磁铁的

Shutdown, removed the row fan, fan struck by hand, the sense of rotation of the fan is very flexible, so use flat screwdriver inserted under the roots of the gap fanleaf bend to the will of the fan and fan-Block separation and jumped over the fan, the fan to see in the center of a small arc with several magnet surrounded a round shield-shaped, it is clear that this is the fan motor rotor, while the stator is fixed together with the fan-Block a micro-winding, if the fan and fan blocks together, the micro-coil is inserted to the internal rotor.

关机，将该排风扇拆下，用手拨动扇叶时，感觉扇叶的转动很不灵活，故用平头起子插入扇叶根部底下的缝隙内向上翘，将整个扇叶与扇座分离，翻过扇叶时，看到在扇叶的中心部位有一个用数条小弧形磁铁围成的圆罩形，显然，这就是该风扇电机的转子，而定子是与扇座固定在一起的一个微型绕组，若将扇叶与扇座组合在一起，则该微型绕组正好能插在转子的内部。

A strip block is used instead of the ball to eliminate the measurement error caused by the trajectory deviation of the ball when passing the photo gate.And a spring clip is used to replace the electromagnet to eliminate the effect of remanence.

在单摆法中，要求忽视细线的质量且线长及小球尺度相比很大，把小球看成质点，并且小球的摆幅不能超过5°[1~3]；在自由落体法中，一般是用小球作为自由落体，但小球通过光电门时，往往不是小球的质心遮光计时，另外，钢球是用电磁铁通电后吸住的，由于断电的瞬间，电磁铁有剩磁，钢球不立即下落，并且钢球应吸在电磁铁的中心处，这些因素都会影响重力加速度的测量。

After take analyzed deeply for the opened magnet circuit with FEMM (Finite Element Method Magnetics) we find out the field distributing that is separated into three sections . One is the main area what we called as positive field section. Beside the main field there are tow areas that are called the inverted field sections. Loudspeaker arise a very serious distortion when the voice coil moving into inverted field areas. The direction of induced current in the coil part of entered inverted field area is same with the current driving into loudspeaker so that total currents increas largely and heat increase rapidly. With more coils moving into inverted area the voice coil will take on negative inductance properties. It is the main reason that voice coil is burned by heating with increasing current due to arise negative inductance. So opened magnetic circuit is not suitable for the woofers in which the voice coil have wider displacement range. When using this kind magnetic circuit design, the voice coil moving range should be less than the range of positive field to avoid loudspeaker arise serious distortion and heating. Even though voice coil moving range is in the positive area, loudspeaker will still arise more distortion because the field distribution is very cliffy at tow sides of the positive area and full range of magnetic field distribution is not parallel that will arise distortion. Base on above reasons, opened magnetic circuit is not an ideal magnetic circuit for low-frequency loudspeakers. But it can be used in mid-range or high-frequency productions.

开式磁路是由2片钕铁硼磁铁和主导磁板和导磁垫片组成，我们在实践过程中发现这种磁路结构不适合于低频扬声器的使用，我们通过使用FEMM（Finite Element Method Magnetics）软件包对该磁路进行了分析，该磁路的磁场范围被分成3个区域，其中在主导磁板附近形成一个正向磁场，在正向磁场的两边存在反向的磁场，音圈在工作时有很大一部分进入了反向磁场中，在反向磁场内线圈的感应电流方向与驱动电流方向相同，使得音圈呈现出负感抗特性，由于音圈的负感抗特性引起电流的增加导致音圈发热甚至烧毁，因此在扬声器中使用开式磁路时，音圈的运动范围应控制在正向磁场范围之内，否则音圈运动到反向磁场区域时将会产生很大的失真和发热，即使在设计时已经将音圈的运动范围控制在正向磁场范围之内，由于正向磁场的2个边缘磁场强度衰减太快，同时开式磁路中磁场的分布不是平行的，而是自由发散的分布，这样肯定会导致扬声器的非线性失真，因此我们得到的结论是：开式磁路并不是一个理想的磁路，它不适合于低频扬声器的使用，但它还可以应用于中高频扬声器。

The opened magnetic circuit is composed as tow NdFeB permanent magnets and a top plate without U-yoke. After take analyzed deeply for the opened magnet circuit with FEMM (Finite Element Method Magnetics) we find out the field distributing that is separated into three sections . One is the main area what we called as positive field section. Beside the main field there are tow areas that are called the inverted field sections. Loudspeaker arise a very serious distortion when the voice coil moving into inverted field areas. The direction of induced current in the coil part of entered inverted field area is same with the current driving into loudspeaker so that total currents increas largely and heat increase rapidly. With more coils moving into inverted area the voice coil will take on negative inductance properties. It is the main reason that voice coil is burned by heating with increasing current due to arise negative inductance. So opened magnetic circuit is not suitable for the woofers in which the voice coil have wider displacement range. When using this kind magnetic circuit design, the voice coil moving range should be less than the range of positive field to avoid loudspeaker arise serious distortion and heating. Even though voice coil moving range is in the positive area, loudspeaker will still arise more distortion because the field distribution is very cliffy at tow sides of the positive area and full range of magnetic field distribution is not parallel that will arise distortion. Base on above reasons, opened magnetic circuit is not an ideal magnetic circuit for low-frequency loudspeakers. But it can be used in mid-range or high-frequency productions.

开式磁路是由2片钕铁硼磁铁和主导磁板和导磁垫片组成，我们在实践过程中发现这种磁路结构不适合于低频扬声器的使用，我们通过使用FEMM（Finite Element Method Magnetics）软件包对该磁路进行了分析，该磁路的磁场范围被分成3个区域，其中在主导磁板附近形成一个正向磁场，在正向磁场的两边存在反向的磁场，音圈在工作时有很大一部分进入了反向磁场中，在反向磁场内线圈的感应电流方向与驱动电流方向相同，使得音圈呈现出负感抗特性，由于音圈的负感抗特性引起电流的增加导致音圈发热甚至烧毁，因此在扬声器中使用开式磁路时，音圈的运动范围应控制在正向磁场范围之内，否则音圈运动到反向磁场区域时将会产生很大的失真和发热，即使在设计时已经将音圈的运动范围控制在正向磁场范围之内，由于正向磁场的2个边缘磁场强度衰减太快，同时开式磁路中磁场的分布不是平行的，而是自由发散的分布，这样肯定会导致扬声器的非线性失真，因此我们得到的结论是：开式磁路并不是一个理想的磁路，它不适合于低频扬声器的使用，但它还可以应用于中高频扬声器。

Good translated term or name resembles an artistic high-quality goods not only, make the audience obtains skill, the edify; of contented, beautiful enjoyment and exalted sentiment and resemble a magnet, can attract an audience to watch appreciation movie, rise to guide very well inspect and sales promotion action, it is an artistic high-quality goods more, prolonged is unforgettable, have appreciate and the double value that collect.

好的译名不仅像一件艺术精品，使观众得到艺术的，陶、美的享受和高尚情操的陶冶；而且像一块磁铁，能吸引观众去观看欣赏影片，起到很好的导视和促销功能，更是一件艺术精品，经久难忘，具有鉴赏和收藏的双重价值。

During the study of magnetite oxidation, a function for calculating the"equivalent osmosing thickness"of oxygen through the reacted product layer covered the unreacted part is put forward based on the oxidation process properties. It is this function that make the oxidation process model successful.

在球团矿内磁铁矿的氧化过程的研究中，作者针对磁铁矿粉氧化的特点，提出了磁铁矿颗粒表面生成的三氧化二铁产物层的当量扩散厚度的计算函数，将其引入全温度范围球团矿内磁铁矿的氧化过程模型，并获得成功。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。