PbO-B2O3-CuV2O6掺杂对(Pb,Ca,La)(Fe,Nb)O3陶瓷微波介电性能的影响

研究了PbO3-CuV2O6(PBC)玻璃对(Pb,Ca,La)(Fe,Nb)O3(PCLFN)陶瓷微波介电性能的影响.当纯PCLFN陶瓷在1150℃烧结,介电常数εr=103,品质因数与频率之积Qf=5640 GHz,频率温度系数τf=7.1×10-6/℃.PBC玻璃添加剂能降低PCLFN陶瓷的烧结温度到1 050℃左右,同时能保持良好的介电性能.随着PBC玻璃添加量的质量分数从1.0%增加2.0%,陶瓷的Qf值减小.掺杂ω(PBC)=1%玻璃、在1 050℃烧结的陶瓷样品,能获得良好的微波介电性能为Qf=5 392 GHz,τf=8.18×10-6/℃,εr=101.     

杂卤石制备硫酸钾工艺研究

采用Ca(OH)2溶液作溶浸剂,通过溶浸实验考察了温度、溶浸剂用量(液固比)、反应时间、溶浸剂浓度对杂卤石中K+浸出率的影响,按照优化的溶浸工艺条件,溶浸剂选5％ Ca(OH)2,液固比4:1,40℃下搅拌反应3h,K+的浸出率可达90.06％.提出了可行的杂卤石提取硫酸钾的工艺.     

脉冲电晕结合Ca(OH)2吸收法脱硫脱硝

Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products.It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption.The removal of SO2 increased to 75%with the corona discharge,compared with 60%removal only with Ca(OH)2 absorption.About 40%removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption.It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively,and then absorbed by the alkali in the reactor.The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent,compared with using CaCO3 or ZnO.     

白光LED用荧光材料Ca2SiO3Cl2:Eu,Mn的制备及其光学性能研究

采用水热法合成制备了Ca2SiO3Cl2:Eu,Mn荧光材料,通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、荧光分光光度计(PL)等对样品的晶相、颗粒形貌及发光性能进行了研究。     

A rate equation for Ca(OH)2 and CO2 reaction in a spouted bed reactor at low gas concentrations

In the present study, the carbonation reaction of hydrated lime in semi-dry condition is investigated experimentally in a laboratory-scale spouted bed reactor. Results show that for operating conditions where the concentration of CO₂ is low, the capture efficiency is raised by increasing the inlet CO₂ concentration. Additionally, because of the inconsistency between the experimental reaction rate and the calculated values based on the previous proposed equations, a new rate equation is introduced that considers the dependency of CO₂ concentration too. To validate the proposed equation, its predictions were compared with another set of experimental data.     

Zr4+B位置换对(Pb0.5Ca0.5)(Fe(0.5)Nb0.5)O3

研究了Zr4+离子B位置换改性对(Pb0.5Ca0.5)(Fe0.5Nb0.5)O3陶瓷微波介电性能.实验结果表明,(Pb0.5Ca0.5)(Fe0.5Nb0.5)O3(PCFNZ)陶瓷样品呈现单一斜方钙钛矿相结构.随Zr(4+)离子的置换量增加,PCFNZ陶瓷体系的Qr值和晶粒尺寸逐渐减小;介电常数εr随着置换量增加...     

等通道转角挤压对生物Mg-Zn-Ca合金显微组织与腐蚀行为的影响

旨在探讨等通道转角挤压(equal-channel-angular-pressed,ECAP)对生物医用Mg-3Zn-0.2Ca合金的显微组织以及腐蚀行为的影响。对铸态Mg-3Zn-0.2Ca合金进行了1,2,4道次的剪切挤压变形。采用光学显微组织观察、X射线反射法、电化学等手段研究了挤压道次对镁合金显微组织、织构以及腐蚀行为的影响,也特别关注了ECAP对试样的不同截面方向的显微组织演变以及模拟体液(simulatedbodyfluid,SBF)电化学腐蚀行为的影响。结果表明:ECAP变形后铸态Mg-3Zn-0.2Ca镁合金晶粒逐渐细化,变形后镁合金呈现出与挤压方向呈一定角度的002面剪切织构;随着挤压道次增加,合金的耐蚀性先增加后降低。等通道转角挤压对合金耐蚀性的影响是晶粒尺寸、晶体缺陷和织构变化的综合效果;ECAP变形后合金不同截面方向呈现不同的耐蚀性,垂直于挤压方向截面的耐蚀性优于另2个方向截面的耐蚀性。     

析出相对含Ca镁合金腐蚀行为的影响

利用XRD、SEM、TEM和EDS等方法表征了Mg-Al-Zn-xCa(x=0、1.25%、1.74%、2.53%)合金腐蚀前后的组织结构,并采用失重法、电化学法、扫描探针显微镜(SPM)研究了合金腐蚀行为。结果表明：合金主要由α-Mg、β-Mg₁₇Al₁₂、Al₂Ca和(Mg,Al)₂Ca 组成。随着Ca含量的增加,合金组织中枝晶臂减小,主要沿晶界分布的Mg₁₇Al₁₂尺寸、数量逐渐减小, Al₂Ca由骨骼状连接成网状,(Mg,Al)₂Ca增多长大。腐蚀测试结果显示：添加Ca后的合金中α+β共晶减少,导致腐蚀通道变窄且比例减小。Ca元素能够使阳极自腐蚀电位升高,形成的Al₂Ca阴极相抑制了析氢过程。合金中主要析出相Al₂Ca 与α-Mg的电势差小于β-Mg₁₇Al₁₂与α-Mg的电势差。     

Wettability and biomineralisation of laser cladded Si doped TiCN biocoating

Surface textured Si doped TiCN coatings were synthesised on Ti–6Al–4V alloy by laser cladding technique. Phase constituent examination by X-ray diffraction revealed the formation of similar phases of TiC_0.2N_0.8 and Ti₅Si₄ within all coated samples. Laser coated samples presented much higher surface free energy compared to Ti–6Al–4V control due to the textured structure, which in turn demonstrated a better wettability and improved biomineralisation. Variation of silica content presented no significant influence on surface free energy, indicating that the silica content can be varied in a large range. The mineralised samples obtained after immersion in simulated body fluid were characterised to understand the mechanism and kinetics of Ca–P precipitation. The results confirmed that the precipitation kinetics of Ca–P was influenced by the substitution of silica.     

负载磷钼杂多酸/La0.7Ca0.3Fe0.25Co0.75O3/聚吡咯的制备及光催化性能研究

采用甘氨酸-硝酸盐燃烧法成功制备了La0.7Ca0.3Fe0.25Co0.75O3钙钛矿型复合氧化物,以(NH4)2S2O8为氧化剂,运用化学氧化法合成La0.7Ca0.3Fe0.25Co0.75O3/聚吡咯薄膜,然后通过静电自组装方法制备了一种新的表面负载修饰型复合光催化剂La0.7Ca0.3Fe0.25Co0.75O3/PPy/PMO12。采用XRD、SEM、FT-IR对催化剂的物化结构进行了表征。光催化性能测试是以亚甲基蓝染料的水溶液为降解目标,结果表明,PMo12的负载修饰改进了La0.7Ca0.3-Fe0.25Co0.75O3/PPy光催化剂的催化活性。