. The method also considers the different medication stages of the same chronic disease. Extensive experiments show that our method can outperform the existing methods by 20% in terms of F-measure. 展开更多
关键词 disease PROGRESSION HETEROGENEOUS network healthcare INSURANCE FRAUD
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