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Chinese Chemical Letters 2014年第5期25卷 815-818页

作者： Yong Zhang Mei-Ying Xu tie-kun jiang Wei-Zhe Huang jiang-Yu Wu School of Material Sciences & Engineering Wuhan Institute of Technology

Low generational（G0–G2,G for generation） polyamidoamine（PAMAM） dendrimers were investigated as enhancers to improve the aqueous solubility of folic acid at pH 11 and pH 5.In these two cases,the solubility of folic acid increases with both the dendrimer concentration and generation.However,the solubilization mechanism is different.The electrostatic interaction between the primary amines of dendrimers and the ionized carboxylic groups of folic acid dominates the dissolution process at pH 11 while the increase of the solubility of folic acid at pH 5 is attributed to the hydrophobic encapsulation inside the dendrimer molecules.In addition,for comparison ethylenediamine was used as a small molecule control to examine the ‘‘dendritic effect＇＇ in the dendrimer-related solubilization process.Interestingly,PAMAM dendrimers exhibit,at pH 5,a significant superiority over ethylenediamine in enhancing solubility,whereas this ‘‘dendritic effect＇＇ cannot be observed under the basic condition.

关键词： Polyamidoamine Dendrimer Folic acid Electrostatic interaction Hydrophobic encapsulation

Numerical and experimental investigation into the evolution of the shock wave when a muzzle jet impacts a constrained moving body

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Defence Technology（防务技术） 2024年第3期33卷 317-326页

作者： Zijie Li Hao Wang Changshun Chen kun jiang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing 210016China

The gun-track launch system is a new special launch device that connects the track outside the muzzle.Because it is constrained by the track,the characteristics of development of the muzzle jet differ from those of the traditional muzzle jet.Specifically,it changes from freely developing to doing so in a constrained manner,where this results in an asymmetric direction of flow as well as spatio-temporal coupling-induced interference between various shock waves and the formation of vortices.In this background,the authors of this article formulate and consider the development and characteristics of evolution of the muzzle jet as it impacts a constrained moving body.We designed simulations to test the gun-track launch system,and established a numerical model based on the dynamic grid method to explore the development and characteristics of propagation of disturbances when the muzzle jet impacted a constrained moving body.We also considered models without a constrained track for the sake of comparison.The results showed that the muzzle jet assumed a circumferential asymmetric shape,and tended to develop in the area above the muzzle.Because the test platform was close to the ground,the muzzle jet was subjected to reflections from it that enhanced the development and evolution of various forms of shock waves and vortices in the muzzle jet to exacerbate its rate of distortion and asymmetric characteristics.This in turn led to significant differences in the changes in pressure at symmetric points that would otherwise have been identical.The results of a comparative analysis showed that the constrained track could hinder the influence of reflections from the ground on the muzzle jet to some extent,and could reduce the velocity of the shock waves inducing the motion of the muzzle as well as the Mach number of the moving body.The work here provides a theoretical basis and the requisite technical support for applications of the gun-track launch system.It also sheds light on the technical bottlenecks that need to be considered

关键词： Shock wave/vortex interference Muzzle jet Constrained boundary Dynamic grid

Characteristics of Particulate Matter Emissions for Low-Sulfur Heavy Oil Used in Low-Speed Two-Stroke Diesel Engines of Ocean-Going Ships

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Journal of Thermal Science 2024年第2期33卷 739-750页

作者： WU Gang MA Qianli WEI Lijiang jiang Guohe WANG Tengfei LI tie Merchant Marine College Shanghai Maritime UniversityShanghai201306China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China

In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples were collected in situ from the engine exhaust to determine the detailed physical and chemical properties.The nanostructure and morphology of the nanoparticles were analyzed using transmission electron microscopy images(TEM).The results show that volatile organic carbon(OC) accounts for more than 80% in the HFO particles and leads to an increase in particle size.The thermodynamic conditions of a low-speed engine favor the behavior of capturing the soluble organic components.A large number of spherical char HFO particles with aerodynamic diameters of 0.2 μm-0.5 μm and a suspected inner metal core were detected.The two peak aerodynamic diameters of the HFO nanoparticles are 15 nm and 86 nm.The morphological differences among the HFO nanoparticles in varied engine conditions represent the formation process from primary nascent particles to mature graphitized particles caused by thermodynamics.The above study will be valuable for understanding the characteristics of PM emissions from low-sulfur HFO to achieve the ship PM emissions reduction target.

关键词： low-speed diesel engine maritime regulations heavy fuel oil TEM particles size and distribution

Ca_(2)MnO_(4)-layered perovskite modified by NaNO_(3)for chemical-looping oxidative dehydrogenation of ethane to ethylene

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Chinese Journal of Chemical Engineering 2024年第4期68卷 53-64页

作者： Weixiao Ding kun Zhao Shican jiang Zhen Huang Fang He College of Chemistry and Bioengineering Guilin University of TechnologyGuilin 541006China Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the use of Ca_(2)MnO_(4)-layered perovskites modified with NaNO_(3) dopants,serving as redox catalysts(also known as oxygen carriers),for the CL-ODH of ethane within a temperature range of 700-780℃.Our findings revealed that the incorporation of NaNO_(3) as a modifier significantly-nhanced the selectivity for-thylene generation from Ca_(2)MnO_(4).At 750℃and a gas hourly space velocity of 1300 h^(-1),we achieved an-thane conversion up to 68.17%,accompanied by a corresponding-thylene yield of 57.39%.X-ray photoelectron spectroscopy analysis unveiled that the doping NaNO_(3) onto Ca_(2)MnO_(4) not only played a role in reducing the oxidation state of Mn ions but also increased the lattice oxygen content of the redox catalyst.Furthermore,formation of NaNO_(3) shell on the surface of Ca_(2)MnO_(4) led to a reduction in the concentration of manganese sites and modulated the oxygen-releasing behavior in a step-wise manner.This modulation contributed significantly to the enhanced selectivity for ethylene of the NaNO_(3)-doped Ca_(2)MnO_(4) catalyst.These findings provide compelling evidence for the potential of Ca_(2)MnO_(4)-layered perovskites as promising redox catalysts in the context of CL-ODH reactions.

关键词： Chemical-looping oxidative dehydrogenation Ethane Ethylene NaNO_(3)-doped Ca_(2)MnO_(4)redox catalyst Layered perovskites

Disentangling distinct Cu surface sites for electrocatalytic CO_(2)-to-CO and CO-to-C_(2+)conversion

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Science China Chemistry 2024年第4期67卷 1047-1048页

作者： kun jiang Wen-Bin Cai Interdisciplinary Science Research Centre School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Electrochemical CO_(2)reduction reaction(CO_(2)RR)is a promising strategy to curb anthropogenic carbon emissions,for which intermittent renewable electricity could be stored as chemical energy within carbon-based fuel... 详细信息

关键词： carbon Electrochemical surface

Fifty-five cases of hepatic alveolar echinococcosis combined with lymph node metastasis:A retrospective study

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World Journal of Gastroenterology 2024年第23期30卷 2981-2990页

作者： Yilizhati Aimaitijiang tie-Min jiang Ying-Mei Shao Tuerganaili Aji State Key Laboratory on Pathogenesis Prevention and Treatment of High Incidence Diseases in Central AsiaThe First Clinical CollegeXinjiang Medical UniversityUrumqi 830011Xinjiang Uygur Autonomous RegionChina The First Ward of Hepatobiliary and Pancreatic Surgery Tumor Hospital Affiliated to Xinjiang Medical UniversityUrumqi 830011Xinjiang Uygur Autonomous RegionChina Department of Hepatobiliary&Hydatid Diseases Digestive&Vascular Surgery CenterThe First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054Xinjiang Uygur Autonomous RegionChina Xinjiang Clinical Research Center for Echinococcosis and Hepatobiliary Diseases The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054Xinjiang Uygur Autonomous RegionChina

BACKGROUND Lymph node metastasis is a specific type of metastasis in hepatic alveolar echinococcosis(AE).Currently,there is a scarcity of describing the clinical characteristics and lymph node metastasis rules of patients with hepatic AE combined with lymph node metastasis and its mechanism and management are still controversial.Radical hepatectomy combined with regional lymph node dissection is a better treatment.AIM To analyse the clinical features of hepatic AE combined with lymph node metastasis to explore its treatment and efficacy.METHODS A total of 623 patients with hepatic AE admitted to the First Affiliated Hospital of Xinjiang Medical University from 1 January 2012 to 1 January 2022 were retrospectively analysed.Fifty-five patients with combined lymph node metastasis were analysed for their clinical data,diagnosis and treatment methods,follow-up efficacy,and characteristics of lymph node metastasis.Finally,we comparatively analysed the lymph node metastasis rates at different sites.Categorical variables are expressed as frequencies and percentages,and the analysis of difference was performed using theχ2 test.The Bonferroni method was used for pairwise comparisons when statistical differences existed between multiple categorical variables.RESULTS A lymph node metastasis rate of 8.8%(55/623)was reported in patients with hepatic AE,with a female predilection(69.1%)and a statistically significant sex difference(χ2=8.018,P=0.005).Of the 55 patients with lymph node metastasis,72.7%had a parasite lesion,neighbouring organ invasion,and metastasis stage of P3N1M0 and above,of which 67.3%,78.2%,and 34.5%of hepatic AE lesions invaded the bile ducts,blood vessels,and distant metastases,respectively.Detection rates of lymph node metastasis of 16.4%,21.7%,and 34.2%were reported for a preoperative abdominal ultrasound,magnetic resonance imaging,and computed tomography examinations.All patients were intraoperatively suspected with enlarged lymph nodes and underwent radical hepatectomy combined with regional lymph node

关键词： Echinococcosis Radical hepatectomy Lymph node metastasis Lymph node dissection Alveolar echinococcosis Hepatic

Discovering Latent Variables for the Tasks With Confounders in Multi-Agent Reinforcement Learning

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1591-1604页

作者： kun jiang Wenzhang Liu Yuanda Wang Lu Dong Changyin Sun the School of Automation Southeast UniversityNanjing 210096China the School of Artificial Intelligence Anhui UniversityHefei 230601China IEEE the School of Cyber Science and Engineering Southeast UniversityNanjing 211189China the Engineering Research Center of Autonomous Unmanned System Technology Ministry of EducationHefei 230601China

Efficient exploration in complex coordination tasks has been considered a challenging problem in multi-agent reinforcement learning(MARL). It is significantly more difficult for those tasks with latent variables that agents cannot directly observe. However, most of the existing latent variable discovery methods lack a clear representation of latent variables and an effective evaluation of the influence of latent variables on the agent. In this paper, we propose a new MARL algorithm based on the soft actor-critic method for complex continuous control tasks with confounders. It is called the multi-agent soft actor-critic with latent variable(MASAC-LV) algorithm, which uses variational inference theory to infer the compact latent variables representation space from a large amount of offline experience.Besides, we derive the counterfactual policy whose input has no latent variables and quantify the difference between the actual policy and the counterfactual policy via a distance function. This quantified difference is considered an intrinsic motivation that gives additional rewards based on how much the latent variable affects each agent. The proposed algorithm is evaluated on two collaboration tasks with confounders, and the experimental results demonstrate the effectiveness of MASAC-LV compared to other baseline algorithms.

关键词： Latent variable model maximum entropy multi-agent reinforcement learning(MARL) multi-agent system

Thermal stability of permafrost under U-shaped crushed rock embankment of the Qinghai-Tibet Railway

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Advances in Climate Change Research 2024年第1期15卷 158-169页

作者： kun-Ming XU Guan-Li jiang Ji CHEN Qing-Bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Beiluhe Observation Station of Frozen Soil Environment and Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China

The U-shaped crushed rock embankment(UCRE),of which widely utilized in the permafrost regions along the Qinghai-Tibet Railway,has the capability to rapidly reduce the ground temperature of the underlying permafrost.However,there remains uncertainty regarding the adaptation of UCRE to climate change and its long-term cooling trend.This study focuses on nine UCRE monitoring sites along the Qinghai-Tibet Railway to analyze the dynamic variations of the ground temperature underlying permafrost from 2006 to 2020.The efficiency of UCRE in stabilizing permafrost temperature in different permafrost zones is evaluated by considering the permafrost table,ground temperature,and MAGT,as well as the temperature difference between the top and bottom of the crushed rock layer and the ground temperature variation index(GTVI).The results show that UCRE is suitable for application in extremely unstable warm permafrost regions where the MAGT is higher than-0.5℃.Moreover,UCRE effectively diminishes the disparity in permafrost thermal stability between the sunny and shaded shoulders of the embankment.The short-term and long-term effect of cooling permafrost is experiencing a change related with permafrost stability.Notably,in stable cold permafrost regions with MAGT lower than-1.5℃,the long-term cooling effect of UCRE on permafrost seems to gradually di-minishes,but UCRE continues to fulfill the role of stabilizing the underlying permafrost thermal state over the long-term.These results show that UCRE can quickly restore and stabilize the thermal state of permafrost in the early stages of construction,and adapt to the influence of future climate change.The findings provide important guidance for understanding the variations of permafrost thermal stability beneath the embankment in permafrost regions,as well as for improving the embankment stability and operational safety of the Qinghai-Tibet Railway.

关键词： Qinghai-Tibet Railway U-shaped crushed rock embankment Climate change Permafrost zone Ground temperature variation index Long-term coolingrole

Spatio-temporal variation of water salinity in mangroves revealed by continuous monitoring and its relationship to floristic diversity

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Plant Diversity 2024年第1期46卷 134-143页

作者： Wei Wang kun Xin Yujun Chen Yuechao Chen Zhongmao jiang Nong Sheng Baowen Liao Yanmei Xiong Research Institute of Tropical Forestry Chinese Academy of ForestryGuangzhou 510520PR China Guangdong Zhanjiang Mangrove National Nature Reserve Administration Zhanjiang 524088PR China

Salinity is among the most critical factors limiting the growth and species distribution of coastal plants.Water salinity in estuarine ecosystems varies temporally and spatially,but the variation patterns across different time scales and salinity fluctuation have rarely been quantified.The effects of salinity on floristic diversity in mangroves are not fully understood due to the temporal and spatial heterogeneity of salinity.In this study,we monitored water salinity at an interval of 10-min over one year in three mangrove catchment areas representing the outer part,middle part,and inner part respectively of Dongzhai Bay,Hainan,China.The number of mangrove community types and dominant mangrove species of the three catchment areas were also investigated.We found that the diurnal variation and dry-season intra-month variation in water salinity were driven by tidal cycles.The seasonal variation in water salinity was mainly driven by rainfall with higher salinity occurring in the dry season and lower salinity occurring in the wet season.Spatially,water salinity was highest at the outer part,intermediate at the middle part,and lowest at the inner part of the bay.The intra-month and annual fluctuations of water salinity were highest at the middle part and lowest at the outer part of the bay.The number of mangrove community types and dominant species were lowest at the outer part,intermediate at the middle part,and highest at the inner part of the bay.These results suggest that the temporal variation of water salinity in mangroves is driven by different factors at different time scales and therefore it is necessary to measure water salinity at different time scales to get a complete picture of the saline environment that mangroves experience.Spatially,lower salinity levels benefit mangrove species richness within a bay landscape,however,further research is needed to distinguish the effects of salinity fluctuation and salinity level in affecting mangrove species richness.

关键词： Coastal wetlands Mangroves Salinity fluctuation Species diversity Species richness

{1012}twin–twin intersection-induced lattice rotation and dynamic recrystallization in Mg–6Al–3Sn–2Zn alloy

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Journal of Magnesium and Alloys 2024年第4期12卷 1529-1539页

作者： Bin-jiang Lv Sen Wang Fu-Hao Gao Ning Cui Yi-Nan Li tie-Wei Xu Feng Guo School of Mechanical and Automotive Engineering Qingdao University of Technology266520China Key Lab of industrial Fluid Energy Conservation and Pollution Control Qingdao University of Technology266520China

This study investigated the formation mechanism of new grains due to twin–twin intersections in a coarse-grained Mg–6Al–3Sn–2Zn alloy during different strain rates of an isothermal compression.The results of electron backscattered diffraction investigations showed that the activated twins were primarily{1012}tension twins,and 60°boundaries formed due to twin–twin intersections under different strain rates.Isolated twin variants with 60°boundaries transformed into new grains through lattice rotations at a low strain rate(0.01 s^(−1)).At a high strain rate(10 s^(−1)),the regions surrounded by subgrain boundaries through high-density dislocation arrangement and the 60°boundaries transformed into new grains via dynamic recrystallization.

关键词： Mg alloy Twin-twin intersection Lattice rotation Dynamic recrystallization