Identification of multiple inputs single output errors-in-variables system using cumulant

A higher-order cumulant-based weighted least square（HOCWLS） and a higher-order cumulant-based iterative least square（HOCILS） are derived for multiple inputs single output（MISO） errors-in-variables（EIV） systems from noisy input/output data. Whether the noises of the input/output of the system are white or colored, the proposed algorithms can be insensitive to these noises and yield unbiased estimates. To realize adaptive parameter estimates, a higher-order cumulant-based recursive least square（HOCRLS） method is also studied. Convergence analysis of the HOCRLS is conducted by using the stochastic process theory and the stochastic martingale theory. It indicates that the parameter estimation error of HOCRLS consistently converges to zero under a generalized persistent excitation condition. The usefulness of the proposed algorithms is assessed through numerical simulations.

Thiol Ligand-Modified Au for Highly Efficient Electroreduction of Nitrate to Ammonia

Electroreduction of nitrate(NO_(3)-)to ammonia(NH_(3))is an environmentally friendly route for NH_(3)production,serving as an appealing alternative to the Haber-Bosch process.Recently,various noble metal-based electrocatalysts have been reported for electroreduction of NO_(3)-.However,the application of pure metal electrocatalysts is still limited by unsatisfactory performance,owing to the weak adsorption of nitrogen-containing intermediates on the surface of pure metal electrocatalysts.In this work,we report thiol ligand-modified Au nanoparticles as the effective electrocatalysts toward electroreduction of NO_(3)-.Specifically,three mercaptobenzoic acid(MBA)isomers,thiosalicylic acid(ortho-MBA),3-mercaptobenzoic acid(meta-MBA),and 4-mercaptobenzoic acid(para-MBA),were employed to modify the surface of the Au nanocatalyst.During the NO_(3)-electroreduction,para-MBA modified Au(denoted as para-Au/C)displayed the highest catalytic activity among these Au-based catalysts.At-1.0 V versus reversible hydrogen electrode(vs RHE),para-Au/C exhibited a partial current density for NH_(3)of 472.2 mA cm^(-2),which was 1.7 times that of the pristine Au catalyst.Meanwhile,the Faradaic efficiency(FE)for NH_(3)reached 98.7%at-1.0 V vs RHE for para-Au/C.The modification of para-MBA significantly improved the intrinsic activity of the Au/C catalyst,thus accelerating the kinetics of NO_(3)-reduction and giving rise to a high NH_(3)yield rate of para-Au/C.

肺炎克雷伯菌中同时具有高毒力和碳青霉烯类耐药性的“超级细菌”:这类新兴医院感染病原菌正在中国迅速发展

高毒力肺炎克雷伯菌(hvKP)和碳青霉烯耐药肺炎克雷伯菌(CRKP)是两种引发严重感染的细菌.hvKP通常在年轻健康的人群中引发社区获得性感染,如肝脓肿、眼内炎和脑膜炎.而CRKP则主要与医院获得性感染有关,包括尿路感染、肺炎、败血症和软组织感染.然而,近年来出现了碳青霉烯耐药高毒力肺炎克雷伯菌(CR-hvKP),使得两种细菌之间的界限逐渐模糊.CR-hvKP具有多重耐药性、高毒力和高传播性等特点,对人类健康造成了严重威胁.目前,大多数CR-hvKP的病例报告来自中国等亚洲国家.CR-hvKP的形成机制通常是hvKP或CRKP分别获得携带碳青霉烯耐药基因或毒力基因的质粒,或者两者的杂交质粒而成.该综述概述了CR-hvKP的关键耐药机制、毒力因子、临床表现和预后,并探讨了其在中国的演化过程和流行情况.

Molecule diffusion behaviours of waterproof sealants into silicone rubber insulation for submarine cable joint based on molecular dynamics simulations

The repair joints of high-voltage cables play a significant role in the urgent cable main-tenance,by recovering cable conductor,insulation,shielding layer and waterproof layer especially for submarine cables.However,the molecule diffusion and permeation pro-cesses from waterproof sealant into the cable joint insulation occur,leading to the insulation ageing and deterioration.In this article,the molecule diffusion behaviours of six typical molecules from the asphalt-based and polyurethane-based waterproof sealants into silicone rubber insulation are investigated.The results show that the order of diffusion coefficients is as follows,phenanthrene>fluoranthene>pyrene>benzo[k]fluoranthene>indeno[1,2,3-cd]pyrene>polyurethane(PU).The relative molecular mass and binding energy are pivotal factors affecting the diffusion behaviour,while there is a linear relationship between the logarithm of the diffusion coefficient and the ratio of binding energy to relative molecular mass.Besides,the rising ambient temperature in-creases the fraction of free volume of silicone rubber and decreases the binding energy,thus resulting in a higher diffusion coefficient and an enhanced permeation process of the asphalt-based sealant.In summary,the PU-based waterproof sealant,with a much lower permeability than the asphalt-based material,has a potential application in the waterproof layer for high-voltage submarine cable repair joints.

Influence of morphological variations on the AC breakdown of XLPE insulation in submarine cable factory joints

Extruded crosslinked polyethylene(XLPE)submarine cables with factory joints play a significant role in cross-sea transmission interconnection projects.Morphological variations in the insulation of submarine cables and factory joints are caused by differences in process parameters.The dielectric properties of XLPE are affected by its morphology.In this study,samples of XLPE insulating materials were taken from the cable bulk,cable–joint transition,and factory joint,respectively,of a 500 kV high-voltage AC submarine cable.The crosslinked morphology was obtained by extraction and infrared spectrometer.The crystal morphology was obtained by the way of etchant,differential scanning calorimetry,and X-ray diffractometry.The Weibull distribution was used to gather statistics of AC breakdown strength.The results show that in comparison with the cable bulk,the contents of crosslinked byproducts are higher in the cable–joint transition and factory joint.At the same time,there is a sparse distribution in terms of crystal morphology,with the appearance of smaller grains and lower crystallinity,in the cable–joint transition and factory joint.These morphological variations would generate more heat during electron transport and lengthen the free paths of electrons,then lead to the occurrence of AC breakdown.The results might provide insights into the optimisation of the morphology of XLPE,in particular submarine cable factory joints.

Characterization of two SARS-CoV-2 subgenomic RNA dynamics in severe COVID-19 patients

Little is known about Subgenomic RNA(sgRNA)dynamics in patients with Coronavirus diseases 2019(COVID-19).We collected 147 throat swabs,74 gut swabs and 46 plasma samples from 117 COVID-19 patients recruited in the LOTUS China trial(ChiCTR2000029308)and compared E and orf7a sgRNA load in patients with different illness duration,outcome,and comorbidities.Both sgRNAs were detected in all the three types of samples,with longest duration of 25,13,and 17 days for E sgRNA,and 32,28,and 17 days for orf7a sgRNA in throat,gut,and plasma,respectively.A total of 95%(57/60)of patients had no E sgRNA detected after 10 days post treatment,though 86%of them were still E RNA positive.High correlation on titer was observed between sgRNA encoding E and orf7a gene.sgRNA showed similar variation in the standard care and Lopinavir-Ritonavir group.Patients with diabetes and heart diseases showed higher pharyngeal E sgRNA at the first day(P=0.016 and 0.013,respectively)but no difference at five days after treatment,compared with patients without such commodities.Patients with hypertension and cerebrovascular diseases showed no difference in the pharyngeal sgRNA levels at both one and five days after treatment,compared with patients without these two commodities.E sgRNA levels in the initial infection showed no correlation with the serum antibody against spike,nucleoprotein,and receptor binding domains at ten days later.sgRNA lasted a long period in COVID-19 patients and might have little effect on humoral response.