双极性

The magnetite with a mean diameter of 8nm was prepared by chemical coprecipitation methods. By the addition of nonionized oleic acid to the suspension of magnetite in solution during precipitation, the magnetite nanoparticles were coated with a double surfactant layer. A gel-like precipitated precursor is then formed because of the hydrophobic interaction among those coated units. By transferring of this precursor to an organic solvent, the surfactant double layer on Fe〓O〓 nanoparticles reduces to one; however, it still remains as a double layer by transferring to an alkaline aqueous solution. Both these cases give in stable colloids of superparamagnetic Fe〓O〓 nanoparticles.

从解决无机磁性Fe〓O〓颗粒与有机烯类单体的相容性入手，采用化学共沉淀法，制备了平均直径为8nm的超顺磁性Fe〓O〓颗粒，在制备过程中以非离子形式引入油酸，在Fe〓O〓颗粒表面形成一个具有双层结构的疏水外壳，并通过疏水相互作用凝聚成磁性Fe〓O〓凝胶，能够以单分子层结构形式溶解在非极性溶剂中，也能够以双分子层结构形式溶解在碱性水溶液中，形成稳定的超顺磁性Fe〓O〓溶胶。

The grafting effect and mechanism was charac- terized by FTIR,The heat stability of unvulcanized and dynamical mechanical proper- ty of vulc- lcanizates of SBR and SBR-g- were tested by TG and DMA respectively. medium-resistance properties of SBR and SBR-g- vulcan- izates were also investigated.The results showed that addition of St accelerated GMA grafting onto SBR and control the decomposition of SBR. When the conditions were GMA/St/DCP was 8/4/0.3 and grafting temperature was 160℃.

结果表明，St对提高接枝率、抑制SBR的降解起到了积极的作用；SBR中聚丁二烯的α－H和双键共同参与了GMA/St熔融接枝反应；当SBR/GMA/St/DCP=100/8/4/0.3、接枝温度为160℃时，SBR的接枝率较高（23.78%），SBR–g–硫化胶的拉伸强度和撕裂强度比SBR硫化胶的分别提高了119%和27.4%；SBR–（GMA--co-St）未硫化胶的Tg比SBR未硫化胶的高，而耐热分解性能优于SBR未硫化胶；SBR–g–硫化胶在低温条件下的刚性增大、弹性降低、具有较低的内耗，在常温下的阻尼性能较高，但弹性性能保持较好；SBR–g–硫化胶的耐热稳定性以及耐非极性有机溶剂的性能优于SBR硫化胶。

Cable .Make use of this principle, we can quickly locate the target cable or break point from large amount of cables, under carpet, the inner of decoration wall and over ceiling1 operation is simple , reliable , the interface is nimble , use is broad , bionic form , carry-over are convenient, since our link tester has two signal output port, it can work when switch is running, this is very convenient. 2 applies to all metal cable such as network cable , tele phone line cable , video cable , automobile circuit .it can not be work with high voltage(above 80V),if you want to locate it ,please turn off the cable power supply3 can test the telephone line polarity, connectedness, rough position of breaking point.4 uses the two crocodile clamp to avoid getting rid of the job of make network cable. Use the RJ45/RJ11 interface can connect to the network and the telephone line directly.5 link tester can find out that pair of circuit line cable from large mount of cables. 6 high amplitude ranks 200 times amplification circuit is sui table to locate long distance cable.7 two-sided network lines sequence indicator is easy to examine the network line cable whether or not correctly conveniently. 8 portable types multifunctional bag can encase most of your engineering tools; remit your messy carry-over of implement bothering. 9 adopt two 9V batteries.

线路通产品特点：1 操作简单、性能可靠，接口灵活、用途广泛，仿生外形、携带方便，由于本设备采用了信号双路输出方式，可以解决交换机工作状态下使用，避免了关掉交换机影响其他线路的使用的麻烦。2 适用于查找网络电缆、电话线路、视频电缆、汽车电路、无强电状态下的所有金属电缆。3 可以测试电话线路极性、连通性，断点大概位置。4 两个鳄鱼嘴夹，避免了去做水晶头的麻烦，RJ45/RJ11接口线，可直接连接网络和电话线模块。5 寻线器快速地在众多紊乱的线路中找出需要查找的那一对线路线缆。6 高音频振幅级别200倍的放大电路，适合长距离电缆定位。7 双面网络线续灯可以更直观方便的检查校正网络线续线路连接是否正确。8 便携式多功能软包，可以把您工程施工、维护的基本工具装齐，免除您工具散乱携带的麻烦。9 本寻线器采用2节9V电池。

Be work with high voltage(above 80V),if you want to locate it ,please turn off the cable power supply3 can test the telephone line polarity, connectedness, rough position of breaking point.4 uses the two crocodile clamp to avoid getting rid of the job of make network cable. Use the RJ45/RJ11 interface can connect to the network and the telephone line directly.5 link tester can find out that pair of circuit line cable from large mount of cables. 6 high amplitude ranks 200 times amplification circuit is suitable to locate long distance cable.7 two-sided network lines sequence indicator is easy to examine the network line cable whether or not correctly conveniently. 8 portable types multifunctional bag can encase most of your engineering tools; remit your messy carry-over of implement bothering. 9 adopt two 9V batteries.

l线路通产品特点：1 操作简单、性能可靠，接口灵活、用途广泛，仿生外形、携带方便，由于本设备采用了信号双路输出方式，可以解决交换机工作状态下使用，避免了关掉交换机影响其他线路的使用的麻烦。2 适用于查找网络电缆、电话线路、视频电缆、汽车电路、无强电状态下的所有金属电缆。3 可以测试电话线路极性、连通性，断点大概位置。4 两个鳄鱼嘴夹，避免了去做水晶头的麻烦，RJ45/RJ11接口线，可直接连接网络和电话线模块。5 寻线器快速地在众多紊乱的线路中找出需要查找的那一对线路线缆。6 高音频振幅级别200倍的放大电路，适合长距离电缆定位。7 双面网络线续灯可以更直观方便的检查校正网络线续线路连接是否正确。8 便携式多功能软包，可以把您工程施工、维护的基本工具装齐，免除您工具散乱携带的麻烦。9 本寻线器采用2节9V电池。

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％。