检索结果-南通市图书馆

Achieving ultrahigh electrocatalytic NH_(3) yield rate on Fe-doped Bi_(2)WO_(6) electrocatalyst

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2021年第8期14卷 2711-2716页

作者： Yongqin Liu Liang huang Youxing fang Xinyang Zhu Shaojun Dong College of Chemistry Jilin UniversityChangchun 130012China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of ScienceChangchun 130022China

NH_(3),derived from electrocatalytic nitrogen reduction reaction(NRR),is promising to satisfy the need of food production and serve as a carbon-free liquid energy carrier in the near *** major challenges remain in enhancing NH_(3) yield rate and conversion efficiency of available *** work achieved an ultrahigh electrocatalytic NH_(3)yield rate on the_(0.50)Fe-Bi_(2)W0_(6) catalyst by a facile Fe-doped *** to 289μg·h^(-1)·mg_(cat)^(-1) of NH_(3) formation rate was obtained at-0.75 V ***,which was reliably quantized by indophenol blue and ^(1)H NMR *** impressive result is an order of magnitude higher than that of the reported Fe-and Bi-based catalysts,even more superior than the result of single atom Ru *** key of the outstanding NRR behaviors on the_(0.50)Fe-Bi_(2)W0_(6) catalyst is the significant hydrogen evolution reaction(HER)suppression and the synergy between Bi and Fe,which can effectively modulate the electron distribution and accelerate the electron *** work endows a new insight to further explore the high-performance electrocatalysts toward NRR.

关键词： electrocatalytic ammonia synthesis ultrahigh NH_(3)yield rate Fe-doped Bi_(2)WO_(6) synergy effect suppressing HER

Preparation and characterization of HMX/NH_(2)-GO composite with enhanced thermal safety and desensitization

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第11期18卷 2074-2082页

作者： Yu-lan Song Qi huang Bo Jin Ru-fang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

To improve the safety of HMX,HMX/NH_(2)-GO composite was prepared with aqueous ammonia functionalized graphene oxide(NH_(2)-GO).The composite was characterized by SEM,Zeta potential,XPS,Raman spectrum,XRD,HPLC,DSC and BAM sensitivity *** results indicated that the functionalization with aqueous ammonia can enhance the interaction between GO and HMX,and more efficiently desensitize the *** optimal impact sensitivity of the HMX/NH_(2)-GO composite can be not less than 40 J,which is also the most insensitivity compared to the previous reports prepared by coating desensitization with non-energetic desensitized ***,the potential reason for the different impact and friction sensitivity was also discussed,which may bring a novel perspective to achieve the desensitization of energetic material.

关键词： HMX GO Ammonia Surface coating technology

Response regimes of nonlinear energy harvesters with a resistorinductor resonant circuit by complexification-averaging method

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第6期64卷 1212-1227页

作者： huang DongMei CHEN JiaYi ZHOU ShengXi fang XueLai LI Wei School of Mathematics and Statistics Xidian UniversityXi'an 710071China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

In this paper, the steady-state response regimes of nonlinear energy harvesters with a resistor-inductor resonant circuit are theoretically investigated. The complexification averaging(CA) method is used to theoretically analyze the energy harvesting performance and reduce the motion equations into a set of first-order differential equations. The amplitudes and phases of both the response displacement and the output voltage are derived, and the corresponding stability conditions are determined. The response regimes are studied with the variation of nonlinear stiffness coefficients and coupling parameters, which are verified by the time domain analysis. The frequency island phenomenon is found and analyzed. Additionally, the backbone curve for deducing the extreme vibration frequency and amplitude is derived. Simultaneously, the analytical expressions of the switching points(critical amplitude and frequency) to identify the hardening and softening properties are established. Accordingly, a criterion is given to determine the occurrence of the jump phenomenon, and its effectiveness is verified. Overall, this paper presents an in-depth theoretical analysis of nonlinear energy harvesters with a resistor-inductor resonant circuit. It presents the theoretical framework and guidance for more extensive evaluations and understanding the theoretical analysis of nonlinear energy harvesters with external circuits.

关键词： energy harvesting complexification averaging method nonlinear vibration

Wire and arc additive manufacturing of dissimilar 2319 and 5B06 aluminum alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第29期124卷 65-75页

作者： Tianxing Chang Xuewei fang Gang Liu Hongkai Zhang Ke huang State Key Laboratory for Manufacturing Systems Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

Aluminum alloy is the most widely used light alloy at *** combining different types of aluminum alloys,their functional properties can be *** the present research,two components composed of 2319(Al-6.5Cu)and 5B06(Al-6.4Mg)dissimilar alloys were fabricated by wire and arc additive manufacturing(WAAM).The deposited component with the bottom half of 2319 and the top half of 5B06 exhibits better mechanical properties than its counterpart deposited vice *** ultimate tensile strength,yield strength,and elongation are 258.5 MPa,139.3 MPa,and 5.6%,respectively,which are only slightly inferior to the mechanical properties of 2319 base *** results show that for both components,fracture occurred at a layer thickness above the interface layer during the tensile test,regardless of the deposition *** appears that the thermal stress due to the long dwell time and the remelting of the S-AlCu Mg phase are the main factors promoting crack *** on the deposition order,cracks propagate either along the aggregated pores or stripθ-AlCu phase distributed along the grain *** analyzing the heat input and selecting the appropriate depositing order,the strength of WAAM dissimilar aluminum alloys can be effectively improved through the proper control of microstructure and internal defects.

关键词： Wire and arc additive manufacturing Dissimilar materials Defects Microstructure Mechanical Properties Aluminum alloy

Experimental study of stratified lean burn characteristics on a dual injection gasoline engine

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2022年第6期16卷 900-915页

作者： Chun XIA Tingyu ZHAO Junhua fang Lei ZHU Zhen huang Key laboratory of Power Machinery and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Due to increasingly stringent fuel consumption and emission regulation,improving thermal efficiency and reducing particulate matter emissions are two main issues for next generation gasoline *** burn mode could greatly reduce pumping loss and decrease the fuel consumption of gasoline engines,although the burning rate is decreased by higher diluted intake *** this study,dual injection stratified combustion mode is used to accelerate the burning rate of lean burn by increasing the fuel concentration near the spark *** effects of engine control parameters such as the excess air coefficient(Lambda),direct injection(DI)ratio,spark interval with DI,and DI timing on combustion,fuel consumption,gaseous emissions,and particulate emissions of a dual injection gasoline engine are *** is shown that the lean burn limit can be extended to Lambda=1.8 with a low compression ratio of 10,while the fuel consumption can be obviously improved at Lambda=*** exists a spark window for dual injection stratified lean burn mode,in which the spark timing has a weak effect on *** optimization of the control parameters,the brake specific fuel consumption(BSFC)decreases 9.05%more than that of original stoichiometric combustion with DI as 2 bar brake mean effective pressure(BMEP)at a 2000 r/min engine *** NO_(x) emissions before threeway catalyst(TWC)are 71.31%lower than that of the original engine while the particle number(PN)is 81.45%lower than the original *** dual injection stratified lean burn has a wide range of applications which can effectively reduce fuel consumption and particulate *** BSFC reduction rate is higher than 5%and the PN reduction rate is more than 50%with the speed lower than 2400 r/min and the load lower than 5 bar.

关键词： dual injection stratified lean burn gasoline engine particulate matter emission combustion analysis

Experiments on Cu-isotope fractionation between chlorine-bearing fluid and silicate magma: implications for fluid exsolution and porphyry Cu deposits

在线全文

学校读者我要写书评

暂无评论

National Science Review 2020年第8期7卷 1319-1330页

作者： Haihao Guo Ying Xia Ruixia Bai Xingchao Zhang fang huang Bayerisches Geoinstitut University of Bayreuth Department of Earth and Planetary Sciences Mc Gill University CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Sciences University of Science and Technology of China CAS Center for Excellence in Comparative Planetology

Hydrothermal fluid is essential for transporting metals in the crust and mantle. To explore the potential of Cu isotopes as a tracer of hydrothermal-fluid activity, Cu-isotope fractionation factors between Cl-bearing aqueous fluids and silicate magmas(andesite, dacite, rhyolite dacite, rhyolite and haplogranite) were experimentally calibrated. Fluids containing 1.75–14 wt.% Cl were mixed together with rock powders in Au95Cu5alloy capsules, which were equilibrated in cold-seal pressure vessels for 5–13 days at 800–850℃ and 2 kbar. The elemental and Cu-isotopic compositions of the recovered aqueous fluid and solid phases were analyzed by(LA-) ICP–MS and multi-collector inductively coupled plasma mass spectrometry,respectively. Our experimental results show that the fluid phases are consistently enriched in heavy Cu isotope(65Cu) relative to the coexisting silicates. The Cu-isotope fractionation factor(65CuFLUID-MELT)ranges from 0.08 ± 0.01 to 0.69 ± 0.02. The experimental results show that the Cu-isotopic fractionation factors between aqueous fluids and silicates strongly depend on the Cu speciation in the fluids(e.g. CuCl(H2O), CuCl2–and Cu Cl32-) and silicate melts(Cu O1/2), suggesting that the exsolved fluids may have higher δ65Cu than the residual magmas. Our results suggest the elevated δ65Cu values in Cu-enriched rocks could be produced by addition of aqueous fluids exsolved from magmas. Together with previous studies on Cu isotopes in the brine and vapor phases of porphyry deposits, our results are helpful for better understanding Cu-mineralization processes.

关键词： Cu isotopes cold-seal pressure vessels aqueous fluids silicate magma porphyry deposit

Multidimensional modulation of light fields via a combination of two-dimensional materials and meta-structures

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第6期66卷 36-52页

作者： Zhipeng ZHENG Yijing huang Feng WU Han ZHANG Zheyu fang School of Physics State Key Laboratory for Mesoscopic PhysicsAcademy for Advanced Interdisciplinary StudiesCollaborative Innovation Center of Quantum MatterNano-optoelectronics Frontier Center of Ministry of EducationPeking University

In recent years, researchers have increasingly directed their attention towards modulating light fields through the unique properties of two-dimensional materials and the free designability of ***, transition metal sulfides, transition metal nitrides, and other two-dimensional materials have emerged as star materials in recent years due to their extraordinary properties that are vastly different from those of traditional three-dimensional materials. As a result, these materials hold immense potential for further exploration and research. Taking advantage of the free designability of meta-structures can be an effective means of unlocking the full potential of 2D materials. Accordingly, this review presents an overview of recent research progress in the area of light field modulation achieved by combining 2D materials with metastructures. The review initially covers the properties of 2D materials, followed by the concepts, principles,design, and preparation of meta-structures. Then the review delves into the concrete examples of the impact and effect of the combination on light field modulation. Lastly, the review concludes with a comprehensive summary and analysis of the current challenges and potential future developments of combining 2D materials with meta-structures.

关键词： two-dimensional materials electromagnetic meta-structures light field modulation surface plasma polarisation surface plasmon

同方期刊数据库

Reinforcement learning-based missile terminal guidance of maneuvering targets with decoys

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2023年第12期36卷 309-324页

作者： Tianbo DENG Hao huang Yangwang fang Jie YAN Haoyu CHENG School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Unmanned System Research Institute Northwestern Polytechnical UniversityXi’an 710072China

In this paper,a missile terminal guidance law based on a new Deep Deterministic Policy Gradient(DDPG)algorithm is proposed to intercept a maneuvering target equipped with an infrared ***,to deal with the issue that the missile cannot accurately distinguish the target from the decoy,the energy center method is employed to obtain the equivalent energy center(called virtual target)of the target and decoy,and the model for the missile and the virtual decoy is ***,an improved DDPG algorithm is proposed based on a trusted-search strategy,which significantly increases the train efficiency of the previous DDPG ***,combining the established model,the network obtained by the improved DDPG algorithm and the reward function,an intelligent missile terminal guidance scheme is ***,a heuristic reward function is designed for training and learning in combat ***,the effectiveness and robustness of the proposed guidance law are verified by Monte Carlo tests,and the simulation results obtained by the proposed scheme and other methods are compared to further demonstrate its superior performance.

关键词： Deep deterministic policy gradient Infrared decoy Maneuvering target Reinforcement learning Terminal guidance law

Shear behavior of ultra-high-performance concrete beams prestressed with external carbon fiber-reinforced polymer tendons

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第6期15卷 1426-1440页

作者： Li JIA Zhi fang Maurizio GUADAGNINI Kypros PILAKOUTAS Zhengmeng huang College of Civil Engineering Hunan UniversityChangsha 410082China Key Laboratory for Wind and Bridge Engineering of Hunan Province Changsha 410082China Department of Civil and Structural Engineering The University of SheffieldSheffield S13JDUK Guizhou Transportation Planning Survey and Design Academe Co.Ltd. Guiyang 550003China

The ultra-high-performance concrete(UHPC)and fiber-reinforced polymer(FRP)are well-accepted high-performance materials in the field of civil *** combination of these advanced materials could contribute to improvement of structural performance and corrosion ***,only limited studies are available for shear behavior of UHPC beams reinforced with FRP bars,and few suggestions exist for prediction methods for shear *** paper presents an experimental investigation on the shear behavior of UHPC beams reinforced with glass FRP(GFRP)and prestressed with external carbon FRP(CFRP)*** failure mode of all specimens with various shear span to depth ratios from 1.7 to 4.5 was diagonal tension *** shear span to depth ratio had a significant influence on the shear capacity,and the effective prestressing stress affected the crack *** experimental results were then applied to evaluate the equations given in different codes/recommendations for FRPreinforced concrete structures or UHPC *** comparison results indicate that NF P 18-710 and JSCE CES82 could appropriately estimate shear capacity of the slender specimens with a shear span to depth ratio of ***,a new shear design equation was proposed to take into account the effect of the shear span to depth ratio and the steel fiber content on shear capacity.

关键词： beam external prestressing ultra-high-performance concrete fiber-reinforced polymers shear behavior design equation