The shaping form of an untwisted yarn-end for the air splicer is analyzed and then a cosine curve form which will have practically good splicing effect is proposed. The yarn motion in the splicing nozzle by applying h...The shaping form of an untwisted yarn-end for the air splicer is analyzed and then a cosine curve form which will have practically good splicing effect is proposed. The yarn motion in the splicing nozzle by applying hydrodynamics and the splicing principle of the air splicer are also studied.展开更多
This paper presents a study of the relationship between the magnetic properties and microstructure of nanocomposite Ni/MnO, Ni/CoO, Co/MnO, Co/CoO. The objective is to understand how the coupling interface FM/AFM （fe...This paper presents a study of the relationship between the magnetic properties and microstructure of nanocomposite Ni/MnO, Ni/CoO, Co/MnO, Co/CoO. The objective is to understand how the coupling interface FM/AFM （ferromagnetic/anti-ferromagnetic） manifests itself in magnetic response of these materials to an applied field. Sample preparation was performed using mechanochemical synthesis by means of a ball mill planetary type high power at normal atmosphere. The characterization was done by XRD （X-ray diffraction）, SEM （scanning electron microscopy） and VSM （vibrating sample magnetometry）. Analyzing the XRD peaks of the samples studied, there was a decrease in the average particle diameter with increasing milling time, which is important in the magnetic interactions of the atoms of the surface. In addition, the diffraction pattern showed formation of new phases by oxidation interfering with the magnetic measurements. Analyses by SEM show chipboard multiform nano- and micrometer-sized grains on the surface of the clusters being responsible for the interaction. The magnetic measurements show a strong coupling between the phases present in nanocomposites showing once again that the MS （mechanosynthesis） is a powerful technique for this kind of purpose. The effect of the decrease in crystallite size leads to large variations of magnetic properties of the material which have been specifically observed changes in HC （coercive field） in the RM （remanent magnetization） and SM （saturation magnetization）. The decrease in crystallite size in the course of grinding intensifies the effects that depend on the surface-to-volume ratio of the material. M vs. T measures were taken for different values of applied field and found a jump in the moment of the sample near the N6el temperature of the antiferromagnetic.展开更多
The single event effect(SEE) is an important consideration in electronic devices used in space environments because it can lead to spacecraft anomalies and failures. The linear energy transfer(LET) of ions is commonly...The single event effect(SEE) is an important consideration in electronic devices used in space environments because it can lead to spacecraft anomalies and failures. The linear energy transfer(LET) of ions is commonly investigated in studies of SEE. The use of a thin detector is an economical way of directly measuring the LET in space. An LET telescope consists of a thin detector as the front detector(D1), along with a back detector that indicates whether D1 was penetrated. The particle radiation effect monitor(PREM) introduced in this paper is designed to categorize the LET into four bins of 0.2–0.4, 0.4–1.0, 1.0–2.0 and 2.0–20 Me V·cm^2/mg, and one integral bin of LET>20 Me V·cm^2/mg. After calibration with heavy ions and Geant4 analysis, the LET boundaries of the first four bins are determined to be 0.236, 0.479, 1.196, 2.254, and 17.551 Me V·cm^2/mg, whereas that of the integral bin is determined to be LET>14.790 Me V·cm^2/mg. The acceptances are calculated by Geant4 analysis as 0.452, 0.451, 0.476, 0.446, and 1.334, respectively. The LET accuracy is shown to depend on the thickness of D1; as D1 is made thinner, the accuracy of the measured values increases.展开更多
The Sr3Tl5 phase was prepared by high temperature synthesis techniques through reaction of the high purity elements in the welded Nb tubes.The structure established through X-ray structural analysis shows the compound...The Sr3Tl5 phase was prepared by high temperature synthesis techniques through reaction of the high purity elements in the welded Nb tubes.The structure established through X-ray structural analysis shows the compound is a good hypoelectronic trielide example of the Pu3Pd5 structural type in which skeletal electron count is lower than in a traditional Zintl phase(Cmcm,Z = 4;a = 10.604(2) ,b = 8.675(2) ,and c = 10.985(2) ;V = 1010.5(3) 3).The strontium size and the compound's polarity appear responsible for this thallium phase crystallization in the Pu3Pd5 family type rather than the isoelectronic Sr3In5 version.A first-principle electronic structure calculation(LMTO) demonstrates that the strontium atoms participate substantially in Sr-Tl bonding in the structure.展开更多
文摘The shaping form of an untwisted yarn-end for the air splicer is analyzed and then a cosine curve form which will have practically good splicing effect is proposed. The yarn motion in the splicing nozzle by applying hydrodynamics and the splicing principle of the air splicer are also studied.
文摘This paper presents a study of the relationship between the magnetic properties and microstructure of nanocomposite Ni/MnO, Ni/CoO, Co/MnO, Co/CoO. The objective is to understand how the coupling interface FM/AFM （ferromagnetic/anti-ferromagnetic） manifests itself in magnetic response of these materials to an applied field. Sample preparation was performed using mechanochemical synthesis by means of a ball mill planetary type high power at normal atmosphere. The characterization was done by XRD （X-ray diffraction）, SEM （scanning electron microscopy） and VSM （vibrating sample magnetometry）. Analyzing the XRD peaks of the samples studied, there was a decrease in the average particle diameter with increasing milling time, which is important in the magnetic interactions of the atoms of the surface. In addition, the diffraction pattern showed formation of new phases by oxidation interfering with the magnetic measurements. Analyses by SEM show chipboard multiform nano- and micrometer-sized grains on the surface of the clusters being responsible for the interaction. The magnetic measurements show a strong coupling between the phases present in nanocomposites showing once again that the MS （mechanosynthesis） is a powerful technique for this kind of purpose. The effect of the decrease in crystallite size leads to large variations of magnetic properties of the material which have been specifically observed changes in HC （coercive field） in the RM （remanent magnetization） and SM （saturation magnetization）. The decrease in crystallite size in the course of grinding intensifies the effects that depend on the surface-to-volume ratio of the material. M vs. T measures were taken for different values of applied field and found a jump in the moment of the sample near the N6el temperature of the antiferromagnetic.
基金supported by the National Natural Science Foundation of China(Grant No.41374181)the National Key Scientific Instrument and Equipment Development ProjectsChina(Grant No.2012YQ03014207)
文摘The single event effect(SEE) is an important consideration in electronic devices used in space environments because it can lead to spacecraft anomalies and failures. The linear energy transfer(LET) of ions is commonly investigated in studies of SEE. The use of a thin detector is an economical way of directly measuring the LET in space. An LET telescope consists of a thin detector as the front detector(D1), along with a back detector that indicates whether D1 was penetrated. The particle radiation effect monitor(PREM) introduced in this paper is designed to categorize the LET into four bins of 0.2–0.4, 0.4–1.0, 1.0–2.0 and 2.0–20 Me V·cm^2/mg, and one integral bin of LET>20 Me V·cm^2/mg. After calibration with heavy ions and Geant4 analysis, the LET boundaries of the first four bins are determined to be 0.236, 0.479, 1.196, 2.254, and 17.551 Me V·cm^2/mg, whereas that of the integral bin is determined to be LET>14.790 Me V·cm^2/mg. The acceptances are calculated by Geant4 analysis as 0.452, 0.451, 0.476, 0.446, and 1.334, respectively. The LET accuracy is shown to depend on the thickness of D1; as D1 is made thinner, the accuracy of the measured values increases.
基金supporting (by his DOE grant DE-AC02-07CH11358) the visit of J. C. Dai to Ames Laboratory, where principal part of this research was carried outthe National Natural Science Foundation of China (50971063)+1 种基金the Natural Science Foundation of Fujian Province of China (2010J01042 & 2011J01047)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China for supporting
文摘The Sr3Tl5 phase was prepared by high temperature synthesis techniques through reaction of the high purity elements in the welded Nb tubes.The structure established through X-ray structural analysis shows the compound is a good hypoelectronic trielide example of the Pu3Pd5 structural type in which skeletal electron count is lower than in a traditional Zintl phase(Cmcm,Z = 4;a = 10.604(2) ,b = 8.675(2) ,and c = 10.985(2) ;V = 1010.5(3) 3).The strontium size and the compound's polarity appear responsible for this thallium phase crystallization in the Pu3Pd5 family type rather than the isoelectronic Sr3In5 version.A first-principle electronic structure calculation(LMTO) demonstrates that the strontium atoms participate substantially in Sr-Tl bonding in the structure.
