检索结果-南通市图书馆

Acta Geologica Sinica(English Edition) 2013年第3期87卷 686-689页

作者： wang Xuri Chiappe M. LUIS TENG Fangfang ji qiang Institute of Geology Chinese Academy of Geological Sciences The Dinosaur Institute Natural History Museum of Los Angeles County Xinghai Paleontological Museum of Dalian

We describe a new species of Early Cretaceous bird from the Yixian Formation of Liaoning Province. Xinghaiornis lini gen. et sp. nov. is relatively large and characterized by a long, toothless rostrum and an elevated pedal digit I. The design of the skull and feet suggests that this bird was likely a mud-prober. This discovery provides strong support indicating that this avian trophic specialization originated at least 125 million years ago.

关键词： Early Cretaceous Xinghaiornis lini Yixian Formation avian trophic specialization

Simulation of chemical kinetics in sodium-concrete interactions

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Nuclear Science and Techniques 2006年第1期17卷 53-60页

作者： ZHANG Bin ZHU ji-Zhou SHAN jian-qiang wang Xue-Rong Nuclear Safety Group Nuclear Engineering Department Xi＇an Jiaotong University Xi＇an 710049 China

Sodium-concrete interaction is a key safety-related issue in safety analysis of liquid metal cooled fast breeder reactors (LMFBRs). The chemical kinetics model is a key component of the sodium-concrete interaction model. Conservation equations integrated in sodium-concrete interaction model cannot be solved without a set of re-lationships that couple the equations together, and this may be done by the chemical kinetics model. Simultaneously, simulation of chemical kinetics is difficult due to complexity of the mechanism of chemical reactions between sodium and concrete. This paper describes the chemical kinetics simulation under some hypotheses. The chemical kinetics model was integrated with the conservation equations to form a computer code. Penetration depth, penetration rate, hydrogen flux, reaction heat, etc. can be provided by this code. Theoretical models and computational procedure were recounted in detail. Good agreements of an overall transient behavior were obtained in a series of sodium-concrete interaction experiment analysis. Comparison between analytical and experimental results showed that the chemical kinetics model presented in this paper was creditable and reasonable for simulating the sodium-concrete interactions.

关键词：化学动力学钠凝固交互作用 LMFBRs

The impact of Bt cotton adoption on the stability of pesticide use

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Journal of Integrative Agriculture 2017年第10期16卷 2346-2356页

作者： QIAO Fang-bin HUANG ji-kun wang Shu-kun LI qiang China Economics and Management Academy Central University of Finance and Economics China Center for Agricultural Policy School of Advanced Agricultural SciencesPeking University Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences School of Economics & Management Beijing Forestry University

Even though the impact of Bacillus thuringiensis （Bt） cotton on pesticide use has been well documented, all previous stud- ies focus on the mean value of pesticide use. Using seven unique waves of panel data collected between 1999 and 2012 in China, we show that Bt cotton adoption has not only caused a reduction of the mean value of pasticide use, but also a reduction of the standard deviation of pesticide use. We conclude that Bt technology adoption has also contributed to the stability of pesticide use in cotton production. We believe that this contribution is theoretically and practically relevant because of the long length of our unique dataset.

关键词： stability pesticide use Bt cotton household panel data China

Adaptive waveform design based on Morlet wavelet for ultra-wideband MIMO radar

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Journal of Systems Engineering and Electronics 2016年第2期27卷 362-369页

作者： Chenhe ji Yaoliang Song qiang Du School of Electronic and Optical Engineering Nanjing University of Science and Technology

For the issue of deterioration in detection performance caused by dynamically changing environment in ultra-wideband（UWB） multiple input multiple output（MIMO） radar, this paper proposes a novel adaptive waveform design which is aimed to improve the ability of discriminating target and clutter from the radar scene. Firstly, a sequence of Morlet wavelet pulses with frequency hopping and pulse position modulation by Welch-Costas array is designed. Then a waveform optimization solution is proposed which is achieved by applying the minimization mutual-information（MI） strategy. After that, with subsequent iterations of the algorithm, simulation results demonstrate that the optimal waveform design method brings an improvement in the target detection ability in the presence of noise and clutter.

关键词： ultra-wideband(UWB) radar multiple input multiple output(MIMO) waveform design Morlet wavelet mutual information(MI)

Photocatalytic degradating methyl orange in water phase by UV-irradiated CdS carried by carbon nanotubes

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Science China(Technological Sciences) 2007年第3期50卷 279-289页

作者： LI ChenSha TANG YaPing KANG BoNan wang BinSong ZHOU Feng MA qiang XIAO ji wang DaZhi LIANG ji Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China New Material Division Institute of Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China Department of Chemistry Tsinghua UniversityBeijing 100084China School of Chemistry and Materials Science Heilongjiang UniversityHarbin 150080China

A new candidate for photocatalytic degradating organic dyes,CdS carried by car-bon nanotubes(CdS/CNTs) ,is reported. The degradation ratio curves of methyl orange in water phase show that the capability for degradating organic molecules of CdS/CNTs is obviously higher than that of separated CdS. The degradation ca-pability enhances as the increase of the amount of net CdS catalyst,the ratio of carbon nanotubes to CdS,and the area of the template,and is influenced by the pH value and the temperature of aqueous solution. These results suggest that the photocatalyst of CdS/CNTs is very suitable for potential applications in organic waste removal from water.

关键词： carbon nanotube cadmium sulfide methyl orange photocatalysis

Reduction of residual stress in porous Ti6Al4V by in situ double scanning during laser additive manufacturing

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1844-1853页

作者： Yi-wa Luo Ming-yong wang ji-guo Tu Yu jiang Shu-qiang jiao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Department of Orthopedics Peking University Third HospitalBeijing 100191China

Selective laser melting(SLM)technology plays an important role in the preparation of porous titanium(Ti)implants with complex structures and precise ***,the processing characteristics of this technology,which include rapid melting and solidification,lead to products with high residual ***,an in situ method was developed to restrain the residual stress and improve the mechanical strength of porous Ti alloys during laser additive *** brief,porous Ti6Al4V was prepared by an SLM three-dimensional(3D)printer equipped with a double laser system that could rescan each layer immediately after solidification of the molten powder,thus reducing the temperature gradient and avoiding rapid melting and *** indicated that double scanning can provide stronger bonding conditions for the honeycomb structure and improve the yield strength and elastic modulus of the *** with an energy density of 75%resulted in 33.5%–38.0%reductions in residual *** porosities of double-scanned specimens were 2%–4%lower than those of singlescanned specimens,and the differences noted increased with increasing sheet *** rescanning laser power should be reduced during the preparation of porous Ti with thick cell walls to ensure dimensional accuracy.

关键词： porous titanium selective laser melting additive manufacturing residual stress mechanical properties

Identifying Three New AGNs among Fermi Unidentified Gigaelectronvolt Sources

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Research in Astronomy and Astrophysics 2024年第7期24卷 257-267页

作者： Shun-Hao ji Zhong-Xiang wang qiang-Meng Huang Ruo-Heng Yang Department of Astronomy School of Physics and AstronomyYunnan UniversityKunming 650091China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

We report our identification of three gigaelectronvoltγ-ray sources,4FGL J0502.6+0036,4FGL J1055.9+6507,and 4FGL J1708.2+5519,as Active Galactic Nuclei(AGNs).They are listed in the latest Fermi-Large Area Telescope source catalog as unidentified *** find that the sources all showedγ-ray flux variations in recent *** different survey catalogs,we are able to find a radio source within the error circle of each source's *** analysis of optical sources in the fields allows us to determine the optical counterparts,which showed similar variation patterns to those seen inγ-*** optical counterparts have reported redshifts of 0.6,1.5,and 2.3,respectively,estimated from photometric *** addition,we also obtain an X-ray spectrum of 4FGL J0502.6+0036 and a flux upper limit on the X-ray emission of 4FGL J1055.9+6507 by analyzing the archival *** broadband spectral energy distributions of the three sources from radio toγ-rays are *** mainly theγ-ray properties of the three sources with those of different sub-classes of AGNs,we tentatively identify them as *** optical spectroscopy is highly warranted for obtaining their spectral features and thus verifying the identification.

关键词： gamma-rays galaxies-(galaxies)BL Lacertae objects general-(galaxies)quasars general

Recent progress in metal-organic frameworks(Part II—material application)

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Science China Chemistry 2025年

作者： jiandong Pang Wentao jiang Xue-Wen Zhang Hao-Long Zhou Yuxiu Sun Wei Gong Bin wang Fuyin Ma Linwei He Long Chen qiang Chen He-Qi Zheng Yuanjing Cui Wen-jie Shi Chao Zhang Mei wang Yue-Biao Zhang jie-Peng Zhang Chongli Zhong Yong Cui Shuao wang jian-Rong Li Guodong Qian Tong-Bu Lu Huan Pang Xian-He Bu Institute for New Energy Materials and Low Carbon Technologies School of Materials Science and Engineering Tianjin University of Technology School of Chemistry and Chemical Engineering Yangzhou University School of Materials Science and Engineering Nankai University School of Physical Science and Technology ShanghaiTech University MOE Key Laboratory of Bioinorganic and Synthetic Chemistry GBRCE for Functional Molecular Engineering School of Chemistry IGCMESun Yat-sen University Department of Chemistry Shantou University School of Chemical Engineering and Technology Tiangong University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences Soochow University College of Materials Science & Engineering Beijing University of Technology State Key Laboratory of Silicon and Advanced Semiconductor Materials Cyrus Tang Center for Sensor Materials and ApplicationsSchool of Materials Science & Engineering Zhejiang University

As a class of functional crystalline porous materials, metal-organic frameworks(MOFs) gained rapid development in the past three decades and a large number of MOFs with ordered structures, high surface areas, and functionalized channels have been investigated. MOFs and MOF-derived/composite materials show great potential in many application fields. In this review, we discussed the main applications of MOFs and MOF-derived/composite materials in small molecule storage, separation, luminescence, sensing, multitype catalysis, and energy storage. In addition, challenges and problems in the future research of MOFsrelated fields are also discussed.

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Active Landslide Detection Based on Sentinel-1 Data and InSAR Technology in Zhouqu County, Gansu Province, Northwest China

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Journal of Earth Science 2021年第5期32卷 1092-1103页

作者： Cong Dai Weile Li Dong wang Huiyan Lu qiang Xu ji jian State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Earth Sciences Chengdu University of TechnologyChengdu 610059China China Railway Eryuan Engineering Group Co.Ltd. Chengdu 610031China

Zhouqu County in Gansu Province, Northwest China, is typically highly prone to landslides. On July 12, 2018, a landslide blocked the Bailong River near Zhouqu County, posing a serious threat to the life and property of local residents and the safety of infrastructure. Small baseline subset interferometry synthetic aperture radar technology(SBAS-In SAR) was adopted to identify the potential active landslides in the surrounding area of Zhouqu County, using ascending and descending orbit Sentinel-1 satellite images taken from October 2017 to December 2018. The surface deformation areas detected by SBAS-In SAR were verified by optical remote sensing image interpretation and field investigation, and a total of 23 active landslides were identified finally. The deformation characteristics of four typical landslides are analysed in detail using deformation velocity and rainfall data. It is found that the deformation velocity of landslides in this area is mainly affected by rainfall and there is a lag effect. The results can provide a reference for the prevention and control of landslide risk in Zhouqu County.

关键词： Zhouqu County landslide detection small baseline subset interferometry

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Techniques for Design and Implementation of an FPGA-Specific Physical Unclonable Function

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Journal of Computer Science & Technology 2016年第1期31卷 124-136页

作者： ji-Liang Zhang qiang Wu Yi-Peng Ding Yong-qiang Lv qiang Zhou Zhi-Hua Xia Xing-Ming Sun Xing-Wei wang Software College Northeastern University Shenyang 110819 China College of Information Science and Engineering Hunan University Changsha 410082 China School of Physics and Electronics Central South University Changsha 410083 China Research Institute of Information Technology Tsinghua University Beijing 100084 China School of Computer and Software Nanjing University of Information Science and Technology Nanjing 210044 China

Physical unclonable function （PUF） makes use of the uncontrollable process variations during the production of IC to generate a unique signature for each IC. It has a wide application in security such as FPGA intellectual property （IP） protection, key generation and digital rights management. Ring oscillator （RO） PUF and Arbiter PUF are the most popular PUFs, but they are not specially designed for FPGA. RO PUF incurs high resource overhead while obtaining less challenge-response pairs, and requires ＂hard macros＂ to implement on FPGAs. The arbiter PUF brings low resource overhead, but its structure has big bias when it is mapped on FPGAs. Anderson PUF can address these weaknesses of current Arbiter and RO PUFs implemented on FPGAs. However, it cannot be directly implemented on the new generation 28 nm FPGAs. In order to address these problems, this paper designs and implements a delay-based PUF that uses two LUTs in an SLICEM to implement two 16-bit shift registers of the PUF, 2-to-1 multiplexers in the carry chain to implement the multiplexers of the PUF, and any one of the 8 flip-flops to latch 1-bit PUF signatures. The proposed delay-based PUF is completely realized on 28 nm commercial FPGAs, and the experimental results show its high uniqueness, reliability and reconfigurability. Moreover, we test the impact of aging on it, and the results show that the effect of aging on the proposed PUF is insignificant, with only 6% bit-flips. Finally, the prospects of the proposed PUF in the FPGA binding and volatile key generation are discussed.

关键词： physical unclonable function (PUF) FPGA intellectual property protection fabrication variation hardware security