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Properties of electrodeposited amorphous Fe-Ni-W alloy deposits

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Transactions of Nonferrous Metals Society of China 2006年第6期7卷 1289-1294页

作者：何凤姣王淼陆欣 college of Chemistry and Chemical Engineering Hunan University yingcai Technology Co.Ltd

A new technique of electroplating amorphous Fe-Ni-W alloy deposits was *** structure and morphology o Fe-Ni-W alloy deposit were detected by XRD and *** friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium *** corrosion properties against 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide were also *** experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wea than hard chromium deposits under dry sliding *** oil sliding condition,except their better wear resistance,the deposits can protect their counterparts against *** deposits plated on brass and AISI 1045 steel show good behavior against corrosion o 5% sodium chloride,5% sulfuric acid and 5% sodium *** bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.

关键词： electrodeposition amorphous Fe-Ni-W alloy deposits wear resistance corrosion resistance

QoS-oriented packet scheduling scheme for opportunistic networks

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The Journal of China Universities of Posts and Telecommunications 2017年第3期24卷 51-57页

作者： Yao Wenbin Chen Yin Zong Ming Wang Dongbin Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and Telecommunications School of Computer Science Beijing University of Posts and Telecommunications yingcai honors college University of Electronic Science and Technology of China National Engineering Laboratory for Mobile Network Security Beijing University of Posts and Telecommunications

The unique characteristics of opportunistic networks （ONs）, such as intermittent connectivity and limited network resources, makes it difficult to support quality of service （QoS） provisioning, particularly to guarantee delivery ratio and delivery delay. In this paper, we propose a QoS-oriented packet scheduling scheme （QPSS） to make decisions for bundle transmissions to satisfy the needs for the delivery ratio and delivery delay constraints of bundles. Different from prior works, a novel bundle classification method based on the reliability and latency requirements is utilized to decide the traffic class of bundles. A scheduling algorithm of traffic class and bundle redundancy is used to maintain a forwarding and dropping priority queue and allocate network resources in QPSS. Simulation results indicate that our scheme not only achieves a higher overall delivery ratio but also obtains an approximate 14% increase in terms of the amount of eligible bundles.

关键词： opportunistic networks packet scheduling QoS traffic class of bundles

Pre-course student performance prediction with multi-instance multi-label learning

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Science China(Information Sciences) 2019年第2期62卷 200-205页

作者： Yuling MA Chaoran CUI Xiushan NIE Gongping YANG Kashif SHAHEED Yilong YIN Software college Shandong University School of Information Engineering Shandong Yingcai College School of Computer Science and Technology Shandong University of Finance and Economics

Dear editor,Studying courses is one of the most basic and important tasks for college students. For each new course, the initial period of learning is crucial for students, and seriously influences subsequent learning activities. However, given a large number of classes in universities, it has become impossible for teachers to keep track of the individual performance of each student. In these circumstances, it is desirable to predict each student’s performance on a certain course prior to its commencement.

关键词： KNN DT Pre-course student performance prediction with multi-instance multi-label learning SVM Figure BCS

A Comprehensive Method to Reject Detection Outliers by Combining Template Descriptor with Sparse 3D Point Clouds

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Journal of Shanghai Jiaotong university(Science) 2017年第2期22卷 188-192页

作者：郭立 honors college Northwestern Polytechnical UniversityXi’an 710072China

We are using a template descriptor on the image in order to try and find the object. However, we have a sparse 3D point clouds of the world that is not used at all when looking for the object in the images. Considering there are many false alarms during the detection, we are interested in exploring how to combine the detections on the image with the 3D point clouds in order to reject some detection outliers. In this experiment we use semi-direct-monocular visual odometry (SVO) to provide 3D points coordinates and camera poses to project 3D points to 2D image coordinates. By un-projecting points in the tracking on the selection tree (TST) detection box back to 3D space, we can use 3D Gaussian ellipsoid fitting to determine object scales. By ruling out different scales of detected objects, we can reject most of the detection outliers of the object. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

关键词： semi-direct-monocular visual odometry(SVO) tracking on the selection tree(TST)-recognizer 3D point-clouds Gaussian ellipsoid fitting

Effect of Free-Stream Mach Number on the Base Thermal Environment of LaunchVehicle

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Journal of Thermal Science 2024年第6期33卷 2426-2436页

作者： WANG Xu XU Xu YU Jiaqi YANG Qingchun School of Astronautics Beihang UniversityBeijing 100191China Shenyuan honors college Beihang UniversityBeijing 100191China

Convective heating of the rocket base caused by high-temperature reverse flow has long been a focus of thermal protection *** distinctive structural characteristics,the base thermal environment of a twin-nozzle engine proves more susceptible to the recirculation region than its multi-nozzle *** the transonic stage,significant alterations in the flow field structure at the rocket base strongly influence the recirculation *** study investigated the thermal environment of the rocket base with a twin-nozzle configuration in freestream at Mach numbers of 0.6 to *** indicate that the freestream Mach number significantly affects the thermal environment at the rocket base during the transonic *** increase of Mach number from 0.6 to 1.0 causes the convective heating of the rocket base to increase by 7.7 *** phenomenon arises due to the plume-induced shock wave caused by the impact of the supersonic free shear layer and plume shear layer while the flight speed exceeds the sound *** interaction between the shock wave and the shear layer amplifies turbulence in the recirculation region and at the inflection point,resulting in a stronger high-temperature reverse *** addition,the cause of low-altitude base heating was analyzed,and it was found that the mechanism is different from the high-temperature countercurrent effect caused by plume interaction.

关键词： rocket base heating free stream Mach number shock-turbulence interaction twin-nozzle

Effect of mixing section configurations on combustion efficiency of Mg-CO_(2)Martian ramjet

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Chinese Journal of Aeronautics 2023年第4期36卷 165-173页

作者： Xu WANG Yanpeng BU Xu XU Qingchun YANG School of Astronautics Beihang UniversityBeijing 100191China Shenyuan honors college Beihang UniversityBeijing 100191China

Experiments were conducted to determine the effects of the mixing section configurations on the Mg-CO_(2)Martian ramjet combustion *** was carried out at a mainstream mass flow rate of 110 g/s and a temperature of 810 *** chamber pressure was measured under different configurations and Oxidizer to Fuel(O/F)*** showed that the engine achieved self-sustaining combustion and worked stably during *** pre-combustion chamber is needed to increase the combustion efficiency and promote the full combustion of the *** the configuration of the pre-combustion chamber,the best combustion efficiency reached 80%when radial powder injection and lateral carbon dioxide intake were *** addition,the O/F ratio in the pre-combustion chamber decreased from 0.67 to 0.31,resulting in an 8%increase in the combustion *** was speculated that different mixing section configurations and the variations in an O/F ratio within the pre-combustion chamber impacted the combustion efficiency and in essence,all affected the flow velocity and residence time of the two-phase flow in the com-bustion chamber.

关键词： Combustion efficiency Magnesium-base fuel Martian ramjet Mars exploration Structural configurations

A real-time abnormal operation pattern detection method for building energy systems based on association rule bases

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Building Simulation 2022年第1期15卷 69-81页

作者： Chaobo Zhang Yang Zhao Yangze Zhou Xuejun Zhang Tingting Li Institute of Refrigeration and Cryogenics Zhejiang UniversityHangzhouChina Chu Kochen honors college Zhejiang UniversityHangzhouChina

Expert systems are effective for anomaly detection in building energy ***,it is usually inefficient to establish comprehensive rule bases manually for complex building energy *** rule mining is available to accelerate the establishment of the rule bases due to its powerful capability of discovering rules from numerous *** paper proposes a real-time abnormal operation pattern detection method towards building energy *** can benefit from both expert systems and association rule *** rules are utilized to establish association rule bases of abnormal and normal operation *** established rule bases are then utilized to develop an expert system for real-time detection of abnormal operation *** proposed method is applied to an actual chiller plant for evaluating its *** show that 15 types of known abnormal operation patterns and 11 types of unknown abnormal operation patterns are detected successfully by the proposed method.

关键词： building energy systems building energy conservation expert systems association rule mining anomaly detection

Lie Symmetry Analysis and Conservation Laws of a Generalized Time Fractional Foam Drainage Equation

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Communications in Theoretical Physics 2016年第7期65卷 35-40页

作者：王丽田守富赵振涛宋晓秋 Department of Mathematics China University of Mining and Technology Sun Yueqi honors college China University of Mining and Technology

In this paper, a generalized time fractional nonlinear foam drainage equation is investigated by means of the Lie group analysis method. Based on the Riemann–Liouville derivative, the Lie point symmetries and symmetry reductions of the equation are derived, respectively. Furthermore, conservation laws with two kinds of independent variables of the equation are performed by making use of the nonlinear self-adjointness method.

关键词： a generalized time fractional nonlinear foam drainage equation Riemann–Liouville derivative Lie point symmetry symmetry reduction conservation law

Multiple off-axis acoustic vortices generated by dual coaxial vortex beams

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Chinese Physics B 2018年第2期27卷 393-400页

作者：李雯戴思捷马青玉郭各朴丁鹤平 Key Laboratory of Optoelectronics of Jiangsu Province School of Physics and TechnologyNanjing Normal University honors college Nanjing Normal University

As a kind of special acoustic field, the helical wavefront of an acoustic vortex（AV） beam is demonstrated to have a pressure zero with phase singularity at the center in the transverse plane. The orbital angular momentum of AVs can be applied to the field of particle manipulation, which attracts more and more attention in acoustic researches. In this paper,by using the simplified circular array of point sources, dual coaxial AV beams are excited by the even-and odd-numbered sources with the topological charges of l_E and l_O based on the phase-coded approach, and the composite acoustic field with an on-axis center-AV and multiple off-axis sub-AVs can be generated by the superimposition of the AV beams for｜l_E｜ ≠ ｜l_O｜. The generation of edge phase dislocation is theoretically derived and numerically analyzed for l_E=-l_O. The numbers and the topological charges as well as the locations of the center-AV and sub-AVs are demonstrated, which are proved to be determined by the topological charges of the coaxial AV beams. The proposed approach breaks through the limit of only one on-axis AV with a single topological charge along the beam axis, and also provides the feasibility of off-axis particle trapping with multiple AVs in object manipulation.

关键词： dual coaxial acoustic vortex(AV) beams multiple off-axis AVs on-axis center-AV topological charge phase-coded approach