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基于ucos φ的失步解列装置 被引量:86
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作者 宗洪良 任祖怡 +3 位作者 郑玉平 邵学俭 孙光辉 沈国荣 《电力系统自动化》 EI CSCD 北大核心 2003年第19期83-85,共3页
通过对电力系统异步运行状态的分析 ,提出了利用振荡中心电压的变化特征来判断系统失步的失步解列装置。该装置的判据简单明确、概念清晰 ,可以判别加速性失步和减速性失步 ,并自动适应系统结构的变化和运行方式的变化。
关键词 电力系统安全自动装置 失步解列 振荡中心电压 继电保护
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A mini review of NiFe-based materials as highly active oxygen evolution reaction electrocatalysts 被引量:83
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作者 Ming Gong Hongjie Dai 《Nano Research》 SCIE EI CAS CSCD 2015年第1期23-39,共17页
Oxygen evolution reaction (OER) electrolysis, as an important reaction involved in water splitting and rechargeable metal-air batteries, has attracted increasing attention for clean energy generation and efficient e... Oxygen evolution reaction (OER) electrolysis, as an important reaction involved in water splitting and rechargeable metal-air batteries, has attracted increasing attention for clean energy generation and efficient energy storage. Nickel/iron (NiFe)-based compounds have been known as active OER catalysts since the last century, and renewed interest has been witnessed in recent years on developing advanced NiFe-based materials for better activity and stability. In this review, we present the early discovery and recent progress on NiFe-based OER electrocatalysts in terms of chemical properties, synthetic methodologies and catalytic performances. The advantages and disadvantages of each class of NiFe-based compounds are summarized, including NiFe alloys, electrodeposited films and layered double hydroxide nanoplates. Some mechanistic studies of the active phase of NiFe-based compounds are introduced and discussed to give insight into the nature of active catalytic sites, which could facilitate further improving NiFe based OER electrocatalysts. Finally, some applications of NiFe- based compounds for OER are described, including the development of an electrolyzer operating with a single AAA battery with voltage below 1.5 V and high performance rechargeable Zn-air batteries. 展开更多
关键词 oxygen evolution reaction ELECTROCATALYSIS nickel-iron water splitting
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岩石的劈裂和卸载破坏机制 被引量:57
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作者 王明洋 范鹏贤 李文培 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2010年第2期234-241,共8页
概括含缺陷的岩体结构模型,并利用其研究岩石在加载和卸载时内部出现的拉应力及其对岩石破坏模式的影响。为模拟深部岩体的赋存环境,研究3种受力条件下的岩石应力状态:单轴无侧限压缩、具有初始静水压力时的加载和初始静水压力作用下岩... 概括含缺陷的岩体结构模型,并利用其研究岩石在加载和卸载时内部出现的拉应力及其对岩石破坏模式的影响。为模拟深部岩体的赋存环境,研究3种受力条件下的岩石应力状态:单轴无侧限压缩、具有初始静水压力时的加载和初始静水压力作用下岩石的卸载。分析表明,无论是加载还是卸载,岩体中均将出现局部拉应力。在加载情况下,岩体中出现的拉应力有可能导致平行于加载方向的劈裂;而在卸载情况下,岩石中将在缺陷处形成平行于卸载方向的拉应力。岩石中出现的拉应力主要与岩体内缺陷的物理参数、初始应力大小和卸载速率有关。对卸载时初始应力和卸载速率对缺陷应力集中的影响进行分析,结果表明:卸载速率越快,缺陷处的应力集中越大,若缺陷尺寸较大,岩体中的局部拉应力和初始应力近似成正比。根据得到的局部应力表达式,在深地下工程中,快速卸载将必然导致岩体的拉伸破坏。 展开更多
关键词 岩石力学 缺陷 应力集中 劈裂 卸载破坏
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广义Logit交通方式划分预测方法 被引量:23
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作者 王正 刘安 郑萍 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 1999年第3期314-318,共5页
针对交通方式划分预测方法存在的不足,基于对交通方式个体选择行为的微观经济解释,利用随机效用理论,通过方式效用相关描述参数的引入,建立了广义 Logit 方式划分预测模型.最后。
关键词 交通方式 划分 随机效用 预测 交通规划
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微电网并网标准研究 被引量:47
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作者 杨志淳 乐健 +1 位作者 刘开培 谢雪景 《电力系统保护与控制》 EI CSCD 北大核心 2012年第2期66-71,76,共7页
根据现有的国内外相关标准和规范,从电力系统的角度初步研究了微电网并网、并网运行以及解列过程的技术要求。提出了微电网并网的基本要求和并网准则,基于配电网可靠性考虑,对微电网并网时接入点、接入容量和接入方式提出了要求。对微... 根据现有的国内外相关标准和规范,从电力系统的角度初步研究了微电网并网、并网运行以及解列过程的技术要求。提出了微电网并网的基本要求和并网准则,基于配电网可靠性考虑,对微电网并网时接入点、接入容量和接入方式提出了要求。对微电网接入电网引起的电能质量、有功功率和无功功率控制、电压调节、继电保护、通信、监测和电能计量等问题进行了分析。将微电网的解列分为正常解列和事故解列,着重强调事故解列时孤岛区域的划分原则及解列要求。通过对微电网接入电网所需考虑的关键问题进行分析探讨,为制定微电网的接入标准提供了一定的基础。 展开更多
关键词 微电网 电力系统 并网 并网运行 解列 电能质量 继电保护
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三河尖煤矿冲击矿压发生机制分析 被引量:33
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作者 张晓春 缪协兴 +1 位作者 翟明华 杨挺青 《岩石力学与工程学报》 EI CAS CSCD 北大核心 1998年第5期508-513,共6页
探讨了三河尖矿发生的片帮型冲击矿压机制。在压应力集中区内,巷道自由表面附近裂纹生成、扩展和贯通,在巷道壁内部由表及里重复顺壁形成薄煤岩层,在应力增加或外界扰动下薄壁层屈曲破坏,剥落崩出,形成冲击矿压,其主要形式为突然... 探讨了三河尖矿发生的片帮型冲击矿压机制。在压应力集中区内,巷道自由表面附近裂纹生成、扩展和贯通,在巷道壁内部由表及里重复顺壁形成薄煤岩层,在应力增加或外界扰动下薄壁层屈曲破坏,剥落崩出,形成冲击矿压,其主要形式为突然的煤层片帮。此外,结合煤层的倾斜赋存环境。 展开更多
关键词 冲击矿压 裂纹扩展 片帮 煤矿
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A review on TiO_2-based Z-scheme photocatalysts 被引量:40
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作者 Kezhen Qi Bei Cheng Jiaguo Yu 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第12期1936-1955,共20页
TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the... TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the reaction mechanism of Z‐scheme photocatalysts,recent research progress in the application of TiO2‐based Z‐scheme photocatalysts,and improved methods for photocatalytic performance enhancement are explored.Their applications,including water splitting,CO2reduction,decomposition of volatile organic compounds,and degradation of organic pollutants,are also described.The main factors affecting the photocatalytic performance of TiO2‐based Z‐scheme photocatalysts,such as pH,conductive medium,cocatalyst,architecture,and mass ratio,are discussed.Concluding remarks are presented,and some suggestions for the future development of TiO2‐based Z‐scheme photocatalysts are highlighted. 展开更多
关键词 TIO2 Z‐scheme photocatalyst Water splitting CO2 reduction Pollutant degradation
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Interfacial engineering of graphitic carbon nitride(g-C_3N_4)-based metal sulfide heterojunction photocatalysts for energy conversion: A review 被引量:33
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作者 Yijie Ren Deqian Zeng Wee-Jun Ong 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第3期289-319,共31页
As one of the most appealing and attractive technologies, photocatalysis is widely used as a promising method to circumvent the environmental and energy problems. Due to its chemical stability and unique physicochemic... As one of the most appealing and attractive technologies, photocatalysis is widely used as a promising method to circumvent the environmental and energy problems. Due to its chemical stability and unique physicochemical, graphitic carbon nitride (g-C3N4) has become research hotspots in the community. However, g-C3N4 photocatalyst still suffers from many problems, resulting in unsatisfactory photocatalytic activity such as low specific surface area, high charge recombination and insufficient visible light utilization. Since 2009, g-C3N4-based heterostructures have attracted the attention of scientists worldwide for their greatly enhanced photocatalytic performance. Overall, this review summarizes the recent advances of g-C3N4-based nanocomposites modified with transition metal sulfide (TMS), including (1) preparation of pristine g-C3N4,(2) modification strategies of g-C3N4,(3) design principles of TMS-modified g-C3N4 heterostructured photocatalysts, and (4) applications in energy conversion. What is more, the characteristics and transfer mechanisms of each classification of the metal sulfide heterojunction system will be critically reviewed, spanning from the following categories:(1) Type I heterojunction,(2) Type II heterojunction,(3) p-n heterojunction,(4) Schottky junction and (5) Z-scheme heterojunction. Apart from that, the application of g-C3N4-based heterostructured photocatalysts in H2 evolution, CO2 reduction, N2 fixation and pollutant degradation will also be systematically presented. Last but not least, this review will conclude with invigorating perspectives, limitations and prospects for further advancing g-C3N4-based heterostructured photocatalysts toward practical benefits for a sustainable future. 展开更多
关键词 Graphitic carbon nitride Metal sulfide PHOTOCATALYSIS Energy transformation Water splitting Reduction of carbon dioxide Pollutant degradation Nitrogen fixation
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国内13家儿童医院片剂分剂量问卷调查与儿童适宜规格的建议 被引量:33
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作者 李英 贾露露 +1 位作者 胡泊洋 王晓玲 《中国新药杂志》 CAS CSCD 北大核心 2015年第23期2756-2760,共5页
目的:了解儿科临床口服片剂分剂量现状,获得建议优先增加儿童适宜规格的药品目录,并给出建议增加的具体规格。方法:采用自编调查表,收集国内13家儿童医院片剂分剂量使用数据,经汇总分析,获得最常拆分药品、其最常拆分规格以及最希望的... 目的:了解儿科临床口服片剂分剂量现状,获得建议优先增加儿童适宜规格的药品目录,并给出建议增加的具体规格。方法:采用自编调查表,收集国内13家儿童医院片剂分剂量使用数据,经汇总分析,获得最常拆分药品、其最常拆分规格以及最希望的规格。结果:本次调查共涉及120种药品,124个品规,其中6种药品为半数以上(≥7家)医院均进行拆分的品规;60种药品为单独报道(1家)拆分的药品。建议增加以下药品的儿童适宜规格:螺内酯片5 mg,氢氯噻嗪片5 mg,氯硝西泮片1 mg,巯嘌呤片12.5 mg,苯巴比妥片10 mg,卡托普利片5 mg,醋酸泼尼松片2.5 mg,双嘧达莫片12.5 mg,呋塞米片5 mg。结论:儿童适宜规格缺乏,儿科口服片剂分剂量使用现象普遍。其中,抗菌药物、抗癫痫药和降压药是儿科最常分剂量使用的药物种类。儿科片剂分剂量使用难以保证剂量准确性,存在药物治疗安全隐患。为减少儿科片剂二次拆分现象,需政府、医药企业和医院多方面共同努力。 展开更多
关键词 儿童适宜规格 片剂 分剂量 合理用药 问卷调查
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A review and perspective on molybdenum-based electrocatalysts for hydrogen evolution reaction 被引量:32
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作者 Wei Hua Huan-Huan Sun +1 位作者 Fei Xu Jian-Gan Wang 《Rare Metals》 SCIE EI CAS CSCD 2020年第4期335-351,共17页
Water electrolysis has been considered as a sustainable way for producing renewable energy of hydrogen.However,this process requires a low-cost and high-efficient hydrogen evolution reaction(HER)catalyst to improve th... Water electrolysis has been considered as a sustainable way for producing renewable energy of hydrogen.However,this process requires a low-cost and high-efficient hydrogen evolution reaction(HER)catalyst to improve the overall reaction efficiency.Molybdenum(Mo)-based electrocatalysts are regarded as the promising candidates to replace the benchmark but expensive Ptbased HER catalysts,due to their high activity and stability in a wide pH range.In this review,we present a comprehensive and critical summary on the recent progress in the Mo-based electrodes for HER,including molybdenum alloys,molybdenum sulfides,molybdenum selenides,molybdenum carbides,molybdenum phosphides,molybdenum borides,molybdenum nitrides,and molybdenum oxides.Particular attention is mainly focused on the synthetic methods of Mo-based materials,the strategies for increasing the catalytic activity,and the relationship between structure/composition and electrocatalytic performance.Finally,the future development and perspectives of Mo-based electrocatalysts toward high HER performance are proposed. 展开更多
关键词 Mo-based materials ELECTROCATALYSTS Hydrogen evolution reaction Water splitting
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Characteristics of the Onset of the Asian Summer Monsoon and the Importance of Asian-Australian "Land Bridge" 被引量:30
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作者 何金海 温敏 +1 位作者 王黎娟 徐海明 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第6期951-963,共13页
Based on summarizing previous achievements and characteristics of Asian summer monsoon and the role using data as long and new as possible, the onset of Asian-Australian "land bridge" in the onset of summer monsoon ... Based on summarizing previous achievements and characteristics of Asian summer monsoon and the role using data as long and new as possible, the onset of Asian-Australian "land bridge" in the onset of summer monsoon are further discussed. In particular, the earliest onset area of Asian summer monsoon is comparatively analyzed, and the sudden and progressive characteristics of the onset of summer monsoon in different regions are discussed, Furthermore, the relationships among such critical events during the onset of Asian summer monsoon as the splitting of subtropical high belt over the Bay of Bengal (BOB), the initiation of convection over Indo-China Peninsula, the westward advance, reestablishment of South Asian High, and the rapid northward progression of convection originated from Sumatra in early summer are studied. The important impact of the proper collocation of she latent heating over Indo-China Peninsula and the sensible heating over Indian Peninsula on the splitting of the subtropical high belt, the deepening of BOB trough, the activating of Sri Lanka vortex (twin vortexes in the Northern and Southern Hemispheres), and the subsequent onset of South China Sea summer monsoon are emphasized. 展开更多
关键词 Asian summer monsoon onset Asian-Australian "land bridge" splitting of subtropical highbelt
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油桃果实细胞组织结构与裂果的关系 被引量:17
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作者 田玉命 韩明玉 《西北农业学报》 CSCD 2000年第1期108-110,T001-T002,共5页
对油桃、普通桃果实细胞组织结构的变化进行了电镜扫描观察。结果表明 ,油桃果面组织和果皮、果肉细胞结构与裂果关系密切 :1普通桃果面有密集的茸毛保护 ,而油桃果面无茸毛保护 ;除气孔外 ,油桃果面有波纹状裂痕 ,随果实生长裂痕明显 ... 对油桃、普通桃果实细胞组织结构的变化进行了电镜扫描观察。结果表明 ,油桃果面组织和果皮、果肉细胞结构与裂果关系密切 :1普通桃果面有密集的茸毛保护 ,而油桃果面无茸毛保护 ;除气孔外 ,油桃果面有波纹状裂痕 ,随果实生长裂痕明显 ,若遇外界不良因子侵袭产生裂缝 ,使果皮细胞裸露 ,就会产生裂果 ;2普通桃果皮细胞厚 ,层数多 ,多为横向排列 ,紧密 ,间隙小 ,而油桃果皮细胞薄 ,多为纵向排列 ,松散 ,间隙大 ,果肉细胞膨大时易将果皮撑裂 ;3果实着色期果肉细胞膨大速率油桃高于普通桃 ,油桃果肉细胞对果皮细胞施加的膨压增长的越快 ,越易引起裂果。 展开更多
关键词 油桃 品种 油桃果实 细胞组织结构 裂果
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大型火电机组动态频率响应特性 被引量:25
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作者 王一振 马世英 +1 位作者 王青 马世俊 《电网技术》 EI CSCD 北大核心 2013年第1期106-111,共6页
当电网发生解列故障时大型火电机组的动态频率响应特性对于维持系统频率安全和稳定具有至关重要的作用。以频率最大偏移量及其出现时刻为研究关注点,建立了解列后大型火电机组频率调节动态模型,提出一种通过求解四阶线性定常非齐次状态... 当电网发生解列故障时大型火电机组的动态频率响应特性对于维持系统频率安全和稳定具有至关重要的作用。以频率最大偏移量及其出现时刻为研究关注点,建立了解列后大型火电机组频率调节动态模型,提出一种通过求解四阶线性定常非齐次状态方程组确定频率最大偏移量及其出现时刻的方法。以此为基础,采用一台600MW火电机组的实测参数,深入分析了机组一次调频限幅、调差系数、前馈系数3个重要参数对解列后电网频率动态过程的影响。研究结果可用于指导解列后电网频率安全稳定措施的制定。 展开更多
关键词 解列 火电机组 频率稳定 动态响应 一次调频限幅 调差系数 前馈系数
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螺栓排数和自攻螺钉对木梁柱节点抗侧力性能的影响 被引量:24
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作者 何敏娟 赵艺 +1 位作者 高承勇 张家华 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第6期845-852,共8页
通过4组梁柱节点在单调和往复加载下的抗侧力试验,得到了各组节点的破坏模式、弯矩-转角曲线、滞回曲线、强度、刚度、延性及耗能性能,研究了不同螺栓排数和自攻螺钉加强对节点抗侧力性能的影响.结果表明,普通节点中裂缝出现早,开展迅速... 通过4组梁柱节点在单调和往复加载下的抗侧力试验,得到了各组节点的破坏模式、弯矩-转角曲线、滞回曲线、强度、刚度、延性及耗能性能,研究了不同螺栓排数和自攻螺钉加强对节点抗侧力性能的影响.结果表明,普通节点中裂缝出现早,开展迅速;增加螺栓排数可提高节点的强度和延性,其中强度提高更明显;自攻螺钉加强可明显减轻和延缓木材的开裂,提升节点的延性和抗震性能. 展开更多
关键词 节点抗侧力 螺栓排数 自攻螺钉 劈裂 延性
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Ternary NiCoP nanosheet arrays: An excellent bifunctional catalyst for alkaline overall water splitting 被引量:21
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作者 Yingjie Li Haichuan Zhang +3 位作者 Ming Jiang Yun Kuang Xiaoming Sun Xue Duan 《Nano Research》 SCIE EI CAS CSCD 2016年第8期2251-2259,共9页
Exploring bifunctional catalysts for the hydrogen and oxygen evolution reactions (HER and OER) with high efficiency, low cost, and easy integration is extremely crucial for future renewable energy systems. Herein, t... Exploring bifunctional catalysts for the hydrogen and oxygen evolution reactions (HER and OER) with high efficiency, low cost, and easy integration is extremely crucial for future renewable energy systems. Herein, ternary NiCoP nanosheet arrays (NSAs) were fabricated on 3D Ni foam by a facile hydrothermal method followed by phosphorization. These arrays serve as bifunctional alkaline catalysts, exhibiting excellent electrocatalytic performance and good working stability for both the HER and OER. The overpotentials of the NiCoP NSA electrode required to drive a current density of 50 mA/cm2 for the HER and OER are as low as 133 and 308 mV, respectively, which is ascribed to excellent intrinsic electrocatalytic activity, fast electron transport, and a unique superaerophobic structure. When NiCoP was integrated as both anodic and cathodic material, the electrolyzer required a potential as low as -1.77 V to drive a current density of 50 mA/cm2 for overall water splitting, which is much smaller than a reported electrolyzer using the same kind of phosphide-based material and is even better than the combination of Pt/C and Ir/C, the best known noble metal-based electrodes. Combining satisfactory working stability and high activity, this NiCoP electrode paves the way for exploring overall water splitting catalysts. 展开更多
关键词 bifunctional catalysts water splitting NiCoP nanosheets superaerophobic electrode
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Shear-wave splitting in the crust:Regional compressive stress from polarizations of fast shear-waves 被引量:21
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作者 Yuan Gao Yutao Shi +1 位作者 Jing Wu Lingxue Tai 《Earthquake Science》 CSCD 2012年第1期35-45,共11页
When propagating through anisotropic rocks in the crust, shear-waves split into faster and slower components with almost orthogonal polarizations. For nearly vertical propagation the polarization of fast shear- wave ... When propagating through anisotropic rocks in the crust, shear-waves split into faster and slower components with almost orthogonal polarizations. For nearly vertical propagation the polarization of fast shear- wave (PFS) is parallel to both the strike of the cracks and the direction of maximum horizontal stress, therefore it is possible to use PFS to study stress in the crust. This study discusses several examples in which PFS is applied to deduce the compressive stress in North China, Longmenshan fault zone of east edge of Tibetan plateau and Yunnan zone of southeast edge of Tibetan plateau, also discusses temporal variations of PFS orientations of 1999 Xiuyan earthquake sequences of northeastern China. The results are consistent to those of other independent traditional stress measurements. There is a bridge between crustal PFS and the crustal principal compressive stress although there are many unclear disturbance sources. This study suggests the PFS results could be used to deduce regional and in situ principal compressive stress in the crust only if there are enough seismic stations and enough data. At least, PFS is a useful choice in the zone where there are a large number of dense seismic stations. 展开更多
关键词 polarization of fast shear-wave shear-wave splitting compressive stress in the crust seismic anisotropy
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Fast formation of single-unit-cell-thick and defect-rich layered double hydroxide nanosheets with highly enhanced oxygen evolution reaction for water splitting 被引量:20
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作者 Rui Gao Dongpeng Yan 《Nano Research》 SCIE EI CAS CSCD 2018年第4期1883-1894,共12页
The development of high-efficiency electrocatalysts for oxygen evolution reactions (OERs) plays an important role in the water-splitting process. Herein, we report a facile way to obtain two-dimensional (2D) singl... The development of high-efficiency electrocatalysts for oxygen evolution reactions (OERs) plays an important role in the water-splitting process. Herein, we report a facile way to obtain two-dimensional (2D) single-unit-cell-thick layered double hydroxide (LDH) nanosheets (NSs, - 1.3 nm) within only 5 min. These nanosheets presented significantly enhanced OER performance compared to bulk LDH systems fabricated using the conventional co-precipitation method. The current strategy further allowed control over the chemical compositions and electrochemical activities of the LDH NSs. For example, CoFe-LDH NSs presented the lowest overpotential of 0.28 V at 10 mA/cm2, and the NiFe-LDHs NSs showed Tafel slopes of 33.4 mV/decade and nearly 100% faradaic efficiency, thus outperforming state-of-the-art IrO2 water electrolysis catalysts. Moreover, positron annihilation lifetime spectroscopy and high-resolution transmission electron microscopy observations confirmed that rich defects and distorted lattices occurred within the 2D LDH NSs, which could supply abundant electrochemically active OER sites. Periodic calculations based on density functional theory (DFT) further showed that the CoFe- and NiFe-LDHs presented very low energy gaps and obvious spin-polarization behavior, which facilitated high electron mobility during the OER process. Therefore, this work presents a combined experimental and theoretical study on 2D single-unit-cell-thick LDH NSs with high OER activities, which have potential application in water splitting for renewable energy. 展开更多
关键词 single-unit-cell defect-rich oxygen evolution reaction water splitting
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Upper mantle anisotropy and crust-mantle deformation pattern beneath the Chinese mainland 被引量:21
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作者 WANG ChunYong CHANG LiJun +3 位作者 DING ZhiFeng LIU QiongLin LIAO WuLin Lucy M FLESCH 《Science China Earth Sciences》 SCIE EI CAS 2014年第1期132-143,共12页
Over the past 10 years, the number of broadband seismic stations in China has increased significantly. The broadband seismic records contain information about shear-wave splitting which plays an important role in reve... Over the past 10 years, the number of broadband seismic stations in China has increased significantly. The broadband seismic records contain information about shear-wave splitting which plays an important role in revealing the upper mantle anisotropy in the Chinese mainland. Based on teleseismic SKS and SKKS phases recorded in the seismic stations, we used the analytical method of minimum transverse energy to determine the fast wave polarization direction and delay time of shear-wave splitting. We also collected results of shear-wave splitting in China and the surrounding regions from previously published papers. From the combined dataset we formed a shear-wave splitting dataset containing 1020 parameter pairs. These splitting parameters re- veal the complexity of the upper mantle anisotropy image. Our statistical analysis indicates stronger upper mantle anisotropy in the Chinese mainland, with an average shear-wave time delay of 0,95 s; the anisotropy in the western region is slightly larger (1.01 s) than in the eastern region (0.92 s). On a larger scale, the SKS splitting and surface deformation data in the Tibetan Plateau and the Tianshan region jointly support the lithospheric deformation mode, i.e. the crust-lithospheric mantle coherent deformation. In eastern China, the average fast-wave direction is approximately parallel to the direction of the absolute plate motion; thus, the upper mantle anisotropy can be attributed to the asthenospheric flow. The area from the Ordos block to the Sichuan Basin in central China is the transition zone of deformation modes between the east and the west regions, where the anisotropy images are more complicated, exhibiting "fossil" anisotropy and/or two-layer anis^3trc^py. The c^llisi(3n between the Indian Plate and the Eurasian Plate is the main factor of upper mantle anisotropy in the western region of the Chinese mainland, while the upper mantle anisotropy in the eastern region is related to the subduction of the Pacific Plate and the Philippine Sea Plate be 展开更多
关键词 shear-wave splitting upper mantle anisotropy lithosphere deformation asthenospheric flow absolute plate motion
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Electrocatalytic water splitting:Mechanism and electrocatalyst design 被引量:17
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作者 Han Wu Qiaoxian Huang +2 位作者 Yuanyuan Shi Jiangwei Chang Siyu Lu 《Nano Research》 SCIE EI CSCD 2023年第7期9142-9157,共16页
Hydrogen energy,a new type of clean and efficient energy,has assumed precedence in decarbonizing and building a sustainable carbon-neutral economy.Recently,hydrogen production from water splitting has seen considerabl... Hydrogen energy,a new type of clean and efficient energy,has assumed precedence in decarbonizing and building a sustainable carbon-neutral economy.Recently,hydrogen production from water splitting has seen considerable advancements owing to its advantages such as zero carbon emissions,safety,and high product purity.To overcome the large energy barrier and high cost of water splitting,numerous efficient electrocatalysts have been designed and reported.However,various difficulties in promoting the industrialization of electrocatalytic water splitting remain.Further,as high-performance electrocatalysts that satisfy industrial requirements are urgently needed,a better understanding of water-splitting systems is required.In this paper,the latest progress in water electrolysis is reviewed,and experimental evidence from in situ/operando spectroscopic surveys and computational analyses is summarized to present a mechanistic understanding of hydrogen and oxygen evolution reactions.Furthermore,some promising strategies,including alloying,morphological engineering,interface construction,defect engineering,and strain engineering for designing and synthesizing electrocatalysts are highlighted.We believe that this review will provide a knowledge-guided design in fundamental science and further inspire technical engineering developments for constructing efficient electrocatalysts for water splitting. 展开更多
关键词 water splitting MECHANISM operando spectroscopy design strategy
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Particle flow study on strength and meso-mechanism of Brazilian splitting test for jointed rock mass 被引量:19
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作者 Sheng-Qi Yang Yan-Hua Huang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第4期547-558,共12页
A discrete element method (DEM) called particle flow code (PFC2D) was used to construct a model for Brazilian disc splitting test in the present study. Based on the experimental results of intact Brazilian disc of... A discrete element method (DEM) called particle flow code (PFC2D) was used to construct a model for Brazilian disc splitting test in the present study. Based on the experimental results of intact Brazilian disc of rock-like material, a set of micro-parameters in PFC2D that reflected the macro-mechanical behavior of rock-like materials were obtained. And then PFC2D was used to simulate Brazilian splitting test for jointed rock mass specimens and specimen containing a central straight notch. The effect of joint angle and notch angle on the tensile strength and failure mode of jointed rock specimens was detailed analyzed. In order to reveal the meso-mechanical mechanism of crack coalescence, displacement trend lines were applied to analyze the displacement evolution during the crack initiation and propagation. The investigated conclusions can be described as follows. (1) The tensile strength of jointed rock mass disc specimen is dependent to the joint angle. As the joint angle increases, the tensile strength of jointed rock specimen takes on a nonlinear variance. (2) The tensile strength of jointed rock mass disc specimen containing a central straight notch distributes as a function of both joint angle and notch angle. (3) Three major failure modes, i.e., pure tensile failure, shear failure and mixed tension and shear failure mode are observed in jointed rock mass disc specimens under Brazilian test. (4) The notch angle roles on crack initiation and and joint angle play important propagation characteristics of jointed rock mass disc specimen containing a central straight notch under Brazilian test. 展开更多
关键词 Jointed rock mass Brazilian splitting test. Ten-sile strength· Failure mode PFC2D
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