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排序方式: 共有3143条查询结果,搜索用时 46 毫秒
991.
992.
The demand of higher energy density and higher power capacity of lithium(Li)-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes(CNTs), with their unique properties such as 1D tubular structure, high electrical and thermal conductivities, and extremely large surface area, have been used as materials to prepare cathodes for Li-ion batteries. The structure and morphology of CNTs were analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The functional groups on the purified CNT surface such as –COOH, –OH were characterized by Fourier Transform infrared spectroscopy. The electrode materials were fabricated from LiMn2O4(LMO), doped spinel LiNi0.5Mn1.5O4, and purified CNTs via solid-state reaction. The structure and morphology of the electrode were characterized using XRD, SEM, and TEM. Finally, the efficiency of the electrode materials using CNTs was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. 相似文献
993.
Suzuki T Tran LH Yogo M Idota O Kitamoto N Kawai K Takamizawa K 《Journal of Bioscience and Bioengineering》2005,100(4):472-474
A gene of Aspergillus oryzae, ladA, which encodes L-arabinitol 4-dehydrogenase (EC 1.1.1.12), and its cDNA were cloned in Escherichia coli. The gene consisted of a 1209-bp coding region, interrupted by a 59-bp intron, which encoded a 382-amino-acid polypeptide (40,812 Da). The protein showed 67% identity to a well-studied L-arabinitol 4-dehydrogenase (Lad1) of Hypocrea jecorina. The cell-free extract of E. coli, which expressed ladA cDNA, showed L-arabinitol dehydrogenase activity with NAD+. It was also reactive for ribitol and xylitol. 相似文献
994.
Effects of conjugated linoleic acid on color and lipid oxidation of beef patties during cold storage
The effects of conjugated linoleic acid (CLA) on color and lipid oxidation of beef patties were investigated. Ground beef was divided into three batches. The control patties were prepared with 90% lean meat and 10% tallow. The second treatment consisted of 90% lean meat with 9.5% tallow+0.5% CLA sources. The third treatment consisted of 90% lean meat with 8% tallow+2% CLA sources. The patties were wrap-packaged and then stored at 4° for 14 days. The CLA concentration significantly increased (P<0.05) by substituting CLA sources for fat. Storage of the patties did not alter the CLA concentration in beef patties. The treatment substituted with CLA sources had significantly lower TBARS (2-thiobarbituric acid-reactive substances) values (P<0.05) than the control. For oxymyoglobin contents and a* value, substituted CLA sources treatments had significantly higher values than the control. However, L* value significantly increased by substituting CLA sources for fat. 相似文献
995.
996.
Won-Bo Shim Kwang-Soo Ha Min-Gon Kim Jeong-Sook Kim Duck-Hwa Chung 《Food science and biotechnology》2014,23(6):2103-2108
Ochratoxin A (OTA), a mycotoxin classified as a potentially carcinogenic to humans, is slightly soluble in water. In this study, the transfer rate of OTA in herbal medicines to decoctions was investigated. Herbal medicine decoctions were prepared by boiling and autoclaving herbal medicines contaminated with OTA after soaking and not soaking in water. OTA amounts in decoctions and residues were analyzed using HPLC. Transfer of OTA (12.72–61.33%) from herbal medicines to decoctions was observed. Soaking and autoclaving steps enhanced the transfer rate of OTA to decoctions. The results meant that there is a potential risk for consumption of herbal medicine decoctions. Therefore, regular monitoring for mycotoxins, including OTA, in herbal medicines and proper management to ensure the safety of herbal medicines is necessary to protect consumers. 相似文献
997.
998.
Himadri Acharya Youn Jung Park Yeon Sik Choi Jinwoo Sung Taehee Kim Dong Ha Kim Cheolmin Park 《Reactive and Functional Polymers》2011,71(12):1195-1201
In this study, we demonstrate control over the localized surface plasmon band (SPB) of a micellar poly(styrene-block-4vinylpyridine) (PS-b-P4VP) copolymer thin film composite that includes Ag and Au nanoparticles (NPs) in the presence of single walled carbon nanotubes (SWCNTs). Ag and Au NPs are preferentially located in the P4VP core and the PS corona of ordered spherical PS-b-P4VP copolymer micelles, respectively. This structure gave rise to a single SPB due to the coupling of Ag and Au SPBs. The non-covalent addition of SWCNTs in the block copolymer micelles shifts the coupled SPB to a lower wavelength. The maximum shift in the coupled SPB of approximately 30 nm was achieved in the PS-b-P4VP/Ag/Au NPs composite. The carbon nanotube induced modulation of the coupled SPB stems from the charge accumulation effect of the SWCNTs placed between the two types of nanoparticles. 相似文献
999.
Dong-Seok KimTae-Hyeon Kim Chul-Ho WonHee-Sung Kang Ki-Won KimKi-Sik Im Yong Soo LeeSung-Ho Hahm Jung-Hee Lee Jae-Hoon LeeJong-Bong Ha Youngho BaeSorin Cristoloveanu 《Microelectronic Engineering》2011,88(7):1221-1224
We have grown high quality GaN layers on (1 1 1)-oriented silicon substrate using a two-step growth method and fabricated high-performance normally-off n-channel GaN Schottky-barrier MOSFET (SB-MOSFET). Indium-tin-oxide (ITO) was used as Schottky-barrier contact for source and drain (S/D) because the work function of ITO is close to the electron affinity of GaN. Due to enhanced crystalline quality and reduced surface roughness of GaN layer grown by two-step process, the fabricated device exhibited much improved performances: sufficiently high threshold voltage of 3.75 V, subthreshold slope of 171 mV/dec, low specific on-resistance of 9.98 mΩ cm2, and very high field-effect mobility of 271 cm2/V s. This is the highest mobility value among the GaN MOSFETs ever reported so far. 相似文献
1000.
Sin-Young Jung Tae-Jung Ha Won-Seon Seo Young Soo Lim Sangwoo Shin Hyung Hee Cho Hyung-Ho Park 《Journal of Electronic Materials》2011,40(5):652-656
Mesoporous materials have pores with diameters between 2 nm and 50 nm, the presence of which generally decreases the thermal
conductivity of the material. By incorporating mesoporous structures into thermoelectric materials, the thermoelectric properties
of these materials can be improved. Although TiO2 is an ordinary insulator, reduced TiO2 shows better electrical conductivity and is therefore a potential thermoelectric material. Furthermore, the addition of a
dopant to TiO2 can improve its electrical conductivity. We hypothesized that, by doping ordered mesoporous TiO2 films with niobium, we would be able to minimize the thermal conductivity and maximize the electrical conductivity. To investigate
the effects of Nb doping and a mesoporous structure on the thermoelectric characteristics of TiO2 films, Nb-doped mesoporous films were investigated using x-ray diffraction, ellipsometry, four-point probe measurements,
and thermal conductivity analysis. We found that Nb doping of ordered mesoporous TiO2 films improved their thermoelectric properties. 相似文献