Formation and magnetic properties of the Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds have been investigated.It has been found that formation of single phase compounds Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) with Nd_(3)(Fe,Ti)_(29)-...Formation and magnetic properties of the Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds have been investigated.It has been found that formation of single phase compounds Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) with Nd_(3)(Fe,Ti)_(29)-type structure depends strongly on the content of stabilizing element Cr,and the solid-solution limit of Co in Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds increases with Cr content.Pure Co-based Gd_(3)Co_(29-y)Cr_(y) compounds with Nd_(3)(Fe,Ti)_(29)-type structure have been successfully synthesized with y=6.5 and 7.0.The Curie temperature Tc of Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds increases with increasing Co content x at fixed y,whereas increase of the Cr content leads to an obvious decrease of Tc of the Gd_(3)Co_(29-y)Cr_(y) compounds.Composition dependence of the saturation magnetization at 5 K reaches a maximum around x=7.5 and y=4.It is worth noting that substitution of Co for Fe results in a significant change of magnetocrystalline anisotropy of the Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds and changes the easy magnetization direction from basal-plane to easy-axis when x>10 and y=4.展开更多
Magnetic and structural properties of YCo_(12-x)Ti_(x) compounds have been investigated by x-ray diffraction an magnetic measurements.X-ray diffraction patterns of aligned powder samples indicate that the easy magneti...Magnetic and structural properties of YCo_(12-x)Ti_(x) compounds have been investigated by x-ray diffraction an magnetic measurements.X-ray diffraction patterns of aligned powder samples indicate that the easy magnetiB zation direction at room temperature is along the c-axis for all the compounds.The lattice parameters increase monotonously while Curie temperature TC decreases with increasing Ti content.It was found that all the com pounds investigated are strong ferromagnets by analysis of magnetic moments using a magnetic valence model.The values of anisotropy fields B_(a)at room temperature and 1.5K decrease with increasing x.The easy-axisanisotropy of the YCo_(12-x)Ti_(x)compounds is mainly contributed by the Co atoms at 8i sites according to the individual-site-anisotropy model.展开更多
Structural and magnetic properties of Tb(Fe_(1-x)Ni_(x))_(11.3)Nb_(0.7) compounds have been investigated.The x-ray diffraction patterns show that all compounds crystallize in the ThMn12-type structure and that all sam...Structural and magnetic properties of Tb(Fe_(1-x)Ni_(x))_(11.3)Nb_(0.7) compounds have been investigated.The x-ray diffraction patterns show that all compounds crystallize in the ThMn12-type structure and that all samples are almost of single phase.The lattice constants monotonously decrease with increasing Ni content.The Curie temperature Tc clearly increases and the saturation moment Ms monotonously decreases with increasing Ni content.X-ray diffraction patterns of aligned samples at room temperature show that for x≤0.2 the easy magnetization direction is in the plane while for the x=0.25 compound the easy magnetization direction is along the c-axis.In the compounds with x≤0.20 spin reorientation occurs above room temperature whereas in the compounds with x>0.2 there is a spin reorientation below room temperature.It has been found that Ni contributes positively to the T-sublattice moment MT.展开更多
There are two standpoints to explain the formation of the peak of magnetic susceptibility versus temperature in CeNiSn.One is the presence of the pseudo-gapped density of states(DOS)while the other is the development ...There are two standpoints to explain the formation of the peak of magnetic susceptibility versus temperature in CeNiSn.One is the presence of the pseudo-gapped density of states(DOS)while the other is the development of an antiferromagnetic correlation.To check which one is more reasonable,an experiment is designed on measuring magnetic susceptibility under different magnetic fields.It is found that magnetic field can shift the peak of the magnetic susceptibility to lower temperatures while by calculation the presence of the pseudo-gapped DOS cannot shift the peak,which gives another evidence of the existence of antiferromagnetic correlations and is discussed in the light of some recent theoretical model.展开更多
The scientific evidenee of acupuncture studies has been improved in recent years,and one of the important manifestations is that more and more acupuncture clinical trials and mechanism researches have been published i...The scientific evidenee of acupuncture studies has been improved in recent years,and one of the important manifestations is that more and more acupuncture clinical trials and mechanism researches have been published in the source periodicals of Science Citation Index(SCI).This study summarized the dominant diseases of acupuncture focusing on of acupuncture efficacy and mechanisms,and discussed the existing problems,highlight!ng the directi on of future developme nts.Most clinical studies were published in journals with journal impact factor(JIF)score of 10 or above,and majority of the basic researches had JIF scores of 5 to 10.The above literature were further divided according to the International Classification of Diseases(ICD).The most concerned diseases in these articles were neurological diseases,musculoskeletal system and connective tissue diseases,tumor and digestive system diseases.The therapeutic effect and mechanism of acupuncture on each kind of disease were summarized.The results showed that the therapeutic effect of acupuncture on nerve injury focused on the anti-oxidation pathway,neuroprotective and anti-inflammatory processes.The antiinflammatory effect also played an important role in the treatme nt of musculoskeletal diseases.The an algesic effect was underlined in most of these studies.Clinical trials were well carried out on acupuncture curative effect of tumor complications and side effects of chemo-radiotherapy,but the potential mechanisms have not been clarified.Somato-visceral reflex was suggested to be strongly associated with the effects of acupuncture changing the motor activity of the gastrointestinal tract.Functional magnetic resonance imaging studies indicated that non-specific effects play important roles in acupuncture analgesia.Lines of evidenee have pointed out that the regulation of neuro-endocrine-immune networks may be a common switch of acupuncture on different nerve system diseases.展开更多
基金Supported by the National Natural Science Foundation of China under Grand No.58971061.
文摘Formation and magnetic properties of the Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds have been investigated.It has been found that formation of single phase compounds Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) with Nd_(3)(Fe,Ti)_(29)-type structure depends strongly on the content of stabilizing element Cr,and the solid-solution limit of Co in Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds increases with Cr content.Pure Co-based Gd_(3)Co_(29-y)Cr_(y) compounds with Nd_(3)(Fe,Ti)_(29)-type structure have been successfully synthesized with y=6.5 and 7.0.The Curie temperature Tc of Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds increases with increasing Co content x at fixed y,whereas increase of the Cr content leads to an obvious decrease of Tc of the Gd_(3)Co_(29-y)Cr_(y) compounds.Composition dependence of the saturation magnetization at 5 K reaches a maximum around x=7.5 and y=4.It is worth noting that substitution of Co for Fe results in a significant change of magnetocrystalline anisotropy of the Gd_(3)Fe_(29-x-y)Co_(x)Cr_(y) compounds and changes the easy magnetization direction from basal-plane to easy-axis when x>10 and y=4.
基金Supported by the National Natural Science Foundation of China under Grant No.59631070.
文摘Magnetic and structural properties of YCo_(12-x)Ti_(x) compounds have been investigated by x-ray diffraction an magnetic measurements.X-ray diffraction patterns of aligned powder samples indicate that the easy magnetiB zation direction at room temperature is along the c-axis for all the compounds.The lattice parameters increase monotonously while Curie temperature TC decreases with increasing Ti content.It was found that all the com pounds investigated are strong ferromagnets by analysis of magnetic moments using a magnetic valence model.The values of anisotropy fields B_(a)at room temperature and 1.5K decrease with increasing x.The easy-axisanisotropy of the YCo_(12-x)Ti_(x)compounds is mainly contributed by the Co atoms at 8i sites according to the individual-site-anisotropy model.
基金Supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars,State Education Commission。
文摘Structural and magnetic properties of Tb(Fe_(1-x)Ni_(x))_(11.3)Nb_(0.7) compounds have been investigated.The x-ray diffraction patterns show that all compounds crystallize in the ThMn12-type structure and that all samples are almost of single phase.The lattice constants monotonously decrease with increasing Ni content.The Curie temperature Tc clearly increases and the saturation moment Ms monotonously decreases with increasing Ni content.X-ray diffraction patterns of aligned samples at room temperature show that for x≤0.2 the easy magnetization direction is in the plane while for the x=0.25 compound the easy magnetization direction is along the c-axis.In the compounds with x≤0.20 spin reorientation occurs above room temperature whereas in the compounds with x>0.2 there is a spin reorientation below room temperature.It has been found that Ni contributes positively to the T-sublattice moment MT.
基金Supported by the National Natural Science Foundation of China under Grant No.19274049the National Commission of Science and Technology。
文摘There are two standpoints to explain the formation of the peak of magnetic susceptibility versus temperature in CeNiSn.One is the presence of the pseudo-gapped density of states(DOS)while the other is the development of an antiferromagnetic correlation.To check which one is more reasonable,an experiment is designed on measuring magnetic susceptibility under different magnetic fields.It is found that magnetic field can shift the peak of the magnetic susceptibility to lower temperatures while by calculation the presence of the pseudo-gapped DOS cannot shift the peak,which gives another evidence of the existence of antiferromagnetic correlations and is discussed in the light of some recent theoretical model.
基金the National Natural Science Foundation of China(Nos.81704146,81503637 and 81503636)the Natural Science Foundation of Tianjin(No.16JCYBJC43500)。
文摘The scientific evidenee of acupuncture studies has been improved in recent years,and one of the important manifestations is that more and more acupuncture clinical trials and mechanism researches have been published in the source periodicals of Science Citation Index(SCI).This study summarized the dominant diseases of acupuncture focusing on of acupuncture efficacy and mechanisms,and discussed the existing problems,highlight!ng the directi on of future developme nts.Most clinical studies were published in journals with journal impact factor(JIF)score of 10 or above,and majority of the basic researches had JIF scores of 5 to 10.The above literature were further divided according to the International Classification of Diseases(ICD).The most concerned diseases in these articles were neurological diseases,musculoskeletal system and connective tissue diseases,tumor and digestive system diseases.The therapeutic effect and mechanism of acupuncture on each kind of disease were summarized.The results showed that the therapeutic effect of acupuncture on nerve injury focused on the anti-oxidation pathway,neuroprotective and anti-inflammatory processes.The antiinflammatory effect also played an important role in the treatme nt of musculoskeletal diseases.The an algesic effect was underlined in most of these studies.Clinical trials were well carried out on acupuncture curative effect of tumor complications and side effects of chemo-radiotherapy,but the potential mechanisms have not been clarified.Somato-visceral reflex was suggested to be strongly associated with the effects of acupuncture changing the motor activity of the gastrointestinal tract.Functional magnetic resonance imaging studies indicated that non-specific effects play important roles in acupuncture analgesia.Lines of evidenee have pointed out that the regulation of neuro-endocrine-immune networks may be a common switch of acupuncture on different nerve system diseases.
