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排序方式: 共有1169条查询结果,搜索用时 15 毫秒
971.
Jun Hyung Lim Jong Hyun Shim Jun Hyuk Choi Jin Hyun Park Won Kim Jinho Joo Chan-Joong Kim 《Physica C: Superconductivity and its Applications》2009,469(15-20):1182-1185
We fabricated nano-carbon (NC) doped MgB2 bulks using an in situ process in order to improve the critical current density (Jc) under a high magnetic field and evaluated the correlated effects of the doped carbon content and sintering temperature on the phase formation, microstructure and critical properties. MgB2−xCx bulks with x = 0 and 0.05 were fabricated by pressing the powder into pellets and sintering at 800 °C, 900 °C, or 1000 °C for 30 min.We observed that NC was an effective dopant for MgB2 and that part of it was incorporated into the MgB2 while the other part remained (undoped), which reduced the grain size. The actual C content was estimated to be 68–90% of the nominal content. The NC doped samples exhibited lower Tc values and better Jc(B) behavior than the undoped samples. The doped sample sintered at 900 °C showed the highest Jc value due to its high doping level, small amount of second phase, and fine grains. On the other hand, the Jc was decreased at a sintering temperature of 1000 °C as a result of the formation of MgB4 phase. 相似文献
972.
Kyoung Won Jang Dong Hyun Cho Sang Hun Shin Wook Jae Yoo Jeong Ki Seo Bongsoo Lee Sin Kim Joo Hyun Moon Young-Ho Cho Byung Gi Park 《Optical Review》2009,16(3):383-386
Abstact A scintillating fiber-optic dosimeter has many advantages such as real-time readout, high-resolution measurement, water-equivalence
and no corrections for temperature, pressure and humidity. Organic scintillator which has water or tissue equivalent characteristics
is very important to measure absorbed dose, dose rate and dose distributions exactly without any corrections and due to its
small size, the sensitive volume enables accurate dose measurements in regions of high dose gradients with high spatial resolution.
In this study, a scintillating fiber-optic dosimeter with an organic scintillator is fabricated to measure high-energy photon
beam from a clinical linear accelerator. And we have measured linear responses of a fiber-optic dosimeter according to dose
rates and monitor units of a clinical linear accelerator. Also, a percent depth dose curve for 6MV photon beam with different
field sizes are obtained. 相似文献
973.
974.
Heptachlor induced nigral dopaminergic neuronal loss and Parkinsonism-like movement deficits in mice
Seokheon Hong Joohyun Hwang Joo Yeon Kim Ki Soon Shin Shin Jung Kang 《Experimental & molecular medicine》2014,46(2):e80
Epidemiological studies have suggested an association between pesticide exposure and Parkinson''s disease. In this study, we examined the neurotoxicity of an organochlorine pesticide, heptachlor, in vitro and in vivo. In cultured SH-SY5Y cells, heptachlor induced mitochondria-mediated apoptosis. When injected into mice intraperitoneally on a subchronic schedule, heptachlor induced selective loss of dopaminergic neurons in the substantia nigra pars compacta. In addition, the heptachlor injection induced gliosis of microglia and astrocytes selectively in the ventral midbrain area. When the general locomotor activities were monitored by open field test, the heptachlor injection did not induce any gross motor dysfunction. However, the compound induced Parkinsonism-like movement deficits when assessed by a gait and a pole test. These results suggest that heptachlor can induce Parkinson''s disease-related neurotoxicities in vivo. 相似文献
975.
Synthesis,photoluminescence and Judd–Ofelt parameters of LiNa3P2O7:Eu3+ orthorhombic microstructures
976.
Kyoungil Cho Dr. Sang Moon Lee Dr. Hae Jin Kim Dr. Yoon-Joo Ko Prof. Eun Joo Kang Prof. Dr. Seung Uk Son 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(4):788-794
This work shows that a hollow and microporous metal-free N,N′-phenylenebis(salicylideneimine) (salphen) network (H-MSN) can be engineered by Sonogashira coupling of [tetraiodo{di(Zn-salphen)}] building blocks with 1,4-diethynylbenzene in the presence of silica templates and by successive Zn and silica etching. Iron(III) ions could be incorporated into the H-MSN to form hollow and microporous Fe–disalphen networks (H-MFeSN) with enhanced microporosity and surface area. The H-MFeSN showed efficient catalytic performance and recyclability in the CO2 conversion to cyclic carbonates. 相似文献
977.
Uuriintuya Dembereldorj Seon Young Choi Erdene‐Ochir Ganbold Nam Woong Song Doseok Kim Jaebum Choo So Yeong Lee Sehun Kim Sang‐Woo Joo 《Photochemistry and photobiology》2014,90(3):659-666
Gold nanorod‐attached PEGylated graphene‐oxide (AuNR‐PEG‐GO) nanocomposites were tested for a photothermal platform both in vitro and in vivo. Cytotoxicity of AuNR was reduced after encapsulation with PEG‐GO along with the removal of cetyltrimethylammonium bromide (CTAB) from AuNR by HCl treatment. Cellular internalization of the CTAB‐eliminated AuNR‐PEG‐GO nanocomposites was examined using dark‐field microscopy (DFM), confocal Raman microscopy and transmission electron microscopy (TEM). To determine the photothermal effect of the AuNR‐PEG‐GO nanocomposites, A431 epidermoid carcinoma cells were irradiated with Xe‐lamp light (60 W cm?2) for 5 min after treatment with the AuNR‐PEG‐GO nanocomposites for 24 h. Cell viability significantly decreased by ~40% when the AuNR‐PEG‐GO‐encapsulated nanocomposites were irradiated with light as compared with the cells treated with only the AuNR‐PEG‐GO nanocomposites without any illumination. In vivo tumor experiments also indicated that HCl‐treated AuNR‐PEG‐GO nanocomposites might efficiently reduce tumor volumes via photothermal processes. Our graphene and AuNR nanocomposites will be useful for an effective photothermal therapy. 相似文献
978.
979.
980.
So Young Jeong Hyo Jung Moon Min Hee Park Min Kyung Joo Byeongmoon Jeong 《Journal of polymer science. Part A, Polymer chemistry》2012,50(15):3184-3191
We report a poly(ethylene glycol)‐poly(L ‐alanine)‐azobenzene‐poly(L ‐alanine)‐poly(ethylene glycol) (PEG‐PA‐Z‐PA‐PEG) as a temperature and light sensitive polymer. The poly(ethylene glycol)‐poly(L ‐alanine) diblock copolymers with a flexible‐rigid block structure were coupled by an azobenzene group that undergoes a reversible configurational change between “trans” and “cis” upon exposure to UV and vis light. The single azobenzene molecule embedded in the middle of a block copolymer with a flexible (shell)‐rigid (core) structure significantly affected molecular assembly, micelle size, polypeptide secondary structure, and sol‐to‐gel transition temperature of the polymer aqueous solution, depending on its exposure to UV or vis light. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献