共查询到20条相似文献,搜索用时 972 毫秒
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通过对原苏联(俄罗斯)、美国等国外可靠性技术的分析,概述了可靠性技术的特点和发展简况,并从可靠性技术的应用考虑,提出必须解决可靠性技术的标准化问题,即明确可靠性技术标准化的主要目的、任务和标准基本内容与结构组成及解决的问题,同时对与国际标准接轨的问题提出了建议。 相似文献
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刘锋利 《桂林航天工业高等专科学校学报》2009,14(1)
YZ-01型液压传动实验台存在的问题是,学生每次做完实验后,经常出现较严重的漏油现象。不仅造成浪费,污染实验室环境,而且影响下一次实验的正常进行。为此,对漏油问题进行了深入详细的分析,指出了问题的原因,提出了解决方法,有效解决了漏油问题。 相似文献
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刘锋利 《桂林航天工业高等专科学校学报》2009,14(1)
Yz-01型液压传动实验台存在的问题是,学生每次做完实验后,经常出现较严重的漏油现象.不仅造成浪费,污染实验室环境,而且影响下一次实验的正常进行.为此,对漏油问题进行了深入详细的分析,指出了问题的原因,提出了解决方法,有效解决了漏油问题. 相似文献
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研究了目前通信卫星地面测试队伍组织的现状,对组织专业化测试队伍前后所需解决的问题和解决方法做了详细的探讨,提出了专业化测试队伍组织的一种方案。 相似文献
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论文通过对传统讲授教学法在经济法课程教学中不足的分析,提出引入案例教学法,并对其具体应用进行了步骤上的总结。文章还分析了案例教学法实施中遇到的一些问题,并针对问题提出了解决的办法。 相似文献
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胡微 《北华航天工业学院学报》2006,16(5):42-44
本文根据股份合作制企业的特点,并结合股权转让的基本原理,剖析了我国股份合作制企业股权转让过程中常见的法律问题,并对问题的解决提出几点建议. 相似文献
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目前学籍管理中存在的问题及解决办法 总被引:3,自引:0,他引:3
张忠斌 《华北航天工业学院学报》2003,13(3):54-56
文章就教务管理过程中学生学籍管理、成绩管理等方面存在的问题,提出了相应的解决办法,对教务管理工作的进一步规范化有较大的参考价值。 相似文献
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本文从数学建模及其重要意义角度出发,指出了学习数学建模的必要性和现在数学教学中存在的主要问题。学习高等数学的目的在于应用数学思想方法解决实际问题,将数学建模思想渗透到高等数学课程中,可提高学生应用数学知识和方法解决实际问题的能力,培养学生的数学素养、创新意识、创新精神和能力,从教学内容、教学手段、评价方法等各个环节注重数学建模思想的渗透,使数学建模意识成为学生思考问题的方法和习惯。 相似文献
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In this first part of our paper, it is suggested to use solutions to boundary value problems in the optimization problems (in impulse formulation) for spacecraft trajectories in order to obtain the initial approximation, when boundary value problems of the maximum principle are solved numerically by the shooting method. The technique suggested is applied to the problems of optimal control over motion of the center of mass of a spacecraft controlled by the thrust vector of jet engine with limited thrust in an arbitrary gravitational field in a vacuum. The method is based on a modified (in comparison to the classic scheme) shooting method computation together with the method of continuation along a parameter (maximum reactive acceleration, initial thrust-to-weight ratio, or any other parameter equivalent to them). This technique allows one to obtain the initial approximation with a high precision, and it is applicable to a wide range of optimal control problems solved using the maximum principle, if the impulse formulation makes sense for these problems. 相似文献
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《Acta Astronautica》1987,15(8):577-581
The future missions of the National Aeronautics and Space administration (NASA) directed at solar system exploration, astrophysical, planetary and Earth Sciences observations will require advanced capabilities for acquiring data from space platforms. For example, NASA's terrestrial observation program is confronted by a range of challenging and important new problems derived from advances in the Earth Sciences over the past twenty years. New observational approaches appear promising for solving older problems which will benefit meteorology, agriculture, mineralogy, and geodynamics. Furthermore, many of the problems which space observations may help to solve are inherently interdisciplinary of the above areas. Although much is known about the Earth, the unifying concepts are still to be established and remote sensing from space will continue to be a vital experimental tool. 相似文献
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G. V. Mozhaev 《Cosmic Research》2001,39(6):594-606
In a previous paper [1], as a result of group-theoretic decomposition, one of the problems of the optimization of the flexible correction process was reduced to a series of subproblems. In this paper, the analytical solutions to these subproblems are obtained by the sweep method. A series of other similar problems with different variants of flexibility is also considered; the decomposition of these problems is performed, and their analytical solutions are presented. It is shown for some numerical examples that flexible corrections require essentially lower fuel consumption than the rigid correction, where all parameters characterizing the absolute motion of a satellite system are corrected to their nominal values. 相似文献
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At the Earth Observation Summit in 2003 at the US Department of State, environmental ministers from more than 30 countries joined three US cabinet secretaries to plan the creation of a system for international sharing of data about the atmosphere, the oceans and the land. The meeting grew in part out of commitments by leaders at a G-8 summit meeting in France to build an integrated global earth environmental monitoring system. Opportunities and problems both figure prominently in implementation of the Summit's vision. The challenges include who pays for infrastructure, training, and administration; whether to control data access; how to include the private sector; and whether problems of collective action will plague the effort. 相似文献
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Valeriy I. Timoshenko Igor S. Belotserkovets Vjacheslav P. Gusinin 《Acta Astronautica》2009,65(9-10):1231-1237
Some problems of methane-containing hydrocarbon fuel combustion are discussed. It seems that reduction of methane burnout zone length is one from main problems of designing new type engine. It is very important at the creation of combustion chambers of a rocket-ramjet engine for prospective space shuttle launch vehicles. 相似文献
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随着社会经济的发展,人类社会面临着越来越严重的环境污染与资源匮乏问题。为了实现人类社会的可持续发展,必须重视并大力发展静脉产业。我国城市静脉产业经过几年的发展,已经取得了一定的成绩,但仍存在着诸多问题,必须有针对性的加以解决,为其长远目标的实现提供保障。 相似文献
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针对火星大气进入段飞行器的飞行能力分析问题,提出一种基于解析同伦法的纵向可达区(开伞点高度-航程剖面)计算方法。该方法首先分别为最大航程问题/最小航程问题和最大/小开伞高度问题构造最优解已知的初始辅助优化问题,并以此为出发点最终求取原最优问题的解。在求解4个子优化问题的基础上,通过构造合适的同伦参数延拓出纵向可达区。〖JP2〗仿真结果表明,该方法有效避免了最优问题协态初值猜测困难的问题,通过设计合适的同伦参数,可以快速求取任意初始路径角下的开伞点最大/最小航程、最大开伞高度以及纵向可达区。 相似文献