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1.
Monolithic columns were introduced in the early 1990s and have become increasingly popular as efficient stationary phases for most of the important chromatographic separation modes. Monoliths are functionally distinct from porous particle-based media in their reliance on convective mass transport. This makes resolution and capacity independent of flow rate. Monoliths also lack a void volume. This eliminates eddy dispersion and permits high-resolution separations with extremely short flow paths. The analytical value of these features is the subject of recent reviews. Nowadays, among other types of rigid macroporous monoliths, the polymethacrylate-based materials are the largest and most examined class of these sorbents. In this review, the applications of polymethacrylate-based monolithic columns are summarized for the separation, purification and analysis of low and high molecular mass compounds in the different HPLC formats, including micro- and large-scale HPLC modes.  相似文献   
2.
金振洪  周复正 《激光杂志》1994,15(3):97-101
分析了铝酸镁镧晶体用于半导体激光泵浦的优点,用LDA纵向泵浦Nd:LMA单块固体激光器,得到波长为1.05μm,连续功率为30mW的TEM模激光输出,线偏振度为100%泵浦阈值功率为250mW。  相似文献   
3.
In recent years the use of monolithic polymers in separation science has greatly increased due to the advantages these materials present over particle-based stationary phases, such as their relative ease of preparation and good permeability. For these reasons, these materials present high potential as stationary phases for the separation and purification of large molecules such as proteins, peptides, nucleic acids and cells. An example of this is the wide range of commercial available polymer-based monolithic columns now present in the market.  相似文献   
4.
Nd:LMA自锁模飞秒激光器腔结构最佳化设计   总被引:1,自引:0,他引:1  
赵卫  杨鸿儒 《光子学报》1998,27(12):1098-1101
Nd:LMA晶体相对低的非线性折射率n2,使得针对Ti:Sapphire自锁模激光器设计的腔,对Nd:LMA介质而言并没有提供足够的自幅度调制(SAM).为了在Nd:LMA激光器上实现自锁模,在腔内引入一个具有大的非线性系数n2、快的响应时间的SF57介质,这样就使得激光腔的结构比较特殊.在这篇文章里利用ABCD传输矩阵对该激光器的结构从理论上进行了分析和计算,使腔结构达到了最佳化设计.  相似文献   
5.
Diode-PumpedMonolithicNd:LMALaser¥LUJiang;HUANGZhaoming;JINZhenhong;WANGYangjun(OpticalFiberInstitute,,ShanghaiUniversityofSc...  相似文献   
6.
赵卫  杨鸿儒  王水才 《光学学报》2000,20(7):47-951
描述了用激光二极管抽运的全固体Nd:LMA自锁模飞秒激光振荡器,通过理论计算和分析,在其腔内加入-非线性系数较大的介质,同时对腔结构进行优化设计,实现了自锁模。它直接产生波长为1054nm的激光,输出激光脉冲的宽度达610fs,光谱宽度为2.1nm,输出功率达15mW。  相似文献   
7.
 将一种矩阵算法拓展应用于数值求解多模耦合模微分方程, 并使用该矩阵算法对大模场啁啾光纤光栅的光谱特性进行了理论研究。结果表明, 大模场多模光纤光栅因模式的自耦合和互耦合而使反射谱存在多个反射峰, 这与单模光纤光栅的反射谱不同。由于光栅周期存在啁啾, 大模场光纤光栅的反射峰分裂, 且峰值反射率减小。使用高斯切趾函数可使反射峰分裂在一定程度上得到改善。  相似文献   
8.
杨鸿儒  阎兴隆 《光学学报》1997,17(10):407-1409
报道有一个3W激光二极管端面泵浦Nd:LMA激光器,实验采用三镜折迭像散补偿腔。在1054nm波长,激光器连续输出功率达620mW,斜率效率为50%,光-光转换效率20%,在1083nm波长处,激光器连续输出功率为64mW,斜率效率为6%,光转换效率2.1%。  相似文献   
9.
Mobile users expect a network service, in which seamless handoff occurs while moving on a next generation wireless network. In addition, in smart factories (SFs), communication is required between factory floor and manufacturing zone, as well as connectivity towards office IT, or remote production facilities that are connected via wide area network or internet. For this purpose, interworking between heterogeneous networks is important, but there has been little research on global mobility support. Therefore, this paper proposes Proxy‐LMA technology, a mobile IP‐based global internetworking system, to improve global mobility and interoperability in the SFs network environment. The purpose of the proposed Proxy‐LMA system is to support global mobility by using mobility management protocols such as PMIPv6 and MIPv6 in heterogeneous network environment. As a result of the performance evaluation, Proxy‐LMA system is more efficient than other methods in terms of signaling cost and response delay in heterogeneous network environment. Software‐based networking in SFs enables them to easily adapt the communication network to changing requirements. Similar to cloud‐based systems, such SFs could be seen as production clusters that could be rented and configured as needed. The SF network uses software‐defined networking combined with network functions virtualization, to achieve the required flexibility. Despite the fact that the technology is nowadays not yet ready for deployment in today's manufacturing networks, a novel network architecture for SFs based on software‐defined networking and network virtualization is here proposed, to support smart services, especially for Industrie 4.0.  相似文献   
10.
Adiabatic bend transitions in large mode area multimode fibres were investigated theoretically using the beam propagation method. Adiabatic bend transducers preserve the power of guided light in the fundamental mode while guiding from one level of curvature to another for improved operation of mode filters and fibre amplifiers. A method is shown and used to find the optimised guidance path. Applications of these transducers include modal power back-converters, and guidance paths into and out of higher order mode filtering devices which work on bending.  相似文献   
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