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排序方式: 共有1258条查询结果,搜索用时 0 毫秒
931.
Youngjun Lee Toshiyuki Fujimoto Shinya Yamanaka Yoshikazu Kuga 《Advanced Powder Technology》2021,32(5):1619-1626
Environmental pollution by organic dyes used in industry is a serious problem in developing countries. Environmentally friendly treatment methods are being studied because conventional methods require chemical or additional decomposition treatment. In particular, oxidation via a photocatalyst is a promising alternative due to its chemical and physical stabilities and low cost. However, electron-hole recombination limits the photocatalytic activity in semiconductor photocatalysts such as ZnO and TiO2. This study investigates control of electron-hole recombination of the photocatalyst by loading Au on ZnO (Au/ZnO). Using the Ultrasonic Spray Pyrolysis (USP) method, Au/ZnO particle generation is easily achieved under various conditions. XRD analysis confirms the crystal peaks of ZnO and Au. The EDX mapping and STEM images of the particles show that the Au crystals are well dispersed in the inner and outer portions of ZnO. The photocatalytic decomposition rate of organic dye (Rhodamine-B) is faster than that of ZnO in all Au/ZnO particles, and the best photocatalytic activity occurs in particles with 0.1 mass% Au supported on ZnO particles. In addition, optimal photolysis activity occurs in 100 mL of 5 mg/L RhB aqueous solution and 10 mg dose of Au/ZnO particles. 相似文献
932.
Masafumi Inaba Takumi Ochiai Kazuyoshi Ohara Ryogo Kato Tasuku Maki Toshiyuki Ohashi Hiroshi Kawarada 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(48)
For sp2 or sp3 carbon material growth, it is important to investigate the precursors or intermediates just before growth. In this study, the density of ethylene (C2H4) outside the plasma discharge space and just before reaching the carbon nanotube (CNT) growth region is investigated by vacuum ultraviolet absorption spectroscopy for plasma discharge in an antenna‐type remote plasma chemical vapor deposition with a CH4/H2 system, with which the growth of very long (≈0.5 cm) CNT forests is achieved. Single‐wall CNT forests have the potential for application as electrodes in battery cells, vertical wiring for high current applications, and thermal interface materials. It is observed that the plasma discharge decomposes the CH4 source gas and forms C2Hx species, which reversibly reform to C2H4 in the plasma‐off state. In addition, the density of the formed C2H4 has a strong correlation to the CNT growth rate. Therefore, the C2H4 density is a good indicator of the density of C2Hx species for CNT growth in the CH4/H2 plasma system. 相似文献
933.
Kida T Nakano T Fujino Y Matsumura C Miyawaki K Kato E Akashi M 《Analytical chemistry》2008,80(1):317-320
This paper describes the complete removal of chlorinated aromatic compounds from insulating oil by a channel-type gamma-cyclodextrin (gamma-CD) assembly as a new adsorbent. Using this type of adsorbent (50-60 wt % of oil), 1,2,4- and 1,3,5-trichlorobenzenes, 2- and 4-chlorobiphenyls (2- and 4-MCBs), 4,4'-dichlorobiphenyl (4,4'-DiCB), and 3,4,4'-trichlorobiphenyl (3,4,4'-TrCB), whose initial concentrations were 100 ppm, were completely removed from the insulating oil. Competitive adsorption experiments using a mixture of 2-MCB and 4-MCB or a mixture of 4-MCB, 4,4'-DiCB, and 3,4,4'-TrCB revealed that selective adsorption based on the shape and size of the chlorinated aromatics was achieved by the channel-type gamma-CD assembly, implying that inclusion into the cavity of the channel-type gamma-CD was responsible for the removal of chlorinated aromatics from insulating oil. It was also found that more than 70% of adsorbed chlorinated aromatics was easily recovered from the channel-type gamma-CD by simply washing with n-hexane, and chlorinated aromatics were completely removed from the insulating oil even by the regenerated adsorbent, indicating that the gamma-CD assembly can be easily regenerated and recycled. 相似文献
934.
Sugiyama H Koshoubu J Kashiwabara S Nagoshi T Larsen RA Akao K 《Applied spectroscopy》2008,62(1):17-23
A time-resolved infrared (IR) imaging system combined with a multichannel IR microscope, which utilizes a 16 channel linear array (LA) detector, and step-scan Fourier transform infrared (FT-IR) microscope was developed. The LA detector integrates a readout circuit on each detector element, so the detected signals can be read simultaneously. Thus, this system can perform high speed imaging using the step-scan method, similar to a single channel detector. To verify the capabilities of this system, a reflective sample was examined whose position was altered using a piezo actuator activated by an alternating voltage. In addition, the localization of relaxation dynamics for the liquid crystal (LC) molecules in an LC cell under oscillating electric field conditions was detected by this system. 相似文献
935.
Silva AK Egito ES Nagashima-Junior T Araujo IB Silva EL Soares LA Carrico AS 《Drug development and industrial pharmacy》2008,34(10):1111-1116
Aqueous suspensions containing magnetic microparticles have been increasingly used in biosciences and biotechnology. This work describes an experimental procedure to produce superparamagnetic microparticles. The particles were prepared based on the coprecipitation of iron salts in alkaline medium. Afterwards, characterization was performed. Characterization data demonstrated that magnetite was the dominant phase in the analyzed sample, and 50% of them were in the size range of 0.5-5 microm. The results suggest that the experimental protocol provided a simple synthesis route to produce superparamagnetic microparticles. Such properties may be very useful for biotechnological purposes. 相似文献
936.
Yukio Makino Takashi Yoshioka Hiromi Nakano Toshiyuki Ueno Shoji Miyake 《中国稀土学报(英文版)》2008,26(2):141-145
Roles of rare earth oxide (RE2O3) additives in millimeter-wave(MM) sintering of AIN were investigated from the standpoints of phase diagram, heating characteristics of rare earth oxides, and morphology of intergranular oxide phase. In the millimeter-wave sintering of AIN, densification temperature decreased with the decrease of the ionic radius of rare earth ion and was closely related with the eutectic temperature in the RE2Oa-Al2O3 binary system. The lowest densification temperature in the millimeter-wave sintering of AIN with Yb2O3 additive was attributed to the largest heating rate of Yb2O3-Al2O3 binary oxide under millimeter-wave radiation. Furthermore, the lowest densification temperature could be attained while selecting the Yb2O3 content so as to form the intergranular phase with the eutectic composition in the Yb2O3-Al2O3 binary system. The result showed good agreement with the above mentioned during the sintering of Si3N4 with Yb2O3-Al2O3 additive. From TEM observation, it was verified that film-like intergranular oxide phase formed under millimeter-wave radiation was favorable for attaining high thermal conductivity in the Yb2O3 added AINs. 相似文献
937.
Vinu A Miyahara M Hossain KZ Takahashi M Balasubramanian VV Mori T Ariga K 《Journal of nanoscience and nanotechnology》2007,7(3):828-832
In this paper, adsorption of lysozyme onto two kinds of mesoporous adsorbents (KIT-5 and AISBA-15) has been investigated and the results on the effects of pore geometry and stability of the adsorbents are also discussed. The KIT-5 mesoporous silica materials possess cage-type pore geometry while the AISBA-15 adsorbent has mesopores of cylindrical type with rather large diameter (9.7 nm). Adsorption of lysozyme onto AISBA-15 aluminosilicate obeys a Langmuir isotherm, resulting in pore occupation of 25 to 30%. In contrast, the KIT-5 adsorbents showed very small adsorption capacities for the lysozyme adsorption, typically falling in 6 to 13% of pore occupation. The cage-type KIT-5 adsorbents have narrow channel (4 to 6 nm) where penetration of the lysozyme (3 x 3 x 4.5 nm) might be restricted. The KIT-5 adsorbent tends to collapse after long-time immersion in water, as indicated by XRD patterns, while the AISBA-15 adsorbent retains its regular structure even after immersion in basic water for 4 days. These facts confirm superiority of the AISBA-15 as an adsorbent as compared with the KIT-5 mesoporous silicates. This research strikingly demonstrates the selection of mesoporous materials is crucial to achieve efficient immobilization of biomaterials in aqueous environment. 相似文献
938.
We developed a method for selective isolation of N-blocked peptides from a complex mixture such as an enzymatic digest of a protein. The approach is based on a newly designed isocyanate-resin (resin-NCO), which specifically reacts with alpha-amino or imino groups. This method, then, permits the isolation of N-blocked peptides, even those containing Lys, from a peptide mixture as intact forms by trapping N-free peptides via covalent bonding to the resin-NCO. The present study demonstrates the performance of this method for the selective isolation of N-blocked peptides by applying it to several peptide mixtures, including proteolytic digests. 相似文献
939.
We report a novel rubber film made by a simple mixing method, which realizes a steep temperature dependence of the contact angle of water at a critical temperature of 41 °C. We mixed a common SBR with a known temperature‐responsive PNIPA to make a thermo‐responsive rubber. This rubber film distinctly showed a switch of surface wettability between hydrophilic below 41 °C and hydrophobic above 41 °C. The switching property is possibly controlled by the mixing ratio of PNIPA to SBR, preparation method, added chemicals, and so on. This mixing technique will be applied for the control of surface wetting properties by temperature on various SBR‐like rubber materials, such as wet‐brake performance of automobile tires on a rainy day.
940.