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1.
采用磁控溅射法制备出以ITO为基底的纯Cu薄膜,考察溅射时间和基底温度等工艺条件对生长Cu薄膜的影响。用电子扫描显微镜(SEM)、X射线衍射仪(XRD)对薄膜的形貌、厚度和结构进行表征。实验结果表明:在一定范围内调控衬底温度和溅射时间,可获得不同形貌、尺寸和厚度的Cu薄膜,所得薄膜的晶体结构为面心立方结构,均沿(111)方向择优生长。时间是控制晶粒尺寸的重要因素,溅射时间为40 min,所得薄膜粒子较小,结晶度好,且薄膜致密均匀,随着镀膜时间的增加,膜厚与之成线性关系增加,沉积速率为0.242μm/min;温度对薄膜形貌影响显著,100℃时可获得由小粒子堆积成的类柱状结构组成的薄膜,200℃时可获得由小粒子堆积成的球形团簇组成的薄膜,随着镀膜温度的增加,膜厚与之不呈线性关系,沉积速率随温度的增加而增大;该方法所制备铜薄膜在催化、传感器等领域有潜在的应用价值。  相似文献   
2.
采用铸造法制备原位自生亚共晶Al-10Mg2Si复合材料,研究Cu和T6热处理对该复合材料组织与力学性能的影响。结果表明:适量Cu的添加能显著减小共晶Mg2Si相晶粒尺寸,使其晶体结构由粗大的长条状和汉字状转变为细小的条状和纤维状;同时使针状的β-Al5Fe Si相转变为细小的不规则富Cu颗粒。经T6热处理后,质量分数为1.5%的Cu复合材料中的共晶Mg2Si相完全球化。质量分数为1.5%的Cu添加同时提高了材料铸态下的抗拉强度(Rm)、屈服强度(Rp0.2)和伸长率(A),达317、169 MPa和2.3%,比未添加Cu提高了42.2%、24.3%和53.3%;经T6热处理的Rm和Rp0.2值分别增至332、181 MPa,而A值保持不变。同时,材料由脆性断裂完全转变为韧性断裂。  相似文献   
3.
为了优化Q345B低碳钢的表面使用性能,设计相应的药芯焊丝并采用TIG沉积方法制备了Cu基熔覆层,通过OM、SEM、EDS、XRD和显微硬度测试等方法,研究了Cu基熔覆层的微观组织、元素分布、物相组成、界面元素扩散和表面硬度等。结果显示,在成分过冷的影响下,Cu基熔覆层由界面至顶部形成了不同的晶粒形貌。熔覆层主要由FCC结构的Cu-Ni-Cr-Fe固溶体、富Cr析出相和单质C元素组成,其中,由于微观偏析的存在,固溶体内元素分布不均匀,Ni、Fe元素主要富集在枝晶内,在枝晶间浓度较低;富Cr析出相主要以球状或棒状分布在基体上,少量单质C也在基体内均匀分布。研究表明,得益于合金元素的固溶强化和第二相粒子的第二相强化作用,熔覆层平均硬度达到202.8 HV0.1,高于纯铜和Q345B基体。  相似文献   
4.
Metal-support interaction and catalyst pretreatment are important for industrial catalysis. This work investigated the effect of supports (SiO2, CeO2, TiO2 and ZrO2) for Cu–Pd catalyst with high Cu/Pd ratio (Cu/Pd = 33.5) regarding catalyst cost, and the reduction temperatures of 350 °C and 550 °C were compared. The activity based on catalyst weight follows the order of Si > Ce > Zr > Ti when reduced at 350 °C. The reduction temperature leads to the surface reconstruction over the SiO2, CeO2 and TiO2 catalysts, while results in phase transition over Cu–Pd/ZrO2. The effect of reduction temperature on catalytic performance is prominent for the SiO2 and ZrO2 supported catalysts but not for the CeO2 and TiO2 ones. Among the investigated catalysts, Zr-350 exhibits the highest methanol yield. This work reveals the importance of the supports and pretreatment conditions on the physical-chemical properties and the catalytic performance of the Cu–Pd bimetallic catalysts.  相似文献   
5.
闵高瑜  李鑫  赵峰  何伟  胡益斌 《辐射防护》2022,42(3):252-256
采用西门子公司生产的数字化X射线透视摄影系统,在不同的附加铜滤过(0、0.1、0.2、0.3 mm)下,对不同厚度的聚甲基丙烯酸甲酯(PMMA)模体进行胸部摄影。利用对比度噪声比评估不同附加铜滤过对图像质量的影响,同时使用辐射剂量仪记录不同铜滤过下的体表入射剂量,以探讨数字化胸部X射线摄影中,附加铜滤过对受检者体表入射剂量的影响。结果表明,不同附加铜滤过下,图像的对比度噪声比没有明显变化。在不同厚度的PMMA模体下,附加0.1 mm铜、0.2 mm铜、0.3 mm铜后的体表入射剂量,与没有添加铜滤过时相比分别下降了24%~29%、33%~42%和39%~47%,且差别均有统计学意义(p<0.05)。说明在数字化胸部X射线摄影中,适当增加铜滤过,不会影响图像质量,但能有效减少受检者的体表入射剂量。  相似文献   
6.
An improved glucose-chelator-albumin bioconjugate (GluCAB) derivative, GluCAB-2Mal, has been synthesized and studied for in vivo 64Cu-PET/CT imaging in breast cancer mice models together with its first-generation analogue GluCAB-1Mal. The radioligand works on the principle of tumor targeting through the enhanced permeability and retention (EPR) effect with a supportive role played by glucose metabolism. [64Cu]Cu-GluCAB-2Mal (99 % RCP) exhibited high serum stability with immediate binding to serum proteins. In vivo experiments for comparison between tumor targeting of [64Cu]Cu-GluCAB-2Mal and previous-generation [64Cu]Cu-GluCAB-1Mal encompassed microPET/CT imaging and biodistribution analysis in an allograft E0771 breast cancer mouse model. Tumor uptake of [64Cu]Cu-GluCAB-2Mal was clearly evident with twice as much accumulation as compared to its predecessor and a tumor/muscle ratio of up to 5 after 24 h. Further comparison indicated a decrease in liver accumulation for [64Cu]Cu-Glu-CAB-2Mal.  相似文献   
7.
以实验室研发的高碳高铬50Cr15MoV含Cu抗菌刀具用钢为研究材料,采用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)和维氏硬度计研究了其在不同热处理工艺下的微观组织和力学性能变化,探索了50Cr15MoV含Cu新型刀具用钢最佳热处理工艺。结果表明,50Cr15MoV含Cu刀具用钢的硬度在正火温度低于1050 ℃时逐渐升高,高于1050 ℃后逐渐降低,并随着回火温度的升高而逐渐下降,同时,50Cr15MoV含Cu刀具用钢经过500 ℃时效30 min后,由于富Cu相的析出,获得良好的抗菌性能,因此50Cr15MoV含Cu刀具用钢最佳热处理工艺为1050 ℃正火保温30 min后油淬+200 ℃回火保温90 min后空冷+500 ℃时效30 min后空冷。  相似文献   
8.
Synthesis of nanocrystalline pristine and Mn-doped calcium copper titanate quadruple perovskites, CaCu3?xMnxTi4?xMnxO12 (x = 0, 0.5, and 1.0) by modified citrate solution combustion method has been reported. Powder X-ray diffraction patterns attest the phase purity of the perovskite materials. Average particle sizes of all the materials obtained from the Scherrer's formula are in the range of 55–70 nm. The specific surface areas for all the perovskites obtained from BET isotherms are found to be low as expected for the condensed oxide systems and fall in the range of 13–17 m2 g?1. Transmission electron microscopy studies show a reduction in particle size of CaCu3Ti4O12 with increase in Mn doping. Ca and Ti are present in +2 and +4 oxidation states in all the materials as demonstrated by X-ray photoelectron spectroscopy analyses. Cu2+ gets reduced in CaCu3Ti4O12 with higher Mn content. Mn is observed to be present only in +3 oxidation state. All the materials have been examined to be active in CO oxidation as well as H2 production from methanol steam reforming. CaCu3Ti4O12 with ~14 at.% Mn is found to show best catalytic activities among these materials. A comprehensive analysis of the catalytic activities of these perovskites toward CO oxidation and H2 production from MSR reveal the cooperative activity of copper-manganese in the doped perovskites and it is more effective at lower manganese content.  相似文献   
9.
SAPO-34,SAPO-5/34 based catalysts doped with Cu,Ce as active components were synthesized via a one-pot hydrothermal method by using different amounts of additive(a-cellulose),and their catalytic activities were measured for selective catalytic reduction(SCR) of NO with NH3.The synthesized Cu-Ce co-doped products switch from cubic SAPO-34,to flower-like aggregated SAPO-5/34,hybrid crystal SAPO-5/34,and finally to spherical aggregated SAPO-34 with the increase of α-cellulose amount.The Cu-Ce co-doped SAPO-5/34 hybrid crystal structure catalysts with 0.75 mol ratios of C/P(Cu-Ce/SP-0.75)exhibit excellent NH3-SCR activity with higher than 90% NO_x conversion in the temperature range of 180-450℃,at WHSV of 20000 mL/(g·h).Furthermore,the catalyst displays outstanding sulfur resistance and NO_X conversion maintains above 90% at 200-450℃ after adding 100 ppm of SO_2.The characteristic results suggest that the high deNO_X performance of Cu-Ce/SP-0.75 is due to the enhanced accessibility,abundant activity species,excellent redox property and high adsorptive and activated capacity for NH3.  相似文献   
10.
Reliable joints of Ti3SiC2 ceramic and TC11 alloy were diffusion bonded with a 50 μm thick Cu interlayer. The typical interfacial structure of the diffusion boned joint, which was dependent on the interdiffusion and chemical reactions between Al, Si and Ti atoms from the base materials and Cu interlayer, was TC11/α-Ti + β-Ti + Ti2Cu + TiCu/Ti5Si4 + TiSiCu/Cu(s, s)/Ti3SiC2. The influence of bonding temperature and time on the interfacial structure and mechanical properties of Ti3SiC2/Cu/TC11 joint was analyzed. With the increase of bonding temperature and time, the joint shear strength was gradually increased due to enhanced atomic diffusion. However, the thickness of Ti5Si4 and TiSiCu layers with high microhardness increased for a long holding time, resulting in the reduction of bonding strength. The maximum shear strength of 251 ± 6 MPa was obtained for the joint diffusion bonded at 850 °C for 60 min, and fracture primarily occurred at the diffusion layer adjacent to the Ti3SiC2 substrate. This work provided an economical and convenient solution for broadening the engineering application of Ti3SiC2 ceramic.  相似文献   
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