Based on the engineering background of double-unit face mining under complicated geological conditions and the lagging fully-mechanized face surpassing the fore mechanized face of double-unit face in Zhou Yuanshan coa...Based on the engineering background of double-unit face mining under complicated geological conditions and the lagging fully-mechanized face surpassing the fore mechanized face of double-unit face in Zhou Yuanshan coal mine, strata-pressure behavior in the process was analyzed based on FLAC3D and on-site measurement. The results show that the stress concentration factor of superposition abutment pressure and the alternate distance of double-unit face are meeting gauss function, the relationship between the depth of stress concentration point and alternate distance also meets gaussian function. When the alternate distance is larger than 24 m, the superimposition of pilot support pressure in the double-unit face is weak. When the alternate distance is more than 12-15 m, the changes of the roof subsidence coefficient and the depth of stress con- centration point are stabilized; when the alternate distance is 3-6 m, the fore working face end is in the greatest impact area of superposition abutment pressure, this area should be avoided in determining the reasonable alternate distance.展开更多
I systematize thoughts within the scope of J6zef Ba6ka＇s philosophical system known as recentivism. I analyze the axiology of recentivism in two categories： recens （i.e., ＂now＂） and pure-mindedness. Also, I diff...I systematize thoughts within the scope of J6zef Ba6ka＇s philosophical system known as recentivism. I analyze the axiology of recentivism in two categories： recens （i.e., ＂now＂） and pure-mindedness. Also, I differentiate among pure-mindedness, which is a quality of homo euthyphronicus （i.e., pure-minded man）, simplicity, which is a quality of homo simplex （i.e., simple man）, and complexity, which is a quality of homo technicus （i.e., technical man）. Moreover, I present different meanings of pure-mindedness which form the basis for reflection in the axiology of recentivism, i.e., the ethics of pure-mindedness, euthyphronics, and esthetics. Then, I use these meanings of pure-mindedness to define the attitude of homo euthyphronicus. Homo euthyphronicus is a man who seeks balance between simplicity and complexity in the modem world, which is highly complex and full of civilization-related threats, while stressing the importance of axioiogical values.展开更多
We study the effect of two non-interacting impurity atoms near by a one-dimensional nanowire, which is modeled as a tight-binding hopping model. The virtual single-electron hopping between two impurities will induce a...We study the effect of two non-interacting impurity atoms near by a one-dimensional nanowire, which is modeled as a tight-binding hopping model. The virtual single-electron hopping between two impurities will induce an additional energy depending on the distance of two impurities, which gives a electronic Casimir–Polder effect. We find that the Casimir–Polder force between the two impurities decreases with the impurity-impurity distance exponentially.And the effects of nanowire and finite temperature on the Casimir–Polder force are also discussed in detail, respectively.展开更多
Dy3+/Eu3+ co-doped cubic lattice Na YF4 single crystal with high quality in the size of ~Φ1.0 cm×10.0 cm was grown by an improved Bridgman method using potassium fluoride(KF) as assistant flux. X-ray diffraction...Dy3+/Eu3+ co-doped cubic lattice Na YF4 single crystal with high quality in the size of ~Φ1.0 cm×10.0 cm was grown by an improved Bridgman method using potassium fluoride(KF) as assistant flux. X-ray diffraction(XRD), absorption spectra, excitation spectra and emission spectra are measured to investigate the phase and luminescent properties of the crystal. The effects of excitation wavelength and concentrations of Dy3+ and Eu3+ ions on the luminescent characteristics are analyzed. The Na YF4 single crystal with the doping molar concentrations of 1.205% Dy3+ and 0.366% Eu3+ exhibits an excellent white light emission with chromaticity coordinates of x=0.321, y=0.332. It indicates that the Dy3+/Eu3+ co-doped cubic lattice Na YF4 single crystal can be a potential luminescent material for the ultraviolet(UV) light excited white light emitting diode(w-LED).展开更多
基金Supported by the National Natural Science Foundation of China （50974059）
文摘Based on the engineering background of double-unit face mining under complicated geological conditions and the lagging fully-mechanized face surpassing the fore mechanized face of double-unit face in Zhou Yuanshan coal mine, strata-pressure behavior in the process was analyzed based on FLAC3D and on-site measurement. The results show that the stress concentration factor of superposition abutment pressure and the alternate distance of double-unit face are meeting gauss function, the relationship between the depth of stress concentration point and alternate distance also meets gaussian function. When the alternate distance is larger than 24 m, the superimposition of pilot support pressure in the double-unit face is weak. When the alternate distance is more than 12-15 m, the changes of the roof subsidence coefficient and the depth of stress con- centration point are stabilized; when the alternate distance is 3-6 m, the fore working face end is in the greatest impact area of superposition abutment pressure, this area should be avoided in determining the reasonable alternate distance.
文摘I systematize thoughts within the scope of J6zef Ba6ka＇s philosophical system known as recentivism. I analyze the axiology of recentivism in two categories： recens （i.e., ＂now＂） and pure-mindedness. Also, I differentiate among pure-mindedness, which is a quality of homo euthyphronicus （i.e., pure-minded man）, simplicity, which is a quality of homo simplex （i.e., simple man）, and complexity, which is a quality of homo technicus （i.e., technical man）. Moreover, I present different meanings of pure-mindedness which form the basis for reflection in the axiology of recentivism, i.e., the ethics of pure-mindedness, euthyphronics, and esthetics. Then, I use these meanings of pure-mindedness to define the attitude of homo euthyphronicus. Homo euthyphronicus is a man who seeks balance between simplicity and complexity in the modem world, which is highly complex and full of civilization-related threats, while stressing the importance of axioiogical values.
基金Supported by National Natural Science Foundation of China under Grants Nos.11175044,11105021,11204028,and 11547242the Natural Science Foundation of Jilin Province under Grant No.201115007+1 种基金the Foundation of Changchun University of Science and Technology under Grant No.XQNJJ-2015-04supported by China Postdoctoral Science Foundation under Grant No.2015M580966
文摘We study the effect of two non-interacting impurity atoms near by a one-dimensional nanowire, which is modeled as a tight-binding hopping model. The virtual single-electron hopping between two impurities will induce an additional energy depending on the distance of two impurities, which gives a electronic Casimir–Polder effect. We find that the Casimir–Polder force between the two impurities decreases with the impurity-impurity distance exponentially.And the effects of nanowire and finite temperature on the Casimir–Polder force are also discussed in detail, respectively.
基金supported by the National Natural Science Foundation of China(Nos.51472125 and 51272109)the K.C.Wong Magna Fund in Ningbo University
文摘Dy3+/Eu3+ co-doped cubic lattice Na YF4 single crystal with high quality in the size of ~Φ1.0 cm×10.0 cm was grown by an improved Bridgman method using potassium fluoride(KF) as assistant flux. X-ray diffraction(XRD), absorption spectra, excitation spectra and emission spectra are measured to investigate the phase and luminescent properties of the crystal. The effects of excitation wavelength and concentrations of Dy3+ and Eu3+ ions on the luminescent characteristics are analyzed. The Na YF4 single crystal with the doping molar concentrations of 1.205% Dy3+ and 0.366% Eu3+ exhibits an excellent white light emission with chromaticity coordinates of x=0.321, y=0.332. It indicates that the Dy3+/Eu3+ co-doped cubic lattice Na YF4 single crystal can be a potential luminescent material for the ultraviolet(UV) light excited white light emitting diode(w-LED).
