浅谈with(without)复合结构

科技人员对于with+名词构成的介词短语在句中的作用比较熟悉,但对于由with(without)+名词+分词(或其它词)构成的这种特殊结构(也可简称为with复合结构)却不太理解,有的甚至对其含义及在句中的功能模糊不清,感到似是而非。     

土壤微生物对不同作物根系活动的响应

以中国科学院海伦农业生态实验站为平台,研究了不同作物（大豆、小麦和玉米）根系对根际微生物种群（细菌、真菌和放线茵）组成和数量的影响。结果表明：3种作物根际微生物数量均表现为细菌的数量显著多于放线茵和真菌的数量,作物之间的微生物总数量多少表现为大豆〉小麦〉玉米,各作物间差异显著（P〈0．05）。根际三大微生物种群的变化情况为真菌、放线茵数量的变化趋势相同,均表现为大豆〉玉米〉小麦,细菌数量的变化情况为大豆〉小麦〉玉米。不同施肥处理中,玉米根际微生物总数变化情况为NPK〉NK〉PK〉CK,且施NK和NPK处理极显著增加根际微生物数量（P〈0．01）,增幅为54．9％和243．2％;NK处理下,大豆根际真菌数量表现为显著性降低（P〈0．05）,而细菌显著性增加（P〈0．05）;小麦根际微生物数量在NK处理下极显著增加,增幅为64．9％（P〈0．01）。图4,表2,参19。     

An SEIRS epidemic model with two delays and pulse vaccination*

Pulse vaccination is an effective and important strategy to eradicate an infectious disease. The authors investigate an SEIRS epidemic model with two delays and pulse vaccination. By using the discrete dynamical system determined by stroboscopic map, the authors obtain that the infectious population dies out if R△ 〈 1, and the infectious population is uniformly persistent if R^△ 〉 1. The results indicate that a short period of pulse vaccination or a large pulse vaccination rate is a sufficient condition to eradicate the disease.     

关中东部不同土地利用方式对土壤质地影响探讨

以陕西关中渭北作为研究区,选取典型农业耕地和人工苹果林地,分析出这两种土地利用方式对土壤粒度分布的影响。结果表明：①研究区土壤主要由粉砂和黏粒组成,占总含量的80％以上,总体属于粉砂质黏壤土;②不同土地利用方式土壤砂（〉50μm）、粉砂（2μm～50μm）和黏粒（〈2μm）含量差异显著。耕作土壤2v～50μm含量明显低于人工苹果林地,而〈2μm和〉50μm含量却高于苹果林地;③不同土地利用方式土壤粒度分布的变异系数不同。耕作土壤粒度分布的变异系数整体小于苹果林地土壤。耕作土壤,〈2μm和〉50μm的的变异系数在上层较高,2μm-50μm的变异系数在整个剖面变化不大。苹果林地土壤,〈2μm的变异系数在上层较低,〉50μm变异系数的变化与〈2μm相反,2μm～50μm的变异系数在整个剖面变化不大。究其原因,人类活动如不同的耕作或管理方式以及种植作物类型可能是影响土壤粒度分布的主要因素。图1,表2,参10。     

对《分派问题的矩阵型算法》一文的看法

本刊1983年第1期发表了赵成旭同志写的《分派问题的矩阵型算法》(以下简称《矩阵法》)一文后,陆续收到虞英军、费本初、滕传琳、齐天锡、程坦、丁文仁等同志的来稿,指出“矩阵法”虽然比“匈牙利法”简单,但是缺乏理论论证,因此,不能确保得出最优解。与此同时,还提出了其它一些算法。该文作者赵成旭同志也来信说,发现《矩阵法》不完善,并随信寄来改进算法的文稿。由于本刊篇幅所限,现选登虞英军同志写的《对〈分派问题的矩阵型算法〉一文的看法》,其余来稿就不一一刊登了,请谅。     

连通、几乎局部连通无爪图是完全圈可扩的

设Ｇ是一个图,Ｂ ＝ ｛ｖ ∈Ｖ（Ｇ）｜〈Ｎ（ｖ）〉不连通｝．如果Ｂ是独立集,并且ｖ ∈Ｂ,ｕ ∈Ｖ（Ｇ）, 使〈Ｎ（ｕ） ∪｛ｕ｝〉连通,则称Ｇ是几乎局部连通图．本文证明：连通、几乎局部连通无爪图是完全圈可扩的．     

吉林西部盐碱化苇塘养殖生态工程研究——牛心套保湿地盐碱水环境对虾生长与阳离子组成的关系

采用盐碱水生长试验,研究凡纳滨对虾（Litopenaeus vannamei）生长与水环境K＋、Ca^2＋、Mg^2＋、Na^＋/K^＋和M/D（离子系数）的关系,探讨盐碱化苇塘养殖对虾技术。结果表明,在碱度、盐度和pH分别为10.32 mmol.L-1～38.50 mmol.L-1,0.102%～0.334%及8.5～9.5的盐碱水中,幼虾27 d的体质量特定生长率（SGRW）无显著性差异（P〉0.05）,平均为（3.16±0.41）%.d-1。SGRW与阳离子组成因子的简单相关性都存在其他因子不显著（P〉0.05）的影响效应。SGRW分别与K＋质量浓度的偏相关性不显著（P〉0.05）,与Ca^2＋、Mg^2＋质量浓度的偏相关性显著（P〈0.05）,与Na^＋/K^＋、M/D（离子系数）的偏相关性极显著（P〈0.01）。SGRW分别与M/D及Mg^2＋质量浓度的偏回归关系显著（P〈0.05）,与Na＋/K＋极显著（P〈0.01）,与K^＋、Ca^2＋不显著（P〉0.05）。盐碱水环境中Mg^2＋、Na^＋/K＋及M/D（离子系数）共同影响对虾的生长;添加CaCl有利于苇塘养虾。     

Forced Oscillations of a Class of Nonlinear Dispersive Wave Equations and their Stability

It has been observed in laboratory experiments that when nonlinear dispersive waves are forced periodically from one end of undisturbed stretch of the medium of propagation, the signal eventually becomes temporally periodic at each spatial point. The observation has been confirmed mathematically in the context of the damped Korteweg-de Vries （KdV） equation and the damped Benjamin-Bona-Mahony （BBM） equation. In this paper we intend to show the same results hold for the pure KdV equation （without the damping terms） posed on a finite domain. Consideration is given to the initial-boundary-value problem {ut＋ux＋uux＋uxxx=0, u（x,0）=φ（x）, 0〈x〈1, t〉0,u（0,t）=h（t）, u（1,t） = 0, ux（1,t） = 0, t〉0.It is shown that if the boundary forcing h is periodic with small ampitude, then the small amplitude solution u of （＊） becomes eventually time-periodic. Viewing （＊） （without the initial condition） as an infinite-dimensional dynamical system in the Hilbert space L^2（0, 1）, we also demonstrate that for a given periodic boundary forcing with small amplitude, the system （＊） admits a （locally） unique limit cycle, or forced oscillation, which is locally exponentially stable. A list of open problems are included for the interested readers to conduct further investigations.     

Partially function linear error-in-response models with validation data

This paper considers partial function linear models of the form Y =∫X(t)β(t)dt + g(T)with Y measured with error. The authors propose an estimation procedure when the basis functions are data driven, such as with functional principal components. Estimators of β(t) and g(t) with the primary data and validation data are presented and some asymptotic results are given. Finite sample properties are investigated through some simulation study and a real data application.     

工程控制论

控制论的一个分支学科,是关于受控工程系统的分析、设计和运行的理论。法国物理学家和数学家安培(A.M.Ampre,1755-1836)于1834年用控制论(cybernfique)这一名词称呼管理国家的科学。第二次世界大战前后,自动控制技术在军事装备和工业设备中开始应用,实现了对某些机械系统和电气系统的自动化操作。美国、日本和苏联的科学家们(C.Shannon,1938;A.Nakasima,1938;1941)先后创立了用仅有两种工作状态的继电器组成逻辑自动机的理论,并用于实践。在这一时期前后又出现了关于信息的计量方法和传输理论(R.V.L.Hartly,1928;C.Shannon,     

采用偏心铁氧体的8mm E面T结波导环行器

提出了偏心放置铁氧体圆盘进行带宽展宽的方法,给出近似计算,并利用HFSS9进行仿真和优化,研制了8mm宽带E面T结波导环行器,测试结果验证了仿真和计算的正确性;与以前的E面T结环行器相比,采用该方法设计的环行器,无需引入匹配垫片既可在较宽的频带内（27.1-29.1GHz）,使其驻波比、隔离度和插入损耗（VSWR〈1.4,隔离度〉17dB,插入损耗〈0.7dB）有较为明显的提高。     

基于自校正MPC的舰载机着舰控制技术

针对模型参数不准确条件下的全自动着舰控制技术进行了研究,设计了一种基于保辛伪谱算法(symplectic pseudospectral method,SP)和带遗忘因子递推最小二乘法(recursive least squares with forgetting factor,FFRLS)的舰载机着舰自校正模型预测控制...     

混合分布估计算法求解模糊分布式装配柔性车间调度问题

针对分布式环境下作业时间的不确定性,本文以三角模糊数描述工件加工时间及产品装配时间,建立了以生产成本、拖期时间为目标的分布式装配柔性模糊车间调度模型(distributed assembly flexible job shop scheduling problem with fuzzy processing time,DAFJSPF),并提出了一种混合差分搜索及变邻域搜索的分布估计算法(HEDA-DEV)进行求解.首先,根据问题的特点,设计了一种新的多维编码方案;其次,提出基于概率模型的相似系数和两种变异算子,实现变异策略的动态选择;为提高算法的寻优能力,设计了 5种变邻域结构,并按特定的搜索策略协同处理.最后,通过不同规模、不同柔性的实例仿真对比实验,验证了该算法在求解DAFJSPF具有较强的优势.     

无信号内干扰的MAMU-CDSK混沌通信系统

针对相关延迟键控(correlation delay shift keying, CDSK)系统误码性能差的缺点,提出无信号内干扰的多进制多用户CDSK(multiple ary multiple user CDSK with no intra signal interference, NISI-MAMU-CDSK)混沌通信系统。该系统能够传输多个用户的数据信息,并将各个用户的数据信息由二进制码元经分组后映射为多进制码元,同时通过编码一组相互正交的Walsh码序列来代替CDSK系统的延迟结构,使得解调时能够消除信号内干扰。推导了在加性高斯白噪声信道和Rayleigh衰落信道中的误码率公式并进行了蒙特卡罗仿真实验。理论分析与仿真结果表明:NISI-MAMU-CDSK系统有效提高了误码性能和传输速率,在混沌通信领域有很好的实际应用价值。     

Control and Stabilization of the Rosenau Equation Posed on a Periodic Domain

This paper considers the Rosenau equation with a moving control?t u + ?_t?_x~4 u + ?_xu + u?x u = a(x + ct)h(x, t), c = 0, x ∈ T = R/(2πZ), t 0.The authors prove that the Rosenau equation with a moving control is locally exact controllable in Hs(T) with s ≥ 0 and globally exponential stable in H~s(T) with s ≥ 2. The two results nontrivially extend the work of(Rosier L and Zhang B Y, 2013) from the BBM equation to the Rosenau equation.     

Heuristics for Online Scheduling on Identical Parallel Machines with Two GoS Levels

This paper considers the online scheduling problem on m(m ≥ 3) parallel machines(the first k machines with grade 1 and the remaining m-k machines with grade 2) with two Go S levels and makespan as the objective function. The jobs arrive over time with grade 1 or 2 and an arrival job can be assigned to a machine only when the grade of the job is no less than the grade of the machine. Three cases are considered:(i) For k = 1, the authors present an online algorithm with competitive ratio of9/5.(ii) For 1 k m-1, an online algorithm with competitive ratio of 2.280 is proposed.(iii)For k = m-1, an online algorithm is presented with competitive ratio of 2. All the three algorithms are based on greedy algorithm with a similar structure. At last, numerical instances are given and the average competitive ratios of the instances show good performance of the proposed algorithms.     

A deep reinforcement learning method for multi-stage equipment development planning in uncertain environments

Equipment development planning(EDP) is usually a long-term process often performed in an environment with high uncertainty. The traditional multi-stage dynamic programming cannot cope with this kind of uncertainty with unpredictable situations. To deal with this problem, a multi-stage EDP model based on a deep reinforcement learning(DRL) algorithm is proposed to respond quickly to any environmental changes within a reasonable range. Firstly, the basic problem of multi-stage EDP is described, and...     

Research on improved integrated FDD/FTC with effectiveness factors

This paper investigates the integrated fault detection and diagnosis(FDD) with fault tolerant control(FTC) method of the control system with recoverable faults.Firstly,a quasi-linear parameter-varying(QLPV) model is set up,in which effectiveness factors are modeled as time-varying parameters to quantify actuators and sensors faults.Based on the certainty equivalency principle,replacing the real time states in the nonlinear term of the QLPV model with the estimated states,the parameters and states can be estimated by a two-stage Kalman filtering algorithm.Then,a polynomial eigenstructure assignment(PEA) controller with time-varying parameters and states is designed to guarantee the performance of the system with recoverable faults.Finally,mathematical simulation is performed to validate the solution in a satellite closed-loop attitude control system,and simulation results show that the solution is fast and effective for on-orbit real-time computation.     

COVERING TWO DIGRAPHS WITH ARBORESCENCES

Let G_1 and G_2 be finite digraphs,both with vertex set V.Suppose that each vertexv of V has nonnegative integers f(v) and g(v) with f(v)≤g(v),and each arc e of G_4 hasnonnegative integers a_i(e) and b_i(e) with a_i(e)≤b_i(e),i=1,2.In this paper we give anecessary and sufficient condition for the existence of k arborescences in G_4 covering each are(?) of G_i at least a_i(e) and at most b_i(e) times,i=1,2,and satisfying the condition that foreach v in Vf(v)≤r_1(v)=r_2(v)≤g(v)where r_4(v) denote the number of the arborescences in G_(?) rooted at v.     

基于传感器网络的气体源定位方法研究

提出一种分层结构的自组织无线传感器网络(WSN)用于气体污染源的定位研究,可以广泛应用于反恐、环境监控等场景。在修正的气体污染源浓度衰减模型基础上,提出一种改进的非线性最小二乘算法(I-NLS)以及极大似然算法(MLE)用于气体污染源定位。仿真试验对比研究了两种算法在不同的传感器节点以及背景噪声情况下对预估定位误差的影响。试验结果表明了这种分层结构的WSN用于气体污染源定位是可行的,同时验证了I-NLS、MLE两种算法定位的有效性。