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| 1 | Enzymatic activity and chromatographic characteristics of the cell membrane immobilized on silica surface显示文摘A new cell membrane preparation, silica carrier cell membrane (CCM), has been presented, in which cell membrane was immobilized on silica which acted as carrier by the adsorption. The surface characteristics of the silica CCM have been tested by a scanning electron microscope and surface energy spectrometer. Comparison has been made of the changeable rule of enzymatic activity of rabbit red cell membrane in three states: the silica CCM, the suspension and the precipitation cell membranes, with temperature and time. The result showed that the silica CCM still keeps the same enzymatic activity as the other two states of cell membranes. The interactions between calcium antagonists and rabbit red and cardiac muscle cell membranes, and the stereoscopic interactions between dihydropridines and rabbit cerebellar cell membrane have been investigated by the chromatographic system of the silica CCM as a stationary phase. From the foregoing results, the chromatographic parameters obtained from the system would | Langchong He Guangde Yang Xindu Geng | 1999 | Chinese Science Bulletin1999,44,9: | 58 |
| 2 | SiO2气凝胶常压干燥工艺与隔热应用进展显示文摘综述了SiO2气凝胶常压制备技术及其复合隔热材料的最新研究进展。着重介绍了提高凝胶网络基架强度、添加干燥控制化学添加剂、表面改性、降低毛细管力等几种SiO2气凝胶常压干燥工艺,并回顾了几种SiO2气凝胶复合隔热材料的应用现状。 | 陈晓红 胡子君 宋怀河 王非 | 2010 | 宇航材料工艺2010,,6: | 18 |
| 3 | Rattle-Type Silica Colloidal Particles Prepared by a Surface- Protected Etching Process显示文摘This paper explores the capability of the“surface-protected etching”process for the creation of rattle-type SiO_(2)@void@SiO_(2) colloidal structures featuring a mesoporous silica shell and a mesoporous movable silica core.The surface-protected etching process involves stabilization of the particle surface using a polymer ligand,and then selective etching of the interior to form hollow structures.In this paper,this strategy has been extended to the formation of rattle-like structures by etching SiO_(2)@SiO_(2) core shell particles which are synthesized by a two-step sol gel process.The key is to introduce a protecting polymer of polyvinylpyrrolidone(PVP)to the surface of both core and shell in order to tailor their relative stability against chemical etching.Upon reacting with NaOH,the outer layer silica becomes a hollow shell as only the surface layer is protected by PVP and the interior is removed,while the core remains its original size thanks to the protection of PVP on its surface.This process can be carried out at room temperature without the need of additional templates or complicated heterogeneous coating procedures.The etching process also results in the rattle-type colloids having mesoscale pores with two distinct average sizes.In our demonstration of a model drug delivery process,such mesoporous structures show an interesting two-step elution profile which is believed to be related to the unique porous rattle structures. | Qiao Zhang Jianping Ge James Goebl Yongxing Hu Zhenda Lu Yadong Yin | 2009 | Nano Research2009,2,7: | 18 |
| 4 | Characteristics of thermally-enhanced bentonite grouts for geothermal heat exchanger in South Korea显示文摘The thermal conductivity and viscosity of bentonite grouts have been evaluated and compared each other to determine the suitability of these materials for backfilling vertical boreholes of ground heat exchangers.Seven bentonite grouts from different product sources were considered in this paper.Two additives,silica sand and graphite were added in bentonite grouts to enhance thermal performance.The bentonite grouts indicate that both the thermal conductivity and the viscosity increase with the content of silica sand and graphite.Therefore,it is recommended to select cautiously the amount of silica sand and graphite considering not only thermal conductivity but also viscosity for the optimum condition of backfilling.Finally,the effect of salinity in the pore water on the change of swelling potential of the bentonite-based grouts has been quantitatively evaluated to show the feasibility of bentonite grouts in the coastal area. | Chulho LEE Kangja LEE Hangseok CHOI Hyo-Pum CHOI | 2010 | Science China(Technological Sciences)2010,53,1: | 16 |
| 5 | Ultralow-loss geometric phase and polarization shaping by ultrafast laser writing in silica glass显示文摘Polarization and geometric phase shaping via a space-variant anisotropy has attracted considerable interest for fabrication of flat optical elements and generation of vector beams with applications in various areas of science and technology.Among the methods for anisotropy patterning,imprinting of self-assembled nanograting structures in silica glass by femtosecond laser writing is promising for the fabrication of space-variant birefringent optics with high thermal and chemical durability and high optical damage threshold.However,a drawback is the optical loss due to the light scattering by nanograting structures,which has limited the application.Here,we report a new type of ultrafast laser-induced modification in silica glass,which consists of randomly distributed nanopores elongated in the direction perpendicular to the polarization,providing controllable birefringent structures with transmittance as high as 99% in the visible and near-infrared ranges and >90% in the UV range down to 330 nm.The observed anisotropic nanoporous silica structures are fundamentally different from the femtosecond laser-induced nanogratings and conventional nanoporous silica.A mechanism of nanocavitation via interstitial oxygen generation mediated by multiphoton and avanlanche defect ionization is proposed.We demonstrate ultralow-loss geometrical phase optical elements,including geometrical phase prism and lens,and a vector beam convertor in silica glass. | Masaaki Sakakura Yuhao Lei Lei Wang Yan-Hao Yu Peter G.Kazansky | 2020 | Light(Science & Applications)2020,9,1: | 14 |
| 6 | Ablation and radar-wave transmission performances of the nitride ceramic matrix composites显示文摘The 2.5 dimensional silica fiber reinforced nitride matrix composites (2.5D SiO2f/Si3N4-BN) were prepared through the preceramic polymer impregnation pyro- lysis (PIP) method. The ablation and radar-wave transparent performances of the composite at high temperature were evaluated under arc jet. The composition and ablation surface microstructures were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the 2.5D SiO2f/Si3N4-BN composites have a linear ablation rate of 0.33 mm/s and high radar-wave trans- parent ratio of 98.6%. The fused layer and the matrix are protected by each other, and no fused layer accumulates on the ablation surface. The nitride composite is a high-temperature ablation resistivity and microwave transparent material. | JIANG YongGang ZHANG ChangRui CAO Feng WANG SiQing HU HaiFeng QI GongJin | 2008 | Science China(Technological Sciences)2008,51,1: | 14 |
| 7 | Adsorption properties of nitrobenzene in wastewater with silica aerogels显示文摘The adsorption properties of nitrobenzene from wastewater by hydrophobic silica aerogels were investigated.The effects of adsorption intensity by pH value,adsorption temperature,adsorption time and the amount of the silica aerogels were studied.The adsorption principle and mechanism of silica aerogels adsorbing nitrobenzene were discussed along with the Freundlich equation.The results showed that the adsorption intensity of the hydrophobic silica aerogels could reach 68.76% at better adsorption conditions of adsorption temperature 25°C,pH value 8.35,the amount of SiO2 aerogels dosage 3.33 g/L,and adsorption time of 30 min,and that the adsorption properties were related to the hydrophobility of aerogels,surface area of organic solution,structure of aerogels. | CUI Sheng1,LIU XueYong2,LIU Yu2,SHEN XiaoDong1,LIN BenLan1,3,HAN GuiFang1 & WU ZhanWu1 1 College of Material Science and Engineering,Nanjing University of Technology,Nanjing 210009,China 2 Institute of Chemical Materials,CAEP,Mianyang 621900,China 3 Editorial Board of Journal,Nanjing University of Technology,Nanjing 210009,China | 2010 | Science China(Technological Sciences)2010,53,9: | 13 |
| 8 | 硅胶催化双氧水甲酸氧化噻吩类化合物的研究显示文摘Thiophene (C4H4S) and 3-methylthiophene(3-MC4H4S) are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking (FCC) gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide (H2O2) and formic acid system over a series of silica gel loaded with metal oxide. The silica gel loaded with copper and cobalt (1:1) oxide was found very active for the model compound oxidation using H2O2/formic acid, while the silica gel unloaded with metal oxide was less active. The sulfur removal rate of thiophenes was different as solvent was changed. And the conversation of C4H4S and 3-MC4H4S was improved at higher temperature,but reduced when olefin was added. The sulfur removal rate of model sulfur compounds was enhanced when the phase transfer catalyst emulsifier polyethylene glycol octyl phenyl ether or tetrabutylammonium bromide(TBAB)in a H2O2 and formic acid system with the addition of TBAB, a bromine substitution trend appeared in the oxidation of thiophenes, suggesting the influence of TBAB. | 陈兰菊 郭绍辉 赵地顺 | 2006 | Chinese Journal of Chemical Engineering2006,14,6: | 12 |
| 9 | Hybrids perfluorosulfonic acid ionomer and silicon oxide membrane for application in ion-exchange polymer-metal composite actuators显示文摘This paper reports a new technique to fabricate an ion-exchange polymer-metal composite (IPMC) actuator. This technique is based on a hybrid organic-inorganic composite membrane. In the fabrication course, silica oxide particles, prepared from hydrolysis of tetraethyl orthosilicate in situ with sol-gel reaction, co-crystallize with perfluorosulfonate acid (PFSA) ionomer. Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) analyses demonstrate that a highly water-saving hybrid membrane is formed. Measurements of mechanical properties reveal that elastic modulus and hardness of the hybrid membrane are about 2 times compared to a commercial PFSA membrane. Scanning electron microscopy (SEM) results show that the hybrid membrane has a high porosity. Inside the membrane pores, there exists a great quantity of micro scale channels in the range of 100―300 nm. After fabrication of IPMC actuator, an electric current sensor, a force sensor, and a high speed camera are assembled and used to evaluate IPMC performance. It is shown that, compared to an IPMC actuator made from a commercial membrane, the electromechanical performance of the new actuator increases 6―8 times; when it is actuated in air, its stable non-water working time is prolonged for 6―7 times. | GUO DongJie DING HaiTao WEI HaiJu HE QingSong YU Min DAI ZhenDong | 2009 | Science China(Technological Sciences)2009,52,10: | 10 |
| 10 | Silica coating onto graphene for improving thermal conductivity and electrical insulation of graphene/polydimethylsiloxane nanocomposites显示文摘Graphene possess extremely high thermal conductivity, and they have been regarded as prominent candidates to be used in thermal management of electronic devices. However, addition of graphene inevitably causes dramatic decrease in electrical insulation, which is generally unacceptable for thermal interface materials(TIMs) in real electronic industry. Developing graphene-based nanocomposites with high thermal conductivity and satisfactory electrical insulation is still a challenging issue. In this study,we developed a novel hybrid nanocomposite by incorporating silica-coated graphene nanoplatelets(Silica@GNPs) with polydimethylsiloxane(PDMS) matrix. The obtained Silica@GNP/PDMS composites showed satisfactory electrical insulation(electrical resistivity of over 10^(13)Ωcm) and high thermal conductivity of 0.497 W m-1K-1, increasing by 155% compared with that of neat PDMS, even higher than that of GNP/PDMS composites. Such high thermal conductivity and satisfactory electrical insulation is mainly attributed to the insulating silica-coating, good compatibility between components, strong interfacial bonding, uniform dispersion, and high-efficiency heat transport pathways. There is great potential for the Silica@GNP/PDMS composites to be used as high-performance TIMs in electronic industry. | Chaoxuan Shen Han Wang Tengxin Zhang You Zeng | 2019 | Journal of Materials Science & Technology2019,35,1: | 9 |
| 11 | A novel nonviral nanoparticle gene vector: Poly-L-lysine- silica nanoparticles显示文摘DNA delivery is a core technology for gene structure and function research as well as clinical settings. The ability to safely and efficiently targeted transfer foreign DNA into cells is a fundamental goal in biotechnology. With the development of nanobiotechnology, nanoparticle gene vectors brought about new hope to reach the goal. In our research, silica nanoparticles (SiNP) were synthesized first in a microemulsion system polyoxyethylene nonylphenyl ether (OP-10)/cyclohexane/ammonium hydroxide, at the same time the effects of SiNP size and its distribution were elucidated by orthogonal analysis; then poly-L-lysine (PLL) was linked on the surface of SiNP by nanoparticle surface energy and electrostatically binding; lastly a novel complex nanomate-rial-poly-L-lysine-silica nanoparticles (PLL-SiNP) wasprepared. The analysis of plasmid DNA binding and DNase I enzymatic degradation discovered that PLL-SiNP could bind DNA, and protect it against enzymatic degradation. Cell transfection showed that | Shiguo Zhu Hongbin Lu Juanjuan Xiang Ke Tang Bicheng Zhang Ming Zhou Chen Tan Guiyuan Li | 2002 | Chinese Science Bulletin2002,47,8: | 9 |
| 12 | SALVIANOLIC ACID H,A NEW DEPSIDE FROM SALVIA CAVALERIEI VAR.SIMPLICIFOLIA显示文摘A new depside named salvianolic acid H was isolated from the aqueous extract of Salviacavaleriei vat.simplicifolia,along with salvianolic acid A,B,C,isosalvianolic acid C,lithospermic acid,rosmarinic acid,R-(+)-β-(3,4-dihydroxyphenyl)lacticacid and protocatechualdehyde.Rosmarinic acid wasobtained as the major component. | Hai Jun ZHANG Lian Niang LI Institute of Materia Medica,Chinese Academy of Medical Sciences 1 Xian Nong Tan Street,Beijing 100050,China | 1993 | Chinese Chemical Letters1993,4,6: | 7 |
| 13 | Application of nano silica to improve self-healing of asphalt mixes显示文摘Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing. | Ganjei Mohamad Amin Aflaki Esmail | 2017 | Journal of Central South University2017,24,5: | 7 |
| 14 | Effect of removing silica in rice husk for the preparation of activated carbon for supercapacitor applications显示文摘Renewable biomass-derived activated carbons have attracted attentions for supercapacitor applications. Rice husk is a kind of abundant biomass, which has been studied for the preparation of hierarchical activated carbons. Rice husk is rich in silica. Silica in rice husk affects the formation of pore structure in the KOH activation process, which further affects the electrochemical performance of the resultant activated carbon for supercapacitors. In this paper, the effects of silica in rice husk on the activation process were investigated. When the silica in rice husk is not removed, KOH preferentially reacts with silica to produce silicate, which hinders the formation and enlargement of mesopores;the obtained activated carbon exhibits high microporous ratio, high specific area (up to 3263 m^2/g), high specific capacitance (315 F/g at 0.5 A/g), but poor rate capability (51.7%capacitance retention with increasing the current density from 0.5 A/g to 20 A/g). When the silica in rice husk is removed, the pores produced by the removal of silica are etched to mesopores in activation process;the obtained activated carbon exhibits high mesoporous ratio, relative high specific surface area of 2804 m2/g and relative high capacitance of 278 F/g at 0.5 A/g with excellent rate capability (76.6%capacitance retention with increasing the current density from 0.5 A/g to 20 A/g). | Dechen Liu Wenli Zhang Weimin Huang | 2019 | Chinese Chemical Letters2019,30,6: | 7 |
| 15 | Preparation of polystyrene/silica nanocomposites by radical copolymerization of styrene with silica macromonomer显示文摘A two-stage process has been developed to generate the silica-based macromonomer through surface-modification of silica with polymerizable vinyl groups. The silica surfaces were treated with excess 2,4-toluene diisocynate (TDI), after which the residual isocyanate groups were converted into polymerizable vinyl groups by reaction with hydroxypropylacrylate (HPA). Thus, polystyrene/silica nanocomposites were prepared by conventional radical copolymerization of styrene with silica macromonomer. The main effecting factors, such as ratios of styrene to the macromonomer, together with polymerization time on the copolymerization were studied in detail. FTIR, DSC and TGA were utilized to characterize the nanocomposites. Experimental results revealed that the silica nanoparticles act as cross-linking points in the polystytene/silica nanocomposites, and the glass transition temperatures of the nanocomposites are higher than that of the corresponding pure polystyrene. The glass transition temperatures of nanocomposites increased with the increasing of silica contents, which were further ascertained by DSC. | OU BaoLi1,2 & LI DuXin2 1 College of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China 2 State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China | 2007 | Science China Chemistry2007,50,3: | 6 |
| 16 | 纳米SiO_2负载Preyssler杂多酸催化剂对水杨酸与苄醇或脂肪醇酯化反应的催化性能(英文)显示文摘An efficient and environmentally benign procedure for the catalytic esterification of salicylic acid with aliphatic alcohols, CnH2n+1OH(n=1-5)and benzylic alcohols,RC6H4CH2OH(R=H,NO2,OCH3,Br,Cl,Me)was developed using nano-SiO2-supported Preyssler heteropolyacid both under thermal conditions and microwave irradiation.Silica nanostructures were obtained through a sol-gel method and were characterized by transmission electron microscopy and powder X-ray diffraction.The effects of various parameters such as solvent type,molar ratio of substrates,Preyssler heteropolyacid loading on silica,catalyst amount,temperature,and reaction time were studied and the optimum conditions were obtained.It has been found that the catalyst with 30 wt%loading is highly active and shows high yields in esterification reactions.The use of nano-SiO2-supported Preyssler heteropolyacid coupled with microwave irradiation allows a solvent-free,rapid(3 min),and high-yielding reaction.This catalyst can be easily recovered and reused for many times without a significant loss in its activity. | Fatemeh F. BAMOHARRAM Majid M. HERAVI Javad EBRAHIMI Ali AHMADPOUR Mojtaba ZEBARJAD | 2011 | 催化学报2011,32,5: | 6 |
| 17 | Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP显示文摘Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2,4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles. | OU BaoLi1,2 LI DuXin2 1 College of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411201, China 2 State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083, China | 2008 | Science China Chemistry2008,51,1: | 6 |
| 18 | Photocatalytic Oxidative Desulfurization of Dibenzothiophene on TiO2 Modified Bimodal Mesoporous Silica显示文摘By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, FTIR, UVvis,SEM, EDS, and TEM techniques. The test results showed that TiO_2 was amorphous, the TiO_2/BMMS catalyst had an ordered bimodal mesoporous structure, and the chemical interaction existed between BMMS and TiO_2. Since the TiO_2/BMMS had a lower band gap, its photocatalytic activity was better than TiO_2. Under UV irradiation a one-pot PODS system was set up, using TiO_2/BMMS as the catalyst, H_2O_2 as the oxidant, and methanol as the solvent. The TiO_2/BMMS catalyst showed better photocatalytic activity than the mono-modal mesoporous TiO_2/SBA-15 catalyst, and the desulfurization rate of dibenzothiophene(DBT) over TiO_2/BMMS catalyst could reach 99._2%. The TiO_2/BMMS catalyst also had so good stability that the desulfurization rate of DBT did not drop apparently after 8 cycles of reusing, and could still be close to 90%. | Xu Meizhen Yang Lina Li Jian | 2017 | China Petroleum Processing & Petrochemical Technology2017,19,3: | 6 |
| 19 | Probing the hydration of composite cement pastes containing fly ash and silica fume by proton NMR spin-lattice relaxation显示文摘Proton NMR spin-lattice relaxation (T1) was used as a prober for observing the hydration process of composite cement pastes blending fly ash and silica fume during the early age.The distribution at initial time,evolution curves and signals intensity of T1 were shown in this paper.Results demonstrate that the T1 distribution curves at initial time exhibit two peaks,which are regarded as two different water phases in the pastes.The evolution curves of T1 are in good agreement with the hydration process of composite pastes and could be roughly divided into four stages:initial period,dormant period,acceleration period and steady period.The hydration mechanism for each stage was discussed.The hydration of the composite cement pastes was retarded by the addition of fly ash and silica fume when compared to that of pure cement.However,the hydration degree of the cement in the blends was promoted. | SHE AnMing & YAO Wu Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education,Shanghai 200092,China | 2010 | Science China(Technological Sciences)2010,53,6: | 6 |
| 20 | Synthesis of Nanoscale Shell-core Titania Coated Silica Particles in the Presence of Polyether Polyamine and the Phase Transition显示文摘The nanoscale titania coated silica was prepared via a two-step precipitating approach, where the nanoscale silica nuclei were first prepared by passing an aqueous solution of sodium silicate through an ion-exchange resin bed, then coated with the precipitation from hydrolyzed butyl titanate in an ethanol-hexane mixture at a low pH value in the presence of poly(ethylene oxide) polyamine salt(PPA) at a high temperature of 90 ℃. In the second-step precipitating process, the spontaneously precipitated titania shell on the silica nuclei was stabilized in the suspension solution with the help of the adsorption of PPA on the particles. A possible precipitating mechanism was suggested. Furthermore, the amorphous titania shell could undergo crystallization from the amorphous to the anatase structure at a high temperature of 650 ℃, and a further phase transition from the anatase to the rutile structure in the different sintering processes at a rising temperature of 750 ℃. | HUA Feng-jun 1, SUN Jun 2, HONG Ke 2, GAO Lian 1 and YANG Yu-liang 1** 1. Key Laboratory of Molecular Engineering of Polymer, Fudan University, Shanghai 200433, P. R. China 2. State Key Laboratory of High Performance Ceramics and Superfine Micros | 2002 | Chemical Research in Chinese Universities2002,18,1: | 6 |