The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2. The crystal structu...The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2. The crystal structure comprises discrete neutral Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2 units. The copper atom,located on the crystallographic twofold axis,is coordinated with two nitrogen atoms of terminal 4,4′-bipy ligands and two water molecules at the equatorial positions,and two dihydrogen phosphate oxygen atoms at the axial positions,forming an elongated octahedron. The complex is a two-dimensional distorted rhomboidal network possessing two kinds of rhomboids with dimensions of ca . 1.6792 nm×0.3203 nm and 1.2778 nm×0.3198 nm,respectively. The two-dimensional networks are stacked parallelly on each other along c -axis to give an extended three-dimensional channel network with an interlayer distance of ca . 0.5030 nm. Crystal data: triclinic,space group P -_1,a =1.0253(2) nm,b =1.4501(3) nm,c =0.79715(16) nm, α =97.91(3)°,β = 90.99(3)° ,γ =85.54(3)°,V =1.1703(4) nm 3,Z =2,R =0.0892,wR =0.2451.展开更多
We report on a new type of Fano effect, named as Andreev-Fano effect, in a hybrid normal-metal/supeeconductor (N/S) interferometer embedded with a quantum dot. Compared with the conventional Fano effect, AndreevFano e...We report on a new type of Fano effect, named as Andreev-Fano effect, in a hybrid normal-metal/supeeconductor (N/S) interferometer embedded with a quantum dot. Compared with the conventional Fano effect, AndreevFano effect has some new features related to the characteristics of Andreev reflection. In the Iinear response regime, the line shape is the square of the conventional Fano shape, while in the nonlinear transport, a sharp resonant structure is superposed on an expanded interference pattern, which is qualitatively different from the conventional Fano effect. The phase dependence of the hybrid N/S interferometer is also distinguished from those of all-N or all-S interferometers.展开更多
We develop a theory for the nonequilibrium coherent transport through a mesoscopic region, based on the nonequilibrium Green function technique. The theory requires the weak coupling between the central mesoscopic re...We develop a theory for the nonequilibrium coherent transport through a mesoscopic region, based on the nonequilibrium Green function technique. The theory requires the weak coupling between the central mesoscopic region and the multiple electrodes, but allows arbitrary hopping and interaction in the central region. An equation determining the nonequilibrium distribution in the central interacting region is derived and plays an important role in the theory.The theory is applied to two special cases for demonstrations, revealing the novel effects associated with the combination of phase coherence, Coulomb interaction, and nonequilibrium distribution.展开更多
We study Andreev tunneling through a ferromagnet/quantum-dot (QD)/superconductor system. By usingnonequilibrum Green function method, the averaged occupation of electrons in QD and the Andreev tunneling currentare stu...We study Andreev tunneling through a ferromagnet/quantum-dot (QD)/superconductor system. By usingnonequilibrum Green function method, the averaged occupation of electrons in QD and the Andreev tunneling currentare studied. Comparing to the norma-metal/quantum-dot/superconductor, the system shows significant changes: (i)The averaged occupations of spin-up and spin-down electrons are not equal. (ii) With the increase of the polarizationof ferromagnetic lead, the Andreev reflection current decreases. (iii) However, even the ferromagnetic lead reaches fullpolarization, the averaged occupation of spin-down electrons is not zero. The physics of these changes is discussed.展开更多
Objective: to analyze the effect of one-to-one stratified teaching mode in operating room interns. Methods: 60 interns were selected to teach through one-to-one stratification (observation) and basic (control) to obse...Objective: to analyze the effect of one-to-one stratified teaching mode in operating room interns. Methods: 60 interns were selected to teach through one-to-one stratification (observation) and basic (control) to observe the effect. Results: compared with teaching satisfaction expertise score, the control group was lower and p 0.05. The teaching effect of the control group was lower than the observation group (43.33%, 83.33%, X210.335, p 0.05);the total clinical thinking ability of the control group was lower than the observation group [(65.21±12.44)points,(85.16±16.38)points,t5.313,p<0.05)];The results of the control group were higher than those of the observation group (P 0.05). Conclusion: choose one-to-one stratified teaching mode in the operating room.展开更多
Grain-size distributions of the reticulate red clay in Xuancheng, Anhui Province, and Jiujiang, Taihe and Ganzhou, Jiangxi Province, are analyzed. The results are as follows: (1) Generally fine and uniform, grain-size...Grain-size distributions of the reticulate red clay in Xuancheng, Anhui Province, and Jiujiang, Taihe and Ganzhou, Jiangxi Province, are analyzed. The results are as follows: (1) Generally fine and uniform, grain-size charac- teristics of the reticulate red clay in Xuancheng and Jiujiang are much similar, with no >2 mm gravels, 0.30% and 1.14% of >63 μm fraction on average, respectively, and 34.65% and 37.20% of 10―50 μm fraction, which is apparently accumu- lated. The patterns of the grain-size distribution curves of the uppermost yellow-brown earth of the profiles in the two ar- eas much resemble those of the loess in northern China and the Xiashu loess in southeastern China, while the patterns of the other layers also apparently show some attributes inher- ited from the above. The grain-size distribution patterns of the quartz separated from the whole profiles in the areas are almost identical, which could also be compared with those of the loess and the Xiashu loess. All the features above reveal aeolian characteristics of the reticulated red clay in these two areas. (2) The reticulate red clay in Taihe and Ganzhou is much coarser than that in Xuancheng and Jiujiang, with high content of >63 μm fraction and relatively low content of 10―50 μm fraction. The variations in grain-size distribu- tions of the profiles are also observed. The grain-size distri- bution patterns of both the original samples and the quartz of the red clay could hardly be compared with those of the loess and the Xiashu loess. All the features above reveal their alluvial or diluvial origins. (3) The multiple origins of the reticulate red clay in the areas reflect the diversity and com- plexity of the Quaternary environment in southern China. The existence of the reticulate red clay with aeolian charac- teristics brings forth objective evidence for the occurrence of large-scale dust deposition in southern China during the Quaternary glacial periods. Further investigation and study on the regional distribution of this kind of the red clay will be conducive to revealing the southern border of the large-scale dust deposition in southern China during the Quaternary glacial periods.展开更多
文摘The combination of both 4,4′-bipyridine(4,4′-bipy) and dihydrogen phosphate anion ligands with copper(Ⅱ) results in the formation of a novel layered compound Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2. The crystal structure comprises discrete neutral Cu(4,4′-bipy)_2(H_2PO_4)_2(H_2O)_2 units. The copper atom,located on the crystallographic twofold axis,is coordinated with two nitrogen atoms of terminal 4,4′-bipy ligands and two water molecules at the equatorial positions,and two dihydrogen phosphate oxygen atoms at the axial positions,forming an elongated octahedron. The complex is a two-dimensional distorted rhomboidal network possessing two kinds of rhomboids with dimensions of ca . 1.6792 nm×0.3203 nm and 1.2778 nm×0.3198 nm,respectively. The two-dimensional networks are stacked parallelly on each other along c -axis to give an extended three-dimensional channel network with an interlayer distance of ca . 0.5030 nm. Crystal data: triclinic,space group P -_1,a =1.0253(2) nm,b =1.4501(3) nm,c =0.79715(16) nm, α =97.91(3)°,β = 90.99(3)° ,γ =85.54(3)°,V =1.1703(4) nm 3,Z =2,R =0.0892,wR =0.2451.
文摘We report on a new type of Fano effect, named as Andreev-Fano effect, in a hybrid normal-metal/supeeconductor (N/S) interferometer embedded with a quantum dot. Compared with the conventional Fano effect, AndreevFano effect has some new features related to the characteristics of Andreev reflection. In the Iinear response regime, the line shape is the square of the conventional Fano shape, while in the nonlinear transport, a sharp resonant structure is superposed on an expanded interference pattern, which is qualitatively different from the conventional Fano effect. The phase dependence of the hybrid N/S interferometer is also distinguished from those of all-N or all-S interferometers.
文摘We develop a theory for the nonequilibrium coherent transport through a mesoscopic region, based on the nonequilibrium Green function technique. The theory requires the weak coupling between the central mesoscopic region and the multiple electrodes, but allows arbitrary hopping and interaction in the central region. An equation determining the nonequilibrium distribution in the central interacting region is derived and plays an important role in the theory.The theory is applied to two special cases for demonstrations, revealing the novel effects associated with the combination of phase coherence, Coulomb interaction, and nonequilibrium distribution.
基金国家自然科学基金，国家自然科学基金，the State Key Laboratory for Mesoscopic Physics in Peking University
文摘We study Andreev tunneling through a ferromagnet/quantum-dot (QD)/superconductor system. By usingnonequilibrum Green function method, the averaged occupation of electrons in QD and the Andreev tunneling currentare studied. Comparing to the norma-metal/quantum-dot/superconductor, the system shows significant changes: (i)The averaged occupations of spin-up and spin-down electrons are not equal. (ii) With the increase of the polarizationof ferromagnetic lead, the Andreev reflection current decreases. (iii) However, even the ferromagnetic lead reaches fullpolarization, the averaged occupation of spin-down electrons is not zero. The physics of these changes is discussed.
文摘Objective: to analyze the effect of one-to-one stratified teaching mode in operating room interns. Methods: 60 interns were selected to teach through one-to-one stratification (observation) and basic (control) to observe the effect. Results: compared with teaching satisfaction expertise score, the control group was lower and p 0.05. The teaching effect of the control group was lower than the observation group (43.33%, 83.33%, X210.335, p 0.05);the total clinical thinking ability of the control group was lower than the observation group [(65.21±12.44)points,(85.16±16.38)points,t5.313,p<0.05)];The results of the control group were higher than those of the observation group (P 0.05). Conclusion: choose one-to-one stratified teaching mode in the operating room.
基金This work was sup-ported by the N ational Natural Science Foundation of China(Grant Nos.40101013 and 40325007).
文摘Grain-size distributions of the reticulate red clay in Xuancheng, Anhui Province, and Jiujiang, Taihe and Ganzhou, Jiangxi Province, are analyzed. The results are as follows: (1) Generally fine and uniform, grain-size charac- teristics of the reticulate red clay in Xuancheng and Jiujiang are much similar, with no >2 mm gravels, 0.30% and 1.14% of >63 μm fraction on average, respectively, and 34.65% and 37.20% of 10―50 μm fraction, which is apparently accumu- lated. The patterns of the grain-size distribution curves of the uppermost yellow-brown earth of the profiles in the two ar- eas much resemble those of the loess in northern China and the Xiashu loess in southeastern China, while the patterns of the other layers also apparently show some attributes inher- ited from the above. The grain-size distribution patterns of the quartz separated from the whole profiles in the areas are almost identical, which could also be compared with those of the loess and the Xiashu loess. All the features above reveal aeolian characteristics of the reticulated red clay in these two areas. (2) The reticulate red clay in Taihe and Ganzhou is much coarser than that in Xuancheng and Jiujiang, with high content of >63 μm fraction and relatively low content of 10―50 μm fraction. The variations in grain-size distribu- tions of the profiles are also observed. The grain-size distri- bution patterns of both the original samples and the quartz of the red clay could hardly be compared with those of the loess and the Xiashu loess. All the features above reveal their alluvial or diluvial origins. (3) The multiple origins of the reticulate red clay in the areas reflect the diversity and com- plexity of the Quaternary environment in southern China. The existence of the reticulate red clay with aeolian charac- teristics brings forth objective evidence for the occurrence of large-scale dust deposition in southern China during the Quaternary glacial periods. Further investigation and study on the regional distribution of this kind of the red clay will be conducive to revealing the southern border of the large-scale dust deposition in southern China during the Quaternary glacial periods.
