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抑制硅转移的制浆工艺及机理研究 被引量:9
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作者 徐永建 蒲文娟 +1 位作者 张美云 刘振华 《中国造纸学报》 CAS CSCD 2007年第4期36-39,共4页
对氧化铝抑制硅转移的烧碱-蒽醌法制浆工艺进行了研究,对其机理也进行了初步探讨。研究发现,当氧化铝用量超过3%时,对二氧化硅的转移具有显著的抑制作用,明显地提高了纸浆纤维的灰分及二氧化硅含量。氧化铝抑制硅转移机理的初步研究发现... 对氧化铝抑制硅转移的烧碱-蒽醌法制浆工艺进行了研究,对其机理也进行了初步探讨。研究发现,当氧化铝用量超过3%时,对二氧化硅的转移具有显著的抑制作用,明显地提高了纸浆纤维的灰分及二氧化硅含量。氧化铝抑制硅转移机理的初步研究发现,添加氧化铝后连接表皮细胞的硅细胞依然存在,导致大量硅留着在纸浆中,也可能是生成了某些不溶于碱的矿物质而导致纸浆灰分和硅含量增加,关于抑制硅转移的机理问题仍需深入研究。 展开更多
关键词 硅转移 氧化铝 氢氧化铝
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多孔硅外延转移技术制备以氮化硅为绝缘埋层的SOI新结构 被引量:2
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作者 谢欣云 刘卫丽 +3 位作者 门传玲 林青 沈勤我 林成鲁 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第2期189-193,共5页
为减少自加热效应 ,利用多孔硅外延转移技术成功地制备出一种以氮化硅为埋层的 SOI新结构 .高分辨率透射电镜和扩展电阻测试结果表明得到的 SOI新结构具有很好的结构和电学性能 ,退火后的氮化硅埋层为非晶结构 .
关键词 绝缘埋层 氮化薄膜 SOI结构 多孔外延转移
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CpRu(PPh_3)_2SSi^iPr_3与SCNR(R=Ph,1-Naphthyl)反应的结构、成键与机理的理论研究 被引量:4
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作者 丁养军 张振伟 +1 位作者 朱树芬 毕思玮 《化学学报》 SCIE CAS CSCD 北大核心 2007年第10期943-949,共7页
应用密度泛函理论(DFT),通过CpRu(PH3)2SSiiPr3(Cp=环戊二烯负离子;iPr=异丙基)与SCNH模型化反应,探讨了CpRu(PPh3)2SSiiPr3与SCNR(R=苯基,萘基)的反应机理,分析了反应所涉及的各相关化合物的结构与成键特征.反应中首先失去一个膦配体,... 应用密度泛函理论(DFT),通过CpRu(PH3)2SSiiPr3(Cp=环戊二烯负离子;iPr=异丙基)与SCNH模型化反应,探讨了CpRu(PPh3)2SSiiPr3与SCNR(R=苯基,萘基)的反应机理,分析了反应所涉及的各相关化合物的结构与成键特征.反应中首先失去一个膦配体,生成一个中间体.该中间体中,硫原子采取sp2杂化,硫原子剩余的一个p轨道与金属中心上的d轨道具有相同的对称性,因而该p轨道上的孤电子对可与金属中心上的d轨道形成π键,导致Cp环中心,Ru,S1,P和Si原子在同一平面内,而不是S1,P和Si原子偏离该平面.计算结果预测,S=C双键中的π键打开,生成含金属中心的四元环螯合物一步为反应的决速步骤.空间位阻的减小、π共轭体系的生成以及螯合环的存在,是导致该反应热力学有利的重要原因. 展开更多
关键词 密度泛函理论 反应机理 钉配合物 烷基转移
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A Novel Sub-50nm Poly-Si Gate Patterning Technology
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作者 张盛东 韩汝琦 +3 位作者 刘晓彦 关旭东 李婷 张大成 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第5期565-568,共4页
A novel low-cost sub-50nm poly-Si gate patterning technology is proposed and experimentally demonstrated.The technology is resolution-independent,ie.,it does not contain any critical photolithographic steps.The nano-s... A novel low-cost sub-50nm poly-Si gate patterning technology is proposed and experimentally demonstrated.The technology is resolution-independent,ie.,it does not contain any critical photolithographic steps.The nano-scale masking pattern for gate formation is formed according to the image transfer of an edge-defined spacer.Experimental results reveal that the resultant gate length,about 75 to 85 percent of the thickness,is determined by the thickness of the film to form the spacer.From SEM photograph,the cross-section of the poly-Si gate is seen to be an inverted-trapezoid,which is useful to reduce the gate resistance. 展开更多
关键词 poly-Si gate sub-50nm image transfer LITHOGRAPHY
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Properties of Novel Reactive Transfer Printing of Silk 被引量:3
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《Journal of Donghua University(English Edition)》 EI CAS 2013年第6期514-520,共7页
The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted... The novel reactive transfer printing of silk was carried out through a hot-press adhesion and steaming. The special transfer paper was prepared by coating the paste mainly containing hot-melt adhesive hlgh-substituted hydroxypropyl cellulose (H-HPC) and printing thickener earboxymethyl cellulose (CMC). The effects of each ingredient in the paste on color yield of the prints and dye penetration were investigated. The major results indicate that, color yield is chiefly governed by the adhesion extent imparted by H-HPC, the type of fixing alkaline agent, and the content of urea. Trichloroacetic acid (TCAA) as the fixing alkaline agent and adding 5% urea can enhance the color depth obviously. Dye penetration depends on the coating quantity on the transfer paper, the contents of urea and dicyandiamide. The printed silk possesses a higher color yield, color fastness of grade 3 or above, clear sharpness, and good handle when the paste contains 3 % H-HPC, 0. 7 % CMC, 3 % TCAA, 5 % urea, 3 % dicyandiamide, and 0. 5 % physical sorbent nano-silica. 展开更多
关键词 transfer printing transfer paper SILK reactive dye high- substituted hydroxypropyl cellulose H - HPC trichloroacetic acid TCAA
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Collision-induced Rotational Energy Transfer in an Atom-Diatom System
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作者 Yan-qing Ni Jian Li Feng-cai Ma 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2008年第5期457-462,共6页
As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, based on the first-Born approximation of time-dependent perturbation theory, taking ... As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, based on the first-Born approximation of time-dependent perturbation theory, taking into account the anisotropic Lennard-Jones interaction potential and the long-range interaction potential, the differential interference angles in singlet-triplet mixed states of CO A^1Π(v=9)-e3∑-(v=1) system in collision with He, Ne, Ar, and other partners were calculated theoretically. The relationships of differential interference angle versus impact parameters, including collision parameter b and velocity, are obtained. 展开更多
关键词 Rotational energy transfer Collision-induced quantum interference Interference angle
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The Limit of Rotational Energy Transfer in Atom-Diatom Collision and the Hard Ellipsoid Potential Model
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作者 Dharmendra Singh Flrozla 《Journal of Chemistry and Chemical Engineering》 2014年第2期180-186,共7页
The limit of rotational energy transfer in atom-diatomic systems due to inelastic collision was investigated over the wide range of collision energy, reduced mass and potential parameters of F2-He system. The IICS (i... The limit of rotational energy transfer in atom-diatomic systems due to inelastic collision was investigated over the wide range of collision energy, reduced mass and potential parameters of F2-He system. The IICS (integral inelastic cross-sections) is obtained by the IOSAM (infinite order sudden approximation method) and predicted by PG (power-gap) law in the variation of cross-sections. The investigation provided that the classical limit of angular momentum transfer is given by hard ellipsoid potential is meaningful even the cross-sections computed on the real potential, provided the classical turning point on the surface of soft potential is assumed as hard potential surface. 展开更多
关键词 Diatomic collision with inert gas atom inelastic scattering rotational energy transfer.
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Adsorption and Transfer Properties for Toluene and pDichlorobenzene in Dense CO_2/Silica Gel Packed Bed System by Moment Method and Time-Domain Analysis
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作者 杨晓宁 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第3期280-288,共9页
Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficie... Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated. 展开更多
关键词 supercritical CO2 ADSORPTION CHROMATOGRAPHY moment method time-domain analysis
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草类及竹类原料中硅的含量及分布 被引量:5
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作者 徐永建 唐凌云 +2 位作者 朱振峰 田勇 张鼎军 《纸和造纸》 北大核心 2011年第11期42-44,共3页
介绍草类和竹类原料中的硅含量及其分布情况,以及硅在预处理过程中的转移规律。草类原料的硅含量明显高于竹材原料硅含量,稻草中的硅主要集中在叶片和叶鞘中,麦草中的硅主要集中在穗、节和秆中,而竹材中的硅主要集中在外表皮层中。硅在... 介绍草类和竹类原料中的硅含量及其分布情况,以及硅在预处理过程中的转移规律。草类原料的硅含量明显高于竹材原料硅含量,稻草中的硅主要集中在叶片和叶鞘中,麦草中的硅主要集中在穗、节和秆中,而竹材中的硅主要集中在外表皮层中。硅在植物体中的分布情况及存在状态对制浆过程中硅的转移率有重要影响,竹类原料80%~90%的硅溶出转移到黑液中,而草类原料硅的溶出率只有60%~70%。 展开更多
关键词 非木材原料 含量 分布 硅转移
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Synthesis of ZSM-5 with the silica source from industrial hexafluorosilicic acid as transalkylation catalyst 被引量:1
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作者 Fang Jin Xianqiao Wang +3 位作者 Tieliang Liu Linbo Xiao Ming Yuan Yangchun Fan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第9期1303-1313,共11页
A new effective process to improve the utilization of industrial fluorosilicic acid of phosphate fertilizer by-product has been investigated to comprehensive application of the silicon and fluorine source. Two-step am... A new effective process to improve the utilization of industrial fluorosilicic acid of phosphate fertilizer by-product has been investigated to comprehensive application of the silicon and fluorine source. Two-step ammoniation was applied to recover high-quality silica. The recovered silica can be used to hydrothermal synthesize ZSM-5 zeolite without impurity phase contamination, which was confirmed by XRD, TG, SEM, BET and EDS characteristic techniques. It was found that with the increase of SiO_2/Al_2O_3 ratio and the extension of reaction time, the crystal type transform from the orthorhombic to the monoclinic phase. The impurity fluorine content of the recovered SiO_2 from H_2SiF_6 has great influence on the hydrothermal process for ZSM-5 crystal structure formation.Moreover, the increase of fluorine ions content in the hydrothermal process can control the crystal morphology and size of synthesized ZSM-5. Catalytic properties of synthesized HZSM-5 with different SiO_2/Al_2O_3 ratio in transalkylation of toluene and 1,2,4-trimethylbenzene show good and stable catalytic performance. The ZSM-5 synthesized with recovered silica source exhibits similar catalyst life as the performance of small particle size HZSM-5, because the ZSM-5 synthesized with the silica source from industrial hexafluorosilicic acid prefers a thin disk crystal along the b axis direction, which shortens the diffusion distance of generated products. 展开更多
关键词 Hexafluorosilicic acid Silica Hydrothermal synthesis ZSM-5 zeolite Transalkylation
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SOIM新结构的制备及其性能的研究 被引量:2
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作者 谢欣云 林青 +3 位作者 门传玲 刘卫丽 徐安怀 林成鲁 《物理学报》 SCIE EI CAS CSCD 北大核心 2003年第1期207-210,共4页
制备在以SiO2 为绝缘埋层的SOI材料上的电子器件存在着自加热问题 .为减少自加热效应和满足一些特殊器件 电路的要求 ,利用多孔硅外延转移技术制备出以二氧化硅和氮化硅为多绝缘埋层的SOI新结构 .高分辨率透射电镜和扩展电阻测试结果... 制备在以SiO2 为绝缘埋层的SOI材料上的电子器件存在着自加热问题 .为减少自加热效应和满足一些特殊器件 电路的要求 ,利用多孔硅外延转移技术制备出以二氧化硅和氮化硅为多绝缘埋层的SOI新结构 .高分辨率透射电镜和扩展电阻测试结果表明得到的SOIM新结构具有很好的结构和电学性能 ,退火后的氮化硅埋层为非晶结构 . 展开更多
关键词 制备 氮化薄膜 二氧化薄膜 SOIM新结构 多孔外延转移 电绝缘隔离性能
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Preparation of poly (N-isopropylacrylamide) brush bonded on silicon substrate and its water-based lubricating property 被引量:10
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作者 LIU YuHong XIAO YuQi LUO JianBin 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第12期3352-3358,共7页
The poly (N-isopropylacrylamide) brush was covalently bonded on an initiator-coated silicon wafer via surface-initiated atom transfer radical polymerization. The polymer brush was (76.2±0.1) nm in thickness (by e... The poly (N-isopropylacrylamide) brush was covalently bonded on an initiator-coated silicon wafer via surface-initiated atom transfer radical polymerization. The polymer brush was (76.2±0.1) nm in thickness (by ellipsometer) with a grafting density of ca. 0.27 chains/nm 2 . The tribological properties of the poly (N-isopropylacrylamide) brush were investigated by means of ball-on-disk tests in a rotational mode under water lubrication for tribological application. The experimental results exhibited a low friction coefficient of ca. 0.03. The excellent lubrication property of the brush was due to its amide groups in the polymer chains. It was supposed that the good lubrication property of the brush was attributed to the cross-linked polymer network formed by the hydrogen bond association of N-H…O==C and the water molecular layer adsorbed by the terminal amide groups in the brush. The poly (N-isopropylacrylamide) solution also exhibits a lubrication property due to physical adsorption of the polymer chains. 展开更多
关键词 poly(N-isopropylacrylamide) brush surface-initiated atom transfer radical polymerization water-based lubricatingproperties
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Colourimetric redox-polyaniline nanoindicator for in situ vesicular trafficking of intracellular transport 被引量:2
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作者 Eun Bi Choi Jihye Choi +9 位作者 Seo Ryung Bae Hyun-Ouk Kim EunjiJang Byunghoon Kang Myeong-Hoon Kim Byeongyoon Kim Jin-Suck Suh Kwangyeol Lee Yong-Min Huh Seungjoo Haam 《Nano Research》 SCIE EI CAS CSCD 2015年第4期1169-1179,共11页
Vesicular pH modulates the function of many organelles and plays a pivotal role in cell metabolism processes such as proliferation and apoptosis. Here, we introduce a simple colorimetric redox-polyaniline nanoindicato... Vesicular pH modulates the function of many organelles and plays a pivotal role in cell metabolism processes such as proliferation and apoptosis. Here, we introduce a simple colorimetric redox-polyaniline nanoindicator, which can detect and quantify a broader biogenic pH range with superior sensitivity compared to pre-established trafficking agents employing one-dimensional turn-on of the fluorescence resonance-energy-transfer (FRET) signal. We fabricated polyaniline- based nanoprobes, which exhibited convertible transition states according to the proton levels, as an in situ indicator of vesicular transport pH. Silica-coated Fe304-MnO heterometal nanoparticles were synthesised and utilised as a metal oxidant to polymerise the aniline monomer. Finally, silica-coated polyaniline nanoparticles with adsorbed cyanine dye fluorophores Cy3 and Cy7 (FPSNIcyB and FPSNIcy7) were fabricated as proton-sensitive nanoindicators. Owing to the selective quenching induced by the local pH variations of vesicular transport, FPSNIcy3 and FPSNIcy7 demonstrated excellent intracellular trafficking and provided sensitive optical indication of minute proton levels. 展开更多
关键词 redox PH intraceUular compartments organic quencher conducting polymer nanoindicator
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