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| 1 | Periodicity and Stability in Periodic n-Species Lotka-Volterra Competition System with Feedback Controls and Deviating Arguments显示文摘By using the method of coincidence degree and Lyapunov functional, a set of easily applicable criteria are established for the global existence and global asymptotic stability of strictly positive(componentwise)periodic solution of a periodic n-species Lotka-Volterra competition system with feedback controls and several deviating arguments.The problem considered in this paper is in many aspects more general and incorporate as special cases various problems which have been studied extensively in the literature.Moreover,our new criteria,which improve and generalize some well known results, can be easily checked. | MengFAN KeWANG PatriciaJ.Y.WONG RaviP.AGARWAL | 2003 | Acta Mathematica Sinica,English Series2003，19，4： | 17 |
| 2 | Effect of Electrical Current on the Tribological Behavior of the Cu-WS_2-G Composites in Air and Vacuum显示文摘As the traditional graphite-based composites cannot meet the requirement of rapid developing modern industry, novel sliding electrical contact materials with high self-lubricating performance in multiple environments are eagerly required. Herein a copper-based composite with WS2 and graphite as solid lubricant are fabricated by powder metallurgy hot-pressed method. The friction and wear behaviors of the composites with and without current are investigated under the condition with sliding velocity of 10 m/s and normal load of 2.5N/cm 2 in both air and vacuum. Morphologies of the worn surfaces are observed by optical microscope and compositions of the lubricating films are analyzed by XPS. Surface profile curves and roughness of the worn surfaces are obtained by 2205 surface profiler. The results of wear tests show that the friction coefficient and wear volume loss of the composites with current are greater than that without current in both air and vacuum due to the adverse effects of electrical current which damaged the lubricating film partially and roughed the worn surfaces. XPS results demonstrate that the lubricating film formed in air is composed of oxides of Cu, WS2 , elemental S and graphite, while the lubricating film formed in vacuum is composed of Cu, WS2 and graphite. Because of the synergetic lubricating action of oxides of Cu, WS2 and graphite, the composites show low friction coefficient and wear volume loss in air condition. Owing to the fact that graphite loses its lubricity which makes WS2 become the only lubricant, severe adhesive and abrasive wear occur and result in a high value of wear rate in vacuum condition. The formation of the lubricating film on the contact interface between the brush and ring is one of the factors which can greatly affect the wear performance of the brushes. The low contact voltage drop of the composites in vacuum condition is attributed to the high content of Cu in the surface film. This study fabricated a kind of new sliding electrical contact self-lubricating composite with dual-lubricant which can work well in both air and vacuum environments and provides a comprehensive analysis on the lubrication mechanisms of the composite. | QIAN Gang FENG Yi LI Bin HUANG Shiyin LIU Hongjuan DING Kewang | 2013 | Chinese Journal of Mechanical Engineering2013，26，2： | 8 |
| 3 | Heme oxygenase-1 alleviates ischemia/reperfusion injury in aged liver显示文摘AIM: To investigate if ischemia/reperfusion (I/R) injury in aged liver could be alleviated by heme oxygenase-1 (HO-1).METHODS: Three groups of SD rats (16 mo old) were studied. Group 1: control donors received physiological saline 24 h before their livers were harvested; group 2: donors were pretreated with hemih 24 h before their livers were harvested; and group 3: donors received hemin 24 h before their livers were harvested and zinc protoporphyrin (ZnPP,HO-1 inhibitor) was given to recipients at reperfusion. The harvested livers were stored in University of Wisconsin solution (4 ℃) for 6 h, and then transplanted to syngeneic rats. Serum glutamic oxaloacetic transaminase (SGOT),apoptotic cells, and apoptotic gene were measured 3, 6,12, 24, 48 h after reperfusion. We measured the apoptotic index by TUNEL, determined the expression of antiapoptotic Bcl-2 and proapoptotic (caspase-3) gene products by Western blot.RESULTS: After 3, 6, 12, 24, and 48 h of reperfusion, the SGOT levels (584.4±85.8 u/L, 999.2±125.2 u/L, 423.4±161.3u/L, 257.8±95.8 u/L, and 122.4±26.4 u/L) in hemin group were significantly (all P<0.05) lower than those in saline group (1082.2±101.2 u/L, 1775.2±328.3 u/L, 840.4±137.8 u/L,448.6±74.3 u/L, and 306.2±49.3 u/L). Liver HO-1 enzymatic activity correlated with beneficial effects of hemin and deleterious effects of adjunctive ZnPP treatment. Markedly less apoptotic (TUNEL+) liver cells 3, 6, 12, 24, and 48 h after reperfusion (5.16±0.73, 10.2±0.67, 9.28±0.78, 7.14±1.12,and 4.78±0.65) (P<0.05) could be detected in hemin liver grafts, as compared to controls (7.82±1.05, 15.94±1.82,11.67±1.59, 8.28±1.09, and 6.36±0.67). We detected the increased levels of Bcl-2 (1.5-fold) expression and compared with saline controls. These differences were most pronounced at 12 h after transplantation. In contrast, an active form of proapoptotic caspase-3 (p20) protein was found to be 2.9-fold lower at 24 h in hemin-pretreated group, as compared to saline liver transplant controls.CONCLUSION: HO-1 overexpression can provide potent protection against cold I/R injury. This effect depends, at least in part, on HO-1-mediated inhibition of antiapoptotic mechanism. | Xue-HaoWang KeWang FengZhang Xiang-ChengLi JunLi Wei-De JunGuo Xiao-FengQian YeFan | 2005 | World Journal of Gastroenterology2005，11，5： | 6 |
| 4 | Friction and wear properties of Cu-based self-lubricating composites in air and vacuum conditions显示文摘Cu-based self-lubricating materials containing two different solid lubricants (graphite and MoS 2 ) were fabricated by P/M hot pressing techniques. Physical and mechanical properties of the samples were examined. The effects of graphite and MoS 2 contents on friction coefficient and wear rate were investigated by a ring-on-disc wear machine in air and vacuum conditions, respectively. Tribo-films formed on the worn surfaces were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicated that density, hardness and bending strength all increased with the increasing content of MoS 2 , while the relative density was opposite. Sample B containing 15 vol. pct graphite and 15 vol. pct MoS 2 possessed superior tribological properties both in air and vacuum conditions. However, the tribo-films formed on the worn surfaces of the sample B were greatly discrepant in composition at different testing conditions. In air, the volume ratio of MoS 2 and graphite in the tribo-films is 0.31:1 whereas the ratio in vacuum is 1.07:1. | Shiyin HUANG Yi FENG Kewang DING Gang QIAN Hongjuan LIU Yang WANG | 2012 | Acta Metallurgica Sinica(English Letters)2012，25，5： | 3 |
| 5 | MicroRNA-363-3p suppresses anoikis resistance in human papillary thyroid carcinoma via targeting integrin alpha 6显示文摘MicroRNAs are highly conserved endogenous small noncoding RNAs and demonstrated to play important roles in the metastatic cascade of papillary thyroid carcinoma(PTC),including the process of anoikis resistance.In this study,the correlation between miRNA-363-3p(miR-363-3p)expression and PTC metastasis was analyzed based on clinical data,and the effect and related mechanism of miR-363-3p on anoikis resistance in B-CPAP cells were further investigated.First,miR-363-3p was found to be down-regulated in PTC tissue,which was correlated with the advanced clinical stage and lymph node(LN)metastasis.Then,functional study revealed that miR-363-3p was also down-regulated in B-CPAP cells compared with that in thyroid epithelial Nthy-ori3-1 cells,and miR-363-3p transfection could suppress anoikis resistance of B-CPAP cells.Finally,integrin alpha 6(ITGA6)was validated as the target gene of miR-363-3p,and restoration of ITGA6 expression attenuated miR-363-3p’s inhibitory effect on anoikis resistance in B-CPAP cells.These findings contribute to understand the role of miR-363-3p in the metastatic cascade of PTC and suggest the potential clinical value of miR-363-3p for the prevention of PTC metastasis. | Yi Pan Xue Zhu KeWang Yu Chen | 2019 | Acta Biochimica et Biophysica Sinica2019，51，8： | 2 |
| 6 | Provenance and paleogeography of Carboniferous-Permian strata in the Bayanhot Basin:Constraints from sedimentary records and detrital zircon geochronology显示文摘The Bayanhot Basin is a superimposed basin that experienced multiple-staged tectonic movements;it is in the eastern Alxa Block,adjacent to the North China Craton(NCC)and the North Qilian Orogenic Belt(NQOB).There are well-developed Paleozoic-Cenozoic strata in this basin,and these provide a crucial window to a greater understanding of the amalgamation process and source-to-sink relationships between the Alxa Block and surrounding tectonic units.However,due to intensive post-depositional modification,and lack of subsurface data,several fundamental issues-including the distribution and evolution of the depositional systems,provenance supplies and source-to-sink relationships during the Carboniferous-Permian remain unclear and thus hinder hydrocarbon exploration and limit the geological understanding of this basin.Employing integrated outcrop surveys,new drilling data,and detrital zircon dating,this study examines the paleogeographic distribution and evolution,and provenance characteristics of the Carboniferous-Permian strata in the Bayanhot Basin.Our results show that the Bayanhot Basin experienced a long-term depositional evolution process from transgression to retrogression during the Carboniferous-late Permian.The transgression extent could reach the central basin in the early Carboniferous.The maximum regional transgression occurred in the early Permian and might connect the Qilian and North China seas with each other.Subsequently,a gradual regression followed until the end of the Permian.The northwestern NCC appeared as a paleo-uplift area and served as a sediments provenance area for the Alxa Block at that time.The NCC,Bayanwula Mountain,and NQOB jointly served as major provenances during the Carboniferous-Permian.There was no ocean separation,nor was there an orogenic belt between the Alxa Block and the NCC that provided sediments for both sides during the Carboniferous-Permian.The accretion of the Alxa and North China blocks should have been completed before the Carboniferous period. | Junfeng Zhao Yijun Zhou KeWang Xuan Li Zhanrong Ma Zhengzhong Ruan DongWang Rui Xue | 2021 | Geoscience Frontiers2021，12，3： | 2 |
| 7 | A Highly Selective and Sensitive Fluorescence Probe for the Hypochlorite Anion显示文摘 | XinqiChen XiaochunWang ShujuanWang WenShi KeWang HuiminMa | 2008 | Chemistry – A European Journal2008，，15： | 1 |
| 8 | Islet cell tumor arising from a heterotopic pancreas in the duodenal wall with ulceration显示文摘 | Lucilene F Tolentino Hanson Lee Tony Maung Bruce E Stabile Kewang Li Samuel W French | 2003 | Experimental and Molecular Pathology2003，，1： | 1 |
| 9 | Electrical sliding friction and wear properties of Cu–MoS 2 –graphite–WS 2 nanotubes composites in air and vacuum conditions显示文摘 | Shiyin Huang Yi Feng Hongjuan Liu Kewang Ding Gang Qian | 2013 | Materials Science & Engineering A2013，，： | 1 |
| 10 | Polymer passivation of defects in inorganic perovskite solar cells显示文摘Inorganic perovskite solar cells(IPSCs)have attained attention due to their excellent thermal and phase stability.In this work,we demonstrate a novel approach for fabricating IPSCs,using the strategies of interface passivation and anti-solvent before spin-coating perovskite.Poly(methyl methacrylate)(PMMA)and chlorobenzene(CB)are used as passivator and anti-solvent,respectively.The CB improves the perovskite crystal morphology.Meanwhile,PMMA passivates the defects between poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)and perovskite layer,thus increasing the short-circuit current.Excitingly,we find that PMMA benefits the grain boundaries(GBs)of perovskite,which makes it more humidity-resistant,increasing the stability of perovskite film.Especially,PMMA mitigates interfacial charge losses,and the devices based on CsPbI_(3-x)Br_(x)passivated by PMMA exhibit the power conversion efficiency(PCE)much higher than those based on pure CsPbI_(3-x)Br_(x). | ZHANG Meng ZHANG Fanghui SHI Kewang ZHANG Wenxi HUANG Jin QIU Huimin | 2022 | Optoelectronics Letters2022，18，6： | 1 |
| 11 | Evolutionary engineering of yeast for closed-circulating ethanol fermentation in PDMS membrane bioreactor显示文摘 | Wenwu Ding Zeyi Xiao Xiaoyu Tang Kewang Deng Shengwei Fu Yandong Jiang Lin Yuan | 2011 | Biochemical Engineering Journal2011，，： | 1 |
| 12 | Brittle–ductile transition in the PETG/PC blends by adding PTW elastomer显示文摘 | XinlanZhang KeWang BoLi FengChen QiangFu | 2010 | Polym Adv Technol2010，，6： | 1 |
| 13 | Data partition and parallel evaluation of datalog programs显示文摘 | Zhang Weining Kewang Siu-Cheung Chau | 1995 | IEEE Transaction on Knowledge and Data Engineering1995，7，1： | 1 |
| 14 | Scalable Electrophysiology of Millimeter-Scale Animals with Electrode Devices显示文摘Millimeter-scale animals such as Caenorhabditis elegans,Drosophila larvae,zebrafish,and bees serve as powerful model organisms in the fields of neurobiology and neuroethology.Various methods exist for recording large-scale electrophysiological signals from these animals.Existing approaches often lack,however,real-time,uninterrupted investigations due to their rigid constructs,geometric constraints,and mechanical mismatch in integration with soft organisms.The recent research establishes the foundations for 3-dimensional flexible bioelectronic interfaces that incorporate microfabricated components and nanoelectronic function with adjustable mechanical properties and multidimensional variability,offering unique capabilities for chronic,stable interrogation and stimulation of millimeter-scale animals and miniature tissue constructs.This review summarizes the most advanced technologies for electrophysiological studies,based on methods of 3-dimensional flexible bioelectronics.A concluding section addresses the challenges of these devices in achieving freestanding,robust,and multifunctional biointerfaces. | Kairu Dong Wen-Che Liu Yuyan Su Yidan Lyu Hao Huang Nenggan Zheng John A.Rogers Kewang Nan | 2023 | Biomedical Engineering Frontiers2023，4，1： | 0 |
| 15 | An Inverse Problem of an Unknown Source in a Heat Equation | WEI Suhua Institute of Computational Mathematics, Academia Sinica, ZHENG Kewang Hebei Science and Technology University. | 1998 | Systems Science and Systems Engineering1998，8，1： | 0 |
| 16 | Advanced heterostructure of Pd nanosheets@Pt nanoparticles boosts methanol electrooxidation显示文摘Heterostructures have emerged as elaborate structures to improve catalytic activity owing to their combined surface and distinct inverse interface.However,fabricating advanced nanocatalysts with facetdependent interface remains an unexploited and promising area.Herein,we render the controlled growth of Pt nanoparticles(NPs)on Pd nanosheets(NSs)by regulating the reduction kinetics of Pt^(2+)with solvents.Specifically,the fast reduction kinetic makes the Pt NPs uniformly deposited on the Pd NSs(U-Pd@Pt HS),while the slow reduction kinetic leads to the preferential growth of Pt NPs on the edge of the Pd NSs(E-Pd@Pt HS).Density functional theory calculations demonstrate that Pd(111)-Pt interface in U-Pd@Pt HS induces the electron-deficient status of Pd substrates,triggering the d-band center downshift and amplifying the Pd-Pt intermetallic interaction.The synergy between the electronic effect and interfacial effect facilitates the removal of poisonous intermediates on U-Pd@Pt HS.By virtue of the Pd NSs@Pt NPs interface,the heterostructure achieves exceptional methanol oxidation reaction activity as well as improved durability.This study innovatively proposes heterostructure engineering with facetdependent interfacial modulation,offering instructive guidelines for the rational design of versatile heterocatalysts. | Jie Li Cheng Wang Yuefan Zhang Shinichi Hata Kewang Zhang Changqing Ye Yukihide Shiraishi Yukou Du | 2023 | Journal of Energy Chemistry2023，，10： | 0 |
| 17 | Relaxor-like dielectric behavior and its effect on energy storage performance in P(TFE-HFP-VDF) terpolymers显示文摘Capacitors are critical components in many advanced electronic and electrical systems,such as pulse power systems,due to their fast charging-discharging speed and high power density[1-4].The ever-increasing demand for compact energy storage devices requires the dielectrics,which are the energy storage materials in capacitors,to have a higher energy density and low dielectric loss[2,3].Furthermore,a stable high-temperature performance is another important parameter to be considered for some applications in which high-temperature conditions are present,such as hybrid vehicles[4-7]. | KeWang Yi Jie Liu Yang Zhou XinPing Hu ShiHai Zhang BaoJin Chu | 2020 | Science China(Physics,Mechanics & Astronomy)2020，63，2： | 0 |
| 18 | Asplenium sanshuiense sp. nov.:the Lowest Latitude Fossil Record of the Genus显示文摘Extant Asplenium is one of the most widespread fern groups and occurs in the temperate and tropical regions.However,the fossil records of this genus are poorly documented,especially in the low latitudes.Here,a new species,Asplenium sanshuiense sp.nov.is described from the early Eocene of Sanshui Basin,Guangdong Province,South China.This is the lowest modern latitude fossil record of Asplenium and the first fossil assignment of A.section Darea(Jussieu) Bak.,as well as the first fossil record of Asplemum reported from South China.This new species shows that Asplenium had already spread into South China by the early Eocene and the section Darea(Jussieu) Bak.was identifiable within the genus Asplenium during that time.This new species,combined with previous fossil spore-pollen records indicates a warm and humid climate in the Sanshui Basin of the early Eocene. | XU Kewang LIAO Wenbo JIN Jianhua LIU Xiaoyan | 2017 | Acta Geologica Sinica(English Edition)2017，91，4： | 0 |
| 19 | The first mitogenome of Lauraceae(Cinnamomum chekiangense)显示文摘There are three distinct genetic systems in higher plants,the dominant nuclear genome and the semi-autonomous organelle genomes(plastids and mitochondria).In contrast to the conserved plastid genome(plastome),the plant mitochondrial genome(mitogenome)is characterized by an intriguing“evolutionary paradox”distinguished by a remarkably low mutation rate but with a significantly high rearrangement rate(Palmer and Herbon,1988;Lai et al.,2022). | Changwei Bi Ning Sun Fuchuan Han Kewang Xu Yong Yang David K.Ferguson | 2024 | Plant Diversity2024，46，1： | 0 |
| 20 | HOMOGENIZATION OF INCOMPRESSIBLE EULER EQUATIONS显示文摘In this paper, we perform a nonlinear multiscale analysis for incompressible Euler equations with rapidly oscillating initial data. The initial condition for velocity field is assumed to have two scales. The fast scale velocity component is periodic and is of order one.One of the important questions is how the two-scale velocity structure propagates in time and whether nonlinear interaction will generate more scales dynamically. By using a Lagrangian framework to describe the propagation of small scale solution, we show that the two-scale structure is preserved dynamically. Moreover, we derive a well-posed homogenized equation for the incompressible Euler equations. Preliminary numerical experiments are presented to demonstrate that the homogenized equation captures the correct averaged solution of the incompressible Euler equation. | ThomasY.Hou Dan-pingYang KeWang | 2004 | Journal of Computational Mathematics2004，22，2： | 0 |
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