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华慢  龚元元  梁晖  卢江 《高分子学报》2013,(9):1165-1171
以偶氮二异丁脒盐酸盐(V50)作为引发剂,失水山梨醇硬脂酸酯(Span60)和聚二甲基硅氧烷PEG-7磷酸酯为复合分散剂,蔗糖烯丙基醚和三甲基丙基聚氧乙烯(15)醚三丙烯酸酯为复合交联剂,丙烯酸为单体,正已烷为反应介质,采用反相悬浮聚合方法制备了球状卡波树脂.用光学显微镜和扫描电镜分别对聚合反应的成粒过程和产物的形貌进行了研究.结果表明,聚合体系呈现典型的悬浮聚合相态特征,并获得了堆积密度较高(0.65 g/cm3)的球状卡波树脂.聚合反应动力学研究结果表明,该反相悬浮聚合的聚合速率对单体浓度和引发剂浓度的反应级数分别约为1.36和0.70;聚合反应的表观活化能为78.0 kJ/mol.交联剂对卡波树脂的性能有重要的影响,通过适度交联可提高产物的增稠效率及其抗剪切性能.  相似文献   
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针对海洋石油海上生产特点,设计一套海上重大生产设施及移动船舶监控系统。此套监控系统是具有海油特色的监控系统,主要以海上重大生产设施,例如海上石油平台、输油输气管线及移动船舶为监控对象。管理者利用此套系统可以对石油平台、输油输气管线及移动船舶周围海域情况进行监控,并在此基础上完成预警、告警、调度及指挥等重大功能。同时海上移动船舶可在无通信链路的情况下实现船舶的自导航功能。本系统主要创新点体现在:具有海油特色的特有标绘图层;系统标绘数据的远程更新及针对海上各种重大生产设施的特色预警报瞽功能。  相似文献   
3.
本文针对海洋石油已有视频监控系统的特点,设计一套中海油视频监控管理系统。以中国海洋石油专用网络平台为依托,实现海油级视频监控平台与各专业公司原有视频监控系统平台的集成,实现海油总部对各专业公司生产现场动态实时视频监控。  相似文献   
4.
We synthesize the perovskite compound Sm Cr0.9Fe0.1O3 by the sol–gel method and investigate its exchange bias properties through thermomagnetic and isothermal magnetization measurements. The sign reversals of the exchange bias field are observed at the magnetization compensation temperatures 29.6 K and 96.2 K. It is demonstrated that the occurrence of the exchange bias originates from the antiferromagnetic coupling between the Cr-rich and Fe–Cr regions, of which the net magnetization is temperature-dependent. These results imply that there are potential applications in single systems with sign reversals of both magnetization and exchange bias.  相似文献   
5.
In this work, we tuned the magnetostructural transformation and the coupled magnetocaloric properties of Mn_(48-x)V_xNi_(42)Sn_(10)(x = 0, 1, 2, and 3) ferromagnetic shape memory alloys prepared by means of partial replacement of Mn by V. It is observed that the martensitic transformation temperatures decrease with the increase of V content. The shift of the transition temperatures to lower temperatures driven by the applied field, the metamagnetic behavior, and the thermal hysteresis indicates the first-order nature for the magnetostructural transformation. The entropy changes with a magnetic field variation of 0–5 T are 15.2, 18.8, and 24.3 J·kg~(-1)·K~(-1) for the x = 0, 1, and 2 samples, respectively. The tunable martensitic transformation temperature, enhanced field driving capacity, and large entropy change suggest that Mn_(48-x)V_xNi_(42)Sn_(10) alloys have a potential for applications in magnetic cooling refrigeration.  相似文献   
6.
We investigate the influence of Sb-doping on the martensitic transformation and magnetocaloric effect in Mn_(50)Ni_(40)Sn_(10-x)Sb_x(x = 1, 2, 3, and 4) alloys. All the prepared samples exhibit a B2-type structure with the space group F m3 m at room temperature. The substitution of Sb increases the valence electron concentration and decreases the unit cell volume. As a result, the magnetostructural transformation shifts rapidly towards higher temperatures as x increases.The changes in magnetic entropy under different magnetic field variations are explored around this transformation. The isothermal magnetization curves exhibit typical metamagnetic behavior, indicating that the magnetostructural transformation can be induced by a magnetic field. The tunable martensitic transformation and magnetic entropy changes suggest that Mn_(50)Ni_(40)Sn_(10-x)Sb_x alloys are attractive candidates for applications in solid-state refrigeration.  相似文献   
7.
刘俊  龚元元  徐桂舟  徐锋 《中国物理 B》2017,26(9):97501-097501
An investigation on the magnetostructural transformation and magnetocaloric properties of Ni_(48-x)Co_2Mn_(38+x)Sn_(12)(x = 0, 1.0, 1.5, 2.0, and 2.5) ferromagnetic shape memory alloys is carried out. With the partial replacement of Ni by Mn in the Ni_(48)Co_2Mn_(38)Sn_(12) alloy, the electron concentration decreases. As a result, the martensitic transformation temperature is decreased into the temperature window between the Curie-temperatures of austenite and martensite. Thus, the samples with x = 1.5 and 2.0 exhibit the magnetostructural transformation between the weak-magnetization martensite and ferromagnetic austenite at room temperature. The structural transformation can be induced not only by the temperature,but also by the magnetic field. Accompanied by the magnetic-field-induced magnetostructural transformation, a considerable magnetocaloric effect is observed. With the increase of x, the maximum entropy change decreases, but the effective magnetic cooling capacity increases.  相似文献   
8.
The magnetostructural coupling between magnetic and structure transitions plays an important role in the multifunctional applications of magentocaloric materials. In this work, ferromagnetism and magnetostructural transformation are achieved in nonmagnetic V-doped MnNiGe alloys. With simultaneously reducing the transformation temperature and converting antiferromagnetic martensite to ferromagnetic state, the magnetostructural transformation between ferromagnetic orthorhombic phase and paramagnetic hexagonal phase is established in a temperature region as large as 130 K. The magnetic-field-induced magnetostructural transformation is accompanied by considerable magnetocaloric effect.  相似文献   
9.
The magnetic phase transition and magnetocaloric effect are studied in a series of Mn1-xZnxCoGe(x = 0.01, 0.02,0.04, and 0.08) alloys. By introducing a small quantity of Zn element, the structural transformation temperature of the MnCoGe alloy is greatly reduced and a first-order magnetostructural transition is observed. Further increasing the Zn concentration results in a second-order ferromagnetic transition. Large room-temperature magnetocaloric effects with small magnetic hysteresis are obtained in alloys with x = 0.01 and 0.02, which suggests their potential application in magnetic refrigeration.  相似文献   
10.
短波通信在海洋石油中的应用   总被引:1,自引:0,他引:1  
本文针对海洋石油海上通信特点,设计了一套短波通信集中控制系统,使系统管理人员能够在监控中心完成对多台分散的短波发射机进行有效的管理。它改变现有只能在发射机本地进行接收和发送话音的现状,实现了异地、分布式的控制发射机与接收机的功能。它通过软件将短波发射机与接收机结合在一起,实现短波通信业务的数字化。  相似文献   
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