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当前,我国高等学校的教师队伍存在着各种不合理的结构。这种不合理的结构影响着教学质量的提高。如果不加以重视,不从现在起就采取有效措施,将会产生严重的后果。目前教师队伍的不合理结构,主要表现在:①年龄结构不合理,年龄老化现象比较严重。据去年有关部门统计,全国教授平均年龄为六十五岁,副教授为五十三点三岁,讲师为四十五岁,平均年龄较国外高十至十五岁。②职称比例不合理,高职称比例偏低。 相似文献
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In this paper, a novel surface-enhanced Raman scattering (SERS) sensor combined with fused biconical taper fiber (FBTF) and
film coated with silver sols is proposed. This structure is designed to significantly increase the SERS active surface when
the length of the taper is increased and the radius is reduced, since the penetration depth is inversely proportional to the
taper radius and proportional to the taper length according to the fiber-optic evanescent-wave theory. Based on the SERS sensing
principle, the feasibility of FBTF sensor is analyzed in this paper. As a result, the Raman spectrum of R6G is obtained from
the fused biconical taper zone surface coating with the silver sols in our experiments. The detected concentration is up to
10−7mol/L. 相似文献
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In this paper, we present a simple and fast spectra inversion method to reconstruct the temperature distribution along single
fiber Bragg grating (FBG) temperature sensor. This is a fully distributed sensing method based on the simulated annealing
evolutionary (SAE) algorithm. Several modifications are made to improve the algorithm efficiency, including choosing the most
superior chromosome, setting up the boundary of every gene according to the density of resonance peaks of the reflection spectrum,
and dynamically modifying the boundary with the algorithm running. Numerical simulation results show that both the convergence
rate and the fluctuation are significantly improved. A high spatial temperature resolution of 0.25 mm has been achieved at
the time cost of 86 s. 相似文献
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lintroductionCalculationofthepropagationconstantsofplanardielectricwaveguidescuirentlyusedinintegratedopticsisnecessarytbraccuratelydesigningcomponentssuchasdirectionalcouplersandmodulatol.slll.Solutionforathreelayerslabwaveguideissimpleandwellknownasthel… 相似文献
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A novel quantum dots (QDs) optical fiber amplifier was proposed and demonstrated. It was fabricated by dipcoating the PbSe
QDs doped sol onto the taper region of fiber coupler. The PbSe QDs was synthesized according to a colloidal method. A lower
refractive index sol was also synthesized as the host of PbSe QDs. A standard single mode fiber was used to make the fusion
tapered fiber coupler which had double input and output ports. With the simple structure, a signal and a pump can be injected
into the amplifier and excite the PbSe QDs through evanescent wave. The experimental results indicated that the amplified
light wave was observed at 1 550 nm wavelength with 980 nm wavelength laser diode as pump. 相似文献
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