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Science China Chemistry 2010年第7期53卷 1586-1591页

作者： liu ling liu Zhao-Tie liu Zhong-Wen XUE Dong Key Laboratory of Applied Surface and Colloid Chemistry(Shaanxi Normal University) Ministry of EducationXi’an 710062China School of Chemistry&Materials Science Shaanxi Normal UniversityXi’an 710062China

The direct asymmetric aldol reaction between various aldehydes and acetone catalyzed by L-proline catalyst was successfully carried out in supercritical CO_(2) (scCO_(2)) and 1,1,1,2-tetrafluoroethane (R-134a) *** enantioselectivity of 84% ee to the targeted product was achieved under 20 MPa,40 °C,and 15 mol% of the catalyst in supercritical CO_(2) (scCO_(2)) *** effects of reaction parameters,such as temperature,pressure,catalyst loading and different substituted aldehydes on both enantioselectivity and aldol yield were *** titled reaction was also performed in 1,1,1,2-tetrafluoroethane,and the obtained results were compared with those in *** new reaction procedure provides an environmental asymmetric aldol reaction system as compared with that in organic solvents.

关键词： L-proline asymmetric aldol reaction supercritical CO_(2) 1,2-tetrafluoroethane fluid

Adverse Effect of TiO2 Nanoparticles on Antioxidant System and Antitumor Activities of Macroalgae Gracilaria lemaneiformis

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Journal of Ocean University of China 2019年第5期18卷 1130-1138页

作者： liu Jie YIN Pinghe ZHAO ling Department of Chemistry Jinan UniversityGuangzhou 510632China Research Center of Analysis and Test Jinan UniversityGuangzhou 510632China Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation of Guangdong Higher Education Institutes Department of Environmental EngineeringJinan UniversityGuangzhou 510632China

Recently,the widespread use of TiO2 nanoparticles(nano-TiO2)has attracted the global concern regarding their adverse effects to aquatic *** may get to the aquatic environments and harm the growth of *** paper presents the studies of nano-TiO2 concentrations influence on the photosynthetic characteristics,antioxidant system and antitumor activity of marine macroalgae Gracilaria lemaneiformis after exposed to 0,5,10,20 or 40 mg L^-1 of *** showed that the photosynthetic pigment content of *** obviously decreased and the antioxidant defense system was significantly disturbed after exposure to *** with control,the maximum level of malondialdehyde showed 3.3-fold increase for 15 days exposure to *** activity of superoxide dismutase and catalase enhanced obviously by *** aqueous extract of ***(AEGL)possesses anticancer activity against HepG2 liver cancer cells proliferation and the 48 h-cell inhibition exceeds 35%.But the toxicity of nano-TiO2 would inhibit the anticancer activity of *** *** was exposed to nano-TiO2,the effect of the aqueous extract of *** on the cell inhibition,reactive oxygen species production,apoptosis,cycle arrest of HepG2 cells significantly lessened,and which were linearly associated with nano-TiO2 exposure *** results further confirmed that nano-TiO2 can inhibit the anticancer activity of *** results in this work imply that macroalgae can be an effective biomarker of nano-TiO2 contaminant,and can be useful indicator to evaluate ecological effects of increasing pollutants in marine ecosystem.

关键词： anticancer activity Gracilaria lemaneiformis macroalgae nanoparticles oxidative damage photosynthetic pigment

Cell-based therapies for age-related macular degeneration:cell replacement versus paracrine effects

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Neural Regeneration Research 2021年第6期16卷 1214-1215页

作者： Xiaoyan Peng ling Gao Yongqing liu Department of Ophthalmology Beijing Tongren HospitalCapital Medical UniversityBeijingChina Department of Ophthalmology Second Affiliated Hospital of Xiangya Medical SchoolCentral South China UniversityChangshaHunan ProvinceChina James Graham Brown Cancer Center Department of Ophthalmology and Visual SciencesBirth Defects CenterUniversity of Louisville School of MedicineLouisvilleKYUSA

Age-related macular degeneration(AMD)is a leading cause for severe visual loss and legal blindness in seniors *** molecular basis for the disease remains poorly understood,likely involving genetic and environment-related ocular *** pathogenesis proceeds slowly,started with deposits of fatty proteins(drusen)in the Bruch’s membrane,followed by gradual impairments of the posterior choriocapillaris and the anterior retinal pigment epithelium(RPE),and lead to irreversible degeneration of the light receiving neurons(photoreceptor)and vision ***,AMD is divided into two subgroups:dry or atrophy form and wet or exudative *** percent of AMD patients have the wet form.

关键词： degeneration legal irreversible

Online Scheduling on a Parallel Batch Machine with Delivery Times and Limited Restarts

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Journal of the Operations Research Society of China 2022年第1期10卷 113-131页

作者： Hai-ling liu Xi-Wen Lu Department of Mathematics East China University of Science and TechnologyShanghai 200237China College of Science Henan University of EngineeringZhengzhou 451191HenanChina

The online scheduling on an unbounded parallel batch machine with delivery times and limited restarts is studied in this ***,online means that jobs arrive over time and the characteristics of a job become known until it *** restarts mean that once a running batch contains at least one restarted job,it cannot be restarted *** goal is to minimize the time by which all jobs have been *** consider a restricted model that the delivery time of each job is no more than its processing *** present a best possible online algorithm with a competitive ratio of 3/2 for the problem.

关键词： Online scheduling Parallel batch Limited restart Delivery time

Optimal power and subcarrier allocation with partial side information for downlink OFDMA system

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The Journal of China Universities of Posts and Telecommunications 2010年第5期17卷 50-57页

作者： ZENG ling-kang liu Yuan-an XIE Gang CHANG ling-jun Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In this paper,we investigate the power and subcarrier allocation issue in the case of partial side information for downlink orthogonal frequency division multiple access （OFDMA） *** method is utilized to characterize the necessary conditions of the optimal solution and the uniqueness of the optimal solution is *** game theoretical concept,surplus function is also introduced to analyze the optimal *** on the theoretical analysis,we propose iterative surplus balancing algorithm （ISBA） that can jointly assign the power and subcarriers in multiple rounds,and then the optimality of ISBA is *** results are presented to show the characteristics of the theoretical analysis and ISBA.

关键词： resource allocation partial side information OFDMA surplus function game theory

Improved method for analyzing the degradation of estrogens in water by solid-phase extraction coupled with ultra performance liquid chromatography-ultraviolet detection

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Journal of Environmental Sciences 2011年第4期23卷 693-698页

作者： Minggang Zheng ling Wang Yuandui Bi Feng liu College of Chemistry and Chemical Engineering and Environment Qingdao University Qingdao 266071 China The First Institute of Oceanography Qingdao 266101 China.

We established an improved method for the determination of four estrogens including estriol （E3）, 17β-estradiol （E2）, 17α-ethynyl- estrodiol （EE2） and estrone （E1） in water. The method consisted of solid-phase extraction （0.5 L water） and subsequent analysis of analytes by ultra-performance liquid chromatography （UPLC） with an ultraviolet detector （UVD）. Base-line separation was achieved for all studied estrogens using a column （50 mm × 2.1 mm） packed with 1.7 μm particle size stationary phase. Recovery was higher than 88% and detection limits ranged between 12.5–23.7 ng/L for the four estrogens, with the RSD ranging from 7% to 11%. The method was successfully applied to determine E2 and EE2 in simulated natural water, which found that about 70% of E2 was degraded （with a half-life of about 30 hr） within 48 hr and about 55% of EE2 was degraded （with a half-life of about 36 hr）. Low levels of E1 were found, however E3 was undetectable during the process.

关键词： estrogens base-lined separation half-life degradation

High Hardware Utilization and Low Memory Block Requirement Decoding of QC-LDPC Codes

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Chinese Journal of Aeronautics 2012年第5期25卷 747-756页

作者： ZHAO ling liu Rongke HOU Yi ZHANG Xiaolin School of Electronics and Information Engineering Beihang UniversityBeijing 100191China

This paper presents a simple yet effective decoding for general quasi-cyclic low-density parity-check （QC-LDPC） codes, which not only achieves high hardware utility efficiency （HUE）, but also brings about great memory block reduction without any performance degradation. The main idea is to split the check matrix into several row blocks, then to perform the improved mes- sage passing computations sequentially block by block. As the decoding algorithm improves, the sequential tie between the two-phase computations is broken, so that the two-phase computations can be overlapped which bring in high HUE. Two over- lapping schemes are also presented, each of which suits a different situation. In addition, an efficient memory arrangement scheme is proposed to reduce the great memory block requirement of the LDPC decoder. As an example, for the 0.4 rate LDPC code selected from Chinese Digital TV Terrestrial Broadcasting （DTTB）, our decoding saves over 80% memory blocks com- pared with the conventional decoding, and the decoder achieves 0.97 HUE. Finally, the 0.4 rate LDPC decoder is implemented on an FPGA device EP2S30 （speed grade -5）. Using 8 row processing units, the decoder can achieve a maximum net throughput of 28.5 Mbps at 20 iterations.

关键词： wireless communication channel coding low-density parity-check (LDPC) codes decoding hardware utility effi-ciency overlapping

Simultaneous inversion of seismic scattering and absorption attenuation using coda energies

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Science China Earth Sciences 2024年第12期67卷 3939-3949页

作者： Jia WEI Qiancheng liu ling CHEN Liang ZHAO State Key Laboratory of Lithospheric and Environmental Coevolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and TechnologyShenzhen 518055China

Simultaneous inversion of scattering and absorption attenuation is of great significance for investigating small-scale inhomogeneities and inelastic properties of the ***,applying this to complex geophysical issues is constrained by the costly computational requirements for simulations and inversions using existing *** coupling effects between the scattering and absorption coefficients cause parameter crosstalk artifacts in multi-parameter inversion,significantly increasing the nonlinearity of the inverse *** paper proposes a robust and effective simultaneous inversion method for scattering and absorption *** propagation of coda energy is modeled using the finite-element method based on the frequency-domain diffusion *** employ the truncated Gauss-Newton technique for the simultaneous estimation of scattering and absorption coefficients to decouple the two attenuation parameters during the inversion ***,the inversion may reach a local minimum if the energy frequency is inappropriate due to a phase mismatch between the simulated and measured *** mitigate this issue,we provide a frequency selection criterion that considers the substantial spectral shift of the energy density spectrum toward lower *** examples using synthetic and experimental data indicate that our method can significantly reduce computational complexity and suppress two-parameter crosstalk without requiring a precise initial attenuation model.

关键词： Scattering attenuation Absorption attenuation Simultaneous inversion Coda energy

Trotter–Kato Approximations of Impulsive Neutral SPDEs in Hilbert Spaces

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1229-1243页

作者： Ming liu Xia ZHANG ling Fei DAI School of Mathematical Sciences Tiangong UniversityTianjin 300387P.R.China

This paper studies a class of impulsive neutral stochastic partial differential equations in real Hilbert *** main goal here is to consider the Trotter-Kato approximations of mild solutions of such equations in the pth-mean(p≥2).As an application,a classical limit theorem on the dependence of such equations on a parameter is *** novelty of this paper is that the combination of this approximating system and such equations has not been considered before.

关键词： Impulsive neutral stochastic partial diferential equation Trotter-Kato approximations classical limit theorem

Dimensions estimation for cone-cylinder target based on sliding-type scatterers analysis

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Journal of Systems Engineering and Electronics 2017年第1期28卷 10-18页

作者： Yuling liu Xizhang Wei Bo Peng Yongshun ling School of Electronic Science and Engineering National University of Defense TechnologyChangsha 410073China Electronic Engineering Institute of PLA Hefei 230000China

Scatterers often exhibit aspect or frequency dependence which affects the micro-Doppler shift in scattering response. For cone-cylinder targets, sliding-type scatterers which slide on the edge discontinuity with the change of the incident angle are the most dominant nonideal scattering models. A method is proposed to discriminate among the scatterers on the cone-cylinder target based on the deviation degree of micro-Doppler from sinusoid. By extracting the amplitude and initial phase, the micro-Doppler is estimated as sinusoid. Then the deviation degree is evaluated by the error between the extracted sinusoidal micro-Doppler and the actual micro-Doppler curve. Threshold for the classification is determined with the simulation data. After classification, the micro-Doppler features of sliding-type scatterers are exploited to estimate the target dimensions. The influence of parameters errors and noise on estimation of target dimensions is also illustrated with the simulation data. © 1990-2011 Beijing Institute of Aerospace Information.

关键词： Cylinders (shapes)