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Wyszukujesz frazę "Liu, R." wg kryterium: Autor


Tytuł:
Shear Bond Strength Comparison between Conventional Dental Nano Zirconia Combinations and New Functionally Graded Nano Zirconia Combinations after Thermal-Mechanical Cycling
Autorzy:
Sun, T.
Lai, R.
Liu, R.
Shao, L.
Tematy:
87.85.jc
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Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/1215622.pdf  Link otwiera się w nowym oknie
Opis:
The aim of the study was to evaluate the core-veneer bond strength of graded zirconia combinations and compared those to conventional zirconia combinations after thermal and mechanical tests. Conventional zirconia-veneer combinations and graded zirconia-veneer combinations were made into cylinders. Prior to shear bond testing, half of each group was subjected to thermal and mechanical cycling testing at three conditional levels. All specimens were thereafter subjected to a shear force. The fractured surfaces were visually analyzed with scanning electron microscopy. The shear bond strength values of functionally graded zirconia combinations were significantly higher than zirconia combinations, irrespective of the fatigue conditions (P < 0.05). The shear bond strength values of graded zirconia combinations and zirconia combinations before thermal-mechanical cycling were higher than after (P < 0.05). The shear bond strength values of graded zirconia combinations was $40.99 ± 2.22$ MPa, $39.44 ± 2.36$ MPa, $37.45 ± 2.06$ MPa, and $36.87 ± 2.18$ MPa for conditions 0 to 3, respectively. The shear bond strength values were $26.75 ± 2.16$ MPa, $23.95 ± 2.16$ MPa, $21.65 ± 2.14$ MPa, and $20.49 ± 2.16$ MPa for zirconia combinations from conditions 0 to 3, respectively. The functionally graded zirconia combinations exhibited greater shear bond strength than zirconia combinations, irrespective of the fatigue conditions. Thermal-mechanical cycling had an impact on the shear bond strength of both graded zirconia combinations and conventional zirconia combinations.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption kinetics of fluoride on bone char and its regeneration
Autorzy:
Hu, J.
Wu, D.
Rao, R.
Liu, R.
Lai, W.
Tematy:
chlorine compounds
fluorine compounds
ions
sodium compounds
sulfur compounds
adsorption kinetics
chemical reaction equilibrium
correlation coefficient
Freundlich equation
optimal conditions
layered double hydroxides
aqueous-solution
drinking water
equilibrium
adsorbent
związki chloru
związki fluoru
jod
związki sodu
związki siarki
kinetyka adsorpcji
równowaga reakcji chemicznej
współczynnik korelacji
równanie Freundlicha
woda pitna
równanie Langmuira
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/206892.pdf  Link otwiera się w nowym oknie
Opis:
The adsorbent of bone char (BC), produced from the pyrolysis of crushed animal bones, was dominated by the mesopores of the Brunauer Emmett Teller (BET) surface area. The optimal condition for defluoridation with BC was a pH level near 5.0. Chloride and nitrate ions could increase fluoride adsorption capacity in contrast with the effect of sulfate and carbonate ions. The interchangeability between fluoride and hydroxyl groups on BC sorbent was proved by the Fourier transform infrared spectroscopy. Langmuir equation had a better correlation coefficient than the Freundlich equation at various temperatures. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, Ea and S*, have been calculated to describe the nature of fluoride adsorption onto BC. Negative Delta G degrees and Delta H degrees values at various temperatures indicate a spontaneous process, and its exothermic effect, respectively. However, a positive Delta S degrees value represents an increasing process for entropy. The E-a and S* values ranging from 5 to 40 kj.mol-1 and 0 to 1, respectively, demonstrated that the adsorption is dominated by physical process, although the adsorption kinetic process was involved external diffusion, intraparticle diffusion and chemical reaction equilibrium stage. A high concentration of NaOH solution increases efficiency of removing adsorbed F- ions from the BC surface.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing the Thermal Protective Performance of Firefighters Protective Fabrics by Incorporating Phase Change Materials
Polepszenie właściwości termicznych odzieży ochronnej strażaków poprzez zastosowanie materiałów zmiennofazowych
Autorzy:
Zhu, F L
Feng, Q Q
Liu, R
Yu, B
Zhou, Y
Tematy:
phase change material
fire protective clothing
thermal protective performance
materiał zmiennofazowy
odzież ochronna
ochrona termiczna odzieży
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Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:
https://bibliotekanauki.pl/articles/231560.pdf  Link otwiera się w nowym oknie
Opis:
A composite fabric consisting of an outer shell, moisture barrier, thermal liner and comfort layer used for firefighters’ protective clothing, was incorporated with shape-stabilised phase change material (PCM) powder in order to improve the thermal protection capability provided by thermal protective clothing. Then we conducted a series of FTP (fire testing protection) experiments to investigate the effects of PCM location and phase change temperature on the heat protection efficiency of firefighters’ protective fabrics (FFPFs). Simultaneously the thermoregulation performance of the composite fabrics with PCMs was evaluated by using step-cooling experimental technology during the cooling process. Data from the FTP tests were also compared with those from the existing enthalpy formulation model of heat transfer through FFPFs embedded with PCMs. It was concluded that the use of PCMs could improve the heat buffering capacity. However, as PCM has a moderate melting temperature, it is better than the other two samples because they have a lower and higher melting temperature. Therefore PX 52 PCMs (melting temperature: 47 - 53 °C) could provided the maximum heat protection time compared with the other two kinds of PCMs.
W celu zwiększenia zdolności ochrony termicznej odzieży ochronnej dla strażaków, przy użyciu stabilizowanego materiału zmiennofazowego w postaci proszku, stworzono materiał kompozytowy składający się z powłoki zewnętrznej, warstwy stanowiącej barierę dla wilgoci, wkładki termicznej i warstwy zapewniającej komfort. W celu zbadania wpływu umieszczenia materiału zmiennofazowego i temperatury przemiany fazowej na efektywność ochrony cieplnej przeprowadzono serię eksperymentów (testy ochrony przeciwpożarowej). Jednocześnie oceniono zdolność termoregulacji tkanin kompozytowych, oceny tej dokonano stosując technikę stopniowego chłodzenia. Dane z badań porównano z danymi teoretycznymi. Stwierdzono, że stosowanie materiałów zmiennofazowych może poprawić zdolność buforowania ciepła. Określono optymalny rodzaj materiału zmiennofazowego.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High pressures studies on hydrides of selected manganese alloys
Autorzy:
Sugiura, H.
Filipek, S.
Paul-Boncour, V.
Marchuk, I.
Liu, R.
Pyun, S.
Tematy:
deuterides/hydrides
high pressure
ferromagnetic fcc-manganese
Laves phases
equation of state
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Wydawca:
Instytut Chemii i Techniki Jądrowej
Powiązania:
https://bibliotekanauki.pl/articles/146225.pdf  Link otwiera się w nowym oknie
Opis:
Specific behavior found in hydrides formed in manganese, Mn-Ni and YMn2 under high pressure is presented and discussed. The synthesis of ferromagnetic fcc-manganese was proved. Parameters of the equations of state (EOS) derived from measurements in the diamond anvil cell (DAC) are summarized for manganese hydrides and for hydrides derived from YMn2 Laves phase. It was found that the compression behavior of recently discovered YMn2H6 is different from YMn2-based hydrides with lower hydrogen content.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of the Energetic Additive Coated MgH2 on the Power of Emulsion Explosives Sensitized by Glass Microballoons
Autorzy:
Cheng, Y.
Wang, Q.
Liu, F.
Ma, H.
Shen, Z.
Guo, Z.
Liu, R.
Tematy:
emulsion explosive
power
hydrogen storage material
magnesium hydride
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Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/357940.pdf  Link otwiera się w nowym oknie
Opis:
Traditional emulsion explosives, in spite of excellent water resistance, safe handling and good storage performance, have low power problems which seriously hinders their use. In order to improve the power of emulsion explosives, a hydrogen based emulsion explosive was devised. Scanning electron microscope pictures and experimental storage results show that the coating effect and stability of coated magnesium hydride (MgH2) are very good. The power of an emulsion explosive sensitized by glass microballoons was significantly increased (24.30 mm compression of lead block) after adding coated MgH2, compared to only 16.10 mm compression when not added. Thus emulsion explosives with coated MgH2 as an energetic additive have many potential applications.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toluene Mono-nitration in a Semi-batch Reactor
Autorzy:
Chen, L. P.
Chen, W. P.
Liu, Y.
Peng, J. H.
Liu, R. H.
Tematy:
toluene mono-nitration
apparent activation energy
semi-batch reaction
thermal hazard
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Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/358853.pdf  Link otwiera się w nowym oknie
Opis:
Toluene mono-nitration in a semi-batch reactor was investigated with reaction calorimeter (RC1). The mixed acid HNO3/H2SO4/H2O (wt%) was used in proportion 13/66/21, which is similar to industrial parameters. The exothermic rates at different reaction temperatures were compared, and then the curves of heat generation rate after dosing were analyzed. The Maximal Temperature attainable by runaway of the desired Synthetic Reaction (MTSR) under different conditions were calculated for the course hazard evaluation. The results showed that the average reaction heat of mono-nitration was between 169.07~177.11 kJ mol-1, and the special heat of reactant was about 2 kJ kg-1 K-1. Average Ea of second order kinetic was about 30 kJ mol-1, and reaction rate was 10-4 mol s-1 l-1 order of magnitude when the strength of sulphuric acid was about 73.5%. It was also found that when temperature or stirring speed increases, the potential heat accumulation decreases.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Crystal Structure, and Properties of a Novel, Highly Sensitive Energetic, Coordination Compound: Iron (II) Carbohydrazide Perchlorate
Autorzy:
Liu, R.
Zhou, Z.
Qi, S.
Yang, L.
Wu, B.
Huang, H.
Zhang, T.
Tematy:
iron (II) carbohydrazide perchlorate
energetic material
high
sensitivity
DFT
energy gap
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Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/358343.pdf  Link otwiera się w nowym oknie
Opis:
A single crystal of iron (II) carbohydrazide perchlorate [FeII (CHZ)3](ClO4)2 (FeCP), a novel, lead-free, energetic coordination compound, was synthesized and its structure determined by X-ray single crystal diffraction for the frst time. The crystal belongs to the monoclinic system P2(1)/n space group, with a = 1.0066(2) nm, b = 0.8458(2) nm, c = 2.1194(4) nm, β = 100.693(3)° and Z = 4. The central Fe(II) ion is coordinated to three bidentate carbohydrazide units through the carbonyl oxygen atom and an amino nitrogen atom, forming a six-coordinated, non-centrosymmetric complex cation. The thermal analyses by differential scanning calorimetry and thermogravimetry show that the onset temperature of thermal decomposition (152.7 °C) and the critical temperature of thermal explosion of FeCP (161.2 °C) are both much lower than those of other transition metal carbohydrazide perchlorate compounds, and also those of some other primary explosives in service. FeCP has a high enthalpy of combustion, as measured by oxygen bomb calorimetry. The impact, friction and fame sensitivity tests indicate that FeCP is extremely sensitive and hazardous. Unexpected explosions occurred even during the operational processes. In order to explore the intrinsic cause of these explosions, theoretical calculations of the orbital energies were performed based on DTF. These results reveal that the impact sensitivity is positively correlated with the energy gap between HOMO and LUMO: the smaller energy gap results in the higher impact sensitivity.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
XANES Study of La$\text{}_{0.75-x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$ Solid Solutions
Autorzy:
Drozd, V. A.
Pęka̶a, M.
Liu, R. S.
Lee, J.-F.
Chen, J. M.
Tematy:
75.47.Lx
61.10.Ht
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Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:
https://bibliotekanauki.pl/articles/2046755.pdf  Link otwiera się w nowym oknie
Opis:
A series of solid solutions La$\text{}_{0. 75-x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$ with 0.0≤x≤0.75 was prepared via carbonate precursor precipitation method. Final sintering was performed at 1250ºC in oxygen flow atmosphere. The samples obtained were characterized by scanning electron microscope, X-ray diffraction measurements. Oxygen stoichiometry was analyzed by iodometric titration method. X-ray absorption spectroscopic methods of Mn L-edge and Mn K-edge X-ray absorption near edge structure were used to study oxidation state of manganese in the solid solutions and elucidate features of their local crystal structure. Orthorhombic crystal structure characteristics of the solid solutions were refined by Rietveld method. An increase in oxygen deficiency and average manganese oxidation state were found to accompany Gd concentration increase in La$\text{}_{0.75-x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$. These results are consistent with Mn L-edge X-ray absorption near edge structure spectra, where a gradual change of Mn oxidation state with Gd concentration increase was detected. Origins of oxygen deficiency La$\text{}_{0.75- x}$Gd$\text{}_{x}$Ca$\text{}_{0.25}$MnO$\text{}_{3-δ}$ are discussed in terms of structural disorder caused by Gd substitution for La.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Very small embryonic-like stem cells (VSELs) represent a real challenge in stem cell biology : recent pros and cons in the midst of a lively debate
Autorzy:
Ratajczak, M. Z.
Suszynska, M.
Wojakowski, W.
Liu, R.
Mierzejewska, K.
Ratajczak, J.
Kucia, M.
Shin, D. M.
Zuba-Surma, Ewa
Opis:
The concept that adult tissue, including bone marrow (BM), contains early-development cells with broader differentiation potential has again been recently challenged. In response, we would like to review the accumulated evidence from several independent laboratories that adult tissues, including BM, harbor a population of very rare stem cells that may cross germ layers in their differentiation potential. Thus, the BM stem cell compartment hierarchy needs to be revisited. These dormant, early-development cells that our group described as very small embryonic-like stem cells (VSELs) most likely overlap with similar populations of stem cells that have been identified in adult tissues by other investigators as the result of various experimental strategies and have been given various names. As reported, murine VSELs have some pluripotent stem cell characteristics. Moreover, they display several epiblast/germline markers that suggest their embryonic origin and developmental deposition in adult BM. Moreover, at the molecular level, changes in expression of parentally imprinted genes (for example, Igf2–H19) and resistance to insulin/insulin-like growth factor signaling (IIS) regulates their quiescent state in adult tissues. In several emergency situations related to organ damage, VSELs can be activated and mobilized into peripheral blood, and in appropriate animal models they contribute to tissue organ/regeneration. Interestingly, their number correlates with lifespan in mice, and they may also be involved in some malignancies. VSELs have been successfully isolated in several laboratories; however, some investigators experience problems with their isolation.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł

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