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Science China Chemistry 2024年第4期67卷 1039-1040页

作者： jie Li Xiao feng Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster ScienceMinistry of EducationAdvanced Technology Research Institute(Jinan)Frontiers Science Center for High Energy MaterialSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Scandium(Sc)is recognized as a“strategic”and“critical”element by several countries,including the *** Russia,owing to its wide range of applications in high-tech fields such as superconductivity,alloys,lasers,nucle... 详细信息

关键词： alloys coordination network

Microstructure evolution and formation mechanism of laser-ignited SHS joining between Cf/Al composites and TiAl alloys with Ni-Al-Ti interlayer

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Rare Metals 2017年第9期36卷 746-752页

作者： Guang-jie feng Zhuo-Ran Li Shi-Cheng feng Wei-jie Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

In this study, Cf/Al composites and TiAl alloys were joined by a new method named laser-ignited selfpropagating synthesis（SHS）. Mixed powders of 63.0Ni-31.9Al-5.1Ti（wt%） were used as joining *** joint was got. The microstructure evolution and formation mechanism of the SHS joint were investigated by scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS） and X-ray diffraction（XRD）. Results show that localized melting occurs on both sides. One γ-Ni（0.35）Al（0.30）Ti（0.35） and two Ni-Al reaction layers form,respectively, in the TiAl/interlayer and Cf/Al/interlayer interfaces. The combustion of Ni-Al-Ti interlayer begins with the sharp reaction of Ni and Al. The interlayer product is a eutectic organization of NiAl and Al-rich γ.

关键词： SHS Joining Microstructure Formationmechanism Ni-Al-Ti interlayer

A novel method for AFRPs burrs removal:Principle of mechanochemo-induced fiber fracture

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Chinese Journal of Aeronautics 2024年第7期37卷 522-538页

作者： jie XU Bo LI Pingfa feng Qiang WANG feng feng Division of Advanced Manufacturing Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Changhe Aircraft Industry(Group)Co.Ltd Jingdezhen 333000China

Burrs generated during the machining of Aramid-Fiber-Reinforced Composites(AFRPs)pose a challenge for the production efficiency of aircraft and helicopter housing *** studies have generally attempted to suppress burrs by referring to delamination suppression *** contrast to stratification,burrs are remediable machining *** such,a mechanochemical method with burrs trimming technological strategy are implemented to effectively combat ***,we clarify the mechanism by which aramid fibers cannot be cut off using analytical and numerical *** addition,the mechanism of fiber fracture with Modified Polyurethane Reactive Polymer(M-PUR),and development of anti-burr devices(thermostatic adhesive sealed generator)are ***,the experimental results show that the reduction rate in burr length is 87%-91%through the mechanochemical *** method not only opens a new avenue to solve the burr problem of aramid fibers but also builds an interdisciplinary bridge between polymer science and composite machining.

关键词： Mechanochemical method Burrs Orthogonal cutting Aramid fiber-reinforced composites Milling

Hydrogen-bonded 1D and 2D Assemblies of Tetraiso-butyl-resorcin[4]arene in the Crystalline State

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Chinese Journal of Structural Chemistry 2005年第7期24卷 824-830,739页

作者： LIUXiang LIUYu-jie ZHANGQian-feng DepartmentofAppliedChemistry SchoolofChemicalEngineeringandChemistryAnhuiUniversityofTechnologyMaanshanAnhui243002China

X-ray crystal structures of co-crystals involving tetra-iso-butyl-resorcin[4]arene 1 with both acetone and acetonitrile solvents were reported. The component 1?2(CH3)2CO 2 assembles such that the resorcin[4]arene adopts a C2v conformation and the acetone serves as hydrogen bond acceptors, forming a 1D hydrogen-bonded polymer. 2 (C50H68O10) crystallizes in the triclinic, space group P1 with a = 10.0440(7), b = 13.7498(9), c = 17.6374(12) ?, α = 77.726(2), β = 86.733(2), γ = 88.634(2)o, V = 2376.1(3) ?3, Dc = 1.159 g/cm3, and Z = 2. The assembly process of component 1?2CH3CN?H2O 3 yields a 2D hydrogen-bonded polymer formed by intermolecular hydrogen bonds between resorcin[4]arene and water molecules. In the case of component 3, the acetonitrile molecule serves as guest inside the bowl of resorcin[4]arene host. 3 (C48H64N2O9) crystallizes in the monoclinic, space group P2/n with a = 13.7570(18), b = 9.0961(12), c = 19.453(3) ?, β = 103.017(3)o, V = 2371.7(5) ?3, Dc = 1.138 g/cm3, and Z = 2.

关键词： resorcinarene hydrogen-bonding host-guest chemistry supramolecular chemistry

Area Efficient Pattern Representation of Binary Neural Networks on RRAM

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Journal of Computer Science & Technology 2021年第5期36卷 1155-1166页

作者： feng Wang Guo-jie Luo Guang-Yu Sun Yu-Hao Wang Di-min Niu Hong-Zhong Zheng Center for Energy-Efficient Computing and Applications Peking UniversityBeijing 100871China Pingtouge Alibaba GroupHangzhou 310052China

Resistive random access memory(RRAM)has been demonstrated to implement multiply-and-accumulate(MAC)operations using a highly parallel analog fashion,which dramatically accelerates the convolutional neural networks(CNNs).Since CNNs require considerable converters between analog crossbars and digital peripheral circuits,recent studies map the binary neural networks(BNNs)onto RRAM and binarize the weights to{+1,-1}.However,two mainstream representations for BNN weights introduce patterns of redundant 0s and 1s when dealing with negative *** this work,we reduce the area of redundant 0s and 1s by proposing a BNN weight representation framework based on the novel pattern representation and a corresponding ***,we spilt the weight matrix into several small matrices by clustering adjacent columns ***,we extract 1s'patterns,i.e.,the submatrices only containing 1s,from the small weight matrix,such that each final output can be represented by the sum of several ***,we map these patterns onto RRAM crossbars,including pattern computation crossbars(PCCs)and pattern accumulation crossbars(PACs).Finally,we compare the pattern representation with two mainstream representations and adopt the more area efficient *** evaluation results demonstrate that our framework can save over 20%of crossbar area effectively,compared with two mainstream representations.

关键词： binary neural network(BNN) pattern resistive random access memory(RRAM)

Research progresses of cathodic hydrogen evolution in advanced lead–acid batteries

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Science Bulletin 2016年第6期61卷 451-458页

作者： feng Wang Chen Hu min Zhou Kangli Wang Jiali Lian jie Yan Shijie Cheng Kai Jiang State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074 China China Electric Power Research Institute Beijing 100192 China

Integrating high content carbon into the negative electrodes of advanced lead–acid batteries effectively eliminates the sulfation and improves the cycle life,but brings the problem of hydrogen evolution,which increases inner pressure and accelerates the water *** this review,the mechanism of hydrogen evolution reaction in advanced lead–acid batteries,including lead–carbon battery and ultrabattery,is briefly *** strategies on suppression hydrogen evolution via structure modifications of carbon materials and adding hydrogen evolution inhibitors are summarized as *** review points out effective ways to inhibit hydrogen evolution and prolong the cycling life of advanced lead–acid battery,especially in high-rate partial-state-of-charge applications.

关键词： Lead–carbon battery Ultrabattery Hydrogen evolution reaction Hydrogen inhibition

Grain Growth Behavior of Inconel 625 Superalloy

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Journal of Iron and Steel Research International 2016年第10期23卷 1111-1118页

作者： min LIU Wen-jie ZHENG Jin-zhong XIANG Zhi-gang SONG En-xiang PU Han feng School of Physics Science and Technology Yunnan University Kunming 650093 Yunnan China Central Iron and Steel Research Institute Beijing 100081 China School of Materials Science and Engineering Tsinghua University Beijing 100084 China

The grain growth（GG）behavior of Inconel 625 superalloy was studied in the temperature range of 900-1 250 ℃and holding time range of 10-80 *** of the alloy were characterized by optical metallography,scanning electron microscopy（SEM）and transmission electron microscopy（TEM）.Grains grew obviously with either increasing temperature or extending holding time at temperatures above 1 050℃.However,at temperatures lower than 1 050 ℃,the GG was sluggish due to the pinning effect of carbide particles on grain boundary（GB）.Threshold temperature for transition from mixed grain structure to uniform one was considered to be around 1 100℃.Once the temperatures surpassed 1 200℃,an instant increase in the grain size occurred showing no dependence on holding *** analysis showed that the dominant second phase formed heterogeneously on the GB was M6 C,which significantly impeded grain *** the basis of experimental data,the mathematical model of GG was established,which can describe GG behavior of Inconel 625 alloy during solution treatment（ST）at 1 100-1 250 ℃.The activation energy for GG of Inconel 625 alloy was 207.3kJ,which suggested that the GG of Inconel 625 alloy was controlled by the process of GB diffusion.

关键词： Inconel 625 alloy growth kinetics solution treatment precipitation

Removal of bromate ion using powdered activated carbon

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Journal of Environmental Sciences 2010年第12期22卷 1846-1853页

作者： Lian Wang jie Zhang Jingze Liu Hong He min Yang Jianwei Yu Zichuan Ma feng Jiang College of Life Science Hebei Normal University Shijiazhuang 050016 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China College of Chemistry & Material Science Hebei Normal University Shijiazhuang 050016 China Beijing YADU Indoor Environmental Protection Science and Technology Co. Ltd. Beijing 102206 China

Bromate ion （BrO3-） removal from drinking water by powdered activated carbons （PACs） in bath mode was evaluated under various operational conditions. Six kinds of PACs, including wood-based carbon, fruit-based carbon, coal-based carbon, and these three carbons thermally deoxidized in a nitrogen atmosphere, were selected to investigate their capacity on BrO3- removal. With the highest zeta potential value and being richly mesoporous, coal-based carbon had a high and an excellent BrO3- adsorption efficiency. The removal content of BrO3- by per gram of coal-based carbon was 0.45 mg within 5 hr in 100 μg/L bromate solution. The surface characteristics of PACs and bromide formation revealed that both physical and chemical PACs properties simultaneously affected the adsorptionreduction process. Under acidic conditions, PACs possessed high zeta value and adequate basic groups and exhibited neutral or positive charges, promoting BrO3- adsorption-reduction on the carbon surface. Interestingly, the PACs thermally deoxidized in N2 atmosphere optimized their properties, e.g. increasing their zeta values and decreasing the oxygen content which accelerated the BrO3- removal rate. The maximum adsorption capacity of fruit-based carbon was the highest among all tested carbons （99.6 mg/g）, possibly due to its highest pore volume. Remarkably, the thermal regeneration of PACs in N2 atmosphere could completely recover the adsorption capacity of PACs. The kinetic data obtained from carbons was analyzed using pseudo second-order and intraparticle diffusion models, with results showing that the intraparticle diffusion was the more applicable model to describe adsorption of BrO3- onto PACs.

关键词： bromate powdered activated carbons adsorption-reduction process adsorption capacity

Low Surface Brightness Galaxies Selected by Different Model Fitting

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Research in Astronomy and Astrophysics 2024年第1期24卷 223-236页

作者： Bing-Qing Zhang Hong Wu Wei Du Pin-Song Zhao min He feng-jie Lei Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

We present a study of low surface brightness galaxies(LSBGs) selected by fitting the images for all the galaxies inα.40 SDSS DR7 sample with two kinds of single-component models and two kinds of two-component models(disk+bulge):single exponential,single sersic,exponential+deVaucular(exp+deV),and exponential+sérsic(exp+ser).Under the criteria of the B band disk central surface brightness μ_(0,disk)(B)≥22.5 mag arcsec^(-2) and the axis ratio b/a> 0.3,we selected four none-edge-on LSBG samples from each of the models which contain 1105,1038,207,and 75 galaxies,*** are 756 galaxies in common between LSBGs selected by exponential and sersic models,corresponding to 68.42% of LSBGs selected by the exponential model and 72.83% of LSBGs selected by the sersic model,the rest of the discrepancy is due to the difference in obtaining μ_(0) between the exponential and sersic *** on the fitting,in the range of 0.5≤n≤1.5,the relation of μ_(0) from two models can be written as μ_(0,sérsic)-μ_(0,exp)=-1.34(n-1).The LSBGs selected by disk+bulge models(LSBG_(2)comps) are more massive than LSBGs selected by single-component models(LSBG_1comp),and also show a larger disk *** the bulges in the majority of our LSBG_(2)comps are not prominent,more than 60% of our LSBG_(2)comps will not be selected if we adopt a single-component model *** also identified 31 giant low surface brightness galaxies(gLSBGs) from LSBG_(2)*** are located at the same region in the color-magnitude diagram as other *** we compared different criteria of gLSBGs selection,we find that for gas-rich LSBGs,M_(*)> 10^(10)M_⊙ is the best to distinguish between gLSBGs and normal LSBGs with bulge.

关键词： catalogs galaxies:spiral galaxies:bulges methods:data analysis methods:statistical

Solar Flare Forecast Model Based on Resampling and Fusion Method

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Research in Astronomy and Astrophysics 2022年第8期22卷 238-248页

作者： jie Wan Jun-feng Fu Dai-min Tan Ke Han Meng-Yao Yu Peng E Laboratory for Space Environment and Physical Sciences Harbin Institute of TechnologyHarbin 150001China School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150001China School of Computer and Information Engineering Harbin University of CommerceHarbin 150028China

Predicting the activity of solar flares is of great significance for studying its physical mechanism and the impact on human production and *** such as class imbalance,high time-series sensitivity,and over-localization of important features exist in the sample data used for flare *** design a solar flare fusion method based on resampling and the CNN-GRU algorithm to try to solve the above *** order to verify the effectiveness of this fusion method,first,we compared the forecast performance of different resampling methods by keeping the forecast model ***,we used the resampling algorithm with high performance to combine some single forecast models and fusion forecast models *** use the 2010-2017 sunspot data set to train and test the performance of the flare model in predicting flare events in the next 48 *** the conclusion of the above steps,we prove that the resampling method SMOTE and its variant SMOTE-ENN are more advantageous in class imbalance problem of flare *** addition,after the fusion of one-dimensional convolution and recurrent network with"forget-gate",combined with the SMOTE-ENN to achieve TSS=61%,HSS=61%,TP_(Rate)=77%and TN_(Rate)=83%.This proves that the fusion model based on resampling and the CNN-GRU algorithm is more suitable for solar flare forecasting.

关键词： (Sun:)sunspots Sun:flares Sun:X-rays gamma-rays Sun:magnetic fields Sun:corona