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The world's major textile powers: Special advantages and a new chapter in trade
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《China Textile》 2024年第1期18-18,共1页
Several countries have become notable production powers in the global textile market due to their unique advantages and strengths.In 2023,these countries not only occupied a leading position in terms of textile produc... Several countries have become notable production powers in the global textile market due to their unique advantages and strengths.In 2023,these countries not only occupied a leading position in terms of textile production scale,but also showed their unique charm in terms of technological innovation,market layout and foreign trade strategy.By thoroughly understanding the characteristics and advantages of the textile industry in these countries,as well as their performance in foreign trade,we can better grasp the development trends and opportunities of the global textile market.We look forward to these countries continuing to play a leading role in the global textile market and writing a new brilliant chapter. 展开更多
关键词 powers thoroughly TEXTILE
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基于Powershap特征选择的电力系统暂态稳定评估
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作者 陈超 余成波 左立昕 《热力发电》 CAS CSCD 北大核心 2024年第8期143-151,共9页
为进一步提高暂态稳定评估(transient stability assessment,TSA)的精准度和可靠性,提出一种基于统计学与Shapley值结合的特征选择方法(Powershap),并建立电力系统TSA模型。首先,根据电力系统运行时的稳态分量构建输入特征集,采用Powers... 为进一步提高暂态稳定评估(transient stability assessment,TSA)的精准度和可靠性,提出一种基于统计学与Shapley值结合的特征选择方法(Powershap),并建立电力系统TSA模型。首先,根据电力系统运行时的稳态分量构建输入特征集,采用Powershap将数据集分为多个数据子集进行训练,筛选出关键特征集;其次,利用关键特征集训练多个CatBoost模型并进行TSA,生成TSA模型;最后,在新英格兰10机39节点系统和加入新能源发电的新英格兰54机118节点系统上进行仿真实验,并给出评估结果。实验得出:在新英格兰10机39节点系统中采用基于Powershap特征选择的方法进行分类,其准确率能够达到99.79%;在改进的新英格兰54机118节点系统上,其准确率能够达到99.49%,说明该方法能够有效进行电力系统暂态稳定评估,并且验证了所提TSA模型具有较好的鲁棒性与泛化能力。 展开更多
关键词 电力系统 暂态稳定评估 特征选择 powershap CatBoost
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利用PowerSATELITE进行广义无功功率测量与分析
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作者 李智勇 吴为麟 +1 位作者 汤谷浩次 户井雅则 《仪器仪表学报》 EI CAS CSCD 北大核心 2006年第z1期18-19,31,共3页
介绍了一种新型电能计测终端Power SATELITE(saving assist tool of energy loggering intelligent terminal)。在非正弦波形下利用该仪器进行广义无功功率测量,并与传统功率仪器测量值进行比较,最后总结了两者值差的一般规律。
关键词 广义无功功率 非正弦波形 power SATELITE
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基于Powersystem模块的直流调速系统仿真研究 被引量:1
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作者 马青 《光盘技术》 2009年第2期46-46,14,共2页
以控制系统的传递函数为基础,使用MATLAB Powersystem工具箱,对转速、电流双闭环直流调速系统进行了仿真,仿真结果表明采用该模块能够更接近调速控制系统实际性能指标。
关键词 直流调速系统 仿真 power System模块
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T.C.POWERS若干重要理论评述 被引量:11
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作者 慕晓 许仲梓 唐明述 《硅酸盐通报》 CAS CSCD 北大核心 1995年第1期27-31,共5页
本文就所收集到的文献对Powers部分理论进行了简要评述,以期正确认识和运用Powers理论。
关键词 powers理论 水泥石 孔结构 强度 碱-骨料反应
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基于Matlab/SimPowerSystems的电力电子研究型实验 被引量:11
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作者 余有灵 徐志宇 胡明忠 《实验技术与管理》 CAS 北大核心 2015年第11期118-120,135,共4页
利用Matlab仿真技术拓展了电力电子实验的深度和广度,为其注入更多的研究性因素。首先搭建Matlab/SimPowerSystems仿真模型加以求解,引导学生对仿真结果进行理论分析和定量推导,启发学生对非预期的实验现象进行思考和讨论,给出定性解释... 利用Matlab仿真技术拓展了电力电子实验的深度和广度,为其注入更多的研究性因素。首先搭建Matlab/SimPowerSystems仿真模型加以求解,引导学生对仿真结果进行理论分析和定量推导,启发学生对非预期的实验现象进行思考和讨论,给出定性解释。通过研究型实验的系统化训练,激发学生探索的精神、自主学习的能力、观察和研究的科研素养,教学质量显著提升。 展开更多
关键词 电力电子 Matlab/Simpowersystems 仿真 教学改革 研究型实验
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基于SimPowerSystems的电力系统仿真与潮流分析 被引量:3
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作者 陈众 文艺 陈小林 《长沙电力学院学报(自然科学版)》 2004年第3期27-30,34,共5页
叙述了用MATLAB软件中的SIMULINK以及SimPowerSystems工具箱进行简单电力系统仿真的基本过程,并利用Powergui对相应系统进行动态仿真和系统潮流分析.对位于不同节点类型处的负荷模型仿真系统进行了讨论,并给出了模型的实现方法.
关键词 电力系统 仿真 潮流分析
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ICU患者置入Power PICC导管特殊异位原因分析
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作者 莫春玲 屈盈莹 李宝琪 《岭南急诊医学杂志》 2024年第1期58-60,共3页
目的:探讨ICU患者置入Power PICC导管后头端反折向上至同侧和对侧锁骨下静脉、头臂静脉等特殊异位的相关因素。方法:回顾性分析2021年9月至2022年9月某三甲医院ICU 520例PICC置管患者,通过胸部X线确定PICC导管头端反折向上至对侧和同侧... 目的:探讨ICU患者置入Power PICC导管后头端反折向上至同侧和对侧锁骨下静脉、头臂静脉等特殊异位的相关因素。方法:回顾性分析2021年9月至2022年9月某三甲医院ICU 520例PICC置管患者,通过胸部X线确定PICC导管头端反折向上至对侧和同侧锁骨下静脉、头臂静脉的患者,分析其特殊异位发生因素。结果:胸部X线结果显示25例患者PICC管头端反折向上异位至对侧和同侧锁骨下静脉、头臂静脉或颈内静脉,异位发生率4.8%,不同静脉置管反折异位发生率相比差异无统计学意义,P>0.05。结论:ICU患者PICC置入发生导管头端反折向上至同侧和对侧锁骨下静脉、头臂静脉等特殊异位的发生因素较多,包括同时留置CVC或血透管、正在滴注或泵入多种药物、PICC管头端异位的隐匿性、导管材质、自身疾病及机械通气等危险因素。 展开更多
关键词 ICU患者 power PICC 异位 原因分析
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基于SimPowerSystems的电力系统仿真实践教学研究 被引量:3
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作者 高红亮 张先鹤 詹习生 《湖北师范学院学报(自然科学版)》 2014年第1期87-90,共4页
对电力系统仿真实践教学进行了研究,重点对基于SimPowerSystems工具的电力系统仿真过程进行了详细论述,首先介绍了电力系统仿真各部件模型,接着详细论述了基于SimPowerSystems的电力系统仿真模型建立过程,包括具体步骤和相关指标,最后... 对电力系统仿真实践教学进行了研究,重点对基于SimPowerSystems工具的电力系统仿真过程进行了详细论述,首先介绍了电力系统仿真各部件模型,接着详细论述了基于SimPowerSystems的电力系统仿真模型建立过程,包括具体步骤和相关指标,最后通过某地区实际电力系统仿真模型的建立和运行分析,说明通过SimPowerSystems进行电力系统仿真实践教学和研究是十分有效的途径. 展开更多
关键词 Simpowersystems 电力系统 SIMULINK 实践教学
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Approach to the Geopolitical Influences of Great Powers in Southeast Asia: Case Studies of China and the US 被引量:3
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作者 QIN Qi CHENG Shengkui +3 位作者 LI Fei ZHANG Shuwen WU Liang ZHANG Dan 《Chinese Geographical Science》 SCIE CSCD 2019年第2期341-351,共11页
A quantitative approach to the national geopolitical influence is helpful to provide a reference for national sustainable development on the international stage, based on describing national diplomatic capacity and ov... A quantitative approach to the national geopolitical influence is helpful to provide a reference for national sustainable development on the international stage, based on describing national diplomatic capacity and overseas influence. Herein, this study proposes a complex geopolitical influence model, considering the affected nations' response. The geopolitical influences of great power in the affected nation are correlated with overall strength, the acceptance degree of the affected nation to the great power and the distance between both sides. Then, the geopolitical influences of China and the US in Southeast Asia countries are empirically analyzed from 2005 to 2015. The geopolitical influence of China in Southeast Asia has been largely growing for the past decades, accompanying with a constant trend of the US' effects. It is believed that China and the US can coexist peacefully in Southeast Asia to promote the regional development, and jointly create an open, inclusive and balanced regional cooperation architecture that benefits all nations in this region and great powers, through mutual political trust and economic beneficial cooperation. This study may contribute to advancing the policy debate and determining the optimal cooperation in pledging commitment to a new and sustainable model of great power relationship among the various regional geopolitical options. 展开更多
关键词 geopolitical influence GREAT power SOUTHEAST ASIA China the US
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Influences of laser powers on microstructure and properties of the coatings on the AZ91HP magnesium alloy 被引量:2
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作者 Yali GAO Dangsheng XIONG +1 位作者 Cunshan WANG Yongzhe CHEN 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2009年第3期167-173,共7页
Al-Si alloy coatings were prepared on AZ91HP magnesium alloy by broad-beam laser cladding; the influences of the powers on the microstructure and properties of the coatings were discussed. It was found that the micros... Al-Si alloy coatings were prepared on AZ91HP magnesium alloy by broad-beam laser cladding; the influences of the powers on the microstructure and properties of the coatings were discussed. It was found that the microstructure of the coatings at the powers of 3 and 3.5 kW was characterized by Mg2Si dendrites, and needle-like Mg2Al3 (hcp) dispersing in the Mg17Al12 matrix, whereas the coating at the power of 2.5 kW was composed of the petal-like Mg2Al3 (fcc) as well as the needle-like Mg2Al3 (hcp). The coating at the power of 4 kW appeared as α-Mg solid solution and Mg2Si, Mg17Al12, as well as Mg2Al3 (hcp). The coatings with the powers of 3 and 3.5 kW exhibited higher microhardness and better wear resistance because of more Mg2Si and Mg17Al12. However, the coating at the power of 2.5 kW displayed better corrosion resistance. 展开更多
关键词 Magnesium alloy Al-Si alloy Laser cladding Laser power
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Study on the measureto improve the arcstabilization in smaller current welding for the variable polarity GTAW powersource 被引量:2
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作者 张广军 耿正 +1 位作者 吴林 殷树言 《China Welding》 EI CAS 2000年第1期78-82,共5页
The variable polarity power source which incorporates a constant current power and a secondary inverter does not need special apparatus for stabilizing arc. The pulse for stabilizing arc is created by the circuit stru... The variable polarity power source which incorporates a constant current power and a secondary inverter does not need special apparatus for stabilizing arc. The pulse for stabilizing arc is created by the circuit structure itself. The paper analyzes the principle of acquiring the pulse, provides the better method to improve the arc stabilization under smaller welding current. Test shows the arc is highly stable , and the process has no high frequency electromagnetic interference, which is suitable for automatic welding case. 展开更多
关键词 variable polarity power source stabilizing arc aluminum GTAW
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Development of high frequency pulse power source using two powersfor TIG welding 被引量:1
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作者 张广军 耿正 +1 位作者 吴林 梁群 《China Welding》 EI CAS 1999年第2期38-42,共5页
A high frequency pulse power source for TIG welding is developed. The structure of two powers is adopted. The by pass circuit effectively eliminates the effect of the cable equivalent inductance. The maximum frequenc... A high frequency pulse power source for TIG welding is developed. The structure of two powers is adopted. The by pass circuit effectively eliminates the effect of the cable equivalent inductance. The maximum frequency of the output pulse current reaches to 16 kHz . The base current and the peak current can be regulated separately. 展开更多
关键词 high frequency pulse TIG welding arc welding power source
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One Additive Diophantine Inequality with Mixed Powers 2 and 4 被引量:2
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作者 龚克 李伟平 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第1期1-7,共7页
In this paper, it is shown that: if λ1 ,……λs axe nonzero real numbers, not all of the same sign, such that A1/A2 is irrational, then for any real number η and ε 〉 0 the inequality |λ1x1^2 + λ2x2^2+ λ3x3^... In this paper, it is shown that: if λ1 ,……λs axe nonzero real numbers, not all of the same sign, such that A1/A2 is irrational, then for any real number η and ε 〉 0 the inequality |λ1x1^2 + λ2x2^2+ λ3x3^4+ λsx3^4+……λsx8^4 +η〈 ε has infinitely many solutions in positive integers x1,... ,xs. 展开更多
关键词 Diophantine inequality mixed powers circle method
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The Powers Sums, Bernoulli Numbers, Bernoulli Polynomials Rethinked 被引量:1
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作者 Do Tan Si 《Applied Mathematics》 2019年第3期100-112,共13页
Utilizing translation operators we get the powers sums on arithmetic progressions and the Bernoulli polynomials of order munder the form of differential operators acting on monomials. It follows that (d/dn-d/dz) appli... Utilizing translation operators we get the powers sums on arithmetic progressions and the Bernoulli polynomials of order munder the form of differential operators acting on monomials. It follows that (d/dn-d/dz) applied on a power sum has a meaning and is exactly equal to the Bernoulli polynomial of the same order. From this new property we get the formula giving powers sums in term of sums of successive derivatives of Bernoulli polynomial multiplied withprimitives of the same order of n. Then by changing the two arguments z,n into Z=z(z-1), λ where λ designed the 1st order power sums and proving that Bernoulli polynomials of odd order vanish for arguments equal to 0, 1/2, 1, we obtain easily the Faulhaber formula for powers sums in term of polynomials in λ having coefficients depending on Z. These coefficients are found to be derivatives of odd powers sums on integers expressed in Z. By the way we obtain the link between Faulhaber formulae for powers sums on integers and on arithmetic progressions. To complete the work we propose tables for calculating in easiest manners possibly the Bernoulli numbers, the Bernoulli polynomials, the powers sums and the Faulhaber formula for powers sums. 展开更多
关键词 BERNOULLI Numbers BERNOULLI POLYNOMIALS powers SUMS Faulhaber CONJECTURE Shift OPERATOR OPERATOR Calculus
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Incidence Colorings of Powers of Circuits 被引量:1
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作者 LI De-ming LIU Ming-ju 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第2期159-167,共9页
The incidence chromatic number of G is the least number of colors such that G has an incidence coloring. It is proved that the incidence chromatic number of Cn^p, the p-th power of the circuit graph, is 2p + 1 if and... The incidence chromatic number of G is the least number of colors such that G has an incidence coloring. It is proved that the incidence chromatic number of Cn^p, the p-th power of the circuit graph, is 2p + 1 if and only if n = k(2p + 1), for other cases: its incidence chromatic number is at most 2p + [r/k] + 2, where n = k(p + 1) + r, k is a positive integer. This upper bound is tight for some cases. 展开更多
关键词 incidence coloring circuit powers PARTITION
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基于Simulink/Powersys的含二极管电路仿真研究
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作者 蒋保臣 郑亚民 《青岛建筑工程学院学报》 2004年第2期97-99,共3页
以含有二极管的整流滤波电路为例建立了 simulink模型和 powersys模型并进行了仿真 ,得出了正确的仿真结果 。
关键词 simulink 电力系统模块库 电路 二极管
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Power-V诱导的钻柱黏滑振动特征分析
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作者 王文昌 段浩宇 +2 位作者 李宁 王孝亮 狄勤丰 《上海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期299-307,共9页
黏滑是石油钻井过程中影响钻井效率和井下钻柱安全的一种振动形式.垂直钻井系统Power-V在提供有效控斜力的同时,还会诱导钻柱黏滑振动.通过研究垂直钻井系统Power-V与井壁的接触作用及钻头与地层的相互作用模型,基于钻柱动力学有限元方... 黏滑是石油钻井过程中影响钻井效率和井下钻柱安全的一种振动形式.垂直钻井系统Power-V在提供有效控斜力的同时,还会诱导钻柱黏滑振动.通过研究垂直钻井系统Power-V与井壁的接触作用及钻头与地层的相互作用模型,基于钻柱动力学有限元方法,深入分析Power-V的作用机理,研究其对扭转振动的影响,指出Power-V和井壁间的相互作用会导致钻柱与井壁的摩阻显著增加,进而引起摩阻扭矩的增大,诱导井下黏滑振动.实测振动数据证实,Power-V与井壁间的相互作用是引起钻柱黏滑振动的关键因素.这对于揭示黏滑振动的成因和更好地发挥Power-V的作用具有重要意义. 展开更多
关键词 黏滑振动 钻柱动力学 振动信号测量 power-V
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基于调和概率语言术语集的Power平均算子
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作者 辛树琦 王兴 郑小建 《福建师范大学学报(自然科学版)》 CAS 北大核心 2024年第2期1-13,共13页
实践发现现存概率语言Power平均算子在应用中存在概率信息丢失、计算过于繁琐等问题,针对这些问题,提出一种基于调和概率语言术语集的Power平均算子。结合新的基本运算法则与新的支撑度,给出新的概率语言Power平均算子、概率语言Power... 实践发现现存概率语言Power平均算子在应用中存在概率信息丢失、计算过于繁琐等问题,针对这些问题,提出一种基于调和概率语言术语集的Power平均算子。结合新的基本运算法则与新的支撑度,给出新的概率语言Power平均算子、概率语言Power几何平均算子、概率语言Power加权平均算子、概率语言Power加权几何平均算子,同时论证分析了这几类新型算子的性质。最后通过实验数据,将提出的算子与现存算子进行对比分析,验证了所提算子的有效性与可行性。 展开更多
关键词 概率语言术语集 概率语言power平均算子 决策
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Reflected and transmitted powers of arbitrarily polarized plane waves at interface between chiral and achiral media
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作者 Yan-Feng Lu Yi-Ping Han 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第2期215-222,共8页
A study has been made on the reflected and transmitted powers generated when an arbitrarily polarized plane wave impinges at a planar interface separating an isotropic achiral medium(IAM) and an isotropic chiral mediu... A study has been made on the reflected and transmitted powers generated when an arbitrarily polarized plane wave impinges at a planar interface separating an isotropic achiral medium(IAM) and an isotropic chiral medium(ICM). It follows that the theoretical formulas are derived for the normalized reflection and transmission powers from an IAM–ICM interface for an arbitrary polarized incident wave, and those at an ICM–IAM interface for right-hand circularly polarized(RCP) or left-hand circularly polarized(LCP) incident wave are also obtained. The behavior of the reflected and transmitted waves in different cases is studied, and the dependence of the reflection/transmission of the incident wave on the incident angle and the parameters of the media is investigated in detail. Our numerical results show that high transmission is exhibited under the impedance matching condition and the incident wave can be split into two waves of the same circular polarization state in the case of the ICM–IAM interface, which indicates that circular polarizing beam splitter is achieved. 展开更多
关键词 CHIRAL media REFLECTION power transmission power FRESNEL COEFFICIENT
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