排序方式: 共有74条查询结果,搜索用时 156 毫秒
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石墨电极直接电氧化合成D-阿拉伯糖 总被引:1,自引:0,他引:1
本文报道采用石墨电极直接电氧化D_葡萄糖酸钠(NaGL)合成D_阿拉伯糖研究结果.研究了葡萄糖酸钠浓度、电解电压、温度及电解液组成对电流效率和合成产率的影响。同时指出采用液体电解池进行恒电位电解,其效果比恒电流电解法更好 相似文献
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寻找新光源, 特别是企图利用PXR作为激光光源引起了人们广泛关注。 要成功获得相干(衍射)的PXR光源, 粒子的运动必须是稳定的。 但是由于晶体弯曲,系统可能变得不稳定, 从而对PXR的反射、 衍射、 聚焦和谱分布均会产生直接影响。 在经典力学框架内和偶极近似下, 引入正弦平方势, 把粒子在弯晶中的运动方程化为具有常数力矩的摆方程。 利用Jacobian椭圆函数和椭圆积分分析了系统的相平面特征。 结果表明, 系统的稳定性与弯晶“曲率”Q有关, 当条件0≤Q<1满足时, 系统是稳定的。 An exploration of a new light source by PXR as Laser gived rise to extensive attention. The particle motion must be stable in order to obtain coherent PXR source. But, an instability of system is possible due to the effect of bent crystal, thus the reflection, the diffraction, the focus and the spectral distribution of PXR will be effected.In the classical mechanics frame and dipole approximation the particle motion equation in bent crystal is reduced to the pendulum equation with a constant momentum by the sine squared potential.The phase planar properties are analysed by means of Jacobian elliptic function and the elliptic integral. It shows that the stability of the system is related to the curvature Q of the bent crystal. When the condition 0≤Q<1 is satisfied, the system is stable。 相似文献
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针对超声成像逐点聚焦延时参数容量大、工程实现困难的问题,提出一种基于相对声程差的高精度逐点聚焦实现方法。该方法对逐点聚焦延时参数进行分解,压缩存储,并在逐点聚焦过程中实时解压生成聚焦延时参数,用于高精度的逐点聚焦中。为了验证该方法,本文以128阵元16通道的凸阵探头为例,进行了相关的数学推导和证明。在此基础上,给出了基于FPGA(Field Programmable Gate Array)的高精度逐点聚焦模块的硬件实现原理框图,并对该逐点聚焦方法的性能进行了分析讨论,验证了该方法的优越性。 相似文献
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Ultrathin Fe films were epitaxially grown on Si(lll) by using an ultrathin iron silicide film with p(2 × 2) surface reconstruction as a template. The surface structure and magnetic properties were investigated in situ by low energy electron diffraction (LEED), scanning tunnelling microscopy (STM), and surface magneto-optical effect (SMOKE). Polar SMOKE hysteresis loops demonstrate that the Fe ultrathin films with thickness t 〈 6 ML (monolayers) exhibit perpen-dicular magnetic anisotropy. The characters of M-H loops with the external magnetic field at difference angles and the angular dependence of coercivity suggest that the domain-wall pinning plays a dominant role in the magnetization reversal process.[第一段] 相似文献
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蛋白质微阵列芯片技术及其在抗体筛选中的应用 总被引:3,自引:0,他引:3
以兔IgG为模式蛋白质,对其在醛基修饰玻片表面的固定浓度、固定时间和温度等条件进行了优化,结果表明:在室温下,当固定蛋白质的浓度为1g/L、固定时间为4h时,可获得理想的蛋白质固定效果;蛋白质的定量检测范围为1μg/L~10mg/L。按优化的蛋白质微阵列芯片制作条件将规模化制备的抗体制作成抗体微阵列芯片,通过与荧光标记的人球蛋白和人白蛋白的相互作用,实现了对不同抗体株抗球蛋白和抗白蛋白活性的快速筛选与比较。 相似文献
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Near-Infrared Emission from Organic Light-Emitting Diodes Based on Copper Phthalocyanine with a Periodically Arranged Alq3:CuPc/DCM Multilayer Structure 下载免费PDF全文
We demonstrate near-infrared organic light-emitting devices with a periodically arranged tris(8-quinolinolato)aluminum (Alq3):copper phthalocyanine (CuPc)/4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminost-yry)-4H-pyran (DCM) multilayer structure. DCM and Alq3 doped with CuPc were periodically deposited. Room-temperature electrophosphorescence was observed at about 1.1 μm due to transitions from the first excited triplet state to the singlet ground state (T1 - S0) of CuPc. In this device, we utilize the overlap between the Q band πr - π^* at about 625nm of the absorption spectra of CuPc and the PL spectra of the DCM. The near-infrared emission intensity of the CuPc-doped Alq3 device with DCM increases about 2.5 times larger than that of the device without DCM. We attribute the efficiency enhancement to the better overlap between the PL spectra of DCM and the absorption spectra of CuPc. 相似文献