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111.
Shaofeng Wang Jianwei Xu Yuejin Tong Lin Wang Chaobin He 《Polymer International》2005,54(9):1268-1274
A novel cholesterol‐imprinted polymer (CMIP‐H) was prepared by a hybrid method of covalent imprinting and non‐covalent imprinting. This approach involves the copolymerization of a template‐containing monomer, cholesteryl 2‐hydroxyethyl methacrylate carbonate, and a cross‐linker, followed by hydrolysis to afford a flexible guest‐binding site accompanied with the easy and efficient removal of a ‘sacrificial spacer’. The effect of solvent on the binding capacity of CMIP‐H towards cholesterol was studied, indicating that a good binding capacity towards cholesterol could be achieved in a less‐polar solvent. The binding experiments of CMIP‐H towards a series of structural analogues of cholesterol, including cholesterol acetate, progesterone and stigmasterol, were carried out in hexane. The results showed that CMIP‐H almost did not bind cholesterol acetate at all because the hydrogen‐bonding site is blocked. It exhibited a similar binding towards both cholesterol and stigmasterol, but much higher binding towards progesterone. Copyright © 2005 Society of Chemical Industry 相似文献
112.
Zhibin Xiong Haitao Liu Chunxiang Zhu Sin J.K.O. 《Electron Devices, IEEE Transactions on》2005,52(12):2629-2633
In this paper, a new polysilicon CMOS self-aligned double-gate thin-film transistor (SA-DG TFT) technology is proposed and experimentally demonstrated. The self-alignment between the top- and bottom-gate is realized by a backlight exposure technique. The structure has an ultrathin channel region (300 /spl Aring/) and a thick source/drain region. Experimental results show that this technology provides excellent current saturation due to a combination of the effective reduction in the drain field and the full depletion of the ultrathin channel. Moreover, for n-channel devices, the SA-DG TFT has a 4.2 times higher on-current (V/sub gs/=20V) as compared to the conventional single-gate TFT. Whereas for the p-channel devices, the SADG TFT has a 3.6 times higher on-current (V/sub gs/=-20V) compared to the conventional single-gate device. 相似文献
113.
众所周如,西藏地区是研究地球深部结构和构造的窗口,是研究大陆板块学说的重要场所,也是寻找热源和其它矿产资源的有利地区.因此,世界各国地学科学家都希望在本地区进行科学研究工作,或与我国科学工作者协作共同探索这一重要地区.中国和法国的地质、地球物理科学家经商讨共同组成“中法喜马拉雅山地质研究队”,对西藏中部广大地区进行地质、地球物理的科学研究工作.深部地震探测是地球物理研究中的重要内容.中法双方共同决定,在中国西藏南部的日喀则地区至北边的那曲地区作地震探测工作.为了探测地壳上地幔的结构,1981年在西藏的南部佩枯错至普莫雍错500公里的喜马拉雅山北麓——雅鲁藏布江地区进行了人工爆炸地震探测工作.本文是中法地质研究队合作的深部地震探测资料的解释结果. 相似文献
114.
Zirconium(IV) tungstoiodophosphate has been synthesized under a variety of conditions. The most chemically and thermally stable
sample is prepared by adding a mixture of aqueous solutions of 0·5 mol L−1 sodium tungstate, potassium iodate and 1 mol L−1 orthophosphoric acid to aqueous solution of 0·1 mol L−1 zirconium(IV) oxychloride. Its ion exchange capacity for Na+ and K+ was found to be 2·20 and 2·35 meq g−1 dry exchanger, respectively. The material has been characterized on the basis of chemical composition, pH titration, Fourier
transform infrared spectroscopy (FTIR) and thermogravimetric analysis. The effect on the exchange capacity of drying the exchanger
at different temperatures has been studied. The analytical importance of the material has been established by quantitative
separation of Pb2+ from other metal ions. 相似文献
115.
Jonathan P. Belnoue Giang D. Nguyen Alexander M. Korsunsky 《International Journal of Fracture》2007,144(1):53-60
This paper presents a new 1-D non-local damage-plasticity deformation model for ductile materials. It uses the thermodynamic
framework described in Houlsby and Puzrin (2000) and holds, nevertheless, some similarities with Lemaitre’s (1971) approach.
A 1D finite element (FE) model of a bar fixed at one end and loaded in tension at the other end is introduced. This simple
model demonstrates how the approach can be implemented within the finite element framework, and that it is capable of capturing
both the pre-peak hardening and post-peak softening (generally responsible for models instability) due to damage-induced stiffness
and strength reduction characteristic of ductile materials. It is also shown that the approach has further advantages of achieving
some degree of mesh independence, and of being able to capture deformation size effects. Finally, it is illustrated how the
model permits the calculation of essential work of rupture (EWR), i.e. the specific energy per unit cross-sectional area that
is needed to cause tensile failure of a specimen. 相似文献
116.
A photochromic nanocomposite based on Keggin structure phosphomolybdic acid (PMoA) well dispersed in polyethyleneglycol (PEG) was fabricated. TEM image showed that PMoA nanoparticles with narrow size distribution were finely dispersed in polymer matrix. FT-IR results showed that the Keggin geometry of polyoxometalates was still preserved inside the composites and strong coulombic interaction was built between PMoA and polymer matrix. Under UV irradiation, the film was reduced photochemically to yield a blue species, which was in accordance with a charge-transfer mechanism. 相似文献
117.
Yewang Su Baohua Ji Yonggang Huang Kehchih Hwang 《Journal of Materials Science》2007,42(21):8885-8893
Wet adhesion is widely adopted in biological adhesion systems in nature. Wet adhesion is studied in this paper with the focus
on the effect of different contact shapes (flat, concave, convex, and ring-like) on the adhesion force. The evolution of the
liquid bridge between a fiber tip and substrate during the detaching process shows two transition points. The first transition
from the radius-controlled to the contact-angle controlled process is critical to influence the strength and robustness of
adhesion. We show that a concave shape is more effective than a flat one, while a convex shape has no advantage. A ring-like
contact shape has advantages in a hydrophobic environment and on a rough surface. 相似文献
118.
Jinting Jiu Seiji Isoda Motonari Adachi Hao Wang 《Journal of Materials Science: Materials in Electronics》2007,18(6):593-597
Nanocrystalline TiO2 with 3–10 nm in diameter was prepared with a surfactant-template method. Dye-sensitized solar cells were assembled using
the prepared nanocrystalline TiO2 with large surface area and high crystallinity, which achieved significant higher Jsc when compared to cells fabricated with
bigger particles of 25 nm in diameter. In the cells with nanocrystalline TiO2, the sintering temperature drastically affected the conversion performance of the cells. 相似文献
119.
Irine Banu Lucy 《Journal of Materials Science》2007,42(14):5875-5879
Capacitance and dielectric loss measurements were carried out using an Al/Cu–GeO2/Al sandwich structure for 0 to 10 vol% Cu films, 120–400 nm thick, deposited at 0.4–1.5 nm/s in the frequency and temperature
range 1–106 Hz and 90–573 K, respectively. The variation of capacitance and dielectric loss with frequency and temperature follows the
Goswami and Goswami model. Capacitance decreases slowly with increasing thickness and also varies with the change in deposition
rate of the cermet film. 相似文献
120.
The field emission characteristics of an oxidized porous polysilicon (OPPS) were investigated with a Pt/Ti multilayer electrode,
which showed highly efficient and stable electron emission characteristics compared with those of conventional Au/NiCr electrodes.
The thin Ti layer played an important role in promoting the adhesion of Pt to SiO2 surface and the distribution of the electric field on the OPPS surface. Additionally, the Ti layer efficiently blocked the
diffusion of emitter metal, which resulted in more reliable emission characteristics. 相似文献