The research on the influence of RE on the directional solidified microstructure of tin lead alloy reveals that the addition of RE can cause chopping and irregular lamellar and smaller lamellar spacing. When RE conte...The research on the influence of RE on the directional solidified microstructure of tin lead alloy reveals that the addition of RE can cause chopping and irregular lamellar and smaller lamellar spacing. When RE content increases, the microstructure changes to peritectic structure. Moreover, the eutectic point of Sn Pb alloy deviates because the affinity of RE for Sn, which results in the existence of primary Pb rich phases contained hypocutectic grown layers. Sn RE intermetallic compound has no effect on the solidification of Sn Pb alloy.展开更多
The effect of the rare earths on the high temperature properties of deformed leaded-brasses has been stu- died with the high temperature tensile test.The results show that the rare earth additives can increase elongat...The effect of the rare earths on the high temperature properties of deformed leaded-brasses has been stu- died with the high temperature tensile test.The results show that the rare earth additives can increase elongation of alloys at high temperature,but they had little effect on the maximum flow stress.With the help of SEM. X-ray diffraction instrument,quantitative metallography analysis instrument,etc.,the effect of the rare earth elements on the mierostrueture of alloys has also been examined.展开更多
Effect of different contents of La and Ga on the wettability and the mierostrueture of interface of Sn-8.9Zn- 2.7Bi trinary alloys was studied. The results show that different contents of La and Ga have significant ef...Effect of different contents of La and Ga on the wettability and the mierostrueture of interface of Sn-8.9Zn- 2.7Bi trinary alloys was studied. The results show that different contents of La and Ga have significant effect on the wettability of Sn-Zn-Bi based lead-free solder under the condition of both atmosphere and nitrogen. By adding suitable amount of Ga, Cu and La to Sn-Zn-Bi solder, a new lead-free solder Sn-8.9Zn-2.7Bi- 1.0Ga-0.5Cu-0.2La with better wettability was prepared, which has a wetting angle of 25.1° to Cu.展开更多
针对临时接地线防误操作需求,提出了遵从国家电网输变电物联网Lo Ra(Long Range Radio)组网规范的智能接地线实现方案。系统基于M-XL6无线模组实现LoRa组网,采用A40i核心板实现边缘代理平台,完成无线网络管理及与变电站内网数据交互。...针对临时接地线防误操作需求,提出了遵从国家电网输变电物联网Lo Ra(Long Range Radio)组网规范的智能接地线实现方案。系统基于M-XL6无线模组实现LoRa组网,采用A40i核心板实现边缘代理平台,完成无线网络管理及与变电站内网数据交互。智能接地线以HC32L073为主控,采用RFID实现挂接检测,LoRa通信上传挂接数据;同时设计了基于信道复用的低功耗空中唤醒功能,实现了防误系统的实时校验,并保证智能接地线的长期使用。经试点站测试,该智能接地线系统可以满足输变电站综合智能防误使用需求。展开更多
In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leac...In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leaching solutions using sulfide precipitation method were made. It was found that only about 53% of zinc and over 70% of the lead could be leached out of the dusts, while the other 47% of zinc and 30% of lead were left in the leaching residues. The zinc and lead in the resultant leaching solution can be effectively and selectively separated. When the weight ratio of sodium sulfide (M.W. = 222-240) to Pb was kept at 1.8, the lead in the solution could be precipitated out quantitatively while all the zinc was remained in the solution. The zinc left in the solution can be further recovered by the addition of extra sodium sulfide with a weight ratio of sodium sulfide to the zinc over 2.6. The resultant filtrate can be recycled to the leaching of dust in the next leaching process.展开更多
Trace amounts of La were utilized to improve the melting behaviors,microstructures,tensile properties and microhardness of Sn-3.0Ag-0.5Cu lead-free solder alloy. La has little effect on the melting behavior of Sn-3.0A...Trace amounts of La were utilized to improve the melting behaviors,microstructures,tensile properties and microhardness of Sn-3.0Ag-0.5Cu lead-free solder alloy. La has little effect on the melting behavior of Sn-3.0Ag-0.5Cu alloy according to the differential thermal analysis(DTA) tests. The X-ray diffraction(XRD) patterns show that β-Sn,Ag3Sn and Cu6Sn5 coexist in the as-cast solder alloys and LaSn3 phases emerge when adding 0.4% La. The microstructures modified by La are more uniform and much finer than that of baseline alloy,and the coarse LaSn3 particles with complex dendrites are observed by optical microscopy(OM) and scanning electron microscopy(SEM) when the addition of La is up to 0.4%. The composition of the LaSn3 phases is identified by energy-dispersive spectroscopy(EDS). There are considerable improvements in mechanical properties with 0.05% and 0.1% addition,but degenerations by adding 0.4%La. The Vickers microhardness of β-Sn and eutectic area are both enhanced with the addition of La and the microhardness of LaSn3 is much larger than those of β-Sn and eutectic area.展开更多
Lead borate glasses xB2O3+(99–x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-...Lead borate glasses xB2O3+(99–x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-7FJ(J=0–4) were analyzed to give variation of the relative electric dipole line strengths with the composition of glasses so as to examine the crucial implicit assumption of independent electric dipole line strength on the composition of glass in the Phys.Rev.Lett.2003,91,203903 paper studying l...展开更多
文摘The research on the influence of RE on the directional solidified microstructure of tin lead alloy reveals that the addition of RE can cause chopping and irregular lamellar and smaller lamellar spacing. When RE content increases, the microstructure changes to peritectic structure. Moreover, the eutectic point of Sn Pb alloy deviates because the affinity of RE for Sn, which results in the existence of primary Pb rich phases contained hypocutectic grown layers. Sn RE intermetallic compound has no effect on the solidification of Sn Pb alloy.
文摘The effect of the rare earths on the high temperature properties of deformed leaded-brasses has been stu- died with the high temperature tensile test.The results show that the rare earth additives can increase elongation of alloys at high temperature,but they had little effect on the maximum flow stress.With the help of SEM. X-ray diffraction instrument,quantitative metallography analysis instrument,etc.,the effect of the rare earth elements on the mierostrueture of alloys has also been examined.
文摘Effect of different contents of La and Ga on the wettability and the mierostrueture of interface of Sn-8.9Zn- 2.7Bi trinary alloys was studied. The results show that different contents of La and Ga have significant effect on the wettability of Sn-Zn-Bi based lead-free solder under the condition of both atmosphere and nitrogen. By adding suitable amount of Ga, Cu and La to Sn-Zn-Bi solder, a new lead-free solder Sn-8.9Zn-2.7Bi- 1.0Ga-0.5Cu-0.2La with better wettability was prepared, which has a wetting angle of 25.1° to Cu.
文摘针对临时接地线防误操作需求,提出了遵从国家电网输变电物联网Lo Ra(Long Range Radio)组网规范的智能接地线实现方案。系统基于M-XL6无线模组实现LoRa组网,采用A40i核心板实现边缘代理平台,完成无线网络管理及与变电站内网数据交互。智能接地线以HC32L073为主控,采用RFID实现挂接检测,LoRa通信上传挂接数据;同时设计了基于信道复用的低功耗空中唤醒功能,实现了防误系统的实时校验,并保证智能接地线的长期使用。经试点站测试,该智能接地线系统可以满足输变电站综合智能防误使用需求。
文摘In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leaching solutions using sulfide precipitation method were made. It was found that only about 53% of zinc and over 70% of the lead could be leached out of the dusts, while the other 47% of zinc and 30% of lead were left in the leaching residues. The zinc and lead in the resultant leaching solution can be effectively and selectively separated. When the weight ratio of sodium sulfide (M.W. = 222-240) to Pb was kept at 1.8, the lead in the solution could be precipitated out quantitatively while all the zinc was remained in the solution. The zinc left in the solution can be further recovered by the addition of extra sodium sulfide with a weight ratio of sodium sulfide to the zinc over 2.6. The resultant filtrate can be recycled to the leaching of dust in the next leaching process.
文摘Trace amounts of La were utilized to improve the melting behaviors,microstructures,tensile properties and microhardness of Sn-3.0Ag-0.5Cu lead-free solder alloy. La has little effect on the melting behavior of Sn-3.0Ag-0.5Cu alloy according to the differential thermal analysis(DTA) tests. The X-ray diffraction(XRD) patterns show that β-Sn,Ag3Sn and Cu6Sn5 coexist in the as-cast solder alloys and LaSn3 phases emerge when adding 0.4% La. The microstructures modified by La are more uniform and much finer than that of baseline alloy,and the coarse LaSn3 particles with complex dendrites are observed by optical microscopy(OM) and scanning electron microscopy(SEM) when the addition of La is up to 0.4%. The composition of the LaSn3 phases is identified by energy-dispersive spectroscopy(EDS). There are considerable improvements in mechanical properties with 0.05% and 0.1% addition,but degenerations by adding 0.4%La. The Vickers microhardness of β-Sn and eutectic area are both enhanced with the addition of La and the microhardness of LaSn3 is much larger than those of β-Sn and eutectic area.
基金supported by the National Natural Science Foundation of China (10874253 and 10874173)
文摘Lead borate glasses xB2O3+(99–x)PbO+0.5Eu2O3(x=70,60,...,10) were prepared by melt-quenching method.The luminescent properties were characterized with excitation and emission spectra.The emission intensities for 5D0-7FJ(J=0–4) were analyzed to give variation of the relative electric dipole line strengths with the composition of glasses so as to examine the crucial implicit assumption of independent electric dipole line strength on the composition of glass in the Phys.Rev.Lett.2003,91,203903 paper studying l...
