The molecular structure of the title compound 5 ( l menthyloxy) 3 chloro 4 pyrrolidinyl 2(5H) furanone, C 18 H 28 ClNO 3(Ⅰ), has been determined by X ray diffraction at 296(1)K. The crystal is mo...The molecular structure of the title compound 5 ( l menthyloxy) 3 chloro 4 pyrrolidinyl 2(5H) furanone, C 18 H 28 ClNO 3(Ⅰ), has been determined by X ray diffraction at 296(1)K. The crystal is monoclinic with space group P2 1, a=9 457(3), b=10.413(3), c=9.525(2) , β=95.19(2)°, V=934(1) 3, Z=2, M r=341.88, D x =1.22 g/cm 3, μ =2.15 cm -1 , F(000)=368. The final R factor is 0 059, and R w is 0.065 for 1020 observed reflections with I≥3σ(I) . The absolute configuration at C(14) of the acetal carbon was proved to be S , taking into account the known configuration of 1R, 2S, 5R menthyl moiety. There are three rings in the molecule of this compound: the furanone ring, the pyrrolidine ring and the mentholoxy group ring. The franone ring is connected with the pyrrolidine ring and the mentholoxy ring by N atom and μ 2 O bridge atom respectively.展开更多
The crystal structure of the title compound 1, C 22 H 30 BrNO 3, was determined by X ray analysis at 296(1)K. The crystal belongs to othorhombic system, space group P2 12 12 1 with a=9.842(5), b=12....The crystal structure of the title compound 1, C 22 H 30 BrNO 3, was determined by X ray analysis at 296(1)K. The crystal belongs to othorhombic system, space group P2 12 12 1 with a=9.842(5), b=12.510(5), c=17.763(6) , V=2187(3) 3, Z=4, M r=436.37, D x =1.33 g/cm 3, μ =18.79 cm 1 , F(000) =912 and the final R=0.047 and R w=0.053 for 1429 observed reflections with I≥3σ(I). Structure analysis reveals that the absolute configuration at C 14 of the acetal carbon of the title compound is S.展开更多
Nucleating and propagating of nanocrack formed in dislocation free zone (DFZ) for the brittle TiAl alloy has been studied through in-situ tensile test in TEM and analyzed using microfracture mechanics. The results sho...Nucleating and propagating of nanocrack formed in dislocation free zone (DFZ) for the brittle TiAl alloy has been studied through in-situ tensile test in TEM and analyzed using microfracture mechanics. The results show that a lot of dislocations can be emitted from a crack tip when the applied stress intensity K-la is larger than the stress intensity for dislocation emission K-le = 1.4 MPa . m(1/2) and a dislocation free zone, which sometimes is a close zone, can form after reaching equilibrium. The DFZ is a elastic zone with large strain and then the stress in the DFZ might equal to the cohesive strength sigma(th) because the crack tip is still sharp. When K-la is larger than the stress intensity for nanocrack nucleation K-li = 2.4 MPa . m(1/2), the stress within a certain range in the DFZ would equal to sigma(th) and then a nanocrack initiates in the DFZ or sometimes at the notch tip. The nanocrack formed in the DFZ is stable and can propagate a small distance in cleavage mode through multiplication and movement of dislocation in the plastic zone, during keeping constant displacement. Increasing K-la, can make the crack stably propagate continuously or discontinuously and it means that the stress intensify for crack propagation, K-lp, is larger than K-li. Therefore, K-le [K-li [K-lp [K-lC.展开更多
文摘The molecular structure of the title compound 5 ( l menthyloxy) 3 chloro 4 pyrrolidinyl 2(5H) furanone, C 18 H 28 ClNO 3(Ⅰ), has been determined by X ray diffraction at 296(1)K. The crystal is monoclinic with space group P2 1, a=9 457(3), b=10.413(3), c=9.525(2) , β=95.19(2)°, V=934(1) 3, Z=2, M r=341.88, D x =1.22 g/cm 3, μ =2.15 cm -1 , F(000)=368. The final R factor is 0 059, and R w is 0.065 for 1020 observed reflections with I≥3σ(I) . The absolute configuration at C(14) of the acetal carbon was proved to be S , taking into account the known configuration of 1R, 2S, 5R menthyl moiety. There are three rings in the molecule of this compound: the furanone ring, the pyrrolidine ring and the mentholoxy group ring. The franone ring is connected with the pyrrolidine ring and the mentholoxy ring by N atom and μ 2 O bridge atom respectively.
文摘The crystal structure of the title compound 1, C 22 H 30 BrNO 3, was determined by X ray analysis at 296(1)K. The crystal belongs to othorhombic system, space group P2 12 12 1 with a=9.842(5), b=12.510(5), c=17.763(6) , V=2187(3) 3, Z=4, M r=436.37, D x =1.33 g/cm 3, μ =18.79 cm 1 , F(000) =912 and the final R=0.047 and R w=0.053 for 1429 observed reflections with I≥3σ(I). Structure analysis reveals that the absolute configuration at C 14 of the acetal carbon of the title compound is S.
文摘Nucleating and propagating of nanocrack formed in dislocation free zone (DFZ) for the brittle TiAl alloy has been studied through in-situ tensile test in TEM and analyzed using microfracture mechanics. The results show that a lot of dislocations can be emitted from a crack tip when the applied stress intensity K-la is larger than the stress intensity for dislocation emission K-le = 1.4 MPa . m(1/2) and a dislocation free zone, which sometimes is a close zone, can form after reaching equilibrium. The DFZ is a elastic zone with large strain and then the stress in the DFZ might equal to the cohesive strength sigma(th) because the crack tip is still sharp. When K-la is larger than the stress intensity for nanocrack nucleation K-li = 2.4 MPa . m(1/2), the stress within a certain range in the DFZ would equal to sigma(th) and then a nanocrack initiates in the DFZ or sometimes at the notch tip. The nanocrack formed in the DFZ is stable and can propagate a small distance in cleavage mode through multiplication and movement of dislocation in the plastic zone, during keeping constant displacement. Increasing K-la, can make the crack stably propagate continuously or discontinuously and it means that the stress intensify for crack propagation, K-lp, is larger than K-li. Therefore, K-le [K-li [K-lp [K-lC.
