检索结果-南通市图书馆

A rice geranylgeranyl reductase is essential for chloroplast development

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第10期20卷 2592-2600页

作者： LIU Xi YI xin YANG Yan-rong HUANG Qian-qian Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection/Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake Huaiyin Normal UniversityHuai’an 223300P.R.China

Chloroplasts are essential for plant photosynthesis and *** genes have been identified that regulate plant chloroplast ***,it is not known at a molecular level how these genes regulate chloroplast *** this study,we isolated a mutant ygl2(yellow-green leaf2)that exhibited a pigment-defective ***2 encodes a geranylgeranyl reductase,and in mutant ygl2,there was a single base change(T1361G)located in the third exon of YGL2 that resulted in a missense mutation(L454R)in the encoded *** electron microscopy revealed that chloroplast development was impaired in the ygl2 *** expression levels of plastid-encoded genes were significantly altered in the ygl2 ***,in a yeast two-hybrid assay,we found that YGL2 interacted with the RNA editing factor MORF8.

关键词： rice(Oryza sativa L.) chloroplast YGL2 geranylgeranyl reductase

Sensitivity analysis of Biome-BGCMuSo for gross and net primary productivity of typical forests in China

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2022年第1期9卷 111-123页

作者： Hongge Ren Li Zhang Min Yan xin Tian xingbo Zheng Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing100094China University of Chinese Academy of Sciences Beijing100049China Institute of Forest Resource Information Techniques Chinese Academy of ForestryBeijing100091China Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang110016China Research Station of Changbai Mountain Forest Ecosystems Chinese Academy of SciencesAntu133613JilinChina

Background:Process-based models are widely used to simulate forest productivity,but complex parameterization and calibration challenge the application and development of these *** analysis of numerous parameters is an essential step in model calibration and carbon flux ***,parameters are not dependent on each other,and the results of sensitivity analysis usually vary due to different forest types and ***,global and representative sensitivity analysis would provide reliable information for simple ***:To determine the contributions of input parameters to gross primary productivity(GPP)and net primary productivity(NPP),regression analysis and extended Fourier amplitude sensitivity testing(EFAST)were conducted for Biome-BGCMuSo to calculate the sensitivity index of the parameters at four observation sites under climate gradient from ***:Generally,GPP and NPP were highly sensitive to C:Nleaf(C:N of leaves),Wint(canopy water interception coefficient),k(canopy light extinction coefficient),FLNR(fraction of leaf N in Rubisco),MRpern(coefficient of linear relationship between tissue N and maintenance respiration),VPDf(vapor pressure deficit complete conductance reduction),and SLA1(canopy average specific leaf area in phenological phase 1)at all observation *** sensitive parameters occurred at four observation sites within different climate *** and NPP were particularly sensitive to FLNR,SLA1 and Wint,and C:Nleaf in temperate,alpine and subtropical zones,***:The results indicated that sensitivity parameters of China's forest ecosystems change with climate *** found that parameter calibration should be performed according to plant functional type(PFT),and more attention needs to be paid to the differences in climate and *** findings contribute to determining the target parameters in field experiments and model calibration.

关键词： Sensitivity analysis Biome-BGCMuSo Productivity Regression analysis EFAST

Modified clustered comb pilot-aided fast time-varying channel estimation for OFDM system

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Transportation 2012年第4期20卷 220-226页

作者： xin LI Pingzhi FAN Institute of Mobile Communications Southwest Jiaotong University

As high-speed railway is booming worldwide, the communication system with fast-time varying channel has drawn great attention. The comb pilot based linear minimum mean square error （LMMSE） channel estimator is proved to be an effective method for fast time-varying channel estimation. In this paper, the clustered comb pilot-aided chan- nel estimation for orthogonal frequency-division multiplexing （OFDM） system is discussed, where the time varying channel is approximated by a basis expansion model （BEM）. A modified clustered comb pilot structure is proposed and justified to improve the estimation performance compared with the clustered comb pilot proposed by Tang. Based on the complex-exponential BEM （CE-BEM） model, a suboptimal-pilot structure is proposed. In addition, optimal pilot length is analyzed and simulated with a predefined total number of pilots. The simulation results show that the modi- fied clustered comb pilot can greatly reduce the estimation error especially with high Doppler spread. The suboptimal- pilot structure with guard pilot approximation is proven to be competitive. Optimal nonzero pilot lengths for different Doppler spread are obtained by simulation with a predefined channel order and fixed pilot subcarriers.

关键词： OFDM LMMSE BEM clustered comb pilot high mobility

Research progress on intelligent operation and maintenance of bridges

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 173-187页

作者： Wanshui Han Gan Yang Shizhi Chen Kai Zhou xin Xu School of Highway Chang'an UniversityXi'an 710064China

In the context of the increasing scale of bridges and the increasing service life of bridges,it is very important to carry out efficient,accurate and intelligent bridge operation and *** recent years,advanced equipment,technology and intelligent algorithms have developed *** is necessary to apply advanced equipment and algorithms to bridge operation and maintenance business to facilitate the digitalization and intelligence of bridge operation and *** grasp the research progress on the bridge intelligent operation and maintenance,this paper summarizes the research progress in recent years from the aspects of intelligent detection equipment and technology,intelligent monitoring equipment and technology,intelligent data analysis,intelligent evaluation and early warning,and intelligent repair and *** to the review,more and more smart devices have been used to replace human beings to detect dangerous and hidden bridge *** the same time,image processing,radar and other technologies have been used to analyze component damage more objectively and *** solve the shortcomings of traditional sensors such as short life and low robustness,more non-contact measurement methods have been *** have proposed various intelligent algorithms to process the massive amount of bridge health monitoring data to improve the quality of the *** achieve the rapid perception of bridge status and timely early warning of structural abnormalities,different from traditional theoretical calculations,scholars have tried to use data-driven methods to intelligently evaluate and early warning of bridge structural *** terms of intelligent repair and maintenance,more intelligent algorithms have been used to optimize structural maintenance strategies and determine the best maintenance time by integrating multisource heterogeneous *** these provide strong support for the automation,digitization and intelligence o

关键词： Bridge engineering Bridge intelligent operation and maintenance Intelligent equipment Technology and algorithms

Broadband Terahertz Transmission Modulation Based on Hybrid Graphene-Metal Metamaterial

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2018年第2期16卷 98-104页

作者： Lan-Ju Liang Zhang Zhang xin Yan xin Ding De-Quan Wei Qi-Li Yang Zhen-Hua Li Jian-Quan Yao College of Precision Instrument and Opto-Electronics Engineering Tianjin UniversityTianjin 300072 School of Opto-Electronic Engineering Zaozhuang UniversityZaozhuang 277160

A novel patterned metamaterial,composed of graphene layer and metal periodic array of split ring resonators （SRRs） and cross-shapedresonators （CSRs）, with broadband terahertz （THz） wave modulation was proposed and theoretically studied. It demonstrated that a broad passband high transmission of over 96.1% in the frequency range from 1.02 THz to 1.66 THz and two narrow band resonance frequencies f1 and f2 could be generated. The modulation depth of transmission was 29.2% when the graphene layer was covered on the metal metamaterial surface, and the modulation depth could be further increased by increasing the Fermi energy of graphene layer and reached approximately 79.5% at 1.0 eV in a broadband THz frequency range. The resonance frequencies of f1 and f2 were blue-shifted, and their modulation depths reached about 63.2% and 18%, respectively. These results show that the ultrathin graphene-metal metamaterial exhibits potential to achieve highperformance active THz devices and may offer widespread applications.

关键词： Graphene metamaterial modulator terahertz

A study of particles penetration in sieving process on a linear vibration screen

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2015年第4期2卷 299-305页

作者： Zhanfu Li xin Tong School of Mechanical Engineering and Automation HuaqiaoUniversity Xiamen 361021 China

This paper presented an investigation of particle collision and penetration using the discrete element method to understand the motion of particles and improve theoretical treatment in the sieving process. The process progressively was divided into looseness, stratification, collision, and penetration. Particle penetration has a direct effect on the screening performance. The penetration probability was defined, and the mathematical relationships between particle penetration and vibration parameters were established using the least squares method. To obtain the ideal penetration probability for materials the amplitude and frequency should preferably be near 3.0 mm and 25 Hz, respectively. The vibration direction angle has only a slight effect on penetration. The stage of the screening process from 0.1 to 0.7 s is the primary region for collision and penetration. This paper focused on the sieving process to more fully understand how particle collision and penetration influence the screening efficiency.

关键词： Penetration probability Collision Discrete element method Sieving process

Joint Optimization of Communications and Computing Resources Allocation for Deterministic Transmission in Wireless Edge Networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2022年第5期19卷 1-11页

作者： Lanjing Chen Zhiyong Chen Bin Xia xin Jiang Feng Hu School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China China Mobile Industry Research Institute Shanghai 201206China

Motivated by 5th generation wireless systems(5G),a large number of emerging applications appear,which put forward higher requirements for the task’s transmission determinacy,which refers to the delay and *** satisfy the deterministic requirement,mobile edge computing(MEC)is envisioned as a promising technique for reducing the end-to-end delay *** this paper,we consider delaysensitive task and jitter-sensitive task,and then formulate the joint communications and computing optimization problem under the latency,the total bandwidth,the total transmission power of base station(BS)and the computing ability of the MEC server constraints to minimize the delay and jitter in a multiuser MEC *** of the problems are nonconvex,we decouple them into some subproblems and propose the corresponding algorithms to obtain a suboptimal ***,numerical results show that the proposed algorithms have a significant performance gain over the traditional solution in terms of the delay and the jitter.

关键词： mobile edge computing deterministic transmission delay and jitter resource allocation

Local-State Routing in Satellite Constellation Networks from the Perspective of Complex Network

在线全文

学校读者我要写书评

暂无评论

China Communications 2023年第7期20卷 72-88页

作者： xin Xu Jun Cai Aijun Liu Chaoying Dong Chen Han Institute of Communication Engineering Army Engineering University of PLANanjing 210007China The Unit 94973 of the Chinese People’s Liberation Army Hangzhou 310000China The Sixty-Third Research Institute National University of Defense TechnologyNanjing 210007China

Routing algorithms in satellite constellation networks usually make use of the local state information to adapt to the topology and traffic dynamics,since it’s difficult to obtain the global states in time due to the spatial large-scale feature of constellation ***,they use different range of local states and give these states distinct ***,the behind design criterion is ambiguous and often based on *** paper discusses the problem from the perspective of complex network.A universal local-state routing model with tunable parameters is presented to generalize the common characteristics of local-state routing algorithms for satellite constellation *** on this,the impacts of localstate routing algorithms on performance and the correlation between routing and traffic dynamics are analyzed in *** them,the tunable parameters,the congestion propagation process,the critical packet sending rate,and the network robustness are discussed *** results show that routing algorithms can achieve a satisfactory performance by maintaining a limited state awareness capability and obtaining the states in a range below the average path *** provides a valuable design basis for routing algorithms in satellite constellation networks.

关键词： satellite constellation local state routing traffic dynamics complex networks robustness

Crystalline-magnetism action in biomimetic mineralization of calcium carbonate

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第7期59卷 146-152页

作者： Chaoqun Wu Xun Liu Fujun Yao xin Yang Yan Wang Wenyuan Hu State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang 621000China Materials Science and Engineering Southwest University of Science and TechnologyMianyang 621000China National Health Commission Key Laboratory of Nuclear Technology Medical Transformation Mianyang Central HospitalMianyang 621010China

The influence of minor environmental factors,such as the geomagnetic field,on the biomineralization of nacres,is often ignored but a great deal of research has confirmed its important role in the normal mineralization of calcium *** the geomagnetic field is weak,its cumulative effects need to be considered given that the biomineralization process can take ***,the authors of this paper have investigated the effects of weak magnetic fields(25 Gs or 50 Gs)on calcium carbonate mineralization and analyzed the mechanism *** results show that even a weak magnetic field conduces to the formation of vaterite or aragonite,in the induction order of precursor→vaterite→*** stronger the magnetic field and the longer the time,the more obvious the induction *** effect of a magnetic field is strongest in the aging stage and weakest in the solution *** by egg-white protein and by a magnetic field inhibit each other,but they both restrict particle *** findings highlight the importance of minor environmental factors for biomineralization and can serve as a reference for biomimetic preparation of a CaCO_(3)nacre-like structure and for anti-scale technology for circulating cooling water.

关键词： Biomimetic mineralization Calcium carbonate Magnetic field Egg-white protein