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Ballistic Trajectory Extrapolation and Correction of Firing Precision for Multiple Launch Rocket System

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第2期36卷 232-241页

作者： ZHA Qicheng RUI xiaoting WANG Guoping YU Hailong Institute of Launch Dynamics School of Energy and Power EngineeringNanjing University of Science and Technology

The research on multiple launch rocket system(MLRS)is now even more demanding in terms of reducing the time for dynamic calculations and improving the firing accuracy,keeping the cost as low as *** study employs multibody system transfer matrix method(MSTMM),to model *** use of this method provides effective and fast calculations of dynamic characteristics,initial disturbance and firing ***,a new method of rapid extrapolation of ballistic trajectory of MLRS is proposed by using the position information of radar *** extrapolation point is then simulated and compared with the actual results,which demonstrates a good *** closed?loop fire correction method is used to improve the firing accuracy of MLRS at low cost.

关键词： multi-body system transfer matrix method(MSTMM) multiple launch rocket system(MLRS) dynamic modeling ballistic trajectory extrapolation fire correction method

An Algorithm for Determination of Projectile Attitude Angles in Projectile Trajectory Prediction

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第2期35卷 361-370页

作者： Zha Qicheng Rui xiaoting Yu Hailong Zhou Qinbo Institute of Launch Dynamics School of Energy and Power EngineeringNanjing University of Science and Technology

A fast and accurate algorithm is established in this paper to increase the precision of ballistic trajectory *** algorithm is based on the six-degree-of-freedom(6 DOF)trajectory equations,to estimate the projectile attitude angles in every measuring ***,the algorithm utilizes the Davidon-Fletcher-Powell(DFP)method to solve nonlinear equations and Doppler radar trajectory test information containing only position coordinates of the projectile to reconstruct the angular ***″position coordinates by the test″and″angular displacements by reconstruction″at the end phase of the radar measurement are used as an initial value for the trajectory computation to extrapolate the trajectory impact *** numerical simulations validate the proposed method and demonstrate that the estimated impact point agrees very well with the real ***,other artillery trajectory can be predicted by the algorithm,and other trajectory models,such as 4 DOF and 5 DOF models,can also be incorporated into the proposed algorithm.

关键词： ballistic trajectory impact point prediction Davidon-Fletcher-Powell method six-degree-of-freedom trajectory model Doppler radar data

Wearable strain sensing textile based on one-dimensional stretchable and weavable yarn sensors

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Nano Research 2018年第11期11卷 5799-5811页

作者： xiaoting Li Haibo Hu Tao Hua Bingang Xu Shouxiang Jiang Nanotechnology Center Institute of Textiles & Clothing The Hong Kong Polytechnic University Hung Horn Kowloon Hong Kong999077 China

Flexible, wearable, and even stretchable sensors are the key components of smart electronic textiles. However, most reported flexible and wearable sensors for wearable electronics are usually fabricated in two-dimensional (2D) planar strip configurations, which cannot be properly integrated into textile structures and thus greatly degrade intrinsic properties such as the softness, flexibility, and air permeability of textiles and the aesthetic feeling of clothing. In this work, a new one-dimensional weavable strain sensing yarn consisting of an elastic polyurethane (PU) core, a conductive Ag-nanoparticles/graphene-microsheets composite sheath, and a silicone encapsulation layer was designed and fabricated through an easily manipulated protocol. Arising from the reasonable structural design and appropriate material selection, the as-fabricated strain sensor not only exhibited excellent flexibility, stretchability, and highly repeatable electromechanical stability (a repeatability error of 1.56%) but also possessed both high sensitivity (a gauge factor of nearly 500) and a relatively wide working range (0-50% applied strain) with good linearity (a correlation coefficient of 0.98). In addition, the facile, nearly all-solution-based fabrication protocol enabled the scalable production of long conductive yarns. Thus, the proper yarn length and superb mechanical properties endowed the stretchable conductive yarn with good weavability. The excellent wearability of the stretchable conductive yarn was derived from the outermost isolating, hydrophobic, and biocompatible silicone encapsulation layer. A wearable high-sensitivity strain sensing textile, fabricated by directly weaving the as-prepared yarn-based sensor, showed great potential for application to wearable textile sensors for real-time monitoring of human motions from vigorous walking to subtle and complex pronunciations.

关键词： stretchable weavable polyurethane elastomer one-dimensional (1D) strain sensing textiles sensor

Numerical modeling of double-ring infiltrometers for determining saturated hydraulic conductivity of heterogeneous and anisotropic soils

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Pedosphere 2024年第6期34卷 1111-1122页

作者： xiaoting XIE Hongxiang ZHOU Laosheng WU Jun MAN Institute of Soil Science Chinese Academy of Sciences Department of Geographic Science Faculty of Arts and Sciences Beijing Normal University at Zhuhai College of Metrology and Measurement Engineering China Jiliang University Department of Environmental Sciences University of California

Philip’s two-term infiltration equation has been widely used to infer soil saturated hydraulic conductivity (Ks),the accuracy of which is usually influenced by the size of infiltration rings and soil *** studies have primarily focused on exploring the ring-size dependence of Ks estimations under specific soil conditions (e.g.,soil isotropy and/or uniform initial water content).This study aimed to provide a comprehensive analysis by systematically considering eight heterogeneous and anisotropic soils with nonuniform initial water ***,we examined the validity of Philip’s infiltration equation as well as the recently proposed two forms (i.e.,infiltration and time forms) of Parlange’s infiltration equation both theoretically and in practical applications of double-ring *** the time form of Parlange’s equation was applied to infer Ks using double-ring infiltrometer measurements with different combinations of six inner ring diameters (10,20,40,80,120,and 200 cm) and three buffer index (defined as the ratio of the difference between inner and outer ring diameters to the outer ring diameter) values (0.20,0.33,and 0.50).For each infiltrometer set,20 stochastic Ks fields were randomly generated by adopting five standard deviation values (0.1,0.3,0.5,0.7,and 0.9).Furthermore,we investigated the effects of five horizontal correlation lengths (30,60,150,300,and 600 cm) on Ks *** results demonstrated that Parlange’s equation,compared to Philip’s equation,was more universal in describing the cumulative infiltration relationship for the test *** combination of inner ring diameter and buffer index of 40 cm and 0.2,respectively,which satisfied most of the practical requirements for determining Ks in the Soil Water Infiltration Global (SWIG) database was *** the horizontal correlation length exceeded a threshold (i.e.,150 cm in our study),the inner ring diameter was required to increase to 80 *** findings co

关键词： heterogeneous soil infiltration equation numerical modeling soil anisotropy soil hydraulic conductivity

Multicomponent platinum-free nanoporous Pd-based alloy as an active and methanol-tolerant electrocatalyst for the oxygen reduction reaction

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Nano Research 2016年第6期9卷 1831-1843页

作者： xiaoting Chen Conghui Si Ying Wang Yi Ding Zhonghua Zhang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University Jingshi Road 17923 Jinan 25006 I China School of Materials Science and Engineering Tianjin University of Technology 391 BinshuiXidao Xiqing District Tianjin 300384 China

Development of high-performance oxygen reduction reaction （ORR） catalysts is crucial to improve proton exchange membrane fuel cells. herein, a multicomponent nanoporous PdCuTiA1 （np-PdCuTiA1） electrocatalyst has been synthesized by a facile one-step dealloying strategy. The np-PdCuTiA1 catalyst exhibits a three-dimensional bicontinuous interpenetrating ligament/channel structure with an ultrafine length scale of -3.7 nm. The half-wave potential of np PdCuTiA1 is 0.873 V vs. Rhe, more positive than those of PdC （0.756 V vs. Rhe） and PtC （0.864 V vs. Rhe） catalysts. The np-PdCuTiAl alloy shows a 4-electron reaction pathway with similar Tafel slopes to PtC. Remarkably, the half-wave potential shows a negative shift of only 12 mV for np-PdCuTiA1 in the presence of methanol, and this negative shift is much lower than those of the PdC （50 mV） and PtC （165 mV） catalysts. The enhanced ORR activity of np-PdCuTiA1 has been further rationalized through density functional theory calculations.

关键词： direct methanol fuel cells oxygen reduction reaction methanol tolerance electrocatalyst nanoporous alloys dealloying

Sulfur vacancies and heterogeneous interfaces promote high performance sodium storage of bimetallic chalcogenide hollow nanospheres

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Journal of Energy Chemistry 2024年第8期95卷 596-610,I0013页

作者： Shiyue Cao xiaoting Xu Qiming Liu Huijuan Zhu Ting Hu Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education School of Physics and TechnologyWuhan UniversityWuhan 430072HubeiChina

Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion ***,due to low inherent conductivity and significant volume expansion,the electrochemical performance is greatly *** this study,a nickel/manganese sulfide material(Ni_(0.96)S_(x)/MnS_(y)-NC)with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple *** introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur *** interface collectively creates an internal electric field,improving the mobility of electrons and ions,increasing the number of electrochemically active sites,and further optimizing the performance of Na~+*** direction of electron flow is confirmed by Density functional theory(DFT)*** hollow nano-spherical material provides a buffer for expansion,facilitating rapid transfer *** innovative discovery involves the interaction between the ether-based electrolyte and copper foil,leading to the formation of Cu_9S_5,which grafts the active material and copper current collector,reinforcing mechanical *** results in a new heterostructure of Cu_9S_5 with Ni_(0.96)S_(x)/MnS_(y),contributing to the stabilization of structural integrity for long-cycle ***,Ni_(0.96)S_(x)/MnS_(y)-NC exhibits excellent electrochemical properties following our modification *** stability performance,Ni0_(.96)S_(x)/MnS_(y)-NC demonstrates an average decay rate of 0.00944%after 10,000 cycles at an extremely high current density of 10000 mA g^(-1),A full cell with a high capacity of 304.2 mA h g^(-1)was also successfully assembled by using Na_(3)V_(2)(PO_(4))_(3)/C as the *** study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.

关键词： Sulfur vacancies heterogeneous interface Interactions Sodium ion batteries

Deployment of Edge Computing Nodes in IoT:Effective Implementation of Simulated Annealing Method Based on User Location

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China Communications 2024年第1期21卷 279-296页

作者： Junhui Zhao Ziyang Zhang Zhenghao Yi xiaoting Ma Qingmiao Zhang School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China School of Information Engineering East China Jiaotong UniversityNanchang 330013China

Edge computing paradigm for 5G architecture has been considered as one of the most effective ways to realize low latency and highly reliable communication,which brings computing tasks and network resources to the edge of *** deployment of edge computing nodes is a key factor affecting the service performance of edge computing *** this paper,we propose a method for deploying edge computing nodes based on user *** the combination of Simulation of Urban Mobility(SUMO)and Network Simulator-3(NS-3),a simulation platform is built to generate data of hotspot areas in Io T *** effectively using the data generated by the communication between users in Io T scenario,the location area of the user terminal can be *** this basis,the deployment problem is expressed as a mixed integer linear problem,which can be solved by Simulated Annealing(SA)*** analysis of the results shows that,compared with the traditional method,the proposed method has faster convergence speed and better performance.

关键词： deployment problem edge computing internet of things machine learning

Synthesis and Dyes Adsorption Properties of Calix[4]crown-grafted Chitosan Chelating Polymer

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Chemical Research in Chinese Universities 2015年第6期31卷 1051-1055页

作者： FANG xiaoting GUO Hongyu YANG Fafu BAI Xiaoyan College of Chemistry and Chemical Engineering Fujian Normal University Fuzhou 350007 P. R. China Fujian Key Laboratory of Polymer Materials Fujian Normal University Fuzhou 350007 P. R. China

By the Schiff-base condensation of formacyl calix[4]crown（2） with raw chitosan, a novel calix[4]crown- grafted chitosan chelating polymer（3） was conveniently prepared in good yield. The structure of polymer 3 was con- firmed by elemental analysis, infrared（IR） spectrometry and X-ray diffraction（XRD） analysis. The elemental analysis suggests that the grafting degree of calixcrown unit was 22% on the amino groups of chitosan. The morphological characteristic of polymer 3 was studied by scanning electron microscopy（SEM）. Polymer 3 possessed loose porous and smooth morphology of surface. The dyes adsorption abilities of polymer 3 for a series of organic dyes[Orange I（OI）, Neutral red（NR）, Victoria blue B（VB） and Brilliant green（BG）] were studied by solid-liquid adsorption expe- riments. The adsorption percentages increased from 45%-60%（raw chitosan for dyes） to 75%-90%（polymer 3 for dyes）. The highest adsorption percentage reached 89% for VB. The saturated adsorption capacities for OI, NR, VB and BG were as high as 622, 564, 854 and 781 mg/g, respectively. The adsorption abilities kept stable at 70%-90% in the scope of pH=5-9. The adsorption abilities for anionic dye（OI） decreased gradually with the increase of pH and the opposite trend was observed for cationic dyes（NR, BG, VB）. The adsorption percentages were 70%--90% after five times＇ cycles for adsorption.

关键词： Calixcrown Chitosan Adsorption Dye

Preparation of Ultrafine TATB and the Technology for Crystal Morphology Control

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Chinese Journal of Chemistry 2012年第2期30卷 293-298页

作者： Yang,Li Ren,xiaoting Li,Tiecheng Wang,Shiwei Zhang,Tonglai State Key Laboratory of Explosion Seience and Technology Beijing Institute of TechnologyBeijing 100081China The 42nd Institute of the Fourth Academy of China Aerospace Science and Technology Corporation Xiangyang 441003China

The ultrafine 1,3,5-triamino-2,4,6-trinitrobenzene （TATB） has been prepared by using solvent and non-solvent method, and the influencing factors in close relationship with the grain size and crystal morphology control such as categories and dosage of surfactants, volume ratio of solvent to non-solvent have also been considered in this paper. It showed that these factors had remarkable effect on the crystal morphology, particle size and agglomeration during the crystallization process. By using 0.095% （mass percentage） ionic surfactant （S） as the additive and using spray-drops feeding device as the dropping equipment, 1.06 g TATB raw materials have been refined into free-running ellipsoid and spherical TATB grains with the grain size from 30 to 50 nm. By using 0.014% （mass percentage） non-ionic surfactant （P） as the additive, spherical TATB grains with the particle diameter of 50 nm and with narrow particle-size distribution have also been obtained. It was shown by the characterizations that the ultrafine particle of TATB had better heat resisting evenness and its 5 seconds ignition point is advanced by 7.5 K.

关键词： 1,3,5-triamino-2,4,6-trinitrobenzene solvent and non-solvent method ultrafine crystal morphology crystal growth surfactants