尚未解决

It is important and difficult to calculate the heat emitting from the wall rock at drifting face.

掘进工作面的围岩散热是至今尚未解决的一个重要问题。

But some crucial problems have not been resolved, especially themechanism of plants to resist the abiotic stress.

然而，还有许多重要的问题尚未解决，尤其是高等植物对非生物胁迫的反应机制方面。

Main factors to bring ultrasonic level measurement error were studied and emendable error model of ultrasonic level measurement instrument was established according to the error characteristics in the process of measuring.

本论文运用化学计量学中的回归分析法、最优化方法、模式识别方法和计算机技术，对原油生产集输过程的实时盘库系统（目前国内尚未解决的难题）和气相色谱分析进行研究，完成了以下研究工作。

This thesis investigates the profile extraction and shape optimization on the result of topology optimization of planar compliant mechanisms. The main context includes the following work:(1) summarizing and analyzing the recent research status, some harvest and unsolved problems;(2) analyzing the conceptual design of planar path-generating compliant mechanisms and its mathematical model and tools;(3) Modifying the method of density contour as the method of profile extraction, and developing a method to optimize the density function in the profile extraction according to the requirement of the design of compliant mechanism;(4) developing a method to abstract the compliant mechanism into a form of links and joints by using the principle of connectivity on topology;(5) developing a method of shape optimization of planar path-generating compliant mechanisms, by representing the profile of the abstracted compliant mechanism as simple curves such as straight lines and arcs, establishing the models of the size optimization of the parameters of these curves, so that the compliant mechanism has a machinable shape;(6) At last, proving the feasibleness and effectiveness of the design method by making simulation design and validating it in FEA software.

主要工作包括：(1)分析了柔顺机构拓扑优化和形状优化的研究现状，分析了目前柔顺机构的研究重点、主要成果和尚未解决的问题；(2)分析了基于SIMP的柔顺机构概念设计方法及其相关工具和模型；(3)针对柔顺机构轮廓提取的特殊要求，提出了密度等值线法的改进方案，对密度函数插值点密度值进行优化，提出优化模型和选择优化算法；(4)根据轨迹输出平面全柔顺机构自身的形状特点，提出了轨迹输出平面全柔顺机构的抽象方法，即应用拓扑学上的连通性原理将柔顺机构抽象成杆件和结点形式，并对相应的数学原理进行了证明；(5)提出了平面全柔顺机构的形状还原和尺寸优化方法，对抽象的柔顺机构进行还原，将其轮廓还原成简单曲线的连接，从而建立尺寸优化模型，对机构进行尺寸优化设计，在得到可加工的机构轮廓的同时又能对关键部位进行特别处理；(6)进行了柔顺机构的数值仿真设计，并将所得设计结果导入商用有限元软件中进行仿真实验，证明了设计方法的可行性和有效性。

However, some risks to the sustainability of economic growth at the lobal level remain, owing to unresolved structural problems and persistent macroeconomic imbalances in major industrialised countries.

但是由于主要工业国家存在尚未解决的结构性问题和持续性的宏观经济失衡，因此也存在一些在全球范围内影响经济增长可持续性的风险。

Whilst the question of specie payments is in abeyance the prudent business man is careful about contracting debts payable in the distant future.

以硬币偿付的问题尚未解决，谨慎的商人正小心地处理须经长期偿付的债务。

Whilstthe question of specie payments is in abeyance the prudent business manis careful about contracting debts payable in the distant future.

以硬币偿付的问题尚未解决，谨慎的商人正小心地处理须经长期偿付的债务。

At the end of this thesis, I have sumed up the experience and lessons of develop this system , and propose the problem and imagination not solved yet, I hope to have an opportunity to perfect the system in the future, make this system more practical, stalwart , ripe!

在本论文的最后，总结了本系统开发中的经验教训，提出了尚未解决的问题及设想，希望今后能够有机会完善，使本系统更加实用，健壮，成熟！

As for the previous qin dynasty ' s research , the study of xia dynasty have made progeress , yet many problens haven ' t stllt been resoled

摘要就先秦史断代研究来说，夏史研究虽取得一些进展，但有许多问题尚未解决。

However, two major problems remain unsolved on the application of smart antennas.

当前，这一领域的研究还存在许多尚未解决的开放式问题。

In her eyes, because that is the doorway toher heart * the place where love resides.

女人的漂亮必須從她的眼睛中去看，因為那是她心靈的窗戶和愛居住的地方

I will send some postcards to you.

我会向你发送一些明信片。