查询词典 difficult problem

Next the discussion in this study, about an ellipse with an angle of attack and two circular cylinders with different diameters in the flow, the aim of this study is investigated for the ability of the present numerical method by solving the suppression of the vortex shedding flow behind the two-cylinder system which was kind of difficult to reach by a Cartesian grid method. In this study, the suppression of the vortex shedding flow is tested to solve a uniform flow past through two different diameter cylindrical in the flow field with Fractional Step Method and Immersed Boundary Method.The numerical method which we investigated is showed that the results of the problem is appropriable in other literatures.

接著探讨流过具攻角之椭圆柱体流场及流过圆柱抑制涡漩逸出之流场，目的是要研究利用控制圆柱来抑制下游涡流的流场行为，本文采用分步法配合内嵌边界法数值解析一均匀流流经两不同直径的圆柱流场，来测试抑制涡流逸出的问题，根据现有的数值结果发现试验运用了合适的方法且得到令人满意的结果。

Based on consider hereinbefore, this dissertation discusses several aspects on the problem of the sustainable and optimum exploitation of groundwater resources as follows:①reviewed entirely the origin and evolvement of the concept "sustainable development", stated and commented the study status in queue on"sustainable development"around national and international range, thorough discussed the science connotation about the concept "sustainable development";②looked back and commented across-the aboard some furthest basic concept and proposition related to groundwater resources, put forward self opinions on a few existent mistake points of view and chaos understandings;③expatiated entirely on the content and meaning of the theory of changeable groundwater resources system, contrast with the traditional methods of groundwater resources calculation and evaluation, combined example to show the application of this theory;④thorough analyzed the difficult and complexity to forecast the groundwater resources, fully stated the traditional methods of groundwater resources forecasting, pointed out the characteristic and applying condition of these forecasting method, introduced the main ideas and methods of wavelet analysis developed recently, and the MATLAB software be known as the fifths era computer language, and its accessory wavelet analysis toolbox, applied these methods and tools to analyze the groundwater dynamic curve, adopted the B-J method and Morte-Carlo method, combined with the theory of changeable groundwater resources system, discussed the new view on the forecast of groundwater resources;⑤synthetically analyzed the characteristics and limitations of the present all kind of groundwater manage model, combined mathematical programming, mathematical statistics, random process and the theory of variation system of groundwater resources on the unite optimum attempter of surface water and groundwater, emphasized how to make the model more nicety, more simple, more practicality;⑥analyzed the inside condition and outside condition to assure the sustainable and optimum exploitation of groundwater resources, the inside conditions are the follows: correct resources idea, scientific methods of resources calculation and evaluation, credible forecast methods of resources, exercisable measures of resources management, the outside conditions are the follows: the development idea of high layer, the transform of manage system, the matched policy and rule of law, the adjusted of economy lever, the improve of cultural diathesis, the boosting up of water-saving consciousness and detail measures, the control of population rising, the prevention and cure of water pollute, the renew and rebuild of ecology;⑦scan the sustainable and optimum exploitation of groundwater resources from the high level of metagalaxy, earth system science, and philosophy;⑧point out the more directions on groundwater resources.

它将为制定水资源的可持续发展目标和战略决策提供科学依据，为制定社会、经济可持续发展战略提供理论基础。基于以上考虑，论文主要从以下几方面对地下水资源可持续开发问题进行了比较深入的探讨：①全面回顾了&可持续发展&概念的由来与演变，对国内外&可持续发展&的研究现状进行了述评，并对&可持续发展&概念的科学内涵进行了深入探讨；②对涉及地下水资源的一些最基本的概念和命题进行了全面的回顾和评述，对目前仍然存在的一些错误观点和混乱认识提出了自己的见解；③全面阐述了地下水资源变值系统理论的内容和意义，并与传统的地下水资源计算评价方法进行了对比分析，结合实例具体说明了方法的应用；④深入分析了地下水资源预测预报工作的极端重要性和复杂性，对传统的地下水资源动态预测方法进行了全面的评述，指出了各类预测预报方法的特点及适用条件，对最近二十多年刚发展起来的小波分析技术的主要思想和方法及其应用范围，以及号称第五代计算机语言的MATLAB软件和附带的小波分析工具箱进行了介绍，并应用于地下水动态过程线的分析，采用时间序列中的B-J法，蒙特卡罗方法，与地下水资源变值系统理论相结合，探讨了地下水动态资料分析和地下水资源预测预报的新思路；⑤综合分析了现今各类地下水管理模型的特点及缺陷，将数学规划、数理统计、随机过程等与地下水变值系统理论相结合进行地表水地下水或多水源的联合优化调度，使模型更准确、更实用；⑥对保证地下水资源可持续开发的内部条件和外部条件进行了分析，内部条件主要是正确的资源观，科学的资源计算与评价方法，可靠的资源预测预报技术，可操作的资源管理措施，外部条件主要是高层发展思路、管理体制的变革、配套的政策法规、经济杠杆的调节、人文素质的提高、节水意识的增强及具体节水措施、人口增长的控制、水体污染的防治、生态的恢复和重建等；⑦从宇宙科学、地球系统科学及哲学的高度审视地下水资源的可持续开发；⑧指出了地下水资源可持续开发的进一步研究方向。

As you can tell, the autistic problem has a long way and difficult task to be accomplished in China.

由此可见，孤独症的问题在中国将会有很长的路要走，很大的工作要完成。

Due to the problem that the relative parameters of aviatic sensing image are often difficult to get, A line scan and data fitting method was presented in order to obtain whole gray change in image, and then to correct image vignetting phenomenon.

针对航空遥感影像在拍摄过程中相关参数不易获取的问题，提出了利用逐行扫描及数据拟合的方法来获取影像整体灰度变化情况，从而实现影像渐晕现象的复原。

The people very are early realize CVT are facilitate driving, enhance the vehicles fuel oil efficient ideal installment, appears the bipyramid ball, the plate, the hooped column body from several dozens years ago and so on develops the leather belt transmission, but as a result of the rubbing surface friction coefficient and the components withstanding unit pressure limit, adds in the processing craft and the control difficult problem, cannot transmit compares the high efficiency, only limits uses in on the compact car.

人们很早就意识到CVT是方便驾驶、提高车辆燃油经济性的理想装置，由几十年前出现的双锥体球、盘、环柱体等发展到皮带传动，但由于摩擦面的摩擦系数及零件承受单位压力的限制，加之加工工艺和控制上的难题，不能传递较大功率，仅限用于微型汽车上。

For example, before my successful ascent of La Rambla I waited 5 hours! If the route has got an easy start I warm up on it and then I'm ready for the harder sections above. The problem comes if a route is difficult right from the start. And when I climb bouldery routes I rest for just one or two hours between one attempt and the next.

当我攀岩时，如果在热身活动时我觉得这条路线开头很容易，我就会充分准备一鼓作气拿下这条路线；相反，如果开始就让我觉得颇有难度，尤其是在攀一些漂砾路线时，我就会在每次尝试之间休息1、2个小时，养好精神再进行下一次。

The article first point out the factors which affect and restrict many people to brut private vehicle ,through analysis ,the present situation and the prospect of the private vehicle market in our country .the article finally analyzed the factors which restrict the car coming into each family this article proposed the reasonable counter-measures in the view of this difficult problem, and has unified the actual cases to make the automobile.

本文首先通过对国内私家车市场的现状及前景分析，指出影响制约私人购买汽车的主要因素的这一难题。最后对轿车进入家庭的制约因素进行了分析，本文针对这一难题，提出了较为科学合理的对策研究，并结合实际的成功的经销案例，使汽车快步走进千家万户。

It is a common problem to survey some boundary points in difficult area during the implementation of cadastral surveying.

地籍测量中对某些可望而不可及的界址点的测量是经常遇到的问题。

To the research of activity of cheeper science dug, we from check study proceed with, use design and directive case through work analyse and delibrate, will clarify we are opposite in the design in activity of cheeper science dug and guidance the understanding of the respect such as the design of the structural sex of the difficult easy degree of content of dug of mobile programming, cheeper, material, problem and think.

对幼儿科学探究活动的探究，我们从案例探究入手，通过活动设计和指导案例的剖析和研讨，来阐明我们在幼儿科学探究活动的设计和指导中对活动的程序设计、幼儿探究内容的难易程度、材料的结构性、新问题的设计等方面的熟悉和思索。

How to evaluate the enhancement algorithm is also a difficult problem, from the point of color adaptation, a color image enhancement and evaluation algorithmis given considering the two color characteristics: color naturalness index and color colorfulness index. Finally, we presents a new approach to color image denoising based on Human Visual System model.

随后，本文还从人眼的颜色适应角度出发提出了一能够种评估颜色增强的算法，这种算法对彩色图象的分量按照von-Kries模型重新调整比例，并利用颜色的自然性系数和生动性系数在自然图象意义上给出了评估准则。

A backer of an Afghan law that critics say legalizes marital rape has rejected the international outcry as foreign meddling.

饱受批评的一项法律的拥护者说合法化的婚内暴力不会受国际舆论的干涉。

Years ago, a ancient Egyptian fleet went to the Land of punt for seeking a kind of flavor named "myrrh", and aromatic plants which has dense exotic style for the queen Hatshepsut.

3500年前的一个古埃及的舰队到&彭特之地&寻找一种叫没药的香料。