检索结果-南通市图书馆

Journal of Thermal Science 2024年第4期33卷 1590-1606页

作者： ZHANG cong GUAN Yuanhang HUANG Zhen HAN Dong Key Laboratory for Power Machinery and Engineering Ministry of EducationShanghai Jiao Tong UniversityShanghai200240China College of Smart Energy Shanghai Jiao Tong UniversityShanghai200240China Shanghai Non-carbon Energy Conversion and Utilization Institute Shanghai200240China

The ignition tendency of diesel fuels is highly sensitive to ambient conditions and fuel *** this study,the ignition characteristics of different diesel surrogate fuels with the same derived cetane numbers(DCN)were measured and compared in varied thermodynamic and oxidizing *** combustion pressures,heat release rates,ignition delays,and combustion delays of the test fuels were *** experimental results showed that the diesel surrogate fuels with the same DCNs exhibit similar ignition propensity at standard DCN test ***,for the test conditions of high cetane fuels,high ambient temperatures,and suficient oxygen concentrations,surrogate fuels with the same DCN have similar ignition behaviors,and using the DCN to evaluate fuel ignition tendency is ***,for the test conditions of low cetane fuels,low ambient temperatures,and reduced oxygen concentrations,different ignition behaviors are observed for the surrogate fuels with the same DCN,so at these conditions using DCN as the evaluation index for fuel ignition tendency may lead to higher uncertainty.

关键词： diesel fuels surrogate fuels derived cetane numbers constant volume combustion chamber

Performance evaluation for multi-target tracking with temporal dimension specifics

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 446-458页

作者： Zhenzhen SU Hongbing JI cong TIAN Yongquan ZHANG School of Computer Science and Technology Xidian UniversityXi’an 710071China School of Electronic Engineering Xidian UniversityXi’an 710071China

With the great development of Multi-Target Tracking(MTT)technologies,many MTT algorithms have been proposed with their own advantages and *** to the fact that requirements to MTT algorithms vary from the application scenarios,performance evaluation is significant to select an appropriate MTT algorithm for the specific application *** this paper,we propose a performance evaluation method on the sets of trajectories with temporal dimension specifics to compare the estimated trajectories with the true *** proposed method evaluates the estimate results of an MTT algorithm in terms of tracking accuracy,continuity and ***,its computation is based on a multi-dimensional assignment problem,which is formulated as a computable form using linear *** enhance the influence of recent estimated states of the trajectories in the evaluation,an attention function is used to reweight the trajectory errors at different time ***,simulation results show that the proposed performance evaluation method is able to evaluate many aspects of the MTT *** evaluations are worthy for selecting suitable MTT algorithms in different application scenarios.

关键词： Multi-target tracking Temporal dimension specifics Performance evaluation Random finite sets Linear programming

Brain Cognition Mechanism-Inspired Hierarchical Navigation Method for Mobile Robots

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第2期21卷 852-865页

作者： Qiang Zou Chengdong Wu Ming cong Dong Liu Faculty of Robot Science and Engineering Northeastern UniversityShenyang110819China School of Mechanical Engineering Dalian University of TechnologyDalian116024China

Autonomous navigation is a fundamental problem in *** methods generally build point cloud map or dense feature map in perceptual space;due to lack of cognition and memory formation mechanism,traditional methods exist poor robustness and low cognitive *** a new navigation technology that draws inspiration from mammal’s navigation,bionic navigation method can map perceptual information into cognitive space,and have strong autonomy and environment *** improve the robot’s autonomous navigation ability,this paper proposes a cognitive map-based hierarchical navigation ***,the mammals’navigation-related grid cells and head direction cells are modeled to provide the robots with location *** then a global path planning strategy based on cognitive map is proposed,which can anticipate one preferred global path to the target with high efficiency and short ***,a hierarchical motion controlling method is proposed,with which the target navigation can be divided into several sub-target navigation,and the mobile robot can reach to these sub-targets with high confidence ***,some experiments are implemented,the results show that the proposed path planning method can avoid passing through obstacles and obtain one preferred global path to the target with high efficiency,and the time cost does not increase extremely with the increase of experience nodes *** motion controlling results show that the mobile robot can arrive at the target successfully only depending on its self-motion information,which is an effective attempt and reflects strong bionic properties.

关键词： Bionic navigation Spatial localization cells Global path planning Hierarchical motion controlling

A Study of the Effect of the Miller Cycle on the Combustion of a Supercharged Marine Diesel Engine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2024年第5期121卷 1363-1380页

作者： Lingjie Zhao cong Li Mechanical and Automotive Engineering School Shanghai University of Engineering ScienceShanghai201600China

The Miller cycle is a program that effectively reduces NOx emissions from marine diesel engines by lowering the maximum combustion temperature in the cylinder,thereby reducing NOx *** effectively investigate the impact of Miller cycle optimum combustion performance and emission capability under high load conditions,this study will perform a one-dimensional simulation of the performance of a marine diesel engine,as well as a threedimensional simulation of the combustion in the cylinder.A 6-cylinder four-stroke single-stage supercharged diesel engine is taken as the research *** chassis dynamometer and other related equipment are used to build the test system,carry out the diesel engine bench test,and collect experimental *** simulation results are compared with the test results,and the error is less than 5%.In this study,the authors will use simulation software to simulate several Miller cycle scenarios designed for early inlet valve closure and analyze the impact of the Miller cycle on combustion and emissions at 100%load *** comparing the flow field distribution of the engine at 1500 r/min condition,it was found that proper EIVC can prolong the ignition latency period and homogeneous fuel-air mixture combustion acceleration,but it can reduce pressure and temperature within the piston chamber and NOx ***,the Miller cycle reduces end-of-compression temperatures,which increases combustion duration and exhaust temperatures,making it difficult to improve fuel economy at the optimum fuel consumption point,and closing the intake valves prematurely leads to excessive fuel ***,temperature and heat release rate within the piston chamber,NOx,and SOOT generation were significantly enhanced.

关键词： Miller cycle EIVC combustion NOx emissions marine diesel

Reduced exciton binding energy and diverse molecular stacking enable high-performance organic solar cells with V_(OC)over 1.1 V

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第9期67卷 3140-3152页

作者： Tingting Dai Jiahao Lu Ailing Tang Yuhan Meng Peiqing cong Zongtao wang Erjun Zhou National Center for Nanoscience and Technology Beijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Chemical Engineering Guangxi Minzu UniversityNanning 530006China Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou 450003China

High-voltage organic solar cells(OSCs)have received increasing attention because of their promising applications in tandem devices and indoor photovoltaics,but the trade-off between energy loss and charge generation induced by exciton binding energy(E_(b))has become one of the biggest bottlenecks limiting the development of this ***,a wide bandgap(WBG)nonfullerene acceptor BTA503 with reduced E_(b) is designed by changing the phenyl side chain on the central core of Cl-BTA5 to an alkyl *** diverseπ-πinteractions and enhanced molecular stacking of BTA503 are responsible for its reduced E_(b).Furthermore,both the diminished charge recombination and the fast exciton dissociation caused by the small E_(b) favor the generation of more charge carriers for the PTQ10:BTA503 *** efficient Forster resonance energy transfer(FRET)and multiple π-π stacking patterns provide additional charge transfer and transport ***,the PTQ10:BTA503-based OSC device achieves a V_(OC)of 1.112 V and a PCE of 12.70%,which is higher than that of PTQ10:Cl-BTA5(PCE=10.92%).Simultaneously,the thick film(~300 nm)binary device of PTQ10:BTA503 achieves a PCE of 10.13% with a V_(OC)of 1.102 V,which is the best result for thick film high-voltage *** importantly,the ternary device of PTQ10:BTA503:Cl-BTA5(1:0.9:0.1)realizes a champion PCE of 13.12% with a V_(OC)of 1.126 *** study demonstrates that it is an effective strategy to reduce E_(b) of A_(2)-A_(1)-D-A_(1)-A_(2) type WBG acceptors by modulating the side chains on D unit,which further favors the corresponding devices to obtain world-record PCE and improves their potential for commercial applications.

关键词： exciton binding energy intermolecular interaction wide-bandgap acceptor high V_(OC) organic solar cells

Hybrid ion/electron interfacial regulation stabilizes the cobalt/oxygen redox of ultrahigh-voltage lithium cobalt oxide for fast-charging cyclability

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第13期69卷 2071-2079页

作者： Zhihong Bi Anping Zhang Gongrui wang cong Dong Pratteek Das Xiaoyu Shi Zhong-Shuai Wu State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory of Clean Energy Chinese Academy of SciencesDalian 116023China

High-voltage and fast-charging LiCoO_(2)(LCO)is key to high-energy/power-density Li-ion ***,unstable surface structure and unfavorable electronic/ionic conductivity severely hinder its high-voltage fast-charging ***,we construct a Li/Na-B-Mg-Si-O-F-rich mixed ion/electron interface network on the 4.65 V LCO electrode to enhance its rate capability and long-term cycling ***,the resulting artificial hybrid conductive network enhances the reversible conversion of Co^(3+)/^(4+)/O_(2)/nredox by the interfacial ion–electron cooperation and suppresses interface side reactions,inducing an ultrathin yet compact cathode electrolyte ***,the derived near-surface Na+/Mg2+/Si^(4+)-pillared local intercalation structure greatly promotes the Li^(+)diffusion around the 4.55 V phase transition and stabilizes the cathode ***,excellent 3 C(1 C=274 mA g1)fast charging performance is demonstrated with 73.8%capacity retention over 1000 *** findings shed new insights to the fundamental mechanism of interfacial ion/electron synergy in stabilizing and enhancing fast-charging cathode materials.

关键词： High-voltage Fast-charging LiCoO_(2) Interfacial ion-electron cooperation Local intercalation

Tuning the local coordination environment of silver(Ⅰ) coordination networks with counterions for enhanced electrocatalytic CO_(2) reduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1524-1530页

作者： Xiaofeng Cui Xueting wang cong Fu Bing Liu Mei-Yan Gao Tingting Kong Yujie Xiong Anhui Engineering Research Center of Carbon Neutrality The Key Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Laboratory of Molecular-Based MaterialsCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China Department of Chemical Sciences Bernal InstituteUniversity of LimerickLimerick V94 T9PXRepublic of Ireland School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China School of Chemical and Material Engineering Jiangnan UniversityWuxi 214122China

Very recently, the local coordination environment of active sites has been found to strongly influence their performance in electrocatalytic CO_(2) reduction by tuning the intrinsic kinetics of CO_(2) activation and intermediate stabilization. It is imperative to elucidate the mechanism for such an influence towards the rational design of efficient catalysts;however, the complex interactions between the multiple factors involved in the system make it challenging to establish a clear structure–performance relationship. In this work, we chose ion-intercalated silver(I)-based coordination networks(AgCNs) with a well-defined structure as a model platform, which enables us to understand the regulation mechanism of counterions as the counterions are the only tuning factor involved in such a system. We prepared two isostructural Ag CNs with different intercalation ions or counterions of BF_(4)^(-) and ClO_(4)^(-)(named as AgCNs-BF_(4) and AgCNs-ClO_(4)) and found that the former has a more competitive CO_(2) electroreduction performance than the latter. AgCNs-BF_(4) achieves the highest Faradaic efficiency for CO_(2) to CO of 87.1% at-1.0 V(vs. RHE) with a higher partial current density, while AgCNs-ClO_(4) exhibits only 77.2% at the same applied *** characterizations and theoretical calculation reveal that the presence of BF_(4)^(-)is more favorable for stabilizing the COOH^(*) intermediate by weakening hydrogen bonds, which accounts for the superior activity of Ag CNs-BF_(4).

关键词： electrocatalytic CO_(2) reduction coordination networks local environment counterions intercalation ions

Graphdiyne oxide substrate-enhanced peroxidase-mimicking performance of Ru nanoparticles with physiological pH preference

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1123-1131页

作者： cong Xu Wenjie Ma Haozhi wang Leihou Shao Weiqi Li Ping Yu Lanqun Mao Beijing National Laboratory for Molecular Science Key Laboratory of Analytical Chemistry for Living BiosystemsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China College of Chemistry Beijing Normal UniversityBeijing 100875China

Modulating electronic structure of metal nanoparticles via metal–support interaction has attracted intense interest in the field of catalytic ***,the roles of supporting substrates in regulating catalytic properties of nanozymes remain *** this study,we find that the use of graphdiyne oxide(GDYO)as the substrate for self-terminating growth of Ru nanoparticles(Ru@GDYO)endows the peroxidase-like activity of Ru nanoparticles with intrinsic physiological pH preference and natural horseradish peroxidase(HRP)comparable *** nanoparticles electrolessly deposited onto GDYO possess a partially oxidized electronic structure owing to limited charge transfer between Ru and GDYO,contributing to the intrinsic physiological pH preference of the peroxidase-mimicking *** importantly,the substrate GDYO plays an influential factor in enhancing catalytic activity,that is,the activity of Ru@GDYO is much higher than that of Ru nanoparticles deposited on other carbon substrates including graphene oxides and *** demonstrate the application of Ru@GDYO nanozyme in neutral solutions,we employ Ru@GDYO with nicotinamide adenine dinucleotide(NAD+)-dependent dehydrogenases in physiological conditions to realize a sustainable cascade reaction by means of forming continuous NAD^(+)/dihydronicotiamide adenine dinucleotide(NADH)*** finding represents a promising perspective on designing high-performance peroxidase-mimicking nanozymes with broader applicability,raising fundamental understanding of structure–activity relationship,and investigating new applications of nanozymes in biological systems.

关键词： nanozyme graphdiyne reactive oxygen species electroless deposition metal–support interaction

Optical manipulation of ratio-designable Janus microspheres

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1239-1249页

作者： YULU CHEN cong ZHAI XIAOQING GAO HAN wang ZUZENG LIN XIAOWEI ZHOU CHUNGUANG HU State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Angular optical trapping based on Janus microspheres has been proven to be a novel method to achieve controllable *** contrast to natural birefringent crystals,Janus microspheres are chemically synthesized of two compositions with different refractive ***,their structures can be artificially regulated,which brings excellent potential for fine and multi-degree-of-freedom manipulation in the optical ***,it is a considerable challenge to model the interaction of heterogeneous particles with the optical field,and there has also been no experimental study on the optical manipulation of microspheres with such designable refractive index *** the specific structure affects the kinematic properties of Janus microspheres remains ***,we report systematic research on the optical trapping and rotating of various ratio-designable Janus *** employ an efficient T-matrix method to rapidly calculate the optical force and torque on Janus microspheres to obtain their trapped postures and rotational characteristics in the optical *** have developed a robust microfluidic-based scheme to prepare Janus *** experimental results demonstrate that within a specific ratio range,the rotation radii of microspheres vary linearly and the orientations of microsphere are always aligned with the light polarization *** is of great importance in guiding the design of Janus *** their orientations flip at a particular ratio,all consistent with the *** work provides a reliable theoretical analysis and experimental strategy for studying the interaction of heterogeneous particles with the optical field and further expands the diverse manipulation capabilities of optical tweezers.

关键词： polarization ratio refractive

Influence of Trailing-Edge Wear on the Vibrational Behavior of Wind Turbine Blades

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第2期20卷 337-348页

作者： Yuanjun Dai Xin Wei Baohua Li cong wang Kunju Shi Mechanical College Shanghai Dian Ji UniversityShanghai201306China College of Energy Engineering Xinjiang Institute of EngineeringUrumqi830091China

To study the impact of the trailing-edge wear on the vibrational behavior of wind-turbine blades,unworn blades and trailing-edge worn blades have been assessed through relevant modal *** to these experiments,the natural frequencies of trailing-edge worn blades-1,-2,and-3 increase the most in the second to fourth order,theﬁfth order increases in the middle,and theﬁrst order increases the *** damping ratio data indi-cate that,in general,theﬁrstﬁve-order damping ratios of trailing-edge worn blades-1 and trailing-edge worn blades-2 are reduced,and theﬁrstﬁve-order damping ratios of trailing-edge worn blades-3 are slightly *** mode shape diagram shows that the trailing-edge worn blades-1 and-2 have a large swing in the tip and the blade,whereas the second-and third-order vibration shapes of the trailing edge-worn blade-3 tend to be ***,all these results reveal that the blade’s mass and the wear area are the main fac-tors affecting the vibration characteristics of wind turbine blades.

关键词： Wind turbine modal test natural frequency damping ratio mode shape