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Precision wire electrochemical machining of thick structures in powder superalloy René88DT using a partially insulated tube electrode

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Advances in Manufacturing 2023年第4期11卷 618-635页

作者： Cheng Tang Zhao Han Zhong-qi Zhou Xiao-long Fang Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China

Wire electrochemical machining(WECM)is a potential method for manufacturing macrostructures from difficult-to-cut materials,such as turbine slots,with good surface integrity and low *** this study,a novel tube electrode with array holes in the front and insulation in the back was applied using WECM to improve the machining precision and ***,assisted by an immersion electrolyte and axial flushing,the electrolyte-deficient gap was supplemented to achieve the cutting of a very thick *** simulation results indicated that this method could effectively reduce the machining gap and improve the uniformity of the electric-and flow-field *** verified that when the uninsulated range(machining angle)was reduced from 360°to 90°,the side machining gap was reduced from 462.5µm to 175µ***,using optimized machining parameters,array slits with gaps as small as(175±10)μm were machined on a powder superalloy René88DT sample with a thickness of 10 mm at a feed rate of 16µm/*** feasibility of fabricating complex profiles using this method was verified using a self-designed servo device.

关键词： Wire electrochemical machining(WECM) Tube electrode Partial insulation Machining angle Electrolyte flushing Surface quality

High-temperature oxidation behavior and degradation mechanism of chromium-coated zirconium alloy cladding: a review

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Tungsten 2025年第1期 50-70页

作者： Yi Li Bei-qi Wang Xin-Yin Zhang Shi-Jie Wang Cong-Yi Li Hui-long Yang Ran-Ran Su Tong Liu School of Mechanical Engineering Shanghai Jiao Tong University College and Graduate School of Arts and Sciences University of Virginia Global Institute of Future Technology Shanghai Jiao Tong University

Accident-tolerant fuels(ATF) have been extensively studied to reduce the production rate and total amount of heat and hydrogen generated from high-temperature steam oxidation during severe ***-coated zirconium alloy cladding has become one of the most promising candidates for ATF because of its excellent corrosion and oxidation *** paper provides a comprehensive overview of the research progress on oxidation behaviors and degradation mechanisms in chromium-coated zirconium alloy cladding under high-temperature *** techniques to strengthen the oxidation resistance are highlighted and ***,challenges and opportunities for various future directions are addressed.

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Comparison with Molecular Surface Electrostatic Potential and Thermal Reactivity of Nitramines

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含能材料 2015年第12期23卷 1155-1161页

作者： Svatopluk Zeman Zdenek Friedl Monika Bartoskova qi-long YAN Institute of Energetic Materials Faculty of Chemical TechnologyUniversityo f PardubiceCZ-53210PardubicetheCzechRepublic Facultyof Chemistry Brno Universityof TechnologyCZ.-61200Brnothe Czech Republic

Molecular surface electrostatic potentials V_S(r) ( ESP) of seventeen nitramines have been calculated. As a criterion of the imbalance between the maximum positive,V_(S,max) and minimum negative,V_(S,min),values of molecular surface electrostatic potentials their sum was derived and used as a new simple characteristic for ESPs-V_(S,Σ). These V_(S,Σ) values have close relationships with the Arrhenius parameters,activation energy E_a and preexponent log A,of thermal decomposition of the nitramines studied. The correlation between the V_(S,Σ) values and heats of fusion of the nitramines studied is described. These findings suggested analyzing the physico-chemical behavior of the nitramine crystals during this decomposition; in this connection an investigation was carried out using isothermal thermogravimetry and scanning electron microscopy of thermally exposed crystals of cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole( sintering of its crystal surfaces),of β-1,3,5,7-tetranitro-1,3,5,7-tetrazocane( cracking of its crystals during β !δ transition) and of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane. The results suggest a need to study the pre-decomposition states on thermal decomposition of the nitramines' molecule's crystals.

关键词：爆破器料含能材料材料烟火材料

Analysis of hidden-charm pentaquark molecular states with and without strangeness via the QCD sum rules

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Chinese Physics C 2021年第12期45卷 42-52页

作者： zhi-Gang Wang qi Xin Department of Physics North China Electric Power UniversityBaoding 071003China

In this study,we investigate the,D∑c,D≡c',D∑c^(*),D^(*)∑c,D^(*)≡c',D^(*)∑c^(*),and D^(*)≡c'^(*)pentaquark mo-lecular states with and without strangeness via the QCD sum rules in detail,focusing on the light flavor,SU(3),breaking effects,and make predictions for new pentaquark molecular states besides assigning P_(c)(4312),P_(c)(4380),Pc(4440),P_(c)(4457),and P_(cs)(4459)*** the future,we can search for these pentaquark molecular states in the decay of ∧_(b)^(0),≡H_(b)^(0),and ≡_(b)^(-) Furthermore,we discuss high-dimensional vacuum condensates in detail.

关键词： pentaquark molecular states QCD sum rules

Formaldehyde degradation by UV/TiO_2/O_3 process using continuous flow mode

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Journal of Environmental Sciences 2007年第9期19卷 1136-1140页

作者： qi Hong SUN De-zhi CHI Guo-qing School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China.

The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g,, it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84--24 mg/m^3 by O3/TiO2flJV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m^3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/（m^***） and Langmuir adsorption coefficient K of 0.0268 m^3/mg were obtained.

关键词： UV/TiO2/O3 process formaldehyde continuous flow mode

Numerical and experimental study on the hydraulic characteristics of a vertical axial pump under various clearances of flare tube

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Journal of Hydrodynamics 2023年第1期35卷 125-144页

作者： Jia-qi Chen zhi-kui He zhi-yang Hu Hong-bo Shi Xikun Wang Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang212013China Chongqing Pump Industry Co.Ltd. Chongqing400033China

In order to investigate the characteristics of a vertical axial flow pump under various clearances of flare tube, the bell-shaped inlet and box culvert outlet channels with flare tube are studied numerically and experimentally. Then, the cases of inlet and outlet channels with the least hydraulic loss are selected to form an integral pump system, for which both numerical simulation and experimental investigation are carried out. The numerical results agree well with the experimental data. It is shown that the clearances of the interfaces between different components of the pump system have a significant impact on the internal flow structure, turbulent entropy and hydraulic performance of the inlet and outlet channels. For the cases of normalized bottom clearance less than 0.5 and normalized top clearance larger than 0.4, the internal flow and hydraulic performance indexes of inlet and outlet channels are relatively poor. There also exists a critical clearance in either inlet or outlet channel at which the hydraulic loss reaches the maximum. The results serve as an important reference for the design as well as safe and efficient operation of the vertical axial flow pump system.

关键词： Axial flow pump clearance of flare tube numerical simulation experiment hydrodynamic characteristics

Partial improvement in performance of patients with severe Alzheimer's disease at an early stage of fornix deep brain stimulation

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Neural Regeneration Research 2018年第12期13卷 2164-2172页

作者： zhi-qi Mao Xin Wang Xin Xu zhi-qiang Cui long-Sheng Pan Xiao-Jing Ning Bai-Xuan Xu Lin Ma zhi-Pei Ling Jian-Jun Jia Xin-Guang Yu Department of Neurosurgery Chinese PLA General Hospital School of Medicine Nankai University Department of Nuclear Medicine Chinese PLA General Hospital Department of Radiology Chinese PLA General Hospital Department of Neurology Chinese PLA General Hospital

Deep brain stimulation is a therapy for Alzheimer＇s disease（AD） that has previously been used for mainly mild to moderate cases. This study provides the first evidence of early alterations in performance induced by stimulation targeted at the fornix in severe AD patients. The performance of the five cases enrolled in this study was scored with specialized assessments including the Mini-Mental State Examination and Clinical Dementia Rating, both before and at an early stage after deep brain stimulation. The burden of caregivers was also evaluated using the Zarit Caregiver Burden Interview. As a whole, the cognitive performance of patients remained stable or improved to varying degrees, and caregiver burden was decreased. Individually, an improved mental state or social performance was observed in three patients, and one of these three patients showed remarkable improvement in long-term memory. The conditions of another patient deteriorated because of inappropriate antipsychotic medications that were administered by his caregivers. Taken together, deep brain stimulation was capable of improving some cognitive aspects in patients with severe AD, and of ameliorating their emotional and social performance, at least at an early stage. However, long-term effects induced by deep brain stimulation in patients with severe AD need to be further validated. More research should focus on clarifying the mechanism of deep brain stimulation. This study was registered with ***（NCT03115814） on April 14, 2017.

关键词： Alzheimer's disease deep brain stimulation fornix cognition memory mood performance early stage functional neurosurgery dementia

Deinterleaving of radar pulse based on implicit feature

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Journal of Systems Engineering and Electronics 2023年第6期34卷 1537-1549页

作者： GUO qiang TENG long WU Xinliang qi Liangang SONG Wenming College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China China National Aeronautical Radio Electronics Research Institute Shanghai 200030China

In the complex countermeasure environment,the pulse description words(PDWs)of the same type of multi-function radar emitters are similar in multiple ***,it is difficult for conventional methods to deinterleave such *** order to solve this problem,a pulse deinterleaving method based on implicit features is proposed in this *** proposed method introduces long short-term memory(LSTM)neural networks and statistical analysis to mine new features from similar PDW features,that is,the variation law(implicit features)of pulse sequences of different radiation sources over *** multi-function radar emitter is deinterleaved based on the pulse sequence variation *** results show that the proposed method not only achieves satisfactory performance,but also has good robustness.

关键词： multi-functional radars of the same type pulse deinterleaving pulse amplitude implicit feature long short-term memory(LSTM)neural networks.

Tuning the reactivity of Al-Ni by fine coating of halogen-containing energetic composites

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Defence Technology（防务技术） 2022年第10期18卷 1810-1821页

作者： Su-lan Yang Ke-juan Meng Wu-xi Xie Hong-qi Nie qi-long Yan Science and Technology on Combustion Internal Flow and Thermo-Structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China b Xi'an Modern Chemistry Research Institute Xi'an710065China

In this paper,various core-shell structured Al—Ni@ECs composites have been prepared by a spray-drying *** involved ECs refer to the energetic composites(ECs)of ammonium perchlorate/nitrocellulose(AP/NC,NA)and polyvinylidene fluoride/hexanitrohexaazaisowurtzitane(PVDF/CL-20,PC).Two Al—Ni mixtures were prepared at atomic ratios of 1:1 and 1:3 and named as Al/Ni and Al/3Ni,*** thermal reactivity and combustion behaviors of Al—Ni@ECs composites have been comprehensively *** showed that the reactivity and combustion performance of Al—Ni could be enhanced by introducing both NA and PC energetic *** which the Al/Ni@NA composite exhibited higher reactivity and improved combustion *** measured flame propagation rate(v=20.6 mm/s),average combustion wave temperature(T_(max)=1567.0°C)and maximum temperature rise rate(γ_(t)=1633.6°C/s)of Al/Ni@NA are higher than that of the Al/Ni(v=15.8 mm/s,T_(max)=858.0°C,andγ_(t)=143.5°C/s).The enhancement in combustion properties could be due to presence of the acidic gaseous products from ECs,which could etch the Al_(2)O_(3)shell on the surface of Al particles,and make the inner active Al to be easier transported,so that an intimate and faster intermetallic reaction between Al and Ni would be ***,the morphologies and chemical compositions of the condensed combustion products(CCPs)of Al—Ni@ECs composites were found to be different depending on the types of *** compositions of CCPs are dominated with the Al—Ni intermetallics,combining with a trace amount of Al_(5)O_(6)N and Al_(2)O_(3).

关键词： Arrested high energy ball milling Intermetallic alloy Combustion performance Energetic composites Reactivity control