贵州地区牛蹄塘组底部烃源岩地球化学特征

优质烃源岩发育与热水沉积有着紧密的联系,通过对贵州地区下寒武统牛蹄塘组底部烃源岩地球化学特征研究发现,牛蹄塘组底部地层受陆源输入和热水沉积作用共同影响。沉积物中稀土元素总量变化范围较大,受热水沉积作用影响强的地层稀土元素总量极低。牛蹄塘组底部As、Sb元素异常富集和正Eu异常表明,热水沉积作用对黔东南的羊跳剖面和九门剖面影响较强,对黔西的联兴和温水剖面影响较弱。δEu/Al值可用来判别并指示热水沉积作用的影响强度,对热水沉积作用的理论研究具有指导意义。     

放入式电子测压器的校准技术研究

电子测压器是理想的火炮膛压测试仪器,用经过静态标定的测压器测得的火炮膛压峰值与铜柱测压器测得的峰值相比散布很大.究其原因可能是选用的压力传感器的带宽无法完全覆盖膛压信号的带宽,也可能是火炮发射时的恶劣环境改变了传感器的动态特性.针对上述问题,通过准δ函数校准法得出压力传感器的频响特性完全满足测量膛压的要求.设计了模拟膛压校准装置,能模拟火炮膛内高温高压环境,产生幅值在80 MPa~800 MPa,脉宽在10 ms~20 ms的压力信号.实弹测试数据表明,经过模拟应用环境校准后的测压器所测压力峰值分布稳定性好、置信度高.     

用粉煤灰和制革废水污泥等制备地聚合物材料

以粉煤灰、制革废水污泥及偏高岭土为主要原料,氢氧化钾为碱激活剂合成了一系列地聚合物材料.通过抗压强度和重金属溶出量研究了地聚合物材料的力学性能及其重金属的固化效果.结果表明,以粉煤灰和制革废水污泥制备的地聚合物材料具备一定的抗压强度,对重金属有较好的固化效果.XRD,SEM,IR研究表明,地聚合物材料为无定形态,地聚合反应使Si—O键对应的1 088 cm-1处伸缩振动峰向低波数方向明显移动.     

四川盆地海相三叠纪硫同位素组成与地质成因分析

文章通过对四川盆地海相三叠纪蒸发岩硫同位素δ^34S组成特征的对比分析,针对该区域三叠系δ^34S具有异常高值并且呈现随时间由早到晚逐渐轻化的特点,结合其沉积地质背景、物化条件,特别是对复杂条件下同位素分馏、地质地球化学特征的研究,对硬石膏的δ^34S异常高值和随蒸发而逐渐贫化的地质成因进行了探讨,旨在为重建古环境及地层的划分和对比提供重要依据。研究表明,硬石膏中δ^34S异常高值的产生主要是处在封闭环境、硫酸盐细菌还原时的同位素分馏作用的结果。     

用氡室连续测量涂膜阻氡率方法及其算法

为解决在测量涂膜阻氡率时带来的环保、经济、重复利用氡源、连续测量寻找体系平衡态等问题,在本测量系统中设计了利用廉价易得的铀矿粉作为氡源的氡室。采取以不锈钢丝网为骨架制作无衬底涂膜样板,消除衬底在测量涂膜阻氡率时带来的影响。运用统计物理学原理,找出涂膜影响氡室内的氡浓度和集氡室内的氡浓度的规律,从而推导出了一种反映涂膜阻氡率的算法。提出了涂料阻氡性能新的表示方法;提出了一个新的物理量——Pδ值(防氡值)。研究结果表明:用氡室测量涂膜阻氡率方法及其算法是可行的,可作为测量涂膜阻氡率的通用标准方法,还可作为涂膜等薄膜的隔氧性能的测量方法。     

盐添加量和热处理对内酯鱼糜凝胶品质的影响

采用葡萄糖酸内酯(GDL)诱导鲢鱼糜形成凝胶,考察了食盐添加量和热处理对内酯鱼糜凝胶品质的影响。结果表明,食盐添加量对内酯鱼糜凝胶的持水性和质构特性具有显著影响,鱼糜凝胶的失水率和蒸煮损失均随盐含量的增加而显著降低,凝胶强度和弹性在0.5%～2%的食盐添加范围内随盐添加量的增加而提高,当食盐添加量为1.5%～2%时,内酯鱼糜凝胶强度和弹性显著提高。随食盐添加量的增加,鱼糜凝胶的白度略有下降。蒸煮处理导致内酯鱼糜破断强度和硬度显著增加,弹性略有下降。      

大连刺参多糖的提取纯化及体外抗氧化活性研究

以大连刺参为原料,多糖提取率为指标,通过单因素实验和响应面试验法优化木瓜蛋白酶提取刺参多糖的酶解工艺条件;以蛋白脱除率为指标,通过单因素实验和正交试验法,优化D-葡萄糖酸-δ-内酯(GDL)对刺参多糖的脱蛋白工艺;并检测经过提取纯化后的刺参多糖的体外抗氧化活性。结果表明,刺参多糖的最佳提取工艺为:加酶量1.60%、pH7.30、温度54.0 ℃,在此条件下刺参多糖提取率为5.34%;最佳脱蛋白工艺条件为:反应温度60 ℃、反应时间2 h、GDL溶液(w/w,20%)加入量2.5 mL,蛋白脱除率为95.8%。提取纯化的刺参多糖清除DPPH自由基、羟自由基、超氧阴离子和ABTS自由基的IC₅₀分别为0.3、4.5、3.9、0.85 mg/mL。刺参多糖浓度为3.0 mg/mL时,ABTS⁺自由基的清除能力最强,达到90.4%,且与阳性对照V_C的清除能力相差不大。说明刺参多糖具有较好的体外抗氧化活性。     

Two-channel false data injection attacks on multi-sensor remote state estimation

This paper investigates a security problem in cyber-physical systems (CPSs) under multisensory framework. In the considered system, the feedback and feed-forward channels may suffer from false data injection (FDI) attacks. The attacker aims at disturbing the systems by modifying the sensors' measurements and injecting external control inputs while keep ( $ϵ,\delta$)-stealthiness. Two types of multi-sensor fusion Kalman filters, which are equivalent in the absence of attacks, are adopted by the remote state estimator. When the system is maliciously attacked, the necessary and sufficient condition is obtained to guarantee the equivalence of the sequential Kalman filter and data compression Kalman filter under two-channel attacks. Moreover, suboptimal ( $ϵ,\delta$)-stealthiness attack strategies for these Kalman filters are obtained by applying two-stage optimization method, convex analysis and monotonic optimization techniques. Finally, simulations on a numerical example of a quadrotor are carried out to validate the feasibility of theoretical results.     

Evolution behavior of δ phase in Cu12Sn2Ni alloy and the corresponding effects on alloy property

With the increase of tin content in tin bronze, the rise of δ phase made the strength, hardness of tin bronze increase and the ductility decrease sharply, that difficult to process. In this paper, the Cu12Sn2Ni alloy was prepared by centrifugal casting, the microstructure and phase formation before and after heat treatment were observed by x-ray diffraction, scanning electron microscope, and transmission electron microscope. The results showed that the as-cast sample microstructure was composed of equiaxed grains rather than coarse dendrites. centrifugal casting inhibits tin diffusion to form metastable phase β′-Cu_13.7Sn. The as-cast sample had good deformability and its tensile strength and elongation were 381.9 MPa and 12.4 %, respectively, which are higher than the mechanical properties of gravity casting. The tensile strength and elongation of the sample after furnace cooling at 620 °C/8 min are 439.5 MPa and 24.4 %, respectively, the increase was 16.6 % and 85.07 %, compared with the as-cast samples, due to the solid solution strengthening, the second phase strengthening and the homogenization of the microstructure.     

Synergistic mechanism of isolated Fe3+ and highly dispersed Ptδ+ over zeolite for boosting propane dehydrogenation

Pt-based catalysts have been widely investigated in propane dehydrogenation (PDH) owing to their high activity in C H activation, while it suffers from Pt sintering and coke deposition. We develop a transition metal Fe and zeolite support synergistic-modified method to realize the highly dispersed and stable Pt species inside zeolite over Pt/Fe-silicate-1. And it shows the excellent PDH performance with propylene generation rate of 51.6 mol C₃H₆ g_Pt⁻¹ h⁻¹ and low deactivation rate constant k_d of 0.017 h⁻¹ as well as a high TOF_Pt of 37.6 s⁻¹ at 550°C. The systematic characterizations reveal the isolated Fe³⁺ species could significantly improve Pt dispersity and regulate Pt electronic density to realize a more positive Pt^δ+ species inside Silicalite-1 pore. And the further in situ DRIFTS experiments demonstrate that the synergistic effect between the appropriate acidic Fe sites and the highly dispersed Pt^δ+ species around Fe species are responsible for the superior PDH performance.