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Precession effects on a liquid planetary core

Research in Astronomy and Astrophysics 2018年第2期18卷 115-124页

作者： Min liu li-gang li Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China University of Chinese Academy of Sciences Beijing 100049 China

Motivated by the desire to understand the rich dynamics of precessionally driven flow in a liquid planetary core, we investigate, through numerical simulations, the precessing fluid motion in a ro- taring cylindrical annulus, which simultaneously possesses slow precession. The same problem has been studied extensively in cylinders, where the precessing flow is characterized by three key parameters： the Ekman number E, the Poincar6 number Po and the radius-height aspect ratio F. While in an annulus, there is another parameter, the inner-radius-height aspect ratio T, which also plays an important role in controlling the structure and evolution of the flow. By decomposing the nonlinear solution into a set of inertial modes, we demonstrate the properties of both weakly and moderately precessing flows. It is found that, when the precessional force is weak, the flow is stable with a constant amplitude of kinetic energy. As the precessional force increases, our simulation suggests that the nonlinear interaction be- tween the boundary effects and the inertial modes can trigger more turbulence, introducing a transitional regime of rich dynamics to disordered flow. The inertial mode u111, followed by u113 or u112, always dominates the precessing flow when 0.001 ≤Po ≤ 0.05, ranging from weak to moderate precession. Moreover, the precessing flow in an annulus shows more stability than in a cylinder which is likely to be caused by the effect of the inner boundary that restricts the growth of resonant and non-resonant inertial modes. Furthermore, the mechanism of triadic resonance is not found in the transitional regime from a laminar to disordered flow.

关键词： Astrometry and Celestial Mechanics: terrestrial planets -- planets and satellites: interiors-- planets and satellites: instabilities: waves

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Performance Evaluation of Advanced Wave Energy Converters in the Nearshore Areas of the North Indian Ocean

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China Ocean Engineering 2022年第6期36卷 980-993页

作者： WAN Yong ZHANG Wen FAN Chen-qing li li-gang DAI Yong-shou The College of Oceanography and Space Informatics China University of PetroleumQingdao 266580China The Laboratory of Physical Oceanography and Remote Sensing The First Institute of OceanographySOAQingdao 266061China

The 21st Century Maritime Silk Road is a profound measure for mankind,whilst its development is severely restricted by the energy shortage of surrounding *** the core construction area of Maritime Silk Road,the North Indian Ocean is rich in wave *** development and utilization of wave energy not only can overcome energy shortage,but also promote communication between peripheral ***,previous researchers often focused on wave energy itself,without combining devices to analyze wave energy ***,we conducted an overall assessment of wave energy resources using 20-year ERA5 data and determined the sites considered as superior for the construction of Wave Energy Farm(WEF)in the coastal *** order to point out which type of Wave Energy Converter(WEC)is best suited for the sites,we carried out the performance evaluation of eight advanced WECs using three parameters:the mean power output,the capacity factor and the capture width *** results show that the performance of Wave Star is superior to other devices,which is supposed to be the primary consideration of the Wave Energy Farms(WEFs)in the future.

关键词： ocean energy wave energy characteristics site selection wave energy converter performance evaluation

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Development of Near Infrared Spectroscopy for Rapid Quality Assessment of Red Ginseng

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Chemical Research in Chinese Universities 2009年第5期25卷 633-637页

作者： NIE li-xing WANG gang-li liN Rui-chao National Institute for the Control of Pharmaceutical and Biological Products Beijing 100050 P. R. China

Near infrared spectroscopy（NIRS） was developed as a rapid analysis method for the qualitative and quantitative assessment of the quality of red ginseng. Discriminant analysis（DA） based on principal component analysis and Mahalanobis distance was used to distinguish red ginseng from counterfeits non-destructively. The result shows that the proposed method could distinguish red ginseng from counterfeits correctly and no misclassified sample was found in both training and test sets. The partial least squares（PLS） algorithm was used to predict the sum of ginsenosides Re and Rgl and the content of ginsenoside Rb1. Two calibration models were developed to correlate NIR spectra with the reference values determined by HPLC method. The correlation coefficient（R）, the root mean square error of calibration（RMSEC） and the root mean square error of prediction（RMSEP） were as follows： R=0.9827, RMSEC=0.0163%, RMSEP=0.0250% for the sum of ginsenosides Re and Rgl; R=0.9869, RMSEC=0.0156%, RMSEP=0.0256% for content of ginsenoside Rb1. The overall results demonstrate that NIRS coupled with chemometrics could be successfully applied as a rapid, precise and cost-effective method not only to identify the red ginseng from counterfeits but also to determine simultaneously some chemical compositions in red ginseng.

关键词： Near infrared soectroscopy Red ginseng Discriminant analysis Partial least squares

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Quantum state manipulation of single-Cesium-atom qubit in a micro-optical trap

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Frontiers of physics 2014年第5期9卷 634-639页

作者： Zhi-Hui Wang gang li Ya-li Tian Tian-Cai Zhang State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan 030006 China

Based on single Cesium atoims trapped in a 1064 nm microscopic optical trap we have exhibited a single qubit encoded in the Cesium ＂clock states＂. The single qubit initialization, detection and the fast state rotation with high efficiencies are demonstrated and this state manipulation is crucial for quantmn information processing. The ground ~ates Rabi flopping rate of 229.0 ± 0.6 kHz is realized hy a two-photon Raman process. A clock states dephasing time of 3.0 ± 0.7 ms is measured, while all irreversible homogeneous dephasing time of 124 ± 17 ms is achieved by using the spin-echo technique. This well-controlled single atom provides an ideal quantmn qubit and quantmn node for quantum information processing.

关键词： qubit single atom Rabi flopping spin-echo dephasing time

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Erythropoietin Receptor Gene (EPOR) Polymorphisms are Associated with Sow litter Sizes

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Agricultural Sciences in China 2011年第6期10卷 931-937页

作者： ZHANG Long-chao WANG li-gang li Yong YAN Hua ZHAO Ke-bin WANG li-xian Institute of Animal Science Chinese Academy of Agricultural Sciences Beijing 100193 P.R. China

The erythropoietin receptor （EPOR） has shown to play an important role in fetal survival by promoting the maturation of red blood cells in many studies of uterine capacity and litter size in swine. In this study, we screened the porcine EPOR gene for mutations and identified five single nucleotide polymorphisms （SNPs）： g.705G〉T in intron 1, g.2 373C〉T in intron 4, and g.2 882C〉T, g.3 035A〉G, and g.3 132A〉T in intron 6. We then genotyped 247 Beijing Black （BB） sows and compared the polymorphism data with the litter sizes of 1 375 parities among the sows. At first parity, there was no association of g.2 882C〉T and g.3 132A〉T with litter sizes. However, the CT sows in g.2 882C〉T had 2.13 higher total number born （TNB）（P〈0.01） and 1.81 higher number born alive （NBA）（P〈0.01） than the CC sows and the heterozygous sows in g.3 132A〉T had the highest litter size when compared to the two homozygotes for the later parities （P〈0.05）. In the g.3 035A〉G SNP, for the later parities, the TNB of the sows with the GG genotype was 3.81 higher （P〈0.01） and the NBA was 2.75 higher （P〈0.01） than that with the AA genotype but no difference at first parity. The G allele of the EPOR g.705G〉T SNP was associated with a greater litter size at both the first parity （P〈0.05） and later parities （P〈0.01）. Furthermore, we determined the allele frequencies for this SNP among five Chinese indigenous pig breeds （Erhualian, Laiwu Black, Meishan, Min, and Rongchang） and three western commercial pig breeds （Duroc, Landrace, and Large White）. The G allele of the EPOR g.705G〉T SNP was significantly more common in the more prolific Chinese breeds. These results indicated that the EPOR could be an important candidate gene for litter size and g.705G〉T can serve as a useful genetic marker for improving litter size in both first and later parities in swine.

关键词： erythropoietin receptor litter size pig single nucleotide polymorphism

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SENSORING DROPLET SPRAY TRANSFER IN MIG WELDING BASED ON ARC SPECTRUM SIGNAL

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Chinese Journal of Mechanical Engineering 2001年第3期14卷 237-242页

作者： liu gang,li Junyue,li Huan,Fan Ronghuan (School of Material Engineering, Tianjin University) 天津大学材料科学与加工自动化系天津

The method to detect droplet transfer by means of arc spectrum, while the experiment sets, testing principle and data processing procedure,are presented. The experiment and analysis results show that arc spectrum signal can be utilized to detect and measure the transfer procedure, the transfer modes and the transfer parameters. The arc spectrum signal enjoys excellent quality with high signal amplitude. Each transfer mode has its specific typical signal mode, and the pulse outline corresponds to an integrated transferring procedure of one droplet. All these features of arc spectrum signal can be easily applied hi the control of transfer procedure,the identification and stabilization of transfer mode and the measurement of transfer parameters.

关键词： MIG welding Arc spectrum Signal feature Droplet transfer Detection

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FLUID CHARACTERISTICS OF ROTARY WING HEAT METER WITH SINGLE-CHANNEL

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Journal of Hydrodynamics 2008年第1期20卷 101-107页

作者： Du Guang-sheng liu Zheng-gang li li liU Yong-hui MA Yong-kun MENG liang School of Energy and Power Engineering Shandong University Jinan 250061China

Fluid characteristics of a rotary wing heat meter with single-channel were studied through theretical analysis, numerical simulation and experiments. The obtained results show that the number of vanes can obviously influence the heat meter, but the water temperature seldom influence the meter , and the optimal number of vane is 6-8.

关键词： heat meter numerical simulation meter

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Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique

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Chinese Medical Sciences Journal 2012年第4期27卷 225-231页

作者： Kai Sun Guo-rong liu Yue-chun li Rui-juan Han li-fang Cui li-jun Ma li-gang li Chang-yong li Department of Radiology Baotou Central Hospital Department of Cardiology Baotou Central Hospital CT BM Clinic Marketing Siemens Healthcare Department of Physiology School of Basic Medical Sciences Wuhan University

Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

关键词： dual-source computed tomography coronary angiography contrastenhancement test bolus technique bolus-tracking technique

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Feasibility and Diagnostic Accuracy for Assessment of Coronary Artery Stenosis of Prospectively Electrocardiogram-gated High-pitch Spiral Acquisition Mode Dual-source CT Coronary Angiography in Patients with Relatively Higher Heart Rates: in Comparison wit

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Chinese Medical Sciences Journal 2012年第4期27卷 213-219页

作者： Kai Sun Rui-juan Han li-fang Cui Rui-ping Zhao li-jun Ma li-jun Wang li-gang li Chang-yong li Department of Radiology Baotou Central Hospital Department of Cardiology Baotou Central Hospital CT BM Clinic Marketing Siemens Healthcare Department of Physiology School of Basic Medical Sciences Wuhan University

Objective To prospectively investigate the diagnostic accuracy for coronary artery stenosis of prospectively electrocardiogram-triggered spiral acquisition mode (high pitch mode) dual-source computed tomography coronary angiography (CTCA) in patients with relatively higher heart rates (HR) compared with catheter coronary angiography (CCA). Methods Forty-seven consecutive patients with relatively higher HR (>65 and linded and independent observers with regard to image quality on a three-point scale (1: excellent to 3: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). Considered CCA as the standard of reference, the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Radiation dose values were calculated using the dose-length product. Results Image quality was rated as being score 1 in 92.4% of segments, score 2 in 6.1% of segmentsand score 3 in 1.5% of segments. The average image quality score per segment was 1.064±0.306. The HR variability of patients with image score 1, 2 and 3 were 2.29±1.06 bpm, 5.17±1.37 bpm, 8.88±1.53 bpm, respectively. The average HR variability of patients with different image scores were significantly different (F=170.402, P=0.001). The sensitivity, specificity, positive and negative predictive values were 92.6%, 97.0%, 87.6%, 98.3%, respectively, per segment and 90.0%, 95.2%, 85.3%, 96.9%, respectively, per vessel and 100%, 63.6%, 90.0%, 100%, respectively, per patient. The effective radiation dose was on average 0.86±0.16 mSv. Conclusion In patients with HR more than 65 bpm and below 100 bpm without cardiac arrhythmia, the prospecti

关键词： dual-source computed tomography coronary angiography high pitch prospectively electrocardiogram-triggered spiral mode high heart rate diagnostic accuracy

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Removal of arsenic from water by silver nanoparticles and Fe-Ce mixed oxide supported on polymeric anion exchanger

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Journal of Environmental Sciences 2025年第5期151卷 540-549页

作者： li li Su-juan Yu Rong-gang Zheng Qing-cun li Rui liu Jing-fu liu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances Institute of Environment and HealthJianghan UniversityWuhan 430056China University of Chinese Academy of Sciences Beijing 100049China Department of Ecology and Resources Engineering He Tao CollegeInner Mongolia 015000China

By encapsulating nanoscale particles of goethite(α-FeO(OH)),hydrous ceric oxide(CeO_(2)·H_(2)O,HCO)and silver nanoparticles(AgNPs)in the pores of polystyrene anion exchanger D201,a novel nanocomposite FeO(OH)-HCO-Ag-D201 was prepared for the effective removal of arsenic from *** isotherm study shows that FeO(OH)-HCO-Ag-D201 has excellent adsorption performance for As(III)and As(V),with an increased adsorption capacity of As(III)to 40.12 mg/g compared to that of 22.03 mg/g by the composite adsorbent without AgNPs(FeO(OH)-HCO-D201).The adsorption kinetics data showed that the sorption rate of FeO(OH)-HCO-Ag-D201 for As(III)is less than that for As(V),and the adsorption of As(III)and As(V)were consistent with the pseudo-second-order model and the pseudofirst-order model,*** or basic conditions are favored for the adsorption of As(III/V)by FeO(OH)-*** with nitrate/chloride/bicarbonate,sulfate/silicate/phosphate showed more remarkable inhibition of arsenic removal by FeO(OH)-HCO-Ag-D201,whereas natural organic matter showed no interference to the arsenic *** As(V)adsorption involved different interactions such as electrostatic attraction and surface complexation,while the adsorption of As(III)involved the part oxidization of As(III)to As(V)and the simultaneous adsorption of As(III)and As(V).In addition to the Ce(IV)in CeO_(2)·H_(2)O acted as an oxidant,the synergistic effect ofα-FeO(OH)and AgNPs also contributed to the oxidization of As(III)to As(V).Moreover,the reusable property suggested that this FeO(OH)-HCO-Ag-D201 nanocomposite has great potential for arsenic-contaminated water purification.

关键词： FeO(OH)-HCO-Ag-D201 Arsenic removal Synergistic effect Oxidation Electrostatic attraction Surface complexation

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