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861.
Yan-zheng Bai Ze-bing Zhou Hai-bo Tu Shu-chao Wu Lin Cai Li Liu Jun Luo 《Frontiers of Physics in China》2009,4(2):205-208
Low noise position measurement is fundamental for space inertial sensors, and at present the capacitive position sensor is
widely employed for space inertial sensors. The design for the possible suppression of the front-end electric noises for a
capacitive sensor is presented. A prototype capacitive sensor with 2×10−6pF/Hz1/2 at frequency above 0.04 Hz is achieved and further improvements are discussed.
相似文献
862.
Ding Wang Ye Liu Chun‐Yan Hong Cai‐Yuan Pan 《Journal of polymer science. Part A, Polymer chemistry》2005,43(21):5127-5137
Novel hyperbranched poly(amido amine)s containing tertiary amines in the backbones and acryl as terminal groups were synthesized via the Michael addition polymerizations of trifunctional amines with twofold molar diacrylamide. The hyperbranched structures of these poly(amido amine)s were verified by 13C NMR (INVGATE). The polymerization mechanisms were clarified by following the polymerization process with NMR method, and the results show that the reactivity of secondary amine formed in situ is much lower than that of the secondary amine in 1‐(2‐aminoethyl) piperazine (AEPZ) ring and the primary amine. The secondary amine formed in situ was almost kept out of the reaction before the primary and secondary amines in AEPZ were consumed, leading to the formation of the AB2 intermediate, and the further reaction of the AB2 yielded the hyperbranched polymers. The molecular weights and properties of poly(amindo amine)s obtained were characterized by GPC, DSC, and TGA, respectively. Based on the reaction of active acryl groups in the polymers obtained with glucosamine, hyperbranched polymers containing sugar were formed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5127–5137, 2005 相似文献
863.
The unsteady, three-dimensional full Navier-Stokes equations are solved using a Beam-Warming implicit algorithm in this paper. Computations of the flow over a 76° sweep delta wing at 36.5° angle of attack is presented. The sectional streamlines are depicted and the evolution of the instantaneous crossflow topology of the leading-edge vortex is analyzed. It is found that, along the axis, the topology of the primary vortex alters several times starting from stable focus near the apex to unstable focus, and lasts back to stable focus near wake edge; The stable limit cycle and unstable limit cycle are shown in this evolution. These various altering topologies stem from the stretching and compression of the vortex core. 相似文献
864.
865.
Zhong-Min Cai 《Acta Mechanica Solida Sinica》1991,4(1):89-99
In this paper an analytical solution for finite deformation at the simple extension of a hypoelastic cylindrical bar of grade zero under constant velocity is obtained. It is found that the difference between stress-strain curves at different tensile velocities is only due to the inertial terms in the solution. The axial stress due to inertia increases with the square of ratio of tensile velocities. 相似文献
866.
Shuang Cai Taoguang Huo Ning Li Zhili Xiong Famei Li 《Biomedical chromatography : BMC》2009,23(7):782-786
An UPLC/MS/MS based metabonomic method was developed and applied to the elucidation of biomarker of metformin action. The plasma metabolite profiling in healthy volunteers before and after per os metformin was determined with UPLC/MS/MS and analyzed by using multivariate statistics. Significant difference in endogenous metabolite profiles was revealed before and after administration of metformin. Four biomarkers found were lysophosphatidylcholines (LPCs), and their structures were tentatively identified to be 16:0 LPC, 18:0 LPC, 18:1 LPC and 18:2 LPC according to the molecular ions information and corresponding fragments of product ion scan. Lysophosphatidylcholine in blood may be involved in metformin treatment. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
867.
868.
Martin M.F.Choi 《中国化学快报》2009,20(2):210-212
A novel mode-filtered light gas sensor has been reported.It was constructed by inserting an optical fiber deposited by a thin silicone cladding of cryptophane A into a fused-silica capillary.When different concentration of methane gas was introduced to the sensor,the phenomenon that mode-filtered light intensity decreased with the increasing concentration of methane was observed. And a linear relationship was obtained within the methane concentration range of 0.0-16.0%(v/v).The detection limit was 0.06% ... 相似文献
869.
Wen‐Na Zhao Lei Han Cheng‐Cai Luo 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(8):m280-m282
The title novel mixed μ2‐SH‐ and μ3‐SH‐bridged tetranuclear copper(I) complex, cyclo‐bis[μ2‐bis(diphenylphosphino)amine]di‐μ3‐sulfanido‐di‐μ2‐sulfanido‐tetracopper(I) methanol disolvate, [Cu4(SH)4(C24H21NP2)2]·2CH3OH, has crystallographically imposed centrosymmetry and affords a neutral Cu4S4 core with a distorted step‐like structure. The distances of 2.8458 (16) and 2.8179 (16) Å between copper(I) centres indicate the presence of ligand‐supported Cu...Cu interactions. Strong N—H...O and O—H...S hydrogen bonds between the tetranuclear cluster and methanol solvent molecules result in a two‐dimensional hydrogen‐bonded supramolecular network. This complex is the first example of a coinage tetranuclear metal complex with mixed μ2‐SH‐ and μ3‐SH‐bridged chromophores. 相似文献
870.