Fe基非晶合金增强1060铝基多层复合材料的组织与性能

采用累积叠轧焊+中间退火法复合轧制1060Al/Fe基非晶多层铝合金复合板材。利用光学显微镜、扫描电镜、X-衍射分析仪以及拉伸试验机分析Al基复合材料的微观组织结构变化、断口形貌、物相组成以及力学性能。结果表明:Fe基非晶复合材料的增强体在300 ℃中间退火过程中发生部分晶化,在累积变形轧制过程中发生破碎,并随着变形道次的增加,破碎程度随之增大;复合板前6道次的累积轧制变形出现了明显的加工软化现象,并且随着变形道次的增加,其加工软化的效果愈明显;随着累积轧制变形道次增加,Al基复合材料的力学性能发生了明显的变化,第2道次轧制变形后屈服强度与抗拉强度达到了最大值为140 MPa和156 MPa,伸长率为5.53%,达到最佳综合性能。     

冷轧变形量及再结晶对TC4合金组织与性能的影响

通过XRD、OM、EDS、SEM和万能试验机等方法,研究了不同冷变形量对TC4合金微观组织及力学性能的影响以及相同再结晶处理对不同冷变形量合金再结晶程度的影响。结果表明,冷轧制使得TC4合金产生加工硬化,相较固溶试样,35%和48%冷变形量试样的抗拉强度分别提高451 MPa和228 MPa。再结晶工艺相同时,随着变形量的增大,合金的抗拉强度逐渐降低。     

Performance analysis of hybrid power configurations: Impact on primary energy intensity,carbon dioxide emissions,and life cycle costs

Utilization of Natural gas and Hydrogen to support current and future building energy needs to offset the total electric demand while improving the grid resiliency and energy efficiency was investigated. Demand side energy management will play an important role in efficiently managing the available energy resources. Performance assessment of different power generation and energy management configurations is presented in this paper. Development of solutions in addressing grid resiliency by providing the ability to design suitable configurations for meeting individual building energy needs is discussed. Primary movers (PM) such as internal combustion engines (ICE) and fuel cells (FC) along with small scale auxiliary renewable energy source such as photovoltaics (PV) were considered. Key attributes of total carbon foot-print, life cycle costs including capital and operational expenditure, electric grid offset or peak shaving capability, thermal energy availability and its further potential to offset total electric demand, and primary energy intensity are analyzed and discussed in detail.     

A new high-pressure clearance seal with flexible laddered piston assembly in oil-free miniature compressor for potential hydrogen applications and investigation on its dynamic sealing efficiency

In this paper, a new flexible laddered piston assembly of clearance seal without any soft seal part was proposed for a long life time run of high-pressure stage in oil-free miniature compressor for potential hydrogen applications. In this assembly, the functions of radial load bearing and gas sealing were undertaken independently by large and small piston. The dynamic sealing performance evaluation was carried out by comprehensively considering the real-time variation of gas properties and piston motion with thermodynamic process in the compression chamber. Simulation study shows that the introduced clearance gap has a great influence on the expansion, compression and discharge process. Leakage through the clearance would lead to the in-cylinder pressure drop during the discharge process and bring about oscillation and earlier closure of the discharge valve. Sealing clearance exert more significant influence on the sealing efficiency in the high-pressure stage compared to sealing length and shaft speed.     

不同温度作用后混凝土强度变化规律的研究

对C20,C40混凝土的标准立方体试件,进行了在高温100℃,300℃,500℃,700℃,900℃作用2 h后自然冷却、静置6 h的抗压强度试验以及在400℃和600℃分别持续加热1 h,2 h,3 h,4 h,5 h后自然冷却、静置6 h的抗压强度试验,分析讨论了不同的高温作用后混凝土材料劣化的机理以及对抗压强度的影响,探讨了抗压强度变化的规律。     

A study on the hydrogen storage performance of graphene–Pd(T)–graphene structure

The 1–6 H₂ molecule adsorption energy and electronic properties of sandwich graphene–Pd(T)–Graphene (G–Pd(T)–G) structure were studied by the first-principle analysis. The binding energies, adsorption energies, and adsorption distances of Pd atoms-modified single-layer graphene and bilayer graphene with H₂ molecules at B, H, T adsorption sites were calculated. In bilayer graphene, the adsorption properties at T sites were found to be more stable than those at B and H sites. The binding energy of Pd atoms (4.16 eV) on bilayer graphene was higher than the experimental cohesion energy of Pd atoms (3.89 eV), and this phenomenon eliminated the impact of metal clusters on adsorption properties. It was found that three H₂ molecules were stably adsorbed on the G–Pd(T)–G structure with an average adsorption energy of 0.22 eV. Therefore, it can be speculated that G–Pd(T)–G is an excellent hydrogen storage material.     

利用鸡蛋壳制备过氧化钙的工艺研究

以鸡蛋壳为钙源，制备过氧化钙，并考察了反应时间，蛋壳灰分的用量以及稳定剂（双氧水）的用量等因素对产物产率的影响。由实验结果得出最佳条件为反应时间20mm，稳定剂用量为21mL，蛋壳灰份用量为2．0g，其产率最高。最高产率为78．1％。     

基于Contourlet域K-L变换的SAR图像相干斑抑制

针对SAR图像相干斑噪声去除问题,提出了一种基于多尺度分解的Contourlet域K-L变换的SAR图像去噪的新方法。方法首先对源图像进行Contourlet分解,在不同频段的子带图像中,利用K-L变换进行能量保持即提出信号的主要特征,用重构图像来进行去噪,最后通过Contourlet逆变换得到去噪之后的图像。在SAR图像上的实验结果表明,方法不仅较好地保持了图像的纹理和细节特征及边缘特征,且信噪比也较高。