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Environmental characteristics of Mid-Holocene recorded by lacustrine sediments from Lake Daihai, north environment sensitive zone, china

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Science china Earth Sciences 2006年第9期49卷 968-981页

作者： SUN Qianli1,2, ZHOU Jie1, SHEN Ji3. CHEN Peng1,2, WU Feng1,2 & xiE xiuping1,2 1. state Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, xi’an 710075, china 2. Graduate university of Chinese Academy of Sciences, Beijing 10003., china 3. Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, china 1. state Key Lab of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China 2. Graduate university of Chinese Academy of Sciences Beijing 100039 China 3. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China

Climate proxies, such as total organic carbon and nitrogen (TOC, TN), carbonate content (CaCO3., grain-size and pollen of the sediment core retrieved from enclosed Lake Daihai which lies in the north china environment sensitive zone are analyzed to reconstruct the environment evolution of the area based on high-resolution radiocarbon chronology. The results reveal that the TOC and TN contents of the sediments correlate well with pollen percentage and pollen flux variations during the Holocene, and both reach their peak values simultaneously at 6.7―3.5 ka BP (calendar age, 7.6―3.6 ka BP). Since 6.7 ka BP, both the CaCO3.and organic matter contents of the core have simultaneous variations, and their high values also occur during 6.7―3.5 ka BP. While during 9.0―6.7 ka BP (calendar age, 10―7.6 ka BP) relatively lower level of organic matter content and pollen flux corre- spond to the higher level of carbonate content. The above relations suggest that during 6.7―3.5 ka BP, the productivity and effective precipitation were greatly improved in the lake drainage area, and this would probably strengthen the hydrodynamic conditions, enhancing organic matter, pollen and carbonate inputs from terrestrial sources. Such processes would account for the enrichment of both organic matter and carbonate in the sediments. While during 9.0―6.7 ka BP, the lower level of or- ganic matter, pollen flux but high carbonate content show depressed productivity and declined vege- tation coverage. The higher carbonate content at this stage would have probably resulted from the higher evaporation ratio of the lake water under relatively drier climate conditions. Therefore, it is in- ferred that during 6.7―3.5 ka BP, the climate was more humid with abundant rainfalls and vegetation was more flourishing in the Lake Daihai area. This can be seen as Holocene Climate Optimum (HCO). As a result, this has evident discrepancies with the traditional notion that the HCO occurs at Early Holocene or early Mid

关键词： Lake Daihai, Mid-Holocene, lacustrine sediments, environmental characteristics.

An e-quality control model for multistage machining processes of workpieces

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Science china(Technological Sciences) 2008年第12期51卷 2168-2184页

作者： LIU DaoYu,JIANG PingYu & ZHANG YingFeng state Key laboratory for Manufacturing Systems Engineering,xi’an Jiaotong university,xi’an 710049,{3. state Key laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University Xi’an 710049 China

To track and control the changes of process quality attributes in multistage machining processes(MMPs),an e-quality control(e-QC) model is *** e-QC model is defined as a quality information service node with e-formalizing technology,whose input/output and intermediate process(that is IPO) are known to other nodes,and its implemention in MMPs is *** order to establish the e-QC model,a measuring network is constructed to acquire the original quality data,and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC,which can be tracked by information template network in real ***,a hierarchical control method is adopted to coordinate e-QCs,in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process *** last,a prototype is developed to verify the proposed methods.

关键词： machining process flow e-quality control model measuring network information template quality information tracking hierarchical control

Inferring the spin distribution of binary black holes using deep learning

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Chinese Physics C 2024年第10期48卷 275-283页

作者： Li Tang xi-Long Fan School of Math and Physics Mianyang Teachers'CollegeMianyang 621000China School of Physics and Technology Wuhan UniversityWuhan 430072 China

The spin characteristics of black holes offer valuable insights into the evolutionary pathways of their progenitor *** is crucial for understanding the broader population properties of black *** hierarchical Bayesian inference techniques employed to discern these properties often demand substantial time,and consensus regarding the spin distribution of binary black hole(BBH)systems remains *** this study,leveraging observations from GWTC-3.we adopted a machine learning approach to infer the spin distribution of black holes within BBH ***,we developed a deep neural network(DNN)and trained it using data generated from a Beta *** training strategy,involving the segregation of data into 10 bins,not only expedites model training but also enhances the versatility and adaptability of the DNN to accommodate the growing volume of gravitational wave *** Monte Carlo-bootstrap(MC-bootstrap)to generate observation-simulated samples,we derived spin distribution parameters:α=1.3.(-0.18)^(+0.25),β=1.70_(-0.29)^(+0.24)for the larger BH sample and α=1.3._(-0.20)^(+0.3.),β=1.63.(-0.20)^(+0.3.) for the smaller BH *** our constraints,the distributions of component spin magnitudes suggest the likelihood of both black holes in the BBH merger possessing non-zero spin.

关键词： gravitational wave black hole merges deep learning

A modified multi-reference second order perturbation theory

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中国科学：化学英文版 2010年第4期53卷 933-939页

作者： LI AnYang1, HAN Huixian2, SUO BingBing3. WANG YuBin3.& WEN ZhenYi3.1Institute of Computational Chemistry, Chongqing university of Post and Telecommunications, Chongqing 400065, china 2Department of Physics, Northwest university, xi’ an 710069, china 3.nstitute of Modern Physics, Northwest university, xi’ an 710069, china 1. Institute of Computational Chemistry Chongqing University of Post and Telecommunications Chongqing 400065 China2. Department of Physics Northwest University Xi’ an 710069 China3. Institute of Modern Physics Northwest University Xi’ an 710069 China

A new scheme with extended model space is proposed to improve the calculation of multi-reference second order perturbation theory (MRPT2). The new scheme preserves the concise code structure of the original program, and avoids intruder states in constructions of the potential energy surface, which is confirmed by a series of comparable calculations. The new MRPT2 program is an available tool for the research of molecular excited states and electronic spectrum.

关键词： perturbation theory multi-reference intruder state

CONSTRAINTS ON THE CRACK TIP PLASTIC FIELDS UNDER LARGE SCALE YIELD

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Acta Mechanica Solida Sinica 2001年第2期14卷 138-146页

作者： Xu Fei~1 Guo Wanlin~(1,2) (1 state Key laboratory of Mechanical Structure Strength and Vibration, xi’an Jiaotong university, xi’an 710049, {3.) (2 School of Aeronautics and Astronautics,Nanjing university of Aeronautics and Astronautics, Nanjing 210016, {3.) state Key laboratory of Mechanical Structure Strength and Vibration Xl'an Jiaotong University，Xi'an 710049，China state Key laboratory of Mechanical Structure Strength and Vibration Xl'an Jiaotong University，Xi'an 710049，China School of Aeronautics and Astronautics Nanfing University of Aeronautics and Astronautics，Nanjing 210016，China

Plane strain elastic-plastic finite element analyses are used tostudy the stress, strain fields around a straight crack in powerhardening plastic material. Center crack panel (CCP), single edgecrack panel (SECP) and double edge crack panel (DECP) tensionspecimens are analyzed with various crack lengths. Two localconstraint parameters, i.e. in-plane stress ratio T_x andout-of-plane constraint T_z are an- alyzed, which are defined astangential stress dividing normal (open) stress and out-of-planestress dividing the sum of tangential stress and normal stressrespectively.

关键词： constraint in-plane stress ratio out-of-plane constraint

X-ray spectra induced in highly charged 40Ar^q+ interacting with Au surface

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Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 203-212页

作者： ZHANG xiao’an1,2, xiAO Guoqing1, YANG Zhihu1, CHEN ximeng3. ZHAO Yongtao1, LI Fuli4, ZHANG Yinping1, CUI Ying3. ZHANG Hongqiang3. XU Xu3. SHAO Jianxiong3.& ZHAN Wenlong11. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73.000, china 2. Department of Physics, xianyang Normal university, xianyang 712000, china 3. Department of Modern Physics, Lanzhou university, Lanzhou 73.000, china 4. Department of Applied Physics, xi’an Jiaotong university, xi’an 710049, china 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. Department of Physics Xianyang Normal University Xianyang 712000 China 3. Department of Modern Physics Lanzhou University Lanzhou 730000 China 4. Department of Applied Physics Xi’an Jiaotong University Xi’an 710049 China

By use of optical spectrum technology, the spectra of X-ray induced by highly charged 40Arq+ ions interacting with Au surface have been studied. The results show that the argon Kα X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar16+ion, with electronic con-figuration 1s2 in its ground state below the solid surface. The yield of the projectile Kα X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy.

关键词： highly charged ion hollow multi-electron excitation X- ray.

Multi-carbazole derivatives for two-photon absorption data storage:Synthesis,optical properties and theoretical calculation

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Science china Chemistry 2010年第4期53卷 884-890页

作者： LI Lin1, YANG Jiaxiang1,2, WANG Caixia1, HU ZhangJun1, TIAN YuPeng1,2, LI Jing3. WANG ChuanKui3. LI Ming4, CHENG GuangHua4, TANG HuoHong5, HUANG WenHao5, TAO XuTang2 & JIANG MinHua2 1Department of Chemistry, Anhui university, Hefei 23.03., china 2state Key {3. of Crystal Materials, Institute of Crystal Materials of Shandong university, Jinan 250100, china 3.epartment of Physics, Shandong Normal university, Jinan 250014, china 4state Key {3. of Transient Optics and Photonics, xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, xi’an 710119, china 5Department of Precision Machinery and Precision Instrumentation, university of Science and Technology of china, Hefei 23.026, china 1. Department of Chemistry Anhui University Hefei 230039 China2. State Key Laboratory of Crystal Materials Institute of Crystal Materials of Shandong University Jinan 250100 China3. Department of Physics Shandong Normal University Jinan 250014 China4. State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710119 China5. Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei 230026 China

Two novel quadrupolar organic compounds, 3.(4-((E)-2-(9-butyl-9H-carbazol-6-yl) vinyl)styryl)-9-propyl-9H-carbazole (BCSPC) and 3.(3.(3.((1E)-2-(4-((E)-2-(3.(3.5-bis(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazol-6-yl)vinyl)phenyl) vinyl)-9-butyl-9H-carbazol-6-yl)-5-(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazole (BCPBC), with different conjugated arms, have been designed and synthesized. Their one-and two-photon absorption (TPA) and excited fluorescence properties have been experimentally investigated. The two-photon absorption cross-sections of two compounds were estimated by two-photon excited fluorescence technique using 200 fs, 76 MHz, Ti:sapphire laser, which are 22 and 154 GM for BCSPC and BCPBC, respectively. The optimal excitation wavelengths are 780 nm for both BCSPC and BCPBC. A data recording experiment proved the potential application of the materials.

关键词： initiator optical data storage fluorescence two-photon absorption theoretical calculation

Distributed fiber optic sensors for tunnel monitoring:A state-of-the-art review

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3841-3863页

作者： Xuehui Zhang Honghu Zhu xi Jiang Wout Broere Geo-Engineering Section Department of Geoscience and EngineeringDelft University of TechnologyDelft2628CNthe Netherlands School of Earth Sciences and Engineering Nanjing UniversityNanjing210023China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina

Distributed fiber optic sensors(DFOSs)possess the capability to measure strain and temperature variations over long distances,demonstrating outstanding potential for monitoring underground *** study presents a state-of-the-art review of the DFOS applications for monitoring and assessing the deformation behavior of typical tunnel infrastructure,including bored tunnels,conventional tunnels,as well as immersed and cut-and-cover *** systems based on Brillouin and Rayleigh scattering principles are both *** implementing DFOS monitoring,the fiber optic cable can be primarily installed along transverse and longitudinal directions to(1)measure distributed strains by continuously adhering the fiber to the structure’s surface or embedding it in the lining,or(2)measure point displacements by spot-anchoring it on the lining *** are four critical aspects of DFOS monitoring,including proper selection of the sensing fiber,selection of the measuring principle for the specific application,design of an effective sensor layout,and establishment of robust field sensor *** four issues are comprehensively discussed,and practical suggestions are provided for the implementation of DFOS in tunnel infrastructure monitoring.

关键词： Distributed fiber optic sensor(DFOS) Tunnel infrastructure Distributed strain sensing Point displacement monitoring Field instrumentation

Surface pollen and modern vegetation in Southern xinjiang,china

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Science china Earth Sciences 2024年第2期67卷 510-530页

作者： Yun ZHANG Lixin CHEN Yaoyao xi Zhaochen KONG xianguo QIAO state Key laboratory of Black Soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun130102China Institute of Botany Chinese Academy of SciencesBeijing100093China Key laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China university of Chinese Academy of Sciences Beijing100049China School of Geosciences and Resources China University of Geosciences(Beijing)Beijing100083China

The study of modern pollen,and vegetation can improve the accuracy of paleoenvironmental reconstruction based on fossil pollen data.A total of 188 pollen surface samples were collected from Southern xinjiang(3.°00’–43.00’N,74°00’–94°00’E)in china,with an elevation range of 888–453. *** pollen and vegetation were studied in the northern region of the Kunlun Mountains and the southern region of the Tianshan *** results showed that the surface pollen assemblages on the southern slope of the Tianshan Mountains(3.3.–1124 m)were divided into three pollen zones,namely,montane steppe,montane desert steppe,and montane *** zones were dominated by Artemisia,Chenopodiaceae,and Ephedra *** surface pollen assemblages in the eastern Pamir Plateau(453.–1287 m)could be divided into alpine meadow,montane desert steppe,and montane desert zones,which were predominantly characterized by Artemisia,Chenopodiaceae,and Asteraceae ***,the Southern Tarim Basin(3.48–888 m)comprised montane desert steppe and montane desert zones,which was dominated by Artemisia and Chenopodiaceae *** geographic distribution of the surface pollen sites obtained using ArcGIS,the R-value,and Pearson correlation analyses indicated that the over-represented Picea and Pinus pollen were of external origin and were transported by wind,water(rivers),and ice(glacier movement).Over-representation of Ephedra and Nitraria pollen was mainly distributed in the montane desert and desert steppe zones,*** from Chenopodiaceae and Artemisia were over-represented and broadly distributed across Southern *** pollen was concentrated in areas with walnut trees,strongly indicating the presence of local parent *** to the Hybrid Singleparticle Lagrangian integrated Trajectory model,more Pinus pollen was transported to the Pamir region by external airflows during spring and summer,resulting in its higher surface pollen *** elucidating t

关键词： Surface pollen Vegetation Distribution Picea Southern xinjiang