Results 31 to 40 of about 25,196 (239)
Abstract Water distribution networks are costly long‐term investments, prompting researchers to seek cost reduction and efficient design solutions using optimization techniques. In this context, the Penalty‐Free Multi‐Objective Evolutionary Algorithm (PFMOEA) is employed alongside pressure‐dependent analysis (PDA) to optimize water distribution systems
Emily Kambalame, John Ndiritu
wiley +1 more source
Theoritical investigations of structural stability, mechanical and thermodynamics properties for γ’ precipitates in Co-based superalloys [PDF]
随着国防科技的迅猛发展,新一代的航空航天飞机对发动机涡轮叶片材料的承温能力提出更高的要求。传统Ni基高温合金由于熔点的限制,其最高使用温度已不能满足需要。寻找下一代新型高温合金以满足发展更高效率航空发动机的需求是国内外学术界和产业应用领域共同关注的焦点。最近,新型γ’析出相强化型Co基合金的发现在全世界掀起了开发新型钴基高温材料的热潮。类似于γ’-Ni3Al,γ’析出相在新型Co基高温合金中起到了至关重要的作用。γ’相的结构稳定性、弹性力学性质与温度的依存关系直接决定了Co基合金在高温下的性能表现 ...
许伟伟
core
论水库旱限水位分期控制的必要性与计算方法探讨 Necessity and Methods for Reservoir Seasonal Drought Control Water Level
为应对日益频繁的干旱问题,新生了旱限水位理念。通过与水库死水位和消落水位相对比,阐述了水库旱限水位的内涵。通过类比水库汛限水位,论述了水库旱限水位分时段控制的必要性;采用三峡水库和隔河岩水库常规调度结果,论述了旱限水位的分时段控制应主要考虑水库低水位时段并综合水库入流和需水特征参数予以选取。依据这一原则,提出了开展旱限水位分期控制的计算方法。 Similar to the reservoir flood control water level, the drought control water ...
刘攀, 李立平, 吴荣飞, 李凯
semanticscholar +1 more source
测定半数致死量LD50(或半数有效量ED50)是药理学、毒理学的一项经常性重要工作。其计算方法一般认为以Bliss氏早年提出的算法最严谨、精确。但由于人工计算繁杂、费时,该法末能得到推广。本文作者用BASIC语言编制了带作图的该法计算LD50的计算程序。 计算基本步骤及框图 按本法计算LD50的过程,其基本步骤是:①从原始数据求死亡概率单位对剂量对数的回归方程(第零次逼近);②从第j次逼近的(加权)回归方程计算第(j+1)次逼近的加权回归方程;③若第(j+1)次加权回归方程不能满足精度要求 ...
肖建初
doaj
China's Eco‐Civilisation, Climate Leviathan, and Hobbesian Energy Transition
Abstract Scholars have hitherto tended to theorise China's ecological civilisation project either as a form of environmental authoritarianism or as a vision of eco‐socialism. This paper contributes to the conversation by conducting a textual analysis of Chinese scholarly discussions on eco‐civilisation.
David Chen
wiley +1 more source
Applicability and Structure Optimization of Cyclone Separator Based on Numerical Simulation [PDF]
旋风分离器是一种利用气-固两相流体的涡旋运动使固体颗粒在离心力的作用下从气流中分离出来的设备,它具有结构简单、操作维护简便、制造安装价格低等优点,被广泛应用于石油、化工、冶金等领域。由于其内部流场具有强旋流湍流特征,气流和颗粒的运动十分复杂,传统的实验方法很难深入研究其内部流场规律和分离机理,随着计算流体动力学的发展,数值仿真分析成为研究旋风分离器的主要手段。 旋风分离器的工况和结构参数会对其性能产生决定性影响。对于一个给定的旋风分离器,其工况参数包括颗粒半径、颗粒密度和入口速度 ...
吕智
core
Heart rate variability in horses with and without severe equine asthma
Abstract Background Equine asthma in severe form (severe equine asthma [sEA]) shares remarkable similarities with human asthma. Human studies detected changes in the autonomic nervous system function in asthmatic patients based on heart rate variability (HRV) analysis. Study design Observational study. Objectives To investigate the relationship between
Zsófia Nyerges‐Bohák+5 more
wiley +1 more source
Calculation of Young's Modulus and Coefficient of Linear Expansion on Several Solid Solution with Cubic Structure [PDF]
杨氏模量和线膨胀系数是表征金属材料重要的物理量。但是,目前已有的二元及多元合金固溶体的杨氏模量和线膨胀系数的实验数据十分有限。因此,利用合理的理论模型来实现对杨氏模量和线膨胀系数的计算并建立性能数据库十分重要,能够为材料设计提供必要的基础信息。本课题组在应用相图计算技术建立热力学数据库和指导合金的成分设计方面取得了不错的成效。本研究基于相图计算的研究方法,考虑温度和成分两个变量的影响,开展合金溶体相的杨氏模量和线膨胀系数的计算。其具体研究成果如下: (1)借鉴计算相图(CALPHAD)方法的研究思路 ...
林明娜
core
伪循环(QC)低密度奇偶校验(LDPC)码可以给光纤通信系统带来更高的编码增益,但译码过程需要的对数似然比(LLR)的计算很复杂。为了降低LDPC译码器硬件设计的复杂度,文章提出一种光纤信道下简化的LLR的计算方法。仿真结果表明,该计算方法与原计算方法相比仅有0.05 dB的译码性能损失。
王伟, 许渤
doaj
Abstract The formal engagement of diverse stakeholder groups in environmental policy design and implementation is increasingly common. While engaging diverse stakeholders in common fora can help address complex environmental dilemmas, insofar as different stakeholders have varying perspectives and resources to contribute, this same variance can lead to
Graham Ambrose+2 more
wiley +1 more source