Effect of temperature and pH value on cation exchange performance of a natural clay for selective (Cu2t, Co2t) removal: Equilibrium, sorption and kinetics

This work aims at investigating the strain effect,created by varying pH solution and continuous heating cycle,on the cation exchange process in the case of Na-rich montmorillonite sample in contact with bi-ionic solution with variable concentration,saturated respectively by Co2+ and Cu2+ cations.The ionic exchange process is characterized using XRD analysis obtained through the comparison of experimental XRD patterns with calculated ones,which allowed us to determine several structural parameters related to the nature,abundance,size,position and organization of exchangeable cation and water molecule in the interlamellar space along the caxis.Indeed,the proposed theoretical models,for the stressed samples,show that the structure presents an interstratified hydration character and proves the coexistence of more than two ’’crystallite’’ specie in the structure.The perturbation types have an obvious effect on the selective exchange process for all stressed samples,where the interlayer space is characterized by the coexistence of more one exchangeable cation.     

基于广义Hamilton算法的正定矩阵系统上的控制

考虑控制输出仅依赖控制输入的正定矩阵系统, 控制的最优性被描述为输出矩阵尽可能接近目标矩阵. 控制输入和目标矩阵之间的度量采用测地距离, 则基于广义Hamilton算法可得到从控制输入到最终控制输出的最优控制轨迹. 最后, 给出了正定矩阵系统上控制问题的数值模拟结果.      

HDI/癸二酸二辛酯二元体系气液平衡数据的测定及关联

采用准静态方法测定了368.75~423.00 K温度范围内1，6-己二异氰酸酯（HDI）单组分的饱和蒸汽压，以及HDI与癸二酸二辛酯（DOS）在369.81~424.55 K温度范围内的气液相平衡数据。借助Aspen Plus软件对实验数据进行回归，得到了溶液理论中非随即（局部）双液体（NRTL）模型方程、Wilson模型参数及关联偏差，结果表明，两种模型拟合得到的温度平均绝对偏差均小于1.55 K。进而计算了二元组分相对挥发度，发现HDI与DOS在0.300~0.900 kPa范围内存在最高共沸现象，共沸物中HDI的摩尔分数为0.105~0.112。因此，在HDI精制分离时，循环溶剂中会携带10%左右的HDI。     

正定Hermite矩阵流形上代数Lyapunov方程的信息几何算法

对于正定Hermite矩阵流形上的代数Lyapunov方程 A H X + XA + P =0, 基于流形的黎曼几何结构, 作者以矩阵- A H X + XA 和 P 之间的测地距离为目标函数, 提出了代数Lyapunov方程数值解的信息几何算法. 最后,给出了正定Hermite矩阵流形上的代数Lyapunov方程的数值模拟结果.      

硬脂酸改性处理TC4钛合金微弧氧化膜层耐蚀性的研究

在Ti₆Al₄V合金微弧氧化膜层上采用硬脂酸改性处理实现了陶瓷膜层的疏水化转变，显著提高了钛合金的耐蚀性能。利用接触角测试仪、扫描电子显微镜（SEM）、能谱仪（EDS）和傅里叶变换红外光谱仪（FT-IR）对膜层的润湿性、稳定性、微观结构和化学组成进行了分析，并通过动电位极化曲线和电化学阻抗分析了其腐蚀行为。结果表明，改性处理得到的疏水微弧氧化膜层试样能有效修复微弧氧化膜层缺陷，提高钛合金的耐蚀性能，说明硬脂酸改性处理与微弧氧化技术相结合有助于拓宽微弧氧化技术在钛合金上的应用。     

Hereditary parkinsonism with dementia is caused by mutations in ATP13A2, encoding a lysosomal type 5 P-type ATPase

Neurodegenerative disorders such as Parkinson and Alzheimer disease cause motor and cognitive dysfunction and belong to a heterogeneous group of common and disabling disorders. Although the complex molecular pathophysiology of neurodegeneration is largely unknown, major advances have been achieved by elucidating the genetic defects underlying mendelian forms of these diseases. This has led to the discovery of common pathophysiological pathways such as enhanced oxidative stress, protein misfolding and aggregation and dysfunction of the ubiquitin-proteasome system. Here, we describe loss-of-function mutations in a previously uncharacterized, predominantly neuronal P-type ATPase gene, ATP13A2, underlying an autosomal recessive form of early-onset parkinsonism with pyramidal degeneration and dementia (PARK9, Kufor-Rakeb syndrome). Whereas the wild-type protein was located in the lysosome of transiently transfected cells, the unstable truncated mutants were retained in the endoplasmic reticulum and degraded by the proteasome. Our findings link a class of proteins with unknown function and substrate specificity to the protein networks implicated in neurodegeneration and parkinsonism.     

Meta-Analysis on the associations between Prenatal Perfluoroalkyl Substances Exposure and Adverse Birth Outcomes

The epidemiological associations between the prenatal perfluoroalkyl substances(PFASs) exposure and the reproductive outcomes remain controversial. A continuous evaluation is needed to combine the inconsistent results. In this study, we explored the associations between PFASs exposure and the low birth weight(LBW), preterm birth and small for gestational age(SGA). The quality of selected literature, quantitative estimates, publication bias and subgroup analysis were performed on the basis of 17 retrieved articles published before December 2020. The results showed a significant positive association between the perfluorooctane sulfonate(PFOS) exposure and the risk of LBW [Odds ratio(OR)=1.17; 95% confidence interval(CI): 1.01, 1.36; heterogeneity: P=0.30, I~2=17%]. The positive association was also observed between the PFOS and the risk of preterm birth(OR=1.19; 95% CI: 1.01, 1.39, P=0.007; I~2=62%). There was a paucity of evidence regarding the negative effects of perfluorooctanoic acid(PFOA), perfluorohexanesulfonic acid(PFHxS) and perfluorononanoic acid(PFNA) on the pregnancy outcomes. The findings from the subgroup analysis(the sampling period, the birth gender and biologic specimens) did not substantially altered the results of the overall pooled estimate ORs. The increased prevalence of negative birth outcomes with gestational PFASs exposure warrants further explorations from biological process perspective.