Results 41 to 50 of about 253,021 (198)
青葉山周辺から産する鉱物標本の産出層準－ 仙台地域の地学教材の基礎資料 － [PDF]
, 2019 Mineral specimens occurring around the Aobayama Hill have been utilized as scientific study objects, also as familiar geology-teaching materials in the Sendai area.
佐藤 奈月 +4 more
core +1 more source
Rare Metals, EarlyView.ABSTRACT Although lithium metal has been regarded as an ideal anode material for high‐energy‐density batteries, its practical applications remain hindered by many serious challenges. Three‐dimensional (3D) porous Cu current collectors demonstrate potential in ensuring uniform Li deposition.
Meng‐Qi Zhu +7 more
wiley +1 more source
The Analysis of China‘s Wage Profile and its Determinants: based on the Data from CHNS Questionnaire Surveys. [PDF]
, 2016 工资问题研究一直是劳动经济学领域的热点问题。中国改革开放以来，劳动力市场发生了巨大的变化。我国劳动力工资分布如何？劳动力工资的决定因素有哪些？本文将对我国劳动力市场这些基本而重要的问题，利用代表性的微观调查数据和前沿的计量经济学方法，进行科学的考察和分析。 文章第一部分首先分别考察工资-时间分布和工资-年龄分布。工资-时间的分布符合中国经济实际增长的情况，保持了稳步增长的趋势。工资-年龄分布在总体上以及男性群体、东部省份群体、大学及以上群体、城市地区、私营三资企业群体符合倒U型分布，实际工资在50 ...
翟柯
core
Dual‐Stage Heat Treatment for Enhanced Hydrogen Storage Properties of Mg−Ni−Y Alloys
Rare Metals, EarlyView.ABSTRACT Mg−Ni−Y alloy is considered to be one of the most promising hydrogen storage materials, but its high dehydrogenation energy barrier hinders its practical application. A dual‐stage heat treatment (490°C × 4 h + 550°C × 4 h) is applied to optimize the microstructure and hydrogen storage performance of a vacuum‐melted Mg94Ni3Y3 alloy.
You Lv +6 more
wiley +1 more source
Characterization of mechanical properties and primary investigation of pyrolysis and sintering of polycarbosilane-derived continuous fibers [PDF]
, 2005 Hi-NicalonSiC纤维是通过先驱体法制备并已商品化的高性能连续纤维，是制备耐高温SiC/SiC复合材料的关键原材料。降低纤维中氧的含量可提高其高温使用性能，而降低纤维的直径、减少缺陷可提高其力学性能。本论文主要对Hi-NicalonSiC纤维的力学性能进行系统表征并对PCS制备连续SiC纤维的烧成工艺进行初步探索。对Hi-NicalonSiC纤维的研究结果表明：①纤维的强度服从Weibull分布；纤维的模量服从正态分布；纤维的应变服从正态分布；纤维的直径分布服从正态分布。②Hi ...
吴清良
core
Rare Metals, EarlyView.ABSTRACT As a promising alternative to sluggish Li2CO3‐based Li‐CO2 electrochemistry, Li2C2O4 offers a favorable 2e− discharge pathway, yet its selective formation and reversible decomposition remain debated. Herein, we propose a nonmetal‐metal synergistic catalyst—B‐Ti coregulated layered transition metal boride Ti18B18O9/graphene (B‐Ti/TiBOG)—to ...
Qiong Peng +8 more
wiley +1 more source
Dianci bileiqi, 2018 电位分布及温度分布情况是对避雷器健康运行进行评价的重要指标,直接关系到整支避雷器的运行寿命,在无均压措施的情况下,将导致老化速度加快,甚至发生热崩溃。对避雷器的电位分布情况进行测试是对避雷器进行均压的首要条件,但传统检测手段均为基于有线光纤方式进行电位分布采集。本项目基于高性能AVR微处理器,便携式单片微型计算机采样,无线通信,同步采样分析等手段,成功研制了避雷器电位分布及温度分布无线检测系统。对避雷器电位分布及温度分布情况以无线同步方式进行测试,避免了测试现场繁琐的光纤布线 ...
李佳奇 +5 more
doaj
Dianci bileiqi, 2023 大量分布式新能源并网所带来的高随机性和强波动性将引发配电网的暂态过电压行为，是分布式能源发展的痼疾之一。本研究总结了分布式新能源并网接入系统产生的暂态过电压问题，并总结了过电压抑制方法，分析了分布式新能源接入系统中暂态过电压机理，包括功率变化、不对称故障、工作频率和谐振等因素。在此基础上，总结了分布式抑制暂态过电压的方法，包括母线调节和逆变器控制等手段，并指出了抑制方法的优缺点，最后针对分布式新能源高渗透率化和大量负荷随机性接入角度进行了展望。本研究有助于更好地理解分布式新能源接入暂态过电压问题 ...
牛嘉琪
doaj
Asymptotic distribution of the product of trimmed sums(一类截断部分和乘积的渐近正态性)
Zhejiang Daxue xuebao. Lixue ban, 2007 对于取值为正的独立同分布且平方可积的随机变量X1，X2，…且有连续的分布函数，令Mn = max{X1，X2, …，Xn}，对某固定常数a>0，令，截断和Tn（a）= Sn — Sn(a），在X的分布满足中尾分布的条件时，截断和Tn(a)的乘积为渐近对数正态.
ZOUHai-lian(邹海连) +1 more
doaj +1 more source
On the Damage Tolerance of Diffusion Bonded Titanium–Aluminum Phase Biomimetic Composites
Rare Metals, EarlyView.ABSTRACT The biomimetic design principles of natural structures involve the strategic integration of stiff and compliant phases to synergistically enhance strength and toughness. Its evolutionary refined natural armor, characterized by a specialized microarchitecture, enables superior damage tolerance.
Shuai Tong +10 more
wiley +1 more source