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Probing the sign-changeable interaction between dark energy and dark matter with current observations

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Science China(Physics,Mechanics & Astronomy) 2018年第3期61卷 1-9页

作者： Juan-Juan Guo Jing-Fei Zhang Yun-He Li dong-ze He Xin Zhang Department of Physics College of Sciences Northeastern University Center for High Energy Physics Peking University

We consider the models of vacuum energy interacting with cold dark matter in this study, in which the coupling can change sigh during the cosmological evolution. We parameterize the running coupling b by the form b（a） = boa ＋ be（1 - a）, where at the earlytime the coupling is given by a constant be and today the coupling is described by another constant bo. We explore six specific models with （i） Q = b（a）Hoρo, （ii） Q = b（a）Hoρde, （iii） Q = b（a）Hoρc, （iv） Q = b（a）Hρo, （v） Q = b（a）Hρde, and （vi） Q = b（a）Hρc. The current observational data sets we use to constrain the models include the JLA compilation of type Ia supernova data, the Planck 2015 distance priors data of cosmic microwave background observation, the baryon acoustic oscillations measurements and the Hubble constant direct measurement. We find that, for all the models, we have b0 〈 0 and be 〉 0 at around the lolevel, and b0 and be are in extremely strong anti-correlation. Our results show that the coupling changes sign during the evolution at about the lolevel, i.e., the energy transfer is from dark matter to dark energy when dark matter dominates the universe and the energy transfer is from dark energy to dark matter when dark energy dominates the universe.

关键词： interacting dark energy sign-changeable interaction running coupling observational constraints

Peroxy natural products

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Natural Products and Bioprospecting 2013年第5期3卷 161-206页

作者： dong-ze LIU Ji-Kai LIU Tianjin Institute of Industrial Biotechnology Chinese Academy of ScienceTianjin 300308China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

This review covers the structures and biological activities of peroxy natural products from a wide variety of terrestrial fungi,higher plants,and marine *** that confirm or revise structures or stereochemistries have ... 详细信息

关键词： organisms. fir chemi

Classification and existence of positive entire k-convex radial solutions for generalized nonlinear k-Hessian system

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Applied Mathematics:A Journal of Chinese Universities 2021年第4期36卷 564-582页

作者： ZHANG Li-hong YANG ze-dong WANG Guo-tao Mohammad M.Rashidi School of Mathematics and Computer Science Shanxi Normal University Shanghai Automotive Wind Tunnel Center Tongji University

In this paper, we consider the following generalized nonlinear k-Hessian system■,where G is a nonlinear operator and Sk(λ(Dz~2))stands for the k-Hessian operator. We first are interested in the classification of positive entire k-convex radial solutions for the k-Hessian system if φ(|x|, z1, z2) = b(|x|)φ(z1, z2) and ψ(|x|, z1, z2) = h(|x|)ψ(z1). Moreover, with the help of the monotone iterative method, some new existence results on the positive entire k-convex radial solutions of the k-Hessian system with the special non-linearities ψ, φ are given, which improve and extend many previous works.

关键词： 35J60 35B08 35B09 k -Hessian system entire blow-up classification of radial solutions monotone iterative method

甘草提取物的生物学功能及其在动物生产中的应用

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饲料研究 2024年第3期47卷 138-142页

作者：牟林林张冬梅尤佳庄煦申忠宝韩微波刘泽东王建丽黑龙江省农业科学院草业研究所黑龙江哈尔滨150086 黑龙江省农业科学院畜牧兽医分院黑龙江齐齐哈尔161005

甘草是豆科甘草属多年生草本植物,属药食同源植物。甘草中富含三萜皂苷类、黄酮类、香豆素、多糖类等多种生物活性成分,具有抗癌、消炎、抑菌等生物学功能。此外,甘草地上部分茎叶繁茂,营养价值高于禾本科植物,是家畜的优良饲料。天然... 详细信息

甘草是豆科甘草属多年生草本植物,属药食同源植物。甘草中富含三萜皂苷类、黄酮类、香豆素、多糖类等多种生物活性成分,具有抗癌、消炎、抑菌等生物学功能。此外,甘草地上部分茎叶繁茂,营养价值高于禾本科植物,是家畜的优良饲料。天然中草药添加剂可以促进动物生长,提高动物免疫力,推动我国畜牧业进一步发展。文章综述了甘草的活性成分、生物学功能及其在动物生产中的应用,以期为甘草饲料化的综合开发与利用提供参考。

关键词：甘草活性成分生物学功能动物生产

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Intelligent logistics system of steel bar warehouse based on ubiquitous information

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International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1367-1377页

作者： Hai-nan He Xiao-chen Wang Gong-zhuang Peng dong Xu Yang Liu Min Jiang ze-dong Wu Da Zhang He Yan National Engineering Research Center for Advanced Rolling Technology University of Science and Technology BeijingBeijing 100083China

Internet of Things and artificial intelligence technology are the key elements of the intelligent construction of iron and steel production warehouse. This paper puts forward a whole set of intelligent scheme for bar warehouse crane for the guidance of metallurgical process engineering, including cluster rapid self-awareness technology of the smart crane, precise self-executing technique of crane with rigid-flexible hybrid structure, multi-body system kinematics model of the smart crane sling and the swing characteristics model at different azimuth, antiswing control technology based on the optimization objective function, the vehicle model recognition system based on lidar, and the clustering crane dynamic scheduling method based on multi-agent reinforcement learning. The complete intelligent logistics system of the bar warehouse has changed the original operation mode of the warehouse area and realized the unmanned operation and intelligent scheduling of the crane,which is of great significance for improving the production efficiency, reducing the production cost, and improving the product quality.

关键词： intelligent warehouse crane vehicle identification anti-pendulum control multi-agent reinforcement learning

Double glow plasma carburization on zirconium to improve surface hardness and wear resistance

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Rare Metals 2017年第7期36卷 569-573页

作者： Jian-Qing Wang Hong-Bo Yang Bing Zhang Wei Xi ze dong Qin Jing State Key Laboratory o'f Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

Though some important progress in the excel- lent mechanical properties of zirconium alloys have been reported, their high surface hardness and good wear prop- erties need to be explored further. In this work, a carbur- ized layer was formed on the surface of commercially pure zirconium by a double glow plasma hydrogen-free car- burizing technique. Commercial high-purity graphite was used as the carbon source material. X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dis- persive spectroscopy （EDS）, Vickers hardness test, friction and wear test were used to characterize the samples car- burized. The carburized layer could be clearly observed under a microscope. XRD patterns indicate that the zirco- nium carbide phase is formed in the carburized layer. The surface hardness of the sample increases significantly after carburization. Friction and wear tests results show that wear resistance and friction coefficient of zirconium are improved considerably after carburization. Surface plastic deformation is arrested to a low extent in contrast with pure zirconium because of the presence of ZrC phases during the wear test. The results may provide new insight into methods for surface strengthening of zirconium alloys.

关键词： Zirconium alloys Carburization Hardness Wear resistance

Association between SERPING1 rs2511989 polymorphism and age-related macular degeneration: Meta-analysis

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 385-394页

作者： Yi dong ze-dong Li Xin-Yu Fang Xue-Feng Shi Song Chen Xin Tang Tianjin Medical University Clinical College of Ophthalmology Tianjin Medical UniversityTianjin Eye Hospital Department of Epidemiology and Statistics School of Public Health Anhui Medical University

AIM: To investigate the association between SERPING1rs2511989(G>A) polymorphism and age-related macular degeneration(AMD).METHODS: A number of electronic databases(up to July 15, 2014) were searched independently by two investigators. A Meta-analysis was performed on the association between SERPING1 rs2511989 polymorphism and AMD. Pooled odds ratios(ORs) with 95% confidence intervals(CIs) were ***: Eight studies with 16 cohorts consisting of9163 cases and 6813 controls were included in this Metaanalysis. There was no significant association between rs2511989 polymorphism and AMD under all genetic models in overall estimates(A vs G: OR= 0.938, 95%CI =0.858-1.025; AA vs GG:OR =0.871, 95% CI =0.719-1.056;AG vs GG: OR =0.944, 95% CI =0.845-1.054; AA +AG vs GG: OR =0.927, 95% CI =0.823-1.044; AA vs AG +GG:OR =0.890, 95% CI =0.780-1.034). Cumulative Meta-analyses also showed a trend of no association between rs2511989 polymorphism and AMD as information accumulated by year. Subgroup analysis and Meta-regression analysis indicated that age-matching status was the main source of heterogeneity. Sensitivity analysis found the results in overall comparisons and subgroup comparisons of white subjects under the allele model were found to have significantly statistical differences after studies deviating from Hardy-Weinberg equilibrium(HWE) were excluded(overall: OR=0.918, 95%CI = 0.844-0.999, P =0.049; whites: OR =0.901, 95% CI =0.817-0.994, P =0.038). However, the results were notsufficiently robust for further sensitivity analysis and statistical differences disappeared on applying Bonferroni correction(with a significance level set at 0.05/25).CONCLUSION: This Meta-analysis indicates that SERPING1 rs2511989 polymorphism and AMD tend to have no association with each other. Age matching status is a big confounding factor, and more studies with subtle designs are warranted in future.

关键词： age-relatedmaculardegeneration SERPING1 single nucleotide polymorphism Meta-analysis

Microstructure and superconducting properties of (BaTiO3,Y2O3)-doped YBCO films under different firing temperatures

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Rare Metals 2017年第1期36卷 37-41页

作者： Hong-Yan Wang Fa-Zhu Ding Hong-Wei Gu Hui-Liang Zhang ze-Bin dong University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Applied Superconductivity Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190 China

YBaCuO(YBCO) films with co-doping of Ba Ti O(BTO) and YOnanostructures were successfully fabricated on La Al O(LAO) substrate by metal organic deposition using trifluoroacetates(TFA-MOD). The focus of this study was to optimize the process conditions during the firing heat treatment of high critical current density(J C)-co-doped YBCO films. The effect of the firing temperatures on both the surface morphology and the superconducting properties for the doped YBCO films was systematically studied. According to the X-ray diffraction(XRD) and scanning electron microscopy(SEM) results,the films prepared at 820 and 850 °C show poor electrical performance due to impurity phases and large pores. In contrast, the dense YBCO films prepared at 830 and840 °C with the critical current densities of 10 MA-cm(77 K, 0 T) are obtained.

关键词： YBa2Cu3O7-x BaTiO3 and Y2O3 nanostructures Firing temperature TFA-MOD

Redshift drift constraints on f（T） gravity

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Frontiers of physics 2015年第5期10卷 1-6页

作者： Jia-Jia Geng Rui-Yun Guo dong-ze He Jing-Fei Zhang Xin Zhang Department of Physics College of Sciences Northeastern University Shenyang 110004 China Center for High Energy Physics Peking University Beijing 100080 China

We explore the impact of the Sandage-Loeb （SL） test on the precision of cosmological constraints for f（T） gravity theories. The SL test is an important supplement to current cosmological observations because it measures the redshift drift in the Lyman-α forest in the spectra of distant quasars, covering the ＂redshift desert＂ of 2 ≤ z ≤ 5. To avoid data inconsistency, we use the best-fit models based on current combined observational data as fiducial models to simulate 30 mock SL test data. We quantify the impact of these SL test data on parameter estimation for f（T） gravity theories. Two typical f（T） models are considered, the power-law model f（T）pL and the exponential-form model f（T）Exp. The results show that the SL test can effectively break the existing strong degeneracy between the present-day matter density Ωm and the Hubble constant Ho in other cosmological observations. For the considered f（T） models, a 30-year observation of the SL test can improve the constraint precision of Ωm and H0 enormously but cannot effectively improve the constraint precision of the model parameters.

关键词： redshift drift cosmological constraints dark energy modified gravity f(T) gravity