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Exploring the spectral information content in the LAMOST medium-resolution survey(MRS)

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Research in Astronomy and Astrophysics 2020年第4期20卷 57-68页

作者： Bo Zhang Chao liu Chun-Qian Li Li-cai Deng Tai-Sheng Yan jian-Rong Shi Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Although high-resolution stellar spectra allow us to derive precise stellar labels(effective temperature,metallicity,surface gravity,elemental abundances,etc.)based on resolved atomic lines and molecular bands,low-resolution spectra have been proved to be competitive in determining many stellar labels at comparable *** is useful to consider the spectral information content when assessing the capability of a stellar spectrum in deriving precise stellar *** this work,we quantify the information content brought by the LAMOST-II medium-resolution spectroscopic survey(MRS)using the gradient spectra as well as the coefficients-of-dependence(CODs).In general,the wavelength coverage of the MRS well constrains the stellar labels but the sensitivities of different stellar labels vary with spectral types and metallicity of the stars of ***,this affects the performance of the stellar label determination from the MRS *** applying the SLAM method to the synthetic spectra which mimic the MRS data,we find that the precision of the fundamental stellar parameters Teff,log g and[M/H]are better when combining both the blue and red bands of the *** is especially important for warm stars because the Hαline located in the red part plays a more important role in determining the effective temperature for warm *** blue and red parts together,we are able to reach similar performance to the low-resolution spectra except for warm ***,at[M/H]-2.0 dex,the uncertainties of fundamental stellar labels estimated from MRS are substantially larger than that from low-resolution *** also tested the uncertainties of Teff,log g and[M/H]from MRS data induced from the radial velocity mismatch and find that a mismatch of about 1 km s-1,which is typical for LAMOST MRS data,would not significantly affect the stellar label ***,reference precision limits are calculated using synthetic gradient spectra,according to which we expect a

关键词： methods:data analysis methods:statistical stars:fundamental parameters stars:abundances

Online Scheduling on Two Parallel Identical Machines Under a Grade of Service Provision

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Journal of the Operations Research Society of China 2022年第4期10卷 689-702页

作者： Shuang cai Ke liu Data Department Beijing Kingsoft Cloud Network Technology Co.Ltd.Beijing100086China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100190China

In this paper,we investigate online scheduling problems on two parallel identical machines under a grade of service provision with makespan as the objective *** jobs arrive over time and each job can be scheduled only when it has already been *** consider three different versions:(i)the two machines cannot be idle at the same time until all arrived jobs have been processed;(ii)further to the first problem,jobs are processed on a first-come,first-serviced basis;(iii)each job must be assigned to one of the two machines as soon as it *** for three online scheduling problems,optimal online algorithms are proposed with competitive ratio(√5+1)/2,(√5+1)/2 and 5/3.

关键词： Online scheduling Parallel machines A grade of service provision GoS

Effect of aspect ratio on triaxial compression of multi-sphere ellipsoid assemblies simulated using a discrete element method

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Particuology 2017年第3期15卷 49-62页

作者： jian Gong Jun liu State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

Here, we present a numerical investigation of the mechanical behavior of ellipsoids under triaxial com- pression for a range of aspect ratios. Our simulations use a multi-sphere approach in a three-dimensional discrete element method. All assemblies were prepared at their densest condition, and triaxial compres- sion tests were performed up to extremely large strains, until a critical state was reached. The stress-strain relationship and the void ratio-strain behavior were evaluated. We found that the stress-dilatancy rela- tionship of ellipsoids with different aspect ratios could be expressed as a linear equation. In particular, the aspect ratio influenced the position of the critical state lines for these assemblies. Particle-scale char- acteristics at the critical state indicate that particles tend to be flat lying, and the obstruction of particle rotation that occurs with longer particles affects their contact mechanics. Lastly, anisotropic coefficients related to aspect ratio were investigated to probe the microscopic origins of the macroscopic behavior. A detailed analysis of geometrical and mechanical anisotropies revealed the microscopic mechanisms underlying the dependency of peak and residual strengths on aspect ratio.

关键词： EllipsoidsAspect ratio DEM Triaxial compression Particle shape Macro-micro response

Three-dimensional structure of the hepatitis B core antigen particle truncated at residue 154

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Science China(Life Sciences) 2011年第2期54卷 171-174页

作者： liu ShuYu HE jian LI KunPeng DAI AGuang cai ChangJie ZHANG JingQiang State Key Laboratory of Biocontrol Life Sciences School Sun Yat-sen University Guangzhou 510275 China Guangzhou East Campus Lab Center Sun Yat-sen University Guangzhou 510006 China Third Affiliated Hospital of Sun Yat-sen University Guangzhou 510080 China

The three-dimensional structure of recombinant hepatitis B core antigen（HBcAg） particles truncated at residue 154（HBcAg-154） was determined to 7.8 A resolution by cryo-electron microscopy（cryoEM） and computer *** capsid of HBcAg-154 is mainly constituted by α-helical folds,highly similar to that of *** C-terminal region between residues 155 and 183 of the core protein is more crucial to the encapsidation of RNA,and the short C-terminal tail of HBcAg-154 results in a nearly empty capsid.

关键词： HBcAg-154 particle capsid RNA cryoEM

Modeling of suspended sediment by coupled wave-current model in the Zhujiang(Pearl) River Estuary

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Acta Oceanologica Sinica 2019年第7期38卷 22-35页

作者： Guangping liu Shuqun cai State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China Institution of South China Sea Ecology and Environmental Engineering Chinese Academy of SciencesGuangzhou 510301China

A three-dimensional wave-current-sediment coupled numerical model is developed to understand the sediment transport dynamics in the Zhujiang(Pearl)River Estuary(ZRE),*** model results are in good agreement with observed data,and statistics show good model skill *** studies are conducted to assess the scenarios of suspended sediment in the ZRE under the effects of different forcing(river discharges,waves,and winds).The model results indicate that the estuarine gravitational circulation plays an important role in the development of estuarine turbidity maximum in the ZRE,particularly during neap *** increased river discharge can result in a seaward sediment *** suspended sediment concentration(SSC)in the bottom increases with both wave bottom orbital velocity and wave *** of the shallow water depth,the effect of waves on sediment in the west shoal is greater than that in the east *** southwesterly wind-induced wave affects the SSC more than those resulting from the northeasterly wind,while the northeasterly wind-driven circulation has a slightly greater influence on the SSC than that of the southwesterly ***,a steady southwesterly wind condition favors the increase of the SSC in the Lingding Bay more so than a steady northeasterly wind *** the other forcings are same,the averaged SSC under a steady southwesterly wind condition is about 1.1 times that resulting from a steady northeasterly wind.

关键词： sediment transport turbidity Regional Ocean Modeling System(ROMS) Zhujiang River Estuary

Polarized imaging dynamic light scattering for simultaneous measurement of nanoparticle size and morphology

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Particuology 2024年第2期85卷 213-223页

作者： Bingyao Wang Tianyi cai Xiaoshu cai Wu Zhou Zeqi liu Schoolof Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai200093China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093China Jiaxing MeaParTech Instrument Technology Co. LtdZhejiang314000China

The performance of nanoparticles is often affected by particle size and ***,electron microscopy or atomic force microscopy is typically utilized to determine the size and morphology of ***,there are issues such as difficult sample preparation,long processing times,and challenges in quantitative ***,it is of great significance to develop a fast,accu-rate,and statistical method to measure the size and morphology of *** this study,a new method,called polarized imaging dynamic light scattering(PIDLS),is *** nanoparticles are irradiated with a vertical linearly polarized laser beam,and a polarization camera collected the dynamic light scattering images of particles at four different polarization directions(0°,45°,90°,and 135°)at a scattering angle of 90°.The average particle size and distribution are obtained using the imaging dy-namic light scattering method at 0°polarization direction,and the morphology of the particles is ob-tained based on the depolarization patterns of the scattered *** optical sphericityΦis defined based on the degree of linear polarization(DoLP).It is also implemented for the quantitative evaluation of the sphericity of the nanoparticles,including spherical,octahedral,nanoplate,nanorod,and linear *** with the Poincarésphere parameterψ,the morphology of the nanoparticles can be roughly *** addition,PIDLS enables the measurement of particle size and morphology distributions simultaneously for evaluating the uniformity of *** effectiveness of PIDLS is verified by the measurement of five kinds of industrial titanium dioxide as well.

关键词： Imaging dynamic light scattering Polarized light scattering Non-spherical nanoparticles Morphology Online measurement

Infant formula safety concerns and consequences in China

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World Journal of Pediatrics 2014年第1期10卷 7-9页

作者： Ai-Ling Ji Yin-Ling Irene Wong Tong-jian cai jianghong liu Department of Nutrition&Food Hygiene and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment School of Public HealthFourth Military Medical UniversityXi'an 710032China Department of Occupational&Environmental Health School of Public HealthFourth Military Medical UniversityXi'an 710032China School of Nursing University of PennsylvaniaPhiladelphiaPA 19104USA School of Social Policy&Practice University of PennsylvaniaPhiladelphiaPA 19104USA

Food safety is an important public health problem for the entire world,especially developing *** safety incidents in China in the recent years have threatened the health of the Chinese citizens.[1]Many products,including chicken,pork,beef and rice and so on,were found to be unsafe for *** tainted with pesticides,pork tainted with clenbuterol,fish treated with cancer-causing antimicrobials,eggs colored with industrial dye,fake liquor that could induce blindness or death,exploding watermelons,and recycled"drainage oil"containing carcinogens and traces of aflatoxin have been put on the people's daily dining table.[2,3]The outcome was outrage across the *** confidence in the food industry *** turned pale at the mention of"food".Some people even started to plant vegetables in their own house.[4]

关键词： developing countries public health food industry

On Total Colorings of Some Special 1-planar Graphs

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Acta Mathematicae Applicatae Sinica 2017年第3期33卷 607-618页

作者： Lin SUN jian-liang WU Hua cai Department of Mathematics Changji University School of Mathematics Shandong University

A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this paper, we verify the total coloring conjecture for every 1-planar graph G if either △（G） ≥9 and g（G）≥ 4, or △（G） ≥ 7 and g（G）≥5, where △（G） is the maximum degree of G and g（G） is the girth of G.

关键词： 1-planar graph total coloring discharging method girth r-minimal graph

Baseband Design for 5G UDN Base Stations:Methods and Implementation

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China Communications 2017年第5期14卷 59-77页

作者： Zhaoyun cai Dake liu Lab of Application Specific Instruction-set Processors Beijing Institute of TechnologyBeijing 100081China

Baseband design and implementation for micro/pico base stations （mBS） in 5G ultra-dense network （UDN） is studied. Low cost is an essential requirement for mBS baseband in UDN. Digital baseband cost of ASIC/ASIP （Application Specific Integrated Circuit / Instruction-set processor） is of the most uncertainty in roBS system. However. the actual costs and hardware feasibility of the baseband are yet unknown to network deployers and researchers. In this paper, we studied the baseband hardware system design and implementation for low-cost roBS. We analyzed popular baseband algorithms and architectures for both full-digital and hybrid beamforming （BF） for UDN. We then proposed feasible chip-level solutions for the baseband with up to 128-antenna BS system, and estimated their implementation cost. Results show that among lull-digital BF algorithms, zero-forcing is a choice of high performance and low cost; for hybrid BF, 4×32 architecture （32 RF chains） provides good reduction in baseband cost with acceptable performance loss, thus it can be a preferable solution under low cost consider- ation. The proposed system planning method can also be used for the design of other related systems.

关键词： 5G Communication ASIC/ASIP UDN baseband implementation massive MIMO