Role of cetyltrimethyl ammonium bromide, crystal violet and humic acid in the degradation of diclofenac under simulated sunlight irradiation

The photodegradation of diclofenac in the absence/presence of cetyltrimethyl ammonium bromide,crystal violet and humic acid under simulated sunlight has been studied.Under the study conditions,it is apparent that cetyltrimethyl ammonium bromide and crystal violet concentrations inhibit effects on the photodegradation of diclofenac.Humic acid has no distinct effect on the photodegradation of diclofenac.Crystal violet has an obvious antagonistic action for humic acid and a similar antagonistic action between cetyltrimethyl ammonium bromide and crystal violet.Cetyltrimethyl ammonium bromide and humic acid have synergistic effect.An antagonistic action is present between cetyltrimethyl ammonium bromide,crystal violet and humic acid.Moreover,a simple linear model which describes the obtained results is shown.     

高岭石质密封传压介质金刚石合成扩大试验研究

以高岭石替代叶蜡石为主要原料制作密封传压介质并进行了金刚石合成扩大试验。分别以试块密度、腔体直径和热处理工艺为因素进行了条件试验。根据平均单产量、粗粒级含量、高强度颗粒含量、锤耗以及合成稳定性对实验结果进行表征。结果表明:φ40 mm腔体与φ42 mm腔体使用效果较好,而φ44 mm腔体合成稳定性相对较差。通过三段升温,最高温度320℃的低温长时热处理工艺,φ44 mm腔体密封传压介质稳定性明显增加。采用以上最优条件,φ44 mm腔体高岭石质密封传压介质的使用效果为:平均单产120 ct,≥130 N晶粒所占比例为40%,≥50/60晶粒比例为80%,锤耗小于1.2 kg/1×104ct,合成稳定性较好。通过以上结果得出结论:高岭石质密封传压介质合成金刚石的效果与叶蜡石质密封传压介质相当,试验中采用的高岭石适合制作金刚石合成用密封传压介质。     

pH值对金刚石表面化学镀镍的影响

本文以金刚石颗粒表面化学镀的方法镀覆镍金属层为背景,通过X射线衍射(XRD)、扫描电镜(SEM)等测试手段研究了pH值对镀层的组织、形貌及镀速的影响。结果表明:当镀液的pH值低于10.5时,镀速几乎为零,反应不能发生;pH值在10.5～12时,镀速随pH值的增加而增大,且镀速增加较快,XRD图谱中有镍峰存在,镍峰随pH值的增加而增强,基体有裸露现象;当pH值在13左右时,镀速较为稳定,镍衍射峰较强,镀层较为均匀,无裸露现象;pH值接近14时,镀层较为粗糙,且有脱落现象。在pH值等于13的条件下二次化学镀,基体表面得到的镀层厚度大约为1.5μm,镀层致密度较好,且包覆严实。     

Controlled synchronization of discrete-time chaotic systems under communication constraints

This paper investigates the controlled synchronization problem for a class of nonlinear discrete-time chaotic systems subject to limited communication capacity. A general chaotic master system and its slave system with a controller are connected via a limited capacity channel. In this case, the effect of quantization errors is considered. A practical quantized scheme is proposed so that the synchronization error is input-to-state stable with respect to the transmission error. Meanwhile, the transmission error decays to zero exponentially. This implies that the synchronization error converges to zero under a limited communication channel. A?simulation example for the Fold chaotic system is presented to illustrate the effectiveness of the proposed method.     

Generalized synchronization of the fractional-order chaos in weighted complex dynamical networks with nonidentical nodes

A fractional-order weighted complex network consists of a number of nodes, which are the fractional-order chaotic systems, and weighted connections between the nodes. In this paper, we investigate generalized chaotic synchronization of the general fractional-order weighted complex dynamical networks with nonidentical nodes. The well-studied integer-order complex networks are the special cases of the fractional-order ones. Based on the stability theory of linear fraction-order systems, the nonlinear controllers are designed to make the fractional-order complex dynamical networks with distinct nodes asymptotically synchronize onto any smooth goal dynamics. Numerical simulations are provided to verify the theoretical results. It is worth noting that the synchronization effect sensitively depends on both the fractional order ?? and the feedback gain k _i . Moreover, generalized synchronization of the fractional-order weighted networks can still be achieved effectively with the existence of noise perturbation.     

Stabilization of impulsive switched linear systems with saturated control input

This paper considers the stabilization problem of impulsive switched linear systems with saturated control input, in which the impulses are viewed as control or disturbances. Under arbitrary switching rule and dwell time switching rule, the local stabilization conditions are obtained in terms of LMIs, respectively. The corresponding optimization problems are formulated to obtain a bigger attractive region. Our results show that impulsive control can recover part of attractive region, or allow a wide range of switching signals. If the impulses occur as disturbances, we have to increase the dwell time of switching signals to offset the effects of disturbances. Numerical examples are given to show the effectiveness of the results proposed.     

Stability and bifurcation periodic solutions in a Lotka–Volterra competition system with multiple delays

This paper is concerned with a Lotka?CVolterra competition system with multiple delays. Firstly, we investigate the existence and stability of the positive equilibrium. In particular, we find that the system has Hopf bifurcation at the positive equilibrium, whereas this singularity does not occur for the corresponding system with two delays when interspecies competition is weaker than intraspecies competition. Secondly, we analyze the stability of the periodic solutions by reducing the original system on the center manifold. Finally, some numerical examples are given to verify our theoretical results.     

Hopf bifurcation analysis in a delayed oncolytic virus dynamics with continuous control

A delayed oncolytic virus dynamics with continuous control is investigated. The local stability of the infected equilibrium is discussed by analyzing the associated characteristic transcendental equation. By choosing the delay ?? as a bifurcation parameter, we show that Hopf bifurcation can occur as the delay ?? crosses some critical values. Using the normal form theory and the center manifold reduction, explicit formulae are derived to determine the direction of bifurcations and the stability and other properties of bifurcating periodic solutions. Numerical simulations are carried out to support the theoretical results.     

聚双环戊二烯自润滑材料的高速干摩擦行为

采用拟反应注射成型法制备了含油聚双环戊二烯(PDCPD)材料.利用MMS-1G型摩擦磨损试验机考察了PDCPD材料在摩擦速率处于中高速(5～20 m/s)下的摩擦学性能.结果表明:含油PDCPD材料在中高速干摩擦下,表现出比纯PDCPD更优良的减摩耐磨性能.纯PDCPD材料的耐磨性受摩擦速率的影响相对较小,而PDCPD含油复合材料对摩擦速率更为敏感.在较低的摩擦速率下,纯PDCPD的磨损模式呈现明显的磨粒磨损;较高摩擦速率下,纯PDCPD主要为黏着磨损和微坑损伤.含油PDCPD材料具有完全不同于纯PDCPD的磨损模式,表现为轻微的表面擦伤和疲劳磨损.     

含氮杂环硼酸酯添加剂的合成及其摩擦学性能

从分子设计的观点出发,合成了1种新型的含氮杂环硼酸酯添加剂.采用四球摩擦磨损试验机评价了其在液体石蜡中的摩擦学性能,并采用扫描电子显微镜观察分析钢球磨斑的表面形貌.结果表明:在液体石蜡中加入含氮杂环硼酸酯添加剂后,承载能力有较大提高,磨斑直径明显减少.