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313篇 您的检索式:作者名="Longfei"
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1The TanSat mission: preliminary global observations显示文摘The Chinese global carbon dioxide monitoring satellite (Tan Sat) was launched successfully in December2016 and has completed its on-orbit tests and calibration. Tan Sat aims to measure the atmospheric column-averaged dry air mole fractions of carbon dioxide (XCO_2) with a precision of 4 ppm at the regional scale, and in addition, to derive global and regional CO2fluxes. Progress towards these objectives is reviewed and the first scientific results from Tan Sat measurements are presented. Tan Sat on-orbit tests indicate that the Atmospheric Carbon dioxide Grating Spectrometer is in normal working status and is beginning to produce L1B products. The preliminary Tan Sat XCO_2products have been retrieved by an algorithm and compared to NASA Orbiting Carbon Observatory-2 (OCO-2) measurements during an overlapping observation period. Furthermore, the XCO_2retrievals have been validated against eight groundsite measurement datasets from the Total Carbon Column Observing Network, for which the preliminary conclusion is that Tan Sat has met the precision design requirement, with an average bias of 2.11 ppm.The first scientific observations are presented, namely, the seasonal distributions of XCO_2over land on a global scale.Yi Liu Jing Wang Lu Yao Xi Chen Zhaonan Cai Dongxu Yang Zengshan Yin Songyan Gu Longfei Tian Naimeng Lu Daren Lyu 2018Science Bulletin2018,63,18:23
2Progress of the technique of coal microwave desulfurization显示文摘With the advantages of its fast speed,effective and moderate controllable conditions,desulfurization of coal by microwave has become research focus in the field of clean coal technology.Coal is a homogeneous mixture which consists of various components with different dielectric properties,so their abilities to absorb microwaves are different,and the sulfur-containing components are better absorbers of microwave,which makes them can be selectively heated and reacted under microwave irradiation.There still remain controversies on the principle of microwave desulfurization at present,thermal effects or non-thermal effects.The point of thermal effects of microwave is mainly base on its characters of rapidly and selectly heating.While,in view of non-thermal effect,direct interactions between the microwave electromagnetic field and sulfur containing components are proposed.It is a fundamental problem to determine the dielectric properties of coal and the sulfur-containing components to reveal the interaction of microwave and sulfur-containing compounds.However,the test of dielectric property of coal is affected by many factors,which makes it difficult to measure dielectric properties accurately.In order to achieve better desulfurization effect,the researchers employ methods of adding chemical additives such as acid,alkali,oxidant,reductant,or changing the reaction atmosphere,or combining with other methods such as magnetic separation,ultrasonic and microorganism.Researchers in this field have also put forward several processes,and have obtained a number of patents.Obscurity of microwave desulfurization mechanism,uncertainties in qualitative and quantitative analysis of sulfur-containing functional groups in coal,and the lack of special microwave equipment have limited further development of microwave desulfurization technology.Xiuxiang Tao Ning Xu Maohua Xie Longfei Tang 2014International Journal of Coal Science & Technology2014,1,1:15
3Soil Erosion and Its Basic Characteristics at Karst Rocky-desertified Land Consolidation Area: A Case Study at Muzhe Village of Xichou County in Southeast Yunnan, China显示文摘Xichou County of Wenshan Zhuang and Miao Autonomous Prefecture in southeast Yunnan is one of the karst mountainous areas in southwest China showing typical rock desertification. During this study, we set up three soil erosion contrast test spots at Muzhe Village, Benggu Township, Xichou County, which was the birthplace of the Xichou rock-desertified land consolidation mode. The three spots included the terrace land spot (already consolidated land), sloping land spot (unconsolidated sloping land under rock desertification), and standard runoff spot (bare land spot). In 2007, a whole-year complete observation was conducted during the rainy season and 'rainfall-erosion' data were obtained for 32 times. Our analysis showed that during the entire observation period, the number of the rainfalls that led to soil erosion accounted for 34.04% of the number of all rainfalls and the amount of the rainfalls that led to soil erosion accounted for 84.17% of the total amount of all rainfalls. The average erosive rainfall standard in the three test spots was 11.0 mm, slightly higher than the 10 mm standard that has been adopted all over China, but lower than the 12.7 mm standard of the US and the 13.0 mm standard of Japan. According to single-factor analysis, the soil loss in the sloping land spot (L2) and that in the bare land spot (L3) are correlated to certain extent to many other factors, including the single precipitation (P), rainfall intensity during the maximum ten minutes (I10), rainfall intensity during the maximum 20 minutes (I20), rainfall intensity during the maximum 30 minutes (I30), rainfall intensity during the maximum 40 minutes (I40), and rainfall intensity during the maximum 60 minutes (I60). Among these factors, they are of the highest relativity with I60. According to double-factor analysis, both L2 and L3 are of good relativity with P and I60. According to multi-factor analysis, L2 and L3 are also of good relativity with seven rainfall indexes, namely, P, Ia (average rainfall intensity), I10, I20, I30, I40, and I60, with their related coefficient R reaching 0.906 and 0.914, respectively. The annual soil losses in the three test spots are widely different: 1030.70 t/km2·a in the terrace land spot, which indicates a low-level erosion; 12913.22 t/km2·a in the sloping land spot (unconsolidated spot), some 12.5 times than that in the terrace land spot, which indicates an ultra-high-level erosion; and 19511.67 t/km2·a in the bare land spot, some 18.9 times than that in terrace land spot, indicating an acute erosion. These figures fully show that the Xichou rock-desertified land consolidation mode plays a significant role in soil conservation.YANG Zisheng YANG Longfei ZHANG Bosheng 2010Journal of Mountain Science2010,7,1:14
4Studies on aeroservoelasticity semi-physical simulation test for missiles显示文摘Missiles may be damaged when aeroservoelastic problem occurs,which is caused by the interaction of structure flexibility and flight control system.Because of the limit of wind tunnel test condition,numerical methods are mostly used in previous aeroservoelastic studies.However,series of assumptions and simplification on structures,aerodynamics and flight control systems are unavoidably introduced,and various nonlinear factors are also ignored,therefore,they result in considerable errors.A novel method called aeroservoelasticity semi-physical simulation test is proposed in this paper,which takes the flexible missile with control system as the test object.Vibration signals at several locations of the missile are measured by accelerometers,then corresponding unsteady aerodynamics is computed based on the fact that airflow at high Mach is nearly quasi-steady,and finally unsteady aerodynamics is exerted simultaneously by shakers at certain locations of the missile.The aeroservoelasticity semi-physical simulation test system can be constructed after the control system is closed.Open loop transfer function test and closed loop stability test are carried out in sequence.The test principle and method proposed in this paper are verified by the concordance between the results of numerical simulation and experiment.WU ZhiGang CHU LongFei YUAN RuiZhi YANG Chao TANG ChangHong 2012Science China(Technological Sciences)2012,55,9:14
5Direct conversion of astrocytes into neuronal cells by drug cocktail显示文摘Lin Cheng Longfei Gao Wuqiang Guan Jianxin Mao Wenxiang Hu Binlong- Qiu Jian Zhao Yongchun Yu Gang Pei 2015Cell Research2015,25,11:14
6Robust Position Anti-Interference Control for PMSM Servo System With Uncertain Disturbance显示文摘Aiming to suppress the influence of uncertain disturbances in the drive control of permanent magnet synchronous machines(PMSM),such as the parameter uncertainties and load disturbance,a robust anti-interference control for the angular position tracking control of a PMSM servo system has been proposed in this paper.During the position tracking,uncertain system disturbances being regarded as a lumped unknown term will be online observed by a nonlinear disturbance observer(NDOB),of which the influence will consequently be counteracted by a robust backstepping compensator(RBC).The asymptotical stability of proposed control scheme is analyzed and designed according to the Lyapunov stability criterion,and its convergence against the system uncertain disturbance is verified on a prototype PMSM servo platform and shows good performance in rotor angular position tracking and anti-interference.Longfei Li Jie Xiao Yun Zhao Kan Liu Xiaoyan Peng Haozhe Luan Kaiqing Li 2020CES Transactions on Electrical Machines and Systems2020,4,2:13
7Key residues of the receptor binding motif in the spike protein of SARS-CoV-2 that interact with ACE2 and neutralizing antibodies显示文摘Coronavirus disease 2019(COVID-19),caused by the novel human coronavirus SARS-CoV-2,is currently a major threat to public health worldwide.The viral spike protein binds the host receptor angiotensin-converting enzyme 2(ACE2)via the receptor-binding domain(RBD),and thus is believed to be a major target to block viral entry.Both SARS-CoV-2 and SARS-CoV share this mechanism.Here we functionally analyzed the key amino acid residues located within receptor binding motif of RBD that may interact with human ACE2 and available neutralizing antibodies.The in vivo experiments showed that immunization with either the SARS-CoV RBD or SARS-CoV-2 RBD was able to induce strong clade-specific neutralizing antibodies in mice;however,the cross-neutralizing activity was much weaker,indicating that there are distinct antigenic features in the RBDs of the two viruses.This finding was confirmed with the available neutralizing monoclonal antibodies against SARS-CoV or SARS-CoV-2.It is worth noting that a newly developed SARS-CoV-2 human antibody,HA001,was able to neutralize SARS-CoV-2,but failed to recognize SARS-CoV.Moreover,the potential epitope residues of HA001 were identified as A475 and F486 in the SARS-CoV-2 RBD,representing new binding sites for neutralizing antibodies.Overall,our study has revealed the presence of different key epitopes between SARS-CoV and SARSCoV-2,which indicates the necessity to develop new prophylactic vaccine and antibody drugs for specific control of the COVID-19 pandemic although the available agents obtained from the SARS-CoV study are unneglectable.Chunyan Yi Xiaoyu Sun Jing Ye Longfei Ding Meiqin Liu Zhuo Yang Xiao Lu Yaguang Zhang Liyang Ma Wangpeng Gu Aidong Qu Jianqing Xu Zhengli Shi Zhiyang Ling Bing Sun 2020Cellular & Molecular Immunology2020,17,6:13
8Design of a New Intelligent Anti-voltage Sag Control Module for AC Contactors显示文摘智能抗电压跌落交流接触器多使用在连续生产的企业中,不允许意外断电,针对这一特点,设计一款新型智能抗电压跌落控制模块,具有交流供电模式和控制模块直流可控供电模式。当控制模块正常时,通过控制模块给交流接触器线圈供电,具有直流无声运行、抗电压跌落等功能;一旦控制模块自身发生严重故障,起动转换电路,切断控制模块,通过有触点开关直接提供交流电给交流接触器线圈,维持生产系统正常工作,同时发出报警信号,在系统正常停机的情况下更换控制模块。详细分析了该智能控制模块的工作原理,尤其对开关电源的设计及有触点开关与无触点开关构成的转换电路进行分析,并进行仿真与实验研究。仿真和实验结果验证了所提方法的有效性。TANG Longfei XU Zhihong 2012中国电机工程学报2012,32,27:12
9Improved CICA Algorithm Used for Single Channel Compound Fault Diagnosis of Rolling Bearings显示文摘A Compound fault signal usually contains multiple characteristic signals and strong confusion noise, which makes it difficult to separate week fault signals from them through conventional ways, such as FFT-based envelope detection, wavelet transform or empirical mode decomposition individually. In order to realize single channel compound fault diagnosis of bearings and improve the diagnosis accuracy, an improved CICA algorithm named constrained independent component analysis based on the energy method(E-CICA) is proposed. With the approach, the single channel vibration signal is firstly decomposed into several wavelet coefficients by discrete wavelet transform(DWT) method for the purpose of obtaining multichannel signals. Then the envelope signals of the reconstructed wavelet coefficients are selected as the input of E-CICA algorithm, which fulfills the requirements that the number of sensors is greater than or equal to that of the source signals and makes it more suitable to be processed by CICA strategy. The frequency energy ratio(ER) of each wavelet reconstructed signal to the total energy of the given synchronous signal is calculated, and then the synchronous signal with maximum ER value is set as the reference signal accordingly. By this way, the reference signal contains a priori knowledge of fault source signal and the influence on fault signal extraction accuracy which is caused by the initial phase angle and the duty ratio of the reference signal in the traditional CICA algorithm is avoided. Experimental results show that E-CICA algorithm can effectively separate out the outer-race defect and the rollers defect from the single channel compound fault and fulfill the needs of compound fault diagnosis of rolling bearings, and the running time is 0.12% of that of the traditional CICA algorithm and the extraction accuracy is 1.4 times of that of CICA as well. The proposed research provides a new method to separate single channel compound fault signals.CHEN Guohua QIE Longfei ZHANG Aijun HAN Jin 2016Chinese Journal of Mechanical Engineering2016,29,1:12
10Analysis of a 1 kW organic Rankine cycle using a scroll expander for engine coolant and exhaust heat recovery显示文摘引擎浪费热恢复技术的发展由于升起吸引曾经增加的兴趣严格的政策要求和环境担心。这份报纸论述了引擎冷却剂的学习并且用器官的 Rankine 周期(海怪) 用尽热恢复。八个工作液体被选择评估并且比较综合浪费热恢复系统的性能。而非主要集中于利用的常规引擎海怪系统用尽精力,这个工作建议充分由改变海怪系统的设计参数使用引擎冷却剂精力。案例研究作为热来源选择了一台小引擎为力量生产用滚动扩展驾驶海怪系统。评估结果建议那在引擎下面评估了状况,充分恢复引擎冷却剂精力的解决方案能比常规引擎海怪系统的完成更高的发电表演。结果建议那补充说当工作液体是干燥的,外套倾倒系统的热需求时,到 ORC 系统的一个恢复者能潜在地改进系统表演能被 12% 在最佳的条件下面减少。当蒸发的 ORC 和压缩温度分别地被放在 85C 和 30C 时,综合引擎浪费热恢复系统能作为工作液体与 R600, R600a 或 n 戊烷在 9.3% 改进全面系统效率。Yiji LU Anthony Paul ROSKILLY Long JIANG Longfei CHEN Xiaoli YU 2017Frontiers in Energy2017,11,4:10
11Optimization and test for spraying parameters of cotton defoliant sprayer显示文摘Boom sprayer is widely used in large farm crops because of its high working efficiency and favorable spraying effect.But there are still some problems in cotton defoliant spraying in Xinjiang,China.Cotton is planted in a high density in Xinjiang,the row space is(10+66)cm,leaves in two adjacent rows are seriously overlapped,the lower leavers are poorly sprayed,so the defoliation effect is poor,and the cotton quality is degraded.To solve this problem and improve the defoliant droplets coverage on the cotton canopy,the original boom spraying was modified,and the spraying pardameters was optimized by the central combination test and design concept of Box-Behnken based on a single-factor test.A quadratic polynomial model of droplets coverage was created by using working parameters including horizontal spraying boom height,hang boom height and nozzles angle as the influential factors and the mean droplets coverage on cotton canopy as the target function,and the effectiveness of mode and interaction of factors were analyzed.The model was optimized and analyzed using the regression analysis method and response surface analysis method of software Design-Expert 7.0.0,and the optimal combination of spraying parameters was obtained.The results showed that the droplets coverage on cotton canopy were influenced by boom height,sprayer height and angled nozzles sequentially from large to small,and the optimal combination of spraying parameters was under horizontal spraying boom height of 134 cm,hang spraying boom height of 27.5 cm and nozzles angle of 21°.The mean droplets coverage of experimental value and predicted value on cotton canopy were 19.6%and 20.43%respectively in such conditions,and the relative error to the estimated value on the model was–4.25%.The research result can provide a reference for further optimizing the spraying parameters of cotton defoliant sprayer.Qin Weicai Xue Xinyu Cui Longfei Zhou Qingqing Xu Zhufeng Chang Feilong 2016International Journal of Agricultural and Biological Engineering2016,9,4:9
12Presence of carboxylate salts in marine carbonate strata of the Ordos Basin and their impact on hydrocarbon generation evaluation of low TOC, high maturity source rocks显示文摘The total organic carbon(TOC)in the marine source rock of the Ordos Basin mostly ranges from 0.2%to 0.5%.The industrial standard commonly states that the TOC value has to be no less than 0.5%(0.4%for high mature or over-mature source rock)to form large petroleum reservoirs.However,gas source correlation indicates that the natural gas in the Jingbian gas field does receive contribution from marine source rocks.In order to determine the effect of carboxylate salts(or called as organic acid salts)on TOC in highly mature source rocks with low TOC value,we sampled the Ordovician marine source rock and the Permian transitional facies source rock in one drilled well in the southern Ordos Basin and performed infrared and GC-MS analysis.It is found that both kerogen-derived organic acids and carboxylate salt-conversed organic acids exist in both marine and transitional facies source rocks.The carboxylate salt-conversed organic acids mainly come from the complete acidification of carboxylate salts,which confirms the presence of carboxylate salts in the marine source rocks.Although the C16:O peak is the main peak for the organic acids both before and after acidification,the carboxylate salt-conversed organic acids have much less relative abundance ahead of C16:O compared with that of the kerogen-based and free organic acids.This observation suggests that the kerogen-based and free organic acids mainly decarboxylate to form lower carboxylic acids,whereas the carboxylate salt-conversed organic acids mainly break down into paraffins.By using calcium hexadecanoate as the reference to quantify the kerogen-derived and carboxylate salt-conversed organic acids,the high TOC(>2.0%)marine source rocks have low carboxylate salt content and the low TOC(0.2%–0.5%)marine source rocks contain high content of carboxylate salt.Therefore,for the marine source rocks with 0.2%–0.5%TOC,the carboxylate salts may be a potential gas source at high maturity stage.LIU QuanYou JIN ZhiJun LIU WenHui LU LongFei MENG QianXiang TAO Ye HAN PinLong 2013Science China Earth Sciences2013,56,12:9
13microRNA-29b is a novel mediator of Sox2 function in the regulation of somatic cell reprogramming显示文摘成纤维细胞能由 Yamanaka 因素(OSKM ) 的申请是进导致的 pluripotent 干细胞(iPSCs ) 的 reprogrammed,但是位于这 reprogramming 下面的机制仍然保持糟糕理解。这里,我们报导 Sox2 直接调整内长的 microRNA-29b (miR-29b ) 表示为调停 OSKM 、调停 OSK 的 reprogramming 在 iPSC 产生和那 miR-29b 表情期间被要求。Dnmt3a 和 Dnmt3b 在 miR-29b 和那 Dnmt3a 和 Dnmt3b 表示的 vivo 目标的机械学的研究表演相反地在 reprogramming 期间与 miR-29b 表示被相关。而且, reprogramming 上的 miR-29b 的效果能被 Dnmt3a 或 Dnmt3b overexpression 堵住。进一步的实验显示发信号的 miR-29b-DNMT 显著地涉及 DNA methylation 相关的 reprogramming 事件的规定,例如 mesenchymal-to-epithelial 转变(相遇) 并且 Dlk1-Dio3 区域抄写。因此,我们的研究不仅表明 miR-29b 是 reprogramming 因素 Sox2 的一个新奇调停人而且为 Sox2 在驾驶表明调整 DNA 的轴的 miR-29b-DNMT 的 multistep 机制提供证据 methylation 相关的事件在 reprogramming 期间。Xudong Guo Qidong Liu Guiying Wang Songcheng Zhu Longfei Gao Wujun Hong Yafang Chen Minjuan Wu Houqi Liu Cizhong Jiang Jiuhong Kang 2013Cell Research2013,23,1:9
14Optimized design and test for a pendulum suspension of the crop spray boom in dynamic conditions based on a six DOF motion simulator显示文摘Spray deposit distribution from a field sprayer is mainly affected by the boom movements when the tractor is driven over a rough soil surface,the pendulum suspension that used to reduce and control the movement of spray boom by isolating the boom from vibrations of the tractor will directly enhance uniform deposition of chemicals.However,how to match the parameters of the suspension with the properties of the boom is the key problem.The dynamic rigid-flexible coupling model of the virtual prototype of the spray boom suspension system was established by using ADAMS and ABAQUS software.An optimization of the suspension parameters for a large spay boom was carried out based on the optimal Latin hypercube design,radial basis function neural network,and multi-objective genetic algorithm NSGA-II.After modified parameters of the suspension,the travel of the sprayer on a typical field motion track was simulated based on a six DOF motion simulator,and the dynamic behavior of the boom suspension was measured.The results show that RMS of the measured boom roll angle and the boom center displacement for optimized solution were reduced by 14.76%and 12.43%compared with the original suspension.Finally,the inertial measurement unit(IMU)was used to measure the movements of the sprayer vehicle during the pesticide application on the Hongze Lake Farm,the experiment of field condition reproduced by using the six DOF motion simulator,the standard deviation of the roll angle and vibration displacement for the optimized sprayer boom are only 0.6382°and 62.279 mm respectively.The research provides theoretical basis and experimental method for parameter optimization of large scale boom suspension.Longfei Cui Hanping Mao Xinyu Xue Suming Ding Baiyu Qiao 2018International Journal of Agricultural and Biological Engineering2018,11,3:9
15Mitigation of cross-eye jamming using a dual-polarization array显示文摘This paper presents an approach for mitigating the cross-eye jamming using a dual-polarization array. By transmitting a sum beam and a difference beam in two orthogonal polarimetric channels, a synthesized transmitted beam with spatially varying polarization is produced, such that the polarization of the transmitted radar wave varies in azimuth or elevation. Thus, the phases of the signals received on the two antennas of a cross-eye jammer become unequal, and an additional phase difference is introduced to disrupt the 180? phase shifting in the retrodirective loop of the jammer. By means of beam scanning in a small angular range,the optimal beam steering configuration can be found to maximize the phase error for the mitigation of cross-eye jamming. As a result, the jamming performance of the cross-eye jammer degrades largely. Theoretical analysis and simulation results indicate that the proposed method is valid and feasible.MA Jiazhi SHI Longfei XIAO Shunping WANG Xuesong 2018Journal of Systems Engineering and Electronics2018,29,3:9
16EFFECT: an efficient flexible privacy-preserving data aggregation scheme with authentication in smart grid显示文摘Smart grid is considered as a promising approach to solve the problems of carbon emission and energy crisis. In smart grid, the power consumption data are collected to optimize the energy utilization.However, security issues in communications still present practical concerns. To cope with these challenges, we propose EFFECT, an efficient flexible privacy-preserving aggregation scheme with authentication in smart grid. Specifically, in the proposed scheme, we achieve both data source authentication and data aggregation in high efficiency. Besides, in order to adapt to the dynamic smart grid system, the threshold for aggregation is adjusted according to the energy consumption information of each particular residential area and the time period, which can support fault-tolerance while ensuring individual data privacy during aggregation.Detailed security analysis shows that our scheme can satisfy the desired security requirements of smart grid.In addition, we compare our scheme with existing schemes to demonstrate the effectiveness of our proposed scheme in terms of low computational complexity and communication overhead.Zhitao GUAN Yue ZHANG Liehuang ZHU Longfei WU Shui YU 2019Science China(Information Sciences)2019,62,3:8
17Machine learning assisted design of γ′-strengthened Co-base superalloys with multi-performance optimization显示文摘Designing a material with multiple desired properties is a great challenge,especially in a complex material system.Here,we propose a material design strategy to simultaneously optimize multiple targeted properties of multi-component Co-base superalloys via machine learning.The microstructural stability,γ′solvus temperature,γ′volume fraction,density,processing window,freezing range,and oxidation resistance were simultaneously optimized.Pei Liu Haiyou Huang Stoichko Antonov Cheng Wen Dezhen Xue Houwen Chen Longfei Li Qiang Feng Toshihiro Omori Yanjing Su 2020npj Computational Materials2020,,1:8
18Full time-domain nonlinear coupled dynamic analysis of a truss spar and its mooring/riser system in irregular wave显示文摘A new full time-domain nonlinear coupled method has been established and then applied to predict the responses of a Truss Spar in irregular wave.For the coupled analysis,a second-order time-domain approach is developed to calculate the wave forces,and a finite element model based on rod theory is established in three dimensions in a global coordinate system.In numerical implementation,the higher-order boundary element method(HOBEM)is employed to solve the velocity potential,and the 4th-order Adams-Bashforth-Moultn scheme is used to update the second-order wave surface.In deriving convergent solutions,the hull displacements and mooring tensions are kept consistent at the fairlead and the motion equations of platform and mooring-lines/risers are solved simultaneously using Newmark-integration scheme including Newton-Raphson iteration.Both the coupled quasi-static analysis and the coupled dynamic analysis are performed.The numerical simulation results are also compared with the model test results,and they coincide very well as a whole.The slow-drift responses can be clearly observed in the time histories of displacements and mooring tensions.Some important characteristics of the coupled responses are concluded.YANG MinDong TENG Bin XIAO LongFei NING DeZhi SHI ZhongMin QU Yan 2014Science China(Physics,Mechanics & Astronomy)2014,57,1:8
19Periodic atomization characteristics of simplex swirl injector induced by klystron effect显示文摘The atomization dynamic characteristics of a simplex swirl injector was investigated experimentally by using a hydrodynamic mechanical pulsator and the shadow photography technique. The frequency response characteristics of the fluid film and atomization fluctuations and their correlations with pressure fluctuations were obtained by using an in-house code of image processing. It is demonstrated that the klystron effect induced by periodic pressure fluctuations results in periodic liquid film fluctuation with large amplitudes, periodic superposition of droplets and reduction of the breakup length. It was found that the atomization of the simplex swirl injector only responds to the pressure fluctuation in frequency range approximately from 0 to 300 Hz, and it is particularly sensitive to pressure fluctuations at frequencies from 100 to 200 Hz. According to this experiment, the responsive frequency limitation is merely affected by injector configuration, rather than the supply line.Anlong YANG Shangrong YANG Yunfei XU Longfei LI 2018Chinese Journal of Aeronautics2018,31,5:8
20Non‑Magnetic Bimetallic MOF‑Derived Porous Carbon‑Wrapped TiO2/ ZrTiO4 Composites for Efficient Electromagnetic Wave Absorption显示文摘Modern communication technologies put forward higher requirements for electromagnetic wave(EMW)absorption materials.Metal-organic framework(MOF)derivatives have been widely concerned with its diverse advantages.To break the mindset of magneticderivative design,and make up the shortage of monometallic non-magnetic derivatives,we first try non-magnetic bimetallic MOFs derivatives to achieve efficient EMW absorption.The porous carbon-wrapped TiO2/ZrTiO4 composites derived from PCN-415(TiZr-MOFs)are qualified with a minimum reflection loss of−67.8 dB(2.16 mm,13.0 GHz),and a maximum effective absorption bandwidth of 5.9 GHz(2.70 mm).Through in-depth discussions,the synergy of enhanced interfacial polarization and other attenuation mechanisms in the composites is revealed.Therefore,this work confirms the huge potentials of nonmagnetic bimetallic MOFs derivatives in EMW absorption applications.Jing Qiao Xue Zhang Chang Liu Longfei Lyu Yunfei Yang Zhou Wang Lili Wu Wei Liu Fenglong Wang Jiurong Liu 2021Nano-Micro Letters2021,13,5:7
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