Fiber swelling to improve cycle performance of paper-based separator for lithium-ion batteries application

It is well established that paper-based separators display short-circuit risk in lithium-ion batteries due to their intrinsic micron-sized pores.In this research,we have adjusted pore structure of paper by fiber swelling in liquid electrolyte.Specifically,the paper-based separator is prepared by propionylated sisal fibers through a wet papermaking process.Scanning electron microscope(SEM)and multi-range X-ray nano-computed tomography(CT)images display strong swelling of modified fibers after electrolyte absorption,which can effectively decrease the pore size of separator.Due to the high electrolyte uptake(817 wt%),paper-based separator exhibits ionic conductivity of 2.93 mS cm^(-1).^(7)Li solid-state NMR spectroscopy and Gaussian simulation reveal that the formation of local high Li^(+)ion concentration in the separator and its low absorption energy with Li^(+) ion(62.2 kcal mol^(-1))is conducive to the ionic transportation.In particular,the assembled Li/separator/LiFePO_(4) cell displays wide electrochemical stability window(5.2 V)and excellent cycle performance(capacity retention of 96.6%after 100 cycles at 0.5C)due to the reduced side reactions as well as enhanced electrolyte absorption and retention capacity by propionylation.Our proposed strategy will provide a novel perspective to design high-performance biobased separators to boost the development of clean and sustainable energy economy.

Nitrogen cold plasma treatment stabilizes Cu^(0)/Cu^(+) electrocatalysts to enhance CO_(2) to C2 conversion

Cu-based materials are ideal catalysts for CO_(2) electrocatalytic reduction reaction(CO_(2)RR) into multicarbon products.However,such reactions require stringent conditions on local environments of catalyst surfaces,which currently are the global pressing challenges.Here,a stabilized activation of Cu^(0)/Cu^(+)-onAg interface by N_(2) cold plasma treatment was developed for improving Faradaic efficiency(FE) of CO_(2)RR into C2 products.The resultant Ag@Cu-CuN_x exhibits a C2 FE of 72% with a partial current density of-14.9 mA cm^(-2) at-1.0 V vs.RHE(reversible hydrogen electrode).Combining density functional theory(DFT) and experimental investigations,we unveiled that Cu^(0)/Cu^(+) species can be co ntrollably tu ned by the incorporation of nitrogen to form CuN_x on Ag surface,i.e.,Ag@Cu-CuN_x.This strategy enhances ^(*)CO intermediates generation and accelerates C-C coupling both thermodynamically and kinetically.The intermediates O^(*)C^(*)CO,^(*)COOH,and ^(*)CO were detected by in-situ attenuated total internal reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS).The uncovered CO_(2)RR-into-C2 products were carried out along CO_(2)→^(*)COOH→^(*)CO→O^(*)C^(*)CO→^(*)C_(2)H_(3)O→^(*)C_(2)H_(4)O→ C_(2)H_(5)OH(or ^(*)C_(2)H_(3)O→^(*)O+C_(2)H_(4)) paths over Ag@Cu-CuN_x electrocatalyst.This work provides a new approach to design Cu-based electrocatalysts with high-efficiency,mild condition,and stable CO_(2)RR to C2 products.

Aging Resistance Evaluation of Aged Paper Reinforced with Different Nanocelluloses

Paper documents experience severe acidification and embrittlement.Nanocellulose is an excellent reinforcement material for paper documents owing to its compatibility and excellent mechanical strength.However,little research has been conducted on the aging resistance of nanocellulose-reinforced paper.In this study,six types of nanocelluloses were used to reinforce aged paper.The reinforcement and anti-aging performances were evaluated,and the anti-aging mechanism was further clarified.Nanocellulose with a high degree of polymerization can better enhance aged paper,and non-chemical nanocellulose also shows better anti-aging performance,such as nanocellulose prepared by mechanical or biological methods.However,nanocellulose prepared using chemical methods exhibits poor reinforcement and anti-aging performance.This is because it has a small particle size that is not beneficial for physical crosslinking with paper fibers.More importantly,the introduction of acidic or oxidizing groups on nanocellulose accelerates the acid hydrolysis and oxidation rate of paper fibers,especially nanocellulose prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl oxidation,which should not be used to protect paper documents.

Amplitude of sensory nerve action potential in early stage diabetic peripheral neuropathy:an analysis of 500 cases

Early diagnosis of diabetic peripheral neuropathy is important for the successful treatment of diabetes mellitus. In the present study, we recruited 500 diabetic patients from the Fourth Affiliated Hospital of Kunming Medical University in China from June 2008 to September 2013：221 cases showed symptoms of peripheral neuropathy （symptomatic group） and 279 cases had no symptoms of peripheral impairment （asymptomatic group）. One hundred healthy control subjects were also recruited. Nerve conduction studies revealed that distal motor latency was longer, sensory nerve conduction velocity was slower, and sensory nerve action potential and amplitude of compound muscle action potential were significantly lower in the median, ulnar, posterior tibial and common peroneal nerve in the diabetic groups compared with control subjects. Moreover, the alterations were more obvious in patients with symptoms of peripheral neuropathy. Of the 500 diabetic patients, neural conduction abnormalities were detected in 358 cases （71.6%）, among which impairment of the common peroneal nerve was most prominent. Sensory nerve abnormality was more obvious than motor nerve abnormality in the diabetic groups. The amplitude of sensory nerve action potential was the most sensitive measure of peripheral neuropathy. Our results reveal that varying degrees of nerve conduction changes are present in the early, asymptomatic stage of diabetic peripheral neuropathy.

Tooth loss inhibits neurogenesis in the dentate gyrus of adult mice

Tooth loss has been shown to affect learning and memory in mice and increases the risk of Alz- heimer＇s disease. The dentate gyrus is strongly associated with cognitive function. This study hypothesized that tooth loss affects neurons in the dentate gyrus. Adult male mice were randomly assigned to either the tooth loss group or normal control group. In the tooth loss group, the left maxillary and mandibular molars were extracted. Normal control mice did not receive any intervention. Immunofluorescence staining revealed that the density and absorbance of double- cortinand neuronal nuclear antigen-positive cells were lower in the tooth loss group than in the normal control group. These data suggest that tooth loss may inhibit neurogenesis in the dentate gyrus of adult mice.

Anisotropic Total Variation Regularization Based NAS-RIF Blind Restoration Method for OCT Image

Based on anisotropic total variation regularization(ATVR), a nonnegativity and support constraints recursive inverse filtering(NAS-RIF) blind restoration method is proposed to enhance the quality of optical coherence tomography(OCT) image. First, ATVR is introduced into the cost function of NAS-RIF to improve the noise robustness and retain the details in the image.Since the split Bregman iterative is used to optimize the ATVR based cost function, the ATVR based NAS-RIF blind restoration method is then constructed. Furthermore, combined with the geometric nonlinear diffusion filter and the Poisson-distribution-based minimum error thresholding, the ATVR based NAS-RIF blind restoration method is used to realize the blind OCT image restoration. The experimental results demonstrate that the ATVR based NAS-RIF blind restoration method can successfully retain the details in the OCT images. In addition, the signal-to-noise ratio of the blind restored OCT images can be improved, along with the noise robustness.

Influence of freeze tube deviation on the development of frozen wall during long cross-passage construction

This paper investigates the influence of the deviation in freeze pipe installation on the development of the frozen wall in long cross passages by numerical simulation with ANSYS software.The study case is from the artificial ground freezing project along the Fuzhou Metro Line 2 between Ziyang Station and Wuliting Station.Two freezepipe configurations,i.e.,one with perfectly aligned pipes without any deviation from design and another with randomly distributed deviation,are included for comparison.The effect of the random deviation in the freeze pipes on frozen wall interconnection time,the thickness of the frozen wall and the development of the temperature field is explored.For the characteristic section of the numerical model at a depth of 25 m,it is found that the frozen wall interconnection time under the random deviation case and no deviation case is 24 days and 18 days,respectively.The difference in the thickness of the thinnest frozen wall segment between the random deviation and no deviation cases is the largest in the early freezing stage(up to 0.75 m),which decreases with time to 0.31 m in the late freezing stage.The effects of random deviation are more significant in the early freezing stage and diminish as the freezing time increases.

Influence of superior cervical ganglionectomy on hippocampal neurogenesis and learning and memory in adult rats

BACKGROUND： Studies have shown that neurogenesis in the dentate gyrus plays an important role in learning and memory. However, studies have not determined whether the superior cervical ganglion or the sympathetic nerve system influences hippocampal neurogenesis or learning and memory in adult rats. OBJECTIVE： To observe differences in dentate gyrus neurogenesis, as well as learning and memory, in adult rats following superior cervical ganglionectomy. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Immunohistochemistry Laboratory of the School of Life Sciences in Lanzhou University from July 2006 to July 2007. MATERIALS： Doublecortin polyclonal antibody was provided by Santa Cruz Biotechnology, USA; avidin-biotin-peroxidase complex was purchased from Zhongshan Goldenbride Biotechnology, China; Morris water maze was bought from Taimeng Technology, China. METHODS： A total of 20 adult, male, Wistar rats were randomly divided into surgery and control groups, with 10 rats in each group. In the surgery group, the bilateral superior cervical ganglions were transected. In the control group, the superior cervical ganglions were only exposed, but no ganglionectomy was performed. MAIN OUTCOME MEASURES： To examine distribution, morphology, and number of newborn neurons in the dentate gyrus using doublecortin immunohistochemistry at 36 days following surgical procedures. To examine ability of learning and memory in adult rats using the Morris water maze at 30 days following surgical procedures. RESULTS： Doublecortin immunohistochemical results showed that a reduction in the number of doublecortin-positive neurons in the surgery group compared to the control group （P 〈 0.05）, while the distribution of doublecortin-positive neurons was identical in the two groups. The surgery group exhibited significantly worse performance in learning and spatial memory tasks compared to the control group （P 〈 0.05）. CONCLUSION： Superior cervical ganglienectomy inhibited neurogenesis in the dentate gyrus and decreased learning and memory abilities in adult rats.

Designing a P2-type cathode material with Li in both Na and transition metal layers for Na-ion batteries

P2-type layered oxides have been considered as promising cathode materials for Na-ion batteries,but the capac-ity decay resulting from the Na+/vacancy ordering and phase transformation limits their future large-scale applica-tions.Herein,the impact of Li-doping in different layers on the structure and electrochemical performance of P2-type Na_(0.7)Ni_(0.35)Mn_(0.65)O_(2) is investigated.It can be found that Li ions successfully enter both the Na and transition metal layers.The strategy of Li-doping can improve the cycling stability and rate capability of P2-type layered oxides,which promotes the development of high-performance Na-ion batteries.

Effects of Microbial Pesticides on Prevention and Control of Cucumber Downy Mildew

This experiment was carried out to explore the effects of microbial pesticides on prevention and control of cucumber downy mildew.Three kinds of microbial pesticides( Recharge,Dynamic F,and 3. 0% amino-oligosaccharin AS) were used and clean water was taken as the control( CK). The experiment showed that Recharge and 3. 0% amino-oligosaccharin AS had better control effect on cucumber downy mildew.After the first application,the average control effect of Recharge and 3. 0% amino-oligosaccharin AS was higher than 50%. After the third application,the average control effect of Recharge and 3. 0% amino-oligosaccharin AS was higher than 20%. The control effect of Dynamic F on cucumber downy mildew was relatively poor,and the average control effect after the first application was 38. 34%,and the average control effect after the third application was only 15. 64%. According to the experimental results,the average control effect of three pesticides after application showed a gradual decline trend.

Cloning and Bioinformation Analysis of Carbonic Anhydrase Gene FsCA1 of Tibet Wild Buckwheat

A carbonic anhydrase( CA) transcript was obtained from the Contig library according to the published sequencing information of the buckwheat transcripts. The full length of the CA gene was amplified by reverse transcription PCR( RT-PCR). The bioinformatics analysis showed that the full length of Fs CA1 gene was 1233 bp and open reading frame was 978 bp,and encoding 325 amino acids. The molecular weight was 35. 11 ku and the isoelectric point was 7. 59; there were 9 α helices,6 β folds,many randon coil and extension chain,containing one signal peptide and one transmembrane region,having a 2 amino acid conserved domains with typical beta-type carbonic anhydrase. Subcellular localization showed that the protein is most likely to appear in the chloroplast. The three-dimensional structure model of Fs CA1 was built by homologous modeling method,indicating that the homo-octamer of buckwheat CA and pea CA could match well,so it can be inferred that buckwheat CA is also homo-octamer. Real-time quantitative PCR was used to detect the expression of Fs CA1 in different organs of buckwheat.The results showed that Fs CA1 had the highest expression level in leaves,then in the stems,and the lowest in roots.

Analysis of Protein Content and Genetic Diversity in Pea Germplasm in Tibet

To grasp protein content and composition of pea resource in Tibet Plateau,54 pea materials from different eco-geographical environments of Tibet were collected and arranged in this paper.Based on SDS-PAGE,electrophoresis and genetic diversity analysis of water-solubility and salt-solubility proteins from 54 pea materials were conducted,and the relationship between geographical ecological factors(longitude,latitude and altitude) and total protein content was studied.The research results showed that total protein contents of 54 pea materials were between17.58% and 28.67%,in which water-solubility protein accounted for 86.12%-91.40%,while salt-solubility protein accounted for 4.76-8.29%.Total protein content of Tibet pea showed significantly positive correlation with longitude,certain positive correlation with latitude and certain negative correlation with altitude.SDS-PAGE of water-solubility and salt-solubility proteins from 54 pea materials respectively detected 1588 and 699 protein bands.Based on different mobility ratios,there were 43 kinds of water-solubility protein bands,and diversity index was between 0 and 0.5.Its relative molecular weight was between 24.87 and 149.54 ku,showing the low molecular weight region of24.71-50.41 ku and high molecular weight region of 56.34-88.08 ku.There were 24 salt-solubility protein bands based on different mobility ratios,with the diversity index of 0-0.5,and relative molecular weight was between 24.85 and 91.24 ku.According to the altitude,54 pea resources were divided into 4 geographical groups.Gene diversity indexes of each group were respectively 0.23,0.18,0.35 and 0.31,and Shannon information indexes were respectively 0.33,0.41,0.52 and 0.46.It showed that the variation of pea protein was related to altitude.In clustering analysis,the tested resources were divided into seven classes,showing that water-solubility and salt-solubility proteins could reflect genetic relationship among germplasm resources at certain degree.The research could provide theoretical basis for the development of Tibet pea resources and selection of good parents.

Aberration correction for deformable-mirror-based remote focusing enables high-accuracy whole-cell super-resolution imaging

Single-molecule localization microscopy(SMLM)enables three-dimensional(3D)investigation of nanoscale structures in biological samples,offering unique insights into their organization.However,traditional 3D super-resolution microscopy using high numerical aperture(NA)objectives is limited by imaging depth of field(DOF),restricting their practical application to relatively thin biological samples.Here,we developed a unified solution for thick sample super-resolution imaging using a deformable mirror(DM)which served for fast remote focusing,optimized point spread function(PSF)engineering,and accurate aberration correction.By effectively correcting the system aberrations introduced during remote focusing and sample aberrations at different imaging depths,we achieved high-accuracy,large DOF imaging(~8μm)of the whole-cell organelles[i.e.,nuclear pore complex(NPC),microtubules,and mitochondria]with a nearly uniform resolution of approximately 35 nm across the entire cellular volume.

BaTiO_(3)@Au nanoheterostructure suppresses triple-negative breast cancer by persistently disrupting mitochondrial energy metabolism

Abnormal metabolism has become a potential target for highly malignant and invasive triple-negative breast cancer(TNBC)due to its relatively low response to traditional therapeutics.The existing metabolic interventions demonstrated unsatisfactory therapeutic outcomes and potential systemic toxicity,resulting from the metabolic instability and limited targeting ability of inhibitors as well as complex tumor microenvironment.To address these limitations,here we developed a robust pyroelectric BaTiO_(3)@Au core–shell nanostructure(BTO@Au)to selectively and persistently block energy generation of tumor cells.Stimulated by near-infrared(NIR)laser,the Au shell could generate heat to activate the BaTiO_(3)core to produce reactive oxygen species(ROS)regardless of the constrained microenvironment,thus prominently inhibits mitochondrial oxidative phosphorylation(OXPHOS)and reduces ATP production to induce TNBC cell apoptosis.The therapeutic effects have been well demonstrated in vitro and in vivo,paving a new way for the development of metabolic interventions.

Distributed Flocking Algorithm for Multi-UAV System Based on Behavior Method and Topological Communication

There are many interesting flocking phenomena in nature,such as joint predation and group migration,and the intrinsic communication patterns of flocking are essential for studying group behavior.Traditional models of communication such as the pigeon flock model and the wolf pack model define all agents within a perceptual distance as the neighborhoods,and some models have fixed communicating numbers.There is a significant impact on the quality of the flocking formation when encountering poor initial state of the flocking,multiple obstacles,or loss of certain agents.To solve this problem,this paper proposes a local communication model with nearest agents in four directions.Based on this model and behavioral method,two distributed flocking formation algorithms are designed in this paper for different scenarios,namely the flocking algorithm and the circular formation algorithm.Numerical simulation results show that the flocking can pass through the obstacle area and re-formation smoothly,and also the formation quality of the flocking is better compared with the traditional communication model.

电场可逆调控二维单层氧化物磁电性能研究

具有原子层厚度的氧化物磁性材料拥有将二维磁性应用到下一代自旋电子学新兴领域的巨大潜力,引起了研究者的广泛关注.因此,实现二维单层氧化物磁、电性能的磁场和电场调控,为未来低功耗自旋电子器件提供了广阔应用前景.然而,电场调控二维单层氧化物磁性报道很少.本工作利用离子液体门电压进行质子掺杂,实现了对二维单层氧化物(SrRuO_(3))_(1)/(SrTiO_(3))_(N)(N=1,3)磁、电性能的电场可逆调控.随着质子掺杂浓度提高,在(SrRuO_(3))_(1)/(SrTiO_(3))_(1)中观察到了从铁磁金属到反铁磁绝缘态相变,并伴随着磁各向异性的转变.理论分析表明,质子掺杂引起的能带结构改变是结构和磁、电性能相变的主要原因.同时,SrTiO_(3)层起到质子筛作用,在质子的演化过程中扮演重要角色.该研究通过电场调控二维单层氧化物的结构和物性,为实现材料的多功能性提供了重要思路,同时也为实现低功耗功能器件提供了应用潜力.

Guaranteed cost control and anti-windup design of saturated switched systems

In this paper,the problem of guaranteed cost control and anti-windup design is studied for a class of switched systems with actuator saturation.The switching strategy and anti-windup compensator are designed to ensure the asymptotic stability of the closed-loop system and to obtain the minimum upper bound of the cost function.Some sufficient conditions for the existence of an anti-windup compensator of guaranteed cost are given by using the multiple Lyapunov functions method.On this basis,the minimum upper bound of the cost function is determined by solving the optimisation problem under the constraint of linear matrix inequality(LMI).Finally,a numerical example is given to verify the effectiveness of the proposed method.

Non-fragile stabilisation of nonlinear switched systems with actuator saturation

For nonlinear continuous-time switched systems,the problem ofhowto overcome the controller vulnerability is studied when the saturating actuator is considered.The sufficient condition of non-fragile stabilisation of the system is derived by using the method of multiple Lyapunov functions.Then,a switching law and the non-fragile state feedback controllers are designed such that the closed-loop system can be asymptotically stabilised at the origin.Finally,when some scalar parameters of the closed-loop system are given,the design issue of the non-fragile state feedback controllers and the switching law,which aim at enlarging the estimation of domain of attraction for closed-loop system,is transformed into a convex optimisation issue with linear matrix inequalities(LMI)constraints,and a numerical example is given to verify the effectiveness of the proposed method.

点集拓扑学之杨忠道定理的一个机械化证明

本文给出一种用高阶逻辑自动证明语言Isabelle在计算机中表示拓扑空间中开集、闭集、邻域和导集等基本概念的方法,在此基础上证明点集拓扑学中著名的杨忠道定理,即一拓扑空间的任意单点集的导集为闭集,则其任意子集的导集亦为闭集.

Ferromagnetic and ferroelectric properties of Aurivillius phase Bi_9Fe_(4.7)Me_(0.3)Ti_3O_(27)(Me 5 Fe, Co, Ni, Mn)

New Aurivillius phase Bi9Fe4.7Me0.3Ti3O27(Me = Fe, Co, Ni, Mn) oxides have been prepared using a citrate combustion method. X-ray diffraction on powders and high-resolution transmission electron microscopy investigation confirmed that the Bi9Fe4.7Me0.3Ti3O27 samples are with an eight-layer structure. Both ferromagnetic and ferroelectric investigations suggested that Co or Ni substitution could enhance their multiferroic properties,while Mn substitution depressed them. Among all the samples, Bi9Fe4.7Co0.3Ti3O27 sample exhibits the largest remnant polarization of Pr*3.8 l C/cm2, and the largest remnant magnetization of Mr*0.06 lB/f.u. with a Curie temperature about 764 K, while the Bi9Fe4.7Ni0.3Ti3O27 sample has the largest spontaneous magnetization(0.26 lB/f.u.). The improved ferromagnetic properties ofboth Bi9Fe4.7Co0.3Ti3O27 and Bi9Fe4.7Ni0.3Ti3O27 can be ascribed to the spin canting of magnetic ion-based sublattices via the Dzyaloshinskii–Moriya interaction and also the magnetic ions exchanging interactions(Fe3–O–Co3or Fe3–O–Ni3).