查询词典 difficult problem

The difficult part of this "lily pad problem" is that people tend to assume that, if lily pads need 29 days to spread over half of the pond, it would probably take them a few more days to blanket the other half, while the terrible end will in fact come the day after.

"睡莲叶子问题"使人不解的地方使人们趋向于这样设想：如果睡莲叶子蔓延29天才超过池子的一半面积，那么覆盖其另一半可能需要更多的时间。然而，实际上，可怕的结果在第二天就来临了。

It was pointed out that even if for m ≥ 3, the existence of C~m solutions of the linear iterative functional equation F -= 0 is a difficult and very interesting problem.

有关文献指出，当m≥3时，即使是线性型的迭代函数方程F-∑_(k=1)~nλ_kf~k=0的C~m解的存在性也是一个困难而很有意思的问题。

Gregory House is a doctor 』『 atypical, he never wore robes, always bearded, leaning on a cane, eating jelly beans all day long like a knock painkillers; he is convinced that everyone is lying 『』, or trying Avoid contact with patients or their families to meet, or a mockery of his best satire can be, even for patients acrimony; his diagnostic method deviant, repeatedly instructed subordinates three little ducks 』『 house-breaking patients into the room to find the source of illness; not hesitate to take extreme experimental treatment, the patient or their own force to the edge of death, is to unlock a Road for the difficult medical problem.

Gregory House是一名『非典型医生』，他从不穿白大褂，永远是胡子拉碴，拄着一根拐杖，成天吃糖豆似的磕止痛片；他坚信『每个人都说谎』，要么竭力避免与病人或家属见面，要么极尽讽刺嘲弄之能，甚至对病人恶言相向；他的诊断方式离经叛道，多番指示手下三只『小鸭子』破病人家门而入，寻找致病源头；不惜采取极端的实验性治疗方案，把病人或自己迫向死亡边缘，为的是解开一道道棘手的医学难题。

"When accounting for a merchandising firm, the problem of properly matching revenues and expenses becomes more difficult because of a large inventory of items, seasonal fluctuations and inventory purchasing policies."

为商业企业作帐时，收入和支出的恰当配比变得更加困难，因为有大量的库存，季节性波动，以及进货存库策略等原因。

"When accounting for a merchandising firm, the problem of properly matching revenues and expenses becomes more difficult because of a large inventory of items, seasonal fluctuation s and inventory purchasing policies."

为商业企业作帐时，收入和支出的恰当配比变得更加困难，因为有大量的库存，季节性波动，以及进货存库策略等原因。

This math problem is too difficult for him.

这道数学题对他来说太难了。

This math problem is too difficult for me to work out.

这道数学题太难，我做不出来。

At the same time, to counter the problem that traditional coding method of genetic algorithm is difficult to design for this model, conventional genetic algorithm is modified by extending encoding method form digital string to matrix and defining corresponding genetic operator operation, this make encoding clear and understanding easy.

同时，针对遗传算法传统编码方案所存在的问题，提出了遗传算法的改进方案，将染色体结构由传统的数字串扩展到多维数组，并定义了相应的遗传算子操作，使得编码清晰、易于理解，遗传算子操作方便。

We can imagine that, if the subjects close their eyes and make a difficult mental arithmetic problem.

我们可以设想，如果让受检者闭上眼睛，作一个困难的心算题。

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。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。