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A NATURAL GRADIENT ALGORITHM FOR THE SOLUTION OF LYAPUNOV EQUATIONS BASED ON THE GEODESIC DISTANCE

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Journal of Computational Mathematics 2014年第1期32卷 93-106页

作者： Xiaomin Duan Huafei Sun Zhenning Zhang School of Mathematics Bcijing Institute of Technology Beijing 100081 China School of Science Dalian Jiaotong University Dalian 116028 China College of applied scienees Beijing University of Technology Beijing 100123 China

A new framework based on the curved Riemannian manifold is proposed to calculate the numerical solution of the Lyapunov matrix equation by using a natural gradient descent algorithm and taking the geodesic distance as the objective function. Moreover, a gradient descent algorithm based on the classical Euclidean distance is provided to compare with this natural gradient descent algorithm. Furthermore, the behaviors of two proposed algorithms and the conventional modified conjugate gradient algorithm are compared and demonstrated by two simulation examples. By comparison, it is shown that the convergence speed of the natural gradient descent algorithm is faster than both of the gradient descent algorithm and the conventional modified conjugate gradient algorithm in solving the Lyapunov equation.

关键词： Lyapunov equation Geodesic distance Natural gradient descent algorithm.

Effect of Molecular Weight and Processing Additive on the Performance of Low Bandgap Polymer Solar Cells

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Chinese Journal of Chemistry 2012年第9期30卷 2052-2058页

作者：赵晓礼唐浩为杨大磊李慧徐文涛尹丽杨小牛 Polymer Composites Engineering Laboratory Changehun Institute of Applied ChemistryChinese Academy of ScieneesRenmin St.5625ChangchunJilin 130022China State Key Laboratory of Polymer Physics and Chemistry Changchun institute of Applied ChemistryChinese Academy of SciencesRenmin St.5625ChangchunJilin 130022China Graduate School of the Chinese Academy of Sciences Beijing 100049China Changchun university of Technology ChangchunJilin 130012China

In this work, we synthesized a low bandgap polymer polysilole（-2,6-diyl-alt-5-octylthieno[3,4-c]pyrrole-4,6- dione）（PDTSTPD） with different molecular weights （Mn）. The devices based on PDTSTPD/PC71BM composite are prepared and the dependence of power conversion efficiency （PCE） of the devices on the M,1 of conjugated poly- mers is addressed. We found the hole mobility of PDTSTPD is dependent on the Mn of the polymer, which should be the main reason contributing to the drastic difference of device performance, i.e. the PCE of the device using 10 kDa polymer is only 0.52%, in contrast to 2.3% for 24 kDa polymer device. This PCE data is then further improved to 5.0% via using 1,8-diiodoctane as processing additive to achieve an optimized morphology for the photoactive layer with an appropriate length-scale of phase separation for both exciton dissociation and charge transportation.

关键词： bulk-heterojunction molecular weights low band gap semiconducting polymers solar cells

Cloud point extraction coupled with HPLC-UV for the determination of phthalate esters in environmental water samples

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Journal of Environmental Sciences 2007年第7期19卷 874-878页

作者： WANG Ling JIANG Gui-bin CAI Ya-qi HE Bin WANG Ya-wei SHEN Da-zhong School of Chemistry and Chemical Engineering Shah Dong University Jinan 250100 China. State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Scienees Beijing 100085 China

A method based on cloud point extraction was developed to determine phthalate esters including di-ethyl-phthalate （DEP）, di- （2-ethylhexyl）-phthalate （DEHP） and di-cyclohexyl-phthalate （DCP） in environmental water samples using high-performance liquid chromatography separation and ultraviolet detection （HPLC-UV）. The non-ionic surfactant Triton X-114 was chosen as extraction solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na2SO4, equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, the method can achieve preconcentration factors of 35, 88, 111 and detection of limits of 2.0, 3.8, 1.0 ng/ml for DEP, DEHP and DCP in 10-ml water sample, respectively. The proposed method was successfully applied to the determination of trace amount of phathalate esters in effluent water of the wastewater treatment plant and the lixivium of plastic fragments.

关键词： phthalate esters cloud point extraction Triton X-114 non-ionic surfactant, HPLC-UV

The Convergence of Krylov Subspace Methods for Large Unsymmetric Linear Systems

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Acta Mathematica Sinica,English Series 1998年第4期14卷 507-518页

作者： Jia Zhongxiao, Department of applied Mathematics, Dalian university of Technology, Dalian 116024, China Department of applied Mathematics Dalian University of Technology

The convergence problem of many Krylov subspace methods, e.g., fom, GCR, GMRES and QMR, for solving large unsymmetric (non-Hermitian) linear systems is considered in a unified way when the coefficient matrix A is defective and its spectrum lies in the open right (left) half plane. Related theoretical error bounds are established and some intrinsic relationships between the convergence speed and the spectrum of A are exposed. It is shown that these methods are likely to converge slowly once one of the three cases occurs: A is defective, the distribution of its spectrum is not favorable, or the Jordan basis of A is ill conditioned. In the proof, some properties on the higher order derivatives of Chebyshev polynomials in an ellipse in the complex plane are derived, one of which corrects a result that has been used extensively in the literature.

关键词： Unsymmetric linear systems Convergence Krylov subspace The Chebyshev polynomials Defective Derivatives

Enhancing Human-Machine Interaction:Real-Time Emotion Recognition through Speech Analysis

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Journal of Computer Science Research 2023年第3期5卷 22-45页

作者： Dominik Esteves de Andrade Rüdiger Buchkremer Institute of IT Management and Digitization Research(IFID) FOM University of Applied SciencesDusseldorf40476Germany

Humans,as intricate beings driven by a multitude of emotions,possess a remarkable ability to decipher and respond to socio-affective ***,many individuals and machines struggle to interpret such nuanced signals,including variations in tone of *** paper explores the potential of intelligent technologies to bridge this gap and improve the quality of *** particular,the authors propose a real-time processing method that captures and evaluates emotions in speech,utilizing a terminal device like the Raspberry Pi ***,the authors provide an overview of the current research landscape surrounding speech emotional recognition and delve into our methodology,which involves analyzing audio files from renowned emotional speech *** aid incomprehension,the authors present visualizations of these audio files in situ,employing dB-scaled Mel spectrograms generated through TensorFlow and *** authors use a support vector machine kernel and a Convolutional Neural Network with transfer learning to classify ***,the classification accuracies achieved are 70% and 77%,respectively,demonstrating the efficacy of our approach when executed on an edge device rather than relying on a *** system can evaluate pure emotion in speech and provide corresponding visualizations to depict the speaker’s emotional state in less than one second on a Raspberry *** findings pave the way for more effective and emotionally intelligent human-machine interactions in various domains.

关键词： Speech emotion recognition Edge computing Real-time computing Raspberry Pi

New Half-sandwich Zirconium(Ⅳ) Complexes Containing Salicylaldimine Ligands： Synthesis, Characterizations and Catalytic Properties

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Chemical Research in Chinese Universities 2014年第5期30卷 825-830页

作者： LIU Kefeng YAO Gang WU Wenlei GAO Bo Yellow River Dalta Jingbo Research Institute of Chemical Industry Boxing 256500 P. R. China School of Materials Science and Engineering Changchun University of Science and Technology Changchun 130022 P. R. China Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry Chinese Academy of Scienees Changehun 130022 P. R. China

Two new half-sandwich zirconium（IV） complexes bearing salicylaldimine ligands of the type Cp＊Zr[2-tBu-4-R-6-（CH=NiPr）C6H2O]C12[R=H（1）, tBu（2）] were prepared by the reaction of Cp＊ZrC13 with the corresponding lithium of salicylaldimine ligands 2-tBu-4-R-6-（CH=NiPr）C6H2OLi[R=H（LiLa）, tBu（LiLb）]. Com- plexes 1 and 2 were characterized by 1H NMR, BC NMR spectroscopy and elemental analysis. When activated with AliBu3 and Ph3CB（C6F5）4, both complexes 1 and 2 exhibited reasonable catalytic activities for ethylene polymeriza- tion, producing polyethylenes with moderate molecular weight. Complexes 1 and 2 also exhibited reasonable catalyt- ic activities for ethylene copolymerization with 1-hexene, producing poly（ethylene-co-l-hexene）s with moderate molecular weight and reasonable 1-hexene content.

关键词： Zirconium complex Metallocene catalyst Ethylene polymerization Olefin copolymerization

Logistics Implications of Urban Road Pricing

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Journal of Traffic and Transportation Engineering 2014年第2期2卷 125-132页

作者： Matthias Klumpp Torsten Mamer Institute for Logistics and Service Management FOM University of Applied Sciences Essen Essen D-45141 Germany

Urban road pricing schemes are becoming increasingly popular among researchers and politicians as they promise a handle on increasing inner city traffic and economy as well as sustainable improvements for cities facing huge congestion and pollution problems. As in the cases of London and Stockholm, many European cities are going to implement such toll systems, especially as also the European Commission is voting for such pricing schemes in the recent white book on transportation and traffic, This research therefore provides a description of different urban road pricing schemes, their cost implications for city （last mile） transport as well as the decision and management options derived from these schemes for logistics companies. These options are furthermore checked regarding their advantages and disadvantages under the described toll schemes.

关键词： Urban road pricing efficient city toll last-mile logistics global navigation satellite system logistics impact.

THEORIES AND METHODS OF STRATEGIC ENVIRONMENTAL ASSESSMENT OF MODERN LOGISTICS DEVELOPMENT——A Case Study of Dalian City, China

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Chinese Geographical Science 2005年第2期15卷 145-150页

作者： XULing SHANGJin-cheng WANGYu-mei Northeast Institute of Geography and Agricultural Ecology Chinese Academy of ScieneesChangchun 130012P.R.China Graduate School of Chinese Academy of Sciences Beijing 100039P.R.China Department of Environmental Sciences and Engineering Northeast Normal UniversityChangchun 130024P.R.China

Modern logistics is a new industry during the construction of national economy. Based on analyzing the environmental problem that was led by the limitation of the strategy during enacting the program of the modern logistics, SEA for modern logistics was implemented. In this paper, procedure and indicator system in the SEA are constructed, and Environmental Check List to identify environmental impact factors of SEA for modern logistics is established. And a conception that indicates friendly degree of logistics system with resources and environment, degree of green, is introduced. With the example of modern logistics program of Dalian in China, two methods are applied, AHP and Fuzzy Comprehensive Evaluation Method, in the implement of SEA for modern logistics development. It is concluded that degree of green of modern logistics in Dalian is high. However, several important factors should be paid much attention to in the SEA for modern logistics as well as in the formulation and implement of modern logistics in Dalian.

关键词： modern logistics strategic environmental assessment (SEA) degree of green Dalian

Economic Growth and CO<sub>2</sub>-Emissions: What If Vietnam Followed China’s Development Path?

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American Journal of Climate Change 2017年第1期6卷 99-115页

作者： Andreas Oberheitmann fom university of applied Sciences Sino-German School of Business and Technology Essen Germany RWI-Leibniz Institut für Wirtschaftsforschung (RWI Essen) Essen Germany

Vietnam and China both are quickly emerging market economies in Asia. China has had an unprecedented economic growth in Asia for the past 30 years. Also, Vietnam’s GDP is increasing, but more slowly. However, Vietnam is starting to catch up. Against this background, this article assesses the question what the economic and environmental impacts in Vietnam would be, if the country followed China’s development path. Based on econometric analysis, it is shown that currently, Vietnam is lagging behind China in terms of economic growth for 11 years. Although Vietnam and China have a similar primary energy mix in the early 1980s, China is still massively relying on coal, whereas Vietnam starts to develop hydro power in the late 1980s on large scale. Due to a quick growth of per-capita income, per capita emissions in China are already catching up with those of North-European economies such as Denmark, Finland and Germany. The question arises, what if Vietnam followed China’s development path. Using econometric models of GDP and CO2-emissions, two scenarios for Vietnam are analyzed, a scenario following China’s development path and one alternative scenario pursuing the current development patterns until 2050. The results show that the additional impact of following China’s economic development path is minor. Vietnam would only have a 0.5% percentage point per annum higher GDP growth. In other words, Vietnam would grow relatively quickly anyway. However, following China’s development path also in terms of high CO2-emissions per capita, would increase the growth of CO2-emissions in Vietnam by 2.3 percentage points per annum and would lead to an increase of CO2-emissions in 2050 by 2.6 bn. tons compared with the scenario in which Vietnam sticks to its own development patterns. However, in that case, Vietnam also had a 25% lower per capita income compared with the scenario following China’s development path. Here, the people and government in Vietnam have to make a strategic cho

关键词： Vietnam China Economic Development CO2-Emissions per Capita Co-Integration Analysis