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Resource scheduling in downlink LTE-advanced system with carrier aggregation

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The Journal of China Universities of Posts and Telecommunications 2012年第1期19卷 44-49,123页

作者： lin Le-xiang LIU yuan-an LIU fang XIE Gang LIU Kai-ming GE Xin-yang School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this paper, we focus on the resource scheduling in the downlink of long term evolution advanced （LTE-A） assuming equal power allocation among subcarriers. Considering the backward compatibility, the LTE-A system serves LTE-A and long term evolution （LTE） users together with carrier aggregation （CA） technology. When CA is applied, a well-designed resource scheduling scheme is essential to the LTE-A system. Joint scheduling （JS） and independent scheduling （INS） are two resource scheduling schemes. JS is optimal in performance but with high complexity. Whereas INS is applied, the LTE users will acquire few resources because they can not support CA technology. And the system fairness is disappointing. In order to improve the system fairness without bringing high complexity to the system, an improved proportional fair （PF） scheduling algorithm base on INS is proposed. In this algorithm, we design a weigh factor which is related with the number of the carriers and the percentage of LTE users. Simulation result shows that the proposed algorithm can effectively enhance the throughput of LTE users and improve the system fairness.

关键词： LTE-advanced system resource allocation cartier aggregation proportional fairness

Stoichiometric evolutions of PH3 under high pressure:implication for high-Tc superconducting hydrides

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National Science Review 2019年第3期6卷 524-531页

作者： Ye yuan Yinwei Li Guoyong fang Guangtao Liu Cuiying Pei Xin Li Haiyan Zheng Ke Yang lin Wang Center for High Pressure Science and Technology Advanced Research School of Physics and Electronic Engineering Jiangsu Normal University Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials Engineering Wenzhou University Department of Physics Fudan University Shanghai Institute of Applied Physics Chinese Academy of Sciences

The superconductivity of hydrides under high pressure has attracted a great deal of attention since the recent observation of the superconducting transition at 203 K in strongly compressed *** has been realized that the stoichiometry of hydrides might change under high pressure,which is crucial in understanding the superconducting *** this study,PH3was studied to understand its superconducting transition and stoichiometry under high pressure using Raman,IR and X-ray diffraction measurements,as well as theoretical ***3is stable below 11.7 GPa and then it starts to dehydrogenate through two dimerization processes at room temperature and pressures up to 25 *** resulting phosphorus hydrides,P2H4and P4H6,were verified experimentally and can be recovered to ambient *** further compression above 35 GPa,the P4H6directly decomposed into elemental *** temperature can greatly hinder polymerization/decomposition under high pressure and retains P4H6up to at least 205 *** superconductivity transition temperature of P4H6is predicted to be 67 K at 200 GPa,which agrees with the reported result,suggesting that it might be responsible for superconductivity at higher *** results clearly show that P2H4and P4H6are the only stable P–H compounds between PH3and elemental phosphorus,which is helpful for shedding light on the superconducting mechanism.

关键词： high pressure hydrides superconductivity stoichiometric evolution

“1+1>2”:Highly efficient removal of organic pollutants by composite nanofibrous membrane based on the synergistic effect of adsorption and photocatalysis

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Journal of Materials Science & Technology 2022年第29期124卷 76-85页

作者： yuanting Xu Wanting lin Dandan yuan Shifan Chen fang Li Yanping Long Chao He Weifeng Zhao Changsheng Zhao College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310027China Med-X Center for Materials Sichuan UniversityChengdu 610041China College of Chemical Engineering Sichuan UniversityChengdu 610065China

Adsorption and photocatalysis are regarded as two desirable technologies for wastewater remediation,but are still unsatisfactory in removal effect,eco-friendly regeneration and facile *** this study,we developed a composite nanofibrous membrane material with excellent removal performance for organic pollutants based on synergistic adsorption and photocatalysis.A novel boron-doped,nitrogen-deficient graphitic carbon nitride(B-C3N4)photocatalyst as well as an amphiphilic copolymer of methyl methacrylate and acrylic acid(p(MMA-AA))were synthesized respectively,and then used to modify polyethersulfone for the fabrication of composite nanofibrous membrane with improved hydrophilicity,negativelycharge property and enhanced visible light response ***,the synergistic effect of adsorption and photocatalytic degradation for organic pollutants were identified especially and resulted in an excellent removal efficiency even superior to the combination of adsorption and photocatalytic degradation,which could be called a“1+1>2”*** addition,the regeneration and reusability,the purification ability for multicomponent wastewater,and the photocatalytic mechanism,were investigated and discussed *** this work,we not only prepared the nanofibrous membrane with synergistic effect of adsorption and photocatalysis,but also provided a versatile approach to design dualfunctional support material to ensure the practical applications of powdery photocatalyst in wastewater treatment.

关键词： Composite nanofibrous membrane material Wastewater remediation Photocatalytic degradation Adsorption Synergistic effect

Deriving the three-dimensional structure of ZnO nanowires/nanobelts by scanning transmission electron microscope tomography

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Nano Research 2013年第4期6卷 253-262页

作者： Yong Ding fang Zhang Zhong lin Wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332-0245 USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing China

Characterizing the three-dimensional （3D） shape of a nanostructure by con- ventional imaging techniques in scanning electron microscopy and transmission electron microscopy can be limited or complicated by various factors, such as two-dimensional （2D） projection, diffraction contrast and unsure orientation of the nanostructure with respect to the electron beam direction. In this paper, in conjunction with electron diffraction and imaging, the 3D morphologies of ZnO nanowires and nanobelts synthesized via vapor deposition were reconstructed by electron tomography in a scanning transmission electron microscope （STEM）. The cross-sections of these one-dimensional （1D） nanostructures include triangle, hexagonal, and rectangle shapes. By combining the reconstructed shape with the crystalline information supplied by electron diffraction patterns recorded from the same nanowire/nanobelt, the growth direction and its exposed surfaces were uniquely identified. In total, three different growth directions were confirmed. These directions are 〈 0001 〉, 〈21 10 〉 and 〈21 13 〉, corresponding to 〈001〉, 〈100〉 and 〈101〉 orientations in three-index notation. The 〈0001〉 growth nanowires show triangle or hexagonal cross-sections, with exposed {01]-0} side surfaces. The dominant surfaces of the 〈21 10〉 growth nanobelt are _＋（0001） planes. Both hexagonal and rectangle cross-sections were observed in the 〈 2]-13 〉 growth ZnO nanostructures. Their surfaces include the {01]-0}, {]-101} and {2112} planes. The nanobelts with a large aspect ratio of ~10 normally grow along the 〈 21 10 〉 direction, while nanobelts with small aspect ratio grow along 〈21 13 〉 growth direction. The approach and methodology demonstrated here can be extended to any nanostructures that even amorphous. can be crystalline, polycrystalline or

关键词： ZnO nanowire nanobelt TEM STEM electron tornography

ON CONTRACTION AND SEMI-CONTRACTION FACTORS OF GSOR METHOD FOR AUGMENTED linEAR SYSTEMS

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Journal of Computational Mathematics 2010年第6期28卷 901-912页

作者： fang Chen Yao-lin Jiang Bing Zheng Department of Mathematical Sciences Xi'an Jiaotong University Xi'an 710049 China School of Science Xi'an University of Post and Telecommunications Xi'an 710121 China Department of Mathematical Sciences Xi ' an Jiaotong University Xi ' an 710049 China School of Mathematics and Statistics Lanzhou University Lanzhou 730000 China

The generalized successive overrelaxation （GSOR） method was presented and studied by Bai, Parlett and Wang [Numer. Math. 102（2005）, pp.1-38] for solving the augmented system of linear equations, and the optimal iteration parameters and the corresponding optimal convergence factor were exactly obtained. In this paper, we further estimate the contraction and the semi-contraction factors of the GSOR method. The motivation of the study is that the convergence speed of an iteration method is actually decided by the contraction factor but not by the spectral radius in finite-step iteration computations. For the nonsingular augmented linear system, under some restrictions we obtain the contraction domain of the parameters involved, which guarantees that the contraction factor of the GSOR method is less than one. For the singular but consistent augmented linear system, we also obtain the semi-contraction domain of the parameters in a similar fashion. Finally, we use two numerical examples to verify the theoretical results and the effectiveness of the GSOR method.

关键词： Contraction and semi-contraction factors, Augmented linear system, GSOR method Convergence.

Ultrasound-assisted synthesis and preliminary bioactivity of novel 2H-1,2,4-thiadiazolo[2,3-a]pyrimidine derivatives containing fluorine

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Chinese Chemical Letters 2012年第5期23卷 561-564页

作者： Mao Rong Wang lin Jiang Shao fang Zhou Ze yuan Zhang Zeng Chen Ji College of Chemistry and Material Science Shandong Agricultural UniversityTai'an 271018China

Eight novel 5,7-disubstituted-2-{5-methyl-3-（4-trifluoromethylphenyl）isoxazol-4-ylcarbonylimino}-2H-1,2,4-thiadiazolo[2,3- a]pyrimidines were synthesized by multi-step reactions in yields 68-85%.Reactions were carried out either by ultrasound irradiation or conventional method,and found it was faster and more efficient under ultrasonic *** herbicidal activities against Echinochloa crus-galli,Digitaria sanguinalis and Chenopodium serotinum were also evaluated by flat-utensil method,and the results indicated that the target compounds exhibited significant activities,some were even higher than the control herbicide.

关键词： 2H-1 2 4-Thiadiazolo[2 3-a]pyrimidine Synthesis Ultrasound Bioactivity

Small-Scale Brightenings in the UV Continuum of an M9.1 Solar Flare

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Chinese Journal of Astronomy and Astrophysics 2007年第5期7卷 721-732页

作者： lin Wang Cheng fang Ming-De Ding Department of Astronomy Nanjing University Nanjing 210093

We analyze an M9.1 two-ribbon solar flare which occurred on 2004 July 22 using the TRACE white-light and 1700 A images, the RHESSI, and the SOHO/MDI data. We find many small-scale fast-varying brightenings that appeared in the white-light and 1700 A images along the flare ribbons. Some of them underwent rapid motions in weak magnetic field regions. We identify these short-lived brightenings as UV continuum enhancement. Our preliminary result shows that the brightenings are closely related to the HXR emission. They have a lifetime of 30-60 s and a typical size of about 1＂-2＂. The intensity enhancement is about 150-200 times the mean value of the quiet-Sun. According to previous works, we infer that the 1700A enhancement may be dominated by the increased emission of 1680A continuum coming from the temperature minimum region. The impulsive feature in the 1700 A light curves of the small-scale brightenings may be due to the irradiation of the impulsive CIv line intensity caused by the bombardment of non-thermal electron beams.

关键词： Sun activity -- Sun flares -- Sun UV radiation

Spectral and Mechanistic Studies of the Reactions of Substituted 1,5-Benzothiazepine with Dichloroacetyl Chloride and Triethylamine

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Chinese Chemical Letters 2001年第10期12卷 851-854页

作者： Xin ZHOU Shrong Shi lin Jin fang yuan Zhe Ming WANG Hong Zhong WANG College of Chemical and Molecular Engineering Peking UniversityBeijing 100871 Department of Biological Sciences&Biotechnology Tsinghua UniversityBeijing 100084

A [2+2] cycloaddition adduct 2 and a novel ring-opening product 3 were obtained from the reactions of 2,3-benzothiazepines 1 with dichloroacetyl chloride and triethylamine. The relative ratios of 2 and 3 were affected by the addition order of reactants and reaction temperature. The structures were determined by spectral data and the reaction mechanisms for the formation of 2 and 3 were elucidated.

关键词： benzothiazepine dichloroacetyl chloride cycloaddition adduct ring-opening product

Copper-catalyzed Ullmann-type synthesis of diaryl ethers assisted by salicylaldimine ligands

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Chinese Chemical Letters 2014年第2期25卷 337-340页

作者： Cun-Wei Qian Wen-lin Lv Qian-Shou Zong Mao-yuan Wang Dong fang School of Chemistry and Chemical Engineering Yancheng Teachers University School of Biological and Chemical Engineering Jiaxing University

A series of salicylaldimine ligands were designed to promote the copper-catalyzed Ullmann cross- coupling reaction. After a screening process, 2-（（2-isopropylphenylimino）methyl）phenol was found to serve as a good supporting ligand for this reaction. Employing this Schiff-base ligand as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides and aryl iodides with various phenols successfully proceeded in good yields under mild conditions. Various diaryl ethers were obtained with excellent yields in dioxane in the presence of K3P04 and a catalytic amount of copper（I） salt.

关键词： Copper catalyst Salicylaldimine ligands Ullmann coupling Diaryl ethers