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Cu^(2+)污染下农作物叶片特征光谱探究

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光谱学与光谱分析 2025年第1期45卷 264-271页

作者：张超吴轩杨可明齐钒宇夏天中国地质调查局发展研究中心北京100037 中国地质大学(北京)地球科学与资源学院北京100083 全国地质资料馆北京100037 中国矿业大学(北京)地球科学与测绘工程学院北京100083 中国资源卫星应用中心北京100094

为探究重金属胁迫下农作物污染响应的敏感叶型及谱段,设计了室外温室环境下的不同铜胁迫梯度玉米花盆试验。以玉米叶片为探究对象,利用仪器测定了出穂期玉米叶片的高光谱反射率数据以及叶片中重金属含量数据,为研究提供了基础数据。从... 详细信息

为探究重金属胁迫下农作物污染响应的敏感叶型及谱段,设计了室外温室环境下的不同铜胁迫梯度玉米花盆试验。以玉米叶片为探究对象,利用仪器测定了出穂期玉米叶片的高光谱反射率数据以及叶片中重金属含量数据,为研究提供了基础数据。从频率域角度,结合时频分析的方法设计了叶片光谱探测法(LSDM),获得了重金属铜胁迫下敏感叶型及谱段,为农作物重金属监测提供技术支撑。根据玉米的生长过程,从老叶(O)、中叶(M)、新叶(N)光谱350~1300 nm的全谱段和子谱段角度进行探究。(1)对铜胁迫下玉米叶片的高光谱反射率数据进行双微分(SOD)和包络线移除(CR),转换到频率域上,结合时频分析的方法进行Daubechies小波6层分解。(2)根据信号异常点、小波高值点和SODCR曲线高值点,定义玉米叶片的光谱异常参数(SAP)。异常变化反射率ACR(异常反射率与其后一个相邻波段反射率差值的绝对值);异常小波系数AWC(异常小波系数与其后一个相邻波段小波系数差值的绝对值);异常SODCR值ASV(异常点SODCR值与其后一个相邻波段SODCR值差值的绝对值)。通过光谱异常参数与玉米叶片重金属含量的相关关系,探究对铜污染响应敏感的叶型及谱段。结果表明,叶片光谱探测法LSDM能高效地对玉米叶片弱信息进行增强,并准确定位出重金属铜胁迫引起的光谱异常谱段位置,异常变化范围集中在350~800 nm内;光谱异常参数能定量地衡量玉米叶片在重金属铜胁迫下的光谱异常;在不同铜胁迫梯度下,玉米新叶(N)为敏感叶型,敏感谱段为蓝边、绿峰、黄边、红谷。该研究有望为其他谷类农作物及其冠层尺度重金属监测提供技术支撑。

关键词：重金属胁迫玉米叶片高光谱敏感叶型敏感谱段

Simulation Study on Hydrogen-Heating-Power Poly-Generation System based on Solar Driven Supercritical Water Biomass Gasification with Compressed Gas Products as an Energy Storage System

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Journal of Thermal Science 2020年第2期29卷 365-377页

作者： JIN Hui WANG Cui fan chao State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

Supercritical water gasification driven by solar energy is a promising way for clean utilization of biomass with high moisture content, but direct discharge of liquid residual causes energy waste and decreases energy efficiency. To reduce energy waste, a poly-generation system for hydrogen-rich gas production coupling heat supply and power generation based on supercritical water gasification of biomass driven by concentrated solar energy was established in this paper, which also provided a novel energy storage method to overcome the shortcomings of solar discontinuity. Thermodynamic model of the system was proposed and life cycle assessment(LCA) of the system was conducted. Influence of different parameters(temperature of 600℃ to 800℃, outlet temperature of heat exchanger of 42℃ to 56℃, biomass slurry concentration of 5% to 6.5%) on the gasification performance, energy and exergy efficiency, energy distribution and global warming potential(GWP) was discussed. The results indicated that hydrogen yield increased as gasification temperature increased since free radical reaction was enhanced which gas production reaction was classified into. Molar fraction of hydrogen increased as gasification temperature increased and reached 65.6% at 750℃. Energy and exergy efficiency of the system reached 74.84% and 34.87% at 700℃ and 600℃ respectively and that of gas production was 18.15% at 650℃, which was the highest. Increasing reaction temperature and decreasing biomass slurry concentration were effective ways to decrease GWP. Optimal operating parameter was reaction temperature of 650℃, outlet temperature of heat exchanger of 50℃ and biomass concentration of 5%.

关键词： biomass supercritical water gasification poly-generation system thermodynamics analysis energy storage life cycle assessment

Machine Learning Spectroscopy Using a 2-Stage,Generalized Constituent Contribution Protocol

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Research 2023年第4期2023卷 765-775页

作者： Jinming fan chao Qian Shaodong Zhou College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang University310027 HangzhouP.R.China Institute of Zhejiang University-Quzhou Zheda Rd.#99324000 QuzhouP.R.China

A corrected group contribution(CGC)-molecule contribution(MC)-Bayesian neural network(BNN)protocol for accurate prediction of absorption spectra is *** combination of BNN with CGC methods,the full absorption spectra of various molecules are afforded accurately and efficiently—by using only a small dataset for ***,with a small training sample(1,000 samples to ensure the accuracy of ***,with2,000)to achieve comparable ***,by employing an MC method designed specifically for CGC that properly interprets the mixing rule,the spectra of mixtures are obtained with high *** logical origins of the good performance of the protocol are discussed in *** that such a constituent contribution protocol combines chemical principles and data-driven tools,most likely,it will be proven efficient to solve molecular-property-relevant problems in wider fields.

关键词： prediction absorption properly

Unifying logic rules and machine learning for entity enhancing

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Science China(Information Sciences) 2020年第7期63卷 142-160页

作者： Wenfei fan Ping LU chao TIAN School of Informatics University of Edinburgh Shenzhen Institute of Computing Sciences Shenzhen University Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang University Alibaba Group

This paper proposes a notion of entity enhancing, which unifies entity resolution and conflict resolution, to identify tuples that refer to the same real-world entity and at the same time, correct semantic inconsistencies. We propose to unify rule-based and machine learning(ML) methods for entity enhancing, by embedding ML classifiers as predicates in logic rules. We model entity enhancing by extending the chase. We show that the chase warrants correctness justification and the Church-Rosser property. Moreover, we settle fundamental problems associated with entity enhancing, including the enhancing, consistency, satisfiability,and implication problems, ranging from NP-complete and coNP-complete to Π~p-complete. Taken together,these provide a new theoretical framework for unifying entity resolution and conflict resolution.

关键词： logic rules machine learning entity enhancing entity resolution conflict resolution

Test on Stochastic Block Model:Local Smoothing and Extreme Value Theory

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Journal of Systems Science & Complexity 2022年第4期35卷 1535-1556页

作者： WU fan KONG Xinbing XU chao School of Mathematics Southeast UniversityNanjing211819China School of Statistics and Mathematics Nanjing Audit UniversityNanjing211815China School of Information Engineering Nanjing Audit UniversityNanjing211815China

In this paper,to obtain a consistent estimator of the number of communities,the authors present a new sequential testing procedure,based on the locally smoothed adjacency matrix and the extreme value *** the null hypothesis,the test statistic converges to the type I extreme value distribution,and otherwise,it explodes fast and the divergence rate could even reach n in the strong signal case where n is the size of the network,guaranteeing high detection *** method is simple to use and serves as an alternative approach to the novel one in Lei(2016)using random matrix *** detect the change of the community structure,the authors also propose a two-sample test for the stochastic block model with two observed adjacency *** studies justify the *** authors apply the proposed method to the political blog data set and find reasonable group structures.

关键词： Extreme value distribution network data stochastic block model

Stabilizing and reinforcing effects of different fibers on asphalt mortar performance

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Petroleum Science 2015年第1期12卷 189-196页

作者： Meng-Meng Wu Rui Li Yu-Zhen Zhang Liang fan Yu-chao lv Jian-Ming Wei State Key Laboratory of Heavy Oil Processing China University of Petroleum (East China)

Physical properties of different fibers （mineral, cellulose, or carbon fiber） and their stabilizing and reinforcing effects on asphalt mortar performance were studied. Scanning electron microscopy was used to study the effect of fiber＇s microstructure on asphalt mortar＇s performance. Laboratory tests of mesh-basket draindown and oven heating were designed and performed to evaluate the fibers＇ asphalt absorption and thermostability. A cone penetration test was used to study the flow resistance of fiber-modified asphalt mortar. Results showed that fiber can form a three-dimensional network structure in asphalt, and this network can be retained at high temperature. This network of fibers favors the formation of a thick coating of mastic without asphalt draining down. Cellulose fiber possessed a greater effect on asphalt absorption and sta- bilization than did the other fibers （mineral and carbon fiber）. A dynamic shear rheometer was used to evaluate their rheological properties and rut resistance. Results indicated that fiber can effectively improve the rut and flow resistance of asphalt mortar. However, the bending beam rheometer results demonstrated that the addition of fiber had negative effects on the creep stiffness and creep rate of asphalt mortar.

关键词： Fiber Asphalt mortar SEM Rheology Mechanical properties

A Symbol Timing Recovery Algorithm of M-PSK Signals for Burst Modem Applications with Small Packet Size

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China Communications 2016年第6期13卷 138-146页

作者： Yu Chi Lan Chen chao lv Institute of Microelectronics Chinese Academy of Sciences

Feedforward symbol timing recovery techniques are particularly important for initial acquisition in burst modems. However, these techniques either have large calculation burden or sensitive to frequency offsets. In this paper, we proposed an efficient symbol timing recovery algorithm of MPSK signals named OMQ(Ordered Maximum power using Quadratic approximation partially) algorithm which is based on the Quadratic Approximation(QA) algorithm. We used ordered statistic sorting method to reduce the computational complexity further, meanwhile maximum mean power principle was used to decrease frequency offset sensitivity. The proposed algorithm adopts estimation-down sampling structure which is suitable for small packet size transmission. The results show that, while comparing with the QA algorithm, the computational complexity is reduced by 75% at most when 8 samples per symbol are used. The proposed algorithm shows better performance in terms of the jitter variance and sensitivity to frequency offsets.

关键词： symbol timing maximum mean power ordered statistic Quadratic Approximation

Analytical long-term evolution and perturbation compensation models for BeiDou MEO satellites

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Chinese Journal of Aeronautics 2018年第2期31卷 330-338页

作者： Li fan Min HU chao JIANG School of Aerospace Engineering Tsinghua University Beijing 100084 China Space Engineering University Beijing 101416 China College of Aerospace Science and Engineering National University of Defense Technology Changsha 410073 China

The current paper establishes the analytical models of the long-term evolution and perturbation compensation strategy for Medium Earth Orbits（MEO）shallow-resonant navigation constellation,with application to the Chinese Bei Dou Navigation Satellite System（BDS）.The long-term perturbation model for the relative motion is developed based on the Hamiltonian model,and the long-term evolution law is *** relationship between the control boundary of the constellation and the offset of the orbital elements is analyzed,and a general analytical method for calculating the offset of the orbit elements is *** analytical model is further improved when the luni-solar perturbations are *** long-term evolutions of the BDS MEO constellation within 10 years are illustrated,and the effectiveness of the proposed analytical perturbation compensation calculation approach is compared with the traditional numerical *** found the fundamental reason for the nonlinear variations of the relative longitude of ascending node and the mean argument of latitude is the long-periodic variations of the orbital inclination due to the luni-solar *** proposed analytical approach can avoid the numerical iterations,and reveal the essential relationship between the orbital element offsets and the secular drifts of the constellation ***,there is no need for maintaining the BDS MEO constellation within 10 years while using the perturbation compensation method.

关键词： BeiDou Navigation Satellite System (BDS) Long-term evolution Luni-solar perturbations Medium Earth Orbits(MEO) Perturbation compensation

Saturation attack based route planning and threat avoidance algorithm for cruise missiles

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Journal of Systems Engineering and Electronics 2011年第6期22卷 948-953页

作者： Guanghui Wang Xuefeng Sun Liping Zhang chao lv Department of Command Naval Aeronautical and Astronautical University Yantai 264001 P. R. China Graduate Student Brigade Naval Aeronautical and Astronautical University Yantai 264001 P. R. China

According to the characteristic of cruise missiles,navigation point setting is simplified,and the principle of route planning for saturation attack and a concept of reference route are put *** the help of the shortest-tangent idea in route-planning and the algorithm of back reasoning from targets,a reference route algorithm is built on the shortest range and threat *** a route-flight-time algorithm is built on navigation *** on the conditions of multi-direction saturation attack,a route planning algorithm of multi-direction saturation attack is built on reference route,route-flight-time,and impact *** results show that the algorithm can realize missiles fired in a salvo launch reaching the target simultaneously from different directions while avoiding threat.

关键词： aerospace system engineering control and navigation technology of aero-craft mission planning route planning cruise missile saturation attack threat avoidance.