在困难中

At present, many difficulties and problems remain in the economic and social development.

当前，在经济和社会发展中还存在不少困难和问题。

It is quite complex and difficult to simulate bolt pretension accurately in the analysis of bolt joint by finite element method.

在螺栓联接的有限元分析中准确模拟螺栓的预紧力是一项复杂而困难的工作。

The use of porous prolled ANFO explosives prill in the experiment of open chamber blasting helps to solve a series of problems in the process of using ammonium nitrate fuel such as its liability to stick to the hole wall and the difficulty in loading explosive power etc.

在露天药壶爆破中试验使用多孔粒状铵油炸药，解决了使用粉状铵梯炸药时因药粉易粘孔壁、装药困难等原因引起的一系列问题，提高了爆破作业的安全性和爆破效果，降低了爆破成本。

H owever, in the process of tapping, with the characteristics of secret in content of file information, stagnating behind in delivery, the primitiveness of its fu nction and the decentralization in its taking care of, the tapping archives info rmation under the condition of network encounters unprecedented difficulties.

但在开发的过程中，由于档案信息具有内容的机密性、传递的滞后性、作用的原始性和保管的分散性等特点，使网络环境下的档案信息开发遇到了前所未有的困难。

It is difficult at times to determine which is the principal or important term in a phrase.

在一个短语中，决定哪个词是主要词或重要词，有时是很困难的。

Based on the radical conditions of genetic equilibrium, the principle of linkage equilibrium condition and process, for two gene loci is introduced by precise mathematical reasoning.

由于许多教科书中关于连锁平衡的介绍，多是引用结论或是推导不太严谨，使学生在学习群体遗传学时对理解连锁平衡的原理感到困难。

The community correction system as an alternative to pris...

作为一个全新的事物，社区矫正在中国生长的社会条件、理论基础、体制环境和资源状况等基础性问题，直接影响和决定着它的前景，而对其发展中困难和问题的认识，无疑具有重要理论价值和实践意义。

The oil producer's astute risk management will make it the envy of Opec, the oil cartel whose members are struggling with a collapse in prices from last year's peak of $147 a barrel and who are due to meet tomorrow to discuss output levels.

石油生产国的充满智慧的风险管理措施使其成为OPEC中唯一幸免于难的国家。油价在去年达到147美元一桶后急速下滑，OPEC组织的其他成员国正面临巨大的困难，并将于明天会面讨论石油产量问题。

The flux hysteresis controller was ignored in the constant torque region and an improved method was proposed to make the estimation of torque easier.The proper stator voltage space vector was selected based on the output of the torque hysteresis controller and the sector which the current rotor flux locates in.

摘 要：针对无刷直流电机直接转矩控制中磁链观测困难、控制复杂等问题，提出了一种应用于无刷直流电机二二导通方式下的新型直接转矩控制方法：在电机基频以下调速时，略去了常规的磁链观测控制环节，改进了转矩计算方法，通过转矩滞环控制选择所施加的空间电压矢量。

A new brushless DC motor DTC scheme was studied to solve those problems associated with direct torque controlof brushless DC motor,such as difficulty to control flux and complexity to estimate torque.The flux hysteresis controller was ignored in the constant torque region and an improved method was proposed to make the estimation of torque easier.The proper stator voltage space vector was selected based on the output of the torque hysteresis controller and the sector which the current rotor flux locates in.

摘 要：针对无刷直流电机直接转矩控制中磁链观测困难、控制复杂等问题，提出了一种应用于无刷直流电机二二导通方式下的新型直接转矩控制方法：在电机基频以下调速时，略去了常规的磁链观测控制环节，改进了转矩计算方法，通过转矩滞环控制选择所施加的空间电压矢量。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。