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Visual and auditory cues facilitate cache pilferage of Siberian chipmunks(Tamias sibiricus)under indoor conditions

Integrative Zoology 2019年第4期14卷 354-365页

作者： Hongyu niu wei CHU Xianfeng YI Hongmao ZHANG Institute of Ecology and Evolution School of Life SciencesCentral China Normal UniversityWuhanChina College of Life Sciences Jiangxi Normal UniversityNanchangChina Xiamen Shuangshi High School at Haicang XiamenChina.

In the struggle for survival,scatter-hoarding rodents are known to cache food and pilfer the caches of *** extent to which rodents utilize auditory/visual cues from conspecifics to improve cache-pilfering is un***,Siberian chipmunks(Tamias sibiricus)were allowed to search for caches of Corylus heterophylla seeds(man-made caches and animal-made caches)after experiencing cues from a conspecific’s cache-searching *** each type of cache,3 experimental scenarios were presented:(1)alone(control);(2)auditory/visual(hearing and seeing conspecific’s cache-searching events);and(3)auditory only(hearing conspecific’s cache-searching events only)with random *** subjects located man-made caches faster,harvested more caches,and hoarded more seeds both in the auditory/visual and the auditory only treatments compared to the control,while scatter-hoarding more seeds in the auditory/visual treatment but larder-hoarding more seeds in the auditory only *** to the control,the animals spent less time locating animal-made caches,harvested more caches,ate fewer seeds,larder-hoarded more seeds and hoarded more seeds in total both in the auditory/visual and the auditory only treatments,while eating more seeds and hoarded fewer seeds in total in the auditory only treatment than in the auditory/visual *** results also show that females spent less time locating the animal-made caches,but they scatter-hoarded fewer seeds than males in the auditory/visual treat*** the best of our knowledge,this is the first report that visual and/or auditory cues of conspecifics improve cache-pilfering and hoarding in rodents.

关键词： cache pilferage cache protection food hoarding observational spatial memory rodents

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Modified Homotopy Perturbation Method for Certain Strongly Nonlinear Oscillators

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Chinese Physics Letters 2012年第6期29卷 50-53页

作者： niu Yao-Bin WANG Zhong-wei DONG Si-wei College of Aerospace and Materials Engineering National University of Defense TechnologyChangsha 410073

A new modified homotopy perturbation method is presented for strongly non-linear oscillation by coupling the homotopy perturbation method and the modified Lindstedt-Poincare *** advantage of this method is that it does not need a small parameter in the physical system as in He's homotopy perturbation method,and the accuracy is greatly *** examples are tested,and the obtained results show that the current method is very effective and convenient for solving strongly nonlinear oscillators.

关键词： method perturbation homotopy

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Samarium doped apatite-type orange-red emitting phosphor Ca5（PO4）2SiO4 with satisfactory thermal properties for n-UV w-LEDs

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Journal of Rare Earths 2019年第9期37卷 949-954,I0002页

作者： Ze Zhang Jialiang niu wei Zhou Dingdian Xu Huanhuan Du Department of Chemistry School of ScienceBeijing Technology and Business University

A novel single-phase Sm^3+activated Ca5(PO4)2SiO4 phosphor was successfully fabricated via a conventional solid-state method,which can be e fficie ntly excited by near ultraviolet(n-UV)light-emitting *** crystal structure and luminescence properties were characterized and analyzed systematically by using relevant *** Ca5(PO4)2SiO4:Sm^3+phosphor shows an orange-red emission peaking at600 nm under the excitation of 403 nm and the optimal doping concentration of Sm^3+is determined to be 0.08,The critical distance of Ca5(PO4)2SiO4:0.08 Sm^3+is calculated to be 1.849 nm and concentration quenching mechanism of the Sm^3+in Ca5(PO4)2SiO4 host is ascribed to energy transfer between nearestneighbor *** decay time of Ca5(PO4)2 SiO4:0,08 Sm^3+is determined to be 1.1957 *** addition,the effect of temperature on the emission intensity was also studied,72.4%of the initial intensity is still preserved at 250℃,better thermal stability compared to commercial phosphor YAG:Ce^3+indicates that Ca5(PO4)2SiO4:0.08 Sm^3+has excellent thermal stability and active energy is deduced to be 0.130 *** the results demonstrate that orange-red emitting Ca5(PO4)2SiO4:0.08 Sm3+phosphor exhibits good luminescent *** to the excellent thermal quenching luminescence property,Ca5(PO4)2SiO4:0.08 Sm^3+phosphor can be applied in n-UV white light emitting diodes and serve as the warm part of white light.

关键词： Phosphors Ca5(PO4)2SiO4:Sm^3+ Luminescence Orange-red phosphor Rare earths

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On traceable iterated line graph and hamiltonian path index

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 239-252页

作者： niu Zhao-hong XIONG Li-ming YANG wei-hua School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Mathematics and Statistics Beijing Key Laboratory on MCAACIBeijing Institute of TechnologyBeijing 100081China Department of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

Xiong and Liu[21]gave a characterization of the graphs G for which the n-iterated line graph L^(n)(G)is hamiltonian,for n≥*** this paper,we study the existence of a hamiltonian path in L^(n)(G),and give a characterization of G for which L^(n)(G)has a hamiltonian *** applications,we use this characterization to give several upper bounds on the hamiltonian path index of a graph.

关键词： iterated line graph traceable hamiltonian index hamiltonian path index

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Dynamic mechanical behavior of ultra-high strength steel 30CrMnSiNi2A at high strain rates and elevated temperatures

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Journal of Iron and Steel Research International 2017年第7期24卷 724-729页

作者： Qiu-lin niu wei-wei Ming Ming Chen Si-wen Tang Peng-nan Li College of Mechanical and Electrical Engineering Hunan University of Science and Technology Hunan Provincial Key Laboratory of High Efficiency and Precision Machining of Difficult-to-Cut Material Hunan University of Science and Technology School of Mechanical Engineering Shanghai Jiao Tong University

During high speed machining in the field of manufacture,chip formation is a severe plastic deformation process including large strain,high strain rate and high *** the strain rate in high speed cutting process can be achieved to 105 s^（-1）.30CrMnSiNi2Asteel is a kind of important high-strength low-alloy structural steel with wide application *** the dynamic mechanical properties of30CrMnSiNi2Aunder the conditions of high strain rate and high temperature is necessary to construct the constitutive relation model for high speed *** dynamic compressive mechanical properties of30CrMnSiNi2Asteel were studied using split Hopkinson pressure bar（SHPB）tests at 30-700°C and3000-10000s^（-1）.The stress-strain curves of 30CrMnSiNi2Asteel at different temperatures and strain rates were investigated,and the strain hardening effect and temperature effect were *** results show that 30CrMnSiNi2Ahas obvious temperature sensitivity at 300°***,the flow stress decreased significantly with the increase of *** strain hardening effect of the material at high strain rate is not significant with the increase of *** strain rate hardening effect is obvious with increasing the *** to the experimental results,the established Johnson-Cook（J-C）constitutive model of 30CrMnSiNi2Asteel could be used at high strain rate and high temperature.

关键词： 30CrMnSiNi2A steel Dynamic mechanical behavior Split Hopkinson pressure bar High temperature High strain rate Ultra-high strength steel

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Does Diffuse Circumnuclear Gas around Sgr A^(*) Achieve Collisional Ionization Equilibrium or Remain Non-equilibrium Ionization?

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Research in Astronomy and Astrophysics 2023年第8期23卷 103-116页

作者： Shu niu Fu-Guo Xie wei Sun Li Ji Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Dark Matter and Space Astronomy Chinese Academy of SciencesNanjing 210023China

The feeding and feedback processes at the vicinity of a supermassive black hole(BH)are essential for our understanding of the connection between supermassive BH and its host *** this work,we provide a detailed investigation,both observational and theoretical,on the diffuse(~2"-20",~0.08-0.8 pc)X-ray emission around Sgr A*.Over two-decade Chandra observations are gathered to obtain highest signal-to-noise to *** find that,the line center of iron lines of the outer 8"-18"region,ε_(c)=6.65+0.02-0.03 keV,is comparable to that(ε_(c)=6.60+0.05-0.03 keV)of the inner 2"-5"*** is somewhat unexpected,since the gas temperature decreases further away from the central *** on a dynamical inflow-outflow model that considers the gas feeding by stellar winds from Wolf-Rayet stars,we calculate the X-ray spectrum based on both the conventional collisional ionization equilibrium(CIE)assumption,and the newly developed non-equilibrium ionization(NEI)*** find that,theoretically gases within~8"-10"remain in a CIE state,outside of this radius they will be in the NEI state.A comparison of the properties of~6.6 keV iron lines between CIE and NEI is ***,the NEI interpretation of outer region is supported by the Chandra line center ε_(c) measurements of this region.

关键词： X-rays diffuse background-galaxies active-Galaxy center-(galaxies:)quasars emission lines

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BHONEM:Binary High-Order Network Embedding Methods for Net worked-Guarantee Loans

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Journal of Computer Science & Technology 2019年第3期34卷 657-669页

作者： Da-wei Cheng Yi Tu Zhen-wei Ma Zhi-Bin niu Li-Qing Zhang Department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Mathematical Science Shanghai Jiao Tong University.Shanghai 200240China School of Computer Software Tianjin UniversityTianjin 300354China

Networked-guarantee loans may cause systemic risk related concern for the government and banks in *** prediction of the default of enterprise loans is a typical machine learning based classification problem, and the networked guarantee makes this problem very difficult to solve. As we know, a complex network is usually stored and represented by an adjacency matrix. It is a high-dimensional and sparse matrix, whereas machine-learning methods usually need lowdimensional dense feature representations. Therefore, in this paper, we propose a binary higher-order network embedding method to learn the low-dimensional representations of a guarantee network. We first set vertices of this heterogeneous economic network by binary roles (guarantor and guarantee), and then define high-order adjacent measures based on their roles and economic domain knowledge. Afterwards, we design a penalty parameter in the objective function to balance the importance of network structure and adjacency. We optimize it by negative sampling based gradient descent algorithms,which solve the limitation of stochastic gradient descent on weighted edges without compromising efficiency. Finally, we test our proposed method on three real-world network datasets. The result shows that this method outperforms other start-of-the-art algorithms for both classification accuracy and robustness, especially in a guarantee network.

关键词： networked-guarantee loan high-order network embedding representative learning gradient descent

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Allometry-based estimation of forest aboveground biomass combining LiDAR canopy height attributes and optical spectral indexes

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Forest Ecosystems 2022年第5期9卷 617-629页

作者： Qiuli Yang Yanjun Su Tianyu Hu Shichao jin Xiaoqiang Liu Chunyue niu Zhonghua Liu Maggi Kelly Jianxin wei Qinghua Guo State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China University of Chinese Academy of Sciences Beijing100049China Plant Phenomics Research Centre Academy for Advanced Interdisciplinary StudiesCollaborative Innovation Centre for Modern Crop Production co-sponsored by Province and MinistryNanjing Agricultural UniversityNanjing210095China Department of Environmental Sciences Policy and ManagementUniversity of CaliforniaBerkeleyCA94720-3114USA Division of Agriculture and Natural Resources University of CaliforniaBerkeleyCA94720-3114USA College of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqiXinjiang830017China Xinjiang Lidar Applied Engineering Technology Research Center UrumqiXinjiang830002China Xinjiang Land and Resources Information Center UrumqiXinjiang830002China Institute of Remote Sensing and Geographic Information System School of Earth and Space SciencesPeking UniversityBeijing100871China

Accurate estimates of forest aboveground biomass(AGB)are essential for global carbon cycle studies and have widely relied on approaches using spectral and structural information of forest canopies extracted from various remote sensing ***,combining the advantages of active and passive data sources to improve estimation accuracy remains ***,we proposed a new approach for forest AGB modeling based on allometric relationships and using the form of power-law to integrate structural and spectral *** 60 km^(2) of drone light detection and ranging(LiDAR)data and 1,370 field plot measurements,covering the four major forest types of China(coniferous forest,sub-tropical broadleaf forest,coniferous and broadleaf-leaved mixed forest,and tropical broadleaf forest),were collected together with Sentinel-2 images to evaluate the proposed *** results show that the most universally useful structural and spectral metrics are the average values of canopy height and spectral index rather than their maximum *** with structural attributes used alone,combining structural and spectral information can improve the estimation accuracy of AGB,increasing R^(2) by about 10%and reducing the root mean square error by about 22%;the accuracy of the proposed approach can yield a R^(2) of 0.7 in different forests *** proposed approach performs the best in coniferous forest,followed by sub-tropical broadleaf forest,coniferous and broadleaf-leaved mixed forest,and then tropical broadleaf ***,the simple linear regression used in the proposed method is less sensitive to sample size and outperforms statistically multivariate machine learning-based regression models such as stepwise multiple regression,artificial neural networks,and Random *** proposed approach may provide an alternative solution to map large-scale forest biomass using space-borne LiDAR and optical images with high accuracy.

关键词： Forest aboveground biomass Drone LiDAR Allometric relationship Power law Tree height Vegetation index

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Bright semiconductor single-photon sources pumped by heterogeneously integrated micropillar lasers with electrical injections

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Light(Science & Applications) 2023年第3期12卷 489-496页

作者： Xueshi Li Shunfa Liu Yuming wei Jiantao Ma Changkun Song Ying Yu Rongbin Su wei Geng Haiqiao Ni Hanqing Liu Xiangbin Su Zhichuan niu You-ling Chen jin Liu State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSchool of Electronics and Information TechnologySun Yat-sen University510275GuangzhouChina Hisilicon Research Huawei Technologies Co.Ltd518129ShenzhenChina State Key Laboratory for Superlattice and Microstructures State Key Laboratory on Integrated OptoelectronicsInstitute of SemiconductorsChinese Academy of Sciences100083BeijingChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049BeijingChina

The emerging hybrid integrated quantum photonics combines the advantages of different functional components into a single chip to meet the stringent requirements for quantum information *** the tremendous progress in hybrid integrations of III-V quantum emitters with silicon-based photonic circuits and superconducting single-photon detectors,on-chip optical excitations of quantum emitters via miniaturized lasers towards single-photon sources(SPSs)with low power consumptions,small device footprints,and excellent coherence properties is highly desirable yet *** this work,we present realizations of bright semiconductor SPSs heterogeneously integrated with on-chip electrically-injected *** from previous one-by-one transfer printing technique implemented in hybrid quantum dot(QD)photonic devices,multiple deterministically coupled QD-circular Bragg Grating(CBG)SPSs were integrated with electrically-injected micropillar lasers at one time via a potentially scalable transfer printing process assisted by the wide-field photoluminescence(PL)imaging *** pumped by electrically-injected microlasers,pure single photons are generated with a high-brightness of a count rate of 3.8 M/s and an extraction efficiency of 25.44%.Such a high-brightness is due to the enhancement by the cavity mode of the CBG,which is confirmed by a Purcell factor of *** work provides a powerful tool for advancing hybrid integrated quantum photonics in general and boosts the developments for realizing highly-compact,energy-efficient and coherent SPSs in particular.

关键词： pumped quantum photon

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Precambrian Tectonic Affinity of the Southern Langshan Area, Northeastern Margin of the Alxa Block: Evidence from Zircon U-Pb Dating and Lu-Hf Isotopes

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Acta Geologica Sinica(English Edition) 2022年第5期96卷 1516-1533页

作者： niu Pengfei QU Junfeng ZHANG jin ZHANG Beihang ZHAO Heng Key Laboratory of Deep-Earth Dynamics Ministry of Natural Resources of GeologyInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China

The Alxa Block is the westernmost part of the North China Craton(NCC), and is regarded as one of the basement components of the NCC. Its geological evolution is of great significance for the understanding of the ***, the Precambrian basement of the Alxa Block is still poorly studied. In this study, we present new in situ LA-ICPMS zircon U-Pb and Lu-Hf isotope data from the Diebusige Metamorphic Complex(DMC) which located in the eastern Alxa Block. Field and petrological studies show that the DMC consists mainly of metamorphic supracrustal rocks and minor metamorphic plutonic rocks and has experienced amphibolite-granulite facies metamorphism. Zircon U-Pb dating results suggested that the amphibolite sample yields a crystallization age of 2636 ± 14 Ma and metamorphic ages of 2517–2454 Ma and 1988–1952 Ma, proving the existence of exposed Archean rocks in the Langshan area and indicating that late Neoarchean to Paleoproterozoic metamorphic events existed in the Alxa Block. Two paragneiss samples show that the magmatic detrital zircons from the DMC yield 207Pb/206Pb ages ranging from 2.48 Ga to 2.10 Ga with two youngest peaks at 2.13 Ga and 2.16 Ga, respectively, and they were also overprinted by metamorphic events at 1.97–1.90 Ga and 1.89–1.79Ga. Compilation of U-Pb ages of magmatic detrital and metamorphic zircons suggested that the main part of the DMC may have been formed at 2.1–2.0 Ga. Zircon Lu-Hf isotope data show that the source materials of the main part of the DMC were originated from the reworking of ancient Archean crust(3.45–2.78 Ga). The Hf isotope characteristics and the tectonothermal event records exhibit different evolution history with the Khondalite Belt and the Yinshan Block and the other basements of the Alxa Block, indicating that the Langshan was likely an independent terrain before the middle Paleoproterozoic and was subjected to the middle to late Paleoproterozoic tectonothermal events with the Khondalite Belt as a whole.

关键词： zircon U-Pb dating Hf isotop Paleoproterozoic Neoarchean Diebusige Metamorphic Complex Alxa Block North China Craton

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