Results 31 to 40 of about 13,682 (165)

A Study on Complexity of Foreign Exchange Market and Artificial Foreign Exchange Market [PDF]

open access: yes, 2009
浮动汇率制度下,外汇市场上汇率的持续异常波动是经济学中最让人困惑和难以给予理论解释的经济现象之一。从20世纪70年代的宏观模型到90年代末以来日益盛行的外汇市场微观结构理论研究,虽然大量的研究工作取得了很多令人鼓舞的进展,但至今还不能很好解释汇率内在生成机制及其波动特性。与之相对应,汇率理论中微观基础和宏观规律之间的联系也一直没有得到合理的说明。近年来,随着复杂性科学在经济和金融研究中的应用,出现了一种崭新的金融市场研究方法——计算实验金融学。计算实验金融学借助多主体仿真技术构建人工金融市场 ...
黄光晓
core  

Adaptive Crystallization of NiFe‐MIL‐55 Nanorods: Atomically Precise Shape Control and Dual‐Function Electrocatalytic Performance

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT NiFe‐based MIL‐55 metal‐organic frameworks (MOFs) face challenges in achieving atomically precise composition and reliable methods for uniform growth. This study addresses these challenges by applying a slow evaporation crystallization technique to crude colloidal MIL‐55 products from hydrothermal synthesis, resulting in highly uniform ...
H. R. Haris   +10 more
wiley   +1 more source

Research on Diffusion of Innovation Products Based on Consumer Preferences Differences [PDF]

open access: yes, 2011
对创新扩散的研究基本上是在假定消费者之间无差异的情况下进行的,由于进行了一定的简化,研究与现实有较大的出入,所得的研究结论也不能有效地解释和指导实践。本文对消费者异质性特别是消费者偏好差异的相关研究进行综述,阐明在创新扩散的研究中考虑消费者个体偏好差异的必要性。此外,在创新产品的市场扩散中,网络效应和跟风效应是创新产品特别是数字信息产品被消费者采纳的重要影响因素。当消费者偏好存在差异的时候,网络效应和跟风效应作用下的创新产品是如何扩散的,这是一个值得研究的问题。 针对此种情况,本文站在消费者个体角度 ...
黄汉洲
core  

Climate stability drives multidimensional nestedness of amphibian assemblages in a Chinese sky island system

open access: yesFunctional Ecology, Volume 40, Issue 3, Page 636-654, March 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The nested subset pattern (nestedness) has been widely used to explain species distributions in island and fragmented systems. Mountain sky islands serve as critical natural laboratories for understanding the evolutionary consequences of geographic isolation and climate
Caiwen Zhang   +5 more
wiley   +1 more source

基于改进遗传算法与支持度的模糊系统优化建模方法

open access: yes智能科学与技术学报, 2020
模糊系统是一种可解释性强的人工智能方法,经典Wang-Mendel(WM)方法因能从数据中自动获取模糊规则,而成为一种重要的智能建模方法。但是该方法存在规则数目较多、精度不高等不足,且目前的改进方法普遍存在计算复杂、效率低等问题。为此,提出一种改进遗传算法与基于支持度的规则约简相结合的模糊系统优化建模新方法——遗传模糊系统(GFS),通过优化模糊系统的结构及隶属函数参数,由目标函数的不同组合构成GFS1、GFS2与GFS3这3种模型的具体实现算法。在标准及加噪的电能输出数据集上进行模糊建模试验 ...
杜宏庆   +4 more
doaj  

Exploration of Supersaturated Ni-doped Monocrystalline Silicon Material Prepared by Continuous-wave Laser Irradiation [PDF]

open access: yes, 2015
由于过饱和掺杂的硅基杂质中间带材料在中间带太阳电池和红外探测器等领域具有良好的应用前景,近年来受到了各国科研工作者的广泛关注和研究。本文首次选用Ni作为掺杂元素,从理论和实验两方面对Ni掺杂过饱和单晶Si材料形成中间带的可行性进行了探索。理论方面,基于密度泛函理论(DFT)对Ni掺杂体Si的形成能、电子结构和光学性质进行了第一性原理计算。实验方面,采用溅射镀膜结合连续线形激光扫描的方法成功制备了Ni掺杂过饱和单晶Si材料;并对Ni掺杂过饱和单晶Si材料的结晶特性与光电特性进行了表征与分析 ...
陈蓉
core  

Designing High‐Strength and High‐Ductility Cast Mg–Zn–Al–Mn–Sn Alloys via τ‐Mg32(Al,Zn)49 Phase Tuning and Twin Boundary Toughening Optimisation

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Achieving a simultaneous enhancement of strength and ductility remains a critical bottleneck for the large‐scale and cost‐effective engineering application of magnesium alloys. In this work, guided by first‐principles calculations, we tailored the τ‐Mg32(Al,Zn)49 phase and optimised twin boundary, thereby designing and successfully ...
Yun‐Xuan Zhou   +8 more
wiley   +1 more source

Computational Experiments for Study of the Competition Diffusion of New Products with Local Network Effects Based on Complex Social Networks [PDF]

open access: yes, 2013
采用基于复杂社会网络视角的新产品竞争微观扩散模型,应用计算实验的方法分析局部网络效应下用户基础、产品内在价值以及初始种子用户的选择等因素对产品竞争扩散的影响。研究结果表明,与全局网络效应不同的是,在局部网络效应中,影响新产品竞争扩散的关键因素不是用户基础而是社会网络中消费者的交互作用,该作用加快了信息传播、产品扩散的速度;产品自身内在价值的加大可以弥补局部网络效应强度较弱的产品竞争弱势。此外,选择Hub节点作为初始种子用户将有利于产品的扩散并最终占有更有优势的竞争格局。This paper,by the
周琦萍, 徐迪, 杨芳
core  

N,W‐Cooperative Modulation of Ni3S2 for Efficient Electrocatalytic Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Ni3S2 has emerged as a promising catalyst for the electrochemical oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), driven by its distinctive physicochemical properties. However, its practical catalytic efficiency is severely hindered by abundant electrochemically inactive surface sites and poor ...
Cheng‐Feng Yi   +5 more
wiley   +1 more source

基于深度学习的准部分子模型研究核物质状态方程

open access: yesHe jishu
在极端相对论重离子碰撞条件下,精确构建有限重子化学势μB区域的量子色动力学(Quantum Chromodynamics,QCD)物质状态方程(Equation of State,EoS)是当前高能核物理研究的核心难题之一。本研究提出一种基于深度学习的准部分子模型,通过构建三个深度神经网络,成功实现了零μB条件下QCD状态方程的高精度重建。同时,经深入分析四阶广义磁化率χ4B在不同温度和μB下的单调性行为,大致限定了QCD临界点可能存在的区间为(T,μB)=((0.113±0.019) GeV,(0 ...
李 甫鹏, 庞 龙刚, 秦 广友
doaj   +1 more source

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