Recorded recurrent deep reinforcement learning guidance laws for intercepting endoatmospheric maneuvering missiles

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.

Optimal deployment of swarm positions in cooperative interception of multiple UAV swarms

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.

Budget constrained flow interception location model for congested systems

To study location problems with congestion demand, a bi-objective model based on flow intercep-tion problem is proposed.The model is formulated from the view of M/M/m queuing systems.Service quantity and quality are simultaneously considered as objectives, with constraint on total cost.Service quality includes deviation distance from preplanned trips and customers＇ waiting time.Service quantity is the number of intercep-tion customers.A multi-objective evolutionary algorithm combined with greedy heuristic is proposed.Finally a computational experiment is given, and the algorithm is proved to be efficient.

Influencing factor analysis of interception probability and classification-regression neural network based estimation

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.

Three Core Technical Systems and Engineering Application of Regional Lightning Protection

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.

滇池环湖截污体系优选截留率及其影响因素研究

农村农业非点源污染是滇池污染负荷的主要来源之一,环湖截污治污体系对农村农业污水的截留具有重要意义。为实现对该体系的自动化控制,有效支撑智能化控制平台的高效运行,本研究在前期通过对比分析,确定截污治污体系截流井采用基于总磷(TP)浓度阈值控制模式对农村农业非点源污染物负荷截留效果最好的基础上,针对环湖截污治污体系现状条件下,采用TP浓度阈值控制模式对应的优选截留率进行研究,探讨了重现期和雨峰系数的影响,并就选择性截留后枯、平和丰水年农业农村非点源污染负荷的入湖系数进行计算。结果表明,(1)当干渠发生溢流时,存在优选TP浓度阈值,当截留TP浓度大于等于该阈值的径流时,可以使溢流进入滇池的污染物负荷最小,此时截留径流量与总径流量的比值即为优选截留率。(2)随重现期的增大,TP浓度阈值的设定值整体呈减小趋势,所截留的污染物平均浓度减小,优选截留率减小。(3)随雨峰系数增大,TP浓度阈值的设定值增大,优选截留率变化不大。(4)考虑基于TP浓度阈值控制模式的环湖截污系统截留作用后,滇池农业农村非点源污染负荷的入湖系数:枯、平、丰水年COD分别为0.09、0.14、0.23;总氮分别为0.10、0.22、0.31;TP分别为0.07、0.12、0.19,均较不考虑环湖截污系统截留作用时显著降低。(5)采用TP浓度阈值控制模式,在枯、平及丰水年均可有效提升截污干渠末端水质净化厂的进水浓度,增强处理工艺的运行稳定性。

酚酞基聚醚醚酮/聚乙烯亚胺复合超滤膜的制备与性能研究

目的 制备纯水通量较高的复合超滤膜,实现染料废水的高效快速分离。方法 采用相分离转化法,以丙酮为非溶剂,酚酞基聚醚醚酮和聚乙烯亚胺为研究对象,在室温条件下,开发出一种性能较好的酚酞基聚醚醚酮/聚乙烯亚胺复合超滤膜;分析酚酞基聚醚醚酮(PEEK-WC)质量分数、聚乙烯亚胺(PEI)添加量、改性反应时间等工艺因素对复合超滤膜性能的影响。结果 随着反应沉积时间的增加,复合超滤膜的水通量呈上升趋势;随着聚乙烯亚胺质量分数增加,复合超滤膜的水通量不断增加;复合超滤膜的最优制备条件为PEI与PEEK-WC的质量比为20%,PEEK-WC与NMP的质量比为15%,反应时间为12 h。结论 酚酞基聚醚醚酮/聚乙烯亚胺复合超滤膜具有良好的截留效果和抗细菌污染性。

A novel electro-Fenton hybrid system for enhancing the interception of volatile organic compounds in membrane distillation desalination

Membrane distillation(MD)is a promising alternative desalination technology,but the hydrophobic membrane cannot intercept volatile organic compounds(VOCs),resulting in aggravation in the quality of permeate.In term of this,electro-Fenton(EF)was coupled with sweeping gas membrane distillation(SGMD)in a more efficient way to construct an advanced oxidation barrier at the gas-liquid interface,so that the VOCs could be trapped in this layer to guarantee the water quality of the distillate.During the so-called EF-MD process,an interfacial interception barrier containing hydroxyl radical formed on the hydrophobic membrane surface.It contributed to the high phenol rejection of 90.2% with the permeate phenol concentration lower than 1.50 mg/L.Effective interceptions can be achieved in a wide temperature range,even though the permeate flux of phenol was also intensified.The EF-MD system was robust to high salinity and could electrochemically regenerate ferrous ions,which endowed the long-term stability of the system.This novel EF-MD configuration proposed a valuable strategy to intercept VOCs in MD and will broaden the application of MD in hypersaline wastewater treatment.

Effects of dense planting patterns on photosynthetic traits of different vertical layers and yield of wheat under different nitrogen rates

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.

Physical Layer Security Performance Analysis in Multi-Antenna NOMA-Based UAV Relay Networks

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.

北方岩溶区降水入渗补给系数及补给机制:以羊庄岩溶水系统为例

为建立北方岩溶区水文地质参数系列,提高岩溶地下水可采资源计算精度,笔者团队于20世纪80年代开始,在山东羊庄封闭式泉排型岩溶水系统开展了岩溶水均衡试验研究,积累了40余年的监测试验数据。根据长期野外水均衡要素观测资料,推导出裸露型、半覆盖型和覆盖型岩溶区降水入渗补给系数计算公式,建立了岩溶区降水入渗补给系数α与降水量P和地下水位埋深D的相关方程,以及可调控的最大降水入渗补给系数系列,揭示了降水入渗补给过程与α变化机制。结果表明:α随水位埋深D的改变而改变,每个降水量P段分别对应一个最大降水入渗补给系数α_(max)和最大降水入渗补给量即补给极限G_(max),相应的水位埋深便是最佳水位埋深D_(critical)。D>D_(critical)时,包气带截留量随着水位埋深的增大而增大,α<α_(max);D<D_(critical)时,地表径流量随着地下水位埋深的减小而增大,α<α_(max)。不同的降水量段对应不同的D_(critical),降水量增大时,对应的α_(max)及D_(critical)也增大。在任意水位埋深时,G_(max)为蓄满产流临界降水量与包气带最大截流量之差。本研究解决了岩溶区降水入渗补给的关键科学问题,即揭示降水入渗补给机制、建立降水入渗补给系数与降水量和水位埋深的定量关系,提升了我国北方岩溶水资源基础性研究水平。

某高速公路弃渣场设计与稳定性分析

基于西南地区某高速公路新建沟道型、2级防护、堆放高度35.00 m的弃渣场,设计并验算弃渣场的排水系统,论证弃渣场建成后河道排洪的合理性及安全性,并进行整体稳定性分析。结果表明:弃渣场排水沟尺寸能满足100年一遇洪水过流要求,且至少有0.66 m安全超高;弃渣场边坡整体处于稳定状态;在地震工况下边坡处于欠稳定-基本稳定状态,弃渣体前缘临空面高6.00 m,最大剩余推力848.6kN/m,设计采用抗滑桩进行支挡防护。

一种雷达搜跟转换近似时间最优控制方法

为解决时间最优控制(time optimal control,TOC)存在的颤抖和鲁棒性下降问题,提出一种雷达搜跟转换近似时间最优控制(proximateTOC,PTOC)方法。以搜跟雷达方位伺服作为研究对象,在电机角速度和角加速度受约束的条件下,设计近似时间最优控制器,建立控制数学模型,并基于Matlab进行仿真论证及实物验证。验证结果表明:该算法切实可行,能达到系统技术指标要求,可广泛应用于搜跟一体雷达伺服系统中。

使用处方预审核智能决策系统拦截急诊患者用药错误的回顾性分析

目的分析预审核智能决策系统拦截急诊患者严重用药差错处方的特点,并为提高用药安全和合理用药提供建议。方法通过该系统提取新疆医科大学第一附属医院2022年4月-2023年3月拦截的用药错误处方。回顾性分析用药错误处方的特点。比较人工审核模式与预审核智能决策系统应用后处方不合格率情况。结果预审智能决策系统共拦截用药错误处方5347条,占处方总量的3.11%。用药错误分类采用帕累托图法进行分析,给药剂量、溶媒不合适、给药途径和给药频率为主要因素,分别占26.86%、22.69%、12.83%和10.87%;药物需稀释后使用为次要因素,占10.21%;患者条件、精二药品需单独开具处方、禁用和选用剂型不合适为一般因素,分别占9.95%、4.10%、1.98%和0.52%。人工审核处方不合格率0.242%,预审核智能决策系统审核处方不合格率0.037%,差异有统计学意义(P=0.000)。结论处方预审核智能决策系统在审方药师的监督下,可以验证处方,提高处方的准确性,并提高急诊用药安全性。

玉带溪流域合流制片区截污方案溢流污染特征分析

为明确玉带溪流域合流制片区不同截污方案的溢流污染特征及溢流控制效果,选择玉带溪北支上游合流制片区为研究区域,构建排水系统模型,在全年各等级降雨情景下,对合流制片区末端截污和截流式分流两种工程方案的合流制溢流污染特征指标进行对比研究。结果表明,截流式分流改造方案在溢流频次、溢流总量、溢流历时、溢流量均值、溢流量峰值和溢流污染负荷方面总体优于末端截污方案。其中,在全年各等级降雨情景下,末端截污方案的溢流量削减率为12.9%~77.5%,而截流式分流改造方案的溢流量削减率为40.6%~98.8%。在溢流污染负荷削减方面,降雨等级为中雨或大雨时,末端截污方案对3种污染物(化学需氧量、氨氮、总磷)的溢流污染负荷削减率均达到64%以上,而截流式分流改造方案的削减率均达到89%以上;降雨等级为暴雨及以上时,末端截污方案的溢流污染负荷削减率均小于50%,而截流式分流方案的削减率均达到60%以上。因此,通过溢流污染特征分析研究有利于掌握不同截污方案的污染物排放规律及溢流削减效果,对经济有效地控制合流制溢流污染具有指导性意义。

用于农田非点源污染控制的生态拦截型沟渠系统设计与效果研究

生态拦截沟渠是应对农田非点源污染的有效策略。以嘉兴市善县3处农田为研究对象,根据当地农业生产状况和生态条件,设计了一种以生态拦截为核心机制的沟渠结构,通过对该沟渠末端不同时间节点排水中氮磷含量的监测,验证了生态拦截沟渠在农田非点源污染控制中的有效性,结合监测结果提出了意见与建议。

使用INTERCEPT血液系统制备血浆的临床前安全试验

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。

Nitrogen interception in floodwater of rice field in Taihu region of China

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.

Novel TPN control algorithm for exoatmospheric intercept

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.