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The weak form market efficiency investigation of American, European and Asian stock markets
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作者 Nuray Ergul 《Chinese Business Review》 2010年第10期1-11,共11页
This paper investigates the empirical validity of the Weak Form Efficient Market Hypothesis for American, European and Asian stock markets. Random Walk Hypothesis is used to prove weak form efficiency in American, Eur... This paper investigates the empirical validity of the Weak Form Efficient Market Hypothesis for American, European and Asian stock markets. Random Walk Hypothesis is used to prove weak form efficiency in American, European and Asian stock indices. ADF and PP Unit Root Tests have been used to test unit root in time series of daily data of American, European and Asian stock indices. Results show that sample of stock markets are weak-form efficient in terms of the Random Walk Hypothesis. 展开更多
关键词 weak form efficiency Random Walk Hypothesis unit root tests
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Prediction of efficient outputs based on GM(1,N) model and weak DEA efficiency 被引量:2
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作者 Jiefang Wang Sifeng Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第6期933-939,共7页
This paper expresses the efficient outputs of decisionmaking unit(DMU) as the sum of "average outputs" forecasted by a GM(1,N) model and "increased outputs" which reflect the difficulty to realize efficient ou... This paper expresses the efficient outputs of decisionmaking unit(DMU) as the sum of "average outputs" forecasted by a GM(1,N) model and "increased outputs" which reflect the difficulty to realize efficient outputs.The increased outputs are solved by linear programming using data envelopment analysis efficiency theories,wherein a new sample is introduced whose inputs are equal to the budget in the issue No.n + 1 and outputs are forecasted by the GM(1,N) model.The shortcoming in the existing methods that the forecasted efficient outputs may be less than the possible actual outputs according to developing trends of input-output rate in the periods of pre-n is overcome.The new prediction method provides decision-makers with more decisionmaking information,and the initial conditions are easy to be given. 展开更多
关键词 efficient outputs GM(1 N) model data envelopment analysis(DEA) weak DEA efficiency prediction.
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High-efficiency forming processes for complex thin-walled titanium alloys components: state-of-the-art and perspectives 被引量:16
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作者 Kehuan Wang Liliang Wang +4 位作者 Kailun Zheng Zhubin He Denis J Politis Gang Liu Shijian Yuan 《International Journal of Extreme Manufacturing》 2020年第3期17-40,共24页
Complex thin-walled titanium alloy components play a key role in the aircraft,aerospace and marine industries,offering the advantages of reduced weight and increased thermal resistance.The geometrical complexity,dimen... Complex thin-walled titanium alloy components play a key role in the aircraft,aerospace and marine industries,offering the advantages of reduced weight and increased thermal resistance.The geometrical complexity,dimensional accuracy and in-service properties are essential to fulfill the high-performance standards required in new transportation systems,which brings new challenges to titanium alloy forming technologies.Traditional forming processes,such as superplastic forming or hot pressing,cannot meet all demands of modern applications due to their limited properties,low productivity and high cost.This has encouraged industry and research groups to develop novel high-efficiency forming processes.Hot gas pressure forming and hot stamping-quenching technologies have been developed for the manufacture of tubular and panel components,and are believed to be the cut-edge processes guaranteeing dimensional accuracy,microstructure and mechanical properties.This article intends to provide a critical review of high-efficiency titanium alloy forming processes,concentrating on latest investigations of controlling dimensional accuracy,microstructure and properties.The advantages and limitations of individual forming process are comprehensively analyzed,through which,future research trends of high-efficiency forming are identified including trends in process integration,processing window design,full cycle and multi-objective optimization.This review aims to provide a guide for researchers and process designers on the manufacture of thin-walled titanium alloy components whilst achieving high dimensional accuracy and satisfying performance properties with high efficiency and low cost. 展开更多
关键词 titanium alloys complex thin-walled components high efficiency hot gas pressure forming hot stamping-quenching
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IoT-enabled energy efficiency monitoring and analysis method for energy saving in sheet metal forming workshop 被引量:2
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作者 GAN Lei HUANG Hai-hong +2 位作者 LI Lei XIONG Wei LIU Zhi-feng 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第1期239-258,共20页
Sheet metal forming,as a typical energy-intensive process,consumes massive energy.Due to the significant difference between sheet metal forming and machining,manufacturers still lack an effective method to monitor and... Sheet metal forming,as a typical energy-intensive process,consumes massive energy.Due to the significant difference between sheet metal forming and machining,manufacturers still lack an effective method to monitor and analyze the energy efficiency in the sheet metal forming workshop.To this end,an energy efficiency monitoring and analysis(EEMA)method,which is supported by Internet of Things(IoT),is proposed.The characteristics in a forming workshop are first analyzed,and then the architecture of the method is expatiated-detailedly.Energy efficiency indicators at machine level,process level,and workshop level are defined,respectively.Finally,a sheet metal forming workshop for the deformation of panels of forklift was investigated to validate the effectiveness and benefits of the proposed method.With the application of the IoT-enabled method,various energy-saving decisions can be made by the management of the enterprises for energy efficiency improvement and energy consumption reduction(EEIECR)in the sheet metal forming workshop. 展开更多
关键词 sheet metal forming workshop energy efficiency monitoring Internet of Things(IoT)
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Responses of Phosphorus Use Efficiency, Grain Yield, and Quality to Phosphorus Application Amount of Weak-Gluten Wheat 被引量:19
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作者 ZHU Xin-kai LI Chun-yan JIANG Zong-qing HUANG Lian-lian FENG Chao-nian GUO Wen-shan PENG Yong-xin 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第7期1103-1110,共8页
Phosphorus (P) is one of the most widely occurring nutrients for development and growth of wheat. In this study, the effects of P application amount on grain yield, protein content, and phosphorus use efficiency (... Phosphorus (P) is one of the most widely occurring nutrients for development and growth of wheat. In this study, the effects of P application amount on grain yield, protein content, and phosphorus use efficiency (PUE) were studied by agronomic management of P fertilizer on spring weak-gluten wheat (Triticum aestivum L.) grown under field conditions for 2 yr. The experiments were performed at five levels of P205 application amount, including 0, 72, 108, 144, and 180 kg ha-1. As a result, with increase in P fertilizer, grain yield, and P agricultural efficiency (AEp) increased in a quadratic equitation, but partial factor productivity of P (PFPp) decreased in a logarithmic eq. When 108 kg ha-1 P2Os was applied, the grain yield reached the highest level, but the protein content in gain was lower than 11.5%, a threshold for the protein content to evaluate weak-gluten wheat suitable for production of cake and biscuit. Yangmai 13 and Ningmai 9 could tolerate to higher P level of soils than Yangmai 9 that had more loss in grain yield when P fertilizer was over-applied. AEp had a concomitant relationship with grain yield and was a better descriptor for P use efficiency in the wheat. A high P use efficiency resulted in leaf area index (LAI), increased chlorophyll content and photosynthetic rate, and stable acid phophatase (APase) activity to accumulate more dry matter after anthesis, which explained that the optimum P fertilizer increased grain yield and improved grain quality of weak-gluten wheat. 展开更多
关键词 phosphorus fertilizer phosphorus use efficiency grain yield and quality weak-gluten wheat
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MAJOR-EFFICIENT SOLUTIONS AND WEAKLY MAJOR-EFFICIENT SOLUTIONS OF MULTIOBJECTIVE PROGRAMMING 被引量:12
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作者 HU YUDA(Dept.of Appl.Math.,Shanghai Jiao Tony Univ.,Shanghai 200030) 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1994年第1期85-94,共10页
In this papert the theory of major efficiency for multiobjective programmingis established.The major-efficient solutions and weakly major-efficient solutions of multiobjective programming given here are Pareto efficie... In this papert the theory of major efficiency for multiobjective programmingis established.The major-efficient solutions and weakly major-efficient solutions of multiobjective programming given here are Pareto efficient solutions of the same multiobjectiveprogramming problem, but the converse is not true. In a ceratin sense , these solutionsare in fact better than any other Pareto efficient solutions. Some basic theorems whichcharacterize major-efficient solutions and weakly major-efficient solutions of multiobjective programming are stated and proved. Furthermore,the existence and some geometricproperties of these solutions are studied. 展开更多
关键词 Multiobjective Programming Pareto efficient Solution Major-efficientSolution weakly Major-efficient Solution.
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Weak WT_2-class of differential forms and weakly A-harmonic tensors 被引量:3
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作者 GAO Hong-ya WANG Yan-yan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2010年第3期359-366,共8页
In this paper, we give the definition of weak WT2-class of differential forms, and then obtain its weak reverse Holder inequality. As an application, we give an alternative proof of the higher integrability result of ... In this paper, we give the definition of weak WT2-class of differential forms, and then obtain its weak reverse Holder inequality. As an application, we give an alternative proof of the higher integrability result of weakly A-harmonic tensors due to B. Stroffolini. 展开更多
关键词 weak WT2-class of differential forms weak reverse HSlder inequality weakly A-harmonic tensor higher integrability.
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Form invariance and conserved quantity for weakly nonholonomic system 被引量:2
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作者 吴惠彬 梅凤翔 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第10期1293-1300,共8页
The form invariance and the conserved quantity for a weakly nonholonomic system (WNS) are studied. The WNS is a nonholonomic system (NS) whose constraint equations contain a small parameter. The differential equat... The form invariance and the conserved quantity for a weakly nonholonomic system (WNS) are studied. The WNS is a nonholonomic system (NS) whose constraint equations contain a small parameter. The differential equations of motion of the system are established. The definition and the criterion of form invariance of the system are given. The conserved quantity deduced from the form invariance is obtained. Finally, an illustrative example is shown. 展开更多
关键词 weakly nonholonomic system (WNS) form invariance conserved quantity
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Form invariance and approximate conserved quantity of Appell equations for a weakly nonholonomic system 被引量:1
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作者 贾利群 张美玲 +1 位作者 王肖肖 韩月林 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第7期32-36,共5页
A weakly nonholonomic system is a nonholonomic system whose constraint equations contain a small parameter. The form invariance and the approximate conserved quantity of the Appell equations for a weakly nonholonomic ... A weakly nonholonomic system is a nonholonomic system whose constraint equations contain a small parameter. The form invariance and the approximate conserved quantity of the Appell equations for a weakly nonholonomic system are studied. The Appell equations for the weakly nonholonomic system are established, and the definition and the criterion of form invariance of the system are given. The structural equation of form invariance for the weakly nonholonomic system and the approximate conserved quantity deduced from the form invariance of the system are obtained. Finally, an example is given to illustrate the application of the results. 展开更多
关键词 weakly nonholonomic system Appell equations form invariance approximate conservedquantity
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Strong/weak limits and strong/weak differentials of multi-variable indeterminate forms. I: Deduction and geometric illustration
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作者 宋光世 《Journal of Chongqing University》 CAS 2003年第2期104-108,共5页
Strong and weak limits as well as strong and weak differentials of multi-variable indeterminate forms are discussed based on the thorough exploration of differentiation to solve the strong and weak limits and differen... Strong and weak limits as well as strong and weak differentials of multi-variable indeterminate forms are discussed based on the thorough exploration of differentiation to solve the strong and weak limits and differentials of unitary indeterminate forms. The fruit of this work is going to be reported in three parts. The first part presents the standard analysis on this subject which supplements, systematizes and advances L. Hospital抯 principles on differential calculus by applying special ,general, and limit guaranteeing theories together with K(t) and XhK0 theories. The combination of theoretical analysis and geometric signification makes the derivation intuitional, visual and easy to perceive. 展开更多
关键词 strong limit weak limit strong differential weak differential indeterminate form multi-variable special form general form
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A LEAST SQUARE BASED WEAK GALERKIN FINITE ELEMENT METHOD FOR SECOND ORDER ELLIPTIC EQUATIONS IN NON-DIVERGENCE FORM
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作者 Peng ZHU Xiaoshen WANG 《Acta Mathematica Scientia》 SCIE CSCD 2020年第5期1553-1562,共10页
This article is devoted to establishing a least square based weak Galerkin method for second order elliptic equations in non-divergence form using a discrete weak Hessian operator.Naturally,the resulting linear system... This article is devoted to establishing a least square based weak Galerkin method for second order elliptic equations in non-divergence form using a discrete weak Hessian operator.Naturally,the resulting linear system is symmetric and positive definite,and thus the algorithm is easy to implement and analyze.Convergence analysis in the H2 equivalent norm is established on an arbitrary shape regular polygonal mesh.A superconvergence result is proved when the coefficient matrix is constant or piecewise constant.Numerical examples are performed which not only verify the theoretical results but also reveal some unexpected superconvergence phenomena. 展开更多
关键词 least square based weak Galerkin method non-divergence form weak Hessian operator polygonal mesh
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Flexural and eigen-buckling analysis of steel-concrete partially composite plates using weak form quadrature element method
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作者 XIA Jun SHEN Zhi-qiang +1 位作者 LIU Kun SUN Cheng-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第11期3087-3102,共16页
Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrat... Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrature element method(QEM).Both of the derivatives and integrals in the variational description of a problem to be solved are directly evaluated by the aid of identical numerical interpolation points in the weak form QEM.The effectiveness of the presented numerical model is validated by comparing numerical results of the weak form QEM with those from FEM or analytic solution.It can be observed that only one quadrature element is fully competent for flexural and eigen-buckling analysis of a rectangular partially composite plate with shear connection stiffness commonly used.The numerical integration order of quadrature element can be adjusted neatly to meet the convergence requirement.The quadrature element model presented here is an effective and promising tool for further analysis of steel-concrete PCPs under more general circumstances.Parametric studies on the shear connection stiffness and length-width ratio of the plate are also presented.It is shown that the flexural deflections and the critical buckling loads of PCPs are significantly affected by the shear connection stiffness when its value is within a certain range. 展开更多
关键词 weak form quadrature element method partially composite plates interlayer slip flexural analysis eigen-buckling analysis
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Planar Weak Form Quadrature Beam Elements Based on Absolute Nodal Coordinate Formulation: A Structural Mechanics Approach
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作者 Huayi Li Hongzhi Zhong 《Journal of Applied Mathematics and Physics》 2022年第11期3475-3484,共10页
A planar nonlinear weak form quadrature beam element of arbitrary number of axial nodes is proposed on the basis of the absolute nodal coordinate formulation (ANCF). Elastic forces of the element are established throu... A planar nonlinear weak form quadrature beam element of arbitrary number of axial nodes is proposed on the basis of the absolute nodal coordinate formulation (ANCF). Elastic forces of the element are established through geometrically exact beam theory, resulting in good consistency with classical beam theory. Two examples with strong geometrical nonlinearity are presented to verify the effec-tiveness of the formulation. 展开更多
关键词 Absolute Nodal Coordinate formulation weak form Quadrature Element Geometrically Nonlinear Analysis
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THE WILD SOLUTIONS OF THE INDUCED FORM UNDER THE SPLINE WAVELET BASIS IN WEAKLY DAMPED FORCED KdV EQUATION
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作者 林玉蕊 田立新 刘曾荣 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第12期0-0,0-0+0-0,共6页
关键词 THE WILD SOLUTIONS OF THE INDUCED form UNDER THE SPLINE WAVELET BASIS IN weakLY DAMPED FORCED KdV EQUATION
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Is the“Weak Form”of CLT Being Adoptedin China ?
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作者 Zhu Xiaoyan 《山东师范大学外国语学院学报(基础英语教育)》 2005年第4期28-33,共6页
This paper, based on the hi sto rical background of CLT(communicative language teaching), mainly addresses the k ey issues concerning the weak form of CLT. This is an area few people have paid attention to in the past... This paper, based on the hi sto rical background of CLT(communicative language teaching), mainly addresses the k ey issues concerning the weak form of CLT. This is an area few people have paid attention to in the past few years in China. Therefore, its main concepts and f e atures are discussed with relevance to literature and an empirical study on four novice teachers of English. Finally, the research shows that the weak form of CLT is being conducted in Chinese secondary schools. 展开更多
关键词 CLT 计算机语言翻译程序 中国 中学 英语教学
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地铁入口空间布局对室内空气质量的影响研究 被引量:1
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作者 王薇 张蕾 +1 位作者 夏斯涵 代萌萌 《地下空间与工程学报》 CSCD 北大核心 2024年第2期677-689,共13页
城市地铁地处繁华地区,结构封闭,周边环境污染源较多,室内易积累污染物。本研究重点关注地铁口空间布局对室外颗粒物进入的影响,在调研中选取地铁站入口方向、顶棚形态、入口高宽比3个形态指标作为影响因子,经过实测验证CFD模型的可行性... 城市地铁地处繁华地区,结构封闭,周边环境污染源较多,室内易积累污染物。本研究重点关注地铁口空间布局对室外颗粒物进入的影响,在调研中选取地铁站入口方向、顶棚形态、入口高宽比3个形态指标作为影响因子,经过实测验证CFD模型的可行性后,选择RNG k-ε模型模拟不同风速下各地铁口形态的室内污染情况。结果表明:(1)侧向比正向入口颗粒拦截率高一倍;(2)入口高宽比小于1∶1时入口宽度越大,地铁站整体空气质量越好;(3)顶棚形态对室内颗粒物的消减排列为:斜顶>平顶>无顶;(4)地铁口空间形态对不同直径的颗粒拦截效果不同。形态设计可以改善站内颗粒物进入情况,通过空气对流、回流减少室外污染物的直接灌入。 展开更多
关键词 地铁站 地下污染物 空间形态 优化策略 拦截率
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广义弱形式自由单元法
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作者 高效伟 刘华雩 +4 位作者 崔苗 杨恺 吕军 彭海峰 阮波 《力学学报》 EI CAS CSCD 北大核心 2024年第9期2741-2751,共11页
自由单元法(FrEM)是一种单元配点法,吸收了有限元法等参单元的插值稳定性与无网格法使用灵活的优点,具有稳定性好和灵活性高的性能.FrEM在每个配置点只需要一个通过自由选择周围节点而形成的独立的等参单元,不需要考虑单元之间节点的相... 自由单元法(FrEM)是一种单元配点法,吸收了有限元法等参单元的插值稳定性与无网格法使用灵活的优点,具有稳定性好和灵活性高的性能.FrEM在每个配置点只需要一个通过自由选择周围节点而形成的独立的等参单元,不需要考虑单元之间节点的相互连接关系,这种自由性使得人们可以按照学科性质形成所需要的单元,因而FrEM既适用于固体力学,也适用于流体力学问题的求解.然而,FrEM所用单元需要至少有一个内部节点(用于方程的配点),以致有限元法中单元节点相连的网格不能在FrEM中直接使用.文章基于对应于配置点的等参单元形函数在与其不相连的边界上为0的特性和配置点等效节点力平衡关系,提出了一种广义弱形式自由单元法(GFrEM).该方法是一种使用单元逐点建立配置方程的单元配点法,具有如下特点:(1)突破了现有自由单元法中单元需要内部节点的限制,因而可以使用线性单元和高阶单元;(2)突破了现有自由单元法中一个配置点使用一个单元的限制,可以使用与配置点相连的任意多个单元;(3)可以使用任意形式的规则单元和多边形/多面体单元;(4)如果使用单元节点相连的传统有限元法网格,则GFrEM自然演变为传统的有限元法.论文将给出几个固体力学方面的应用算例,展示所提方法的有效性. 展开更多
关键词 广义自由单元法 弱形式 配点法 无网格法 有限元法
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弱光下锑基太阳电池的光谱响应与性能优化
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作者 曹宇 凌同 +6 位作者 曲鹏 王长刚 赵耀 那艳玲 江崇旭 胡子阳 周静 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第2期519-526,共8页
锑基薄膜太阳电池因其制备方法简单,原材料丰富,光电性能稳定等优点而得到了快速发展。其中锑基吸光层材料(硫化锑、硫硒化锑、硒化锑)具有高吸收系数特点,因而在室内或者水下等弱光条件下具有相当大的应用潜力。通过构造两种衰减光谱... 锑基薄膜太阳电池因其制备方法简单,原材料丰富,光电性能稳定等优点而得到了快速发展。其中锑基吸光层材料(硫化锑、硫硒化锑、硒化锑)具有高吸收系数特点,因而在室内或者水下等弱光条件下具有相当大的应用潜力。通过构造两种衰减光谱以研究新型锑基薄膜太阳电池在弱光下的光电响应。首先通过厚度调节硒化锑太阳电池的吸光能力,发现当吸光层厚度较薄时,电池的光电转换效率存在较大差值;而当吸光层厚度过厚时,电池性能又因载流子复合的增大而降低。在吸光层厚度处于合适的0.4~1.2μm之间时,硒化锑太阳电池在长波衰减光谱和短波衰减光谱下都能获得高于16%的转换效率。然后通过硒含量调节锑基太阳电池的光谱吸收范围,发现长波衰减光谱下,锑基太阳电池的器件性能显著高于标准光谱,并且在20%~40%硒含量下能够获得最佳的转换效率。而在短波衰减光谱下,锑基太阳电池的最佳性能出现在硒含量为60%的情况下。因而在弱光条件下,锑基太阳电池的最佳硒含量需要通过具体的光谱特性确定。最后研究了两种衰减光谱下,硫化锑/硒化锑双结叠层太阳电池的光谱响应特性。发现在短波衰减光谱下,叠层太阳电池效率会随着总厚度的增加而增加。而在长波衰减光谱下,叠层太阳电池的最佳性能能够一直保持在较高水平。当叠层电池总厚度为2μm,且硫化锑顶电池厚度在0.5~1.2μm之间时,器件在两种衰减光谱下都能够实现光谱能量在两个子电池中的合理分配,使得叠层电池效率能够保持在20%以上。通过该研究对锑基太阳电池器件结构的合理设计,能够保证单结和双结器件在不同弱光条件下的高性能输出,为高环境适应性的锑基薄膜太阳电池的研发提供技术支持。 展开更多
关键词 锑基薄膜太阳电池 衰减光谱 弱光响应 吸光层厚度 转换效率
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河南矿区高灰细泥煤泥水的絮凝沉降试验研究
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作者 鲁忠良 王擘昊 +3 位作者 于跃先 史长亮 何俊 王婕 《河南理工大学学报(自然科学版)》 CAS 北大核心 2024年第1期35-41,共7页
目的随着采煤机械化程度的提高和重介质选煤工艺普及,入选浮煤泥中高灰细泥的含量逐渐增加。高灰细泥是影响煤泥水沉降效率的最直接因素,对煤泥水中的高灰细泥进行处理,直接关系着煤炭资源生产和水资源利用。针对河南矿区煤泥水具有高... 目的随着采煤机械化程度的提高和重介质选煤工艺普及,入选浮煤泥中高灰细泥的含量逐渐增加。高灰细泥是影响煤泥水沉降效率的最直接因素,对煤泥水中的高灰细泥进行处理,直接关系着煤炭资源生产和水资源利用。针对河南矿区煤泥水具有高灰细泥的特性,方法通过设计正交试验测试不同种类的絮凝剂和搅拌速度对煤泥水的沉降率的影响及其之间的相互作用的效果,提高煤泥水沉降效率。结果结果表明:六偏磷酸钠与聚丙烯酰胺的分散性能及絮凝性能更优,搅拌速度、六偏磷酸钠用量、聚丙烯酰胺用量对高灰细泥煤泥水沉降率的影响程度依次减小,搅拌速度和聚丙烯酰胺用量之间的相互关系对沉降率影响最为显著;当六偏磷酸钠用量40.08 mg/L、聚丙烯酰胺用量5.75 mg/L、搅拌速度411.12 r/min,沉降率可达95.5%,沉降率提高的原因在于高灰细泥絮凝过程中絮团成球明显,絮凝剂的桥接作用可以使分散颗粒聚团并发展为球形,长条不规则颗粒明显减少,颗粒群粒形的改变有助于煤泥水的沉降,在一定搅拌速度下粒形保持较为规整,可增加沉降概率,使煤泥水得以有效沉降。结论通过改善煤泥水中颗粒的粒度粒形特性,可以有效提高河南矿区高灰细泥煤泥水的沉降效率。研究结果可为处理高灰细泥煤泥水提供理论支持和实践参考。 展开更多
关键词 河南矿区 煤泥水 高灰细泥 沉降率 粒形
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医用X射线防护材料的研究进展
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作者 李伟 魏乐倩 +4 位作者 王泽宇 王莎莎 毛吉富 王富军 王璐 《产业用纺织品》 2024年第6期11-18,31,共9页
介绍了医用X射线与生物系统的相互作用机理及物理防护原理,分析了具有医用X射线屏蔽能力的柔性复合材料的研究进展。探讨了铅、铋、钨等防X射线功能颗粒及聚合物基材的性能特征,总结了涂层法、溶胶-凝胶法、纺丝法等成型方法的优缺点。... 介绍了医用X射线与生物系统的相互作用机理及物理防护原理,分析了具有医用X射线屏蔽能力的柔性复合材料的研究进展。探讨了铅、铋、钨等防X射线功能颗粒及聚合物基材的性能特征,总结了涂层法、溶胶-凝胶法、纺丝法等成型方法的优缺点。研究表明,现有X射线防护材料在提升防护效果和使用便捷性方面具有重要意义,但面临性能优化和成本控制方面的挑战。未来研究应聚焦新型功能颗粒的开发、复合材料结构设计的优化及环保高效屏蔽材料的探索等方面,以进一步提升医用X射线防护材料的性能,拓宽其应用前景。 展开更多
关键词 X射线 防护材料 屏蔽效率 医用 功能粒子 成型方法
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