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排序方式: 共有399条查询结果,搜索用时 15 毫秒
261.
通过问卷调查结合访谈和观察,对石河子市小学科学课程学与教的现状进行调查,结果发现:学生对科学课具有浓厚的兴趣,且非常喜欢现行的教材,但因本区小学科学教师师资不足、专业素养不高,加之教学设备有限,教学资源匮乏,多数学校班级规模过大,导致实践环节得不到保障,影响了课程教学质量。据此,强化小学科学教师队伍建设,加大科学教育经费的投入力度,缩减班级规模,改善学习环境,是本区适应新课改提高科学课程教学质量的有效途径。 相似文献
262.
Jordi Molas‐Gallart 《Defence and Peace Economics》2013,24(2):141-158
It is often stated that technological change in the military field is characterised by the introduction of radical innovations rather than by incremental processes of technological change. This article illustrates the diversity of military innovation by arguing that technological change in missiles systems is dominated by incremental change. While some large weapons platforms display the design rigidities normally associated with complex systems, missiles are characterised by “flexible modularity”. Flexible modularity facilitates the continuous introduction of upgrades, and makes missile systems amenable to gradual technological change. Besides, it has significant implications for the future role of missile systems, and poses special problems for missile disarmament and technology control initiatives. 相似文献
263.
Martin C. McGuire 《Defence and Peace Economics》2013,24(5-6):529-534
This brief introduction celebrates the 20th Anniversary of the Journal, Defence and Peace Economics. Suggesting elements of an agenda for the future of this branch of economics, I raise several topics that are new and that seem to indicate that the field will expand and shift focus substantially in future years. 相似文献
264.
Edward T. Barrett 《Journal of Military Ethics》2013,12(1):4-17
While most normative evaluations of military cyber-operations have emerged from the legal community, this article assesses the legitimacy of such operations from a philosophical-ethical perspective. After reviewing the relationship between rights forfeiture and the jus ad bellum and jus in bello criteria of the just war tradition, it applies these criteria to several aspects of cyber-operations, including responses to cyber-activities, the use of cyber-capabilities affecting combatants and civilians, and the use of these capabilities by contractors. Finally, it briefly addresses the legitimacy of limiting rights to privacy and anonymity in service of preventing cyber-harm. 相似文献
265.
《Arms and Armour》2013,10(2):154-177
AbstractAmongst the armour in the collection of the British Museum is a kettle-hat (Object Number: P&;E 1856,0701·2243) that was found in London during the second quarter of the nineteenth century. In January 2010, the kettle-hat was conserved before its loan to the Royal Armouries Museum for display at the Tower of London. New findings that occurred during conservation led to the most in-depth technical examination and analysis of this relatively unknown helmet since its discovery.This paper aims to interpret the British Museum’s kettle-hat from art historical perspectives in order to place it in a wider context. The development of the kettle-hat during the 14th and 15th centuries is described along with the subsequent derivatives of transitional or progressive forms of helmet. Through stylistic comparison and consideration of related evidence it is suggested that the British Museum kettle-hat dates to the late 14th century and is of western European, possibly English, workmanship. Furthermore, although the British Museum helmet has much in common with typical forms of kettle-hat, it also has features, such as a short tail-piece, that suggest it may be closely related to some early forms of sallet. 相似文献
266.
如何实现长方体元件光学面形位误差的高精度测量以及怎样利用测量数据对这些误差进行修正加工是制造过程中的主要问题。提出一种基于波面干涉的长方体类光学元件形位误差测量方法,借助大口径干涉仪和高精度端齿盘搭建测量系统,实现了长方体类光学元件1μm/400mm精度的平行度和垂直度测量,获得了高精度的形位误差综合分布数据,并利用磁流变、小磨头数控抛光等现代光学加工手段实现了此类光学元件的高精度加工。 相似文献
267.
智能理论在BIT设计与故障诊断中的应用 总被引:20,自引:0,他引:20
近20年来机内测试(BIT)技术从理论到应用取得了显著进展,已成为提高产品测试性和诊断能力的有效途径。本文概述了BIT技术的特点,分析了国内外BIT的发展趋势,对BIT智能化从系统设计、信息处理到综合决策各阶段进行概括,对专家系统、神经网络、模糊理论、信息融合等智能理论在BIT中的应用进行了综合分析,并初步建立智能BIT的理论框架 相似文献
268.
LiYuju LiHonghui 《兵团教育学院学报》1999,9(2):84-86
The article discusses the importance of thinking in English in learning English. Thecoment of thinking in English is also offered in the essay. The way how to think in English is suggested inthe paper. 相似文献
269.
杨学军 《国防科技大学学报》1991,13(2):107-112
基于小粒度并行结构的分类,提出了结构范式的概念。在此基础上,探讨了多向嵌套循环的并行执行问题,提出了父、母、子进程的概念以及面向多向嵌套循环的FMS 处理机调度策略 相似文献
270.
在确立正确的空间站环境污染概念的基础上,依据污染成因可将其分为本体污染(分子污染)、羽流污染(操作污染)和粒子云污染三大污染源。针对各自不同的形成机理,提出进行污染潜势预报的相应的分析模式,作为研制环境污染分析的仿真软件的基础。对于最严重的污染源羽流污染,从建模、算法、流场模拟与效应分析出发,作一体化处理,构思模块式结构的仿真软件框架,为防止污染,研制和发展实用的污染控制系统提供依据 相似文献