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Intercepts allocation for layered defense 被引量:1
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作者 Longyue Li Fuxian Liu +2 位作者 Guangzheng Long Pengsong Guo Yingying Mei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第3期602-611,共10页
One important mission of the strategic defense is to develop an integrated, layered ballistic missile defense system(BMDS). Considering the problem of assigning limited defense weapons to incoming ballistic missiles... One important mission of the strategic defense is to develop an integrated, layered ballistic missile defense system(BMDS). Considering the problem of assigning limited defense weapons to incoming ballistic missiles, we illustrate how defense weapons, ballistic missiles, kill probability and effectiveness of defense(ED) are interrelated and how to understand this relationship for achieving the best allocation plan. Motivated by the queueing theory, in which the available resources are not sufficient to satisfy the demands placed upon them at all times, the layered deployed defense weapon is modeled as a queueing system to shoot Poisson arrived targets. Simultaneously, examples, of optimum intercepts allocation problems under different constraints are presented. The four theorems determine the allocation rules of intercepts to targets that maximize ED or minimize the cost to achieve a required ED. 展开更多
关键词 intercepts allocation layered defense queueing theory effectiveness of defense
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‘Relationships between relationships’ in forest stands: intercepts and exponents analyses 被引量:1
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作者 Vladimir L.Gavrikov 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期575-582,共8页
Relationships between diameter at breast height(dbh) versus stand density, and tree height versus dbh(height curve) were explored with the aim to find if there were functional links between correspondent parameters of... Relationships between diameter at breast height(dbh) versus stand density, and tree height versus dbh(height curve) were explored with the aim to find if there were functional links between correspondent parameters of the relationships, exponents and intercepts of their power functions. A geometric model of a forest stand using a conic approximation suggested that there should be interrelations between correspondent exponents and intercepts of the relationships. It is equivalent to a type of ‘relationship between relationships’ that might exist in a forest stand undergoing self-thinning, and means that parameters of one relationship may be predicted from parameters of another. The predictions of the model were tested with data on forest stand structure from published databases that involved a number of trees species and site quality levels. It was found that the correspondent exponents and intercepts may be directly recalculated from one another for the simplest case when the total stem surface area was independent of stand density. For cases where total stem surface area changes with the drop of density, it is possible to develop a generalization of the model in which the interrelationships between correspondent parameters(exponents and intercepts) may be still established. 展开更多
关键词 Total stem surface area SELF-THINNING Conic approximation Power function Exponent INTERCEPT Scots pine
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Influences of tree characters on throughfall and stemflow from rainfall and fog in Popa Mountain Park, Myanmar
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作者 Yadanar Zaw Hiroki Oue 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第6期210-219,共10页
Available water for communities is insufficient in the central part of Myanmar due to limited rainfall and surface water resources.Over the last two decades,affores-tation and reforestation projects have been implemen... Available water for communities is insufficient in the central part of Myanmar due to limited rainfall and surface water resources.Over the last two decades,affores-tation and reforestation projects have been implemented in this region to provide sufficient water to local communities,expecting forested areas to store more rainwater than other land uses.However,there has been no research and very limited information on rainfall partitioning into throughfall(TF)and stemflow(SF),particularly concerning tree char-acters.Gross rainfall,TF under different canopy types,and SF of different tree types were measured in 2019.TF and SF were frequently observed even without rain but under foggy conditions.Therefore,both were partitioned into TF and SF from rainfall and fog individually.Sparser canopies resulted in larger TF from rainfall than denser canopies.However,a denser canopy delivered larger TF from fog than a sparser one.TF rates from rainfall in sparser and denser canopies were 54.5%and 51.5%,respectively,while those from fog were 15.2%and 27.2%,respectively.As a result,total TF rate in the denser canopy(70.7%)was significantly larger than that from the sparser one(64.3%).Short trees with small crown projection area and smooth bark(Type I)resulted in larger SF from rainfall than taller trees with large crown projection area and rough bark(Type II).How-ever,Type II trees resulted in larger SF from fog.SF rates by rainfall from Type I and II trees were 17.5%and 12.2%,respectively,while those by fog were 22.2%and 39.5%,respectively.No significant total SF rates were found for Type I(22.5%)and II trees(20.1%).A denser canopy results in larger TF,and Type I trees result in larger SF.In an area where foggy conditions occur frequently and for a lengthy period,however,Type II trees will result in larger SF.These three tree characters(dense canopies,short trees with small crown projection area and smooth bark,and tall trees with large crown projection area and rough bark)should be con-sidered for afforestation and reforestation projects in the Popa Mountain Park to enhance net water input by forests. 展开更多
关键词 Gross rainfall Fog interception THROUGHFALL STEMFLOW
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Effects of dense planting patterns on photosynthetic traits of different vertical layers and yield of wheat under different nitrogen rates
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作者 Cuicun Wang Ke Zhang +9 位作者 Qing Liu Xiufeng Zhang Zhikuan Shi Xue Wang Caili Guo Qiang Cao Yongchao Tian Yan Zhu Xiaojun Liu Weixing Cao 《The Crop Journal》 SCIE CSCD 2024年第2期594-604,共11页
A two-year field experiment was conducted to measure the effects of densification methods on photosynthesis and yield of densely planted wheat.Inter-plant and inter-row distances were used to define ratefixed pattern(... A two-year field experiment was conducted to measure the effects of densification methods on photosynthesis and yield of densely planted wheat.Inter-plant and inter-row distances were used to define ratefixed pattern(RR)and row-fixed pattern(RS)density treatments.Meanwhile,four nitrogen(N)rates(0,144,192,and 240 kg N ha-1,termed N0,N144,N192,and N240)were applied with three densities(225,292.5,and 360×10^(4)plants ha^(-1),termed D225,D292.5,and D360).The wheat canopy was clipped into three equal vertical layers(top,middle,and bottom layers),and their chlorophyll density(Ch D)and photosynthetically active radiation interception(FIPAR)were measured.Results showed that the response of Ch D and FIPAR to N rate,density,and pattern varied with different layers.N rate,density,and pattern had significant interaction effects on Ch D.The maximum values of whole-canopy Ch D in the two seasons appeared in N240 combined with D292.5 and D360 under RR,respectively.Across two growing seasons,FIPAR values of RR were higher than those of RS by 29.37%for the top layer and 5.68%for the middle layer,while lower than those of RS by 20.62%for the bottom layer on average.With a low N supply(N0),grain yield was not significantly affected by density for both patterns.At N240,increasing density significantly increased yield under RR,but D360 of RS significantly decreased yield by 3.72%and 9.00%versus D225 in two seasons,respectively.With an appropriate and sufficient N application,RR increased the yield of densely planted wheat more than RS.Additionally,the maximum yield in two seasons appeared in the combination of D360 with N144 or N192 rather than of D225 with N240 under both patterns,suggesting that dense planting combined with an appropriate N-reduction application is feasible to increase photosynthesis capacity and yield. 展开更多
关键词 Chlorophyll density Densification method Nitrogen Photosynthetically active radiation INTERCEPTION WHEAT
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Physical Layer Security Performance Analysis in Multi-Antenna NOMA-Based UAV Relay Networks
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作者 Huang Haiyan Zhang Hongsheng +1 位作者 Liang Linlin Li Yahong 《China Communications》 SCIE CSCD 2024年第9期98-108,共11页
With the increasing number of communication devices and the complexity of communication environments,unmanned aerial vehicles(UAV),due to their flexible deployment and convenient networking capabilities,have shown sig... With the increasing number of communication devices and the complexity of communication environments,unmanned aerial vehicles(UAV),due to their flexible deployment and convenient networking capabilities,have shown significant advantages in tasks such as high-density communication areas and emergency rescue within special communication scenarios.Considering the openness of air-toground wireless communication,it is more susceptible to eavesdropping attacks.As a result,the introduction of physical layer security(PLS)in UAV communication systems is crucial to safeguard the security of transmitted data.In this paper,we investigate the PLS issues in a UAV cooperative communication system operating in Nakagami-m fading channels with the presence of friendly interference.It considers the effects of imperfect successive interference cancellation(i SIC)and power allocation coefficients on system performance based on non-orthogonal multiple access(NOMA)techniques.By deriving closed-form expressions for the outage probabilities at the receiving users and the intercept probability of UAV eavesdropper(U-EAV),the performance of the considered cooperative UAV-assisted NOMA relay system with the presence of friendly interference is evaluated. 展开更多
关键词 intercept probability NOMA OUTAGE
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Recorded recurrent deep reinforcement learning guidance laws for intercepting endoatmospheric maneuvering missiles
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作者 Xiaoqi Qiu Peng Lai +1 位作者 Changsheng Gao Wuxing Jing 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期457-470,共14页
This work proposes a recorded recurrent twin delayed deep deterministic(RRTD3)policy gradient algorithm to solve the challenge of constructing guidance laws for intercepting endoatmospheric maneuvering missiles with u... This work proposes a recorded recurrent twin delayed deep deterministic(RRTD3)policy gradient algorithm to solve the challenge of constructing guidance laws for intercepting endoatmospheric maneuvering missiles with uncertainties and observation noise.The attack-defense engagement scenario is modeled as a partially observable Markov decision process(POMDP).Given the benefits of recurrent neural networks(RNNs)in processing sequence information,an RNN layer is incorporated into the agent’s policy network to alleviate the bottleneck of traditional deep reinforcement learning methods while dealing with POMDPs.The measurements from the interceptor’s seeker during each guidance cycle are combined into one sequence as the input to the policy network since the detection frequency of an interceptor is usually higher than its guidance frequency.During training,the hidden states of the RNN layer in the policy network are recorded to overcome the partially observable problem that this RNN layer causes inside the agent.The training curves show that the proposed RRTD3 successfully enhances data efficiency,training speed,and training stability.The test results confirm the advantages of the RRTD3-based guidance laws over some conventional guidance laws. 展开更多
关键词 Endoatmospheric interception Missile guidance Reinforcement learning Markov decision process Recurrent neural networks
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Optimal deployment of swarm positions in cooperative interception of multiple UAV swarms 被引量:1
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作者 Chengcai Wang Ao Wu +3 位作者 Yueqi Hou Xiaolong Liang Luo Xu Xiaomo Wang 《Digital Communications and Networks》 SCIE CSCD 2023年第2期567-579,共13页
In order to prevent the attacker from breaking through the blockade of the interception,deploying multiple Unmanned Aerial Vehicle(UAV)swarms on the interception line is a new combat style.To solve the optimal deploym... In order to prevent the attacker from breaking through the blockade of the interception,deploying multiple Unmanned Aerial Vehicle(UAV)swarms on the interception line is a new combat style.To solve the optimal deployment of swarm positions in the cooperative interception,an optimal deployment optimization model is presented by minimizing the penetration zones'area and the analytical expression of the optimal deployment positions is deduced.Firstly,from the view of the attackers breaking through the interception line,the situations of vertical penetration and oblique penetration are analyzed respectively,and the mathematical models of penetration zones are obtained under the condition of a single UAV swarm and multiple UAV swarms.Secondly,based on the optimization goal of minimizing the penetration area,the optimal deployment optimization model for swarm positions is proposed,and the analytical solution of the optimal deployment is solved by using the convex programming theory.Finally,the proposed optimal deployment is compared with the uniform deployment and random deployment to verify the validity of the theoretical analysis. 展开更多
关键词 UAV Swarm Cooperative interception Deployment optimization Convex programming
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Influencing factor analysis of interception probability and classification-regression neural network based estimation
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作者 NAN Yi YI Guoxing +2 位作者 HU Lei WANG Changhong TU Zhenbiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第4期992-1006,共15页
The interception probability of a single missile is the basis for combat plan design and weapon performance evaluation,while its influencing factors are complex and mutually coupled.Existing calculation methods have v... The interception probability of a single missile is the basis for combat plan design and weapon performance evaluation,while its influencing factors are complex and mutually coupled.Existing calculation methods have very limited analysis of the influence mechanism of influencing factors,and none of them has analyzed the influence of the guidance law.This paper considers the influencing factors of both the interceptor and the target more comprehensively.Interceptor parameters include speed,guidance law,guidance error,fuze error,and fragment killing ability,while target performance includes speed,maneuverability,and vulnerability.In this paper,an interception model is established,Monte Carlo simulation is carried out,and the influence mechanism of each factor is analyzed based on the model and simulation results.Finally,this paper proposes a classification-regression neural network to quickly estimate the interception probability based on the value of influencing factors.The proposed method reduces the interference of invalid interception data to valid data,so its prediction accuracy is significantly better than that of pure regression neural networks. 展开更多
关键词 interception probability simulation modeling analysis of influencing factors probability estimation neural networks
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Three Core Technical Systems and Engineering Application of Regional Lightning Protection
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作者 Zhen CHEN Yu HUANG +4 位作者 Ziqin GAO Yixian QIU Xiaofeng LUO Xiaoning ZHANG Jixi LIU 《Meteorological and Environmental Research》 CAS 2023年第3期48-53,共6页
Regional lightning protection is a complete theoretical system,mainly including:lightning interception technology(LIPT),lightning strong electromagnetic pulse high-energy absorption technology(MSPD),and regional light... Regional lightning protection is a complete theoretical system,mainly including:lightning interception technology(LIPT),lightning strong electromagnetic pulse high-energy absorption technology(MSPD),and regional lightning activity law analysis technology(RLLA).Lightning interception technology uses dispersive waveguide resonant cavity technology to achieve the functions of 46.55 m longer than upward leader of ordinary lightning rod,significantly reducing lightning strike point current by 40%,optimizing space electromagnetic field environment,and effectively intercepting overhead and side lightning strikes,and overcome the limitations of traditional lightning rod.The lightning strong electromagnetic pulse high-energy absorption technology uses distributed parameter balance technology,special disconnector for short circuit current,and parity pairing technology to achieve stronger surge absorption capacity than traditional single pulse SPD and international advanced technical indicators such as timely breaking under power frequency short circuit current,and good energy and time coordination.The analysis technology of regional lightning activity laws accurately identifies lightning strike points through comprehensive analysis of regional lightning activity laws,physical parameters of ion clouds,and the impact on ground electric fields.The three core technology systems complement each other,achieving all-round protection against direct lightning strike and lightning electromagnetic pulse.Several projects achieved zero lightning damage,effectively ensuring the safety of buildings and electronic and electrical equipment in the protected area. 展开更多
关键词 Regional lightning protection Lightning interception technology Multi-pulse high-energy absorption technology Lightning point identification technology
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Influence of canopy on precipitation and its nutrient elements in broadleaved/Korean pine forest on the northern slope of Changbai Mountain 被引量:3
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作者 肖以华 代力民 +3 位作者 牛德奎 佟富春 陈高 邓红兵 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第3期201-204,251,共4页
The precipitation distribution quantity of canopy in broadleaved/Korean pine forest was measured during the growing season (Jun.–Sept.) in 2001 in the Changbai Mountain, Jilin Province, P. R. China. Results indicated... The precipitation distribution quantity of canopy in broadleaved/Korean pine forest was measured during the growing season (Jun.–Sept.) in 2001 in the Changbai Mountain, Jilin Province, P. R. China. Results indicated that the amounts of stemflow, throughfall, and interception were 37.39, 322.12 and 109.69 mm, accounting for 7.97%, 68.65% and 23.38% of the total rainfall, respectively. The rate of stemflow was higher in Jul. and Aug. than other months. The rate of throughfall dropped off from Jun. to Sept., however, rate of interception changed contrarily from 19.43% to 31.02% during the growing season. According to our analysis, the concentration of nutrient elements were arranged as Ca>Mg>N>K>Fe>P>Cu>Mn for rainfall, K>N>Mg>Ca>P>Fe>Mn>Cu for throughfall, and Mn>P>K>Cu>Fe>N>Mg>Ca for being leached through canopy. Nutrients concentration in stewflow and throughfall changed significantly when rainfall passed canopy, and concentration of all elements increased except for Ca and Mg. 展开更多
关键词 Broadleaved/Korean pine forest Precipitation distribution Concentration Nutrient elements CANOPY STEMFLOW THROUGHFALL INTERCEPTION
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Research on Water Conservation Function of Typical Forests in Jinyun Mountain 被引量:4
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作者 李杨 王百田 +1 位作者 饶良懿 王玉杰 《Agricultural Science & Technology》 CAS 2012年第1期181-188,共8页
[Objective] This study aimed to explore the relationship between different forest types and water conservation function. [Method] Based on field survey and experimental analysis, water conservation function of four ty... [Objective] This study aimed to explore the relationship between different forest types and water conservation function. [Method] Based on field survey and experimental analysis, water conservation function of four typical forest stands in Jinyun Mountain of Chongqing was explored, including conifer-broadleaved mixed for- est, evergreen broad-leaved forest, bamboo forest and shrub forest. [Result] The re- sults showed that the order of saturated water storage capacity of soil in four forest stands was shrub forest (266.48 mm) 〉 conifer-broadleaved mixed forest (190.40 mm) 〉 evergreen broad-leaved forest (186.80 mm) 〉 bamboo forest (174.80 mm); the order of maximum water-holding capacity of litter was shrub forest (8.06 mm) 〉 conifer-broadleaved mixed forest (4.71 mm) 〉 evergreen broad-leaved forest (4.32 mm) 〉 bamboo forest (3.34 mm); the order of canopy interception in various forest stands was conifer-broadleaved mixed forest (16.15%) 〉 evergreen broad-leaved for- est (14.70%) 〉 bamboo forest (12.64%). [Conclusion] The study had great signifi- cance to rational manage forest resources, improve water environment and realize scientific management and use of water resources. 展开更多
关键词 Water conservation Jinyun Mountain Canopy interception Water-holding of litter Water conservation of soil
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RESEARCH ON NONLINEAR DISTORTION IN AMPLIFIERS 被引量:2
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作者 王成华 包骅 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2000年第2期182-187,共6页
Transistors are nonlinear devices, which can produce nonlinear distortion in amplifier while amplifying signals. For weak nonlinear distortion, the expressions of total harmonic distortion (THD), the second order in... Transistors are nonlinear devices, which can produce nonlinear distortion in amplifier while amplifying signals. For weak nonlinear distortion, the expressions of total harmonic distortion (THD), the second order intermodulation distortion(IM2 ), the third order intermodulation distortion(IM 3) and intercept point(IP 3) are deduced. With the aid of software Multisim, we simulate transistor common emitter amplifier, transistor common emitter amplifier with resistor in emitter, differential amplifier and differential amplifier with resistor between emitters. The simulational results and theoretical analyses are almost the same. 展开更多
关键词 nonlinear distortion intermodulation distortion intercept point negative feedback differential amplifier
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EXCEL函数在混合成本分解中的巧用 被引量:2
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作者 王雍欣 《中国乡镇企业会计》 2014年第5期33-35,共3页
混合成本分解是成本性态分析的前提和基础。传统的混合成本分解方法工作量大,计算复杂,难以记忆。利用EXCEL的CORREL、SLOPE和INTERCEPT函数可以有效简化混合成本分解问题。
关键词 混合成本分解 CORREL SLOPE INTERCEPT
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使用INTERCEPT血液系统制备血浆的临床前安全试验
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作者 叶兵 《国外医学(输血及血液学分册)》 2004年第3期285-285,共1页
背景和目的 最近发展的血浆INTERCEPT血液系统,通过添加新的补骨脂素,amotosalen HCl(AMOTOSALEN),然后用A段紫外线照射,来灭活可能造成新鲜冻干血浆污染的病毒、细菌、原生物和白细胞。
关键词 INTERCEPT 血液系统 制备 血浆 安全试验
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常规血库制品程序中血小板INTERCEPT血液系统的应用:单采血小板的评价
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作者 叶兵 《国外医学(输血及血液学分册)》 2004年第5期475-475,共1页
关键词 常规血库制品程序 血小板 INTERCEPT血液系统 单采血小板 评价
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Influence of plant architecture on maize physiology and yield in the Heilonggang River valley 被引量:14
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作者 Shoubing Huang Yingbo Gao +3 位作者 Yebei Li Lina Xu Hongbin Tao Pu Wang 《The Crop Journal》 SCIE CAS CSCD 2017年第1期52-62,共11页
The size and distribution of leaf area determine light interception in a crop canopy and influence overall photosynthesis and yield. Optimized plant architecture renders modern maize hybrids(Zea mays L.) more producti... The size and distribution of leaf area determine light interception in a crop canopy and influence overall photosynthesis and yield. Optimized plant architecture renders modern maize hybrids(Zea mays L.) more productive, owing to their tolerance of high plant densities. To determine physiological and yield response to maize plant architecture, a field experiment was conducted in 2010 and 2011. With the modern maize hybrid ZD958, three plant architectures, namely triangle, diamond and original plants, were included at two plant densities, 60,000 and 90,000 plants ha-1. Triangle and diamond plants were derived from the original plant by spraying the chemical regulator Jindele(active ingredients,ethephon, and cycocel) at different vegetative stages. To assess the effects of plant architecture, a light interception model was developed. Plant height, ear height, leaf size,and leaf orientation of the two regulated plant architectures were significantly reduced or altered compared with those of the original plants. On average across both plant densities and years, the original plants showed higher yield than the triangle and diamond plants,probably because of larger leaf area. The two-year mean grain yield of the original and diamond plants were almost the same at 90,000 plants ha-1(8714 vs. 8798 kg ha-1). The yield increase(up to 5%) of the diamonds plant at high plant densities was a result of increased kernel number per ear, which was likely a consequence of improved plant architecture in the top and middle canopy layers. The optimized light distribution within the canopy can delay leaf senescence, especially for triangle plants. The fraction of incident radiation simulated by the interception model successfully reflected plant architecture traits. Integration of canopy openness is expected to increase the simulation accuracy of the present model. Maize plant architecture with increased tolerance of high densities is probably dependent on the smaller but flatter leaves around the ear. 展开更多
关键词 MAIZE Light interception YIELD Light interception model Leaf senescence
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Nitrogen interception in floodwater of rice field in Taihu region of China 被引量:16
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作者 LIANG Xin-qiang CHEN Ying-xu LI Hua TIAN Guang-ming ZHANG Zhi-jian NI Wu-zhong HE Miao-miao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第12期1474-1481,共8页
A field experiment located in Taihu Lake Basin of China was conducted, by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen (N) export in a typical rice field through "... A field experiment located in Taihu Lake Basin of China was conducted, by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen (N) export in a typical rice field through "zero-drainage water management" combined with sound irrigation, rainfall forecasting and field drying. N concentrations in floodwater rapidly declined before the first event of field drying after three split fertilizations, and subsequently tended to rearm to the background level. Before the first field drying, total particulate nitrogen (TPN) was the predominant N form in floodwater of plots with no N input, dissolved inorganic nitrogen (DIN) on plots that received urea only, and dissolved organic nitrogen (DON) on plots treated with the mixture of urea and manure. Thereafter TPN became the major form. No N export was found from the rice field, but total nitrogen (TN) of 15.8 kg/hm^2 was remained, mainly due to soil N sorption. The results recommended the zero-drainage water management for full-scale areas for minimizing N export. 展开更多
关键词 NITROGEN paddy field surface floodwater INTERCEPTION Taihu region
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Novel TPN control algorithm for exoatmospheric intercept 被引量:14
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作者 Chen Lei Zhang Bing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1290-1295,共6页
A novel control algorithm with fixed pulse thrust, based on true proportional navigation(TPN), is proposed for exoatmospheric intercept.According to the TPN guidance law and pulse thrust characteristics, the princip... A novel control algorithm with fixed pulse thrust, based on true proportional navigation(TPN), is proposed for exoatmospheric intercept.According to the TPN guidance law and pulse thrust characteristics, the principle of control command is presented, the control stability and precision are analyzed.With the help of the TPN guidance law, the algorithm can automatically modulate the turn-on time and duration of the thrust, which could effectively limit the impact of measure noise of the line-of-sight(LOS) angle and rate on the interception miss-distance.At last, the number-theoretic method(NTM) is introduced to acquire the relation between control algorithm and miss-distance, even as it simulates the intercept process with initial state noise.And the reliability of the algorithm is demonstrated with the simulation result. 展开更多
关键词 exoatmospheric intercept true proportional navigation pulse thrust control algorithm numbertheoretic method.
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Mulching mode and planting density affect canopy interception loss of rainfall and water use efficiency of dryland maize on the Loess Plateau of China 被引量:8
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作者 ZHENG Jing FAN Junliang +4 位作者 ZHANG Fucang YAN Shicheng GUO Jinjin CHEN Dongfeng LI Zhijun 《Journal of Arid Land》 SCIE CSCD 2018年第5期794-808,共15页
High and efficient use of limited rainwater resources is of crucial importance for the crop production in arid and semi-arid areas. To investigate the effects of different soil and crop management practices(i.e., mul... High and efficient use of limited rainwater resources is of crucial importance for the crop production in arid and semi-arid areas. To investigate the effects of different soil and crop management practices(i.e., mulching mode treatments: flat cultivation with non-mulching, flat cultivation with straw mulching, plastic-covered ridge with bare furrow and plastic-covered ridge with straw-covered furrow; and planting density treatments: low planting density of 45,000 plants/hm^2, medium planting density of 67,500 plants/hm^2 and high planting density of 90,000 plants/hm^2) on rainfall partitioning by dryland maize canopy, especially the resulted net rainfall input beneath the maize canopy, we measured the gross rainfall, throughfall and stemflow at different growth stages of dryland maize in 2015 and 2016 on the Loess Plateau of China. The canopy interception loss was estimated by the water balance method. Soil water storage, leaf area index, grain yield(as well as it components) and water use efficiency of dryland maize were measured or calculated. Results showed that the cumulative throughfall, cumulative stemflow and cumulative canopy interception loss during the whole growing season accounted for 42.3%–77.5%, 15.1%–36.3% and 7.4%–21.4% of the total gross rainfall under different treatments, respectively. Soil mulching could promote the growth and development of dryland maize and enhance the capability of stemflow production and canopy interception loss, thereby increasing the relative stemflow and relative canopy interception loss and reducing the relative throughfall. The relative stemflow and relative canopy interception loss generally increased with increasing planting density, while the relative throughfall decreased with increasing planting density. During the two experimental years, mulching mode had no significant influence on net rainfall due to the compensation between throughfall and stemflow, whereas planting density significantly affected net rainfall. The highest grain yield and water use efficiency of dryland maize were obtained under the combination of medium planting density of 67,500 plants/hm^2 and mulching mode of plastic-covered ridge with straw-covered furrow. Soil mulching can reduce soil evaporation and retain more soil water for dryland maize without reducing the net rainfall input beneath the maize canopy, which may alleviate the contradiction between high soil water consumption and insufficient rainfall input of the soil. In conclusion, the application of medium planting density(67,500 plants/hm^2) under plastic-covered ridge with bare furrow is recommended for increasing dryland maize production on the Loess Plateau of China. 展开更多
关键词 dryland maize THROUGHFALL STEMFLOW canopy interception loss yield water use efficiency Loess Plateau
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Sensor radiation interception risk control in target tracking 被引量:4
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作者 Ce Pang Gan-lin Shan +1 位作者 Wei-ning Ma Gong-guo Xu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第3期695-704,共10页
This paper is mainly on the problem of radiation interception risk control in sensor network for target tracking.Firstly,the sensor radiation interception risk is defined as the product of the interception probability... This paper is mainly on the problem of radiation interception risk control in sensor network for target tracking.Firstly,the sensor radiation interception risk is defined as the product of the interception probability and the cost caused by the interception.Secondly,the radiation interception probability model and cost model are established,based on which the calculation method of interception risk can be obtained.Thirdly,a sensor scheduling model of radiation risk control is established,taking the minimum interception risk as the objective function.Then the Hungarian algorithm is proposed to obtain sensor scheduling scheme.Finally,simulation experiments are mad to prove the effectiveness of the methods proposed in this paper,which shows that compared with the sensor radiation interception probability control method,the interception risk control method can keep the sensor scheduling scheme in low risk as well as protect sensors of importance in the sensor network. 展开更多
关键词 Radio frequency stealth Target tracking Interception probability Interception risk Hungary algorithm
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