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991.
We report a method for manipulating feature sizes in Si-based grating structures by thermal oxidation, which allows the realization of fin width/period ratios not directly accessible by laser interference lithography. Taking advantage of the expansion in volume associated with the thermal oxidation of Si, grating structures with very high fin width/period ratios of the order of 0.96 were obtained, whereas subsequent chemical etching of the oxide yields grating structures with fin width/period ratios as small as ~0.06. 相似文献
992.
Shorubalko I Leturcq R Pfund A Tyndall D Krischek R Schön S Ensslin K 《Nano letters》2008,8(2):382-385
A highly sensitive charge detector is realized for a quantum dot in an InAs nanowire. We have developed a self-aligned etching process to fabricate in a single step a quantum point contact in a two-dimensional electron gas and a quantum dot in an InAs nanowire. The quantum dot is strongly coupled to the underlying point contact that is used as a charge detector. The addition of one electron to the quantum dot leads to a change of the conductance of the charge detector by typically 20%. The charge sensitivity of the detector is used to measure Coulomb diamonds as well as charging events outside the dot. Charge stability diagrams measured by transport through the quantum dot and charge detection merge perfectly. 相似文献
993.
994.
本文的主要目的是讨论不可压缩粘性流体的Navier-Stokes方程的数值模拟。本文所用的方法是对时间用一阶精度算了分裂离散化,对空间度是用Uzawa方法对L2-投影及H1-投影求解Stokes问题,以及利用类波动方程方法求解平流问题。这两种投影格式都很容易实现。我们利用它们求解经典顶盖驱动方腔流问题直至雷诺数7500都取得了一致结果。当雷诺数处于区间[8575,8590](对应[8600,8625])时,运用L2-投影(对应H1-投影)得到的结果具有时间周期性,这表明Hopf分支的产生。当雷诺数为10000时,存在两个主导频率相互作用。 相似文献
995.
A disodium salt of azotetrazolate (SAZ) has been prepared and characterized by elemental, UV, 13C NMR, FT-IR, and crystallographic analyses. Single crystals of the pentahydrate were grown by slow evaporation of an aqueous solution under reduced pressure. The crystal structure of SAZ has been determined by X-ray diffraction. The crystal lattice is triclinic P1 (no. 2) with lattice parameters a=7.115(1)A, b=7.559(1)A, c=12.025(1)A, alpha=79.75(1) degrees , beta=81.12(1) degrees , gamma=68.16(1) degrees and V=587.97(12)A3. Explosion delay studies have been undertaken using the tube furnace technique. The thermal stability of the compound has been discussed in the light of TG-DSC and explosion delay. 相似文献
996.
Electromagnetic interference shielding properties of carbon nanofiber- and multi-walled carbon nanotube-filled polystyrene composites were investigated in the frequency range of 8.2-12.4 GHz (X-band). It was observed that the shielding effectiveness of composites was frequency independent, and increased with the increase of carbon nanofiber or nanotube loading. At the same filler loading, multi-walled carbon nanotube-filled polystyrene composites exhibited higher shielding effectiveness compared to those filled with carbon nanofibers. In particular, carbon nanotubes were more effective than nanofibers in providing high EMI shielding at low filler loadings. The experimental data showed that the shielding effectiveness of the composite containing 7 wt% carbon nanotubes could reach more than 26 dB, implying that such a composite can be used as a potential electromagnetic interference shielding material. The dominant shielding mechanism of carbon nanotube-filled polystyrene composites was also discussed. 相似文献
997.
Laville E Sayd T Santé-Lhoutellier V Morzel M Labas R Franck M Chambon C Monin G 《Meat science》2005,70(1):167-172
Pig semimembranosus muscles, sampled from normal hams or from PSE-zones of defective hams, were analysed by histochemistry and electrophoretic techniques. PSE zones were characterised by a disorganisation of fibre alignment and a significant increase of inter fibre spacing (26.2% vs. 16.9%, p<0.05). Protein solubility was significantly lower in defective muscle (55.4 vs. 91.5mg/g, p<0.001). SDS-PAGE evidenced in such samples a lower abundance of the 97, 40 and 26kDa bands in the sarcoplasmic fraction and a higher abundance of the 97, 58, 34, 31, 15 and 11kDa bands in the myofibrillar fraction. Intensity of the MHC band (200kDa) was lower in PSE zone samples. By 2-D electrophoresis, it was shown that troponin T, MLC 1 and alpha-crystallin were less proteolysed in defective muscles, while creatine kinase fragments were more represented. One form of HSP 27 was absent from PSE zone samples. Overall, meat from PSE-zones and fast pH fall-PSE meat show numerous histological and biochemical similarities, particularly in their protein characteristics. 相似文献
998.
Niels?H.?StoffersEmail author Matthijs?Dekker Jozef?P.?H.?Linssen Angela?St?rmer Roland?Franz Martinus?A.?J.?S.?van?Boekel 《European Food Research and Technology》2005,220(2):156-162
Nylon 6 and nylon 12 food packaging materials used as sausage casings are typically exposed to fatty food on one side and boiling water on the other during the cooking process. To simulate the migration behaviour under these conditions, a special migration cell was constructed and filled with olive oil on one side of the polymer and water on the other to find out what amounts of the migrants will transfer to either side and phase at 100 °C. Results show that when a nylon 6 film is exposed to the conditions as described above, total mass transfer of the monomer—caprolactam—into the water phase occurs after 2 h at 100 °C. Nylon 12 sausage casings release similar amounts of their monomer—laurolactam—into both the aqueous and oil phase. An existing computer migration model was adapted to simulate the situation of simultaneous two-sided migration applying previously determined diffusion and partitioning coefficients. The suitability of the model was confirmed by experimental data. 相似文献
999.
Hoffmann K Blaudszun J Brunken C Tauber R Höpker WW Steinhart H 《Molecular nutrition & food research》2005,49(8):756-762
The objective of the present study was to examine differences in the fatty acid composition of subcellular fractions from normal and cancerous parts of human testes. The conjugated linoleic acid (CLA) content was significantly higher in total testicular carcinoma (TC), but significantly lower in the mitochondrial fraction of TC in comparison to normal testicular tissue. The subcellular distribution pattern of CLA was similar to that of monounsaturated fatty acids, but different to that of 18:2n-6 (linoleic acid), underlining the different physiological properties of CLA and 18 : 2n-6. Because polyunsaturated fatty acids (PUFAs) have been suggested to have an effect on cancer risk and previous research has found that CLA inhibits the metabolism of 18 : 2n-6 into 20 : 4n-6, the contents of n-6 and n-3 PUFAs were determined. Significant differences were observed for 18 : 2n-6, 18 : 3n-3, 20 : 5n-3, and 22 : 6n-3, with 18 : 2n-6, 18 : 3n-3, and 20 : 5n-3 contents being higher and 22 : 6n-3 content being lower in TC than in normal testicular tissue. These results indicate a changed availability of substrates for the cyclooxygenase (COX) or lipooxygenase (LOX) pathways generating eicosanoids. Although not statistically significant, the reduced content of 20 : 4n-6 shown in this study might be due to an increased metabolism of this fatty acid into eicosanoids. 相似文献
1000.
Protein-protein interactions are crucial for all cellular events. To analyze protein-protein interactions in live mammalian cells, we developed novel protein translocation biosensors composed of glutathione S-transferase, mutants of GFP, and a rational combination of nuclear import and export signals. Nuclear accumulation of the cytoplasmic biosensors served as the reliable indicator, which was induced by the formation of protein complexes and could easily be detected by fluorescence microscopy. The efficacy of the system was systematically investigated by mapping the p53/mdm2 protein interaction interface. Specificity and general applicability of the biosensors were confirmed by studying additional classes of protein interaction domains (IDs), e.g., the leucine zipper IDs of Jun/Fos and the coiled-coil ID of Bcr-Abl in different cell lines. Importantly, we found that, in comparison to protein complementation assays, our system proved highly efficient and reversible and thus suited for the identification of molecular decoys to prevent specific protein-protein interactions in living cells. Reversibility was demonstrated in competition experiments by overexpressing the specific IDs or by the application of a p53/mdm2 protein interaction inhibitor. Thus, besides the convenient mapping of protein IDs in living cells, the modular translocation system has great potential to be employed in numerous cell-based assays for the identification of small-molecule protein interaction inhibitors as potential novel therapeutics. 相似文献