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    题名 作者 年代 出处 被引量
1Programmable time-domain digital-coding metasurface for non-linear harmonic manipulation and new wireless communication systems显示文摘Optical non-linear phenomena are typically observed in natural materials interacting with light at high intensities, and they benefit a diverse range of applications from communication to sensing. However,controlling harmonic conversion with high efficiency and flexibility remains a major issue in modern optical and radio-frequency systems. Here, we introduce a dynamic time-domain digital-coding metasurface that enables efficient manipulation of spectral harmonic distribution. By dynamically modulating the local phase of the surface reflectivity, we achieve accurate control of different harmonics in a highly programmable and dynamic fashion, enabling unusual responses, such as velocity illusion. As a relevant application, we propose and realize a novel architecture for wireless communication systems based on the time-domain digital-coding metasurface, which largely simplifies the architecture of modern communication systems, at the same time yielding excellent performance for real-time signal transmission. The presented work, from new concept to new system, opens new pathways in the application of metamaterials to practical technology.Jie Zhao Xi Yang Jun Yan Dai Qiang Cheng Xiang Li Ning Hua Qi Jun Chen Ke Guo Dong Bai Shuo Liu Shi Jin Andrea Alù Tie Jun Cui 2019National Science Review2019,6,2:46
2Ideotype root architecture for efficient nitrogen acquisition by maize in intensive cropping systems显示文摘The use of nitrogen(N) fertilizers has contributed to the production of a food supply sufficient for both animals and humans despite some negative environmental impact.Sustaining food production by increasing N use efficiency in intensive cropping systems has become a major concern for scientists,environmental groups,and agricultural policymakers worldwide.In high-yielding maize systems the major method of N loss is nitrate leaching.In this review paper,the characteristic of nitrate movement in the soil,N uptake by maize as well as the regulation of root growth by soil N availability are discussed.We suggest that an ideotype root architecture for efficient N acquisition in maize should include(i) deeper roots with high activity that are able to uptake nitrate before it moves downward into deep soil;(ii) vigorous lateral root growth under high N input conditions so as to increase spatial N availability in the soil;and(iii) strong response of lateral root growth to localized nitrogen supply so as to utilize unevenly distributed nitrate especially under limited N conditions.MI GuoHua,CHEN FanJun,WU QiuPing,LAI NingWei,YUAN LiXing & ZHANG FuSuo* Key Laboratory of Plant Nutrition,MOA Key Laboratory of Plant-Soil Interaction,MOE College of Resources and Environmental Science,China Agricultural University,Beijing 100193,China 2010Science China(Life Sciences)2010,53,12:35
3Crop Phenomics and High-Throughput Phenotyping:Past Decades,Current Challenges,and Future Perspectives显示文摘Since whole-genome sequencing of many crops has been achieved,crop functional genomics studies have stepped into the big-data and high-throughput era.However,acquisition of large-scale phenotypic data has become one of the major bottlenecks hindering crop breeding and functional genomics studies.Nevertheless,recent technological advances provide us potential solutions to relieve this bottleneck and to explore advanced methods for large-scale phenotyping data acquisition and processing in the coming years.In this article,we review the major progress on high-throughput phenotyping in controlled environments and field conditions as well as its use for post-harvest yield and quality assessment in the past decades.We then discuss the latest multi-omics research combining high-throughput phenotyping with genetic studies.Finally,we propose some conceptual challenges and provide our perspectives on how to bridge the phenotype-genotype gap.It is no doubt that accurate high-throughput phenotyping will accelerate plant genetic improvements and promote the next green revolution in crop breeding.Wanneng Yang Hui Feng Xuehai Zhang Jian Zhang John H.Doonan William David Batchelor Lizhong Xiong Jianbing Yan 2020Molecular Plant2020,13,2:38
4Wireless Communications with Programmable Metasurface:Transceiver Design and Experimental Results显示文摘Metasurfaces have drawn significant attentions due to their superior capability in tailoring electromagnetic waves with a wide frequency range, from microwave to visible light. Recently, programmable metasurfaces have demonstrated the ability of manipulating the amplitude or phase of electromagnetic waves in a programmable manner in real time, which renders them especially appealing in the applications of wireless communications. In this paper, we present the fundamental principle of applying programmable metasurface as transmitter for wireless communications. Then, we establish a prototype system of metasurface-based transmitter to conduct several experiments and measurements over the air, which practically demonstrate the feasibility of using programmable metasurfaces in future communication systems. By exploiting the dynamically controllable property of programmable metasurface, the design, implementation and experimental evaluation of the proposed metasurface-based wireless communication system are presented with the prototype, which realizes single carrier quadrature phase shift keying(QPSK) transmission over the air. In the developed prototype, the phase of the reflected electromagnetic wave of programma-ble metasurface is directly manipulated in real time according to the baseband control signal, which achieves 2.048 Mbps data transfer rate with video streaming transmission over the air. In addition, experimental result is provided to compare the performance of the proposed metasurface-based architecture against the conventional one. With the slight increase of the transmit power by 5 dB, the same bit error rate(BER) performance can be achieved as the conventional system in the absence of channel coding. Such a result is encouraging considering that the metasurface-based system has the advantages of low hardware cost and simple structure, thus leading to a promising new architecture for wireless communications.Wankai Tang Xiang Li Jun Yan Dai Shi Jin Yong Zeng Qiang Cheng Tie Jun Cui 2019China Communications2019,16,5:23
5New advances in virtual plant research显示文摘Virtual plants are computer simulations of the growth, development and deployment of plants in a three-dimensional space. Over the past 20 years, significant progress has been made in virtual plant modeling corresponding to the rapid advances in information technology. Virtual plant research has broad applications in agronomy, forestry, ecology, and remote sensing areas. In this review, we attempt to introduce the significance, modeling methodology, and main advances in virtual plant research and applications. The challenges associated with virtual plant modeling in agronomy applications, including the interaction mechanism between plant and environment and root system modeling, are also discussed. Insights into applications of virtual plants in agronomy are given in the areas of performing virtual experiments to accurately quantify the utilization of soil water and nutrients, to design crop ideotype on computers, and to improve crop planting.Yan Guo Baoguo Li 2001Chinese Science Bulletin2001,46,11:21
6基于Revit Architecture族模型的古建参数化建模初探显示文摘由Autodesk公司开发的Revit Architecture软件经过逐渐的改进,目前已经具有了非常完善的建筑参数化设计功能。其提供的族(Famliy)参数模型与构件编写平台在古建参数化建模中也能发挥重要的作用。本文以攒尖亭的参数化建模过程为例,介绍基于族模型的古建参数化建模的初步方法,包括参数设置、主体结构与屋顶部分的参数化建模过程;在此基础上介绍古建参数化详图构件的图纸表达和软件在古建参数化建模方面局限与发展前景。罗翔 吉国华 2009中外建筑2009,,8:19
7Hierarchy modeling of subsurface palaeochannel reservoir architecture显示文摘The studies on fluvial reservoir architecture are mainly aimed at outcrop and modern deposition,but rarely at the subsurface reservoir,so there are few effective methods to predict the distribution of subsurface reservoir architectures. In this paper,taking the meandering river reservoir of Guantao formation Gudao Oilfield,Jiyang depression,Baohai Gulf Basin,East China as an example,the archi-tectural modeling method of complex meandering belt reservoir is proposed,that is hierarchy con-straint,pattern fitting and multi-dimensional interaction. Architectures of meandering river reservoir can be divided into three hierarchies: meandering channel sandbody,point bar and lateral accretion body. Different hierarchies of the quantitative architecture pattern are fitted to subsurface well data (including dynamic monitoring data) in different hierarchies through one-dimensional hole,2D profiles and plane and 3D space,which are verified by each other. And then 3D model in different hierarchies is established. At the same time,the quantificational relationship between width of active river and the scale of point bar is set up,and the scale of lateral accretion sand body and shale beddings is con-firmed with horizontal well data. The study not only has significant meaning on the development of geology,but also can improve the oilfield exploitation greatly.WU ShengHe1,YUE DaLi1,LIU JianMin2,SHU QingLin2,FAN Zheng1,3 & LI YuPeng1 1 Earth Sciences and Geoinformatics School,China University of Petroleum,Beijing 102249,China 2 SINOPEC Shengli Oilfield Co. Ltd.,Dongying 257000,China 3 Beijing Telon High-tech Corporation,Beijing 100085,China 2008Science China Earth Sciences2008,51,S2:15
8Sequence Stratigraphy of the Permian--Triassia Boundary Section of Changxing, Zhejiang, Southern China显示文摘Three third-order sequences and about one hundred high-frequency cycles or Milankovitchcycles within the Late Permian Changxingian to Early Triassic Griesbachian are identified in theMeishan Section of Changxing, Zhejiang Province, southern China, the candidate stratotype sec-tion of the global Permo-Triassic boundary, based on a detailed study of the biological,ecological and high-resolution allochthonous cyclic events, microfacies and depositional systems.Furthermore, the stacking pattern of the depositional systems across various Changxingian andGriesbachian sedimentary facies of the Lower Yangtze and the sequence stratigraphic frameworkare outlined with the Meishan section as the principal section. In this paper the habitat types offossil biota are applied to semiquantitative palaeobathymetry and the study of relative sea levelchanges.Zhang Kexin Tong Jinnan Yin Hongfu and Wu Shunbao China University of Geosciences, Wuhan, Hubei 1997Acta Geologica Sinica(English Edition)1997,71,1:14
9Ideal root architecture for phosphorus acquisition of plants under water and phos-phorus coupled stresses: From simulation to application显示文摘Under water and phosphorus (P) coupled stresses, root architecture may be related to P acquisition efficiency of plants. Understanding the relationship between root architecture and P acquisition efficiency may provide basic information for improving P acquisition efficiency of plants. In the present study, we quantitatively described the effects of root architecture on P acquisition efficiency by computer simulation together with controlled biological experiments so as to determine an ideal root architecture for efficient P acquisition under water and P coupled stresses. Our results indicate that under given soil water conditions, the ideal root architecture for P acquisition efficiency of a tap root plant (as represented by common bean) is an 搖mbrella-shape?root system whose basal roots tend to be shallow in the P-rich topsoil and tap roots tend to be deep for water in the subsoil. Meanwhile, the ideal root architecture for a fibrous root plant (as represented by upland rice) is a beard-shape?root system with the moderately dispersed yet uniformly distributed adventitious and lateral roots so as to keep most roots in the topsoil for P and a few roots in the subsoil for water.LIAO Hong GE Zhenyang YAN Xiaolong 2001Chinese Science Bulletin2001,46,16:14
10Natural Variations at TIG1 Encoding a TCP Tran scription Factor Contribute to Plant Architecture Domestication in Rice显示文摘The modification of plant architecture is a crucial target in rice domestication and modern genetic improvement.Although several genes regulating rice plant architecture have been characterized,the molecular mechanisms underlying rice plant architecture domestication remain largely unclear.Here we show that the inclined tiller growth in wild rice is controlled by a single dominant gene,TILLER INCLINED GROWTH 1 (T/Gf),which is located on chromosome 8 and encodes a TCP transcriptional activator.TIG1 is primarily expressed in the adaxial side of the tiller base,promotes cell elongation,and enlarges the tiller angle in wild rice.Variations in the TIG1 promoter of indica cultivars {tig1 allele) resulted in decreased expression of TIG1 in the adaxial side of tiller base and reduced cell length and tiller angle,leading to the transition from inclined tiller growth in wild rice to erect tiller growth during rice domestication.TIG1 positively regulates the expression of EXP A3,EXPB5,and SAUR39 to promote cell elongation and increase the tiller angle.Selective sweep analysis revealed that the tig1 allele was selected in indica cultivars by human beings.The cloning and characterization of TIG1 supports a new scenario of plant architecture evolution in rice.Weifeng Zhang Lubin Tan Hongying Sun Xinhui Zhao Fengxia Liu Hongwei Cai Yongcai Fu Xianyou Sun Ping Gu Zuofeng Zhu Chuanqing Sun 2019Molecular Plant2019,12,8:13
11明日的LA教育显示文摘国际上呈“退化的下降趋势”的百年学科LA,中国“迟到的春天”LA,今天都站在了十字路口。从新技术革命和全球化的视角,探讨了LA教育的使命;提出明日的LA学科应在三大领域集结和拓展;阐述了LA教育的结构和内容。面对发达国家百年来LA教育的广域性走向,结合我国社会经济梯度递进式发展及其人才需求的特点。我国的LA本科生教育应强化能力培养:研究生教育则应明确区分职业型学位与研究型学位的差异,通过价值取向的先进性、方法途径的建设性(或创造性),强化LA的学科特质而获得新生。吴人韦 2006中国园林2006,22,9:13
12Short Panicle 3 controls panicle architecture by upregulating APO2/RFL and increasing cytokinin content in rice显示文摘Inflorescence architecture is a major determinant of spikelet numbers per panicle, a key component of grain yield in rice. In this study, Short Panicle 3(SP3) was identified from a short panicle 3(sp3) mutant in which T-DNA was inserted in the promoter of SP3, resulting in a knockdown mutation. SP3 encodes a DNA binding with one finger(Dof) transcriptional activator. Quantitative real time(q RT)-PCR and RNA in situ hybridization assays confirmed that SP3 is preferentially expressed in the young rice inflorescence, specifically in the branch primordial regions. SP3 acts as a negative regulator of inflorescence meristem abortion by upregulating APO2/RFL. SP3 both up-and downregulates expression of genes involved in cytokinin biosynthesis and catabolism, respectively. Consequently, cytokinin concentrations are decreased in young sp3 panicles, thereby leading to small panicles having fewer branches and spikelets. Our findings support a model in which SP3 regulates panicle architecture by modulating cytokinin homeostasis. Potential applications to rice breeding, through gene-editing of the SP3 promoter are assessed.Yong Huang Xufeng Bai Meifang Luo Yongzhong Xing 2019Journal of Integrative Plant Biology2019,61,9:10
13基于OPC Unified Architecture的服务器研究显示文摘首先介绍现有OPC规范以及其存在的不足,然后介绍OPC基金会即将推出的OPCUnifiedArchitecture规范,并重点研究OPCUnifiedArchitecture服务器的实现机制及方法,通过与现有OPC规范的比较,揭示OPCUA在平台无关性、可互操作性、可靠性等方面的显著优势。孙发 刘枫 2006仪器仪表标准化与计量2006,,5:8
14A comprehensive review on hybrid electric vehicles: architectures and components显示文摘The rapid consumption of fossil fuel and increased environmental damage caused by it have given a strong impetus to the growth and development of fuelefficient vehicles. Hybrid electric vehicles (HEVs) have evolved from their inchoate state and are proving to be a promising solution to the serious existential problem posed to the planet earth. Not only do HEVs provide better fuel economy and lower emissions satisfying environmental legislations, but also they dampen the effect of rising fuel prices on consumers. HEVs combine the drive powers of an internal combustion engine and an electrical machine. The main components of HEVs are energy storage system, motor, bidirectional converter and maximum power point trackers (MPPT, in case of solar-powered HEVs). The performance of HEVs greatly depends on these components and its architecture. This paper presents an extensive review on essential components used in HEVs such as their architectures with advantages and disadvantages, choice of bidirectional converter to obtain high efficiency, combining ultracapacitor with battery to extend the battery life, traction motors’ role and their suitability for a particular application. Inclusion of photovoltaic cell in HEVs is a fairly new concept and has been discussed in detail. Various MPPT techniques used for solar-driven HEVs are also discussed in this paper with their suitability.Krishna Veer Singh Hari Om Bansal Dheerendra Singh 2019Journal of Modern Transportation2019,27,2:8
15Ni@N-doped graphene nanosheets and CNTs hybrids modified separator as efficient polysulfide barrier for high-performance lithium sulfur batteries显示文摘Lithium-sulfur batteries (LSBs) have been regarded as one of the most promising energy storage systems to break through the upper limit of lithium-ion batteries.However,the rampant diffusions of soluble lithium polysulfides (LiPSs) in the electrolyte induced the shuttle effect between anode and cathode,resulting in low sulfur utilization,low energy efficiency and short cycling life.Herein,we prove the rational design and construction of Ni nanoparticles filled in vertically grown N-doped bamboo-like carbon nanotubes (CNTs) on graphene nanosheets (Ni@NG-CNTs) as efficient polysulfide barrier for high-performance LSBs.The unique design integrates graphene nanosheets and CNTs into hierarchical architectures with one-dimensional (1D) CNTs,two-dimensional (2D) ultrethin nanosheets and abundant carbon nanocages.This design provides large surface area for lithium polysulfides (LiPSs) adsorption,accelerates electron transport and enhances electrochemical redox of LiPSs.Benefiting from the unique structural features,the LSBs with the Ni@NG-CNTs as polysulfide barrier keep high reversible specific capacities of 309.1 and 265.0 mAh·g-1 at 5 and 10 C rates after 500 cycles.This work provides a new strategy for constructing self-assembled hybrids of CNTs and graphene nanosheets with abundant carbon nanocages for high-performance LSBs.Xintao Zuo Mengmeng Zhen Cheng Wang 2019Nano Research2019,12,4:8
16基于Revit Architecture“族的方法”的自由建筑形态参数化建模初探显示文摘Revit Architecture作为一款BIM软件可以通过数字信息仿真模拟建筑物所具有的真实信息。基于该软件平台下进行三维建筑形态的设计研究,可以将研究出的形态直接与后续的深化技术相关联。本文用Revit Architecture'族的方法'以单元叠加类型为例,介绍自由建筑形态的参数化建模方法;并在此基础上探讨'族的方法'在自由建筑形态参数化建模方面的优势与局限。陆蕾 2011建筑与文化2011,,3:8
17Short-term power load forecasting using integrated methods based on long short-term memory显示文摘The development of power system informatization,the massive access of distributed power supply and electric vehicles have increased the complexity of power consumption in the distribution network,which puts forward higher requirements for the accuracy and stability of load forecasting.In this paper,an integrated network architecture which consists of the self-organized mapping,chaotic time series,intelligent optimization algorithm and long short-term memory(LSTM)is proposed to extend the load forecasting length,decrease artificial debugging,and improve the prediction precision for the short-term power load forecasting.Compared with LSTM prediction,the algorithm in this paper improves the prediction accuracy by 61.87%in terms of root mean square error(RMSE),and reduces the prediction error by 50%in the 40-fold forecast window under some circumstances.ZHANG WenJie QIN Jian MEI Feng FU JunJie DAI Bo YU WenWu 2020Science China(Technological Sciences)2020,63,4:7
18Fuzzy mathematics and game theory based D2D multicast network construction显示文摘Device to device(D2 D) multi-hop communication in multicast networks solves the contradiction between high speed requirements and limited bandwidth in regional data sharing communication services. However, most networking models demand a large control overhead in eNodeB. Moreover, the topology should be calculated again due to the mobility of terminals, which causes the long delay. In this work, we model multicast network construction in D2 D communication through a fuzzy mathematics and game theory based algorithm. In resource allocation, we assume that user equipment(UE) can detect the available frequency and the fuzzy mathematics is introduced to describe an uncertain relationship between the resource and UE distributedly, which diminishes the time delay. For forming structure, a distributed myopic best response dynamics formation algorithm derived from a novel concept from the coalitional game theory is proposed, in which every UE can self-organize into stable structure without the control from eNodeB to improve its utilities in terms of rate and bit error rate(BER) while accounting for a link maintenance cost, and adapt this topology to environmental changes such as mobility while converging to a Nash equilibrium fast. Simulation results show that the proposed architecture converges to a tree network quickly and presents significant gains in terms of average rate utility reaching up to 50% compared to the star topology where all of the UE is directly connected to eNodeB.LI Zhuoming CHEN Xing ZHANG Yu WANG Peng QIANG Wei LIU Ningqing 2019Journal of Systems Engineering and Electronics2019,30,1:6
19笔式用户界面交互信息模型研究显示文摘笔式用户界面是Post-WIMP界面的重要形态,在许多领域得到广泛应用.笔式界面设计需要设计者和用户的共同参与.捕获用户使用意图是设计笔式用户界面的前提,连接交互信息的表示与控制则是成功构造界面的关键.依据笔式交互信息连续性及模糊性特征,从设计参与者与交互信息管理两个维度建立了笔式用户界面交互信息模型OICM(orthogonal interaction information architecture coordinate model).从问题知识域、交互任务、规则集合以及上下文关联4个不同的象限对模型进行了详细的描述,并给出了基于XML的实现方法.在对模型进行分析后,介绍了基于OICM模型的开发平台和应用系统实例.李杰 田丰 戴国忠 2005软件学报2005,16,1:6
20基于GPU的实时图像拼接显示文摘大视野、高质量的图像信息对地面移动机器人的遥控操作具有非常重要的意义。提出了一种基于先验信息的自适应图像拼接方法。该方法在图像大致重叠区域中均匀选取待匹配点,利用改进的具有旋转不变性的NCC(Normalized Cross Correlation,归一化互相关)匹配方法进行区域相似性度量,通过RANSAC(Random Sample Con-sensus,随机采样一致性)算法估计图像射影变换模型,采用线性淡入淡出法进行图像融合。利用GPU强大的并行处理能力对算法进行了并行化实现,使图像拼接效率比单独采用CPU提高了60倍以上,稳定的拼接速度可达21.3fps。郭一汉 史美萍 吴涛 2012计算机科学2012,39,7:6
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