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    题名 作者 年代 出处 被引量
1Epidemiology of acute kidney injury in intensive care septic patients based on the KDIGO guidelines显示文摘Peng Qianyi Zhang Lina Ai Yuhang Zhang Lemeng 2014Chinese Medical Journal2014,,10:24
2Kinematics and Dynamics Hessian Matrices of Manipulators Based on Screw Theory显示文摘The complexity of the kinematics and dynamics of a manipulator makes it necessary to simplify the modeling process.However,the traditional representations cannot achieve this because of the absence of coordinate invariance.Therefore,the coordinate invariant method is an important research issue.First,the rigid-body acceleration,the time derivative of the twist,is proved to be a screw,and its physical meaning is explained.Based on the twist and the rigid-body acceleration,the acceleration of the end-effector is expressed as a linear-bilinear form,and the kinematics Hessian matrix of the manipulator(represented by Lie bracket)is deduced.Further,Newton-Euler's equation is rewritten as a linear-bilinear form,from which the dynamics Hessian matrix of a rigid body is obtained.The formulae and the dynamics Hessian matrix are proved to be coordinate invariant.Referring to the principle of virtual work,the dynamics Hessian matrix of the parallel manipulator is gotten and the detailed dynamic model is derived.An index of dynamical coupling based on dynamics Hessian matrix is presented.In the end,a foldable parallel manipulator is taken as an example to validate the deduced kinematics and dynamics formulae.The screw theory based method can simplify the kinematics and dynamics of a manipulator,also the corresponding dynamics Hessian matrix can be used to evaluate the dynamical coupling of a manipulator.ZHAO Tieshi GENG Mingchao CHEN Yuhang LI Erwei YANG Jiantao 2015Chinese Journal of Mechanical Engineering2015,28,2:22
3An Accurate and Real-time Method of Self-blast Glass Insulator Location Based on Faster R-CNN and U-net with Aerial Images显示文摘This paper proposes a new deep learning framework for the location of broken insulators(in particular the self-blast glass insulator)in aerial images.We address the broken insulators location problem in a low signal-noise-ratio(SNR)setting.We deal with two modules:1)object detection based on Faster R-CNN,and 2)classification of pixels based on U-net.For the first time,our paper combines the above two modules.This combination is motivated as follows:Faster R-CNN is used to improve SNR,while the U-net is used for classification of pixels.A diverse aerial image set measured by a power grid in China is tested to validate the proposed approach.Furthermore,a comparison is made among different methods and the result shows that our approach is accurate in real time.Zenan Ling Dongxia Zhang Robert C.Qiu Zhijian Jin Yuhang Zhang Xing He Haichun Liu 2019CSEE Journal of Power and Energy Systems2019,5,4:22
4The role of Toll-like receptors in non-infectious lung injury显示文摘在病原体识别的像使用费的受体(TLR ) 的角色在最近的年里是快速地先进的。然而,进在非传染的织物损害的 TLR 的功能的调查刚开始了。以前,我们和其它表明了那碎裂的 hyaluronan (哈) 在织物损害期间积累。CD44 被要求在织物损害期间清除 HA,并且损害了清理哈在不停的发炎的结果。另外,碎裂哈在损害地点由煽动性的房间刺激煽动性的基因的表示。最近,我们识别了那哈碎片要求 TLR2 和 TLR4 刺激老鼠巨噬细胞生产煽动性的 chemokines 和 cytokines。在一个非传染的肺损害模型,在 TLR2 和 TLR4 缺乏的老鼠显示出煽动性的房间的损害 transepithelial 迁居,增加的织物损害,提高的肺上皮的房间 apoptosis,和减少的幸存。在高分子的质量的表示上的肺上皮的房间哈对尖锐的肺损害和 apoptosis 的保护的老鼠,部分地通过 NF-kappaB 的 TLR 依赖的基础激活。在 TLR2 和 TLR4 的夸大的损害缺乏的老鼠看起来由于上皮的房间上的损害 HA-TLR 相互作用。这些研究识别那个主机矩阵部件哈并且 TLR 相互作用提供开始煽动性的回答的信号,维持上皮的房间完整,并且支持从尖锐的肺损害的恢复。房间研究(2006 ) 16:693-701。做 i:10.1038/sj .cr.7310085;出版联机 2006 年 8 月 8 日。Dianhua Jiang Jiurong Liang Yuhang Li Paul W Noble 2006Cell Research2006,16,8:16
5Effects of relative thickness on aerodynamic characteristics of airfoil at a low Reynolds number显示文摘This study focuses on the characteristics of low Reynolds number flow around airfoil of high-altitude unmanned aerial vehicles(HAUAVs) cruising at low speed.Numerical simulation on the flows around several representative airfoils is carried out to investigate the low Reynolds number flow.The water tunnel model tests further validate the accuracy and effectiveness of the numerical method.Then the effects of the relative thickness of airfoil on aerodynamic performance are explored, using the above numerical method, by simulating flows around airfoils of different relative thicknesses(12%, 14%, 16%, 18%), as well as different locations of the maximum relative thickness(x/c = 22%, 26%, 30%, 34%), at a low Reynolds number of 5 · 105.Results show that performance of airfoils at low Reynolds number is mainly affected by the laminar separation bubble.On the premise of good stall characteristics, the value of maximum relative thickness should be as small as possible, and the location of the maximum relative thickness ought to be closer to the trailing edge to obtain fine airfoil performance.The numerical method is feasible for the simulation of low Reynolds number flow.The study can help to provide a basis for the design of low Reynolds number airfoil.Ma Dongli Zhao Yanping Qiao Yuhang Li Guanxiong 2015Chinese Journal of Aeronautics2015,28,4:13
6Correlation between lower gastrointestinal tract symptoms and quality of life in patients with stable chronic obstructive pulmonary disease显示文摘OBJECTIVE:To explore correlations between the symptoms of constipation and abdominal distention and severity of chronic obstructive pulmonary disease(COPD)in patients with stable disease.METHODS:We studied 191 patients with stable COPD(according to defined criteria)in this cross-sectional study from four three-level class A Chinese medicine hospitals in China.We built an Epidata 3.0 database and performed statistical analysis with SPSS,version 17.0.We analyzed correlations between the frequency of lower gastrointestinal tract symptoms(constipation and abdominal distention)and scores for major pulmonary symptoms(cough,sputum and wheezing)based on the St.George's Respiratory Questionnaire(SGRQ),6-minute walking distance(6MWD)and frequency of acute exacerbations of COPD(AECOPD).RESULTS:In addition to their pulmonary symptoms,39.79%and 40.31%of study patients withstable COPD reported constipation and abdominal distention,respectively.Scores for major pulmonary symptoms(cough,sputum and wheezing),AECOPD and SGRQ values in patients with constipation and abdominal distention were significantly greater,and the 6MWD markedly shorter,than in those without them.According to Pearson's correlation analysis,there were strong correlations between these lower gastrointestinal tract symptoms and scores for pulmonary symptoms,SGRQ,6MWD and AECOPD.CONCLUSION:Lower gastrointestinal tract symptoms such as constipation and abdominal distention can adversely affect pulmonary symptoms,frequency of acute exacerbations and quality of life in patients with stable COPD.Yan Sun Fengjie Zheng Yuhang Li Ruohan Wu Yuchao Liu Miao Liu Jinchao Zhang Kuo Gao 2013Journal of Traditional Chinese Medicine2013,33,5:10
7Challenges and recent progress in thermal management with heat pipes for lithium-ion power batteries in electric vehicles显示文摘Electric vehicles(EVs)are globally undergoing rapid developments,and have great potentials to replace the traditional vehicles based on fossil fuels.Power-type lithium-ion batteries(LIBs)have been widely used for EVs,owing to high power densities,good charge/discharge stability,and long cycle life.The driving ranges and acceleration performances are gaining increasing concerns from customers,which depend highly on the power level of LIBs.With the increase in power outputs,rising heat generation significantly affects the battery performances,and in particular operation safety.Meanwhile,the cold-start performance is still an intractable problem under extreme conditions.These challenges put forward higher requirements for a dedicated battery thermal management system(BTMS).Compared to traditional BTMSs in EVs,the heat pipe-based BTMS has great application prospects owing to its compact structure,flexibility,low cost,and especially high thermal conductivity.Encompassing this topic,this review first introduces heat generation phenomena and temperature characteristics of LIBs.Multiple abuse conditions and thermal runaway issues are described afterward.Typical cooling and preheating methods for designing a BTMS are also discussed.More emphasis on this review is put on the use of various heat pipes for BTMSs to enhance the thermal performances of LIBs.For lack of wide application in actual EVs,more efforts should be made to extend the use of heat pipes for constructing an energy-efficient,cost-effective,and reliable BTMS to improve the performances and safety of EVs.HUANG Yao TANG Yong YUAN Wei FANG GuoYun YANG Yang ZHANG XiaoQing WU YaoPeng YUAN YuHang WANG Chun LI JinGuang 2021Science China(Technological Sciences)2021,64,5:10
8Immunogenicity analysis following human immunodeficiency virus recombinant DNA and recombinant vaccinia virus Tian Tan prime-boost immunization显示文摘This study assessed and compared the immunogenicity of various immunization strategies in mice using combinations of recombinant DNA(pCCMp24) and recombinant attenuated vaccinia virus Tian Tan(rddVTT-CCMp24).Intramuscular immunization was performed on days 0(prime) and 21(boost).The immunogenicity of the vaccine schedules was determined by measuring human immunodeficiency virus(HIV)-specific binding antibody levels and cytokine(interleukin-2 and interleukin-4) concentrations in peripheral blood,analyzing lymphocyte proliferation capacity against HIV epitopes and CD4 + /CD8 + cell ratio,and monitoring interferon-gamma levels at different times post-immunization.The results showed that pCCMp24,rddVTT-CCMp24 and their prime-boost immunization induced humoral and cellular immune responses.The pCCMp24/rddVTT-CCMp24 immunization strategy increased CD8 + T cells and induced more IFN-γ-secreting cells compared with single-shot rDNA.The prime-boost immunization strategy also induced the generation of cellular immunological memory to HIV epitope peptides.These results demonstrated that prime-boost immunization with rDNA and rddVTT-CCMp24 had a tendency to induce greater cellular immune response than single-shot vaccinations,especially IFN-γ response,providing a basis for further studies.LIU CunXia DU ShouWen LI Chang WANG YuHang WANG MaoPeng LI Yi YIN RongLan LI Xiao REN DaYong QIN YanQing REN JingQiang JIN NingYi 2013Science China(Life Sciences)2013,56,6:7
9Erosion wear experiments and simulation analysis on bionic anti-erosion sample显示文摘The dorsal surface of a desert lizard has excellent particle erosion resistance.In this paper,a bio-inspired sample was designed and fabricated based on the biological characteristics of the dorsal skin of the desert lizard(Laudakin stoliczkana).The bionic sample consists of two materials with different characteristics,which form a two-layer composite structure.The particle erosion property and erosion wear mechanism of the bionic sample was studied by means of sandblast experiment and numerical simulation,respectively.The experimental results show that,in the stage with steady abrasion rate,the weight loss per unit time of the bionic sample is about 10%lesser than the control sample.The numerical simulation indicated that the two-layer structure of the bionic sample can efficiently absorb the normal stress,and dissipate the stress in the horizontal direction.Thus,the stress concentration on the sample surface is suppressed.The two-layer structure is contributed to the decentralizing of the stress distribution,and thus the occurrence probability of erosion damage can be decreased.ZHANG YuHang HUANG He REN LuQuan 2014Science China(Technological Sciences)2014,57,3:7
10VISCOELASTICITY AND POROELASTICITY IN ELASTOMERIC GELS显示文摘An elastomeric gel is a mixture of a polymer network and a solvent.In response to changes in mechanical forces and in the chemical potential of the solvent in the environment,the gel evolves by two concurrent molecular processes:the conformational change of the network,and the migration of the solvent.The two processes result in viscoelasticity and poroelasticity,and are characterized by two material-specific properties:the time of viscoelastic relaxation and the effective diffusivity of the solvent through the network.The two properties define a materialspecific length.The material-specific time and length enable us to discuss macroscopic observations made over different lengths and times,and identify limiting conditions in which viscoelastic and poroelastic relaxations have either completed or yet started.We formulate a model of homogeneous deformation,and use several examples to illustrate viscoelasticity-limited solvent migration,where the migration of the solvent is pronounced,but the size of the gel is so small that the rate of change is limited by viscoelasticity.We further describe a theory that evolves a gel through inhomogeneous states.Both infinitesimal and finite deformation are considered.Yuhang Hu Zhigang Suo 2012Acta Mechanica Solida Sinica2012,25,5:7
11The histone H3 lysine-27 demethylase Jmjd3 plays a critical role in specific regulation of Th17 cell differentiation显示文摘Interleukin(IL)17-producing T helper(Th17)cells play critical roles in the clearance of extracellular bacteria and fungi as well as the pathogenesis of various autoimmune diseases,such as multiple sclerosis,psoriasis,and ulcerative colitis.Although a global transcriptional regulatory network of Th17 cell differentiation has been mapped recently,the participation of epigenetic modifications in the differentiation process has yet to be elucidated.We demonstrated here that histone H3 lysine-27(H3K27)demethylation,predominantly mediated by the H3K27 demethylase Jmjd3,crucially regulated Th17 cell differentiation.Activation of naı¨ve CD41 T cells immediately induced high expression of Jmjd3.Genetic depletion of Jmjd3 in CD41 T cells specifically impaired Th17 cell differentiation both in vitro and in vivo.Ectopic expression of Jmjd3 largely rescued the impaired differentiation of Th17 cells in vitro in Jmjd3-deficientCD41 T cells.Importantly,Jmjd3-deficient mice were resistant to the induction of experimental autoimmune encephalomyelitis(EAE).Furthermore,inhibition of the H3K27 demethylase activity with the specific inhibitor GSK-J4 dramatically suppressed Th17 cell differentiation in vitro.At the molecular level,Jmjd3 directly bound to and reduced the level of H3K27 trimethylation(me3)at the genomic sites ofRorc,which encodes the masterTh17 transcription factorRorgt,and Th17 cytokine genes such as Il17,Il17f,and Il22.Therefore,our studies established acritical role of Jmjd3-mediatedH3K27demethylation inTh17 cell differentiation andsuggest that Jmjd3 can be a novel therapeutic target for suppressing autoimmune responses.Zhi Liu Wei Cao Longxia Xu Xi Chen Yu Zhan Qian Yang Sanhong Liu Pengfei Chen Yuhang Jiang Xiaohua Sun Yu Tao Yiming Hu Cuifeng Li Qi Wang Ying Wang Charlie Degui Chen Yufang Shi Xiaoren Zhang 2015Journal of Molecular Cell Biology2015,7,6:6
12Elevating H3K27me3 level sensitizes colorectal cancer to oxaliplatin显示文摘Histone methylation is a context-dependent modification that regulates gene expression,and the trimethylation of histone H3 lysine 27(H3K27me3)usually induces gene silencing.Overcoming colorectal cancer(CRC)chemoresistance is currently a huge challenge,but the relationship between H3K27me3 modification and chemoresistance remains largely unclear.Here,we found that H3K27me3 levels positively correlated with the metastasis-free survival of CRC patients and a low H3K27me3 level predicted a poor outcome upon chemotherapeutic drug treatment.Oxaliplatin stimulation significantly induced the expression of H3K27 lysine demethylase 6A/6B(KDM6A/6B),thus decreasing the level of H3K27me3 in CRC cells.Elevation of H3K27me3 level through KDM6A/6B depletion or GSK-J4(a KDM6A/6B inhibitor)treatment significantly enhanced oxaliplatin-induced apoptosis.Conversely,when inhibiting the expression of H3K27me3 by EPZ-6438,an inhibitor of the histone methyltransferase EZH2,the proportion of apoptotic cells remarkably decreased.In addition,the combination of GSK-J4 and oxaliplatin significantly inhibited tumor growth in an oxaliplatin-resistant patient-derived xenograft model.Importantly,we revealed that oxaliplatin treatment dramatically induced NOTCH2 expression,which was caused by downregulation of H3K27me3 level on the NOTCH2 transcription initiation site.Thus,the activated NOTCH signaling promoted the expression of stemness-related genes,which resulted in oxaliplatin resistance.Furthermore,oxaliplatin-induced NOTCH signaling could be interrupted by GSK-J4 treatment.Collectively,our findings suggest that elevating H3K27me3 level can improve drug sensitivity in CRC patients.Qi Wang Xi Chen Yuhang Jiang Sanhong Liu Hanshao Liu Xiaohua Sun Haohao Zhang Zhi Liu Yu Tao Cuifeng Li Yiming Hu Dandan Liu Deji Ye Yongzhong Liu Mingliang Wang Xiaoren Zhang 2020Journal of Molecular Cell Biology2020,12,2:6
13Concrete durability under different circumstances based on multi-factor effects显示文摘Concrete durability has become a hot research field in civil engineering. Concrete structures suffer salt-erosion damage to different degrees in the semi-arid region of North China. The environmental condition is one of the important factors affecting the durability of concrete constructions. To realize fully the interaction between various environmental factors, this paper researched concrete durability in the salt environment under combined actions(immersing, freeze–thaw cycles, and wet–dry cycles). According to the laboratory test data, the concrete-durability degradation law under coupling-effect factors was investigated. The results show that concrete's compressive strength decreases with the increase of salt concentration and immersion time. No matter what the environmental conditions were, the compressive strength-loss ratio increased with the test time. The compressive strength-test results indicate that sodium sulfate has the strongest corrosive effect on concrete durability, followed by calcium chloride, with sodium chloride having the weakest corrosion. Compared with the other two environmental factors, the wet–dry cycle is the key factor affecting concrete durability. Therefore, in engineering practice, the influence of environment conditions on the strength and durability of concrete should be taken into full consideration, especially in the wet–dry environment with salt conditions.Feng Ming ChengCheng Du YuHang Liu XiangYang Shi DongQing Li 2017Research in Cold and Arid Regions2017,9,4:6
14Macroscopic electromagnetic synergy network-enhanced N-doped Ni/C gigahertz microwave absorber with regulable microtopography显示文摘To achieve excellent electromagnetic wave(EMW)absorption properties,the microstructure design of the absorber is critical.In this work,six kinds of N-Ni/C nanostructures with different morphologies were prepared by one-step hydrothermal method and high temperature carbonization by adjusting the types of nickel salts and reaction solvents.The EMW absorption performance of six different morphologies of N-Ni/C nanostructures was compared and analyzed.Among them,it is found that the nanoflowerlike N-Ni/C composite has excellent dielectric loss and magnetic loss synergistic effect due to its polycrystalline structure,and can obtain excellent EMW absorption performance.The minimum reflection loss value at a thickness of 1.9 mm is-59.56 dB at 16.88 GHz,and the effective absorption bandwidth value reaches 6.0 GHz at a thickness of 2.2 mm.Our research shows that different morphologies and multiple lattice structures of nanostructures with the same composition have a significant influence on EMW absorption performance,which provides new research ideas for developing high-performance EMW absorbing materials.Yuelei Pan Qianqian Zhu Jiahui Zhu Yuhang Cheng Bowen Yu Zirui Jia Guanglei Wu 2023Nano Research2023,16,7:5
15Parallel selection of distinct Tof5 alleles drove the adaptation of cultivated and wild soybean to high latitudes显示文摘Photoperiod responsiveness is a key factor limiting the geographic distribution of cultivated soybean and its wild ancestor.In particular,the genetic basis of the adaptation in wild soybean remains poorly understood.In this study,by combining whole-genome resequencing and genome-wide association studies we identified a novel locus,Time of Flowering 5(Tof5),which promotes flowering and enhances adaptation to high latitudes in both wild and cultivated soybean.By genomic,genetic and transgenic analyses we showed that Tof5 en-codes a homolog of Arabidopsis thaliana FRUITFULL(FUL).Importantly,further analyses suggested that different alleles of Tof5 have undergone parallel selection.The Tof5H1 allele was strongly selected by humans after the early domestication of cultivated soybean,while Tof5H2 allele was naturally selected in wild soybean,and in each case facilitating adaptation to high latitudes.Moreover,we found that the key flowering repressor E1 suppresses the transcription of Tof5 by binding to its promoter.In turn,Tof5 physically associates with the promoters of two important FLOWERING LOCUS T(FT),FT2a and FT5a,to upregulate their transcription and promote flowering under long photoperiods.Collectively,ourfindings provide insights into how wild soybean adapted to high latitudes through natural selection and indicate that cultivated soybean underwent changes in the same gene but evolved a distinct allele that was artificially selected after domestication.Lidong Dong Qun Cheng Chao Fang Lingping Kong Hui Yang Zhihong Hou Yongli Li Haiyang Nan Yuhang Zhang Qingshan Chen Chunbao Zhang Kun Kou Tong Su Lingshuang Wang Shichen Li Haiyang Li Xiaoya Lin Yang Tang Xiaohui Zhao Sijia Lu Baohui Liu Fanjiang Kong 2022Molecular Plant2022,15,2:5
16The morphological and phylogenetic characterization for the dinoflagellate Margalefidinium fulvescens (=Cochlodinium fulvescens) isolated from the Jiaozhou Bay, China显示文摘The dinoflagellate genus Margalefidinium has been split from Cochlodinium as a new genus recently and Margalefidinium fulvescens is one of the five Margalefidinium species. Margalefidinium fulvescens is toxic and has been reported from the coastal waters of USA, Canada, Mexico, China, Japan, Indonesia, Korea, Pakistan and Spain. Here we provide the morphological and phylogenetic characterization for an isolate of it from the Jiaozhou Bay, Qingdao, China. Our results showed that the vegetative cells were subspherical to ellipsoidal, 34–60 μm in length, and 19–41 μm in width. Both single cell forms and colonies in chains of 2, 4, or 8 cells were observed in cultures, but chain forms with 2 or 4 cells were observed more often in the field samples. The cingulum was rather deep, encircling the cell approximately twice, but the sulcus was rather narrow, surrounding the cell about one turn. The nucleus was spherical and located at the central epicone. The chloroplasts were granular, brownish, and scattered peripherally. An orange pigmented body also appeared in the epicone. The apical groove appeared vase-like as previously described. Under epi-fluorescence microscopy, a pumpkin-like structure was clearly observed, in which cells were embedded. Cells were observed to exit from the structure, which led us to a hypothesis that the structure may provide cells a shelter to avoid predation or to respond to other stresses. The phylogenetic analyses based on partial LSU rDNA sequences indicated that M. fulvescens from the Jiaozhou Bay was grouped with M. fulvescens populations from other origins and closely related to the clade of M. polykrikoides.Our morphological observations and phylogenetic analyses together confirmed the presence of M. fulvescens in China and our monitoring has also observed the species dominant in the dinoflagellate community of the Jiaozhou Bay in the early autumn of 2015, which alerted us to continually monitor this bloom-forming species in the region.HU Zhangxi DENG Yunyan LI Yuhang TANG Ying Zhong 2018Acta Oceanologica Sinica2018,37,10:5
17Structural insights into a high fidelity variant of SpCas9显示文摘The RNA-guided endonucleases of the CRISPR-Cas9 system, including the most w泊ely used Cas9 from Streptococcus pyogenes (SpCas9)z are becoming a robust genome editing tool in model organisms and hold immense promise for therapeutic applications. Many strategies have bee n employed to overcome the limitati ons caused by SpCas9zs off-target effects and its strin gent requirement for the protospacer adjacent motif (PAM) sequenee. However, the structural mechanisms underlying these strategies remain undefined. Here, we present crystal structure of a SpCas9 variant, xCas9 3.7 that has broad PAM compatibility and high DNA targeting specificity, in complex with a single-guide RNA and its double-stranded DNA targets. Structural comparison revealed that salt bridge-stabilized R1335 is critical for the stringent selection of PAM sequence by SpCas9. Unrestricted rotamerization of this residue by the E1219V mutation in xCas9 3.7 lessens the stringency for PAM recognition and allows SpCas9 to recognize multiple PAM sequences as further supported by biochemical data. Compared to those in wild-type (WT) SpCas9, REC2 and REC3 domains in xCas9 3.7 un dergo striki ng conformati onal changes, leadi ng to reduced con tact with DNA substrate. SpCas9 mutants en gineered to display less interaction with DNA and have conformationally more flexible REC2 and REC3 domains display enhanced specificity for DNA substrates in both biochemical and cellular assays. Taken together, our findings reveal the structural mechanisms underlying the broadened PAM compatibility and high DNA fidelity of xCas9 3.7, which can assist rational engineering of more efficient SpCas9 variants and probably other Cas9 orthologs.Minghui Guo Kuan Ren Yuwei Zhu Ziyun Tang Yuhang Wang Bailing Zhang Zhiwei Huang 2019Cell Research2019,29,3:5
18Rod-shaped thiocyanate-induced abnormal band gap broadening in SCN^- doped CsPbBr3 perovskite nanocrystals显示文摘Yongbing Lou Yandan Niu Dongwen Yang Qiaoling Xu Yuhang Hu Ying Shen Jing Ming Jinxi Chen Lijun Zhang Yixin Zhao 2018Nano Research2018,11,5:5
19Lignin derived multi-doped(N, S, Cl) carbon materials as excellent electrocatalyst for oxygen reduction reaction in proton exchange membrane fuel cells显示文摘Nowadays,hierarchically macro-/meso-/microporous 3D carbon materials have been paid more attention due to their imaginative application potential in specific electrochemistry.Here,we report a dualtemplate strategy using eutectic NaCl/ZnCl2 melt as airtight and swelling agent to obtain 3D mesoporous skeleton structured carbon from renewable lignin.The prepared lignin-derived biocarbon material(LN-3-1)has a high specific surface area(1289 m^2 g^-1),a large pore volume(2.80 cm^3 g^-1),and a well-connected and stable structure.LN-3-1 exhibits extremely high activity and stability in acidic medium for oxygen reduction reaction(ORR),superior to Pt/C catalyst and most non noble-metal catalysts reported in recent literatures.The prepared carbon material was used as a cathode catalyst to assemble a H2-O2 single fuel cell,and its excellent catalytic performance has been confirmed with the maximum power density of 779 mW cm^-2,which is one of the highest power densities among non-metallic catalysts so far.Density functional theory(DFT)calculations indicate that the synergy of chlorine and nitrogen reconciles the intermediate adsorption energies,leading to an appropriate theoretical ORR onset potential.We develop a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in proton-exchange membrane fuel cells.Yixing Shen Yuhang Li Guangxing Yang Qiao Zhang Hong Liang Feng Peng 2020Journal of Energy Chemistry2020,29,5:5
20A large eddy simulation of flows around an underwater vehicle model using an immersed boundary method显示文摘A large eddy simulation(LES) of the flows around an underwater vehicle model at intermediate Reynolds numbers is performed. The underwater vehicle model is taken as the DARPA SUBOFF with full appendages,where the Reynolds number based on the hull length is 1.0×105. An immersed boundary method based on the moving-least-squares reconstruction is used to handle the complex geometric boundaries. The adaptive mesh refinement is utilized to resolve the flows near the hull. The parallel scalabilities of the flow solver are tested on meshes with the number of cells varying from 50 million to 3.2 billion. The parallel solver reaches nearly linear scalability for the flows around the underwater vehicle model. The present simulation captures the essential features of the vortex structures near the hull and in the wake.Both of the time-averaged pressure coefficients and streamwise velocity profiles obtained from the LES are consistent with the characteristics of the flows pass an appended axisymmetric body. The code efficiency and its correct predictions on flow features allow us to perform the full-scale simulations on tens of thousands of cores with billions of grid points for higher-Reynolds-number flows around the underwater vehicles.Shizhao Wang Beiji Shi Yuhang Li Guowei He 2016Theoretical & Applied Mechanics Letters2016,6,6:5
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