混凝土空心砌块建筑设计的若干措施

针对砌块建筑普遍存在的开裂及渗漏现象 ,在模数协调、结构构造、变形控制、墙体抗渗等方面提出了建筑与结构的设计方法和相应的技术措施。     

一种UHF RFID读写器频率合成器的设计与实现

简要介绍了UHF RFID国际标准ISO/IEC18000-6C、EPC Global C1G2及ETSI的空中射频接口要求,采用∑-△调制小数分频PLL频率合成方案,应用LMX2541及ADF4360-8芯片设计了一频率范围在860~960MHz内可跳变的UHF RFID读写器用频率合成器。仿真及实验结果表明,其各项指标均达到或超过ISO/IEC18000-6C、EPC Global C1G2及ETSI标准规定的要求,可以满足未来通用型UHF RFID读写器的应用需求。     

苏里格地区苏X井区盒8段储层粒度中值的计算及其应用

本文在研究苏里格地区石盒子组盒8段岩心分析粒度中值数据基础之上,结合测井资料提供的参数,建立了该区盒8储层粒度中值与自然伽马、密度以及声波时差之间的相关关系式,研究表明,该区盒8段储层粒度中值与自然伽马的一元二次回归关系式相关性最为显著,在利用回归关系式计算出盒8段粒度中值的基础之上,建立了该区盒8段储层的渗透率计算公式,并且取得了好的应用效果。     

智能电池组充电器设计与实现

针对传统充电器用途单一,充电状态不可获知等问题,设计了一种智能电池组充电器.该充电器以ATmega8单片机作为控制核心,实现了通过按键和LCD设置电池参数与查看充电状态,并为不同的电池类型配备了各自的充电控制算法,因此具有通用性.     

不同温度下U_3O_8结构的XRD研究

在大气环境及25～850℃条件下，用X射线衍射(XRD)法研究了八氧化三铀(U3O8)的结构变化情况。在实验温度范围内发现，U3O8存在两种相结构，相变温度约为300℃。低于300℃时，U3O8为底心正交结构(Amm2)，在300℃附近转变为对称性更高的简单六方结构(P-62m)。在两种相结构稳定的温度范围内，U3O8的点阵参数随温度的增加呈现出规律性变化。     

Facile preparation of NaV3O8/polytriphenylamine composites as cathode materials towards high-performance sodium storage

NaV₃O₈/polytriphenylamine composites were synthesized by an in situ oxypolymerization way for the first time. Among them, the NaV₃O₈/20 wt.% polytriphenylamine composite shows better cycling and rate performance. Its discharge capacity retains at 118.9 mAh g⁻¹ after 300 cycles at 120 mA g⁻¹. It also obtains a reversible capacity of 101.7 mAh g⁻¹ at 300 mA g⁻¹ after 100 cycles. These enhanced results arise from the excellent morphology, that is, smaller particles of clear edges and uniform distribution suppress the expansion and deformation of the crystal structure, and avoid large agglomerate particles gathering during the electrochemical reaction. In addition, tight polytriphenylamine (PTPAn) coating also improves the conductivity of NaV₃O₈ cathode and suppresses the dissolution of NaV₃O₈ in electrolyte.     

Study of the biosynthesis of 1-octen-3-ol using a crude homogenate of Agaricus bisporus in a bioreactor

ABSTRACT:  1-Octen-3-ol and 10-oxo- trans -8-decenoic acid are metabolites of the breakdown of linoleic acid (LA) by mushroom enzymes. These compounds can be produced in a bioreactor using a crude mushroom homogenate and the exogenous addition of LA and oxygen. The factors' duration of blending, mushroom–buffer ratio, effect of a surfactant, whole against partially clarified reaction broths, purity of LA, and utilization of stumps instead of whole mushrooms were studied for their effect on reaction yield using a 1-L bioreactor. The results showed the feasibility of using the more inexpensive 60%-pure LA instead of the 99%-pure LA even when a yield loss was involved. Waste stumps could be used instead of whole mushrooms with a yield decline of 26%.     

A study of microstructure and performance of cast Fe–8Cr–2B alloy

The effects of quenching temperature on microstructure and hardness of cast Fe–8Cr–2B alloy containing 0.3 wt% C, 2.0 wt% B, 8.0 wt% Cr, 0.6 wt% Si, and 0.8 wt% Mn were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Rockwell hardness and Vickers microhardness testers. The experimental results indicate that the as‐cast microstructure of cast Fe–8Cr–2B alloy consists of M₂B (M = Fe, Cr), M₇(C, B)₃, α‐Fe, and γ‐Fe. The dendritic matrix composed of lath martensite mixed with a small amount of retained austenite, and the netlike boride M₂B distribute in the grain boundary. After quenching between 950 °C and 1100 °C, the netlike eutectic boride are broken up and a new phase‐M₂₃(C, B)₆ which is distributed in the shape of sphere or short rod‐like are precipitated from the matrix. Both the macrohardness and microhardness of specimens increase with the increasing quenching temperature. At about 1050 °C, the hardness reaches the maximum value. However, when the temperature exceeds 1050 °C, the hardness will decrease slightly. With the increase of tempering temperature, the hardness of cast Fe–8Cr–2B alloy quenching from 1050 °C decreases gradually and its impact toughness increases slightly. Crusher hammer made of cast Fe–8Cr–2B alloy quenching from 1050 °C and tempering from 300 °C has good application effect, and its service life improves by 150–180% than that of high manganese steel hammer.     

Effect of strain waveform on creep-fatigue life for Sn–8Zn–3Bi solder

This paper describes the creep‐fatigue life of Sn–8Zn–3Bi under push–pull loading. Creep‐fatigue tests were carried out using Sn–8Zn–3Bi specimens in fast–fast, fast–slow, slow–fast, slow–slow and hold–time strain waveforms. Creep‐fatigue lives in the slow–slow and hold‐time waveforms showed a small reduction from the fast–fast lives but those in the slow–fast and fast–slow waveforms showed a significant reduction from the fast–fast lives. Conventional creep‐fatigue life prediction methods were applied to the experimental data and the applicability of the methods was discussed. Creep‐fatigue characteristics of Sn–8Zn–3Bi were compared with those of Sn–3.5Ag and Sn–37Pb.