难以控制

The performance of magnetic levitation is determined mainly by the characteristic of its controller and solving the problems of the high precision, high esponse frequency, output immune from the disturbance, the parameter perturbation and the uncertain factors from outside is very difficult. The traditional methods can not meet the needs of the system. So it has great significance to study the control method of magnetic levitation.

磁悬浮系统性能的优劣很大程度上取决于控制器的特性，高精度、高响应频率和输出不受外界干扰的特性以及磁悬浮中参数的摄动和外界不确定的干扰因素都是难以解决的棘手问题，传统控制难以满足系统要求，因此对控制方法的研究有其非常重要的意义。

Secondly, aiming at the difficulty of information sharing between reheating furnace and roughing mill which is brought by the separate control of the two facilities, and the problems of exceeding energy consumption and low security of rolling process given by the difficulty to adjust the heating process of slab dynamically, this paper presents a comprehensive optimizing control strategy of reheating furnace based on the rolling information feedback. In the presented strategy, fuzzy control and neural network are used to feed roll force and slab temperature of therolling process back to reheating furnace and the concrete furnace temperature setting compensation value can be worked out. So that the heating process of slab can be adjusted dynamically according to the heating quality of the slab, and energy consumption can be reduced, the rolling security can be ensured as well.

其次，针对目前加热炉和粗轧机的分离控制带来的生产信息难以共享、钢坯的加热过程难以动态调整而造成的能耗浪费过大、粗轧机轧制安全难以保障等问题，提出了基于轧制信息反馈的加热炉综合优化控制策略，利用模糊控制和神经网络的方法，将粗轧机一侧的能够反映钢坯加热质量好坏的生产信息，如粗轧机的轧制力、钢坯的温度等，反馈到加热炉一侧并计算出炉温设定值的补偿量，从而能够根据钢坯的加热状况动态地调整后续钢坯的加热过程，减少了能耗浪费，保障了轧制安全。

Passive cooling system is composed of multiple sets of fans, which can remove the heat of LED beads adequately even in high room temperature conditions. Besides, KEY's tooth optical cooling technology, completely solved the high-power LED thermal problems.

目前大功率芯片以1W~3W为主。5W以上的单颗LED全由1W或3W合成，能合成10~50W的单颗灯珠，但其需要超大型散热器加风扇来减少光衰，但散热和光衰还是难以控制，可能在3-5年内也难在技术上解决合成灯珠发热太高的问题。

Tobacco bacterial wilt is one of main diseases of tobacco in south China due toits wide occurrence and difficultly being controlled.

烟草青枯病是我国南方烟草产区一种主要病害，发生广，且难以控制，有些发病严重的地方被迫放弃种烟，青枯病已成为烟叶稳定持续发展的重要制约因素。

Inuit guide Band Covick is more concerned with the melting, the disappearance of sea ice and snow pack on a scale that's hard to grasp.

因纽特人向导 Band Covick 更加关注的是冰雪融化，因为难以控制的海洋冰块和雪山正在大量消失。

With respect to safety profile, administration of prednisone in relatively short period was safe and there were no severe side effects exacerbation of angina, infection and poor controlled hypertension etc.

关于安全概况，相对短期的口服强的松是安全的，研究期间没有发现严重副反应(心绞痛恶化、感染和难以控制的高血压等)。

Immunosuppressants When the condition is difficult to control or it is difficult to reduce your oral steroid dose without relapse, an immunosuppressant such as azathioprine or mercaptopurine is used.

免疫抑制剂时的条件是难以控制或是很困难的，以减少您的口服类固醇剂量，没有复发，免疫抑制剂，如硫唑嘌呤或巯基嘌呤是使用。

If bigger studies prove this new approach to treating refractory depression works on even a fraction of that fraction, neurosurgeons could be in for a busy time.

如果范围更广的研究能证明这种聊难以控制的抑郁症新方法能一小部分地陆续进行的话，神经外科医生恐怕要很忙碌了，因为他们要给更多病人带来福音。

The researchers point out that gene flow between crops and their wild relatives is common and difficult to contain.

科学家指出，作物和其野生亲属之间的基因流动相似，难以控制。

Ethnic and religious minorities may still cause trouble too. In the south-east many of Mr Rigi's Baluchis are restive.

少数民族和宗教组织仍可能造成麻烦，东南部许多瑞吉的俾路支许多难以控制。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。