APPLICATION OF THE MODIFIED METHOD OF MULTIPLE SCALES TO THE BENDING PROBLEMS FOR CIRCULAR THIN PLATE AT VERY LARGE DEFLECTION AND THE ASYMPTOTICS OF SOLUTIONS(Ⅱ)

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金属蒸汽中的激光维持爆震波

 应用我们发展的一个激光与金属蒸汽相互作用的简化物理模型对激光维持爆震波的点火激励、传播规律作了数值研究并取得了较好的结果。计算得到的LSD波阈值与激光脉宽的关系表现出典型的幂规律I_th∝τ^-1/2。此外，还得到了一些关于LSD波屏蔽效应的有益结果。在LSD波充分发展的阶段，LSD波阵面的光学厚度可达5~10的量级，这表明LSD波具有很强的屏蔽作用。     

Improved Polysaccharide Production in Submerged Culture of Ganoderma lucidum by the Addition of Coixenolide

Polysaccharides from Ganoderma lucidum have various bioactivities and have been widely used as nutraceuticals and functional foods. Coixenolide was added into the media to enhance the production of mycelia biomass and polysaccharides in the submerged culture of G. lucidum in this work. The results showed that when a level of 0.2 % coixenolide was added at day 1, the biomass, exopolysaccharide, and intracellular polysaccharide reached 5.224, 0.222, and 0.399 g l^?1, respectively, which were 1.39-fold, 2.58-fold, and 2.24-fold compared to that of control. Analysis of the fermentation kinetics of G. lucidum suggested that glucose concentration in the coixenolide-added group decreased more quickly as compared to the control group from days 3 to 9 of the fermentation process, and the polysaccharides biosynthesis were promoted at the same culture period. However, the culture pH profile was not affected by the addition of coixenolide. Enzyme activities analysis indicated that coixenolide affected the synthesis level of phosphoglucose isomerase and α-phosphoglucomutase.     

Preparation and photoluminescence of TiO2/PS composite system

<正>A TiO_2/porous silicon(PS) composite system is prepared by chemical vapor deposition.The crystal form with anatase phase of the samples is evaluated by X-ray diffraction and ultraviolet-visible(UV-vis) absorbance spectra,and the morphology with microsphere of TiO_2 particles is characterized by scanning electron microscopy.The composite system formed by this technique gives a broad blue luminescence and the mechanism of photoluminescence with TiO_2/PS is also discussed.     

Flexible all-biomass gas sensor based on doped carbon quantum dots/nonwoven cotton with discriminative function

Carbon quantum dots (CQDs) co-doped with N, P and S derived from expired milk was prepared by a simple hydrothermal method. By dipping pure cotton face towel (PCFT) into CQDs ink, a flexible all-biomass CQDs/PCFT sensor was prepared for the first time. Due to the heteroatom doping, extremely small particle size of CQDs and excellent permeability of CQDs/PCFT film, the flexible CQDs/PCFT sensor showed the high sensitivity and bending stability. In the range of 0–60° bending states, the responses of CQDs/PCFT sensor to four target analytes changed by less 5.0%. After 3000 bending of 60°, the maximum change of the response to the target analytes was only 6.4%. Interestingly, due to the abundant functional groups and defects of CQDs, the flexible CQDs/PCFT sensor displayed sensing curves of different shapes for different target analytes. In this way, by establishing a database of sensing curves of target analytes, multiple analytes can be detected discriminatively by relying only on single sensor with the help of image recognition. This work provided a reference for the development of cotton fiber based all biomass flexible gas sensor.

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修正多重尺度法在圆薄板大挠度弯曲问题中的应用及其渐近性研究(Ⅰ)

本文应用修正多重尺度法研究圆板在铰链和简单支承条件下的大挠度弯曲。作出其级数解,分析其边界层效应和证明其渐近性。     

APPLICATION OF THE MODIFIED METHOD OF MULTIPLE SCALES TO THE BENDING PROBLEMS FOR CIRCULAR THIN PLATE AT VERY LARGE DEFLECTION ANDTHE ASYMPTOTICS OF SOLUTIONS (Ⅰ)

I.IntroductionThestudyorbendingproblemsforcircularthinplatewithlargedeflectionhasalonghistoryandalotofresearchhasbeendoned~41.Especially,aftertheappearanceoftheChienWeizangmethodthatusestheratioofthecenterdeflectiontothethicknessofP-l'Llteasperturbationparameter,theapplicationofperturbationmethodstothestudyofthebendingproblemsofplatesandshellsbecomesmoreandmorepopular,owingtothet'actthatonlybyusingregularperturbationmethodonecanfinditssufficientlycorrectsolution.OneweaknessinChienWeizangmet…     

THE BOUNDARY VALUE PROBLEMS FOR QUASILINEAR HIGHER ORDER ELLIPTIC EQUATIONS WITH A SMALL PARAMETER

In this paper we deal with the general boundary value problems for quasilinear higherorder elliptic equations with a small parameter before higher derivatives.By using themethod of multiple scales,we have proved that if the solution of degenerated boundary valueproblem exists,then under certain assumptions as the small parameter is sufficiently small,the solution of the origional boundary value problem exists as well and it is unique in a certainfunction space.Besides,the asymptotic expansion of the solution has been constructed.     

4.0-4.5-mum lasing of Fe:ZnSe below 180 K, a new mid-infrared laser material

Lasing of Fe:ZnSe is demonstrated, for the first time to the authors' knowledge, for temperatures ranging from 15 to 180 K. The output wavelength of the Fe:ZnSe laser was observed to tune with temperature from 3.98mum at 15 K to 4.54mum at 180 K. With an Er:YAG laser operating at 2.698mum as the pump source, a maximum energy per pulse of 12muJ at 130 K was produced. Laser slope efficiencies of 3.2% at 19 K and 8.2% at 150 K were determined for an output coupling of 0.6%. A laser emission linewidth of 0.007mum at 3.98mum was measured at 15 K. Absorption and emission spectra and emission lifetimes for Fe:ZnSe are also discussed.     

多重尺度法在圆薄板大挠度弯曲问题中的应用及其渐近性研究(Ⅱ)

本文是第(Ⅰ)部分的继续,研究(Ⅰ)中级数解的渐近性质.求得了级数解的余项按最大模的估计.