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Ultrafast electron diffraction

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Chinese Physics B 2018年第7期27卷 72-80页

作者： Xuan Wang Yutong li beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China collaborative innovation Center of IFZSA（CICIFSA） Shanghai Jiao Tong UniversityShanghai 200240China

Ultrafast electron diffraction （UED） technique has proven to be an innovative tool for providing new insights in lattice dynamics with unprecedented temporal and spatial sensitivities. In this article, we give a brief introduction of this technique using the proposed UED station in the Synergetic Extreme Condition User Facility （SECUF） as a prototype. We briefly discussed UED＇s functionality, working principle, design consideration, and main components. We also briefly reviewed several pioneer works with UED to study structure-function correlations in several research areas. With these efforts, we endeavor to raise the awareness of this tool among those researchers, who may not yet have realized the emerging opportunities offered by this technique.

关键词： ultrafast phenomena lattice dynamics ultrafast electron diffraction

Emission characteristics of offshore fishing ships in the Yellow Bo Sea, China

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Journal of Environmental Sciences 2018年第3期30卷 83-91页

作者： Yingshuai liu Yunshan Ge Jianwei Tan Mingliang Fu Asad Naeem Shah Luqiang li Zhe Ji Yan Ding National Lab of Auto Performance and Emission Test School of Mechanical and Vehicular Engineering Beijing Institute of Technology Beijing 100081 China collaborative innovation Center of Electric Vehicles in beijing Beijing 100081 China State Key Joint Laboratory of ESPC School of Environment Tsinghua University Beijing 10084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084 China collaborative innovation Centre for Regional Environmental Quality Beijing 100084 China Department of Mechanical Engineering University of Engineering and Technology Lahore 54000 Pakistan Vehicle Emission Control Center Ministry of Environmental Protection Beijing 100012 China

Maritime transport has been playing a decisive role in global trade. Its contribution to the air pollution of the sea and coastal areas has been widely recognized. The air pollutant emission inventories of several harbors in China have already been established. However,the emission factors of local ships have not been addressed comprehensively, and thus are lacking from the emission inventories. In this study, on-board emission tests of eight diesel-powered offshore fishing ships were conducted near the coastal region of the northern Yellow Bo Sea fishing ground of Dalian, China. Results show that large amounts of fine particles（ 0.5 μm, 90%） were found in maneuvering mode, which were about five times higher than those during cruise mode. Emission rates as well as emission factors based on both distance and fuel were determined during the cruise and maneuvering modes（including departure and arrival）. Average emission rates and distance-based emission factors of CO, HC and PM were much higher during the maneuvering mode as compared with the cruise mode. However, the average emission rate of Nitrous Oxide（NOx） was higher during the cruise mode as compared with the maneuvering modes. On the contrary, the average distance-based emission factors of NOxwere lower during the cruise mode relative to the maneuvering mode due to the low sailing speed of the latter.

关键词： Marine Offshore fishing ship Emission factor PEMS Operating modes

Emergence of superconductivity from fully incoherent normal state in an iron-based superconductor (Ba_(0.6)K_(0.4))Fe_2As_2

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Science Bulletin 2019年第1期64卷 11-19页

作者： Jianwei Huang lin Zhao Cong li Qiang Gao Jing liu Yong Hu Yu Xu Yongqing Cai Dingsong Wu Ying Ding Cheng Hu Huaxue Zhou Xiaoli Dong Guodong liu Qingyan Wang Shenjin Zhang Zhimin Wang Fengfeng Zhang Feng Yang Qinjun Peng Zuyan Xu Chuangtian Chen Xingjiang Zhou beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Technical institute of Physics and Chemistry Chinese Academy of Sciences Songshan Lake Materials Laboratory collaborative innovation Center of Quantum Matter

In unconventional superconductors, it is generally believed that understanding the physical properties of the normal state is a pre-requisite for understanding the superconductivity mechanism. In conventional superconductors like niobium or lead, the normal state is a Fermi liquid with a well-defined Fermi surface and well-defined quasipartcles along the Fermi surface. Superconductivity is realized in this case by the Fermi surface instability in the superconducting state and the formation and condensation of the electron pairs(Cooper pairing). The high temperature cuprate superconductors, on the other hand, represent another extreme case that superconductivity can be realized in the underdoped region where there is neither well-defined Fermi surface due to the pseudogap formation nor quasiparticles near the antinodal regions in the normal state. Here we report a novel scenario that superconductivity is realized in a system with well-defined Fermi surface but without quasiparticles along the Fermi surface in the normal *** resolution laser-based angle-resolved photoemission measurements have been performed on an optimally-doped iron-based superconductor(Ba_(0.6)K_(0.4))Fe_2As_2. We find that, while sharp superconducting coherence peaks emerge in the superconducting state on the hole-like Fermi surface sheets, no quasiparticle peak is present in the normal state. Its electronic behaviours deviate strongly from a Fermi liquid system. The superconducting gap of such a system exhibits an unusual temperature dependence that it is nearly a constant in the superconducting state and abruptly closes at Tc. These observations have provided a new platform to study unconventional superconductivity in a non-Fermi liquid system.

关键词： (Ba0.6K0.4)Fe2As2 ARPES Superconducting gap Normal state Non-Fermi liquid

In-situ DRIFT assessment on strengthening effect of cerium over FeO_(x)/TiO_(2)catalyst for selective catalytic reduction of NO_(x) with NH_(3)

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Journal of Rare Earths 2021年第5期39卷 526-531页

作者： Hossein Chitsazi Ningqiang Zhang lingcong li Xiaojun liu Rui Wu Junda He liyun Song Hong He beijing Key Laboratory for Green Catalysis and Separation and Key Laboratory of beijing on Regional Air Pollution Control Beijing University of TechnologyBeijing 100124China College of Chemistry Chemical Engineering and Materials ScienceInstitute of Molecular and Nano ScienceShandong Normal UniversityJinan 250014China collaborative innovation Center of Electric Vehicle in beijing Beijing 100081China

Fe-based catalysts have a great potential to be used for selective catalytic reduction(SCR)of NO_(x)with NH3 reaction due to their low cost,nontoxicity and excellent catalytic *** aim of this paper is to investigate Ce doping effect on activity of NH_(3)-SCR over the FeO_(x)/TiO_(2)***-situ diffuse reflectance infrared fourier transform(DRIFT)technology was utilized to verity the adsorbed species on the surface of FeO_(x)/TiO_(2)and FeO_(x)-CeO_(2)/TiO_(2)*** respect to the obtained results,among the four catalysts studied,the FeO_(x)-CeO_(2)/TiO_(2)with the FeO_(x)/CeO_(2)ratio of 3/8 shows the best NO conversion more than 98%in the temperature range of 230—350℃,The active centers for NH_(3)adsorption and activation are assigned to Lewis acid sites over the FeO_(x)-CeO_(2)/TiO_(2)and monodentate nitrates can act as the key intermediate in the ***,both of Langmuir-Hinshelwood and Eley-Rideal mechanisms are observed over the FeO_(x)-CeO_(2)/TiO_(2)catalysts in the SCR.

关键词： Fe-based catalysts Ce doping Selective catalytic reduction In-situ DRIFT Rare earths

Gene engineered exosome reverses T cell exhaustion in cancer immunotherapy

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Bioactive Materials 2024年第4期34卷 466-481页

作者： Peishan li Ying Xie Jinling Wang Chunjie Bao Jialun Duan Yixuan liu Qian Luo Jiarui Xu Yuxin Ren Min Jiang Jianwei li Haitao Guo Huihui Zhao Guiling Wang Yanqin liang Wanliang Lu State Key Laboratory of Natural and Biomimetic Drugs Beijing Key Laboratory of Molecular Pharmaceutics and Drug Delivery SystemsSchool of Pharmaceutical SciencesPeking UniversityBeijing100191China Modern Research Center for Traditional Chinese Medicine Beijing Research Institute of Chinese MedicineBeijing University of Chinese MedicineBeijing100029China beijing institute of collaborative innovation Beijing100044China

Cancer patients by immune checkpoint therapy have achieved long-term remission,with no recurrence of clinical symptoms of cancer for many ***,more than half of cancer patients are not responsive to this therapy due to immune ***,we report a novel gene engineered exosome which is rationally designed by engineering PD1 gene and simultaneously enveloping an immune adjuvant imiquimod(PD1-Imi Exo)for boosting response of cancer immune checkpoint blockage *** results showed that PD1-Imi Exo had a vesicular round shape(approximately 139 nm),revealed a significant targeting and a strong binding effect with both cancer cell and dendritic cell,and demonstrated a remarkable therapeutic efficacy in the melanoma-bearing mice and in the breast cancer-bearing *** mechanism was associated with two facts that PD1-Imi Exo blocked the binding of CD8^(+)T cell with cancer cell,displaying a PD1/PDL1 immune checkpoint blockage effect,and that imiquimod released from PD1-Imi Exo promoted the maturation of immature dendritic cell,exhibiting a reversing effect on the immune exhaustion through activating and restoring function of CD8^(+)T *** conclusion,the gene engineered exosome could be used for reversing T cell exhaustion in cancer *** study also offers a promising new strategy for enhancing PD1/PDL1 therapeutic efficacy,preventing tumor recurrence or metastasis after surgery by rebuilding the patients’immunity,thus consolidating the overall prognosis.

关键词： Gene engineered exosomes T cell exhaustion PD1/PDL1 Imiquimod Cancer immunotherapy

Accurate GW_(0) band gaps and their phonon-induced renormalization in solids

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Chinese Physics B 2021年第11期30卷 82-93页

作者： Tong Shen Xiao-Wei Zhang Min-Ye Zhang Hong Jiang Xin-Zheng li Interdisciplinary institute of light-Element Quantum Materials Research Center for Light-Element Advanced Materialsand Collaborative Innovation Center of Quantum MatterPeking UniversityBeijing 100871China State Key Laboratory for Artificial Microstructure and Mesoscopic Physics Frontier Science Center for Nano-optoelectronics and School of PhysicsPeking UniversityBeijing 100871China International Center for Quantum Materials Collaborative Innovation Center of Quantum Matterand School of PhysicsPeking UniversityBeijing 100871China beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Recent years,huge progress of first-principles methods has been witnessed in calculating the quasiparticle band gaps,with many-body perturbation theory in the GW approximation being the standard choice,where G refers to Green’s function and W denotes the dynamically screened Coulomb ***,the completeness of the basis set has been extensively discussed,but in practice far from carefully *** the static description of the nuclei,the electron–phonon interactions(EPIs)are ubiquitous,which cause zero-point renormalization(ZPR)of the band ***,to obtain high quality band gaps,one needs both accurate quasiparticle energies and accurate treatments of *** this article,we review methods on *** completeness of the basis set is analyzed in the framework of linearized augmented plane waves,by adding high-energy local orbitals(HLOs).The electron–phonon matrix elements and self-energy are discussed,followed by the temperature dependence of the band gaps in both perturbative and non-perturbative *** of such an analysis on bulk wurtzite BeO and monolayer honeycomb BeO are *** HLOs widens their GW_(0) band gaps by∼0.4 eV while ZPR narrows them by similar *** influences cancel each other,which explains the fortuitous agreement between experiment and theory when the basis set is incomplete and the EPIs are *** phonon-induced renormalization,a term often neglected in calculations of the band gaps,is also emphasized by its large magnitude.

关键词： quasiparticle band gaps electron-phonon interactions basis-set completeness Beryllium oxide

Distinctive electrochemical performance of novel Fe-based li-rich cathode material prepared by molten salt method for lithium-ion batteries

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Journal of Energy Chemistry 2019年第6期28卷 37-45页

作者： Taolin Zhao Rixin Ji Hedi Yang Yuxia Zhang Xiuguo Sun Yanting li li li Renjie Chen School of Materials Science and Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043HebeiChina Hebei Provincial Key Laboratory of Traffic Engineering Materials Shijiazhuang 050043HebeiChina School of Materials Science & Engineering Beijing Institute of TechnologyBeijing 100081China collaborative innovation Center of Electric Vehicles in beijing Beijing 100081China

For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity li-rich cathodes has caused considerable *** far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based li-rich *** activate the extra-capacity of Fe-based li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of liOH–liNO3–li2O2 in this *** prepared li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling *** discharge specific capacity shows an upward tendency at 0.1 *** 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is *** redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during ***,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation *** stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of li1.09(Fe0.2Ni0.3Mn0.5)*** study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based li-rich cathode material for high-performance lithium-ion batteries.

关键词： lithium-ion batteries Fe-based material li-rich cathode Molten salt High capacity

Development and application of a throughflow method for high-loaded axial flow compressors

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Science China(Technological Sciences) 2016年第1期59卷 93-108页

作者： li Bo GU Chun Wei li Xiao Tang liU Tai Qiu XIAO Yao Bing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Thermal EngineeringTsinghua UniversityBeijing 100084China Shenyang Engine Design and Research institute Shenyang 110015China collaborative innovation Center of Advanced Aero-Engine Beijing 100191China

In this paper, a novel engineering platform for throughflow analysis based on streamline curvature approach is developed for the research of a 5-stage compressor. The method includes several types of improved loss and deviation angle models, which are combined with the authors' adjustments for the purpose of reflecting the influences of three-dimensional internal flow in high-loaded multistage compressors with higher accuracy. In order to validate the reliability and robustness of the method, a series of test cases, including a subsonic compressor P&W 3S1, a transonic rotor NASA Rotor 1B and especially an advanced high pressure core compressor GE E^3 HPC, are conducted. Then the computation procedure is applied to the research of a 5-stage compressor which is designed for developing an industrial gas turbine. The overall performance and aerodynamic configuration predicted by the procedure, both at design- and part-speed conditions, are analyzed and compared with experimental results, which show a good agreement. Further discussion regarding the universality of the method compared with CFD is made afterwards. The throughflow method is verified as a reliable and convenient tool for aerodynamic design and performance prediction of modern high-loaded compressors. This method is also qualified for use in the further optimization of the 5-stage compressor.

关键词： throughflow method multi-stage compressor high-loaded loss and deviation angle models streamline curvature aerodynamic design performance prediction

Layered K_(0.54)Mn_(0.78)Mg_(0.22)O_(2)as a high-performance cathode material for potassium-ion batteries

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Nano Research 2022年第4期15卷 3143-3149页

作者： Ruling Huang Qing Xue Jiao lin XiXue Zhang Jiahui Zhou Feng Wu li li Renjie Chen beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.Ltd.Beijing 102209China Guangdong Key Laboratory of Battery Safety Guangzhou Institute of Energy TestingGuangzhou 511447China collaborative innovation Center of Electric Vehicles in beijing Beijing 100081China institute of Advanced Technology Beijing Institute of TechnologyJinan 250300China

Layered Mn-based oxides are one of the promising cathode materials for potassium-ion batteries(KIBs)owing to their high theoretical capacities,abundant material supply,and simple synthesis ***,the structural deterioration resulting from the Jahn-Teller effect of Mn ions hinders their further development in ***,a novel Mn-based layered oxide,K_(0.54)Mn_(0.78)Mg_(0.22)O_(2),is successfully designed and fabricated as KIBs cathode for the first *** delivers smooth charging/discharging curves with high specific capacity of 132.4 mAh·g^(‒1)at 20 mA·g^(‒1)and good high-rate cycling stability with a capacity retention of 84%over 100 cycles at 200 mA·g^(‒1).Combining in-situ X-ray diffraction(XRD)and ex-situ X-ray photoelectron spectroscopy(XPS)analysis,the storage of K-ions by K_(0.54)Mn_(0.78)Mg_(0.22)O_(2)is revealed to be a solid-solution processes with reversible slip of the crystal *** studies suggest that the rational doping of inactive Mg2+can effectively suppress the Jahn-Teller effect and provide outstanding structure *** work deepens the understanding of the structural evolution of Mn-based layered materials doped with inactive materials during de/potassiation processes.

关键词： potassium-ion batteries layered metal oxide cathode Jahn−Teller effect Mg doping structural deterioration