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1.
In heat transport devices such as oscillating heat pipe (OHP), dryout phenomena is very important and avoided in order to give the optimum performance. However, from the previous studies (including our studies), the dryout phenomena in OHP and its mechanism are still unclear. In our studies of OHP (Senjaya and Inoue in Appl Thermal Eng 60:251–255, 2013; Int J Heat Mass Transfer 60:816–824, 2013; Int J Heat Mass Transfer 60:825–835, 2013), we introduced the importance and roles of liquid film in the operating principle of OHP. In our previous simulation, the thickness of liquid film was assumed to be uniform along a vapor plug. Then, dryout never occurred because there was the liquid transfer from the liquid film in the cooling section to that in the heating section. In this research, the liquid film is not treated uniformly but it is meshed similarly with the vapor plugs and liquid slugs. All governing equations are also solved in each control volume of liquid film. The simulation results show that dryout occurs in the simulation without bubble generation and growth. Dryout is started in the middle of vapor plug, because the liquid supply from the left and right liquid slugs cannot reach until the liquid film in the middle of vapor plug, and propagates to the left and right sides of a vapor plug. By inserting the bubble generation and growth phenomena, dryout does not occur because the wall of heating section is always wetted during the bubble growth and the thickness of liquid film is almost constant. The effects of meshing size of liquid film and wall temperature of heating section are also investigated. The results show that the smaller meshing size, the smaller liquid transfer rate and the faster of dryout propagation. In the OHP with higher wall temperature of heating section, dryout and its propagation also occur faster. 相似文献
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Chiral Bis(imidazolidine)‐Derived NCN Pincer Rh Complex for Catalytic Asymmetric Mannich Reaction of Malononitrile with N‐Boc Imines 下载免费PDF全文
Prof. Dr. Takayoshi Arai Takuma Moribatake Prof. Dr. Hyuma Masu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(30):10671-10675
Chiral bis(imidazolidine)‐derived NCN–rhodium complexes ([PhBidine‐RhX2] and [tBu‐PhBidine‐RhX2]) were prepared by a C?H insertion method, and the structures were unequivocally determined by X‐ray crystallographic analysis. The [tBu‐PhBidine‐Rh(OAc)2] complex smoothly catalyzed an asymmetric Mannich reaction of malononitrile with N‐Boc imines to give products in up to 94 % ee, which are useful for the synthesis of chiral α‐amino acids. 相似文献
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Organic‐Base‐Driven Intercalation and Delamination for the Production of Functionalized Titanium Carbide Nanosheets with Superior Photothermal Therapeutic Performance 下载免费PDF全文
Dujuan Liang Liang Cheng Xiaojing Yang Zhuang Liu Renzhi Ma Takayoshi Sasaki Fengxia Geng 《Angewandte Chemie (International ed. in English)》2016,55(47):14569-14574
The delamination of titanium carbide sheets, an intriguing class of two‐dimensional materials, has been critically dependent on the extraction of interlayer Al in acidic media, such as concentrated hydrofluoric acid (HF) or a mixture of hydrochloric acid (HCl) and a fluoride salt. Herein, we report an organic‐base‐driven intercalation and delamination of titanium carbide that takes advantage of the amphoteric nature of interlayer Al. The resulting aluminum‐oxoanion‐functionalized titanium carbide sheets manifested unusually strong optical absorption in the near‐infrared (NIR) region with a mass extinction coefficient as high as 29.1 L g?1 cm?1 at 808 nm. Thus, the performance of this material is comparable or even superior to that of state‐of‐the‐art photoabsorption materials, including gold‐based nanostructures, carbon‐based materials, and transition‐metal dichalcogenides. Preliminary studies show that the titanium carbide sheets serve as efficient photothermal agents against tumor cells. 相似文献
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Tomohito Morosaki Tsubasa Suzuki Wei‐Wei Wang Shigeru Nagase Takayoshi Fujii 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(36):9723-9725
Electronic effects on the central carbon atom of carbone, generated by the replacement of the SIV ligand of carbodisulfane (CDS) with other chalcogen ligands (Ph2E, E=S or Se), were investigated. The carbones Ph2E→C←SPh2(NMe) [E=S( 1 ) or Se( 2 )] were synthesized from the corresponding salts, and their molecular structures and electronic properties were characterized. The carbone 2 is the first carbone containing selenium as the coordinated atom. DFT calculations revealed the electronic structures of 1 and 2 , which have two lone pairs of electrons at the carbon center. The trend in HOMO energy levels, estimated by cyclic voltammetry measurements, for the carbones and CDS follows the order of 2 > 1 >CDS. Analysis of a doubly protonated dication and trication complex revealed that the central carbon atom of 2 behaves as a four‐electron donor. 相似文献
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Redox reactions were studied at a single yttria-stabilized zirconia (YSZ)/Pt electrode interface, in parallel with pure YSZ with no catalyst electrode, by in situ analytical electron microscopy at elevated temperatures and in an oxygen atmosphere. In situ electron holography showed that the oxide underwent reduction at elevated temperatures in a vacuum and was consequently reoxidized upon exposure to an oxygen flux at the same temperature. In situ energy loss spectroscopy measurements were in agreement with in situ electron holography observations and indicated that the oxidation state of the host cation zirconium was altered in the reduced state of the YSZ to the metastable state Zr(3+). 相似文献
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Shiro Matsumoto Yasuyuki Sugiyama Seizou Sakata Takayoshi Hayashi 《Liquid crystals》2013,40(5):649-655
Polymers containing droplets of liquid crystal smaller than 100 nm, which have good transparency and easily form films, were prepared under various conditions to evaluate their potential as electro-optic materials for waveguide-type devices. By varying the liquid crystal concentration and the strength of the UV irradiation causing photo-induced phase separation of the droplets, we were able to control the droplet size and density. We have clarified how the birefringence generated in an applied electric field, switching speed, and optical loss of light propagating in the film depend on droplet size and density. Polymer materials having a large electro-optic effect (δn = 0.001 at 8 V μm-1), low propagation loss (~2.5 dB cm-1), and fast response time (~10 μs) have been developed. 相似文献