棋牌游戏app开发

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      1. 磁体使用注意事项 磁学知识 其他
        磁学知识 magnetic knowledge
        • 棋牌游戏app开发1 SHENMESHIYONGCICAILIAODECIXINGNENG,TABAOKUONAXIEZHIBIAO?

                永磁材料的主要磁性能指标是:剩磁(Jr, Br)、矫顽力(HcB)、内禀矫顽力(HcJ)、最大磁能积(BH)max。我们通常所说的永磁材料的磁性能,指的就是这四项。永磁材料的其它磁性能指标还有:居里温度(Tc)、可工作温度(Tw)、剩磁温度系数(α(Br))、内禀矫顽力的温度系数(β(HcJ))、回复导磁率(μrec)、退磁曲线方形度(Hk/HcJ)等。

          棋牌游戏app开发      CHUCIXINGNENGWAI,YONGCICAILIAODEWULIXINGNENGHAIBAOKUOMIDU、DIANDAOLV、REDAOLV、REPENGZHANGXISHUDENG;JIXIEXINGNENGZEBAOKUOWEISHIYINGDU、YANGSHIMOLIANG、KANGYAQIANGDU、KANGLAQIANGDU、CHONGJIRENXINGDENG。CIWAI,YONGCICAILIAODEXINGNENGZHIBIAOZHONGHAIYOUZHONGYAODEYIXIANG,JIUSHIBIAOMIANZHUANGTAIJIQINAIFUSHIXINGNENG。


        • 棋牌游戏app开发2 SHENMEJIAOCICHANGQIANGDU(H)

                1820年,丹麦科学家奥斯特(H. C. Oersted)发现通有电流的导线可以使其附近的磁针发生偏转,从而揭示了电与磁的基本关系,诞生了电磁学。实践表明:通有电流的无限长直导线在其周围所产生的磁场强弱与电流的大小成正比,与离开导线的距离成反比。磁场强度通常用H表示。在国际单位制(SI)中磁场强度的单位为A/m (安培/米),1A/m为载有1安培电流的无限长直导线在距离导线1/(2π)米远处的磁场强度;在CGS单位制(厘米-克-秒)中磁场强度的单位为Oe (奥斯特),以纪念奥斯特对电磁学的贡献,载有1安培电流的无限长直导线在距离导线0.2厘米远处的磁场强度为1Oe,1Oe=1/(4π)×103A/m。

        • 棋牌游戏app开发3 SHENMEJIAOCIJIHUAQIANGDU(J),SHENMEJIAOCIHUAQIANGDU(M),ERZHEYOUHEQUBIE?

                XIANDAICIXUEYANJIUBIAOMING:YIQIECIXIANXIANGDOUQIYUANYUDIANLIU,ERFEIZAOQIXIANGXIANGDEYUDIANHEDUIYINGDE“CIHE”。CIXINGCAILIAOYEBULIWAI,QICIXIANXIANGQIYUANYUCAILIAONEIBUYUANZIZHONGDEJIBENLIZIDEYUNDONG,ZHEIXIEYUNDONGDEJIHEXIAOYINGSHIDECAILIAODUIWAICHENGXIANGEZHONGGEYANGDEHONGGUANCITEXING。JIYUFENZIDIANLIUJIASHE,YIGEBIHEHUANXINGWEIDIANLIU(FENZIDIANLIU)DENGXIAOYUYIGEXIAOCIZHEN,JICIOUJIZI。

                定义在真空中每单位外磁场对材料中一个磁偶极子产生的最大力矩为磁偶极矩pm,每单位材料体积内磁偶极矩的矢量和为该材料的磁极化强度J,其SI单位为T(特斯拉),在CGS单位制中,J的单位为Gs(高斯),1T=104Gs。

                DINGYIYIGECIOUJIZIDECIJUDAXIAODENGYUDIANLIUICHENGYIDIANLIUHUANMIANJIa,JIm=Ia,QISIDANWEIWEIA?m2(ANPEI·MIPINGFANG),ERMEIDANWEICAILIAOTIJINEICIJUDESHILIANGHEWEIGAICAILIAODECIHUAQIANGDUM,QISIDANWEIWEIA/m(ANPEI/MI),YUCICHANGQIANGDUXIANGTONG,CGSDANWEIWEIGs(GAOSI)。

                磁偶极矩和磁矩的关系为pm=μ0m,μ0为真空磁导率,因此M与J的关系为J=μ0M,在SI单位制中,μ0=4π×10-7H/m(亨/米);在CGS单位制中,μ0=1,故磁极化强度与磁化强度的数值相等。


        • 4 SHENMEJIAOCIGANYINGQIANGDU(B),SHENMEJIAOCITONGMIDU(B),BYUH,J,MZHIJIANCUNZAISHENMEYANGDEGUANXI?

          棋牌游戏app开发      LILUNYUSHIJIANJUNBIAOMING,DUIRENHEJIEZHISHIJIAYICICHANGHSHI(GAICICHANGKEYOUWAIBUDIANLIUHUOWAIBUYONGCITITIGONG,YIKEYOUYONGCITIDUIYONGCIJIEZHIZISHENTIGONG,YOUYONGCITIDUIYONGCIJIEZHIZISHENTIGONGDECICHANGYOUCHENGTUICICHANG---CANKAN“SHENMESHITUICICHANG?”),JIEZHINEIBUDECICHANGQIANGDUBINGBUDENGYUH,ERSHIBIAOXIANWEIHYUJIEZHIDECIJIHUAQIANGDUJZHIHE。YOUYUJIEZHINEIBUDECICHANGQIANGDUSHIYOUCICHANGHTONGGUOJIEZHIDEGANYINGERBIAOXIANCHULAIDE,WEIYUHQUBIE,CHENGZHIWEIJIEZHIDECIGANYINGQIANGDU,JIWEIB:

                      B=μ0H+J =μ0(H+M) (SI单位制) (1)

                      B=H+4πM (CGS单位制)

                磁感应强度B的SI单位为T,CGS单位为Gs(1T=104Gs)。

          棋牌游戏app开发      DUIYUFEICIXINGJIEZHIRUKONGQI、SHUI、TONG、LVDENG,QICIJIHUAQIANGDUJHUOCIHUAQIANGDUMJIHUDENGYU0,GUZAIZHEIXIEJIEZHIZHONGDECIGANYINGQIANGDUBWANQUANLAIZIYUCICHANGQIANGDUH,ZAICGSDANWEIZHIZHONGYUCICHANGQIANGDUHSHUZHIXIANGDENG,DANDANWEIBUTONG。

                YOUYUCIXIANXIANGKEYIXINGXIANGDIYONGCILIXIANLAIBIAOSHI,GUCIGANYINGQIANGDUYOUKEDINGYIWEICILIXIANTONGLIANGDEMIANMIDU,JICITONGMIDU,CIGANYINGQIANGDUHECITONGMIDUZAIGAINIANSHANGKEYITONGYONG。


        • 棋牌游戏app开发5 SHENMEJIAOYONGCICAILIAODETUICIQUXIAN?SHENMESHIYONGCITIDEGONGZUODIANHEFUZAIXIAN?

          棋牌游戏app开发      DUIYUTIECIXINGCAILIAOERYAN,CIGANYINGQIANGDUBDUICICHANGQIANGDUHDEXIANGYINGTONGCHANGSHIZHIHOUDE。DANGWAICHANGHZAIRENYILIANGGESHUZHIZHIJIANLAIHUIBIANHUASHI,BYUHDEDUIYINGGUANXIZAIH-BZHIJIAOZUOBIAOXINEISHIYOULIANGTIAOQUXIANGOUCHENGDEYIGEBIHEDEHUIXIAN,BEICHENGWEICIZHIHUIXIAN,ERFEIYITIAOWANGFUQUXIAN。XUANZEBUTONGDEWAICHANGQIANGDU,TONGYIZHONGYONGCICAILIAOKEHUACHUWUXIANDUODECIZHIHUIXIAN。TONGCHANG,WOMENJIANGKENENGSHIJIADEZUIDACHANGQIANG(ZHENGFANXIANG)DEDAODECIZHIHUIXIANZHIDINGWEIYONGCICAILIAODEZHUCIZHIHUIXIAN,QITADEJIAOCICIZHIHUIXIAN。RUGUOZUIDACHANGQIANGNENGJIANGCITIBAOHECIHUA,JIUJIANGZHUCIZHIHUIXIANCHENGWEIBAOHECIZHIHUIXIAN。TU1aXIANSHILESHAOJIENd-Fe-BYONGCITIDEDIANXINGZHUCIZHIHUIXIAN,QIZHONGB-HDEGUANXICHENGWEIBIAOZHUNQUXIAN,J-HDEGUANXICHENGWEINEIBINGQUXIAN。LIANGTIAOQUXIANZAIMEIGEDIANTONGGUOGONGSHI(1)XIANGGUANLIAN,CONGYIGEQUXIANTUIDAOCHULINGYIGEQUXIAN。

          棋牌游戏app开发      TUICIQUXIANSHIZHUCIZHIHUIXIANWEIYUDIER(DENGXIAOYUDISI)XIANGXIANDEBUFENQUXIAN。SHAOJIENd-Fe-BCITIDEDIANXINGTUICIQUXIANRUTU1bSUOSHI,TONGYANGYECUNZAILIANGTIAOTUICIQUXIAN,YITIAOSHIB-HTUICIQUXIAN,HUOCHENGWEIBTUICIQUXIAN;LINGYITIAOSHIJ-HTUICIQUXIAN,HUOJTUICIQUXIAN。

                B-HQUXIANYONGYUCILUSHEJI,YINWEIZAIQUELIQIXIZHONGNENGLIANGSHITADAIBIAOCITIDEJINGSHUCHU。DANGCITIFANGZHIZAIWAICHANGZHONGSHI,NEIBINGQUXIANJ-HYONGYUQUEDINGWAICHANGRUHEGAIBIANCITIDENEIZAITEXING。DANGYONGCITIYUWAICHANGZUOYONGSHI,NEIBINGCIJIHUAQIANGDUDAOZHIZAICITISHANGCHANSHENGLIHUONIUJU,YINWEILISHIYOUCIJIHUAHEWAICHANGZHIJIANDEXIANGHUZUOYONGJUEDING。

                永磁体的工作点是由B-H退磁曲线上坐标(Hd,Bd)定义的一个点,例如图1c中的D点。给定永磁磁路的负载线是穿过原点和D的直线OP(图1c),其斜率为Pc = Bd/Hd棋牌游戏app开发,也称为磁体或磁路的磁导系数,因此负载线也称为磁导系数线。

          图片 1.png

          (a)

          图片 2.png

          (b)

          图片 3.png

          (c)

          TU1:YONGCITIDIANXINGDECIZHIHUIXIAN(a),TUICIQUXIAN(b),QIGONGZUODIANHEGONGZUOXIAN(c)。


        • 6 什么叫剩磁(Jr,Br),为什么在永磁材料的退磁曲线上任意测量点的磁极化强度J值和磁感应强度B值必然小于剩磁Jr和Br值?

                永磁材料B与H响应滞后的一个典型特征,是在闭路状态下经外磁场磁化至饱和后再回到外磁场撤消的状态时,其磁极化强度J和内部磁感应强度B并不会因外磁场H的消失而消失,而是保持一定大小的值,该值即称为该材料的剩余磁极化强度Jr和剩余磁感应强度Br。根据关系式(1)可知,当磁场H为0时,Jr = Br,Jr和Br棋牌游戏app开发的数值和单位都相同,因此统称为剩磁。

                在永磁材料的退磁曲线上,磁场H≤0,关系式 (1) 表明J≤B,从而有J退磁曲线J-H和B退磁曲线B-H二条曲线。随着反向磁场H的绝对值从0逐渐增大,永磁材料的磁极化强度J表现出自Jr减小的变化规律,因此J≤Jr。对于现代常用的铁氧体和稀土永磁材料而言,J退磁曲线在H绝对值较低的区域内可以保持为相对平直的直线,且斜率为正。相应地,B从最大值Br = Jr变化到0,然后变为负值,也不会超过Br;如果B = 0对应的H仍处于J-H曲线的直线区域,则B退磁曲线非常接近于一条直线,但其斜率 k >μ0


        • 7 什么叫矫顽力(HcB),什么叫内禀矫顽力(HcJ)?

                在磁性材料的B退磁曲线上,当反向磁场H的绝对值增大到某一值HcB时,磁体的磁感应强度B=0,称该反向磁场H的绝对值为该材料的矫顽力HcB;在反向磁场H=-HcB时,磁体对外不显示磁通,因此矫顽力HcB表征永磁材料抵抗外部反向磁场或其它退磁效应的能力。矫顽力HcB是磁路设计中的一个重要参量。

                值得注意的是:矫顽力HcB总是小于剩磁Br0。因为从(1)式可以看到,在H= -HcB处,B=0,则μ0HcB=J,问题6已经说明,在J退磁曲线上任意点的磁极化强度值总是小于剩磁Jr,故HcB<Jr0 = Br0。在CGS单位制中,数值上HcB<Jr = Br。例如:Br=12.3kGs的磁体,其HcB不可能大于12.3kOe,换句话说,在数值上剩磁Jr是矫顽力HcB的理论极限。

                当反向磁场H=-HcB时,虽然B = 0,磁体对外不显示磁通,但磁体的磁极化强度J在原磁化方向往往仍保持一个较大的值,也即磁体内部微观磁偶极矩的矢量和并不为0。因此,H =-HcB并不对应磁体内部宏观磁化消失的状况;只有当反向磁场H的绝对值进一步增大到某一值HcJ时,磁体的磁极化强度J = 0,或内部微观磁偶极矩的矢量和为0,称该反向磁场H的绝对值为该材料的内禀矫顽力HcJ

                内禀矫顽力HcJ是永磁材料的一个非常重要的物理参量。对于HcJ远大于HcB的磁体,当反向磁场H的绝对值大于HcB但小于HcJ时,虽然磁体已被退磁到磁感应强度B反向的程度,但其磁极化强度J仍保持原方向,在反向磁场H撤消后,磁体的B仍能因J的保持而回到原来的方向。也就是说,只要反向磁场H的绝对值还未达到HcJ,永磁材料便尚未被完全退磁。因此,内禀矫顽力HcJ是表征永磁材料抵抗外部反向磁场或其它退磁效应以保持其原始磁化状态能力的一个主要指标。

                矫顽力HcB和内禀矫顽力HcJ的单位与磁场强度单位相同。


        • 8 什么最大磁能积(BH)max

                在永磁材料的B退磁曲线上(B-H曲线第二象限),不同的坐标点对应着磁体处在不同的工作状态,B退磁曲线上的某一点所对应的Bm和Hm(纵坐标和横坐标的绝对值)分别代表磁体在该状态下,磁体内部的磁感应强度和磁场的大小(磁场方向与磁感应方向相反),Bm和Hm的乘积(BmHm)代表磁体在该状态下对外做功的能力,等同于单位体积磁体所贮存的磁能量,称为磁能积。在B退磁曲线上的Br点和HcB点,磁体的(BmHm)=0,表示此时磁体对外做功的能力为0,即磁能积为0;磁体在某一状态下(BmHm)的值最大,表示此时磁体对外做功的能力最大,称为该磁体的最大磁能积,或简称磁能积,记为(BH)max或(BH)m。因此,人们通常都希望磁路中的磁体能在其最大磁能积状态下工作。由于Br ≥μ0HcB,最大磁能积(BH)max≤Br2/4μ0

                磁能积的单位在SI制中为J/m3(焦耳/立方米),在CGS制中为GOe(高奥斯特),4π×10 GOe = 1 J/m3


        • 9 什么叫居里温度(Tc),什么叫磁体的可工作温度Tw,二者有何关系?

                随着温度的升高,由于物质内部基本粒子的热振荡加剧,磁性材料内部微观磁偶极矩的排列逐步紊乱,宏观上表现为材料的磁极化强度J随着温度的升高而减小,当温度升高至某一值时,材料的磁极化强度J降为0,此时磁性材料的磁特性变得同空气等非磁性物质一样,将此温度称为该材料的居里温度Tc。居里温度Tc只与磁性材料的成分有关,与材料的显微组织形貌及其分布无关。

                在某一温度下,单个永磁体或永磁体构成磁路的磁性能指标与室温相比会降低一个约定的幅度(例如5%),将该温度称为该单个磁体或磁路中的该永磁体的可工作温度Tw。磁性能指标的约定降低幅度需要视应用条件及要求而定;即使约定幅度相同,同一种永磁材料也会因单个磁体的几何特征差异或磁路结构的差异体现出不同的Tw,因此Tw棋牌游戏app开发不是永磁体固有的材料参数。

                显然,磁性材料的居里温度Tc代表着该材料的理论工作温度极限。事实上,永磁材料的实际可工作Tw远低于Tc。例如,纯三元的Nd-Fe-B磁体的Tc为312℃,而其实际可工作Tw通常不到100℃。通过在Nd-Fe-B合金中添加重稀土金属以及Co、Ga等元素,可显著提高Nd-Fe-B磁体的Tc和可工作Tw。值得注意的是,任何永磁体的可工作Tw不仅与磁体的Tc有关,还与磁体的HcJ等磁性能指标、以及磁体在磁路中的工作状态有关。粘结磁体作为磁粉和粘结剂组成的一个复合体系,粘结剂的耐温特性也可能成为Tw的制约因素。


        • 棋牌游戏app开发10 SHENMESHITUICICHANG?RUHEQUEDINGTUICIYINZIHEGONGZUODIAN?

          DANGYONGCITIXIANGWAIJIETIGONGCIGANYINGQIANGDUBDESHIHOU,TAYEJIZISHENSHIJIALEYIGEYUCIHUAQIANGDUMXIANGFANDECICHANGHd,BEICHENGWEIZITUICICHANG,JIANCHENGWEITUICICHANG。ZAIWANQUANBIHEDECILUZHONG,YONGCITIBUHUIXIANGWAIBUTIGONGCICHANG,CITIZHONGYEMEIYOUTUICICHANG。DANGWAICICHANGWEILINGSHI,TUICICHANGBIANSHIYONGCITINEICUNZAIDEWEIYICICHANG,TAYUCITIDECIHUAQIANGDUMXIANGHUZUOYONGDADAOYIGEPINGHENGZHUANGTAI,GUANLIANHdHEMDESHITUICIYINZIN:

                      Hd = -NM (SI单位制) (2)

                      Hd = -N·4πM (CGS单位制)

                      0 < N < 1

          棋牌游戏app开发YIDANDECHUTUICIYINZI,YONGCITIYIJICILUDEGONGZUOZHUANGTAIJIUQUEDINGLE,YINCI,ZAICILUSHEJIZHONG,QUEDINGYONGCITIDETUICIYINZISHIFEICHANGZHONGYAODE。

                不幸的是,现实中磁性材料的特性参数是不均匀的,M通常也不均匀,以至于Hd在磁体内各处甚至不一定与M反平行,即使形状简单如立方体和圆柱体也是如此,从数学的一般意义上说退磁因子N应该是一个33的矩阵,很难用简单的公式来计算,须通过将磁体的几何形状划分为许多物理性质均匀的简单区域,利用有限元方法借助于计算机进行数值计算而得到。唯一的例外是沿长轴或短轴磁化的椭球形磁体(当然,球体是椭球体的特殊情况),M是均匀的,N只是一个参数,且可以用解析公式计算出来。另外,值得庆幸的是,对于其他形状的磁体而言,假设M均匀且N是一个与几何特征相关的参数,在合理的误差范围内也是恰当的,这种处理尤其在有限元数值计算普及之前发挥了重要作用。由于圆柱体是最实用的磁体形状之一,人们通过实验测量得到了它的退磁因子N与磁体长径比L/D的关系(如图2)。

          图片 1.png

          棋牌游戏app开发TU2:TUICIYINZINYUYUANZHUXINGCITIDEZHANGDUYUZHIJINGL / DZHIBIDEGUANXI(TONGGUOSHIYANCELIANG)。

                JIDINGYONGCITIDETUICIYINZIN,JIUHENRONGYIQUEDINGCITIDEGONGZUODIANHEFUZAIXIAN。JIANGGONGSHI(2)DAIRUGONGSHI(1)JIKEDEDAO:

                      Bd = (1-1/N)μ0Hd = Pc·μ0Hd (SI单位制) (3)

                      Bd = (1-1/N)Hd = PcHd (CGS单位制)

                      Pc棋牌游戏app开发 = 1-1/N < 0

          根据Q5的定义,斜率为Pc的OP直线即负载线,而OP与B-H曲线的交点D即工作点(参见图1c)。例如,一个直径为12.5毫米的圆柱形烧结Nd-Fe-B磁体,假设没有磁轭铁,它的长度是多少,才能使其在最大磁能积附近工作?在图1c中,假设磁体的HcB和Br的绝对值相等,则当负载线OP与坐标轴成-45度角时(BdHd)的乘积是最大的,因此Pc = -1.0,根据公式(3)可算出N = 0.5,再从图2可得到磁体的长径比L/D = 0.47,磁体的长度为5.88毫米。


        • 11 什么叫永磁体的回复导磁率(μrec),什么叫J退磁曲线方形度(Hk/HcJ),它们有何意义?

                当磁体处在动态工作条件下时,外部反向磁场H或磁体内部的退磁场Hd呈周期性变化,此时如图1c所示的工作点D亦呈周期性往复变化,B-H曲线就是一个小回线——动态回复曲线,连接小回线两个端点的直线的斜率即为回复导磁率μrec。显然,回复导磁率μrec表征了磁体在动态工作条件下的稳定性,它也是永磁体的B退磁曲线方形度,因此它是永磁体的一个重要的磁特性指标之一。对于烧结Nd-Fe-B磁体,B退磁曲线为直线且HcB约等于Br,其动态回复曲线就是B退磁曲线的一段,回复导磁率μrec等于B退磁曲线的斜率,且μrec=1.01~1.10;粘结Nd-Fe-B磁体方形度较差,μrec = 1.15~1.20。μrec越小,磁体在动态工作条件下的稳定性就越好。值得注意的是,若磁体的B退磁曲线不是直线,则磁体的μrec棋牌游戏app开发在不同工作点就有不同的值,此时如何把磁体设计在最稳定的工作状态,就显得非常重要。

                定义磁体的J退磁曲线上J=0.9Jr时的反向磁场大小为Hk,Hk/HcJ可以直观地表示磁体的J退磁曲线方形度。对于具有高HcJ的烧结Nd-Fe-B磁体,HcJ远远大于HcB,当反向磁场大于HcB但小于HcJ时,相应的B退磁曲线已进入第三象限。由(1)式可知,此时若磁体的J退磁曲线仍为直线,则相应第三象限的B退磁曲线亦保持直线,磁体的μrec仍保持较小值,在反向外磁场撤消后,磁体的工作点仍能恢复到原来的位置。因此,Hk/HcJ也是永磁体的一个重要的磁特性指标之一,它和μrec一样,表征了磁体在动态工作条件下的稳定性。


        • 12 CIXINGCAILIAOFENWEIJIDALEI,TAMENSHIRUHEHUAFENDE?

                CIXINGCAILIAOFENWEIYONGCICAILIAO、RUANCICAILIAOERDALEI。TONGCHANGJIANGNEIBINGJIAOWANLIDAYU0.8kA/mDECAILIAOCHENGWEIYONGCICAILIAO,JIANGNEIBINGJIAOWANLIXIAOYU0.8kA/mDECAILIAOCHENGWEIRUANCICAILIAO。CHANGYONGDEYONGCICAILIAOFENWEILVNIEGUXIYONGCIHEJIN、TIEGEGUXIYONGCIHEJIN、YONGCITIEYANGTI、XITUYONGCICAILIAOHEFUHEYONGCICAILIAO;YINGYONGZUIDUODERUANCICAILIAOSHITIEGUIHEJIN(GUIGANGPIAN)YIJIGEZHONGRUANCITIEYANGTIDENG。

        • 13 SHENMEJIAONd-Fe-BYONGCITI,TAFENJIDALEI?

                Nd-Fe-B永磁体是1982年发现的迄今为止磁性能最强的永磁材料。其主要化学成分为 Nd(钕)、Fe(铁)、B(硼),其主相晶胞在晶体学上为四方结构,分子式为Nd2Fe14B(简称2:14:1相)。除主相Nd2Fe14B外,Nd-Fe-B永磁体中还含有少量的富Nd相、富B相等其它相。其中主相和富Nd相是决定Nd-Fe-B磁体永磁特性的最重要的两个相。今天,Nd-Fe-B永磁体已广泛应用于计算机、医疗器械、通讯器件、电子器件、磁力机械等领域。

                Nd-Fe-B磁体分为烧结、粘结和热压/热变形三大类。通常的烧结Nd-Fe-B磁体是用粉末冶金方法制造的各向异性致密磁体;而通常的粘结Nd-Fe-B磁体是用快淬的方法获得微晶粉末,每个粉末颗粒内含有多个Nd-Fe-B微晶晶粒,再用聚合物或其它粘结剂将粉末颗粒粘结成大块磁体,因而通常的粘结Nd-Fe-B磁体是非致密的各向同性磁体;热压Nd-Fe-B磁体是将快淬微晶粉末热压后制备的各向同性致密磁体,再经热变形制得各向异性致密磁体。通常的烧结Nd-Fe-B磁体的磁性能远高于粘结Nd-Fe-B磁体,但粘结Nd-Fe-B磁体有着许多烧结Nd-Fe-B磁体不可替代的优点:可以用压缩、注射等成形方法制作尺寸小、形状复杂、几何精度高的永磁体,并容易实现大规模自动化生产;另外,粘结Nd-Fe-B磁体还便于任意方向充磁,能方便制作多极磁体,而这对于烧结Nd-Fe-B磁体来说通常很难实现;由于粘结Nd-Fe-B磁体中主相Nd2Fe14B呈微晶状态,因此它还具有比烧结磁体耐蚀性好等优点。热压/热变形磁体取向度不及烧结磁体,因此磁性能低于后者,但更细小的晶粒使其具有更高的HcJ和更佳的耐腐蚀性。


        • 14 什么叫Nd2Fe14B主相?

          屏幕快照 2017-09-18 10.49.08.png

                主相Nd2Fe14B是Nd-Fe-B永磁体中唯一具有单轴各向异性的硬磁性相,其体积分数占磁体中各相的90%以上,因而称为主相。其晶体结构如图3所示:晶格常数a= 0.882nm,c = 1.224nm,c轴为易磁化轴,每个单胞含有4个分子式的68个原子。Nd2Fe14B相的内禀磁性是:居里温度Tc=585K,室温磁晶各向异性常数K1 = 4.2MJ/m3,K2 = 0.7MJ/m3,磁晶各向异性场μ0Ha = 7.3T,室温饱和磁极化强度Js = 1.61T。Nd2Fe14B的基本磁畴结构参数为:畴壁能密度γ=30MJ/m2,畴壁厚度δ=5.2nm,单畴粒子临界尺寸Dc=0.26μm。

                若磁体的成分中添加了合金元素,主相的晶体结构不会发生变化,但其内禀磁性会发生一定的改变,添加合金元素的主要目的是为了改善磁体的内禀矫顽力或其它特性。值得注意的是:除了少量添加Co外,在磁体中添加其它合金元素都会降低主相Nd2Fe14B的饱和磁极化强度Js


        • 棋牌游戏app开发15 SHENMEJIAOFUNdXIANG,TAYOUHEYIYI?

          棋牌游戏app开发      CHUZHUXIANGNd2Fe14BWAI,Nd-Fe-BCITIZHONGDELINGYIGEZHONGYAODEXIANGJIUSHIFUNdXIANG。FUNdXIANGDECHENGFENHEJIEGOUDOUFEICHANGFUZA:NdHANLIANGKEYICONG55%DAO95%YISHANG,QIJINGTIJIEGOUKEYISHIfcc(MIANXINLIFANG)、dhcp(SHUANGLIUFANG)HUOFEIJINGTAI,QIJIEGOUHECHENGFENSUICITIHEJINDECHENGFEN、GONGYIERBIANHUA。LIRU,ZHUDINGZHONGDEFUNdXIANGDECHENGFEN、JIEGOUYUSHAOJIETAICITISHIBUTONGDE;ERSHAOJIETAICITIZHONGDEFUNdXIANGDECHENGFEN、JIEGOUYUHUIHUOTAICITIYOUBUXIANGTONG。FUNdXIANGDECUNZAISHIDAKUAINd-Fe-BCITIJUYOUGAOJIAOWANLIDEZHONGYAOYUANYIN,YONGCICAILIAOGONGZUOZHEDEZHONGYAORENWUZHIYIJIUSHIRENSHI、LEJIEHEKONGZHIFUNdXIANG。

                若磁体中只存在主相Nd2Fe14B,则磁体在磁化或反磁化过程中,内部的畴壁很容易移动,在宏观上表现为磁体很容易被磁化或反磁化,Nd-Fe-B磁体的矫顽力就很低;若主相Nd2Fe14棋牌游戏app开发B晶粒周围被非磁性的富Nd相包围,则磁体在磁化或反磁化过程中,磁体内部畴壁的移动便只限于一个晶粒内进行,在宏观上表现为磁体较难被磁化或反磁化,Nd-Fe-B磁体的矫顽力就较高。

                Nd-Fe-B磁体中的氧主要富集在富Nd相内,起着破坏富Nd相对主相Nd2Fe14B晶粒的隔离作用,因此氧对Nd-Fe-B磁体的矫顽力的影响很大。此外,氧对富Nd相在烧结后冷却时的共晶行为以及富Nd相与主相之间的边界特征产生重要影响。


        • 16 SHAOJIENd-Fe-BCITIDEZHIZUOGONGYISHISHENMEYANGDELIUCHENG?

          棋牌游戏app开发TONGCHANGDESHAOJIENd-Fe-BCITITONGGUOFENMOYEJINGONGYIZHIBEI,CHANGGUIGONGYILIUCHENGRUXIA:

          屏幕快照 2017-09-18 10.43.52.png

        • 17 SHENMESHIJINGJIEKUOSANJISHU?JINGJIEKUOSANJISHUDECITIYOUSHENMEZHUYAODETEZHENG?

          棋牌游戏app开发      ZAISHAOJIECITIGONGYIZHONG,JINGJIEKUOSANJISHUYIBANSHIZHIZAISHAOJIE/HUIHUOCITIBIAOMIANYINRUZHONGXITUYUANSUDyHUOTb,ZAIJINGRECHULISHIZHONGXITUYANZHEJINGJIEDEYEXIANGKUOSANZHICITINEIBU,CONGERTISHENGCITIDENEIBINGJIAOWANLI。YUCHUANTONGHEJINFANGSHITIANJIAZHONGXITUDEFANGFAXIANGBI,JINGJIEKUOSANFANGFAZHONGDEZHONGXITUBEIGENGYOUHUADIPEIZHIDAOZHUXIANGJINGLIJINBIAOMIANXINGCHENGGAOCIJINGGEXIANGYIXINGCENG,SHIYIZHONGNENGTIGAOCITIJIAOWANLI,QIEDUISHENGCIHECINENGJIMEIYOUTAIDAYINGXIANG,BINGNENGJIESHENGDALIANGZHONGXITUDEYOUXIAOFANGFA。

          棋牌游戏app开发      CAIYONGJINGJIEKUOSANJISHUDECITIYIBANDUICITIJITIDECHICUNYOUYIDINGDEXIANZHI,YIBANCAIYONGYOUYIGEFANGXIANGJIAOBODECITIZUOWEIJITI。JINGJINGJIEKUOSANDECITIZHUYAOTEZHENGSHICITIBIAOMIANDAOCITIZHONGXINKUOSANYUANSUCHENGXIANTIDUFENBU,CITIZHONGZHUXIANGJINGLIYOUBIAOMIANDAOZHONGXINZHONGXITUDEFENBUYECHENGXIANYIDINGTIDUTEZHENG,YOUQISHICITIJINBIAOMIANDEJINGLIGAITEZHENGGENGWEIMINGXIAN。

        • 18 SHAOJIENd-Fe-BCITIDEJIXIEXINGNENGYOUHETEDIAN?

                SHAOJIENd-Fe-BCITIDEJIBENJIXIEXINGNENGRUXIA:

          屏幕快照 2017-09-18 10.39.02.png

          KEJIAN,SHAOJIENd-Fe-BCITISHIYIZHONGDIANXINGDECUIXINGCAILIAO。ZAICITIDEJIAGONG、ZUZHUANG、SHIYONGGUOCHENGZHONG,XUZHUYIFANGZHICITICHENGSHOUJULIEDECHONGJI、PENGZHUANGHEGUODADEZHANGYINGLI,YIMIANCITIKAILIEHUOBENGBIANDIAOJIAO。

          棋牌游戏app开发      ZHIDEZHUYIDESHI,YOUYUCHONGCIZHUANGTAIDESHAOJIENd-Fe-BCITICILIHENQIANG,ZAICAOZUOCIHUAZHUANGTAIDECITISHI,HAIXUTEBIEZHUYIRENSHENANQUAN。DUIYUCHICUNJIAODADECIHUAZHUANGTAICITIDEZUZHUANG,BIXUSHIXIANPEIBEIHAOXIANGYINGDEZUZHUANGGONGJU,FANGZHIYINCITIDEQIANGXIHELIYASHANGSHOUZHI。


        • 19 SHAOJIENd-Fe-BCITIDESHENJIAGONGGONGYIYOUHETEDIAN?

          棋牌游戏app开发      SHAOJIENd-Fe-BCITIDESHENJIAGONGGONGYILIUCHENGSHI:

          棋牌游戏app开发      CITIMAOPI——WAILUNKUOJINGZHENG——QIEGE——JINGMO——DAOJIAO——BIAOMIANTUFU——JIANYAN、CESHI——CHENGPIN

                CITIDEWAILUNKUOJINGZHENGYIBANYONGWUXINMOCHUANG(YUANZHUXINGCITI)HUOPINGMIANMOCHUANG(FANGXINGCITI)WANCHENG,SHIMAOPICITIJUYOUGUIZHENGDEWAILUNKUODUBINGDADAOGUIDINGDEJIHECHICUN。

                QIEGEGONGXUSHIYONGJINGANGSHINEIYUANQIEPIANJI、XIANQIEGEJIHUOXIANJU,JIANGJINGZHENGHOUDEMAOPICITIQIEGECHENGJIEJINCHENGPINDEXINGZHUANGHECHICUN。

          棋牌游戏app开发      JINGMOGONGXUSHIJIANGQIEGEHAODECITIYONGPINGMIANMOCHUANG、SHUANGMIANMOCHUANGHUOQITAMOCHUANGJIANGCITIDECHICUN、XINGWEIGONGCHAJIAGONGDAOCHENGPINSUOGUIDINGDEYAOQIU。

                DAOJIAOSHIDIANDUQIANDEYUCHULIGONGXU,WEIJIANHUANZAIDIANDUGUOCHENGZHONGCITILENGBIANYINDIANLIUMIDUXIANGDUIJIZHONGERZAOCHENGDEDUCENGHOUDUBUJUNYUN。YOUYUTONGCHANGDESHAOJIENd-Fe-BCHENGPINCITICHICUNXIAO、XINGZHUANGBUYI,YINCICAIYONGZHENDONGSHIGUNMOGUANGZHENGGONGYIZUIWEISHIHEGAICHANPINDEDAPILIANGDAOJIAOJIAGONG。ZHENDONGSHIGUNMOGUANGZHENGSHENGCHANXIAOLVGAO、DAOJIAOSUDUKUAI,YIGUANGFANWEISHAOJIENd-Fe-BCITISHENJIAGONGCHANGJIASUOCAIYONG;

          棋牌游戏app开发      BIAOMIANTUFUSHIWEILEZAICITIBIAOMIANXINGCHENGDUICITIDEBAOHUCENG,QIZHONGZUICHANGYONGDESHIDIANDU。DIANDUTONGCHANGCAIYONGZIYOUGUNDUGONGYILAISHIXIAN,DUIYUCHICUNJIAODADECITI,ZECAIYONGGUADUGONGYI。SHAOJIENd-Fe-BCITIDEDIANDUCENGSHICITIDESHIYONGHUANJINGHEWAIGUANYAOQIUFENCHENGDUNi、DUZn、HEJINDU、FUHEDUDENG。

          棋牌游戏app开发      SHAOJIENd-Fe-BCITIDEBIAOMIANBAOHUCENGCHUDIANDUWAI,HAIYOUWULIQIXIANGCHENJI(PVD)FA,FENZHENGFADU、JIANSHEDU、LIZIDUSANLEI,KEXINGCHENGAl、Zn、CrDENGDUCENG;HUAXUEQIXIANGCHENJI(CVD)ZEKEXINGCHENGTi、CrDENGDEDANHUAWU、TANHUAWUDUCENG。CIWAI,SHAOJIENd-Fe-BCITIHAIKEYIYONGBIAOMIANHUAXUEDUNHUA、HUAXUEDU、REJINZI、REPENTU、DIANYONGDENGFANGFAHUODEGEZHONGBUTONGDEBIAOMIANBAOHUCENG。


        • 20 SHAOJIENd-Fe-BCITIDEDIANDUGONGYIYOUHETEDIAN?

                SHAOJIENd-Fe-BCITIDIANDUDEJIBENGONGYIDAZHIKEFENWEIRUXIASANGEJIEDUAN:

          • DUQIANBIAOMIANCHULI

          棋牌游戏app开发      CITIDUQIANYAOJINXINGCHUYOU、QINGXI、JINSHI(HUOHUA)、ZAIQINGXIDENGBIAOMIANCHULI,DIANDUQIANCITIDEBIAOMIANYAOZUODAOWUYOUWU、WUYANGHUAPIJIXIUSHIWUDENG,DUQIANCITIDEBIAOMIANZHUANGKUANGZHIJIEYINGXIANGCHANPINDEDUCENGZHILIANG。

          • DIANDU

                JINGBIAOMIANCHULIHOUDECITIJINXINGDIANDUSHI,DUCENGZHILIANGDEHAOHUAIZHUYAOQUJUEYUDUYEPEIFANGHECAOZUOTIAOJIANDENGYINSU。YINCI,ZAIDIANDUCAOZUOGUOCHENGZHONGBIXUYANGEZUNSHOUGONGYIGUIFAN,KONGZHIHAODUYECHENGFEN、TIANJIAJIPEIBI、GONGZUOWENDU、DIANLIUMIDUDENGCANSHU,BINGGENJUDUCENGHOUDUYAOQIUHECHENJISUDU,KONGZHIHAODIANDUSHIJIAN。

          • DUHOUCHULI

                DUHOUCHULIYESHIDIANDUZHONGDEYIGEZHONGYAOHUANJIE。LIRU,CITIZAIDIANDUHOUYIBANYAOJINXINGZHONGHECHULIHEQINGXI,YOUSHIHAIYAOJINXINGGUANGZECHULI(CHUGUANG)、DUNHUA、YOUJIWUTUFUDENGCHULIYIMANZUCHANPINDETESHUYAOQIU。


        • 棋牌游戏app开发21 SHAOJIECITIDEHEIPIANHECHENGPINJIANCEXIANGMUBAOKUONAXIE?

          棋牌游戏app开发      SHAOJIECITIDEHEIPIANJIANCEXIANGMUYICHICUNJIANCEHEXINGWEIJIANCEWEIZHU。

          • CHICUNJIANCETIAOMUBAOKUOZHANGDU、WAIJING、NEIJING、HOUDU、JIAODUDENG;

          • XINGWEIJIANCETIAOMUBAOKUOPINGXINGDU、YUANDU、CHUIZHIDU、BIAOMIANCUCAODU、LUNKUODU、DAOJIAODENG。

          棋牌游戏app开发SHAOJIECITIDECHENGPINJIANCEXIANGMUZHUYAOBAOKUOCHENGPINQUANCHICUNJIANCE、CHENGPINCITEXINGJIANCE、CHENGPINKEKAOXINGJIANCE、CHENGPINFUGAICENGJIANCE、CHENGPINZHANJIEXINGJIANCEHECHENGPINWAIGUANFENXUANDENGLIUXIANGNEIRONG。

          • CHENGPINQUANCHICUNJIANCEJICHENGPINCHICUNHEXINGWEIJIANCE,JUTIJIANCETIAOMUYUHEIPIANCHICUNHEXINGWEIJIANCEXIANGTONG;

          • 棋牌游戏app开发CHENGPINCITEXINGJIANCETIAOMUBAOKUODANFANGXIANGCHANGWENCITONG、CHENGPINJIAODUCHA、BIAOCHANGQIANGDU、BIAOCHANGFENBUDENG;

          • 棋牌游戏app开发CHENGPINKEKAOXINGJIANCETIAOMUBAOKUOGAOWENJIANCILV(CITONG、BIAOCHANG、CIJU)HEFANGFUSHINENGLIJIANCE(YALISHIYAN、SHIRESHIYAN、YANWUSHIYAN、SHIZHONGSHIYANDENG);

          • CHENGPINFUGAICENGJIANCEYIDUCENGHOUDUJIANCEWEIZHU;

          • CHENGPINZHANJIEXINGJIANCEJIBIAOMIANJINRUNXING、ZUJIANZHANJIEQIANGDUDENGCESHI;

          • WAIGUANFENXUANYAOQIUSHAIXUANCHUWULIEWEN、WUSHAYAN、WUKEBIANDENGQUEXIANDECHENGPIN。

                SHANGSHUJIESHAODESHISHAOJIECITIHEIPIANHECHENGPINDECHANGGUIJIANCEXIANGMU,ERJUTIJIANCEXIANGMUJIANGGENJUBUTONGDECHANPINJINXINGYIDINGTIANJIAHUODIAOZHENG。


        • 棋牌游戏app开发22 ZHANJIENd-Fe-BYONGCITIDEZHIZAOGONGYIGUOCHENGSHISHENME?

                ZHANJIENd-Fe-BYONGCITISHIYOUCIFENYUZHANJIEJI(XIANGJIAO、SULIAOHESHUZHI)HEQITATIANJIAJIANYIDINGBILIJUNYUNHUNHEZHIDE,GENJUKUAICUINd-Fe-BCITIJISHUFAZHANGUOCHENGZHONGCITIDECHUXIANSHUNXUYOUCHENGWEI“MQ-ICITI”。ZHANJIENd-Fe-BCITIYOUSIZHONGCHENGXINGJISHU,BAOKUOYASUOCHENGXING、ZHUSHECHENGXING、JICHUCHENGXINGHEYAYANCHENGXING,QIZHONGYASUOCHENGXINGHEZHUSHECHENGXINGSHIMUQIANZUICHANGYONGDELIANGZHONGCHENGXINGFANGFA。

          屏幕快照 2017-09-18 10.31.27.png

        • 23 ZHANJIENd-Fe-BYONGCITIDEXINGNENGTEDIANYOUNAXIE?

          • YASUOCHENGXINGCITI

                压缩成形磁体由磁粉与热固性树脂混合制成,磁粉含量是所有成形方式的粘结磁体中最高的,粘结剂的含量最少,密度最高可达6.4 g/cm3棋牌游戏app开发。压缩成形磁体的生产效率高,但是沿压制方向密度一致性差。粘结钕铁硼磁体在潮湿的环境很容易氧化,因此压缩成形磁体必须进行表面涂装才能使用。薄壁、环形的压缩成形磁体尤其适用于各种主轴和步进电机中。

          • ZHUSHECHENGXINGCITI

          棋牌游戏app开发      ZHUSHECHENGXINGZHUYAODEYOUDIANSHIJINJINGCHENGXINGBINGQIEYIYUZHICHENGFUZAXINGZHUANG,CHICUNGONGCHAXIAO,SHIHEDAPILIANGSHENGCHAN。ZHUSHECHENGXINGLINGWAIYIGETEDIANSHIKEYIHEQITAJINSHUHUOSULIAOLINGJIANYITICHENGXINGWEIZUJIAN,JIEYUECHENGBEN。ZHUSHECHENGXINGCITIQIANGDUBIYASUOCHENGXINGDECITIYAOGAO,DANCIXINGNENGLVEDI。YOUYUZHANJIEJIHANLIANGJIAOGAO,ZAIXUDUOYINGYONGZHONGKEBUZUOBIAOMIANCHULIZHIJIESHIYONG。

          • JICHUCHENGXINGCITI

                YUZHUSHECHENGXINGCITIXIANGBI,JICHUCHENGXINGCITIDESHUZHIHANLIANGDI,CIXINGNENGGENGGAO。JICHUCHENGXINGCITIJUYOUJIAODIDEKONGXILVHEGENGHAODENAIFUSHIXING,ZAIMOUXIEYINGYONGZHONGKEYIBUZUOTUZHUANGZHIJIESHIYONG。CITIKEYIJIAGONGCHENGZHANGZHI1MIYISHANG,ERQIETONGYITAOMOJUNENGDUIYINGBUTONGZHANGDUDECHANPIN,KELIANXUXINGJICHUCHENGXINGSHICITIYANZHANGDUFANGXIANGDECHICUN、XINGNENGJIHUMEIYOUPIANCHA。

          • YAYANCHENGXINGCITI

          棋牌游戏app开发      YAYANCHENGXINGKEYILIANXUSHENGCHANPIANZHUANGDEROUXINGCITI,DANSHICIFENTIANCHONGLIANGDI,CIXINGNENGYIBANDIYUZHUSHECHENGXINGCITI。YAYANCHENGXINGCITIKEZHICHENGDAICAI、JUANCAI、DAMIANJIBANCAIDENG,ZHICHIGEZHONGJIXIEJIAGONG,RUCHONGKONG、WANQU、QIEDUANDENG。YAYANCHENGXINGCITIYOUXUDUOYONGTU,BIRUGEZHONGDIANJI、CHUANGANQIHEXILIZHUANGZHI。


        • 棋牌游戏app开发24 SHENMESHIREYA/REBIANXINGNd-Fe-BCITI?

          JIANGYIDINGLIDUFANWEIDEGUOCUIHUOZHEZUIYOUKUAICUISUDUXIAZHIDEDEKUAICUINd-Fe-BCIFENZAIBAOHUQIFENXIAHUOZHEZHENKONGTIAOJIANXIA,ZAI700°C~ 800°CSHIJIAYIDINGDEYALIJINXINGREYAHUODEDENAMIJINGGEXIANGTONGXINGZHIMIHUACITICHENGWEIREYACITI。GENJUKUAICUINd-Fe-BCITIJISHUFAZHANGUOCHENGZHONGCITIDECHUXIANSHUNXUYOUCHENGWEI“MQ-II CITI”。

          JIYUGEXIANGTONGXINGNAMIJINGNVTIEPENGREYACITIZAIREBIANXINGGUOCHENGZHONGJINGLIDEYICIHUAZHOUYANYALIFANGXIANGZEYOUQUXIANGDEJIBENYUANLI,JIANGREYACITIZAIZHENKONGHUOBAOHUQIFENTIAOJIANXIAJINXINGDABIANXINGLIANGDERESUXINGBIANXING,ZHIDEDEGEXIANGYIXINGQUANMIDUNVTIEPENGCITICHENGWEIREBIANXINGCITI,GENJUJISHUFAZHANGUOCHENGZHONGCITIDECHUXIANSHUNXUYOUCHENGWEI“MQ-III CITI”。


        • 棋牌游戏app开发25 SHENMESHIFEIJING/NAMIJINGRUANCICAILIAO?

                铁基非晶软磁薄带是利用熔体急冷法(冷却速率106°C/s)在Fe-Si-B合金基体中加入少量Cu和Nb制备出的非晶态合金。非晶合金具有无序的原子结构。而纳米晶软磁材料则是将这些软磁薄带经适当温度退火后部分晶化,形成超细晶粒(晶粒尺寸约为10 nm),相对非晶材料而言具有更优异的软磁特性。非晶、纳米晶软磁材料具有高磁导率、高饱和磁感应强度、低损耗、良好温度特性和温度稳定性等优点,被誉为二十一世纪新型绿色节能材料,广泛应用于信息通讯和电力电子行业,推动并实现了电子产品高频化、小型化和环保节能。
        • 26 SHENMEJIAOCILIXIAN,TAYOUHETEDIAN?

                RENMENJIANGCILIXIANDINGYIWEICHUCHUYUCIGANYINGQIANGDUXIANGQIEDEXIAN,CIGANYINGQIANGDUDEFANGXIANGYUCILIXIANFANGXIANGXIANGTONG,QIDAXIAOYUCILIXIANDEMIDUCHENGZHENGBI。LEJIECILIXIANDEJIBENTEDIANSHIZHANGWOHEFENXICILUDEDEJICHU。

                LILUNHESHIJIANJUNBIAOMING,CILIXIANJUYOUXIASHUJIBENTEDIAN:

          • CILIXIANZONGSHICONGNJICHUFA,JINRUYUQIZUILINJINDESJI,BINGXINGCHENGBIHEHUILU。ZHEIYIXIANXIANGDIANCIXUEZHONGCHENGWEICITONGLIANXUXINGDINGLI,YOUMaxwellFANGCHENGMIAOSHUWEI:

          ▽·B=0          (4)

                SHANGSHIYOUCHENGWEICICHANGDEGAOSIDINGLV,BIAOSHIRENYICICHANGDESANDUWEILING,JITONGGUORENYIBIHEQUMIANDEJINGCITONGZONGSHILING,CILIXIANZONGSHIBIHEDE。

          • TONGDIANLIULEISI,CILIXIANZONGSHIZOUCIZUZUIXIAO(CIDAOLVZUIDA)DELUJING,YINCICILIXIANTONGCHANGCHENGZHIXIANHUOQUXIAN,BUCUNZAICHENGZHIJIAOGUAIWANDECILIXIAN。

          • 棋牌游戏app开发RENYIERTIAOTONGXIANGCILIXIANZHIJIANXIANGHUPAICHI,BUCUNZAIXIANGJIAODECILIXIAN。

          • DANGTIECICAILIAOWEIBAOHESHI,CILIXIANZONGSHICHUIZHIYUTIECICAILIAODEJIXINGMIAN。DANGTIECICAILIAOBAOHESHI,CILIXIANZAIGAITIECICAILIAOZHONGDEXINGWEIYUZAIFEITIECIXINGJIEZHI(RUKONGQI、LV、TONGDENG)ZHONGYIYANG。

          棋牌游戏app开发YOUYUCILIXIANJUYOUZHEIYANGDEJIBENTEXING,YINCIJIEZHIDECIHUAZHUANGTAIQUJUEYUJIEZHIDECIXUETEXINGHEJIHEXINGZHUANG。ZAITONGCHANGQINGKUANGXIA,JIEZHIDOUCHUYUFEIJUNYUNCIHUAZHUANGTAI,YEJIUSHISHUOTONGCHANGJIEZHINEIBUDECILIXIANBUSHIPINGXINGZHIXIAN,ERSHICHENGQUXIANZHUANGTAIQIEFENBUBUJUNYUN;LINGWAI,ZAIZIRANJIEZHONGDIANDEJUEYUANTIBIJIAOCHANGJIAN,DANBUCUNZAICIDEJUEYUANTI,JIBUTONGCAILIAODECIDAOLVCHAYIXIAOYUCAILIAODEDIANDAOLVCHAYI,SHIDETONGCHANGDECILUDOUCUNZAILOUCI。JIEZHICHUYUFEIJUNYUNCIHUAZHUANGTAIHECILUCUNZAILOUCIZHEILIANGGETEZHENG,JIUJUEDINGLECILUDEZHUNQUEJISUANFEICHANGFUZA。


        • 27 SHENMEJIAOCILU,SHENMEJIAOCILUDEKAILU、BILUZHUANGTAI?

          棋牌游戏app开发      CILUSHIZHIYOUYIGEHUODUOGEYONGCITI、ZAILIUDAOXIAN、RUANCITIANYIDINGXINGZHUANGHECHICUNZUHE,YIXINGCHENGJUYOUTEDINGGONGZUOQIXICICHANGDEGOUJIAN。RUANCITIKEYISHICHUNTIE、DITANGANG、Fe-SiHEJIN、Ni-FeHEJIN、Ni-CoHEJINDENGJUYOUGAOCIDAOLVDECAILIAO。RUANCITIYOUCHENGWEIETIE,TAZAICILUZHONGQIZHEKONGZHICITONGLIUXIANG、ZENGJIAJUBUCIGANYINGQIANGDU、FANGZHIHUOJIANSHAOLOUCI、YIJITIGAOZHENGGEGOUJIANDEJIXIEQIANGDUDEZUOYONG。

          棋牌游戏app开发      TONGCHANGJIANGMEIYOURUANCITISHIDANGEYONGCITISUOCHUDECIZHUANGTAICHENGWEIKAILUZHUANGTAI;DANGYONGCITICHUZAIYOUYURUANCITIYIQIGOUCHENGDECITONGHUILUZHONGSHI,CHENGCICITICHUYUBILUZHUANGTAI。ZHIDEZHUYIDESHI,ZHEIGECHENGWEIYOUBIEYUMEIYOUCICHANGQIXI、YONGCITIBUXIANGWAIJIETIGONGCICHANGDEZHENZHENGBILUZHUANGTAI。


        • 28 SHENMEJIAOANPEIDINGLV?

          棋牌游戏app开发      ZAIMAIKESIWEI(Maxwell)FANGCHENGZUZHONG,CICHANGQIANGDUHYUDIANLIUMIDUJDEGUANXIWEI:

          ▽×H=J (5)

                QIJIFENXINGSHIWEI:

          屏幕快照 2017-09-18 10.13.22.png

          棋牌游戏app开发      TABIAOSHI,CICHANGHYANRENYIHUILUDEXIANJIFENDENGYUYIGAIHUILUWEIBIANJIEDERENYIQUMIANNEIDEDIANLIUQIANGDU,ZHEIJIUSHIZHUMINGDEANPEIHUANLUDINGLV。ANPEIHUANLUDINGLVHECITONGLIANXUXINGDINGLISHIQIUJIEYIQIECILUWENTIDELIANGGEJIBENGUANXISHI。

                CONGRENLEIFAXIANTIANRANCISHINENGXIYINTIE、DAOZUOCHENGZHINANZHENYONGYUHANGHAI,DAO1820NIANAOSITEFAXIANDIANHECIZHIJIANDEGUANXI,QIJIANJINGGUOLE2000DUONIANDEMANZHANGLISHI。1825NIANQIANHOU,ANPEIHEOUMUFENBIETICHULETAMENHUASHIDAIDEDINGLV。TONGNIAN,William SturgeonZHICHENGLERENLEILISHISHANGDIYIGEDIANCITIE。1830NIAN,FALADI(Michael Faraday)HEHENGLI(Joseph Henry)FENBIEFAXIANLEDIANCIGANYINGXIANXIANG。1832NIAN,William SturgeonFAMINGLEZHUANDONGSHIDIANCIFADONGJI。1856NIAN,DEGUODEXIMENZI(Werner Siemens)FAMINGLEHUASHIDAIDEDIANDONGJI。1873NIAN,LUNDUNHUANGJIAKEXUEYUANDEMAIKESIWEI(J. C. Maxwell)YONGXITONGERJINGQUEDESHUXUEXINGSHIBIAODALEYOUGUANDIANHECIDEQUANBUDINGLV——MAIKESIWEIFANGCHENGZU,ZHICI,DIANCIXUELILUNJIBENCHENGSHU。MAIKESIWEIFANGCHENGZUNINGJULECONG1820NIANDAO1860NIANJIAN,XUDUOZHIDERENLEIYONGYUANJINIANDEJIECHUKEXUEJIADEGONGXIAN。TAMENSHI:KULUN、ANPEI、FALADI、GAOSI、WEIBO、HEMUHUOZI、HENGLI、JIAOER、LENGCI、BOSONG、MAIKESIWEI、LUOLUNZI、BIAODENG。


        • 棋牌游戏app开发29 YONGCICILUJISUANTONGCHANGCAIYONGSHENMEFANGFA?RUHEGENJUCILUXUANZECITIXINGNENG?

          棋牌游戏app开发      TONGCHANG,CILUSHEJIHEJISUANCAIYONGLIANGZHONGFANGFA:YIZHONGSHIJIYUJIZHONGCANSHUDECILULILUNJINXINGCILUFENXIYUJISUAN;LINGYIZHONGSHIJIYUXIANDAIDIANCICHANGLILUNJINXINGDEYOUXIANYUANCICHANGSHUZHIJISUAN。QIANYIZHONGFANGFAHUODEDEZHUNQUEDUJIAODI,DUIXUDUOYONGCIYINGYONGLAISHUO,QIJINGDUTAICHA;ERHOUZHEDEJINGDUKEDADAO10-3YISHANG。SUIZHEJISUANJIJISHUDEPUJI,MUQIANHOUZHEYIYUELAIYUEBEIGUANGFANDISHIYONG。

                在小气隙时(Lg/Dm < 0.15,Lg为气隙间距,Dm为磁体直径或短边长度),选择高Bs的软磁材料,如Fe-Co合金或低碳钢放在磁体前面,可改善气隙磁场;在中等气隙时(0.15 < Lg/Dm < 0.5),选择高Br磁体;在大气隙时(Lg/Dm> 0.5),选择高HcJ磁体。

          图片 1.png

          棋牌游戏app开发TU5:CILUSHIYITU       

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