民用航空“非法干扰行为”再探讨——以《国际民用航空公约》《附件17》最新修改为视角

防范非法干扰行为是民用航空安保工作的核心。然而,由于中国国内对此类行为的观点不同,导致相关民航规章和规范性文件存在不同的界定,这也直接影响了实际工作的开展。《国际民用航空公约》、《附件17》的最新修订将行为的危害对象明确规定为"民用航空安全"并对行为种类采取了开放式的规定。因此,当前应当以《附件17》第9版为基础,正确认识非法干扰行为的本质及特征,修改相关规章与规范性文件,减少国内规定与国际文件的差异。     

EBPSK系统抗脉冲干扰性能研究

首先介绍了扩展的二元相移键控(EBPSK)调制波形及脉冲干扰模型,提出了一种简单的基于冲击滤波器和限幅的抗干扰传输模型,从理论上分析了该系统对抗脉冲干扰的优势.仿真实验表明,在严重的脉冲干扰情况下,EBPSK系统表现出超强的抗干扰能力,同时,也通过误码率曲线表明了基于限幅的系统模型的有效性,从而为超窄带的EBPSK系统迈入实际应用阶段奠定了基础.     

心理学的遗忘理论对二语损耗的解释力

语言损耗经过三十年的发展,取得了许多有价值的研究成果。在回顾二语损耗研究的基础上,运用心理学遗忘理论中的提取变慢说（或提取失败说）、干扰说以及遗忘曲线,通过对国内外的二语损耗研究结果进行解释,发现提取速度变慢说（或提取失败说）可以解释二语损耗研究中受损者在产出性技能损耗方面的表现以及产出性技能与接受性技能在损耗方面的差异;干扰说可以解释二语损耗研究中受损者在音素、词汇以及形态-句法等方面的损耗。但是,遗忘曲线却无法解释二语损耗研究中出现的＂最初的稳定状态＂现象与二语损耗的倒置假设。     

干涉仪激光三维成像的照明光场特性分析

分析了用于干涉仪成像的照明相干光场的特性。通过对平面波与平面波之间、球面波与球面波之间以及平面波与球面波之间形成的干涉场的描述和对其回波信号分析, 得出了平面波与球面波之间形成的干涉场适用于干涉仪成像的照明光场的结论     

基于认知视角下焦虑心理对大学生英语学习语言输出的影响

焦虑是一种特殊情感因素的反应,是大学生英语学习中普遍存在的现象,尤其在语言输出时,该影响特别突出。其产生与个体的认知特征和认知规律紧密相关。从认知视角入手,分析焦虑心理对大学生英语学习中输出的影响,通过开展合作＂教与学＂及减少输出时焦虑的认知干扰因素,可以降低焦虑对英语学习输出的影响程度。     

一种非正交多址接入下行链路信号检测方法

非正交多址接入（non-orthogonal multiple access,NOMA）下行链路存在严重的多址干扰。软解调-串行干扰消除（successive interference cancellation,SIC）检测方法是一种性能较好的信号检测方法,但是接收机的复杂度比较高。考虑到软解调算法对其他用户信号的信号特征信息并未充分利用,提出一种基于软解调算法改进的联合检测算法,该算法直接利用多用户叠加信号的联合星座图计算用户信号信息比特的软信息,不需要对干扰信号进行检测和重构,可以降低接收机的复杂度。仿真分析表明,与软解调-SIC检测方法相比,联合检测方法在性能损失不超过1．5 dB的情况下,可以将接收机的复杂度降低一半。     

Population fluctuation and persistence of one-host–two-parasitoid systems depending on resource distribution: from parasitizing behavior to population dynamics

Population dynamics and variability were examined in one-host–two-parasitoid experimental systems with different resource distributions: resource-clumped and resource-sparse conditions. The system consists of a seed beetle host, Callosobruchus chinensis, and two parasitoid wasps, Anisopteromalus calandrae (Pteromalidae) and Heterospilus prosopidis (Braconidae). In the resource-clumped condition, suitable hosts for parasitism (the late fourth-instar larvae and pupae) were clumped in 1 large resource patch, but they were scattered evenly among 16 small patches in the resource-sparse condition. Population censuses were conducted at 10-day intervals in long-term cultures, renewing 10 g of azuki beans (Vigna angularis). In both resource conditions, the first period was a single-species system of C. chinensis only, and A. calandrae was added in the second period. The one-host–one-parasitoid system with C. chinensis and A. calandrae showed stable population dynamics with small fluctuations. After addition of H. prosopidis in the third period, two of three replicates persisted to day 800 in each resource condition, although one replicate in each went to extinction at an immediate outbreak of the H. prosopidis population after the introduction. Population variabilities of C. chinensis and H. prosopidis were significantly higher and the mean population size of A. calandrae was significantly smaller in the resource-sparse condition than that in the resource-clumped one. A short-term experiment on parasitism efficiencies revealed that H. prosopidis parasitized significantly more at a low host density in the resource-sparse condition than in the resource-clumped one. Mutual interference of H. prosopidis was weak enough at low parasitoid densities but became abruptly stronger with high densities. Providing fresh hosts in a mixture of already parasitized ones, host-searching behaviors of a parasitoid were recorded by video for 3 h and were compared between the two wasp species. H. prosopidis could parasitize fresh hosts more efficiently than A. calandrae through frequent long-distance walks (walking to distant beans at one bout or outside a clump of beans with hosts and back soon on a distant bean of the clump) after reencounters with parasitized hosts. Considering all the experimental results, populations were judged to be more fragile and more likely to go to extinction in the resource-sparse condition than in the resource-clumped one. A higher attacking efficiency of H. prosopidis destabilized population dynamics more in the resource-sparse condition. Received: December 23, 1998 / Accepted: January 20, 1999     

论汉语复合词的语言价值

汉语复合词是在古代单音词的基础上产生的。复合词具有很强的组合能力、聚合能力和语义干涉造词能力。它不但以其巨大的能产性弥补了造词史上的不足,而且完全满足了现在和将来的造词需求。     

基于外部性的生态隐性脆弱地区生态与经济协调发展分析

研究指出,“生态隐性脆弱地区”是在“生态脆弱区”基础上提出的新概念,是指在生态脆弱区之外,受人类行为影响较多、暴露度高,存在或潜在生态系统失衡或退化风险的区域。生态隐性脆弱地区具有生态系统复合性、与人类行为相关大、对外界影响反应较缓慢三方面的主要特征。基于生态隐性脆弱地区的外部性分析,应从严格生态考核、严格外来投资审核、引进适用绿色技术、健全制度体系、完善生态补偿、强化理念更新六个方面推动生态隐性脆弱地区生态与经济协调发展。     

大学生心理危机干预的理论探源和策略研究

近年来,大学生心理危机事件屡见不鲜,对他们的生活、学习带来了较大的冲击和影响。大学生心理健康与否,不仅仅是大学生的个人问题,同时也是一个重要的社会问题。心理危机干预的理论模式主要包括认知模式、哀伤辅导模式、平衡模式、支持和干预技术模式、心理社会转变模式、教育、支持与训练的社会资源工程模式以及整合的干预模式等;大学生心理危机的类型主要表现为焦虑危机、哀伤危机、失恋危机和自杀危机;大学生心理危机干预的策略主要包括建立心理危机信息反馈系统、构建心理危机预防体系和改善大学生的社会心理环境。