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Drainage of paddy terraces impacts structures and soil properties in the globally important agricultural heritage of Hani Paddy Terraces,China

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International Soil and Water Conservation Research 2024年第1期12卷 64-76页

作者： ming Wang li Rong Yanbo li Jiangcheng Huang Yuanmei Jiao Xiaoyan Wei Institute of International Rivers and Eco-Security Kunming650500China Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Kunming650500China Power China Kunming Engineering Corporation limited Kunming650051China Department of Geography Yunnan Normal UniversityKunming650500China Yunnan Provincial Archives of Surveying and Mapping(Yunnan Provincial Geomatics Centre) Kunming650032China

Marginalization and abandonment of paddy terraces are widespread,but their effects on the sustainability of subsequent agricultural production are still *** Paddy Terraces,included in Globally Important Agriculture Heritage Systems,are threatened by paddy fields ***,changes in terrace structure,the productivity of topsoil(0-20 cm),and soil water holding capacity at 0-70 cm depth were determined in a case study of Hani Paddy Terraces in Amengkong River Basin in Yuanyang County in Southwestern China,which had been converted into dryland terraces for 2-14 *** results showed that:(1)The degree of terrace structures degradation exhibited a U-shaped curve with increasing time since draining,with those drained for 5-9 years having the best structure;(2)Soil productivity index decreased first and then increased with time after conversion;(3)Maximum water holding capacity at 0-70 cm soil depth dramatically decreased after conversion and such trend became increasingly obvious with increasing time since *** study revealed that drainage of paddy terraces along with associated changes in crop and field management led to an increase in soil productivity,but degradation of terrace structures and a decrease in water holding capacity will inhibit restoration to paddy *** findings enhance the understanding of the biophysical changes due to marginalization in paddy terraces.

关键词： Hani paddy terraces Terraces marginalization Terrace structure degradation Soil productivity Water holding capacity

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Autonomous multi-drone racing method based on deep reinforcement learning

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Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： Yu KANG Jian DI ming li Yunbo ZHAO Yuhui WANG Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： racing drone autonomous multi-drone racing sim-to-real deep reinforcement learning Markov game

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Energy release characteristics of PTFE/Al/TiH2 reactive jet with different TiH2 content

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DEFENCE TECHNOLOGY 2024年第9期39卷 168-176页

作者： Jiang, Chunlan Zhang, Jingbo Hu, Rong Mao, liang li, ming Beijing Inst Technol State Key Lab Explos Sci & Technol Beijing 100081 Peoples R China

Titanium hydride (TiH2), a promising high-energy additive, is doped into PTFE/Al to optimize the energy output structure of the reactive jet and strive for better aftereffect damage ability to the target. Six types of PTFE/Al/TiH2 reactive liners with different TiH2 content are prepared by the molding and sintering method. The energy release characteristics of PTFE/Al/TiH2 reactive jet are tested by the transient explosion energy test, and are characterized from pressure and temperature. The reaction delay time, pressure history, and temperature history of the energy release process are obtained, then the actual value of released energy and reaction efficiency of the reactive jet are calculated. The results show that the peak pressure and temperature of the PTFE/Al/TiH2 jet initially increase and then decrease with increasing TiH2 content. When the TiH2 content is 10%, the actual value of released energy and reaction efficiency increased by 24% and 6.4%, respectively, compared to the PTFE/Al jet. The reaction duration of the reactive material is significantly prolonged as the TiH2 content increased from 0% to 30%. Finally, combined with the energy release behaviors of PAT material and the dynamic deformation process of liner, the enhancement mechanism of TiH2 on energy release of the reactive jet is expounded. (c) 2024 China Ordnance Society. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： PTFE/Al/TiH2 Reactive materials Shaped charge Impact energy release characteristics TITANIUM

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Design of new chemicals for advanced electrolytes

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Science China Chemistry 2024年第5期67卷 1378-1380页

作者： Haoran Cheng Zheng Ma Qian li Jun ming State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China University of Science and Technology of China Hefei 230026China

This highlight is inspired by a recent article in Nature Energy in which liu and co-workers [1] from Tsinghua University designed a new asymmetric lithium salt (i.e., lithium 1,1,1-trifluoro-N-[2-[2-(2-methoxy ethoxy)ethoxy]ethyl] methanesulfonamide (li FEA)) and applied it as a new lithium-salt additive in the conventional carbonate-based electrolyte,overcoming the incompatibility issue of carbonate electrolytes with lithium metal in lithium metal batteries (LMBs),even achieving a fast-charging feature.

关键词： lithium carbonate electrolyte

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Analysis of application range of simplified models for field to thermo-field to thermionic emission processes from the cathode

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Plasma Science and Technology 2024年第9期26卷 51-60页

作者： li SUN Zhuo DAI ming XU Wei WANG Zengyao li Applied Physics Department Xi’an University of TechnologyXi’an 710048People’s Republic of China Key Laboratory of Thermo-Fluid Science and Engineering Ministry of EducationSchool of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Electron emission plays a dominant role in plasma-cathode interactions and is a key factor in many plasma phenomena and industrial *** is necessary to illustrate the various electron emission mechanisms and the corresponding applicable description models to evaluate their impacts on discharge *** this study,detailed expressions of the simplified formulas valid for field emission to thermo-field emission to thermionic emission typically used in the numerical simulation are proposed,and the corresponding application ranges are determined in the framework of the Murphy-Good theory,which is commonly regarded as the general model and to be accurate in the full range of conditions of the validity of the *** parameterization was used to evaluate the emission current density of the Murphy-Good formula,and a deviation factor was defined to obtain the application ranges for different work functions(2.5‒5 eV),cathode temperatures(300‒6000 K),and emitted electric fields(10^(5) to 10^(10) V·m^(-1)).The deviation factor was shown to be a nonmonotonic function of the three parameters.A comparative study of particle number densities in atmospheric gas discharge with a tungsten cathode was performed based on the one-dimensional implicit particle-in-cell(PIC)with the Monte Carlo collision(MCC)method according to the aforementioned application *** was found that small differences in emission current density can lead to variations in the distributions of particle number density due to changes in the collisional *** study provides a theoretical basis for selecting emission models for subsequent numerical simulations.

关键词： electron emission processes application range Murphy-Good theory implicit particlein-cell Monte Carlo collision method

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On traceable iterated line graph and hamiltonian path index

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 239-252页

作者： NIU Zhao-hong XIONG li-ming YANG Wei-hua School of Mathematical Sciences Shanxi UniversityTaiyuan 030006China School of Mathematics and Statistics Beijing Key Laboratory on MCAACIBeijing Institute of TechnologyBeijing 100081China Department of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

Xiong and liu[21]gave a characterization of the graphs G for which the n-iterated line graph L^(n)(G)is hamiltonian,for n≥*** this paper,we study the existence of a hamiltonian path in L^(n)(G),and give a characterization of G for which L^(n)(G)has a hamiltonian *** applications,we use this characterization to give several upper bounds on the hamiltonian path index of a graph.

关键词： iterated line graph traceable hamiltonian index hamiltonian path index

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Treatment of esophagogastric anastomotic leak via perianastomotic drain

Treatment of esophagogastric anastomotic leak via perianasto...

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中国第九届全国食管癌学术会议

作者： Qin Jianjun,li yin,Yan ming,Wang Guolei,,Zhang Ruixiang

＜正＞Objective:Our objective was to evaluate the effectiveness of a novel method of perianastomotic drain via ***:The most efficient treatment of such leaks remains controversial and there is no standard management of gastroesophageal anastomotic *** the conservative approach,perianastomotic drain is very useful..Methods:We undertook a retrospective review of 5 patients who developed anastomotic leakage,out of 324 patients undergoing oesophagectomy with gastric *** 5 patients had placement of perianastomotic drain via *** other conservative method of treatment was chosen, consisted of absence of oral intake,naso-gastric suction drainage,enteral feeding（via a naso-jejunal tube） and continued antibiotic ***:The perianastomotic drains were placed successfully in all 5 *** of the patients underwent *** were all *** median period to clinical healing was 33 days（range,23-49 days;mean,36.6days）. The median hospital stay after the perianastomotic drainage procedure in the 5 patients was 37 days（range,28-55 days）.Conclusion:This procedure proved to be safe,and effective in the treatment of esophagogastric anastomotic leaks with perianastomotic drain via *** of the infected material is the most important aspect of treatment.

关键词： Esophagectomy Anastomotic leak Perianastomotic drain

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A review of MXene-derived quantum dots:Synthesis,characterization,properties,and applications

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Particuology 2024年第8期91卷 50-71页

作者： Chunhe Zhou Kar Ban Tan Wenjuan Han li Wang ming Lu The Joint Laboratory of MXene Materials Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of EducationJilin Normal UniversityChangchunJilin 130103China Department of Chemistry Faculty of ScienceUniversiti Putra MalaysiaSerdangSelangor 43400Malaysia

Cutting MXene to a minimum size and forming the derived two-dimensional MXene quantum dots(MQDs),which possess a unique intrinsic layered geometry structure,restricts exciton due to their novel spatial *** gives rise to a broad spectrum of fascinating properties,rendering them for various ***,the correlation between composition,structure,and processing control of MQDs is investigated systematically,giving further insight into the intrinsic and extrinsic *** review also provides an opportunity to explore new compositions,modify the properties,and tailor MQDs into the guided architectural design before any prospective applications.

关键词： MXene Quantum dots Characterization Properties Applications

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Novel process for facile preparation of mesoporous silica-based materials with controllable pore structure from coal fly ash Author links open overlay panel

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Particuology 2024年第8期91卷 128-137页

作者： Jian-ming Gao Zhen li Shujia Ma Yuanyuan Zhang Fangqin Cheng Institute of Resources and Environment Engineering State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste ResourcesShanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related WastesShanxi UniversityTaiyuan 030006China

Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization *** silica could not be synthesized on a large-scale by conventional sol-gel *** this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was *** influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure *** results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline *** controlling the degree of acid etching,mesoporous silica materials with different pore structures can be *** paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.

关键词： Fly ash Mesoporous silica Crystal transformation Acid etching Controllable pore structure

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Keplerate polyoxomolybdate nanoball mediated controllable preparation of metal-doped molybdenum disulfide for electrocatalytic hydrogen evolution in acidic and alkaline media

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Chinese Chemical Letters 2024年第7期35卷 524-528页

作者： Ping Wang Ting Wang ming Xu Ze Gao Hongyu li Bowen li Yuqi Wang Chaoqun Qu ming Feng Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education Jilin Normal UniversityChangchun 130103China School of Science Changchun University of Science and TechnologyChangchun 130022China

Rationally designed novel cost-effective hydrogen evolution reaction(HER)electrocatalysts with controlled surface composition and advanced structural superiority is extremely critical to optimize the HER ***(POMs)with structural diversity and adjustable element compositions represent a promising precursor for rational design and preparation of HER ***,a series of transition metal-doped MoS_(2)materials with different surface engineered structures(Fe,Cr,V doping and S vacancies)(M-MoS_(2)/CC,M=Fe,Cr and V)were fabricated by a simple hydrothermalvulcanization strategy using Keplerate polyoxomolybdate nanoball({Mo_(72)Fe_(30)},{Mo_(72)Cr_(30)},{Mo_(72)V_(30)},{Mo_(132)})as *** enlarged interlayer spacing as well as the integration of homogeneous transition metal doping and abundant sulfur vacancies endows prepared M-MoS_(2)/CC with superior HER electrocatalytic performance and excellent long-term working stability in both acidic and alkaline *** optimized Fe-MoS_(2)/CC afford current densities of 10 and 50 mA/cm^(2)at overpotentials of 188/272 mV and 194/394 mV in 0.5 mol/L H_(2)SO_(4)and 1.0 mol/L KOH aqueous solution,respectively,outperforming most of reported typical transition metal sulfide-based *** work represents an important breakthrough for POMs-mediated highly efficient transition metal sulfide-based HER electrocatalysts with wide range pH activity and may provide new options for the rational design of promising HER electrocatalysts and beyond.

关键词： Polyoxometalate Electrocatalytic Hydrogen evolution reaction Doping MoS_(2)

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