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nano Research 2023年第4期16卷 5676-5684页

作者： Jingshen xu na Lu Mengwei Yuan Genban Sun Beijing Key Laboratory of Energy Conversion and Storage Materials College of ChemistryBeijing Normal UniversityBeijing 100875China Center for Advanced Materials Research Beijing Normal UniversityZhuhai 519087China

Electromagnetic wave absorption materials are widely used in electronic equipment and military ***,high cost and complex preparation processes become a major obstacle in promoting popularization in the civil *** solve the problems above,researchers have made great efforts to develop Fe-based carbon ***,most of the typical composites require a high filling ratio while achieving excellent ***,in this study,carbon nanofibers(CNFs)combined with the hollow rice-grainedα-Fe_(2)O_(3)nanoparticles were prepared by the in-situ transformation *** rational microstructure design provided a solution for reducing the filling ratio,optimizing impedance matching,and improving electromagnetic wave absorption *** strong reflection loss value(−38.1 dB)and broad effective absorption bandwidth(4.6 GHz)for Fe_(2)O_(3)/CNFs composites were achieved with a low filling ratio(20 wt.%),and the analysis of electromagnetic parameters validated that the microstructure of Fe_(2)O_(3)/CNFs plays a crucial role in the performance *** the optimized impedance matching and simple preparation method,Fe_(2)O_(3)/CNFs have broad application prospects in electromagnetic wave absorption.

关键词： electromagnetic wave absorption Fe-based carbon nanofibers impedance matching

Adult neurogenesis in the primate hippocampus

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Zoological Research 2023年第2期44卷 315-322页

作者： Ye Li na-na xu Zhao-Zhe Hao Sheng Liu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouGuangdong 510060China Guangdong Province Key Laboratory of Brain Function and Disease GuangzhouGuangdong 510080China

Adult hippocampal neurogenesis(AHN) is crucial for learning,memory,and *** of AHN may lead to reduced cognitive abilities and neurodegenerative disorders,such as Alzheimer’s *** studies on rodent AHN have clarified the developmental and maturation processes of adult neural stem/progenitor ***,to what extent these findings apply to primates remains *** advances in next-generation sequencing technologies have enabled in-depth investigation of the transcriptome of AHN-related populations at single-cell ***,we summarize studies of AHN in *** suggest that neurogenesis is largely shared across species,but substantial differences also *** gene expression patterns in primates differ from those of *** with rodents,the primate hippocampus has a higher proportion of immature dentate granule cells and a longer maturation period of newly generated granule *** research on species divergence may deepen our understanding of the mechanisms underlying adult neurogenesis in primates.

关键词： Neural precursor cells Immature granule cells Sc-Rna-seq

Covalent sulfur as stable anode for potassium ion battery

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Journal of Energy Chemistry 2021年第11期30卷 645-652,I0015页

作者： na Cheng Patrick xu Bingan Lu Zhigang Liu School of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082HunanChina College of Letter and Science University of CaliforniaBerkeleyCA 94720USA School of Physics and Electronics Hunan UniversityChangsha 410082HunanChina

The potassium bis(fluoro-sulfonyl)imide(KFSI)-based electrolyte has great application prospects in potassium ion batteries (PIBs). However, their development has been limited by the decomposition of electrolytes and the corrosion of Al foils (current collector) at high potential. Here, a N-doping, sulfur-rich chemically bonded porphyrin organic framework (SPOF) with a high potential plateau were synthesized as an anode to lower the redox potential of full cells and further inhibit the corrosion of Al foils. SPOF as anode delivers high reversible capacity (557 mAh g^(−1) at 50 mA g^(−1)), excellent cycling performance (94% capacity retention over 1000 cycles at 500 mA g^(−1)), and superior rate performance. Meanwhile, the ex-situ FTIR, Raman, and HRTEM revealed the stability of N-doping and the reversible covalent sulfur and S–S bonds changes during potassiation/depotassiation. In addition, full cells using SPOF anode and PTCDA cathode showed outstanding performance (high capacity of 300 mAh g^(−1) at 200 mA g^(−1)). And the Al current collector of the full cell was not corroded after 150 cycles. Yet, the Al foils with PTCDA as cathode were seriously corroded. This work provides a new strategy for realizing ultra-high reversible capacity and cyclic stability of PIBs, and also accelerates the process of early commercial application of PIBs.

关键词： Porphyrin organic framework Covalent sulfur Anode Potassium-ion batteries

Control of grain size by G protein signaling in rice

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Journal of Integrative Plant Biology 2019年第5期61卷 533-540页

作者： Ran xu na Li Yunhai Li State Key Laboratory of Plant Cell and Chromosome Engineering CAS Center for Excellence in Molecular Plant SciencesInstitute of Genetics and Developmental Biologythe Chinese Academy of SciencesBeijing 100101China The University of Chinese Academy of Sciences Beijing 100039China

Heterotrimeric G proteins are involved in multiple cellular processes in eukaryotes by sensing and transducing various signals. G protein signaling in plants is quite different from that in animals, and the mechanisms of plant G protein signaling are still largely unknown. Several recent studies have provided new insights into the mechanisms of G protein signaling in rice grain size and yield control. In this review,we summarize recent advances on the function of G proteins in rice grain size control and discuss the potential genetic and molecular mechanisms of plant G protein signaling.

关键词： Heterotrimeric G proteins cellular processes in eukaryotes G protein signaling

Pathway Matters: Prefrontal Control of Negative Emotions via Distinct Downstream Regions

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Neuroscience Bulletin 2022年第2期38卷 226-228页

作者： Junqiang Zheng na Liu Han xu Department of Neurobiology and Department of Neurology of the Second Affiliated Hospital Zhejiang University School of MedicineHangzhou 310058China NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain-Machine IntegrationSchool of Brain Science and Brain MedicineZhejiang UniversityHangzhou 310058China

The infralimbic cortex(IL)is a major subregion of the medial prefrontal cortex(mPFC)that is essential for many advanced brain functions including *** studies have unraveled a critical role of the IL in the processing of negative emotions such as fear and ***,these studies also generate controversial data regarding the precise functions of the IL in the regulation of either fear or *** one hand,pharmacological inactivation of the IL attenuates anxiety-like behaviors and consistently,pharmacological activation of the IL produces anxiety-like behaviors[1].

关键词： inactivation precise Mount

Hydration kinetics of cementitious materials composed of red mud and coal gangue

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International Journal of Minerals,Metallurgy and Materials 2016年第10期23卷 1215-1224页

作者： na Zhang Hong-xu Li Xiao-ming Liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction University of Science and Technology Beijing

To elucidate the intrinsic reaction mechanism of cementitious materials composed of red mud and coal gangue（RGC）, the hydration kinetics of these cementitious materials at 20°C was investigated on the basis of the Krstulovi？-Dabi？ model. An isothermal calorimeter was used to characterize the hydration heat evolution. The results show that the hydration of RGC is controlled by the processes of nucleation and crystal growth（NG）, interaction at phase boundaries（I）, and diffusion（D） in order, and the pozzolanic reactions of slag and compound-activated red mud-coal gangue are mainly controlled by the I process. Slag accelerates the clinker hydration during NG process, whereas the compound-activated red mud-coal gangue retards the hydration of RGC and the time required for I process increases with increasing dosage of red mud-coal gangue in RGC.

关键词： red mud coal gangue cementitious materials hydration kinetics

Mass transfer mechanism and relationship of gas–liquid annular flow in a microfluidic cross-junction device

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Chinese Journal of Chemical Engineering 2023年第12期64卷 37-48页

作者： Xin xu na xu Wei Zhang Junwen Wang Yao Li Chen Yang Shanxi Key Laboratory of Chemical Product Engineering College of Chemical Engineering and TechnologyTaiyuan University of TechnologyTaiyuan 030024China Shanxi Coking Coal in Yuncheng Salt Refco Group Ltd. Yuncheng 044000China

Mass transfer performance of gas–liquid two-phase flow at microscale is the basis of application of microreactor in gas–liquid reaction *** present,few researches on the mass transfer property of annular flow have been ***,the mass transfer mechanism and relationship of gas–liquid annular flow in a microfluidic cross-junction device are studied in the present *** find that the main factors,i.e.,flow pattern,liquid film thickness,liquid hydraulic retention time,phase interface fluctuation,and gas flow vorticity,which influence the flow mass transfer property,are directly affected both by gas and liquid flow *** the influences of gas and liquid velocities on different mass transfer influencing factors are ***,the fitting relationships between gas and liquid flow velocities and mass transfer influencing factors are *** comparing the results from calculations using fitting equations and simulations,it shows that the fitting equations have relatively high degrees of ***,the Pareto front,namely the Pareto optimal solution set,of gas and liquid velocity conditions for the best flow mass transfer property is obtained using the method of multi-objective particle swarm *** is proved that the mass transfer property of the gas–liquid two-phase flow can be obviously enhanced under the guidance of the obtained Pareto optimal solution set through experimental verification.

关键词： Gas-liquid microreactor Annular flow Mass transfer mechanism Mass transfer relationship Multi-objective particle swarm optimization

Far-Field Pattern Tolerance Analysis of Reflector Antenna with Random or System Error Based on Interval Arithmetic

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Chinese Journal of Electronics 2018年第3期27卷 641-647页

作者： LI Peng LI na xu Wanye WANG Wei Key Laboratory of Electronic Equipment Structure Design Ministry of Education Xidian University

A novel analytic approach for the research of effect on electromagnetic performance of reflector antennas with deformation, including random processing error and system error caused by external loads(such as wind,gravity, and solar radiation), in panels of the reflector surface is proposed. The deformations are modeled as error intervals, and their impact on the electromagnetic performance, including radiation power pattern and some main electromagnetic characteristics(such as side lobe level,peak power, and half-power beamwidth), are efficiently estimated by Interval analysis(IA). The closed-form equations indicate the relationship between the error interval and the bounds(upper and lower bounds) of the radiated power pattern interval by exploiting the rules of interval arithmetic. Two kinds of surface errors(random and system error) and two shapes of deformation area(bump-like and sector) are taken into account in the numerical examples to assess the validation and effectiveness of the proposed approach. The results of the examples show that the proposed IA-based approach has great capability and effectiveness regarding the traditional statistical method(such as Monte-Carlo method).

关键词： Reflector antenna Interval analysis Random error System error Power pattern

Phase Compensation of Composite Material Radomes Based on the Radiation Pattern

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Chinese Journal of Mechanical Engineering 2017年第3期30卷 587-594页

作者： Peng LI na LI Wanye xu Liwei SONG Key Laboratory of Electronic Equipment Structure Design of Ministry of Education Xidian UniversityXi'an710071China State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing400044China

Some compensation methods have been pro- posed to mitigate the degradation of radiation characteris- tics caused by composite material radomes, however most of them are complex and not applicable for large radomes, for example, the modification of geometric shape by grinding process. A novel and simple compensation strat- egy based on phase modification is proposed for large reflector antenna-radome systems. Through moving the feed or sub-reflector along axial direction opportunely, the modification of phase distribution in the original aperture of an enclosed reflector antenna can be used to reduce the phase shift caused by composite material radomes. The distortion of far-field pattern can be minimized. The modification formulas are proposed, and the limitation of their application is also discussed. Numerical simulations for a one-piece composite materials sandwich radome and a 40 m multipartite composite materials sandwich radome verify that the novel compensation strategy achieves sat- isfactory compensated results, and improves the distortion of the far-field pattern for the composite material radomes. For one-piece dielectric radome, more than 60% phasedifference caused by radome is reduced. For multipartite radome, the sidelobe level improves about 1.2 dB, the nulling depth improves about 3 dB. The improvement of far-field pattern could be obtained effectively and simply by moving the feed or sub-reflector according to phase shift of the radome.

关键词： Composite materials - Radome Phasecompensation Radiation pattern

Fluid-based Slotting Optimization for Automated Order Picking System with Multiple Dispenser Types

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 529-538页

作者： LIU Peng WU Yaohua ZHOU Chen xu na School of Control Science andEngineering Shandong University Jinan 250061 China School of Industrial and Systems Engineering Georgia Institute of Technology Atlanta GA 30332 USA Business School Shandong Jianzhu University Jinan 250101 China

Slotting strategy heavily influences the throughput and operational cost of automated order picking system with multiple dispenser types, which is called the complex automated order picking system （CAOPS）. Existing research either focuses on one aspect of the slotting optimization problem or only considers one part of CAOPS, such as the Low-volume Dispensers, to develop corresponding slotting strategies. In order to provide a comprehensive and systemic approach, a fluid-based slotting strategy is proposed in this paper. The configuration of CAOPS is presented with specific reference to its fast-picking and restocking subsystems. Based on extended fluid model, a nonlinear mathematical programming model is developed to determine the optimal volume allotted to each stock keeping unit （SKU） in a certain mode by minimize the restocking cost of that mode. Conclusion from the allocation model is specified for the storage modules of high-volume dispensers and low-volume dispensers. Optimal allocation of storage resources in the fast-picking area of CAOPS is then discussed with the aim of identifying the optimal space of each picking mode. The SKU assignment problem referring to the total restocking cost of CAOPS is analyzed and a greedy heuristic with low time complexity is developed according to the characteristics of CAOPS. Real life application from the tobacco industry is presented in order to exemplify the proposed slotting strategy and assess the effectiveness of the developed methodology. Entry-item-quantity （EIQ） based experiential solutions and proposed-model-based near-optimal solutions are compared. The comparison results show that the proposed strategy generates a savings of over 18% referring to the total restocking cost over one-year period. The strategy proposed in this paper, which can handle the multiple dispenser types, provides a practical quantitative slotting method for CAOPS and can help picking-system-designers make slotting decisions efficiently and

关键词： slotting complex automated order picking system restocking cost dispenser