利用水热合成法合成了分子组成为(C6H11NH3)5H(P2Mo5O23)4H2O的杂多化合物, 用单晶X-ray衍射方法测定了它的结构,该晶体属于单斜晶系,空间群P21/c, a = 12.830(3), b = 14.848(3), c = 25.258(5) ? b = 92.95(3), Mr = 1483.62, V = 48...利用水热合成法合成了分子组成为(C6H11NH3)5H(P2Mo5O23)4H2O的杂多化合物, 用单晶X-ray衍射方法测定了它的结构,该晶体属于单斜晶系,空间群P21/c, a = 12.830(3), b = 14.848(3), c = 25.258(5) ? b = 92.95(3), Mr = 1483.62, V = 4805.1(17) 3, Z = 4, Dc = 2.051 g/cm3, m = 1.431 mm-1, F(000) = 3000, I >2s(I) 的可观察衍射点4426个, 最终结构偏差因子R = 0.0464, wR = 0.0801, S = 0.731。在[P2Mo5O23]6-杂多阴离子中5个MoO6八面体通过共边和共角相连, 形成1个近似的五角平面骨架, 2个PO4四面体加在五角平面的两侧。热性质研究表明杂多阴离子骨架在547.4 ℃左右分解。展开更多
A superposing principle, by suitably adding the strain waves from a number of concentrated explosive charges to approximate the waves generated by a cylindrical charge based on the strain wave of a point or small sphe...A superposing principle, by suitably adding the strain waves from a number of concentrated explosive charges to approximate the waves generated by a cylindrical charge based on the strain wave of a point or small spherical explosive charge generated in rock, is used to further study the triggering time of strain gauges installed in radial direction at same distances but different positions surrounding a cylindrical explosive charge in rock. The duration of the first compression phase and peak value of strain wave, and furthermore, their differences are analyzed and some explanations are given. Besides that, the gauge orientation in which the maximum peak value occurs is also discussed. At last, the effect of velocity of detonation(V.O.D.) of a cylindrical explosive charge on the strain waves generated in the surrounding rock is taken as key research and the pattern of peak amplitude of a strain wave varies with the V.O.D. is likely to have been found.展开更多
A new acylated flavonoid glycoside, 3-O-kaempferol-3-O-acetyl-6-O-(p-coumaroyl)-- D-glucopyranoside 1 was isolated from the whole plant of Anaphalis aureo-punctata. The structure was established by spectral methods.
In the stratosphere, CF3Cl（ CFC 13 ） can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase. Since the 1970s, attention has been focused...In the stratosphere, CF3Cl（ CFC 13 ） can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase. Since the 1970s, attention has been focused on the effects of these compounds on the destruction of ozone in the stratosphere and on global warming. Takahashi and coworkers detected ClO radicals and measured the product branching ratios of the title reaction system via the technique of vacuum ultraviolet laser-induced fluorescence. Yu and coworkers studied the mechanisms of the title reaction induced by the photolysis of the CF3Cl-O3 system at 253.7 nm.展开更多
The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) /n-butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,o...The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) /n-butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods.The results indicate that the lamellar,hexagonal and cubic liquid crystals all exist in the above system.Keeping the weight ratio of DAD and C4OH constant,the microphase Structure,2H quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.展开更多
Hydrogen peroxide (H2O2) induces the hypertrophy in cultured H9c2 cardiomyocytes and cell death in glutathione (GSH)-depleted H9c2 cells. In the present study, we observed that pretreatment with a serine protease inhi...Hydrogen peroxide (H2O2) induces the hypertrophy in cultured H9c2 cardiomyocytes and cell death in glutathione (GSH)-depleted H9c2 cells. In the present study, we observed that pretreatment with a serine protease inhibitor, N-a-tosyl-L-lysine chloromethyl ketone (TLCK), significantly prevented the H2O2-induced cell damages in GSH-depleted H9c2 cells in a concentration-dependent manner. The phase contrast microscopy revealed that although the exposure of the GSH-depleted H9c2 cells to H2O2 resulted in a globular shape of the cells, TLCK prevented the occurrence of H2O2-induced morphological changes. TLCK also inhibited the generation of reactive oxygen species in the cells after addition of H2O2, suggesting that the antioxidant action of TLCK is involved in the protection against the cell damages by H2O2. Application of TLCK after ~30 min of exposure to H2O2 could significantly protect the cells from cell damages. The other serine protease inhibitors that were tested could not prevent the cell damages in GSH- depleted H9c2 cells. Pretreatment with an inhibitor of nuclear factor-kB translocation into the nucleus and a proteasome inhibitor did not prevent the cell damages in GSH-depleted H9c2 cells. An inhibitor of p53 significantly prevented the cell damages in GSH-depleted H9c2 cells. These results suggest that antioxidative action of TLCK prevents the death of GSH-depleted H9c2 cardiomyocytes induced by H2O2.展开更多
New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using ...New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using phosphorus pentafluoride or tin tetrachloride as catalyst at low temperature indichloromethane. The monomer was obtained by the reaction of p - bromomethyl -phenyleneazide with 1, 4 -anhydro-α-D-ribose in DMF. The structure of poly(ADANR) was identified by specific rotation and ^(13)C-NMR spectroscopy. Acid chloride-AgCl_4 complex catalyst such as CH_2=C(CH_3)C^+OClO_4^- used in thepolymerization resulted in polymers with mixed structures, i.e. (1→5)-α-D-ribofuranosidic and (1→4)-β-D-ribopyranosidic units. However, with C_6H_5C^+OClO_4^- as catalyst, pure (1→5)-α-D-ribofuranan was obtained.The effects of catalyst, polymerization temperature and time on polymer stereoregularity were examined, andthe mechanism of the ring-opening polymerization was discussed.展开更多
基金Projects(51304239,51374243)supported by the National Natural Science Foundation of China
文摘A superposing principle, by suitably adding the strain waves from a number of concentrated explosive charges to approximate the waves generated by a cylindrical charge based on the strain wave of a point or small spherical explosive charge generated in rock, is used to further study the triggering time of strain gauges installed in radial direction at same distances but different positions surrounding a cylindrical explosive charge in rock. The duration of the first compression phase and peak value of strain wave, and furthermore, their differences are analyzed and some explanations are given. Besides that, the gauge orientation in which the maximum peak value occurs is also discussed. At last, the effect of velocity of detonation(V.O.D.) of a cylindrical explosive charge on the strain waves generated in the surrounding rock is taken as key research and the pattern of peak amplitude of a strain wave varies with the V.O.D. is likely to have been found.
文摘A new acylated flavonoid glycoside, 3-O-kaempferol-3-O-acetyl-6-O-(p-coumaroyl)-- D-glucopyranoside 1 was isolated from the whole plant of Anaphalis aureo-punctata. The structure was established by spectral methods.
基金Acknowledgements This research was financially supported by the National Natural Science Foundation of China （31371088） the Guangdong Provincial Project of Science and Technology （2011B050200005） SRG2015-00004-FHS and MYRG2016-00052-FHS from University of Macao, and the Science and Technology Development Fund （FDCT） of Macao （FDCT 021/2015/A1 and FDCT016/2016/A1）.
基金Supported by the National Natural Science Foundation of China(Nos. 20573064, 20073024) and the Special PhD Foundationof Ministry of Education of P. R. China(No. 20020422027).
文摘In the stratosphere, CF3Cl（ CFC 13 ） can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase. Since the 1970s, attention has been focused on the effects of these compounds on the destruction of ozone in the stratosphere and on global warming. Takahashi and coworkers detected ClO radicals and measured the product branching ratios of the title reaction system via the technique of vacuum ultraviolet laser-induced fluorescence. Yu and coworkers studied the mechanisms of the title reaction induced by the photolysis of the CF3Cl-O3 system at 253.7 nm.
文摘The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) /n-butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods.The results indicate that the lamellar,hexagonal and cubic liquid crystals all exist in the above system.Keeping the weight ratio of DAD and C4OH constant,the microphase Structure,2H quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.
文摘Hydrogen peroxide (H2O2) induces the hypertrophy in cultured H9c2 cardiomyocytes and cell death in glutathione (GSH)-depleted H9c2 cells. In the present study, we observed that pretreatment with a serine protease inhibitor, N-a-tosyl-L-lysine chloromethyl ketone (TLCK), significantly prevented the H2O2-induced cell damages in GSH-depleted H9c2 cells in a concentration-dependent manner. The phase contrast microscopy revealed that although the exposure of the GSH-depleted H9c2 cells to H2O2 resulted in a globular shape of the cells, TLCK prevented the occurrence of H2O2-induced morphological changes. TLCK also inhibited the generation of reactive oxygen species in the cells after addition of H2O2, suggesting that the antioxidant action of TLCK is involved in the protection against the cell damages by H2O2. Application of TLCK after ~30 min of exposure to H2O2 could significantly protect the cells from cell damages. The other serine protease inhibitors that were tested could not prevent the cell damages in GSH- depleted H9c2 cells. Pretreatment with an inhibitor of nuclear factor-kB translocation into the nucleus and a proteasome inhibitor did not prevent the cell damages in GSH-depleted H9c2 cells. An inhibitor of p53 significantly prevented the cell damages in GSH-depleted H9c2 cells. These results suggest that antioxidative action of TLCK prevents the death of GSH-depleted H9c2 cardiomyocytes induced by H2O2.
文摘New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using phosphorus pentafluoride or tin tetrachloride as catalyst at low temperature indichloromethane. The monomer was obtained by the reaction of p - bromomethyl -phenyleneazide with 1, 4 -anhydro-α-D-ribose in DMF. The structure of poly(ADANR) was identified by specific rotation and ^(13)C-NMR spectroscopy. Acid chloride-AgCl_4 complex catalyst such as CH_2=C(CH_3)C^+OClO_4^- used in thepolymerization resulted in polymers with mixed structures, i.e. (1→5)-α-D-ribofuranosidic and (1→4)-β-D-ribopyranosidic units. However, with C_6H_5C^+OClO_4^- as catalyst, pure (1→5)-α-D-ribofuranan was obtained.The effects of catalyst, polymerization temperature and time on polymer stereoregularity were examined, andthe mechanism of the ring-opening polymerization was discussed.
