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101.
102.
T. Luo C. Yu L.-S. Yan S. Kumar Z. Pan A.E. Willner 《Photonics Technology Letters, IEEE》2006,18(15):1606-1608
We demonstrate a simple optical-fiber-based autocorrelator for picosecond short pulses based on degree-of-polarization measurement while tuning the relative delay of the two orthogonal polarization states of the pulse. The pulsewidths of 20-, 40-, and 80-GHz pulse trains and 2-ps pulses generated by a mode-locked laser are measured. The <-10-dBm optical powers are used in the experiment. The measurement results agree well with the measurements using conventional techniques. Compared with conventional autocorrelators, this technique has the advantages of 1) wavelength independent, 2) significant less alignment, and 3) no high power required. 相似文献
103.
广义汉明重量下限函数Lr(j,d)的新证明 总被引:3,自引:0,他引:3
通过几个引理,对广义汉明重量下限函数Lr(j,d)的有限和表达式给出了一个思路简单的证明方法。给出了取整数函数[x],[x]的一些运算性质。 相似文献
104.
Examines the use of magnetic fields to functionally stimulate peripheral nerves. All electric fields are induced via a changing magnetic field whose flux is entirely confined within a closed magnetic circuit. Induced electric fields are simulated using a nonlinear boundary element solver. The induced fields are solved using duality theory. The accuracy of these predictions is verified by saline bath experiments. Next, the theory is applied to the stimulation of nerves using small, partially occluded ferrite and laminated vanadium permendur cores. Experiments demonstrate the successful stimulation of peripheral nerves in the African bullfrog with 11 mA, 153 mV excitations. These results offer a new vista of possibilities in the area of functional nerve stimulation. Unlike functional electric stimulation (FES), FMS does not involve any half cell reactions, and thus would not have the commensurate FES restrictions regarding balanced biphasic stimulation, strength duration balances, and oxidation issues, always exercising care that the electrodes remain in the reversible operating regime 相似文献
105.
106.
Gillespie J.K. Fitch R.C. Sewell J. Dettmer R. Via G.D. Crespo A. Jenkins T.J. Luo B. Mehandru R. Kim J. Ren F. Gila B.P. Onstine A.H. Abernathy C.R. Pearton S.J. 《Electron Device Letters, IEEE》2002,23(9):505-507
The low temperature (100°C) deposition of Sc2O3 or MgO layers is found to significantly increase the output power of AlGaN/GaN HEMTs. At 4 GHz, there was a better than 3 dB increase in output power of 0.5×100 μm2 HEMTs for both types of oxide passivation layers. Both Sc2 O3 and MgO produced larger output power increases at 4 GHz than conventional plasma-enhanced chemical vapor deposited (PECVD) SiNx passivation which typically showed ⩽2 dB increase on the same types of devices. The HEMT gain also in general remained linear over a wider input power range with the Sc2O3 or MgO passivation. These films appear promising for reducing the effects of surface states on the DC and RF performance of AlGaN/GaN HEMTs 相似文献
107.
108.
109.
酶促合成生物柴油反应动力学 总被引:1,自引:0,他引:1
以Candidasp.99-125脂肪酶为催化剂,甘油三油酸酯和甲醇为底物,采用有序机制模型对酶促合成生物柴油的酯交换反应动力学进行了研究,并与经典乒乓机制模型进行了比较。研究结果表明,反应初速率的实验值与有序机制模型方程的计算值吻合很好。对于固定化Candidasp.99-125脂肪酶催化合成生物柴油的酯交换反应机理进行研究,采用有序机制模型比经典乒乓机制模型更为精确。反应过程中,醇抑制为竞争性抑制,在甘油三油酸酯浓度较小的范围内,醇抑制作用较为显著,醇浓度越低反应初速率越快。该有序机制模型可用来预测生物柴油的生产批次或连续反应器中酯交换反应的速率,确定最佳底物油脂和醇的浓度。 相似文献
110.
M Sandoval PR Henry XG Luo RC Littell RD Miles CB Ammerman 《Canadian Metallurgical Quarterly》1998,77(9):1354-1363
Four experiments were conducted to identify several factors that might improve the accuracy and reproducibility of Zn bioavailability assays for chicks. Response of tissue Zn and metallothionein (MT) concentrations to various elevated levels and soluble sources of dietary Zn were measured, as well as the effect of delaying high Zn administration until 7 d posthatching to alleviate the detrimental effect of Zn sulfate on feed intake to 3 wk of age. Bone Zn increased (P < 0.01) in all experiments in response to increasing dietary Zn concentrations. Liver and pancreas MT were affected (P < 0.01) by a source by age interaction and variability that made this criterion unsuitable for bioavailability assays. Lastly, 1-d-old chicks were used to study the effect of delaying feeding of a high-Zn diet up to 7 d of age. The basal diet was fed continuously for 21 d as a control. A diet containing 1,000 ppm Zn was either fed continuously from Day 1, or started on Day 3, 5, or 7. Chicks given high Zn on Day 3, 5, or 7 decreased (P < 0.01) feed intake within 24 h of feeding. Delayed feeding of high dietary Zn might help to alleviate decreased feed intake observed in previous studies. Delaying the onset of high Zn feeding by several days may help alleviate feed intake problems observed with Zn sulfate. Use of either Zn gluconate or Zn acetate as a standard in assays or use of MT synthesis as a bioavailability criterion will probably not be useful to improve accuracy of the estimates. 相似文献