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Decadal length-of-day and geomagnetic changes imply more complex Earth’s core motions

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Science Bulletin 2024年第13期69卷 2038-2041页

作者： Hao ding Jiancheng Li Weiping jiang Wenbin Shen School of Geodesy and Geomatics Hubei Luojia LaboratoryWuhan UniversityWuhan 430079China GNSS Research Center Wuhan UniversityWuhan 430079China

Since the 1950s,the length-of-day variations(DLOD)of the Earth’s rotation have received extensive attention and research in various fields,including geodynamics,geomagnetism,geodesy,seismology,geology,marine science,environmental science,and even biology and *** the abundance of related studies and notable advancements,the underlying mechanism behind the decadal changes in DLOD remains a persistent unresolved *** essential aspect of investigating this issue lies in its potential to unveil the Earth’s core motions[1,2].Despite the presence of various hypothesized and constructed models about the Earth’s core motions,these models typically exhibit simplicity.

关键词： Earth geology geomagnetic

Helicobacter pylori infection and peptic ulcer disease in cirrhotic patients:An updated meta-analysis

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World Journal of Clinical Cases 2021年第24期9卷 7073-7084页

作者： Lin Wei hui-Guo ding Department of Gastroenterology and Hepatology Beijing You’an Hospital Affiliated with Capital Medical UniversityBeijing 100069China

BACKGROUND Peptic ulcer(PU)is more prevalent in patients with liver *** role of Helicobacter pylori(***)infection in the pathogenesis of PU in patients with cirrhosis is still not *** To perform a meta-analysis on the prevalence of *** infection and PU and their association in liver cirrhosis *** We searched PubMed,EMBASE,Web of Science,Cochrane,CNKI,Wangfang,and CQVIP databases from inception to July 10,*** ratio(OR)and 95%confidence interval(CI)were pooled using a random-effects *** statistical heterogeneity among studies(I2-index),subgroup analyses,regression analysis,sensitivity analysis,and the possibility of publication bias were *** A total of 14 studies(13 cross-sectional studies;1 cohort study)involving 2775 individuals(611 cases with PU and 2164 controls)were included in our *** prevalence of PU in patients with cirrhosis was 22%.The prevalence of *** infection was 65.6%in cirrhotic patients with PU,and 52.5%in those *** pooled overall OR was 1.73(95%CI:1.16-2.56,I2=66.2%,P<0.001,Z=2.7,Pz<0.05).We did not find the cause of heterogeneity in the subgroup analyses and meta-regression analysis except for one *** plot did not show significant publication *** results of Begg’s test and Egger’s test indicated no evidence of substantial publication bias(P_(Begg)=0.732,P_(Egger)=0.557).CONCLUSION There is a weakly positive association between *** infection and PU in patients with liver *** is suggested that *** infection may play a role in the pathogenesis of PU in liver cirrhotic patients.

关键词： Helicobacter pylori Peptic ulcer Cirrhosis Meta-analysis Infection

An open-loop control algorithm of the active reflector system of FAST

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Research in Astronomy and Astrophysics 2020年第5期20卷 93-102页

作者： hui Li Peng jiang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

An open-loop control algorithm is put forward for continuous paraboloid deformation of the active reflector system of the Five-hundred-meter Aperture Spherical radio Telescope(FAST).The method is based on a calibration database and interpolation in 2D spatial domain and temperature domain,*** is completely independent of real-time measurement of cable nodes so that it has advantage of working all-weather and no additional electro-magnetic interference(EMI).Furthermore,its control accuracy can be effectively improved via reasonable layout of the calibrated paraboloids and increasing calibration *** deformation safety is considered via calibration as *** its control accuracy is also confirmed via site measurements of paraboloid deformations.

关键词： Astronomical instrumentation:methods and techniques methods:data analysis methods:numerical

Revisit of Dynamical Mechanisms of Transporting Asteroids in the 3:1 Resonance to the Near-Earth Space

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Chinese Journal of Astronomy and Astrophysics 2007年第1期7卷 148-154页

作者： jiang-hui Ji Lin Liu Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 Department of Astronomy Nanjing University Nanjing 210093 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

It is well-known that the asteroids in the main belt trapped in the 3：1 Mean Motion Resonance （MMR） with Jupiter （at semi-major axes -2.5 AU） are few in number, forming one of the so-called Kirkwood Gaps. Wisdom pointed out that chaotic motion of such aster- oids can increase their eccentricities and make them approach and cross the orbit of Mars （or even the Earth）. We numerically investigated the orbital evolution of the asteroids involved in 3：1 MMR （NEOs） over millions of years and revisited the dynamical mechanisms of trasporitng such asteroids into the NEO region. The results show that the dynamical evolution of the asteroids around 2.5 AU is mainly dominated by the 3：1 resonance, the v5 and v6 secular resonances and the Kozai resonance, and these bodies can evolve into NEOs through several of the dynamical mechanisms, so indicating possible dynamical origin of the NEOs.

关键词： celestial mechanics-near-Earth Objects-mean motion resonance-secular resonance

Enhancing forest insect outbreak detection by integrating tree-ring and climate variables

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Journal of Forestry Research 2024年第6期35卷 279-293页

作者： Yao jiang Zhou Wang Zhongrui Zhang Xiaogang ding Shaowei jiang jianguo Huang Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems Guangdong Provincial Key Laboratory of Applied BotanySouth China Botanical GardenChinese Academy of SciencesGuangzhou 510650People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Ministry of Emergency Management of China National Institute of Natural HazardsBeijing 100085People’s Republic of China MOE Key Laboratory of Biosystems Homeostasis and Protection College of Life SciencesZhejiang UniversityHangzhou 310000People’s Republic of China Guangdong Academy of Forestry Guangzhou 510520People’s Republic of China

Annual tree rings are widely recognized as valuable tools for quantifying and reconstructing historical forest ***,the influence of climate can complicate the detection of disturbance signals,leading to limited accuracy in existing *** this study,we propose a random under-sampling boosting(RUB)classifier that integrates both tree-ring and climate variables to enhance the detection of forest insect *** study focused on 32 sites in Alberta,Canada,which documented insect outbreaks from 1939 to *** thorough feature engineering,model development,and tenfold cross-validation,multiple machine learning(ML)models were *** models used ring width indices(RWIs)and climate variables within an 11-year window as input features,with outbreak and non-outbreak occurrences as the corresponding output *** results reveal that the RUB model consistently demonstrated superior overall performance and stability,with an accuracy of 88.1%,which surpassed that of the other ML *** addition,the relative importance of the feature variables followed the order RWIs>mean maximum temperature(Tmax)from May to July>mean total precipita-tion(Pmean)in July>mean minimum temperature(Tmin)in *** importantly,the dfoliatR(an R package for detecting insect defoliation)and curve intervention detec-tion methods were inferior to the RUB *** findings underscore that integrating tree-ring width and climate vari-ables as predictors in machine learning offers a promising avenue for enhancing the accuracy of detecting forest insect outbreaks.

关键词： Forest disturbance Insect outbreaks Machine learning Tree-ring analysis

Encapsulating soluble active species into hollow crystalline porous capsules beyond integration of homogeneous and heterogeneous catalysis

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National Science Review 2020年第1期7卷 37-45页

作者： Guorui Cai Meili ding Qianye Wu Hai-Long jiang Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Soft Matter Chemistry Collaborative Innovation Center of Suzhou Nano Science and Technology Department of Chemistry University of Science and Technology of China

Homogeneous molecular catalysts and heterogeneous catalysts possess complementary strengths, and are of great importance in laboratory/commercial procedures. While various porous hosts, such as polymers, carbons, silica, metal oxides and zeolites, have been used in an attempt to heterogenize homogeneous catalysts, realizing the integration of both functions at the expense of discounting their respective advantages, it remains a significant challenge to truly combine their intrinsic strengths in a single catalyst without compromise. Here, we describe a general template-assisted approach to incorporating soluble molecular catalysts into the hollow porous capsule, which prevents their leaching due to the absence of large intergranular space. In the resultant yolk(soluble)–shell(crystalline) capsules, the soluble yolks can perform their intrinsic activity in a mimetic homogeneous environment, and the crystalline porous shells endow the former with selective permeability, substrate enrichment, size-selective and heterogeneous cascade catalysis, beyond the integration of the respective advantages of homogeneous and heterogeneous catalysts.

关键词： metal–organic frameworks hollow capsules molecular catalyst heterogeneous catalysis cascade reaction

Numerical Study of φ^4 Model by Potential Importance Sampling Method

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Communications in Theoretical Physics 2006年第5期45卷 873-876页

作者： YUAN Qing-Xin ding Guo-hui Department of Mathematics and Physics Zhengzhou Institute of Aeronautical Industry Management Zhengzhou 450015 China Department of Physics Shanghai Jiao Tong University Shanghai 200030 China

We investigate the phenomena of spontaneous symmetry breaking for φ^4 model on a square lattice in the parameter space by using the potential importance samplingmethod, which was proposed by Milchev, Heermann, and Binder [J. Star. Phys. 44 （1986） 749]. The critical values of the parameters allow us to determine the phase diagram of the model. At the same time, some relevant quantifies such as susceptibility and specific heat are also obtained.

关键词： symmetry breaking potential importance sampling method φ4 model

Electron-Electron Collision Term Describing the Reflections Induced Scattering in a Magnetized Plasma

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Chinese Physics Letters 2019年第7期36卷 56-60页

作者： Chao Dong ding Li Chang jiang Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 University of Chinese Academy of Sciences Beijing 100049 Songshan Lake Materials Laboratory Dongguan 523808

For an electron-electron collision with characteristic scale length larger than the relative gyro-radius of the two colliding electrons, when the initial relative parallel kinetic energy cannot surmount the Coulomb repulsive potential, reflection will occur with interchange of the parallel velocities of the two electrons after the collision. The Fokker–Planck approach is employed to derive the electron collision term C_R describing parallel velocity scattering due to the reflections for a magnetized plasma where the average electron gyro-radius is much smaller than the Debye length but much larger than the Landau length. The electron parallel velocity friction and diffusion coefficients due to the reflections are evaluated, which are found not to depend on the electron perpendicular velocity. By studying the temporal evolution of the H quantity due to CR, it is found that C_R eventually makes the system relax to a state in which the electron parallel velocity distribution is decoupled from the perpendicular velocity distribution.

关键词： For an electron-electron scale length larger velocity distribution

Transverse Rutherford Scattering of Electron-Ion Collision in a Uniformly Magnetized Plasma

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Chinese Physics Letters 2022年第2期39卷 43-46页

作者： Chang jiang Chao Dong ding Li Laboratory of Soft Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China

Rutherford scattering formula plays an important role in plasma classical *** is urgent to investigate influence of magnetic field on the Rutherford scattering since the high magnetic field has been widely used in nowadays magnetic confinement fusion,inertial confinement fusion,and magneto-inertial *** order to elucidate the magnetic field effect in a concise manner,we study the electron-ion collisions transverse to the magnetic *** scattering angle is defined using the directions of electron velocity before and after collision,which is obtained *** is found that the scattering angle can be influenced by finite magnetic field *** theoretical results agree well with numerical calculation by checking the dependence of scattering angle on the magnetic field.

关键词： field Electron directions