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Iron uptake, signaling, and sensing in plants

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Plant Communications 2022年第5期3卷 75-87页

作者： gang liang CAS Key Laboratory of Tropical Plant Resources and Sustainable Use Xishuangbanna Tropical Botanical GardenKunmingYunnan 650223China

Iron (Fe) is an essential micronutrient that affects the growth and development of plants because it participates as a cofactor in numerous physiological and biochemical reactions. As a transition metal, Fe is redoxactive. Fe often exists in soil in the form of insoluble ferric hydroxides that are not bioavailable to *** have developed sophisticated mechanisms to ensure an adequate supply of Fe in a fluctuating environment. Plants can sense Fe status and modulate the transcription of Fe uptake-associated genes, finallycontrolling Fe uptake from soil to root. There is a critical need to understand the molecular mechanisms bywhich plants maintain Fe homeostasis in response to Fe fluctuations. This review focuses on recentadvances in elucidating the functions of Fe signaling components. Taking Arabidopsis thaliana and Oryzasativa as examples, this review begins by discussing the Fe acquisition systems that control Fe uptake fromsoil, the major components that regulate Fe uptake systems, and the perception of Fe status. Future explorations of Fe signal transduction will pave the way for understanding the regulatory mechanisms that underlie the maintenance of plant Fe homeostasis.

关键词： iron metal homeostasis Fe uptake Fe signaling Fe sensor plant nutrition

A decision support system for satellite layout integrating multi-objective optimization and multi-attribute decision making

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Journal of Systems Engineering and Electronics 2019年第3期30卷 535-544页

作者： liang Yan’gang QIN Zheng College of Aerospace Science and Engineering National University of Defense Technology

A decision support system, including a multi-objective optimization framework and a multi-attribute decision making approach is proposed for satellite equipment layout. Firstly, given three objectives (to minimize the C.G. offset, the cross moments of inertia and the space debris impact risk), we develop a threedimensional layout optimization model. Unlike most of the previous works just focusing on mass characteristics of the system, a space debris impact risk index is developed. Secondly, we develop an efficient optimization framework for the integration of computer-aided design (CAD) software as well as the optimization algorithm to obtain the Pareto front of the layout optimization problem. Thirdly, after obtaining the candidate solutions, we present a multi-attribute decision making approach, which integrates the smart Pareto filter and the correlation coefficient and standard deviation (CCSD) method to select the best tradeoff solutions on the optimal Pareto fronts. Finally, the framework and the decision making approach are applied to a case study of a satellite platform.

关键词： layout optimization satellite multi-objective optimization Pareto front multi-attribute decision making

Sensor management of LEO constellation based on covariance control

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Journal of Systems Engineering and Electronics 2019年第2期30卷 393-401页

作者： QIN Zheng liang Yan'gang College of Aerospace Science and Engineering National University of Defense Technology

This paper studies the multi-sensor management problem for low earth orbit(LEO) infrared warning constellation used to track a midcourse missile. A covariance control approach, which selects sensor combinations or subset based on the difference between the desired covariance matrix and the actual covariance of each target, is used for sensor management, including some matrix metrics to measure the differentia between two covariance matrices. Besides, to meet the requirements of the space based warning system, the original covariance control approach is improved. Simulation results demonstrate that the covariance control approach is able to provide a better tracking performance by providing a well-designed desired covariance and balance tracking performance goals with system demands.

关键词： sensor management covariance control target tracking accuracy LEO constellation

Harmonic suppressed bandpass filter using composite right/left handed transmission line

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第7期13卷 552-558页

作者： Jian-gang liang He-xiu XU Electromagnetic Field and Microwave Technique Missile InstituteAir Force Engineering UniversityShaanxi 713800China

A wideband composite right/left handed transmission line (CRLH TL) in conjunction with its corresponding equivalent circuit model is studied based on a cascaded complementary single split ring resonator (CCSSRR).The characterization is performed by theory analysis,circuit simulation,and full-wave electromagnetic (EM) *** negative refractive index (NRI) and backward wave propagation performance of the CRLH TL are *** application,a bandpass filter (BPF) with enhanced out-of-band selectivity and harmonic suppression operating at the wireless local area network (WLAN) band is designed,fabricated,and measured by combining the CRLH TL with a complementary electric inductive-capacitive resonator (CELC).Three CELC cells with wideband stopband performance in the conductor strip and ground plane,respectively,are utilized in terms of single negative *** design concept has been verified by the measurement data.

关键词： Composite right/left handed transmission line Cascaded complementary split single ring resonator Bandpass filter Complementary electric inductive-capacitive resonator (CELC) Negative permeability

A method for neutron-induced gamma spectra decomposition analysis based on Geant4 simulation

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Nuclear Science and Techniques 2022年第12期33卷 36-48页

作者： Wei Tang Jin-gang liang Yi Ge Qiong Zhang University of Electronic Science and Technology of China Chengdu 610000China Tsinghua University Beijing 10000China

In various monitoring and detection tools that use pulsed neutron generators as radiation sources,the gamma rays induced by the interaction with various nuclei at different stages of neutron transport can reflect information about the *** gamma rays are generated in two major interactions:inelastic scattering of fast neutrons and radiative capture of thermal neutrons,corresponding to the inelastic and capture gamma rays,***,the two types of gamma rays that reflect different properties of the medium are difficult to collect by normal detectors *** proportion of the two gamma rays needs to be solved for the separation of inelastic and capture ***,this study proposes an optimized spectra decomposition method to calculate the inelastic-to-capture ratio in the measured total gamma spectra based on the net inelastic and capture spectra obtained using the Geant4 *** the simulated data cannot reflect the energy resolution of the measured spectra,we introduce the Gaussian broadening function of the gamma detector while calculating the proportion of the spectra components,and achieve optimization of the proportion values and resolution parameters *** on the results,the total simulated spectra obtained by superimposing the broadened net inelastic and capture gamma spectra according to the calculated inelastic-to-capture ratio are in good agreement with their measured counterpart.

关键词： Neutron-induced gamma Geant4 Spectra analysis

Review on strategies of space-based optical space situational awareness

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Journal of Systems Engineering and Electronics 2021年第5期32卷 1152-1166页

作者： HU Yunpeng LI Kebo liang Yan’gang CHEN Lei College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Unmanned Systems Research Center National Innovation Institute of Defense TechnologyBeijing 100071China

Space-based optical(SBO)space surveillance has attracted widespread interest in the last two decades due to its considerable value in space situation awareness(SSA).SBO observation strategy,which is related to the performance of space surveillance,is the top-level design in SSA missions *** recognized real programs about SBO SAA proposed by the institutions in the U.S.,Canada,Europe,etc.,are summarized firstly,from which an insight of the development trend of SBO SAA can be *** to the aim of the SBO SSA,the missions can be divided into general surveillance and space object ***,there are two major categories for SBO SSA *** general surveillance strategies for observing low earth orbit(LEO)objects and beyond-LEO objects are summarized and compared in terms of coverage rate,revisit time,visibility period,and image ***,the SBO space object tracking strategies,which has experienced from tracking an object with a single satellite to tracking an object with multiple satellites cooperatively,are also ***,this paper looks into the development trend in the future and points out several problems that challenges the SBO SSA.

关键词： space situation awareness(SSA) space-based space surveillance space-based optical(SBO)observation strategy general surveillance space object tracking

Experimental Simulation Study of the Dominant Enrichment Area of Terrestrial Organic Matter in the Shallow-Delta Sedimentary System of the Yacheng Formation in the Qiongdongnan Basin

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Acta Geologica Sinica(English Edition) 2022年第5期96卷 1693-1703页

作者： XU Xinde YANG Xibing QU Tong GAO gang liang gang LI Xing CNOOC China Limited Zhanjiang BranchZhanjiangGuangdong 524057China State Key Laboratory of Petroleum Resources and Prospecting China’s University of PetroleumBeijing 102249China College of Geosciences China’s University of PetroleumBeijing 102249China CNOOC China Limited Hainan BranchHaikou 570312China

Shallow-delta sedimentary systems receive both terrestrial and marine organic matter. As oil and gas exploration activities determine that the source rocks of the deep-water area of the Qiongdongnan Basin, northern South China Sea, are generally rich in and even dominated by terrestrial organic matter, this has led many researchers to examine the rules governing terrestrial organic matter enrichment in shallow-delta sea sedimentary systems. However, the deep burial of source rocks in deep-water areas and the relatively small amount of drilling undertaken have greatly restricted the study of these rules. In this study, the ‘forward modeling' research method was used to observe and analyze the deposition and preservation of terrestrial organic matter through flume experiments, where the depositional results were carefully depicted and sampled. The total organic carbon content of selected samples was measured and when combined with qualitative observations and quantitative comparison results, the dominant enrichment areas of terrestrial organic matter were identified. The experimental results show that the overbank parts of the delta front, the dune countercurrent surface, the low-lying parts, the delta front slope area and the shallow-prodelta sea area are where terrestrial organic matter is predominantly enriched. This provides an important basis and guidance for the prediction of the development areas of marine source rocks with terrestrial input in the deep-water areas of the Qiongdongnan Basin.

关键词： shallow-delta sea sedimentary system deep water area terrestrial organic matter flume experiment enrichment area Qiongdongnan Basin

T-Q diagram analyses and entransy optimization of the organic flash cycle(OFC)

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Science China(Technological Sciences) 2015年第4期58卷 630-637页

作者： WANG Wen Hua CHENG Xue Tao liang Xin gang Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of AerospaceTsinghua University

The electrical power generation from low temperature heat source attracts more and more attentions but the temperature mismatching between the heat sources and working medium in the organic Rankine cycle(ORC)becomes an *** organic flash cycle(OFC)is an effective solution to this *** this paper,the OFC is analyzed by the concept of entransy loss and the T-Q(temperature-heat flow rate)diagram for the heat-work *** equations for cycles of the basic OFC and the OFC whose heat source is the exhaust gas of the turbine in a Brayton cycle(the combined cycle)are derived theoretically and the results indicate that larger entransy loss rate leads to larger output power with prescribed inlet parameters of the hot stream in the discussed cases,which is displayed by the T-Qdiagram *** numerical examples demonstrate that the optimal mass flow rate of the working medium for the maximum entransy loss rate is the same as that for the maximum output *** T-Qdiagram analyses is in accordance with the numerical *** concept of entransy loss can be used as the criteria for the OFC optimization.

关键词： OFC T. Q diagram entransy loss combined cycle optimization

Uniformity principle of temperature difference field in heat transfer optimization

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Chinese Physics B 2019年第6期28卷 245-253页

作者： Xue-Tao Cheng Xin-gang liang Department of Science and Technology of Anhui Province Hefei 230091China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

The uniformity principle of temperature difference field is very useful in heat exchanger analyses and *** this paper, we analyze some other heat transfer optimization problems in the thermal management system of spacecrafts,including the cooling of thermal components, the one-stream series-wound heat exchanger network, the volume-to-point heat conduction problem, and the radiative heat transfer optimization problem, and have found that the uniformity principle of temperature difference field also holds. When the design objectives under the given constraints are achieved, the distributions of the temperature difference fields are uniform. The principle reflects the characteristic of the distribution of potential in the heat transfer optimization problems. It is also shown that the principle is consistent with the entransy theory. Therefore, although the principle is intuitive and phenomenological, the entransy theory can be the physical basis of the principle.

关键词： heat transfer optimization uniformity principle of temperature difference field equipartition of potential entransy theory