钢筋混凝土剪力墙非线性分析二维材料模型研究

本文建立了一种用于钢筋混凝土剪力墙非线性分析的二维混凝土及钢筋本构模型。该模型对混凝土受压、受拉力学行为分别描述,可以对反复荷载作用下钢筋混凝土剪力墙承载力及变形进行较准确分析。为验证模型适用性,计算单片剪力墙在反复荷载作用下非线性力学行为,结果表明：计算结果反映了剪力墙的滞回特性,初步验证了本文模型的正确性和有效性。     

烧结粉尘采用机械输送与气力输送的比较

介绍了烧结厂输灰采用机械输送及气力输送两种方式各自的特点,以实际工程为例,通过技术经济比较可知：气力输送方式在技术上具有较大的优越性,而运行费用较高,但其综合效益要远优于机械输送,在烧结领域值得大力推广。     

机械研磨修复精密偶件的工艺研究

柴油机燃油供给系统作为柴油机的一个重要子系统,其工作质量的好坏,对柴油机动力性、经济性、使用可靠性影响极大。介绍了柴油机燃料系统中精密偶件的磨损原因、磨损部位以及磨损后对柴油机工作的影响;对研磨修复精密偶件的工艺作了详细探讨。     

Cryptomining Malware Detection Based on Edge Computing-Oriented Multi-Modal Features Deep Learning

In recent years, with the increase in the price of cryptocurrencies, the number of malicious cryptomining software has increased significantly. With their powerful spreading ability, cryptomining malware can unknowingly occupy our resources, harm our interests, and damage more legitimate assets. However, although current traditional rule-based malware detection methods have a low false alarm rate, they have a relatively low detection rate when faced with a large volume of emerging malware. Even ...     

振动沉拔钢护筒对周围软土层的挤压效应

通过现场测试,研究振动沉拔钢护筒施工过程对周围软土层的挤压效应,分析了孔压产生和消散规律以及挤压应力在空间上的分布特征。测试结果表明,随着钢护筒沉入深度的增加,沿土层深度的挤压应力峰值呈现逐渐增大并向深层传递的趋势,而孔压峰值也呈现向深层逐步推进的演变过程;在每次沉入或上拔过程中,孔压总是先表现为明显的上升过程,然后又开始下降;沉拔结束后经过较短的时间,挤压应力就减小至非常接近初始应力状态的值,而孔压的消散过程也非常快。     

超声波辅助提取油茶籽油工艺条件研究

以油茶籽为原料,筛选出正己烷为提取油茶籽油的适宜溶剂,并确定了最佳提取方法。考察料液比、提取温度和提取时间等因素对油茶籽油得率的影响,在单因素试验的基础上,通过正交试验确定了提取油茶籽油的较佳工艺条件,并对该工艺条件下提取的油茶籽油进行了理化检测。结果表明:在试验范围内,各因素对油茶籽油得率的影响依次为提取温度>料液比>提取时间。以正己烷为溶剂提取油茶籽油的较佳工艺参数:料液比为1:12、超声波提取温度60℃、提取时间30 min。在该工艺条件下得率达40.89%,所得油茶籽油的各项理化指标均达到了国家标准要求。     

Flow-sonochemiluminescence method for antioxidant capacity analysis

A flow-sonochemiluminescence (SCL) method that offers a fast and simple alternative to the antioxidant capacity analysis is described. Reactive oxygen species (ROS) is generated reagentlessly and in situ in pH 7.4 phosphate buffer saline by ultrasound irradiating. Luminol reacts with the ROS to give SCL. The presence of antioxidant quenches the ROS, which in turn quenches the SCL. By quantifying SCL inhibition, the antioxidant capacity measurement can be achieved. Antioxidants including uric acid, l-ascorbic acid, tannic acid, l-cysteine, citric acid, salicylic, dl-sorbol and glutathione, are selected to test the presented method. Linear relationships between the quenched SCL intensity and antioxidant concentration, IC₅₀ (half-inhibition concentration) of each antioxidant are obtained. Antioxidant capacities of six vegetables extracts (onion, potato, cabbage, carrot, cucumber and spinach) are evaluated. Under the optimized experiment condition, a high detection frequency of 590 h⁻¹ is achieved. Intra- and inter-assay variability investigation shows relatively good precision of this flow-SCL method.     

Photoassisted degradation of azodyes over FeOxH2x-3/Fe0 in the presence of H2O2 at neutral pH values

Fe0 was calcined in air at 200 degrees C and showed enhanced activity in three cycling runs for the degradation of acid red B (ARB) in the presence of H2O2 under UVA irradiation. Subsequently, the catalyst's activity was maintained effectively after 10 successive cycling experiments. Moreover, the catalyst was found to be highly effective for the degradation of nonbiodegradable azodyes ARB, reactive brilliant red X-3B, reactive red K-2G, cationic red X-GRL, and cationic blue X-GRL at neutral pH values. On the basis of characterization by X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra, the surface layer of the catalyst was mainly composed of alpha-FeOOH and gamma-Fe2O3, and the core was Fe0 (FeOxH2x-3/ Fe0). Fe,OxH2x3/Fe0 was very easily recovered from the reaction system by magnetic separation. The degradation of azodyes came from the synergistic effect of the catalysis of galvanic cells and the oxidation of heterogeneous photo-Fenton reaction on the basis of all information obtained under different experimental conditions. By the total organic carbon and GC-MS analysis, the degradation process of ARB was shown to proceed with decolorization and naphthalene ring openings into CO2 and small organic acid.     

反渗透保安过滤器滤芯频繁污堵问题的研究

通过对2级反渗透保安过滤器进出、水及滤芯粘泥成分的研究表明,造成2级反渗透保安过滤器滤芯频繁污堵的水垢样中主要含有滤芯截留的有机物质(乙酸类有机物/盐,还有部分由炼化膜用阻垢剂、杀菌剂引入的其它有机物质)、无机物质(Fe、Ca、Mg型硫酸盐、炼化膜用阻垢剂中磺酸钠等组分)及大量微生物粘泥(TGB、FB).建议重新评选适...     

基于阵列天线接收响应幅度修正的干涉仪算法

干涉仪测向算法通过将接收信号相位差与本地相位差样本进行拟合从而获得信号的来波方向,具有布阵灵活、计算量小等特点,工程应用性较高。但由于存在天线工艺误差以及接收机幅相特性不一致等因素,导致了相位误差的引入。当相位误差具有较大时变性时,本地相位差样本的校准作用将会失效,从而严重影响干涉仪测向算法的性能。为提高干涉仪算法在相位扰动条件下的测向稳定性,本文提出了一种基于天线响应幅度修正的干涉仪测向算法及其优化方法,通过将信号接收幅度引入算法并做加权处理,降低了干涉仪算法的测向误差和对系统幅相一致性的要求。经计算机仿真验证,不同时变相位误差条件下,优化后的干涉仪算法其测向平均误差仅为传统干涉仪测向算法的38%,提高了算法在干扰条件下的精度和稳定性。